Add NSURLSession http client engine

.github/CRONET_GO_VERSION

@@ -1 +1 @@
-ea7cd33752aed62603775af3df946c1b83f4b0b3
+335e5bef5d88fc4474c9a70b865561f45a67de83

adapter/dns.go

@@ -3,6 +3,7 @@ package adapter
 import (
 	"context"
 	"net/netip"
+	"time"
 
 	C "github.com/sagernet/sing-box/constant"
 	"github.com/sagernet/sing-box/log"
@@ -31,12 +32,13 @@ type DNSClient interface {
 }
 
 type DNSQueryOptions struct {
-	Transport      DNSTransport
+	Transport              DNSTransport
-	Strategy       C.DomainStrategy
+	Strategy               C.DomainStrategy
-	LookupStrategy C.DomainStrategy
+	LookupStrategy         C.DomainStrategy
-	DisableCache   bool
+	DisableCache           bool
-	RewriteTTL     *uint32
+	DisableOptimisticCache bool
-	ClientSubnet   netip.Prefix
+	RewriteTTL             *uint32
+	ClientSubnet           netip.Prefix
 }
 
 func DNSQueryOptionsFrom(ctx context.Context, options *option.DomainResolveOptions) (*DNSQueryOptions, error) {
@@ -49,11 +51,12 @@ func DNSQueryOptionsFrom(ctx context.Context, options *option.DomainResolveOptio
 		return nil, E.New("domain resolver not found: " + options.Server)
 	}
 	return &DNSQueryOptions{
-		Transport:    transport,
+		Transport:              transport,
-		Strategy:     C.DomainStrategy(options.Strategy),
+		Strategy:               C.DomainStrategy(options.Strategy),
-		DisableCache: options.DisableCache,
+		DisableCache:           options.DisableCache,
-		RewriteTTL:   options.RewriteTTL,
+		DisableOptimisticCache: options.DisableOptimisticCache,
-		ClientSubnet: options.ClientSubnet.Build(netip.Prefix{}),
+		RewriteTTL:             options.RewriteTTL,
+		ClientSubnet:           options.ClientSubnet.Build(netip.Prefix{}),
 	}, nil
 }
 
@@ -63,6 +66,13 @@ type RDRCStore interface {
 	SaveRDRCAsync(transportName string, qName string, qType uint16, logger logger.Logger)
 }
 
+type DNSCacheStore interface {
+	LoadDNSCache(transportName string, qName string, qType uint16) (rawMessage []byte, expireAt time.Time, loaded bool)
+	SaveDNSCache(transportName string, qName string, qType uint16, rawMessage []byte, expireAt time.Time) error
+	SaveDNSCacheAsync(transportName string, qName string, qType uint16, rawMessage []byte, expireAt time.Time, logger logger.Logger)
+	ClearDNSCache() error
+}
+
 type DNSTransport interface {
 	Lifecycle
 	Type() string

adapter/experimental.go

@@ -47,6 +47,12 @@ type CacheFile interface {
 	StoreRDRC() bool
 	RDRCStore
 
+	StoreDNS() bool
+	DNSCacheStore
+
+	SetDisableExpire(disableExpire bool)
+	SetOptimisticTimeout(timeout time.Duration)
+
 	LoadMode() string
 	StoreMode(mode string) error
 	LoadSelected(group string) string

adapter/http.go

@@ -0,0 +1,22 @@
+package adapter
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing/common/logger"
+)
+
+type HTTPTransport interface {
+	http.RoundTripper
+	CloseIdleConnections()
+	Clone() HTTPTransport
+	Close() error
+}
+
+type HTTPClientManager interface {
+	ResolveTransport(ctx context.Context, logger logger.ContextLogger, options option.HTTPClientOptions) (HTTPTransport, error)
+	DefaultTransport() HTTPTransport
+	ResetNetwork()
+}

adapter/router.go

@@ -2,17 +2,11 @@ package adapter
 
 import (
 	"context"
-	"crypto/tls"
 	"net"
-	"net/http"
-	"sync"
 	"time"
 
-	C "github.com/sagernet/sing-box/constant"
 	"github.com/sagernet/sing-tun"
-	M "github.com/sagernet/sing/common/metadata"
 	N "github.com/sagernet/sing/common/network"
-	"github.com/sagernet/sing/common/ntp"
 	"github.com/sagernet/sing/common/x/list"
 
 	"go4.org/netipx"
@@ -51,7 +45,7 @@ type ConnectionRouterEx interface {
 
 type RuleSet interface {
 	Name() string
-	StartContext(ctx context.Context, startContext *HTTPStartContext) error
+	StartContext(ctx context.Context) error
 	PostStart() error
 	Metadata() RuleSetMetadata
 	ExtractIPSet() []*netipx.IPSet
@@ -77,46 +71,3 @@ type RuleSetMetadata struct {
 	ContainsIPCIDRRule       bool
 	ContainsDNSQueryTypeRule bool
 }
-type HTTPStartContext struct {
-	ctx             context.Context
-	access          sync.Mutex
-	httpClientCache map[string]*http.Client
-}
-
-func NewHTTPStartContext(ctx context.Context) *HTTPStartContext {
-	return &HTTPStartContext{
-		ctx:             ctx,
-		httpClientCache: make(map[string]*http.Client),
-	}
-}
-
-func (c *HTTPStartContext) HTTPClient(detour string, dialer N.Dialer) *http.Client {
-	c.access.Lock()
-	defer c.access.Unlock()
-	if httpClient, loaded := c.httpClientCache[detour]; loaded {
-		return httpClient
-	}
-	httpClient := &http.Client{
-		Transport: &http.Transport{
-			ForceAttemptHTTP2:   true,
-			TLSHandshakeTimeout: C.TCPTimeout,
-			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
-				return dialer.DialContext(ctx, network, M.ParseSocksaddr(addr))
-			},
-			TLSClientConfig: &tls.Config{
-				Time:    ntp.TimeFuncFromContext(c.ctx),
-				RootCAs: RootPoolFromContext(c.ctx),
-			},
-		},
-	}
-	c.httpClientCache[detour] = httpClient
-	return httpClient
-}
-
-func (c *HTTPStartContext) Close() {
-	c.access.Lock()
-	defer c.access.Unlock()
-	for _, client := range c.httpClientCache {
-		client.CloseIdleConnections()
-	}
-}

box.go

@@ -16,12 +16,14 @@ import (
 	boxService "github.com/sagernet/sing-box/adapter/service"
 	"github.com/sagernet/sing-box/common/certificate"
 	"github.com/sagernet/sing-box/common/dialer"
+	"github.com/sagernet/sing-box/common/httpclient"
 	"github.com/sagernet/sing-box/common/taskmonitor"
 	"github.com/sagernet/sing-box/common/tls"
 	C "github.com/sagernet/sing-box/constant"
 	"github.com/sagernet/sing-box/dns"
 	"github.com/sagernet/sing-box/experimental"
 	"github.com/sagernet/sing-box/experimental/cachefile"
+	"github.com/sagernet/sing-box/experimental/deprecated"
 	"github.com/sagernet/sing-box/log"
 	"github.com/sagernet/sing-box/option"
 	"github.com/sagernet/sing-box/protocol/direct"
@@ -50,6 +52,7 @@ type Box struct {
 	dnsRouter           *dns.Router
 	connection          *route.ConnectionManager
 	router              *route.Router
+	httpClientService   adapter.LifecycleService
 	internalService     []adapter.LifecycleService
 	done                chan struct{}
 }
@@ -169,6 +172,7 @@ func New(options Options) (*Box, error) {
 	}
 
 	var internalServices []adapter.LifecycleService
+	routeOptions := common.PtrValueOrDefault(options.Route)
 	certificateOptions := common.PtrValueOrDefault(options.Certificate)
 	if C.IsAndroid || certificateOptions.Store != "" && certificateOptions.Store != C.CertificateStoreSystem ||
 		len(certificateOptions.Certificate) > 0 ||
@@ -181,8 +185,6 @@ func New(options Options) (*Box, error) {
 		service.MustRegister[adapter.CertificateStore](ctx, certificateStore)
 		internalServices = append(internalServices, certificateStore)
 	}
-
-	routeOptions := common.PtrValueOrDefault(options.Route)
 	dnsOptions := common.PtrValueOrDefault(options.DNS)
 	endpointManager := endpoint.NewManager(logFactory.NewLogger("endpoint"), endpointRegistry)
 	inboundManager := inbound.NewManager(logFactory.NewLogger("inbound"), inboundRegistry, endpointManager)
@@ -196,7 +198,10 @@ func New(options Options) (*Box, error) {
 	service.MustRegister[adapter.DNSTransportManager](ctx, dnsTransportManager)
 	service.MustRegister[adapter.ServiceManager](ctx, serviceManager)
 	service.MustRegister[adapter.CertificateProviderManager](ctx, certificateProviderManager)
-	dnsRouter := dns.NewRouter(ctx, logFactory, dnsOptions)
+	dnsRouter, err := dns.NewRouter(ctx, logFactory, dnsOptions)
+	if err != nil {
+		return nil, E.Cause(err, "initialize DNS router")
+	}
 	service.MustRegister[adapter.DNSRouter](ctx, dnsRouter)
 	service.MustRegister[adapter.DNSRuleSetUpdateValidator](ctx, dnsRouter)
 	networkManager, err := route.NewNetworkManager(ctx, logFactory.NewLogger("network"), routeOptions, dnsOptions)
@@ -206,6 +211,10 @@ func New(options Options) (*Box, error) {
 	service.MustRegister[adapter.NetworkManager](ctx, networkManager)
 	connectionManager := route.NewConnectionManager(logFactory.NewLogger("connection"))
 	service.MustRegister[adapter.ConnectionManager](ctx, connectionManager)
+	// Must register after ConnectionManager: the Apple HTTP engine's proxy bridge reads it from the context when Manager.Start resolves the default client.
+	httpClientManager := httpclient.NewManager(ctx, logFactory.NewLogger("httpclient"), options.HTTPClients, routeOptions.DefaultHTTPClient)
+	service.MustRegister[adapter.HTTPClientManager](ctx, httpClientManager)
+	httpClientService := adapter.LifecycleService(httpClientManager)
 	router := route.NewRouter(ctx, logFactory, routeOptions, dnsOptions)
 	service.MustRegister[adapter.Router](ctx, router)
 	err = router.Initialize(routeOptions.Rules, routeOptions.RuleSet)
@@ -365,6 +374,12 @@ func New(options Options) (*Box, error) {
 			&option.LocalDNSServerOptions{},
 		)
 	})
+	httpClientManager.Initialize(func() (*httpclient.Transport, error) {
+		deprecated.Report(ctx, deprecated.OptionImplicitDefaultHTTPClient)
+		var httpClientOptions option.HTTPClientOptions
+		httpClientOptions.DefaultOutbound = true
+		return httpclient.NewTransport(ctx, logFactory.NewLogger("httpclient"), "", httpClientOptions)
+	})
 	if platformInterface != nil {
 		err = platformInterface.Initialize(networkManager)
 		if err != nil {
@@ -372,7 +387,7 @@ func New(options Options) (*Box, error) {
 		}
 	}
 	if needCacheFile {
-		cacheFile := cachefile.New(ctx, common.PtrValueOrDefault(experimentalOptions.CacheFile))
+		cacheFile := cachefile.New(ctx, logFactory.NewLogger("cache-file"), common.PtrValueOrDefault(experimentalOptions.CacheFile))
 		service.MustRegister[adapter.CacheFile](ctx, cacheFile)
 		internalServices = append(internalServices, cacheFile)
 	}
@@ -425,6 +440,7 @@ func New(options Options) (*Box, error) {
 		dnsRouter:           dnsRouter,
 		connection:          connectionManager,
 		router:              router,
+		httpClientService:   httpClientService,
 		createdAt:           createdAt,
 		logFactory:          logFactory,
 		logger:              logFactory.Logger(),
@@ -487,7 +503,15 @@ func (s *Box) preStart() error {
 	if err != nil {
 		return err
 	}
-	err = adapter.Start(s.logger, adapter.StartStateStart, s.outbound, s.dnsTransport, s.network, s.connection, s.router, s.dnsRouter)
+	err = adapter.Start(s.logger, adapter.StartStateStart, s.outbound, s.dnsTransport, s.network, s.connection)
+	if err != nil {
+		return err
+	}
+	err = adapter.StartNamed(s.logger, adapter.StartStateStart, []adapter.LifecycleService{s.httpClientService})
+	if err != nil {
+		return err
+	}
+	err = adapter.Start(s.logger, adapter.StartStateStart, s.router, s.dnsRouter)
 	if err != nil {
 		return err
 	}
@@ -564,6 +588,14 @@ func (s *Box) Close() error {
 		})
 		s.logger.Trace("close ", closeItem.name, " completed (", F.Seconds(time.Since(startTime).Seconds()), "s)")
 	}
+	if s.httpClientService != nil {
+		s.logger.Trace("close ", s.httpClientService.Name())
+		startTime := time.Now()
+		err = E.Append(err, s.httpClientService.Close(), func(err error) error {
+			return E.Cause(err, "close ", s.httpClientService.Name())
+		})
+		s.logger.Trace("close ", s.httpClientService.Name(), " completed (", F.Seconds(time.Since(startTime).Seconds()), "s)")
+	}
 	for _, lifecycleService := range s.internalService {
 		s.logger.Trace("close ", lifecycleService.Name())
 		startTime := time.Now()

cmd/internal/build_libbox/main.go

@@ -204,6 +204,9 @@ func buildApple() {
 		"-target", bindTarget,
 		"-libname=box",
 		"-tags-not-macos=with_low_memory",
+		"-iosversion=15.0",
+		"-macosversion=13.0",
+		"-tvosversion=17.0",
 	}
 	//if !withTailscale {
 	//	args = append(args, "-tags-macos="+strings.Join(memcTags, ","))

cmd/internal/update_certificates/main.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"net/http"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/sagernet/sing-box/log"
@@ -35,21 +36,9 @@ func updateMozillaIncludedRootCAs() error {
 		return err
 	}
 	geoIndex := slices.Index(header, "Geographic Focus")
-	nameIndex := slices.Index(header, "Common Name or Certificate Name")
 	certIndex := slices.Index(header, "PEM Info")
 
-	generated := strings.Builder{}
+	pemBundle := strings.Builder{}
-	generated.WriteString(`// Code generated by 'make update_certificates'. DO NOT EDIT.
-
-package certificate
-
-import "crypto/x509"
-
-var mozillaIncluded *x509.CertPool
-
-func init() {
-	mozillaIncluded = x509.NewCertPool()
-`)
 	for {
 		record, err := reader.Read()
 		if err == io.EOF {
@@ -60,18 +49,12 @@ func init() {
 		if record[geoIndex] == "China" {
 			continue
 		}
-		generated.WriteString("\n	// ")
-		generated.WriteString(record[nameIndex])
-		generated.WriteString("\n")
-		generated.WriteString("	mozillaIncluded.AppendCertsFromPEM([]byte(`")
 		cert := record[certIndex]
-		// Remove single quotes
 		cert = cert[1 : len(cert)-1]
-		generated.WriteString(cert)
+		pemBundle.WriteString(cert)
-		generated.WriteString("`))\n")
+		pemBundle.WriteString("\n")
 	}
-	generated.WriteString("}\n")
+	return writeGeneratedCertificateBundle("mozilla", "mozillaIncluded", pemBundle.String())
-	return os.WriteFile("common/certificate/mozilla.go", []byte(generated.String()), 0o644)
 }
 
 func fetchChinaFingerprints() (map[string]bool, error) {
@@ -119,23 +102,11 @@ func updateChromeIncludedRootCAs() error {
 	if err != nil {
 		return err
 	}
-	subjectIndex := slices.Index(header, "Subject")
 	statusIndex := slices.Index(header, "Google Chrome Status")
 	certIndex := slices.Index(header, "X.509 Certificate (PEM)")
 	fingerprintIndex := slices.Index(header, "SHA-256 Fingerprint")
 
-	generated := strings.Builder{}
+	pemBundle := strings.Builder{}
-	generated.WriteString(`// Code generated by 'make update_certificates'. DO NOT EDIT.
-
-package certificate
-
-import "crypto/x509"
-
-var chromeIncluded *x509.CertPool
-
-func init() {
-	chromeIncluded = x509.NewCertPool()
-`)
 	for {
 		record, err := reader.Read()
 		if err == io.EOF {
@@ -149,18 +120,39 @@ func init() {
 		if chinaFingerprints[record[fingerprintIndex]] {
 			continue
 		}
-		generated.WriteString("\n	// ")
-		generated.WriteString(record[subjectIndex])
-		generated.WriteString("\n")
-		generated.WriteString("	chromeIncluded.AppendCertsFromPEM([]byte(`")
 		cert := record[certIndex]
-		// Remove single quotes if present
 		if len(cert) > 0 && cert[0] == '\'' {
 			cert = cert[1 : len(cert)-1]
 		}
-		generated.WriteString(cert)
+		pemBundle.WriteString(cert)
-		generated.WriteString("`))\n")
+		pemBundle.WriteString("\n")
 	}
-	generated.WriteString("}\n")
+	return writeGeneratedCertificateBundle("chrome", "chromeIncluded", pemBundle.String())
-	return os.WriteFile("common/certificate/chrome.go", []byte(generated.String()), 0o644)
+}
+
+func writeGeneratedCertificateBundle(name string, variableName string, pemBundle string) error {
+	goSource := `// Code generated by 'make update_certificates'. DO NOT EDIT.
+
+package certificate
+
+import (
+	"crypto/x509"
+	_ "embed"
+)
+
+//go:embed ` + name + `.pem
+var ` + variableName + `PEM string
+
+var ` + variableName + ` *x509.CertPool
+
+func init() {
+	` + variableName + ` = x509.NewCertPool()
+	` + variableName + `.AppendCertsFromPEM([]byte(` + variableName + `PEM))
+}
+`
+	err := os.WriteFile(filepath.Join("common/certificate", name+".pem"), []byte(pemBundle), 0o644)
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(filepath.Join("common/certificate", name+".go"), []byte(goSource), 0o644)
 }

common/certificate/store.go

@@ -22,8 +22,10 @@ var _ adapter.CertificateStore = (*Store)(nil)
 
 type Store struct {
 	access                    sync.RWMutex
+	store                     string
 	systemPool                *x509.CertPool
 	currentPool               *x509.CertPool
+	currentPEM                []string
 	certificate               string
 	certificatePaths          []string
 	certificateDirectoryPaths []string
@@ -61,6 +63,7 @@ func NewStore(ctx context.Context, logger logger.Logger, options option.Certific
 		return nil, E.New("unknown certificate store: ", options.Store)
 	}
 	store := &Store{
+		store:                     options.Store,
 		systemPool:                systemPool,
 		certificate:               strings.Join(options.Certificate, "\n"),
 		certificatePaths:          options.CertificatePath,
@@ -123,19 +126,37 @@ func (s *Store) Pool() *x509.CertPool {
 	return s.currentPool
 }
 
+func (s *Store) StoreKind() string {
+	return s.store
+}
+
+func (s *Store) CurrentPEM() []string {
+	s.access.RLock()
+	defer s.access.RUnlock()
+	return append([]string(nil), s.currentPEM...)
+}
+
 func (s *Store) update() error {
 	s.access.Lock()
 	defer s.access.Unlock()
 	var currentPool *x509.CertPool
+	var currentPEM []string
 	if s.systemPool == nil {
 		currentPool = x509.NewCertPool()
 	} else {
 		currentPool = s.systemPool.Clone()
 	}
+	switch s.store {
+	case C.CertificateStoreMozilla:
+		currentPEM = append(currentPEM, mozillaIncludedPEM)
+	case C.CertificateStoreChrome:
+		currentPEM = append(currentPEM, chromeIncludedPEM)
+	}
 	if s.certificate != "" {
 		if !currentPool.AppendCertsFromPEM([]byte(s.certificate)) {
 			return E.New("invalid certificate PEM strings")
 		}
+		currentPEM = append(currentPEM, s.certificate)
 	}
 	for _, path := range s.certificatePaths {
 		pemContent, err := os.ReadFile(path)
@@ -145,6 +166,7 @@ func (s *Store) update() error {
 		if !currentPool.AppendCertsFromPEM(pemContent) {
 			return E.New("invalid certificate PEM file: ", path)
 		}
+		currentPEM = append(currentPEM, string(pemContent))
 	}
 	var firstErr error
 	for _, directoryPath := range s.certificateDirectoryPaths {
@@ -157,8 +179,8 @@ func (s *Store) update() error {
 		}
 		for _, directoryEntry := range directoryEntries {
 			pemContent, err := os.ReadFile(filepath.Join(directoryPath, directoryEntry.Name()))
-			if err == nil {
+			if err == nil && currentPool.AppendCertsFromPEM(pemContent) {
-				currentPool.AppendCertsFromPEM(pemContent)
+				currentPEM = append(currentPEM, string(pemContent))
 			}
 		}
 	}
@@ -166,6 +188,7 @@ func (s *Store) update() error {
 		return firstErr
 	}
 	s.currentPool = currentPool
+	s.currentPEM = currentPEM
 	return nil
 }
 

common/dialer/detour.go

@@ -19,6 +19,7 @@ type DirectDialer interface {
 type DetourDialer struct {
 	outboundManager adapter.OutboundManager
 	detour          string
+	defaultOutbound bool
 	legacyDNSDialer bool
 	dialer          N.Dialer
 	initOnce        sync.Once
@@ -33,6 +34,13 @@ func NewDetour(outboundManager adapter.OutboundManager, detour string, legacyDNS
 	}
 }
 
+func NewDefaultOutboundDetour(outboundManager adapter.OutboundManager) N.Dialer {
+	return &DetourDialer{
+		outboundManager: outboundManager,
+		defaultOutbound: true,
+	}
+}
+
 func InitializeDetour(dialer N.Dialer) error {
 	detourDialer, isDetour := common.Cast[*DetourDialer](dialer)
 	if !isDetour {
@@ -47,12 +55,18 @@ func (d *DetourDialer) Dialer() (N.Dialer, error) {
 }
 
 func (d *DetourDialer) init() {
-	dialer, loaded := d.outboundManager.Outbound(d.detour)
+	var dialer adapter.Outbound
-	if !loaded {
+	if d.detour != "" {
-		d.initErr = E.New("outbound detour not found: ", d.detour)
+		var loaded bool
-		return
+		dialer, loaded = d.outboundManager.Outbound(d.detour)
+		if !loaded {
+			d.initErr = E.New("outbound detour not found: ", d.detour)
+			return
+		}
+	} else {
+		dialer = d.outboundManager.Default()
 	}
-	if !d.legacyDNSDialer {
+	if !d.defaultOutbound && !d.legacyDNSDialer {
 		if directDialer, isDirect := dialer.(DirectDialer); isDirect {
 			if directDialer.IsEmpty() {
 				d.initErr = E.New("detour to an empty direct outbound makes no sense")

common/dialer/dialer.go

@@ -25,6 +25,7 @@ type Options struct {
 	NewDialer        bool
 	LegacyDNSDialer  bool
 	DirectOutbound   bool
+	DefaultOutbound  bool
 }
 
 // TODO: merge with NewWithOptions
@@ -42,19 +43,26 @@ func NewWithOptions(options Options) (N.Dialer, error) {
 		dialer N.Dialer
 		err    error
 	)
+	hasDetour := dialOptions.Detour != "" || options.DefaultOutbound
 	if dialOptions.Detour != "" {
 		outboundManager := service.FromContext[adapter.OutboundManager](options.Context)
 		if outboundManager == nil {
 			return nil, E.New("missing outbound manager")
 		}
 		dialer = NewDetour(outboundManager, dialOptions.Detour, options.LegacyDNSDialer)
+	} else if options.DefaultOutbound {
+		outboundManager := service.FromContext[adapter.OutboundManager](options.Context)
+		if outboundManager == nil {
+			return nil, E.New("missing outbound manager")
+		}
+		dialer = NewDefaultOutboundDetour(outboundManager)
 	} else {
 		dialer, err = NewDefault(options.Context, dialOptions)
 		if err != nil {
 			return nil, err
 		}
 	}
-	if options.RemoteIsDomain && (dialOptions.Detour == "" || options.ResolverOnDetour || dialOptions.DomainResolver != nil && dialOptions.DomainResolver.Server != "") {
+	if options.RemoteIsDomain && (!hasDetour || options.ResolverOnDetour || dialOptions.DomainResolver != nil && dialOptions.DomainResolver.Server != "") {
 		networkManager := service.FromContext[adapter.NetworkManager](options.Context)
 		dnsTransport := service.FromContext[adapter.DNSTransportManager](options.Context)
 		var defaultOptions adapter.NetworkOptions
@@ -87,11 +95,12 @@ func NewWithOptions(options Options) (N.Dialer, error) {
 			}
 			server = dialOptions.DomainResolver.Server
 			dnsQueryOptions = adapter.DNSQueryOptions{
-				Transport:    transport,
+				Transport:              transport,
-				Strategy:     strategy,
+				Strategy:               strategy,
-				DisableCache: dialOptions.DomainResolver.DisableCache,
+				DisableCache:           dialOptions.DomainResolver.DisableCache,
-				RewriteTTL:   dialOptions.DomainResolver.RewriteTTL,
+				DisableOptimisticCache: dialOptions.DomainResolver.DisableOptimisticCache,
-				ClientSubnet: dialOptions.DomainResolver.ClientSubnet.Build(netip.Prefix{}),
+				RewriteTTL:             dialOptions.DomainResolver.RewriteTTL,
+				ClientSubnet:           dialOptions.DomainResolver.ClientSubnet.Build(netip.Prefix{}),
 			}
 			resolveFallbackDelay = time.Duration(dialOptions.FallbackDelay)
 		} else if options.DirectResolver {

common/httpclient/apple_transport_darwin.go

@@ -0,0 +1,442 @@
+//go:build darwin && cgo
+
+package httpclient
+
+/*
+#cgo CFLAGS: -x objective-c -fobjc-arc
+#cgo LDFLAGS: -framework Foundation -framework Security
+
+#include <stdlib.h>
+#include "apple_transport_darwin.h"
+*/
+import "C"
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"unsafe"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/proxybridge"
+	boxTLS "github.com/sagernet/sing-box/common/tls"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+	N "github.com/sagernet/sing/common/network"
+)
+
+const applePinnedHashSize = sha256.Size
+
+func verifyApplePinnedPublicKeySHA256(flatHashes []byte, leafCertificate []byte) error {
+	if len(flatHashes)%applePinnedHashSize != 0 {
+		return E.New("invalid pinned public key list")
+	}
+	knownHashes := make([][]byte, 0, len(flatHashes)/applePinnedHashSize)
+	for offset := 0; offset < len(flatHashes); offset += applePinnedHashSize {
+		knownHashes = append(knownHashes, append([]byte(nil), flatHashes[offset:offset+applePinnedHashSize]...))
+	}
+	return boxTLS.VerifyPublicKeySHA256(knownHashes, [][]byte{leafCertificate})
+}
+
+//export box_apple_http_verify_public_key_sha256
+func box_apple_http_verify_public_key_sha256(knownHashValues *C.uint8_t, knownHashValuesLen C.size_t, leafCert *C.uint8_t, leafCertLen C.size_t) *C.char {
+	flatHashes := C.GoBytes(unsafe.Pointer(knownHashValues), C.int(knownHashValuesLen))
+	leafCertificate := C.GoBytes(unsafe.Pointer(leafCert), C.int(leafCertLen))
+	err := verifyApplePinnedPublicKeySHA256(flatHashes, leafCertificate)
+	if err == nil {
+		return nil
+	}
+	return C.CString(err.Error())
+}
+
+type appleSessionConfig struct {
+	serverName             string
+	minVersion             uint16
+	maxVersion             uint16
+	insecure               bool
+	anchorPEM              string
+	anchorOnly             bool
+	pinnedPublicKeySHA256s []byte
+}
+
+type appleTransportShared struct {
+	logger logger.ContextLogger
+	bridge *proxybridge.Bridge
+	config appleSessionConfig
+	refs   atomic.Int32
+}
+
+type appleTransport struct {
+	shared  *appleTransportShared
+	access  sync.Mutex
+	session *C.box_apple_http_session_t
+	closed  bool
+}
+
+type errorTransport struct {
+	err error
+}
+
+func newAppleTransport(ctx context.Context, logger logger.ContextLogger, rawDialer N.Dialer, options option.HTTPClientOptions) (adapter.HTTPTransport, error) {
+	sessionConfig, err := newAppleSessionConfig(ctx, options)
+	if err != nil {
+		return nil, err
+	}
+	bridge, err := proxybridge.New(ctx, logger, "apple http proxy", rawDialer)
+	if err != nil {
+		return nil, err
+	}
+	shared := &appleTransportShared{
+		logger: logger,
+		bridge: bridge,
+		config: sessionConfig,
+	}
+	shared.refs.Store(1)
+	session, err := shared.newSession()
+	if err != nil {
+		bridge.Close()
+		return nil, err
+	}
+	return &appleTransport{
+		shared:  shared,
+		session: session,
+	}, nil
+}
+
+func newAppleSessionConfig(ctx context.Context, options option.HTTPClientOptions) (appleSessionConfig, error) {
+	version := options.Version
+	if version == 0 {
+		version = 2
+	}
+	switch version {
+	case 2:
+	case 1:
+		return appleSessionConfig{}, E.New("HTTP/1.1 is unsupported in Apple HTTP engine")
+	case 3:
+		return appleSessionConfig{}, E.New("HTTP/3 is unsupported in Apple HTTP engine")
+	default:
+		return appleSessionConfig{}, E.New("unknown HTTP version: ", version)
+	}
+	if options.DisableVersionFallback {
+		return appleSessionConfig{}, E.New("disable_version_fallback is unsupported in Apple HTTP engine")
+	}
+	if options.HTTP2Options != (option.HTTP2Options{}) {
+		return appleSessionConfig{}, E.New("HTTP/2 options are unsupported in Apple HTTP engine")
+	}
+	if options.HTTP3Options != (option.QUICOptions{}) {
+		return appleSessionConfig{}, E.New("QUIC options are unsupported in Apple HTTP engine")
+	}
+
+	tlsOptions := common.PtrValueOrDefault(options.TLS)
+	if tlsOptions.Engine != "" {
+		return appleSessionConfig{}, E.New("tls.engine is unsupported in Apple HTTP engine")
+	}
+	if len(tlsOptions.ALPN) > 0 {
+		return appleSessionConfig{}, E.New("tls.alpn is unsupported in Apple HTTP engine")
+	}
+	validated, err := boxTLS.ValidateAppleTLSOptions(ctx, tlsOptions, "Apple HTTP engine")
+	if err != nil {
+		return appleSessionConfig{}, err
+	}
+
+	config := appleSessionConfig{
+		serverName: tlsOptions.ServerName,
+		minVersion: validated.MinVersion,
+		maxVersion: validated.MaxVersion,
+		insecure:   tlsOptions.Insecure || len(tlsOptions.CertificatePublicKeySHA256) > 0,
+		anchorPEM:  validated.AnchorPEM,
+		anchorOnly: validated.AnchorOnly,
+	}
+	if len(tlsOptions.CertificatePublicKeySHA256) > 0 {
+		config.pinnedPublicKeySHA256s = make([]byte, 0, len(tlsOptions.CertificatePublicKeySHA256)*applePinnedHashSize)
+		for _, hashValue := range tlsOptions.CertificatePublicKeySHA256 {
+			if len(hashValue) != applePinnedHashSize {
+				return appleSessionConfig{}, E.New("invalid certificate_public_key_sha256 length: ", len(hashValue))
+			}
+			config.pinnedPublicKeySHA256s = append(config.pinnedPublicKeySHA256s, hashValue...)
+		}
+	}
+	return config, nil
+}
+
+func (s *appleTransportShared) retain() {
+	s.refs.Add(1)
+}
+
+func (s *appleTransportShared) release() error {
+	if s.refs.Add(-1) == 0 {
+		return s.bridge.Close()
+	}
+	return nil
+}
+
+func (s *appleTransportShared) newSession() (*C.box_apple_http_session_t, error) {
+	cProxyHost := C.CString("127.0.0.1")
+	defer C.free(unsafe.Pointer(cProxyHost))
+	cProxyUsername := C.CString(s.bridge.Username())
+	defer C.free(unsafe.Pointer(cProxyUsername))
+	cProxyPassword := C.CString(s.bridge.Password())
+	defer C.free(unsafe.Pointer(cProxyPassword))
+	var cAnchorPEM *C.char
+	if s.config.anchorPEM != "" {
+		cAnchorPEM = C.CString(s.config.anchorPEM)
+		defer C.free(unsafe.Pointer(cAnchorPEM))
+	}
+	var pinnedPointer *C.uint8_t
+	if len(s.config.pinnedPublicKeySHA256s) > 0 {
+		pinnedPointer = (*C.uint8_t)(C.CBytes(s.config.pinnedPublicKeySHA256s))
+		defer C.free(unsafe.Pointer(pinnedPointer))
+	}
+	cConfig := C.box_apple_http_session_config_t{
+		proxy_host:                   cProxyHost,
+		proxy_port:                   C.int(s.bridge.Port()),
+		proxy_username:               cProxyUsername,
+		proxy_password:               cProxyPassword,
+		min_tls_version:              C.uint16_t(s.config.minVersion),
+		max_tls_version:              C.uint16_t(s.config.maxVersion),
+		insecure:                     C.bool(s.config.insecure),
+		anchor_pem:                   cAnchorPEM,
+		anchor_pem_len:               C.size_t(len(s.config.anchorPEM)),
+		anchor_only:                  C.bool(s.config.anchorOnly),
+		pinned_public_key_sha256:     pinnedPointer,
+		pinned_public_key_sha256_len: C.size_t(len(s.config.pinnedPublicKeySHA256s)),
+	}
+	var cErr *C.char
+	session := C.box_apple_http_session_create(&cConfig, &cErr)
+	if session != nil {
+		return session, nil
+	}
+	return nil, appleCStringError(cErr, "create Apple HTTP session")
+}
+
+func (t *appleTransport) RoundTrip(request *http.Request) (*http.Response, error) {
+	if requestRequiresHTTP1(request) {
+		return nil, E.New("HTTP upgrade requests are unsupported in Apple HTTP engine")
+	}
+	if request.URL == nil {
+		return nil, E.New("missing request URL")
+	}
+	switch request.URL.Scheme {
+	case "http", "https":
+	default:
+		return nil, E.New("unsupported URL scheme: ", request.URL.Scheme)
+	}
+	if request.URL.Scheme == "https" && t.shared.config.serverName != "" && !strings.EqualFold(t.shared.config.serverName, request.URL.Hostname()) {
+		return nil, E.New("tls.server_name is unsupported in Apple HTTP engine unless it matches request host")
+	}
+	var body []byte
+	if request.Body != nil && request.Body != http.NoBody {
+		defer request.Body.Close()
+		var err error
+		body, err = io.ReadAll(request.Body)
+		if err != nil {
+			return nil, err
+		}
+	}
+	headerKeys, headerValues := flattenRequestHeaders(request)
+	cMethod := C.CString(request.Method)
+	defer C.free(unsafe.Pointer(cMethod))
+	cURL := C.CString(request.URL.String())
+	defer C.free(unsafe.Pointer(cURL))
+	cHeaderKeys := make([]*C.char, len(headerKeys))
+	cHeaderValues := make([]*C.char, len(headerValues))
+	defer func() {
+		for _, ptr := range cHeaderKeys {
+			C.free(unsafe.Pointer(ptr))
+		}
+		for _, ptr := range cHeaderValues {
+			C.free(unsafe.Pointer(ptr))
+		}
+	}()
+	for index, value := range headerKeys {
+		cHeaderKeys[index] = C.CString(value)
+	}
+	for index, value := range headerValues {
+		cHeaderValues[index] = C.CString(value)
+	}
+	var headerKeysPointer **C.char
+	var headerValuesPointer **C.char
+	if len(cHeaderKeys) > 0 {
+		pointerArraySize := C.size_t(len(cHeaderKeys)) * C.size_t(unsafe.Sizeof((*C.char)(nil)))
+		headerKeysPointer = (**C.char)(C.malloc(pointerArraySize))
+		defer C.free(unsafe.Pointer(headerKeysPointer))
+		headerValuesPointer = (**C.char)(C.malloc(pointerArraySize))
+		defer C.free(unsafe.Pointer(headerValuesPointer))
+		copy(unsafe.Slice(headerKeysPointer, len(cHeaderKeys)), cHeaderKeys)
+		copy(unsafe.Slice(headerValuesPointer, len(cHeaderValues)), cHeaderValues)
+	}
+	var bodyPointer *C.uint8_t
+	if len(body) > 0 {
+		bodyPointer = (*C.uint8_t)(C.CBytes(body))
+		defer C.free(unsafe.Pointer(bodyPointer))
+	}
+	cRequest := C.box_apple_http_request_t{
+		method:        cMethod,
+		url:           cURL,
+		header_keys:   (**C.char)(headerKeysPointer),
+		header_values: (**C.char)(headerValuesPointer),
+		header_count:  C.size_t(len(cHeaderKeys)),
+		body:          bodyPointer,
+		body_len:      C.size_t(len(body)),
+	}
+	var cErr *C.char
+	var task *C.box_apple_http_task_t
+	t.access.Lock()
+	if t.session == nil {
+		t.access.Unlock()
+		return nil, net.ErrClosed
+	}
+	// Keep the session attached until NSURLSession has created the task.
+	task = C.box_apple_http_session_send_async(t.session, &cRequest, &cErr)
+	t.access.Unlock()
+	if task == nil {
+		return nil, appleCStringError(cErr, "create Apple HTTP request")
+	}
+	cancelDone := make(chan struct{})
+	cancelExit := make(chan struct{})
+	go func() {
+		defer close(cancelExit)
+		select {
+		case <-request.Context().Done():
+			C.box_apple_http_task_cancel(task)
+		case <-cancelDone:
+		}
+	}()
+	cResponse := C.box_apple_http_task_wait(task, &cErr)
+	close(cancelDone)
+	<-cancelExit
+	C.box_apple_http_task_close(task)
+	if cResponse == nil {
+		err := appleCStringError(cErr, "Apple HTTP request failed")
+		if request.Context().Err() != nil {
+			return nil, request.Context().Err()
+		}
+		return nil, err
+	}
+	defer C.box_apple_http_response_free(cResponse)
+	return parseAppleHTTPResponse(request, cResponse), nil
+}
+
+func (t *appleTransport) CloseIdleConnections() {
+	t.access.Lock()
+	if t.closed {
+		t.access.Unlock()
+		return
+	}
+	t.access.Unlock()
+	newSession, err := t.shared.newSession()
+	if err != nil {
+		t.shared.logger.Error(E.Cause(err, "reset Apple HTTP session"))
+		return
+	}
+	t.access.Lock()
+	if t.closed {
+		t.access.Unlock()
+		C.box_apple_http_session_close(newSession)
+		return
+	}
+	oldSession := t.session
+	t.session = newSession
+	t.access.Unlock()
+	C.box_apple_http_session_retire(oldSession)
+}
+
+func (t *appleTransport) Clone() adapter.HTTPTransport {
+	t.shared.retain()
+	session, err := t.shared.newSession()
+	if err != nil {
+		_ = t.shared.release()
+		return &errorTransport{err: err}
+	}
+	return &appleTransport{
+		shared:  t.shared,
+		session: session,
+	}
+}
+
+func (t *appleTransport) Close() error {
+	t.access.Lock()
+	if t.closed {
+		t.access.Unlock()
+		return nil
+	}
+	t.closed = true
+	session := t.session
+	t.session = nil
+	t.access.Unlock()
+	C.box_apple_http_session_close(session)
+	return t.shared.release()
+}
+
+func (t *errorTransport) RoundTrip(request *http.Request) (*http.Response, error) {
+	return nil, t.err
+}
+
+func (t *errorTransport) CloseIdleConnections() {
+}
+
+func (t *errorTransport) Clone() adapter.HTTPTransport {
+	return &errorTransport{err: t.err}
+}
+
+func (t *errorTransport) Close() error {
+	return nil
+}
+
+func flattenRequestHeaders(request *http.Request) ([]string, []string) {
+	var (
+		keys   []string
+		values []string
+	)
+	for key, headerValues := range request.Header {
+		for _, value := range headerValues {
+			keys = append(keys, key)
+			values = append(values, value)
+		}
+	}
+	if request.Host != "" {
+		keys = append(keys, "Host")
+		values = append(values, request.Host)
+	}
+	return keys, values
+}
+
+func parseAppleHTTPResponse(request *http.Request, response *C.box_apple_http_response_t) *http.Response {
+	headers := make(http.Header)
+	headerKeys := unsafe.Slice(response.header_keys, int(response.header_count))
+	headerValues := unsafe.Slice(response.header_values, int(response.header_count))
+	for index := range headerKeys {
+		headers.Add(C.GoString(headerKeys[index]), C.GoString(headerValues[index]))
+	}
+	body := bytes.NewReader(C.GoBytes(unsafe.Pointer(response.body), C.int(response.body_len)))
+	// NSURLSession's completion-handler API does not expose the negotiated protocol;
+	// callers that read Response.Proto will see HTTP/1.1 even when the wire was HTTP/2.
+	return &http.Response{
+		StatusCode:    int(response.status_code),
+		Status:        fmt.Sprintf("%d %s", int(response.status_code), http.StatusText(int(response.status_code))),
+		Proto:         "HTTP/1.1",
+		ProtoMajor:    1,
+		ProtoMinor:    1,
+		Header:        headers,
+		Body:          io.NopCloser(body),
+		ContentLength: int64(body.Len()),
+		Request:       request,
+	}
+}
+
+func appleCStringError(cErr *C.char, message string) error {
+	if cErr == nil {
+		return E.New(message)
+	}
+	defer C.free(unsafe.Pointer(cErr))
+	return E.New(message, ": ", C.GoString(cErr))
+}

common/httpclient/apple_transport_darwin.h

@@ -0,0 +1,69 @@
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+typedef struct box_apple_http_session box_apple_http_session_t;
+typedef struct box_apple_http_task box_apple_http_task_t;
+
+typedef struct box_apple_http_session_config {
+	const char *proxy_host;
+	int proxy_port;
+	const char *proxy_username;
+	const char *proxy_password;
+	uint16_t min_tls_version;
+	uint16_t max_tls_version;
+	bool insecure;
+	const char *anchor_pem;
+	size_t anchor_pem_len;
+	bool anchor_only;
+	const uint8_t *pinned_public_key_sha256;
+	size_t pinned_public_key_sha256_len;
+} box_apple_http_session_config_t;
+
+typedef struct box_apple_http_request {
+	const char *method;
+	const char *url;
+	const char **header_keys;
+	const char **header_values;
+	size_t header_count;
+	const uint8_t *body;
+	size_t body_len;
+} box_apple_http_request_t;
+
+typedef struct box_apple_http_response {
+	int status_code;
+	char **header_keys;
+	char **header_values;
+	size_t header_count;
+	uint8_t *body;
+	size_t body_len;
+	char *error;
+} box_apple_http_response_t;
+
+box_apple_http_session_t *box_apple_http_session_create(
+	const box_apple_http_session_config_t *config,
+	char **error_out
+);
+void box_apple_http_session_retire(box_apple_http_session_t *session);
+void box_apple_http_session_close(box_apple_http_session_t *session);
+
+box_apple_http_task_t *box_apple_http_session_send_async(
+	box_apple_http_session_t *session,
+	const box_apple_http_request_t *request,
+	char **error_out
+);
+box_apple_http_response_t *box_apple_http_task_wait(
+	box_apple_http_task_t *task,
+	char **error_out
+);
+void box_apple_http_task_cancel(box_apple_http_task_t *task);
+void box_apple_http_task_close(box_apple_http_task_t *task);
+
+void box_apple_http_response_free(box_apple_http_response_t *response);
+
+char *box_apple_http_verify_public_key_sha256(
+	uint8_t *known_hash_values,
+	size_t known_hash_values_len,
+	uint8_t *leaf_cert,
+	size_t leaf_cert_len
+);

common/httpclient/apple_transport_darwin.m

@@ -0,0 +1,386 @@
+#import "apple_transport_darwin.h"
+
+#import <CoreFoundation/CFStream.h>
+#import <Foundation/Foundation.h>
+#import <Security/Security.h>
+#import <dispatch/dispatch.h>
+#import <stdlib.h>
+#import <string.h>
+
+typedef struct box_apple_http_session {
+	void *handle;
+} box_apple_http_session_t;
+
+typedef struct box_apple_http_task {
+	void *task;
+	void *done_semaphore;
+	box_apple_http_response_t *response;
+	char *error;
+} box_apple_http_task_t;
+
+static void box_set_error_string(char **error_out, NSString *message) {
+	if (error_out == NULL || *error_out != NULL) {
+		return;
+	}
+	const char *utf8 = [message UTF8String];
+	*error_out = strdup(utf8 != NULL ? utf8 : "unknown error");
+}
+
+static void box_set_error_from_nserror(char **error_out, NSError *error) {
+	if (error == nil) {
+		box_set_error_string(error_out, @"unknown error");
+		return;
+	}
+	box_set_error_string(error_out, error.localizedDescription ?: error.description);
+}
+
+static NSArray *box_parse_certificates_from_pem(const char *pem, size_t pem_len) {
+	if (pem == NULL || pem_len == 0) {
+		return @[];
+	}
+	NSString *content = [[NSString alloc] initWithBytes:pem length:pem_len encoding:NSUTF8StringEncoding];
+	if (content == nil) {
+		return @[];
+	}
+	NSString *beginMarker = @"-----BEGIN CERTIFICATE-----";
+	NSString *endMarker = @"-----END CERTIFICATE-----";
+	NSMutableArray *certificates = [NSMutableArray array];
+	NSUInteger searchFrom = 0;
+	while (searchFrom < content.length) {
+		NSRange beginRange = [content rangeOfString:beginMarker options:0 range:NSMakeRange(searchFrom, content.length - searchFrom)];
+		if (beginRange.location == NSNotFound) {
+			break;
+		}
+		NSUInteger bodyStart = beginRange.location + beginRange.length;
+		NSRange endRange = [content rangeOfString:endMarker options:0 range:NSMakeRange(bodyStart, content.length - bodyStart)];
+		if (endRange.location == NSNotFound) {
+			break;
+		}
+		NSString *base64Section = [content substringWithRange:NSMakeRange(bodyStart, endRange.location - bodyStart)];
+		NSArray<NSString *> *components = [base64Section componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+		NSString *base64Content = [components componentsJoinedByString:@""];
+		NSData *der = [[NSData alloc] initWithBase64EncodedString:base64Content options:0];
+		if (der != nil) {
+			SecCertificateRef certificate = SecCertificateCreateWithData(NULL, (__bridge CFDataRef)der);
+			if (certificate != NULL) {
+				[certificates addObject:(__bridge id)certificate];
+				CFRelease(certificate);
+			}
+		}
+		searchFrom = endRange.location + endRange.length;
+	}
+	return certificates;
+}
+
+static bool box_evaluate_trust(SecTrustRef trustRef, NSArray *anchors, bool anchor_only) {
+	if (trustRef == NULL) {
+		return false;
+	}
+	if (anchors.count > 0 || anchor_only) {
+		CFMutableArrayRef anchorArray = CFArrayCreateMutable(NULL, 0, &kCFTypeArrayCallBacks);
+		for (id certificate in anchors) {
+			CFArrayAppendValue(anchorArray, (__bridge const void *)certificate);
+		}
+		SecTrustSetAnchorCertificates(trustRef, anchorArray);
+		SecTrustSetAnchorCertificatesOnly(trustRef, anchor_only);
+		CFRelease(anchorArray);
+	}
+	CFErrorRef error = NULL;
+	bool result = SecTrustEvaluateWithError(trustRef, &error);
+	if (error != NULL) {
+		CFRelease(error);
+	}
+	return result;
+}
+
+static box_apple_http_response_t *box_create_response(NSHTTPURLResponse *httpResponse, NSData *data) {
+	box_apple_http_response_t *response = calloc(1, sizeof(box_apple_http_response_t));
+	response->status_code = (int)httpResponse.statusCode;
+	NSDictionary *headers = httpResponse.allHeaderFields;
+	response->header_count = headers.count;
+	if (response->header_count > 0) {
+		response->header_keys = calloc(response->header_count, sizeof(char *));
+		response->header_values = calloc(response->header_count, sizeof(char *));
+		NSUInteger index = 0;
+		for (id key in headers) {
+			NSString *keyString = [[key description] copy];
+			NSString *valueString = [[headers[key] description] copy];
+			response->header_keys[index] = strdup(keyString.UTF8String ?: "");
+			response->header_values[index] = strdup(valueString.UTF8String ?: "");
+			index++;
+		}
+	}
+	if (data.length > 0) {
+		response->body_len = data.length;
+		response->body = malloc(data.length);
+		memcpy(response->body, data.bytes, data.length);
+	}
+	return response;
+}
+
+@interface BoxAppleHTTPSessionDelegate : NSObject <NSURLSessionTaskDelegate, NSURLSessionDataDelegate>
+@property(nonatomic, assign) BOOL insecure;
+@property(nonatomic, assign) BOOL anchorOnly;
+@property(nonatomic, strong) NSArray *anchors;
+@property(nonatomic, strong) NSData *pinnedPublicKeyHashes;
+@end
+
+@implementation BoxAppleHTTPSessionDelegate
+
+- (void)URLSession:(NSURLSession *)session
+              task:(NSURLSessionTask *)task
+willPerformHTTPRedirection:(NSHTTPURLResponse *)response
+        newRequest:(NSURLRequest *)request
+ completionHandler:(void (^)(NSURLRequest * _Nullable))completionHandler {
+	completionHandler(nil);
+}
+
+- (void)URLSession:(NSURLSession *)session
+              task:(NSURLSessionTask *)task
+didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge
+ completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential * _Nullable credential))completionHandler {
+	if (![challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {
+		completionHandler(NSURLSessionAuthChallengePerformDefaultHandling, nil);
+		return;
+	}
+	SecTrustRef trustRef = challenge.protectionSpace.serverTrust;
+	if (trustRef == NULL) {
+		completionHandler(NSURLSessionAuthChallengeCancelAuthenticationChallenge, nil);
+		return;
+	}
+	BOOL needsCustomHandling = self.insecure || self.anchorOnly || self.anchors.count > 0 || self.pinnedPublicKeyHashes.length > 0;
+	if (!needsCustomHandling) {
+		completionHandler(NSURLSessionAuthChallengePerformDefaultHandling, nil);
+		return;
+	}
+	BOOL ok = YES;
+	if (!self.insecure) {
+		if (self.anchorOnly || self.anchors.count > 0) {
+			ok = box_evaluate_trust(trustRef, self.anchors, self.anchorOnly);
+		} else {
+			CFErrorRef error = NULL;
+			ok = SecTrustEvaluateWithError(trustRef, &error);
+			if (error != NULL) {
+				CFRelease(error);
+			}
+		}
+	}
+	if (ok && self.pinnedPublicKeyHashes.length > 0) {
+		CFArrayRef certificateChain = SecTrustCopyCertificateChain(trustRef);
+		SecCertificateRef leafCertificate = NULL;
+		if (certificateChain != NULL && CFArrayGetCount(certificateChain) > 0) {
+			leafCertificate = (SecCertificateRef)CFArrayGetValueAtIndex(certificateChain, 0);
+		}
+		if (leafCertificate == NULL) {
+			ok = NO;
+		} else {
+			NSData *leafData = CFBridgingRelease(SecCertificateCopyData(leafCertificate));
+			char *pinError = box_apple_http_verify_public_key_sha256(
+				(uint8_t *)self.pinnedPublicKeyHashes.bytes,
+				self.pinnedPublicKeyHashes.length,
+				(uint8_t *)leafData.bytes,
+				leafData.length
+			);
+			if (pinError != NULL) {
+				free(pinError);
+				ok = NO;
+			}
+		}
+		if (certificateChain != NULL) {
+			CFRelease(certificateChain);
+		}
+	}
+	if (!ok) {
+		completionHandler(NSURLSessionAuthChallengeCancelAuthenticationChallenge, nil);
+		return;
+	}
+	completionHandler(NSURLSessionAuthChallengeUseCredential, [NSURLCredential credentialForTrust:trustRef]);
+}
+
+@end
+
+@interface BoxAppleHTTPSessionHandle : NSObject
+@property(nonatomic, strong) NSURLSession *session;
+@property(nonatomic, strong) BoxAppleHTTPSessionDelegate *delegate;
+@end
+
+@implementation BoxAppleHTTPSessionHandle
+@end
+
+box_apple_http_session_t *box_apple_http_session_create(
+	const box_apple_http_session_config_t *config,
+	char **error_out
+) {
+	@autoreleasepool {
+		NSURLSessionConfiguration *sessionConfig = [NSURLSessionConfiguration ephemeralSessionConfiguration];
+		sessionConfig.URLCache = nil;
+		sessionConfig.HTTPCookieStorage = nil;
+		sessionConfig.URLCredentialStorage = nil;
+		sessionConfig.HTTPShouldSetCookies = NO;
+		if (config != NULL && config->proxy_host != NULL && config->proxy_port > 0) {
+			NSMutableDictionary *proxyDictionary = [NSMutableDictionary dictionary];
+			proxyDictionary[(__bridge NSString *)kCFStreamPropertySOCKSProxyHost] = [NSString stringWithUTF8String:config->proxy_host];
+			proxyDictionary[(__bridge NSString *)kCFStreamPropertySOCKSProxyPort] = @(config->proxy_port);
+			proxyDictionary[(__bridge NSString *)kCFStreamPropertySOCKSVersion] = (__bridge NSString *)kCFStreamSocketSOCKSVersion5;
+			if (config->proxy_username != NULL) {
+				proxyDictionary[(__bridge NSString *)kCFStreamPropertySOCKSUser] = [NSString stringWithUTF8String:config->proxy_username];
+			}
+			if (config->proxy_password != NULL) {
+				proxyDictionary[(__bridge NSString *)kCFStreamPropertySOCKSPassword] = [NSString stringWithUTF8String:config->proxy_password];
+			}
+			sessionConfig.connectionProxyDictionary = proxyDictionary;
+		}
+		if (config != NULL && config->min_tls_version != 0) {
+			sessionConfig.TLSMinimumSupportedProtocolVersion = (tls_protocol_version_t)config->min_tls_version;
+		}
+		if (config != NULL && config->max_tls_version != 0) {
+			sessionConfig.TLSMaximumSupportedProtocolVersion = (tls_protocol_version_t)config->max_tls_version;
+		}
+		BoxAppleHTTPSessionDelegate *delegate = [[BoxAppleHTTPSessionDelegate alloc] init];
+		if (config != NULL) {
+			delegate.insecure = config->insecure;
+			delegate.anchorOnly = config->anchor_only;
+			delegate.anchors = box_parse_certificates_from_pem(config->anchor_pem, config->anchor_pem_len);
+			if (config->pinned_public_key_sha256 != NULL && config->pinned_public_key_sha256_len > 0) {
+				delegate.pinnedPublicKeyHashes = [NSData dataWithBytes:config->pinned_public_key_sha256 length:config->pinned_public_key_sha256_len];
+			}
+		}
+		NSURLSession *session = [NSURLSession sessionWithConfiguration:sessionConfig delegate:delegate delegateQueue:nil];
+		if (session == nil) {
+			box_set_error_string(error_out, @"create URLSession");
+			return NULL;
+		}
+		BoxAppleHTTPSessionHandle *handle = [[BoxAppleHTTPSessionHandle alloc] init];
+		handle.session = session;
+		handle.delegate = delegate;
+		box_apple_http_session_t *sessionHandle = calloc(1, sizeof(box_apple_http_session_t));
+		sessionHandle->handle = (__bridge_retained void *)handle;
+		return sessionHandle;
+	}
+}
+
+void box_apple_http_session_retire(box_apple_http_session_t *session) {
+	if (session == NULL || session->handle == NULL) {
+		return;
+	}
+	BoxAppleHTTPSessionHandle *handle = (__bridge_transfer BoxAppleHTTPSessionHandle *)session->handle;
+	[handle.session finishTasksAndInvalidate];
+	free(session);
+}
+
+void box_apple_http_session_close(box_apple_http_session_t *session) {
+	if (session == NULL || session->handle == NULL) {
+		return;
+	}
+	BoxAppleHTTPSessionHandle *handle = (__bridge_transfer BoxAppleHTTPSessionHandle *)session->handle;
+	[handle.session invalidateAndCancel];
+	free(session);
+}
+
+box_apple_http_task_t *box_apple_http_session_send_async(
+	box_apple_http_session_t *session,
+	const box_apple_http_request_t *request,
+	char **error_out
+) {
+	@autoreleasepool {
+		if (session == NULL || session->handle == NULL || request == NULL || request->method == NULL || request->url == NULL) {
+			box_set_error_string(error_out, @"invalid apple HTTP request");
+			return NULL;
+		}
+		BoxAppleHTTPSessionHandle *handle = (__bridge BoxAppleHTTPSessionHandle *)session->handle;
+		NSURL *requestURL = [NSURL URLWithString:[NSString stringWithUTF8String:request->url]];
+		if (requestURL == nil) {
+			box_set_error_string(error_out, @"invalid request URL");
+			return NULL;
+		}
+		NSMutableURLRequest *urlRequest = [NSMutableURLRequest requestWithURL:requestURL];
+		urlRequest.HTTPMethod = [NSString stringWithUTF8String:request->method];
+		for (size_t index = 0; index < request->header_count; index++) {
+			const char *key = request->header_keys[index];
+			const char *value = request->header_values[index];
+			if (key == NULL || value == NULL) {
+				continue;
+			}
+			[urlRequest addValue:[NSString stringWithUTF8String:value] forHTTPHeaderField:[NSString stringWithUTF8String:key]];
+		}
+		if (request->body != NULL && request->body_len > 0) {
+			urlRequest.HTTPBody = [NSData dataWithBytes:request->body length:request->body_len];
+		}
+		box_apple_http_task_t *task = calloc(1, sizeof(box_apple_http_task_t));
+		dispatch_semaphore_t doneSemaphore = dispatch_semaphore_create(0);
+		task->done_semaphore = (__bridge_retained void *)doneSemaphore;
+		NSURLSessionDataTask *dataTask = [handle.session dataTaskWithRequest:urlRequest completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
+			if (error != nil) {
+				box_set_error_from_nserror(&task->error, error);
+			} else if (![response isKindOfClass:[NSHTTPURLResponse class]]) {
+				box_set_error_string(&task->error, @"unexpected HTTP response type");
+			} else {
+				task->response = box_create_response((NSHTTPURLResponse *)response, data ?: [NSData data]);
+			}
+			dispatch_semaphore_signal((__bridge dispatch_semaphore_t)task->done_semaphore);
+		}];
+		if (dataTask == nil) {
+			box_set_error_string(error_out, @"create data task");
+			box_apple_http_task_close(task);
+			return NULL;
+		}
+		task->task = (__bridge_retained void *)dataTask;
+		[dataTask resume];
+		return task;
+	}
+}
+
+box_apple_http_response_t *box_apple_http_task_wait(
+	box_apple_http_task_t *task,
+	char **error_out
+) {
+	if (task == NULL || task->done_semaphore == NULL) {
+		box_set_error_string(error_out, @"invalid apple HTTP task");
+		return NULL;
+	}
+	dispatch_semaphore_wait((__bridge dispatch_semaphore_t)task->done_semaphore, DISPATCH_TIME_FOREVER);
+	if (task->error != NULL) {
+		box_set_error_string(error_out, [NSString stringWithUTF8String:task->error]);
+		return NULL;
+	}
+	return task->response;
+}
+
+void box_apple_http_task_cancel(box_apple_http_task_t *task) {
+	if (task == NULL || task->task == NULL) {
+		return;
+	}
+	NSURLSessionTask *nsTask = (__bridge NSURLSessionTask *)task->task;
+	[nsTask cancel];
+}
+
+void box_apple_http_task_close(box_apple_http_task_t *task) {
+	if (task == NULL) {
+		return;
+	}
+	if (task->task != NULL) {
+		__unused NSURLSessionTask *nsTask = (__bridge_transfer NSURLSessionTask *)task->task;
+		task->task = NULL;
+	}
+	if (task->done_semaphore != NULL) {
+		__unused dispatch_semaphore_t doneSemaphore = (__bridge_transfer dispatch_semaphore_t)task->done_semaphore;
+		task->done_semaphore = NULL;
+	}
+	free(task->error);
+	free(task);
+}
+
+void box_apple_http_response_free(box_apple_http_response_t *response) {
+	if (response == NULL) {
+		return;
+	}
+	for (size_t index = 0; index < response->header_count; index++) {
+		free(response->header_keys[index]);
+		free(response->header_values[index]);
+	}
+	free(response->header_keys);
+	free(response->header_values);
+	free(response->body);
+	free(response->error);
+	free(response);
+}

common/httpclient/apple_transport_darwin_test.go

@@ -0,0 +1,876 @@
+//go:build darwin && cgo
+
+package httpclient
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	stdtls "crypto/tls"
+	"crypto/x509"
+	"errors"
+	"io"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"slices"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	boxTLS "github.com/sagernet/sing-box/common/tls"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing-box/route"
+	"github.com/sagernet/sing/common/json/badoption"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+	"github.com/sagernet/sing/service"
+)
+
+const appleHTTPTestTimeout = 5 * time.Second
+
+const appleHTTPRecoveryLoops = 5
+
+type appleHTTPTestDialer struct {
+	dialer   net.Dialer
+	listener net.ListenConfig
+	hostMap  map[string]string
+}
+
+type appleHTTPObservedRequest struct {
+	method     string
+	body       string
+	host       string
+	values     []string
+	protoMajor int
+}
+
+type appleHTTPTestServer struct {
+	server         *httptest.Server
+	baseURL        string
+	dialHost       string
+	certificate    stdtls.Certificate
+	certificatePEM string
+	publicKeyHash  []byte
+}
+
+func TestNewAppleSessionConfig(t *testing.T) {
+	serverCertificate, serverCertificatePEM := newAppleHTTPTestCertificate(t, "localhost")
+	serverHash := certificatePublicKeySHA256(t, serverCertificate.Certificate[0])
+	otherHash := bytes.Repeat([]byte{0x7f}, applePinnedHashSize)
+
+	testCases := []struct {
+		name    string
+		options option.HTTPClientOptions
+		check   func(t *testing.T, config appleSessionConfig)
+		wantErr string
+	}{
+		{
+			name: "success with certificate anchors",
+			options: option.HTTPClientOptions{
+				Version: 2,
+				DialerOptions: option.DialerOptions{
+					ConnectTimeout: badoption.Duration(2 * time.Second),
+				},
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						Enabled:     true,
+						ServerName:  "localhost",
+						MinVersion:  "1.2",
+						MaxVersion:  "1.3",
+						Certificate: badoption.Listable[string]{serverCertificatePEM},
+					},
+				},
+			},
+			check: func(t *testing.T, config appleSessionConfig) {
+				t.Helper()
+				if config.serverName != "localhost" {
+					t.Fatalf("unexpected server name: %q", config.serverName)
+				}
+				if config.minVersion != stdtls.VersionTLS12 {
+					t.Fatalf("unexpected min version: %x", config.minVersion)
+				}
+				if config.maxVersion != stdtls.VersionTLS13 {
+					t.Fatalf("unexpected max version: %x", config.maxVersion)
+				}
+				if config.insecure {
+					t.Fatal("unexpected insecure flag")
+				}
+				if !config.anchorOnly {
+					t.Fatal("expected anchor_only")
+				}
+				if !strings.Contains(config.anchorPEM, "BEGIN CERTIFICATE") {
+					t.Fatalf("unexpected anchor pem: %q", config.anchorPEM)
+				}
+				if len(config.pinnedPublicKeySHA256s) != 0 {
+					t.Fatalf("unexpected pinned hashes: %d", len(config.pinnedPublicKeySHA256s))
+				}
+			},
+		},
+		{
+			name: "success with flattened pins",
+			options: option.HTTPClientOptions{
+				Version: 2,
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						Enabled:                    true,
+						Insecure:                   true,
+						CertificatePublicKeySHA256: badoption.Listable[[]byte]{serverHash, otherHash},
+					},
+				},
+			},
+			check: func(t *testing.T, config appleSessionConfig) {
+				t.Helper()
+				if !config.insecure {
+					t.Fatal("expected insecure flag")
+				}
+				if len(config.pinnedPublicKeySHA256s) != 2*applePinnedHashSize {
+					t.Fatalf("unexpected flattened pin length: %d", len(config.pinnedPublicKeySHA256s))
+				}
+				if !bytes.Equal(config.pinnedPublicKeySHA256s[:applePinnedHashSize], serverHash) {
+					t.Fatal("unexpected first pin")
+				}
+				if !bytes.Equal(config.pinnedPublicKeySHA256s[applePinnedHashSize:], otherHash) {
+					t.Fatal("unexpected second pin")
+				}
+				if config.anchorPEM != "" {
+					t.Fatalf("unexpected anchor pem: %q", config.anchorPEM)
+				}
+				if config.anchorOnly {
+					t.Fatal("unexpected anchor_only")
+				}
+			},
+		},
+		{
+			name:    "http11 unsupported",
+			options: option.HTTPClientOptions{Version: 1},
+			wantErr: "HTTP/1.1 is unsupported in Apple HTTP engine",
+		},
+		{
+			name:    "http3 unsupported",
+			options: option.HTTPClientOptions{Version: 3},
+			wantErr: "HTTP/3 is unsupported in Apple HTTP engine",
+		},
+		{
+			name:    "unknown version",
+			options: option.HTTPClientOptions{Version: 9},
+			wantErr: "unknown HTTP version: 9",
+		},
+		{
+			name: "disable version fallback unsupported",
+			options: option.HTTPClientOptions{
+				DisableVersionFallback: true,
+			},
+			wantErr: "disable_version_fallback is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "http2 options unsupported",
+			options: option.HTTPClientOptions{
+				HTTP2Options: option.HTTP2Options{
+					IdleTimeout: badoption.Duration(time.Second),
+				},
+			},
+			wantErr: "HTTP/2 options are unsupported in Apple HTTP engine",
+		},
+		{
+			name: "quic options unsupported",
+			options: option.HTTPClientOptions{
+				HTTP3Options: option.QUICOptions{
+					InitialPacketSize: 1200,
+				},
+			},
+			wantErr: "QUIC options are unsupported in Apple HTTP engine",
+		},
+		{
+			name: "tls engine unsupported",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{Engine: "go"},
+				},
+			},
+			wantErr: "tls.engine is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "disable sni unsupported",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{DisableSNI: true},
+				},
+			},
+			wantErr: "disable_sni is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "alpn unsupported",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						ALPN: badoption.Listable[string]{"h2"},
+					},
+				},
+			},
+			wantErr: "tls.alpn is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "cipher suites unsupported",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						CipherSuites: badoption.Listable[string]{"TLS_AES_128_GCM_SHA256"},
+					},
+				},
+			},
+			wantErr: "cipher_suites is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "curve preferences unsupported",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						CurvePreferences: badoption.Listable[option.CurvePreference]{option.CurvePreference(option.X25519)},
+					},
+				},
+			},
+			wantErr: "curve_preferences is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "client certificate unsupported",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						ClientCertificate: badoption.Listable[string]{"client-certificate"},
+						ClientKey:         badoption.Listable[string]{"client-key"},
+					},
+				},
+			},
+			wantErr: "client certificate is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "tls fragment unsupported",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{Fragment: true},
+				},
+			},
+			wantErr: "tls fragment is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "ktls unsupported",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{KernelTx: true},
+				},
+			},
+			wantErr: "ktls is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "ech unsupported",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						ECH: &option.OutboundECHOptions{Enabled: true},
+					},
+				},
+			},
+			wantErr: "ech is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "utls unsupported",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						UTLS: &option.OutboundUTLSOptions{Enabled: true},
+					},
+				},
+			},
+			wantErr: "utls is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "reality unsupported",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						Reality: &option.OutboundRealityOptions{Enabled: true},
+					},
+				},
+			},
+			wantErr: "reality is unsupported in Apple HTTP engine",
+		},
+		{
+			name: "pin and certificate conflict",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						Certificate:                badoption.Listable[string]{serverCertificatePEM},
+						CertificatePublicKeySHA256: badoption.Listable[[]byte]{serverHash},
+					},
+				},
+			},
+			wantErr: "certificate_public_key_sha256 is conflict with certificate or certificate_path",
+		},
+		{
+			name: "invalid min version",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{MinVersion: "bogus"},
+				},
+			},
+			wantErr: "parse min_version",
+		},
+		{
+			name: "invalid max version",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{MaxVersion: "bogus"},
+				},
+			},
+			wantErr: "parse max_version",
+		},
+		{
+			name: "invalid pin length",
+			options: option.HTTPClientOptions{
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						CertificatePublicKeySHA256: badoption.Listable[[]byte]{{0x01, 0x02}},
+					},
+				},
+			},
+			wantErr: "invalid certificate_public_key_sha256 length: 2",
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			config, err := newAppleSessionConfig(context.Background(), testCase.options)
+			if testCase.wantErr != "" {
+				if err == nil {
+					t.Fatal("expected error")
+				}
+				if !strings.Contains(err.Error(), testCase.wantErr) {
+					t.Fatalf("unexpected error: %v", err)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatal(err)
+			}
+			if testCase.check != nil {
+				testCase.check(t, config)
+			}
+		})
+	}
+}
+
+func TestAppleTransportVerifyPublicKeySHA256(t *testing.T) {
+	serverCertificate, _ := newAppleHTTPTestCertificate(t, "localhost")
+	goodHash := certificatePublicKeySHA256(t, serverCertificate.Certificate[0])
+	badHash := append([]byte(nil), goodHash...)
+	badHash[0] ^= 0xff
+
+	err := verifyApplePinnedPublicKeySHA256(goodHash, serverCertificate.Certificate[0])
+	if err != nil {
+		t.Fatalf("expected correct pin to succeed: %v", err)
+	}
+
+	err = verifyApplePinnedPublicKeySHA256(badHash, serverCertificate.Certificate[0])
+	if err == nil {
+		t.Fatal("expected incorrect pin to fail")
+	}
+	if !strings.Contains(err.Error(), "unrecognized remote public key") {
+		t.Fatalf("unexpected pin mismatch error: %v", err)
+	}
+
+	err = verifyApplePinnedPublicKeySHA256(goodHash[:applePinnedHashSize-1], serverCertificate.Certificate[0])
+	if err == nil {
+		t.Fatal("expected malformed pin list to fail")
+	}
+	if !strings.Contains(err.Error(), "invalid pinned public key list") {
+		t.Fatalf("unexpected malformed pin error: %v", err)
+	}
+}
+
+func TestAppleTransportRoundTripHTTPS(t *testing.T) {
+	requests := make(chan appleHTTPObservedRequest, 1)
+	server := startAppleHTTPTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		body, err := io.ReadAll(r.Body)
+		if err != nil {
+			t.Error(err)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		requests <- appleHTTPObservedRequest{
+			method:     r.Method,
+			body:       string(body),
+			host:       r.Host,
+			values:     append([]string(nil), r.Header.Values("X-Test")...),
+			protoMajor: r.ProtoMajor,
+		}
+		w.Header().Set("X-Reply", "apple")
+		w.WriteHeader(http.StatusCreated)
+		_, _ = w.Write([]byte("response body"))
+	})
+
+	transport := newAppleHTTPTestTransport(t, server, option.HTTPClientOptions{
+		Version: 2,
+		OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+			TLS: appleHTTPServerTLSOptions(server),
+		},
+	})
+
+	request, err := http.NewRequest(http.MethodPost, server.URL("/roundtrip"), bytes.NewReader([]byte("request body")))
+	if err != nil {
+		t.Fatal(err)
+	}
+	request.Header.Add("X-Test", "one")
+	request.Header.Add("X-Test", "two")
+	request.Host = "custom.example"
+
+	response, err := transport.RoundTrip(request)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer response.Body.Close()
+
+	responseBody := readResponseBody(t, response)
+	if response.StatusCode != http.StatusCreated {
+		t.Fatalf("unexpected status code: %d", response.StatusCode)
+	}
+	if response.Status != "201 Created" {
+		t.Fatalf("unexpected status: %q", response.Status)
+	}
+	if response.Header.Get("X-Reply") != "apple" {
+		t.Fatalf("unexpected response header: %q", response.Header.Get("X-Reply"))
+	}
+	if responseBody != "response body" {
+		t.Fatalf("unexpected response body: %q", responseBody)
+	}
+	if response.ContentLength != int64(len(responseBody)) {
+		t.Fatalf("unexpected content length: %d", response.ContentLength)
+	}
+
+	observed := waitObservedRequest(t, requests)
+	if observed.method != http.MethodPost {
+		t.Fatalf("unexpected method: %q", observed.method)
+	}
+	if observed.body != "request body" {
+		t.Fatalf("unexpected request body: %q", observed.body)
+	}
+	if observed.host != "custom.example" {
+		t.Fatalf("unexpected host: %q", observed.host)
+	}
+	if observed.protoMajor != 2 {
+		t.Fatalf("expected HTTP/2 request, got HTTP/%d", observed.protoMajor)
+	}
+	var normalizedValues []string
+	for _, value := range observed.values {
+		for _, part := range strings.Split(value, ",") {
+			normalizedValues = append(normalizedValues, strings.TrimSpace(part))
+		}
+	}
+	slices.Sort(normalizedValues)
+	if !slices.Equal(normalizedValues, []string{"one", "two"}) {
+		t.Fatalf("unexpected header values: %#v", observed.values)
+	}
+}
+
+func TestAppleTransportPinnedPublicKey(t *testing.T) {
+	server := startAppleHTTPTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("pinned"))
+	})
+
+	goodTransport := newAppleHTTPTestTransport(t, server, option.HTTPClientOptions{
+		Version: 2,
+		OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+			TLS: &option.OutboundTLSOptions{
+				Enabled:                    true,
+				ServerName:                 "localhost",
+				Insecure:                   true,
+				CertificatePublicKeySHA256: badoption.Listable[[]byte]{server.publicKeyHash},
+			},
+		},
+	})
+
+	response, err := goodTransport.RoundTrip(newAppleHTTPRequest(t, http.MethodGet, server.URL("/good"), nil))
+	if err != nil {
+		t.Fatalf("expected pinned request to succeed: %v", err)
+	}
+	response.Body.Close()
+
+	badHash := append([]byte(nil), server.publicKeyHash...)
+	badHash[0] ^= 0xff
+	badTransport := newAppleHTTPTestTransport(t, server, option.HTTPClientOptions{
+		Version: 2,
+		OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+			TLS: &option.OutboundTLSOptions{
+				Enabled:                    true,
+				ServerName:                 "localhost",
+				Insecure:                   true,
+				CertificatePublicKeySHA256: badoption.Listable[[]byte]{badHash},
+			},
+		},
+	})
+
+	response, err = badTransport.RoundTrip(newAppleHTTPRequest(t, http.MethodGet, server.URL("/bad"), nil))
+	if err == nil {
+		response.Body.Close()
+		t.Fatal("expected incorrect pinned public key to fail")
+	}
+}
+
+func TestAppleTransportGuardrails(t *testing.T) {
+	testCases := []struct {
+		name          string
+		options       option.HTTPClientOptions
+		buildRequest  func(t *testing.T) *http.Request
+		wantErrSubstr string
+	}{
+		{
+			name: "websocket upgrade rejected",
+			options: option.HTTPClientOptions{
+				Version: 2,
+			},
+			buildRequest: func(t *testing.T) *http.Request {
+				t.Helper()
+				request := newAppleHTTPRequest(t, http.MethodGet, "https://localhost/socket", nil)
+				request.Header.Set("Connection", "Upgrade")
+				request.Header.Set("Upgrade", "websocket")
+				return request
+			},
+			wantErrSubstr: "HTTP upgrade requests are unsupported in Apple HTTP engine",
+		},
+		{
+			name: "missing url rejected",
+			options: option.HTTPClientOptions{
+				Version: 2,
+			},
+			buildRequest: func(t *testing.T) *http.Request {
+				t.Helper()
+				return &http.Request{Method: http.MethodGet}
+			},
+			wantErrSubstr: "missing request URL",
+		},
+		{
+			name: "unsupported scheme rejected",
+			options: option.HTTPClientOptions{
+				Version: 2,
+			},
+			buildRequest: func(t *testing.T) *http.Request {
+				t.Helper()
+				return newAppleHTTPRequest(t, http.MethodGet, "ftp://localhost/file", nil)
+			},
+			wantErrSubstr: "unsupported URL scheme: ftp",
+		},
+		{
+			name: "server name mismatch rejected",
+			options: option.HTTPClientOptions{
+				Version: 2,
+				OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+					TLS: &option.OutboundTLSOptions{
+						Enabled:    true,
+						ServerName: "example.com",
+					},
+				},
+			},
+			buildRequest: func(t *testing.T) *http.Request {
+				t.Helper()
+				return newAppleHTTPRequest(t, http.MethodGet, "https://localhost/path", nil)
+			},
+			wantErrSubstr: "tls.server_name is unsupported in Apple HTTP engine unless it matches request host",
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			transport := newAppleHTTPTestTransport(t, nil, testCase.options)
+			response, err := transport.RoundTrip(testCase.buildRequest(t))
+			if err == nil {
+				response.Body.Close()
+				t.Fatal("expected error")
+			}
+			if !strings.Contains(err.Error(), testCase.wantErrSubstr) {
+				t.Fatalf("unexpected error: %v", err)
+			}
+		})
+	}
+}
+
+func TestAppleTransportCancellationRecovery(t *testing.T) {
+	server := startAppleHTTPTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/block":
+			select {
+			case <-r.Context().Done():
+				return
+			case <-time.After(appleHTTPTestTimeout):
+				http.Error(w, "request was not canceled", http.StatusGatewayTimeout)
+			}
+		default:
+			w.WriteHeader(http.StatusOK)
+			_, _ = w.Write([]byte("ok"))
+		}
+	})
+
+	transport := newAppleHTTPTestTransport(t, server, option.HTTPClientOptions{
+		Version: 2,
+		OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+			TLS: appleHTTPServerTLSOptions(server),
+		},
+	})
+
+	for index := 0; index < appleHTTPRecoveryLoops; index++ {
+		ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+		request := newAppleHTTPRequestWithContext(t, ctx, http.MethodGet, server.URL("/block"), nil)
+		response, err := transport.RoundTrip(request)
+		cancel()
+		if err == nil {
+			response.Body.Close()
+			t.Fatalf("iteration %d: expected cancellation error", index)
+		}
+		if !errors.Is(err, context.DeadlineExceeded) && !errors.Is(err, context.Canceled) {
+			t.Fatalf("iteration %d: unexpected cancellation error: %v", index, err)
+		}
+
+		response, err = transport.RoundTrip(newAppleHTTPRequest(t, http.MethodGet, server.URL("/ok"), nil))
+		if err != nil {
+			t.Fatalf("iteration %d: follow-up request failed: %v", index, err)
+		}
+		if body := readResponseBody(t, response); body != "ok" {
+			response.Body.Close()
+			t.Fatalf("iteration %d: unexpected follow-up body: %q", index, body)
+		}
+		response.Body.Close()
+	}
+}
+
+func TestAppleTransportLifecycle(t *testing.T) {
+	server := startAppleHTTPTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("ok"))
+	})
+
+	transport := newAppleHTTPTestTransport(t, server, option.HTTPClientOptions{
+		Version: 2,
+		OutboundTLSOptionsContainer: option.OutboundTLSOptionsContainer{
+			TLS: appleHTTPServerTLSOptions(server),
+		},
+	})
+	clone := transport.Clone()
+	t.Cleanup(func() {
+		_ = clone.Close()
+	})
+
+	assertAppleHTTPSucceeds(t, transport, server.URL("/original"))
+	assertAppleHTTPSucceeds(t, clone, server.URL("/clone"))
+
+	transport.CloseIdleConnections()
+	assertAppleHTTPSucceeds(t, transport, server.URL("/reset"))
+
+	if err := transport.Close(); err != nil {
+		t.Fatal(err)
+	}
+
+	response, err := transport.RoundTrip(newAppleHTTPRequest(t, http.MethodGet, server.URL("/closed"), nil))
+	if err == nil {
+		response.Body.Close()
+		t.Fatal("expected closed transport to fail")
+	}
+	if !errors.Is(err, net.ErrClosed) {
+		t.Fatalf("unexpected closed transport error: %v", err)
+	}
+
+	assertAppleHTTPSucceeds(t, clone, server.URL("/clone-after-original-close"))
+
+	clone.CloseIdleConnections()
+	assertAppleHTTPSucceeds(t, clone, server.URL("/clone-reset"))
+
+	if err := clone.Close(); err != nil {
+		t.Fatal(err)
+	}
+	response, err = clone.RoundTrip(newAppleHTTPRequest(t, http.MethodGet, server.URL("/clone-closed"), nil))
+	if err == nil {
+		response.Body.Close()
+		t.Fatal("expected closed clone to fail")
+	}
+	if !errors.Is(err, net.ErrClosed) {
+		t.Fatalf("unexpected closed clone error: %v", err)
+	}
+}
+
+func startAppleHTTPTestServer(t *testing.T, handler http.HandlerFunc) *appleHTTPTestServer {
+	t.Helper()
+
+	serverCertificate, serverCertificatePEM := newAppleHTTPTestCertificate(t, "localhost")
+	server := httptest.NewUnstartedServer(handler)
+	server.EnableHTTP2 = true
+	server.TLS = &stdtls.Config{
+		Certificates: []stdtls.Certificate{serverCertificate},
+		MinVersion:   stdtls.VersionTLS12,
+	}
+	server.StartTLS()
+	t.Cleanup(server.Close)
+
+	parsedURL, err := url.Parse(server.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+	baseURL := *parsedURL
+	baseURL.Host = net.JoinHostPort("localhost", parsedURL.Port())
+
+	return &appleHTTPTestServer{
+		server:         server,
+		baseURL:        baseURL.String(),
+		dialHost:       parsedURL.Hostname(),
+		certificate:    serverCertificate,
+		certificatePEM: serverCertificatePEM,
+		publicKeyHash:  certificatePublicKeySHA256(t, serverCertificate.Certificate[0]),
+	}
+}
+
+func (s *appleHTTPTestServer) URL(path string) string {
+	if path == "" {
+		return s.baseURL
+	}
+	if strings.HasPrefix(path, "/") {
+		return s.baseURL + path
+	}
+	return s.baseURL + "/" + path
+}
+
+func newAppleHTTPTestTransport(t *testing.T, server *appleHTTPTestServer, options option.HTTPClientOptions) adapter.HTTPTransport {
+	t.Helper()
+
+	ctx := service.ContextWith[adapter.ConnectionManager](
+		context.Background(),
+		route.NewConnectionManager(log.NewNOPFactory().NewLogger("connection")),
+	)
+	dialer := &appleHTTPTestDialer{
+		hostMap: make(map[string]string),
+	}
+	if server != nil {
+		dialer.hostMap["localhost"] = server.dialHost
+	}
+
+	transport, err := newAppleTransport(ctx, log.NewNOPFactory().NewLogger("httpclient"), dialer, options)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		_ = transport.Close()
+	})
+	return transport
+}
+
+func (d *appleHTTPTestDialer) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
+	host := destination.AddrString()
+	if destination.IsDomain() {
+		host = destination.Fqdn
+		if mappedHost, loaded := d.hostMap[host]; loaded {
+			host = mappedHost
+		}
+	}
+	return d.dialer.DialContext(ctx, network, net.JoinHostPort(host, strconv.Itoa(int(destination.Port))))
+}
+
+func (d *appleHTTPTestDialer) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
+	host := destination.AddrString()
+	if destination.IsDomain() {
+		host = destination.Fqdn
+		if mappedHost, loaded := d.hostMap[host]; loaded {
+			host = mappedHost
+		}
+	}
+	if host == "" {
+		host = "127.0.0.1"
+	}
+	return d.listener.ListenPacket(ctx, N.NetworkUDP, net.JoinHostPort(host, strconv.Itoa(int(destination.Port))))
+}
+
+func newAppleHTTPTestCertificate(t *testing.T, serverName string) (stdtls.Certificate, string) {
+	t.Helper()
+
+	privateKeyPEM, certificatePEM, err := boxTLS.GenerateCertificate(nil, nil, time.Now, serverName, time.Now().Add(time.Hour))
+	if err != nil {
+		t.Fatal(err)
+	}
+	certificate, err := stdtls.X509KeyPair(certificatePEM, privateKeyPEM)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return certificate, string(certificatePEM)
+}
+
+func certificatePublicKeySHA256(t *testing.T, certificateDER []byte) []byte {
+	t.Helper()
+
+	certificate, err := x509.ParseCertificate(certificateDER)
+	if err != nil {
+		t.Fatal(err)
+	}
+	publicKeyDER, err := x509.MarshalPKIXPublicKey(certificate.PublicKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+	hashValue := sha256.Sum256(publicKeyDER)
+	return append([]byte(nil), hashValue[:]...)
+}
+
+func appleHTTPServerTLSOptions(server *appleHTTPTestServer) *option.OutboundTLSOptions {
+	return &option.OutboundTLSOptions{
+		Enabled:     true,
+		ServerName:  "localhost",
+		Certificate: badoption.Listable[string]{server.certificatePEM},
+	}
+}
+
+func newAppleHTTPRequest(t *testing.T, method string, rawURL string, body []byte) *http.Request {
+	t.Helper()
+	return newAppleHTTPRequestWithContext(t, context.Background(), method, rawURL, body)
+}
+
+func newAppleHTTPRequestWithContext(t *testing.T, ctx context.Context, method string, rawURL string, body []byte) *http.Request {
+	t.Helper()
+	request, err := http.NewRequestWithContext(ctx, method, rawURL, bytes.NewReader(body))
+	if err != nil {
+		t.Fatal(err)
+	}
+	return request
+}
+
+func waitObservedRequest(t *testing.T, requests <-chan appleHTTPObservedRequest) appleHTTPObservedRequest {
+	t.Helper()
+
+	select {
+	case request := <-requests:
+		return request
+	case <-time.After(appleHTTPTestTimeout):
+		t.Fatal("timed out waiting for observed request")
+		return appleHTTPObservedRequest{}
+	}
+}
+
+func readResponseBody(t *testing.T, response *http.Response) string {
+	t.Helper()
+
+	body, err := io.ReadAll(response.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(body)
+}
+
+func assertAppleHTTPSucceeds(t *testing.T, transport adapter.HTTPTransport, rawURL string) {
+	t.Helper()
+
+	response, err := transport.RoundTrip(newAppleHTTPRequest(t, http.MethodGet, rawURL, nil))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer response.Body.Close()
+	if body := readResponseBody(t, response); body != "ok" {
+		t.Fatalf("unexpected response body: %q", body)
+	}
+}

common/httpclient/apple_transport_stub.go

@@ -0,0 +1,17 @@
+//go:build !darwin || !cgo
+
+package httpclient
+
+import (
+	"context"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+	N "github.com/sagernet/sing/common/network"
+)
+
+func newAppleTransport(ctx context.Context, logger logger.ContextLogger, rawDialer N.Dialer, options option.HTTPClientOptions) (adapter.HTTPTransport, error) {
+	return nil, E.New("Apple HTTP engine is not available on non-Apple platforms")
+}

common/httpclient/client.go

@@ -0,0 +1,182 @@
+package httpclient
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/dialer"
+	"github.com/sagernet/sing-box/common/tls"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+	N "github.com/sagernet/sing/common/network"
+)
+
+type Transport struct {
+	transport adapter.HTTPTransport
+	dialer    N.Dialer
+	headers   http.Header
+	host      string
+	tag       string
+}
+
+func NewTransport(ctx context.Context, logger logger.ContextLogger, tag string, options option.HTTPClientOptions) (*Transport, error) {
+	rawDialer, err := dialer.NewWithOptions(dialer.Options{
+		Context:          ctx,
+		Options:          options.DialerOptions,
+		RemoteIsDomain:   true,
+		DirectResolver:   options.DirectResolver,
+		ResolverOnDetour: options.ResolveOnDetour,
+		NewDialer:        options.ResolveOnDetour,
+		DefaultOutbound:  options.DefaultOutbound,
+	})
+	if err != nil {
+		return nil, err
+	}
+	switch options.Engine {
+	case C.TLSEngineApple:
+		transport, transportErr := newAppleTransport(ctx, logger, rawDialer, options)
+		if transportErr != nil {
+			return nil, transportErr
+		}
+		headers := options.Headers.Build()
+		host := headers.Get("Host")
+		headers.Del("Host")
+		return &Transport{
+			transport: transport,
+			dialer:    rawDialer,
+			headers:   headers,
+			host:      host,
+			tag:       tag,
+		}, nil
+	case C.TLSEngineDefault, "go":
+	default:
+		return nil, E.New("unknown HTTP engine: ", options.Engine)
+	}
+	tlsOptions := common.PtrValueOrDefault(options.TLS)
+	tlsOptions.Enabled = true
+	baseTLSConfig, err := tls.NewClientWithOptions(tls.ClientOptions{
+		Context:              ctx,
+		Logger:               logger,
+		Options:              tlsOptions,
+		AllowEmptyServerName: true,
+	})
+	if err != nil {
+		return nil, err
+	}
+	return NewTransportWithDialer(rawDialer, baseTLSConfig, tag, options)
+}
+
+func NewTransportWithDialer(rawDialer N.Dialer, baseTLSConfig tls.Config, tag string, options option.HTTPClientOptions) (*Transport, error) {
+	transport, err := newTransport(rawDialer, baseTLSConfig, options)
+	if err != nil {
+		return nil, err
+	}
+	headers := options.Headers.Build()
+	host := headers.Get("Host")
+	headers.Del("Host")
+	return &Transport{
+		transport: transport,
+		dialer:    rawDialer,
+		headers:   headers,
+		host:      host,
+		tag:       tag,
+	}, nil
+}
+
+func newTransport(rawDialer N.Dialer, baseTLSConfig tls.Config, options option.HTTPClientOptions) (adapter.HTTPTransport, error) {
+	version := options.Version
+	if version == 0 {
+		version = 2
+	}
+	fallbackDelay := time.Duration(options.DialerOptions.FallbackDelay)
+	if fallbackDelay == 0 {
+		fallbackDelay = 300 * time.Millisecond
+	}
+	var transport adapter.HTTPTransport
+	var err error
+	switch version {
+	case 1:
+		transport = newHTTP1Transport(rawDialer, baseTLSConfig)
+	case 2:
+		if options.DisableVersionFallback {
+			transport, err = newHTTP2Transport(rawDialer, baseTLSConfig, options.HTTP2Options)
+		} else {
+			transport, err = newHTTP2FallbackTransport(rawDialer, baseTLSConfig, options.HTTP2Options)
+		}
+	case 3:
+		if baseTLSConfig != nil {
+			_, err = baseTLSConfig.STDConfig()
+			if err != nil {
+				return nil, err
+			}
+		}
+		if options.DisableVersionFallback {
+			transport, err = newHTTP3Transport(rawDialer, baseTLSConfig, options.HTTP3Options)
+		} else {
+			var h2Fallback adapter.HTTPTransport
+			h2Fallback, err = newHTTP2FallbackTransport(rawDialer, baseTLSConfig, options.HTTP2Options)
+			if err != nil {
+				return nil, err
+			}
+			transport, err = newHTTP3FallbackTransport(rawDialer, baseTLSConfig, h2Fallback, options.HTTP3Options, fallbackDelay)
+		}
+	default:
+		return nil, E.New("unknown HTTP version: ", version)
+	}
+	if err != nil {
+		return nil, err
+	}
+	return transport, nil
+}
+
+func (c *Transport) RoundTrip(request *http.Request) (*http.Response, error) {
+	if c.tag == "" && len(c.headers) == 0 && c.host == "" {
+		return c.transport.RoundTrip(request)
+	}
+	if c.tag != "" {
+		if transportTag, loaded := transportTagFromContext(request.Context()); loaded && transportTag == c.tag {
+			return nil, E.New("HTTP request loopback in transport[", c.tag, "]")
+		}
+		request = request.Clone(contextWithTransportTag(request.Context(), c.tag))
+	} else {
+		request = request.Clone(request.Context())
+	}
+	applyHeaders(request, c.headers, c.host)
+	return c.transport.RoundTrip(request)
+}
+
+func (c *Transport) CloseIdleConnections() {
+	c.transport.CloseIdleConnections()
+}
+
+func (c *Transport) Clone() adapter.HTTPTransport {
+	return &Transport{
+		transport: c.transport.Clone(),
+		dialer:    c.dialer,
+		headers:   c.headers.Clone(),
+		host:      c.host,
+		tag:       c.tag,
+	}
+}
+
+func (c *Transport) Close() error {
+	return c.transport.Close()
+}
+
+// InitializeDetour eagerly resolves the detour dialer backing transport so that
+// detour misconfigurations surface at startup instead of on the first request.
+func InitializeDetour(transport adapter.HTTPTransport) error {
+	if shared, isShared := transport.(*sharedTransport); isShared {
+		transport = shared.HTTPTransport
+	}
+	inner, isInner := transport.(*Transport)
+	if !isInner {
+		return nil
+	}
+	return dialer.InitializeDetour(inner.dialer)
+}

common/httpclient/context.go

@@ -0,0 +1,14 @@
+package httpclient
+
+import "context"
+
+type transportKey struct{}
+
+func contextWithTransportTag(ctx context.Context, transportTag string) context.Context {
+	return context.WithValue(ctx, transportKey{}, transportTag)
+}
+
+func transportTagFromContext(ctx context.Context) (string, bool) {
+	value, loaded := ctx.Value(transportKey{}).(string)
+	return value, loaded
+}

common/httpclient/helpers.go

@@ -0,0 +1,86 @@
+package httpclient
+
+import (
+	"context"
+	stdTLS "crypto/tls"
+	"io"
+	"net"
+	"net/http"
+	"strings"
+
+	"github.com/sagernet/sing-box/common/tls"
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+func dialTLS(ctx context.Context, rawDialer N.Dialer, baseTLSConfig tls.Config, destination M.Socksaddr, nextProtos []string, expectProto string) (net.Conn, error) {
+	if baseTLSConfig == nil {
+		return nil, E.New("TLS transport unavailable")
+	}
+	tlsConfig := baseTLSConfig.Clone()
+	if tlsConfig.ServerName() == "" && destination.IsValid() {
+		tlsConfig.SetServerName(destination.AddrString())
+	}
+	tlsConfig.SetNextProtos(nextProtos)
+	conn, err := rawDialer.DialContext(ctx, N.NetworkTCP, destination)
+	if err != nil {
+		return nil, err
+	}
+	tlsConn, err := tls.ClientHandshake(ctx, conn, tlsConfig)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+	if expectProto != "" && tlsConn.ConnectionState().NegotiatedProtocol != expectProto {
+		tlsConn.Close()
+		return nil, errHTTP2Fallback
+	}
+	return tlsConn, nil
+}
+
+func applyHeaders(request *http.Request, headers http.Header, host string) {
+	for header, values := range headers {
+		request.Header[header] = append([]string(nil), values...)
+	}
+	if host != "" {
+		request.Host = host
+	}
+}
+
+func requestRequiresHTTP1(request *http.Request) bool {
+	return strings.Contains(strings.ToLower(request.Header.Get("Connection")), "upgrade") &&
+		strings.EqualFold(request.Header.Get("Upgrade"), "websocket")
+}
+
+func requestReplayable(request *http.Request) bool {
+	return request.Body == nil || request.Body == http.NoBody || request.GetBody != nil
+}
+
+func cloneRequestForRetry(request *http.Request) *http.Request {
+	cloned := request.Clone(request.Context())
+	if request.Body != nil && request.Body != http.NoBody && request.GetBody != nil {
+		cloned.Body = mustGetBody(request)
+	}
+	return cloned
+}
+
+func mustGetBody(request *http.Request) io.ReadCloser {
+	body, err := request.GetBody()
+	if err != nil {
+		panic(err)
+	}
+	return body
+}
+
+func buildSTDTLSConfig(baseTLSConfig tls.Config, destination M.Socksaddr, nextProtos []string) (*stdTLS.Config, error) {
+	if baseTLSConfig == nil {
+		return nil, nil
+	}
+	tlsConfig := baseTLSConfig.Clone()
+	if tlsConfig.ServerName() == "" && destination.IsValid() {
+		tlsConfig.SetServerName(destination.AddrString())
+	}
+	tlsConfig.SetNextProtos(nextProtos)
+	return tlsConfig.STDConfig()
+}

common/httpclient/http1_transport.go

@@ -0,0 +1,47 @@
+package httpclient
+
+import (
+	"context"
+	"net"
+	"net/http"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/tls"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+type http1Transport struct {
+	transport *http.Transport
+}
+
+func newHTTP1Transport(rawDialer N.Dialer, baseTLSConfig tls.Config) *http1Transport {
+	transport := &http.Transport{
+		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+			return rawDialer.DialContext(ctx, network, M.ParseSocksaddr(addr))
+		},
+	}
+	if baseTLSConfig != nil {
+		transport.DialTLSContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
+			return dialTLS(ctx, rawDialer, baseTLSConfig, M.ParseSocksaddr(addr), []string{"http/1.1"}, "")
+		}
+	}
+	return &http1Transport{transport: transport}
+}
+
+func (t *http1Transport) RoundTrip(request *http.Request) (*http.Response, error) {
+	return t.transport.RoundTrip(request)
+}
+
+func (t *http1Transport) CloseIdleConnections() {
+	t.transport.CloseIdleConnections()
+}
+
+func (t *http1Transport) Clone() adapter.HTTPTransport {
+	return &http1Transport{transport: t.transport.Clone()}
+}
+
+func (t *http1Transport) Close() error {
+	t.CloseIdleConnections()
+	return nil
+}

common/httpclient/http2_config.go

@@ -0,0 +1,42 @@
+package httpclient
+
+import (
+	stdTLS "crypto/tls"
+	"net/http"
+	"time"
+
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+
+	"golang.org/x/net/http2"
+)
+
+func CloneHTTP2Transport(transport *http2.Transport) *http2.Transport {
+	return &http2.Transport{
+		ReadIdleTimeout: transport.ReadIdleTimeout,
+		PingTimeout:     transport.PingTimeout,
+		DialTLSContext:  transport.DialTLSContext,
+	}
+}
+
+func ConfigureHTTP2Transport(options option.HTTP2Options) (*http2.Transport, error) {
+	stdTransport := &http.Transport{
+		TLSClientConfig: &stdTLS.Config{},
+		HTTP2: &http.HTTP2Config{
+			MaxReceiveBufferPerStream:     int(options.StreamReceiveWindow.Value()),
+			MaxReceiveBufferPerConnection: int(options.ConnectionReceiveWindow.Value()),
+			MaxConcurrentStreams:          options.MaxConcurrentStreams,
+			SendPingTimeout:               time.Duration(options.KeepAlivePeriod),
+			PingTimeout:                   time.Duration(options.IdleTimeout),
+		},
+	}
+	h2Transport, err := http2.ConfigureTransports(stdTransport)
+	if err != nil {
+		return nil, E.Cause(err, "configure HTTP/2 transport")
+	}
+	// ConfigureTransports binds ConnPool to the throwaway http.Transport; sever it so DialTLSContext is used directly.
+	h2Transport.ConnPool = nil
+	h2Transport.ReadIdleTimeout = time.Duration(options.KeepAlivePeriod)
+	h2Transport.PingTimeout = time.Duration(options.IdleTimeout)
+	return h2Transport, nil
+}

common/httpclient/http2_fallback_transport.go

@@ -0,0 +1,93 @@
+package httpclient
+
+import (
+	"context"
+	stdTLS "crypto/tls"
+	"errors"
+	"net"
+	"net/http"
+	"sync/atomic"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/tls"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+
+	"golang.org/x/net/http2"
+)
+
+var errHTTP2Fallback = E.New("fallback to HTTP/1.1")
+
+type http2FallbackTransport struct {
+	h2Transport *http2.Transport
+	h1Transport *http1Transport
+	h2Fallback  *atomic.Bool
+}
+
+func newHTTP2FallbackTransport(rawDialer N.Dialer, baseTLSConfig tls.Config, options option.HTTP2Options) (*http2FallbackTransport, error) {
+	h1 := newHTTP1Transport(rawDialer, baseTLSConfig)
+	var fallback atomic.Bool
+	h2Transport, err := ConfigureHTTP2Transport(options)
+	if err != nil {
+		return nil, err
+	}
+	h2Transport.DialTLSContext = func(ctx context.Context, network, addr string, _ *stdTLS.Config) (net.Conn, error) {
+		conn, dialErr := dialTLS(ctx, rawDialer, baseTLSConfig, M.ParseSocksaddr(addr), []string{http2.NextProtoTLS, "http/1.1"}, http2.NextProtoTLS)
+		if dialErr != nil {
+			if errors.Is(dialErr, errHTTP2Fallback) {
+				fallback.Store(true)
+			}
+			return nil, dialErr
+		}
+		return conn, nil
+	}
+	return &http2FallbackTransport{
+		h2Transport: h2Transport,
+		h1Transport: h1,
+		h2Fallback:  &fallback,
+	}, nil
+}
+
+func (t *http2FallbackTransport) RoundTrip(request *http.Request) (*http.Response, error) {
+	return t.roundTrip(request, true)
+}
+
+func (t *http2FallbackTransport) roundTrip(request *http.Request, allowHTTP1Fallback bool) (*http.Response, error) {
+	if request.URL.Scheme != "https" || requestRequiresHTTP1(request) {
+		return t.h1Transport.RoundTrip(request)
+	}
+	if t.h2Fallback.Load() {
+		if !allowHTTP1Fallback {
+			return nil, errHTTP2Fallback
+		}
+		return t.h1Transport.RoundTrip(request)
+	}
+	response, err := t.h2Transport.RoundTrip(request)
+	if err == nil {
+		return response, nil
+	}
+	if !errors.Is(err, errHTTP2Fallback) || !allowHTTP1Fallback {
+		return nil, err
+	}
+	return t.h1Transport.RoundTrip(cloneRequestForRetry(request))
+}
+
+func (t *http2FallbackTransport) CloseIdleConnections() {
+	t.h1Transport.CloseIdleConnections()
+	t.h2Transport.CloseIdleConnections()
+}
+
+func (t *http2FallbackTransport) Clone() adapter.HTTPTransport {
+	return &http2FallbackTransport{
+		h2Transport: CloneHTTP2Transport(t.h2Transport),
+		h1Transport: t.h1Transport.Clone().(*http1Transport),
+		h2Fallback:  t.h2Fallback,
+	}
+}
+
+func (t *http2FallbackTransport) Close() error {
+	t.CloseIdleConnections()
+	return nil
+}

common/httpclient/http2_transport.go

@@ -0,0 +1,60 @@
+package httpclient
+
+import (
+	"context"
+	stdTLS "crypto/tls"
+	"net"
+	"net/http"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/tls"
+	"github.com/sagernet/sing-box/option"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+
+	"golang.org/x/net/http2"
+)
+
+type http2Transport struct {
+	h2Transport *http2.Transport
+	h1Transport *http1Transport
+}
+
+func newHTTP2Transport(rawDialer N.Dialer, baseTLSConfig tls.Config, options option.HTTP2Options) (*http2Transport, error) {
+	h1 := newHTTP1Transport(rawDialer, baseTLSConfig)
+	h2Transport, err := ConfigureHTTP2Transport(options)
+	if err != nil {
+		return nil, err
+	}
+	h2Transport.DialTLSContext = func(ctx context.Context, network, addr string, _ *stdTLS.Config) (net.Conn, error) {
+		return dialTLS(ctx, rawDialer, baseTLSConfig, M.ParseSocksaddr(addr), []string{http2.NextProtoTLS}, http2.NextProtoTLS)
+	}
+	return &http2Transport{
+		h2Transport: h2Transport,
+		h1Transport: h1,
+	}, nil
+}
+
+func (t *http2Transport) RoundTrip(request *http.Request) (*http.Response, error) {
+	if request.URL.Scheme != "https" || requestRequiresHTTP1(request) {
+		return t.h1Transport.RoundTrip(request)
+	}
+	return t.h2Transport.RoundTrip(request)
+}
+
+func (t *http2Transport) CloseIdleConnections() {
+	t.h1Transport.CloseIdleConnections()
+	t.h2Transport.CloseIdleConnections()
+}
+
+func (t *http2Transport) Clone() adapter.HTTPTransport {
+	return &http2Transport{
+		h2Transport: CloneHTTP2Transport(t.h2Transport),
+		h1Transport: t.h1Transport.Clone().(*http1Transport),
+	}
+}
+
+func (t *http2Transport) Close() error {
+	t.CloseIdleConnections()
+	return nil
+}

common/httpclient/http3_transport.go

@@ -0,0 +1,312 @@
+//go:build with_quic
+
+package httpclient
+
+import (
+	"context"
+	stdTLS "crypto/tls"
+	"errors"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/sagernet/quic-go"
+	"github.com/sagernet/quic-go/http3"
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/tls"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing/common/bufio"
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+type http3Transport struct {
+	h3Transport *http3.Transport
+}
+
+type http3FallbackTransport struct {
+	h3Transport   *http3.Transport
+	h2Fallback    adapter.HTTPTransport
+	fallbackDelay time.Duration
+	brokenAccess  sync.Mutex
+	brokenUntil   time.Time
+	brokenBackoff time.Duration
+}
+
+func newHTTP3RoundTripper(
+	rawDialer N.Dialer,
+	baseTLSConfig tls.Config,
+	options option.QUICOptions,
+) *http3.Transport {
+	var handshakeTimeout time.Duration
+	if baseTLSConfig != nil {
+		handshakeTimeout = baseTLSConfig.HandshakeTimeout()
+	}
+	quicConfig := &quic.Config{
+		InitialStreamReceiveWindow:     options.StreamReceiveWindow.Value(),
+		MaxStreamReceiveWindow:         options.StreamReceiveWindow.Value(),
+		InitialConnectionReceiveWindow: options.ConnectionReceiveWindow.Value(),
+		MaxConnectionReceiveWindow:     options.ConnectionReceiveWindow.Value(),
+		KeepAlivePeriod:                time.Duration(options.KeepAlivePeriod),
+		MaxIdleTimeout:                 time.Duration(options.IdleTimeout),
+		DisablePathMTUDiscovery:        options.DisablePathMTUDiscovery,
+	}
+	if options.InitialPacketSize > 0 {
+		quicConfig.InitialPacketSize = uint16(options.InitialPacketSize)
+	}
+	if options.MaxConcurrentStreams > 0 {
+		quicConfig.MaxIncomingStreams = int64(options.MaxConcurrentStreams)
+	}
+	if handshakeTimeout > 0 {
+		quicConfig.HandshakeIdleTimeout = handshakeTimeout
+	}
+	h3Transport := &http3.Transport{
+		TLSClientConfig: &stdTLS.Config{},
+		QUICConfig:      quicConfig,
+		Dial: func(ctx context.Context, addr string, tlsConfig *stdTLS.Config, quicConfig *quic.Config) (*quic.Conn, error) {
+			if handshakeTimeout > 0 && quicConfig.HandshakeIdleTimeout == 0 {
+				quicConfig = quicConfig.Clone()
+				quicConfig.HandshakeIdleTimeout = handshakeTimeout
+			}
+			if baseTLSConfig != nil {
+				var err error
+				tlsConfig, err = buildSTDTLSConfig(baseTLSConfig, M.ParseSocksaddr(addr), []string{http3.NextProtoH3})
+				if err != nil {
+					return nil, err
+				}
+			} else {
+				tlsConfig = tlsConfig.Clone()
+				tlsConfig.NextProtos = []string{http3.NextProtoH3}
+			}
+			conn, err := rawDialer.DialContext(ctx, N.NetworkUDP, M.ParseSocksaddr(addr))
+			if err != nil {
+				return nil, err
+			}
+			quicConn, err := quic.DialEarly(ctx, bufio.NewUnbindPacketConn(conn), conn.RemoteAddr(), tlsConfig, quicConfig)
+			if err != nil {
+				conn.Close()
+				return nil, err
+			}
+			return quicConn, nil
+		},
+	}
+	return h3Transport
+}
+
+func newHTTP3Transport(
+	rawDialer N.Dialer,
+	baseTLSConfig tls.Config,
+	options option.QUICOptions,
+) (adapter.HTTPTransport, error) {
+	return &http3Transport{
+		h3Transport: newHTTP3RoundTripper(rawDialer, baseTLSConfig, options),
+	}, nil
+}
+
+func newHTTP3FallbackTransport(
+	rawDialer N.Dialer,
+	baseTLSConfig tls.Config,
+	h2Fallback adapter.HTTPTransport,
+	options option.QUICOptions,
+	fallbackDelay time.Duration,
+) (adapter.HTTPTransport, error) {
+	return &http3FallbackTransport{
+		h3Transport:   newHTTP3RoundTripper(rawDialer, baseTLSConfig, options),
+		h2Fallback:    h2Fallback,
+		fallbackDelay: fallbackDelay,
+	}, nil
+}
+
+func (t *http3Transport) RoundTrip(request *http.Request) (*http.Response, error) {
+	return t.h3Transport.RoundTrip(request)
+}
+
+func (t *http3Transport) CloseIdleConnections() {
+	t.h3Transport.CloseIdleConnections()
+}
+
+func (t *http3Transport) Close() error {
+	t.CloseIdleConnections()
+	return t.h3Transport.Close()
+}
+
+func (t *http3Transport) Clone() adapter.HTTPTransport {
+	return &http3Transport{
+		h3Transport: t.h3Transport,
+	}
+}
+
+func (t *http3FallbackTransport) RoundTrip(request *http.Request) (*http.Response, error) {
+	if request.URL.Scheme != "https" || requestRequiresHTTP1(request) {
+		return t.h2Fallback.RoundTrip(request)
+	}
+	return t.roundTripHTTP3(request)
+}
+
+func (t *http3FallbackTransport) roundTripHTTP3(request *http.Request) (*http.Response, error) {
+	if t.h3Broken() {
+		return t.h2FallbackRoundTrip(request)
+	}
+	response, err := t.h3Transport.RoundTripOpt(request, http3.RoundTripOpt{OnlyCachedConn: true})
+	if err == nil {
+		t.clearH3Broken()
+		return response, nil
+	}
+	if !errors.Is(err, http3.ErrNoCachedConn) {
+		t.markH3Broken()
+		return t.h2FallbackRoundTrip(cloneRequestForRetry(request))
+	}
+	if !requestReplayable(request) {
+		response, err = t.h3Transport.RoundTrip(request)
+		if err == nil {
+			t.clearH3Broken()
+			return response, nil
+		}
+		t.markH3Broken()
+		return nil, err
+	}
+	return t.roundTripHTTP3Race(request)
+}
+
+func (t *http3FallbackTransport) roundTripHTTP3Race(request *http.Request) (*http.Response, error) {
+	ctx, cancel := context.WithCancel(request.Context())
+	defer cancel()
+	type result struct {
+		response *http.Response
+		err      error
+		h3       bool
+	}
+	results := make(chan result, 2)
+	startRoundTrip := func(request *http.Request, useH3 bool) {
+		request = request.WithContext(ctx)
+		var (
+			response *http.Response
+			err      error
+		)
+		if useH3 {
+			response, err = t.h3Transport.RoundTrip(request)
+		} else {
+			response, err = t.h2FallbackRoundTrip(request)
+		}
+		results <- result{response: response, err: err, h3: useH3}
+	}
+	goroutines := 1
+	received := 0
+	drainRemaining := func() {
+		cancel()
+		for range goroutines - received {
+			go func() {
+				loser := <-results
+				if loser.response != nil && loser.response.Body != nil {
+					loser.response.Body.Close()
+				}
+			}()
+		}
+	}
+	go startRoundTrip(cloneRequestForRetry(request), true)
+	timer := time.NewTimer(t.fallbackDelay)
+	defer timer.Stop()
+	var (
+		h3Err       error
+		fallbackErr error
+	)
+	for {
+		select {
+		case <-timer.C:
+			if goroutines == 1 {
+				goroutines++
+				go startRoundTrip(cloneRequestForRetry(request), false)
+			}
+		case raceResult := <-results:
+			received++
+			if raceResult.err == nil {
+				if raceResult.h3 {
+					t.clearH3Broken()
+				}
+				drainRemaining()
+				return raceResult.response, nil
+			}
+			if raceResult.h3 {
+				t.markH3Broken()
+				h3Err = raceResult.err
+				if goroutines == 1 {
+					goroutines++
+					if !timer.Stop() {
+						select {
+						case <-timer.C:
+						default:
+						}
+					}
+					go startRoundTrip(cloneRequestForRetry(request), false)
+				}
+			} else {
+				fallbackErr = raceResult.err
+			}
+			if received < goroutines {
+				continue
+			}
+			drainRemaining()
+			switch {
+			case h3Err != nil && fallbackErr != nil:
+				return nil, E.Errors(h3Err, fallbackErr)
+			case fallbackErr != nil:
+				return nil, fallbackErr
+			default:
+				return nil, h3Err
+			}
+		}
+	}
+}
+
+func (t *http3FallbackTransport) h2FallbackRoundTrip(request *http.Request) (*http.Response, error) {
+	if fallback, isFallback := t.h2Fallback.(*http2FallbackTransport); isFallback {
+		return fallback.roundTrip(request, true)
+	}
+	return t.h2Fallback.RoundTrip(request)
+}
+
+func (t *http3FallbackTransport) CloseIdleConnections() {
+	t.h3Transport.CloseIdleConnections()
+	t.h2Fallback.CloseIdleConnections()
+}
+
+func (t *http3FallbackTransport) Close() error {
+	t.CloseIdleConnections()
+	return t.h3Transport.Close()
+}
+
+func (t *http3FallbackTransport) Clone() adapter.HTTPTransport {
+	return &http3FallbackTransport{
+		h3Transport:   t.h3Transport,
+		h2Fallback:    t.h2Fallback.Clone(),
+		fallbackDelay: t.fallbackDelay,
+	}
+}
+
+func (t *http3FallbackTransport) h3Broken() bool {
+	t.brokenAccess.Lock()
+	defer t.brokenAccess.Unlock()
+	return !t.brokenUntil.IsZero() && time.Now().Before(t.brokenUntil)
+}
+
+func (t *http3FallbackTransport) clearH3Broken() {
+	t.brokenAccess.Lock()
+	t.brokenUntil = time.Time{}
+	t.brokenBackoff = 0
+	t.brokenAccess.Unlock()
+}
+
+func (t *http3FallbackTransport) markH3Broken() {
+	t.brokenAccess.Lock()
+	defer t.brokenAccess.Unlock()
+	if t.brokenBackoff == 0 {
+		t.brokenBackoff = 5 * time.Minute
+	} else {
+		t.brokenBackoff *= 2
+		if t.brokenBackoff > 48*time.Hour {
+			t.brokenBackoff = 48 * time.Hour
+		}
+	}
+	t.brokenUntil = time.Now().Add(t.brokenBackoff)
+}

common/httpclient/http3_transport_stub.go

@@ -0,0 +1,31 @@
+//go:build !with_quic
+
+package httpclient
+
+import (
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/tls"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+	N "github.com/sagernet/sing/common/network"
+)
+
+func newHTTP3FallbackTransport(
+	rawDialer N.Dialer,
+	baseTLSConfig tls.Config,
+	h2Fallback adapter.HTTPTransport,
+	options option.QUICOptions,
+	fallbackDelay time.Duration,
+) (adapter.HTTPTransport, error) {
+	return nil, E.New("HTTP/3 requires building with the with_quic tag")
+}
+
+func newHTTP3Transport(
+	rawDialer N.Dialer,
+	baseTLSConfig tls.Config,
+	options option.QUICOptions,
+) (adapter.HTTPTransport, error) {
+	return nil, E.New("HTTP/3 requires building with the with_quic tag")
+}

common/httpclient/manager.go

@@ -0,0 +1,164 @@
+package httpclient
+
+import (
+	"context"
+	"sync"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+)
+
+var (
+	_ adapter.HTTPClientManager = (*Manager)(nil)
+	_ adapter.LifecycleService  = (*Manager)(nil)
+)
+
+type Manager struct {
+	ctx                      context.Context
+	logger                   log.ContextLogger
+	access                   sync.Mutex
+	defines                  map[string]option.HTTPClient
+	transports               map[string]*Transport
+	defaultTag               string
+	defaultTransport         adapter.HTTPTransport
+	defaultTransportFallback func() (*Transport, error)
+	fallbackTransport        *Transport
+}
+
+func NewManager(ctx context.Context, logger log.ContextLogger, clients []option.HTTPClient, defaultHTTPClient string) *Manager {
+	defines := make(map[string]option.HTTPClient, len(clients))
+	for _, client := range clients {
+		defines[client.Tag] = client
+	}
+	defaultTag := defaultHTTPClient
+	if defaultTag == "" && len(clients) > 0 {
+		defaultTag = clients[0].Tag
+	}
+	return &Manager{
+		ctx:        ctx,
+		logger:     logger,
+		defines:    defines,
+		transports: make(map[string]*Transport),
+		defaultTag: defaultTag,
+	}
+}
+
+func (m *Manager) Initialize(defaultTransportFallback func() (*Transport, error)) {
+	m.defaultTransportFallback = defaultTransportFallback
+}
+
+func (m *Manager) Name() string {
+	return "http-client"
+}
+
+func (m *Manager) Start(stage adapter.StartStage) error {
+	if stage != adapter.StartStateStart {
+		return nil
+	}
+	if m.defaultTag != "" {
+		transport, err := m.resolveShared(m.defaultTag)
+		if err != nil {
+			return E.Cause(err, "resolve default http client")
+		}
+		m.defaultTransport = transport
+	} else if m.defaultTransportFallback != nil {
+		transport, err := m.defaultTransportFallback()
+		if err != nil {
+			return E.Cause(err, "create default http client")
+		}
+		m.defaultTransport = transport
+		m.fallbackTransport = transport
+	}
+	return nil
+}
+
+func (m *Manager) DefaultTransport() adapter.HTTPTransport {
+	if m.defaultTransport == nil {
+		return nil
+	}
+	return &sharedTransport{m.defaultTransport}
+}
+
+func (m *Manager) ResolveTransport(ctx context.Context, logger logger.ContextLogger, options option.HTTPClientOptions) (adapter.HTTPTransport, error) {
+	if options.Tag != "" {
+		if options.ResolveOnDetour {
+			define, loaded := m.defines[options.Tag]
+			if !loaded {
+				return nil, E.New("http_client not found: ", options.Tag)
+			}
+			resolvedOptions := define.Options()
+			resolvedOptions.ResolveOnDetour = true
+			return NewTransport(ctx, logger, options.Tag, resolvedOptions)
+		}
+		transport, err := m.resolveShared(options.Tag)
+		if err != nil {
+			return nil, err
+		}
+		return &sharedTransport{transport}, nil
+	}
+	return NewTransport(ctx, logger, "", options)
+}
+
+func (m *Manager) resolveShared(tag string) (adapter.HTTPTransport, error) {
+	m.access.Lock()
+	defer m.access.Unlock()
+	if transport, loaded := m.transports[tag]; loaded {
+		return transport, nil
+	}
+	define, loaded := m.defines[tag]
+	if !loaded {
+		return nil, E.New("http_client not found: ", tag)
+	}
+	transport, err := NewTransport(m.ctx, m.logger, tag, define.Options())
+	if err != nil {
+		return nil, E.Cause(err, "create shared http_client[", tag, "]")
+	}
+	m.transports[tag] = transport
+	return transport, nil
+}
+
+type sharedTransport struct {
+	adapter.HTTPTransport
+}
+
+func (t *sharedTransport) CloseIdleConnections() {
+}
+
+func (t *sharedTransport) Close() error {
+	return nil
+}
+
+func (m *Manager) ResetNetwork() {
+	m.access.Lock()
+	defer m.access.Unlock()
+	for _, transport := range m.transports {
+		transport.CloseIdleConnections()
+	}
+	if m.fallbackTransport != nil {
+		m.fallbackTransport.CloseIdleConnections()
+	}
+}
+
+func (m *Manager) Close() error {
+	m.access.Lock()
+	defer m.access.Unlock()
+	if m.transports == nil {
+		return nil
+	}
+	var err error
+	for _, transport := range m.transports {
+		err = E.Append(err, transport.Close(), func(err error) error {
+			return E.Cause(err, "close http client")
+		})
+	}
+	if m.fallbackTransport != nil {
+		err = E.Append(err, m.fallbackTransport.Close(), func(err error) error {
+			return E.Cause(err, "close default http client")
+		})
+	}
+	m.transports = nil
+	return err
+}

common/proxybridge/bridge.go

@@ -0,0 +1,115 @@
+package proxybridge
+
+import (
+	std_bufio "bufio"
+	"context"
+	"crypto/rand"
+	"encoding/hex"
+	"net"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing/common"
+	"github.com/sagernet/sing/common/auth"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+	"github.com/sagernet/sing/protocol/socks"
+	"github.com/sagernet/sing/service"
+)
+
+type Bridge struct {
+	ctx           context.Context
+	logger        logger.ContextLogger
+	tag           string
+	dialer        N.Dialer
+	connection    adapter.ConnectionManager
+	tcpListener   *net.TCPListener
+	username      string
+	password      string
+	authenticator *auth.Authenticator
+}
+
+func New(ctx context.Context, logger logger.ContextLogger, tag string, dialer N.Dialer) (*Bridge, error) {
+	username := randomHex(16)
+	password := randomHex(16)
+	tcpListener, err := net.ListenTCP("tcp", &net.TCPAddr{IP: net.IPv4(127, 0, 0, 1)})
+	if err != nil {
+		return nil, err
+	}
+	bridge := &Bridge{
+		ctx:           ctx,
+		logger:        logger,
+		tag:           tag,
+		dialer:        dialer,
+		connection:    service.FromContext[adapter.ConnectionManager](ctx),
+		tcpListener:   tcpListener,
+		username:      username,
+		password:      password,
+		authenticator: auth.NewAuthenticator([]auth.User{{Username: username, Password: password}}),
+	}
+	go bridge.acceptLoop()
+	return bridge, nil
+}
+
+func randomHex(size int) string {
+	raw := make([]byte, size)
+	rand.Read(raw)
+	return hex.EncodeToString(raw)
+}
+
+func (b *Bridge) Port() uint16 {
+	return M.SocksaddrFromNet(b.tcpListener.Addr()).Port
+}
+
+func (b *Bridge) Username() string {
+	return b.username
+}
+
+func (b *Bridge) Password() string {
+	return b.password
+}
+
+func (b *Bridge) Close() error {
+	return common.Close(b.tcpListener)
+}
+
+func (b *Bridge) acceptLoop() {
+	for {
+		tcpConn, err := b.tcpListener.AcceptTCP()
+		if err != nil {
+			return
+		}
+		ctx := log.ContextWithNewID(b.ctx)
+		go func() {
+			hErr := socks.HandleConnectionEx(ctx, tcpConn, std_bufio.NewReader(tcpConn), b.authenticator, b, nil, 0, M.SocksaddrFromNet(tcpConn.RemoteAddr()), nil)
+			if hErr == nil {
+				return
+			}
+			if E.IsClosedOrCanceled(hErr) {
+				b.logger.DebugContext(ctx, E.Cause(hErr, b.tag, " connection closed"))
+				return
+			}
+			b.logger.ErrorContext(ctx, E.Cause(hErr, b.tag))
+		}()
+	}
+}
+
+func (b *Bridge) NewConnectionEx(ctx context.Context, conn net.Conn, source M.Socksaddr, destination M.Socksaddr, onClose N.CloseHandlerFunc) {
+	var metadata adapter.InboundContext
+	metadata.Source = source
+	metadata.Destination = destination
+	metadata.Network = N.NetworkTCP
+	b.logger.InfoContext(ctx, b.tag, " connection to ", metadata.Destination)
+	b.connection.NewConnection(ctx, b.dialer, conn, metadata, onClose)
+}
+
+func (b *Bridge) NewPacketConnectionEx(ctx context.Context, conn N.PacketConn, source M.Socksaddr, destination M.Socksaddr, onClose N.CloseHandlerFunc) {
+	var metadata adapter.InboundContext
+	metadata.Source = source
+	metadata.Destination = destination
+	metadata.Network = N.NetworkUDP
+	b.logger.InfoContext(ctx, b.tag, " packet connection to ", metadata.Destination)
+	b.connection.NewPacketConnection(ctx, b.dialer, conn, metadata, onClose)
+}

common/stun/stun.go

@@ -9,6 +9,8 @@ import (
 	"net/netip"
 	"time"
 
+	"github.com/sagernet/sing/common/bufio"
+	"github.com/sagernet/sing/common/bufio/deadline"
 	E "github.com/sagernet/sing/common/exceptions"
 	M "github.com/sagernet/sing/common/metadata"
 	N "github.com/sagernet/sing/common/network"
@@ -431,6 +433,9 @@ func Run(options Options) (*Result, error) {
 	defer func() {
 		_ = packetConn.Close()
 	}()
+	if deadline.NeedAdditionalReadDeadline(packetConn) {
+		packetConn = deadline.NewPacketConn(bufio.NewPacketConn(packetConn))
+	}
 
 	select {
 	case <-ctx.Done():

common/tls/apple_client.go

@@ -0,0 +1,214 @@
+//go:build darwin && cgo
+
+package tls
+
+import (
+	"context"
+	"net"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	boxConstant "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+	"github.com/sagernet/sing/service"
+)
+
+type appleCertificateStore interface {
+	StoreKind() string
+	CurrentPEM() []string
+}
+
+type appleClientConfig struct {
+	serverName                 string
+	nextProtos                 []string
+	handshakeTimeout           time.Duration
+	minVersion                 uint16
+	maxVersion                 uint16
+	insecure                   bool
+	anchorPEM                  string
+	anchorOnly                 bool
+	certificatePublicKeySHA256 [][]byte
+}
+
+func (c *appleClientConfig) ServerName() string {
+	return c.serverName
+}
+
+func (c *appleClientConfig) SetServerName(serverName string) {
+	c.serverName = serverName
+}
+
+func (c *appleClientConfig) NextProtos() []string {
+	return c.nextProtos
+}
+
+func (c *appleClientConfig) SetNextProtos(nextProto []string) {
+	c.nextProtos = append(c.nextProtos[:0], nextProto...)
+}
+
+func (c *appleClientConfig) HandshakeTimeout() time.Duration {
+	return c.handshakeTimeout
+}
+
+func (c *appleClientConfig) SetHandshakeTimeout(timeout time.Duration) {
+	c.handshakeTimeout = timeout
+}
+
+func (c *appleClientConfig) STDConfig() (*STDConfig, error) {
+	return nil, E.New("unsupported usage for Apple TLS engine")
+}
+
+func (c *appleClientConfig) Client(conn net.Conn) (Conn, error) {
+	return nil, os.ErrInvalid
+}
+
+func (c *appleClientConfig) Clone() Config {
+	return &appleClientConfig{
+		serverName:                 c.serverName,
+		nextProtos:                 append([]string(nil), c.nextProtos...),
+		handshakeTimeout:           c.handshakeTimeout,
+		minVersion:                 c.minVersion,
+		maxVersion:                 c.maxVersion,
+		insecure:                   c.insecure,
+		anchorPEM:                  c.anchorPEM,
+		anchorOnly:                 c.anchorOnly,
+		certificatePublicKeySHA256: append([][]byte(nil), c.certificatePublicKeySHA256...),
+	}
+}
+
+func newAppleClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions, allowEmptyServerName bool) (Config, error) {
+	validated, err := ValidateAppleTLSOptions(ctx, options, "Apple TLS engine")
+	if err != nil {
+		return nil, err
+	}
+
+	var serverName string
+	if options.ServerName != "" {
+		serverName = options.ServerName
+	} else if serverAddress != "" {
+		serverName = serverAddress
+	}
+	if serverName == "" && !options.Insecure && !allowEmptyServerName {
+		return nil, errMissingServerName
+	}
+
+	var handshakeTimeout time.Duration
+	if options.HandshakeTimeout > 0 {
+		handshakeTimeout = options.HandshakeTimeout.Build()
+	} else {
+		handshakeTimeout = boxConstant.TCPTimeout
+	}
+
+	return &appleClientConfig{
+		serverName:                 serverName,
+		nextProtos:                 append([]string(nil), options.ALPN...),
+		handshakeTimeout:           handshakeTimeout,
+		minVersion:                 validated.MinVersion,
+		maxVersion:                 validated.MaxVersion,
+		insecure:                   options.Insecure || len(options.CertificatePublicKeySHA256) > 0,
+		anchorPEM:                  validated.AnchorPEM,
+		anchorOnly:                 validated.AnchorOnly,
+		certificatePublicKeySHA256: append([][]byte(nil), options.CertificatePublicKeySHA256...),
+	}, nil
+}
+
+type AppleTLSValidated struct {
+	MinVersion uint16
+	MaxVersion uint16
+	AnchorPEM  string
+	AnchorOnly bool
+}
+
+func ValidateAppleTLSOptions(ctx context.Context, options option.OutboundTLSOptions, engineName string) (AppleTLSValidated, error) {
+	if options.Reality != nil && options.Reality.Enabled {
+		return AppleTLSValidated{}, E.New("reality is unsupported in ", engineName)
+	}
+	if options.UTLS != nil && options.UTLS.Enabled {
+		return AppleTLSValidated{}, E.New("utls is unsupported in ", engineName)
+	}
+	if options.ECH != nil && options.ECH.Enabled {
+		return AppleTLSValidated{}, E.New("ech is unsupported in ", engineName)
+	}
+	if options.DisableSNI {
+		return AppleTLSValidated{}, E.New("disable_sni is unsupported in ", engineName)
+	}
+	if len(options.CipherSuites) > 0 {
+		return AppleTLSValidated{}, E.New("cipher_suites is unsupported in ", engineName)
+	}
+	if len(options.CurvePreferences) > 0 {
+		return AppleTLSValidated{}, E.New("curve_preferences is unsupported in ", engineName)
+	}
+	if len(options.ClientCertificate) > 0 || options.ClientCertificatePath != "" || len(options.ClientKey) > 0 || options.ClientKeyPath != "" {
+		return AppleTLSValidated{}, E.New("client certificate is unsupported in ", engineName)
+	}
+	if options.Fragment || options.RecordFragment {
+		return AppleTLSValidated{}, E.New("tls fragment is unsupported in ", engineName)
+	}
+	if options.KernelTx || options.KernelRx {
+		return AppleTLSValidated{}, E.New("ktls is unsupported in ", engineName)
+	}
+	if len(options.CertificatePublicKeySHA256) > 0 && (len(options.Certificate) > 0 || options.CertificatePath != "") {
+		return AppleTLSValidated{}, E.New("certificate_public_key_sha256 is conflict with certificate or certificate_path")
+	}
+	var minVersion uint16
+	if options.MinVersion != "" {
+		var err error
+		minVersion, err = ParseTLSVersion(options.MinVersion)
+		if err != nil {
+			return AppleTLSValidated{}, E.Cause(err, "parse min_version")
+		}
+	}
+	var maxVersion uint16
+	if options.MaxVersion != "" {
+		var err error
+		maxVersion, err = ParseTLSVersion(options.MaxVersion)
+		if err != nil {
+			return AppleTLSValidated{}, E.Cause(err, "parse max_version")
+		}
+	}
+	anchorPEM, anchorOnly, err := AppleAnchorPEM(ctx, options)
+	if err != nil {
+		return AppleTLSValidated{}, err
+	}
+	return AppleTLSValidated{
+		MinVersion: minVersion,
+		MaxVersion: maxVersion,
+		AnchorPEM:  anchorPEM,
+		AnchorOnly: anchorOnly,
+	}, nil
+}
+
+func AppleAnchorPEM(ctx context.Context, options option.OutboundTLSOptions) (string, bool, error) {
+	if len(options.Certificate) > 0 {
+		return strings.Join(options.Certificate, "\n"), true, nil
+	}
+	if options.CertificatePath != "" {
+		content, err := os.ReadFile(options.CertificatePath)
+		if err != nil {
+			return "", false, E.Cause(err, "read certificate")
+		}
+		return string(content), true, nil
+	}
+
+	certificateStore := service.FromContext[adapter.CertificateStore](ctx)
+	if certificateStore == nil {
+		return "", false, nil
+	}
+	store, ok := certificateStore.(appleCertificateStore)
+	if !ok {
+		return "", false, nil
+	}
+
+	switch store.StoreKind() {
+	case boxConstant.CertificateStoreSystem, "":
+		return strings.Join(store.CurrentPEM(), "\n"), false, nil
+	case boxConstant.CertificateStoreMozilla, boxConstant.CertificateStoreChrome, boxConstant.CertificateStoreNone:
+		return strings.Join(store.CurrentPEM(), "\n"), true, nil
+	default:
+		return "", false, E.New("unsupported certificate store for Apple TLS engine: ", store.StoreKind())
+	}
+}

common/tls/apple_client_platform.go

@@ -0,0 +1,414 @@
+//go:build darwin && cgo
+
+package tls
+
+/*
+#cgo CFLAGS: -x objective-c -fobjc-arc
+#cgo LDFLAGS: -framework Foundation -framework Network -framework Security
+
+#include <stdlib.h>
+#include "apple_client_platform.h"
+*/
+import "C"
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/binary"
+	"io"
+	"math"
+	"net"
+	"os"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
+
+	"golang.org/x/sys/unix"
+)
+
+func (c *appleClientConfig) ClientHandshake(ctx context.Context, conn net.Conn) (Conn, error) {
+	rawSyscallConn, ok := common.Cast[syscall.Conn](conn)
+	if !ok {
+		return nil, E.New("apple TLS: requires fd-backed TCP connection")
+	}
+	syscallConn, err := rawSyscallConn.SyscallConn()
+	if err != nil {
+		return nil, E.Cause(err, "access raw connection")
+	}
+
+	var dupFD int
+	controlErr := syscallConn.Control(func(fd uintptr) {
+		dupFD, err = unix.Dup(int(fd))
+	})
+	if controlErr != nil {
+		return nil, E.Cause(controlErr, "access raw connection")
+	}
+	if err != nil {
+		return nil, E.Cause(err, "duplicate raw connection")
+	}
+
+	serverName := c.serverName
+	serverNamePtr := cStringOrNil(serverName)
+	defer cFree(serverNamePtr)
+
+	alpn := strings.Join(c.nextProtos, "\n")
+	alpnPtr := cStringOrNil(alpn)
+	defer cFree(alpnPtr)
+
+	anchorPEMPtr := cStringOrNil(c.anchorPEM)
+	defer cFree(anchorPEMPtr)
+
+	var errorPtr *C.char
+	client := C.box_apple_tls_client_create(
+		C.int(dupFD),
+		serverNamePtr,
+		alpnPtr,
+		C.size_t(len(alpn)),
+		C.uint16_t(c.minVersion),
+		C.uint16_t(c.maxVersion),
+		C.bool(c.insecure),
+		anchorPEMPtr,
+		C.size_t(len(c.anchorPEM)),
+		C.bool(c.anchorOnly),
+		&errorPtr,
+	)
+	if client == nil {
+		if errorPtr != nil {
+			defer C.free(unsafe.Pointer(errorPtr))
+			return nil, E.New(C.GoString(errorPtr))
+		}
+		return nil, E.New("apple TLS: create connection")
+	}
+	if err = waitAppleTLSClientReady(ctx, client); err != nil {
+		C.box_apple_tls_client_cancel(client)
+		C.box_apple_tls_client_free(client)
+		return nil, err
+	}
+
+	var state C.box_apple_tls_state_t
+	stateOK := C.box_apple_tls_client_copy_state(client, &state, &errorPtr)
+	if !bool(stateOK) {
+		C.box_apple_tls_client_cancel(client)
+		C.box_apple_tls_client_free(client)
+		if errorPtr != nil {
+			defer C.free(unsafe.Pointer(errorPtr))
+			return nil, E.New(C.GoString(errorPtr))
+		}
+		return nil, E.New("apple TLS: read metadata")
+	}
+	defer C.box_apple_tls_state_free(&state)
+
+	connectionState, rawCerts, err := parseAppleTLSState(&state)
+	if err != nil {
+		C.box_apple_tls_client_cancel(client)
+		C.box_apple_tls_client_free(client)
+		return nil, err
+	}
+	if len(c.certificatePublicKeySHA256) > 0 {
+		err = VerifyPublicKeySHA256(c.certificatePublicKeySHA256, rawCerts)
+		if err != nil {
+			C.box_apple_tls_client_cancel(client)
+			C.box_apple_tls_client_free(client)
+			return nil, err
+		}
+	}
+
+	return &appleTLSConn{
+		rawConn: conn,
+		client:  client,
+		state:   connectionState,
+		closed:  make(chan struct{}),
+	}, nil
+}
+
+const appleTLSHandshakePollInterval = 100 * time.Millisecond
+
+func waitAppleTLSClientReady(ctx context.Context, client *C.box_apple_tls_client_t) error {
+	for {
+		if err := ctx.Err(); err != nil {
+			C.box_apple_tls_client_cancel(client)
+			return err
+		}
+
+		waitTimeout := appleTLSHandshakePollInterval
+		if deadline, loaded := ctx.Deadline(); loaded {
+			remaining := time.Until(deadline)
+			if remaining <= 0 {
+				C.box_apple_tls_client_cancel(client)
+				if err := ctx.Err(); err != nil {
+					return err
+				}
+				return context.DeadlineExceeded
+			}
+			if remaining < waitTimeout {
+				waitTimeout = remaining
+			}
+		}
+
+		var errorPtr *C.char
+		waitResult := C.box_apple_tls_client_wait_ready(client, C.int(timeoutFromDuration(waitTimeout)), &errorPtr)
+		switch waitResult {
+		case 1:
+			return nil
+		case -2:
+			continue
+		case 0:
+			if errorPtr != nil {
+				defer C.free(unsafe.Pointer(errorPtr))
+				return E.New(C.GoString(errorPtr))
+			}
+			return E.New("apple TLS: handshake failed")
+		default:
+			return E.New("apple TLS: invalid handshake state")
+		}
+	}
+}
+
+type appleTLSConn struct {
+	rawConn net.Conn
+	client  *C.box_apple_tls_client_t
+	state   tls.ConnectionState
+
+	readAccess  sync.Mutex
+	writeAccess sync.Mutex
+	stateAccess sync.RWMutex
+	closeOnce   sync.Once
+	ioAccess    sync.Mutex
+	ioGroup     sync.WaitGroup
+	closed      chan struct{}
+	readEOF     bool
+}
+
+func (c *appleTLSConn) Read(p []byte) (int, error) {
+	c.readAccess.Lock()
+	defer c.readAccess.Unlock()
+	if c.readEOF {
+		return 0, io.EOF
+	}
+	if len(p) == 0 {
+		return 0, nil
+	}
+
+	client, err := c.acquireClient()
+	if err != nil {
+		return 0, err
+	}
+	defer c.releaseClient()
+
+	var eof C.bool
+	var errorPtr *C.char
+	n := C.box_apple_tls_client_read(client, unsafe.Pointer(&p[0]), C.size_t(len(p)), &eof, &errorPtr)
+	switch {
+	case n >= 0:
+		if bool(eof) {
+			c.readEOF = true
+			if n == 0 {
+				return 0, io.EOF
+			}
+		}
+		return int(n), nil
+	default:
+		if errorPtr != nil {
+			defer C.free(unsafe.Pointer(errorPtr))
+			if c.isClosed() {
+				return 0, net.ErrClosed
+			}
+			return 0, E.New(C.GoString(errorPtr))
+		}
+		return 0, net.ErrClosed
+	}
+}
+
+func (c *appleTLSConn) Write(p []byte) (int, error) {
+	c.writeAccess.Lock()
+	defer c.writeAccess.Unlock()
+	if len(p) == 0 {
+		return 0, nil
+	}
+
+	client, err := c.acquireClient()
+	if err != nil {
+		return 0, err
+	}
+	defer c.releaseClient()
+
+	var errorPtr *C.char
+	n := C.box_apple_tls_client_write(client, unsafe.Pointer(&p[0]), C.size_t(len(p)), &errorPtr)
+	if n >= 0 {
+		return int(n), nil
+	}
+	if errorPtr != nil {
+		defer C.free(unsafe.Pointer(errorPtr))
+		if c.isClosed() {
+			return 0, net.ErrClosed
+		}
+		return 0, E.New(C.GoString(errorPtr))
+	}
+	return 0, net.ErrClosed
+}
+
+func (c *appleTLSConn) Close() error {
+	var closeErr error
+	c.closeOnce.Do(func() {
+		close(c.closed)
+		C.box_apple_tls_client_cancel(c.client)
+		closeErr = c.rawConn.Close()
+		c.ioAccess.Lock()
+		c.ioGroup.Wait()
+		C.box_apple_tls_client_free(c.client)
+		c.client = nil
+		c.ioAccess.Unlock()
+	})
+	return closeErr
+}
+
+func (c *appleTLSConn) LocalAddr() net.Addr {
+	return c.rawConn.LocalAddr()
+}
+
+func (c *appleTLSConn) RemoteAddr() net.Addr {
+	return c.rawConn.RemoteAddr()
+}
+
+func (c *appleTLSConn) SetDeadline(t time.Time) error {
+	return os.ErrInvalid
+}
+
+func (c *appleTLSConn) SetReadDeadline(t time.Time) error {
+	return os.ErrInvalid
+}
+
+func (c *appleTLSConn) SetWriteDeadline(t time.Time) error {
+	return os.ErrInvalid
+}
+
+func (c *appleTLSConn) NeedAdditionalReadDeadline() bool {
+	return true
+}
+
+func (c *appleTLSConn) isClosed() bool {
+	select {
+	case <-c.closed:
+		return true
+	default:
+		return false
+	}
+}
+
+func (c *appleTLSConn) acquireClient() (*C.box_apple_tls_client_t, error) {
+	c.ioAccess.Lock()
+	defer c.ioAccess.Unlock()
+	if c.isClosed() {
+		return nil, net.ErrClosed
+	}
+	client := c.client
+	if client == nil {
+		return nil, net.ErrClosed
+	}
+	c.ioGroup.Add(1)
+	return client, nil
+}
+
+func (c *appleTLSConn) releaseClient() {
+	c.ioGroup.Done()
+}
+
+func (c *appleTLSConn) NetConn() net.Conn {
+	return c.rawConn
+}
+
+func (c *appleTLSConn) HandshakeContext(ctx context.Context) error {
+	return nil
+}
+
+func (c *appleTLSConn) ConnectionState() ConnectionState {
+	c.stateAccess.RLock()
+	defer c.stateAccess.RUnlock()
+	return c.state
+}
+
+func parseAppleTLSState(state *C.box_apple_tls_state_t) (tls.ConnectionState, [][]byte, error) {
+	rawCerts, peerCertificates, err := parseAppleCertChain(state.peer_cert_chain, state.peer_cert_chain_len)
+	if err != nil {
+		return tls.ConnectionState{}, nil, err
+	}
+	var negotiatedProtocol string
+	if state.alpn != nil {
+		negotiatedProtocol = C.GoString(state.alpn)
+	}
+	var serverName string
+	if state.server_name != nil {
+		serverName = C.GoString(state.server_name)
+	}
+	return tls.ConnectionState{
+		Version:            uint16(state.version),
+		HandshakeComplete:  true,
+		CipherSuite:        uint16(state.cipher_suite),
+		NegotiatedProtocol: negotiatedProtocol,
+		ServerName:         serverName,
+		PeerCertificates:   peerCertificates,
+	}, rawCerts, nil
+}
+
+func parseAppleCertChain(chain *C.uint8_t, chainLen C.size_t) ([][]byte, []*x509.Certificate, error) {
+	if chain == nil || chainLen == 0 {
+		return nil, nil, nil
+	}
+	chainBytes := C.GoBytes(unsafe.Pointer(chain), C.int(chainLen))
+	var (
+		rawCerts         [][]byte
+		peerCertificates []*x509.Certificate
+	)
+	for len(chainBytes) >= 4 {
+		certificateLen := binary.BigEndian.Uint32(chainBytes[:4])
+		chainBytes = chainBytes[4:]
+		if len(chainBytes) < int(certificateLen) {
+			return nil, nil, E.New("apple TLS: invalid certificate chain")
+		}
+		certificateData := append([]byte(nil), chainBytes[:certificateLen]...)
+		certificate, err := x509.ParseCertificate(certificateData)
+		if err != nil {
+			return nil, nil, E.Cause(err, "parse peer certificate")
+		}
+		rawCerts = append(rawCerts, certificateData)
+		peerCertificates = append(peerCertificates, certificate)
+		chainBytes = chainBytes[certificateLen:]
+	}
+	if len(chainBytes) != 0 {
+		return nil, nil, E.New("apple TLS: invalid certificate chain")
+	}
+	return rawCerts, peerCertificates, nil
+}
+
+func timeoutFromDuration(timeout time.Duration) int {
+	if timeout <= 0 {
+		return 0
+	}
+	timeoutMilliseconds := int64(timeout / time.Millisecond)
+	if timeout%time.Millisecond != 0 {
+		timeoutMilliseconds++
+	}
+	if timeoutMilliseconds > math.MaxInt32 {
+		return math.MaxInt32
+	}
+	return int(timeoutMilliseconds)
+}
+
+func cStringOrNil(value string) *C.char {
+	if value == "" {
+		return nil
+	}
+	return C.CString(value)
+}
+
+func cFree(pointer *C.char) {
+	if pointer != nil {
+		C.free(unsafe.Pointer(pointer))
+	}
+}

common/tls/apple_client_platform.h

@@ -0,0 +1,37 @@
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <unistd.h>
+
+typedef struct box_apple_tls_client box_apple_tls_client_t;
+
+typedef struct box_apple_tls_state {
+	uint16_t version;
+	uint16_t cipher_suite;
+	char *alpn;
+	char *server_name;
+	uint8_t *peer_cert_chain;
+	size_t peer_cert_chain_len;
+} box_apple_tls_state_t;
+
+box_apple_tls_client_t *box_apple_tls_client_create(
+	int connected_socket,
+	const char *server_name,
+	const char *alpn,
+	size_t alpn_len,
+	uint16_t min_version,
+	uint16_t max_version,
+	bool insecure,
+	const char *anchor_pem,
+	size_t anchor_pem_len,
+	bool anchor_only,
+	char **error_out
+);
+
+int box_apple_tls_client_wait_ready(box_apple_tls_client_t *client, int timeout_msec, char **error_out);
+void box_apple_tls_client_cancel(box_apple_tls_client_t *client);
+void box_apple_tls_client_free(box_apple_tls_client_t *client);
+ssize_t box_apple_tls_client_read(box_apple_tls_client_t *client, void *buffer, size_t buffer_len, bool *eof_out, char **error_out);
+ssize_t box_apple_tls_client_write(box_apple_tls_client_t *client, const void *buffer, size_t buffer_len, char **error_out);
+bool box_apple_tls_client_copy_state(box_apple_tls_client_t *client, box_apple_tls_state_t *state, char **error_out);
+void box_apple_tls_state_free(box_apple_tls_state_t *state);

common/tls/apple_client_platform.m

@@ -0,0 +1,631 @@
+#import "apple_client_platform.h"
+
+#import <Foundation/Foundation.h>
+#import <Network/Network.h>
+#import <Security/Security.h>
+#import <Security/SecProtocolMetadata.h>
+#import <Security/SecProtocolOptions.h>
+#import <Security/SecProtocolTypes.h>
+#import <arpa/inet.h>
+#import <dlfcn.h>
+#import <dispatch/dispatch.h>
+#import <stdatomic.h>
+#import <stdlib.h>
+#import <string.h>
+#import <unistd.h>
+
+typedef nw_connection_t _Nullable (*box_nw_connection_create_with_connected_socket_and_parameters_f)(int connected_socket, nw_parameters_t parameters);
+typedef const char * _Nullable (*box_sec_protocol_metadata_string_accessor_f)(sec_protocol_metadata_t metadata);
+
+typedef struct box_apple_tls_client {
+	void *connection;
+	void *queue;
+	void *ready_semaphore;
+	atomic_int ref_count;
+	atomic_bool ready;
+	atomic_bool ready_done;
+	char *ready_error;
+	box_apple_tls_state_t state;
+} box_apple_tls_client_t;
+
+static nw_connection_t box_apple_tls_connection(box_apple_tls_client_t *client) {
+	if (client == NULL || client->connection == NULL) {
+		return nil;
+	}
+	return (__bridge nw_connection_t)client->connection;
+}
+
+static dispatch_queue_t box_apple_tls_client_queue(box_apple_tls_client_t *client) {
+	if (client == NULL || client->queue == NULL) {
+		return nil;
+	}
+	return (__bridge dispatch_queue_t)client->queue;
+}
+
+static dispatch_semaphore_t box_apple_tls_ready_semaphore(box_apple_tls_client_t *client) {
+	if (client == NULL || client->ready_semaphore == NULL) {
+		return nil;
+	}
+	return (__bridge dispatch_semaphore_t)client->ready_semaphore;
+}
+
+static void box_apple_tls_state_reset(box_apple_tls_state_t *state) {
+	if (state == NULL) {
+		return;
+	}
+	free(state->alpn);
+	free(state->server_name);
+	free(state->peer_cert_chain);
+	memset(state, 0, sizeof(box_apple_tls_state_t));
+}
+
+static void box_apple_tls_client_destroy(box_apple_tls_client_t *client) {
+	free(client->ready_error);
+	box_apple_tls_state_reset(&client->state);
+	if (client->ready_semaphore != NULL) {
+		CFBridgingRelease(client->ready_semaphore);
+	}
+	if (client->connection != NULL) {
+		CFBridgingRelease(client->connection);
+	}
+	if (client->queue != NULL) {
+		CFBridgingRelease(client->queue);
+	}
+	free(client);
+}
+
+static void box_apple_tls_client_release(box_apple_tls_client_t *client) {
+	if (client == NULL) {
+		return;
+	}
+	if (atomic_fetch_sub(&client->ref_count, 1) == 1) {
+		box_apple_tls_client_destroy(client);
+	}
+}
+
+static void box_set_error_string(char **error_out, NSString *message) {
+	if (error_out == NULL || *error_out != NULL) {
+		return;
+	}
+	const char *utf8 = [message UTF8String];
+	*error_out = strdup(utf8 != NULL ? utf8 : "unknown error");
+}
+
+static void box_set_error_message(char **error_out, const char *message) {
+	if (error_out == NULL || *error_out != NULL) {
+		return;
+	}
+	*error_out = strdup(message != NULL ? message : "unknown error");
+}
+
+static void box_set_error_from_nw_error(char **error_out, nw_error_t error) {
+	if (error == NULL) {
+		box_set_error_message(error_out, "unknown network error");
+		return;
+	}
+	CFErrorRef cfError = nw_error_copy_cf_error(error);
+	if (cfError == NULL) {
+		box_set_error_message(error_out, "unknown network error");
+		return;
+	}
+	NSString *description = [(__bridge NSError *)cfError description];
+	box_set_error_string(error_out, description);
+	CFRelease(cfError);
+}
+
+static char *box_apple_tls_metadata_copy_negotiated_protocol(sec_protocol_metadata_t metadata) {
+	static box_sec_protocol_metadata_string_accessor_f copy_fn;
+	static box_sec_protocol_metadata_string_accessor_f get_fn;
+	static dispatch_once_t onceToken;
+	dispatch_once(&onceToken, ^{
+		copy_fn = (box_sec_protocol_metadata_string_accessor_f)dlsym(RTLD_DEFAULT, "sec_protocol_metadata_copy_negotiated_protocol");
+		get_fn = (box_sec_protocol_metadata_string_accessor_f)dlsym(RTLD_DEFAULT, "sec_protocol_metadata_get_negotiated_protocol");
+	});
+	if (copy_fn != NULL) {
+		return (char *)copy_fn(metadata);
+	}
+	if (get_fn != NULL) {
+		const char *protocol = get_fn(metadata);
+		if (protocol != NULL) {
+			return strdup(protocol);
+		}
+	}
+	return NULL;
+}
+
+static char *box_apple_tls_metadata_copy_server_name(sec_protocol_metadata_t metadata) {
+	static box_sec_protocol_metadata_string_accessor_f copy_fn;
+	static box_sec_protocol_metadata_string_accessor_f get_fn;
+	static dispatch_once_t onceToken;
+	dispatch_once(&onceToken, ^{
+		copy_fn = (box_sec_protocol_metadata_string_accessor_f)dlsym(RTLD_DEFAULT, "sec_protocol_metadata_copy_server_name");
+		get_fn = (box_sec_protocol_metadata_string_accessor_f)dlsym(RTLD_DEFAULT, "sec_protocol_metadata_get_server_name");
+	});
+	if (copy_fn != NULL) {
+		return (char *)copy_fn(metadata);
+	}
+	if (get_fn != NULL) {
+		const char *server_name = get_fn(metadata);
+		if (server_name != NULL) {
+			return strdup(server_name);
+		}
+	}
+	return NULL;
+}
+
+static NSArray<NSString *> *box_split_lines(const char *content, size_t content_len) {
+	if (content == NULL || content_len == 0) {
+		return @[];
+	}
+	NSString *string = [[NSString alloc] initWithBytes:content length:content_len encoding:NSUTF8StringEncoding];
+	if (string == nil) {
+		return @[];
+	}
+	NSMutableArray<NSString *> *lines = [NSMutableArray array];
+	[string enumerateLinesUsingBlock:^(NSString *line, BOOL *stop) {
+		if (line.length > 0) {
+			[lines addObject:line];
+		}
+	}];
+	return lines;
+}
+
+static NSArray *box_parse_certificates_from_pem(const char *pem, size_t pem_len) {
+	if (pem == NULL || pem_len == 0) {
+		return @[];
+	}
+	NSString *content = [[NSString alloc] initWithBytes:pem length:pem_len encoding:NSUTF8StringEncoding];
+	if (content == nil) {
+		return @[];
+	}
+	NSString *beginMarker = @"-----BEGIN CERTIFICATE-----";
+	NSString *endMarker = @"-----END CERTIFICATE-----";
+	NSMutableArray *certificates = [NSMutableArray array];
+	NSUInteger searchFrom = 0;
+	while (searchFrom < content.length) {
+		NSRange beginRange = [content rangeOfString:beginMarker options:0 range:NSMakeRange(searchFrom, content.length - searchFrom)];
+		if (beginRange.location == NSNotFound) {
+			break;
+		}
+		NSUInteger bodyStart = beginRange.location + beginRange.length;
+		NSRange endRange = [content rangeOfString:endMarker options:0 range:NSMakeRange(bodyStart, content.length - bodyStart)];
+		if (endRange.location == NSNotFound) {
+			break;
+		}
+		NSString *base64Section = [content substringWithRange:NSMakeRange(bodyStart, endRange.location - bodyStart)];
+		NSArray<NSString *> *components = [base64Section componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+		NSString *base64Content = [components componentsJoinedByString:@""];
+		NSData *der = [[NSData alloc] initWithBase64EncodedString:base64Content options:0];
+		if (der != nil) {
+			SecCertificateRef certificate = SecCertificateCreateWithData(NULL, (__bridge CFDataRef)der);
+			if (certificate != NULL) {
+				[certificates addObject:(__bridge id)certificate];
+				CFRelease(certificate);
+			}
+		}
+		searchFrom = endRange.location + endRange.length;
+	}
+	return certificates;
+}
+
+static bool box_evaluate_trust(sec_trust_t trust, NSArray *anchors, bool anchor_only) {
+	bool result = false;
+	SecTrustRef trustRef = sec_trust_copy_ref(trust);
+	if (trustRef == NULL) {
+		return false;
+	}
+	if (anchors.count > 0 || anchor_only) {
+		CFMutableArrayRef anchorArray = CFArrayCreateMutable(NULL, 0, &kCFTypeArrayCallBacks);
+		for (id certificate in anchors) {
+			CFArrayAppendValue(anchorArray, (__bridge const void *)certificate);
+		}
+		SecTrustSetAnchorCertificates(trustRef, anchorArray);
+		SecTrustSetAnchorCertificatesOnly(trustRef, anchor_only);
+		CFRelease(anchorArray);
+	}
+	CFErrorRef error = NULL;
+	result = SecTrustEvaluateWithError(trustRef, &error);
+	if (error != NULL) {
+		CFRelease(error);
+	}
+	CFRelease(trustRef);
+	return result;
+}
+
+static nw_connection_t box_apple_tls_create_connection(int connected_socket, nw_parameters_t parameters) {
+	static box_nw_connection_create_with_connected_socket_and_parameters_f create_fn;
+	static dispatch_once_t onceToken;
+	dispatch_once(&onceToken, ^{
+		char name[] = "sretemarap_dna_tekcos_detcennoc_htiw_etaerc_noitcennoc_wn";
+		for (size_t i = 0, j = sizeof(name) - 2; i < j; i++, j--) {
+			char t = name[i];
+			name[i] = name[j];
+			name[j] = t;
+		}
+		create_fn = (box_nw_connection_create_with_connected_socket_and_parameters_f)dlsym(RTLD_DEFAULT, name);
+	});
+	if (create_fn == NULL) {
+		return nil;
+	}
+	return create_fn(connected_socket, parameters);
+}
+
+static bool box_apple_tls_state_copy(const box_apple_tls_state_t *source, box_apple_tls_state_t *destination) {
+	memset(destination, 0, sizeof(box_apple_tls_state_t));
+	destination->version = source->version;
+	destination->cipher_suite = source->cipher_suite;
+	if (source->alpn != NULL) {
+		destination->alpn = strdup(source->alpn);
+		if (destination->alpn == NULL) {
+			goto oom;
+		}
+	}
+	if (source->server_name != NULL) {
+		destination->server_name = strdup(source->server_name);
+		if (destination->server_name == NULL) {
+			goto oom;
+		}
+	}
+	if (source->peer_cert_chain_len > 0) {
+		destination->peer_cert_chain = malloc(source->peer_cert_chain_len);
+		if (destination->peer_cert_chain == NULL) {
+			goto oom;
+		}
+		memcpy(destination->peer_cert_chain, source->peer_cert_chain, source->peer_cert_chain_len);
+		destination->peer_cert_chain_len = source->peer_cert_chain_len;
+	}
+	return true;
+
+oom:
+	box_apple_tls_state_reset(destination);
+	return false;
+}
+
+static bool box_apple_tls_state_load(nw_connection_t connection, box_apple_tls_state_t *state, char **error_out) {
+	box_apple_tls_state_reset(state);
+	if (connection == nil) {
+		box_set_error_message(error_out, "apple TLS: invalid client");
+		return false;
+	}
+
+	nw_protocol_definition_t tls_definition = nw_protocol_copy_tls_definition();
+	nw_protocol_metadata_t metadata = nw_connection_copy_protocol_metadata(connection, tls_definition);
+	if (metadata == NULL || !nw_protocol_metadata_is_tls(metadata)) {
+		box_set_error_message(error_out, "apple TLS: metadata unavailable");
+		return false;
+	}
+
+	sec_protocol_metadata_t sec_metadata = nw_tls_copy_sec_protocol_metadata(metadata);
+	if (sec_metadata == NULL) {
+		box_set_error_message(error_out, "apple TLS: metadata unavailable");
+		return false;
+	}
+
+	state->version = (uint16_t)sec_protocol_metadata_get_negotiated_tls_protocol_version(sec_metadata);
+	state->cipher_suite = (uint16_t)sec_protocol_metadata_get_negotiated_tls_ciphersuite(sec_metadata);
+	state->alpn = box_apple_tls_metadata_copy_negotiated_protocol(sec_metadata);
+	state->server_name = box_apple_tls_metadata_copy_server_name(sec_metadata);
+
+	NSMutableData *chain_data = [NSMutableData data];
+	sec_protocol_metadata_access_peer_certificate_chain(sec_metadata, ^(sec_certificate_t certificate) {
+		SecCertificateRef certificate_ref = sec_certificate_copy_ref(certificate);
+		if (certificate_ref == NULL) {
+			return;
+		}
+		CFDataRef certificate_data = SecCertificateCopyData(certificate_ref);
+		CFRelease(certificate_ref);
+		if (certificate_data == NULL) {
+			return;
+		}
+		uint32_t certificate_len = (uint32_t)CFDataGetLength(certificate_data);
+		uint32_t network_len = htonl(certificate_len);
+		[chain_data appendBytes:&network_len length:sizeof(network_len)];
+		[chain_data appendBytes:CFDataGetBytePtr(certificate_data) length:certificate_len];
+		CFRelease(certificate_data);
+	});
+	if (chain_data.length > 0) {
+		state->peer_cert_chain = malloc(chain_data.length);
+		if (state->peer_cert_chain == NULL) {
+			box_set_error_message(error_out, "apple TLS: out of memory");
+			box_apple_tls_state_reset(state);
+			return false;
+		}
+		memcpy(state->peer_cert_chain, chain_data.bytes, chain_data.length);
+		state->peer_cert_chain_len = chain_data.length;
+	}
+	return true;
+}
+
+box_apple_tls_client_t *box_apple_tls_client_create(
+	int connected_socket,
+	const char *server_name,
+	const char *alpn,
+	size_t alpn_len,
+	uint16_t min_version,
+	uint16_t max_version,
+	bool insecure,
+	const char *anchor_pem,
+	size_t anchor_pem_len,
+	bool anchor_only,
+	char **error_out
+) {
+	box_apple_tls_client_t *client = calloc(1, sizeof(box_apple_tls_client_t));
+	if (client == NULL) {
+		close(connected_socket);
+		box_set_error_message(error_out, "apple TLS: out of memory");
+		return NULL;
+	}
+	client->queue = (__bridge_retained void *)dispatch_queue_create("sing-box.apple-private-tls", DISPATCH_QUEUE_SERIAL);
+	client->ready_semaphore = (__bridge_retained void *)dispatch_semaphore_create(0);
+	atomic_init(&client->ref_count, 1);
+	atomic_init(&client->ready, false);
+	atomic_init(&client->ready_done, false);
+
+	NSArray<NSString *> *alpnList = box_split_lines(alpn, alpn_len);
+	NSArray *anchors = box_parse_certificates_from_pem(anchor_pem, anchor_pem_len);
+	nw_parameters_t parameters = nw_parameters_create_secure_tcp(^(nw_protocol_options_t tls_options) {
+		sec_protocol_options_t sec_options = nw_tls_copy_sec_protocol_options(tls_options);
+		if (min_version != 0) {
+			sec_protocol_options_set_min_tls_protocol_version(sec_options, (tls_protocol_version_t)min_version);
+		}
+		if (max_version != 0) {
+			sec_protocol_options_set_max_tls_protocol_version(sec_options, (tls_protocol_version_t)max_version);
+		}
+		if (server_name != NULL && server_name[0] != '\0') {
+			sec_protocol_options_set_tls_server_name(sec_options, server_name);
+		}
+		for (NSString *protocol in alpnList) {
+			sec_protocol_options_add_tls_application_protocol(sec_options, protocol.UTF8String);
+		}
+		sec_protocol_options_set_peer_authentication_required(sec_options, !insecure);
+		if (insecure) {
+			sec_protocol_options_set_verify_block(sec_options, ^(sec_protocol_metadata_t metadata, sec_trust_t trust, sec_protocol_verify_complete_t complete) {
+				complete(true);
+			}, box_apple_tls_client_queue(client));
+		} else if (anchors.count > 0 || anchor_only) {
+			sec_protocol_options_set_verify_block(sec_options, ^(sec_protocol_metadata_t metadata, sec_trust_t trust, sec_protocol_verify_complete_t complete) {
+				complete(box_evaluate_trust(trust, anchors, anchor_only));
+			}, box_apple_tls_client_queue(client));
+		}
+	}, NW_PARAMETERS_DEFAULT_CONFIGURATION);
+
+	nw_connection_t connection = box_apple_tls_create_connection(connected_socket, parameters);
+	if (connection == NULL) {
+		close(connected_socket);
+		if (client->ready_semaphore != NULL) {
+			CFBridgingRelease(client->ready_semaphore);
+		}
+		if (client->queue != NULL) {
+			CFBridgingRelease(client->queue);
+		}
+		free(client);
+		box_set_error_message(error_out, "apple TLS: failed to create connection");
+		return NULL;
+	}
+
+	client->connection = (__bridge_retained void *)connection;
+	atomic_fetch_add(&client->ref_count, 1);
+
+	nw_connection_set_state_changed_handler(connection, ^(nw_connection_state_t state, nw_error_t error) {
+		switch (state) {
+		case nw_connection_state_ready:
+			if (!atomic_load(&client->ready_done)) {
+				atomic_store(&client->ready, box_apple_tls_state_load(connection, &client->state, &client->ready_error));
+				atomic_store(&client->ready_done, true);
+				dispatch_semaphore_signal(box_apple_tls_ready_semaphore(client));
+			}
+			break;
+		case nw_connection_state_failed:
+			if (!atomic_load(&client->ready_done)) {
+				box_set_error_from_nw_error(&client->ready_error, error);
+				atomic_store(&client->ready_done, true);
+				dispatch_semaphore_signal(box_apple_tls_ready_semaphore(client));
+			}
+			break;
+		case nw_connection_state_cancelled:
+			if (!atomic_load(&client->ready_done)) {
+				box_set_error_from_nw_error(&client->ready_error, error);
+				atomic_store(&client->ready_done, true);
+				dispatch_semaphore_signal(box_apple_tls_ready_semaphore(client));
+			}
+			box_apple_tls_client_release(client);
+			break;
+		default:
+			break;
+		}
+	});
+	nw_connection_set_queue(connection, box_apple_tls_client_queue(client));
+	nw_connection_start(connection);
+	return client;
+}
+
+int box_apple_tls_client_wait_ready(box_apple_tls_client_t *client, int timeout_msec, char **error_out) {
+	dispatch_semaphore_t ready_semaphore = box_apple_tls_ready_semaphore(client);
+	if (ready_semaphore == nil) {
+		box_set_error_message(error_out, "apple TLS: invalid client");
+		return 0;
+	}
+	if (!atomic_load(&client->ready_done)) {
+		dispatch_time_t timeout = DISPATCH_TIME_FOREVER;
+		if (timeout_msec >= 0) {
+			timeout = dispatch_time(DISPATCH_TIME_NOW, (int64_t)timeout_msec * NSEC_PER_MSEC);
+		}
+		long wait_result = dispatch_semaphore_wait(ready_semaphore, timeout);
+		if (wait_result != 0) {
+			return -2;
+		}
+	}
+	if (atomic_load(&client->ready)) {
+		return 1;
+	}
+	if (client->ready_error != NULL) {
+		if (error_out != NULL) {
+			*error_out = client->ready_error;
+			client->ready_error = NULL;
+		} else {
+			free(client->ready_error);
+			client->ready_error = NULL;
+		}
+	} else {
+		box_set_error_message(error_out, "apple TLS: handshake failed");
+	}
+	return 0;
+}
+
+void box_apple_tls_client_cancel(box_apple_tls_client_t *client) {
+	if (client == NULL) {
+		return;
+	}
+	nw_connection_t connection = box_apple_tls_connection(client);
+	if (connection != nil) {
+		nw_connection_cancel(connection);
+	}
+}
+
+void box_apple_tls_client_free(box_apple_tls_client_t *client) {
+	if (client == NULL) {
+		return;
+	}
+	nw_connection_t connection = box_apple_tls_connection(client);
+	if (connection != nil) {
+		nw_connection_cancel(connection);
+	}
+	box_apple_tls_client_release(client);
+}
+
+ssize_t box_apple_tls_client_read(box_apple_tls_client_t *client, void *buffer, size_t buffer_len, bool *eof_out, char **error_out) {
+	nw_connection_t connection = box_apple_tls_connection(client);
+	if (connection == nil) {
+		box_set_error_message(error_out, "apple TLS: invalid client");
+		return -1;
+	}
+
+	dispatch_semaphore_t read_semaphore = dispatch_semaphore_create(0);
+	__block NSData *content_data = nil;
+	__block bool read_eof = false;
+	__block char *local_error = NULL;
+
+	nw_connection_receive(connection, 1, (uint32_t)buffer_len, ^(dispatch_data_t content, nw_content_context_t context, bool is_complete, nw_error_t error) {
+		if (content != NULL) {
+			const void *mapped = NULL;
+			size_t mapped_len = 0;
+			dispatch_data_t mapped_data = dispatch_data_create_map(content, &mapped, &mapped_len);
+			if (mapped != NULL && mapped_len > 0) {
+				content_data = [NSData dataWithBytes:mapped length:mapped_len];
+			}
+			(void)mapped_data;
+		}
+		if (error != NULL && content_data.length == 0) {
+			box_set_error_from_nw_error(&local_error, error);
+		}
+		if (is_complete && (context == NULL || nw_content_context_get_is_final(context))) {
+			read_eof = true;
+		}
+		dispatch_semaphore_signal(read_semaphore);
+	});
+
+	dispatch_semaphore_wait(read_semaphore, DISPATCH_TIME_FOREVER);
+	if (local_error != NULL) {
+		if (error_out != NULL) {
+			*error_out = local_error;
+		} else {
+			free(local_error);
+		}
+		return -1;
+	}
+	if (eof_out != NULL) {
+		*eof_out = read_eof;
+	}
+	if (content_data == nil || content_data.length == 0) {
+		return 0;
+	}
+	memcpy(buffer, content_data.bytes, content_data.length);
+	return (ssize_t)content_data.length;
+}
+
+ssize_t box_apple_tls_client_write(box_apple_tls_client_t *client, const void *buffer, size_t buffer_len, char **error_out) {
+	nw_connection_t connection = box_apple_tls_connection(client);
+	if (connection == nil) {
+		box_set_error_message(error_out, "apple TLS: invalid client");
+		return -1;
+	}
+	if (buffer_len == 0) {
+		return 0;
+	}
+
+	void *content_copy = malloc(buffer_len);
+	dispatch_queue_t queue = box_apple_tls_client_queue(client);
+	if (content_copy == NULL) {
+		free(content_copy);
+		box_set_error_message(error_out, "apple TLS: out of memory");
+		return -1;
+	}
+	if (queue == nil) {
+		free(content_copy);
+		box_set_error_message(error_out, "apple TLS: invalid client");
+		return -1;
+	}
+	memcpy(content_copy, buffer, buffer_len);
+	dispatch_data_t content = dispatch_data_create(content_copy, buffer_len, queue, ^{
+		free(content_copy);
+	});
+
+	dispatch_semaphore_t write_semaphore = dispatch_semaphore_create(0);
+	__block char *local_error = NULL;
+
+	nw_connection_send(connection, content, NW_CONNECTION_DEFAULT_STREAM_CONTEXT, false, ^(nw_error_t error) {
+		if (error != NULL) {
+			box_set_error_from_nw_error(&local_error, error);
+		}
+		dispatch_semaphore_signal(write_semaphore);
+	});
+
+	dispatch_semaphore_wait(write_semaphore, DISPATCH_TIME_FOREVER);
+	if (local_error != NULL) {
+		if (error_out != NULL) {
+			*error_out = local_error;
+		} else {
+			free(local_error);
+		}
+		return -1;
+	}
+	return (ssize_t)buffer_len;
+}
+
+bool box_apple_tls_client_copy_state(box_apple_tls_client_t *client, box_apple_tls_state_t *state, char **error_out) {
+	dispatch_queue_t queue = box_apple_tls_client_queue(client);
+	if (queue == nil || state == NULL) {
+		box_set_error_message(error_out, "apple TLS: invalid client");
+		return false;
+	}
+	memset(state, 0, sizeof(box_apple_tls_state_t));
+	__block bool copied = false;
+	__block char *local_error = NULL;
+	dispatch_sync(queue, ^{
+		if (!atomic_load(&client->ready)) {
+			box_set_error_message(&local_error, "apple TLS: metadata unavailable");
+			return;
+		}
+		if (!box_apple_tls_state_copy(&client->state, state)) {
+			box_set_error_message(&local_error, "apple TLS: out of memory");
+			return;
+		}
+		copied = true;
+	});
+	if (copied) {
+		return true;
+	}
+	if (local_error != NULL) {
+		if (error_out != NULL) {
+			*error_out = local_error;
+		} else {
+			free(local_error);
+		}
+	}
+	box_apple_tls_state_reset(state);
+	return false;
+}
+
+void box_apple_tls_state_free(box_apple_tls_state_t *state) {
+	box_apple_tls_state_reset(state);
+}

common/tls/apple_client_platform_test.go

@@ -0,0 +1,301 @@
+//go:build darwin && cgo
+
+package tls
+
+import (
+	"context"
+	stdtls "crypto/tls"
+	"net"
+	"testing"
+	"time"
+
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing/common/json/badoption"
+	"github.com/sagernet/sing/common/logger"
+)
+
+const appleTLSTestTimeout = 5 * time.Second
+
+const (
+	appleTLSSuccessHandshakeLoops = 20
+	appleTLSFailureRecoveryLoops  = 10
+)
+
+type appleTLSServerResult struct {
+	state stdtls.ConnectionState
+	err   error
+}
+
+func TestAppleClientHandshakeAppliesALPNAndVersion(t *testing.T) {
+	serverCertificate, serverCertificatePEM := newAppleTestCertificate(t, "localhost")
+	for index := 0; index < appleTLSSuccessHandshakeLoops; index++ {
+		serverResult, serverAddress := startAppleTLSTestServer(t, &stdtls.Config{
+			Certificates: []stdtls.Certificate{serverCertificate},
+			MinVersion:   stdtls.VersionTLS12,
+			MaxVersion:   stdtls.VersionTLS12,
+			NextProtos:   []string{"h2"},
+		})
+
+		clientConn, err := newAppleTestClientConn(t, serverAddress, option.OutboundTLSOptions{
+			Enabled:     true,
+			Engine:      "apple",
+			ServerName:  "localhost",
+			MinVersion:  "1.2",
+			MaxVersion:  "1.2",
+			ALPN:        badoption.Listable[string]{"h2"},
+			Certificate: badoption.Listable[string]{serverCertificatePEM},
+		})
+		if err != nil {
+			t.Fatalf("iteration %d: %v", index, err)
+		}
+
+		clientState := clientConn.ConnectionState()
+		if clientState.Version != stdtls.VersionTLS12 {
+			_ = clientConn.Close()
+			t.Fatalf("iteration %d: unexpected negotiated version: %x", index, clientState.Version)
+		}
+		if clientState.NegotiatedProtocol != "h2" {
+			_ = clientConn.Close()
+			t.Fatalf("iteration %d: unexpected negotiated protocol: %q", index, clientState.NegotiatedProtocol)
+		}
+		_ = clientConn.Close()
+
+		result := <-serverResult
+		if result.err != nil {
+			t.Fatalf("iteration %d: %v", index, result.err)
+		}
+		if result.state.Version != stdtls.VersionTLS12 {
+			t.Fatalf("iteration %d: server negotiated unexpected version: %x", index, result.state.Version)
+		}
+		if result.state.NegotiatedProtocol != "h2" {
+			t.Fatalf("iteration %d: server negotiated unexpected protocol: %q", index, result.state.NegotiatedProtocol)
+		}
+	}
+}
+
+func TestAppleClientHandshakeRejectsVersionMismatch(t *testing.T) {
+	serverCertificate, serverCertificatePEM := newAppleTestCertificate(t, "localhost")
+	serverResult, serverAddress := startAppleTLSTestServer(t, &stdtls.Config{
+		Certificates: []stdtls.Certificate{serverCertificate},
+		MinVersion:   stdtls.VersionTLS13,
+		MaxVersion:   stdtls.VersionTLS13,
+	})
+
+	clientConn, err := newAppleTestClientConn(t, serverAddress, option.OutboundTLSOptions{
+		Enabled:     true,
+		Engine:      "apple",
+		ServerName:  "localhost",
+		MaxVersion:  "1.2",
+		Certificate: badoption.Listable[string]{serverCertificatePEM},
+	})
+	if err == nil {
+		clientConn.Close()
+		t.Fatal("expected version mismatch handshake to fail")
+	}
+
+	if result := <-serverResult; result.err == nil {
+		t.Fatal("expected server handshake to fail on version mismatch")
+	}
+}
+
+func TestAppleClientHandshakeRejectsServerNameMismatch(t *testing.T) {
+	serverCertificate, serverCertificatePEM := newAppleTestCertificate(t, "localhost")
+	serverResult, serverAddress := startAppleTLSTestServer(t, &stdtls.Config{
+		Certificates: []stdtls.Certificate{serverCertificate},
+	})
+
+	clientConn, err := newAppleTestClientConn(t, serverAddress, option.OutboundTLSOptions{
+		Enabled:     true,
+		Engine:      "apple",
+		ServerName:  "example.com",
+		Certificate: badoption.Listable[string]{serverCertificatePEM},
+	})
+	if err == nil {
+		clientConn.Close()
+		t.Fatal("expected server name mismatch handshake to fail")
+	}
+
+	if result := <-serverResult; result.err == nil {
+		t.Fatal("expected server handshake to fail on server name mismatch")
+	}
+}
+
+func TestAppleClientHandshakeRecoversAfterFailure(t *testing.T) {
+	serverCertificate, serverCertificatePEM := newAppleTestCertificate(t, "localhost")
+	testCases := []struct {
+		name          string
+		serverConfig  *stdtls.Config
+		clientOptions option.OutboundTLSOptions
+	}{
+		{
+			name: "version mismatch",
+			serverConfig: &stdtls.Config{
+				Certificates: []stdtls.Certificate{serverCertificate},
+				MinVersion:   stdtls.VersionTLS13,
+				MaxVersion:   stdtls.VersionTLS13,
+			},
+			clientOptions: option.OutboundTLSOptions{
+				Enabled:     true,
+				Engine:      "apple",
+				ServerName:  "localhost",
+				MaxVersion:  "1.2",
+				Certificate: badoption.Listable[string]{serverCertificatePEM},
+			},
+		},
+		{
+			name: "server name mismatch",
+			serverConfig: &stdtls.Config{
+				Certificates: []stdtls.Certificate{serverCertificate},
+			},
+			clientOptions: option.OutboundTLSOptions{
+				Enabled:     true,
+				Engine:      "apple",
+				ServerName:  "example.com",
+				Certificate: badoption.Listable[string]{serverCertificatePEM},
+			},
+		},
+	}
+	successClientOptions := option.OutboundTLSOptions{
+		Enabled:     true,
+		Engine:      "apple",
+		ServerName:  "localhost",
+		MinVersion:  "1.2",
+		MaxVersion:  "1.2",
+		ALPN:        badoption.Listable[string]{"h2"},
+		Certificate: badoption.Listable[string]{serverCertificatePEM},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			for index := 0; index < appleTLSFailureRecoveryLoops; index++ {
+				failedResult, failedAddress := startAppleTLSTestServer(t, testCase.serverConfig)
+				failedConn, err := newAppleTestClientConn(t, failedAddress, testCase.clientOptions)
+				if err == nil {
+					_ = failedConn.Close()
+					t.Fatalf("iteration %d: expected handshake failure", index)
+				}
+				if result := <-failedResult; result.err == nil {
+					t.Fatalf("iteration %d: expected server handshake failure", index)
+				}
+
+				successResult, successAddress := startAppleTLSTestServer(t, &stdtls.Config{
+					Certificates: []stdtls.Certificate{serverCertificate},
+					MinVersion:   stdtls.VersionTLS12,
+					MaxVersion:   stdtls.VersionTLS12,
+					NextProtos:   []string{"h2"},
+				})
+				successConn, err := newAppleTestClientConn(t, successAddress, successClientOptions)
+				if err != nil {
+					t.Fatalf("iteration %d: follow-up handshake failed: %v", index, err)
+				}
+				clientState := successConn.ConnectionState()
+				if clientState.NegotiatedProtocol != "h2" {
+					_ = successConn.Close()
+					t.Fatalf("iteration %d: unexpected negotiated protocol after failure: %q", index, clientState.NegotiatedProtocol)
+				}
+				_ = successConn.Close()
+
+				result := <-successResult
+				if result.err != nil {
+					t.Fatalf("iteration %d: follow-up server handshake failed: %v", index, result.err)
+				}
+				if result.state.NegotiatedProtocol != "h2" {
+					t.Fatalf("iteration %d: follow-up server negotiated unexpected protocol: %q", index, result.state.NegotiatedProtocol)
+				}
+			}
+		})
+	}
+}
+
+func newAppleTestCertificate(t *testing.T, serverName string) (stdtls.Certificate, string) {
+	t.Helper()
+
+	privateKeyPEM, certificatePEM, err := GenerateCertificate(nil, nil, time.Now, serverName, time.Now().Add(time.Hour))
+	if err != nil {
+		t.Fatal(err)
+	}
+	certificate, err := stdtls.X509KeyPair(certificatePEM, privateKeyPEM)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return certificate, string(certificatePEM)
+}
+
+func startAppleTLSTestServer(t *testing.T, tlsConfig *stdtls.Config) (<-chan appleTLSServerResult, string) {
+	t.Helper()
+
+	listener, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		listener.Close()
+	})
+
+	if tcpListener, isTCP := listener.(*net.TCPListener); isTCP {
+		err = tcpListener.SetDeadline(time.Now().Add(appleTLSTestTimeout))
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	result := make(chan appleTLSServerResult, 1)
+	go func() {
+		defer close(result)
+
+		conn, err := listener.Accept()
+		if err != nil {
+			result <- appleTLSServerResult{err: err}
+			return
+		}
+		defer conn.Close()
+
+		err = conn.SetDeadline(time.Now().Add(appleTLSTestTimeout))
+		if err != nil {
+			result <- appleTLSServerResult{err: err}
+			return
+		}
+
+		tlsConn := stdtls.Server(conn, tlsConfig)
+		defer tlsConn.Close()
+
+		err = tlsConn.Handshake()
+		if err != nil {
+			result <- appleTLSServerResult{err: err}
+			return
+		}
+
+		result <- appleTLSServerResult{state: tlsConn.ConnectionState()}
+	}()
+
+	return result, listener.Addr().String()
+}
+
+func newAppleTestClientConn(t *testing.T, serverAddress string, options option.OutboundTLSOptions) (Conn, error) {
+	t.Helper()
+
+	ctx, cancel := context.WithTimeout(context.Background(), appleTLSTestTimeout)
+	t.Cleanup(cancel)
+
+	clientConfig, err := NewClientWithOptions(ClientOptions{
+		Context:       ctx,
+		Logger:        logger.NOP(),
+		ServerAddress: "",
+		Options:       options,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	conn, err := net.DialTimeout("tcp", serverAddress, appleTLSTestTimeout)
+	if err != nil {
+		return nil, err
+	}
+
+	tlsConn, err := ClientHandshake(ctx, conn, clientConfig)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+	return tlsConn, nil
+}

common/tls/apple_client_stub.go

@@ -0,0 +1,15 @@
+//go:build !darwin || !cgo
+
+package tls
+
+import (
+	"context"
+
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+)
+
+func newAppleClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions, allowEmptyServerName bool) (Config, error) {
+	return nil, E.New("Apple TLS engine is not available on non-Apple platforms")
+}

common/tls/client.go

@@ -10,12 +10,15 @@ import (
 	"github.com/sagernet/sing-box/common/badtls"
 	C "github.com/sagernet/sing-box/constant"
 	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
 	"github.com/sagernet/sing/common/logger"
 	M "github.com/sagernet/sing/common/metadata"
 	N "github.com/sagernet/sing/common/network"
 	aTLS "github.com/sagernet/sing/common/tls"
 )
 
+var errMissingServerName = E.New("missing server_name or insecure=true")
+
 func NewDialerFromOptions(ctx context.Context, logger logger.ContextLogger, dialer N.Dialer, serverAddress string, options option.OutboundTLSOptions) (N.Dialer, error) {
 	if !options.Enabled {
 		return dialer, nil
@@ -42,11 +45,12 @@ func NewClient(ctx context.Context, logger logger.ContextLogger, serverAddress s
 }
 
 type ClientOptions struct {
-	Context        context.Context
+	Context              context.Context
-	Logger         logger.ContextLogger
+	Logger               logger.ContextLogger
-	ServerAddress  string
+	ServerAddress        string
-	Options        option.OutboundTLSOptions
+	Options              option.OutboundTLSOptions
-	KTLSCompatible bool
+	AllowEmptyServerName bool
+	KTLSCompatible       bool
 }
 
 func NewClientWithOptions(options ClientOptions) (Config, error) {
@@ -61,17 +65,22 @@ func NewClientWithOptions(options ClientOptions) (Config, error) {
 	if options.Options.KernelRx {
 		options.Logger.Warn("enabling kTLS RX will definitely reduce performance, please checkout https://sing-box.sagernet.org/configuration/shared/tls/#kernel_rx")
 	}
-	if options.Options.Reality != nil && options.Options.Reality.Enabled {
+	switch options.Options.Engine {
-		return NewRealityClient(options.Context, options.Logger, options.ServerAddress, options.Options)
+	case C.TLSEngineDefault, "go":
-	} else if options.Options.UTLS != nil && options.Options.UTLS.Enabled {
+	case C.TLSEngineApple:
-		return NewUTLSClient(options.Context, options.Logger, options.ServerAddress, options.Options)
+		return newAppleClient(options.Context, options.Logger, options.ServerAddress, options.Options, options.AllowEmptyServerName)
+	default:
+		return nil, E.New("unknown tls engine: ", options.Options.Engine)
 	}
-	return NewSTDClient(options.Context, options.Logger, options.ServerAddress, options.Options)
+	if options.Options.Reality != nil && options.Options.Reality.Enabled {
+		return newRealityClient(options.Context, options.Logger, options.ServerAddress, options.Options, options.AllowEmptyServerName)
+	} else if options.Options.UTLS != nil && options.Options.UTLS.Enabled {
+		return newUTLSClient(options.Context, options.Logger, options.ServerAddress, options.Options, options.AllowEmptyServerName)
+	}
+	return newSTDClient(options.Context, options.Logger, options.ServerAddress, options.Options, options.AllowEmptyServerName)
 }
 
 func ClientHandshake(ctx context.Context, conn net.Conn, config Config) (Conn, error) {
-	ctx, cancel := context.WithTimeout(ctx, C.TCPTimeout)
-	defer cancel()
 	tlsConn, err := aTLS.ClientHandshake(ctx, conn, config)
 	if err != nil {
 		return nil, err

common/tls/reality_client.go

@@ -52,11 +52,15 @@ type RealityClientConfig struct {
 }
 
 func NewRealityClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions) (Config, error) {
+	return newRealityClient(ctx, logger, serverAddress, options, false)
+}
+
+func newRealityClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions, allowEmptyServerName bool) (Config, error) {
 	if options.UTLS == nil || !options.UTLS.Enabled {
 		return nil, E.New("uTLS is required by reality client")
 	}
 
-	uClient, err := NewUTLSClient(ctx, logger, serverAddress, options)
+	uClient, err := newUTLSClient(ctx, logger, serverAddress, options, allowEmptyServerName)
 	if err != nil {
 		return nil, err
 	}
@@ -108,6 +112,14 @@ func (e *RealityClientConfig) SetNextProtos(nextProto []string) {
 	e.uClient.SetNextProtos(nextProto)
 }
 
+func (e *RealityClientConfig) HandshakeTimeout() time.Duration {
+	return e.uClient.HandshakeTimeout()
+}
+
+func (e *RealityClientConfig) SetHandshakeTimeout(timeout time.Duration) {
+	e.uClient.SetHandshakeTimeout(timeout)
+}
+
 func (e *RealityClientConfig) STDConfig() (*STDConfig, error) {
 	return nil, E.New("unsupported usage for reality")
 }

common/tls/reality_server.go

@@ -26,7 +26,8 @@ import (
 var _ ServerConfigCompat = (*RealityServerConfig)(nil)
 
 type RealityServerConfig struct {
-	config *utls.RealityConfig
+	config           *utls.RealityConfig
+	handshakeTimeout time.Duration
 }
 
 func NewRealityServer(ctx context.Context, logger log.ContextLogger, options option.InboundTLSOptions) (ServerConfig, error) {
@@ -130,7 +131,16 @@ func NewRealityServer(ctx context.Context, logger log.ContextLogger, options opt
 	if options.ECH != nil && options.ECH.Enabled {
 		return nil, E.New("Reality is conflict with ECH")
 	}
-	var config ServerConfig = &RealityServerConfig{&tlsConfig}
+	var handshakeTimeout time.Duration
+	if options.HandshakeTimeout > 0 {
+		handshakeTimeout = options.HandshakeTimeout.Build()
+	} else {
+		handshakeTimeout = C.TCPTimeout
+	}
+	var config ServerConfig = &RealityServerConfig{
+		config:           &tlsConfig,
+		handshakeTimeout: handshakeTimeout,
+	}
 	if options.KernelTx || options.KernelRx {
 		if !C.IsLinux {
 			return nil, E.New("kTLS is only supported on Linux")
@@ -161,6 +171,14 @@ func (c *RealityServerConfig) SetNextProtos(nextProto []string) {
 	c.config.NextProtos = nextProto
 }
 
+func (c *RealityServerConfig) HandshakeTimeout() time.Duration {
+	return c.handshakeTimeout
+}
+
+func (c *RealityServerConfig) SetHandshakeTimeout(timeout time.Duration) {
+	c.handshakeTimeout = timeout
+}
+
 func (c *RealityServerConfig) STDConfig() (*tls.Config, error) {
 	return nil, E.New("unsupported usage for reality")
 }
@@ -191,7 +209,8 @@ func (c *RealityServerConfig) ServerHandshake(ctx context.Context, conn net.Conn
 
 func (c *RealityServerConfig) Clone() Config {
 	return &RealityServerConfig{
-		config: c.config.Clone(),
+		config:           c.config.Clone(),
+		handshakeTimeout: c.handshakeTimeout,
 	}
 }
 

common/tls/server.go

@@ -46,8 +46,11 @@ func NewServerWithOptions(options ServerOptions) (ServerConfig, error) {
 }
 
 func ServerHandshake(ctx context.Context, conn net.Conn, config ServerConfig) (Conn, error) {
-	ctx, cancel := context.WithTimeout(ctx, C.TCPTimeout)
+	if config.HandshakeTimeout() == 0 {
-	defer cancel()
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(ctx, C.TCPTimeout)
+		defer cancel()
+	}
 	tlsConn, err := aTLS.ServerHandshake(ctx, conn, config)
 	if err != nil {
 		return nil, err

common/tls/std_client.go

@@ -24,16 +24,30 @@ import (
 type STDClientConfig struct {
 	ctx                   context.Context
 	config                *tls.Config
+	serverName            string
+	disableSNI            bool
+	verifyServerName      bool
+	handshakeTimeout      time.Duration
 	fragment              bool
 	fragmentFallbackDelay time.Duration
 	recordFragment        bool
 }
 
 func (c *STDClientConfig) ServerName() string {
-	return c.config.ServerName
+	return c.serverName
 }
 
 func (c *STDClientConfig) SetServerName(serverName string) {
+	c.serverName = serverName
+	if c.disableSNI {
+		c.config.ServerName = ""
+		if c.verifyServerName {
+			c.config.VerifyConnection = verifyConnection(c.config.RootCAs, c.config.Time, serverName)
+		} else {
+			c.config.VerifyConnection = nil
+		}
+		return
+	}
 	c.config.ServerName = serverName
 }
 
@@ -45,6 +59,14 @@ func (c *STDClientConfig) SetNextProtos(nextProto []string) {
 	c.config.NextProtos = nextProto
 }
 
+func (c *STDClientConfig) HandshakeTimeout() time.Duration {
+	return c.handshakeTimeout
+}
+
+func (c *STDClientConfig) SetHandshakeTimeout(timeout time.Duration) {
+	c.handshakeTimeout = timeout
+}
+
 func (c *STDClientConfig) STDConfig() (*STDConfig, error) {
 	return c.config, nil
 }
@@ -57,13 +79,19 @@ func (c *STDClientConfig) Client(conn net.Conn) (Conn, error) {
 }
 
 func (c *STDClientConfig) Clone() Config {
-	return &STDClientConfig{
+	cloned := &STDClientConfig{
 		ctx:                   c.ctx,
 		config:                c.config.Clone(),
+		serverName:            c.serverName,
+		disableSNI:            c.disableSNI,
+		verifyServerName:      c.verifyServerName,
+		handshakeTimeout:      c.handshakeTimeout,
 		fragment:              c.fragment,
 		fragmentFallbackDelay: c.fragmentFallbackDelay,
 		recordFragment:        c.recordFragment,
 	}
+	cloned.SetServerName(cloned.serverName)
+	return cloned
 }
 
 func (c *STDClientConfig) ECHConfigList() []byte {
@@ -75,41 +103,27 @@ func (c *STDClientConfig) SetECHConfigList(EncryptedClientHelloConfigList []byte
 }
 
 func NewSTDClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions) (Config, error) {
+	return newSTDClient(ctx, logger, serverAddress, options, false)
+}
+
+func newSTDClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions, allowEmptyServerName bool) (Config, error) {
 	var serverName string
 	if options.ServerName != "" {
 		serverName = options.ServerName
 	} else if serverAddress != "" {
 		serverName = serverAddress
 	}
-	if serverName == "" && !options.Insecure {
+	if serverName == "" && !options.Insecure && !allowEmptyServerName {
-		return nil, E.New("missing server_name or insecure=true")
+		return nil, errMissingServerName
 	}
 
 	var tlsConfig tls.Config
 	tlsConfig.Time = ntp.TimeFuncFromContext(ctx)
 	tlsConfig.RootCAs = adapter.RootPoolFromContext(ctx)
-	if !options.DisableSNI {
-		tlsConfig.ServerName = serverName
-	}
 	if options.Insecure {
 		tlsConfig.InsecureSkipVerify = options.Insecure
 	} else if options.DisableSNI {
 		tlsConfig.InsecureSkipVerify = true
-		tlsConfig.VerifyConnection = func(state tls.ConnectionState) error {
-			verifyOptions := x509.VerifyOptions{
-				Roots:         tlsConfig.RootCAs,
-				DNSName:       serverName,
-				Intermediates: x509.NewCertPool(),
-			}
-			for _, cert := range state.PeerCertificates[1:] {
-				verifyOptions.Intermediates.AddCert(cert)
-			}
-			if tlsConfig.Time != nil {
-				verifyOptions.CurrentTime = tlsConfig.Time()
-			}
-			_, err := state.PeerCertificates[0].Verify(verifyOptions)
-			return err
-		}
 	}
 	if len(options.CertificatePublicKeySHA256) > 0 {
 		if len(options.Certificate) > 0 || options.CertificatePath != "" {
@@ -117,7 +131,7 @@ func NewSTDClient(ctx context.Context, logger logger.ContextLogger, serverAddres
 		}
 		tlsConfig.InsecureSkipVerify = true
 		tlsConfig.VerifyPeerCertificate = func(rawCerts [][]byte, verifiedChains [][]*x509.Certificate) error {
-			return verifyPublicKeySHA256(options.CertificatePublicKeySHA256, rawCerts, tlsConfig.Time)
+			return VerifyPublicKeySHA256(options.CertificatePublicKeySHA256, rawCerts)
 		}
 	}
 	if len(options.ALPN) > 0 {
@@ -198,7 +212,24 @@ func NewSTDClient(ctx context.Context, logger logger.ContextLogger, serverAddres
 	} else if len(clientCertificate) > 0 || len(clientKey) > 0 {
 		return nil, E.New("client certificate and client key must be provided together")
 	}
-	var config Config = &STDClientConfig{ctx, &tlsConfig, options.Fragment, time.Duration(options.FragmentFallbackDelay), options.RecordFragment}
+	var handshakeTimeout time.Duration
+	if options.HandshakeTimeout > 0 {
+		handshakeTimeout = options.HandshakeTimeout.Build()
+	} else {
+		handshakeTimeout = C.TCPTimeout
+	}
+	var config Config = &STDClientConfig{
+		ctx:                   ctx,
+		config:                &tlsConfig,
+		serverName:            serverName,
+		disableSNI:            options.DisableSNI,
+		verifyServerName:      options.DisableSNI && !options.Insecure,
+		handshakeTimeout:      handshakeTimeout,
+		fragment:              options.Fragment,
+		fragmentFallbackDelay: time.Duration(options.FragmentFallbackDelay),
+		recordFragment:        options.RecordFragment,
+	}
+	config.SetServerName(serverName)
 	if options.ECH != nil && options.ECH.Enabled {
 		var err error
 		config, err = parseECHClientConfig(ctx, config.(ECHCapableConfig), options)
@@ -220,7 +251,28 @@ func NewSTDClient(ctx context.Context, logger logger.ContextLogger, serverAddres
 	return config, nil
 }
 
-func verifyPublicKeySHA256(knownHashValues [][]byte, rawCerts [][]byte, timeFunc func() time.Time) error {
+func verifyConnection(rootCAs *x509.CertPool, timeFunc func() time.Time, serverName string) func(state tls.ConnectionState) error {
+	return func(state tls.ConnectionState) error {
+		if serverName == "" {
+			return errMissingServerName
+		}
+		verifyOptions := x509.VerifyOptions{
+			Roots:         rootCAs,
+			DNSName:       serverName,
+			Intermediates: x509.NewCertPool(),
+		}
+		for _, cert := range state.PeerCertificates[1:] {
+			verifyOptions.Intermediates.AddCert(cert)
+		}
+		if timeFunc != nil {
+			verifyOptions.CurrentTime = timeFunc()
+		}
+		_, err := state.PeerCertificates[0].Verify(verifyOptions)
+		return err
+	}
+}
+
+func VerifyPublicKeySHA256(knownHashValues [][]byte, rawCerts [][]byte) error {
 	leafCertificate, err := x509.ParseCertificate(rawCerts[0])
 	if err != nil {
 		return E.Cause(err, "failed to parse leaf certificate")

common/tls/std_server.go

@@ -92,6 +92,7 @@ func getACMENextProtos(provider adapter.CertificateProvider) []string {
 type STDServerConfig struct {
 	access                sync.RWMutex
 	config                *tls.Config
+	handshakeTimeout      time.Duration
 	logger                log.Logger
 	certificateProvider   managedCertificateProvider
 	acmeService           adapter.SimpleLifecycle
@@ -139,6 +140,18 @@ func (c *STDServerConfig) SetNextProtos(nextProto []string) {
 	c.config = config
 }
 
+func (c *STDServerConfig) HandshakeTimeout() time.Duration {
+	c.access.RLock()
+	defer c.access.RUnlock()
+	return c.handshakeTimeout
+}
+
+func (c *STDServerConfig) SetHandshakeTimeout(timeout time.Duration) {
+	c.access.Lock()
+	defer c.access.Unlock()
+	c.handshakeTimeout = timeout
+}
+
 func (c *STDServerConfig) hasACMEALPN() bool {
 	if c.acmeService != nil {
 		return true
@@ -165,7 +178,8 @@ func (c *STDServerConfig) Server(conn net.Conn) (Conn, error) {
 
 func (c *STDServerConfig) Clone() Config {
 	return &STDServerConfig{
-		config: c.config.Clone(),
+		config:           c.config.Clone(),
+		handshakeTimeout: c.handshakeTimeout,
 	}
 }
 
@@ -458,7 +472,7 @@ func NewSTDServer(ctx context.Context, logger log.ContextLogger, options option.
 				tlsConfig.ClientAuth = tls.RequestClientCert
 			}
 			tlsConfig.VerifyPeerCertificate = func(rawCerts [][]byte, verifiedChains [][]*x509.Certificate) error {
-				return verifyPublicKeySHA256(options.ClientCertificatePublicKeySHA256, rawCerts, tlsConfig.Time)
+				return VerifyPublicKeySHA256(options.ClientCertificatePublicKeySHA256, rawCerts)
 			}
 		} else {
 			return nil, E.New("missing client_certificate, client_certificate_path or client_certificate_public_key_sha256 for client authentication")
@@ -471,8 +485,15 @@ func NewSTDServer(ctx context.Context, logger log.ContextLogger, options option.
 			return nil, err
 		}
 	}
+	var handshakeTimeout time.Duration
+	if options.HandshakeTimeout > 0 {
+		handshakeTimeout = options.HandshakeTimeout.Build()
+	} else {
+		handshakeTimeout = C.TCPTimeout
+	}
 	serverConfig := &STDServerConfig{
 		config:                tlsConfig,
+		handshakeTimeout:      handshakeTimeout,
 		logger:                logger,
 		certificateProvider:   certificateProvider,
 		acmeService:           acmeService,

common/tls/utls_client.go

@@ -28,6 +28,10 @@ import (
 type UTLSClientConfig struct {
 	ctx                   context.Context
 	config                *utls.Config
+	serverName            string
+	disableSNI            bool
+	verifyServerName      bool
+	handshakeTimeout      time.Duration
 	id                    utls.ClientHelloID
 	fragment              bool
 	fragmentFallbackDelay time.Duration
@@ -35,10 +39,20 @@ type UTLSClientConfig struct {
 }
 
 func (c *UTLSClientConfig) ServerName() string {
-	return c.config.ServerName
+	return c.serverName
 }
 
 func (c *UTLSClientConfig) SetServerName(serverName string) {
+	c.serverName = serverName
+	if c.disableSNI {
+		c.config.ServerName = ""
+		if c.verifyServerName {
+			c.config.InsecureServerNameToVerify = serverName
+		} else {
+			c.config.InsecureServerNameToVerify = ""
+		}
+		return
+	}
 	c.config.ServerName = serverName
 }
 
@@ -53,6 +67,14 @@ func (c *UTLSClientConfig) SetNextProtos(nextProto []string) {
 	c.config.NextProtos = nextProto
 }
 
+func (c *UTLSClientConfig) HandshakeTimeout() time.Duration {
+	return c.handshakeTimeout
+}
+
+func (c *UTLSClientConfig) SetHandshakeTimeout(timeout time.Duration) {
+	c.handshakeTimeout = timeout
+}
+
 func (c *UTLSClientConfig) STDConfig() (*STDConfig, error) {
 	return nil, E.New("unsupported usage for uTLS")
 }
@@ -69,9 +91,20 @@ func (c *UTLSClientConfig) SetSessionIDGenerator(generator func(clientHello []by
 }
 
 func (c *UTLSClientConfig) Clone() Config {
-	return &UTLSClientConfig{
+	cloned := &UTLSClientConfig{
-		c.ctx, c.config.Clone(), c.id, c.fragment, c.fragmentFallbackDelay, c.recordFragment,
+		ctx:                   c.ctx,
+		config:                c.config.Clone(),
+		serverName:            c.serverName,
+		disableSNI:            c.disableSNI,
+		verifyServerName:      c.verifyServerName,
+		handshakeTimeout:      c.handshakeTimeout,
+		id:                    c.id,
+		fragment:              c.fragment,
+		fragmentFallbackDelay: c.fragmentFallbackDelay,
+		recordFragment:        c.recordFragment,
 	}
+	cloned.SetServerName(cloned.serverName)
+	return cloned
 }
 
 func (c *UTLSClientConfig) ECHConfigList() []byte {
@@ -143,29 +176,29 @@ func (c *utlsALPNWrapper) HandshakeContext(ctx context.Context) error {
 }
 
 func NewUTLSClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions) (Config, error) {
+	return newUTLSClient(ctx, logger, serverAddress, options, false)
+}
+
+func newUTLSClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions, allowEmptyServerName bool) (Config, error) {
 	var serverName string
 	if options.ServerName != "" {
 		serverName = options.ServerName
 	} else if serverAddress != "" {
 		serverName = serverAddress
 	}
-	if serverName == "" && !options.Insecure {
+	if serverName == "" && !options.Insecure && !allowEmptyServerName {
-		return nil, E.New("missing server_name or insecure=true")
+		return nil, errMissingServerName
 	}
 
 	var tlsConfig utls.Config
 	tlsConfig.Time = ntp.TimeFuncFromContext(ctx)
 	tlsConfig.RootCAs = adapter.RootPoolFromContext(ctx)
-	if !options.DisableSNI {
-		tlsConfig.ServerName = serverName
-	}
 	if options.Insecure {
 		tlsConfig.InsecureSkipVerify = options.Insecure
 	} else if options.DisableSNI {
 		if options.Reality != nil && options.Reality.Enabled {
 			return nil, E.New("disable_sni is unsupported in reality")
 		}
-		tlsConfig.InsecureServerNameToVerify = serverName
 	}
 	if len(options.CertificatePublicKeySHA256) > 0 {
 		if len(options.Certificate) > 0 || options.CertificatePath != "" {
@@ -173,7 +206,7 @@ func NewUTLSClient(ctx context.Context, logger logger.ContextLogger, serverAddre
 		}
 		tlsConfig.InsecureSkipVerify = true
 		tlsConfig.VerifyPeerCertificate = func(rawCerts [][]byte, verifiedChains [][]*x509.Certificate) error {
-			return verifyPublicKeySHA256(options.CertificatePublicKeySHA256, rawCerts, tlsConfig.Time)
+			return VerifyPublicKeySHA256(options.CertificatePublicKeySHA256, rawCerts)
 		}
 	}
 	if len(options.ALPN) > 0 {
@@ -251,11 +284,29 @@ func NewUTLSClient(ctx context.Context, logger logger.ContextLogger, serverAddre
 	} else if len(clientCertificate) > 0 || len(clientKey) > 0 {
 		return nil, E.New("client certificate and client key must be provided together")
 	}
+	var handshakeTimeout time.Duration
+	if options.HandshakeTimeout > 0 {
+		handshakeTimeout = options.HandshakeTimeout.Build()
+	} else {
+		handshakeTimeout = C.TCPTimeout
+	}
 	id, err := uTLSClientHelloID(options.UTLS.Fingerprint)
 	if err != nil {
 		return nil, err
 	}
-	var config Config = &UTLSClientConfig{ctx, &tlsConfig, id, options.Fragment, time.Duration(options.FragmentFallbackDelay), options.RecordFragment}
+	var config Config = &UTLSClientConfig{
+		ctx:                   ctx,
+		config:                &tlsConfig,
+		serverName:            serverName,
+		disableSNI:            options.DisableSNI,
+		verifyServerName:      options.DisableSNI && !options.Insecure,
+		handshakeTimeout:      handshakeTimeout,
+		id:                    id,
+		fragment:              options.Fragment,
+		fragmentFallbackDelay: time.Duration(options.FragmentFallbackDelay),
+		recordFragment:        options.RecordFragment,
+	}
+	config.SetServerName(serverName)
 	if options.ECH != nil && options.ECH.Enabled {
 		if options.Reality != nil && options.Reality.Enabled {
 			return nil, E.New("Reality is conflict with ECH")

common/tls/utls_stub.go

@@ -12,10 +12,18 @@ import (
 )
 
 func NewUTLSClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions) (Config, error) {
+	return newUTLSClient(ctx, logger, serverAddress, options, false)
+}
+
+func newUTLSClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions, allowEmptyServerName bool) (Config, error) {
 	return nil, E.New(`uTLS is not included in this build, rebuild with -tags with_utls`)
 }
 
 func NewRealityClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions) (Config, error) {
+	return newRealityClient(ctx, logger, serverAddress, options, false)
+}
+
+func newRealityClient(ctx context.Context, logger logger.ContextLogger, serverAddress string, options option.OutboundTLSOptions, allowEmptyServerName bool) (Config, error) {
 	return nil, E.New(`uTLS, which is required by reality is not included in this build, rebuild with -tags with_utls`)
 }
 

constant/tls.go

@@ -1,3 +1,8 @@
 package constant
 
 const ACMETLS1Protocol = "acme-tls/1"
+
+const (
+	TLSEngineDefault = ""
+	TLSEngineApple   = "apple"
+)

dns/client.go

@@ -30,59 +30,63 @@ var (
 var _ adapter.DNSClient = (*Client)(nil)
 
 type Client struct {
-	timeout            time.Duration
+	ctx               context.Context
-	disableCache       bool
+	timeout           time.Duration
-	disableExpire      bool
+	disableCache      bool
-	independentCache   bool
+	disableExpire     bool
-	clientSubnet       netip.Prefix
+	optimisticTimeout time.Duration
-	rdrc               adapter.RDRCStore
+	cacheCapacity     uint32
-	initRDRCFunc       func() adapter.RDRCStore
+	clientSubnet      netip.Prefix
-	logger             logger.ContextLogger
+	rdrc              adapter.RDRCStore
-	cache              freelru.Cache[dns.Question, *dns.Msg]
+	initRDRCFunc      func() adapter.RDRCStore
-	cacheLock          compatible.Map[dns.Question, chan struct{}]
+	dnsCache          adapter.DNSCacheStore
-	transportCache     freelru.Cache[transportCacheKey, *dns.Msg]
+	initDNSCacheFunc  func() adapter.DNSCacheStore
-	transportCacheLock compatible.Map[dns.Question, chan struct{}]
+	logger            logger.ContextLogger
+	cache             freelru.Cache[dnsCacheKey, *dns.Msg]
+	cacheLock         compatible.Map[dnsCacheKey, chan struct{}]
+	backgroundRefresh compatible.Map[dnsCacheKey, struct{}]
 }
 
 type ClientOptions struct {
-	Timeout          time.Duration
+	Context           context.Context
-	DisableCache     bool
+	Timeout           time.Duration
-	DisableExpire    bool
+	DisableCache      bool
-	IndependentCache bool
+	DisableExpire     bool
-	CacheCapacity    uint32
+	OptimisticTimeout time.Duration
-	ClientSubnet     netip.Prefix
+	CacheCapacity     uint32
-	RDRC             func() adapter.RDRCStore
+	ClientSubnet      netip.Prefix
-	Logger           logger.ContextLogger
+	RDRC              func() adapter.RDRCStore
+	DNSCache          func() adapter.DNSCacheStore
+	Logger            logger.ContextLogger
 }
 
 func NewClient(options ClientOptions) *Client {
-	client := &Client{
-		timeout:          options.Timeout,
-		disableCache:     options.DisableCache,
-		disableExpire:    options.DisableExpire,
-		independentCache: options.IndependentCache,
-		clientSubnet:     options.ClientSubnet,
-		initRDRCFunc:     options.RDRC,
-		logger:           options.Logger,
-	}
-	if client.timeout == 0 {
-		client.timeout = C.DNSTimeout
-	}
 	cacheCapacity := options.CacheCapacity
 	if cacheCapacity < 1024 {
 		cacheCapacity = 1024
 	}
-	if !client.disableCache {
+	client := &Client{
-		if !client.independentCache {
+		ctx:               options.Context,
-			client.cache = common.Must1(freelru.NewSharded[dns.Question, *dns.Msg](cacheCapacity, maphash.NewHasher[dns.Question]().Hash32))
+		timeout:           options.Timeout,
-		} else {
+		disableCache:      options.DisableCache,
-			client.transportCache = common.Must1(freelru.NewSharded[transportCacheKey, *dns.Msg](cacheCapacity, maphash.NewHasher[transportCacheKey]().Hash32))
+		disableExpire:     options.DisableExpire,
-		}
+		optimisticTimeout: options.OptimisticTimeout,
+		cacheCapacity:     cacheCapacity,
+		clientSubnet:      options.ClientSubnet,
+		initRDRCFunc:      options.RDRC,
+		initDNSCacheFunc:  options.DNSCache,
+		logger:            options.Logger,
+	}
+	if client.timeout == 0 {
+		client.timeout = C.DNSTimeout
+	}
+	if !client.disableCache && client.initDNSCacheFunc == nil {
+		client.initializeMemoryCache()
 	}
 	return client
 }
 
-type transportCacheKey struct {
+type dnsCacheKey struct {
 	dns.Question
 	transportTag string
 }
@@ -91,6 +95,19 @@ func (c *Client) Start() {
 	if c.initRDRCFunc != nil {
 		c.rdrc = c.initRDRCFunc()
 	}
+	if c.initDNSCacheFunc != nil {
+		c.dnsCache = c.initDNSCacheFunc()
+	}
+	if c.dnsCache == nil {
+		c.initializeMemoryCache()
+	}
+}
+
+func (c *Client) initializeMemoryCache() {
+	if c.disableCache || c.cache != nil {
+		return
+	}
+	c.cache = common.Must1(freelru.NewSharded[dnsCacheKey, *dns.Msg](c.cacheCapacity, maphash.NewHasher[dnsCacheKey]().Hash32))
 }
 
 func extractNegativeTTL(response *dns.Msg) (uint32, bool) {
@@ -107,6 +124,37 @@ func extractNegativeTTL(response *dns.Msg) (uint32, bool) {
 	return 0, false
 }
 
+func computeTimeToLive(response *dns.Msg) uint32 {
+	var timeToLive uint32
+	if len(response.Answer) == 0 {
+		if soaTTL, hasSOA := extractNegativeTTL(response); hasSOA {
+			return soaTTL
+		}
+	}
+	for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
+		for _, record := range recordList {
+			if record.Header().Rrtype == dns.TypeOPT {
+				continue
+			}
+			if timeToLive == 0 || record.Header().Ttl > 0 && record.Header().Ttl < timeToLive {
+				timeToLive = record.Header().Ttl
+			}
+		}
+	}
+	return timeToLive
+}
+
+func normalizeTTL(response *dns.Msg, timeToLive uint32) {
+	for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
+		for _, record := range recordList {
+			if record.Header().Rrtype == dns.TypeOPT {
+				continue
+			}
+			record.Header().Ttl = timeToLive
+		}
+	}
+}
+
 func (c *Client) Exchange(ctx context.Context, transport adapter.DNSTransport, message *dns.Msg, options adapter.DNSQueryOptions, responseChecker func(response *dns.Msg) bool) (*dns.Msg, error) {
 	if len(message.Question) == 0 {
 		if c.logger != nil {
@@ -121,13 +169,7 @@ func (c *Client) Exchange(ctx context.Context, transport adapter.DNSTransport, m
 		}
 		return FixedResponseStatus(message, dns.RcodeSuccess), nil
 	}
-	clientSubnet := options.ClientSubnet
+	message = c.prepareExchangeMessage(message, options)
-	if !clientSubnet.IsValid() {
-		clientSubnet = c.clientSubnet
-	}
-	if clientSubnet.IsValid() {
-		message = SetClientSubnet(message, clientSubnet)
-	}
 
 	isSimpleRequest := len(message.Question) == 1 &&
 		len(message.Ns) == 0 &&
@@ -139,40 +181,32 @@ func (c *Client) Exchange(ctx context.Context, transport adapter.DNSTransport, m
 		!options.ClientSubnet.IsValid()
 	disableCache := !isSimpleRequest || c.disableCache || options.DisableCache
 	if !disableCache {
-		if c.cache != nil {
+		cacheKey := dnsCacheKey{Question: question, transportTag: transport.Tag()}
-			cond, loaded := c.cacheLock.LoadOrStore(question, make(chan struct{}))
+		cond, loaded := c.cacheLock.LoadOrStore(cacheKey, make(chan struct{}))
-			if loaded {
+		if loaded {
-				select {
+			select {
-				case <-cond:
+			case <-cond:
-				case <-ctx.Done():
+			case <-ctx.Done():
-					return nil, ctx.Err()
+				return nil, ctx.Err()
-				}
-			} else {
-				defer func() {
-					c.cacheLock.Delete(question)
-					close(cond)
-				}()
-			}
-		} else if c.transportCache != nil {
-			cond, loaded := c.transportCacheLock.LoadOrStore(question, make(chan struct{}))
-			if loaded {
-				select {
-				case <-cond:
-				case <-ctx.Done():
-					return nil, ctx.Err()
-				}
-			} else {
-				defer func() {
-					c.transportCacheLock.Delete(question)
-					close(cond)
-				}()
 			}
+		} else {
+			defer func() {
+				c.cacheLock.Delete(cacheKey)
+				close(cond)
+			}()
 		}
-		response, ttl := c.loadResponse(question, transport)
+		response, ttl, isStale := c.loadResponse(question, transport)
 		if response != nil {
-			logCachedResponse(c.logger, ctx, response, ttl)
+			if isStale && !options.DisableOptimisticCache {
-			response.Id = message.Id
+				c.backgroundRefreshDNS(transport, question, message.Copy(), options, responseChecker)
-			return response, nil
+				logOptimisticResponse(c.logger, ctx, response)
+				response.Id = message.Id
+				return response, nil
+			} else if !isStale {
+				logCachedResponse(c.logger, ctx, response, ttl)
+				response.Id = message.Id
+				return response, nil
+			}
 		}
 	}
 
@@ -188,52 +222,10 @@ func (c *Client) Exchange(ctx context.Context, transport adapter.DNSTransport, m
 			return nil, ErrResponseRejectedCached
 		}
 	}
-	ctx, cancel := context.WithTimeout(ctx, c.timeout)
+	response, err := c.exchangeToTransport(ctx, transport, message)
-	response, err := transport.Exchange(ctx, message)
-	cancel()
 	if err != nil {
-		var rcodeError RcodeError
+		return nil, err
-		if errors.As(err, &rcodeError) {
-			response = FixedResponseStatus(message, int(rcodeError))
-		} else {
-			return nil, err
-		}
 	}
-	/*if question.Qtype == dns.TypeA || question.Qtype == dns.TypeAAAA {
-		validResponse := response
-	loop:
-		for {
-			var (
-				addresses  int
-				queryCNAME string
-			)
-			for _, rawRR := range validResponse.Answer {
-				switch rr := rawRR.(type) {
-				case *dns.A:
-					break loop
-				case *dns.AAAA:
-					break loop
-				case *dns.CNAME:
-					queryCNAME = rr.Target
-				}
-			}
-			if queryCNAME == "" {
-				break
-			}
-			exMessage := *message
-			exMessage.Question = []dns.Question{{
-				Name:  queryCNAME,
-				Qtype: question.Qtype,
-			}}
-			validResponse, err = c.Exchange(ctx, transport, &exMessage, options, responseChecker)
-			if err != nil {
-				return nil, err
-			}
-		}
-		if validResponse != response {
-			response.Answer = append(response.Answer, validResponse.Answer...)
-		}
-	}*/
 	disableCache = disableCache || (response.Rcode != dns.RcodeSuccess && response.Rcode != dns.RcodeNameError)
 	if responseChecker != nil {
 		var rejected bool
@@ -250,54 +242,7 @@ func (c *Client) Exchange(ctx context.Context, transport adapter.DNSTransport, m
 			return response, ErrResponseRejected
 		}
 	}
-	if question.Qtype == dns.TypeHTTPS {
+	timeToLive := applyResponseOptions(question, response, options)
-		if options.Strategy == C.DomainStrategyIPv4Only || options.Strategy == C.DomainStrategyIPv6Only {
-			for _, rr := range response.Answer {
-				https, isHTTPS := rr.(*dns.HTTPS)
-				if !isHTTPS {
-					continue
-				}
-				content := https.SVCB
-				content.Value = common.Filter(content.Value, func(it dns.SVCBKeyValue) bool {
-					if options.Strategy == C.DomainStrategyIPv4Only {
-						return it.Key() != dns.SVCB_IPV6HINT
-					} else {
-						return it.Key() != dns.SVCB_IPV4HINT
-					}
-				})
-				https.SVCB = content
-			}
-		}
-	}
-	var timeToLive uint32
-	if len(response.Answer) == 0 {
-		if soaTTL, hasSOA := extractNegativeTTL(response); hasSOA {
-			timeToLive = soaTTL
-		}
-	}
-	if timeToLive == 0 {
-		for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
-			for _, record := range recordList {
-				if record.Header().Rrtype == dns.TypeOPT {
-					continue
-				}
-				if timeToLive == 0 || record.Header().Ttl > 0 && record.Header().Ttl < timeToLive {
-					timeToLive = record.Header().Ttl
-				}
-			}
-		}
-	}
-	if options.RewriteTTL != nil {
-		timeToLive = *options.RewriteTTL
-	}
-	for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
-		for _, record := range recordList {
-			if record.Header().Rrtype == dns.TypeOPT {
-				continue
-			}
-			record.Header().Ttl = timeToLive
-		}
-	}
 	if !disableCache {
 		c.storeCache(transport, question, response, timeToLive)
 	}
@@ -363,8 +308,12 @@ func (c *Client) Lookup(ctx context.Context, transport adapter.DNSTransport, dom
 func (c *Client) ClearCache() {
 	if c.cache != nil {
 		c.cache.Purge()
-	} else if c.transportCache != nil {
+	}
-		c.transportCache.Purge()
+	if c.dnsCache != nil {
+		err := c.dnsCache.ClearDNSCache()
+		if err != nil && c.logger != nil {
+			c.logger.Warn("clear DNS cache: ", err)
+		}
 	}
 }
 
@@ -380,24 +329,22 @@ func (c *Client) storeCache(transport adapter.DNSTransport, question dns.Questio
 	if timeToLive == 0 {
 		return
 	}
+	if c.dnsCache != nil {
+		packed, err := message.Pack()
+		if err == nil {
+			expireAt := time.Now().Add(time.Second * time.Duration(timeToLive))
+			c.dnsCache.SaveDNSCacheAsync(transport.Tag(), question.Name, question.Qtype, packed, expireAt, c.logger)
+		}
+		return
+	}
+	if c.cache == nil {
+		return
+	}
+	key := dnsCacheKey{Question: question, transportTag: transport.Tag()}
 	if c.disableExpire {
-		if !c.independentCache {
+		c.cache.Add(key, message.Copy())
-			c.cache.Add(question, message.Copy())
-		} else {
-			c.transportCache.Add(transportCacheKey{
-				Question:     question,
-				transportTag: transport.Tag(),
-			}, message.Copy())
-		}
 	} else {
-		if !c.independentCache {
+		c.cache.AddWithLifetime(key, message.Copy(), time.Second*time.Duration(timeToLive))
-			c.cache.AddWithLifetime(question, message.Copy(), time.Second*time.Duration(timeToLive))
-		} else {
-			c.transportCache.AddWithLifetime(transportCacheKey{
-				Question:     question,
-				transportTag: transport.Tag(),
-			}, message.Copy(), time.Second*time.Duration(timeToLive))
-		}
 	}
 }
 
@@ -407,19 +354,19 @@ func (c *Client) lookupToExchange(ctx context.Context, transport adapter.DNSTran
 		Qtype:  qType,
 		Qclass: dns.ClassINET,
 	}
-	disableCache := c.disableCache || options.DisableCache
-	if !disableCache {
-		cachedAddresses, err := c.questionCache(question, transport)
-		if err != ErrNotCached {
-			return cachedAddresses, err
-		}
-	}
 	message := dns.Msg{
 		MsgHdr: dns.MsgHdr{
 			RecursionDesired: true,
 		},
 		Question: []dns.Question{question},
 	}
+	disableCache := c.disableCache || options.DisableCache
+	if !disableCache {
+		cachedAddresses, err := c.questionCache(ctx, transport, &message, options, responseChecker)
+		if err != ErrNotCached {
+			return cachedAddresses, err
+		}
+	}
 	response, err := c.Exchange(ctx, transport, &message, options, responseChecker)
 	if err != nil {
 		return nil, err
@@ -430,98 +377,177 @@ func (c *Client) lookupToExchange(ctx context.Context, transport adapter.DNSTran
 	return MessageToAddresses(response), nil
 }
 
-func (c *Client) questionCache(question dns.Question, transport adapter.DNSTransport) ([]netip.Addr, error) {
+func (c *Client) questionCache(ctx context.Context, transport adapter.DNSTransport, message *dns.Msg, options adapter.DNSQueryOptions, responseChecker func(response *dns.Msg) bool) ([]netip.Addr, error) {
-	response, _ := c.loadResponse(question, transport)
+	question := message.Question[0]
+	response, _, isStale := c.loadResponse(question, transport)
 	if response == nil {
 		return nil, ErrNotCached
 	}
+	if isStale {
+		if options.DisableOptimisticCache {
+			return nil, ErrNotCached
+		}
+		c.backgroundRefreshDNS(transport, question, c.prepareExchangeMessage(message.Copy(), options), options, responseChecker)
+		logOptimisticResponse(c.logger, ctx, response)
+	}
 	if response.Rcode != dns.RcodeSuccess {
 		return nil, RcodeError(response.Rcode)
 	}
 	return MessageToAddresses(response), nil
 }
 
-func (c *Client) loadResponse(question dns.Question, transport adapter.DNSTransport) (*dns.Msg, int) {
+func (c *Client) loadResponse(question dns.Question, transport adapter.DNSTransport) (*dns.Msg, int, bool) {
-	var (
+	if c.dnsCache != nil {
-		response *dns.Msg
+		return c.loadPersistentResponse(question, transport)
-		loaded   bool
-	)
-	if c.disableExpire {
-		if !c.independentCache {
-			response, loaded = c.cache.Get(question)
-		} else {
-			response, loaded = c.transportCache.Get(transportCacheKey{
-				Question:     question,
-				transportTag: transport.Tag(),
-			})
-		}
-		if !loaded {
-			return nil, 0
-		}
-		return response.Copy(), 0
-	} else {
-		var expireAt time.Time
-		if !c.independentCache {
-			response, expireAt, loaded = c.cache.GetWithLifetime(question)
-		} else {
-			response, expireAt, loaded = c.transportCache.GetWithLifetime(transportCacheKey{
-				Question:     question,
-				transportTag: transport.Tag(),
-			})
-		}
-		if !loaded {
-			return nil, 0
-		}
-		timeNow := time.Now()
-		if timeNow.After(expireAt) {
-			if !c.independentCache {
-				c.cache.Remove(question)
-			} else {
-				c.transportCache.Remove(transportCacheKey{
-					Question:     question,
-					transportTag: transport.Tag(),
-				})
-			}
-			return nil, 0
-		}
-		var originTTL int
-		for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
-			for _, record := range recordList {
-				if record.Header().Rrtype == dns.TypeOPT {
-					continue
-				}
-				if originTTL == 0 || record.Header().Ttl > 0 && int(record.Header().Ttl) < originTTL {
-					originTTL = int(record.Header().Ttl)
-				}
-			}
-		}
-		nowTTL := int(expireAt.Sub(timeNow).Seconds())
-		if nowTTL < 0 {
-			nowTTL = 0
-		}
-		response = response.Copy()
-		if originTTL > 0 {
-			duration := uint32(originTTL - nowTTL)
-			for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
-				for _, record := range recordList {
-					if record.Header().Rrtype == dns.TypeOPT {
-						continue
-					}
-					record.Header().Ttl = record.Header().Ttl - duration
-				}
-			}
-		} else {
-			for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
-				for _, record := range recordList {
-					if record.Header().Rrtype == dns.TypeOPT {
-						continue
-					}
-					record.Header().Ttl = uint32(nowTTL)
-				}
-			}
-		}
-		return response, nowTTL
 	}
+	if c.cache == nil {
+		return nil, 0, false
+	}
+	key := dnsCacheKey{Question: question, transportTag: transport.Tag()}
+	if c.disableExpire {
+		response, loaded := c.cache.Get(key)
+		if !loaded {
+			return nil, 0, false
+		}
+		return response.Copy(), 0, false
+	}
+	response, expireAt, loaded := c.cache.GetWithLifetimeNoExpire(key)
+	if !loaded {
+		return nil, 0, false
+	}
+	timeNow := time.Now()
+	if timeNow.After(expireAt) {
+		if c.optimisticTimeout > 0 && timeNow.Before(expireAt.Add(c.optimisticTimeout)) {
+			response = response.Copy()
+			normalizeTTL(response, 1)
+			return response, 0, true
+		}
+		c.cache.Remove(key)
+		return nil, 0, false
+	}
+	nowTTL := int(expireAt.Sub(timeNow).Seconds())
+	if nowTTL < 0 {
+		nowTTL = 0
+	}
+	response = response.Copy()
+	normalizeTTL(response, uint32(nowTTL))
+	return response, nowTTL, false
+}
+
+func (c *Client) loadPersistentResponse(question dns.Question, transport adapter.DNSTransport) (*dns.Msg, int, bool) {
+	rawMessage, expireAt, loaded := c.dnsCache.LoadDNSCache(transport.Tag(), question.Name, question.Qtype)
+	if !loaded {
+		return nil, 0, false
+	}
+	response := new(dns.Msg)
+	err := response.Unpack(rawMessage)
+	if err != nil {
+		return nil, 0, false
+	}
+	if c.disableExpire {
+		return response, 0, false
+	}
+	timeNow := time.Now()
+	if timeNow.After(expireAt) {
+		if c.optimisticTimeout > 0 && timeNow.Before(expireAt.Add(c.optimisticTimeout)) {
+			normalizeTTL(response, 1)
+			return response, 0, true
+		}
+		return nil, 0, false
+	}
+	nowTTL := int(expireAt.Sub(timeNow).Seconds())
+	if nowTTL < 0 {
+		nowTTL = 0
+	}
+	normalizeTTL(response, uint32(nowTTL))
+	return response, nowTTL, false
+}
+
+func applyResponseOptions(question dns.Question, response *dns.Msg, options adapter.DNSQueryOptions) uint32 {
+	if question.Qtype == dns.TypeHTTPS && (options.Strategy == C.DomainStrategyIPv4Only || options.Strategy == C.DomainStrategyIPv6Only) {
+		for _, rr := range response.Answer {
+			https, isHTTPS := rr.(*dns.HTTPS)
+			if !isHTTPS {
+				continue
+			}
+			content := https.SVCB
+			content.Value = common.Filter(content.Value, func(it dns.SVCBKeyValue) bool {
+				if options.Strategy == C.DomainStrategyIPv4Only {
+					return it.Key() != dns.SVCB_IPV6HINT
+				}
+				return it.Key() != dns.SVCB_IPV4HINT
+			})
+			https.SVCB = content
+		}
+	}
+	timeToLive := computeTimeToLive(response)
+	if options.RewriteTTL != nil {
+		timeToLive = *options.RewriteTTL
+	}
+	normalizeTTL(response, timeToLive)
+	return timeToLive
+}
+
+func (c *Client) backgroundRefreshDNS(transport adapter.DNSTransport, question dns.Question, message *dns.Msg, options adapter.DNSQueryOptions, responseChecker func(response *dns.Msg) bool) {
+	key := dnsCacheKey{Question: question, transportTag: transport.Tag()}
+	_, loaded := c.backgroundRefresh.LoadOrStore(key, struct{}{})
+	if loaded {
+		return
+	}
+	go func() {
+		defer c.backgroundRefresh.Delete(key)
+		ctx := contextWithTransportTag(c.ctx, transport.Tag())
+		response, err := c.exchangeToTransport(ctx, transport, message)
+		if err != nil {
+			if c.logger != nil {
+				c.logger.Debug("optimistic refresh failed for ", FqdnToDomain(question.Name), ": ", err)
+			}
+			return
+		}
+		if responseChecker != nil {
+			var rejected bool
+			if response.Rcode != dns.RcodeSuccess && response.Rcode != dns.RcodeNameError {
+				rejected = true
+			} else {
+				rejected = !responseChecker(response)
+			}
+			if rejected {
+				if c.rdrc != nil {
+					c.rdrc.SaveRDRCAsync(transport.Tag(), question.Name, question.Qtype, c.logger)
+				}
+				return
+			}
+		} else if response.Rcode != dns.RcodeSuccess && response.Rcode != dns.RcodeNameError {
+			return
+		}
+		timeToLive := applyResponseOptions(question, response, options)
+		c.storeCache(transport, question, response, timeToLive)
+	}()
+}
+
+func (c *Client) prepareExchangeMessage(message *dns.Msg, options adapter.DNSQueryOptions) *dns.Msg {
+	clientSubnet := options.ClientSubnet
+	if !clientSubnet.IsValid() {
+		clientSubnet = c.clientSubnet
+	}
+	if clientSubnet.IsValid() {
+		message = SetClientSubnet(message, clientSubnet)
+	}
+	return message
+}
+
+func (c *Client) exchangeToTransport(ctx context.Context, transport adapter.DNSTransport, message *dns.Msg) (*dns.Msg, error) {
+	ctx, cancel := context.WithTimeout(ctx, c.timeout)
+	defer cancel()
+	response, err := transport.Exchange(ctx, message)
+	if err == nil {
+		return response, nil
+	}
+	var rcodeError RcodeError
+	if errors.As(err, &rcodeError) {
+		return FixedResponseStatus(message, int(rcodeError)), nil
+	}
+	return nil, err
 }
 
 func MessageToAddresses(response *dns.Msg) []netip.Addr {

dns/client_log.go

@@ -22,6 +22,19 @@ func logCachedResponse(logger logger.ContextLogger, ctx context.Context, respons
 	}
 }
 
+func logOptimisticResponse(logger logger.ContextLogger, ctx context.Context, response *dns.Msg) {
+	if logger == nil || len(response.Question) == 0 {
+		return
+	}
+	domain := FqdnToDomain(response.Question[0].Name)
+	logger.DebugContext(ctx, "optimistic ", domain, " ", dns.RcodeToString[response.Rcode])
+	for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
+		for _, record := range recordList {
+			logger.InfoContext(ctx, "optimistic ", dns.Type(record.Header().Rrtype).String(), " ", FormatQuestion(record.String()))
+		}
+	}
+}
+
 func logExchangedResponse(logger logger.ContextLogger, ctx context.Context, response *dns.Msg, ttl uint32) {
 	if logger == nil || len(response.Question) == 0 {
 		return

dns/router.go

@@ -51,7 +51,7 @@ type Router struct {
 	closing               bool
 }
 
-func NewRouter(ctx context.Context, logFactory log.Factory, options option.DNSOptions) *Router {
+func NewRouter(ctx context.Context, logFactory log.Factory, options option.DNSOptions) (*Router, error) {
 	router := &Router{
 		ctx:                   ctx,
 		logger:                logFactory.NewLogger("dns"),
@@ -61,12 +61,30 @@ func NewRouter(ctx context.Context, logFactory log.Factory, options option.DNSOp
 		rules:                 make([]adapter.DNSRule, 0, len(options.Rules)),
 		defaultDomainStrategy: C.DomainStrategy(options.Strategy),
 	}
+	if options.DNSClientOptions.IndependentCache {
+		deprecated.Report(ctx, deprecated.OptionIndependentDNSCache)
+	}
+	var optimisticTimeout time.Duration
+	optimisticOptions := common.PtrValueOrDefault(options.DNSClientOptions.Optimistic)
+	if optimisticOptions.Enabled {
+		if options.DNSClientOptions.DisableCache {
+			return nil, E.New("`optimistic` is conflict with `disable_cache`")
+		}
+		if options.DNSClientOptions.DisableExpire {
+			return nil, E.New("`optimistic` is conflict with `disable_expire`")
+		}
+		optimisticTimeout = time.Duration(optimisticOptions.Timeout)
+		if optimisticTimeout == 0 {
+			optimisticTimeout = 3 * 24 * time.Hour
+		}
+	}
 	router.client = NewClient(ClientOptions{
-		DisableCache:     options.DNSClientOptions.DisableCache,
+		Context:           ctx,
-		DisableExpire:    options.DNSClientOptions.DisableExpire,
+		DisableCache:      options.DNSClientOptions.DisableCache,
-		IndependentCache: options.DNSClientOptions.IndependentCache,
+		DisableExpire:     options.DNSClientOptions.DisableExpire,
-		CacheCapacity:    options.DNSClientOptions.CacheCapacity,
+		OptimisticTimeout: optimisticTimeout,
-		ClientSubnet:     options.DNSClientOptions.ClientSubnet.Build(netip.Prefix{}),
+		CacheCapacity:     options.DNSClientOptions.CacheCapacity,
+		ClientSubnet:      options.DNSClientOptions.ClientSubnet.Build(netip.Prefix{}),
 		RDRC: func() adapter.RDRCStore {
 			cacheFile := service.FromContext[adapter.CacheFile](ctx)
 			if cacheFile == nil {
@@ -77,12 +95,24 @@ func NewRouter(ctx context.Context, logFactory log.Factory, options option.DNSOp
 			}
 			return cacheFile
 		},
+		DNSCache: func() adapter.DNSCacheStore {
+			cacheFile := service.FromContext[adapter.CacheFile](ctx)
+			if cacheFile == nil {
+				return nil
+			}
+			if !cacheFile.StoreDNS() {
+				return nil
+			}
+			cacheFile.SetDisableExpire(options.DNSClientOptions.DisableExpire)
+			cacheFile.SetOptimisticTimeout(optimisticTimeout)
+			return cacheFile
+		},
 		Logger: router.logger,
 	})
 	if options.ReverseMapping {
 		router.dnsReverseMapping = common.Must1(freelru.NewSharded[netip.Addr, string](1024, maphash.NewHasher[netip.Addr]().Hash32))
 	}
-	return router
+	return router, nil
 }
 
 func (r *Router) Initialize(rules []option.DNSRule) error {
@@ -319,6 +349,9 @@ func (r *Router) applyDNSRouteOptions(options *adapter.DNSQueryOptions, routeOpt
 	if routeOptions.DisableCache {
 		options.DisableCache = true
 	}
+	if routeOptions.DisableOptimisticCache {
+		options.DisableOptimisticCache = true
+	}
 	if routeOptions.RewriteTTL != nil {
 		options.RewriteTTL = routeOptions.RewriteTTL
 	}
@@ -907,7 +940,9 @@ func dnsRuleModeRequirementsInRule(router adapter.Router, rule option.DNSRule, m
 		return dnsRuleModeRequirementsInDefaultRule(router, rule.DefaultOptions, metadataOverrides)
 	case C.RuleTypeLogical:
 		flags := dnsRuleModeFlags{
-			disabled:           dnsRuleActionType(rule) == C.RuleActionTypeEvaluate || dnsRuleActionType(rule) == C.RuleActionTypeRespond,
+			disabled: dnsRuleActionType(rule) == C.RuleActionTypeEvaluate ||
+				dnsRuleActionType(rule) == C.RuleActionTypeRespond ||
+				dnsRuleActionDisablesLegacyDNSMode(rule.LogicalOptions.DNSRuleAction),
 			neededFromStrategy: dnsRuleActionHasStrategy(rule.LogicalOptions.DNSRuleAction),
 		}
 		flags.needed = flags.neededFromStrategy
@@ -926,7 +961,7 @@ func dnsRuleModeRequirementsInRule(router adapter.Router, rule option.DNSRule, m
 
 func dnsRuleModeRequirementsInDefaultRule(router adapter.Router, rule option.DefaultDNSRule, metadataOverrides map[string]adapter.RuleSetMetadata) (dnsRuleModeFlags, error) {
 	flags := dnsRuleModeFlags{
-		disabled:           defaultRuleDisablesLegacyDNSMode(rule),
+		disabled:           defaultRuleDisablesLegacyDNSMode(rule) || dnsRuleActionDisablesLegacyDNSMode(rule.DNSRuleAction),
 		neededFromStrategy: dnsRuleActionHasStrategy(rule.DNSRuleAction),
 	}
 	flags.needed = defaultRuleNeedsLegacyDNSModeFromAddressFilter(rule) || flags.neededFromStrategy
@@ -1063,6 +1098,17 @@ func validateLegacyDNSModeDisabledDefaultRule(rule option.DefaultDNSRule) (bool,
 	return rule.MatchResponse || rule.Action == C.RuleActionTypeRespond, nil
 }
 
+func dnsRuleActionDisablesLegacyDNSMode(action option.DNSRuleAction) bool {
+	switch action.Action {
+	case "", C.RuleActionTypeRoute, C.RuleActionTypeEvaluate:
+		return action.RouteOptions.DisableOptimisticCache
+	case C.RuleActionTypeRouteOptions:
+		return action.RouteOptionsOptions.DisableOptimisticCache
+	default:
+		return false
+	}
+}
+
 func dnsRuleActionHasStrategy(action option.DNSRuleAction) bool {
 	switch action.Action {
 	case "", C.RuleActionTypeRoute, C.RuleActionTypeEvaluate:

dns/router_test.go

@@ -139,9 +139,9 @@ type fakeRuleSet struct {
 	beforeDecrementReference func()
 }
 
-func (s *fakeRuleSet) Name() string                                                  { return "fake-rule-set" }
+func (s *fakeRuleSet) Name() string                       { return "fake-rule-set" }
-func (s *fakeRuleSet) StartContext(context.Context, *adapter.HTTPStartContext) error { return nil }
+func (s *fakeRuleSet) StartContext(context.Context) error { return nil }
-func (s *fakeRuleSet) PostStart() error                                              { return nil }
+func (s *fakeRuleSet) PostStart() error                   { return nil }
 func (s *fakeRuleSet) Metadata() adapter.RuleSetMetadata {
 	s.access.Lock()
 	metadata := s.metadata

dns/transport/https.go

@@ -3,17 +3,18 @@ package transport
 import (
 	"bytes"
 	"context"
+	"encoding/base64"
 	"errors"
 	"io"
 	"net"
 	"net/http"
 	"net/url"
-	"strconv"
+	"strings"
 	"sync"
 	"time"
 
 	"github.com/sagernet/sing-box/adapter"
-	"github.com/sagernet/sing-box/common/dialer"
+	"github.com/sagernet/sing-box/common/httpclient"
 	"github.com/sagernet/sing-box/common/tls"
 	C "github.com/sagernet/sing-box/constant"
 	"github.com/sagernet/sing-box/dns"
@@ -26,9 +27,9 @@ import (
 	M "github.com/sagernet/sing/common/metadata"
 	N "github.com/sagernet/sing/common/network"
 	sHTTP "github.com/sagernet/sing/protocol/http"
+	"github.com/sagernet/sing/service"
 
 	mDNS "github.com/miekg/dns"
-	"golang.org/x/net/http2"
 )
 
 const MimeType = "application/dns-message"
@@ -42,57 +43,20 @@ func RegisterHTTPS(registry *dns.TransportRegistry) {
 type HTTPSTransport struct {
 	dns.TransportAdapter
 	logger           logger.ContextLogger
-	dialer           N.Dialer
 	destination      *url.URL
-	headers          http.Header
+	method           string
+	host             string
+	queryHeaders     http.Header
 	transportAccess  sync.Mutex
-	transport        *HTTPSTransportWrapper
+	transport        adapter.HTTPTransport
 	transportResetAt time.Time
 }
 
 func NewHTTPS(ctx context.Context, logger log.ContextLogger, tag string, options option.RemoteHTTPSDNSServerOptions) (adapter.DNSTransport, error) {
-	transportDialer, err := dns.NewRemoteDialer(ctx, options.RemoteDNSServerOptions)
-	if err != nil {
-		return nil, err
-	}
-	tlsOptions := common.PtrValueOrDefault(options.TLS)
-	tlsOptions.Enabled = true
-	tlsConfig, err := tls.NewClient(ctx, logger, options.Server, tlsOptions)
-	if err != nil {
-		return nil, err
-	}
-	if len(tlsConfig.NextProtos()) == 0 {
-		tlsConfig.SetNextProtos([]string{http2.NextProtoTLS, "http/1.1"})
-	}
 	headers := options.Headers.Build()
 	host := headers.Get("Host")
-	if host != "" {
+	headers.Del("Host")
-		headers.Del("Host")
+	headers.Set("Accept", MimeType)
-	} else {
-		if tlsConfig.ServerName() != "" {
-			host = tlsConfig.ServerName()
-		} else {
-			host = options.Server
-		}
-	}
-	destinationURL := url.URL{
-		Scheme: "https",
-		Host:   host,
-	}
-	if destinationURL.Host == "" {
-		destinationURL.Host = options.Server
-	}
-	if options.ServerPort != 0 && options.ServerPort != 443 {
-		destinationURL.Host = net.JoinHostPort(destinationURL.Host, strconv.Itoa(int(options.ServerPort)))
-	}
-	path := options.Path
-	if path == "" {
-		path = "/dns-query"
-	}
-	err = sHTTP.URLSetPath(&destinationURL, path)
-	if err != nil {
-		return nil, err
-	}
 	serverAddr := options.DNSServerAddressOptions.Build()
 	if serverAddr.Port == 0 {
 		serverAddr.Port = 443
@@ -100,56 +64,123 @@ func NewHTTPS(ctx context.Context, logger log.ContextLogger, tag string, options
 	if !serverAddr.IsValid() {
 		return nil, E.New("invalid server address: ", serverAddr)
 	}
-	return NewHTTPSRaw(
+	destinationURL := url.URL{
-		dns.NewTransportAdapterWithRemoteOptions(C.DNSTypeHTTPS, tag, options.RemoteDNSServerOptions),
+		Scheme: "https",
-		logger,
+		Host:   doHURLHost(serverAddr, 443),
-		transportDialer,
+	}
-		&destinationURL,
+	path := options.Path
-		headers,
+	if path == "" {
-		serverAddr,
+		path = "/dns-query"
-		tlsConfig,
+	}
-	), nil
+	err := sHTTP.URLSetPath(&destinationURL, path)
+	if err != nil {
+		return nil, err
+	}
+	method := strings.ToUpper(options.Method)
+	if method == "" {
+		method = http.MethodPost
+	}
+	switch method {
+	case http.MethodGet, http.MethodPost:
+	default:
+		return nil, E.New("unsupported HTTPS DNS method: ", options.Method)
+	}
+	if method == http.MethodPost {
+		headers.Set("Content-Type", MimeType)
+	}
+	httpClientOptions := options.HTTPClientOptions
+	tlsOptions := common.PtrValueOrDefault(httpClientOptions.TLS)
+	tlsOptions.Enabled = true
+	httpClientOptions.TLS = &tlsOptions
+	httpClientOptions.Tag = ""
+	httpClientOptions.Headers = nil
+	if options.ServerIsDomain() {
+		httpClientOptions.DirectResolver = true
+	}
+	httpClientManager := service.FromContext[adapter.HTTPClientManager](ctx)
+	transport, err := httpClientManager.ResolveTransport(ctx, logger, httpClientOptions)
+	if err != nil {
+		return nil, err
+	}
+	remoteOptions := option.RemoteDNSServerOptions{
+		RawLocalDNSServerOptions: option.RawLocalDNSServerOptions{
+			DialerOptions: options.DialerOptions,
+		},
+		DNSServerAddressOptions: options.DNSServerAddressOptions,
+	}
+	return &HTTPSTransport{
+		TransportAdapter: dns.NewTransportAdapterWithRemoteOptions(C.DNSTypeHTTPS, tag, remoteOptions),
+		logger:           logger,
+		destination:      &destinationURL,
+		method:           method,
+		host:             host,
+		queryHeaders:     headers,
+		transport:        transport,
+	}, nil
 }
 
-func NewHTTPSRaw(
+func NewHTTPRaw(
 	adapter dns.TransportAdapter,
-	logger log.ContextLogger,
+	logger logger.ContextLogger,
 	dialer N.Dialer,
 	destination *url.URL,
 	headers http.Header,
-	serverAddr M.Socksaddr,
 	tlsConfig tls.Config,
-) *HTTPSTransport {
+	method string,
+) (*HTTPSTransport, error) {
+	if destination.Scheme == "https" && tlsConfig == nil {
+		return nil, E.New("TLS transport unavailable")
+	}
+	queryHeaders := headers.Clone()
+	host := queryHeaders.Get("Host")
+	queryHeaders.Del("Host")
+	queryHeaders.Set("Accept", MimeType)
+	if method == http.MethodPost {
+		queryHeaders.Set("Content-Type", MimeType)
+	}
+	currentTransport, err := httpclient.NewTransportWithDialer(dialer, tlsConfig, "", option.HTTPClientOptions{})
+	if err != nil {
+		return nil, err
+	}
 	return &HTTPSTransport{
 		TransportAdapter: adapter,
 		logger:           logger,
-		dialer:           dialer,
 		destination:      destination,
-		headers:          headers,
+		method:           method,
-		transport:        NewHTTPSTransportWrapper(tls.NewDialer(dialer, tlsConfig), serverAddr),
+		host:             host,
-	}
+		queryHeaders:     queryHeaders,
+		transport:        currentTransport,
+	}, nil
 }
 
 func (t *HTTPSTransport) Start(stage adapter.StartStage) error {
 	if stage != adapter.StartStateStart {
 		return nil
 	}
-	return dialer.InitializeDetour(t.dialer)
+	return httpclient.InitializeDetour(t.transport)
 }
 
 func (t *HTTPSTransport) Close() error {
 	t.transportAccess.Lock()
 	defer t.transportAccess.Unlock()
-	t.transport.CloseIdleConnections()
+	if t.transport == nil {
-	t.transport = t.transport.Clone()
+		return nil
-	return nil
+	}
+	err := t.transport.Close()
+	t.transport = nil
+	return err
 }
 
 func (t *HTTPSTransport) Reset() {
 	t.transportAccess.Lock()
 	defer t.transportAccess.Unlock()
-	t.transport.CloseIdleConnections()
+	if t.transport == nil {
-	t.transport = t.transport.Clone()
+		return
+	}
+	oldTransport := t.transport
+	oldTransport.CloseIdleConnections()
+	// Close is intentionally avoided here because some Clone implementations share transport state.
+	t.transport = oldTransport.Clone()
 }
 
 func (t *HTTPSTransport) Exchange(ctx context.Context, message *mDNS.Msg) (*mDNS.Msg, error) {
@@ -159,11 +190,12 @@ func (t *HTTPSTransport) Exchange(ctx context.Context, message *mDNS.Msg) (*mDNS
 		if errors.Is(err, context.DeadlineExceeded) {
 			t.transportAccess.Lock()
 			defer t.transportAccess.Unlock()
-			if t.transportResetAt.After(startAt) {
+			if t.transport == nil || t.transportResetAt.After(startAt) {
 				return nil, err
 			}
-			t.transport.CloseIdleConnections()
+			oldTransport := t.transport
-			t.transport = t.transport.Clone()
+			oldTransport.CloseIdleConnections()
+			t.transport = oldTransport.Clone()
 			t.transportResetAt = time.Now()
 		}
 		return nil, err
@@ -181,17 +213,32 @@ func (t *HTTPSTransport) exchange(ctx context.Context, message *mDNS.Msg) (*mDNS
 		requestBuffer.Release()
 		return nil, err
 	}
-	request, err := http.NewRequestWithContext(ctx, http.MethodPost, t.destination.String(), bytes.NewReader(rawMessage))
+	requestURL := *t.destination
+	var request *http.Request
+	switch t.method {
+	case http.MethodGet:
+		query := requestURL.Query()
+		query.Set("dns", base64.RawURLEncoding.EncodeToString(rawMessage))
+		requestURL.RawQuery = query.Encode()
+		request, err = http.NewRequestWithContext(ctx, http.MethodGet, requestURL.String(), nil)
+	default:
+		request, err = http.NewRequestWithContext(ctx, http.MethodPost, requestURL.String(), bytes.NewReader(rawMessage))
+	}
 	if err != nil {
 		requestBuffer.Release()
 		return nil, err
 	}
-	request.Header = t.headers.Clone()
+	request.Header = t.queryHeaders.Clone()
-	request.Header.Set("Content-Type", MimeType)
+	if t.host != "" {
-	request.Header.Set("Accept", MimeType)
+		request.Host = t.host
+	}
 	t.transportAccess.Lock()
 	currentTransport := t.transport
 	t.transportAccess.Unlock()
+	if currentTransport == nil {
+		requestBuffer.Release()
+		return nil, net.ErrClosed
+	}
 	response, err := currentTransport.RoundTrip(request)
 	requestBuffer.Release()
 	if err != nil {
@@ -222,3 +269,13 @@ func (t *HTTPSTransport) exchange(ctx context.Context, message *mDNS.Msg) (*mDNS
 	}
 	return &responseMessage, nil
 }
+
+func doHURLHost(serverAddr M.Socksaddr, defaultPort uint16) string {
+	if serverAddr.Port != defaultPort {
+		return serverAddr.String()
+	}
+	if serverAddr.IsIPv6() {
+		return "[" + serverAddr.AddrString() + "]"
+	}
+	return serverAddr.AddrString()
+}

dns/transport/https_transport.go

@@ -1,80 +0,0 @@
-package transport
-
-import (
-	"context"
-	"errors"
-	"net"
-	"net/http"
-	"sync/atomic"
-
-	"github.com/sagernet/sing-box/common/tls"
-	E "github.com/sagernet/sing/common/exceptions"
-	M "github.com/sagernet/sing/common/metadata"
-
-	"golang.org/x/net/http2"
-)
-
-var errFallback = E.New("fallback to HTTP/1.1")
-
-type HTTPSTransportWrapper struct {
-	http2Transport *http2.Transport
-	httpTransport  *http.Transport
-	fallback       *atomic.Bool
-}
-
-func NewHTTPSTransportWrapper(dialer tls.Dialer, serverAddr M.Socksaddr) *HTTPSTransportWrapper {
-	var fallback atomic.Bool
-	return &HTTPSTransportWrapper{
-		http2Transport: &http2.Transport{
-			DialTLSContext: func(ctx context.Context, _, _ string, _ *tls.STDConfig) (net.Conn, error) {
-				tlsConn, err := dialer.DialTLSContext(ctx, serverAddr)
-				if err != nil {
-					return nil, err
-				}
-				state := tlsConn.ConnectionState()
-				if state.NegotiatedProtocol == http2.NextProtoTLS {
-					return tlsConn, nil
-				}
-				tlsConn.Close()
-				fallback.Store(true)
-				return nil, errFallback
-			},
-		},
-		httpTransport: &http.Transport{
-			DialTLSContext: func(ctx context.Context, _, _ string) (net.Conn, error) {
-				return dialer.DialTLSContext(ctx, serverAddr)
-			},
-		},
-		fallback: &fallback,
-	}
-}
-
-func (h *HTTPSTransportWrapper) RoundTrip(request *http.Request) (*http.Response, error) {
-	if h.fallback.Load() {
-		return h.httpTransport.RoundTrip(request)
-	} else {
-		response, err := h.http2Transport.RoundTrip(request)
-		if err != nil {
-			if errors.Is(err, errFallback) {
-				return h.httpTransport.RoundTrip(request)
-			}
-			return nil, err
-		}
-		return response, nil
-	}
-}
-
-func (h *HTTPSTransportWrapper) CloseIdleConnections() {
-	h.http2Transport.CloseIdleConnections()
-	h.httpTransport.CloseIdleConnections()
-}
-
-func (h *HTTPSTransportWrapper) Clone() *HTTPSTransportWrapper {
-	return &HTTPSTransportWrapper{
-		httpTransport: h.httpTransport,
-		http2Transport: &http2.Transport{
-			DialTLSContext: h.http2Transport.DialTLSContext,
-		},
-		fallback: h.fallback,
-	}
-}

dns/transport/local/local_darwin_cgo.go

@@ -4,8 +4,24 @@ package local
 
 /*
 #include <stdlib.h>
+#include <dns.h>
 #include <resolv.h>
-#include <netdb.h>
+
+static void *cgo_dns_open_super() {
+	return (void *)dns_open(NULL);
+}
+
+static void cgo_dns_close(void *opaque) {
+	if (opaque != NULL) dns_free((dns_handle_t)opaque);
+}
+
+static int cgo_dns_search(void *opaque, const char *name, int class, int type,
+	unsigned char *answer, int anslen) {
+	dns_handle_t handle = (dns_handle_t)opaque;
+	struct sockaddr_storage from;
+	uint32_t fromlen = sizeof(from);
+	return dns_search(handle, name, class, type, (char *)answer, anslen, (struct sockaddr *)&from, &fromlen);
+}
 
 static void *cgo_res_init() {
 	res_state state = calloc(1, sizeof(struct __res_state));
@@ -52,7 +68,59 @@ import (
 	mDNS "github.com/miekg/dns"
 )
 
-func resolvSearch(name string, class, qtype int, timeoutSeconds int) (*mDNS.Msg, error) {
+const (
+	darwinResolverHostNotFound = 1
+	darwinResolverTryAgain     = 2
+	darwinResolverNoRecovery   = 3
+	darwinResolverNoData       = 4
+
+	darwinResolverMaxPacketSize = 65535
+)
+
+var errDarwinNeedLargerBuffer = errors.New("darwin resolver response truncated")
+
+func darwinLookupSystemDNS(name string, class, qtype, timeoutSeconds int) (*mDNS.Msg, error) {
+	response, err := darwinSearchWithSystemRouting(name, class, qtype)
+	if err == nil {
+		return response, nil
+	}
+	fallbackResponse, fallbackErr := darwinSearchWithResolv(name, class, qtype, timeoutSeconds)
+	if fallbackErr == nil || fallbackResponse != nil {
+		return fallbackResponse, fallbackErr
+	}
+	return nil, E.Errors(
+		E.Cause(err, "dns_search"),
+		E.Cause(fallbackErr, "res_nsearch"),
+	)
+}
+
+func darwinSearchWithSystemRouting(name string, class, qtype int) (*mDNS.Msg, error) {
+	handle := C.cgo_dns_open_super()
+	if handle == nil {
+		return nil, E.New("dns_open failed")
+	}
+	defer C.cgo_dns_close(handle)
+
+	cName := C.CString(name)
+	defer C.free(unsafe.Pointer(cName))
+
+	bufSize := 1232
+	for {
+		answer := make([]byte, bufSize)
+		n := C.cgo_dns_search(handle, cName, C.int(class), C.int(qtype),
+			(*C.uchar)(unsafe.Pointer(&answer[0])), C.int(len(answer)))
+		if n <= 0 {
+			return nil, E.New("dns_search failed for ", name)
+		}
+		if int(n) > bufSize {
+			bufSize = int(n)
+			continue
+		}
+		return unpackDarwinResolverMessage(answer[:int(n)], "dns_search")
+	}
+}
+
+func darwinSearchWithResolv(name string, class, qtype int, timeoutSeconds int) (*mDNS.Msg, error) {
 	state := C.cgo_res_init()
 	if state == nil {
 		return nil, E.New("res_ninit failed")
@@ -61,6 +129,7 @@ func resolvSearch(name string, class, qtype int, timeoutSeconds int) (*mDNS.Msg,
 
 	cName := C.CString(name)
 	defer C.free(unsafe.Pointer(cName))
+
 	bufSize := 1232
 	for {
 		answer := make([]byte, bufSize)
@@ -74,37 +143,55 @@ func resolvSearch(name string, class, qtype int, timeoutSeconds int) (*mDNS.Msg,
 				bufSize = int(n)
 				continue
 			}
-			var response mDNS.Msg
+			return unpackDarwinResolverMessage(answer[:int(n)], "res_nsearch")
-			err := response.Unpack(answer[:int(n)])
+		}
-			if err != nil {
+		response, err := handleDarwinResolvFailure(name, answer, int(hErrno))
-				return nil, E.Cause(err, "unpack res_nsearch response")
+		if err == nil {
+			return response, nil
+		}
+		if errors.Is(err, errDarwinNeedLargerBuffer) && bufSize < darwinResolverMaxPacketSize {
+			bufSize *= 2
+			if bufSize > darwinResolverMaxPacketSize {
+				bufSize = darwinResolverMaxPacketSize
 			}
-			return &response, nil
+			continue
 		}
-		var response mDNS.Msg
+		return nil, err
-		_ = response.Unpack(answer[:bufSize])
+	}
-		if response.Response {
+}
-			if response.Truncated && bufSize < 65535 {
+
-				bufSize *= 2
+func unpackDarwinResolverMessage(packet []byte, source string) (*mDNS.Msg, error) {
-				if bufSize > 65535 {
+	var response mDNS.Msg
-					bufSize = 65535
+	err := response.Unpack(packet)
-				}
+	if err != nil {
-				continue
+		return nil, E.Cause(err, "unpack ", source, " response")
-			}
+	}
-			return &response, nil
+	return &response, nil
-		}
+}
-		switch hErrno {
+
-		case C.HOST_NOT_FOUND:
+func handleDarwinResolvFailure(name string, answer []byte, hErrno int) (*mDNS.Msg, error) {
-			return nil, dns.RcodeNameError
+	response, err := unpackDarwinResolverMessage(answer, "res_nsearch failure")
-		case C.TRY_AGAIN:
+	if err == nil && response.Response {
-			return nil, dns.RcodeNameError
+		if response.Truncated && len(answer) < darwinResolverMaxPacketSize {
-		case C.NO_RECOVERY:
+			return nil, errDarwinNeedLargerBuffer
-			return nil, dns.RcodeServerFailure
-		case C.NO_DATA:
-			return nil, dns.RcodeSuccess
-		default:
-			return nil, E.New("res_nsearch: unknown error ", int(hErrno), " for ", name)
 		}
+		return response, nil
+	}
+	return nil, darwinResolverHErrno(name, hErrno)
+}
+
+func darwinResolverHErrno(name string, hErrno int) error {
+	switch hErrno {
+	case darwinResolverHostNotFound:
+		return dns.RcodeNameError
+	case darwinResolverTryAgain:
+		return dns.RcodeServerFailure
+	case darwinResolverNoRecovery:
+		return dns.RcodeServerFailure
+	case darwinResolverNoData:
+		return dns.RcodeSuccess
+	default:
+		return E.New("res_nsearch: unknown error ", hErrno, " for ", name)
 	}
 }
 
@@ -141,7 +228,7 @@ func (t *Transport) Exchange(ctx context.Context, message *mDNS.Msg) (*mDNS.Msg,
 	}
 	resultCh := make(chan resolvResult, 1)
 	go func() {
-		response, err := resolvSearch(name, int(question.Qclass), int(question.Qtype), timeoutSeconds)
+		response, err := darwinLookupSystemDNS(name, int(question.Qclass), int(question.Qtype), timeoutSeconds)
 		resultCh <- resolvResult{response, err}
 	}()
 	var result resolvResult

dns/transport/quic/http3.go

@@ -9,6 +9,7 @@ import (
 	"net/url"
 	"strconv"
 	"sync"
+	"time"
 
 	"github.com/sagernet/quic-go"
 	"github.com/sagernet/quic-go/http3"
@@ -40,18 +41,23 @@ func RegisterHTTP3Transport(registry *dns.TransportRegistry) {
 
 type HTTP3Transport struct {
 	dns.TransportAdapter
-	logger          logger.ContextLogger
+	logger           logger.ContextLogger
-	dialer          N.Dialer
+	dialer           N.Dialer
-	destination     *url.URL
+	destination      *url.URL
-	headers         http.Header
+	headers          http.Header
-	serverAddr      M.Socksaddr
+	handshakeTimeout time.Duration
-	tlsConfig       *tls.STDConfig
+	serverAddr       M.Socksaddr
-	transportAccess sync.Mutex
+	tlsConfig        *tls.STDConfig
-	transport       *http3.Transport
+	transportAccess  sync.Mutex
+	transport        *http3.Transport
 }
 
 func NewHTTP3(ctx context.Context, logger log.ContextLogger, tag string, options option.RemoteHTTPSDNSServerOptions) (adapter.DNSTransport, error) {
-	transportDialer, err := dns.NewRemoteDialer(ctx, options.RemoteDNSServerOptions)
+	remoteOptions := option.RemoteDNSServerOptions{
+		DNSServerAddressOptions: options.DNSServerAddressOptions,
+	}
+	remoteOptions.DialerOptions = options.DialerOptions
+	transportDialer, err := dns.NewRemoteDialer(ctx, remoteOptions)
 	if err != nil {
 		return nil, err
 	}
@@ -61,6 +67,7 @@ func NewHTTP3(ctx context.Context, logger log.ContextLogger, tag string, options
 	if err != nil {
 		return nil, err
 	}
+	handshakeTimeout := tlsConfig.HandshakeTimeout()
 	stdConfig, err := tlsConfig.STDConfig()
 	if err != nil {
 		return nil, err
@@ -102,11 +109,12 @@ func NewHTTP3(ctx context.Context, logger log.ContextLogger, tag string, options
 		return nil, E.New("invalid server address: ", serverAddr)
 	}
 	t := &HTTP3Transport{
-		TransportAdapter: dns.NewTransportAdapterWithRemoteOptions(C.DNSTypeHTTP3, tag, options.RemoteDNSServerOptions),
+		TransportAdapter: dns.NewTransportAdapterWithRemoteOptions(C.DNSTypeHTTP3, tag, remoteOptions),
 		logger:           logger,
 		dialer:           transportDialer,
 		destination:      &destinationURL,
 		headers:          headers,
+		handshakeTimeout: handshakeTimeout,
 		serverAddr:       serverAddr,
 		tlsConfig:        stdConfig,
 	}
@@ -115,8 +123,17 @@ func NewHTTP3(ctx context.Context, logger log.ContextLogger, tag string, options
 }
 
 func (t *HTTP3Transport) newTransport() *http3.Transport {
+	quicConfig := &quic.Config{}
+	if t.handshakeTimeout > 0 {
+		quicConfig.HandshakeIdleTimeout = t.handshakeTimeout
+	}
 	return &http3.Transport{
+		QUICConfig: quicConfig,
 		Dial: func(ctx context.Context, addr string, tlsCfg *tls.STDConfig, cfg *quic.Config) (*quic.Conn, error) {
+			if t.handshakeTimeout > 0 && cfg.HandshakeIdleTimeout == 0 {
+				cfg = cfg.Clone()
+				cfg.HandshakeIdleTimeout = t.handshakeTimeout
+			}
 			conn, dialErr := t.dialer.DialContext(ctx, N.NetworkUDP, t.serverAddr)
 			if dialErr != nil {
 				return nil, dialErr

docs/changelog.md

@@ -2,6 +2,29 @@
 icon: material/alert-decagram
 ---
 
+#### 1.14.0-alpha.11
+
+* Add optimistic DNS cache **1**
+* Update NaiveProxy to 147.0.7727.49
+* Fixes and improvements
+
+**1**:
+
+Optimistic DNS cache returns an expired cached response immediately while
+refreshing it in the background, reducing tail latency for repeated
+queries. Enabled via [`optimistic`](/configuration/dns/#optimistic)
+in DNS options, and can be persisted across restarts with the new
+[`store_dns`](/configuration/experimental/cache-file/#store_dns) cache
+file option. A per-query
+[`disable_optimistic_cache`](/configuration/dns/rule_action/#disable_optimistic_cache)
+field is also available on DNS rule actions and the `resolve` route rule
+action.
+
+This deprecates the `independent_cache` DNS option (the DNS cache now
+always keys by transport) and the `store_rdrc` cache file option
+(replaced by `store_dns`); both will be removed in sing-box 1.16.0.
+See [Migration](/migration/#migrate-independent-dns-cache).
+
 #### 1.14.0-alpha.10
 
 * Add `evaluate` DNS rule action and Response Match Fields **1**

docs/configuration/dns/index.md

@@ -2,6 +2,11 @@
 icon: material/alert-decagram
 ---
 
+!!! quote "Changes in sing-box 1.14.0"
+
+    :material-delete-clock: [independent_cache](#independent_cache)  
+    :material-plus: [optimistic](#optimistic)
+
 !!! quote "Changes in sing-box 1.12.0"
 
     :material-decagram: [servers](#servers)
@@ -25,6 +30,7 @@ icon: material/alert-decagram
     "disable_expire": false,
     "independent_cache": false,
     "cache_capacity": 0,
+    "optimistic": false, // or {}
     "reverse_mapping": false,
     "client_subnet": "",
     "fakeip": {}
@@ -57,12 +63,20 @@ One of `prefer_ipv4` `prefer_ipv6` `ipv4_only` `ipv6_only`.
 
 Disable dns cache.
 
+Conflict with `optimistic`.
+
 #### disable_expire
 
 Disable dns cache expire.
 
+Conflict with `optimistic`.
+
 #### independent_cache
 
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    `independent_cache` is deprecated and will be removed in sing-box 1.14.0, check [Migration](/migration/#migrate-independent-dns-cache).
+
 Make each DNS server's cache independent for special purposes. If enabled, will slightly degrade performance.
 
 #### cache_capacity
@@ -73,6 +87,34 @@ LRU cache capacity.
 
 Value less than 1024 will be ignored.
 
+#### optimistic
+
+!!! question "Since sing-box 1.14.0"
+
+Enable optimistic DNS caching. When a cached DNS entry has expired but is still within the timeout window,
+the stale response is returned immediately while a background refresh is triggered.
+
+Conflict with `disable_cache` and `disable_expire`.
+
+Accepts a boolean or an object. When set to `true`, the default timeout of `3d` is used.
+
+```json
+{
+  "enabled": true,
+  "timeout": "3d"
+}
+```
+
+##### enabled
+
+Enable optimistic DNS caching.
+
+##### timeout
+
+The maximum time an expired cache entry can be served optimistically.
+
+`3d` is used by default.
+
 #### reverse_mapping
 
 Stores a reverse mapping of IP addresses after responding to a DNS query in order to provide domain names when routing.

docs/configuration/dns/index.zh.md

@@ -2,6 +2,11 @@
 icon: material/alert-decagram
 ---
 
+!!! quote "sing-box 1.14.0 中的更改"
+
+    :material-delete-clock: [independent_cache](#independent_cache)  
+    :material-plus: [optimistic](#optimistic)
+
 !!! quote "sing-box 1.12.0 中的更改"
 
     :material-decagram: [servers](#servers)
@@ -25,6 +30,7 @@ icon: material/alert-decagram
     "disable_expire": false,
     "independent_cache": false,
     "cache_capacity": 0,
+    "optimistic": false, // or {}
     "reverse_mapping": false,
     "client_subnet": "",
     "fakeip": {}
@@ -56,12 +62,20 @@ icon: material/alert-decagram
 
 禁用 DNS 缓存。
 
+与 `optimistic` 冲突。
+
 #### disable_expire
 
 禁用 DNS 缓存过期。
 
+与 `optimistic` 冲突。
+
 #### independent_cache
 
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    `independent_cache` 已在 sing-box 1.14.0 废弃，且将在 sing-box 1.16.0 中被移除，参阅[迁移指南](/zh/migration/#迁移-independent-dns-cache)。
+
 使每个 DNS 服务器的缓存独立，以满足特殊目的。如果启用，将轻微降低性能。
 
 #### cache_capacity
@@ -72,6 +86,34 @@ LRU 缓存容量。
 
 小于 1024 的值将被忽略。
 
+#### optimistic
+
+!!! question "自 sing-box 1.14.0 起"
+
+启用乐观 DNS 缓存。当缓存的 DNS 条目已过期但仍在超时窗口内时，
+立即返回过期的响应，同时在后台触发刷新。
+
+与 `disable_cache` 和 `disable_expire` 冲突。
+
+接受布尔值或对象。当设置为 `true` 时，使用默认超时 `3d`。
+
+```json
+{
+  "enabled": true,
+  "timeout": "3d"
+}
+```
+
+##### enabled
+
+启用乐观 DNS 缓存。
+
+##### timeout
+
+过期缓存条目可被乐观提供的最长时间。
+
+默认使用 `3d`。
+
 #### reverse_mapping
 
 在响应 DNS 查询后存储 IP 地址的反向映射以为路由目的提供域名。

docs/configuration/dns/rule_action.md

@@ -6,7 +6,8 @@ icon: material/new-box
 
     :material-delete-clock: [strategy](#strategy)  
     :material-plus: [evaluate](#evaluate)  
-    :material-plus: [respond](#respond)
+    :material-plus: [respond](#respond)  
+    :material-plus: [disable_optimistic_cache](#disable_optimistic_cache)
 
 !!! quote "Changes in sing-box 1.12.0"
 
@@ -23,6 +24,7 @@ icon: material/new-box
   "server": "",
   "strategy": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -52,6 +54,12 @@ One of `prefer_ipv4` `prefer_ipv6` `ipv4_only` `ipv6_only`.
 
 Disable cache and save cache in this query.
 
+#### disable_optimistic_cache
+
+!!! question "Since sing-box 1.14.0"
+
+Disable optimistic DNS caching in this query.
+
 #### rewrite_ttl
 
 Rewrite TTL in DNS responses.
@@ -73,6 +81,7 @@ Will override `dns.client_subnet`.
   "action": "evaluate",
   "server": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -97,6 +106,12 @@ Tag of target server.
 
 Disable cache and save cache in this query.
 
+#### disable_optimistic_cache
+
+!!! question "Since sing-box 1.14.0"
+
+Disable optimistic DNS caching in this query.
+
 #### rewrite_ttl
 
 Rewrite TTL in DNS responses.
@@ -131,6 +146,7 @@ Only allowed after a preceding top-level `evaluate` rule. If the action is reach
 {
   "action": "route-options",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }

docs/configuration/dns/rule_action.zh.md

@@ -6,7 +6,8 @@ icon: material/new-box
 
     :material-delete-clock: [strategy](#strategy)  
     :material-plus: [evaluate](#evaluate)  
-    :material-plus: [respond](#respond)
+    :material-plus: [respond](#respond)  
+    :material-plus: [disable_optimistic_cache](#disable_optimistic_cache)
 
 !!! quote "sing-box 1.12.0 中的更改"
 
@@ -23,6 +24,7 @@ icon: material/new-box
   "server": "",
   "strategy": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -52,6 +54,12 @@ icon: material/new-box
 
 在此查询中禁用缓存。
 
+#### disable_optimistic_cache
+
+!!! question "自 sing-box 1.14.0 起"
+
+在此查询中禁用乐观 DNS 缓存。
+
 #### rewrite_ttl
 
 重写 DNS 回应中的 TTL。
@@ -73,6 +81,7 @@ icon: material/new-box
   "action": "evaluate",
   "server": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -95,6 +104,12 @@ icon: material/new-box
 
 在此查询中禁用缓存。
 
+#### disable_optimistic_cache
+
+!!! question "自 sing-box 1.14.0 起"
+
+在此查询中禁用乐观 DNS 缓存。
+
 #### rewrite_ttl
 
 重写 DNS 回应中的 TTL。
@@ -129,6 +144,7 @@ icon: material/new-box
 {
   "action": "route-options",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }

docs/configuration/dns/server/http3.md

@@ -2,6 +2,10 @@
 icon: material/new-box
 ---
 
+!!! quote "Changes in sing-box 1.14.0"
+
+    :material-alert: `headers`, `tls`, Dial Fields moved to [HTTP Client Fields](#http-client-fields)
+
 !!! question "Since sing-box 1.12.0"
 
 # DNS over HTTP3 (DoH3)
@@ -15,27 +19,20 @@ icon: material/new-box
       {
         "type": "h3",
         "tag": "",
-        
+
         "server": "",
-        "server_port": 443,
+        "server_port": 0,
-        
+
         "path": "",
-        "headers": {},
+        "method": "",
-        
+
-        "tls": {},
+        ... // HTTP Client Fields
-        
-        // Dial Fields
       }
     ]
   }
 }
 ```
 
-!!! info "Difference from legacy H3 server"
-
-    * The old server uses default outbound by default unless detour is specified; the new one uses dialer just like outbound, which is equivalent to using an empty direct outbound by default.
-    * The old server uses `address_resolver` and `address_strategy` to resolve the domain name in the server; the new one uses `domain_resolver` and `domain_strategy` in [Dial Fields](/configuration/shared/dial/) instead.
-
 ### Fields
 
 #### server
@@ -58,14 +55,14 @@ The path of the DNS server.
 
 `/dns-query` will be used by default.
 
-#### headers
+#### method
 
-Additional headers to be sent to the DNS server.
+HTTP request method.
 
-#### tls
+Available values: `GET`, `POST`.
 
-TLS configuration, see [TLS](/configuration/shared/tls/#outbound).
+`POST` will be used by default.
 
-### Dial Fields
+### HTTP Client Fields
 
-See [Dial Fields](/configuration/shared/dial/) for details.
+See [HTTP Client Fields](/configuration/shared/http-client/) for details.

docs/configuration/dns/server/http3.zh.md

@@ -2,6 +2,10 @@
 icon: material/new-box
 ---
 
+!!! quote "sing-box 1.14.0 中的更改"
+
+    :material-alert: `headers`、`tls`、拨号字段已移至 [HTTP 客户端字段](#http-客户端字段)
+
 !!! question "自 sing-box 1.12.0 起"
 
 # DNS over HTTP3 (DoH3)
@@ -17,25 +21,18 @@ icon: material/new-box
         "tag": "",
 
         "server": "",
-        "server_port": 443,
+        "server_port": 0,
 
         "path": "",
-        "headers": {},
+        "method": "",
 
-        "tls": {},
+        ... // HTTP 客户端字段
-
-        // 拨号字段
       }
     ]
   }
 }
 ```
 
-!!! info "与旧版 H3 服务器的区别"
-
-    * 旧服务器默认使用默认出站，除非指定了绕行；新服务器像出站一样使用拨号器，相当于默认使用空的直连出站。
-    * 旧服务器使用 `address_resolver` 和 `address_strategy` 来解析服务器中的域名；新服务器改用 [拨号字段](/zh/configuration/shared/dial/) 中的 `domain_resolver` 和 `domain_strategy`。
-
 ### 字段
 
 #### server
@@ -58,14 +55,14 @@ DNS 服务器的路径。
 
 默认使用 `/dns-query`。
 
-#### headers
+#### method
 
-发送到 DNS 服务器的额外标头。
+HTTP 请求方法。
 
-#### tls
+可用值：`GET`、`POST`。
 
-TLS 配置，参阅 [TLS](/zh/configuration/shared/tls/#出站)。
+默认使用 `POST`。
 
-### 拨号字段
+### HTTP 客户端字段
 
-参阅 [拨号字段](/zh/configuration/shared/dial/) 了解详情。
+参阅 [HTTP 客户端字段](/zh/configuration/shared/http-client/) 了解详情。

docs/configuration/dns/server/https.md

@@ -2,6 +2,10 @@
 icon: material/new-box
 ---
 
+!!! quote "Changes in sing-box 1.14.0"
+
+    :material-alert: `headers`, `tls`, Dial Fields moved to [HTTP Client Fields](#http-client-fields)
+
 !!! question "Since sing-box 1.12.0"
 
 # DNS over HTTPS (DoH)
@@ -15,27 +19,20 @@ icon: material/new-box
       {
         "type": "https",
         "tag": "",
-        
+
         "server": "",
-        "server_port": 443,
+        "server_port": 0,
-        
+
         "path": "",
-        "headers": {},
+        "method": "",
-        
+
-        "tls": {},
+        ... // HTTP Client Fields
-        
-        // Dial Fields
       }
     ]
   }
 }
 ```
 
-!!! info "Difference from legacy HTTPS server"
-
-    * The old server uses default outbound by default unless detour is specified; the new one uses dialer just like outbound, which is equivalent to using an empty direct outbound by default.
-    * The old server uses `address_resolver` and `address_strategy` to resolve the domain name in the server; the new one uses `domain_resolver` and `domain_strategy` in [Dial Fields](/configuration/shared/dial/) instead.
-
 ### Fields
 
 #### server
@@ -58,14 +55,14 @@ The path of the DNS server.
 
 `/dns-query` will be used by default.
 
-#### headers
+#### method
 
-Additional headers to be sent to the DNS server.
+HTTP request method.
 
-#### tls
+Available values: `GET`, `POST`.
 
-TLS configuration, see [TLS](/configuration/shared/tls/#outbound).
+`POST` will be used by default.
 
-### Dial Fields
+### HTTP Client Fields
 
-See [Dial Fields](/configuration/shared/dial/) for details.
+See [HTTP Client Fields](/configuration/shared/http-client/) for details.

docs/configuration/dns/server/https.zh.md

@@ -2,6 +2,10 @@
 icon: material/new-box
 ---
 
+!!! quote "sing-box 1.14.0 中的更改"
+
+    :material-alert: `headers`、`tls`、拨号字段已移至 [HTTP 客户端字段](#http-客户端字段)
+
 !!! question "自 sing-box 1.12.0 起"
 
 # DNS over HTTPS (DoH)
@@ -17,25 +21,18 @@ icon: material/new-box
         "tag": "",
 
         "server": "",
-        "server_port": 443,
+        "server_port": 0,
 
         "path": "",
-        "headers": {},
+        "method": "",
 
-        "tls": {},
+        ... // HTTP 客户端字段
-
-        // 拨号字段
       }
     ]
   }
 }
 ```
 
-!!! info "与旧版 HTTPS 服务器的区别"
-
-    * 旧服务器默认使用默认出站，除非指定了绕行；新服务器像出站一样使用拨号器，相当于默认使用空的直连出站。
-    * 旧服务器使用 `address_resolver` 和 `address_strategy` 来解析服务器中的域名；新服务器改用 [拨号字段](/zh/configuration/shared/dial/) 中的 `domain_resolver` 和 `domain_strategy`。
-
 ### 字段
 
 #### server
@@ -58,14 +55,14 @@ DNS 服务器的路径。
 
 默认使用 `/dns-query`。
 
-#### headers
+#### method
 
-发送到 DNS 服务器的额外标头。
+HTTP 请求方法。
 
-#### tls
+可用值：`GET`、`POST`。
 
-TLS 配置，参阅 [TLS](/zh/configuration/shared/tls/#出站)。
+默认使用 `POST`。
 
-### 拨号字段
+### HTTP 客户端字段
 
-参阅 [拨号字段](/zh/configuration/shared/dial/) 了解详情。
+参阅 [HTTP 客户端字段](/zh/configuration/shared/http-client/) 了解详情。

docs/configuration/endpoint/tailscale.md

@@ -2,6 +2,11 @@
 icon: material/new-box
 ---
 
+!!! quote "Changes in sing-box 1.14.0"
+
+    :material-plus: [control_http_client](#control_http_client)  
+    :material-delete-clock: [Dial Fields](#dial-fields)
+
 !!! quote "Changes in sing-box 1.13.0"
 
     :material-plus: [relay_server_port](#relay_server_port)  
@@ -22,6 +27,7 @@ icon: material/new-box
   "state_directory": "",
   "auth_key": "",
   "control_url": "",
+  "control_http_client": {}, // or ""
   "ephemeral": false,
   "hostname": "",
   "accept_routes": false,
@@ -148,10 +154,18 @@ UDP NAT expiration time.
 
 `5m` will be used by default.
 
+#### control_http_client
+
+!!! question "Since sing-box 1.14.0"
+
+HTTP Client for connecting to the Tailscale control plane.
+
+See [HTTP Client Fields](/configuration/shared/http-client/) for details.
+
 ### Dial Fields
 
-!!! note
+!!! failure "Deprecated in sing-box 1.14.0"
 
-    Dial Fields in Tailscale endpoints only control how it connects to the control plane and have nothing to do with actual connections.
+    Dial Fields in Tailscale endpoints are deprecated in sing-box 1.14.0 and will be removed in sing-box 1.16.0, use `control_http_client` instead.
 
 See [Dial Fields](/configuration/shared/dial/) for details.

docs/configuration/endpoint/tailscale.zh.md

@@ -2,6 +2,11 @@
 icon: material/new-box
 ---
 
+!!! quote "sing-box 1.14.0 中的更改"
+
+    :material-plus: [control_http_client](#control_http_client)  
+    :material-delete-clock: [拨号字段](#拨号字段)
+
 !!! quote "sing-box 1.13.0 中的更改"
 
     :material-plus: [relay_server_port](#relay_server_port)  
@@ -22,6 +27,7 @@ icon: material/new-box
   "state_directory": "",
   "auth_key": "",
   "control_url": "",
+  "control_http_client": {}, // 或 ""
   "ephemeral": false,
   "hostname": "",
   "accept_routes": false,
@@ -147,10 +153,18 @@ UDP NAT 过期时间。
 
 默认使用 `5m`。
 
+#### control_http_client
+
+!!! question "自 sing-box 1.14.0 起"
+
+用于连接 Tailscale 控制平面的 HTTP 客户端。
+
+参阅 [HTTP 客户端字段](/zh/configuration/shared/http-client/) 了解详情。
+
 ### 拨号字段
 
-!!! note
+!!! failure "已在 sing-box 1.14.0 废弃"
 
-    Tailscale 端点中的拨号字段仅控制它如何连接到控制平面，与实际连接无关。
+    Tailscale 端点中的拨号字段已在 sing-box 1.14.0 废弃且将在 sing-box 1.16.0 中被移除，请使用 `control_http_client` 代替。
 
 参阅 [拨号字段](/zh/configuration/shared/dial/) 了解详情。

docs/configuration/experimental/cache-file.md

@@ -1,5 +1,10 @@
 !!! question "Since sing-box 1.8.0"
 
+!!! quote "Changes in sing-box 1.14.0"
+
+    :material-delete-clock: [store_rdrc](#store_rdrc)  
+    :material-plus: [store_dns](#store_dns)
+
 !!! quote "Changes in sing-box 1.9.0"
 
     :material-plus: [store_rdrc](#store_rdrc)  
@@ -14,7 +19,8 @@
   "cache_id": "",
   "store_fakeip": false,
   "store_rdrc": false,
-  "rdrc_timeout": ""
+  "rdrc_timeout": "",
+  "store_dns": false
 }
 ```
 
@@ -42,6 +48,10 @@ Store fakeip in the cache file
 
 #### store_rdrc
 
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    `store_rdrc` is deprecated and will be removed in sing-box 1.16.0, check [Migration](/migration/#migrate-store-rdrc).
+
 Store rejected DNS response cache in the cache file
 
 The check results of [Legacy Address Filter Fields](/configuration/dns/rule/#legacy-address-filter-fields)
@@ -52,3 +62,9 @@ will be cached until expiration.
 Timeout of rejected DNS response cache.
 
 `7d` is used by default.
+
+#### store_dns
+
+!!! question "Since sing-box 1.14.0"
+
+Store DNS cache in the cache file.

docs/configuration/experimental/cache-file.zh.md

@@ -1,5 +1,10 @@
 !!! question "自 sing-box 1.8.0 起"
 
+!!! quote "sing-box 1.14.0 中的更改"
+
+    :material-delete-clock: [store_rdrc](#store_rdrc)  
+    :material-plus: [store_dns](#store_dns)
+
 !!! quote "sing-box 1.9.0 中的更改"
 
     :material-plus: [store_rdrc](#store_rdrc)  
@@ -14,7 +19,8 @@
   "cache_id": "",
   "store_fakeip": false,
   "store_rdrc": false,
-  "rdrc_timeout": ""
+  "rdrc_timeout": "",
+  "store_dns": false
 }
 ```
 
@@ -40,6 +46,10 @@
 
 #### store_rdrc
 
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    `store_rdrc` 已在 sing-box 1.14.0 废弃，且将在 sing-box 1.16.0 中被移除，参阅[迁移指南](/zh/migration/#迁移-store_rdrc)。
+
 将拒绝的 DNS 响应缓存存储在缓存文件中。
 
 [旧版地址筛选字段](/zh/configuration/dns/rule/#旧版地址筛选字段) 的检查结果将被缓存至过期。
@@ -49,3 +59,9 @@
 拒绝的 DNS 响应缓存超时。
 
 默认使用 `7d`。
+
+#### store_dns
+
+!!! question "自 sing-box 1.14.0 起"
+
+将 DNS 缓存存储在缓存文件中。

docs/configuration/inbound/hysteria.md

@@ -21,11 +21,16 @@
     }
   ],
   
+  "tls": {},
+
+  ... // QUIC Fields
+
+  // Deprecated
+
   "recv_window_conn": 0,
   "recv_window_client": 0,
   "max_conn_client": 0,
-  "disable_mtu_discovery": false,
+  "disable_mtu_discovery": false
-  "tls": {}
 }
 ```
 
@@ -76,32 +81,38 @@ Authentication password, in base64.
 
 Authentication password.
 
-#### recv_window_conn
-
-The QUIC stream-level flow control window for receiving data.
-
-`15728640 (15 MB/s)` will be used if empty.
-
-#### recv_window_client
-
-The QUIC connection-level flow control window for receiving data.
-
-`67108864 (64 MB/s)` will be used if empty.
-
-#### max_conn_client
-
-The maximum number of QUIC concurrent bidirectional streams that a peer is allowed to open.
-
-`1024` will be used if empty.
-
-#### disable_mtu_discovery
-
-Disables Path MTU Discovery (RFC 8899). Packets will then be at most 1252 (IPv4) / 1232 (IPv6) bytes in size.
-
-Force enabled on for systems other than Linux and Windows (according to upstream).
-
 #### tls
 
 ==Required==
 
-TLS configuration, see [TLS](/configuration/shared/tls/#inbound).
+TLS configuration, see [TLS](/configuration/shared/tls/#inbound).
+
+### QUIC Fields
+
+See [QUIC Fields](/configuration/shared/quic/) for details.
+
+### Deprecated Fields
+
+#### recv_window_conn
+
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    Use QUIC fields `stream_receive_window` instead.
+
+#### recv_window_client
+
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    Use QUIC fields `connection_receive_window` instead.
+
+#### max_conn_client
+
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    Use QUIC fields `max_concurrent_streams` instead.
+
+#### disable_mtu_discovery
+
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    Use QUIC fields `disable_path_mtu_discovery` instead.

docs/configuration/inbound/hysteria.zh.md

@@ -21,11 +21,16 @@
     }
   ],
 
+  "tls": {},
+
+  ... // QUIC 字段
+
+  // 废弃的
+
   "recv_window_conn": 0,
   "recv_window_client": 0,
   "max_conn_client": 0,
-  "disable_mtu_discovery": false,
+  "disable_mtu_discovery": false
-  "tls": {}
 }
 ```
 
@@ -76,32 +81,38 @@ base64 编码的认证密码。
 
 认证密码。
 
-#### recv_window_conn
-
-用于接收数据的 QUIC 流级流控制窗口。
-
-默认 `15728640 (15 MB/s)`。
-
-#### recv_window_client
-
-用于接收数据的 QUIC 连接级流控制窗口。
-
-默认 `67108864 (64 MB/s)`。
-
-#### max_conn_client
-
-允许对等点打开的 QUIC 并发双向流的最大数量。
-
-默认 `1024`。
-
-#### disable_mtu_discovery
-
-禁用路径 MTU 发现 (RFC 8899)。 数据包的大小最多为 1252 (IPv4) / 1232 (IPv6) 字节。
-
-强制为 Linux 和 Windows 以外的系统启用（根据上游）。
-
 #### tls
 
 ==必填==
 
-TLS 配置, 参阅 [TLS](/zh/configuration/shared/tls/#入站)。
+TLS 配置, 参阅 [TLS](/zh/configuration/shared/tls/#入站)。
+
+### QUIC 字段
+
+参阅 [QUIC 字段](/zh/configuration/shared/quic/) 了解详情。
+
+### 废弃字段
+
+#### recv_window_conn
+
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    请使用 QUIC 字段 `stream_receive_window` 代替。
+
+#### recv_window_client
+
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    请使用 QUIC 字段 `connection_receive_window` 代替。
+
+#### max_conn_client
+
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    请使用 QUIC 字段 `max_concurrent_streams` 代替。
+
+#### disable_mtu_discovery
+
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    请使用 QUIC 字段 `disable_path_mtu_discovery` 代替。

docs/configuration/inbound/hysteria2.md

@@ -34,6 +34,9 @@ icon: material/alert-decagram
   ],
   "ignore_client_bandwidth": false,
   "tls": {},
+
+  ... // QUIC Fields
+
   "masquerade": "", // or {}
   "bbr_profile": "",
   "brutal_debug": false
@@ -95,6 +98,10 @@ Deny clients to use the BBR CC.
 
 TLS configuration, see [TLS](/configuration/shared/tls/#inbound).
 
+### QUIC Fields
+
+See [QUIC Fields](/configuration/shared/quic/) for details.
+
 #### masquerade
 
 HTTP3 server behavior (URL string configuration) when authentication fails.

docs/configuration/inbound/hysteria2.zh.md

@@ -34,6 +34,9 @@ icon: material/alert-decagram
   ],
   "ignore_client_bandwidth": false,
   "tls": {},
+
+  ... // QUIC 字段
+
   "masquerade": "", // 或 {}
   "bbr_profile": "",
   "brutal_debug": false
@@ -92,6 +95,10 @@ Hysteria 用户
 
 TLS 配置, 参阅 [TLS](/zh/configuration/shared/tls/#入站)。
 
+### QUIC 字段
+
+参阅 [QUIC 字段](/zh/configuration/shared/quic/) 了解详情。
+
 #### masquerade
 
 HTTP3 服务器认证失败时的行为 （URL 字符串配置）。

docs/configuration/inbound/tuic.md

@@ -18,7 +18,9 @@
   "auth_timeout": "3s",
   "zero_rtt_handshake": false,
   "heartbeat": "10s",
-  "tls": {}
+  "tls": {},
+
+  ... // QUIC Fields
 }
 ```
 
@@ -75,4 +77,8 @@ Interval for sending heartbeat packets for keeping the connection alive
 
 ==Required==
 
-TLS configuration, see [TLS](/configuration/shared/tls/#inbound).
+TLS configuration, see [TLS](/configuration/shared/tls/#inbound).
+
+### QUIC Fields
+
+See [QUIC Fields](/configuration/shared/quic/) for details.

docs/configuration/inbound/tuic.zh.md

@@ -18,7 +18,9 @@
   "auth_timeout": "3s",
   "zero_rtt_handshake": false,
   "heartbeat": "10s",
-  "tls": {}
+  "tls": {},
+
+  ... // QUIC 字段
 }
 ```
 
@@ -75,4 +77,8 @@ QUIC 拥塞控制算法
 
 ==必填==
 
-TLS 配置, 参阅 [TLS](/zh/configuration/shared/tls/#入站)。
+TLS 配置, 参阅 [TLS](/zh/configuration/shared/tls/#入站)。
+
+### QUIC 字段
+
+参阅 [QUIC 字段](/zh/configuration/shared/quic/) 了解详情。

docs/configuration/index.md

@@ -10,6 +10,7 @@ sing-box uses JSON for configuration files.
   "ntp": {},
   "certificate": {},
   "certificate_providers": [],
+  "http_clients": [],
   "endpoints": [],
   "inbounds": [],
   "outbounds": [],
@@ -28,6 +29,7 @@ sing-box uses JSON for configuration files.
 | `ntp`          | [NTP](./ntp/)                   |
 | `certificate`  | [Certificate](./certificate/)   |
 | `certificate_providers` | [Certificate Provider](./shared/certificate-provider/) |
+| `http_clients` | [HTTP Client](./shared/http-client/) |
 | `endpoints`    | [Endpoint](./endpoint/)         |
 | `inbounds`     | [Inbound](./inbound/)           |
 | `outbounds`    | [Outbound](./outbound/)         |

docs/configuration/index.zh.md

@@ -10,6 +10,7 @@ sing-box 使用 JSON 作为配置文件格式。
   "ntp": {},
   "certificate": {},
   "certificate_providers": [],
+  "http_clients": [],
   "endpoints": [],
   "inbounds": [],
   "outbounds": [],
@@ -28,6 +29,7 @@ sing-box 使用 JSON 作为配置文件格式。
 | `ntp`          | [NTP](./ntp/)          |
 | `certificate`  | [证书](./certificate/)   |
 | `certificate_providers` | [证书提供者](./shared/certificate-provider/) |
+| `http_clients` | [HTTP 客户端](./shared/http-client/) |
 | `endpoints`    | [端点](./endpoint/)      |
 | `inbounds`     | [入站](./inbound/)       |
 | `outbounds`    | [出站](./outbound/)      |

docs/configuration/outbound/hysteria.md

@@ -27,13 +27,18 @@ icon: material/new-box
   "obfs": "fuck me till the daylight",
   "auth": "",
   "auth_str": "password",
+  "network": "",
+  "tls": {},
+
+  ... // QUIC Fields
+
+  ... // Dial Fields
+
+  // Deprecated
+
   "recv_window_conn": 0,
   "recv_window": 0,
-  "disable_mtu_discovery": false,
+  "disable_mtu_discovery": false
-  "network": "tcp",
-  "tls": {},
-  
-  ... // Dial Fields
 }
 ```
 
@@ -104,24 +109,6 @@ Authentication password, in base64.
 
 Authentication password.
 
-#### recv_window_conn
-
-The QUIC stream-level flow control window for receiving data.
-
-`15728640 (15 MB/s)` will be used if empty.
-
-#### recv_window
-
-The QUIC connection-level flow control window for receiving data.
-
-`67108864 (64 MB/s)` will be used if empty.
-
-#### disable_mtu_discovery
-
-Disables Path MTU Discovery (RFC 8899). Packets will then be at most 1252 (IPv4) / 1232 (IPv6) bytes in size.
-
-Force enabled on for systems other than Linux and Windows (according to upstream).
-
 #### network
 
 Enabled network
@@ -136,6 +123,30 @@ Both is enabled by default.
 
 TLS configuration, see [TLS](/configuration/shared/tls/#outbound).
 
+### QUIC Fields
+
+See [QUIC Fields](/configuration/shared/quic/) for details.
+
 ### Dial Fields
 
 See [Dial Fields](/configuration/shared/dial/) for details.
+
+### Deprecated Fields
+
+#### recv_window_conn
+
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    Use QUIC fields `stream_receive_window` instead.
+
+#### recv_window
+
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    Use QUIC fields `connection_receive_window` instead.
+
+#### disable_mtu_discovery
+
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    Use QUIC fields `disable_path_mtu_discovery` instead.

docs/configuration/outbound/hysteria.zh.md

@@ -27,13 +27,18 @@ icon: material/new-box
   "obfs": "fuck me till the daylight",
   "auth": "",
   "auth_str": "password",
+  "network": "",
+  "tls": {},
+
+  ... // QUIC 字段
+
+  ... // 拨号字段
+
+  // 废弃的
+
   "recv_window_conn": 0,
   "recv_window": 0,
-  "disable_mtu_discovery": false,
+  "disable_mtu_discovery": false
-  "network": "tcp",
-  "tls": {},
-  
-  ... // 拨号字段
 }
 ```
 
@@ -104,24 +109,6 @@ base64 编码的认证密码。
 
 认证密码。
 
-#### recv_window_conn
-
-用于接收数据的 QUIC 流级流控制窗口。
-
-默认 `15728640 (15 MB/s)`。
-
-#### recv_window
-
-用于接收数据的 QUIC 连接级流控制窗口。
-
-默认 `67108864 (64 MB/s)`。
-
-#### disable_mtu_discovery
-
-禁用路径 MTU 发现 (RFC 8899)。 数据包的大小最多为 1252 (IPv4) / 1232 (IPv6) 字节。
-
-强制为 Linux 和 Windows 以外的系统启用（根据上游）。
-
 #### network
 
 启用的网络协议。
@@ -136,7 +123,30 @@ base64 编码的认证密码。
 
 TLS 配置, 参阅 [TLS](/zh/configuration/shared/tls/#出站)。
 
+### QUIC 字段
+
+参阅 [QUIC 字段](/zh/configuration/shared/quic/) 了解详情。
 
 ### 拨号字段
 
 参阅 [拨号字段](/zh/configuration/shared/dial/)。
+
+### 废弃字段
+
+#### recv_window_conn
+
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    请使用 QUIC 字段 `stream_receive_window` 代替。
+
+#### recv_window
+
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    请使用 QUIC 字段 `connection_receive_window` 代替。
+
+#### disable_mtu_discovery
+
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    请使用 QUIC 字段 `disable_path_mtu_discovery` 代替。

docs/configuration/outbound/hysteria2.md

@@ -31,6 +31,9 @@
   "password": "goofy_ahh_password",
   "network": "tcp",
   "tls": {},
+
+  ... // QUIC Fields
+
   "bbr_profile": "",
   "brutal_debug": false,
 
@@ -124,6 +127,10 @@ Both is enabled by default.
 
 TLS configuration, see [TLS](/configuration/shared/tls/#outbound).
 
+### QUIC Fields
+
+See [QUIC Fields](/configuration/shared/quic/) for details.
+
 #### bbr_profile
 
 !!! question "Since sing-box 1.14.0"

docs/configuration/outbound/hysteria2.zh.md

@@ -31,6 +31,9 @@
   "password": "goofy_ahh_password",
   "network": "tcp",
   "tls": {},
+
+  ... // QUIC 字段
+
   "bbr_profile": "",
   "brutal_debug": false,
 
@@ -122,6 +125,10 @@ QUIC 流量混淆器密码.
 
 TLS 配置, 参阅 [TLS](/zh/configuration/shared/tls/#出站)。
 
+### QUIC 字段
+
+参阅 [QUIC 字段](/zh/configuration/shared/quic/) 了解详情。
+
 #### bbr_profile
 
 !!! question "自 sing-box 1.14.0 起"

docs/configuration/outbound/tuic.md

@@ -16,7 +16,9 @@
   "heartbeat": "10s",
   "network": "tcp",
   "tls": {},
-  
+
+  ... // QUIC Fields
+
   ... // Dial Fields
 }
 ```
@@ -91,6 +93,10 @@ Both is enabled by default.
 
 TLS configuration, see [TLS](/configuration/shared/tls/#outbound).
 
+### QUIC Fields
+
+See [QUIC Fields](/configuration/shared/quic/) for details.
+
 ### Dial Fields
 
 See [Dial Fields](/configuration/shared/dial/) for details.

docs/configuration/outbound/tuic.zh.md

@@ -16,7 +16,9 @@
   "heartbeat": "10s",
   "network": "tcp",
   "tls": {},
-  
+
+  ... // QUIC 字段
+
   ... // 拨号字段
 }
 ```
@@ -99,6 +101,10 @@ UDP 包中继模式
 
 TLS 配置, 参阅 [TLS](/zh/configuration/shared/tls/#出站)。
 
+### QUIC 字段
+
+参阅 [QUIC 字段](/zh/configuration/shared/quic/) 了解详情。
+
 ### 拨号字段
 
 参阅 [拨号字段](/zh/configuration/shared/dial/)。

docs/configuration/route/index.md

@@ -6,6 +6,7 @@ icon: material/alert-decagram
 
 !!! quote "Changes in sing-box 1.14.0"
 
+    :material-plus: [default_http_client](#default_http_client)  
     :material-plus: [find_neighbor](#find_neighbor)  
     :material-plus: [dhcp_lease_files](#dhcp_lease_files)
 
@@ -43,6 +44,7 @@ icon: material/alert-decagram
     "find_process": false,
     "find_neighbor": false,
     "dhcp_lease_files": [],
+    "default_http_client": "",
     "default_domain_resolver": "", // or {}
     "default_network_strategy": "",
     "default_network_type": [],
@@ -147,6 +149,14 @@ Custom DHCP lease file paths for hostname and MAC address resolution.
 
 Automatically detected from common DHCP servers (dnsmasq, odhcpd, ISC dhcpd, Kea) if empty.
 
+#### default_http_client
+
+!!! question "Since sing-box 1.14.0"
+
+Tag of the default [HTTP Client](/configuration/shared/http-client/) used by remote rule-sets.
+
+If empty and `http_clients` is defined, the first HTTP client is used.
+
 #### default_domain_resolver
 
 !!! question "Since sing-box 1.12.0"

docs/configuration/route/index.zh.md

@@ -6,6 +6,7 @@ icon: material/alert-decagram
 
 !!! quote "sing-box 1.14.0 中的更改"
 
+    :material-plus: [default_http_client](#default_http_client)  
     :material-plus: [find_neighbor](#find_neighbor)  
     :material-plus: [dhcp_lease_files](#dhcp_lease_files)
 
@@ -45,6 +46,7 @@ icon: material/alert-decagram
     "find_process": false,
     "find_neighbor": false,
     "dhcp_lease_files": [],
+    "default_http_client": "",
     "default_network_strategy": "",
     "default_fallback_delay": ""
   }
@@ -146,6 +148,14 @@ icon: material/alert-decagram
 
 为空时自动从常见 DHCP 服务器（dnsmasq、odhcpd、ISC dhcpd、Kea）检测。
 
+#### default_http_client
+
+!!! question "自 sing-box 1.14.0 起"
+
+远程规则集使用的默认 [HTTP 客户端](/zh/configuration/shared/http-client/) 的标签。
+
+如果为空且 `http_clients` 已定义，将使用第一个 HTTP 客户端。
+
 #### default_domain_resolver
 
 !!! question "自 sing-box 1.12.0 起"

docs/configuration/route/rule_action.md

@@ -7,6 +7,10 @@ icon: material/new-box
     :material-plus: [bypass](#bypass)  
     :material-alert: [reject](#reject)
 
+!!! quote "Changes in sing-box 1.14.0"
+
+    :material-plus: [resolve.disable_optimistic_cache](#disable_optimistic_cache)
+
 !!! quote "Changes in sing-box 1.12.0"
 
     :material-plus: [tls_fragment](#tls_fragment)  
@@ -279,6 +283,7 @@ Timeout for sniffing.
   "server": "",
   "strategy": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -302,6 +307,12 @@ DNS resolution strategy, available values are: `prefer_ipv4`, `prefer_ipv6`, `ip
 
 Disable cache and save cache in this query.
 
+#### disable_optimistic_cache
+
+!!! question "Since sing-box 1.14.0"
+
+Disable optimistic DNS caching in this query.
+
 #### rewrite_ttl
 
 !!! question "Since sing-box 1.12.0"

docs/configuration/route/rule_action.zh.md

@@ -7,6 +7,10 @@ icon: material/new-box
     :material-plus: [bypass](#bypass)  
     :material-alert: [reject](#reject)
 
+!!! quote "sing-box 1.14.0 中的更改"
+
+    :material-plus: [resolve.disable_optimistic_cache](#disable_optimistic_cache)
+
 !!! quote "sing-box 1.12.0 中的更改"
 
     :material-plus: [tls_fragment](#tls_fragment)  
@@ -268,6 +272,7 @@ UDP 连接超时时间。
   "server": "",
   "strategy": "",
   "disable_cache": false,
+  "disable_optimistic_cache": false,
   "rewrite_ttl": null,
   "client_subnet": null
 }
@@ -291,6 +296,12 @@ DNS 解析策略，可用值有：`prefer_ipv4`、`prefer_ipv6`、`ipv4_only`、
 
 在此查询中禁用缓存。
 
+#### disable_optimistic_cache
+
+!!! question "自 sing-box 1.14.0 起"
+
+在此查询中禁用乐观 DNS 缓存。
+
 #### rewrite_ttl
 
 !!! question "自 sing-box 1.12.0 起"

docs/configuration/rule-set/index.md

@@ -1,3 +1,8 @@
+!!! quote "Changes in sing-box 1.14.0"
+
+    :material-plus: [http_client](#http_client)  
+    :material-delete-clock: [download_detour](#download_detour)
+
 !!! quote "Changes in sing-box 1.10.0"
 
     :material-plus: `type: inline`
@@ -43,8 +48,12 @@
       "tag": "",
       "format": "source", // or binary
       "url": "",
-      "download_detour": "", // optional
+      "http_client": "", // or {}
-      "update_interval": "" // optional
+      "update_interval": "",
+
+      // Deprecated
+
+      "download_detour": ""
     }
     ```
 
@@ -102,14 +111,26 @@ File path of rule-set.
 
 Download URL of rule-set.
 
-#### download_detour
+#### http_client
 
-Tag of the outbound to download rule-set.
+!!! question "Since sing-box 1.14.0"
 
-Default outbound will be used if empty.
+HTTP Client for downloading rule-set.
+
+See [HTTP Client Fields](/configuration/shared/http-client/) for details.
+
+Default transport will be used if empty.
 
 #### update_interval
 
 Update interval of rule-set.
 
 `1d` will be used if empty.
+
+#### download_detour
+
+!!! failure "Deprecated in sing-box 1.14.0"
+
+    `download_detour` is deprecated in sing-box 1.14.0 and will be removed in sing-box 1.16.0, use `http_client` instead.
+
+Tag of the outbound to download rule-set.

docs/configuration/rule-set/index.zh.md

@@ -1,3 +1,8 @@
+!!! quote "sing-box 1.14.0 中的更改"
+
+    :material-plus: [http_client](#http_client)  
+    :material-delete-clock: [download_detour](#download_detour)
+
 !!! quote "sing-box 1.10.0 中的更改"
 
     :material-plus: `type: inline`
@@ -43,8 +48,12 @@
       "tag": "",
       "format": "source", // or binary
       "url": "",
-      "download_detour": "", // 可选
+      "http_client": "", // 或 {}
-      "update_interval": "" // 可选
+      "update_interval": "",
+
+      // 废弃的
+
+      "download_detour": ""
     }
     ```
 
@@ -102,14 +111,26 @@
 
 规则集的下载 URL。
 
-#### download_detour
+#### http_client
 
-用于下载规则集的出站的标签。
+!!! question "自 sing-box 1.14.0 起"
 
-如果为空，将使用默认出站。
+用于下载规则集的 HTTP 客户端。
+
+参阅 [HTTP 客户端字段](/zh/configuration/shared/http-client/) 了解详情。
+
+如果为空，将使用默认传输。
 
 #### update_interval
 
 规则集的更新间隔。
 
 默认使用 `1d`。
+
+#### download_detour
+
+!!! failure "已在 sing-box 1.14.0 废弃"
+
+    `download_detour` 已在 sing-box 1.14.0 废弃且将在 sing-box 1.16.0 中被移除，请使用 `http_client` 代替。
+
+用于下载规则集的出站的标签。

docs/configuration/service/derp.md

@@ -58,9 +58,9 @@ Object format:
 
 ```json
 {
-  "url": "https://my-headscale.com/verify",
+  "url": "",
-  
+
-  ... // Dial Fields
+  ... // HTTP Client Fields
 }
 ```
 

docs/configuration/service/derp.zh.md

@@ -58,9 +58,9 @@ Derper 配置文件路径。
 
 ```json
 {
-  "url": "https://my-headscale.com/verify",
+  "url": "",
 
-  ... // 拨号字段
+  ... // HTTP 客户端字段
 }
 ```
 

docs/configuration/shared/certificate-provider/acme.md

@@ -6,7 +6,7 @@ icon: material/new-box
 
     :material-plus: [account_key](#account_key)  
     :material-plus: [key_type](#key_type)  
-    :material-plus: [detour](#detour)
+    :material-plus: [http_client](#http_client)
 
 # ACME
 
@@ -37,7 +37,7 @@ icon: material/new-box
   },
   "dns01_challenge": {},
   "key_type": "",
-  "detour": ""
+  "http_client": "" // or {}
 }
 ```
 
@@ -141,10 +141,10 @@ The private key type to generate for new certificates.
 | `rsa2048`  | RSA     |
 | `rsa4096`  | RSA     |
 
-#### detour
+#### http_client
 
 !!! question "Since sing-box 1.14.0"
 
-The tag of the upstream outbound.
+HTTP Client for all provider HTTP requests.
 
-All provider HTTP requests will use this outbound.
+See [HTTP Client Fields](/configuration/shared/http-client/) for details.

docs/configuration/shared/certificate-provider/acme.zh.md

@@ -6,7 +6,7 @@ icon: material/new-box
 
     :material-plus: [account_key](#account_key)  
     :material-plus: [key_type](#key_type)  
-    :material-plus: [detour](#detour)
+    :material-plus: [http_client](#http_client)
 
 # ACME
 
@@ -37,7 +37,7 @@ icon: material/new-box
   },
   "dns01_challenge": {},
   "key_type": "",
-  "detour": ""
+  "http_client": "" // 或 {}
 }
 ```
 
@@ -136,10 +136,12 @@ ACME DNS01 质询字段。如果配置，将禁用其他质询方法。
 | `rsa2048` | RSA     |
 | `rsa4096` | RSA     |
 
-#### detour
+#### http_client
 
 !!! question "自 sing-box 1.14.0 起"
 
-上游出站的标签。
+用于所有提供者 HTTP 请求的 HTTP 客户端。
+
+参阅 [HTTP 客户端字段](/zh/configuration/shared/http-client/) 了解详情。
 
 所有提供者 HTTP 请求将使用此出站。

docs/configuration/shared/certificate-provider/cloudflare-origin-ca.md

@@ -19,7 +19,7 @@ icon: material/new-box
   "origin_ca_key": "",
   "request_type": "",
   "requested_validity": 0,
-  "detour": ""
+  "http_client": "" // or {}
 }
 ```
 
@@ -75,8 +75,8 @@ Available values: `7`, `30`, `90`, `365`, `730`, `1095`, `5475`.
 
 `5475` days (15 years) is used if empty.
 
-#### detour
+#### http_client
 
-The tag of the upstream outbound.
+HTTP Client for all provider HTTP requests.
 
-All provider HTTP requests will use this outbound.
+See [HTTP Client Fields](/configuration/shared/http-client/) for details.

docs/configuration/shared/certificate-provider/cloudflare-origin-ca.zh.md

@@ -19,7 +19,7 @@ icon: material/new-box
   "origin_ca_key": "",
   "request_type": "",
   "requested_validity": 0,
-  "detour": ""
+  "http_client": "" // 或 {}
 }
 ```
 
@@ -75,8 +75,8 @@ Cloudflare Origin CA Key。
 
 如果为空，使用 `5475` 天（15 年）。
 
-#### detour
+#### http_client
 
-上游出站的标签。
+用于所有提供者 HTTP 请求的 HTTP 客户端。
 
-所有提供者 HTTP 请求将使用此出站。
+参阅 [HTTP 客户端字段](/zh/configuration/shared/http-client/) 了解详情。

docs/configuration/shared/http-client.md

@@ -0,0 +1,114 @@
+---
+icon: material/new-box
+---
+
+!!! question "Since sing-box 1.14.0"
+
+### Structure
+
+A string or an object.
+
+When string, the tag of a shared [HTTP Client](/configuration/shared/http-client/) defined in top-level `http_clients`.
+
+When object:
+
+```json
+{
+  "engine": "",
+  "version": 0,
+  "disable_version_fallback": false,
+  "headers": {},
+
+  ... // HTTP2 Fields
+
+  "tls": {},
+
+  ... // Dial Fields
+}
+```
+
+### Fields
+
+#### engine
+
+HTTP engine to use.
+
+Values:
+
+* `go` (default)
+* `apple`
+
+`apple` uses NSURLSession, only available on Apple platforms.
+
+!!! warning ""
+
+    Experimental only: due to the high memory overhead of both CGO and Network.framework,
+    do not use in hot paths on iOS and tvOS.
+
+Supported fields:
+
+* `headers`
+* `tls.server_name` (must match request host)
+* `tls.insecure`
+* `tls.min_version` / `tls.max_version`
+* `tls.certificate` / `tls.certificate_path`
+* `tls.certificate_public_key_sha256`
+* Dial Fields
+
+Unsupported fields:
+
+* `version`
+* `disable_version_fallback`
+* HTTP2 Fields
+* QUIC Fields
+* `tls.engine`
+* `tls.alpn`
+* `tls.disable_sni`
+* `tls.cipher_suites`
+* `tls.curve_preferences`
+* `tls.client_certificate` / `tls.client_certificate_path` / `tls.client_key` / `tls.client_key_path`
+* `tls.fragment` / `tls.record_fragment`
+* `tls.kernel_tx` / `tls.kernel_rx`
+* `tls.ech`
+* `tls.utls`
+* `tls.reality`
+
+#### version
+
+HTTP version.
+
+Available values: `1`, `2`, `3`.
+
+`2` is used by default.
+
+When `3`, [HTTP2 Fields](#http2-fields) are replaced by [QUIC Fields](#quic-fields).
+
+#### disable_version_fallback
+
+Disable automatic fallback to lower HTTP version.
+
+#### headers
+
+Custom HTTP headers.
+
+`Host` header is used as request host.
+
+### HTTP2 Fields
+
+When `version` is `2` (default).
+
+See [HTTP2 Fields](/configuration/shared/http2/) for details.
+
+### QUIC Fields
+
+When `version` is `3`.
+
+See [QUIC Fields](/configuration/shared/quic/) for details.
+
+### TLS Fields
+
+See [TLS](/configuration/shared/tls/#outbound) for details.
+
+### Dial Fields
+
+See [Dial Fields](/configuration/shared/dial/) for details.

docs/configuration/shared/http-client.zh.md

@@ -0,0 +1,114 @@
+---
+icon: material/new-box
+---
+
+!!! question "自 sing-box 1.14.0 起"
+
+### 结构
+
+字符串或对象。
+
+当为字符串时，为顶层 `http_clients` 中定义的共享 [HTTP 客户端](/zh/configuration/shared/http-client/) 的标签。
+
+当为对象时：
+
+```json
+{
+  "engine": "",
+  "version": 0,
+  "disable_version_fallback": false,
+  "headers": {},
+
+  ... // HTTP2 字段
+
+  "tls": {},
+
+  ... // 拨号字段
+}
+```
+
+### 字段
+
+#### engine
+
+要使用的 HTTP 引擎。
+
+可用值：
+
+* `go`（默认）
+* `apple`
+
+`apple` 使用 NSURLSession，仅在 Apple 平台可用。
+
+!!! warning ""
+
+    仅供实验用途：由于 CGO 和 Network.framework 占用的内存都很多，
+    不应在 iOS 和 tvOS 的热路径中使用。
+
+支持的字段：
+
+* `headers`
+* `tls.server_name`（必须与请求主机匹配）
+* `tls.insecure`
+* `tls.min_version` / `tls.max_version`
+* `tls.certificate` / `tls.certificate_path`
+* `tls.certificate_public_key_sha256`
+* 拨号字段
+
+不支持的字段：
+
+* `version`
+* `disable_version_fallback`
+* HTTP2 字段
+* QUIC 字段
+* `tls.engine`
+* `tls.alpn`
+* `tls.disable_sni`
+* `tls.cipher_suites`
+* `tls.curve_preferences`
+* `tls.client_certificate` / `tls.client_certificate_path` / `tls.client_key` / `tls.client_key_path`
+* `tls.fragment` / `tls.record_fragment`
+* `tls.kernel_tx` / `tls.kernel_rx`
+* `tls.ech`
+* `tls.utls`
+* `tls.reality`
+
+#### version
+
+HTTP 版本。
+
+可用值：`1`、`2`、`3`。
+
+默认使用 `2`。
+
+当为 `3` 时，[HTTP2 字段](#http2-字段) 替换为 [QUIC 字段](#quic-字段)。
+
+#### disable_version_fallback
+
+禁用自动回退到更低的 HTTP 版本。
+
+#### headers
+
+自定义 HTTP 标头。
+
+`Host` 标头用作请求主机。
+
+### HTTP2 字段
+
+当 `version` 为 `2`（默认）时。
+
+参阅 [HTTP2 字段](/zh/configuration/shared/http2/) 了解详情。
+
+### QUIC 字段
+
+当 `version` 为 `3` 时。
+
+参阅 [QUIC 字段](/zh/configuration/shared/quic/) 了解详情。
+
+### TLS 字段
+
+参阅 [TLS](/zh/configuration/shared/tls/#出站) 了解详情。
+
+### 拨号字段
+
+参阅 [拨号字段](/zh/configuration/shared/dial/) 了解详情。

docs/configuration/shared/http2.md

@@ -0,0 +1,43 @@
+---
+icon: material/new-box
+---
+
+!!! question "Since sing-box 1.14.0"
+
+### Structure
+
+```json
+{
+  "idle_timeout": "",
+  "keep_alive_period": "",
+  "stream_receive_window": "",
+  "connection_receive_window": "",
+  "max_concurrent_streams": 0
+}
+```
+
+### Fields
+
+#### idle_timeout
+
+Idle connection timeout, in golang's Duration format.
+
+#### keep_alive_period
+
+Keep alive period, in golang's Duration format.
+
+#### stream_receive_window
+
+HTTP2 stream-level flow-control receive window size.
+
+Accepts memory size format, e.g. `"64 MB"`.
+
+#### connection_receive_window
+
+HTTP2 connection-level flow-control receive window size.
+
+Accepts memory size format, e.g. `"64 MB"`.
+
+#### max_concurrent_streams
+
+Maximum concurrent streams per connection.

docs/configuration/shared/http2.zh.md

@@ -0,0 +1,43 @@
+---
+icon: material/new-box
+---
+
+!!! question "自 sing-box 1.14.0 起"
+
+### 结构
+
+```json
+{
+  "idle_timeout": "",
+  "keep_alive_period": "",
+  "stream_receive_window": "",
+  "connection_receive_window": "",
+  "max_concurrent_streams": 0
+}
+```
+
+### 字段
+
+#### idle_timeout
+
+空闲连接超时，采用 golang 的 Duration 格式。
+
+#### keep_alive_period
+
+Keep alive 周期，采用 golang 的 Duration 格式。
+
+#### stream_receive_window
+
+HTTP2 流级别流控接收窗口大小。
+
+接受内存大小格式，例如 `"64 MB"`。
+
+#### connection_receive_window
+
+HTTP2 连接级别流控接收窗口大小。
+
+接受内存大小格式，例如 `"64 MB"`。
+
+#### max_concurrent_streams
+
+每个连接的最大并发流数。

docs/configuration/shared/quic.md

@@ -0,0 +1,30 @@
+---
+icon: material/new-box
+---
+
+!!! question "Since sing-box 1.14.0"
+
+### Structure
+
+```json
+{
+  "initial_packet_size": 0,
+  "disable_path_mtu_discovery": false,
+
+  ... // HTTP2 Fields
+}
+```
+
+### Fields
+
+#### initial_packet_size
+
+Initial QUIC packet size.
+
+#### disable_path_mtu_discovery
+
+Disable QUIC path MTU discovery.
+
+### HTTP2 Fields
+
+See [HTTP2 Fields](/configuration/shared/http2/) for details.

docs/configuration/shared/quic.zh.md

@@ -0,0 +1,30 @@
+---
+icon: material/new-box
+---
+
+!!! question "自 sing-box 1.14.0 起"
+
+### 结构
+
+```json
+{
+  "initial_packet_size": 0,
+  "disable_path_mtu_discovery": false,
+
+  ... // HTTP2 字段
+}
+```
+
+### 字段
+
+#### initial_packet_size
+
+初始 QUIC 数据包大小。
+
+#### disable_path_mtu_discovery
+
+禁用 QUIC 路径 MTU 发现。
+
+### HTTP2 字段
+
+参阅 [HTTP2 字段](/zh/configuration/shared/http2/) 了解详情。