diff options
Diffstat (limited to 'src/pkg/crypto/tls/cipher_suites.go')
| -rw-r--r-- | src/pkg/crypto/tls/cipher_suites.go | 146 |
1 files changed, 112 insertions, 34 deletions
diff --git a/src/pkg/crypto/tls/cipher_suites.go b/src/pkg/crypto/tls/cipher_suites.go index a647e19aa..39a51459d 100644 --- a/src/pkg/crypto/tls/cipher_suites.go +++ b/src/pkg/crypto/tls/cipher_suites.go @@ -34,6 +34,22 @@ type keyAgreement interface { 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 { @@ -42,24 +58,30 @@ type cipherSuite struct { keyLen int macLen int ivLen int - ka func() keyAgreement - // If elliptic is set, a server will only consider this ciphersuite if - // the ClientHello indicated that the client supports an elliptic curve - // and point format that we can handle. - elliptic bool - cipher func(key, iv []byte, isRead bool) interface{} - mac func(version uint16, macKey []byte) macFunction + 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{ - {TLS_RSA_WITH_RC4_128_SHA, 16, 20, 0, rsaKA, false, cipherRC4, macSHA1}, - {TLS_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, rsaKA, false, cipher3DES, macSHA1}, - {TLS_RSA_WITH_AES_128_CBC_SHA, 16, 20, 16, rsaKA, false, cipherAES, macSHA1}, - {TLS_RSA_WITH_AES_256_CBC_SHA, 32, 20, 16, rsaKA, false, cipherAES, macSHA1}, - {TLS_ECDHE_RSA_WITH_RC4_128_SHA, 16, 20, 0, ecdheRSAKA, true, cipherRC4, macSHA1}, - {TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, ecdheRSAKA, true, cipher3DES, macSHA1}, - {TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, 16, 20, 16, ecdheRSAKA, true, cipherAES, macSHA1}, - {TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, 32, 20, 16, ecdheRSAKA, true, cipherAES, macSHA1}, + // 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{} { @@ -85,7 +107,7 @@ func cipherAES(key, iv []byte, isRead bool) interface{} { // macSHA1 returns a macFunction for the given protocol version. func macSHA1(version uint16, key []byte) macFunction { - if version == versionSSL30 { + if version == VersionSSL30 { mac := ssl30MAC{ h: sha1.New(), key: make([]byte, len(key)), @@ -98,7 +120,47 @@ func macSHA1(version uint16, key []byte) macFunction { type macFunction interface { Size() int - MAC(digestBuf, seq, data []byte) []byte + 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 @@ -116,7 +178,7 @@ var ssl30Pad1 = [48]byte{0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0 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, record []byte) []byte { +func (s ssl30MAC) MAC(digestBuf, seq, header, data []byte) []byte { padLength := 48 if s.h.Size() == 20 { padLength = 40 @@ -126,9 +188,9 @@ func (s ssl30MAC) MAC(digestBuf, seq, record []byte) []byte { 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:]) + s.h.Write(header[:1]) + s.h.Write(header[3:5]) + s.h.Write(data) digestBuf = s.h.Sum(digestBuf[:0]) s.h.Reset() @@ -147,19 +209,30 @@ func (s tls10MAC) Size() int { return s.h.Size() } -func (s tls10MAC) MAC(digestBuf, seq, record []byte) []byte { +func (s tls10MAC) MAC(digestBuf, seq, header, data []byte) []byte { s.h.Reset() s.h.Write(seq) - s.h.Write(record) + s.h.Write(header) + s.h.Write(data) return s.h.Sum(digestBuf[:0]) } -func rsaKA() keyAgreement { +func rsaKA(version uint16) keyAgreement { return rsaKeyAgreement{} } -func ecdheRSAKA() keyAgreement { - return new(ecdheRSAKeyAgreement) +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 @@ -181,12 +254,17 @@ func mutualCipherSuite(have []uint16, want uint16) *cipherSuite { // 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_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_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 ) |