libstdc++: Remove std::__is_pointer and std::__is_scalar [PR115497]
[official-gcc.git] / libgo / go / crypto / tls / cipher_suites.go
blobd164991eec94c1c05f53d837e2bdadcded4c0717
1 // Copyright 2010 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 package tls
7 import (
8 "crypto"
9 "crypto/aes"
10 "crypto/cipher"
11 "crypto/des"
12 "crypto/hmac"
13 "crypto/rc4"
14 "crypto/sha1"
15 "crypto/sha256"
16 "fmt"
17 "hash"
18 "internal/cpu"
19 "runtime"
21 "golang.org/x/crypto/chacha20poly1305"
24 // CipherSuite is a TLS cipher suite. Note that most functions in this package
25 // accept and expose cipher suite IDs instead of this type.
26 type CipherSuite struct {
27 ID uint16
28 Name string
30 // Supported versions is the list of TLS protocol versions that can
31 // negotiate this cipher suite.
32 SupportedVersions []uint16
34 // Insecure is true if the cipher suite has known security issues
35 // due to its primitives, design, or implementation.
36 Insecure bool
39 var (
40 supportedUpToTLS12 = []uint16{VersionTLS10, VersionTLS11, VersionTLS12}
41 supportedOnlyTLS12 = []uint16{VersionTLS12}
42 supportedOnlyTLS13 = []uint16{VersionTLS13}
45 // CipherSuites returns a list of cipher suites currently implemented by this
46 // package, excluding those with security issues, which are returned by
47 // InsecureCipherSuites.
49 // The list is sorted by ID. Note that the default cipher suites selected by
50 // this package might depend on logic that can't be captured by a static list,
51 // and might not match those returned by this function.
52 func CipherSuites() []*CipherSuite {
53 return []*CipherSuite{
54 {TLS_RSA_WITH_AES_128_CBC_SHA, "TLS_RSA_WITH_AES_128_CBC_SHA", supportedUpToTLS12, false},
55 {TLS_RSA_WITH_AES_256_CBC_SHA, "TLS_RSA_WITH_AES_256_CBC_SHA", supportedUpToTLS12, false},
56 {TLS_RSA_WITH_AES_128_GCM_SHA256, "TLS_RSA_WITH_AES_128_GCM_SHA256", supportedOnlyTLS12, false},
57 {TLS_RSA_WITH_AES_256_GCM_SHA384, "TLS_RSA_WITH_AES_256_GCM_SHA384", supportedOnlyTLS12, false},
59 {TLS_AES_128_GCM_SHA256, "TLS_AES_128_GCM_SHA256", supportedOnlyTLS13, false},
60 {TLS_AES_256_GCM_SHA384, "TLS_AES_256_GCM_SHA384", supportedOnlyTLS13, false},
61 {TLS_CHACHA20_POLY1305_SHA256, "TLS_CHACHA20_POLY1305_SHA256", supportedOnlyTLS13, false},
63 {TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA", supportedUpToTLS12, false},
64 {TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA", supportedUpToTLS12, false},
65 {TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA", supportedUpToTLS12, false},
66 {TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA", supportedUpToTLS12, false},
67 {TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256", supportedOnlyTLS12, false},
68 {TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384", supportedOnlyTLS12, false},
69 {TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256", supportedOnlyTLS12, false},
70 {TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384", supportedOnlyTLS12, false},
71 {TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256, "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256", supportedOnlyTLS12, false},
72 {TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256", supportedOnlyTLS12, false},
76 // InsecureCipherSuites returns a list of cipher suites currently implemented by
77 // this package and which have security issues.
79 // Most applications should not use the cipher suites in this list, and should
80 // only use those returned by CipherSuites.
81 func InsecureCipherSuites() []*CipherSuite {
82 // This list includes RC4, CBC_SHA256, and 3DES cipher suites. See
83 // cipherSuitesPreferenceOrder for details.
84 return []*CipherSuite{
85 {TLS_RSA_WITH_RC4_128_SHA, "TLS_RSA_WITH_RC4_128_SHA", supportedUpToTLS12, true},
86 {TLS_RSA_WITH_3DES_EDE_CBC_SHA, "TLS_RSA_WITH_3DES_EDE_CBC_SHA", supportedUpToTLS12, true},
87 {TLS_RSA_WITH_AES_128_CBC_SHA256, "TLS_RSA_WITH_AES_128_CBC_SHA256", supportedOnlyTLS12, true},
88 {TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, "TLS_ECDHE_ECDSA_WITH_RC4_128_SHA", supportedUpToTLS12, true},
89 {TLS_ECDHE_RSA_WITH_RC4_128_SHA, "TLS_ECDHE_RSA_WITH_RC4_128_SHA", supportedUpToTLS12, true},
90 {TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA", supportedUpToTLS12, true},
91 {TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256", supportedOnlyTLS12, true},
92 {TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256", supportedOnlyTLS12, true},
96 // CipherSuiteName returns the standard name for the passed cipher suite ID
97 // (e.g. "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256"), or a fallback representation
98 // of the ID value if the cipher suite is not implemented by this package.
99 func CipherSuiteName(id uint16) string {
100 for _, c := range CipherSuites() {
101 if c.ID == id {
102 return c.Name
105 for _, c := range InsecureCipherSuites() {
106 if c.ID == id {
107 return c.Name
110 return fmt.Sprintf("0x%04X", id)
113 const (
114 // suiteECDHE indicates that the cipher suite involves elliptic curve
115 // Diffie-Hellman. This means that it should only be selected when the
116 // client indicates that it supports ECC with a curve and point format
117 // that we're happy with.
118 suiteECDHE = 1 << iota
119 // suiteECSign indicates that the cipher suite involves an ECDSA or
120 // EdDSA signature and therefore may only be selected when the server's
121 // certificate is ECDSA or EdDSA. If this is not set then the cipher suite
122 // is RSA based.
123 suiteECSign
124 // suiteTLS12 indicates that the cipher suite should only be advertised
125 // and accepted when using TLS 1.2.
126 suiteTLS12
127 // suiteSHA384 indicates that the cipher suite uses SHA384 as the
128 // handshake hash.
129 suiteSHA384
132 // A cipherSuite is a TLS 1.0–1.2 cipher suite, and defines the key exchange
133 // mechanism, as well as the cipher+MAC pair or the AEAD.
134 type cipherSuite struct {
135 id uint16
136 // the lengths, in bytes, of the key material needed for each component.
137 keyLen int
138 macLen int
139 ivLen int
140 ka func(version uint16) keyAgreement
141 // flags is a bitmask of the suite* values, above.
142 flags int
143 cipher func(key, iv []byte, isRead bool) any
144 mac func(key []byte) hash.Hash
145 aead func(key, fixedNonce []byte) aead
148 var cipherSuites = []*cipherSuite{ // TODO: replace with a map, since the order doesn't matter.
149 {TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305, 32, 0, 12, ecdheRSAKA, suiteECDHE | suiteTLS12, nil, nil, aeadChaCha20Poly1305},
150 {TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, 32, 0, 12, ecdheECDSAKA, suiteECDHE | suiteECSign | suiteTLS12, nil, nil, aeadChaCha20Poly1305},
151 {TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, ecdheRSAKA, suiteECDHE | suiteTLS12, nil, nil, aeadAESGCM},
152 {TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, ecdheECDSAKA, suiteECDHE | suiteECSign | suiteTLS12, nil, nil, aeadAESGCM},
153 {TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, 32, 0, 4, ecdheRSAKA, suiteECDHE | suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM},
154 {TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, 32, 0, 4, ecdheECDSAKA, suiteECDHE | suiteECSign | suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM},
155 {TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, 16, 32, 16, ecdheRSAKA, suiteECDHE | suiteTLS12, cipherAES, macSHA256, nil},
156 {TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, 16, 20, 16, ecdheRSAKA, suiteECDHE, cipherAES, macSHA1, nil},
157 {TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, 16, 32, 16, ecdheECDSAKA, suiteECDHE | suiteECSign | suiteTLS12, cipherAES, macSHA256, nil},
158 {TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, 16, 20, 16, ecdheECDSAKA, suiteECDHE | suiteECSign, cipherAES, macSHA1, nil},
159 {TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, 32, 20, 16, ecdheRSAKA, suiteECDHE, cipherAES, macSHA1, nil},
160 {TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, 32, 20, 16, ecdheECDSAKA, suiteECDHE | suiteECSign, cipherAES, macSHA1, nil},
161 {TLS_RSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, rsaKA, suiteTLS12, nil, nil, aeadAESGCM},
162 {TLS_RSA_WITH_AES_256_GCM_SHA384, 32, 0, 4, rsaKA, suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM},
163 {TLS_RSA_WITH_AES_128_CBC_SHA256, 16, 32, 16, rsaKA, suiteTLS12, cipherAES, macSHA256, nil},
164 {TLS_RSA_WITH_AES_128_CBC_SHA, 16, 20, 16, rsaKA, 0, cipherAES, macSHA1, nil},
165 {TLS_RSA_WITH_AES_256_CBC_SHA, 32, 20, 16, rsaKA, 0, cipherAES, macSHA1, nil},
166 {TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, ecdheRSAKA, suiteECDHE, cipher3DES, macSHA1, nil},
167 {TLS_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, rsaKA, 0, cipher3DES, macSHA1, nil},
168 {TLS_RSA_WITH_RC4_128_SHA, 16, 20, 0, rsaKA, 0, cipherRC4, macSHA1, nil},
169 {TLS_ECDHE_RSA_WITH_RC4_128_SHA, 16, 20, 0, ecdheRSAKA, suiteECDHE, cipherRC4, macSHA1, nil},
170 {TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, 16, 20, 0, ecdheECDSAKA, suiteECDHE | suiteECSign, cipherRC4, macSHA1, nil},
173 // selectCipherSuite returns the first TLS 1.0–1.2 cipher suite from ids which
174 // is also in supportedIDs and passes the ok filter.
175 func selectCipherSuite(ids, supportedIDs []uint16, ok func(*cipherSuite) bool) *cipherSuite {
176 for _, id := range ids {
177 candidate := cipherSuiteByID(id)
178 if candidate == nil || !ok(candidate) {
179 continue
182 for _, suppID := range supportedIDs {
183 if id == suppID {
184 return candidate
188 return nil
191 // A cipherSuiteTLS13 defines only the pair of the AEAD algorithm and hash
192 // algorithm to be used with HKDF. See RFC 8446, Appendix B.4.
193 type cipherSuiteTLS13 struct {
194 id uint16
195 keyLen int
196 aead func(key, fixedNonce []byte) aead
197 hash crypto.Hash
200 var cipherSuitesTLS13 = []*cipherSuiteTLS13{ // TODO: replace with a map.
201 {TLS_AES_128_GCM_SHA256, 16, aeadAESGCMTLS13, crypto.SHA256},
202 {TLS_CHACHA20_POLY1305_SHA256, 32, aeadChaCha20Poly1305, crypto.SHA256},
203 {TLS_AES_256_GCM_SHA384, 32, aeadAESGCMTLS13, crypto.SHA384},
206 // cipherSuitesPreferenceOrder is the order in which we'll select (on the
207 // server) or advertise (on the client) TLS 1.0–1.2 cipher suites.
209 // Cipher suites are filtered but not reordered based on the application and
210 // peer's preferences, meaning we'll never select a suite lower in this list if
211 // any higher one is available. This makes it more defensible to keep weaker
212 // cipher suites enabled, especially on the server side where we get the last
213 // word, since there are no known downgrade attacks on cipher suites selection.
215 // The list is sorted by applying the following priority rules, stopping at the
216 // first (most important) applicable one:
218 // - Anything else comes before RC4
220 // RC4 has practically exploitable biases. See https://www.rc4nomore.com.
222 // - Anything else comes before CBC_SHA256
224 // SHA-256 variants of the CBC ciphersuites don't implement any Lucky13
225 // countermeasures. See http://www.isg.rhul.ac.uk/tls/Lucky13.html and
226 // https://www.imperialviolet.org/2013/02/04/luckythirteen.html.
228 // - Anything else comes before 3DES
230 // 3DES has 64-bit blocks, which makes it fundamentally susceptible to
231 // birthday attacks. See https://sweet32.info.
233 // - ECDHE comes before anything else
235 // Once we got the broken stuff out of the way, the most important
236 // property a cipher suite can have is forward secrecy. We don't
237 // implement FFDHE, so that means ECDHE.
239 // - AEADs come before CBC ciphers
241 // Even with Lucky13 countermeasures, MAC-then-Encrypt CBC cipher suites
242 // are fundamentally fragile, and suffered from an endless sequence of
243 // padding oracle attacks. See https://eprint.iacr.org/2015/1129,
244 // https://www.imperialviolet.org/2014/12/08/poodleagain.html, and
245 // https://blog.cloudflare.com/yet-another-padding-oracle-in-openssl-cbc-ciphersuites/.
247 // - AES comes before ChaCha20
249 // When AES hardware is available, AES-128-GCM and AES-256-GCM are faster
250 // than ChaCha20Poly1305.
252 // When AES hardware is not available, AES-128-GCM is one or more of: much
253 // slower, way more complex, and less safe (because not constant time)
254 // than ChaCha20Poly1305.
256 // We use this list if we think both peers have AES hardware, and
257 // cipherSuitesPreferenceOrderNoAES otherwise.
259 // - AES-128 comes before AES-256
261 // The only potential advantages of AES-256 are better multi-target
262 // margins, and hypothetical post-quantum properties. Neither apply to
263 // TLS, and AES-256 is slower due to its four extra rounds (which don't
264 // contribute to the advantages above).
266 // - ECDSA comes before RSA
268 // The relative order of ECDSA and RSA cipher suites doesn't matter,
269 // as they depend on the certificate. Pick one to get a stable order.
271 var cipherSuitesPreferenceOrder = []uint16{
272 // AEADs w/ ECDHE
273 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
274 TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
275 TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
277 // CBC w/ ECDHE
278 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
279 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
281 // AEADs w/o ECDHE
282 TLS_RSA_WITH_AES_128_GCM_SHA256,
283 TLS_RSA_WITH_AES_256_GCM_SHA384,
285 // CBC w/o ECDHE
286 TLS_RSA_WITH_AES_128_CBC_SHA,
287 TLS_RSA_WITH_AES_256_CBC_SHA,
289 // 3DES
290 TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
291 TLS_RSA_WITH_3DES_EDE_CBC_SHA,
293 // CBC_SHA256
294 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
295 TLS_RSA_WITH_AES_128_CBC_SHA256,
297 // RC4
298 TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA,
299 TLS_RSA_WITH_RC4_128_SHA,
302 var cipherSuitesPreferenceOrderNoAES = []uint16{
303 // ChaCha20Poly1305
304 TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
306 // AES-GCM w/ ECDHE
307 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
308 TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
310 // The rest of cipherSuitesPreferenceOrder.
311 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
312 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
313 TLS_RSA_WITH_AES_128_GCM_SHA256,
314 TLS_RSA_WITH_AES_256_GCM_SHA384,
315 TLS_RSA_WITH_AES_128_CBC_SHA,
316 TLS_RSA_WITH_AES_256_CBC_SHA,
317 TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
318 TLS_RSA_WITH_3DES_EDE_CBC_SHA,
319 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
320 TLS_RSA_WITH_AES_128_CBC_SHA256,
321 TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA,
322 TLS_RSA_WITH_RC4_128_SHA,
325 // disabledCipherSuites are not used unless explicitly listed in
326 // Config.CipherSuites. They MUST be at the end of cipherSuitesPreferenceOrder.
327 var disabledCipherSuites = []uint16{
328 // CBC_SHA256
329 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
330 TLS_RSA_WITH_AES_128_CBC_SHA256,
332 // RC4
333 TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA,
334 TLS_RSA_WITH_RC4_128_SHA,
337 var (
338 defaultCipherSuitesLen = len(cipherSuitesPreferenceOrder) - len(disabledCipherSuites)
339 defaultCipherSuites = cipherSuitesPreferenceOrder[:defaultCipherSuitesLen]
342 // defaultCipherSuitesTLS13 is also the preference order, since there are no
343 // disabled by default TLS 1.3 cipher suites. The same AES vs ChaCha20 logic as
344 // cipherSuitesPreferenceOrder applies.
345 var defaultCipherSuitesTLS13 = []uint16{
346 TLS_AES_128_GCM_SHA256,
347 TLS_AES_256_GCM_SHA384,
348 TLS_CHACHA20_POLY1305_SHA256,
351 var defaultCipherSuitesTLS13NoAES = []uint16{
352 TLS_CHACHA20_POLY1305_SHA256,
353 TLS_AES_128_GCM_SHA256,
354 TLS_AES_256_GCM_SHA384,
357 var (
358 hasGCMAsmAMD64 = cpu.X86.HasAES && cpu.X86.HasPCLMULQDQ
359 hasGCMAsmARM64 = cpu.ARM64.HasAES && cpu.ARM64.HasPMULL
360 // Keep in sync with crypto/aes/cipher_s390x.go.
361 hasGCMAsmS390X = cpu.S390X.HasAES && cpu.S390X.HasAESCBC && cpu.S390X.HasAESCTR &&
362 (cpu.S390X.HasGHASH || cpu.S390X.HasAESGCM)
364 hasAESGCMHardwareSupport = runtime.GOARCH == "amd64" && hasGCMAsmAMD64 ||
365 runtime.GOARCH == "arm64" && hasGCMAsmARM64 ||
366 runtime.GOARCH == "s390x" && hasGCMAsmS390X
369 var aesgcmCiphers = map[uint16]bool{
370 // TLS 1.2
371 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256: true,
372 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384: true,
373 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256: true,
374 TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384: true,
375 // TLS 1.3
376 TLS_AES_128_GCM_SHA256: true,
377 TLS_AES_256_GCM_SHA384: true,
380 var nonAESGCMAEADCiphers = map[uint16]bool{
381 // TLS 1.2
382 TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305: true,
383 TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305: true,
384 // TLS 1.3
385 TLS_CHACHA20_POLY1305_SHA256: true,
388 // aesgcmPreferred returns whether the first known cipher in the preference list
389 // is an AES-GCM cipher, implying the peer has hardware support for it.
390 func aesgcmPreferred(ciphers []uint16) bool {
391 for _, cID := range ciphers {
392 if c := cipherSuiteByID(cID); c != nil {
393 return aesgcmCiphers[cID]
395 if c := cipherSuiteTLS13ByID(cID); c != nil {
396 return aesgcmCiphers[cID]
399 return false
402 func cipherRC4(key, iv []byte, isRead bool) any {
403 cipher, _ := rc4.NewCipher(key)
404 return cipher
407 func cipher3DES(key, iv []byte, isRead bool) any {
408 block, _ := des.NewTripleDESCipher(key)
409 if isRead {
410 return cipher.NewCBCDecrypter(block, iv)
412 return cipher.NewCBCEncrypter(block, iv)
415 func cipherAES(key, iv []byte, isRead bool) any {
416 block, _ := aes.NewCipher(key)
417 if isRead {
418 return cipher.NewCBCDecrypter(block, iv)
420 return cipher.NewCBCEncrypter(block, iv)
423 // macSHA1 returns a SHA-1 based constant time MAC.
424 func macSHA1(key []byte) hash.Hash {
425 return hmac.New(newConstantTimeHash(sha1.New), key)
428 // macSHA256 returns a SHA-256 based MAC. This is only supported in TLS 1.2 and
429 // is currently only used in disabled-by-default cipher suites.
430 func macSHA256(key []byte) hash.Hash {
431 return hmac.New(sha256.New, key)
434 type aead interface {
435 cipher.AEAD
437 // explicitNonceLen returns the number of bytes of explicit nonce
438 // included in each record. This is eight for older AEADs and
439 // zero for modern ones.
440 explicitNonceLen() int
443 const (
444 aeadNonceLength = 12
445 noncePrefixLength = 4
448 // prefixNonceAEAD wraps an AEAD and prefixes a fixed portion of the nonce to
449 // each call.
450 type prefixNonceAEAD struct {
451 // nonce contains the fixed part of the nonce in the first four bytes.
452 nonce [aeadNonceLength]byte
453 aead cipher.AEAD
456 func (f *prefixNonceAEAD) NonceSize() int { return aeadNonceLength - noncePrefixLength }
457 func (f *prefixNonceAEAD) Overhead() int { return f.aead.Overhead() }
458 func (f *prefixNonceAEAD) explicitNonceLen() int { return f.NonceSize() }
460 func (f *prefixNonceAEAD) Seal(out, nonce, plaintext, additionalData []byte) []byte {
461 copy(f.nonce[4:], nonce)
462 return f.aead.Seal(out, f.nonce[:], plaintext, additionalData)
465 func (f *prefixNonceAEAD) Open(out, nonce, ciphertext, additionalData []byte) ([]byte, error) {
466 copy(f.nonce[4:], nonce)
467 return f.aead.Open(out, f.nonce[:], ciphertext, additionalData)
470 // xoredNonceAEAD wraps an AEAD by XORing in a fixed pattern to the nonce
471 // before each call.
472 type xorNonceAEAD struct {
473 nonceMask [aeadNonceLength]byte
474 aead cipher.AEAD
477 func (f *xorNonceAEAD) NonceSize() int { return 8 } // 64-bit sequence number
478 func (f *xorNonceAEAD) Overhead() int { return f.aead.Overhead() }
479 func (f *xorNonceAEAD) explicitNonceLen() int { return 0 }
481 func (f *xorNonceAEAD) Seal(out, nonce, plaintext, additionalData []byte) []byte {
482 for i, b := range nonce {
483 f.nonceMask[4+i] ^= b
485 result := f.aead.Seal(out, f.nonceMask[:], plaintext, additionalData)
486 for i, b := range nonce {
487 f.nonceMask[4+i] ^= b
490 return result
493 func (f *xorNonceAEAD) Open(out, nonce, ciphertext, additionalData []byte) ([]byte, error) {
494 for i, b := range nonce {
495 f.nonceMask[4+i] ^= b
497 result, err := f.aead.Open(out, f.nonceMask[:], ciphertext, additionalData)
498 for i, b := range nonce {
499 f.nonceMask[4+i] ^= b
502 return result, err
505 func aeadAESGCM(key, noncePrefix []byte) aead {
506 if len(noncePrefix) != noncePrefixLength {
507 panic("tls: internal error: wrong nonce length")
509 aes, err := aes.NewCipher(key)
510 if err != nil {
511 panic(err)
513 aead, err := cipher.NewGCM(aes)
514 if err != nil {
515 panic(err)
518 ret := &prefixNonceAEAD{aead: aead}
519 copy(ret.nonce[:], noncePrefix)
520 return ret
523 func aeadAESGCMTLS13(key, nonceMask []byte) aead {
524 if len(nonceMask) != aeadNonceLength {
525 panic("tls: internal error: wrong nonce length")
527 aes, err := aes.NewCipher(key)
528 if err != nil {
529 panic(err)
531 aead, err := cipher.NewGCM(aes)
532 if err != nil {
533 panic(err)
536 ret := &xorNonceAEAD{aead: aead}
537 copy(ret.nonceMask[:], nonceMask)
538 return ret
541 func aeadChaCha20Poly1305(key, nonceMask []byte) aead {
542 if len(nonceMask) != aeadNonceLength {
543 panic("tls: internal error: wrong nonce length")
545 aead, err := chacha20poly1305.New(key)
546 if err != nil {
547 panic(err)
550 ret := &xorNonceAEAD{aead: aead}
551 copy(ret.nonceMask[:], nonceMask)
552 return ret
555 type constantTimeHash interface {
556 hash.Hash
557 ConstantTimeSum(b []byte) []byte
560 // cthWrapper wraps any hash.Hash that implements ConstantTimeSum, and replaces
561 // with that all calls to Sum. It's used to obtain a ConstantTimeSum-based HMAC.
562 type cthWrapper struct {
563 h constantTimeHash
566 func (c *cthWrapper) Size() int { return c.h.Size() }
567 func (c *cthWrapper) BlockSize() int { return c.h.BlockSize() }
568 func (c *cthWrapper) Reset() { c.h.Reset() }
569 func (c *cthWrapper) Write(p []byte) (int, error) { return c.h.Write(p) }
570 func (c *cthWrapper) Sum(b []byte) []byte { return c.h.ConstantTimeSum(b) }
572 func newConstantTimeHash(h func() hash.Hash) func() hash.Hash {
573 return func() hash.Hash {
574 return &cthWrapper{h().(constantTimeHash)}
578 // tls10MAC implements the TLS 1.0 MAC function. RFC 2246, Section 6.2.3.
579 func tls10MAC(h hash.Hash, out, seq, header, data, extra []byte) []byte {
580 h.Reset()
581 h.Write(seq)
582 h.Write(header)
583 h.Write(data)
584 res := h.Sum(out)
585 if extra != nil {
586 h.Write(extra)
588 return res
591 func rsaKA(version uint16) keyAgreement {
592 return rsaKeyAgreement{}
595 func ecdheECDSAKA(version uint16) keyAgreement {
596 return &ecdheKeyAgreement{
597 isRSA: false,
598 version: version,
602 func ecdheRSAKA(version uint16) keyAgreement {
603 return &ecdheKeyAgreement{
604 isRSA: true,
605 version: version,
609 // mutualCipherSuite returns a cipherSuite given a list of supported
610 // ciphersuites and the id requested by the peer.
611 func mutualCipherSuite(have []uint16, want uint16) *cipherSuite {
612 for _, id := range have {
613 if id == want {
614 return cipherSuiteByID(id)
617 return nil
620 func cipherSuiteByID(id uint16) *cipherSuite {
621 for _, cipherSuite := range cipherSuites {
622 if cipherSuite.id == id {
623 return cipherSuite
626 return nil
629 func mutualCipherSuiteTLS13(have []uint16, want uint16) *cipherSuiteTLS13 {
630 for _, id := range have {
631 if id == want {
632 return cipherSuiteTLS13ByID(id)
635 return nil
638 func cipherSuiteTLS13ByID(id uint16) *cipherSuiteTLS13 {
639 for _, cipherSuite := range cipherSuitesTLS13 {
640 if cipherSuite.id == id {
641 return cipherSuite
644 return nil
647 // A list of cipher suite IDs that are, or have been, implemented by this
648 // package.
650 // See https://www.iana.org/assignments/tls-parameters/tls-parameters.xml
651 const (
652 // TLS 1.0 - 1.2 cipher suites.
653 TLS_RSA_WITH_RC4_128_SHA uint16 = 0x0005
654 TLS_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0x000a
655 TLS_RSA_WITH_AES_128_CBC_SHA uint16 = 0x002f
656 TLS_RSA_WITH_AES_256_CBC_SHA uint16 = 0x0035
657 TLS_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0x003c
658 TLS_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0x009c
659 TLS_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0x009d
660 TLS_ECDHE_ECDSA_WITH_RC4_128_SHA uint16 = 0xc007
661 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA uint16 = 0xc009
662 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA uint16 = 0xc00a
663 TLS_ECDHE_RSA_WITH_RC4_128_SHA uint16 = 0xc011
664 TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xc012
665 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA uint16 = 0xc013
666 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA uint16 = 0xc014
667 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 uint16 = 0xc023
668 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0xc027
669 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0xc02f
670 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 uint16 = 0xc02b
671 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0xc030
672 TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 uint16 = 0xc02c
673 TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xcca8
674 TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xcca9
676 // TLS 1.3 cipher suites.
677 TLS_AES_128_GCM_SHA256 uint16 = 0x1301
678 TLS_AES_256_GCM_SHA384 uint16 = 0x1302
679 TLS_CHACHA20_POLY1305_SHA256 uint16 = 0x1303
681 // TLS_FALLBACK_SCSV isn't a standard cipher suite but an indicator
682 // that the client is doing version fallback. See RFC 7507.
683 TLS_FALLBACK_SCSV uint16 = 0x5600
685 // Legacy names for the corresponding cipher suites with the correct _SHA256
686 // suffix, retained for backward compatibility.
687 TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 = TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
688 TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305 = TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256