| // 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 main | |
| import ( | |
| "crypto/aes" | |
| "crypto/cipher" | |
| "crypto/des" | |
| "crypto/hmac" | |
| "crypto/md5" | |
| "crypto/rc4" | |
| "crypto/sha1" | |
| "crypto/sha256" | |
| "crypto/sha512" | |
| "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 | |
| // suiteSHA384 indicates that the cipher suite uses SHA384 as the | |
| // handshake hash. | |
| suiteSHA384 | |
| // suiteNoDTLS indicates that the cipher suite cannot be used | |
| // in DTLS. | |
| suiteNoDTLS | |
| // suitePSK indicates that the cipher suite authenticates with | |
| // a pre-shared key rather than a server private key. | |
| suitePSK | |
| ) | |
| // 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_AES_256_GCM_SHA384, 32, 0, 4, ecdheRSAKA, suiteECDHE | suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM}, | |
| {TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, 32, 0, 4, ecdheECDSAKA, suiteECDHE | suiteECDSA | suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM}, | |
| {TLS_ECDHE_RSA_WITH_RC4_128_SHA, 16, 20, 0, ecdheRSAKA, suiteECDHE | suiteNoDTLS, cipherRC4, macSHA1, nil}, | |
| {TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, 16, 20, 0, ecdheECDSAKA, suiteECDHE | suiteECDSA | suiteNoDTLS, cipherRC4, macSHA1, nil}, | |
| {TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, 16, 32, 16, ecdheRSAKA, suiteECDHE | suiteTLS12, cipherAES, macSHA256, nil}, | |
| {TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, 16, 32, 16, ecdheECDSAKA, suiteECDHE | suiteECDSA | suiteTLS12, cipherAES, macSHA256, 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_SHA384, 32, 48, 16, ecdheRSAKA, suiteECDHE | suiteTLS12 | suiteSHA384, cipherAES, macSHA384, nil}, | |
| {TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384, 32, 48, 16, ecdheECDSAKA, suiteECDHE | suiteECDSA | suiteTLS12 | suiteSHA384, cipherAES, macSHA384, 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_DHE_RSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, dheRSAKA, suiteTLS12, nil, nil, aeadAESGCM}, | |
| {TLS_DHE_RSA_WITH_AES_256_GCM_SHA384, 32, 0, 4, dheRSAKA, suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM}, | |
| {TLS_DHE_RSA_WITH_AES_128_CBC_SHA256, 16, 32, 16, dheRSAKA, suiteTLS12, cipherAES, macSHA256, nil}, | |
| {TLS_DHE_RSA_WITH_AES_256_CBC_SHA256, 32, 32, 16, dheRSAKA, suiteTLS12, cipherAES, macSHA256, nil}, | |
| {TLS_DHE_RSA_WITH_AES_128_CBC_SHA, 16, 20, 16, dheRSAKA, 0, cipherAES, macSHA1, nil}, | |
| {TLS_DHE_RSA_WITH_AES_256_CBC_SHA, 32, 20, 16, dheRSAKA, 0, cipherAES, macSHA1, nil}, | |
| {TLS_RSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, rsaKA, suiteTLS12, nil, nil, aeadAESGCM}, | |
| {TLS_RSA_WITH_AES_256_GCM_SHA384, 32, 0, 4, rsaKA, suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM}, | |
| {TLS_RSA_WITH_RC4_128_SHA, 16, 20, 0, rsaKA, suiteNoDTLS, cipherRC4, macSHA1, nil}, | |
| {TLS_RSA_WITH_RC4_128_MD5, 16, 16, 0, rsaKA, suiteNoDTLS, cipherRC4, macMD5, nil}, | |
| {TLS_RSA_WITH_AES_128_CBC_SHA256, 16, 32, 16, rsaKA, suiteTLS12, cipherAES, macSHA256, nil}, | |
| {TLS_RSA_WITH_AES_256_CBC_SHA256, 32, 32, 16, rsaKA, suiteTLS12, cipherAES, macSHA256, 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_DHE_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, dheRSAKA, 0, cipher3DES, macSHA1, nil}, | |
| {TLS_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, rsaKA, 0, cipher3DES, macSHA1, nil}, | |
| {TLS_ECDHE_PSK_WITH_AES_128_GCM_SHA256, 16, 0, 4, ecdhePSKKA, suiteECDHE | suiteTLS12 | suitePSK, nil, nil, aeadAESGCM}, | |
| {TLS_PSK_WITH_RC4_128_SHA, 16, 20, 0, pskKA, suiteNoDTLS | suitePSK, cipherRC4, macSHA1, nil}, | |
| {TLS_PSK_WITH_AES_128_CBC_SHA, 16, 20, 16, pskKA, suitePSK, cipherAES, macSHA1, nil}, | |
| {TLS_PSK_WITH_AES_256_CBC_SHA, 32, 20, 16, pskKA, suitePSK, cipherAES, 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)} | |
| } | |
| func macMD5(version uint16, key []byte) macFunction { | |
| if version == VersionSSL30 { | |
| mac := ssl30MAC{ | |
| h: md5.New(), | |
| key: make([]byte, len(key)), | |
| } | |
| copy(mac.key, key) | |
| return mac | |
| } | |
| return tls10MAC{hmac.New(md5.New, key)} | |
| } | |
| func macSHA256(version uint16, key []byte) macFunction { | |
| if version == VersionSSL30 { | |
| mac := ssl30MAC{ | |
| h: sha256.New(), | |
| key: make([]byte, len(key)), | |
| } | |
| copy(mac.key, key) | |
| return mac | |
| } | |
| return tls10MAC{hmac.New(sha256.New, key)} | |
| } | |
| func macSHA384(version uint16, key []byte) macFunction { | |
| if version == VersionSSL30 { | |
| mac := ssl30MAC{ | |
| h: sha512.New384(), | |
| key: make([]byte, len(key)), | |
| } | |
| copy(mac.key, key) | |
| return mac | |
| } | |
| return tls10MAC{hmac.New(sha512.New384, key)} | |
| } | |
| type macFunction interface { | |
| Size() int | |
| MAC(digestBuf, seq, header, length, 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, length, 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(length) | |
| 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, length, data []byte) []byte { | |
| s.h.Reset() | |
| s.h.Write(seq) | |
| s.h.Write(header) | |
| s.h.Write(length) | |
| s.h.Write(data) | |
| return s.h.Sum(digestBuf[:0]) | |
| } | |
| func rsaKA(version uint16) keyAgreement { | |
| return &rsaKeyAgreement{} | |
| } | |
| func ecdheECDSAKA(version uint16) keyAgreement { | |
| return &ecdheKeyAgreement{ | |
| auth: &signedKeyAgreement{ | |
| sigType: signatureECDSA, | |
| version: version, | |
| }, | |
| } | |
| } | |
| func ecdheRSAKA(version uint16) keyAgreement { | |
| return &ecdheKeyAgreement{ | |
| auth: &signedKeyAgreement{ | |
| sigType: signatureRSA, | |
| version: version, | |
| }, | |
| } | |
| } | |
| func dheRSAKA(version uint16) keyAgreement { | |
| return &dheKeyAgreement{ | |
| auth: &signedKeyAgreement{ | |
| sigType: signatureRSA, | |
| version: version, | |
| }, | |
| } | |
| } | |
| func pskKA(version uint16) keyAgreement { | |
| return &pskKeyAgreement{ | |
| base: &nilKeyAgreement{}, | |
| } | |
| } | |
| func ecdhePSKKA(version uint16) keyAgreement { | |
| return &pskKeyAgreement{ | |
| base: &ecdheKeyAgreement{ | |
| auth: &nilKeyAgreementAuthentication{}, | |
| }, | |
| } | |
| } | |
| // 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_MD5 uint16 = 0x0004 | |
| TLS_RSA_WITH_RC4_128_SHA uint16 = 0x0005 | |
| TLS_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0x000a | |
| TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0x0016 | |
| TLS_RSA_WITH_AES_128_CBC_SHA uint16 = 0x002f | |
| TLS_DHE_RSA_WITH_AES_128_CBC_SHA uint16 = 0x0033 | |
| TLS_RSA_WITH_AES_256_CBC_SHA uint16 = 0x0035 | |
| TLS_DHE_RSA_WITH_AES_256_CBC_SHA uint16 = 0x0039 | |
| TLS_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0x003c | |
| TLS_RSA_WITH_AES_256_CBC_SHA256 uint16 = 0x003d | |
| TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0x0067 | |
| TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 uint16 = 0x006b | |
| TLS_PSK_WITH_RC4_128_SHA uint16 = 0x008a | |
| TLS_PSK_WITH_AES_128_CBC_SHA uint16 = 0x008c | |
| TLS_PSK_WITH_AES_256_CBC_SHA uint16 = 0x008d | |
| TLS_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0x009c | |
| TLS_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0x009d | |
| TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0x009e | |
| TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0x009f | |
| 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_ECDSA_WITH_AES_128_CBC_SHA256 uint16 = 0xc023 | |
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 uint16 = 0xc024 | |
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0xc027 | |
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 uint16 = 0xc028 | |
| TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 uint16 = 0xc02b | |
| TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 uint16 = 0xc02c | |
| TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0xc02f | |
| TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0xc030 | |
| fallbackSCSV uint16 = 0x5600 | |
| ) | |
| // Additional cipher suite IDs, not IANA-assigned. | |
| const ( | |
| TLS_ECDHE_PSK_WITH_AES_128_GCM_SHA256 uint16 = 0xcafe | |
| ) |