Enigma Machine Emulator in Python
For now, I am not going to translate this article into English because there are many web pages that explain the details about the Enigma machines in English.
The source code below might be uploaded to GitHub.
はじめに
第二次世界大戦中, ナチスドイツ軍が使用していた Enigma 暗号機のエミュレータを Python で書いた (書き直した).
以前のやつは継承とか使っていたが, バラバラにした.
Bombeを書こうと思い始めたので, リファクタリングになっているかわからないがリファクタした.
記事の最後にソースコードを置いてある.
オリジナルのリフレクタとロータの追加機能はまだテストしていない.
オリジナルのリフレクタとロータを動かせるようになった(たぶん).
Enigma に関する英語記事はたくさんあるが, 日本語ではほとんどない. ここで軽い解説を書こうと思う.
後で.
動作
この記事の最後にあるコードを実行すると次の結果が得られる.
test.py
動作確認.
$ python ./test.py
Enigma machine emulator version 1.4.8
Registered reflectors:
{
"A": "EJMZALYXVBWFCRQUONTSPIKHGD",
"B": "YRUHQSLDPXNGOKMIEBFZCWVJAT",
"C": "FVPJIAOYEDRZXWGCTKUQSBNMHL",
"B Thin": "ENKQAUYWJICOPBLMDXZVFTHRGS",
"C Thin": "RDOBJNTKVEHMLFCWZAXGYIPSUQ"
}
Registered rotors:
{
"I": "EKMFLGDQVZNTOWYHXUSPAIBRCJ",
"II": "AJDKSIRUXBLHWTMCQGZNPYFVOE",
"III": "BDFHJLCPRTXVZNYEIWGAKMUSQO",
"IV": "ESOVPZJAYQUIRHXLNFTGKDCMWB",
"V": "VZBRGITYUPSDNHLXAWMJQOFECK",
"VI": "JPGVOUMFYQBENHZRDKASXLICTW",
"VII": "NZJHGRCXMYSWBOUFAIVLPEKQDT",
"VIII": "FKQHTLXOCBJSPDZRAMEWNIUYGV",
"Beta": "LEYJVCNIXWPBQMDRTAKZGFUHOS",
"Gamma": "FSOKANUERHMBTIYCWLQPZXVGJD"
}
Registered plugboards:
{
"Plugs": "KHYDVGFBQRALPNSMIJOTZEWXCU"
}
wirings:
{
"reflector": {
"name": "C Thin",
"wiring": "RDOBJNTKVEHMLFCWZAXGYIPSUQ",
"pairs": {
"A": "R",
"B": "D",
"C": "O",
"E": "J",
"F": "N",
"G": "T",
"H": "K",
"I": "V",
"L": "M",
"P": "W",
"Q": "Z",
"S": "X",
"U": "Y"
}
},
"rotors": [
{
"name": "Gamma",
"wiring": "FSOKANUERHMBTIYCWLQPZXVGJD",
"turnover_position": [],
"initial_position": "T",
"ring_position": "M"
},
{
"name": "III",
"wiring": "BDFHJLCPRTXVZNYEIWGAKMUSQO",
"turnover_position": [
"V"
],
"initial_position": "P",
"ring_position": "S"
},
{
"name": "VIII",
"wiring": "FKQHTLXOCBJSPDZRAMEWNIUYGV",
"turnover_position": [
"Z",
"M"
],
"initial_position": "X",
"ring_position": "F"
},
{
"name": "II",
"wiring": "AJDKSIRUXBLHWTMCQGZNPYFVOE",
"turnover_position": [
"E"
],
"initial_position": "J",
"ring_position": "Z"
}
],
"plugboard": {
"name": "Plugs",
"wiring": "KHYDVGFBQRALPNSMIJOTZEWXCU",
"pairs": {
"A": "K",
"B": "H",
"C": "Y",
"E": "V",
"F": "G",
"I": "Q",
"J": "R",
"M": "P",
"O": "S",
"U": "Z"
}
},
"keeps_initial_state": false
}
initial positions of the rotors:
[
"T",
"P",
"X",
"J"
]
plain: I really don't know why it works.
formatted: IREALLYDONTKNOWWHYITWORKSX
encoded: NHTFFMGYHDEMIQUTGXQSMKBDHG
decoded: IREALLYDONTKNOWWHYITWORKSX
current positions of the rotors:
[
"T",
"P",
"Y",
"J"
]
original.py
オリジナルの設定ができる. 今回は3ロータで配線はランダムにしたので実行毎に結果が変わる.
$ ./original.py 3
wirings:
{
"reflector": {
"name": "original reflector",
"wiring": "PDTBJRNXOEYVWGIAUFZCQLMHKS",
"pairs": {
"E": "J",
"K": "Y",
"C": "T",
"Q": "U",
"M": "W",
"S": "Z",
"A": "P",
"F": "R",
"L": "V",
"G": "N",
"H": "X",
"I": "O",
"B": "D"
}
},
"rotors": [
{
"name": "original rotor 1",
"wiring": "IXROUDJVGEHKATFPZMBQSNWLCY",
"turnover_position": [
"A",
"X"
],
"initial_position": "A",
"ring_position": "E"
},
{
"name": "original rotor 2",
"wiring": "DQPWVZOYCBTHIMJSUFAERKNGLX",
"turnover_position": [
"D",
"W"
],
"initial_position": "Q",
"ring_position": "J"
},
{
"name": "original rotor 3",
"wiring": "HRCNFKAPYTQJSZUOXMGVDWBEIL",
"turnover_position": [
"Z",
"A"
],
"initial_position": "U",
"ring_position": "T"
}
],
"plugboard": {
"name": "original plugboard",
"wiring": "DYGAJRCIHETVWSXQPFNKZLMOBU",
"pairs": {
"F": "R",
"P": "Q",
"C": "G",
"K": "T",
"B": "Y",
"A": "D",
"E": "J",
"O": "X",
"M": "W",
"U": "Z",
"H": "I",
"L": "V",
"N": "S"
}
},
"keeps_initial_state": true
}
initial positions of the rotors:
[
"A",
"U",
"K"
]
plain: Ich weiss wirklich nicht, warum sie funktioniert.
formatted: ICHWEISSWIRKLICHNICHTWARUMSIEFUNKTIONIERTX
encoded: QNAIBHJYPTWZNUEPUYYIOKFUKTBYAUBIZMCNJMDDKV
decoded: ICHWEISSWIRKLICHNICHTWARUMSIEFUNKTIONIERTX
Source code
enigma/__init__.py
# -*- coding: utf-8 -*- """ Enigma machine emulator Copyright (C) 2017, 2018 Vanaestea Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. """ from . import component from . import emulator PROG_NAME = 'Enigma machine emulator' VERSION = '1.4.8' AUTHOR = 'Vanaestea' LICENSE = 'MIT'
enigma/component.py
# -*- coding: utf-8 -*- """ Enigma machine emulator Copyright (C) 2017, 2018 Vanaestea Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. """ from abc import ABC, abstractmethod from collections import Counter from operator import itemgetter import string _MOD_BASE = len(string.ascii_uppercase) class BaseComponent(ABC): _shifts_in = {} _shifts_out = {} _wirings = {} def __init__(self): self._name = None self._wiring = None self._shift_in = None self._shift_out = None @abstractmethod def _set_shifts(self): pass @abstractmethod def set(self): pass @abstractmethod def add(self): pass @abstractmethod def encode(self): pass @abstractmethod def decode(self): pass @property def wiring(self): return self._wiring @property def name(self): return self._name @classmethod def get_list(cls): return cls._wirings class Rotor(BaseComponent): _wirings = { 'I': 'EKMFLGDQVZNTOWYHXUSPAIBRCJ', 'II': 'AJDKSIRUXBLHWTMCQGZNPYFVOE', 'III': 'BDFHJLCPRTXVZNYEIWGAKMUSQO', 'IV': 'ESOVPZJAYQUIRHXLNFTGKDCMWB', 'V': 'VZBRGITYUPSDNHLXAWMJQOFECK', 'VI': 'JPGVOUMFYQBENHZRDKASXLICTW', 'VII': 'NZJHGRCXMYSWBOUFAIVLPEKQDT', 'VIII': 'FKQHTLXOCBJSPDZRAMEWNIUYGV', 'Beta': 'LEYJVCNIXWPBQMDRTAKZGFUHOS', 'Gamma': 'FSOKANUERHMBTIYCWLQPZXVGJD', } # A turnover position is one character ahead of the real one _turnovers = { 'I': (17,), # R 'II': (5,), # E 'III': (22,), # V 'IV': (10,), # J 'V': (0,), # Z 'VI': (0, 13), # Z+M 'VII': (0, 13), # Z+M 'VIII': (0, 13), # Z+M 'Beta': (), # nothing 'Gamma': (), # nothing } def __init__(self): super().__init__() self._turnover = None self._initial_shift = 0 self._shift = 0 self._ring = 0 self._fixed = False def _set_shifts(self, name): self._shifts_in[name] = tuple(ord(ch) - ord('A') for ch in self._wirings[self._name]) self._shifts_out[name] = tuple(i for i, _ in sorted(enumerate(self._shifts_in[name]), key=itemgetter(1))) def set_with_shift(self, name, initial_shift, ring): if name not in self._wirings or\ initial_shift < 0 or _MOD_BASE <= initial_shift or\ ring < 0 or _MOD_BASE <= ring: return False self._name = name if name not in self._shifts_in: self._set_shifts(name) self._shift_in = self._shifts_in[name] self._shift_out = self._shifts_out[name] self._wiring = self._wirings[name] self._turnover = self._turnovers[name] self._ring = ring self._shift = self._initial_shift = initial_shift self._fixed = True if len(self._turnover) == 0 else False return True def set(self, name, initial_position, ring_position): return self.set_with_shift(name, ord(initial_position) - ord('A'), ord(ring_position) - ord('A')) def add_with_shift(self, name, wiring, turnover): if name not in self._wirings and\ Counter(wiring) == Counter(string.ascii_uppercase): for idx in turnover: if idx < 0 or _MOD_BASE <= idx: break else: self._wirings[name] = wiring self._turnovers[name] = tuple(sorted((i + 1) % _MOD_BASE for i in turnover)) return True return False def add(self, name, wiring, turnover_position): return self.add_with_shift(name, wiring, tuple(ord(pos) - ord('A') for pos in turnover_position)) def encode(self, idx, shift, ring=0): return self._shift_in[(idx + self._shift - self._ring - shift + ring) % _MOD_BASE] def decode(self, idx, shift, ring=0): return self._shift_out[(idx + self._shift - self._ring - shift + ring) % _MOD_BASE] def reset(self): self._shift = self._initial_shift def step(self): if not self._fixed: self._shift = (self._shift + 1) % _MOD_BASE def on_turnover(self, next_to_fast=False): for idx in self._turnover: if next_to_fast: if (self._shift + 1) % _MOD_BASE == idx: break elif self._shift == idx: break else: return False return True @property def initial_shift(self): return self._initial_shift @initial_shift.setter def initial_shift(self, initial_shift): if 0 <= initial_shift < _MOD_BASE: self._initial_shift = initial_shift else: raise ValueError() @property def initial_position(self): return chr(self.initial_shift + ord('A')) @initial_position.setter def initial_position(self, initial_position): self.initial_shift = ord(initial_position) - ord('A') @property def shift(self): return self._shift @shift.setter def shift(self, shift): if 0 <= shift < _MOD_BASE: self._shift = shift else: raise ValueError() @property def position(self): return chr(self.shift + ord('A')) @position.setter def position(self, position): self.shift = ord(position) - ord('A') @property def ring(self): return self._ring @ring.setter def ring(self, ring): if 0 <= ring < _MOD_BASE: self._ring = ring else: raise ValueError() @property def ring_position(self): return chr(self.ring + ord('A')) @ring_position.setter def ring_position(self, ring_position): self.ring = ord(ring_position) - ord('A') # return the real turnover shift @property def turnover(self): return (self._turnover + _MOD_BASE - 1) % _MOD_BASE # return the real turnover position @property def turnover_position(self): return tuple(chr(ord('A') + (idx + _MOD_BASE - 1) % _MOD_BASE) for idx in self._turnover) @property def is_fixed(self): return self._fixed class PairwiseComponent(BaseComponent): _wirings_pairs = {} def __init__(self): super().__init__() self._pairs = None def _is_pairwise(self, pairs): s = set() t = set(string.ascii_uppercase) for k, v in pairs.items(): if k in s or k not in t: break s.add(k) if v in s or v not in t: break s.add(v) else: return True return False def _set_pairs(self, name): shifts = self._shifts_in[name] pairs = {} s = set() for i, e in enumerate(shifts): if i == e or i in s or e in s: continue pairs[chr(i + ord('A'))] = chr(e + ord('A')) s.add(i) s.add(e) self._wirings_pairs[name] = pairs def set(self, name): if name not in self._wirings: return False self._name = name self._wiring = self._wirings[name] if name not in self._shifts_in: self._set_shifts(name) self._shift_in = self._shifts_in[name] self._shift_out = self._shifts_out[name] if name not in self._wirings_pairs: self._set_pairs(name) self._pairs = self._wirings_pairs[name] return True def add(self, name, pairs): if name in self._wirings or not self._is_pairwise(pairs): return False self._wirings_pairs[name] = dict((k, v) if k < v else (v, k) for k, v in tuple(pairs.items())) a = list(string.ascii_uppercase) for k, v in self._wirings_pairs[name].items(): i = ord(k) - ord('A') j = ord(v) - ord('A') a[i], a[j] = a[j], a[i] self._wirings[name] = ''.join(a) return True @property def pairs(self): return self._pairs @classmethod def get_pairs_list(cls): return cls.pairs class Reflector(PairwiseComponent): _wirings = { 'A': 'EJMZALYXVBWFCRQUONTSPIKHGD', 'B': 'YRUHQSLDPXNGOKMIEBFZCWVJAT', 'C': 'FVPJIAOYEDRZXWGCTKUQSBNMHL', 'B Thin': 'ENKQAUYWJICOPBLMDXZVFTHRGS', 'C Thin': 'RDOBJNTKVEHMLFCWZAXGYIPSUQ', } def _set_shifts(self, name): self._shifts_in[name] = tuple(ord(ch) - ord('A') for ch in self._wirings[self._name]) self._shifts_out[name] = None def encode(self, idx, shift, ring=0): return self._shift_in[(idx - shift + ring) % _MOD_BASE] def decode(self, idx, shift, ring=0): return encode(idx, shift, ring) class Plugboard(PairwiseComponent): def _set_shifts(self, name): self._shifts_in[name] = tuple(ord(ch) - ord('A') for ch in self._wirings[name]) self._shifts_out[name] = tuple(i for i, _ in sorted(enumerate(self._shifts_in[name]), key=itemgetter(1))) def encode(self, idx): return self._shift_in[idx] def decode(self, idx, shift, ring=0): return self._shift_out[(idx - shift + ring) % _MOD_BASE]
enigma/emulator.py
# -*- coding: utf-8 -*- """ Enigma machine emulator Copyright (C) 2017, 2018 Vanaestea Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. """ from . import component import string class Enigma(object): def __init__(self, keeps_initial_state=True): self._reflector = component.Reflector() self._rotors = [] self._plugboard = component.Plugboard() self._keeps_initial_state = keeps_initial_state def set_reflector(self, name): return self._reflector.set(name) def add_reflector(self, name, wiring): return self._reflector.add(name, wiring) def append_rotor(self, name, initial_position='A', ring_position='A'): rotor = component.Rotor() if rotor.set(name, initial_position, ring_position): self._rotors.append(rotor) return True return False # deprecated def push_rotor(self, name, initial_position='A', ring_position='A'): self.append_rotor(name, initial_position, ring_position) def add_rotor(self, name, wiring, turnover=('A',)): rotor = component.Rotor() return rotor.add(name, wiring, turnover) def replace_rotor(self, index, name, initial_position='A', ring_position='A'): rotor = component.Rotor() if rotor.set(name, initial_position, ring_position): self._rotors[index] = rotor return True return False def insert_rotor(self, index, name, initial_position='A', ring_position='A'): rotor = component.Rotor() if rotor.set(name, initial_position, ring_position): self._rotors.insert(index, rotor) return True return False def clear_rotors(self): self._rotors.clear() def add_plugboard(self, name, pairs): return self._plugboard.add(name, pairs) def set_plugboard(self, name): return self._plugboard.set(name) def add_set_plugboard(self, name, pairs): if self._plugboard.add(name, pairs): return self._plugboard.set(name) return False def reset(self): for rotor in self._rotors: rotor.reset() def set_initial_positions(self, positions): positions = positions.upper() try: for rotor, pos in zip(self._rotors, positions): rotor.initial_position = pos except: return False self.reset() return True def is_text_valid(self, text): if set(text.upper()) <= set(string.ascii_uppercase): return True return False def encode(self, text): if self._keeps_initial_state: self.reset() text = text.upper() if not self.is_text_valid(text): raise ValueError('The text includes invalid characters') o = [] for ch in text: idx = ord(ch) - ord('A') # Step i = len(self._rotors) - 1 self._rotors[i].step() i -= 1 if i > 0 and (self._rotors[i + 1].on_turnover() or\ self._rotors[i].on_turnover(True)): self._rotors[i].step() while i > 0: if self._rotors[i].on_turnover(): i -= 1 self._rotors[i].step() else: break # Encode # Incoming e = self._plugboard.encode(idx) shift = 0 ring = 0 for rotor in reversed(self._rotors): e = rotor.encode(e, shift, ring) shift = rotor.shift ring = rotor.ring e = self._reflector.encode(e, shift, ring) # Outgoing shift = 0 ring = 0 for rotor in self._rotors: e = rotor.decode(e, shift, ring) shift = rotor.shift ring = rotor.ring e = self._plugboard.decode(e, shift, ring) o.append(chr(e + ord('A'))) return ''.join(o) def decode(self, text): return self.encode(text) def get_setting(self): return { 'reflector': { 'name': self._reflector.name, 'wiring': self._reflector.wiring, 'pairs': self._reflector.pairs }, 'rotors': tuple( { 'name': rotor.name, 'wiring': rotor.wiring, 'turnover_position': tuple(e for e in rotor.turnover_position), 'initial_position': rotor.initial_position, 'ring_position': rotor.ring_position, } for rotor in self._rotors ), 'plugboard': { 'name': self._plugboard.name, 'wiring': self._plugboard.wiring, 'pairs': self._plugboard.pairs, }, 'keeps_initial_state': self._keeps_initial_state, } def get_positions(self): return [rotor.position for rotor in self._rotors]
test.py
#!/usr/bin/env python3 # -*- coding: utf-8 -*- import enigma from enigma import emulator from enigma import component import json def main(): print('{} version {}'.format(enigma.PROG_NAME, enigma.VERSION)) print() e = emulator.Enigma(False) e.set_reflector('C Thin') e.append_rotor('Gamma', 'T', 'M') e.append_rotor('III', 'P', 'S') e.append_rotor('VIII', 'X', 'F') e.append_rotor('II', 'J', 'Z') e.add_set_plugboard('Plugs', {'A':'K', 'B':'H', 'C':'Y', 'E':'V', 'F':'G', 'I':'Q', 'J':'R', 'M':'P', 'O':'S', 'U':'Z'}) print('Registered reflectors:') print(json.dumps(component.Reflector.get_list(), indent=4)) print('Registered rotors:') print(json.dumps(component.Rotor.get_list(), indent=4)) print('Registered plugboards:') print(json.dumps(component.Plugboard.get_list(), indent=4)) print() print('wirings:') print(json.dumps(e.get_setting(), indent=4)) print() print('initial positions of the rotors:') print(json.dumps(e.get_positions(), indent=4)) print() plain = "I really don't know why it works." formatted = plain.replace(' ', '').replace("'", '').replace('.', 'X').upper() encoded = e.encode(formatted) e.reset() decoded = e.decode(encoded) print('plain: {}'.format(plain)) print('formatted: {}'.format(formatted)) print('encoded: {}'.format(encoded)) print('decoded: {}'.format(decoded)) print() print('current positions of the rotors:') print(json.dumps(e.get_positions(), indent=4)) if __name__ == '__main__': main()
original.py
#!/usr/bin/env python3 # -*- coding: utf-8 -*- import sys import json from random import choice, shuffle from string import ascii_uppercase from enigma import emulator def main(): if len(sys.argv) != 2: sys.exit() n = int(sys.argv[1]) e = emulator.Enigma() a = list(ascii_uppercase) shuffle(a) e.add_reflector('original reflector', {a:b for a, b in zip(a[0::2], a[1::2])}) e.set_reflector('original reflector') shuffle(a) e.add_set_plugboard('original plugboard', {a:b for a, b in zip(a[0::2], a[1::2])}) for i in range(n): name = 'original rotor {}'.format(i + 1) shuffle(a) e.add_rotor(name, ''.join(a), tuple(set((choice(a), choice(a))))) e.append_rotor(name, choice(a), choice(a)) plain = 'Ich weiss wirklich nicht, warum sie funktioniert.' formatted = plain.replace(' ', '').replace(',', '').replace('.', 'X').upper() enc = e.encode(formatted) dec = e.decode(enc) print('wirings:') print(json.dumps(e.get_setting(), indent=4)) print() print('initial positions of the rotors:') print(json.dumps(e.get_positions(), indent=4)) print() print('plain: {}'.format(plain)) print('formatted: {}'.format(formatted)) print('encoded: {}'.format(enc)) print('decoded: {}'.format(dec)) if __name__ == '__main__': main()
