/Doc/library/md5.rst
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- :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.