org.bouncycastle.crypto.signers.Ed25519Signer 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.crypto.signers;

import java.io.ByteArrayOutputStream;

import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.CryptoServicesRegistrar;
import org.bouncycastle.crypto.Signer;
import org.bouncycastle.crypto.params.Ed25519PrivateKeyParameters;
import org.bouncycastle.crypto.params.Ed25519PublicKeyParameters;
import org.bouncycastle.math.ec.rfc8032.Ed25519;
import org.bouncycastle.util.Arrays;

public class Ed25519Signer
    implements Signer
{
    private final Buffer buffer = new Buffer();

    private boolean forSigning;
    private Ed25519PrivateKeyParameters privateKey;
    private Ed25519PublicKeyParameters publicKey;

    public Ed25519Signer()
    {
    }

    public void init(boolean forSigning, CipherParameters parameters)
    {
        this.forSigning = forSigning;

        if (forSigning)
        {
            this.privateKey = (Ed25519PrivateKeyParameters)parameters;
            this.publicKey = null;
        }
        else
        {
            this.privateKey = null;
            this.publicKey = (Ed25519PublicKeyParameters)parameters;
        }

        CryptoServicesRegistrar.checkConstraints(Utils.getDefaultProperties("Ed25519", 128, parameters, forSigning));
        
        reset();
    }

    public void update(byte b)
    {
        buffer.write(b);
    }

    public void update(byte[] buf, int off, int len)
    {
        buffer.write(buf, off, len);
    }

    public byte[] generateSignature()
    {
        if (!forSigning || null == privateKey)
        {
            throw new IllegalStateException("Ed25519Signer not initialised for signature generation.");
        }

        return buffer.generateSignature(privateKey);
    }

    public boolean verifySignature(byte[] signature)
    {
        if (forSigning || null == publicKey)
        {
            throw new IllegalStateException("Ed25519Signer not initialised for verification");
        }

        return buffer.verifySignature(publicKey, signature);
    }

    public void reset()
    {
        buffer.reset();
    }

    private static final class Buffer extends ByteArrayOutputStream
    {
        synchronized byte[] generateSignature(Ed25519PrivateKeyParameters privateKey)
        {
            byte[] signature = new byte[Ed25519PrivateKeyParameters.SIGNATURE_SIZE];
            privateKey.sign(Ed25519.Algorithm.Ed25519, null, buf, 0, count, signature, 0);
            reset();
            return signature;
        }

        synchronized boolean verifySignature(Ed25519PublicKeyParameters publicKey, byte[] signature)
        {
            if (Ed25519.SIGNATURE_SIZE != signature.length)
            {
                reset();
                return false;
            }

            boolean result = publicKey.verify(Ed25519.Algorithm.Ed25519, null, buf, 0, count, signature, 0);
            reset();
            return result;
        }

        public synchronized void reset()
        {
            Arrays.fill(buf, 0, count, (byte)0);
            this.count = 0;
        }
    }
}