context: using System;
  
  using NUnit.Framework;
  
  using Org.BouncyCastle.Asn1.X9;
  using Org.BouncyCastle.Crypto;
  using Org.BouncyCastle.Crypto.Parameters;
  using Org.BouncyCastle.Math;
  using Org.BouncyCastle.Math.EC;
  using Org.BouncyCastle.Pkcs;
  using Org.BouncyCastle.Security;
  using Org.BouncyCastle.Utilities;
  using Org.BouncyCastle.Utilities.Encoders;
  using Org.BouncyCastle.Utilities.Test;
  using Org.BouncyCastle.X509;
  
  namespace Org.BouncyCastle.Tests
  {
      [TestFixture]
      public class DHTest
          : SimpleTest
      {
          private static readonly BigInteger g512 = new BigInteger("153d5d6172adb43045b68ae8e1de1070b6137005686d29d3d73a7749199681ee5b212c9b96bfdcfa5b20cd5e3fd2044895d609cf9b410b7a0f12ca1cb9a428cc", 16);
          private static readonly BigInteger p512 = new BigInteger("9494fec095f3b85ee286542b3836fc81a5dd0a0349b4c239dd38744d488cf8e31db8bcb7d33b41abb9e5a33cca9144b1cef332c94bf0573bf047a3aca98cdf3b", 16);
  
          private static readonly BigInteger g768 = new BigInteger("7c240073c1316c621df461b71ebb0cdcc90a6e5527e5e126633d131f87461c4dc4afc60c2cb0f053b6758871489a69613e2a8b4c8acde23954c08c81cbd36132cfd64d69e4ed9f8e51ed6e516297206672d5c0a69135df0a5dcf010d289a9ca1", 16);
          private static readonly BigInteger p768 = new BigInteger("8c9dd223debed1b80103b8b309715be009d48860ed5ae9b9d5d8159508efd802e3ad4501a7f7e1cfec78844489148cd72da24b21eddd01aa624291c48393e277cfc529e37075eccef957f3616f962d15b44aeab4039d01b817fde9eaa12fd73f", 16);
  
          private static readonly BigInteger g1024 = new BigInteger("1db17639cdf96bc4eabba19454f0b7e5bd4e14862889a725c96eb61048dcd676ceb303d586e30f060dbafd8a571a39c4d823982117da5cc4e0f89c77388b7a08896362429b94a18a327604eb7ff227bffbc83459ade299e57b5f77b50fb045250934938efa145511166e3197373e1b5b1e52de713eb49792bedde722c6717abf", 16);
          private static readonly BigInteger p1024 = new BigInteger("a00e283b3c624e5b2b4d9fbc2653b5185d99499b00fd1bf244c6f0bb817b4d1c451b2958d62a0f8a38caef059fb5ecd25d75ed9af403f5b5bdab97a642902f824e3c13789fed95fa106ddfe0ff4a707c85e2eb77d49e68f2808bcea18ce128b178cd287c6bc00efa9a1ad2a673fe0dceace53166f75b81d6709d5f8af7c66bb7", 16);
  
          // public key with mismatched oid/parameters
          private byte[] oldPubEnc = Base64.Decode(
              "MIIBnzCCARQGByqGSM4+AgEwggEHAoGBAPxSrN417g43VAM9sZRf1dt6AocAf7D6" +
              "WVCtqEDcBJrMzt63+g+BNJzhXVtbZ9kp9vw8L/0PHgzv0Ot/kOLX7Khn+JalOECW" +
              "YlkyBhmOVbjR79TY5u2GAlvG6pqpizieQNBCEMlUuYuK1Iwseil6VoRuA13Zm7uw" +
              "WO1eZmaJtY7LAoGAQaPRCFKM5rEdkMrV9FNzeSsYRs8m3DqPnnJHpuySpyO9wUcX" +
              "OOJcJY5qvHbDO5SxHXu/+bMgXmVT6dXI5o0UeYqJR7fj6pR4E6T0FwG55RFr5Ok4" +
              "3C4cpXmaOu176SyWuoDqGs1RDGmYQjwbZUi23DjaaTFUly9LCYXMliKrQfEDgYQA" +
              "AoGAQUGCBN4TaBw1BpdBXdTvTfCU69XDB3eyU2FOBE3UWhpx9D8XJlx4f5DpA4Y6" +
              "6sQMuCbhfmjEph8W7/sbMurM/awR+PSR8tTY7jeQV0OkmAYdGK2nzh0ZSifMO1oE" +
              "NNhN2O62TLs67msxT28S4/S89+LMtc98mevQ2SX+JF3wEVU=");
  
          // bogus key with full PKCS parameter set
          private byte[] oldFullParams = Base64.Decode(
              "MIIBIzCCARgGByqGSM4+AgEwggELAoGBAP1/U4EddRIpUt9KnC7s5Of2EbdSPO9E" +
              "AMMeP4C2USZpRV1AIlH7WT2NWPq/xfW6MPbLm1Vs14E7gB00b/JmYLdrmVClpJ+f" +
              "6AR7ECLCT7up1/63xhv4O1fnxqimFQ8E+4P208UewwI1VBNaFpEy9nXzrith1yrv" +
              "8iIDGZ3RSAHHAoGBAPfhoIXWmz3ey7yrXDa4V7l5lK+7+jrqgvlXTAs9B4JnUVlX" +
              "jrrUWU/mcQcQgYC0SRZxI+hMKBYTt88JMozIpuE8FnqLVHyNKOCjrh4rs6Z1kW6j" +
              "fwv6ITVi8ftiegEkO8yk8b6oUZCJqIPf4VrlnwaSi2ZegHtVJWQBTDv+z0kqAgFk" +
              "AwUAAgIH0A==");
  
          private byte[] samplePubEnc = Base64.Decode(
              "MIIBpjCCARsGCSqGSIb3DQEDATCCAQwCgYEA/X9TgR11EilS30qcLuzk5/YRt1I8" +
              "70QAwx4/gLZRJmlFXUAiUftZPY1Y+r/F9bow9subVWzXgTuAHTRv8mZgt2uZUKWk" +
              "n5/oBHsQIsJPu6nX/rfGG/g7V+fGqKYVDwT7g/bTxR7DAjVUE1oWkTL2dfOuK2HX" +
              "Ku/yIgMZndFIAccCgYEA9+GghdabPd7LvKtcNrhXuXmUr7v6OuqC+VdMCz0HgmdR" +
              "WVeOutRZT+ZxBxCBgLRJFnEj6EwoFhO3zwkyjMim4TwWeotUfI0o4KOuHiuzpnWR" +
              "bqN/C/ohNWLx+2J6ASQ7zKTxvqhRkImog9/hWuWfBpKLZl6Ae1UlZAFMO/7PSSoC" +
              "AgIAA4GEAAKBgEIiqxoUW6E6GChoOgcfNbVFclW91ITf5MFSUGQwt2R0RHoOhxvO" +
              "lZhNs++d0VPATLAyXovjfgENT9SGCbuZttYcqqLdKTbMXBWPek+rfnAl9E4iEMED" +
              "IDd83FJTKs9hQcPAm7zmp0Xm1bGF9CbUFjP5G02265z7eBmHDaT0SNlB");
  
          private byte[] samplePrivEnc = Base64.Decode(
              "MIIBZgIBADCCARsGCSqGSIb3DQEDATCCAQwCgYEA/X9TgR11EilS30qcLuzk5/YR" +
              "t1I870QAwx4/gLZRJmlFXUAiUftZPY1Y+r/F9bow9subVWzXgTuAHTRv8mZgt2uZ" +
              "UKWkn5/oBHsQIsJPu6nX/rfGG/g7V+fGqKYVDwT7g/bTxR7DAjVUE1oWkTL2dfOu" +
              "K2HXKu/yIgMZndFIAccCgYEA9+GghdabPd7LvKtcNrhXuXmUr7v6OuqC+VdMCz0H" +
              "gmdRWVeOutRZT+ZxBxCBgLRJFnEj6EwoFhO3zwkyjMim4TwWeotUfI0o4KOuHiuz" +
              "pnWRbqN/C/ohNWLx+2J6ASQ7zKTxvqhRkImog9/hWuWfBpKLZl6Ae1UlZAFMO/7P" +
              "SSoCAgIABEICQAZYXnBHazxXUUdFP4NIf2Ipu7du0suJPZQKKff81wymi2zfCfHh" +
              "uhe9gQ9xdm4GpzeNtrQ8/MzpTy+ZVrtd29Q=");
  
          public override string Name
          {
              get { return "DH"; }
          }
  
          private void doTestGP(
              string		algName,
              int         size,
              int         privateValueSize,
              BigInteger  g,
              BigInteger  p)
          {
              IAsymmetricCipherKeyPairGenerator keyGen = GeneratorUtilities.GetKeyPairGenerator(algName);
  
              DHParameters dhParams = new DHParameters(p, g, null, privateValueSize);
              KeyGenerationParameters kgp = new DHKeyGenerationParameters(new SecureRandom(), dhParams);
  
              keyGen.Init(kgp);
  
              //
              // a side
              //
              AsymmetricCipherKeyPair aKeyPair = keyGen.GenerateKeyPair();
  
              IBasicAgreement aKeyAgreeBasic = AgreementUtilities.GetBasicAgreement(algName);
  
              checkKeySize(privateValueSize, aKeyPair);
  
              aKeyAgreeBasic.Init(aKeyPair.Private);
  
              //
              // b side
              //
              AsymmetricCipherKeyPair bKeyPair = keyGen.GenerateKeyPair();
  
              IBasicAgreement bKeyAgreeBasic = AgreementUtilities.GetBasicAgreement(algName);
  
              checkKeySize(privateValueSize, bKeyPair);
  
              bKeyAgreeBasic.Init(bKeyPair.Private);
  
              //
              // agreement
              //
  //			aKeyAgreeBasic.doPhase(bKeyPair.Public, true);
  //			bKeyAgreeBasic.doPhase(aKeyPair.Public, true);
  //
  //			BigInteger  k1 = new BigInteger(aKeyAgreeBasic.generateSecret());
  //			BigInteger  k2 = new BigInteger(bKeyAgreeBasic.generateSecret());
              BigInteger k1 = aKeyAgreeBasic.CalculateAgreement(bKeyPair.Public);
              BigInteger k2 = bKeyAgreeBasic.CalculateAgreement(aKeyPair.Public);
  
              if (!k1.Equals(k2))
              {
                  Fail(size + " bit 2-way test failed");
              }
  
              //
              // public key encoding test
              //
  //			byte[]              pubEnc = aKeyPair.Public.GetEncoded();
              byte[] pubEnc = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(aKeyPair.Public).GetDerEncoded();
  
  //			KeyFactory          keyFac = KeyFactory.getInstance(algName);
  //			X509EncodedKeySpec  pubX509 = new X509EncodedKeySpec(pubEnc);
  //			DHPublicKey         pubKey = (DHPublicKey)keyFac.generatePublic(pubX509);
              DHPublicKeyParameters pubKey = (DHPublicKeyParameters) PublicKeyFactory.CreateKey(pubEnc);
  //			DHParameterSpec     spec = pubKey.Parameters;
              DHParameters spec = pubKey.Parameters;
  
              if (!spec.G.Equals(dhParams.G) || !spec.P.Equals(dhParams.P))
              {
                  Fail(size + " bit public key encoding/decoding test failed on parameters");
              }
  
              if (!((DHPublicKeyParameters)aKeyPair.Public).Y.Equals(pubKey.Y))
              {
                  Fail(size + " bit public key encoding/decoding test failed on y value");
              }
  
              //
              // public key serialisation test
              //
              // TODO Put back in
  //			MemoryStream bOut = new MemoryStream();
  //			ObjectOutputStream oOut = new ObjectOutputStream(bOut);
  //
  //			oOut.WriteObject(aKeyPair.Public);
  //
  //			MemoryStream bIn = new MemoryStream(bOut.ToArray(), false);
  //			ObjectInputStream oIn = new ObjectInputStream(bIn);
  //
  //			pubKey = (DHPublicKeyParameters)oIn.ReadObject();
              spec = pubKey.Parameters;
  
              if (!spec.G.Equals(dhParams.G) || !spec.P.Equals(dhParams.P))
              {
                  Fail(size + " bit public key serialisation test failed on parameters");
              }
  
              if (!((DHPublicKeyParameters)aKeyPair.Public).Y.Equals(pubKey.Y))
              {
                  Fail(size + " bit public key serialisation test failed on y value");
              }
  
              //
              // private key encoding test
              //
  //			byte[] privEnc = aKeyPair.Private.GetEncoded();
              byte[] privEnc = PrivateKeyInfoFactory.CreatePrivateKeyInfo(aKeyPair.Private).GetDerEncoded();
  //			PKCS8EncodedKeySpec privPKCS8 = new PKCS8EncodedKeySpec(privEnc);
  //			DHPrivateKeyParameters privKey = (DHPrivateKey)keyFac.generatePrivate(privPKCS8);
              DHPrivateKeyParameters privKey = (DHPrivateKeyParameters) PrivateKeyFactory.CreateKey(privEnc);
  
              spec = privKey.Parameters;
  
              if (!spec.G.Equals(dhParams.G) || !spec.P.Equals(dhParams.P))
              {
                  Fail(size + " bit private key encoding/decoding test failed on parameters");
              }
  
              if (!((DHPrivateKeyParameters)aKeyPair.Private).X.Equals(privKey.X))
              {
                  Fail(size + " bit private key encoding/decoding test failed on y value");
              }
  
              //
              // private key serialisation test
              //
              // TODO Put back in
  //			bOut = new MemoryStream();
  //			oOut = new ObjectOutputStream(bOut);
  //
  //			oOut.WriteObject(aKeyPair.Private);
  //
  //			bIn = new MemoryStream(bOut.ToArray(), false);
  //			oIn = new ObjectInputStream(bIn);
  //
  //			privKey = (DHPrivateKeyParameters)oIn.ReadObject();
              spec = privKey.Parameters;
  
              if (!spec.G.Equals(dhParams.G) || !spec.P.Equals(dhParams.P))
              {
                  Fail(size + " bit private key serialisation test failed on parameters");
              }
  
              if (!((DHPrivateKeyParameters)aKeyPair.Private).X.Equals(privKey.X))
              {
                  Fail(size + " bit private key serialisation test failed on y value");
              }
  
              //
              // three party test
              //
              IAsymmetricCipherKeyPairGenerator aPairGen = GeneratorUtilities.GetKeyPairGenerator(algName);
              aPairGen.Init(new DHKeyGenerationParameters(new SecureRandom(), spec));
              AsymmetricCipherKeyPair aPair = aPairGen.GenerateKeyPair();
  
              IAsymmetricCipherKeyPairGenerator bPairGen = GeneratorUtilities.GetKeyPairGenerator(algName);
              bPairGen.Init(new DHKeyGenerationParameters(new SecureRandom(), spec));
              AsymmetricCipherKeyPair bPair = bPairGen.GenerateKeyPair();
  
              IAsymmetricCipherKeyPairGenerator cPairGen = GeneratorUtilities.GetKeyPairGenerator(algName);
              cPairGen.Init(new DHKeyGenerationParameters(new SecureRandom(), spec));
              AsymmetricCipherKeyPair cPair = cPairGen.GenerateKeyPair();
  
  
              IBasicAgreement aKeyAgree = AgreementUtilities.GetBasicAgreement(algName);
              aKeyAgree.Init(aPair.Private);
  
              IBasicAgreement bKeyAgree = AgreementUtilities.GetBasicAgreement(algName);
              bKeyAgree.Init(bPair.Private);
  
              IBasicAgreement cKeyAgree = AgreementUtilities.GetBasicAgreement(algName);
              cKeyAgree.Init(cPair.Private);
  
  //			Key ac = aKeyAgree.doPhase(cPair.Public, false);
  //			Key ba = bKeyAgree.doPhase(aPair.Public, false);
  //			Key cb = cKeyAgree.doPhase(bPair.Public, false);
  //
  //			aKeyAgree.doPhase(cb, true);
  //			bKeyAgree.doPhase(ac, true);
  //			cKeyAgree.doPhase(ba, true);
  //
  //			BigInteger aShared = new BigInteger(aKeyAgree.generateSecret());
  //			BigInteger bShared = new BigInteger(bKeyAgree.generateSecret());
  //			BigInteger cShared = new BigInteger(cKeyAgree.generateSecret());
  
              DHPublicKeyParameters ac = new DHPublicKeyParameters(aKeyAgree.CalculateAgreement(cPair.Public), spec);
              DHPublicKeyParameters ba = new DHPublicKeyParameters(bKeyAgree.CalculateAgreement(aPair.Public), spec);
              DHPublicKeyParameters cb = new DHPublicKeyParameters(cKeyAgree.CalculateAgreement(bPair.Public), spec);
  
              BigInteger aShared = aKeyAgree.CalculateAgreement(cb);
              BigInteger bShared = bKeyAgree.CalculateAgreement(ac);
              BigInteger cShared = cKeyAgree.CalculateAgreement(ba);
  
              if (!aShared.Equals(bShared))
              {
                  Fail(size + " bit 3-way test failed (a and b differ)");
              }
  
              if (!cShared.Equals(bShared))
              {
                  Fail(size + " bit 3-way test failed (c and b differ)");
              }
          }
  
          private void doTestExplicitWrapping(
              int			size,
              int			privateValueSize,
              BigInteger	g,
              BigInteger	p)
          {
              DHParameters dhParams = new DHParameters(p, g, null, privateValueSize);
  
              IAsymmetricCipherKeyPairGenerator keyGen = GeneratorUtilities.GetKeyPairGenerator("DH");
  
              keyGen.Init(new DHKeyGenerationParameters(new SecureRandom(), dhParams));
  
              //
              // a side
              //
              AsymmetricCipherKeyPair aKeyPair = keyGen.GenerateKeyPair();
  
              IBasicAgreement aKeyAgree = AgreementUtilities.GetBasicAgreement("DH");
  
              checkKeySize(privateValueSize, aKeyPair);
  
              aKeyAgree.Init(aKeyPair.Private);
  
              //
              // b side
              //
              AsymmetricCipherKeyPair bKeyPair = keyGen.GenerateKeyPair();
  
              IBasicAgreement bKeyAgree = AgreementUtilities.GetBasicAgreement("DH");
  
              checkKeySize(privateValueSize, bKeyPair);
  
              bKeyAgree.Init(bKeyPair.Private);
  
              //
              // agreement
              //
  //			aKeyAgree.doPhase(bKeyPair.Public, true);
  //			bKeyAgree.doPhase(aKeyPair.Public, true);
  //
  //			SecretKey k1 = aKeyAgree.generateSecret(PkcsObjectIdentifiers.IdAlgCms3DesWrap.Id);
  //			SecretKey k2 = bKeyAgree.generateSecret(PkcsObjectIdentifiers.IdAlgCms3DesWrap.Id);
  
              // TODO Does this really test the same thing as the above code?
              BigInteger b1 = aKeyAgree.CalculateAgreement(bKeyPair.Public);
              BigInteger b2 = bKeyAgree.CalculateAgreement(aKeyPair.Public);
  
              if (!b1.Equals(b2))
              {
                  Fail("Explicit wrapping test failed");
              }
          }
  
          private void checkKeySize(
              int						privateValueSize,
              AsymmetricCipherKeyPair	aKeyPair)
          {
              if (privateValueSize != 0)
              {
                  DHPrivateKeyParameters key = (DHPrivateKeyParameters)aKeyPair.Private;
  
                  if (key.X.BitLength != privateValueSize)
                  {
                      Fail("limited key check failed for key size " + privateValueSize);
                  }
              }
          }
  
  // TODO Put back in
  //    private void doTestRandom(
  //        int         size)
  //    {
  //        AlgorithmParameterGenerator a = AlgorithmParameterGenerator.getInstance("DH");
  //        a.init(size, new SecureRandom());
  //        AlgorithmParameters parameters = a.generateParameters();
  //
  //        byte[] encodeParams = parameters.GetEncoded();
  //
  //        AlgorithmParameters a2 = AlgorithmParameters.getInstance("DH");
  //        a2.init(encodeParams);
  //
  //        // a and a2 should be equivalent!
  //        byte[] encodeParams_2 = a2.GetEncoded();
  //
  //        if (!areEqual(encodeParams, encodeParams_2))
  //        {
  //            Fail("encode/Decode parameters failed");
  //        }
  //
  //        DHParameterSpec dhP = (DHParameterSpec)parameters.getParameterSpec(DHParameterSpec.class);
  //
  //        doTestGP("DH", size, 0, dhP.G, dhP.P);
  //    }
  
          [Test]
          public void TestECDH()
          {
              DoTestECDH("ECDH");
          }
  
          [Test]
          public void TestECDHC()
          {
              DoTestECDH("ECDHC");
          }
  
          private void DoTestECDH(string algorithm)
          {
              IAsymmetricCipherKeyPairGenerator g = GeneratorUtilities.GetKeyPairGenerator(algorithm);
  
              X9ECParameters x9 = ECNamedCurveTable.GetByName("prime239v1");
              ECDomainParameters ecSpec = new ECDomainParameters(x9.Curve, x9.G, x9.N, x9.H);
  
              g.Init(new ECKeyGenerationParameters(ecSpec, new SecureRandom()));
  
              //
              // a side
              //
              AsymmetricCipherKeyPair aKeyPair = g.GenerateKeyPair();
  
              IBasicAgreement aKeyAgreeBasic = AgreementUtilities.GetBasicAgreement(algorithm);
  
              aKeyAgreeBasic.Init(aKeyPair.Private);
  
              //
              // b side
              //
              AsymmetricCipherKeyPair bKeyPair = g.GenerateKeyPair();
  
              IBasicAgreement bKeyAgreeBasic = AgreementUtilities.GetBasicAgreement(algorithm);
  
              bKeyAgreeBasic.Init(bKeyPair.Private);
  
              //
              // agreement
              //
              BigInteger k1 = aKeyAgreeBasic.CalculateAgreement(bKeyPair.Public);
              BigInteger k2 = bKeyAgreeBasic.CalculateAgreement(aKeyPair.Public);
  
              if (!k1.Equals(k2))
              {
                  Fail(algorithm + " 2-way test failed");
              }
  
              //
              // public key encoding test
              //
  //			byte[] pubEnc = aKeyPair.Public.GetEncoded();
              byte[] pubEnc = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(aKeyPair.Public).GetDerEncoded();
  
  //			KeyFactory keyFac = KeyFactory.getInstance(algorithm);
  //			X509EncodedKeySpec pubX509 = new X509EncodedKeySpec(pubEnc);
  //			ECPublicKey pubKey = (ECPublicKey)keyFac.generatePublic(pubX509);
              ECPublicKeyParameters pubKey = (ECPublicKeyParameters) PublicKeyFactory.CreateKey(pubEnc);
  
              ECDomainParameters ecDP = pubKey.Parameters;
  
  //			if (!pubKey.getW().Equals(((ECPublicKeyParameters)aKeyPair.Public).getW()))
              ECPoint pq1 = pubKey.Q.Normalize(), pq2 = ((ECPublicKeyParameters)aKeyPair.Public).Q.Normalize();
              if (!pq1.Equals(pq2))
              {
  //				Console.WriteLine(" expected " + pubKey.getW().getAffineX() + " got " + ((ECPublicKey)aKeyPair.Public).getW().getAffineX());
  //				Console.WriteLine(" expected " + pubKey.getW().getAffineY() + " got " + ((ECPublicKey)aKeyPair.Public).getW().getAffineY());
  //				Fail(algorithm + " public key encoding (W test) failed");
                  Console.WriteLine(" expected " + pq1.AffineXCoord.ToBigInteger()
                      + " got " + pq2.AffineXCoord.ToBigInteger());
                  Console.WriteLine(" expected " + pq1.AffineYCoord.ToBigInteger()
                      + " got " + pq2.AffineYCoord.ToBigInteger());
                  Fail(algorithm + " public key encoding (Q test) failed");
              }
  
  //			if (!pubKey.Parameters.getGenerator().Equals(((ECPublicKeyParameters)aKeyPair.Public).Parameters.getGenerator()))
              if (!pubKey.Parameters.G.Equals(((ECPublicKeyParameters)aKeyPair.Public).Parameters.G))
              {
                  Fail(algorithm + " public key encoding (G test) failed");
              }
  
              //
              // private key encoding test
              //
  //			byte[] privEnc = aKeyPair.Private.GetEncoded();
              byte[] privEnc = PrivateKeyInfoFactory.CreatePrivateKeyInfo(aKeyPair.Private).GetDerEncoded();
  
  //			PKCS8EncodedKeySpec privPKCS8 = new PKCS8EncodedKeySpec(privEnc);
  //			ECPrivateKey        privKey = (ECPrivateKey)keyFac.generatePrivate(privPKCS8);
              ECPrivateKeyParameters privKey = (ECPrivateKeyParameters) PrivateKeyFactory.CreateKey(privEnc);
  
  //			if (!privKey.getS().Equals(((ECPrivateKey)aKeyPair.Private).getS()))
              if (!privKey.D.Equals(((ECPrivateKeyParameters)aKeyPair.Private).D))
              {
  //				Fail(algorithm + " private key encoding (S test) failed");
                  Fail(algorithm + " private key encoding (D test) failed");
              }
  
  //			if (!privKey.Parameters.getGenerator().Equals(((ECPrivateKey)aKeyPair.Private).Parameters.getGenerator()))
              if (!privKey.Parameters.G.Equals(((ECPrivateKeyParameters)aKeyPair.Private).Parameters.G))
              {
                  Fail(algorithm + " private key encoding (G test) failed");
              }
          }
  
          [Test]
          public void TestExceptions()
          {
              DHParameters dhParams = new DHParameters(p512, g512);
  
              try
              {
                  IBasicAgreement aKeyAgreeBasic = AgreementUtilities.GetBasicAgreement("DH");
  
  //				aKeyAgreeBasic.generateSecret("DES");
                  aKeyAgreeBasic.CalculateAgreement(null);
              }
              catch (InvalidOperationException)
              {
                  // okay
              }
              catch (Exception e)
              {
                  Fail("Unexpected exception: " + e, e);
              }
          }
  
          private void doTestDesAndDesEde(
              BigInteger	g,
              BigInteger	p)
          {
              DHParameters dhParams = new DHParameters(p, g, null, 256);
  
              IAsymmetricCipherKeyPairGenerator keyGen = GeneratorUtilities.GetKeyPairGenerator("DH");
  
              keyGen.Init(new DHKeyGenerationParameters(new SecureRandom(), dhParams));
  
              AsymmetricCipherKeyPair kp = keyGen.GenerateKeyPair();
  
              IBasicAgreement keyAgreement = AgreementUtilities.GetBasicAgreement("DH");
  
              keyAgreement.Init(kp.Private);
              BigInteger agreed = keyAgreement.CalculateAgreement(kp.Public);
              byte[] agreedBytes = agreed.ToByteArrayUnsigned();
  
              // TODO Figure out where the magic happens of choosing the right
              // bytes from 'agreedBytes' for each key type - need C# equivalent?
              // (see JCEDHKeyAgreement.engineGenerateSecret)
  
  //			SecretKey key = keyAgreement.generateSecret("DES");
  //
  //			if (key.getEncoded().length != 8)
  //			{
  //				Fail("DES length wrong");
  //			}
  //
  //			if (!DESKeySpec.isParityAdjusted(key.getEncoded(), 0))
  //			{
  //				Fail("DES parity wrong");
  //			}
  //
  //			key = keyAgreement.generateSecret("DESEDE");
  //
  //			if (key.getEncoded().length != 24)
  //			{
  //				Fail("DESEDE length wrong");
  //			}
  //
  //			if (!DESedeKeySpec.isParityAdjusted(key.getEncoded(), 0))
  //			{
  //				Fail("DESEDE parity wrong");
  //			}
  //
  //			key = keyAgreement.generateSecret("Blowfish");
  //
  //			if (key.getEncoded().length != 16)
  //			{
  //				Fail("Blowfish length wrong");
  //			}
          }
  
          [Test]
          public void TestFunction()
          {
              doTestGP("DH", 512, 0, g512, p512);
              doTestGP("DiffieHellman", 768, 0, g768, p768);
              doTestGP("DIFFIEHELLMAN", 1024, 0, g1024, p1024);
              doTestGP("DH", 512, 64, g512, p512);
              doTestGP("DiffieHellman", 768, 128, g768, p768);
              doTestGP("DIFFIEHELLMAN", 1024, 256, g1024, p1024);
              doTestExplicitWrapping(512, 0, g512, p512);
              doTestDesAndDesEde(g768, p768);
  
              // TODO Put back in
              //doTestRandom(256);
          }
  
          [Test]
          public void TestEnc()
          {
  //			KeyFactory kFact = KeyFactory.getInstance("DH", "BC");
  //			
  //			Key k = kFact.generatePrivate(new PKCS8EncodedKeySpec(samplePrivEnc));
              AsymmetricKeyParameter k = PrivateKeyFactory.CreateKey(samplePrivEnc);
              byte[] encoded = PrivateKeyInfoFactory.CreatePrivateKeyInfo(k).GetEncoded();
  
              if (!Arrays.AreEqual(samplePrivEnc, encoded))
              {
                  Fail("private key re-encode failed");
              }
  
  //			k = kFact.generatePublic(new X509EncodedKeySpec(samplePubEnc));
              k = PublicKeyFactory.CreateKey(samplePubEnc);
              encoded = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(k).GetEncoded();
  
  
gt:             if (!Arrays.AreEqual(samplePubEnc, encoded))