96 lines
2.7 KiB
ReStructuredText
96 lines
2.7 KiB
ReStructuredText
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:mod:`md5` --- MD5 message digest algorithm
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===========================================
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.. module:: md5
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:synopsis: RSA's MD5 message digest algorithm.
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.. deprecated:: 2.5
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Use the :mod:`hashlib` module instead.
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.. index::
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single: message digest, MD5
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single: checksum; MD5
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This module implements the interface to RSA's MD5 message digest algorithm (see
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also Internet :rfc:`1321`). Its use is quite straightforward: use :func:`new`
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to create an md5 object. You can now feed this object with arbitrary strings
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using the :meth:`update` method, and at any point you can ask it for the
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:dfn:`digest` (a strong kind of 128-bit checksum, a.k.a. "fingerprint") of the
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concatenation of the strings fed to it so far using the :meth:`digest` method.
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For example, to obtain the digest of the string ``'Nobody inspects the spammish
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repetition'``::
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>>> import md5
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>>> m = md5.new()
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>>> m.update("Nobody inspects")
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>>> m.update(" the spammish repetition")
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>>> m.digest()
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'\xbbd\x9c\x83\xdd\x1e\xa5\xc9\xd9\xde\xc9\xa1\x8d\xf0\xff\xe9'
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More condensed::
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>>> md5.new("Nobody inspects the spammish repetition").digest()
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'\xbbd\x9c\x83\xdd\x1e\xa5\xc9\xd9\xde\xc9\xa1\x8d\xf0\xff\xe9'
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The following values are provided as constants in the module and as attributes
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of the md5 objects returned by :func:`new`:
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.. data:: digest_size
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The size of the resulting digest in bytes. This is always ``16``.
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The md5 module provides the following functions:
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.. function:: new([arg])
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Return a new md5 object. If *arg* is present, the method call ``update(arg)``
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is made.
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.. function:: md5([arg])
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For backward compatibility reasons, this is an alternative name for the
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:func:`new` function.
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An md5 object has the following methods:
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.. method:: md5.update(arg)
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Update the md5 object with the string *arg*. Repeated calls are equivalent to a
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single call with the concatenation of all the arguments: ``m.update(a);
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m.update(b)`` is equivalent to ``m.update(a+b)``.
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.. method:: md5.digest()
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Return the digest of the strings passed to the :meth:`update` method so far.
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This is a 16-byte string which may contain non-ASCII characters, including null
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bytes.
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.. method:: md5.hexdigest()
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Like :meth:`digest` except the digest is returned as a string of length 32,
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containing only hexadecimal digits. This may be used to exchange the value
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safely in email or other non-binary environments.
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.. method:: md5.copy()
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Return a copy ("clone") of the md5 object. This can be used to efficiently
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compute the digests of strings that share a common initial substring.
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.. seealso::
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Module :mod:`sha`
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Similar module implementing the Secure Hash Algorithm (SHA). The SHA algorithm
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is considered a more secure hash.
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