8i$ d Z ddlZ ddlZej Z eej ZddlZ e d ed D Z e d ed D ZdZ G d d Zdd Zd Zy# e $ r dZdZddl mZ Y Sw xY w)zqHMAC (Keyed-Hashing for Message Authentication) module. Implements the HMAC algorithm as described by RFC 2104. N)_compare_digestc # &