41 lines
1.1 KiB
C#
41 lines
1.1 KiB
C#
using System;
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using Org.BouncyCastle.Crypto.Parameters;
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using Org.BouncyCastle.Math;
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namespace Org.BouncyCastle.Crypto.Generators
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{
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/**
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* a ElGamal key pair generator.
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* <p>
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* This Generates keys consistent for use with ElGamal as described in
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* page 164 of "Handbook of Applied Cryptography".</p>
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*/
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public class ElGamalKeyPairGenerator
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: IAsymmetricCipherKeyPairGenerator
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{
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private ElGamalKeyGenerationParameters param;
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public void Init(
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KeyGenerationParameters parameters)
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{
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this.param = (ElGamalKeyGenerationParameters) parameters;
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}
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public AsymmetricCipherKeyPair GenerateKeyPair()
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{
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DHKeyGeneratorHelper helper = DHKeyGeneratorHelper.Instance;
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ElGamalParameters elParams = param.Parameters;
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BigInteger p = elParams.P;
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BigInteger x = helper.CalculatePrivate(p, param.Random, elParams.L);
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BigInteger y = helper.CalculatePublic(p, elParams.G, x);
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return new AsymmetricCipherKeyPair(
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new ElGamalPublicKeyParameters(y, elParams),
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new ElGamalPrivateKeyParameters(x, elParams));
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}
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}
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}
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