package org.bouncycastle.jce.provider;import java.security.InvalidKeyException;import java.security.PrivateKey;import java.security.PublicKey;import java.security.interfaces.DSAPrivateKey;import java.security.interfaces.DSAPublicKey;import org.bouncycastle.crypto.params.AsymmetricKeyParameter;import org.bouncycastle.crypto.params.DSAParameters;import org.bouncycastle.crypto.params.DSAPrivateKeyParameters;import org.bouncycastle.crypto.params.DSAPublicKeyParameters;/** * utility class for converting jce/jca DSA objects * objects into their org.bouncycastle.crypto counterparts. */public class DSAUtil{    static public AsymmetricKeyParameter generatePublicKeyParameter(        PublicKey    key)        throws InvalidKeyException    {        if (key instanceof DSAPublicKey)        {            DSAPublicKey    k = (DSAPublicKey)key;            return new DSAPublicKeyParameters(k.getY(),                new DSAParameters(k.getParams().getP(), k.getParams().getQ(), k.getParams().getG()));        }        throw new InvalidKeyException("can't identify DSA public key: " + key.getClass().getName());    }    static public AsymmetricKeyParameter generatePrivateKeyParameter(        PrivateKey    key)        throws InvalidKeyException    {        if (key instanceof DSAPrivateKey)        {            DSAPrivateKey    k = (DSAPrivateKey)key;            return new DSAPrivateKeyParameters(k.getX(),                new DSAParameters(k.getParams().getP(), k.getParams().getQ(), k.getParams().getG()));        }                                throw new InvalidKeyException("can't identify DSA private key.");    }}