org.bouncycastle.jce.provider.JCEDHPublicKey Maven / Gradle / Ivy
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.ASN1Integer;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.pkcs.DHParameter;
import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.asn1.x9.DHDomainParameters;
import org.bouncycastle.asn1.x9.X9ObjectIdentifiers;
import org.bouncycastle.crypto.params.DHPublicKeyParameters;
import org.bouncycastle.jcajce.provider.asymmetric.util.KeyUtil;
public class JCEDHPublicKey
implements DHPublicKey
{
static final long serialVersionUID = -216691575254424324L;
private BigInteger y;
private DHParameterSpec dhSpec;
private SubjectPublicKeyInfo info;
JCEDHPublicKey(
DHPublicKeySpec spec)
{
this.y = spec.getY();
this.dhSpec = new DHParameterSpec(spec.getP(), spec.getG());
}
JCEDHPublicKey(
DHPublicKey key)
{
this.y = key.getY();
this.dhSpec = key.getParams();
}
JCEDHPublicKey(
DHPublicKeyParameters params)
{
this.y = params.getY();
this.dhSpec = new DHParameterSpec(params.getParameters().getP(), params.getParameters().getG(), params.getParameters().getL());
}
JCEDHPublicKey(
BigInteger y,
DHParameterSpec dhSpec)
{
this.y = y;
this.dhSpec = dhSpec;
}
JCEDHPublicKey(
SubjectPublicKeyInfo info)
{
this.info = info;
ASN1Integer derY;
try
{
derY = (ASN1Integer)info.parsePublicKey();
}
catch (IOException e)
{
throw new IllegalArgumentException("invalid info structure in DH public key");
}
this.y = derY.getValue();
ASN1Sequence seq = ASN1Sequence.getInstance(info.getAlgorithmId().getParameters());
ASN1ObjectIdentifier id = info.getAlgorithmId().getAlgorithm();
// we need the PKCS check to handle older keys marked with the X9 oid.
if (id.equals(PKCSObjectIdentifiers.dhKeyAgreement) || isPKCSParam(seq))
{
DHParameter params = DHParameter.getInstance(seq);
if (params.getL() != null)
{
this.dhSpec = new DHParameterSpec(params.getP(), params.getG(), params.getL().intValue());
}
else
{
this.dhSpec = new DHParameterSpec(params.getP(), params.getG());
}
}
else if (id.equals(X9ObjectIdentifiers.dhpublicnumber))
{
DHDomainParameters params = DHDomainParameters.getInstance(seq);
this.dhSpec = new DHParameterSpec(params.getP().getValue(), params.getG().getValue());
}
else
{
throw new IllegalArgumentException("unknown algorithm type: " + id);
}
}
public String getAlgorithm()
{
return "DH";
}
public String getFormat()
{
return "X.509";
}
public byte[] getEncoded()
{
if (info != null)
{
return KeyUtil.getEncodedSubjectPublicKeyInfo(info);
}
return KeyUtil.getEncodedSubjectPublicKeyInfo(new AlgorithmIdentifier(PKCSObjectIdentifiers.dhKeyAgreement, new DHParameter(dhSpec.getP(), dhSpec.getG(), dhSpec.getL())), new ASN1Integer(y));
}
public DHParameterSpec getParams()
{
return dhSpec;
}
public BigInteger getY()
{
return y;
}
private boolean isPKCSParam(ASN1Sequence seq)
{
if (seq.size() == 2)
{
return true;
}
if (seq.size() > 3)
{
return false;
}
ASN1Integer l = ASN1Integer.getInstance(seq.getObjectAt(2));
ASN1Integer p = ASN1Integer.getInstance(seq.getObjectAt(0));
if (l.getValue().compareTo(BigInteger.valueOf(p.getValue().bitLength())) > 0)
{
return false;
}
return true;
}
private void readObject(
ObjectInputStream in)
throws IOException, ClassNotFoundException
{
this.y = (BigInteger)in.readObject();
this.dhSpec = new DHParameterSpec((BigInteger)in.readObject(), (BigInteger)in.readObject(), in.readInt());
}
private void writeObject(
ObjectOutputStream out)
throws IOException
{
out.writeObject(this.getY());
out.writeObject(dhSpec.getP());
out.writeObject(dhSpec.getG());
out.writeInt(dhSpec.getL());
}
}