crypto/tls: support SSLv3

It would be nice not to have to support this since all the clients
that we care about support TLSv1 by now. However, due to buggy
implementations of SSLv3 on the Internet which can't do version
negotiation correctly, browsers will sometimes switch to SSLv3. Since
there's no good way for a browser tell a network problem from a buggy
server, this downgrade can occur even if the server in question is
actually working correctly.

So we need to support SSLv3 for robustness :(

Fixes #1703.

R=bradfitz
CC=golang-dev
https://golang.org/cl/5018045
This commit is contained in:
Adam Langley 2011-09-14 15:32:19 -04:00
parent 39082848cf
commit 76c2ff557a
12 changed files with 430 additions and 117 deletions

View File

@ -9,6 +9,7 @@ import (
"crypto/cipher"
"crypto/hmac"
"crypto/rc4"
"crypto/sha1"
"crypto/x509"
"hash"
"os"
@ -23,7 +24,7 @@ type keyAgreement interface {
// ServerKeyExchange message, generateServerKeyExchange can return nil,
// nil.
generateServerKeyExchange(*Config, *clientHelloMsg, *serverHelloMsg) (*serverKeyExchangeMsg, os.Error)
processClientKeyExchange(*Config, *clientKeyExchangeMsg) ([]byte, os.Error)
processClientKeyExchange(*Config, *clientKeyExchangeMsg, uint16) ([]byte, os.Error)
// On the client side, the next two methods are called in order.
@ -46,14 +47,14 @@ type cipherSuite struct {
// and point format that we can handle.
elliptic bool
cipher func(key, iv []byte, isRead bool) interface{}
mac func(macKey []byte) hash.Hash
mac func(version uint16, macKey []byte) macFunction
}
var cipherSuites = map[uint16]*cipherSuite{
TLS_RSA_WITH_RC4_128_SHA: &cipherSuite{16, 20, 0, rsaKA, false, cipherRC4, hmacSHA1},
TLS_RSA_WITH_AES_128_CBC_SHA: &cipherSuite{16, 20, 16, rsaKA, false, cipherAES, hmacSHA1},
TLS_ECDHE_RSA_WITH_RC4_128_SHA: &cipherSuite{16, 20, 0, ecdheRSAKA, true, cipherRC4, hmacSHA1},
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA: &cipherSuite{16, 20, 16, ecdheRSAKA, true, cipherAES, hmacSHA1},
TLS_RSA_WITH_RC4_128_SHA: &cipherSuite{16, 20, 0, rsaKA, false, cipherRC4, macSHA1},
TLS_RSA_WITH_AES_128_CBC_SHA: &cipherSuite{16, 20, 16, rsaKA, false, cipherAES, macSHA1},
TLS_ECDHE_RSA_WITH_RC4_128_SHA: &cipherSuite{16, 20, 0, ecdheRSAKA, true, cipherRC4, macSHA1},
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA: &cipherSuite{16, 20, 16, ecdheRSAKA, true, cipherAES, macSHA1},
}
func cipherRC4(key, iv []byte, isRead bool) interface{} {
@ -69,8 +70,75 @@ func cipherAES(key, iv []byte, isRead bool) interface{} {
return cipher.NewCBCEncrypter(block, iv)
}
func hmacSHA1(key []byte) hash.Hash {
return hmac.NewSHA1(key)
// macSHA1 returns a macFunction for the given protocol version.
func macSHA1(version uint16, key []byte) macFunction {
if version == versionSSL30 {
mac := ssl30MAC{
h: sha1.New(),
key: make([]byte, len(key)),
}
copy(mac.key, key)
return mac
}
return tls10MAC{hmac.NewSHA1(key)}
}
type macFunction interface {
Size() int
MAC(seq, data []byte) []byte
}
// ssl30MAC implements the SSLv3 MAC function, as defined in
// www.mozilla.org/projects/security/pki/nss/ssl/draft302.txt section 5.2.3.1
type ssl30MAC struct {
h hash.Hash
key []byte
}
func (s ssl30MAC) Size() int {
return s.h.Size()
}
var ssl30Pad1 = [48]byte{0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36}
var ssl30Pad2 = [48]byte{0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c}
func (s ssl30MAC) MAC(seq, record []byte) []byte {
padLength := 48
if s.h.Size() == 20 {
padLength = 40
}
s.h.Reset()
s.h.Write(s.key)
s.h.Write(ssl30Pad1[:padLength])
s.h.Write(seq)
s.h.Write(record[:1])
s.h.Write(record[3:5])
s.h.Write(record[recordHeaderLen:])
digest := s.h.Sum()
s.h.Reset()
s.h.Write(s.key)
s.h.Write(ssl30Pad2[:padLength])
s.h.Write(digest)
return s.h.Sum()
}
// tls10MAC implements the TLS 1.0 MAC function. RFC 2246, section 6.2.3.
type tls10MAC struct {
h hash.Hash
}
func (s tls10MAC) Size() int {
return s.h.Size()
}
func (s tls10MAC) MAC(seq, record []byte) []byte {
s.h.Reset()
s.h.Write(seq)
s.h.Write(record)
return s.h.Sum()
}
func rsaKA() keyAgreement {

View File

@ -20,8 +20,11 @@ const (
recordHeaderLen = 5 // record header length
maxHandshake = 65536 // maximum handshake we support (protocol max is 16 MB)
minVersion = 0x0301 // minimum supported version - TLS 1.0
maxVersion = 0x0301 // maximum supported version - TLS 1.0
versionSSL30 = 0x0300
versionTLS10 = 0x0301
minVersion = versionSSL30
maxVersion = versionTLS10
)
// TLS record types.

50
conn.go
View File

@ -11,7 +11,6 @@ import (
"crypto/cipher"
"crypto/subtle"
"crypto/x509"
"hash"
"io"
"net"
"os"
@ -108,18 +107,20 @@ func (c *Conn) SetWriteTimeout(nsec int64) os.Error {
// connection, either sending or receiving.
type halfConn struct {
sync.Mutex
cipher interface{} // cipher algorithm
mac hash.Hash // MAC algorithm
seq [8]byte // 64-bit sequence number
bfree *block // list of free blocks
version uint16 // protocol version
cipher interface{} // cipher algorithm
mac macFunction
seq [8]byte // 64-bit sequence number
bfree *block // list of free blocks
nextCipher interface{} // next encryption state
nextMac hash.Hash // next MAC algorithm
nextMac macFunction // next MAC algorithm
}
// prepareCipherSpec sets the encryption and MAC states
// that a subsequent changeCipherSpec will use.
func (hc *halfConn) prepareCipherSpec(cipher interface{}, mac hash.Hash) {
func (hc *halfConn) prepareCipherSpec(version uint16, cipher interface{}, mac macFunction) {
hc.version = version
hc.nextCipher = cipher
hc.nextMac = mac
}
@ -197,6 +198,22 @@ func removePadding(payload []byte) ([]byte, byte) {
return payload[:len(payload)-int(toRemove)], good
}
// removePaddingSSL30 is a replacement for removePadding in the case that the
// protocol version is SSLv3. In this version, the contents of the padding
// are random and cannot be checked.
func removePaddingSSL30(payload []byte) ([]byte, byte) {
if len(payload) < 1 {
return payload, 0
}
paddingLen := int(payload[len(payload)-1]) + 1
if paddingLen > len(payload) {
return payload, 0
}
return payload[:len(payload)-paddingLen], 255
}
func roundUp(a, b int) int {
return a + (b-a%b)%b
}
@ -226,7 +243,11 @@ func (hc *halfConn) decrypt(b *block) (bool, alert) {
}
c.CryptBlocks(payload, payload)
payload, paddingGood = removePadding(payload)
if hc.version == versionSSL30 {
payload, paddingGood = removePaddingSSL30(payload)
} else {
payload, paddingGood = removePadding(payload)
}
b.resize(recordHeaderLen + len(payload))
// note that we still have a timing side-channel in the
@ -256,13 +277,10 @@ func (hc *halfConn) decrypt(b *block) (bool, alert) {
b.data[4] = byte(n)
b.resize(recordHeaderLen + n)
remoteMAC := payload[n:]
hc.mac.Reset()
hc.mac.Write(hc.seq[0:])
localMAC := hc.mac.MAC(hc.seq[0:], b.data)
hc.incSeq()
hc.mac.Write(b.data)
if subtle.ConstantTimeCompare(hc.mac.Sum(), remoteMAC) != 1 || paddingGood != 255 {
if subtle.ConstantTimeCompare(localMAC, remoteMAC) != 1 || paddingGood != 255 {
return false, alertBadRecordMAC
}
}
@ -291,11 +309,9 @@ func padToBlockSize(payload []byte, blockSize int) (prefix, finalBlock []byte) {
func (hc *halfConn) encrypt(b *block) (bool, alert) {
// mac
if hc.mac != nil {
hc.mac.Reset()
hc.mac.Write(hc.seq[0:])
mac := hc.mac.MAC(hc.seq[0:], b.data)
hc.incSeq()
hc.mac.Write(b.data)
mac := hc.mac.Sum()
n := len(b.data)
b.resize(n + len(mac))
copy(b.data[n:], mac)

View File

@ -14,7 +14,7 @@ import (
)
func (c *Conn) clientHandshake() os.Error {
finishedHash := newFinishedHash()
finishedHash := newFinishedHash(versionTLS10)
if c.config == nil {
c.config = defaultConfig()
@ -247,11 +247,11 @@ func (c *Conn) clientHandshake() os.Error {
}
masterSecret, clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV :=
keysFromPreMasterSecret10(preMasterSecret, hello.random, serverHello.random, suite.macLen, suite.keyLen, suite.ivLen)
keysFromPreMasterSecret(c.vers, preMasterSecret, hello.random, serverHello.random, suite.macLen, suite.keyLen, suite.ivLen)
clientCipher := suite.cipher(clientKey, clientIV, false /* not for reading */ )
clientHash := suite.mac(clientMAC)
c.out.prepareCipherSpec(clientCipher, clientHash)
clientHash := suite.mac(c.vers, clientMAC)
c.out.prepareCipherSpec(c.vers, clientCipher, clientHash)
c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
if serverHello.nextProtoNeg {
@ -271,8 +271,8 @@ func (c *Conn) clientHandshake() os.Error {
c.writeRecord(recordTypeHandshake, finished.marshal())
serverCipher := suite.cipher(serverKey, serverIV, true /* for reading */ )
serverHash := suite.mac(serverMAC)
c.in.prepareCipherSpec(serverCipher, serverHash)
serverHash := suite.mac(c.vers, serverMAC)
c.in.prepareCipherSpec(c.vers, serverCipher, serverHash)
c.readRecord(recordTypeChangeCipherSpec)
if c.err != nil {
return c.err

View File

@ -18,6 +18,7 @@ func testClientScript(t *testing.T, name string, clientScript [][]byte, config *
go func() {
cli.Write([]byte("hello\n"))
cli.Close()
c.Close()
}()
defer c.Close()

View File

@ -676,9 +676,9 @@ func (m *finishedMsg) marshal() (x []byte) {
return m.raw
}
x = make([]byte, 16)
x = make([]byte, 4+len(m.verifyData))
x[0] = typeFinished
x[3] = 12
x[3] = byte(len(m.verifyData))
copy(x[4:], m.verifyData)
m.raw = x
return
@ -686,7 +686,7 @@ func (m *finishedMsg) marshal() (x []byte) {
func (m *finishedMsg) unmarshal(data []byte) bool {
m.raw = data
if len(data) != 4+12 {
if len(data) < 4 {
return false
}
m.verifyData = data[4:]

View File

@ -14,13 +14,13 @@ import (
var tests = []interface{}{
&clientHelloMsg{},
&serverHelloMsg{},
&finishedMsg{},
&certificateMsg{},
&certificateRequestMsg{},
&certificateVerifyMsg{},
&certificateStatusMsg{},
&clientKeyExchangeMsg{},
&finishedMsg{},
&nextProtoMsg{},
}
@ -59,11 +59,12 @@ func TestMarshalUnmarshal(t *testing.T) {
break
}
if i >= 2 {
// The first two message types (ClientHello and
// ServerHello) are allowed to have parsable
// prefixes because the extension data is
// optional.
if i >= 3 {
// The first three message types (ClientHello,
// ServerHello and Finished) are allowed to
// have parsable prefixes because the extension
// data is optional and the length of the
// Finished varies across versions.
for j := 0; j < len(marshaled); j++ {
if m2.unmarshal(marshaled[0:j]) {
t.Errorf("#%d unmarshaled a prefix of length %d of %#v", i, j, m1)

View File

@ -30,7 +30,7 @@ func (c *Conn) serverHandshake() os.Error {
c.vers = vers
c.haveVers = true
finishedHash := newFinishedHash()
finishedHash := newFinishedHash(vers)
finishedHash.Write(clientHello.marshal())
hello := new(serverHelloMsg)
@ -128,7 +128,6 @@ FindCipherSuite:
}
keyAgreement := suite.ka()
skx, err := keyAgreement.generateServerKeyExchange(config, clientHello, hello)
if err != nil {
c.sendAlert(alertHandshakeFailure)
@ -235,18 +234,18 @@ FindCipherSuite:
finishedHash.Write(certVerify.marshal())
}
preMasterSecret, err := keyAgreement.processClientKeyExchange(config, ckx)
preMasterSecret, err := keyAgreement.processClientKeyExchange(config, ckx, c.vers)
if err != nil {
c.sendAlert(alertHandshakeFailure)
return err
}
masterSecret, clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV :=
keysFromPreMasterSecret10(preMasterSecret, clientHello.random, hello.random, suite.macLen, suite.keyLen, suite.ivLen)
keysFromPreMasterSecret(c.vers, preMasterSecret, clientHello.random, hello.random, suite.macLen, suite.keyLen, suite.ivLen)
clientCipher := suite.cipher(clientKey, clientIV, true /* for reading */ )
clientHash := suite.mac(clientMAC)
c.in.prepareCipherSpec(clientCipher, clientHash)
clientHash := suite.mac(c.vers, clientMAC)
c.in.prepareCipherSpec(c.vers, clientCipher, clientHash)
c.readRecord(recordTypeChangeCipherSpec)
if err := c.error(); err != nil {
return err
@ -283,8 +282,8 @@ FindCipherSuite:
finishedHash.Write(clientFinished.marshal())
serverCipher := suite.cipher(serverKey, serverIV, false /* not for reading */ )
serverHash := suite.mac(serverMAC)
c.out.prepareCipherSpec(serverCipher, serverHash)
serverHash := suite.mac(c.vers, serverMAC)
c.out.prepareCipherSpec(c.vers, serverCipher, serverHash)
c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
finished := new(finishedMsg)

View File

@ -62,7 +62,7 @@ func TestSimpleError(t *testing.T) {
testClientHelloFailure(t, &serverHelloDoneMsg{}, alertUnexpectedMessage)
}
var badProtocolVersions = []uint16{0x0000, 0x0005, 0x0100, 0x0105, 0x0200, 0x0205, 0x0300}
var badProtocolVersions = []uint16{0x0000, 0x0005, 0x0100, 0x0105, 0x0200, 0x0205}
func TestRejectBadProtocolVersion(t *testing.T) {
for _, v := range badProtocolVersions {
@ -112,6 +112,7 @@ func testServerScript(t *testing.T, name string, serverScript [][]byte, config *
go func() {
srv.Write([]byte("hello, world\n"))
srv.Close()
s.Close()
}()
defer c.Close()
@ -121,9 +122,9 @@ func testServerScript(t *testing.T, name string, serverScript [][]byte, config *
continue
}
bb := make([]byte, len(b))
_, err := io.ReadFull(c, bb)
n, err := io.ReadFull(c, bb)
if err != nil {
t.Fatalf("%s #%d: %s", name, i, err)
t.Fatalf("%s #%d: %s\nRead %d, wanted %d, got %x, wanted %x\n", name, i, err, n, len(bb), bb[:n], b)
}
if !bytes.Equal(b, bb) {
t.Fatalf("%s #%d: mismatch on read: got:%x want:%x", name, i, bb, b)
@ -142,50 +143,8 @@ func TestHandshakeServerAES(t *testing.T) {
testServerScript(t, "AES", aesServerScript, aesConfig)
}
func TestUnexpectedTLS(t *testing.T) {
l, err := Listen("tcp", "127.0.0.1:0", testConfig)
if err != nil {
t.Fatal(err)
}
ch := make(chan os.Error, 1)
done := make(chan bool)
go func() {
// Simulate HTTP client trying to do unencrypted HTTP on TLS port.
c, err := net.Dial("tcp", l.Addr().String())
if err != nil {
ch <- err
<-done
return
}
defer func() {
<-done
c.Close()
}()
_, err = c.Write([]byte("GET / HTTP/1.0\r\nHost: www.google.com\r\n\r\n"))
if err != nil {
ch <- err
return
}
ch <- nil
}()
c, err := l.Accept()
if err != nil {
t.Fatal(err)
}
buf := make([]byte, 100)
n, err := c.Read(buf)
if n > 0 || err == nil {
t.Errorf("TLS Read = %d, %v, want error", n, err)
}
t.Logf("%d, %v", n, err)
err = <-ch
done <- true
if err != nil {
t.Errorf("TLS Write: %v", err)
}
func TestHandshakeServerSSLv3(t *testing.T) {
testServerScript(t, "SSLv3", sslv3ServerScript, testConfig)
}
var serve = flag.Bool("serve", false, "run a TLS server on :10443")
@ -561,3 +520,165 @@ var aesServerScript = [][]byte{
0xcd, 0x84, 0xf0,
},
}
var sslv3ServerScript = [][]byte{
{
0x16, 0x03, 0x00, 0x00, 0x41, 0x01, 0x00, 0x00,
0x3d, 0x03, 0x00, 0x4e, 0x70, 0xe2, 0x18, 0x86,
0xd6, 0xc6, 0x6f, 0xf3, 0xc8, 0xf4, 0x02, 0xd6,
0x4d, 0xee, 0x17, 0x32, 0x4b, 0xd2, 0x78, 0xd8,
0xa1, 0x03, 0x5d, 0x68, 0x82, 0x89, 0xbe, 0xfd,
0x12, 0xb9, 0x06, 0x00, 0x00, 0x16, 0x00, 0x33,
0x00, 0x39, 0x00, 0x16, 0x00, 0x32, 0x00, 0x38,
0x00, 0x13, 0x00, 0x2f, 0x00, 0x35, 0x00, 0x0a,
0x00, 0x05, 0x00, 0x04, 0x01, 0x00,
},
{
0x16, 0x03, 0x00, 0x00, 0x2a, 0x02, 0x00, 0x00,
0x26, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 0x16,
0x03, 0x00, 0x02, 0xbe, 0x0b, 0x00, 0x02, 0xba,
0x00, 0x02, 0xb7, 0x00, 0x02, 0xb4, 0x30, 0x82,
0x02, 0xb0, 0x30, 0x82, 0x02, 0x19, 0xa0, 0x03,
0x02, 0x01, 0x02, 0x02, 0x09, 0x00, 0x85, 0xb0,
0xbb, 0xa4, 0x8a, 0x7f, 0xb8, 0xca, 0x30, 0x0d,
0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d,
0x01, 0x01, 0x05, 0x05, 0x00, 0x30, 0x45, 0x31,
0x0b, 0x30, 0x09, 0x06, 0x03, 0x55, 0x04, 0x06,
0x13, 0x02, 0x41, 0x55, 0x31, 0x13, 0x30, 0x11,
0x06, 0x03, 0x55, 0x04, 0x08, 0x13, 0x0a, 0x53,
0x6f, 0x6d, 0x65, 0x2d, 0x53, 0x74, 0x61, 0x74,
0x65, 0x31, 0x21, 0x30, 0x1f, 0x06, 0x03, 0x55,
0x04, 0x0a, 0x13, 0x18, 0x49, 0x6e, 0x74, 0x65,
0x72, 0x6e, 0x65, 0x74, 0x20, 0x57, 0x69, 0x64,
0x67, 0x69, 0x74, 0x73, 0x20, 0x50, 0x74, 0x79,
0x20, 0x4c, 0x74, 0x64, 0x30, 0x1e, 0x17, 0x0d,
0x31, 0x30, 0x30, 0x34, 0x32, 0x34, 0x30, 0x39,
0x30, 0x39, 0x33, 0x38, 0x5a, 0x17, 0x0d, 0x31,
0x31, 0x30, 0x34, 0x32, 0x34, 0x30, 0x39, 0x30,
0x39, 0x33, 0x38, 0x5a, 0x30, 0x45, 0x31, 0x0b,
0x30, 0x09, 0x06, 0x03, 0x55, 0x04, 0x06, 0x13,
0x02, 0x41, 0x55, 0x31, 0x13, 0x30, 0x11, 0x06,
0x03, 0x55, 0x04, 0x08, 0x13, 0x0a, 0x53, 0x6f,
0x6d, 0x65, 0x2d, 0x53, 0x74, 0x61, 0x74, 0x65,
0x31, 0x21, 0x30, 0x1f, 0x06, 0x03, 0x55, 0x04,
0x0a, 0x13, 0x18, 0x49, 0x6e, 0x74, 0x65, 0x72,
0x6e, 0x65, 0x74, 0x20, 0x57, 0x69, 0x64, 0x67,
0x69, 0x74, 0x73, 0x20, 0x50, 0x74, 0x79, 0x20,
0x4c, 0x74, 0x64, 0x30, 0x81, 0x9f, 0x30, 0x0d,
0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d,
0x01, 0x01, 0x01, 0x05, 0x00, 0x03, 0x81, 0x8d,
0x00, 0x30, 0x81, 0x89, 0x02, 0x81, 0x81, 0x00,
0xbb, 0x79, 0xd6, 0xf5, 0x17, 0xb5, 0xe5, 0xbf,
0x46, 0x10, 0xd0, 0xdc, 0x69, 0xbe, 0xe6, 0x2b,
0x07, 0x43, 0x5a, 0xd0, 0x03, 0x2d, 0x8a, 0x7a,
0x43, 0x85, 0xb7, 0x14, 0x52, 0xe7, 0xa5, 0x65,
0x4c, 0x2c, 0x78, 0xb8, 0x23, 0x8c, 0xb5, 0xb4,
0x82, 0xe5, 0xde, 0x1f, 0x95, 0x3b, 0x7e, 0x62,
0xa5, 0x2c, 0xa5, 0x33, 0xd6, 0xfe, 0x12, 0x5c,
0x7a, 0x56, 0xfc, 0xf5, 0x06, 0xbf, 0xfa, 0x58,
0x7b, 0x26, 0x3f, 0xb5, 0xcd, 0x04, 0xd3, 0xd0,
0xc9, 0x21, 0x96, 0x4a, 0xc7, 0xf4, 0x54, 0x9f,
0x5a, 0xbf, 0xef, 0x42, 0x71, 0x00, 0xfe, 0x18,
0x99, 0x07, 0x7f, 0x7e, 0x88, 0x7d, 0x7d, 0xf1,
0x04, 0x39, 0xc4, 0xa2, 0x2e, 0xdb, 0x51, 0xc9,
0x7c, 0xe3, 0xc0, 0x4c, 0x3b, 0x32, 0x66, 0x01,
0xcf, 0xaf, 0xb1, 0x1d, 0xb8, 0x71, 0x9a, 0x1d,
0xdb, 0xdb, 0x89, 0x6b, 0xae, 0xda, 0x2d, 0x79,
0x02, 0x03, 0x01, 0x00, 0x01, 0xa3, 0x81, 0xa7,
0x30, 0x81, 0xa4, 0x30, 0x1d, 0x06, 0x03, 0x55,
0x1d, 0x0e, 0x04, 0x16, 0x04, 0x14, 0xb1, 0xad,
0xe2, 0x85, 0x5a, 0xcf, 0xcb, 0x28, 0xdb, 0x69,
0xce, 0x23, 0x69, 0xde, 0xd3, 0x26, 0x8e, 0x18,
0x88, 0x39, 0x30, 0x75, 0x06, 0x03, 0x55, 0x1d,
0x23, 0x04, 0x6e, 0x30, 0x6c, 0x80, 0x14, 0xb1,
0xad, 0xe2, 0x85, 0x5a, 0xcf, 0xcb, 0x28, 0xdb,
0x69, 0xce, 0x23, 0x69, 0xde, 0xd3, 0x26, 0x8e,
0x18, 0x88, 0x39, 0xa1, 0x49, 0xa4, 0x47, 0x30,
0x45, 0x31, 0x0b, 0x30, 0x09, 0x06, 0x03, 0x55,
0x04, 0x06, 0x13, 0x02, 0x41, 0x55, 0x31, 0x13,
0x30, 0x11, 0x06, 0x03, 0x55, 0x04, 0x08, 0x13,
0x0a, 0x53, 0x6f, 0x6d, 0x65, 0x2d, 0x53, 0x74,
0x61, 0x74, 0x65, 0x31, 0x21, 0x30, 0x1f, 0x06,
0x03, 0x55, 0x04, 0x0a, 0x13, 0x18, 0x49, 0x6e,
0x74, 0x65, 0x72, 0x6e, 0x65, 0x74, 0x20, 0x57,
0x69, 0x64, 0x67, 0x69, 0x74, 0x73, 0x20, 0x50,
0x74, 0x79, 0x20, 0x4c, 0x74, 0x64, 0x82, 0x09,
0x00, 0x85, 0xb0, 0xbb, 0xa4, 0x8a, 0x7f, 0xb8,
0xca, 0x30, 0x0c, 0x06, 0x03, 0x55, 0x1d, 0x13,
0x04, 0x05, 0x30, 0x03, 0x01, 0x01, 0xff, 0x30,
0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7,
0x0d, 0x01, 0x01, 0x05, 0x05, 0x00, 0x03, 0x81,
0x81, 0x00, 0x08, 0x6c, 0x45, 0x24, 0xc7, 0x6b,
0xb1, 0x59, 0xab, 0x0c, 0x52, 0xcc, 0xf2, 0xb0,
0x14, 0xd7, 0x87, 0x9d, 0x7a, 0x64, 0x75, 0xb5,
0x5a, 0x95, 0x66, 0xe4, 0xc5, 0x2b, 0x8e, 0xae,
0x12, 0x66, 0x1f, 0xeb, 0x4f, 0x38, 0xb3, 0x6e,
0x60, 0xd3, 0x92, 0xfd, 0xf7, 0x41, 0x08, 0xb5,
0x25, 0x13, 0xb1, 0x18, 0x7a, 0x24, 0xfb, 0x30,
0x1d, 0xba, 0xed, 0x98, 0xb9, 0x17, 0xec, 0xe7,
0xd7, 0x31, 0x59, 0xdb, 0x95, 0xd3, 0x1d, 0x78,
0xea, 0x50, 0x56, 0x5c, 0xd5, 0x82, 0x5a, 0x2d,
0x5a, 0x5f, 0x33, 0xc4, 0xb6, 0xd8, 0xc9, 0x75,
0x90, 0x96, 0x8c, 0x0f, 0x52, 0x98, 0xb5, 0xcd,
0x98, 0x1f, 0x89, 0x20, 0x5f, 0xf2, 0xa0, 0x1c,
0xa3, 0x1b, 0x96, 0x94, 0xdd, 0xa9, 0xfd, 0x57,
0xe9, 0x70, 0xe8, 0x26, 0x6d, 0x71, 0x99, 0x9b,
0x26, 0x6e, 0x38, 0x50, 0x29, 0x6c, 0x90, 0xa7,
0xbd, 0xd9, 0x16, 0x03, 0x00, 0x00, 0x04, 0x0e,
0x00, 0x00, 0x00,
},
{
0x16, 0x03, 0x00, 0x00, 0x84, 0x10, 0x00, 0x00,
0x80, 0x74, 0x0e, 0x3a, 0xcf, 0xba, 0x9f, 0x1a,
0x9b, 0xb2, 0xa4, 0xc7, 0x5d, 0xf3, 0x0c, 0x80,
0x06, 0x80, 0xf3, 0x57, 0xb2, 0xd9, 0x36, 0x24,
0x6a, 0x06, 0x13, 0x40, 0xf9, 0x7c, 0xb9, 0x3e,
0x4b, 0x68, 0x4f, 0x21, 0x90, 0x2d, 0xbd, 0xca,
0xd4, 0x83, 0xf0, 0x7a, 0xeb, 0x7a, 0x74, 0x1b,
0xcd, 0xfe, 0x69, 0xef, 0xc0, 0x86, 0xa0, 0x24,
0x31, 0x65, 0x40, 0xd2, 0xdd, 0x6f, 0xb9, 0xd7,
0x8d, 0xc1, 0x69, 0x60, 0x44, 0x7a, 0x75, 0xfb,
0x42, 0x6a, 0x0f, 0x66, 0x45, 0x10, 0x73, 0xee,
0x87, 0x28, 0x37, 0x83, 0x86, 0xd8, 0x5a, 0xc8,
0x60, 0x87, 0xda, 0x33, 0x87, 0xaf, 0x34, 0x8b,
0xf5, 0x61, 0x63, 0x7a, 0x5c, 0x60, 0x26, 0xb9,
0xdb, 0xa1, 0xb7, 0xe3, 0x60, 0x38, 0x94, 0x5c,
0x83, 0x23, 0xd6, 0x8d, 0xc2, 0x14, 0x4a, 0x0f,
0x0e, 0x4f, 0xf9, 0x4e, 0x7b, 0x15, 0xcd, 0x18,
0x04, 0x14, 0x03, 0x00, 0x00, 0x01, 0x01, 0x16,
0x03, 0x00, 0x00, 0x3c, 0xbd, 0xbc, 0xec, 0xdc,
0x79, 0xb1, 0xae, 0x16, 0xc9, 0x26, 0x9a, 0xc0,
0xc0, 0x2c, 0x33, 0x36, 0x13, 0x91, 0x58, 0x5d,
0x7d, 0xee, 0x4e, 0xd8, 0x7e, 0xac, 0x88, 0x87,
0x0a, 0x75, 0x66, 0xb1, 0x44, 0x79, 0x2f, 0x42,
0xe8, 0x92, 0x74, 0x4c, 0xab, 0x36, 0xc8, 0x17,
0x5f, 0x02, 0x8a, 0x20, 0x53, 0xe9, 0x1d, 0xb4,
0xfe, 0x5c, 0x2b, 0xd9, 0x0a, 0xfb, 0xc6, 0x63,
},
{
0x14, 0x03, 0x00, 0x00, 0x01, 0x01, 0x16, 0x03,
0x00, 0x00, 0x3c, 0xaa, 0xa1, 0x98, 0xc4, 0x6b,
0x5a, 0x16, 0x3f, 0x5f, 0xa4, 0x96, 0x3e, 0x78,
0xe4, 0x6f, 0x49, 0x05, 0x47, 0xc4, 0x05, 0x60,
0xeb, 0x0b, 0x45, 0xe3, 0xbc, 0x50, 0x11, 0x24,
0x5f, 0x01, 0xd7, 0xb8, 0x8f, 0x60, 0x63, 0x66,
0xbd, 0x3e, 0xd9, 0xa8, 0x80, 0x43, 0x9f, 0x0b,
0x51, 0x61, 0xed, 0x13, 0xc6, 0x21, 0xd0, 0xfe,
0xbc, 0x17, 0x3c, 0x36, 0xb0, 0x82, 0x7f, 0x17,
0x03, 0x00, 0x00, 0x21, 0xee, 0x44, 0xf3, 0xa6,
0x88, 0x9d, 0x78, 0x44, 0xde, 0xdf, 0xeb, 0xc5,
0xad, 0xc4, 0xcc, 0x56, 0x5c, 0x54, 0x96, 0x52,
0x3f, 0xd9, 0x40, 0x6e, 0x79, 0xd8, 0x58, 0x78,
0x4f, 0x5a, 0xe9, 0x06, 0xef, 0x15, 0x03, 0x00,
0x00, 0x16, 0xd3, 0xc2, 0x52, 0x99, 0x2a, 0x84,
0xc4, 0x52, 0x5f, 0x3b, 0x19, 0xe7, 0xfc, 0x65,
0xaf, 0xd3, 0xb7, 0xa3, 0xcc, 0x4a, 0x1d, 0x2e,
},
}

View File

@ -24,7 +24,7 @@ func (ka rsaKeyAgreement) generateServerKeyExchange(config *Config, clientHello
return nil, nil
}
func (ka rsaKeyAgreement) processClientKeyExchange(config *Config, ckx *clientKeyExchangeMsg) ([]byte, os.Error) {
func (ka rsaKeyAgreement) processClientKeyExchange(config *Config, ckx *clientKeyExchangeMsg, version uint16) ([]byte, os.Error) {
preMasterSecret := make([]byte, 48)
_, err := io.ReadFull(config.rand(), preMasterSecret[2:])
if err != nil {
@ -34,11 +34,15 @@ func (ka rsaKeyAgreement) processClientKeyExchange(config *Config, ckx *clientKe
if len(ckx.ciphertext) < 2 {
return nil, os.NewError("bad ClientKeyExchange")
}
ciphertextLen := int(ckx.ciphertext[0])<<8 | int(ckx.ciphertext[1])
if ciphertextLen != len(ckx.ciphertext)-2 {
return nil, os.NewError("bad ClientKeyExchange")
ciphertext := ckx.ciphertext
if version != versionSSL30 {
ciphertextLen := int(ckx.ciphertext[0])<<8 | int(ckx.ciphertext[1])
if ciphertextLen != len(ckx.ciphertext)-2 {
return nil, os.NewError("bad ClientKeyExchange")
}
ciphertext = ckx.ciphertext[2:]
}
ciphertext := ckx.ciphertext[2:]
err = rsa.DecryptPKCS1v15SessionKey(config.rand(), config.Certificates[0].PrivateKey, ciphertext, preMasterSecret)
if err != nil {
@ -159,7 +163,7 @@ Curve:
return skx, nil
}
func (ka *ecdheRSAKeyAgreement) processClientKeyExchange(config *Config, ckx *clientKeyExchangeMsg) ([]byte, os.Error) {
func (ka *ecdheRSAKeyAgreement) processClientKeyExchange(config *Config, ckx *clientKeyExchangeMsg, version uint16) ([]byte, os.Error) {
if len(ckx.ciphertext) == 0 || int(ckx.ciphertext[0]) != len(ckx.ciphertext)-1 {
return nil, os.NewError("bad ClientKeyExchange")
}

107
prf.go
View File

@ -63,6 +63,39 @@ func pRF10(result, secret, label, seed []byte) {
}
}
// pRF30 implements the SSL 3.0 pseudo-random function, as defined in
// www.mozilla.org/projects/security/pki/nss/ssl/draft302.txt section 6.
func pRF30(result, secret, label, seed []byte) {
hashSHA1 := sha1.New()
hashMD5 := md5.New()
done := 0
i := 0
// RFC5246 section 6.3 says that the largest PRF output needed is 128
// bytes. Since no more ciphersuites will be added to SSLv3, this will
// remain true. Each iteration gives us 16 bytes so 10 iterations will
// be sufficient.
var b [11]byte
for done < len(result) {
for j := 0; j <= i; j++ {
b[j] = 'A' + byte(i)
}
hashSHA1.Reset()
hashSHA1.Write(b[:i+1])
hashSHA1.Write(secret)
hashSHA1.Write(seed)
digest := hashSHA1.Sum()
hashMD5.Reset()
hashMD5.Write(secret)
hashMD5.Write(digest)
done += copy(result[done:], hashMD5.Sum())
i++
}
}
const (
tlsRandomLength = 32 // Length of a random nonce in TLS 1.1.
masterSecretLength = 48 // Length of a master secret in TLS 1.1.
@ -77,19 +110,24 @@ var serverFinishedLabel = []byte("server finished")
// keysFromPreMasterSecret generates the connection keys from the pre master
// secret, given the lengths of the MAC key, cipher key and IV, as defined in
// RFC 2246, section 6.3.
func keysFromPreMasterSecret10(preMasterSecret, clientRandom, serverRandom []byte, macLen, keyLen, ivLen int) (masterSecret, clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV []byte) {
func keysFromPreMasterSecret(version uint16, preMasterSecret, clientRandom, serverRandom []byte, macLen, keyLen, ivLen int) (masterSecret, clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV []byte) {
prf := pRF10
if version == versionSSL30 {
prf = pRF30
}
var seed [tlsRandomLength * 2]byte
copy(seed[0:len(clientRandom)], clientRandom)
copy(seed[len(clientRandom):], serverRandom)
masterSecret = make([]byte, masterSecretLength)
pRF10(masterSecret, preMasterSecret, masterSecretLabel, seed[0:])
prf(masterSecret, preMasterSecret, masterSecretLabel, seed[0:])
copy(seed[0:len(clientRandom)], serverRandom)
copy(seed[len(serverRandom):], clientRandom)
n := 2*macLen + 2*keyLen + 2*ivLen
keyMaterial := make([]byte, n)
pRF10(keyMaterial, masterSecret, keyExpansionLabel, seed[0:])
prf(keyMaterial, masterSecret, keyExpansionLabel, seed[0:])
clientMAC = keyMaterial[:macLen]
keyMaterial = keyMaterial[macLen:]
serverMAC = keyMaterial[:macLen]
@ -104,6 +142,10 @@ func keysFromPreMasterSecret10(preMasterSecret, clientRandom, serverRandom []byt
return
}
func newFinishedHash(version uint16) finishedHash {
return finishedHash{md5.New(), sha1.New(), md5.New(), sha1.New(), version}
}
// A finishedHash calculates the hash of a set of handshake messages suitable
// for including in a Finished message.
type finishedHash struct {
@ -111,10 +153,7 @@ type finishedHash struct {
clientSHA1 hash.Hash
serverMD5 hash.Hash
serverSHA1 hash.Hash
}
func newFinishedHash() finishedHash {
return finishedHash{md5.New(), sha1.New(), md5.New(), sha1.New()}
version uint16
}
func (h finishedHash) Write(msg []byte) (n int, err os.Error) {
@ -125,9 +164,10 @@ func (h finishedHash) Write(msg []byte) (n int, err os.Error) {
return len(msg), nil
}
// finishedSum calculates the contents of the verify_data member of a Finished
// message given the MD5 and SHA1 hashes of a set of handshake messages.
func finishedSum(md5, sha1, label, masterSecret []byte) []byte {
// finishedSum10 calculates the contents of the verify_data member of a TLSv1
// Finished message given the MD5 and SHA1 hashes of a set of handshake
// messages.
func finishedSum10(md5, sha1, label, masterSecret []byte) []byte {
seed := make([]byte, len(md5)+len(sha1))
copy(seed, md5)
copy(seed[len(md5):], sha1)
@ -136,18 +176,61 @@ func finishedSum(md5, sha1, label, masterSecret []byte) []byte {
return out
}
// finishedSum30 calculates the contents of the verify_data member of a SSLv3
// Finished message given the MD5 and SHA1 hashes of a set of handshake
// messages.
func finishedSum30(md5, sha1 hash.Hash, masterSecret []byte, magic [4]byte) []byte {
md5.Write(magic[:])
md5.Write(masterSecret)
md5.Write(ssl30Pad1[:])
md5Digest := md5.Sum()
md5.Reset()
md5.Write(masterSecret)
md5.Write(ssl30Pad2[:])
md5.Write(md5Digest)
md5Digest = md5.Sum()
sha1.Write(magic[:])
sha1.Write(masterSecret)
sha1.Write(ssl30Pad1[:40])
sha1Digest := sha1.Sum()
sha1.Reset()
sha1.Write(masterSecret)
sha1.Write(ssl30Pad2[:40])
sha1.Write(sha1Digest)
sha1Digest = sha1.Sum()
ret := make([]byte, len(md5Digest)+len(sha1Digest))
copy(ret, md5Digest)
copy(ret[len(md5Digest):], sha1Digest)
return ret
}
var ssl3ClientFinishedMagic = [4]byte{0x43, 0x4c, 0x4e, 0x54}
var ssl3ServerFinishedMagic = [4]byte{0x53, 0x52, 0x56, 0x52}
// clientSum returns the contents of the verify_data member of a client's
// Finished message.
func (h finishedHash) clientSum(masterSecret []byte) []byte {
if h.version == versionSSL30 {
return finishedSum30(h.clientMD5, h.clientSHA1, masterSecret, ssl3ClientFinishedMagic)
}
md5 := h.clientMD5.Sum()
sha1 := h.clientSHA1.Sum()
return finishedSum(md5, sha1, clientFinishedLabel, masterSecret)
return finishedSum10(md5, sha1, clientFinishedLabel, masterSecret)
}
// serverSum returns the contents of the verify_data member of a server's
// Finished message.
func (h finishedHash) serverSum(masterSecret []byte) []byte {
if h.version == versionSSL30 {
return finishedSum30(h.serverMD5, h.serverSHA1, masterSecret, ssl3ServerFinishedMagic)
}
md5 := h.serverMD5.Sum()
sha1 := h.serverSHA1.Sum()
return finishedSum(md5, sha1, serverFinishedLabel, masterSecret)
return finishedSum10(md5, sha1, serverFinishedLabel, masterSecret)
}

View File

@ -34,6 +34,7 @@ func TestSplitPreMasterSecret(t *testing.T) {
}
type testKeysFromTest struct {
version uint16
preMasterSecret string
clientRandom, serverRandom string
masterSecret string
@ -47,7 +48,7 @@ func TestKeysFromPreMasterSecret(t *testing.T) {
in, _ := hex.DecodeString(test.preMasterSecret)
clientRandom, _ := hex.DecodeString(test.clientRandom)
serverRandom, _ := hex.DecodeString(test.serverRandom)
master, clientMAC, serverMAC, clientKey, serverKey, _, _ := keysFromPreMasterSecret10(in, clientRandom, serverRandom, test.macLen, test.keyLen, 0)
master, clientMAC, serverMAC, clientKey, serverKey, _, _ := keysFromPreMasterSecret(test.version, in, clientRandom, serverRandom, test.macLen, test.keyLen, 0)
masterString := hex.EncodeToString(master)
clientMACString := hex.EncodeToString(clientMAC)
serverMACString := hex.EncodeToString(serverMAC)
@ -58,7 +59,7 @@ func TestKeysFromPreMasterSecret(t *testing.T) {
serverMACString != test.serverMAC ||
clientKeyString != test.clientKey ||
serverKeyString != test.serverKey {
t.Errorf("#%d: got: (%s, %s, %s, %s, %s) want: (%s, %s, %s, %s %s)", i, masterString, clientMACString, serverMACString, clientKeyString, serverMACString, test.masterSecret, test.clientMAC, test.serverMAC, test.clientKey, test.serverKey)
t.Errorf("#%d: got: (%s, %s, %s, %s, %s) want: (%s, %s, %s, %s, %s)", i, masterString, clientMACString, serverMACString, clientKeyString, serverKeyString, test.masterSecret, test.clientMAC, test.serverMAC, test.clientKey, test.serverKey)
}
}
}
@ -66,6 +67,7 @@ func TestKeysFromPreMasterSecret(t *testing.T) {
// These test vectors were generated from GnuTLS using `gnutls-cli --insecure -d 9 `
var testKeysFromTests = []testKeysFromTest{
{
versionTLS10,
"0302cac83ad4b1db3b9ab49ad05957de2a504a634a386fc600889321e1a971f57479466830ac3e6f468e87f5385fa0c5",
"4ae66303755184a3917fcb44880605fcc53baa01912b22ed94473fc69cebd558",
"4ae663020ec16e6bb5130be918cfcafd4d765979a3136a5d50c593446e4e44db",
@ -78,6 +80,7 @@ var testKeysFromTests = []testKeysFromTest{
16,
},
{
versionTLS10,
"03023f7527316bc12cbcd69e4b9e8275d62c028f27e65c745cfcddc7ce01bd3570a111378b63848127f1c36e5f9e4890",
"4ae66364b5ea56b20ce4e25555aed2d7e67f42788dd03f3fee4adae0459ab106",
"4ae66363ab815cbf6a248b87d6b556184e945e9b97fbdf247858b0bdafacfa1c",
@ -90,6 +93,7 @@ var testKeysFromTests = []testKeysFromTest{
16,
},
{
versionTLS10,
"832d515f1d61eebb2be56ba0ef79879efb9b527504abb386fb4310ed5d0e3b1f220d3bb6b455033a2773e6d8bdf951d278a187482b400d45deb88a5d5a6bb7d6a7a1decc04eb9ef0642876cd4a82d374d3b6ff35f0351dc5d411104de431375355addc39bfb1f6329fb163b0bc298d658338930d07d313cd980a7e3d9196cac1",
"4ae663b2ee389c0de147c509d8f18f5052afc4aaf9699efe8cb05ece883d3a5e",
"4ae664d503fd4cff50cfc1fb8fc606580f87b0fcdac9554ba0e01d785bdf278e",
@ -101,4 +105,17 @@ var testKeysFromTests = []testKeysFromTest{
20,
16,
},
{
versionSSL30,
"832d515f1d61eebb2be56ba0ef79879efb9b527504abb386fb4310ed5d0e3b1f220d3bb6b455033a2773e6d8bdf951d278a187482b400d45deb88a5d5a6bb7d6a7a1decc04eb9ef0642876cd4a82d374d3b6ff35f0351dc5d411104de431375355addc39bfb1f6329fb163b0bc298d658338930d07d313cd980a7e3d9196cac1",
"4ae663b2ee389c0de147c509d8f18f5052afc4aaf9699efe8cb05ece883d3a5e",
"4ae664d503fd4cff50cfc1fb8fc606580f87b0fcdac9554ba0e01d785bdf278e",
"a614863e56299dcffeea2938f22c2ba023768dbe4b3f6877bc9c346c6ae529b51d9cb87ff9695ea4d01f2205584405b2",
"2c450d5b6f6e2013ac6bea6a0b32200d4e1ffb94",
"7a7a7438769536f2fb1ae49a61f0703b79b2dc53",
"f8f6b26c10f12855c9aafb1e0e839ccf",
"2b9d4b4a60cb7f396780ebff50650419",
20,
16,
},
}