Org.BouncyCastle.Crypto.Signers.DsaSigner.Init C# (CSharp) Method

		public void Init(
			bool				forSigning,
			ICipherParameters	parameters)
		{
			if (forSigning)
			{
				if (parameters is ParametersWithRandom)
				{
					ParametersWithRandom rParam = (ParametersWithRandom)parameters;

					this.random = rParam.Random;
					parameters = rParam.Parameters;
				}
				else
				{
					this.random = new SecureRandom();
				}

				if (!(parameters is DsaPrivateKeyParameters))
					throw new InvalidKeyException("DSA private key required for signing");

				this.key = (DsaPrivateKeyParameters) parameters;
			}
			else
			{
				if (!(parameters is DsaPublicKeyParameters))
					throw new InvalidKeyException("DSA public key required for verification");

				this.key = (DsaPublicKeyParameters) parameters;
			}
		}

        public void TestNONEwithDSA()
        {
            byte[] dummySha1 = Hex.Decode("01020304050607080910111213141516");

            SecureRandom rand = new SecureRandom();

            DsaParametersGenerator pGen = new DsaParametersGenerator();
            pGen.Init(512, 80, rand);

            IAsymmetricCipherKeyPairGenerator g = GeneratorUtilities.GetKeyPairGenerator("DSA");
            g.Init(new DsaKeyGenerationParameters(rand, pGen.GenerateParameters()));

            IAsymmetricCipherKeyPair kp = g.GenerateKeyPair();

            ISigner sig = SignerUtilities.GetSigner("NONEwithDSA");
            sig.Init(true, kp.Private);
            sig.BlockUpdate(dummySha1, 0, dummySha1.Length);
            byte[] sigBytes = sig.GenerateSignature();

            sig.Init(false, kp.Public);
            sig.BlockUpdate(dummySha1, 0, dummySha1.Length);
            sig.VerifySignature(sigBytes);

            // reset test

            sig.BlockUpdate(dummySha1, 0, dummySha1.Length);

            if (!sig.VerifySignature(sigBytes))
            {
                Fail("NONEwithDSA failed to reset");
            }

            // lightweight test
            DsaSigner signer = new DsaSigner();
            Asn1Sequence derSig = Asn1Sequence.GetInstance(Asn1Object.FromByteArray(sigBytes));

            signer.Init(false, kp.Public);

            if (!signer.VerifySignature(dummySha1,
                DerInteger.GetInstance(derSig[0]).Value, DerInteger.GetInstance(derSig[1]).Value))
            {
                Fail("NONEwithDSA not really NONE!");
            }
        }