Examples with FixedPointCombMultiplier org.bouncycastle.math.ec.FixedPointCombMultiplier used on opensource projects

Example 1 with FixedPointCombMultiplier

use of org.bouncycastle.math.ec.FixedPointCombMultiplier in project athenz by yahoo.

the class Crypto method extractPublicKey.

public static PublicKey extractPublicKey(PrivateKey privateKey) throws CryptoException {
    // we only support RSA and ECDSA private keys
    PublicKey publicKey = null;
    switch(privateKey.getAlgorithm()) {
        case RSA:
            try {
                KeyFactory kf = KeyFactory.getInstance(RSA, BC_PROVIDER);
                RSAPrivateCrtKey rsaCrtKey = (RSAPrivateCrtKey) privateKey;
                RSAPublicKeySpec keySpec = new RSAPublicKeySpec(rsaCrtKey.getModulus(), rsaCrtKey.getPublicExponent());
                publicKey = kf.generatePublic(keySpec);
            } catch (NoSuchProviderException ex) {
                LOG.error("extractPublicKey: RSA - Caught NoSuchProviderException exception: " + ex.getMessage());
                throw new CryptoException(ex);
            } catch (NoSuchAlgorithmException ex) {
                LOG.error("extractPublicKey: RSA - Caught NoSuchAlgorithmException exception: " + ex.getMessage());
                throw new CryptoException(ex);
            } catch (InvalidKeySpecException ex) {
                LOG.error("extractPublicKey: RSA - Caught InvalidKeySpecException exception: " + ex.getMessage());
                throw new CryptoException(ex);
            }
            break;
        case ECDSA:
            try {
                KeyFactory kf = KeyFactory.getInstance(ECDSA, BC_PROVIDER);
                BCECPrivateKey ecPrivKey = (BCECPrivateKey) privateKey;
                ECMultiplier ecMultiplier = new FixedPointCombMultiplier();
                ECParameterSpec ecParamSpec = (ECParameterSpec) ecPrivKey.getParameters();
                ECPoint ecPointQ = ecMultiplier.multiply(ecParamSpec.getG(), ecPrivKey.getD());
                ECPublicKeySpec keySpec = new ECPublicKeySpec(ecPointQ, ecParamSpec);
                publicKey = kf.generatePublic(keySpec);
            } catch (NoSuchProviderException ex) {
                LOG.error("extractPublicKey: ECDSA - Caught NoSuchProviderException exception: " + ex.getMessage());
                throw new CryptoException(ex);
            } catch (NoSuchAlgorithmException ex) {
                LOG.error("extractPublicKey: ECDSA - Caught NoSuchAlgorithmException exception: " + ex.getMessage());
                throw new CryptoException(ex);
            } catch (InvalidKeySpecException ex) {
                LOG.error("extractPublicKey: ECDSA - Caught InvalidKeySpecException exception: " + ex.getMessage());
                throw new CryptoException(ex);
            }
            break;
        default:
            String msg = "Unsupported Key Algorithm: " + privateKey.getAlgorithm();
            LOG.error("extractPublicKey: " + msg);
            throw new CryptoException(msg);
    }
    return publicKey;
}