// generate an elgamal key pair
func ElgamalGenerate(priv *elgamal.PrivateKey, rand io.Reader) (err error) {
priv.P = elgp
priv.G = elgg
xBytes := make([]byte, priv.P.BitLen()/8)
_, err = io.ReadFull(rand, xBytes)
if err == nil {
// set private key
priv.X = new(big.Int).SetBytes(xBytes)
// compute public key
priv.Y = new(big.Int).Exp(priv.G, priv.X, priv.P)
}
return
}
func (pk *PrivateKey) parseElGamalPrivateKey(data []byte) (err 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
}