org.bouncycastle.jce.provider.JCEDHPublicKey Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of bcprov-ext-debug-jdk18on Show documentation
The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for Java 1.8 and later with debug enabled.
The newest version!
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.DomainParameters;
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.getAlgorithm().getParameters());
        ASN1ObjectIdentifier id = info.getAlgorithm().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))
        {
            DomainParameters params = DomainParameters.getInstance(seq);

            this.dhSpec = new DHParameterSpec(params.getP(), params.getG());
        }
        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());
    }
}