docs: def rsa_check_base64_sign_str(self, cipher, sign, b64=True):
          """
              验证服务端数据 ``rsa`` 签名
  
          """
          with open(self.key_file) as fp:
              key_ = RSA.importKey(fp.read())
              v = pkcs.new(key_)
              sign = base64.b64decode(sign) if b64 else sign
              cipher = helper.to_bytes(cipher)
              # if hasattr(cipher, 'encode'):
              #     cipher = cipher.encode('utf-8')
              return v.verify(SHA.new(cipher), sign)