diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/ssh/keys.go')
| -rw-r--r-- | vendor/golang.org/x/crypto/ssh/keys.go | 198 |
1 files changed, 168 insertions, 30 deletions
diff --git a/vendor/golang.org/x/crypto/ssh/keys.go b/vendor/golang.org/x/crypto/ssh/keys.go index c148ad4c..06f537c1 100644 --- a/vendor/golang.org/x/crypto/ssh/keys.go +++ b/vendor/golang.org/x/crypto/ssh/keys.go @@ -7,6 +7,8 @@ package ssh import ( "bytes" "crypto" + "crypto/aes" + "crypto/cipher" "crypto/dsa" "crypto/ecdsa" "crypto/elliptic" @@ -25,6 +27,7 @@ import ( "strings" "golang.org/x/crypto/ed25519" + "golang.org/x/crypto/ssh/internal/bcrypt_pbkdf" ) // These constants represent the algorithm names for key types supported by this @@ -559,9 +562,11 @@ func parseED25519(in []byte) (out PublicKey, rest []byte, err error) { return nil, nil, err } - key := ed25519.PublicKey(w.KeyBytes) + if l := len(w.KeyBytes); l != ed25519.PublicKeySize { + return nil, nil, fmt.Errorf("invalid size %d for Ed25519 public key", l) + } - return (ed25519PublicKey)(key), w.Rest, nil + return ed25519PublicKey(w.KeyBytes), w.Rest, nil } func (k ed25519PublicKey) Marshal() []byte { @@ -579,9 +584,11 @@ func (k ed25519PublicKey) Verify(b []byte, sig *Signature) error { if sig.Format != k.Type() { return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, k.Type()) } + if l := len(k); l != ed25519.PublicKeySize { + return fmt.Errorf("ssh: invalid size %d for Ed25519 public key", l) + } - edKey := (ed25519.PublicKey)(k) - if ok := ed25519.Verify(edKey, b, sig.Blob); !ok { + if ok := ed25519.Verify(ed25519.PublicKey(k), b, sig.Blob); !ok { return errors.New("ssh: signature did not verify") } @@ -835,6 +842,10 @@ func parseSKEd25519(in []byte) (out PublicKey, rest []byte, err error) { return nil, nil, err } + if l := len(w.KeyBytes); l != ed25519.PublicKeySize { + return nil, nil, fmt.Errorf("invalid size %d for Ed25519 public key", l) + } + key := new(skEd25519PublicKey) key.application = w.Application key.PublicKey = ed25519.PublicKey(w.KeyBytes) @@ -859,6 +870,9 @@ 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()) } + if l := len(k.PublicKey); l != ed25519.PublicKeySize { + return fmt.Errorf("invalid size %d for Ed25519 public key", l) + } h := sha256.New() h.Write([]byte(k.application)) @@ -895,8 +909,7 @@ func (k *skEd25519PublicKey) Verify(data []byte, sig *Signature) error { original := Marshal(blob) - edKey := (ed25519.PublicKey)(k.PublicKey) - if ok := ed25519.Verify(edKey, original, edSig.Signature); !ok { + if ok := ed25519.Verify(k.PublicKey, original, edSig.Signature); !ok { return errors.New("ssh: signature did not verify") } @@ -1048,7 +1061,10 @@ func NewPublicKey(key interface{}) (PublicKey, error) { case *dsa.PublicKey: return (*dsaPublicKey)(key), nil case ed25519.PublicKey: - return (ed25519PublicKey)(key), nil + if l := len(key); l != ed25519.PublicKeySize { + return nil, fmt.Errorf("ssh: invalid size %d for Ed25519 public key", l) + } + return ed25519PublicKey(key), nil default: return nil, fmt.Errorf("ssh: unsupported key type %T", key) } @@ -1122,21 +1138,25 @@ func ParseRawPrivateKey(pemBytes []byte) (interface{}, error) { case "DSA PRIVATE KEY": return ParseDSAPrivateKey(block.Bytes) case "OPENSSH PRIVATE KEY": - return parseOpenSSHPrivateKey(block.Bytes) + return parseOpenSSHPrivateKey(block.Bytes, unencryptedOpenSSHKey) default: return nil, fmt.Errorf("ssh: unsupported key type %q", block.Type) } } // ParseRawPrivateKeyWithPassphrase returns a private key decrypted with -// passphrase from a PEM encoded private key. If wrong passphrase, return -// x509.IncorrectPasswordError. +// passphrase from a PEM encoded private key. If the passphrase is wrong, it +// will return x509.IncorrectPasswordError. func ParseRawPrivateKeyWithPassphrase(pemBytes, passphrase []byte) (interface{}, error) { block, _ := pem.Decode(pemBytes) if block == nil { return nil, errors.New("ssh: no key found") } + if block.Type == "OPENSSH PRIVATE KEY" { + return parseOpenSSHPrivateKey(block.Bytes, passphraseProtectedOpenSSHKey(passphrase)) + } + if !encryptedBlock(block) || !x509.IsEncryptedPEMBlock(block) { return nil, errors.New("ssh: not an encrypted key") } @@ -1193,9 +1213,60 @@ func ParseDSAPrivateKey(der []byte) (*dsa.PrivateKey, error) { }, nil } -// Implemented based on the documentation at -// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.key -func parseOpenSSHPrivateKey(key []byte) (crypto.PrivateKey, error) { +func unencryptedOpenSSHKey(cipherName, kdfName, kdfOpts string, privKeyBlock []byte) ([]byte, error) { + if kdfName != "none" || cipherName != "none" { + return nil, &PassphraseMissingError{} + } + if kdfOpts != "" { + return nil, errors.New("ssh: invalid openssh private key") + } + return privKeyBlock, nil +} + +func passphraseProtectedOpenSSHKey(passphrase []byte) openSSHDecryptFunc { + return func(cipherName, kdfName, kdfOpts string, privKeyBlock []byte) ([]byte, error) { + if kdfName == "none" || cipherName == "none" { + return nil, errors.New("ssh: key is not password protected") + } + if kdfName != "bcrypt" { + return nil, fmt.Errorf("ssh: unknown KDF %q, only supports %q", kdfName, "bcrypt") + } + + var opts struct { + Salt string + Rounds uint32 + } + if err := Unmarshal([]byte(kdfOpts), &opts); err != nil { + return nil, err + } + + k, err := bcrypt_pbkdf.Key(passphrase, []byte(opts.Salt), int(opts.Rounds), 32+16) + if err != nil { + return nil, err + } + key, iv := k[:32], k[32:] + + if cipherName != "aes256-ctr" { + return nil, fmt.Errorf("ssh: unknown cipher %q, only supports %q", cipherName, "aes256-ctr") + } + c, err := aes.NewCipher(key) + if err != nil { + return nil, err + } + ctr := cipher.NewCTR(c, iv) + ctr.XORKeyStream(privKeyBlock, privKeyBlock) + + return privKeyBlock, nil + } +} + +type openSSHDecryptFunc func(CipherName, KdfName, KdfOpts string, PrivKeyBlock []byte) ([]byte, error) + +// parseOpenSSHPrivateKey parses an OpenSSH private key, using the decrypt +// function to unwrap the encrypted portion. unencryptedOpenSSHKey can be used +// as the decrypt function to parse an unencrypted private key. See +// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.key. +func parseOpenSSHPrivateKey(key []byte, decrypt openSSHDecryptFunc) (crypto.PrivateKey, error) { const magic = "openssh-key-v1\x00" if len(key) < len(magic) || string(key[:len(magic)]) != magic { return nil, errors.New("ssh: invalid openssh private key format") @@ -1214,9 +1285,22 @@ func parseOpenSSHPrivateKey(key []byte) (crypto.PrivateKey, error) { if err := Unmarshal(remaining, &w); err != nil { return nil, err } + if w.NumKeys != 1 { + // We only support single key files, and so does OpenSSH. + // https://github.com/openssh/openssh-portable/blob/4103a3ec7/sshkey.c#L4171 + return nil, errors.New("ssh: multi-key files are not supported") + } - if w.KdfName != "none" || w.CipherName != "none" { - return nil, errors.New("ssh: cannot decode encrypted private keys") + privKeyBlock, err := decrypt(w.CipherName, w.KdfName, w.KdfOpts, w.PrivKeyBlock) + if err != nil { + if err, ok := err.(*PassphraseMissingError); ok { + pub, errPub := ParsePublicKey(w.PubKey) + if errPub != nil { + return nil, fmt.Errorf("ssh: failed to parse embedded public key: %v", errPub) + } + err.PublicKey = pub + } + return nil, err } pk1 := struct { @@ -1226,15 +1310,13 @@ func parseOpenSSHPrivateKey(key []byte) (crypto.PrivateKey, error) { Rest []byte `ssh:"rest"` }{} - if err := Unmarshal(w.PrivKeyBlock, &pk1); err != nil { - return nil, err - } - - if pk1.Check1 != pk1.Check2 { - return nil, errors.New("ssh: checkint mismatch") + if err := Unmarshal(privKeyBlock, &pk1); err != nil || pk1.Check1 != pk1.Check2 { + if w.CipherName != "none" { + return nil, x509.IncorrectPasswordError + } + return nil, errors.New("ssh: malformed OpenSSH key") } - // we only handle ed25519 and rsa keys currently switch pk1.Keytype { case KeyAlgoRSA: // https://github.com/openssh/openssh-portable/blob/master/sshkey.c#L2760-L2773 @@ -1253,10 +1335,8 @@ func parseOpenSSHPrivateKey(key []byte) (crypto.PrivateKey, error) { return nil, err } - for i, b := range key.Pad { - if int(b) != i+1 { - return nil, errors.New("ssh: padding not as expected") - } + if err := checkOpenSSHKeyPadding(key.Pad); err != nil { + return nil, err } pk := &rsa.PrivateKey{ @@ -1291,20 +1371,78 @@ func parseOpenSSHPrivateKey(key []byte) (crypto.PrivateKey, error) { return nil, errors.New("ssh: private key unexpected length") } - for i, b := range key.Pad { - if int(b) != i+1 { - return nil, errors.New("ssh: padding not as expected") - } + if err := checkOpenSSHKeyPadding(key.Pad); err != nil { + return nil, err } pk := ed25519.PrivateKey(make([]byte, ed25519.PrivateKeySize)) copy(pk, key.Priv) return &pk, nil + case KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521: + key := struct { + Curve string + Pub []byte + D *big.Int + Comment string + Pad []byte `ssh:"rest"` + }{} + + if err := Unmarshal(pk1.Rest, &key); err != nil { + return nil, err + } + + if err := checkOpenSSHKeyPadding(key.Pad); err != nil { + return nil, err + } + + var curve elliptic.Curve + switch key.Curve { + case "nistp256": + curve = elliptic.P256() + case "nistp384": + curve = elliptic.P384() + case "nistp521": + curve = elliptic.P521() + default: + return nil, errors.New("ssh: unhandled elliptic curve: " + key.Curve) + } + + X, Y := elliptic.Unmarshal(curve, key.Pub) + if X == nil || Y == nil { + return nil, errors.New("ssh: failed to unmarshal public key") + } + + if key.D.Cmp(curve.Params().N) >= 0 { + return nil, errors.New("ssh: scalar is out of range") + } + + x, y := curve.ScalarBaseMult(key.D.Bytes()) + if x.Cmp(X) != 0 || y.Cmp(Y) != 0 { + return nil, errors.New("ssh: public key does not match private key") + } + + return &ecdsa.PrivateKey{ + PublicKey: ecdsa.PublicKey{ + Curve: curve, + X: X, + Y: Y, + }, + D: key.D, + }, nil default: return nil, errors.New("ssh: unhandled key type") } } +func checkOpenSSHKeyPadding(pad []byte) error { + for i, b := range pad { + if int(b) != i+1 { + return errors.New("ssh: padding not as expected") + } + } + return nil +} + // FingerprintLegacyMD5 returns the user presentation of the key's // fingerprint as described by RFC 4716 section 4. func FingerprintLegacyMD5(pubKey PublicKey) string { |