Merge pull request #553 from XTLS/tls/reject-unknown-sni

Add: reject unknown SNI

infra/conf/transport_internet.go

@@ -322,6 +322,7 @@ type TLSConfig struct {
 	CipherSuites             string           `json:"cipherSuites"`
 	PreferServerCipherSuites bool             `json:"preferServerCipherSuites"`
 	Fingerprint              string           `json:"fingerprint"`
+	RejectUnknownSNI         bool             `json:"rejectUnknownSni"`
 }
 
 // Build implements Buildable.
@@ -350,6 +351,7 @@ func (c *TLSConfig) Build() (proto.Message, error) {
 	config.CipherSuites = c.CipherSuites
 	config.PreferServerCipherSuites = c.PreferServerCipherSuites
 	config.Fingerprint = strings.ToLower(c.Fingerprint)
+	config.RejectUnknownSni = c.RejectUnknownSNI
 	return config, nil
 }
 
@@ -413,6 +415,7 @@ type XTLSConfig struct {
 	MaxVersion               string            `json:"maxVersion"`
 	CipherSuites             string            `json:"cipherSuites"`
 	PreferServerCipherSuites bool              `json:"preferServerCipherSuites"`
+	RejectUnknownSNI         bool              `json:"rejectUnknownSni"`
 }
 
 // Build implements Buildable.
@@ -440,6 +443,7 @@ func (c *XTLSConfig) Build() (proto.Message, error) {
 	config.MaxVersion = c.MaxVersion
 	config.CipherSuites = c.CipherSuites
 	config.PreferServerCipherSuites = c.PreferServerCipherSuites
+	config.RejectUnknownSni = c.RejectUnknownSNI
 	return config, nil
 }
 

transport/internet/tls/config.go

@@ -211,13 +211,13 @@ func getGetCertificateFunc(c *tls.Config, ca []*Certificate) func(hello *tls.Cli
 	}
 }
 
-func getNewGetCertficateFunc(certs []*tls.Certificate) func(hello *tls.ClientHelloInfo) (*tls.Certificate, error) {
+func getNewGetCertificateFunc(certs []*tls.Certificate, rejectUnknownSNI bool) func(hello *tls.ClientHelloInfo) (*tls.Certificate, error) {
 	return func(hello *tls.ClientHelloInfo) (*tls.Certificate, error) {
 		if len(certs) == 0 {
-			return nil, newError("empty certs")
+			return nil, errNoCertificates
 		}
 		sni := strings.ToLower(hello.ServerName)
-		if len(certs) == 1 || sni == "" {
+		if !rejectUnknownSNI && (len(certs) == 1 || sni == "") {
 			return certs[0], nil
 		}
 		gsni := "*"
@@ -234,6 +234,9 @@ func getNewGetCertficateFunc(certs []*tls.Certificate) func(hello *tls.ClientHel
 				}
 			}
 		}
+		if rejectUnknownSNI {
+			return nil, errNoCertificates
+		}
 		return certs[0], nil
 	}
 }
@@ -275,7 +278,7 @@ func (c *Config) GetTLSConfig(opts ...Option) *tls.Config {
 	if len(caCerts) > 0 {
 		config.GetCertificate = getGetCertificateFunc(config, caCerts)
 	} else {
-		config.GetCertificate = getNewGetCertficateFunc(c.BuildCertificates())
+		config.GetCertificate = getNewGetCertificateFunc(c.BuildCertificates(), c.RejectUnknownSni)
 	}
 
 	if sn := c.parseServerName(); len(sn) > 0 {

transport/internet/tls/config.pb.go

@@ -1,7 +1,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.25.0
-// 	protoc        v3.15.6
+// 	protoc        v3.15.8
 // source: transport/internet/tls/config.proto
 
 package tls
@@ -201,7 +201,8 @@ type Config struct {
 	// Whether the server selects its most preferred ciphersuite.
 	PreferServerCipherSuites bool `protobuf:"varint,10,opt,name=prefer_server_cipher_suites,json=preferServerCipherSuites,proto3" json:"prefer_server_cipher_suites,omitempty"`
 	// TLS Client Hello fingerprint (uTLS).
-	Fingerprint string `protobuf:"bytes,11,opt,name=fingerprint,proto3" json:"fingerprint,omitempty"`
+	Fingerprint      string `protobuf:"bytes,11,opt,name=fingerprint,proto3" json:"fingerprint,omitempty"`
+	RejectUnknownSni bool   `protobuf:"varint,12,opt,name=reject_unknown_sni,json=rejectUnknownSni,proto3" json:"reject_unknown_sni,omitempty"`
 }
 
 func (x *Config) Reset() {
@@ -313,6 +314,13 @@ func (x *Config) GetFingerprint() string {
 	return ""
 }
 
+func (x *Config) GetRejectUnknownSni() bool {
+	if x != nil {
+		return x.RejectUnknownSni
+	}
+	return false
+}
+
 var File_transport_internet_tls_config_proto protoreflect.FileDescriptor
 
 var file_transport_internet_tls_config_proto_rawDesc = []byte{
@@ -342,7 +350,7 @@ var file_transport_internet_tls_config_proto_rawDesc = []byte{
 	0x43, 0x49, 0x50, 0x48, 0x45, 0x52, 0x4d, 0x45, 0x4e, 0x54, 0x10, 0x00, 0x12, 0x14, 0x0a, 0x10,
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@@ -373,15 +381,18 @@ var file_transport_internet_tls_config_proto_rawDesc = []byte{
 	0x01, 0x28, 0x08, 0x52, 0x18, 0x70, 0x72, 0x65, 0x66, 0x65, 0x72, 0x53, 0x65, 0x72, 0x76, 0x65,
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 }
 
 var (

transport/internet/tls/config.proto

@@ -67,4 +67,6 @@ message Config {
 
   // TLS Client Hello fingerprint (uTLS).
   string fingerprint = 11;
+
+  bool reject_unknown_sni = 12;
 }

transport/internet/tls/unsafe.go

@@ -0,0 +1,6 @@
+package tls
+
+import _ "unsafe"
+
+//go:linkname errNoCertificates crypto/tls.errNoCertificates
+var errNoCertificates error

transport/internet/xtls/config.go

@@ -212,13 +212,13 @@ func getGetCertificateFunc(c *xtls.Config, ca []*Certificate) func(hello *xtls.C
 	}
 }
 
-func getNewGetCertficateFunc(certs []*xtls.Certificate) func(hello *xtls.ClientHelloInfo) (*xtls.Certificate, error) {
+func getNewGetCertificateFunc(certs []*xtls.Certificate, rejectUnknownSNI bool) func(hello *xtls.ClientHelloInfo) (*xtls.Certificate, error) {
 	return func(hello *xtls.ClientHelloInfo) (*xtls.Certificate, error) {
 		if len(certs) == 0 {
-			return nil, newError("empty certs")
+			return nil, errNoCertificates
 		}
 		sni := strings.ToLower(hello.ServerName)
-		if len(certs) == 1 || sni == "" {
+		if !rejectUnknownSNI && (len(certs) == 1 || sni == "") {
 			return certs[0], nil
 		}
 		gsni := "*"
@@ -235,6 +235,9 @@ func getNewGetCertficateFunc(certs []*xtls.Certificate) func(hello *xtls.ClientH
 				}
 			}
 		}
+		if rejectUnknownSNI {
+			return nil, errNoCertificates
+		}
 		return certs[0], nil
 	}
 }
@@ -276,7 +279,7 @@ func (c *Config) GetXTLSConfig(opts ...Option) *xtls.Config {
 	if len(caCerts) > 0 {
 		config.GetCertificate = getGetCertificateFunc(config, caCerts)
 	} else {
-		config.GetCertificate = getNewGetCertficateFunc(c.BuildCertificates())
+		config.GetCertificate = getNewGetCertificateFunc(c.BuildCertificates(), c.RejectUnknownSni)
 	}
 
 	if sn := c.parseServerName(); len(sn) > 0 {

transport/internet/xtls/config.pb.go

@@ -1,7 +1,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.25.0
-// 	protoc        v3.14.0
+// 	protoc        v3.15.8
 // source: transport/internet/xtls/config.proto
 
 package xtls
@@ -200,6 +200,7 @@ type Config struct {
 	CipherSuites string `protobuf:"bytes,9,opt,name=cipher_suites,json=cipherSuites,proto3" json:"cipher_suites,omitempty"`
 	// Whether the server selects its most preferred ciphersuite.
 	PreferServerCipherSuites bool `protobuf:"varint,10,opt,name=prefer_server_cipher_suites,json=preferServerCipherSuites,proto3" json:"prefer_server_cipher_suites,omitempty"`
+	RejectUnknownSni         bool `protobuf:"varint,12,opt,name=reject_unknown_sni,json=rejectUnknownSni,proto3" json:"reject_unknown_sni,omitempty"`
 }
 
 func (x *Config) Reset() {
@@ -304,6 +305,13 @@ func (x *Config) GetPreferServerCipherSuites() bool {
 	return false
 }
 
+func (x *Config) GetRejectUnknownSni() bool {
+	if x != nil {
+		return x.RejectUnknownSni
+	}
+	return false
+}
+
 var File_transport_internet_xtls_config_proto protoreflect.FileDescriptor
 
 var file_transport_internet_xtls_config_proto_rawDesc = []byte{
@@ -333,7 +341,7 @@ var file_transport_internet_xtls_config_proto_rawDesc = []byte{
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@@ -363,15 +371,17 @@ var file_transport_internet_xtls_config_proto_rawDesc = []byte{
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 }
 
 var (

transport/internet/xtls/config.proto

@@ -64,4 +64,7 @@ message Config {
 
   // Whether the server selects its most preferred ciphersuite.
   bool prefer_server_cipher_suites = 10;
+
+
+  bool reject_unknown_sni = 12;
 }

transport/internet/xtls/unsafe.go

@@ -0,0 +1,6 @@
+package xtls
+
+import _ "unsafe"
+
+//go:linkname errNoCertificates github.com/xtls/go.errNoCertificates
+var errNoCertificates error