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The FIPS 140-2 Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms certified to FIPS 140-2 level 1. This jar contains the debug version JCE provider and low-level API for the BC-FJA version 1.0.2.3, FIPS Certificate #3514. Please note the debug jar is not certified.

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/***************************************************************/
/******    DO NOT EDIT THIS CLASS bc-java SOURCE FILE     ******/
/***************************************************************/
package org.bouncycastle.crypto.general;

import java.math.BigInteger;
import java.security.SecureRandom;

import org.bouncycastle.crypto.internal.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.internal.AsymmetricCipherKeyPairGenerator;
import org.bouncycastle.crypto.internal.KeyGenerationParameters;

/**
 * a GOST3410 key pair generator.
 * This generates GOST3410 keys in line with the method described
 * in GOST R 34.10-94.
 */
class Gost3410KeyPairGenerator
    implements AsymmetricCipherKeyPairGenerator
{
    private static final BigInteger ZERO = BigInteger.valueOf(0);

    private Gost3410KeyGenerationParameters param;

    public void init(
        KeyGenerationParameters param)
    {
        this.param = (Gost3410KeyGenerationParameters)param;
    }

    public AsymmetricCipherKeyPair generateKeyPair()
    {
        BigInteger p, q, a, x, y;
        Gost3410Parameters GOST3410Params = param.getParameters();
        SecureRandom random = param.getRandom();

        q = GOST3410Params.getQ();
        p = GOST3410Params.getP();
        a = GOST3410Params.getA();

        do
        {
            x = new BigInteger(256, random);
        }
        while (x.equals(ZERO) || x.compareTo(q) >= 0);

        //
        // calculate the public key.
        //
        y = a.modPow(x, p);

        return new AsymmetricCipherKeyPair(
            new Gost3410PublicKeyParameters(y, GOST3410Params),
            new Gost3410PrivateKeyParameters(x, GOST3410Params));
    }
}