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.
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 {
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.
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() {
105 for _
, c
:= range InsecureCipherSuites() {
110 return fmt
.Sprintf("0x%04X", id
)
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
124 // suiteTLS12 indicates that the cipher suite should only be advertised
125 // and accepted when using TLS 1.2.
127 // suiteSHA384 indicates that the cipher suite uses SHA384 as the
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 {
136 // the lengths, in bytes, of the key material needed for each component.
140 ka
func(version
uint16) keyAgreement
141 // flags is a bitmask of the suite* values, above.
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
) {
182 for _
, suppID
:= range supportedIDs
{
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 {
196 aead
func(key
, fixedNonce
[]byte) aead
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{
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
,
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
,
282 TLS_RSA_WITH_AES_128_GCM_SHA256
,
283 TLS_RSA_WITH_AES_256_GCM_SHA384
,
286 TLS_RSA_WITH_AES_128_CBC_SHA
,
287 TLS_RSA_WITH_AES_256_CBC_SHA
,
290 TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
,
291 TLS_RSA_WITH_3DES_EDE_CBC_SHA
,
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
,
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{
304 TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305
, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305
,
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{
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
,
333 TLS_ECDHE_ECDSA_WITH_RC4_128_SHA
, TLS_ECDHE_RSA_WITH_RC4_128_SHA
,
334 TLS_RSA_WITH_RC4_128_SHA
,
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
,
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{
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,
376 TLS_AES_128_GCM_SHA256
: true,
377 TLS_AES_256_GCM_SHA384
: true,
380 var nonAESGCMAEADCiphers
= map[uint16]bool{
382 TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305
: true,
383 TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305
: true,
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
]
402 func cipherRC4(key
, iv
[]byte, isRead
bool) any
{
403 cipher
, _
:= rc4
.NewCipher(key
)
407 func cipher3DES(key
, iv
[]byte, isRead
bool) any
{
408 block
, _
:= des
.NewTripleDESCipher(key
)
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
)
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 {
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
445 noncePrefixLength
= 4
448 // prefixNonceAEAD wraps an AEAD and prefixes a fixed portion of the nonce to
450 type prefixNonceAEAD
struct {
451 // nonce contains the fixed part of the nonce in the first four bytes.
452 nonce
[aeadNonceLength
]byte
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
472 type xorNonceAEAD
struct {
473 nonceMask
[aeadNonceLength
]byte
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
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
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
)
513 aead
, err
:= cipher
.NewGCM(aes
)
518 ret
:= &prefixNonceAEAD
{aead
: aead
}
519 copy(ret
.nonce
[:], noncePrefix
)
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
)
531 aead
, err
:= cipher
.NewGCM(aes
)
536 ret
:= &xorNonceAEAD
{aead
: aead
}
537 copy(ret
.nonceMask
[:], nonceMask
)
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
)
550 ret
:= &xorNonceAEAD
{aead
: aead
}
551 copy(ret
.nonceMask
[:], nonceMask
)
555 type constantTimeHash
interface {
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 {
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 {
591 func rsaKA(version
uint16) keyAgreement
{
592 return rsaKeyAgreement
{}
595 func ecdheECDSAKA(version
uint16) keyAgreement
{
596 return &ecdheKeyAgreement
{
602 func ecdheRSAKA(version
uint16) keyAgreement
{
603 return &ecdheKeyAgreement
{
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
{
614 return cipherSuiteByID(id
)
620 func cipherSuiteByID(id
uint16) *cipherSuite
{
621 for _
, cipherSuite
:= range cipherSuites
{
622 if cipherSuite
.id
== id
{
629 func mutualCipherSuiteTLS13(have
[]uint16, want
uint16) *cipherSuiteTLS13
{
630 for _
, id
:= range have
{
632 return cipherSuiteTLS13ByID(id
)
638 func cipherSuiteTLS13ByID(id
uint16) *cipherSuiteTLS13
{
639 for _
, cipherSuite
:= range cipherSuitesTLS13
{
640 if cipherSuite
.id
== id
{
647 // A list of cipher suite IDs that are, or have been, implemented by this
650 // See https://www.iana.org/assignments/tls-parameters/tls-parameters.xml
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