public void Test_SHA1withRSA_Sign_Verify()
        {
            string content = @"Hello World";

            byte[] buffer = Encoding.UTF8.GetBytes(content);

            string signature = SHA1withRSA.Sign(RSAPrivateKeyXmlString, buffer);
            bool   verified  = SHA1withRSA.Verify(RSAPublicKeyXmlString, buffer, signature);

            Assert.IsTrue(verified);
        }
        public static bool Test_SHA1withRSA_Sign_Verify_With_DotNet(
            string privateKeyXmlString, string publicKeyXmlString)
        {
            string content = @"Hello World";

            byte[] buffer = Encoding.UTF8.GetBytes(content);

            string signature = SHA1withRSA.Sign(privateKeyXmlString, buffer);
            bool   verified  = SHA1withRSA.Verify(publicKeyXmlString, buffer, signature);

            return(verified);
        }
        public static bool Test_SHA1withRSA_Sign_With_DotNet_Then_Verify_With_BouncyCastle(
            string privateKeyXmlString, RsaKeyParameters rsaPublic)
        {
            string content = @"Hello World";

            byte[] buffer = Encoding.UTF8.GetBytes(content);

            string signature = SHA1withRSA.Sign(privateKeyXmlString, buffer);

            var signer = SignerUtilities.GetSigner(@"SHA-1withRSA");

            signer.Init(false, rsaPublic);
            signer.BlockUpdate(buffer, 0, buffer.Length);

            byte[] signedHash = Convert.FromBase64String(signature);
            bool   verified   = signer.VerifySignature(signedHash);

            return(verified);
        }