using System;
using System.IO;

using NUnit.Framework;

using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.Sec;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Asn1.X9;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Math.EC;
using Org.BouncyCastle.Utilities;
using Org.BouncyCastle.Utilities.Encoders;
using Org.BouncyCastle.Utilities.Test;

namespace Org.BouncyCastle.Asn1.Tests
{
    [TestFixture]
    public class X9Test
        : SimpleTest
    {
        private static readonly byte[] namedPub = Base64.Decode("MDcwEwYHKoZIzj0CAQYIKoZIzj0DAQEDIAADG5xRI+Iki/JrvL20hoDUa7Cggzorv5B9yyqSMjYu");
        private static readonly byte[] expPub = Base64.Decode(
              "MIH8MIHXBgcqhkjOPQIBMIHLAgEBMCkGByqGSM49AQECHn///////////////3///////4AAAA"
            + "AAAH///////zBXBB5///////////////9///////+AAAAAAAB///////wEHiVXBfoqMGZUsfTL"
            + "A9anUKMMJQEC1JiHF9m6FattPgMVAH1zdBaP/jRxtgqFdoahlHXTv6L/BB8DZ2iujhi7ks/PAF"
            + "yUmqLG2UhT0OZgu/hUsclQX+laAh5///////////////9///+XXetBs6YFfDxDIUZSZVECAQED"
            + "IAADG5xRI+Iki/JrvL20hoDUa7Cggzorv5B9yyqSMjYu");

        private static readonly byte[] namedPriv = Base64.Decode("MDkCAQAwEwYHKoZIzj0CAQYIKoZIzj0DAQEEHzAdAgEBBBgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAo=");
        private static readonly byte[] expPriv = Base64.Decode(
              "MIIBBAIBADCB1wYHKoZIzj0CATCBywIBATApBgcqhkjOPQEBAh5///////////////9///////"
            + "+AAAAAAAB///////8wVwQef///////////////f///////gAAAAAAAf//////8BB4lVwX6KjBmVL"
            + "H0ywPWp1CjDCUBAtSYhxfZuhWrbT4DFQB9c3QWj/40cbYKhXaGoZR107+i/wQfA2doro4Yu5LPzw"
            + "BclJqixtlIU9DmYLv4VLHJUF/pWgIef///////////////f///l13rQbOmBXw8QyFGUmVRAgEBBC"
            + "UwIwIBAQQeAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAU");

        private void EncodePublicKey()
        {
            X9ECParameters ecP = X962NamedCurves.GetByOid(X9ObjectIdentifiers.Prime239v3);

            if (X9IntegerConverter.GetByteLength(ecP.Curve) != 30)
            {
                Fail("wrong byte length reported for curve");
            }

            if (ecP.Curve.FieldSize != 239)
            {
                Fail("wrong field size reported for curve");
            }

            //
            // named curve
            //
            X962Parameters _params = new X962Parameters(X9ObjectIdentifiers.Prime192v1);
            ECPoint point = ecP.G.Multiply(BigInteger.ValueOf(100));

            DerOctetString p = new DerOctetString(point.GetEncoded(true));

            SubjectPublicKeyInfo info = new SubjectPublicKeyInfo(new AlgorithmIdentifier(X9ObjectIdentifiers.IdECPublicKey, _params), p.GetOctets());
            if (!Arrays.AreEqual(info.GetEncoded(), namedPub))
            {
                Fail("failed public named generation");
            }

            X9ECPoint x9P = new X9ECPoint(ecP.Curve, p);

            if (!Arrays.AreEqual(p.GetOctets(), x9P.GetPointEncoding()))
            {
                Fail("point encoding not preserved");
            }

            Asn1Object o = Asn1Object.FromByteArray(namedPub);

            if (!info.Equals(o))
            {
                Fail("failed public named equality");
            }

            //
            // explicit curve parameters
            //
            _params = new X962Parameters(ecP);

            info = new SubjectPublicKeyInfo(new AlgorithmIdentifier(X9ObjectIdentifiers.IdECPublicKey, _params), p.GetOctets());

            if (!Arrays.AreEqual(info.GetEncoded(), expPub))
            {
                Fail("failed public explicit generation");
            }

            o = Asn1Object.FromByteArray(expPub);

            if (!info.Equals(o))
            {
                Fail("failed public explicit equality");
            }
        }

        private void EncodePrivateKey()
        {
            X9ECParameters ecP = X962NamedCurves.GetByOid(X9ObjectIdentifiers.Prime192v1);

            //
            // named curve
            //
            X962Parameters _params = new X962Parameters(X9ObjectIdentifiers.Prime192v1);

            PrivateKeyInfo info = new PrivateKeyInfo(new AlgorithmIdentifier(X9ObjectIdentifiers.IdECPublicKey, _params),
                new ECPrivateKeyStructure(ecP.N.BitLength, BigInteger.Ten).ToAsn1Object());

            if (!Arrays.AreEqual(info.GetEncoded(), namedPriv))
            {
                Fail("failed private named generation");
            }

            Asn1Object o = Asn1Object.FromByteArray(namedPriv);

            if (!info.Equals(o))
            {
                Fail("failed private named equality");
            }

            //
            // explicit curve parameters
            //
            ecP = X962NamedCurves.GetByOid(X9ObjectIdentifiers.Prime239v3);

            _params = new X962Parameters(ecP);

            info = new PrivateKeyInfo(new AlgorithmIdentifier(X9ObjectIdentifiers.IdECPublicKey, _params),
                new ECPrivateKeyStructure(ecP.N.BitLength, BigInteger.ValueOf(20)).ToAsn1Object());

            if (!Arrays.AreEqual(info.GetEncoded(), expPriv))
            {
                Fail("failed private explicit generation");
            }

            o = Asn1Object.FromByteArray(expPriv);

            if (!info.Equals(o))
            {
                Fail("failed private explicit equality");
            }
        }

        public override void PerformTest()
        {
            EncodePublicKey();
            EncodePrivateKey();
        }

        public override string Name
        {
            get { return "X9"; }
        }

        public static void Main(
            string[] args)
        {
            RunTest(new X9Test());
        }

        [Test]
        public void TestFunction()
        {
            string resultText = Perform().ToString();

            Assert.AreEqual(Name + ": Okay", resultText);
        }
    }
}