|  | // 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 runner | 
|  |  | 
|  | import ( | 
|  | "crypto" | 
|  | "crypto/aes" | 
|  | "crypto/cipher" | 
|  | "crypto/des" | 
|  | "crypto/hmac" | 
|  | "crypto/md5" | 
|  | "crypto/sha1" | 
|  | "crypto/sha256" | 
|  | "crypto/sha512" | 
|  | "crypto/x509" | 
|  | "hash" | 
|  | "slices" | 
|  |  | 
|  | "golang.org/x/crypto/chacha20poly1305" | 
|  | ) | 
|  |  | 
|  | // a keyAgreement implements the client and server side of a TLS key agreement | 
|  | // protocol by generating and processing key exchange messages. | 
|  | type keyAgreement interface { | 
|  | // On the server side, the first two methods are called in order. | 
|  |  | 
|  | // In the case that the key agreement protocol doesn't use a | 
|  | // ServerKeyExchange message, generateServerKeyExchange can return nil, | 
|  | // nil. | 
|  | generateServerKeyExchange(*Config, *Credential, *clientHelloMsg, *serverHelloMsg, uint16) (*serverKeyExchangeMsg, error) | 
|  | processClientKeyExchange(*Config, *Credential, *clientKeyExchangeMsg, uint16) ([]byte, error) | 
|  |  | 
|  | // On the client side, the next two methods are called in order. | 
|  |  | 
|  | // This method may not be called if the server doesn't send a | 
|  | // ServerKeyExchange message. | 
|  | processServerKeyExchange(*Config, *clientHelloMsg, *serverHelloMsg, crypto.PublicKey, *serverKeyExchangeMsg) error | 
|  | generateClientKeyExchange(*Config, *clientHelloMsg, *x509.Certificate) ([]byte, *clientKeyExchangeMsg, error) | 
|  |  | 
|  | // peerSignatureAlgorithm returns the signature algorithm used by the | 
|  | // peer, or zero if not applicable. | 
|  | peerSignatureAlgorithm() signatureAlgorithm | 
|  | } | 
|  |  | 
|  | const ( | 
|  | // suiteECDH indicates that the cipher suite involves elliptic curve | 
|  | // Diffie-Hellman. This means that it should only be selected when the | 
|  | // client indicates that it supports ECC with a curve and point format | 
|  | // that we're happy with. | 
|  | suiteECDHE = 1 << iota | 
|  | // suiteECDSA indicates that the cipher suite involves an ECDSA | 
|  | // signature and therefore may only be selected when the server's | 
|  | // certificate is ECDSA. If this is not set then the cipher suite is | 
|  | // RSA based. | 
|  | suiteECDSA | 
|  | // suiteTLS12 indicates that the cipher suite should only be advertised | 
|  | // and accepted when using TLS 1.2 or greater. | 
|  | suiteTLS12 | 
|  | // suiteTLS13 indicates that the cipher suite can be used with TLS 1.3. | 
|  | // Cipher suites lacking this flag may not be used with TLS 1.3. | 
|  | suiteTLS13 | 
|  | // suiteSHA384 indicates that the cipher suite uses SHA384 as the | 
|  | // handshake hash. | 
|  | suiteSHA384 | 
|  | // suitePSK indicates that the cipher suite authenticates with | 
|  | // a pre-shared key rather than a server private key. | 
|  | suitePSK | 
|  | ) | 
|  |  | 
|  | type tlsAead struct { | 
|  | cipher.AEAD | 
|  | explicitNonce bool | 
|  | } | 
|  |  | 
|  | // A cipherSuite is a specific combination of key agreement, cipher and MAC | 
|  | // function. All cipher suites currently assume RSA key agreement. | 
|  | type cipherSuite struct { | 
|  | id uint16 | 
|  | // the lengths, in bytes, of the key material needed for each component. | 
|  | keyLen int | 
|  | macLen int | 
|  | ivLen  func(version uint16) 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(version uint16, macKey []byte) macFunction | 
|  | aead   func(version uint16, key, fixedNonce []byte) *tlsAead | 
|  | } | 
|  |  | 
|  | func (cs cipherSuite) hash() crypto.Hash { | 
|  | if cs.flags&suiteSHA384 != 0 { | 
|  | return crypto.SHA384 | 
|  | } | 
|  | return crypto.SHA256 | 
|  | } | 
|  |  | 
|  | var cipherSuites = []*cipherSuite{ | 
|  | {TLS_CHACHA20_POLY1305_SHA256, 32, 0, ivLenChaCha20Poly1305, nil, suiteTLS13, nil, nil, aeadCHACHA20POLY1305}, | 
|  | {TLS_AES_128_GCM_SHA256, 16, 0, ivLenAESGCM, nil, suiteTLS13, nil, nil, aeadAESGCM}, | 
|  | {TLS_AES_256_GCM_SHA384, 32, 0, ivLenAESGCM, nil, suiteTLS13 | suiteSHA384, nil, nil, aeadAESGCM}, | 
|  | {TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, 32, 0, ivLenChaCha20Poly1305, ecdheECDSAKA, suiteECDHE | suiteECDSA | suiteTLS12, nil, nil, aeadCHACHA20POLY1305}, | 
|  | {TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256, 32, 0, ivLenChaCha20Poly1305, ecdheRSAKA, suiteECDHE | suiteTLS12, nil, nil, aeadCHACHA20POLY1305}, | 
|  | {TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, 16, 0, ivLenAESGCM, ecdheRSAKA, suiteECDHE | suiteTLS12, nil, nil, aeadAESGCM}, | 
|  | {TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, 16, 0, ivLenAESGCM, ecdheECDSAKA, suiteECDHE | suiteECDSA | suiteTLS12, nil, nil, aeadAESGCM}, | 
|  | {TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, 32, 0, ivLenAESGCM, ecdheRSAKA, suiteECDHE | suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM}, | 
|  | {TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, 32, 0, ivLenAESGCM, ecdheECDSAKA, suiteECDHE | suiteECDSA | suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM}, | 
|  | {TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, 16, 32, ivLenAES, ecdheRSAKA, suiteECDHE | suiteTLS12, cipherAES, macSHA256, nil}, | 
|  | {TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, 16, 32, ivLenAES, ecdheECDSAKA, suiteECDHE | suiteECDSA | suiteTLS12, cipherAES, macSHA256, nil}, | 
|  | {TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, 16, 20, ivLenAES, ecdheRSAKA, suiteECDHE, cipherAES, macSHA1, nil}, | 
|  | {TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, 16, 20, ivLenAES, ecdheECDSAKA, suiteECDHE | suiteECDSA, cipherAES, macSHA1, nil}, | 
|  | {TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384, 32, 48, ivLenAES, ecdheRSAKA, suiteECDHE | suiteTLS12 | suiteSHA384, cipherAES, macSHA384, nil}, | 
|  | {TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384, 32, 48, ivLenAES, ecdheECDSAKA, suiteECDHE | suiteECDSA | suiteTLS12 | suiteSHA384, cipherAES, macSHA384, nil}, | 
|  | {TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, 32, 20, ivLenAES, ecdheRSAKA, suiteECDHE, cipherAES, macSHA1, nil}, | 
|  | {TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, 32, 20, ivLenAES, ecdheECDSAKA, suiteECDHE | suiteECDSA, cipherAES, macSHA1, nil}, | 
|  | {TLS_RSA_WITH_AES_128_GCM_SHA256, 16, 0, ivLenAESGCM, rsaKA, suiteTLS12, nil, nil, aeadAESGCM}, | 
|  | {TLS_RSA_WITH_AES_256_GCM_SHA384, 32, 0, ivLenAESGCM, rsaKA, suiteTLS12 | suiteSHA384, nil, nil, aeadAESGCM}, | 
|  | {TLS_RSA_WITH_AES_128_CBC_SHA256, 16, 32, ivLenAES, rsaKA, suiteTLS12, cipherAES, macSHA256, nil}, | 
|  | {TLS_RSA_WITH_AES_256_CBC_SHA256, 32, 32, ivLenAES, rsaKA, suiteTLS12, cipherAES, macSHA256, nil}, | 
|  | {TLS_RSA_WITH_AES_128_CBC_SHA, 16, 20, ivLenAES, rsaKA, 0, cipherAES, macSHA1, nil}, | 
|  | {TLS_RSA_WITH_AES_256_CBC_SHA, 32, 20, ivLenAES, rsaKA, 0, cipherAES, macSHA1, nil}, | 
|  | {TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, ivLen3DES, ecdheRSAKA, suiteECDHE, cipher3DES, macSHA1, nil}, | 
|  | {TLS_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, ivLen3DES, rsaKA, 0, cipher3DES, macSHA1, nil}, | 
|  | {TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256, 32, 0, ivLenChaCha20Poly1305, ecdhePSKKA, suiteECDHE | suitePSK | suiteTLS12, nil, nil, aeadCHACHA20POLY1305}, | 
|  | {TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA, 16, 20, ivLenAES, ecdhePSKKA, suiteECDHE | suitePSK, cipherAES, macSHA1, nil}, | 
|  | {TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA, 32, 20, ivLenAES, ecdhePSKKA, suiteECDHE | suitePSK, cipherAES, macSHA1, nil}, | 
|  | {TLS_PSK_WITH_AES_128_CBC_SHA, 16, 20, ivLenAES, pskKA, suitePSK, cipherAES, macSHA1, nil}, | 
|  | {TLS_PSK_WITH_AES_256_CBC_SHA, 32, 20, ivLenAES, pskKA, suitePSK, cipherAES, macSHA1, nil}, | 
|  | } | 
|  |  | 
|  | func ivLenChaCha20Poly1305(vers uint16) int { | 
|  | return 12 | 
|  | } | 
|  |  | 
|  | func ivLenAESGCM(vers uint16) int { | 
|  | if vers >= VersionTLS13 { | 
|  | return 12 | 
|  | } | 
|  | return 4 | 
|  | } | 
|  |  | 
|  | func ivLenAES(vers uint16) int { | 
|  | return 16 | 
|  | } | 
|  |  | 
|  | func ivLen3DES(vers uint16) int { | 
|  | return 8 | 
|  | } | 
|  |  | 
|  | type nullCipher struct{} | 
|  |  | 
|  | func cipherNull(key, iv []byte, isRead bool) any { | 
|  | return nullCipher{} | 
|  | } | 
|  |  | 
|  | type cbcMode struct { | 
|  | cipher.BlockMode | 
|  | new func(iv []byte) cipher.BlockMode | 
|  | } | 
|  |  | 
|  | func (c *cbcMode) SetIV(iv []byte) { | 
|  | c.BlockMode = c.new(iv) | 
|  | } | 
|  |  | 
|  | func cipher3DES(key, iv []byte, isRead bool) any { | 
|  | c := &cbcMode{} | 
|  | block, _ := des.NewTripleDESCipher(key) | 
|  | if isRead { | 
|  | c.new = func(iv []byte) cipher.BlockMode { return cipher.NewCBCDecrypter(block, iv) } | 
|  | } else { | 
|  | c.new = func(iv []byte) cipher.BlockMode { return cipher.NewCBCEncrypter(block, iv) } | 
|  | } | 
|  | c.SetIV(iv) | 
|  | return c | 
|  | } | 
|  |  | 
|  | func cipherAES(key, iv []byte, isRead bool) any { | 
|  | c := &cbcMode{} | 
|  | block, _ := aes.NewCipher(key) | 
|  | if isRead { | 
|  | c.new = func(iv []byte) cipher.BlockMode { return cipher.NewCBCDecrypter(block, iv) } | 
|  | } else { | 
|  | c.new = func(iv []byte) cipher.BlockMode { return cipher.NewCBCEncrypter(block, iv) } | 
|  | } | 
|  | c.SetIV(iv) | 
|  | return c | 
|  | } | 
|  |  | 
|  | // macSHA1 returns a macFunction for the given protocol version. | 
|  | func macSHA1(version uint16, key []byte) macFunction { | 
|  | return tls10MAC{hmac.New(sha1.New, key)} | 
|  | } | 
|  |  | 
|  | func macMD5(version uint16, key []byte) macFunction { | 
|  | return tls10MAC{hmac.New(md5.New, key)} | 
|  | } | 
|  |  | 
|  | func macSHA256(version uint16, key []byte) macFunction { | 
|  | return tls10MAC{hmac.New(sha256.New, key)} | 
|  | } | 
|  |  | 
|  | func macSHA384(version uint16, key []byte) macFunction { | 
|  | return tls10MAC{hmac.New(sha512.New384, key)} | 
|  | } | 
|  |  | 
|  | type macFunction interface { | 
|  | Size() int | 
|  | MAC(digestBuf, seq, header, length, data []byte) []byte | 
|  | } | 
|  |  | 
|  | // fixedNonceAEAD wraps an AEAD and prefixes a fixed portion of the nonce to | 
|  | // each call. | 
|  | type fixedNonceAEAD struct { | 
|  | // sealNonce and openNonce are buffers where the larger nonce will be | 
|  | // constructed. Since a seal and open operation may be running | 
|  | // concurrently, there is a separate buffer for each. | 
|  | sealNonce, openNonce []byte | 
|  | aead                 cipher.AEAD | 
|  | } | 
|  |  | 
|  | func (f *fixedNonceAEAD) NonceSize() int { return 8 } | 
|  | func (f *fixedNonceAEAD) Overhead() int  { return f.aead.Overhead() } | 
|  |  | 
|  | func (f *fixedNonceAEAD) Seal(out, nonce, plaintext, additionalData []byte) []byte { | 
|  | copy(f.sealNonce[len(f.sealNonce)-8:], nonce) | 
|  | return f.aead.Seal(out, f.sealNonce, plaintext, additionalData) | 
|  | } | 
|  |  | 
|  | func (f *fixedNonceAEAD) Open(out, nonce, plaintext, additionalData []byte) ([]byte, error) { | 
|  | copy(f.openNonce[len(f.openNonce)-8:], nonce) | 
|  | return f.aead.Open(out, f.openNonce, plaintext, additionalData) | 
|  | } | 
|  |  | 
|  | func aeadAESGCM(version uint16, key, fixedNonce []byte) *tlsAead { | 
|  | aes, err := aes.NewCipher(key) | 
|  | if err != nil { | 
|  | panic(err) | 
|  | } | 
|  | aead, err := cipher.NewGCM(aes) | 
|  | if err != nil { | 
|  | panic(err) | 
|  | } | 
|  |  | 
|  | nonce1, nonce2 := make([]byte, 12), make([]byte, 12) | 
|  | copy(nonce1, fixedNonce) | 
|  | copy(nonce2, fixedNonce) | 
|  |  | 
|  | if version >= VersionTLS13 { | 
|  | return &tlsAead{&xorNonceAEAD{nonce1, nonce2, aead}, false} | 
|  | } | 
|  |  | 
|  | return &tlsAead{&fixedNonceAEAD{nonce1, nonce2, aead}, true} | 
|  | } | 
|  |  | 
|  | func xorSlice(out, in []byte) { | 
|  | for i := range out { | 
|  | out[i] ^= in[i] | 
|  | } | 
|  | } | 
|  |  | 
|  | // xorNonceAEAD wraps an AEAD and XORs a fixed portion of the nonce, left-padded | 
|  | // if necessary, each call. | 
|  | type xorNonceAEAD struct { | 
|  | // sealNonce and openNonce are buffers where the larger nonce will be | 
|  | // constructed. Since a seal and open operation may be running | 
|  | // concurrently, there is a separate buffer for each. | 
|  | sealNonce, openNonce []byte | 
|  | aead                 cipher.AEAD | 
|  | } | 
|  |  | 
|  | func (x *xorNonceAEAD) NonceSize() int { return 8 } | 
|  | func (x *xorNonceAEAD) Overhead() int  { return x.aead.Overhead() } | 
|  |  | 
|  | func (x *xorNonceAEAD) Seal(out, nonce, plaintext, additionalData []byte) []byte { | 
|  | xorSlice(x.sealNonce[len(x.sealNonce)-len(nonce):], nonce) | 
|  | ret := x.aead.Seal(out, x.sealNonce, plaintext, additionalData) | 
|  | xorSlice(x.sealNonce[len(x.sealNonce)-len(nonce):], nonce) | 
|  | return ret | 
|  | } | 
|  |  | 
|  | func (x *xorNonceAEAD) Open(out, nonce, plaintext, additionalData []byte) ([]byte, error) { | 
|  | xorSlice(x.openNonce[len(x.openNonce)-len(nonce):], nonce) | 
|  | ret, err := x.aead.Open(out, x.openNonce, plaintext, additionalData) | 
|  | xorSlice(x.openNonce[len(x.openNonce)-len(nonce):], nonce) | 
|  | return ret, err | 
|  | } | 
|  |  | 
|  | func aeadCHACHA20POLY1305(version uint16, key, fixedNonce []byte) *tlsAead { | 
|  | aead, err := chacha20poly1305.New(key) | 
|  | if err != nil { | 
|  | panic(err) | 
|  | } | 
|  |  | 
|  | nonce1, nonce2 := make([]byte, len(fixedNonce)), make([]byte, len(fixedNonce)) | 
|  | copy(nonce1, fixedNonce) | 
|  | copy(nonce2, fixedNonce) | 
|  |  | 
|  | return &tlsAead{&xorNonceAEAD{nonce1, nonce2, aead}, false} | 
|  | } | 
|  |  | 
|  | // tls10MAC implements the TLS 1.0 MAC function. RFC 2246, section 6.2.3. | 
|  | type tls10MAC struct { | 
|  | h hash.Hash | 
|  | } | 
|  |  | 
|  | func (s tls10MAC) Size() int { | 
|  | return s.h.Size() | 
|  | } | 
|  |  | 
|  | func (s tls10MAC) MAC(digestBuf, seq, header, length, data []byte) []byte { | 
|  | s.h.Reset() | 
|  | s.h.Write(seq) | 
|  | s.h.Write(header) | 
|  | s.h.Write(length) | 
|  | s.h.Write(data) | 
|  | return s.h.Sum(digestBuf[:0]) | 
|  | } | 
|  |  | 
|  | func rsaKA(version uint16) keyAgreement { | 
|  | return &rsaKeyAgreement{version: version} | 
|  | } | 
|  |  | 
|  | func ecdheECDSAKA(version uint16) keyAgreement { | 
|  | return &ecdheKeyAgreement{ | 
|  | auth: &signedKeyAgreement{ | 
|  | keyType: keyTypeECDSA, | 
|  | version: version, | 
|  | }, | 
|  | } | 
|  | } | 
|  |  | 
|  | func ecdheRSAKA(version uint16) keyAgreement { | 
|  | return &ecdheKeyAgreement{ | 
|  | auth: &signedKeyAgreement{ | 
|  | keyType: keyTypeRSA, | 
|  | version: version, | 
|  | }, | 
|  | } | 
|  | } | 
|  |  | 
|  | func pskKA(version uint16) keyAgreement { | 
|  | return &pskKeyAgreement{ | 
|  | base: &nilKeyAgreement{}, | 
|  | } | 
|  | } | 
|  |  | 
|  | func ecdhePSKKA(version uint16) keyAgreement { | 
|  | return &pskKeyAgreement{ | 
|  | base: &ecdheKeyAgreement{ | 
|  | auth: &nilKeyAgreementAuthentication{}, | 
|  | }, | 
|  | } | 
|  | } | 
|  |  | 
|  | // mutualCipherSuite returns a cipherSuite given a list of supported | 
|  | // ciphersuites and the id requested by the peer. | 
|  | func mutualCipherSuite(have []uint16, id uint16) *cipherSuite { | 
|  | if slices.Contains(have, id) { | 
|  | return cipherSuiteFromID(id) | 
|  | } | 
|  | return nil | 
|  | } | 
|  |  | 
|  | func cipherSuiteFromID(id uint16) *cipherSuite { | 
|  | for _, suite := range cipherSuites { | 
|  | if suite.id == id { | 
|  | return suite | 
|  | } | 
|  | } | 
|  | return nil | 
|  | } | 
|  |  | 
|  | // A list of the possible cipher suite ids. Taken from | 
|  | // http://www.iana.org/assignments/tls-parameters/tls-parameters.xml | 
|  | const ( | 
|  | TLS_RSA_WITH_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_256_CBC_SHA256               uint16 = 0x003d | 
|  | TLS_PSK_WITH_AES_128_CBC_SHA                  uint16 = 0x008c | 
|  | TLS_PSK_WITH_AES_256_CBC_SHA                  uint16 = 0x008d | 
|  | TLS_RSA_WITH_AES_128_GCM_SHA256               uint16 = 0x009c | 
|  | TLS_RSA_WITH_AES_256_GCM_SHA384               uint16 = 0x009d | 
|  | TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA          uint16 = 0xc009 | 
|  | TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA          uint16 = 0xc00a | 
|  | TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA           uint16 = 0xc012 | 
|  | TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA            uint16 = 0xc013 | 
|  | TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA            uint16 = 0xc014 | 
|  | TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256       uint16 = 0xc023 | 
|  | TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384       uint16 = 0xc024 | 
|  | TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256         uint16 = 0xc027 | 
|  | TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384         uint16 = 0xc028 | 
|  | TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256       uint16 = 0xc02b | 
|  | TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384       uint16 = 0xc02c | 
|  | TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256         uint16 = 0xc02f | 
|  | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384         uint16 = 0xc030 | 
|  | TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA            uint16 = 0xc035 | 
|  | TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA            uint16 = 0xc036 | 
|  | TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256   uint16 = 0xcca8 | 
|  | TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xcca9 | 
|  | TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256   uint16 = 0xccac | 
|  | renegotiationSCSV                             uint16 = 0x00ff | 
|  | fallbackSCSV                                  uint16 = 0x5600 | 
|  | ) | 
|  |  | 
|  | // Additional cipher suite IDs, not IANA-assigned. | 
|  | const ( | 
|  | TLS_AES_128_GCM_SHA256       uint16 = 0x1301 | 
|  | TLS_AES_256_GCM_SHA384       uint16 = 0x1302 | 
|  | TLS_CHACHA20_POLY1305_SHA256 uint16 = 0x1303 | 
|  | ) |