package org.bouncycastle.jce.provider;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.math.BigInteger;import javax.crypto.interfaces.DHPublicKey;import javax.crypto.spec.DHParameterSpec;import javax.crypto.spec.DHPublicKeySpec;import org.bouncycastle.asn1.ASN1Sequence;import org.bouncycastle.asn1.DERInteger;import org.bouncycastle.asn1.oiw.ElGamalParameter;import org.bouncycastle.asn1.oiw.OIWObjectIdentifiers;import org.bouncycastle.asn1.x509.AlgorithmIdentifier;import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;import org.bouncycastle.crypto.params.ElGamalPublicKeyParameters;import org.bouncycastle.jce.interfaces.ElGamalPublicKey;import org.bouncycastle.jce.spec.ElGamalParameterSpec;import org.bouncycastle.jce.spec.ElGamalPublicKeySpec;public class JCEElGamalPublicKey    implements ElGamalPublicKey, DHPublicKey{    private BigInteger              y;    private ElGamalParameterSpec    elSpec;    JCEElGamalPublicKey(        ElGamalPublicKeySpec    spec)    {        this.y = spec.getY();        this.elSpec = new ElGamalParameterSpec(spec.getParams().getP(), spec.getParams().getG());    }    JCEElGamalPublicKey(        DHPublicKeySpec    spec)    {        this.y = spec.getY();        this.elSpec = new ElGamalParameterSpec(spec.getP(), spec.getG());    }        JCEElGamalPublicKey(        ElGamalPublicKey    key)    {        this.y = key.getY();        this.elSpec = key.getParameters();    }    JCEElGamalPublicKey(        DHPublicKey    key)    {        this.y = key.getY();        this.elSpec = new ElGamalParameterSpec(key.getParams().getP(), key.getParams().getG());    }        JCEElGamalPublicKey(        ElGamalPublicKeyParameters  params)    {        this.y = params.getY();        this.elSpec = new ElGamalParameterSpec(params.getParameters().getP(), params.getParameters().getG());    }    JCEElGamalPublicKey(        BigInteger              y,        ElGamalParameterSpec    elSpec)    {        this.y = y;        this.elSpec = elSpec;    }    JCEElGamalPublicKey(        SubjectPublicKeyInfo    info)    {        ElGamalParameter        params = new ElGamalParameter((ASN1Sequence)info.getAlgorithmId().getParameters());        DERInteger              derY = null;        try        {            derY = (DERInteger)info.getPublicKey();        }        catch (IOException e)        {            throw new IllegalArgumentException("invalid info structure in DSA public key");        }        this.y = derY.getValue();        this.elSpec = new ElGamalParameterSpec(params.getP(), params.getG());    }    public String getAlgorithm()    {        return "ElGamal";    }    public String getFormat()    {        return "X.509";    }    public byte[] getEncoded()    {        SubjectPublicKeyInfo    info = new SubjectPublicKeyInfo(new AlgorithmIdentifier(OIWObjectIdentifiers.elGamalAlgorithm, new ElGamalParameter(elSpec.getP(), elSpec.getG()).getDERObject()), new DERInteger(y));        return info.getDEREncoded();    }    public ElGamalParameterSpec getParameters()    {        return elSpec;    }        public DHParameterSpec getParams()    {        return new DHParameterSpec(elSpec.getP(), elSpec.getG());    }    public BigInteger getY()    {        return y;    }    private void readObject(        ObjectInputStream   in)        throws IOException, ClassNotFoundException    {        this.y = (BigInteger)in.readObject();        this.elSpec = new ElGamalParameterSpec((BigInteger)in.readObject(), (BigInteger)in.readObject());    }    private void writeObject(        ObjectOutputStream  out)        throws IOException    {        out.writeObject(this.getY());        out.writeObject(elSpec.getP());        out.writeObject(elSpec.getG());    }}