org.bouncycastle.jcajce.provider.asymmetric.dsa.BCDSAPublicKey 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.jcajce.provider.asymmetric.dsa;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.math.BigInteger;
import java.security.interfaces.DSAParams;
import java.security.interfaces.DSAPublicKey;
import java.security.spec.DSAParameterSpec;
import java.security.spec.DSAPublicKeySpec;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1Integer;
import org.bouncycastle.asn1.DERNull;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.asn1.x509.DSAParameter;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.asn1.x9.X9ObjectIdentifiers;
import org.bouncycastle.crypto.params.DSAPublicKeyParameters;
import org.bouncycastle.jcajce.provider.asymmetric.util.KeyUtil;
import org.bouncycastle.util.Strings;

public class BCDSAPublicKey
    implements DSAPublicKey
{
    private static final long serialVersionUID = 1752452449903495175L;
    private static BigInteger ZERO = BigInteger.valueOf(0);

    private BigInteger      y;

    private transient DSAPublicKeyParameters lwKeyParams;
    private transient DSAParams              dsaSpec;

    BCDSAPublicKey(
        DSAPublicKeySpec spec)
    {
        this.y = spec.getY();
        this.dsaSpec = new DSAParameterSpec(spec.getP(), spec.getQ(), spec.getG());
        this.lwKeyParams = new DSAPublicKeyParameters(y, DSAUtil.toDSAParameters(dsaSpec));
    }

    BCDSAPublicKey(
        DSAPublicKey key)
    {
        this.y = key.getY();
        this.dsaSpec = key.getParams();
        this.lwKeyParams = new DSAPublicKeyParameters(y, DSAUtil.toDSAParameters(dsaSpec));
    }

    BCDSAPublicKey(
        DSAPublicKeyParameters params)
    {
        this.y = params.getY();
        if (params.getParameters() != null)
        {
            this.dsaSpec = new DSAParameterSpec(params.getParameters().getP(), params.getParameters().getQ(), params.getParameters().getG());
        }
        else
        {
            this.dsaSpec = null;
        }
        this.lwKeyParams = params;
    }

    public BCDSAPublicKey(
        SubjectPublicKeyInfo info)
    {
        ASN1Integer              derY;

        try
        {
            derY = (ASN1Integer)info.parsePublicKey();
        }
        catch (IOException e)
        {
            throw new IllegalArgumentException("invalid info structure in DSA public key");
        }

        this.y = derY.getValue();

        if (isNotNull(info.getAlgorithm().getParameters()))
        {
            DSAParameter params = DSAParameter.getInstance(info.getAlgorithm().getParameters());
            
            this.dsaSpec = new DSAParameterSpec(params.getP(), params.getQ(), params.getG());
        }
        else
        {
            this.dsaSpec = null;
        }

        this.lwKeyParams = new DSAPublicKeyParameters(y, DSAUtil.toDSAParameters(dsaSpec));
    }

    private boolean isNotNull(ASN1Encodable parameters)
    {
        return parameters != null && !DERNull.INSTANCE.equals(parameters.toASN1Primitive());
    }

    public String getAlgorithm()
    {
        return "DSA";
    }

    public String getFormat()
    {
        return "X.509";
    }

    DSAPublicKeyParameters engineGetKeyParameters()
    {
        return lwKeyParams;
    }

    public byte[] getEncoded()
    {
        if (dsaSpec == null)
        {
            return KeyUtil.getEncodedSubjectPublicKeyInfo(new AlgorithmIdentifier(X9ObjectIdentifiers.id_dsa), new ASN1Integer(y));
        }

        return KeyUtil.getEncodedSubjectPublicKeyInfo(new AlgorithmIdentifier(X9ObjectIdentifiers.id_dsa, new DSAParameter(dsaSpec.getP(), dsaSpec.getQ(), dsaSpec.getG()).toASN1Primitive()), new ASN1Integer(y));
    }

    public DSAParams getParams()
    {
        return dsaSpec;
    }

    public BigInteger getY()
    {
        return y;
    }

    public String toString()
    {
        StringBuffer    buf = new StringBuffer();
        String          nl = Strings.lineSeparator();

        buf.append("DSA Public Key [").append(DSAUtil.generateKeyFingerprint(y, getParams())).append("]").append(nl);
        buf.append("            Y: ").append(this.getY().toString(16)).append(nl);

        return buf.toString();
    }

    public int hashCode()
    {
        if (dsaSpec != null)
        {
            return this.getY().hashCode() ^ this.getParams().getG().hashCode()
                ^ this.getParams().getP().hashCode() ^ this.getParams().getQ().hashCode();
        }
        else
        {
            return this.getY().hashCode();
        }
    }

    public boolean equals(
        Object o)
    {
        if (!(o instanceof DSAPublicKey))
        {
            return false;
        }
        
        DSAPublicKey other = (DSAPublicKey)o;

        if (this.dsaSpec != null)
        {
            return this.getY().equals(other.getY())
                && other.getParams() != null
                && this.getParams().getG().equals(other.getParams().getG())
                && this.getParams().getP().equals(other.getParams().getP())
                && this.getParams().getQ().equals(other.getParams().getQ());
        }
        else
        {
            return this.getY().equals(other.getY()) && other.getParams() == null;
        }
    }

    private void readObject(
        ObjectInputStream in)
        throws IOException, ClassNotFoundException
    {
        in.defaultReadObject();

        BigInteger p = (BigInteger)in.readObject();
        if (p.equals(ZERO))
        {
            this.dsaSpec = null;
        }
        else
        {
            this.dsaSpec = new DSAParameterSpec(p, (BigInteger)in.readObject(), (BigInteger)in.readObject());
        }
        this.lwKeyParams = new DSAPublicKeyParameters(y, DSAUtil.toDSAParameters(dsaSpec));
    }

    private void writeObject(
        ObjectOutputStream out)
        throws IOException
    {
        out.defaultWriteObject();

        if (dsaSpec == null)
        {
            out.writeObject(ZERO);
        }
        else
        {
            out.writeObject(dsaSpec.getP());
            out.writeObject(dsaSpec.getQ());
            out.writeObject(dsaSpec.getG());
        }
    }
}