/// <summary>
        ///  Encrypt RestSharp request payloads.
        /// </summary>
        /// <param name="request">A RestSharp request object</param>
        public void InterceptRequest(IRestRequest request)
        {
            if (request == null)
            {
                throw new ArgumentNullException(nameof(request));
            }

            try
            {
                // Check request actually has a payload
                var bodyParam = request.Parameters.FirstOrDefault(param => param.Type == ParameterType.RequestBody);
                if (bodyParam == null)
                {
                    // Nothing to encrypt
                    return;
                }
                var payload = bodyParam.Value.ToString();
                if (string.IsNullOrEmpty(payload))
                {
                    // Nothing to encrypt
                    return;
                }

                // Encrypt fields & update headers
                string encryptedPayload;
                if (_config.UseHttpHeaders())
                {
                    // Generate encryption params and add them as HTTP headers
                    var parameters = FieldLevelEncryptionParams.Generate(_config);
                    UpdateRequestHeader(request, _config.IvHeaderName, parameters.IvValue);
                    UpdateRequestHeader(request, _config.EncryptedKeyHeaderName, parameters.EncryptedKeyValue);
                    UpdateRequestHeader(request, _config.EncryptionCertificateFingerprintHeaderName, _config.EncryptionCertificateFingerprint);
                    UpdateRequestHeader(request, _config.EncryptionKeyFingerprintHeaderName, _config.EncryptionKeyFingerprint);
                    UpdateRequestHeader(request, _config.OaepPaddingDigestAlgorithmHeaderName, parameters.OaepPaddingDigestAlgorithmValue);
                    encryptedPayload = FieldLevelEncryption.EncryptPayload(payload, _config, parameters);
                }
                else
                {
                    // Encryption params will be stored in the payload
                    encryptedPayload = FieldLevelEncryption.EncryptPayload(payload, _config);
                }

                // Update body and content length
                bodyParam.Value = encryptedPayload;
                UpdateRequestHeader(request, "Content-Length", encryptedPayload.Length);
            }
            catch (EncryptionException)
            {
                throw;
            }
            catch (Exception e)
            {
                throw new EncryptionException("Failed to intercept and encrypt request!", e);
            }
        }
        public void TestGenerate_Nominal()
        {
            // GIVEN
            var config = TestUtils.GetTestFieldLevelEncryptionConfigBuilder().Build();

            // WHEN
            var parameters = FieldLevelEncryptionParams.Generate(config);

            // THEN
            Assert.IsNotNull(parameters.IvValue);
            Assert.IsNotNull(parameters.GetIvBytes());
            Assert.IsNotNull(parameters.EncryptedKeyValue);
            Assert.IsNotNull(parameters.GetSecretKeyBytes());
            Assert.AreEqual("SHA256", parameters.OaepPaddingDigestAlgorithmValue);
        }
        /// <summary>
        /// Encrypt a RestSharp request payload.
        /// </summary>
        /// <param name="request">A RestSharp request object</param>
        /// <param name="payload">The payload to be encrypted</param>
        /// <returns>The encrypted payload</returns>
        internal override string EncryptPayload(IRestRequest request, string payload)
        {
            // Encrypt fields & update headers
            string encryptedPayload;

            if (_config.UseHttpHeaders())
            {
                // Generate encryption params and add them as HTTP headers
                var parameters = FieldLevelEncryptionParams.Generate(_config);
                UpdateRequestHeader(request, _config.IvHeaderName, parameters.IvValue);
                UpdateRequestHeader(request, _config.EncryptedKeyHeaderName, parameters.EncryptedKeyValue);
                UpdateRequestHeader(request, _config.EncryptionCertificateFingerprintHeaderName, _config.EncryptionCertificateFingerprint);
                UpdateRequestHeader(request, _config.EncryptionKeyFingerprintHeaderName, _config.EncryptionKeyFingerprint);
                UpdateRequestHeader(request, _config.OaepPaddingDigestAlgorithmHeaderName, parameters.OaepPaddingDigestAlgorithmValue);
                encryptedPayload = FieldLevelEncryption.EncryptPayload(payload.ToString(), _config, parameters);
            }
            else
            {
                // Encryption params will be stored in the payload
                encryptedPayload = FieldLevelEncryption.EncryptPayload(payload.ToString(), _config);
            }
            return(encryptedPayload);
        }