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+
+:mod:`crypt` --- Function to check Unix passwords
+=================================================
+
+.. module:: crypt
+   :platform: Unix
+   :synopsis: The crypt() function used to check Unix passwords.
+.. moduleauthor:: Steven D. Majewski <sdm7g@virginia.edu>
+.. sectionauthor:: Steven D. Majewski <sdm7g@virginia.edu>
+.. sectionauthor:: Peter Funk <pf@artcom-gmbh.de>
+
+
+.. index::
+   single: crypt(3)
+   pair: cipher; DES
+
+This module implements an interface to the :manpage:`crypt(3)` routine, which is
+a one-way hash function based upon a modified DES algorithm; see the Unix man
+page for further details.  Possible uses include allowing Python scripts to
+accept typed passwords from the user, or attempting to crack Unix passwords with
+a dictionary.
+
+.. index:: single: crypt(3)
+
+Notice that the behavior of this module depends on the actual implementation  of
+the :manpage:`crypt(3)` routine in the running system.  Therefore, any
+extensions available on the current implementation will also  be available on
+this module.
+
+
+.. function:: crypt(word, salt)
+
+   *word* will usually be a user's password as typed at a prompt or  in a graphical
+   interface.  *salt* is usually a random two-character string which will be used
+   to perturb the DES algorithm in one of 4096 ways.  The characters in *salt* must
+   be in the set ``[./a-zA-Z0-9]``.  Returns the hashed password as a string, which
+   will be composed of characters from the same alphabet as the salt (the first two
+   characters represent the salt itself).
+
+   .. index:: single: crypt(3)
+
+   Since a few :manpage:`crypt(3)` extensions allow different values, with
+   different sizes in the *salt*, it is recommended to use  the full crypted
+   password as salt when checking for a password.
+
+A simple example illustrating typical use::
+
+   import crypt, getpass, pwd
+
+   def raw_input(prompt):
+       import sys
+       sys.stdout.write(prompt)
+       sys.stdout.flush()
+       return sys.stdin.readline()
+
+   def login():
+       username = raw_input('Python login:')
+       cryptedpasswd = pwd.getpwnam(username)[1]
+       if cryptedpasswd:
+           if cryptedpasswd == 'x' or cryptedpasswd == '*': 
+               raise "Sorry, currently no support for shadow passwords"
+           cleartext = getpass.getpass()
+           return crypt.crypt(cleartext, cryptedpasswd) == cryptedpasswd
+       else:
+           return 1
+