org.bouncycastle.pqc.crypto.picnic.PicnicSigner 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.pqc.crypto.picnic;

import org.bouncycastle.util.Arrays;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.pqc.crypto.MessageSigner;
import org.bouncycastle.util.Pack;

public class PicnicSigner
    implements MessageSigner
{
    private PicnicPrivateKeyParameters privKey;
    private PicnicPublicKeyParameters pubKey;

    public PicnicSigner()
    {
    }

    public void init(boolean forSigning, CipherParameters param)
    {
        if(forSigning)
        {
            privKey = (PicnicPrivateKeyParameters) param;
        }
        else
        {
            pubKey = (PicnicPublicKeyParameters) param;
        }

    }

    public byte[] generateSignature(byte[] message)
    {
        PicnicEngine engine = privKey.getParameters().getEngine();
        byte[] sig = new byte[engine.getSignatureSize(message.length)];
        engine.crypto_sign(sig, message , privKey.getEncoded());

        byte[] signature = new byte[engine.getTrueSignatureSize()];
        System.arraycopy(sig, message.length + 4, signature, 0, engine.getTrueSignatureSize());
        return signature;
    }

    public boolean verifySignature(byte[] message, byte[] signature)
    {
        PicnicEngine engine = pubKey.getParameters().getEngine();
        byte[] verify_message = new byte[message.length];
        byte[] attached_signature = Arrays.concatenate(Pack.intToLittleEndian(signature.length), message, signature);

        boolean verify = engine.crypto_sign_open(verify_message, attached_signature, pubKey.getEncoded());
        if(!Arrays.areEqual(message, verify_message))
        {
            return false;
        }
        return verify;
    }
}