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path: root/vendor/golang.org/x/crypto/ssh/keys.go
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Diffstat (limited to 'vendor/golang.org/x/crypto/ssh/keys.go')
-rw-r--r--vendor/golang.org/x/crypto/ssh/keys.go474
1 files changed, 420 insertions, 54 deletions
diff --git a/vendor/golang.org/x/crypto/ssh/keys.go b/vendor/golang.org/x/crypto/ssh/keys.go
index 969804794..06f537c13 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"
@@ -25,17 +27,20 @@ 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
// 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 +63,13 @@ 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
@@ -553,9 +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 {
@@ -573,9 +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")
}
@@ -685,6 +698,224 @@ 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
+ }
+
+ 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)
+
+ 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())
+ }
+ 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))
+ 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)
+
+ if ok := ed25519.Verify(k.PublicKey, 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
@@ -830,14 +1061,18 @@ 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)
}
}
// 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 +1085,8 @@ 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 +1102,21 @@ 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 +1124,7 @@ 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 {
@@ -890,33 +1138,35 @@ 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.
-func ParseRawPrivateKeyWithPassphrase(pemBytes, passPhrase []byte) (interface{}, error) {
+// 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")
}
- 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 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")
+ }
+
+ 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 +1176,6 @@ 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)
}
@@ -965,9 +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")
@@ -986,9 +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 {
@@ -998,15 +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
@@ -1025,10 +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{
@@ -1063,20 +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 {
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-10-20 22:34:04 +0000