golang cipher_suites 代码
文件路径：/src/crypto/tls/cipher_suites.go
/ 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/internal/boring"
"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 {
h := sha1.New
/ The BoringCrypto SHA1 does not have a constant-time
/ checksum function, so don't try to use it.
if !boring.Enabled {
h = newConstantTimeHash(h)
}
return hmac.New(h, 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)
}
var aead cipher.AEAD
if boring.Enabled {
aead, err = boring.NewGCMTLS(aes)
} else {
boring.Unreachable()
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 {
boring.Unreachable()
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
)