package org.bouncycastle.jcajce.provider.asymmetric.elgamal;
import java.security.InvalidKeyException;
import java.security.PrivateKey;
import java.security.PublicKey;
import javax.crypto.interfaces.DHPrivateKey;
import javax.crypto.interfaces.DHPublicKey;
import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
import org.bouncycastle.crypto.params.ElGamalParameters;
import org.bouncycastle.crypto.params.ElGamalPrivateKeyParameters;
import org.bouncycastle.crypto.params.ElGamalPublicKeyParameters;
import org.bouncycastle.jce.interfaces.ElGamalPrivateKey;
import org.bouncycastle.jce.interfaces.ElGamalPublicKey;
/**
* utility class for converting jce/jca ElGamal objects
* objects into their org.bouncycastle.crypto counterparts.
*/
public class ElGamalUtil
{
static public AsymmetricKeyParameter generatePublicKeyParameter(
PublicKey key)
throws InvalidKeyException
{
if (key instanceof ElGamalPublicKey)
{
ElGamalPublicKey k = (ElGamalPublicKey)key;
return new ElGamalPublicKeyParameters(k.getY(),
new ElGamalParameters(k.getParameters().getP(), k.getParameters().getG()));
}
else if (key instanceof DHPublicKey)
{
DHPublicKey k = (DHPublicKey)key;
return new ElGamalPublicKeyParameters(k.getY(),
new ElGamalParameters(k.getParams().getP(), k.getParams().getG()));
}
throw new InvalidKeyException("can't identify public key for El Gamal.");
}
static public AsymmetricKeyParameter generatePrivateKeyParameter(
PrivateKey key)
throws InvalidKeyException
{
if (key instanceof ElGamalPrivateKey)
{
ElGamalPrivateKey k = (ElGamalPrivateKey)key;
return new ElGamalPrivateKeyParameters(k.getX(),
new ElGamalParameters(k.getParameters().getP(), k.getParameters().getG()));
}
else if (key instanceof DHPrivateKey)
{
DHPrivateKey k = (DHPrivateKey)key;
return new ElGamalPrivateKeyParameters(k.getX(),
new ElGamalParameters(k.getParams().getP(), k.getParams().getG()));
}
throw new InvalidKeyException("can't identify private key for El Gamal.");
}
}