/// <summary> /// Add a signature to a Hash of parameters. The signature will be generated /// from the app secret and the provided parameters, and should be used /// whenever signed data needs to be sent to GoCardless (e.g. when creating /// a new subscription). The signature will be added to the hash under the /// key signature. /// </summary> /// <param name="params">the parameters to sign</param> /// <returns>the parameters with the new signature key</returns> private static Utils.HashParams SignParams(Utils.HashParams @params) { var signature = Utils.GetSignatureForParams(@params, GoCardless.AccountDetails.AppSecret); @params.Add("signature", signature); return @params; }