// Copyright 2009 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package qtls import ( "errors" "fmt" "strings" "golang.org/x/crypto/cryptobyte" ) // The marshalingFunction type is an adapter to allow the use of ordinary // functions as cryptobyte.MarshalingValue. type marshalingFunction func(b *cryptobyte.Builder) error func (f marshalingFunction) Marshal(b *cryptobyte.Builder) error { return f(b) } // addBytesWithLength appends a sequence of bytes to the cryptobyte.Builder. If // the length of the sequence is not the value specified, it produces an error. func addBytesWithLength(b *cryptobyte.Builder, v []byte, n int) { b.AddValue(marshalingFunction(func(b *cryptobyte.Builder) error { if len(v) != n { return fmt.Errorf("invalid value length: expected %d, got %d", n, len(v)) } b.AddBytes(v) return nil })) } // addUint64 appends a big-endian, 64-bit value to the cryptobyte.Builder. func addUint64(b *cryptobyte.Builder, v uint64) { b.AddUint32(uint32(v >> 32)) b.AddUint32(uint32(v)) } // readUint64 decodes a big-endian, 64-bit value into out and advances over it. // It reports whether the read was successful. func readUint64(s *cryptobyte.String, out *uint64) bool { var hi, lo uint32 if !s.ReadUint32(&hi) || !s.ReadUint32(&lo) { return false } *out = uint64(hi)<<32 | uint64(lo) return true } // readUint8LengthPrefixed acts like s.ReadUint8LengthPrefixed, but targets a // []byte instead of a cryptobyte.String. func readUint8LengthPrefixed(s *cryptobyte.String, out *[]byte) bool { return s.ReadUint8LengthPrefixed((*cryptobyte.String)(out)) } // readUint16LengthPrefixed acts like s.ReadUint16LengthPrefixed, but targets a // []byte instead of a cryptobyte.String. func readUint16LengthPrefixed(s *cryptobyte.String, out *[]byte) bool { return s.ReadUint16LengthPrefixed((*cryptobyte.String)(out)) } // readUint24LengthPrefixed acts like s.ReadUint24LengthPrefixed, but targets a // []byte instead of a cryptobyte.String. func readUint24LengthPrefixed(s *cryptobyte.String, out *[]byte) bool { return s.ReadUint24LengthPrefixed((*cryptobyte.String)(out)) } type clientHelloMsg struct { raw []byte vers uint16 random []byte sessionId []byte cipherSuites []uint16 compressionMethods []uint8 serverName string ocspStapling bool supportedCurves []CurveID supportedPoints []uint8 ticketSupported bool sessionTicket []uint8 supportedSignatureAlgorithms []SignatureScheme supportedSignatureAlgorithmsCert []SignatureScheme secureRenegotiationSupported bool secureRenegotiation []byte alpnProtocols []string scts bool supportedVersions []uint16 cookie []byte keyShares []keyShare earlyData bool pskModes []uint8 pskIdentities []pskIdentity pskBinders [][]byte additionalExtensions []Extension } func (m *clientHelloMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } var exts cryptobyte.Builder if len(m.serverName) > 0 { // RFC 6066, Section 3 exts.AddUint16(extensionServerName) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint8(0) // name_type = host_name exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes([]byte(m.serverName)) }) }) }) } if m.ocspStapling { // RFC 4366, Section 3.6 exts.AddUint16(extensionStatusRequest) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint8(1) // status_type = ocsp exts.AddUint16(0) // empty responder_id_list exts.AddUint16(0) // empty request_extensions }) } if len(m.supportedCurves) > 0 { // RFC 4492, sections 5.1.1 and RFC 8446, Section 4.2.7 exts.AddUint16(extensionSupportedCurves) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { for _, curve := range m.supportedCurves { exts.AddUint16(uint16(curve)) } }) }) } if len(m.supportedPoints) > 0 { // RFC 4492, Section 5.1.2 exts.AddUint16(extensionSupportedPoints) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint8LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(m.supportedPoints) }) }) } if m.ticketSupported { // RFC 5077, Section 3.2 exts.AddUint16(extensionSessionTicket) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(m.sessionTicket) }) } if len(m.supportedSignatureAlgorithms) > 0 { // RFC 5246, Section 7.4.1.4.1 exts.AddUint16(extensionSignatureAlgorithms) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { for _, sigAlgo := range m.supportedSignatureAlgorithms { exts.AddUint16(uint16(sigAlgo)) } }) }) } if len(m.supportedSignatureAlgorithmsCert) > 0 { // RFC 8446, Section 4.2.3 exts.AddUint16(extensionSignatureAlgorithmsCert) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { for _, sigAlgo := range m.supportedSignatureAlgorithmsCert { exts.AddUint16(uint16(sigAlgo)) } }) }) } if m.secureRenegotiationSupported { // RFC 5746, Section 3.2 exts.AddUint16(extensionRenegotiationInfo) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint8LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(m.secureRenegotiation) }) }) } if len(m.alpnProtocols) > 0 { // RFC 7301, Section 3.1 exts.AddUint16(extensionALPN) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { for _, proto := range m.alpnProtocols { exts.AddUint8LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes([]byte(proto)) }) } }) }) } if m.scts { // RFC 6962, Section 3.3.1 exts.AddUint16(extensionSCT) exts.AddUint16(0) // empty extension_data } if len(m.supportedVersions) > 0 { // RFC 8446, Section 4.2.1 exts.AddUint16(extensionSupportedVersions) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint8LengthPrefixed(func(exts *cryptobyte.Builder) { for _, vers := range m.supportedVersions { exts.AddUint16(vers) } }) }) } if len(m.cookie) > 0 { // RFC 8446, Section 4.2.2 exts.AddUint16(extensionCookie) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(m.cookie) }) }) } if len(m.keyShares) > 0 { // RFC 8446, Section 4.2.8 exts.AddUint16(extensionKeyShare) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { for _, ks := range m.keyShares { exts.AddUint16(uint16(ks.group)) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(ks.data) }) } }) }) } if m.earlyData { // RFC 8446, Section 4.2.10 exts.AddUint16(extensionEarlyData) exts.AddUint16(0) // empty extension_data } if len(m.pskModes) > 0 { // RFC 8446, Section 4.2.9 exts.AddUint16(extensionPSKModes) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint8LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(m.pskModes) }) }) } for _, ext := range m.additionalExtensions { exts.AddUint16(ext.Type) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(ext.Data) }) } if len(m.pskIdentities) > 0 { // pre_shared_key must be the last extension // RFC 8446, Section 4.2.11 exts.AddUint16(extensionPreSharedKey) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { for _, psk := range m.pskIdentities { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(psk.label) }) exts.AddUint32(psk.obfuscatedTicketAge) } }) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { for _, binder := range m.pskBinders { exts.AddUint8LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(binder) }) } }) }) } extBytes, err := exts.Bytes() if err != nil { return nil, err } var b cryptobyte.Builder b.AddUint8(typeClientHello) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint16(m.vers) addBytesWithLength(b, m.random, 32) b.AddUint8LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(m.sessionId) }) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { for _, suite := range m.cipherSuites { b.AddUint16(suite) } }) b.AddUint8LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(m.compressionMethods) }) if len(extBytes) > 0 { b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(extBytes) }) } }) m.raw, err = b.Bytes() return m.raw, err } // marshalWithoutBinders returns the ClientHello through the // PreSharedKeyExtension.identities field, according to RFC 8446, Section // 4.2.11.2. Note that m.pskBinders must be set to slices of the correct length. func (m *clientHelloMsg) marshalWithoutBinders() ([]byte, error) { bindersLen := 2 // uint16 length prefix for _, binder := range m.pskBinders { bindersLen += 1 // uint8 length prefix bindersLen += len(binder) } fullMessage, err := m.marshal() if err != nil { return nil, err } return fullMessage[:len(fullMessage)-bindersLen], nil } // updateBinders updates the m.pskBinders field, if necessary updating the // cached marshaled representation. The supplied binders must have the same // length as the current m.pskBinders. func (m *clientHelloMsg) updateBinders(pskBinders [][]byte) error { if len(pskBinders) != len(m.pskBinders) { return errors.New("tls: internal error: pskBinders length mismatch") } for i := range m.pskBinders { if len(pskBinders[i]) != len(m.pskBinders[i]) { return errors.New("tls: internal error: pskBinders length mismatch") } } m.pskBinders = pskBinders if m.raw != nil { helloBytes, err := m.marshalWithoutBinders() if err != nil { return err } lenWithoutBinders := len(helloBytes) b := cryptobyte.NewFixedBuilder(m.raw[:lenWithoutBinders]) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { for _, binder := range m.pskBinders { b.AddUint8LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(binder) }) } }) if out, err := b.Bytes(); err != nil || len(out) != len(m.raw) { return errors.New("tls: internal error: failed to update binders") } } return nil } func (m *clientHelloMsg) unmarshal(data []byte) bool { *m = clientHelloMsg{raw: data} s := cryptobyte.String(data) if !s.Skip(4) || // message type and uint24 length field !s.ReadUint16(&m.vers) || !s.ReadBytes(&m.random, 32) || !readUint8LengthPrefixed(&s, &m.sessionId) { return false } var cipherSuites cryptobyte.String if !s.ReadUint16LengthPrefixed(&cipherSuites) { return false } m.cipherSuites = []uint16{} m.secureRenegotiationSupported = false for !cipherSuites.Empty() { var suite uint16 if !cipherSuites.ReadUint16(&suite) { return false } if suite == scsvRenegotiation { m.secureRenegotiationSupported = true } m.cipherSuites = append(m.cipherSuites, suite) } if !readUint8LengthPrefixed(&s, &m.compressionMethods) { return false } if s.Empty() { // ClientHello is optionally followed by extension data return true } var extensions cryptobyte.String if !s.ReadUint16LengthPrefixed(&extensions) || !s.Empty() { return false } seenExts := make(map[uint16]bool) for !extensions.Empty() { var extension uint16 var extData cryptobyte.String if !extensions.ReadUint16(&extension) || !extensions.ReadUint16LengthPrefixed(&extData) { return false } if seenExts[extension] { return false } seenExts[extension] = true switch extension { case extensionServerName: // RFC 6066, Section 3 var nameList cryptobyte.String if !extData.ReadUint16LengthPrefixed(&nameList) || nameList.Empty() { return false } for !nameList.Empty() { var nameType uint8 var serverName cryptobyte.String if !nameList.ReadUint8(&nameType) || !nameList.ReadUint16LengthPrefixed(&serverName) || serverName.Empty() { return false } if nameType != 0 { continue } if len(m.serverName) != 0 { // Multiple names of the same name_type are prohibited. return false } m.serverName = string(serverName) // An SNI value may not include a trailing dot. if strings.HasSuffix(m.serverName, ".") { return false } } case extensionStatusRequest: // RFC 4366, Section 3.6 var statusType uint8 var ignored cryptobyte.String if !extData.ReadUint8(&statusType) || !extData.ReadUint16LengthPrefixed(&ignored) || !extData.ReadUint16LengthPrefixed(&ignored) { return false } m.ocspStapling = statusType == statusTypeOCSP case extensionSupportedCurves: // RFC 4492, sections 5.1.1 and RFC 8446, Section 4.2.7 var curves cryptobyte.String if !extData.ReadUint16LengthPrefixed(&curves) || curves.Empty() { return false } for !curves.Empty() { var curve uint16 if !curves.ReadUint16(&curve) { return false } m.supportedCurves = append(m.supportedCurves, CurveID(curve)) } case extensionSupportedPoints: // RFC 4492, Section 5.1.2 if !readUint8LengthPrefixed(&extData, &m.supportedPoints) || len(m.supportedPoints) == 0 { return false } case extensionSessionTicket: // RFC 5077, Section 3.2 m.ticketSupported = true extData.ReadBytes(&m.sessionTicket, len(extData)) case extensionSignatureAlgorithms: // RFC 5246, Section 7.4.1.4.1 var sigAndAlgs cryptobyte.String if !extData.ReadUint16LengthPrefixed(&sigAndAlgs) || sigAndAlgs.Empty() { return false } for !sigAndAlgs.Empty() { var sigAndAlg uint16 if !sigAndAlgs.ReadUint16(&sigAndAlg) { return false } m.supportedSignatureAlgorithms = append( m.supportedSignatureAlgorithms, SignatureScheme(sigAndAlg)) } case extensionSignatureAlgorithmsCert: // RFC 8446, Section 4.2.3 var sigAndAlgs cryptobyte.String if !extData.ReadUint16LengthPrefixed(&sigAndAlgs) || sigAndAlgs.Empty() { return false } for !sigAndAlgs.Empty() { var sigAndAlg uint16 if !sigAndAlgs.ReadUint16(&sigAndAlg) { return false } m.supportedSignatureAlgorithmsCert = append( m.supportedSignatureAlgorithmsCert, SignatureScheme(sigAndAlg)) } case extensionRenegotiationInfo: // RFC 5746, Section 3.2 if !readUint8LengthPrefixed(&extData, &m.secureRenegotiation) { return false } m.secureRenegotiationSupported = true case extensionALPN: // RFC 7301, Section 3.1 var protoList cryptobyte.String if !extData.ReadUint16LengthPrefixed(&protoList) || protoList.Empty() { return false } for !protoList.Empty() { var proto cryptobyte.String if !protoList.ReadUint8LengthPrefixed(&proto) || proto.Empty() { return false } m.alpnProtocols = append(m.alpnProtocols, string(proto)) } case extensionSCT: // RFC 6962, Section 3.3.1 m.scts = true case extensionSupportedVersions: // RFC 8446, Section 4.2.1 var versList cryptobyte.String if !extData.ReadUint8LengthPrefixed(&versList) || versList.Empty() { return false } for !versList.Empty() { var vers uint16 if !versList.ReadUint16(&vers) { return false } m.supportedVersions = append(m.supportedVersions, vers) } case extensionCookie: // RFC 8446, Section 4.2.2 if !readUint16LengthPrefixed(&extData, &m.cookie) || len(m.cookie) == 0 { return false } case extensionKeyShare: // RFC 8446, Section 4.2.8 var clientShares cryptobyte.String if !extData.ReadUint16LengthPrefixed(&clientShares) { return false } for !clientShares.Empty() { var ks keyShare if !clientShares.ReadUint16((*uint16)(&ks.group)) || !readUint16LengthPrefixed(&clientShares, &ks.data) || len(ks.data) == 0 { return false } m.keyShares = append(m.keyShares, ks) } case extensionEarlyData: // RFC 8446, Section 4.2.10 m.earlyData = true case extensionPSKModes: // RFC 8446, Section 4.2.9 if !readUint8LengthPrefixed(&extData, &m.pskModes) { return false } case extensionPreSharedKey: // RFC 8446, Section 4.2.11 if !extensions.Empty() { return false // pre_shared_key must be the last extension } var identities cryptobyte.String if !extData.ReadUint16LengthPrefixed(&identities) || identities.Empty() { return false } for !identities.Empty() { var psk pskIdentity if !readUint16LengthPrefixed(&identities, &psk.label) || !identities.ReadUint32(&psk.obfuscatedTicketAge) || len(psk.label) == 0 { return false } m.pskIdentities = append(m.pskIdentities, psk) } var binders cryptobyte.String if !extData.ReadUint16LengthPrefixed(&binders) || binders.Empty() { return false } for !binders.Empty() { var binder []byte if !readUint8LengthPrefixed(&binders, &binder) || len(binder) == 0 { return false } m.pskBinders = append(m.pskBinders, binder) } default: m.additionalExtensions = append(m.additionalExtensions, Extension{Type: extension, Data: extData}) continue } if !extData.Empty() { return false } } return true } type serverHelloMsg struct { raw []byte vers uint16 random []byte sessionId []byte cipherSuite uint16 compressionMethod uint8 ocspStapling bool ticketSupported bool secureRenegotiationSupported bool secureRenegotiation []byte alpnProtocol string scts [][]byte supportedVersion uint16 serverShare keyShare selectedIdentityPresent bool selectedIdentity uint16 supportedPoints []uint8 // HelloRetryRequest extensions cookie []byte selectedGroup CurveID } func (m *serverHelloMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } var exts cryptobyte.Builder if m.ocspStapling { exts.AddUint16(extensionStatusRequest) exts.AddUint16(0) // empty extension_data } if m.ticketSupported { exts.AddUint16(extensionSessionTicket) exts.AddUint16(0) // empty extension_data } if m.secureRenegotiationSupported { exts.AddUint16(extensionRenegotiationInfo) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint8LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(m.secureRenegotiation) }) }) } if len(m.alpnProtocol) > 0 { exts.AddUint16(extensionALPN) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint8LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes([]byte(m.alpnProtocol)) }) }) }) } if len(m.scts) > 0 { exts.AddUint16(extensionSCT) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { for _, sct := range m.scts { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(sct) }) } }) }) } if m.supportedVersion != 0 { exts.AddUint16(extensionSupportedVersions) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16(m.supportedVersion) }) } if m.serverShare.group != 0 { exts.AddUint16(extensionKeyShare) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16(uint16(m.serverShare.group)) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(m.serverShare.data) }) }) } if m.selectedIdentityPresent { exts.AddUint16(extensionPreSharedKey) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16(m.selectedIdentity) }) } if len(m.cookie) > 0 { exts.AddUint16(extensionCookie) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(m.cookie) }) }) } if m.selectedGroup != 0 { exts.AddUint16(extensionKeyShare) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint16(uint16(m.selectedGroup)) }) } if len(m.supportedPoints) > 0 { exts.AddUint16(extensionSupportedPoints) exts.AddUint16LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddUint8LengthPrefixed(func(exts *cryptobyte.Builder) { exts.AddBytes(m.supportedPoints) }) }) } extBytes, err := exts.Bytes() if err != nil { return nil, err } var b cryptobyte.Builder b.AddUint8(typeServerHello) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint16(m.vers) addBytesWithLength(b, m.random, 32) b.AddUint8LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(m.sessionId) }) b.AddUint16(m.cipherSuite) b.AddUint8(m.compressionMethod) if len(extBytes) > 0 { b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(extBytes) }) } }) m.raw, err = b.Bytes() return m.raw, err } func (m *serverHelloMsg) unmarshal(data []byte) bool { *m = serverHelloMsg{raw: data} s := cryptobyte.String(data) if !s.Skip(4) || // message type and uint24 length field !s.ReadUint16(&m.vers) || !s.ReadBytes(&m.random, 32) || !readUint8LengthPrefixed(&s, &m.sessionId) || !s.ReadUint16(&m.cipherSuite) || !s.ReadUint8(&m.compressionMethod) { return false } if s.Empty() { // ServerHello is optionally followed by extension data return true } var extensions cryptobyte.String if !s.ReadUint16LengthPrefixed(&extensions) || !s.Empty() { return false } seenExts := make(map[uint16]bool) for !extensions.Empty() { var extension uint16 var extData cryptobyte.String if !extensions.ReadUint16(&extension) || !extensions.ReadUint16LengthPrefixed(&extData) { return false } if seenExts[extension] { return false } seenExts[extension] = true switch extension { case extensionStatusRequest: m.ocspStapling = true case extensionSessionTicket: m.ticketSupported = true case extensionRenegotiationInfo: if !readUint8LengthPrefixed(&extData, &m.secureRenegotiation) { return false } m.secureRenegotiationSupported = true case extensionALPN: var protoList cryptobyte.String if !extData.ReadUint16LengthPrefixed(&protoList) || protoList.Empty() { return false } var proto cryptobyte.String if !protoList.ReadUint8LengthPrefixed(&proto) || proto.Empty() || !protoList.Empty() { return false } m.alpnProtocol = string(proto) case extensionSCT: var sctList cryptobyte.String if !extData.ReadUint16LengthPrefixed(&sctList) || sctList.Empty() { return false } for !sctList.Empty() { var sct []byte if !readUint16LengthPrefixed(&sctList, &sct) || len(sct) == 0 { return false } m.scts = append(m.scts, sct) } case extensionSupportedVersions: if !extData.ReadUint16(&m.supportedVersion) { return false } case extensionCookie: if !readUint16LengthPrefixed(&extData, &m.cookie) || len(m.cookie) == 0 { return false } case extensionKeyShare: // This extension has different formats in SH and HRR, accept either // and let the handshake logic decide. See RFC 8446, Section 4.2.8. if len(extData) == 2 { if !extData.ReadUint16((*uint16)(&m.selectedGroup)) { return false } } else { if !extData.ReadUint16((*uint16)(&m.serverShare.group)) || !readUint16LengthPrefixed(&extData, &m.serverShare.data) { return false } } case extensionPreSharedKey: m.selectedIdentityPresent = true if !extData.ReadUint16(&m.selectedIdentity) { return false } case extensionSupportedPoints: // RFC 4492, Section 5.1.2 if !readUint8LengthPrefixed(&extData, &m.supportedPoints) || len(m.supportedPoints) == 0 { return false } default: // Ignore unknown extensions. continue } if !extData.Empty() { return false } } return true } type encryptedExtensionsMsg struct { raw []byte alpnProtocol string earlyData bool additionalExtensions []Extension } func (m *encryptedExtensionsMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } var b cryptobyte.Builder b.AddUint8(typeEncryptedExtensions) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { if len(m.alpnProtocol) > 0 { b.AddUint16(extensionALPN) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint8LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes([]byte(m.alpnProtocol)) }) }) }) } if m.earlyData { // RFC 8446, Section 4.2.10 b.AddUint16(extensionEarlyData) b.AddUint16(0) // empty extension_data } for _, ext := range m.additionalExtensions { b.AddUint16(ext.Type) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(ext.Data) }) } }) }) var err error m.raw, err = b.Bytes() return m.raw, err } func (m *encryptedExtensionsMsg) unmarshal(data []byte) bool { *m = encryptedExtensionsMsg{raw: data} s := cryptobyte.String(data) var extensions cryptobyte.String if !s.Skip(4) || // message type and uint24 length field !s.ReadUint16LengthPrefixed(&extensions) || !s.Empty() { return false } for !extensions.Empty() { var ext uint16 var extData cryptobyte.String if !extensions.ReadUint16(&ext) || !extensions.ReadUint16LengthPrefixed(&extData) { return false } switch ext { case extensionALPN: var protoList cryptobyte.String if !extData.ReadUint16LengthPrefixed(&protoList) || protoList.Empty() { return false } var proto cryptobyte.String if !protoList.ReadUint8LengthPrefixed(&proto) || proto.Empty() || !protoList.Empty() { return false } m.alpnProtocol = string(proto) case extensionEarlyData: m.earlyData = true default: m.additionalExtensions = append(m.additionalExtensions, Extension{Type: ext, Data: extData}) continue } if !extData.Empty() { return false } } return true } type endOfEarlyDataMsg struct{} func (m *endOfEarlyDataMsg) marshal() ([]byte, error) { x := make([]byte, 4) x[0] = typeEndOfEarlyData return x, nil } func (m *endOfEarlyDataMsg) unmarshal(data []byte) bool { return len(data) == 4 } type keyUpdateMsg struct { raw []byte updateRequested bool } func (m *keyUpdateMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } var b cryptobyte.Builder b.AddUint8(typeKeyUpdate) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { if m.updateRequested { b.AddUint8(1) } else { b.AddUint8(0) } }) var err error m.raw, err = b.Bytes() return m.raw, err } func (m *keyUpdateMsg) unmarshal(data []byte) bool { m.raw = data s := cryptobyte.String(data) var updateRequested uint8 if !s.Skip(4) || // message type and uint24 length field !s.ReadUint8(&updateRequested) || !s.Empty() { return false } switch updateRequested { case 0: m.updateRequested = false case 1: m.updateRequested = true default: return false } return true } type newSessionTicketMsgTLS13 struct { raw []byte lifetime uint32 ageAdd uint32 nonce []byte label []byte maxEarlyData uint32 } func (m *newSessionTicketMsgTLS13) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } var b cryptobyte.Builder b.AddUint8(typeNewSessionTicket) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint32(m.lifetime) b.AddUint32(m.ageAdd) b.AddUint8LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(m.nonce) }) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(m.label) }) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { if m.maxEarlyData > 0 { b.AddUint16(extensionEarlyData) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint32(m.maxEarlyData) }) } }) }) var err error m.raw, err = b.Bytes() return m.raw, err } func (m *newSessionTicketMsgTLS13) unmarshal(data []byte) bool { *m = newSessionTicketMsgTLS13{raw: data} s := cryptobyte.String(data) var extensions cryptobyte.String if !s.Skip(4) || // message type and uint24 length field !s.ReadUint32(&m.lifetime) || !s.ReadUint32(&m.ageAdd) || !readUint8LengthPrefixed(&s, &m.nonce) || !readUint16LengthPrefixed(&s, &m.label) || !s.ReadUint16LengthPrefixed(&extensions) || !s.Empty() { return false } for !extensions.Empty() { var extension uint16 var extData cryptobyte.String if !extensions.ReadUint16(&extension) || !extensions.ReadUint16LengthPrefixed(&extData) { return false } switch extension { case extensionEarlyData: if !extData.ReadUint32(&m.maxEarlyData) { return false } default: // Ignore unknown extensions. continue } if !extData.Empty() { return false } } return true } type certificateRequestMsgTLS13 struct { raw []byte ocspStapling bool scts bool supportedSignatureAlgorithms []SignatureScheme supportedSignatureAlgorithmsCert []SignatureScheme certificateAuthorities [][]byte } func (m *certificateRequestMsgTLS13) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } var b cryptobyte.Builder b.AddUint8(typeCertificateRequest) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { // certificate_request_context (SHALL be zero length unless used for // post-handshake authentication) b.AddUint8(0) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { if m.ocspStapling { b.AddUint16(extensionStatusRequest) b.AddUint16(0) // empty extension_data } if m.scts { // RFC 8446, Section 4.4.2.1 makes no mention of // signed_certificate_timestamp in CertificateRequest, but // "Extensions in the Certificate message from the client MUST // correspond to extensions in the CertificateRequest message // from the server." and it appears in the table in Section 4.2. b.AddUint16(extensionSCT) b.AddUint16(0) // empty extension_data } if len(m.supportedSignatureAlgorithms) > 0 { b.AddUint16(extensionSignatureAlgorithms) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { for _, sigAlgo := range m.supportedSignatureAlgorithms { b.AddUint16(uint16(sigAlgo)) } }) }) } if len(m.supportedSignatureAlgorithmsCert) > 0 { b.AddUint16(extensionSignatureAlgorithmsCert) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { for _, sigAlgo := range m.supportedSignatureAlgorithmsCert { b.AddUint16(uint16(sigAlgo)) } }) }) } if len(m.certificateAuthorities) > 0 { b.AddUint16(extensionCertificateAuthorities) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { for _, ca := range m.certificateAuthorities { b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(ca) }) } }) }) } }) }) var err error m.raw, err = b.Bytes() return m.raw, err } func (m *certificateRequestMsgTLS13) unmarshal(data []byte) bool { *m = certificateRequestMsgTLS13{raw: data} s := cryptobyte.String(data) var context, extensions cryptobyte.String if !s.Skip(4) || // message type and uint24 length field !s.ReadUint8LengthPrefixed(&context) || !context.Empty() || !s.ReadUint16LengthPrefixed(&extensions) || !s.Empty() { return false } for !extensions.Empty() { var extension uint16 var extData cryptobyte.String if !extensions.ReadUint16(&extension) || !extensions.ReadUint16LengthPrefixed(&extData) { return false } switch extension { case extensionStatusRequest: m.ocspStapling = true case extensionSCT: m.scts = true case extensionSignatureAlgorithms: var sigAndAlgs cryptobyte.String if !extData.ReadUint16LengthPrefixed(&sigAndAlgs) || sigAndAlgs.Empty() { return false } for !sigAndAlgs.Empty() { var sigAndAlg uint16 if !sigAndAlgs.ReadUint16(&sigAndAlg) { return false } m.supportedSignatureAlgorithms = append( m.supportedSignatureAlgorithms, SignatureScheme(sigAndAlg)) } case extensionSignatureAlgorithmsCert: var sigAndAlgs cryptobyte.String if !extData.ReadUint16LengthPrefixed(&sigAndAlgs) || sigAndAlgs.Empty() { return false } for !sigAndAlgs.Empty() { var sigAndAlg uint16 if !sigAndAlgs.ReadUint16(&sigAndAlg) { return false } m.supportedSignatureAlgorithmsCert = append( m.supportedSignatureAlgorithmsCert, SignatureScheme(sigAndAlg)) } case extensionCertificateAuthorities: var auths cryptobyte.String if !extData.ReadUint16LengthPrefixed(&auths) || auths.Empty() { return false } for !auths.Empty() { var ca []byte if !readUint16LengthPrefixed(&auths, &ca) || len(ca) == 0 { return false } m.certificateAuthorities = append(m.certificateAuthorities, ca) } default: // Ignore unknown extensions. continue } if !extData.Empty() { return false } } return true } type certificateMsg struct { raw []byte certificates [][]byte } func (m *certificateMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } var i int for _, slice := range m.certificates { i += len(slice) } length := 3 + 3*len(m.certificates) + i x := make([]byte, 4+length) x[0] = typeCertificate x[1] = uint8(length >> 16) x[2] = uint8(length >> 8) x[3] = uint8(length) certificateOctets := length - 3 x[4] = uint8(certificateOctets >> 16) x[5] = uint8(certificateOctets >> 8) x[6] = uint8(certificateOctets) y := x[7:] for _, slice := range m.certificates { y[0] = uint8(len(slice) >> 16) y[1] = uint8(len(slice) >> 8) y[2] = uint8(len(slice)) copy(y[3:], slice) y = y[3+len(slice):] } m.raw = x return m.raw, nil } func (m *certificateMsg) unmarshal(data []byte) bool { if len(data) < 7 { return false } m.raw = data certsLen := uint32(data[4])<<16 | uint32(data[5])<<8 | uint32(data[6]) if uint32(len(data)) != certsLen+7 { return false } numCerts := 0 d := data[7:] for certsLen > 0 { if len(d) < 4 { return false } certLen := uint32(d[0])<<16 | uint32(d[1])<<8 | uint32(d[2]) if uint32(len(d)) < 3+certLen { return false } d = d[3+certLen:] certsLen -= 3 + certLen numCerts++ } m.certificates = make([][]byte, numCerts) d = data[7:] for i := 0; i < numCerts; i++ { certLen := uint32(d[0])<<16 | uint32(d[1])<<8 | uint32(d[2]) m.certificates[i] = d[3 : 3+certLen] d = d[3+certLen:] } return true } type certificateMsgTLS13 struct { raw []byte certificate Certificate ocspStapling bool scts bool } func (m *certificateMsgTLS13) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } var b cryptobyte.Builder b.AddUint8(typeCertificate) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint8(0) // certificate_request_context certificate := m.certificate if !m.ocspStapling { certificate.OCSPStaple = nil } if !m.scts { certificate.SignedCertificateTimestamps = nil } marshalCertificate(b, certificate) }) var err error m.raw, err = b.Bytes() return m.raw, err } func marshalCertificate(b *cryptobyte.Builder, certificate Certificate) { b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { for i, cert := range certificate.Certificate { b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(cert) }) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { if i > 0 { // This library only supports OCSP and SCT for leaf certificates. return } if certificate.OCSPStaple != nil { b.AddUint16(extensionStatusRequest) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint8(statusTypeOCSP) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(certificate.OCSPStaple) }) }) } if certificate.SignedCertificateTimestamps != nil { b.AddUint16(extensionSCT) b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { for _, sct := range certificate.SignedCertificateTimestamps { b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(sct) }) } }) }) } }) } }) } func (m *certificateMsgTLS13) unmarshal(data []byte) bool { *m = certificateMsgTLS13{raw: data} s := cryptobyte.String(data) var context cryptobyte.String if !s.Skip(4) || // message type and uint24 length field !s.ReadUint8LengthPrefixed(&context) || !context.Empty() || !unmarshalCertificate(&s, &m.certificate) || !s.Empty() { return false } m.scts = m.certificate.SignedCertificateTimestamps != nil m.ocspStapling = m.certificate.OCSPStaple != nil return true } func unmarshalCertificate(s *cryptobyte.String, certificate *Certificate) bool { var certList cryptobyte.String if !s.ReadUint24LengthPrefixed(&certList) { return false } for !certList.Empty() { var cert []byte var extensions cryptobyte.String if !readUint24LengthPrefixed(&certList, &cert) || !certList.ReadUint16LengthPrefixed(&extensions) { return false } certificate.Certificate = append(certificate.Certificate, cert) for !extensions.Empty() { var extension uint16 var extData cryptobyte.String if !extensions.ReadUint16(&extension) || !extensions.ReadUint16LengthPrefixed(&extData) { return false } if len(certificate.Certificate) > 1 { // This library only supports OCSP and SCT for leaf certificates. continue } switch extension { case extensionStatusRequest: var statusType uint8 if !extData.ReadUint8(&statusType) || statusType != statusTypeOCSP || !readUint24LengthPrefixed(&extData, &certificate.OCSPStaple) || len(certificate.OCSPStaple) == 0 { return false } case extensionSCT: var sctList cryptobyte.String if !extData.ReadUint16LengthPrefixed(&sctList) || sctList.Empty() { return false } for !sctList.Empty() { var sct []byte if !readUint16LengthPrefixed(&sctList, &sct) || len(sct) == 0 { return false } certificate.SignedCertificateTimestamps = append( certificate.SignedCertificateTimestamps, sct) } default: // Ignore unknown extensions. continue } if !extData.Empty() { return false } } } return true } type serverKeyExchangeMsg struct { raw []byte key []byte } func (m *serverKeyExchangeMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } length := len(m.key) x := make([]byte, length+4) x[0] = typeServerKeyExchange x[1] = uint8(length >> 16) x[2] = uint8(length >> 8) x[3] = uint8(length) copy(x[4:], m.key) m.raw = x return x, nil } func (m *serverKeyExchangeMsg) unmarshal(data []byte) bool { m.raw = data if len(data) < 4 { return false } m.key = data[4:] return true } type certificateStatusMsg struct { raw []byte response []byte } func (m *certificateStatusMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } var b cryptobyte.Builder b.AddUint8(typeCertificateStatus) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { b.AddUint8(statusTypeOCSP) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(m.response) }) }) var err error m.raw, err = b.Bytes() return m.raw, err } func (m *certificateStatusMsg) unmarshal(data []byte) bool { m.raw = data s := cryptobyte.String(data) var statusType uint8 if !s.Skip(4) || // message type and uint24 length field !s.ReadUint8(&statusType) || statusType != statusTypeOCSP || !readUint24LengthPrefixed(&s, &m.response) || len(m.response) == 0 || !s.Empty() { return false } return true } type serverHelloDoneMsg struct{} func (m *serverHelloDoneMsg) marshal() ([]byte, error) { x := make([]byte, 4) x[0] = typeServerHelloDone return x, nil } func (m *serverHelloDoneMsg) unmarshal(data []byte) bool { return len(data) == 4 } type clientKeyExchangeMsg struct { raw []byte ciphertext []byte } func (m *clientKeyExchangeMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } length := len(m.ciphertext) x := make([]byte, length+4) x[0] = typeClientKeyExchange x[1] = uint8(length >> 16) x[2] = uint8(length >> 8) x[3] = uint8(length) copy(x[4:], m.ciphertext) m.raw = x return x, nil } func (m *clientKeyExchangeMsg) unmarshal(data []byte) bool { m.raw = data if len(data) < 4 { return false } l := int(data[1])<<16 | int(data[2])<<8 | int(data[3]) if l != len(data)-4 { return false } m.ciphertext = data[4:] return true } type finishedMsg struct { raw []byte verifyData []byte } func (m *finishedMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } var b cryptobyte.Builder b.AddUint8(typeFinished) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(m.verifyData) }) var err error m.raw, err = b.Bytes() return m.raw, err } func (m *finishedMsg) unmarshal(data []byte) bool { m.raw = data s := cryptobyte.String(data) return s.Skip(1) && readUint24LengthPrefixed(&s, &m.verifyData) && s.Empty() } type certificateRequestMsg struct { raw []byte // hasSignatureAlgorithm indicates whether this message includes a list of // supported signature algorithms. This change was introduced with TLS 1.2. hasSignatureAlgorithm bool certificateTypes []byte supportedSignatureAlgorithms []SignatureScheme certificateAuthorities [][]byte } func (m *certificateRequestMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } // See RFC 4346, Section 7.4.4. length := 1 + len(m.certificateTypes) + 2 casLength := 0 for _, ca := range m.certificateAuthorities { casLength += 2 + len(ca) } length += casLength if m.hasSignatureAlgorithm { length += 2 + 2*len(m.supportedSignatureAlgorithms) } x := make([]byte, 4+length) x[0] = typeCertificateRequest x[1] = uint8(length >> 16) x[2] = uint8(length >> 8) x[3] = uint8(length) x[4] = uint8(len(m.certificateTypes)) copy(x[5:], m.certificateTypes) y := x[5+len(m.certificateTypes):] if m.hasSignatureAlgorithm { n := len(m.supportedSignatureAlgorithms) * 2 y[0] = uint8(n >> 8) y[1] = uint8(n) y = y[2:] for _, sigAlgo := range m.supportedSignatureAlgorithms { y[0] = uint8(sigAlgo >> 8) y[1] = uint8(sigAlgo) y = y[2:] } } y[0] = uint8(casLength >> 8) y[1] = uint8(casLength) y = y[2:] for _, ca := range m.certificateAuthorities { y[0] = uint8(len(ca) >> 8) y[1] = uint8(len(ca)) y = y[2:] copy(y, ca) y = y[len(ca):] } m.raw = x return m.raw, nil } func (m *certificateRequestMsg) unmarshal(data []byte) bool { m.raw = data if len(data) < 5 { return false } length := uint32(data[1])<<16 | uint32(data[2])<<8 | uint32(data[3]) if uint32(len(data))-4 != length { return false } numCertTypes := int(data[4]) data = data[5:] if numCertTypes == 0 || len(data) <= numCertTypes { return false } m.certificateTypes = make([]byte, numCertTypes) if copy(m.certificateTypes, data) != numCertTypes { return false } data = data[numCertTypes:] if m.hasSignatureAlgorithm { if len(data) < 2 { return false } sigAndHashLen := uint16(data[0])<<8 | uint16(data[1]) data = data[2:] if sigAndHashLen&1 != 0 { return false } if len(data) < int(sigAndHashLen) { return false } numSigAlgos := sigAndHashLen / 2 m.supportedSignatureAlgorithms = make([]SignatureScheme, numSigAlgos) for i := range m.supportedSignatureAlgorithms { m.supportedSignatureAlgorithms[i] = SignatureScheme(data[0])<<8 | SignatureScheme(data[1]) data = data[2:] } } if len(data) < 2 { return false } casLength := uint16(data[0])<<8 | uint16(data[1]) data = data[2:] if len(data) < int(casLength) { return false } cas := make([]byte, casLength) copy(cas, data) data = data[casLength:] m.certificateAuthorities = nil for len(cas) > 0 { if len(cas) < 2 { return false } caLen := uint16(cas[0])<<8 | uint16(cas[1]) cas = cas[2:] if len(cas) < int(caLen) { return false } m.certificateAuthorities = append(m.certificateAuthorities, cas[:caLen]) cas = cas[caLen:] } return len(data) == 0 } type certificateVerifyMsg struct { raw []byte hasSignatureAlgorithm bool // format change introduced in TLS 1.2 signatureAlgorithm SignatureScheme signature []byte } func (m *certificateVerifyMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } var b cryptobyte.Builder b.AddUint8(typeCertificateVerify) b.AddUint24LengthPrefixed(func(b *cryptobyte.Builder) { if m.hasSignatureAlgorithm { b.AddUint16(uint16(m.signatureAlgorithm)) } b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) { b.AddBytes(m.signature) }) }) var err error m.raw, err = b.Bytes() return m.raw, err } func (m *certificateVerifyMsg) unmarshal(data []byte) bool { m.raw = data s := cryptobyte.String(data) if !s.Skip(4) { // message type and uint24 length field return false } if m.hasSignatureAlgorithm { if !s.ReadUint16((*uint16)(&m.signatureAlgorithm)) { return false } } return readUint16LengthPrefixed(&s, &m.signature) && s.Empty() } type newSessionTicketMsg struct { raw []byte ticket []byte } func (m *newSessionTicketMsg) marshal() ([]byte, error) { if m.raw != nil { return m.raw, nil } // See RFC 5077, Section 3.3. ticketLen := len(m.ticket) length := 2 + 4 + ticketLen x := make([]byte, 4+length) x[0] = typeNewSessionTicket x[1] = uint8(length >> 16) x[2] = uint8(length >> 8) x[3] = uint8(length) x[8] = uint8(ticketLen >> 8) x[9] = uint8(ticketLen) copy(x[10:], m.ticket) m.raw = x return m.raw, nil } func (m *newSessionTicketMsg) unmarshal(data []byte) bool { m.raw = data if len(data) < 10 { return false } length := uint32(data[1])<<16 | uint32(data[2])<<8 | uint32(data[3]) if uint32(len(data))-4 != length { return false } ticketLen := int(data[8])<<8 + int(data[9]) if len(data)-10 != ticketLen { return false } m.ticket = data[10:] return true } type helloRequestMsg struct { } func (*helloRequestMsg) marshal() ([]byte, error) { return []byte{typeHelloRequest, 0, 0, 0}, nil } func (*helloRequestMsg) unmarshal(data []byte) bool { return len(data) == 4 } type transcriptHash interface { Write([]byte) (int, error) } // transcriptMsg is a helper used to marshal and hash messages which typically // are not written to the wire, and as such aren't hashed during Conn.writeRecord. func transcriptMsg(msg handshakeMessage, h transcriptHash) error { data, err := msg.marshal() if err != nil { return err } h.Write(data) return nil }