th5/handshake_messages.go
Adam Langley cbf5c897cb crypto/tls: add client-side SNI support and PeerCertificates.
SNI (Server Name Indication) is a way for a TLS client to
indicate to the server which name it knows the server by. This
allows the server to have several names and return the correct
certificate for each (virtual hosting).

PeerCertificates returns the list of certificates presented by
server.

R=r
CC=golang-dev
https://golang.org/cl/1741053
2010-07-21 11:36:01 -04:00

671 lines
13 KiB
Go

// 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 tls
type clientHelloMsg struct {
raw []byte
vers uint16
random []byte
sessionId []byte
cipherSuites []uint16
compressionMethods []uint8
nextProtoNeg bool
serverName string
ocspStapling bool
}
func (m *clientHelloMsg) marshal() []byte {
if m.raw != nil {
return m.raw
}
length := 2 + 32 + 1 + len(m.sessionId) + 2 + len(m.cipherSuites)*2 + 1 + len(m.compressionMethods)
numExtensions := 0
extensionsLength := 0
if m.nextProtoNeg {
numExtensions++
}
if m.ocspStapling {
extensionsLength += 1 + 2 + 2
numExtensions++
}
if len(m.serverName) > 0 {
extensionsLength += 5 + len(m.serverName)
numExtensions++
}
if numExtensions > 0 {
extensionsLength += 4 * numExtensions
length += 2 + extensionsLength
}
x := make([]byte, 4+length)
x[0] = typeClientHello
x[1] = uint8(length >> 16)
x[2] = uint8(length >> 8)
x[3] = uint8(length)
x[4] = uint8(m.vers >> 8)
x[5] = uint8(m.vers)
copy(x[6:38], m.random)
x[38] = uint8(len(m.sessionId))
copy(x[39:39+len(m.sessionId)], m.sessionId)
y := x[39+len(m.sessionId):]
y[0] = uint8(len(m.cipherSuites) >> 7)
y[1] = uint8(len(m.cipherSuites) << 1)
for i, suite := range m.cipherSuites {
y[2+i*2] = uint8(suite >> 8)
y[3+i*2] = uint8(suite)
}
z := y[2+len(m.cipherSuites)*2:]
z[0] = uint8(len(m.compressionMethods))
copy(z[1:], m.compressionMethods)
z = z[1+len(m.compressionMethods):]
if numExtensions > 0 {
z[0] = byte(extensionsLength >> 8)
z[1] = byte(extensionsLength)
z = z[2:]
}
if m.nextProtoNeg {
z[0] = byte(extensionNextProtoNeg >> 8)
z[1] = byte(extensionNextProtoNeg)
// The length is always 0
z = z[4:]
}
if len(m.serverName) > 0 {
z[0] = byte(extensionServerName >> 8)
z[1] = byte(extensionServerName)
l := len(m.serverName) + 5
z[2] = byte(l >> 8)
z[3] = byte(l)
z = z[4:]
// RFC 3546, section 3.1
//
// struct {
// NameType name_type;
// select (name_type) {
// case host_name: HostName;
// } name;
// } ServerName;
//
// enum {
// host_name(0), (255)
// } NameType;
//
// opaque HostName<1..2^16-1>;
//
// struct {
// ServerName server_name_list<1..2^16-1>
// } ServerNameList;
z[0] = byte((len(m.serverName) + 3) >> 8)
z[1] = byte(len(m.serverName) + 3)
z[3] = byte(len(m.serverName) >> 8)
z[4] = byte(len(m.serverName))
copy(z[5:], []byte(m.serverName))
z = z[l:]
}
if m.ocspStapling {
// RFC 4366, section 3.6
z[0] = byte(extensionStatusRequest >> 8)
z[1] = byte(extensionStatusRequest)
z[2] = 0
z[3] = 5
z[4] = 1 // OCSP type
// Two zero valued uint16s for the two lengths.
z = z[9:]
}
m.raw = x
return x
}
func (m *clientHelloMsg) unmarshal(data []byte) bool {
if len(data) < 42 {
return false
}
m.raw = data
m.vers = uint16(data[4])<<8 | uint16(data[5])
m.random = data[6:38]
sessionIdLen := int(data[38])
if sessionIdLen > 32 || len(data) < 39+sessionIdLen {
return false
}
m.sessionId = data[39 : 39+sessionIdLen]
data = data[39+sessionIdLen:]
if len(data) < 2 {
return false
}
// cipherSuiteLen is the number of bytes of cipher suite numbers. Since
// they are uint16s, the number must be even.
cipherSuiteLen := int(data[0])<<8 | int(data[1])
if cipherSuiteLen%2 == 1 || len(data) < 2+cipherSuiteLen {
return false
}
numCipherSuites := cipherSuiteLen / 2
m.cipherSuites = make([]uint16, numCipherSuites)
for i := 0; i < numCipherSuites; i++ {
m.cipherSuites[i] = uint16(data[2+2*i])<<8 | uint16(data[3+2*i])
}
data = data[2+cipherSuiteLen:]
if len(data) < 1 {
return false
}
compressionMethodsLen := int(data[0])
if len(data) < 1+compressionMethodsLen {
return false
}
m.compressionMethods = data[1 : 1+compressionMethodsLen]
data = data[1+compressionMethodsLen:]
m.nextProtoNeg = false
m.serverName = ""
m.ocspStapling = false
if len(data) == 0 {
// ClientHello is optionally followed by extension data
return true
}
if len(data) < 2 {
return false
}
extensionsLength := int(data[0])<<8 | int(data[1])
data = data[2:]
if extensionsLength != len(data) {
return false
}
for len(data) != 0 {
if len(data) < 4 {
return false
}
extension := uint16(data[0])<<8 | uint16(data[1])
length := int(data[2])<<8 | int(data[3])
data = data[4:]
if len(data) < length {
return false
}
switch extension {
case extensionServerName:
if length < 2 {
return false
}
numNames := int(data[0])<<8 | int(data[1])
d := data[2:]
for i := 0; i < numNames; i++ {
if len(d) < 3 {
return false
}
nameType := d[0]
nameLen := int(d[1])<<8 | int(d[2])
d = d[3:]
if len(d) < nameLen {
return false
}
if nameType == 0 {
m.serverName = string(d[0:nameLen])
break
}
d = d[nameLen:]
}
case extensionNextProtoNeg:
if length > 0 {
return false
}
m.nextProtoNeg = true
case extensionStatusRequest:
m.ocspStapling = length > 0 && data[0] == statusTypeOCSP
}
data = data[length:]
}
return true
}
type serverHelloMsg struct {
raw []byte
vers uint16
random []byte
sessionId []byte
cipherSuite uint16
compressionMethod uint8
nextProtoNeg bool
nextProtos []string
certStatus bool
}
func (m *serverHelloMsg) marshal() []byte {
if m.raw != nil {
return m.raw
}
length := 38 + len(m.sessionId)
numExtensions := 0
extensionsLength := 0
nextProtoLen := 0
if m.nextProtoNeg {
numExtensions++
for _, v := range m.nextProtos {
nextProtoLen += len(v)
}
nextProtoLen += len(m.nextProtos)
extensionsLength += nextProtoLen
}
if m.certStatus {
numExtensions++
}
if numExtensions > 0 {
extensionsLength += 4 * numExtensions
length += 2 + extensionsLength
}
x := make([]byte, 4+length)
x[0] = typeServerHello
x[1] = uint8(length >> 16)
x[2] = uint8(length >> 8)
x[3] = uint8(length)
x[4] = uint8(m.vers >> 8)
x[5] = uint8(m.vers)
copy(x[6:38], m.random)
x[38] = uint8(len(m.sessionId))
copy(x[39:39+len(m.sessionId)], m.sessionId)
z := x[39+len(m.sessionId):]
z[0] = uint8(m.cipherSuite >> 8)
z[1] = uint8(m.cipherSuite)
z[2] = uint8(m.compressionMethod)
z = z[3:]
if numExtensions > 0 {
z[0] = byte(extensionsLength >> 8)
z[1] = byte(extensionsLength)
z = z[2:]
}
if m.nextProtoNeg {
z[0] = byte(extensionNextProtoNeg >> 8)
z[1] = byte(extensionNextProtoNeg)
z[2] = byte(nextProtoLen >> 8)
z[3] = byte(nextProtoLen)
z = z[4:]
for _, v := range m.nextProtos {
l := len(v)
if l > 255 {
l = 255
}
z[0] = byte(l)
copy(z[1:], []byte(v[0:l]))
z = z[1+l:]
}
}
if m.certStatus {
z[0] = byte(extensionStatusRequest >> 8)
z[1] = byte(extensionStatusRequest)
z = z[4:]
}
m.raw = x
return x
}
func append(slice []string, elem string) []string {
if len(slice) < cap(slice) {
slice = slice[0 : len(slice)+1]
slice[len(slice)-1] = elem
return slice
}
fresh := make([]string, len(slice)+1, cap(slice)*2+1)
copy(fresh, slice)
fresh[len(slice)] = elem
return fresh
}
func (m *serverHelloMsg) unmarshal(data []byte) bool {
if len(data) < 42 {
return false
}
m.raw = data
m.vers = uint16(data[4])<<8 | uint16(data[5])
m.random = data[6:38]
sessionIdLen := int(data[38])
if sessionIdLen > 32 || len(data) < 39+sessionIdLen {
return false
}
m.sessionId = data[39 : 39+sessionIdLen]
data = data[39+sessionIdLen:]
if len(data) < 3 {
return false
}
m.cipherSuite = uint16(data[0])<<8 | uint16(data[1])
m.compressionMethod = data[2]
data = data[3:]
m.nextProtoNeg = false
m.nextProtos = nil
m.certStatus = false
if len(data) == 0 {
// ServerHello is optionally followed by extension data
return true
}
if len(data) < 2 {
return false
}
extensionsLength := int(data[0])<<8 | int(data[1])
data = data[2:]
if len(data) != extensionsLength {
return false
}
for len(data) != 0 {
if len(data) < 4 {
return false
}
extension := uint16(data[0])<<8 | uint16(data[1])
length := int(data[2])<<8 | int(data[3])
data = data[4:]
if len(data) < length {
return false
}
switch extension {
case extensionNextProtoNeg:
m.nextProtoNeg = true
d := data
for len(d) > 0 {
l := int(d[0])
d = d[1:]
if l == 0 || l > len(d) {
return false
}
m.nextProtos = append(m.nextProtos, string(d[0:l]))
d = d[l:]
}
case extensionStatusRequest:
if length > 0 {
return false
}
m.certStatus = true
}
data = data[length:]
}
return true
}
type certificateMsg struct {
raw []byte
certificates [][]byte
}
func (m *certificateMsg) marshal() (x []byte) {
if m.raw != nil {
return m.raw
}
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
}
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])<<24 | 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])<<24 | uint32(d[1])<<8 | uint32(d[2])
m.certificates[i] = d[3 : 3+certLen]
d = d[3+certLen:]
}
return true
}
type certificateStatusMsg struct {
raw []byte
statusType uint8
response []byte
}
func (m *certificateStatusMsg) marshal() []byte {
if m.raw != nil {
return m.raw
}
var x []byte
if m.statusType == statusTypeOCSP {
x = make([]byte, 4+4+len(m.response))
x[0] = typeCertificateStatus
l := len(m.response) + 4
x[1] = byte(l >> 16)
x[2] = byte(l >> 8)
x[3] = byte(l)
x[4] = statusTypeOCSP
l -= 4
x[5] = byte(l >> 16)
x[6] = byte(l >> 8)
x[7] = byte(l)
copy(x[8:], m.response)
} else {
x = []byte{typeCertificateStatus, 0, 0, 1, m.statusType}
}
m.raw = x
return x
}
func (m *certificateStatusMsg) unmarshal(data []byte) bool {
m.raw = data
if len(data) < 5 {
return false
}
m.statusType = data[4]
m.response = nil
if m.statusType == statusTypeOCSP {
if len(data) < 8 {
return false
}
respLen := uint32(data[5])<<16 | uint32(data[6])<<8 | uint32(data[7])
if uint32(len(data)) != 4+4+respLen {
return false
}
m.response = data[8:]
}
return true
}
type serverHelloDoneMsg struct{}
func (m *serverHelloDoneMsg) marshal() []byte {
x := make([]byte, 4)
x[0] = typeServerHelloDone
return x
}
func (m *serverHelloDoneMsg) unmarshal(data []byte) bool {
return len(data) == 4
}
type clientKeyExchangeMsg struct {
raw []byte
ciphertext []byte
}
func (m *clientKeyExchangeMsg) marshal() []byte {
if m.raw != nil {
return m.raw
}
length := len(m.ciphertext) + 2
x := make([]byte, length+4)
x[0] = typeClientKeyExchange
x[1] = uint8(length >> 16)
x[2] = uint8(length >> 8)
x[3] = uint8(length)
x[4] = uint8(len(m.ciphertext) >> 8)
x[5] = uint8(len(m.ciphertext))
copy(x[6:], m.ciphertext)
m.raw = x
return x
}
func (m *clientKeyExchangeMsg) unmarshal(data []byte) bool {
m.raw = data
if len(data) < 7 {
return false
}
cipherTextLen := int(data[4])<<8 | int(data[5])
if len(data) != 6+cipherTextLen {
return false
}
m.ciphertext = data[6:]
return true
}
type finishedMsg struct {
raw []byte
verifyData []byte
}
func (m *finishedMsg) marshal() (x []byte) {
if m.raw != nil {
return m.raw
}
x = make([]byte, 16)
x[0] = typeFinished
x[3] = 12
copy(x[4:], m.verifyData)
m.raw = x
return
}
func (m *finishedMsg) unmarshal(data []byte) bool {
m.raw = data
if len(data) != 4+12 {
return false
}
m.verifyData = data[4:]
return true
}
type nextProtoMsg struct {
raw []byte
proto string
}
func (m *nextProtoMsg) marshal() []byte {
if m.raw != nil {
return m.raw
}
l := len(m.proto)
if l > 255 {
l = 255
}
padding := 32 - (l+2)%32
length := l + padding + 2
x := make([]byte, length+4)
x[0] = typeNextProtocol
x[1] = uint8(length >> 16)
x[2] = uint8(length >> 8)
x[3] = uint8(length)
y := x[4:]
y[0] = byte(l)
copy(y[1:], []byte(m.proto[0:l]))
y = y[1+l:]
y[0] = byte(padding)
m.raw = x
return x
}
func (m *nextProtoMsg) unmarshal(data []byte) bool {
m.raw = data
if len(data) < 5 {
return false
}
data = data[4:]
protoLen := int(data[0])
data = data[1:]
if len(data) < protoLen {
return false
}
m.proto = string(data[0:protoLen])
data = data[protoLen:]
if len(data) < 1 {
return false
}
paddingLen := int(data[0])
data = data[1:]
if len(data) != paddingLen {
return false
}
return true
}