Examples with ECKeyPairGenerator com.github.zhenwei.core.crypto.generators.ECKeyPairGenerator used on opensource projects

Example 1 with ECKeyPairGenerator

use of com.github.zhenwei.core.crypto.generators.ECKeyPairGenerator in project LinLong-Java by zhenwei1108.

the class ECNRSigner method generateSignature.

// Section 7.2.5 ECSP-NR, pg 34
/**
 * generate a signature for the given message using the key we were initialised with.  Generally,
 * the order of the curve should be at least as long as the hash of the message of interest, and
 * with ECNR it *must* be at least as long.
 *
 * @param digest the digest to be signed.
 * @throws DataLengthException if the digest is longer than the key allows
 */
public BigInteger[] generateSignature(byte[] digest) {
    if (!this.forSigning) {
        throw new IllegalStateException("not initialised for signing");
    }
    BigInteger n = getOrder();
    BigInteger e = new BigInteger(1, digest);
    ECPrivateKeyParameters privKey = (ECPrivateKeyParameters) key;
    if (e.compareTo(n) >= 0) {
        throw new DataLengthException("input too large for ECNR key");
    }
    BigInteger r = null;
    BigInteger s = null;
    AsymmetricCipherKeyPair tempPair;
    do // generate r
    {
        // generate another, but very temporary, key pair using
        // the same EC parameters
        ECKeyPairGenerator keyGen = new ECKeyPairGenerator();
        keyGen.init(new ECKeyGenerationParameters(privKey.getParameters(), this.random));
        tempPair = keyGen.generateKeyPair();
        // BigInteger Vx = tempPair.getPublic().getW().getAffineX();
        // get temp's public key
        ECPublicKeyParameters V = (ECPublicKeyParameters) tempPair.getPublic();
        BigInteger Vx = V.getQ().getAffineXCoord().toBigInteger();
        r = Vx.add(e).mod(n);
    } while (r.equals(ECConstants.ZERO));
    // generate s
    // private key value
    BigInteger x = privKey.getD();
    // temp's private key value
    BigInteger u = ((ECPrivateKeyParameters) tempPair.getPrivate()).getD();
    s = u.subtract(r.multiply(x)).mod(n);
    BigInteger[] res = new BigInteger[2];
    res[0] = r;
    res[1] = s;
    return res;
}

Example 2 with ECKeyPairGenerator

use of com.github.zhenwei.core.crypto.generators.ECKeyPairGenerator in project LinLong-Java by zhenwei1108.

the class IESCipher method engineDoFinal.

// Finalisation methods
public byte[] engineDoFinal(byte[] input, int inputOffset, int inputLen) throws IllegalBlockSizeException, BadPaddingException {
    if (inputLen != 0) {
        buffer.write(input, inputOffset, inputLen);
    }
    final byte[] in = buffer.toByteArray();
    buffer.reset();
    // Convert parameters for use in IESEngine
    CipherParameters params = new IESWithCipherParameters(engineSpec.getDerivationV(), engineSpec.getEncodingV(), engineSpec.getMacKeySize(), engineSpec.getCipherKeySize());
    if (engineSpec.getNonce() != null) {
        params = new ParametersWithIV(params, engineSpec.getNonce());
    }
    final ECDomainParameters ecParams = ((ECKeyParameters) key).getParameters();
    final byte[] V;
    if (otherKeyParameter != null) {
        try {
            if (state == Cipher.ENCRYPT_MODE || state == Cipher.WRAP_MODE) {
                engine.init(true, otherKeyParameter, key, params);
            } else {
                engine.init(false, key, otherKeyParameter, params);
            }
            return engine.processBlock(in, 0, in.length);
        } catch (Exception e) {
            throw new BadBlockException("unable to process block", e);
        }
    }
    if (state == Cipher.ENCRYPT_MODE || state == Cipher.WRAP_MODE) {
        // Generate the ephemeral key pair
        ECKeyPairGenerator gen = new ECKeyPairGenerator();
        gen.init(new ECKeyGenerationParameters(ecParams, random));
        final boolean usePointCompression = engineSpec.getPointCompression();
        EphemeralKeyPairGenerator kGen = new EphemeralKeyPairGenerator(gen, new KeyEncoder() {

            public byte[] getEncoded(AsymmetricKeyParameter keyParameter) {
                return ((ECPublicKeyParameters) keyParameter).getQ().getEncoded(usePointCompression);
            }
        });
        // Encrypt the buffer
        try {
            engine.init(key, params, kGen);
            return engine.processBlock(in, 0, in.length);
        } catch (final Exception e) {
            throw new BadBlockException("unable to process block", e);
        }
    } else if (state == Cipher.DECRYPT_MODE || state == Cipher.UNWRAP_MODE) {
        // Decrypt the buffer
        try {
            engine.init(key, params, new ECIESPublicKeyParser(ecParams));
            return engine.processBlock(in, 0, in.length);
        } catch (InvalidCipherTextException e) {
            throw new BadBlockException("unable to process block", e);
        }
    } else {
        throw new IllegalStateException("cipher not initialised");
    }
}