Org.BouncyCastle.Crypto.Signers.PssSigner.VerifySignature C# (CSharp) Method

		public virtual bool VerifySignature(
			byte[] signature)
		{
			contentDigest1.DoFinal(mDash, mDash.Length - hLen - sLen);

			byte[] b = cipher.ProcessBlock(signature, 0, signature.Length);
			b.CopyTo(block, block.Length - b.Length);

			if (block[block.Length - 1] != trailer)
			{
				ClearBlock(block);
				return false;
			}

			byte[] dbMask = MaskGeneratorFunction1(block, block.Length - hLen - 1, hLen, block.Length - hLen - 1);

			for (int i = 0; i != dbMask.Length; i++)
			{
				block[i] ^= dbMask[i];
			}

			block[0] &= (byte) ((0xff >> ((block.Length * 8) - emBits)));

			for (int i = 0; i != block.Length - hLen - sLen - 2; i++)
			{
				if (block[i] != 0)
				{
					ClearBlock(block);
					return false;
				}
			}

			if (block[block.Length - hLen - sLen - 2] != 0x01)
			{
				ClearBlock(block);
				return false;
			}

			Array.Copy(block, block.Length - sLen - hLen - 1, mDash, mDash.Length - sLen, sLen);

			contentDigest2.BlockUpdate(mDash, 0, mDash.Length);
			contentDigest2.DoFinal(mDash, mDash.Length - hLen);

			for (int i = block.Length - hLen - 1, j = mDash.Length - hLen; j != mDash.Length; i++, j++)
			{
				if ((block[i] ^ mDash[j]) != 0)
				{
					ClearBlock(mDash);
					ClearBlock(block);
					return false;
				}
			}

			ClearBlock(mDash);
			ClearBlock(block);

			return true;
		}

        private void doTestSig(
			int					id,
			RsaKeyParameters	pub,
			RsaKeyParameters	prv,
			byte[]				slt,
			byte[]				msg,
			byte[]				sig)
        {
            PssSigner eng = new PssSigner(new RsaEngine(), new Sha1Digest(), 20);

            eng.Init(true, new ParametersWithRandom(prv, new FixedRandom(slt)));

            eng.BlockUpdate(msg, 0, msg.Length);

            byte[] s = eng.GenerateSignature();

            if (!AreEqual(s, sig))
            {
                Fail("test " + id + " failed generation");
            }

            eng.Init(false, pub);

            eng.BlockUpdate(msg, 0, msg.Length);

            if (!eng.VerifySignature(s))
            {
                Fail("test " + id + " failed verification");
            }
        }