import org.bouncycastle.crypto.generators.DHKeyPairGenerator; //导入依赖的package包/类
public byte[] generateServerKeyExchange()
    throws IOException
{

    if (this.dhParameters == null)
    {
        throw new TlsFatalAlert(AlertDescription.internal_error);
    }

    ByteArrayOutputStream buf = new ByteArrayOutputStream();

    DHKeyPairGenerator kpg = new DHKeyPairGenerator();
    kpg.init(new DHKeyGenerationParameters(context.getSecureRandom(), this.dhParameters));
    AsymmetricCipherKeyPair kp = kpg.generateKeyPair();

    BigInteger Ys = ((DHPublicKeyParameters)kp.getPublic()).getY();

    TlsDHUtils.writeDHParameter(dhParameters.getP(), buf);
    TlsDHUtils.writeDHParameter(dhParameters.getG(), buf);
    TlsDHUtils.writeDHParameter(Ys, buf);

    byte[] digestInput = buf.toByteArray();

    Digest d = new CombinedHash();
    SecurityParameters securityParameters = context.getSecurityParameters();
    d.update(securityParameters.clientRandom, 0, securityParameters.clientRandom.length);
    d.update(securityParameters.serverRandom, 0, securityParameters.serverRandom.length);
    d.update(digestInput, 0, digestInput.length);

    byte[] hash = new byte[d.getDigestSize()];
    d.doFinal(hash, 0);

    byte[] sigBytes = serverCredentials.generateCertificateSignature(hash);
    /*
     * TODO RFC 5246 4.7. digitally-signed element needs SignatureAndHashAlgorithm prepended from TLS 1.2
     */
    TlsUtils.writeOpaque16(sigBytes, buf);

    return buf.toByteArray();
}
 

import org.bouncycastle.crypto.generators.DHKeyPairGenerator; //导入依赖的package包/类
/**
 * calculate our initial message.
 */
public BigInteger calculateMessage()
{
    DHKeyPairGenerator dhGen = new DHKeyPairGenerator();
    dhGen.init(new DHKeyGenerationParameters(random, dhParams));
    AsymmetricCipherKeyPair dhPair = dhGen.generateKeyPair();

    this.privateValue = ((DHPrivateKeyParameters)dhPair.getPrivate()).getX();

    return ((DHPublicKeyParameters)dhPair.getPublic()).getY();
}
 

import org.bouncycastle.crypto.generators.DHKeyPairGenerator; //导入依赖的package包/类
private void testGPWithRandom(
    DHKeyPairGenerator kpGen)
{
    //
    // generate first pair
    //
    AsymmetricCipherKeyPair     pair = kpGen.generateKeyPair();

    DHPublicKeyParameters       pu1 = (DHPublicKeyParameters)pair.getPublic();
    DHPrivateKeyParameters      pv1 = (DHPrivateKeyParameters)pair.getPrivate();
    //
    // generate second pair
    //
    pair = kpGen.generateKeyPair();

    DHPublicKeyParameters       pu2 = (DHPublicKeyParameters)pair.getPublic();
    DHPrivateKeyParameters      pv2 = (DHPrivateKeyParameters)pair.getPrivate();

    //
    // two way
    //
    DHAgreement    e1 = new DHAgreement();
    DHAgreement    e2 = new DHAgreement();

    e1.init(new ParametersWithRandom(pv1, new SecureRandom()));
    e2.init(new ParametersWithRandom(pv2, new SecureRandom()));

    BigInteger   m1 = e1.calculateMessage();
    BigInteger   m2 = e2.calculateMessage();

    BigInteger   k1 = e1.calculateAgreement(pu2, m2);
    BigInteger   k2 = e2.calculateAgreement(pu1, m1);
    
    if (!k1.equals(k2))
    {
        fail("basic with random 2-way test failed");
    }
}
 

import org.bouncycastle.crypto.generators.DHKeyPairGenerator; //导入依赖的package包/类
private DHKeyPairGenerator getDHKeyPairGenerator(
    BigInteger g,
    BigInteger p)
{
    DHParameters                dhParams = new DHParameters(p, g);
    DHKeyGenerationParameters   params = new DHKeyGenerationParameters(new SecureRandom(), dhParams);
    DHKeyPairGenerator          kpGen = new DHKeyPairGenerator();

    kpGen.init(params);
    
    return kpGen;
}
 

import org.bouncycastle.crypto.generators.DHKeyPairGenerator; //导入依赖的package包/类
private void testDH(
    int         size,
    BigInteger  g,
    BigInteger  p)
{
    DHKeyPairGenerator kpGen = getDHKeyPairGenerator(g, p);

    //
    // generate first pair
    //
    AsymmetricCipherKeyPair     pair = kpGen.generateKeyPair();

    DHPublicKeyParameters       pu1 = (DHPublicKeyParameters)pair.getPublic();
    DHPrivateKeyParameters      pv1 = (DHPrivateKeyParameters)pair.getPrivate();
    //
    // generate second pair
    //
    pair = kpGen.generateKeyPair();

    DHPublicKeyParameters       pu2 = (DHPublicKeyParameters)pair.getPublic();
    DHPrivateKeyParameters      pv2 = (DHPrivateKeyParameters)pair.getPrivate();

    //
    // two way
    //
    DHAgreement    e1 = new DHAgreement();
    DHAgreement    e2 = new DHAgreement();

    e1.init(pv1);
    e2.init(pv2);

    BigInteger  m1 = e1.calculateMessage();
    BigInteger  m2 = e2.calculateMessage();

    BigInteger   k1 = e1.calculateAgreement(pu2, m2);
    BigInteger   k2 = e2.calculateAgreement(pu1, m1);

    if (!k1.equals(k2))
    {
        fail(size + " bit 2-way test failed");
    }
}