1 files changed, 275 insertions, 0 deletions
diff --git a/src/crypto/tls/cipher_suites.go b/src/crypto/tls/cipher_suites.go
new file mode 100644
index 000000000..226e06d68
--- /dev/null
+++ b/src/crypto/tls/cipher_suites.go
@@ -0,0 +1,275 @@
+// Copyright 2010 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/aes"
+	"crypto/cipher"
+	"crypto/des"
+	"crypto/hmac"
+	"crypto/rc4"
+	"crypto/sha1"
+	"crypto/x509"
+	"hash"
+)
+
+// a keyAgreement implements the client and server side of a TLS key agreement
+// protocol by generating and processing key exchange messages.
+type keyAgreement interface {
+	// On the server side, the first two methods are called in order.
+
+	// In the case that the key agreement protocol doesn't use a
+	// ServerKeyExchange message, generateServerKeyExchange can return nil,
+	// nil.
+	generateServerKeyExchange(*Config, *Certificate, *clientHelloMsg, *serverHelloMsg) (*serverKeyExchangeMsg, error)
+	processClientKeyExchange(*Config, *Certificate, *clientKeyExchangeMsg, uint16) ([]byte, error)
+
+	// On the client side, the next two methods are called in order.
+
+	// This method may not be called if the server doesn't send a
+	// ServerKeyExchange message.
+	processServerKeyExchange(*Config, *clientHelloMsg, *serverHelloMsg, *x509.Certificate, *serverKeyExchangeMsg) error
+	generateClientKeyExchange(*Config, *clientHelloMsg, *x509.Certificate) ([]byte, *clientKeyExchangeMsg, error)
+}
+
+const (
+	// suiteECDH indicates that the cipher suite involves elliptic curve
+	// Diffie-Hellman. This means that it should only be selected when the
+	// client indicates that it supports ECC with a curve and point format
+	// that we're happy with.
+	suiteECDHE = 1 << iota
+	// suiteECDSA indicates that the cipher suite involves an ECDSA
+	// signature and therefore may only be selected when the server's
+	// certificate is ECDSA. If this is not set then the cipher suite is
+	// RSA based.
+	suiteECDSA
+	// suiteTLS12 indicates that the cipher suite should only be advertised
+	// and accepted when using TLS 1.2.
+	suiteTLS12
+)
+
+// A cipherSuite is a specific combination of key agreement, cipher and MAC
+// function. All cipher suites currently assume RSA key agreement.
+type cipherSuite struct {
+	id uint16
+	// the lengths, in bytes, of the key material needed for each component.
+	keyLen int
+	macLen int
+	ivLen  int
+	ka     func(version uint16) keyAgreement
+	// flags is a bitmask of the suite* values, above.
+	flags  int
+	cipher func(key, iv []byte, isRead bool) interface{}
+	mac    func(version uint16, macKey []byte) macFunction
+	aead   func(key, fixedNonce []byte) cipher.AEAD
+}
+
+var cipherSuites = []*cipherSuite{
+	// Ciphersuite order is chosen so that ECDHE comes before plain RSA
+	// and RC4 comes before AES (because of the Lucky13 attack).
+	{TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, ecdheRSAKA, suiteECDHE | suiteTLS12, nil, nil, aeadAESGCM},
+	{TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, ecdheECDSAKA, suiteECDHE | suiteECDSA | suiteTLS12, nil, nil, aeadAESGCM},
+	{TLS_ECDHE_RSA_WITH_RC4_128_SHA, 16, 20, 0, ecdheRSAKA, suiteECDHE, cipherRC4, macSHA1, nil},
+	{TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, 16, 20, 0, ecdheECDSAKA, suiteECDHE | suiteECDSA, cipherRC4, macSHA1, nil},
+	{TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, 16, 20, 16, ecdheRSAKA, suiteECDHE, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, 16, 20, 16, ecdheECDSAKA, suiteECDHE | suiteECDSA, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, 32, 20, 16, ecdheRSAKA, suiteECDHE, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, 32, 20, 16, ecdheECDSAKA, suiteECDHE | suiteECDSA, cipherAES, macSHA1, nil},
+	{TLS_RSA_WITH_RC4_128_SHA, 16, 20, 0, rsaKA, 0, cipherRC4, macSHA1, nil},
+	{TLS_RSA_WITH_AES_128_CBC_SHA, 16, 20, 16, rsaKA, 0, cipherAES, macSHA1, nil},
+	{TLS_RSA_WITH_AES_256_CBC_SHA, 32, 20, 16, rsaKA, 0, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, ecdheRSAKA, suiteECDHE, cipher3DES, macSHA1, nil},
+	{TLS_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, rsaKA, 0, cipher3DES, macSHA1, nil},
+}
+
+func cipherRC4(key, iv []byte, isRead bool) interface{} {
+	cipher, _ := rc4.NewCipher(key)
+	return cipher
+}
+
+func cipher3DES(key, iv []byte, isRead bool) interface{} {
+	block, _ := des.NewTripleDESCipher(key)
+	if isRead {
+		return cipher.NewCBCDecrypter(block, iv)
+	}
+	return cipher.NewCBCEncrypter(block, iv)
+}
+
+func cipherAES(key, iv []byte, isRead bool) interface{} {
+	block, _ := aes.NewCipher(key)
+	if isRead {
+		return cipher.NewCBCDecrypter(block, iv)
+	}
+	return cipher.NewCBCEncrypter(block, iv)
+}
+
+// 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.New(sha1.New, key)}
+}
+
+type macFunction interface {
+	Size() int
+	MAC(digestBuf, seq, header, data []byte) []byte
+}
+
+// fixedNonceAEAD wraps an AEAD and prefixes a fixed portion of the nonce to
+// each call.
+type fixedNonceAEAD struct {
+	// sealNonce and openNonce are buffers where the larger nonce will be
+	// constructed. Since a seal and open operation may be running
+	// concurrently, there is a separate buffer for each.
+	sealNonce, openNonce []byte
+	aead                 cipher.AEAD
+}
+
+func (f *fixedNonceAEAD) NonceSize() int { return 8 }
+func (f *fixedNonceAEAD) Overhead() int  { return f.aead.Overhead() }
+
+func (f *fixedNonceAEAD) Seal(out, nonce, plaintext, additionalData []byte) []byte {
+	copy(f.sealNonce[len(f.sealNonce)-8:], nonce)
+	return f.aead.Seal(out, f.sealNonce, plaintext, additionalData)
+}
+
+func (f *fixedNonceAEAD) Open(out, nonce, plaintext, additionalData []byte) ([]byte, error) {
+	copy(f.openNonce[len(f.openNonce)-8:], nonce)
+	return f.aead.Open(out, f.openNonce, plaintext, additionalData)
+}
+
+func aeadAESGCM(key, fixedNonce []byte) cipher.AEAD {
+	aes, err := aes.NewCipher(key)
+	if err != nil {
+		panic(err)
+	}
+	aead, err := cipher.NewGCM(aes)
+	if err != nil {
+		panic(err)
+	}
+
+	nonce1, nonce2 := make([]byte, 12), make([]byte, 12)
+	copy(nonce1, fixedNonce)
+	copy(nonce2, fixedNonce)
+
+	return &fixedNonceAEAD{nonce1, nonce2, aead}
+}
+
+// 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(digestBuf, seq, header, data []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(header[:1])
+	s.h.Write(header[3:5])
+	s.h.Write(data)
+	digestBuf = s.h.Sum(digestBuf[:0])
+
+	s.h.Reset()
+	s.h.Write(s.key)
+	s.h.Write(ssl30Pad2[:padLength])
+	s.h.Write(digestBuf)
+	return s.h.Sum(digestBuf[:0])
+}
+
+// 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(digestBuf, seq, header, data []byte) []byte {
+	s.h.Reset()
+	s.h.Write(seq)
+	s.h.Write(header)
+	s.h.Write(data)
+	return s.h.Sum(digestBuf[:0])
+}
+
+func rsaKA(version uint16) keyAgreement {
+	return rsaKeyAgreement{}
+}
+
+func ecdheECDSAKA(version uint16) keyAgreement {
+	return &ecdheKeyAgreement{
+		sigType: signatureECDSA,
+		version: version,
+	}
+}
+
+func ecdheRSAKA(version uint16) keyAgreement {
+	return &ecdheKeyAgreement{
+		sigType: signatureRSA,
+		version: version,
+	}
+}
+
+// mutualCipherSuite returns a cipherSuite given a list of supported
+// ciphersuites and the id requested by the peer.
+func mutualCipherSuite(have []uint16, want uint16) *cipherSuite {
+	for _, id := range have {
+		if id == want {
+			for _, suite := range cipherSuites {
+				if suite.id == want {
+					return suite
+				}
+			}
+			return nil
+		}
+	}
+	return nil
+}
+
+// A list of the possible cipher suite ids. Taken from
+// http://www.iana.org/assignments/tls-parameters/tls-parameters.xml
+const (
+	TLS_RSA_WITH_RC4_128_SHA                uint16 = 0x0005
+	TLS_RSA_WITH_3DES_EDE_CBC_SHA           uint16 = 0x000a
+	TLS_RSA_WITH_AES_128_CBC_SHA            uint16 = 0x002f
+	TLS_RSA_WITH_AES_256_CBC_SHA            uint16 = 0x0035
+	TLS_ECDHE_ECDSA_WITH_RC4_128_SHA        uint16 = 0xc007
+	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA    uint16 = 0xc009
+	TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA    uint16 = 0xc00a
+	TLS_ECDHE_RSA_WITH_RC4_128_SHA          uint16 = 0xc011
+	TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA     uint16 = 0xc012
+	TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA      uint16 = 0xc013
+	TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA      uint16 = 0xc014
+	TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256   uint16 = 0xc02f
+	TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 uint16 = 0xc02b
+
+	// TLS_FALLBACK_SCSV isn't a standard cipher suite but an indicator
+	// that the client is doing version fallback. See
+	// https://tools.ietf.org/html/draft-ietf-tls-downgrade-scsv-00.
+	TLS_FALLBACK_SCSV uint16 = 0x5600
+)