- // 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
- )
|