package org.bouncycastle.jcajce.provider.asymmetric.dh;
import java.io.IOException;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.InvalidParameterSpecException;
import javax.crypto.spec.DHParameterSpec;
import org.bouncycastle.asn1.ASN1Encoding;
import org.bouncycastle.asn1.pkcs.DHParameter;
public class AlgorithmParametersSpi
extends java.security.AlgorithmParametersSpi
{
DHParameterSpec currentSpec;
protected boolean isASN1FormatString(String format)
{
return format == null || format.equals("ASN.1");
}
protected AlgorithmParameterSpec engineGetParameterSpec(
Class paramSpec)
throws InvalidParameterSpecException
{
if (paramSpec == null)
{
throw new NullPointerException("argument to getParameterSpec must not be null");
}
return localEngineGetParameterSpec(paramSpec);
}
/**
* Return the PKCS#3 ASN.1 structure DHParameter.
* <p>
* <pre>
* DHParameter ::= SEQUENCE {
* prime INTEGER, -- p
* base INTEGER, -- g
* privateValueLength INTEGER OPTIONAL}
* </pre>
*/
protected byte[] engineGetEncoded()
{
DHParameter dhP = new DHParameter(currentSpec.getP(), currentSpec.getG(), currentSpec.getL());
try
{
return dhP.getEncoded(ASN1Encoding.DER);
}
catch (IOException e)
{
throw new RuntimeException("Error encoding DHParameters");
}
}
protected byte[] engineGetEncoded(
String format)
{
if (isASN1FormatString(format))
{
return engineGetEncoded();
}
return null;
}
protected AlgorithmParameterSpec localEngineGetParameterSpec(
Class paramSpec)
throws InvalidParameterSpecException
{
if (paramSpec == DHParameterSpec.class)
{
return currentSpec;
}
throw new InvalidParameterSpecException("unknown parameter spec passed to DH parameters object.");
}
protected void engineInit(
AlgorithmParameterSpec paramSpec)
throws InvalidParameterSpecException
{
if (!(paramSpec instanceof DHParameterSpec))
{
throw new InvalidParameterSpecException("DHParameterSpec required to initialise a Diffie-Hellman algorithm parameters object");
}
this.currentSpec = (DHParameterSpec)paramSpec;
}
protected void engineInit(
byte[] params)
throws IOException
{
try
{
DHParameter dhP = DHParameter.getInstance(params);
if (dhP.getL() != null)
{
currentSpec = new DHParameterSpec(dhP.getP(), dhP.getG(), dhP.getL().intValue());
}
else
{
currentSpec = new DHParameterSpec(dhP.getP(), dhP.getG());
}
}
catch (ClassCastException e)
{
throw new IOException("Not a valid DH Parameter encoding.");
}
catch (ArrayIndexOutOfBoundsException e)
{
throw new IOException("Not a valid DH Parameter encoding.");
}
}
protected void engineInit(
byte[] params,
String format)
throws IOException
{
if (isASN1FormatString(format))
{
engineInit(params);
}
else
{
throw new IOException("Unknown parameter format " + format);
}
}
protected String engineToString()
{
return "Diffie-Hellman Parameters";
}
}