diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/ssh/keys.go')
| -rw-r--r-- | vendor/golang.org/x/crypto/ssh/keys.go | 280 |
1 files changed, 254 insertions, 26 deletions
diff --git a/vendor/golang.org/x/crypto/ssh/keys.go b/vendor/golang.org/x/crypto/ssh/keys.go index 969804794f..c148ad4c4f 100644 --- a/vendor/golang.org/x/crypto/ssh/keys.go +++ b/vendor/golang.org/x/crypto/ssh/keys.go @@ -30,12 +30,14 @@ import ( // These constants represent the algorithm names for key types supported by this // package. const ( - KeyAlgoRSA = "ssh-rsa" - KeyAlgoDSA = "ssh-dss" - KeyAlgoECDSA256 = "ecdsa-sha2-nistp256" - KeyAlgoECDSA384 = "ecdsa-sha2-nistp384" - KeyAlgoECDSA521 = "ecdsa-sha2-nistp521" - KeyAlgoED25519 = "ssh-ed25519" + KeyAlgoRSA = "ssh-rsa" + KeyAlgoDSA = "ssh-dss" + KeyAlgoECDSA256 = "ecdsa-sha2-nistp256" + KeyAlgoSKECDSA256 = "sk-ecdsa-sha2-nistp256@openssh.com" + KeyAlgoECDSA384 = "ecdsa-sha2-nistp384" + KeyAlgoECDSA521 = "ecdsa-sha2-nistp521" + KeyAlgoED25519 = "ssh-ed25519" + KeyAlgoSKED25519 = "sk-ssh-ed25519@openssh.com" ) // These constants represent non-default signature algorithms that are supported @@ -58,9 +60,13 @@ func parsePubKey(in []byte, algo string) (pubKey PublicKey, rest []byte, err err return parseDSA(in) case KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521: return parseECDSA(in) + case KeyAlgoSKECDSA256: + return parseSKECDSA(in) case KeyAlgoED25519: return parseED25519(in) - case CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01, CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoED25519v01: + case KeyAlgoSKED25519: + return parseSKEd25519(in) + case CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01, CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoSKECDSA256v01, CertAlgoED25519v01, CertAlgoSKED25519v01: cert, err := parseCert(in, certToPrivAlgo(algo)) if err != nil { return nil, nil, err @@ -685,6 +691,218 @@ func (k *ecdsaPublicKey) CryptoPublicKey() crypto.PublicKey { return (*ecdsa.PublicKey)(k) } +// skFields holds the additional fields present in U2F/FIDO2 signatures. +// See openssh/PROTOCOL.u2f 'SSH U2F Signatures' for details. +type skFields struct { + // Flags contains U2F/FIDO2 flags such as 'user present' + Flags byte + // Counter is a monotonic signature counter which can be + // used to detect concurrent use of a private key, should + // it be extracted from hardware. + Counter uint32 +} + +type skECDSAPublicKey struct { + // application is a URL-like string, typically "ssh:" for SSH. + // see openssh/PROTOCOL.u2f for details. + application string + ecdsa.PublicKey +} + +func (k *skECDSAPublicKey) Type() string { + return KeyAlgoSKECDSA256 +} + +func (k *skECDSAPublicKey) nistID() string { + return "nistp256" +} + +func parseSKECDSA(in []byte) (out PublicKey, rest []byte, err error) { + var w struct { + Curve string + KeyBytes []byte + Application string + Rest []byte `ssh:"rest"` + } + + if err := Unmarshal(in, &w); err != nil { + return nil, nil, err + } + + key := new(skECDSAPublicKey) + key.application = w.Application + + if w.Curve != "nistp256" { + return nil, nil, errors.New("ssh: unsupported curve") + } + key.Curve = elliptic.P256() + + key.X, key.Y = elliptic.Unmarshal(key.Curve, w.KeyBytes) + if key.X == nil || key.Y == nil { + return nil, nil, errors.New("ssh: invalid curve point") + } + + return key, w.Rest, nil +} + +func (k *skECDSAPublicKey) Marshal() []byte { + // See RFC 5656, section 3.1. + keyBytes := elliptic.Marshal(k.Curve, k.X, k.Y) + w := struct { + Name string + ID string + Key []byte + Application string + }{ + k.Type(), + k.nistID(), + keyBytes, + k.application, + } + + return Marshal(&w) +} + +func (k *skECDSAPublicKey) Verify(data []byte, sig *Signature) error { + if sig.Format != k.Type() { + return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, k.Type()) + } + + h := ecHash(k.Curve).New() + h.Write([]byte(k.application)) + appDigest := h.Sum(nil) + + h.Reset() + h.Write(data) + dataDigest := h.Sum(nil) + + var ecSig struct { + R *big.Int + S *big.Int + } + if err := Unmarshal(sig.Blob, &ecSig); err != nil { + return err + } + + var skf skFields + if err := Unmarshal(sig.Rest, &skf); err != nil { + return err + } + + blob := struct { + ApplicationDigest []byte `ssh:"rest"` + Flags byte + Counter uint32 + MessageDigest []byte `ssh:"rest"` + }{ + appDigest, + skf.Flags, + skf.Counter, + dataDigest, + } + + original := Marshal(blob) + + h.Reset() + h.Write(original) + digest := h.Sum(nil) + + if ecdsa.Verify((*ecdsa.PublicKey)(&k.PublicKey), digest, ecSig.R, ecSig.S) { + return nil + } + return errors.New("ssh: signature did not verify") +} + +type skEd25519PublicKey struct { + // application is a URL-like string, typically "ssh:" for SSH. + // see openssh/PROTOCOL.u2f for details. + application string + ed25519.PublicKey +} + +func (k *skEd25519PublicKey) Type() string { + return KeyAlgoSKED25519 +} + +func parseSKEd25519(in []byte) (out PublicKey, rest []byte, err error) { + var w struct { + KeyBytes []byte + Application string + Rest []byte `ssh:"rest"` + } + + if err := Unmarshal(in, &w); err != nil { + return nil, nil, err + } + + key := new(skEd25519PublicKey) + key.application = w.Application + key.PublicKey = ed25519.PublicKey(w.KeyBytes) + + return key, w.Rest, nil +} + +func (k *skEd25519PublicKey) Marshal() []byte { + w := struct { + Name string + KeyBytes []byte + Application string + }{ + KeyAlgoSKED25519, + []byte(k.PublicKey), + k.application, + } + return Marshal(&w) +} + +func (k *skEd25519PublicKey) Verify(data []byte, sig *Signature) error { + if sig.Format != k.Type() { + return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, k.Type()) + } + + h := sha256.New() + h.Write([]byte(k.application)) + appDigest := h.Sum(nil) + + h.Reset() + h.Write(data) + dataDigest := h.Sum(nil) + + var edSig struct { + Signature []byte `ssh:"rest"` + } + + if err := Unmarshal(sig.Blob, &edSig); err != nil { + return err + } + + var skf skFields + if err := Unmarshal(sig.Rest, &skf); err != nil { + return err + } + + blob := struct { + ApplicationDigest []byte `ssh:"rest"` + Flags byte + Counter uint32 + MessageDigest []byte `ssh:"rest"` + }{ + appDigest, + skf.Flags, + skf.Counter, + dataDigest, + } + + original := Marshal(blob) + + edKey := (ed25519.PublicKey)(k.PublicKey) + if ok := ed25519.Verify(edKey, original, edSig.Signature); !ok { + return errors.New("ssh: signature did not verify") + } + + return nil +} + // NewSignerFromKey takes an *rsa.PrivateKey, *dsa.PrivateKey, // *ecdsa.PrivateKey or any other crypto.Signer and returns a // corresponding Signer instance. ECDSA keys must use P-256, P-384 or @@ -837,7 +1055,8 @@ func NewPublicKey(key interface{}) (PublicKey, error) { } // ParsePrivateKey returns a Signer from a PEM encoded private key. It supports -// the same keys as ParseRawPrivateKey. +// the same keys as ParseRawPrivateKey. If the private key is encrypted, it +// will return a PassphraseMissingError. func ParsePrivateKey(pemBytes []byte) (Signer, error) { key, err := ParseRawPrivateKey(pemBytes) if err != nil { @@ -850,8 +1069,8 @@ func ParsePrivateKey(pemBytes []byte) (Signer, error) { // ParsePrivateKeyWithPassphrase returns a Signer from a PEM encoded private // key and passphrase. It supports the same keys as // ParseRawPrivateKeyWithPassphrase. -func ParsePrivateKeyWithPassphrase(pemBytes, passPhrase []byte) (Signer, error) { - key, err := ParseRawPrivateKeyWithPassphrase(pemBytes, passPhrase) +func ParsePrivateKeyWithPassphrase(pemBytes, passphrase []byte) (Signer, error) { + key, err := ParseRawPrivateKeyWithPassphrase(pemBytes, passphrase) if err != nil { return nil, err } @@ -867,8 +1086,21 @@ func encryptedBlock(block *pem.Block) bool { return strings.Contains(block.Headers["Proc-Type"], "ENCRYPTED") } +// A PassphraseMissingError indicates that parsing this private key requires a +// passphrase. Use ParsePrivateKeyWithPassphrase. +type PassphraseMissingError struct { + // PublicKey will be set if the private key format includes an unencrypted + // public key along with the encrypted private key. + PublicKey PublicKey +} + +func (*PassphraseMissingError) Error() string { + return "ssh: this private key is passphrase protected" +} + // ParseRawPrivateKey returns a private key from a PEM encoded private key. It -// supports RSA (PKCS#1), PKCS#8, DSA (OpenSSL), and ECDSA private keys. +// supports RSA (PKCS#1), PKCS#8, DSA (OpenSSL), and ECDSA private keys. If the +// private key is encrypted, it will return a PassphraseMissingError. func ParseRawPrivateKey(pemBytes []byte) (interface{}, error) { block, _ := pem.Decode(pemBytes) if block == nil { @@ -876,7 +1108,7 @@ func ParseRawPrivateKey(pemBytes []byte) (interface{}, error) { } if encryptedBlock(block) { - return nil, errors.New("ssh: cannot decode encrypted private keys") + return nil, &PassphraseMissingError{} } switch block.Type { @@ -899,24 +1131,22 @@ func ParseRawPrivateKey(pemBytes []byte) (interface{}, error) { // ParseRawPrivateKeyWithPassphrase returns a private key decrypted with // passphrase from a PEM encoded private key. If wrong passphrase, return // x509.IncorrectPasswordError. -func ParseRawPrivateKeyWithPassphrase(pemBytes, passPhrase []byte) (interface{}, error) { +func ParseRawPrivateKeyWithPassphrase(pemBytes, passphrase []byte) (interface{}, error) { block, _ := pem.Decode(pemBytes) if block == nil { return nil, errors.New("ssh: no key found") } - buf := block.Bytes - if encryptedBlock(block) { - if x509.IsEncryptedPEMBlock(block) { - var err error - buf, err = x509.DecryptPEMBlock(block, passPhrase) - if err != nil { - if err == x509.IncorrectPasswordError { - return nil, err - } - return nil, fmt.Errorf("ssh: cannot decode encrypted private keys: %v", err) - } + if !encryptedBlock(block) || !x509.IsEncryptedPEMBlock(block) { + return nil, errors.New("ssh: not an encrypted key") + } + + buf, err := x509.DecryptPEMBlock(block, passphrase) + if err != nil { + if err == x509.IncorrectPasswordError { + return nil, err } + return nil, fmt.Errorf("ssh: cannot decode encrypted private keys: %v", err) } switch block.Type { @@ -926,8 +1156,6 @@ func ParseRawPrivateKeyWithPassphrase(pemBytes, passPhrase []byte) (interface{}, return x509.ParseECPrivateKey(buf) case "DSA PRIVATE KEY": return ParseDSAPrivateKey(buf) - case "OPENSSH PRIVATE KEY": - return parseOpenSSHPrivateKey(buf) default: return nil, fmt.Errorf("ssh: unsupported key type %q", block.Type) } |