Examples with DHKeyPairGenerator org.spongycastle.crypto.generators.DHKeyPairGenerator used on opensource projects

Example 1 with DHKeyPairGenerator

use of org.spongycastle.crypto.generators.DHKeyPairGenerator in project Zom-Android by zom.

the class OtrCryptoEngineImpl method generateDHKeyPair.

public KeyPair generateDHKeyPair() throws OtrCryptoException {
    // Generate a AsymmetricCipherKeyPair using BC.
    DHParameters dhParams = new DHParameters(MODULUS, GENERATOR, null, DH_PRIVATE_KEY_MINIMUM_BIT_LENGTH);
    DHKeyGenerationParameters params = new DHKeyGenerationParameters(new SecureRandom(), dhParams);
    DHKeyPairGenerator kpGen = new DHKeyPairGenerator();
    kpGen.init(params);
    AsymmetricCipherKeyPair pair = kpGen.generateKeyPair();
    // Convert this AsymmetricCipherKeyPair to a standard JCE KeyPair.
    DHPublicKeyParameters pub = (DHPublicKeyParameters) pair.getPublic();
    DHPrivateKeyParameters priv = (DHPrivateKeyParameters) pair.getPrivate();
    try {
        KeyFactory keyFac = KeyFactory.getInstance("DH");
        DHPublicKeySpec pubKeySpecs = new DHPublicKeySpec(pub.getY(), MODULUS, GENERATOR);
        DHPublicKey pubKey = (DHPublicKey) keyFac.generatePublic(pubKeySpecs);
        DHParameters dhParameters = priv.getParameters();
        DHPrivateKeySpec privKeySpecs = new DHPrivateKeySpec(priv.getX(), dhParameters.getP(), dhParameters.getG());
        DHPrivateKey privKey = (DHPrivateKey) keyFac.generatePrivate(privKeySpecs);
        return new KeyPair(pubKey, privKey);
    } catch (Exception e) {
        throw new OtrCryptoException(e);
    }
}