def add_request_signature(self, request_data, sign_algorithm=OneLogin_Saml2_Constants.RSA_SHA1):
return self.__build_signature(request_data, '<STR_LIT>', sign_algorithm)<EOL>
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