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Diffstat (limited to 'lc4.py')
| -rw-r--r-- | lc4.py | 493 |
1 files changed, 0 insertions, 493 deletions
@@ -1,493 +0,0 @@ -#!/usr/bin/python2 -# -*- coding: utf-8 -*- -# This software is hereby released into public domain. Use it wisely. -# -# ElsieFour (LC4) and its enhancement LS47 -# version 2.8.1 (2018-07-24) -# -# Original paper by Alan Kaminsky: https://eprint.iacr.org/2017/339.pdf -# Original LC4 Java source: https://www.cs.rit.edu/~ark/parallelcrypto/elsiefour/ -# -# - Python 2 script for LS47 originally written by Mirek Kratochvil (2017) -# See https://gitea.blesmrt.net/exa/ls47 -# - Python 3 port by Bernhard Esslinger / AK (Feb 2018) -# See www.mysterytwisterc3.org -# - New options by CrypTool project (www.cryptool.org) (Feb 2018) in order to -# support both ciphers LC4 and LS47 in one program, to support both ways to -# deal with nonces and keywords, to support reading from file and commandline, -# and to extend test outputs (v2.7). -# - v2.8 extended the testcase and added the fix of the fixpoint-ish problem for ls47 (option -m1): -# python lc4.py -6 -ws thisismysecretkey -es ############## -ns igxf5e -m1 -# igxf5egcyhoo#ny#o5i5 -# python lc4.py -6 -ws thisismysecretkey -es ############## -ns igxf5e -m0 -# igxf5e############## -# -# Sample calls: -# -# 1) Using cipher LC4, enforced with option -6: -# // encrypt (key, message). Following example returns tk5j23tq94_gw9c#lhzs -# python lc4.py -6 -ks s2ferw_nx346ty5odiupq#lmz8ajhgcvk79b -es aaaaaaaaaaaaaaaaaaaa -# // decrypt (key, message). Following example returns aaaaaaaaaaaaaaaaaaaa -# python lc4.py -6 -ks s2ferw_nx346ty5odiupq#lmz8ajhgcvk79b -ds tk5j23tq94_gw9c#lhzs -# python lc4.py -6 -ws thisismysecretkey -es its_my_fathers_son_but_not_my_brother -# python lc4.py -6 -ws thisismysecretkey -ds 6dudfy3u7omoxy4jbscgn37c2se_d8gx6ogk9 -# python lc4.py -6 -ws thisismysecretkey -es its_my_fathers_son_but_not_my_brother -v -nl 6 -# python lc4.py -6 -ws thisismysecretkey -ds q6xojffkncfyz#f5czs49#3mbsco#2iscvbnm#bymaf -v -nl 6 -# -# 2) Using cipher LS47, enforced with option -7: -# python lc4.py -7 -ws s3cret_p4ssw0rd/31337 -es conflagrate_the_rose_bush_at_six!---peace-vector-3 -v -ns 8y(l._4ct' -m0 -# python lc4.py -7 -ws s3cret_p4ssw0rd/31337 -ds y'zbvvs+d2,ky4sy?w(_wkz*7'90v:./s)kcz?mj+gyu8-'h(y,i+v,z+1ws -v -nl 10 -m0 -# python lc4.py -7 -ws s3cret_p4ssw0rd/31337 -ds y'zbvvs+d2,ky4sy?w(_wkz*7'90v:./s)kcz?mj+gyu8-'h(y,i+v,z+1ws -v -ns 8y(l._4ct' -m0 -# -# 3) Using the automatic test (option -t can be combined with options -s and -ws) -# python lc4.py -t -# python lc4.py -t -ws s3cret_p4sswxyz -s peacevector_34 - - -from __future__ import print_function -import sys -import os -import random -import argparse - - -version = "v2.8.1 (2018-07-24)" - -# define alphabet -letters6 = "#_23456789abcdefghijklmnopqrstuvwxyz" -letters6card = "abcdefghijklmnopqrstuvwxyz_23456789#" -letters7 = "_abcdefghijklmnopqrstuvwxyz.,:?!'()0123456789+-*/" -letters7card = "abcdefghijklmnopqrstuvwxyz_.,-+*/:?!'()1234567890" - - -def missing_letters(s,t): - return ''.join(sorted(set(c for c in s if c not in t))) - - -def check_key(key): - illegal = missing_letters(key,letters) - missing = missing_letters(letters,key) - duplicates = ''.join(sorted(c for c in letters if key.count(c)>1)) - - errors = [] - if illegal: errors.append( "Key contains illegal letters: '%s'" % illegal ) - if missing: errors.append( "Key misses some letters: '%s'" % missing ) - if duplicates: errors.append( "Key contains duplicate letters: '%s'" % duplicates ) - - if errors: - errors.append( "The key must be a permutation of the alphabet: %s" % letters ) - raise ValueError("\n".join(errors)) - - -def check_nonce(nonce): - illegal = missing_letters(nonce,letters) - if illegal: - raise ValueError("Nonce contains illegal letters: '%s'" % illegal) - - -def check_plaintext(s): - illegal = missing_letters(s,letters) - if illegal: - raise ValueError("Plaintext contains illegal letters: '%s'" % illegal) - - -def check_ciphertext(s): - illegal = missing_letters(s,letters) - if illegal: - raise ValueError("Ciphertext contains illegal letters: '%s'" % illegal) - - -def find_ix(letter): - m = [l[1] for l in tiles if l[0] == letter] - if len(m) != 1: - raise ValueError("Letter '%c' not in the alphabet!" % letter) - return m[0] - - -def find_pos(key, letter): - p = key.find(letter) - if not (0 <= p < size * size): - raise ValueError("Letter '%c' not in key?!" % letter) - return (p // size, p % size) - - -def add_pos(a, b): - return ((a[0] + b[0]) % size, (a[1] + b[1]) % size) - - -def sub_pos(a, b): - return ((a[0] - b[0]) % size, (a[1] - b[1]) % size) - - -def find_at_pos(key, coord): - return key[coord[1] + coord[0] * size] - - -def rotate_right(key, row, n): - mid = key[size * row:size * (row + 1)] - return key[:size * row] + mid[-n:] + mid[:-n] + key[size * (row + 1):] - - -def rotate_down(key, col, n): - lines = [key[i * size:(i + 1) * size] for i in range(size)] - lefts = [l[:col] for l in lines] - mids = [l[col] for l in lines] - rights = [l[col + 1:] for l in lines] - mids = mids[-n:] + mids[:-n] - return ''.join(lefts[i] + mids[i] + rights[i] for i in range(size)) - - -def rotate_marker_right(m, row, n): - if m[0] != row: - return (m[0], m[1]) - else: - return (m[0], (m[1] + n) % size) - - -def rotate_marker_down(m, col, n): - if m[1] != col: - return (m[0], m[1]) - else: - return ((m[0] + n) % size, m[1]) - - -def derive_key(password, one_indexed): - i = 0 - k = letters - # if using one-indexed arrays, moves the zero element to the end - if one_indexed: k = k[1:]+k[0] - for c in password: - (row, col) = find_ix(c) - k = rotate_down(rotate_right(k, i, col), i, row) - i = (i + 1) % size - return k - - -def encrypt(plaintext): - global key, mp - - ciphertext = '' - for p in plaintext: - pp = find_pos(key, p) - mix = find_ix(find_at_pos(key, mp)) - cp = add_pos(pp, mix) - c = find_at_pos(key, cp) - ciphertext += c - - key = rotate_right(key, pp[0], 1) - if marker_mode==1: mp = rotate_marker_right(mp, pp[0], 1) - cp = find_pos(key, c) - key = rotate_down(key, cp[1], 1) - if marker_mode==1: mp = rotate_marker_down(mp, cp[1], 1) - mp = add_pos(mp, find_ix(c)) - return ciphertext - - -def decrypt(ciphertext): - global key, mp - - plaintext = '' - for c in ciphertext: - cp = find_pos(key, c) - mix = find_ix(find_at_pos(key, mp)) - pp = sub_pos(cp, mix) - p = find_at_pos(key, pp) - plaintext += p - - key = rotate_right(key, pp[0], 1) - if marker_mode==1: mp = rotate_marker_right(mp, pp[0], 1) - cp = find_pos(key, c) - key = rotate_down(key, cp[1], 1) - if marker_mode==1: mp = rotate_marker_down(mp, cp[1], 1) - mp = add_pos(mp, find_ix(c)) - return plaintext - - -def create_random_nonce(size): - return ''.join(random.choice(letters) for i in range(size)) - - -def encrypt_with_nonce(plaintext): - global nonce, nonce_enc - - ciphertext = encrypt(nonce + plaintext) - nonce_enc = ciphertext[:nonce_size] - - if nonce_mode==1: - return nonce + ciphertext[nonce_size:] - else: - return ciphertext - - -def decrypt_with_nonce(ciphertext): - global nonce, nonce_enc - - if nonce_mode==1: - nonce = ciphertext[:nonce_size] - nonce_enc = encrypt(nonce) - return decrypt(ciphertext[nonce_size:]) - else: - plaintext = decrypt(ciphertext) - nonce = plaintext[:nonce_size] - nonce_enc = ciphertext[:nonce_size] - return plaintext[nonce_size:] - - -def eprint(*args, **kwargs): - print(*args, file=sys.stderr, **kwargs) - - -def printinfo(enc=False): # used by test1() and when option -v - eprint('CIPHER : ' + ("LC4" if size==6 else "LS47")) - eprint('ALPHABET : ' + letters) - if szkeyword: - eprint('KEYWORD : ' + szkeyword) - eprint('KEY : ' + initialkey) # key variable modified during process? - eprint('NONCE : ' + nonce) - eprint('NONCE ENC : ' + nonce_enc) - eprint('NONCEMODE : ' + ("Kaminsky" if nonce_mode==1 else "Kratochvil")) - eprint('MARKER : ' + ("Kaminsky" if marker_mode==1 else "Kratochvil")) - if enc: - # if args.signature: print ("args.SIGNA:", args.signature) - if szsignature: print ("SIGNATURE: ", szsignature) - eprint('PLAINTEXT : ' + plaintext) - eprint('CIPHERTEXT: ' + ciphertext) - else: - eprint('CIPHERTEXT: ' + ciphertext) - eprint('PLAINTEXT : ' + plaintext) - - -def test1(size, fixednonce): - # Declaration "global" only needed if you like to write to a global variable - # [here, this is necessary only if the global var. is used within a fct. called by test1()] - # As test1() is called several times don't change args components within this fct. - global letters, nonce_mode, marker_mode, tiles, noncelen, nonce, nonce_size, nonce_enc - global ciphertext, plaintext, key, initialkey, mp - global szkeyword, szsignature - - if size == 7: - CIPHERNAME = "LS47" - letters = letters7 - nonce_mode = 2 - marker_mode = 2 - if fixednonce == 0: - noncelen=10; nonce = create_random_nonce(noncelen) - else: - nonce = 'dr0+:_pij2' # just a sample for testing fixed nonce - else: - CIPHERNAME = "LC4" - letters = letters6 - nonce_mode = 1 - marker_mode = 1 - if fixednonce == 0: - noncelen=6; nonce = create_random_nonce(noncelen) - else: - nonce = 'pjpm5i' # just a sample for testing fixed nonce - - tiles = list(zip(letters, [(x // size, x % size) for x in range(size * size)])) - check_nonce(nonce) - nonce_size = len(nonce) - nonce_enc = "" - - print('\n' + CIPHERNAME) - - if size == 7: - if args.keywordstring: - keyword = args.keywordstring # Allows to use -ws besides -t - else: - keyword = 's3cret_p4ssw0rd/31337' - szkeyword = keyword # This statement needed to show keyword in printinfo() [don't change args.keywordstring within test1()!] - key = derive_key(keyword, false) - else: - key = letters - initialkey = key - check_key(key) - mp = (0, 0) - - if size == 7: - # signature = 'peace-vector-3' # just to name a meaningful value for size=7 - plaintext = 'conflagrate_the_rose_bush_at_six!' - if szsignature: plaintext += szsignature - else: - # signature = '#its_me' # Notice: with size=6 the chars "#", "0", "1", "-" aren't part of the alphabet - plaintext = 'its_my_fathers_son_but_not_my_brother' - if szsignature: plaintext += szsignature - - check_plaintext(plaintext) - ciphertext = encrypt_with_nonce(plaintext) - - key = initialkey; mp = (0, 0) # initialization again - check_ciphertext(ciphertext) - decryptedtext = decrypt_with_nonce(ciphertext) - print('decrypted text: ' + decryptedtext) - - printinfo(True) # Called from test1() with arg TRUE = assume to do decryption - - szkeyword='' - - - -if __name__ == '__main__': - - parser = argparse.ArgumentParser() # how to enforce, that (either no arg), (or only one arg -t, -v), (or give key and enc mode) - - parser.add_argument("-v", "--verbose", help="output additional information on stderr", action="count", default=0) - - mgroup1 = parser.add_mutually_exclusive_group() - mgroup1.add_argument("-6", "--lc4", help="use ElsieFour cipher (6x6 table) (default)", action="store_true") - mgroup1.add_argument("-7", "--ls47", help="use LS47 cipher (7x7 table)", action="store_true") - - parser.add_argument("-pc", "--playingcard", help="Use the \"playing card\" character tables (default: standard tables)", action="store_true") - - mgroup2 = parser.add_mutually_exclusive_group() - mgroup2.add_argument("-ks", "--keystring", metavar="STRING", help="use STRING as key") - mgroup2.add_argument("-kf", "--keyfile", metavar="FILE", help="read key from FILE") - mgroup2.add_argument("-ws", "--keywordstring", metavar="STRING", help="generate key from keyword STRING", default=None) - mgroup2.add_argument("-wf", "--keywordfile", metavar="FILE", help="read keyword from FILE to generate key", default=None) - - mgroup4 = parser.add_mutually_exclusive_group() - mgroup4.add_argument("-es", "--encryptstring", metavar="STRING", help="encrypt STRING") - mgroup4.add_argument("-ef", "--encryptfile", metavar="FILE", help="read plaintext from FILE and encrypt it") - mgroup4.add_argument("-ds", "--decryptstring", metavar="STRING", help="decrypt STRING") - mgroup4.add_argument("-df", "--decryptfile", metavar="FILE", help="read ciphertext from FILE and decrypt it") - mgroup4.add_argument("-t", "--test", help="encrypt and decrypt a string with a given key (with LC4, the given key equals the alphabet). Four cases tested: random/fixed nonce, each with LC4 and LS47", action="store_true") - - mgroup3 = parser.add_mutually_exclusive_group() - mgroup3.add_argument("-nl", "--noncelen", metavar="LENGTH", help="use random nonce of length LENGTH (default: no nonce)", type=int, default=0) - mgroup3.add_argument("-ns", "--noncestring", metavar="STRING", help="use STRING as nonce (default: no nonce)") - - mgroup5 = parser.add_mutually_exclusive_group() - mgroup5.add_argument("-n0", "--nKaminsky", help="use nonce in Kaminsky mode (default for LC4)", action="store_true") - mgroup5.add_argument("-n1", "--nKratochvil", help="use nonce in Kratochvil mode (default for LS47)", action="store_true") - - mgroup6 = parser.add_mutually_exclusive_group() - mgroup6.add_argument("-m0", "--mKaminsky", help="use marker in Kaminsky mode (default for LC4)", action="store_true") - mgroup6.add_argument("-m1", "--mKratochvil", help="use marker in Kratochvil mode (default for LS47)", action="store_true") - - - parser.add_argument("-s", "--signature", help="append SIGNATURE to plaintext when encrypting (default: no signature)") - - args = parser.parse_args() - - if len(sys.argv)==1: - parser.print_help() - sys.exit(1) - if args.verbose and len(sys.argv)==2: - print('Version: ' + version) - # parser.print_help() - sys.exit(1) - - # set cipher - - if args.ls47: - size = 7 - if args.playingcard: - letters = letters7card - else: - letters = letters7 - else: - size = 6 - if args.playingcard: - letters = letters6card - else: - letters = letters6 - - tiles = list(zip(letters, [(x // size, x % size) for x in range(size * size)])) - - # set nonce - - if args.noncestring: - nonce = args.noncestring - elif args.noncelen: - nonce = create_random_nonce(args.noncelen) - else: - nonce = "" - - check_nonce(nonce) - nonce_size = len(nonce) - nonce_enc = "" - - # set nonce mode - - nonce_mode = 1 if size==6 else 2 - if args.nKaminsky: nonce_mode = 1 - if args.nKratochvil: nonce_mode = 2 - - # set marker mode - - marker_mode = 1 if size==6 else 2 - if args.mKaminsky: marker_mode = 1 - if args.mKratochvil: marker_mode = 2 - - # set key - - key = letters - - # helper variables for verbose printing via printinfo() - - szkeyword = '' # global variable which can be changed in test1() [so it can be used as test condition in printinfo() instead of args.keywordstring and instead of test1() manipulating args.keywordstring] - szsignature = '' # global variable which can be changed in test1() [so it can be used as test condition in printinfo() instead of args.keywordstring and instead of test1() manipulating args.keywordstring]. # Allows to use -s besides -t - - if args.signature: # This case here is only necessary if -s should be used together with -t - szsignature = args.signature - - - if args.keywordfile: args.keywordstring = open(args.keywordfile, 'r').read().rstrip('\r\n') - if args.keywordstring: - szkeyword = args.keywordstring - key = derive_key(args.keywordstring, args.playingcard) - - if args.keyfile: args.keystring = open(args.keyfile, 'r').read().rstrip('\r\n') - if args.keystring: key = args.keystring; - - initialkey = key - check_key(key) - - mp = (0, 0) - - # encrypt / decrypt / test - - if args.encryptfile: - args.encryptstring = open(args.encryptfile, 'r').read().rstrip('\r\n') - - if args.decryptfile: - args.decryptstring = open(args.decryptfile, 'r').read().rstrip('\r\n') - - if args.encryptstring: - plaintext = args.encryptstring - if args.signature: - plaintext += args.signature - check_plaintext(plaintext) - ciphertext = encrypt_with_nonce(plaintext) - if args.verbose: - printinfo(True) - else: - print(ciphertext) - - elif args.decryptstring: - ciphertext = args.decryptstring - check_ciphertext(ciphertext) - plaintext = decrypt_with_nonce(ciphertext) - if args.signature and args.verbose: - eprint("--Warning--: the given signature is ignored during decryption") - # Maybe later return result of a check whether given signature equals the end of the decrypted string. - if args.verbose: - printinfo() - else: - print(plaintext) - - elif args.test: - print('\nVersion: ' + version) - print('\n---Test: No nonce provided (only its length), so each call will produce a different ciphertext.') - size = 7; test1(size, 0) - size = 6; test1(size, 0) - print('\n---Test: Nonce provided as string.') - size = 7; test1(size, 1) - size = 6; test1(size, 1) - sys.exit(1) - - else: # you'll never get here (handled via argparse) - # if args.verbose: print('Version : ' + version) - print('ALPHABET : ' + letters) - print('KEY : ' + initialkey) - print('NONCE : ' + nonce) |