crypto/openpgp: add ElGamal support.

R=bradfitz, r
CC=golang-dev
https://golang.org/cl/4639049

1 files changed, 22 insertions, 0 deletions

diff --git a/src/pkg/crypto/openpgp/packet/private_key.go b/src/pkg/crypto/openpgp/packet/private_key.go
index 6244661320..6f8133d981 100644
--- a/src/pkg/crypto/openpgp/packet/private_key.go
+++ b/src/pkg/crypto/openpgp/packet/private_key.go
@@ -9,6 +9,7 @@ import (
 	"bytes"
 	"crypto/cipher"
 	"crypto/dsa"
+	"crypto/openpgp/elgamal"
 	"crypto/openpgp/error"
 	"crypto/openpgp/s2k"
 	"crypto/rsa"
@@ -224,6 +225,8 @@ func (pk *PrivateKey) parsePrivateKey(data []byte) (err os.Error) {
 		return pk.parseRSAPrivateKey(data)
 	case PubKeyAlgoDSA:
 		return pk.parseDSAPrivateKey(data)
+	case PubKeyAlgoElGamal:
+		return pk.parseElGamalPrivateKey(data)
 	}
 	panic("impossible")
 }
@@ -277,3 +280,22 @@ func (pk *PrivateKey) parseDSAPrivateKey(data []byte) (err os.Error) {
 
 	return nil
 }
+
+func (pk *PrivateKey) parseElGamalPrivateKey(data []byte) (err os.Error) {
+	pub := pk.PublicKey.PublicKey.(*elgamal.PublicKey)
+	priv := new(elgamal.PrivateKey)
+	priv.PublicKey = *pub
+
+	buf := bytes.NewBuffer(data)
+	x, _, err := readMPI(buf)
+	if err != nil {
+		return
+	}
+
+	priv.X = new(big.Int).SetBytes(x)
+	pk.PrivateKey = priv
+	pk.Encrypted = false
+	pk.encryptedData = nil
+
+	return nil
+}