get_crypt.py

# coding: utf-8

import crypt
import ctypes
import ctypes.util
import sys


u'''\
残念なことに Python 3 の crypt.crypt は、引数が bytes ではなく unicode 文字列になっている。
Python 2 ならば そのまま crypt.crypt を使う。
Python 2 でないなら ctypes 経由で用意して返す。
引数は crypt((bytearray)word, (bytearray)salt)
'''


def get_crypt():
    if sys.version_info.major == 2:
        def crypt_(word, salt):
            return crypt.crypt(str(word), str(salt))
        return crypt_

    search_targets = ('libcrypt', 'libc')

    for c in search_targets:
        p = ctypes.util.find_library(c)
        if p is not None:
            break
    else:
        raise Exception('require crypt(3) library.')

    cryptlib = ctypes.CDLL(p)
    cryptlib.crypt.argtypes = (ctypes.c_char_p, ctypes.c_char_p)
    cryptlib.crypt.restype = ctypes.c_char_p
    def crypt_(word, salt):
        return cryptlib.crypt(bytes(word), bytes(salt))
    return crypt_

trip.py

# coding: utf-8

import crypt
import string
import unicodedata

import get_crypt


def trip(
    text,
    _crypt=get_crypt.get_crypt(),
    _salty=string.digits + string.ascii_letters + u'./'
):
    if isinstance(text, bytes):
        text = text.decode(u'utf8')
    text = unicodedata.normalize(u'NFC', text)

    word = bytearray((ord(char) & 255 | 128)
                     for char in text)[:13]
    salt = bytearray(ord(char) if char in _salty else ord(b'.')
                     for char in text + u'H.')[:2]
    return _crypt(word, salt)[3:]


def test():
    answer_pairs = (
        (b'', b'jPpg5.obl6'),
        (b'舞２４Ｃ送刀刀刀', b'mQDddDDDmE'),
        (b'刀刀刀刀ながい夜', b'HHHhHVDpfI'),
        (b'落ね刀★どてすぎ', b'stdioUH90w'),
        (b'test', b'0wLIpW0gyQ'),
    )
    for input_, result in answer_pairs:
        assert trip(input_) == result
        assert trip(input_.decode('utf8')) == result


if __name__ == '__main__':
    test()
    while True:
        try:
            text = raw_input()
        except EOFError:
            break
        print(trip(text))