crypt, pwd, getpass - Understand by quick example

crypt_getpass_pwd.py

#!/usr/bin/python

import crypt, getpass, pwd

def main():
    print "##### This programs helps to understand the username/password storage in Operating System #######\n"
    username = raw_input('Python login:')
    try:
        cryptedpasswd = pwd.getpwnam(username).pw_passwd
    except KeyError:
        print "Sorry user name not found"
        return 0
    except exception as er:
        print "Exception: "+str(er)
        return 0

    if cryptedpasswd:
        if 'x' in cryptedpasswd or '*' in cryptedpasswd:
            raise NotImplementedError("Sorry, currently no support for shadow passwords")

        cleartext = getpass.getpass()
        print "salted value: "+str(crypt.crypt(cleartext, cryptedpasswd))
        return crypt.crypt(cleartext, cryptedpasswd) == cryptedpasswd
    else:
        return 1



if __name__ == "__main__":
    try:
        main()
    except NotImplementedError:
        print "Sorry, currently no support for shadow passwords"