1 files changed, 153 insertions, 0 deletions
diff --git a/libgo/go/crypto/tls/prf.go b/libgo/go/crypto/tls/prf.go
new file mode 100644
index 000000000..478cf65f9
--- /dev/null
+++ b/libgo/go/crypto/tls/prf.go
@@ -0,0 +1,153 @@
+// 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
+
+import (
+	"crypto/hmac"
+	"crypto/md5"
+	"crypto/sha1"
+	"hash"
+	"os"
+)
+
+// 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()
+
+	j := 0
+	for j < len(result) {
+		h.Reset()
+		h.Write(a)
+		h.Write(seed)
+		b := h.Sum()
+		todo := len(b)
+		if j+todo > len(result) {
+			todo = len(result) - j
+		}
+		copy(result[j:j+todo], b)
+		j += todo
+
+		h.Reset()
+		h.Write(a)
+		a = h.Sum()
+	}
+}
+
+// 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
+	}
+}
+
+const (
+	tlsRandomLength      = 32 // Length of a random nonce in TLS 1.1.
+	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")
+
+// 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) {
+	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:])
+
+	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:])
+	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
+}
+
+// A finishedHash calculates the hash of a set of handshake messages suitable
+// for including in a Finished message.
+type finishedHash struct {
+	clientMD5  hash.Hash
+	clientSHA1 hash.Hash
+	serverMD5  hash.Hash
+	serverSHA1 hash.Hash
+}
+
+func newFinishedHash() finishedHash {
+	return finishedHash{md5.New(), sha1.New(), md5.New(), sha1.New()}
+}
+
+func (h finishedHash) Write(msg []byte) (n int, err os.Error) {
+	h.clientMD5.Write(msg)
+	h.clientSHA1.Write(msg)
+	h.serverMD5.Write(msg)
+	h.serverSHA1.Write(msg)
+	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 {
+	seed := make([]byte, len(md5)+len(sha1))
+	copy(seed, md5)
+	copy(seed[len(md5):], sha1)
+	out := make([]byte, finishedVerifyLength)
+	pRF10(out, masterSecret, label, seed)
+	return out
+}
+
+// clientSum returns the contents of the verify_data member of a client's
+// Finished message.
+func (h finishedHash) clientSum(masterSecret []byte) []byte {
+	md5 := h.clientMD5.Sum()
+	sha1 := h.clientSHA1.Sum()
+	return finishedSum(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 {
+	md5 := h.serverMD5.Sum()
+	sha1 := h.serverSHA1.Sum()
+	return finishedSum(md5, sha1, serverFinishedLabel, masterSecret)
+}