:mod:`md5` --- MD5 message digest algorithm

===========================================

.. module:: md5

   :synopsis: RSA's MD5 message digest algorithm.

   :deprecated:

.. deprecated:: 2.5

   Use the :mod:`hashlib` module instead.

.. index::

   single: message digest, MD5

   single: checksum; MD5

This module implements the interface to RSA's MD5 message digest  algorithm (see

also Internet :rfc:`1321`).  Its use is quite straightforward: use :func:`new`

to create an md5 object. You can now feed this object with arbitrary strings

using the :meth:`update` method, and at any point you can ask it for the

:dfn:`digest` (a strong kind of 128-bit checksum, a.k.a. "fingerprint") of the

concatenation of the strings fed to it so far using the :meth:`digest` method.

For example, to obtain the digest of the string ``'Nobody inspects the spammish

repetition'``:

   >>> import md5

   >>> m = md5.new()

   >>> m.update("Nobody inspects")

   >>> m.update(" the spammish repetition")

   >>> m.digest()

   '\xbbd\x9c\x83\xdd\x1e\xa5\xc9\xd9\xde\xc9\xa1\x8d\xf0\xff\xe9'

More condensed:

   >>> md5.new("Nobody inspects the spammish repetition").digest()

   '\xbbd\x9c\x83\xdd\x1e\xa5\xc9\xd9\xde\xc9\xa1\x8d\xf0\xff\xe9'

The following values are provided as constants in the module and as attributes

of the md5 objects returned by :func:`new`:

.. data:: digest_size

   The size of the resulting digest in bytes.  This is always ``16``.

The md5 module provides the following functions:

.. function:: new([arg])

   Return a new md5 object.  If *arg* is present, the method call ``update(arg)``

   is made.

.. function:: md5([arg])

   For backward compatibility reasons, this is an alternative name for the

   :func:`new` function.

An md5 object has the following methods:

.. method:: md5.update(arg)

   Update the md5 object with the string *arg*.  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:: md5.digest()

   Return the digest of the strings passed to the :meth:`update` method so far.

   This is a 16-byte string which may contain non-ASCII characters, including null

   bytes.

.. method:: md5.hexdigest()

   Like :meth:`digest` except the digest is returned as a string of length 32,

   containing only hexadecimal digits.  This may  be used to exchange the value

   safely in email or other non-binary environments.

.. method:: md5.copy()

   Return a copy ("clone") of the md5 object.  This can be used to efficiently

   compute the digests of strings that share a common initial substring.

.. seealso::

   Module :mod:`sha`

      Similar module implementing the Secure Hash Algorithm (SHA).  The SHA algorithm

      is considered a more secure hash.