diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/ssh')
| -rw-r--r-- | vendor/golang.org/x/crypto/ssh/common.go | 51 | ||||
| -rw-r--r-- | vendor/golang.org/x/crypto/ssh/kex.go | 12 | ||||
| -rw-r--r-- | vendor/golang.org/x/crypto/ssh/server.go | 21 |
3 files changed, 70 insertions, 14 deletions
diff --git a/vendor/golang.org/x/crypto/ssh/common.go b/vendor/golang.org/x/crypto/ssh/common.go index 9ba6e10a4..b419c761e 100644 --- a/vendor/golang.org/x/crypto/ssh/common.go +++ b/vendor/golang.org/x/crypto/ssh/common.go @@ -49,7 +49,8 @@ var supportedKexAlgos = []string{ // P384 and P521 are not constant-time yet, but since we don't // reuse ephemeral keys, using them for ECDH should be OK. kexAlgoECDH256, kexAlgoECDH384, kexAlgoECDH521, - kexAlgoDH14SHA256, kexAlgoDH14SHA1, kexAlgoDH1SHA1, + kexAlgoDH14SHA256, kexAlgoDH16SHA512, kexAlgoDH14SHA1, + kexAlgoDH1SHA1, } // serverForbiddenKexAlgos contains key exchange algorithms, that are forbidden @@ -59,8 +60,9 @@ var serverForbiddenKexAlgos = map[string]struct{}{ kexAlgoDHGEXSHA256: {}, // server half implementation is only minimal to satisfy the automated tests } -// preferredKexAlgos specifies the default preference for key-exchange algorithms -// in preference order. +// preferredKexAlgos specifies the default preference for key-exchange +// algorithms in preference order. The diffie-hellman-group16-sha512 algorithm +// is disabled by default because it is a bit slower than the others. var preferredKexAlgos = []string{ kexAlgoCurve25519SHA256, kexAlgoCurve25519SHA256LibSSH, kexAlgoECDH256, kexAlgoECDH384, kexAlgoECDH521, @@ -70,12 +72,12 @@ var preferredKexAlgos = []string{ // supportedHostKeyAlgos specifies the supported host-key algorithms (i.e. methods // of authenticating servers) in preference order. var supportedHostKeyAlgos = []string{ - CertAlgoRSASHA512v01, CertAlgoRSASHA256v01, + CertAlgoRSASHA256v01, CertAlgoRSASHA512v01, CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01, CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoED25519v01, KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521, - KeyAlgoRSASHA512, KeyAlgoRSASHA256, + KeyAlgoRSASHA256, KeyAlgoRSASHA512, KeyAlgoRSA, KeyAlgoDSA, KeyAlgoED25519, @@ -85,7 +87,7 @@ var supportedHostKeyAlgos = []string{ // This is based on RFC 4253, section 6.4, but with hmac-md5 variants removed // because they have reached the end of their useful life. var supportedMACs = []string{ - "hmac-sha2-512-etm@openssh.com", "hmac-sha2-256-etm@openssh.com", "hmac-sha2-256", "hmac-sha2-512", "hmac-sha1", "hmac-sha1-96", + "hmac-sha2-256-etm@openssh.com", "hmac-sha2-512-etm@openssh.com", "hmac-sha2-256", "hmac-sha2-512", "hmac-sha1", "hmac-sha1-96", } var supportedCompressions = []string{compressionNone} @@ -119,6 +121,13 @@ func algorithmsForKeyFormat(keyFormat string) []string { } } +// isRSA returns whether algo is a supported RSA algorithm, including certificate +// algorithms. +func isRSA(algo string) bool { + algos := algorithmsForKeyFormat(KeyAlgoRSA) + return contains(algos, underlyingAlgo(algo)) +} + // supportedPubKeyAuthAlgos specifies the supported client public key // authentication algorithms. Note that this doesn't include certificate types // since those use the underlying algorithm. This list is sent to the client if @@ -262,16 +271,16 @@ type Config struct { // unspecified, a size suitable for the chosen cipher is used. RekeyThreshold uint64 - // The allowed key exchanges algorithms. If unspecified then a - // default set of algorithms is used. + // The allowed key exchanges algorithms. If unspecified then a default set + // of algorithms is used. Unsupported values are silently ignored. KeyExchanges []string - // The allowed cipher algorithms. If unspecified then a sensible - // default is used. + // The allowed cipher algorithms. If unspecified then a sensible default is + // used. Unsupported values are silently ignored. Ciphers []string - // The allowed MAC algorithms. If unspecified then a sensible default - // is used. + // The allowed MAC algorithms. If unspecified then a sensible default is + // used. Unsupported values are silently ignored. MACs []string } @@ -288,7 +297,7 @@ func (c *Config) SetDefaults() { var ciphers []string for _, c := range c.Ciphers { if cipherModes[c] != nil { - // reject the cipher if we have no cipherModes definition + // Ignore the cipher if we have no cipherModes definition. ciphers = append(ciphers, c) } } @@ -297,10 +306,26 @@ func (c *Config) SetDefaults() { if c.KeyExchanges == nil { c.KeyExchanges = preferredKexAlgos } + var kexs []string + for _, k := range c.KeyExchanges { + if kexAlgoMap[k] != nil { + // Ignore the KEX if we have no kexAlgoMap definition. + kexs = append(kexs, k) + } + } + c.KeyExchanges = kexs if c.MACs == nil { c.MACs = supportedMACs } + var macs []string + for _, m := range c.MACs { + if macModes[m] != nil { + // Ignore the MAC if we have no macModes definition. + macs = append(macs, m) + } + } + c.MACs = macs if c.RekeyThreshold == 0 { // cipher specific default diff --git a/vendor/golang.org/x/crypto/ssh/kex.go b/vendor/golang.org/x/crypto/ssh/kex.go index 927a90cd4..8a05f7990 100644 --- a/vendor/golang.org/x/crypto/ssh/kex.go +++ b/vendor/golang.org/x/crypto/ssh/kex.go @@ -23,6 +23,7 @@ const ( kexAlgoDH1SHA1 = "diffie-hellman-group1-sha1" kexAlgoDH14SHA1 = "diffie-hellman-group14-sha1" kexAlgoDH14SHA256 = "diffie-hellman-group14-sha256" + kexAlgoDH16SHA512 = "diffie-hellman-group16-sha512" kexAlgoECDH256 = "ecdh-sha2-nistp256" kexAlgoECDH384 = "ecdh-sha2-nistp384" kexAlgoECDH521 = "ecdh-sha2-nistp521" @@ -430,6 +431,17 @@ func init() { hashFunc: crypto.SHA256, } + // This is the group called diffie-hellman-group16-sha512 in RFC + // 8268 and Oakley Group 16 in RFC 3526. + p, _ = new(big.Int).SetString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kexAlgoMap[kexAlgoDH16SHA512] = &dhGroup{ + g: new(big.Int).SetInt64(2), + p: p, + pMinus1: new(big.Int).Sub(p, bigOne), + hashFunc: crypto.SHA512, + } + kexAlgoMap[kexAlgoECDH521] = &ecdh{elliptic.P521()} kexAlgoMap[kexAlgoECDH384] = &ecdh{elliptic.P384()} kexAlgoMap[kexAlgoECDH256] = &ecdh{elliptic.P256()} diff --git a/vendor/golang.org/x/crypto/ssh/server.go b/vendor/golang.org/x/crypto/ssh/server.go index 9e3870292..b21322aff 100644 --- a/vendor/golang.org/x/crypto/ssh/server.go +++ b/vendor/golang.org/x/crypto/ssh/server.go @@ -370,6 +370,25 @@ func gssExchangeToken(gssapiConfig *GSSAPIWithMICConfig, firstToken []byte, s *c return authErr, perms, nil } +// isAlgoCompatible checks if the signature format is compatible with the +// selected algorithm taking into account edge cases that occur with old +// clients. +func isAlgoCompatible(algo, sigFormat string) bool { + // Compatibility for old clients. + // + // For certificate authentication with OpenSSH 7.2-7.7 signature format can + // be rsa-sha2-256 or rsa-sha2-512 for the algorithm + // ssh-rsa-cert-v01@openssh.com. + // + // With gpg-agent < 2.2.6 the algorithm can be rsa-sha2-256 or rsa-sha2-512 + // for signature format ssh-rsa. + if isRSA(algo) && isRSA(sigFormat) { + return true + } + // Standard case: the underlying algorithm must match the signature format. + return underlyingAlgo(algo) == sigFormat +} + // ServerAuthError represents server authentication errors and is // sometimes returned by NewServerConn. It appends any authentication // errors that may occur, and is returned if all of the authentication @@ -567,7 +586,7 @@ userAuthLoop: authErr = fmt.Errorf("ssh: algorithm %q not accepted", sig.Format) break } - if underlyingAlgo(algo) != sig.Format { + if !isAlgoCompatible(algo, sig.Format) { authErr = fmt.Errorf("ssh: signature %q not compatible with selected algorithm %q", sig.Format, algo) break } |