Edit File: hmac.txt
:mod:`hmac` --- Keyed-Hashing for Message Authentication ======================================================== .. module:: hmac :synopsis: Keyed-Hashing for Message Authentication (HMAC) implementation for Python. .. moduleauthor:: Gerhard Häring <ghaering@users.sourceforge.net> .. sectionauthor:: Gerhard Häring <ghaering@users.sourceforge.net> .. versionadded:: 2.2 **Source code:** :source:`Lib/hmac.py` -------------- This module implements the HMAC algorithm as described by :rfc:`2104`. .. function:: new(key[, msg[, digestmod]]) Return a new hmac object. If *msg* is present, the method call ``update(msg)`` is made. *digestmod* is the digest constructor or module for the HMAC object to use. It defaults to the :func:`hashlib.md5` constructor. An HMAC object has the following methods: .. method:: HMAC.update(msg) Update the hmac object with the string *msg*. Repeated calls are equivalent to a single call with the concatenation of all the arguments: ``m.update(a); m.update(b)`` is equivalent to ``m.update(a + b)``. .. method:: HMAC.digest() Return the digest of the strings passed to the :meth:`update` method so far. This string will be the same length as the *digest_size* of the digest given to the constructor. It may contain non-ASCII characters, including NUL bytes. .. method:: HMAC.hexdigest() Like :meth:`digest` except the digest is returned as a string twice the length containing only hexadecimal digits. This may be used to exchange the value safely in email or other non-binary environments. .. method:: HMAC.copy() Return a copy ("clone") of the hmac object. This can be used to efficiently compute the digests of strings that share a common initial substring. .. seealso:: Module :mod:`hashlib` The Python module providing secure hash functions.