twisted.conch.ssh.transport._MACParams(tuple) class documentation

_MACParams represents the parameters necessary to compute SSH MAC (Message Authenticate Codes).

_MACParams is a tuple subclass to maintain compatibility with older versions of the code. The elements of a _MACParams are:

   0. The digest object used for the MAC
   1. The inner pad ("ipad") string
   2. The outer pad ("opad") string
   3. The size of the digest produced by the digest object

_MACParams is also an object lesson in why tuples are a bad type for public APIs.