Builds the Signature of the SAML Request.

        :param request_data: The Request parameters
        :type request_data: dict

        :param sign_algorithm: Signature algorithm method
        :type sign_algorithm: string

def add_request_signature(self, request_data, sign_algorithm=OneLogin_Saml2_Constants.RSA_SHA1):
        """
        Builds the Signature of the SAML Request.

        :param request_data: The Request parameters
        :type request_data: dict

        :param sign_algorithm: Signature algorithm method
        :type sign_algorithm: string
        """
        return self.__build_signature(request_data, 'SAMLRequest', sign_algorithm)