using System;

using NUnit.Framework;

using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Math.EC;
using Org.BouncyCastle.Utilities.Encoders;
using Org.BouncyCastle.Utilities.Test;

namespace Org.BouncyCastle.Tests
{
	[TestFixture]
	public class ECDsa5Test
		: SimpleTest
	{
//		private static readonly byte[] k1 = Hex.Decode("d5014e4b60ef2ba8b6211b4062ba3224e0427dd3");
//		private static readonly byte[] k2 = Hex.Decode("345e8d05c075c3a508df729a1685690e68fcfb8c8117847e89063bca1f85d968fd281540b6e13bd1af989a1fbf17e06462bf511f9d0b140fb48ac1b1baa5bded");
//
//		private SecureRandom random = FixedSecureRandom.From(k1, k2);

		[Test]
		public void DecodeTest()
		{
//			EllipticCurve curve = new EllipticCurve(
//				new ECFieldFp(new BigInteger("6277101735386680763835789423207666416083908700390324961279")), // q
//				new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16), // a
//				new BigInteger("64210519e59c80e70fa7e9ab72243049feb8deecc146b9b1", 16)); // b
			ECCurve curve = new FpCurve(
				new BigInteger("6277101735386680763835789423207666416083908700390324961279"), // q
				new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16), // a
				new BigInteger("64210519e59c80e70fa7e9ab72243049feb8deecc146b9b1", 16)); // b

//			ECPoint p = ECPointUtil.DecodePoint(curve, Hex.Decode("03188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012"));
			ECPoint p = curve.DecodePoint(Hex.Decode("03188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012"));

			BigInteger x = p.X.ToBigInteger(); //p.getAffineX();

			if (!x.Equals(new BigInteger("188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012", 16)))
			{
				Fail("x uncompressed incorrectly");
			}

			BigInteger y = p.Y.ToBigInteger(); //p.getAffineX();
			if (!y.Equals(new BigInteger("7192b95ffc8da78631011ed6b24cdd573f977a11e794811", 16)))
			{
				Fail("y uncompressed incorrectly");
			}
		}

		/**
		* X9.62 - 1998,<br/>
		* J.3.2, Page 155, ECDSA over the field Fp<br/>
		* an example with 239 bit prime
		*/
		[Test]
		public void TestECDsa239BitPrime()
		{
			BigInteger r = new BigInteger("308636143175167811492622547300668018854959378758531778147462058306432176");
			BigInteger s = new BigInteger("323813553209797357708078776831250505931891051755007842781978505179448783");

			byte[] kData = new BigInteger("700000017569056646655505781757157107570501575775705779575555657156756655").ToByteArrayUnsigned();

			SecureRandom k = FixedSecureRandom.From(kData);

//			EllipticCurve curve = new EllipticCurve(
//				new ECFieldFp(new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839")), // q
//				new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
//				new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
			ECCurve curve = new FpCurve(
				new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
				new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
				new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b

			ECDomainParameters spec = new ECDomainParameters(
				curve,
//				ECPointUtil.DecodePoint(curve, Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
				curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
				new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307"), // n
				BigInteger.One); //1); // h

			ECPrivateKeyParameters sKey = new ECPrivateKeyParameters(
				"ECDSA",
				new BigInteger("876300101507107567501066130761671078357010671067781776716671676178726717"), // d
				spec);

			ECPublicKeyParameters vKey = new ECPublicKeyParameters(
				"ECDSA",
//				ECPointUtil.DecodePoint(curve, Hex.Decode("025b6dc53bc61a2548ffb0f671472de6c9521a9d2d2534e65abfcbd5fe0c70")), // Q
				curve.DecodePoint(Hex.Decode("025b6dc53bc61a2548ffb0f671472de6c9521a9d2d2534e65abfcbd5fe0c70")), // Q
				spec);

			ISigner sgr = SignerUtilities.GetSigner("ECDSA");
//			KeyFactory f = KeyFactory.getInstance("ECDSA");
//			AsymmetricKeyParameter sKey = f.generatePrivate(priKey);
//			AsymmetricKeyParameter vKey = f.generatePublic(pubKey);

			sgr.Init(true, new ParametersWithRandom(sKey, k));

			byte[] message = new byte[] { (byte)'a', (byte)'b', (byte)'c' };

			sgr.BlockUpdate(message, 0, message.Length);

			byte[] sigBytes = sgr.GenerateSignature();

			sgr.Init(false, vKey);

			sgr.BlockUpdate(message, 0, message.Length);

			if (!sgr.VerifySignature(sigBytes))
			{
				Fail("239 Bit EC verification failed");
			}

			BigInteger[] sig = derDecode(sigBytes);

			if (!r.Equals(sig[0]))
			{
				Fail("r component wrong." + Environment.NewLine
					+ " expecting: " + r + Environment.NewLine
					+ " got      : " + sig[0]);
			}

			if (!s.Equals(sig[1]))
			{
				Fail("s component wrong." + Environment.NewLine
					+ " expecting: " + s + Environment.NewLine
					+ " got      : " + sig[1]);
			}
		}

		/**
		* X9.62 - 1998,<br/>
		* J.2.1, Page 100, ECDSA over the field F2m<br/>
		* an example with 191 bit binary field
		*/
		[Test]
		public void TestECDsa239BitBinary()
		{
			BigInteger r = new BigInteger("21596333210419611985018340039034612628818151486841789642455876922391552");
			BigInteger s = new BigInteger("197030374000731686738334997654997227052849804072198819102649413465737174");
	    
			byte[] kData = new BigInteger("171278725565216523967285789236956265265265235675811949404040041670216363").ToByteArrayUnsigned();

			SecureRandom k = FixedSecureRandom.From(kData);

//			EllipticCurve curve = new EllipticCurve(
//				new ECFieldF2m(239, // m
//							new int[] { 36 }), // k
//				new BigInteger("32010857077C5431123A46B808906756F543423E8D27877578125778AC76", 16), // a
//				new BigInteger("790408F2EEDAF392B012EDEFB3392F30F4327C0CA3F31FC383C422AA8C16", 16)); // b
			ECCurve curve = new F2mCurve(
				239, // m
				36, // k
				new BigInteger("32010857077C5431123A46B808906756F543423E8D27877578125778AC76", 16), // a
				new BigInteger("790408F2EEDAF392B012EDEFB3392F30F4327C0CA3F31FC383C422AA8C16", 16)); // b

			ECDomainParameters parameters = new ECDomainParameters(
				curve,
//				ECPointUtil.DecodePoint(curve, Hex.Decode("0457927098FA932E7C0A96D3FD5B706EF7E5F5C156E16B7E7C86038552E91D61D8EE5077C33FECF6F1A16B268DE469C3C7744EA9A971649FC7A9616305")), // G
				curve.DecodePoint(Hex.Decode("0457927098FA932E7C0A96D3FD5B706EF7E5F5C156E16B7E7C86038552E91D61D8EE5077C33FECF6F1A16B268DE469C3C7744EA9A971649FC7A9616305")), // G
				new BigInteger("220855883097298041197912187592864814557886993776713230936715041207411783"), // n
				BigInteger.ValueOf(4)); //4); // h

			ECPrivateKeyParameters sKey = new ECPrivateKeyParameters(
				"ECDSA",
				new BigInteger("145642755521911534651321230007534120304391871461646461466464667494947990"), // d
				parameters);

			ECPublicKeyParameters vKey = new ECPublicKeyParameters(
				"ECDSA",
//				ECPointUtil.DecodePoint(curve, Hex.Decode("045894609CCECF9A92533F630DE713A958E96C97CCB8F5ABB5A688A238DEED6DC2D9D0C94EBFB7D526BA6A61764175B99CB6011E2047F9F067293F57F5")), // Q
				curve.DecodePoint(Hex.Decode("045894609CCECF9A92533F630DE713A958E96C97CCB8F5ABB5A688A238DEED6DC2D9D0C94EBFB7D526BA6A61764175B99CB6011E2047F9F067293F57F5")), // Q
				parameters);

			ISigner sgr = SignerUtilities.GetSigner("ECDSA");
//			KeyFactory f = KeyFactory.getInstance("ECDSA");
//			AsymmetricKeyParameter sKey = f.generatePrivate(priKeySpec);
//			AsymmetricKeyParameter vKey = f.generatePublic(pubKeySpec);
			byte[] message = new byte[] { (byte)'a', (byte)'b', (byte)'c' };

			sgr.Init(true, new ParametersWithRandom(sKey, k));

			sgr.BlockUpdate(message, 0, message.Length);

			byte[] sigBytes = sgr.GenerateSignature();

			sgr.Init(false, vKey);

			sgr.BlockUpdate(message, 0, message.Length);

			if (!sgr.VerifySignature(sigBytes))
			{
				Fail("239 Bit EC verification failed");
			}

			BigInteger[] sig = derDecode(sigBytes);

			if (!r.Equals(sig[0]))
			{
				Fail("r component wrong." + Environment.NewLine
					+ " expecting: " + r + Environment.NewLine
					+ " got      : " + sig[0]);
			}

			if (!s.Equals(sig[1]))
			{
				Fail("s component wrong." + Environment.NewLine
					+ " expecting: " + s + Environment.NewLine
					+ " got      : " + sig[1]);
			}
		}

		[Test]
		public void TestGeneration()
		{
			//
			// ECDSA generation test
			//
			byte[] data = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
			ISigner s = SignerUtilities.GetSigner("ECDSA");
			IAsymmetricCipherKeyPairGenerator g = GeneratorUtilities.GetKeyPairGenerator("ECDSA");

//			EllipticCurve curve = new EllipticCurve(
//				new ECFieldFp(new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839")), // q
//				new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
//				new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
			ECCurve curve = new FpCurve(
				new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
				new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
				new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b

			ECDomainParameters ecSpec = new ECDomainParameters(
				curve,
//				ECPointUtil.DecodePoint(curve,
				curve.DecodePoint(
					Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
				new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307"), // n
				BigInteger.One); //1); // h

			g.Init(new ECKeyGenerationParameters(ecSpec, new SecureRandom()));

			AsymmetricCipherKeyPair p = g.GenerateKeyPair();

			AsymmetricKeyParameter sKey = p.Private;
			AsymmetricKeyParameter vKey = p.Public;

			s.Init(true, sKey);

			s.BlockUpdate(data, 0, data.Length);

			byte[] sigBytes = s.GenerateSignature();

			s = SignerUtilities.GetSigner("ECDSA");

			s.Init(false, vKey);

			s.BlockUpdate(data, 0, data.Length);

			if (!s.VerifySignature(sigBytes))
			{
				Fail("ECDSA verification failed");
			}
		}

		protected BigInteger[] derDecode(
			byte[] encoding)
		{
			Asn1Sequence s = (Asn1Sequence) Asn1Object.FromByteArray(encoding);

			return new BigInteger[]
			{
				((DerInteger)s[0]).Value,
				((DerInteger)s[1]).Value
			};
		}

		public override string Name
		{
			get { return "ECDSA5"; }
		}

		public override void PerformTest()
		{
			DecodeTest();
			TestECDsa239BitPrime();
			TestECDsa239BitBinary();
			TestGeneration();
		}

		public static void Main(
			string[] args)
		{
			RunTest(new ECDsa5Test());
		}
	}
}
