code: def check_sha(self, sha, content):
          
          rightful_sha = sha256(bytes("{}{}".format(content, self.secret), "utf-8")).hexdigest()
          return sha == rightful_sha
docs: Check sent sha against the salted hash of the content
  
          :param sha: SHA sent through fproxy-secure-hash header
          :param content: Base 64 encoded Content
          :return: Boolean indicating equality