284 lines
8.4 KiB
Go
284 lines
8.4 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 qtls
|
||
|
|
|
||
|
|
import (
|
||
|
|
"crypto"
|
||
|
|
"crypto/hmac"
|
||
|
|
"crypto/md5"
|
||
|
|
"crypto/sha1"
|
||
|
|
"crypto/sha256"
|
||
|
|
"crypto/sha512"
|
||
|
|
"errors"
|
||
|
|
"fmt"
|
||
|
|
"hash"
|
||
|
|
)
|
||
|
|
|
||
|
|
// Split a premaster secret in two as specified in RFC 4346, Section 5.
|
||
|
|
func splitPreMasterSecret(secret []byte) (s1, s2 []byte) {
|
||
|
|
s1 = secret[0 : (len(secret)+1)/2]
|
||
|
|
s2 = secret[len(secret)/2:]
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
// pHash implements the P_hash function, as defined in RFC 4346, Section 5.
|
||
|
|
func pHash(result, secret, seed []byte, hash func() hash.Hash) {
|
||
|
|
h := hmac.New(hash, secret)
|
||
|
|
h.Write(seed)
|
||
|
|
a := h.Sum(nil)
|
||
|
|
|
||
|
|
j := 0
|
||
|
|
for j < len(result) {
|
||
|
|
h.Reset()
|
||
|
|
h.Write(a)
|
||
|
|
h.Write(seed)
|
||
|
|
b := h.Sum(nil)
|
||
|
|
copy(result[j:], b)
|
||
|
|
j += len(b)
|
||
|
|
|
||
|
|
h.Reset()
|
||
|
|
h.Write(a)
|
||
|
|
a = h.Sum(nil)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// prf10 implements the TLS 1.0 pseudo-random function, as defined in RFC 2246, Section 5.
|
||
|
|
func prf10(result, secret, label, seed []byte) {
|
||
|
|
hashSHA1 := sha1.New
|
||
|
|
hashMD5 := md5.New
|
||
|
|
|
||
|
|
labelAndSeed := make([]byte, len(label)+len(seed))
|
||
|
|
copy(labelAndSeed, label)
|
||
|
|
copy(labelAndSeed[len(label):], seed)
|
||
|
|
|
||
|
|
s1, s2 := splitPreMasterSecret(secret)
|
||
|
|
pHash(result, s1, labelAndSeed, hashMD5)
|
||
|
|
result2 := make([]byte, len(result))
|
||
|
|
pHash(result2, s2, labelAndSeed, hashSHA1)
|
||
|
|
|
||
|
|
for i, b := range result2 {
|
||
|
|
result[i] ^= b
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// prf12 implements the TLS 1.2 pseudo-random function, as defined in RFC 5246, Section 5.
|
||
|
|
func prf12(hashFunc func() hash.Hash) func(result, secret, label, seed []byte) {
|
||
|
|
return func(result, secret, label, seed []byte) {
|
||
|
|
labelAndSeed := make([]byte, len(label)+len(seed))
|
||
|
|
copy(labelAndSeed, label)
|
||
|
|
copy(labelAndSeed[len(label):], seed)
|
||
|
|
|
||
|
|
pHash(result, secret, labelAndSeed, hashFunc)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
const (
|
||
|
|
masterSecretLength = 48 // Length of a master secret in TLS 1.1.
|
||
|
|
finishedVerifyLength = 12 // Length of verify_data in a Finished message.
|
||
|
|
)
|
||
|
|
|
||
|
|
var masterSecretLabel = []byte("master secret")
|
||
|
|
var keyExpansionLabel = []byte("key expansion")
|
||
|
|
var clientFinishedLabel = []byte("client finished")
|
||
|
|
var serverFinishedLabel = []byte("server finished")
|
||
|
|
|
||
|
|
func prfAndHashForVersion(version uint16, suite *cipherSuite) (func(result, secret, label, seed []byte), crypto.Hash) {
|
||
|
|
switch version {
|
||
|
|
case VersionTLS10, VersionTLS11:
|
||
|
|
return prf10, crypto.Hash(0)
|
||
|
|
case VersionTLS12:
|
||
|
|
if suite.flags&suiteSHA384 != 0 {
|
||
|
|
return prf12(sha512.New384), crypto.SHA384
|
||
|
|
}
|
||
|
|
return prf12(sha256.New), crypto.SHA256
|
||
|
|
default:
|
||
|
|
panic("unknown version")
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
func prfForVersion(version uint16, suite *cipherSuite) func(result, secret, label, seed []byte) {
|
||
|
|
prf, _ := prfAndHashForVersion(version, suite)
|
||
|
|
return prf
|
||
|
|
}
|
||
|
|
|
||
|
|
// masterFromPreMasterSecret generates the master secret from the pre-master
|
||
|
|
// secret. See RFC 5246, Section 8.1.
|
||
|
|
func masterFromPreMasterSecret(version uint16, suite *cipherSuite, preMasterSecret, clientRandom, serverRandom []byte) []byte {
|
||
|
|
seed := make([]byte, 0, len(clientRandom)+len(serverRandom))
|
||
|
|
seed = append(seed, clientRandom...)
|
||
|
|
seed = append(seed, serverRandom...)
|
||
|
|
|
||
|
|
masterSecret := make([]byte, masterSecretLength)
|
||
|
|
prfForVersion(version, suite)(masterSecret, preMasterSecret, masterSecretLabel, seed)
|
||
|
|
return masterSecret
|
||
|
|
}
|
||
|
|
|
||
|
|
// keysFromMasterSecret generates the connection keys from the master
|
||
|
|
// secret, given the lengths of the MAC key, cipher key and IV, as defined in
|
||
|
|
// RFC 2246, Section 6.3.
|
||
|
|
func keysFromMasterSecret(version uint16, suite *cipherSuite, masterSecret, clientRandom, serverRandom []byte, macLen, keyLen, ivLen int) (clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV []byte) {
|
||
|
|
seed := make([]byte, 0, len(serverRandom)+len(clientRandom))
|
||
|
|
seed = append(seed, serverRandom...)
|
||
|
|
seed = append(seed, clientRandom...)
|
||
|
|
|
||
|
|
n := 2*macLen + 2*keyLen + 2*ivLen
|
||
|
|
keyMaterial := make([]byte, n)
|
||
|
|
prfForVersion(version, suite)(keyMaterial, masterSecret, keyExpansionLabel, seed)
|
||
|
|
clientMAC = keyMaterial[:macLen]
|
||
|
|
keyMaterial = keyMaterial[macLen:]
|
||
|
|
serverMAC = keyMaterial[:macLen]
|
||
|
|
keyMaterial = keyMaterial[macLen:]
|
||
|
|
clientKey = keyMaterial[:keyLen]
|
||
|
|
keyMaterial = keyMaterial[keyLen:]
|
||
|
|
serverKey = keyMaterial[:keyLen]
|
||
|
|
keyMaterial = keyMaterial[keyLen:]
|
||
|
|
clientIV = keyMaterial[:ivLen]
|
||
|
|
keyMaterial = keyMaterial[ivLen:]
|
||
|
|
serverIV = keyMaterial[:ivLen]
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
func newFinishedHash(version uint16, cipherSuite *cipherSuite) finishedHash {
|
||
|
|
var buffer []byte
|
||
|
|
if version >= VersionTLS12 {
|
||
|
|
buffer = []byte{}
|
||
|
|
}
|
||
|
|
|
||
|
|
prf, hash := prfAndHashForVersion(version, cipherSuite)
|
||
|
|
if hash != 0 {
|
||
|
|
return finishedHash{hash.New(), hash.New(), nil, nil, buffer, version, prf}
|
||
|
|
}
|
||
|
|
|
||
|
|
return finishedHash{sha1.New(), sha1.New(), md5.New(), md5.New(), buffer, version, prf}
|
||
|
|
}
|
||
|
|
|
||
|
|
// A finishedHash calculates the hash of a set of handshake messages suitable
|
||
|
|
// for including in a Finished message.
|
||
|
|
type finishedHash struct {
|
||
|
|
client hash.Hash
|
||
|
|
server hash.Hash
|
||
|
|
|
||
|
|
// Prior to TLS 1.2, an additional MD5 hash is required.
|
||
|
|
clientMD5 hash.Hash
|
||
|
|
serverMD5 hash.Hash
|
||
|
|
|
||
|
|
// In TLS 1.2, a full buffer is sadly required.
|
||
|
|
buffer []byte
|
||
|
|
|
||
|
|
version uint16
|
||
|
|
prf func(result, secret, label, seed []byte)
|
||
|
|
}
|
||
|
|
|
||
|
|
func (h *finishedHash) Write(msg []byte) (n int, err error) {
|
||
|
|
h.client.Write(msg)
|
||
|
|
h.server.Write(msg)
|
||
|
|
|
||
|
|
if h.version < VersionTLS12 {
|
||
|
|
h.clientMD5.Write(msg)
|
||
|
|
h.serverMD5.Write(msg)
|
||
|
|
}
|
||
|
|
|
||
|
|
if h.buffer != nil {
|
||
|
|
h.buffer = append(h.buffer, msg...)
|
||
|
|
}
|
||
|
|
|
||
|
|
return len(msg), nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func (h finishedHash) Sum() []byte {
|
||
|
|
if h.version >= VersionTLS12 {
|
||
|
|
return h.client.Sum(nil)
|
||
|
|
}
|
||
|
|
|
||
|
|
out := make([]byte, 0, md5.Size+sha1.Size)
|
||
|
|
out = h.clientMD5.Sum(out)
|
||
|
|
return h.client.Sum(out)
|
||
|
|
}
|
||
|
|
|
||
|
|
// clientSum returns the contents of the verify_data member of a client's
|
||
|
|
// Finished message.
|
||
|
|
func (h finishedHash) clientSum(masterSecret []byte) []byte {
|
||
|
|
out := make([]byte, finishedVerifyLength)
|
||
|
|
h.prf(out, masterSecret, clientFinishedLabel, h.Sum())
|
||
|
|
return out
|
||
|
|
}
|
||
|
|
|
||
|
|
// serverSum returns the contents of the verify_data member of a server's
|
||
|
|
// Finished message.
|
||
|
|
func (h finishedHash) serverSum(masterSecret []byte) []byte {
|
||
|
|
out := make([]byte, finishedVerifyLength)
|
||
|
|
h.prf(out, masterSecret, serverFinishedLabel, h.Sum())
|
||
|
|
return out
|
||
|
|
}
|
||
|
|
|
||
|
|
// hashForClientCertificate returns the handshake messages so far, pre-hashed if
|
||
|
|
// necessary, suitable for signing by a TLS client certificate.
|
||
|
|
func (h finishedHash) hashForClientCertificate(sigType uint8, hashAlg crypto.Hash, masterSecret []byte) []byte {
|
||
|
|
if (h.version >= VersionTLS12 || sigType == signatureEd25519) && h.buffer == nil {
|
||
|
|
panic("tls: handshake hash for a client certificate requested after discarding the handshake buffer")
|
||
|
|
}
|
||
|
|
|
||
|
|
if sigType == signatureEd25519 {
|
||
|
|
return h.buffer
|
||
|
|
}
|
||
|
|
|
||
|
|
if h.version >= VersionTLS12 {
|
||
|
|
hash := hashAlg.New()
|
||
|
|
hash.Write(h.buffer)
|
||
|
|
return hash.Sum(nil)
|
||
|
|
}
|
||
|
|
|
||
|
|
if sigType == signatureECDSA {
|
||
|
|
return h.server.Sum(nil)
|
||
|
|
}
|
||
|
|
|
||
|
|
return h.Sum()
|
||
|
|
}
|
||
|
|
|
||
|
|
// discardHandshakeBuffer is called when there is no more need to
|
||
|
|
// buffer the entirety of the handshake messages.
|
||
|
|
func (h *finishedHash) discardHandshakeBuffer() {
|
||
|
|
h.buffer = nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// noExportedKeyingMaterial is used as a value of
|
||
|
|
// ConnectionState.ekm when renegotiation is enabled and thus
|
||
|
|
// we wish to fail all key-material export requests.
|
||
|
|
func noExportedKeyingMaterial(label string, context []byte, length int) ([]byte, error) {
|
||
|
|
return nil, errors.New("crypto/tls: ExportKeyingMaterial is unavailable when renegotiation is enabled")
|
||
|
|
}
|
||
|
|
|
||
|
|
// ekmFromMasterSecret generates exported keying material as defined in RFC 5705.
|
||
|
|
func ekmFromMasterSecret(version uint16, suite *cipherSuite, masterSecret, clientRandom, serverRandom []byte) func(string, []byte, int) ([]byte, error) {
|
||
|
|
return func(label string, context []byte, length int) ([]byte, error) {
|
||
|
|
switch label {
|
||
|
|
case "client finished", "server finished", "master secret", "key expansion":
|
||
|
|
// These values are reserved and may not be used.
|
||
|
|
return nil, fmt.Errorf("crypto/tls: reserved ExportKeyingMaterial label: %s", label)
|
||
|
|
}
|
||
|
|
|
||
|
|
seedLen := len(serverRandom) + len(clientRandom)
|
||
|
|
if context != nil {
|
||
|
|
seedLen += 2 + len(context)
|
||
|
|
}
|
||
|
|
seed := make([]byte, 0, seedLen)
|
||
|
|
|
||
|
|
seed = append(seed, clientRandom...)
|
||
|
|
seed = append(seed, serverRandom...)
|
||
|
|
|
||
|
|
if context != nil {
|
||
|
|
if len(context) >= 1<<16 {
|
||
|
|
return nil, fmt.Errorf("crypto/tls: ExportKeyingMaterial context too long")
|
||
|
|
}
|
||
|
|
seed = append(seed, byte(len(context)>>8), byte(len(context)))
|
||
|
|
seed = append(seed, context...)
|
||
|
|
}
|
||
|
|
|
||
|
|
keyMaterial := make([]byte, length)
|
||
|
|
prfForVersion(version, suite)(keyMaterial, masterSecret, []byte(label), seed)
|
||
|
|
return keyMaterial, nil
|
||
|
|
}
|
||
|
|
}
|