public ECKeyGenerationParameters(
			ECDomainParameters	domainParameters,
			SecureRandom		random)
			: base(random, domainParameters.N.BitLength)
        {
            this.domainParams = domainParameters;
        }
		public ECPrivateKeyParameters(
			string				algorithm,
			BigInteger			d,
			ECDomainParameters	parameters)
			: base(algorithm, true, parameters)
		{
			if (d == null)
				throw new ArgumentNullException("d");

			this.d = d;
		}
		public ECPublicKeyParameters(
			string				algorithm,
			ECPoint				q,
			ECDomainParameters	parameters)
			: base(algorithm, false, parameters)
        {
			if (q == null)
				throw new ArgumentNullException("q");

			this.q = q;
		}
		protected ECKeyParameters(
			string				algorithm,
            bool				isPrivate,
            ECDomainParameters	parameters)
			: base(isPrivate)
        {
			if (algorithm == null)
				throw new ArgumentNullException("algorithm");
			if (parameters == null)
				throw new ArgumentNullException("parameters");

			this.algorithm = VerifyAlgorithmName(algorithm);
			this.parameters = parameters;
        }
		protected ECKeyParameters(
			string				algorithm,
			bool				isPrivate,
			DerObjectIdentifier	publicKeyParamSet)
			: base(isPrivate)
		{
			if (algorithm == null)
				throw new ArgumentNullException("algorithm");
			if (publicKeyParamSet == null)
				throw new ArgumentNullException("publicKeyParamSet");

			this.algorithm = VerifyAlgorithmName(algorithm);
			this.parameters = LookupParameters(publicKeyParamSet);
			this.publicKeyParamSet = publicKeyParamSet;
		}
		public void Init(
            KeyGenerationParameters parameters)
        {
			if (parameters is ECKeyGenerationParameters)
			{
				ECKeyGenerationParameters ecP = (ECKeyGenerationParameters) parameters;

				this.publicKeyParamSet = ecP.PublicKeyParamSet;
				this.parameters = ecP.DomainParameters;
			}
			else
			{
				DerObjectIdentifier oid;
				switch (parameters.Strength)
				{
					case 192:
						oid = X9ObjectIdentifiers.Prime192v1;
						break;
					case 224:
						oid = SecObjectIdentifiers.SecP224r1;
						break;
					case 239:
						oid = X9ObjectIdentifiers.Prime239v1;
						break;
					case 256:
						oid = X9ObjectIdentifiers.Prime256v1;
						break;
					case 384:
						oid = SecObjectIdentifiers.SecP384r1;
						break;
					case 521:
						oid = SecObjectIdentifiers.SecP521r1;
						break;
					default:
						throw new InvalidParameterException("unknown key size.");
				}

				X9ECParameters ecps = FindECCurveByOid(oid);

				this.parameters = new ECDomainParameters(
					ecps.Curve, ecps.G, ecps.N, ecps.H, ecps.GetSeed());
			}

			this.random = parameters.Random;
		}
		// The ECMQV Primitive as described in SEC-1, 3.4
		private static ECPoint calculateMqvAgreement(
			ECDomainParameters		parameters,
			ECPrivateKeyParameters	d1U,
			ECPrivateKeyParameters	d2U,
			ECPublicKeyParameters	Q2U,
			ECPublicKeyParameters	Q1V,
			ECPublicKeyParameters	Q2V)
		{
			BigInteger n = parameters.N;
			int e = (n.BitLength + 1) / 2;
			BigInteger powE = BigInteger.One.ShiftLeft(e);

			// The Q2U public key is optional
			ECPoint q;
			if (Q2U == null)
			{
				q = parameters.G.Multiply(d2U.D);
			}
			else
			{
				q = Q2U.Q;
			}

			BigInteger x = q.X.ToBigInteger();
			BigInteger xBar = x.Mod(powE);
			BigInteger Q2UBar = xBar.SetBit(e);
			BigInteger s = d1U.D.Multiply(Q2UBar).Mod(n).Add(d2U.D).Mod(n);

			BigInteger xPrime = Q2V.Q.X.ToBigInteger();
			BigInteger xPrimeBar = xPrime.Mod(powE);
			BigInteger Q2VBar = xPrimeBar.SetBit(e);

			BigInteger hs = parameters.H.Multiply(s).Mod(n);

			//ECPoint p = Q1V.Q.Multiply(Q2VBar).Add(Q2V.Q).Multiply(hs);
			ECPoint p = ECAlgorithms.SumOfTwoMultiplies(
				Q1V.Q, Q2VBar.Multiply(hs).Mod(n), Q2V.Q, hs);

			if (p.IsInfinity)
				throw new InvalidOperationException("Infinity is not a valid agreement value for MQV");

			return p;
		}
		internal static ECDomainParameters LookupParameters(
			DerObjectIdentifier publicKeyParamSet)
		{
			if (publicKeyParamSet == null)
				throw new ArgumentNullException("publicKeyParamSet");

			ECDomainParameters p = ECGost3410NamedCurves.GetByOid(publicKeyParamSet);

			if (p == null)
			{
				X9ECParameters x9 = ECKeyPairGenerator.FindECCurveByOid(publicKeyParamSet);

				if (x9 == null)
				{
					throw new ArgumentException("OID is not a valid public key parameter set", "publicKeyParamSet");
				}

				p = new ECDomainParameters(x9.Curve, x9.G, x9.N, x9.H, x9.GetSeed());
			}

			return p;
		}
		public static AsymmetricKeyParameter CreateKey(
			SubjectPublicKeyInfo keyInfo)
        {
            AlgorithmIdentifier algID = keyInfo.AlgorithmID;
			DerObjectIdentifier algOid = algID.ObjectID;

			// TODO See RSAUtil.isRsaOid in Java build
			if (algOid.Equals(PkcsObjectIdentifiers.RsaEncryption)
				|| algOid.Equals(X509ObjectIdentifiers.IdEARsa)
				|| algOid.Equals(PkcsObjectIdentifiers.IdRsassaPss)
				|| algOid.Equals(PkcsObjectIdentifiers.IdRsaesOaep))
			{
				RsaPublicKeyStructure pubKey = RsaPublicKeyStructure.GetInstance(
					keyInfo.GetPublicKey());

				return new RsaKeyParameters(false, pubKey.Modulus, pubKey.PublicExponent);
			}
			else if (algOid.Equals(X9ObjectIdentifiers.DHPublicNumber))
			{
				Asn1Sequence seq = Asn1Sequence.GetInstance(algID.Parameters.ToAsn1Object());

				DHPublicKey dhPublicKey = DHPublicKey.GetInstance(keyInfo.GetPublicKey());

				BigInteger y = dhPublicKey.Y.Value;

				if (IsPkcsDHParam(seq))
					return ReadPkcsDHParam(algOid, y, seq);

				DHDomainParameters dhParams = DHDomainParameters.GetInstance(seq);

				BigInteger p = dhParams.P.Value;
				BigInteger g = dhParams.G.Value;
				BigInteger q = dhParams.Q.Value;

				BigInteger j = null;
				if (dhParams.J != null)
				{
					j = dhParams.J.Value;
				}

				DHValidationParameters validation = null;
				DHValidationParms dhValidationParms = dhParams.ValidationParms;
				if (dhValidationParms != null)
				{
					byte[] seed = dhValidationParms.Seed.GetBytes();
					BigInteger pgenCounter = dhValidationParms.PgenCounter.Value;

					// TODO Check pgenCounter size?

					validation = new DHValidationParameters(seed, pgenCounter.IntValue);
				}

				return new DHPublicKeyParameters(y, new DHParameters(p, g, q, j, validation));
			}
			else if (algOid.Equals(PkcsObjectIdentifiers.DhKeyAgreement))
			{
				Asn1Sequence seq = Asn1Sequence.GetInstance(algID.Parameters.ToAsn1Object());

				DerInteger derY = (DerInteger) keyInfo.GetPublicKey();

				return ReadPkcsDHParam(algOid, derY.Value, seq);
			}
			else if (algOid.Equals(OiwObjectIdentifiers.ElGamalAlgorithm))
			{
				ElGamalParameter para = new ElGamalParameter(
					Asn1Sequence.GetInstance(algID.Parameters.ToAsn1Object()));
				DerInteger derY = (DerInteger) keyInfo.GetPublicKey();

				return new ElGamalPublicKeyParameters(
					derY.Value,
					new ElGamalParameters(para.P, para.G));
			}
			else if (algOid.Equals(X9ObjectIdentifiers.IdDsa)
				|| algOid.Equals(OiwObjectIdentifiers.DsaWithSha1))
			{
				DerInteger derY = (DerInteger) keyInfo.GetPublicKey();
				Asn1Encodable ae = algID.Parameters;

				DsaParameters parameters = null;
				if (ae != null)
				{
					DsaParameter para = DsaParameter.GetInstance(ae.ToAsn1Object());
					parameters = new DsaParameters(para.P, para.Q, para.G);
				}

				return new DsaPublicKeyParameters(derY.Value, parameters);
			}
			else if (algOid.Equals(X9ObjectIdentifiers.IdECPublicKey))
			{
				X962Parameters para = new X962Parameters(
					algID.Parameters.ToAsn1Object());
				X9ECParameters ecP;

				if (para.IsNamedCurve)
				{
					ecP = ECKeyPairGenerator.FindECCurveByOid((DerObjectIdentifier)para.Parameters);
				}
				else
				{
					ecP = new X9ECParameters((Asn1Sequence)para.Parameters);
				}

				ECDomainParameters dParams = new ECDomainParameters(
					ecP.Curve,
					ecP.G,
					ecP.N,
					ecP.H,
					ecP.GetSeed());

				DerBitString bits = keyInfo.PublicKeyData;
				byte[] data = bits.GetBytes();
				Asn1OctetString key = new DerOctetString(data);

				X9ECPoint derQ = new X9ECPoint(dParams.Curve, key);

				return new ECPublicKeyParameters(derQ.Point, dParams);
			}
			else if (algOid.Equals(CryptoProObjectIdentifiers.GostR3410x2001))
			{
				Gost3410PublicKeyAlgParameters gostParams = new Gost3410PublicKeyAlgParameters(
					(Asn1Sequence) algID.Parameters);

				Asn1OctetString key;
				try
				{
					key = (Asn1OctetString) keyInfo.GetPublicKey();
				}
				catch (IOException)
				{
					throw new ArgumentException("invalid info structure in GOST3410 public key");
				}

				byte[] keyEnc = key.GetOctets();
				byte[] x = new byte[32];
				byte[] y = new byte[32];

				for (int i = 0; i != y.Length; i++)
				{
					x[i] = keyEnc[32 - 1 - i];
				}

				for (int i = 0; i != x.Length; i++)
				{
					y[i] = keyEnc[64 - 1 - i];
				}

				ECDomainParameters ecP = ECGost3410NamedCurves.GetByOid(gostParams.PublicKeyParamSet);

				if (ecP == null)
					return null;

				ECPoint q = ecP.Curve.CreatePoint(new BigInteger(1, x), new BigInteger(1, y), false);

				return new ECPublicKeyParameters("ECGOST3410", q, gostParams.PublicKeyParamSet);
			}
			else if (algOid.Equals(CryptoProObjectIdentifiers.GostR3410x94))
			{
				Gost3410PublicKeyAlgParameters algParams = new Gost3410PublicKeyAlgParameters(
					(Asn1Sequence) algID.Parameters);

				DerOctetString derY;
				try
				{
					derY = (DerOctetString) keyInfo.GetPublicKey();
				}
				catch (IOException)
				{
					throw new ArgumentException("invalid info structure in GOST3410 public key");
				}

				byte[] keyEnc = derY.GetOctets();
				byte[] keyBytes = new byte[keyEnc.Length];

				for (int i = 0; i != keyEnc.Length; i++)
				{
					keyBytes[i] = keyEnc[keyEnc.Length - 1 - i]; // was little endian
				}

				BigInteger y = new BigInteger(1, keyBytes);

				return new Gost3410PublicKeyParameters(y, algParams.PublicKeyParamSet);
			}
            else
            {
                throw new SecurityUtilityException("algorithm identifier in key not recognised: " + algOid);
            }
        }
		public ECPrivateKeyParameters(
			BigInteger			d,
			ECDomainParameters	parameters)
			: this("EC", d, parameters)
		{
		}
		public static AsymmetricKeyParameter CreateKey(
			PrivateKeyInfo keyInfo)
        {
            AlgorithmIdentifier algID = keyInfo.AlgorithmID;
			DerObjectIdentifier algOid = algID.ObjectID;

			// TODO See RSAUtil.isRsaOid in Java build
			if (algOid.Equals(PkcsObjectIdentifiers.RsaEncryption)
				|| algOid.Equals(X509ObjectIdentifiers.IdEARsa)
				|| algOid.Equals(PkcsObjectIdentifiers.IdRsassaPss)
				|| algOid.Equals(PkcsObjectIdentifiers.IdRsaesOaep))
			{
				RsaPrivateKeyStructure keyStructure = new RsaPrivateKeyStructure(
					Asn1Sequence.GetInstance(keyInfo.PrivateKey));

				return new RsaPrivateCrtKeyParameters(
					keyStructure.Modulus,
					keyStructure.PublicExponent,
					keyStructure.PrivateExponent,
					keyStructure.Prime1,
					keyStructure.Prime2,
					keyStructure.Exponent1,
					keyStructure.Exponent2,
					keyStructure.Coefficient);
			}
			// TODO?
//			else if (algOid.Equals(X9ObjectIdentifiers.DHPublicNumber))
			else if (algOid.Equals(PkcsObjectIdentifiers.DhKeyAgreement))
			{
				DHParameter para = new DHParameter(
					Asn1Sequence.GetInstance(algID.Parameters.ToAsn1Object()));
				DerInteger derX = (DerInteger)keyInfo.PrivateKey;

				BigInteger lVal = para.L;
				int l = lVal == null ? 0 : lVal.IntValue;
				DHParameters dhParams = new DHParameters(para.P, para.G, null, l);

				return new DHPrivateKeyParameters(derX.Value, dhParams, algOid);
			}
			else if (algOid.Equals(OiwObjectIdentifiers.ElGamalAlgorithm))
			{
				ElGamalParameter  para = new ElGamalParameter(
					Asn1Sequence.GetInstance(algID.Parameters.ToAsn1Object()));
				DerInteger derX = (DerInteger)keyInfo.PrivateKey;

				return new ElGamalPrivateKeyParameters(
					derX.Value,
					new ElGamalParameters(para.P, para.G));
			}
			else if (algOid.Equals(X9ObjectIdentifiers.IdDsa))
			{
				DerInteger derX = (DerInteger) keyInfo.PrivateKey;
				Asn1Encodable ae = algID.Parameters;

				DsaParameters parameters = null;
				if (ae != null)
				{
					DsaParameter para = DsaParameter.GetInstance(ae.ToAsn1Object());
					parameters = new DsaParameters(para.P, para.Q, para.G);
				}

				return new DsaPrivateKeyParameters(derX.Value, parameters);
			}
			else if (algOid.Equals(X9ObjectIdentifiers.IdECPublicKey))
			{
				X962Parameters para = new X962Parameters(algID.Parameters.ToAsn1Object());
				X9ECParameters ecP;

				if (para.IsNamedCurve)
				{
					ecP = ECKeyPairGenerator.FindECCurveByOid((DerObjectIdentifier) para.Parameters);
				}
				else
				{
					ecP = new X9ECParameters((Asn1Sequence) para.Parameters);
				}

				ECDomainParameters dParams = new ECDomainParameters(
					ecP.Curve,
					ecP.G,
					ecP.N,
					ecP.H,
					ecP.GetSeed());

				ECPrivateKeyStructure ec = new ECPrivateKeyStructure(
					Asn1Sequence.GetInstance(keyInfo.PrivateKey));

				return new ECPrivateKeyParameters(ec.GetKey(), dParams);
			}
			else if (algOid.Equals(CryptoProObjectIdentifiers.GostR3410x2001))
			{
				Gost3410PublicKeyAlgParameters gostParams = new Gost3410PublicKeyAlgParameters(
					Asn1Sequence.GetInstance(algID.Parameters.ToAsn1Object()));

				ECPrivateKeyStructure ec = new ECPrivateKeyStructure(
					Asn1Sequence.GetInstance(keyInfo.PrivateKey));

				ECDomainParameters ecP = ECGost3410NamedCurves.GetByOid(gostParams.PublicKeyParamSet);

				if (ecP == null)
					return null;

				return new ECPrivateKeyParameters("ECGOST3410", ec.GetKey(), gostParams.PublicKeyParamSet);
			}
			else if (algOid.Equals(CryptoProObjectIdentifiers.GostR3410x94))
			{
				Gost3410PublicKeyAlgParameters gostParams = new Gost3410PublicKeyAlgParameters(
					Asn1Sequence.GetInstance(algID.Parameters.ToAsn1Object()));

				DerOctetString derX = (DerOctetString) keyInfo.PrivateKey;
				byte[] keyEnc = derX.GetOctets();
				byte[] keyBytes = new byte[keyEnc.Length];

				for (int i = 0; i != keyEnc.Length; i++)
				{
					keyBytes[i] = keyEnc[keyEnc.Length - 1 - i]; // was little endian
				}

				BigInteger x = new BigInteger(1, keyBytes);

				return new Gost3410PrivateKeyParameters(x, gostParams.PublicKeyParamSet);
			}
			else
			{
				throw new SecurityUtilityException("algorithm identifier in key not recognised");
			}
        }
		protected bool Equals(
			ECDomainParameters other)
		{
			return curve.Equals(other.curve)
				&&	g.Equals(other.g)
				&&	n.Equals(other.n)
				&&	h.Equals(other.h)
				&&	Arrays.AreEqual(seed, other.seed);
		}
		protected virtual void GenerateEphemeralClientKeyExchange(ECDomainParameters ecParams, Stream output)
		{
			AsymmetricCipherKeyPair ecAgreeClientKeyPair = GenerateECKeyPair(ecParams);
			this.ecAgreeClientPrivateKey = (ECPrivateKeyParameters)ecAgreeClientKeyPair.Private;

			byte[] keData = ExternalizeKey((ECPublicKeyParameters)ecAgreeClientKeyPair.Public);
			TlsUtilities.WriteUint24(keData.Length + 1, output);
			TlsUtilities.WriteOpaque8(keData, output);
		}
		protected virtual AsymmetricCipherKeyPair GenerateECKeyPair(ECDomainParameters ecParams)
		{
			ECKeyPairGenerator keyPairGenerator = new ECKeyPairGenerator();
			ECKeyGenerationParameters keyGenerationParameters = new ECKeyGenerationParameters(ecParams,
				context.SecureRandom);
			keyPairGenerator.Init(keyGenerationParameters);
			return keyPairGenerator.GenerateKeyPair();
		}
		protected virtual bool AreOnSameCurve(ECDomainParameters a, ECDomainParameters b)
		{
			// TODO Move to ECDomainParameters.Equals() or other utility method?
			return a.Curve.Equals(b.Curve) && a.G.Equals(b.G) && a.N.Equals(b.N) && a.H.Equals(b.H);
		}
		public ECPublicKeyParameters(
			ECPoint				q,
			ECDomainParameters	parameters)
			: this("EC", q, parameters)
		{
		}
        static ECGost3410NamedCurves()
        {
            BigInteger mod_p = new BigInteger("115792089237316195423570985008687907853269984665640564039457584007913129639319");
            BigInteger mod_q = new BigInteger("115792089237316195423570985008687907853073762908499243225378155805079068850323");

            FpCurve curve = new FpCurve(
                mod_p, // p
                new BigInteger("115792089237316195423570985008687907853269984665640564039457584007913129639316"), // a
                new BigInteger("166")); // b

            ECDomainParameters ecParams = new ECDomainParameters(
                curve,
				curve.CreatePoint(
					BigInteger.One, // x
					new BigInteger("64033881142927202683649881450433473985931760268884941288852745803908878638612"), // y
					false),
                mod_q);

			parameters[CryptoProObjectIdentifiers.GostR3410x2001CryptoProA] = ecParams;

            mod_p = new BigInteger("115792089237316195423570985008687907853269984665640564039457584007913129639319");
            mod_q = new BigInteger("115792089237316195423570985008687907853073762908499243225378155805079068850323");

            curve = new FpCurve(
                mod_p, // p
                new BigInteger("115792089237316195423570985008687907853269984665640564039457584007913129639316"),
                new BigInteger("166"));

            ecParams = new ECDomainParameters(
                curve,
				curve.CreatePoint(
					BigInteger.One, // x
					new BigInteger("64033881142927202683649881450433473985931760268884941288852745803908878638612"), // y
					false),
                mod_q);

            parameters[CryptoProObjectIdentifiers.GostR3410x2001CryptoProXchA] = ecParams;

            mod_p = new BigInteger("57896044618658097711785492504343953926634992332820282019728792003956564823193"); //p
            mod_q = new BigInteger("57896044618658097711785492504343953927102133160255826820068844496087732066703"); //q

            curve = new FpCurve(
                mod_p, // p
                new BigInteger("57896044618658097711785492504343953926634992332820282019728792003956564823190"), // a
                new BigInteger("28091019353058090096996979000309560759124368558014865957655842872397301267595")); // b

            ecParams = new ECDomainParameters(
                curve,
                curve.CreatePoint(
					BigInteger.One, // x
					new BigInteger("28792665814854611296992347458380284135028636778229113005756334730996303888124"), // y
					false),
                mod_q); // q

            parameters[CryptoProObjectIdentifiers.GostR3410x2001CryptoProB] = ecParams;

            mod_p = new BigInteger("70390085352083305199547718019018437841079516630045180471284346843705633502619");
            mod_q = new BigInteger("70390085352083305199547718019018437840920882647164081035322601458352298396601");

            curve = new FpCurve(
                mod_p, // p
                new BigInteger("70390085352083305199547718019018437841079516630045180471284346843705633502616"),
                new BigInteger("32858"));

            ecParams = new ECDomainParameters(
                curve,
                curve.CreatePoint(
					BigInteger.Zero, // x
					new BigInteger("29818893917731240733471273240314769927240550812383695689146495261604565990247"), // y
					false),
                mod_q);

            parameters[CryptoProObjectIdentifiers.GostR3410x2001CryptoProXchB] = ecParams;

            mod_p = new BigInteger("70390085352083305199547718019018437841079516630045180471284346843705633502619"); //p
            mod_q = new BigInteger("70390085352083305199547718019018437840920882647164081035322601458352298396601"); //q
            curve = new FpCurve(
                mod_p, // p
                new BigInteger("70390085352083305199547718019018437841079516630045180471284346843705633502616"), // a
                new BigInteger("32858")); // b

            ecParams = new ECDomainParameters(
                curve,
                curve.CreatePoint(
					BigInteger.Zero, // x
					new BigInteger("29818893917731240733471273240314769927240550812383695689146495261604565990247"), // y
					false),
                mod_q); // q

			parameters[CryptoProObjectIdentifiers.GostR3410x2001CryptoProC] = ecParams;

            objIds["GostR3410-2001-CryptoPro-A"] = CryptoProObjectIdentifiers.GostR3410x2001CryptoProA;
            objIds["GostR3410-2001-CryptoPro-B"] = CryptoProObjectIdentifiers.GostR3410x2001CryptoProB;
            objIds["GostR3410-2001-CryptoPro-C"] = CryptoProObjectIdentifiers.GostR3410x2001CryptoProC;
            objIds["GostR3410-2001-CryptoPro-XchA"] = CryptoProObjectIdentifiers.GostR3410x2001CryptoProXchA;
            objIds["GostR3410-2001-CryptoPro-XchB"] = CryptoProObjectIdentifiers.GostR3410x2001CryptoProXchB;

            names[CryptoProObjectIdentifiers.GostR3410x2001CryptoProA] = "GostR3410-2001-CryptoPro-A";
            names[CryptoProObjectIdentifiers.GostR3410x2001CryptoProB] = "GostR3410-2001-CryptoPro-B";
            names[CryptoProObjectIdentifiers.GostR3410x2001CryptoProC] = "GostR3410-2001-CryptoPro-C";
            names[CryptoProObjectIdentifiers.GostR3410x2001CryptoProXchA] = "GostR3410-2001-CryptoPro-XchA";
            names[CryptoProObjectIdentifiers.GostR3410x2001CryptoProXchB] = "GostR3410-2001-CryptoPro-XchB";
        }
 public ECPrivateKeyParameters(
     BigInteger d,
     ECDomainParameters parameters)
     : this("EC", d, parameters)
 {
 }