| // 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" |
| "crypto/aes" |
| "crypto/cipher" |
| "crypto/des" |
| "crypto/hmac" |
| "crypto/rc4" |
| "crypto/sha1" |
| "crypto/sha256" |
| "fmt" |
| "hash" |
| "internal/cpu" |
| "runtime" |
| |
| "golang.org/x/crypto/chacha20poly1305" |
| ) |
| |
| // CipherSuite is a TLS cipher suite. Note that most functions in this package |
| // accept and expose cipher suite IDs instead of this type. |
| type CipherSuite struct { |
| ID uint16 |
| Name string |
| |
| // Supported versions is the list of TLS protocol versions that can |
| // negotiate this cipher suite. |
| SupportedVersions []uint16 |
| |
| // Insecure is true if the cipher suite has known security issues |
| // due to its primitives, design, or implementation. |
| Insecure bool |
| } |
| |
| var ( |
| supportedUpToTLS12 = []uint16{VersionTLS10, VersionTLS11, VersionTLS12} |
| supportedOnlyTLS12 = []uint16{VersionTLS12} |
| supportedOnlyTLS13 = []uint16{VersionTLS13} |
| ) |
| |
| // CipherSuites returns a list of cipher suites currently implemented by this |
| // package, excluding those with security issues, which are returned by |
| // InsecureCipherSuites. |
| // |
| // The list is sorted by ID. Note that the default cipher suites selected by |
| // this package might depend on logic that can't be captured by a static list, |
| // and might not match those returned by this function. |
| func CipherSuites() []*CipherSuite { |
| return []*CipherSuite{ |
| {TLS_RSA_WITH_AES_128_CBC_SHA, "TLS_RSA_WITH_AES_128_CBC_SHA", supportedUpToTLS12, false}, |
| {TLS_RSA_WITH_AES_256_CBC_SHA, "TLS_RSA_WITH_AES_256_CBC_SHA", supportedUpToTLS12, false}, |
| {TLS_RSA_WITH_AES_128_GCM_SHA256, "TLS_RSA_WITH_AES_128_GCM_SHA256", supportedOnlyTLS12, false}, |
| {TLS_RSA_WITH_AES_256_GCM_SHA384, "TLS_RSA_WITH_AES_256_GCM_SHA384", supportedOnlyTLS12, false}, |
| |
| {TLS_AES_128_GCM_SHA256, "TLS_AES_128_GCM_SHA256", supportedOnlyTLS13, false}, |
| {TLS_AES_256_GCM_SHA384, "TLS_AES_256_GCM_SHA384", supportedOnlyTLS13, false}, |
| {TLS_CHACHA20_POLY1305_SHA256, "TLS_CHACHA20_POLY1305_SHA256", supportedOnlyTLS13, false}, |
| |
| {TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA", supportedUpToTLS12, false}, |
| {TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA", supportedUpToTLS12, false}, |
| {TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA", supportedUpToTLS12, false}, |
| {TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA", supportedUpToTLS12, false}, |
| {TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256", supportedOnlyTLS12, false}, |
| {TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384", supportedOnlyTLS12, false}, |
| {TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256", supportedOnlyTLS12, false}, |
| {TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384", supportedOnlyTLS12, false}, |
| {TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256, "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256", supportedOnlyTLS12, false}, |
| {TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256", supportedOnlyTLS12, false}, |
| } |
| } |
| |
| // InsecureCipherSuites returns a list of cipher suites currently implemented by |
| // this package and which have security issues. |
| // |
| // Most applications should not use the cipher suites in this list, and should |
| // only use those returned by CipherSuites. |
| func InsecureCipherSuites() []*CipherSuite { |
| // This list includes RC4, CBC_SHA256, and 3DES cipher suites. See |
| // cipherSuitesPreferenceOrder for details. |
| return []*CipherSuite{ |
| {TLS_RSA_WITH_RC4_128_SHA, "TLS_RSA_WITH_RC4_128_SHA", supportedUpToTLS12, true}, |
| {TLS_RSA_WITH_3DES_EDE_CBC_SHA, "TLS_RSA_WITH_3DES_EDE_CBC_SHA", supportedUpToTLS12, true}, |
| {TLS_RSA_WITH_AES_128_CBC_SHA256, "TLS_RSA_WITH_AES_128_CBC_SHA256", supportedOnlyTLS12, true}, |
| {TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, "TLS_ECDHE_ECDSA_WITH_RC4_128_SHA", supportedUpToTLS12, true}, |
| {TLS_ECDHE_RSA_WITH_RC4_128_SHA, "TLS_ECDHE_RSA_WITH_RC4_128_SHA", supportedUpToTLS12, true}, |
| {TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA", supportedUpToTLS12, true}, |
| {TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256", supportedOnlyTLS12, true}, |
| {TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256", supportedOnlyTLS12, true}, |
| } |
| } |
| |
| // CipherSuiteName returns the standard name for the passed cipher suite ID |
| // (e.g. "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256"), or a fallback representation |
| // of the ID value if the cipher suite is not implemented by this package. |
| func CipherSuiteName(id uint16) string { |
| for _, c := range CipherSuites() { |
| if c.ID == id { |
| return c.Name |
| } |
| } |
| for _, c := range InsecureCipherSuites() { |
| if c.ID == id { |
| return c.Name |
| } |
| } |
| return fmt.Sprintf("0x%04X", id) |
| } |
| |
| const ( |
| // suiteECDHE 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 |
| // suiteECSign indicates that the cipher suite involves an ECDSA or |
| // EdDSA signature and therefore may only be selected when the server's |
| // certificate is ECDSA or EdDSA. If this is not set then the cipher suite |
| // is RSA based. |
| suiteECSign |
| // 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 |
| ) |
| |
| // A cipherSuite is a TLS 1.0–1.2 cipher suite, and defines the key exchange |
| // mechanism, as well as the cipher+MAC pair or the AEAD. |
| 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) any |
| mac func(key []byte) hash.Hash |
| aead func(key, fixedNonce []byte) aead |
| } |
| |
| var cipherSuites = []*cipherSuite{ // TODO: replace with a map, since the order doesn't matter. |
| {TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305, 32, 0, 12, ecdheRSAKA, suiteECDHE | suiteTLS12, nil, nil, aeadChaCha20Poly1305}, |
| {TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, 32, 0, 12, ecdheECDSAKA, suiteECDHE | suiteECSign | suiteTLS12, nil, nil, aeadChaCha20Poly1305}, |
| {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 | suiteECSign | 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 | suiteECSign | suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM}, |
| {TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, 16, 32, 16, ecdheRSAKA, suiteECDHE | 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_SHA256, 16, 32, 16, ecdheECDSAKA, suiteECDHE | suiteECSign | suiteTLS12, cipherAES, macSHA256, nil}, |
| {TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, 16, 20, 16, ecdheECDSAKA, suiteECDHE | suiteECSign, 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 | suiteECSign, 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_AES_128_CBC_SHA256, 16, 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_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, rsaKA, 0, cipher3DES, macSHA1, nil}, |
| {TLS_RSA_WITH_RC4_128_SHA, 16, 20, 0, rsaKA, 0, cipherRC4, macSHA1, nil}, |
| {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 | suiteECSign, cipherRC4, macSHA1, nil}, |
| } |
| |
| // selectCipherSuite returns the first TLS 1.0–1.2 cipher suite from ids which |
| // is also in supportedIDs and passes the ok filter. |
| func selectCipherSuite(ids, supportedIDs []uint16, ok func(*cipherSuite) bool) *cipherSuite { |
| for _, id := range ids { |
| candidate := cipherSuiteByID(id) |
| if candidate == nil || !ok(candidate) { |
| continue |
| } |
| |
| for _, suppID := range supportedIDs { |
| if id == suppID { |
| return candidate |
| } |
| } |
| } |
| return nil |
| } |
| |
| // A cipherSuiteTLS13 defines only the pair of the AEAD algorithm and hash |
| // algorithm to be used with HKDF. See RFC 8446, Appendix B.4. |
| type cipherSuiteTLS13 struct { |
| id uint16 |
| keyLen int |
| aead func(key, fixedNonce []byte) aead |
| hash crypto.Hash |
| } |
| |
| var cipherSuitesTLS13 = []*cipherSuiteTLS13{ // TODO: replace with a map. |
| {TLS_AES_128_GCM_SHA256, 16, aeadAESGCMTLS13, crypto.SHA256}, |
| {TLS_CHACHA20_POLY1305_SHA256, 32, aeadChaCha20Poly1305, crypto.SHA256}, |
| {TLS_AES_256_GCM_SHA384, 32, aeadAESGCMTLS13, crypto.SHA384}, |
| } |
| |
| // cipherSuitesPreferenceOrder is the order in which we'll select (on the |
| // server) or advertise (on the client) TLS 1.0–1.2 cipher suites. |
| // |
| // Cipher suites are filtered but not reordered based on the application and |
| // peer's preferences, meaning we'll never select a suite lower in this list if |
| // any higher one is available. This makes it more defensible to keep weaker |
| // cipher suites enabled, especially on the server side where we get the last |
| // word, since there are no known downgrade attacks on cipher suites selection. |
| // |
| // The list is sorted by applying the following priority rules, stopping at the |
| // first (most important) applicable one: |
| // |
| // - Anything else comes before RC4 |
| // |
| // RC4 has practically exploitable biases. See https://www.rc4nomore.com. |
| // |
| // - Anything else comes before CBC_SHA256 |
| // |
| // SHA-256 variants of the CBC ciphersuites don't implement any Lucky13 |
| // countermeasures. See http://www.isg.rhul.ac.uk/tls/Lucky13.html and |
| // https://www.imperialviolet.org/2013/02/04/luckythirteen.html. |
| // |
| // - Anything else comes before 3DES |
| // |
| // 3DES has 64-bit blocks, which makes it fundamentally susceptible to |
| // birthday attacks. See https://sweet32.info. |
| // |
| // - ECDHE comes before anything else |
| // |
| // Once we got the broken stuff out of the way, the most important |
| // property a cipher suite can have is forward secrecy. We don't |
| // implement FFDHE, so that means ECDHE. |
| // |
| // - AEADs come before CBC ciphers |
| // |
| // Even with Lucky13 countermeasures, MAC-then-Encrypt CBC cipher suites |
| // are fundamentally fragile, and suffered from an endless sequence of |
| // padding oracle attacks. See https://eprint.iacr.org/2015/1129, |
| // https://www.imperialviolet.org/2014/12/08/poodleagain.html, and |
| // https://blog.cloudflare.com/yet-another-padding-oracle-in-openssl-cbc-ciphersuites/. |
| // |
| // - AES comes before ChaCha20 |
| // |
| // When AES hardware is available, AES-128-GCM and AES-256-GCM are faster |
| // than ChaCha20Poly1305. |
| // |
| // When AES hardware is not available, AES-128-GCM is one or more of: much |
| // slower, way more complex, and less safe (because not constant time) |
| // than ChaCha20Poly1305. |
| // |
| // We use this list if we think both peers have AES hardware, and |
| // cipherSuitesPreferenceOrderNoAES otherwise. |
| // |
| // - AES-128 comes before AES-256 |
| // |
| // The only potential advantages of AES-256 are better multi-target |
| // margins, and hypothetical post-quantum properties. Neither apply to |
| // TLS, and AES-256 is slower due to its four extra rounds (which don't |
| // contribute to the advantages above). |
| // |
| // - ECDSA comes before RSA |
| // |
| // The relative order of ECDSA and RSA cipher suites doesn't matter, |
| // as they depend on the certificate. Pick one to get a stable order. |
| // |
| var cipherSuitesPreferenceOrder = []uint16{ |
| // AEADs w/ ECDHE |
| TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, |
| TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, |
| TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305, |
| |
| // CBC w/ ECDHE |
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, |
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, |
| |
| // AEADs w/o ECDHE |
| TLS_RSA_WITH_AES_128_GCM_SHA256, |
| TLS_RSA_WITH_AES_256_GCM_SHA384, |
| |
| // CBC w/o ECDHE |
| TLS_RSA_WITH_AES_128_CBC_SHA, |
| TLS_RSA_WITH_AES_256_CBC_SHA, |
| |
| // 3DES |
| TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, |
| TLS_RSA_WITH_3DES_EDE_CBC_SHA, |
| |
| // CBC_SHA256 |
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, |
| TLS_RSA_WITH_AES_128_CBC_SHA256, |
| |
| // RC4 |
| TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA, |
| TLS_RSA_WITH_RC4_128_SHA, |
| } |
| |
| var cipherSuitesPreferenceOrderNoAES = []uint16{ |
| // ChaCha20Poly1305 |
| TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305, |
| |
| // AES-GCM w/ ECDHE |
| TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, |
| TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, |
| |
| // The rest of cipherSuitesPreferenceOrder. |
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, |
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, |
| TLS_RSA_WITH_AES_128_GCM_SHA256, |
| TLS_RSA_WITH_AES_256_GCM_SHA384, |
| TLS_RSA_WITH_AES_128_CBC_SHA, |
| TLS_RSA_WITH_AES_256_CBC_SHA, |
| TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, |
| TLS_RSA_WITH_3DES_EDE_CBC_SHA, |
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, |
| TLS_RSA_WITH_AES_128_CBC_SHA256, |
| TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA, |
| TLS_RSA_WITH_RC4_128_SHA, |
| } |
| |
| // disabledCipherSuites are not used unless explicitly listed in |
| // Config.CipherSuites. They MUST be at the end of cipherSuitesPreferenceOrder. |
| var disabledCipherSuites = []uint16{ |
| // CBC_SHA256 |
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, |
| TLS_RSA_WITH_AES_128_CBC_SHA256, |
| |
| // RC4 |
| TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA, |
| TLS_RSA_WITH_RC4_128_SHA, |
| } |
| |
| var ( |
| defaultCipherSuitesLen = len(cipherSuitesPreferenceOrder) - len(disabledCipherSuites) |
| defaultCipherSuites = cipherSuitesPreferenceOrder[:defaultCipherSuitesLen] |
| ) |
| |
| // defaultCipherSuitesTLS13 is also the preference order, since there are no |
| // disabled by default TLS 1.3 cipher suites. The same AES vs ChaCha20 logic as |
| // cipherSuitesPreferenceOrder applies. |
| var defaultCipherSuitesTLS13 = []uint16{ |
| TLS_AES_128_GCM_SHA256, |
| TLS_AES_256_GCM_SHA384, |
| TLS_CHACHA20_POLY1305_SHA256, |
| } |
| |
| var defaultCipherSuitesTLS13NoAES = []uint16{ |
| TLS_CHACHA20_POLY1305_SHA256, |
| TLS_AES_128_GCM_SHA256, |
| TLS_AES_256_GCM_SHA384, |
| } |
| |
| var ( |
| hasGCMAsmAMD64 = cpu.X86.HasAES && cpu.X86.HasPCLMULQDQ |
| hasGCMAsmARM64 = cpu.ARM64.HasAES && cpu.ARM64.HasPMULL |
| // Keep in sync with crypto/aes/cipher_s390x.go. |
| hasGCMAsmS390X = cpu.S390X.HasAES && cpu.S390X.HasAESCBC && cpu.S390X.HasAESCTR && |
| (cpu.S390X.HasGHASH || cpu.S390X.HasAESGCM) |
| |
| hasAESGCMHardwareSupport = runtime.GOARCH == "amd64" && hasGCMAsmAMD64 || |
| runtime.GOARCH == "arm64" && hasGCMAsmARM64 || |
| runtime.GOARCH == "s390x" && hasGCMAsmS390X |
| ) |
| |
| var aesgcmCiphers = map[uint16]bool{ |
| // TLS 1.2 |
| TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256: true, |
| TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384: true, |
| TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256: true, |
| TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384: true, |
| // TLS 1.3 |
| TLS_AES_128_GCM_SHA256: true, |
| TLS_AES_256_GCM_SHA384: true, |
| } |
| |
| var nonAESGCMAEADCiphers = map[uint16]bool{ |
| // TLS 1.2 |
| TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305: true, |
| TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305: true, |
| // TLS 1.3 |
| TLS_CHACHA20_POLY1305_SHA256: true, |
| } |
| |
| // aesgcmPreferred returns whether the first known cipher in the preference list |
| // is an AES-GCM cipher, implying the peer has hardware support for it. |
| func aesgcmPreferred(ciphers []uint16) bool { |
| for _, cID := range ciphers { |
| if c := cipherSuiteByID(cID); c != nil { |
| return aesgcmCiphers[cID] |
| } |
| if c := cipherSuiteTLS13ByID(cID); c != nil { |
| return aesgcmCiphers[cID] |
| } |
| } |
| return false |
| } |
| |
| func cipherRC4(key, iv []byte, isRead bool) any { |
| cipher, _ := rc4.NewCipher(key) |
| return cipher |
| } |
| |
| func cipher3DES(key, iv []byte, isRead bool) any { |
| block, _ := des.NewTripleDESCipher(key) |
| if isRead { |
| return cipher.NewCBCDecrypter(block, iv) |
| } |
| return cipher.NewCBCEncrypter(block, iv) |
| } |
| |
| func cipherAES(key, iv []byte, isRead bool) any { |
| block, _ := aes.NewCipher(key) |
| if isRead { |
| return cipher.NewCBCDecrypter(block, iv) |
| } |
| return cipher.NewCBCEncrypter(block, iv) |
| } |
| |
| // macSHA1 returns a SHA-1 based constant time MAC. |
| func macSHA1(key []byte) hash.Hash { |
| return hmac.New(newConstantTimeHash(sha1.New), key) |
| } |
| |
| // macSHA256 returns a SHA-256 based MAC. This is only supported in TLS 1.2 and |
| // is currently only used in disabled-by-default cipher suites. |
| func macSHA256(key []byte) hash.Hash { |
| return hmac.New(sha256.New, key) |
| } |
| |
| type aead interface { |
| cipher.AEAD |
| |
| // explicitNonceLen returns the number of bytes of explicit nonce |
| // included in each record. This is eight for older AEADs and |
| // zero for modern ones. |
| explicitNonceLen() int |
| } |
| |
| const ( |
| aeadNonceLength = 12 |
| noncePrefixLength = 4 |
| ) |
| |
| // prefixNonceAEAD wraps an AEAD and prefixes a fixed portion of the nonce to |
| // each call. |
| type prefixNonceAEAD struct { |
| // nonce contains the fixed part of the nonce in the first four bytes. |
| nonce [aeadNonceLength]byte |
| aead cipher.AEAD |
| } |
| |
| func (f *prefixNonceAEAD) NonceSize() int { return aeadNonceLength - noncePrefixLength } |
| func (f *prefixNonceAEAD) Overhead() int { return f.aead.Overhead() } |
| func (f *prefixNonceAEAD) explicitNonceLen() int { return f.NonceSize() } |
| |
| func (f *prefixNonceAEAD) Seal(out, nonce, plaintext, additionalData []byte) []byte { |
| copy(f.nonce[4:], nonce) |
| return f.aead.Seal(out, f.nonce[:], plaintext, additionalData) |
| } |
| |
| func (f *prefixNonceAEAD) Open(out, nonce, ciphertext, additionalData []byte) ([]byte, error) { |
| copy(f.nonce[4:], nonce) |
| return f.aead.Open(out, f.nonce[:], ciphertext, additionalData) |
| } |
| |
| // xoredNonceAEAD wraps an AEAD by XORing in a fixed pattern to the nonce |
| // before each call. |
| type xorNonceAEAD struct { |
| nonceMask [aeadNonceLength]byte |
| aead cipher.AEAD |
| } |
| |
| func (f *xorNonceAEAD) NonceSize() int { return 8 } // 64-bit sequence number |
| func (f *xorNonceAEAD) Overhead() int { return f.aead.Overhead() } |
| func (f *xorNonceAEAD) explicitNonceLen() int { return 0 } |
| |
| func (f *xorNonceAEAD) Seal(out, nonce, plaintext, additionalData []byte) []byte { |
| for i, b := range nonce { |
| f.nonceMask[4+i] ^= b |
| } |
| result := f.aead.Seal(out, f.nonceMask[:], plaintext, additionalData) |
| for i, b := range nonce { |
| f.nonceMask[4+i] ^= b |
| } |
| |
| return result |
| } |
| |
| func (f *xorNonceAEAD) Open(out, nonce, ciphertext, additionalData []byte) ([]byte, error) { |
| for i, b := range nonce { |
| f.nonceMask[4+i] ^= b |
| } |
| result, err := f.aead.Open(out, f.nonceMask[:], ciphertext, additionalData) |
| for i, b := range nonce { |
| f.nonceMask[4+i] ^= b |
| } |
| |
| return result, err |
| } |
| |
| func aeadAESGCM(key, noncePrefix []byte) aead { |
| if len(noncePrefix) != noncePrefixLength { |
| panic("tls: internal error: wrong nonce length") |
| } |
| aes, err := aes.NewCipher(key) |
| if err != nil { |
| panic(err) |
| } |
| aead, err := cipher.NewGCM(aes) |
| if err != nil { |
| panic(err) |
| } |
| |
| ret := &prefixNonceAEAD{aead: aead} |
| copy(ret.nonce[:], noncePrefix) |
| return ret |
| } |
| |
| func aeadAESGCMTLS13(key, nonceMask []byte) aead { |
| if len(nonceMask) != aeadNonceLength { |
| panic("tls: internal error: wrong nonce length") |
| } |
| aes, err := aes.NewCipher(key) |
| if err != nil { |
| panic(err) |
| } |
| aead, err := cipher.NewGCM(aes) |
| if err != nil { |
| panic(err) |
| } |
| |
| ret := &xorNonceAEAD{aead: aead} |
| copy(ret.nonceMask[:], nonceMask) |
| return ret |
| } |
| |
| func aeadChaCha20Poly1305(key, nonceMask []byte) aead { |
| if len(nonceMask) != aeadNonceLength { |
| panic("tls: internal error: wrong nonce length") |
| } |
| aead, err := chacha20poly1305.New(key) |
| if err != nil { |
| panic(err) |
| } |
| |
| ret := &xorNonceAEAD{aead: aead} |
| copy(ret.nonceMask[:], nonceMask) |
| return ret |
| } |
| |
| type constantTimeHash interface { |
| hash.Hash |
| ConstantTimeSum(b []byte) []byte |
| } |
| |
| // cthWrapper wraps any hash.Hash that implements ConstantTimeSum, and replaces |
| // with that all calls to Sum. It's used to obtain a ConstantTimeSum-based HMAC. |
| type cthWrapper struct { |
| h constantTimeHash |
| } |
| |
| func (c *cthWrapper) Size() int { return c.h.Size() } |
| func (c *cthWrapper) BlockSize() int { return c.h.BlockSize() } |
| func (c *cthWrapper) Reset() { c.h.Reset() } |
| func (c *cthWrapper) Write(p []byte) (int, error) { return c.h.Write(p) } |
| func (c *cthWrapper) Sum(b []byte) []byte { return c.h.ConstantTimeSum(b) } |
| |
| func newConstantTimeHash(h func() hash.Hash) func() hash.Hash { |
| return func() hash.Hash { |
| return &cthWrapper{h().(constantTimeHash)} |
| } |
| } |
| |
| // tls10MAC implements the TLS 1.0 MAC function. RFC 2246, Section 6.2.3. |
| func tls10MAC(h hash.Hash, out, seq, header, data, extra []byte) []byte { |
| h.Reset() |
| h.Write(seq) |
| h.Write(header) |
| h.Write(data) |
| res := h.Sum(out) |
| if extra != nil { |
| h.Write(extra) |
| } |
| return res |
| } |
| |
| func rsaKA(version uint16) keyAgreement { |
| return rsaKeyAgreement{} |
| } |
| |
| func ecdheECDSAKA(version uint16) keyAgreement { |
| return &ecdheKeyAgreement{ |
| isRSA: false, |
| version: version, |
| } |
| } |
| |
| func ecdheRSAKA(version uint16) keyAgreement { |
| return &ecdheKeyAgreement{ |
| isRSA: true, |
| 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 { |
| return cipherSuiteByID(id) |
| } |
| } |
| return nil |
| } |
| |
| func cipherSuiteByID(id uint16) *cipherSuite { |
| for _, cipherSuite := range cipherSuites { |
| if cipherSuite.id == id { |
| return cipherSuite |
| } |
| } |
| return nil |
| } |
| |
| func mutualCipherSuiteTLS13(have []uint16, want uint16) *cipherSuiteTLS13 { |
| for _, id := range have { |
| if id == want { |
| return cipherSuiteTLS13ByID(id) |
| } |
| } |
| return nil |
| } |
| |
| func cipherSuiteTLS13ByID(id uint16) *cipherSuiteTLS13 { |
| for _, cipherSuite := range cipherSuitesTLS13 { |
| if cipherSuite.id == id { |
| return cipherSuite |
| } |
| } |
| return nil |
| } |
| |
| // A list of cipher suite IDs that are, or have been, implemented by this |
| // package. |
| // |
| // See https://www.iana.org/assignments/tls-parameters/tls-parameters.xml |
| const ( |
| // TLS 1.0 - 1.2 cipher suites. |
| 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_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0x003c |
| TLS_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0x009c |
| TLS_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0x009d |
| 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_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0xc027 |
| TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0xc02f |
| TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 uint16 = 0xc02b |
| TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0xc030 |
| TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 uint16 = 0xc02c |
| TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xcca8 |
| TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xcca9 |
| |
| // TLS 1.3 cipher suites. |
| TLS_AES_128_GCM_SHA256 uint16 = 0x1301 |
| TLS_AES_256_GCM_SHA384 uint16 = 0x1302 |
| TLS_CHACHA20_POLY1305_SHA256 uint16 = 0x1303 |
| |
| // TLS_FALLBACK_SCSV isn't a standard cipher suite but an indicator |
| // that the client is doing version fallback. See RFC 7507. |
| TLS_FALLBACK_SCSV uint16 = 0x5600 |
| |
| // Legacy names for the corresponding cipher suites with the correct _SHA256 |
| // suffix, retained for backward compatibility. |
| TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 = TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 |
| TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305 = TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 |
| ) |