diff options
| -rw-r--r--[-rwxr-xr-x] | lc4.py | 158 |
1 files changed, 108 insertions, 50 deletions
@@ -1,27 +1,47 @@ #!/usr/bin/python2 # -*- coding: utf-8 -*- # This software is hereby released into public domain. Use it wisely. -# +# # ElsieFour (LC4) and its enhancement LS47 -# version 2.7: 2018-02-13 +# version 2.8: 2018-05-30 +# +# 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 script for LS47 originally written by Mirek Kratochvil (2017) +# - Python 2 script for LS47 originally written by Mirek Kratochvil (2017) # See https://github.com/exaexa/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, both ways to deal with nonces, keyword -# usage for both LC4 and LS47, reading from file and commandline, and -# extended test outputs. -# +# 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-ls47.py -6 -ws thisismysecretkey -es ############## -ns igxf5e -m1 +# igxf5egcyhoo#ny#o5i5 +# python lc4-ls47.py -6 -ws thisismysecretkey -es ############## -ns igxf5e -m0 +# igxf5e############## +# # Sample calls: -# - Using cipher LC4, enforced with option -6: +# +# Using cipher LC4, enforced with option -6: +# // encrypt (key, message). Following example returns tk5j23tq94_gw9c#lhzs +# python lc4-ls47.py -6 -ks s2ferw_nx346ty5odiupq#lmz8ajhgcvk79b -es aaaaaaaaaaaaaaaaaaaa +# // decrypt (key, message). Following example returns aaaaaaaaaaaaaaaaaaaa +# python lc4-ls47.py -6 -ks s2ferw_nx346ty5odiupq#lmz8ajhgcvk79b -ds tk5j23tq94_gw9c#lhzs +# python lc4-ls47.py -6 -ws thisismysecretkey -es its_my_fathers_son_but_not_my_brother +# python lc4-ls47.py -6 -ws thisismysecretkey -ds 6dudfy3u7omoxy4jbscgn37c2se_d8gx6ogk9 # python lc4-ls47.py -6 -ws thisismysecretkey -es its_my_fathers_son_but_not_my_brother -v -nl 6 # python lc4-ls47.py -6 -ws thisismysecretkey -ds q6xojffkncfyz#f5czs49#3mbsco#2iscvbnm#bymaf -v -nl 6 -# - Using cipher LS47, enforced with option -7: -# python lc4-ls47.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 -# python lc4-ls47.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' # +# Using cipher LS47, enforced with option -7: +# python lc4-ls47.py -7 -ws s3cret_p4ssw0rd/31337 -es conflagrate_the_rose_bush_at_six!---peace-vector-3 -v -ns 8y(l._4ct' -m0 +# python lc4-ls47.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-ls47.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 +# +# Using the automatic test (option -t can be combined with options -s and -ws) +# python lc4-ls47.py -t +# python lc4-ls47.py -t -ws s3cret_p4sswxyz -s peacevector_34 from __future__ import print_function @@ -31,7 +51,7 @@ import random import argparse -version = "v2.7 (2018-02-13)" +version = "v2.8 (2018-05-30)" letters6 = "#_23456789abcdefghijklmnopqrstuvwxyz" letters7 = "_abcdefghijklmnopqrstuvwxyz.0123456789,-+*/:?!'()" @@ -160,7 +180,7 @@ def encrypt(plaintext): def decrypt(ciphertext): global key, mp - + plaintext = '' for c in ciphertext: cp = find_pos(key, c) @@ -212,17 +232,19 @@ def eprint(*args, **kwargs): print(*args, file=sys.stderr, **kwargs) -def printinfo(enc=False): +def printinfo(enc=False): # used by test1() and when option -v eprint('CIPHER : ' + ("LC4" if size==6 else "LS47")) eprint('ALPHABET : ' + letters) - if args.keywordstring: - eprint('KEYWORD : ' + args.keywordstring) + 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: @@ -230,24 +252,32 @@ def printinfo(enc=False): eprint('PLAINTEXT : ' + plaintext) -def test1(size): - global letters, nonce_mode, marker_mode, tiles, noncelen, nonce, nonce_size, nonce_enc, signature +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; + letters = letters7 nonce_mode = 2 marker_mode = 2 - noncelen=10; nonce = create_random_nonce(noncelen) - # nonce = 'dr0+:_pij2' # just a sample for testing fixed nonce + 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; + letters = letters6 nonce_mode = 1 marker_mode = 1 - noncelen=6; nonce = create_random_nonce(noncelen) - # nonce = 'pjpm5i' # just a sample for testing fixed nonce + 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) @@ -257,7 +287,11 @@ def test1(size): print('\n' + CIPHERNAME) if size == 7: - keyword = 's3cret_p4ssw0rd/31337'; args.keywordstring=keyword + 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) else: key = letters @@ -266,11 +300,13 @@ def test1(size): 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!' - signature = 'peace-vector-3' + 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' - signature = '#its_me' # signature = '' + if szsignature: plaintext += szsignature check_plaintext(plaintext) ciphertext = encrypt_with_nonce(plaintext) @@ -280,20 +316,21 @@ def test1(size): decryptedtext = decrypt_with_nonce(ciphertext) print('decrypted text: ' + decryptedtext) - printinfo(True) - args.keywordstring='' + printinfo(True) # Called from test1() with arg TRUE = assume to do decryption + + szkeyword='' if __name__ == '__main__': - parser = argparse.ArgumentParser() + parser = argparse.ArgumentParser() # how to enforce, that (either no arg), (or only one arg -t, -v), (or give key and enc mode) - mgroup = parser.add_mutually_exclusive_group() parser.add_argument("-v", "--verbose", help="output additional information on stderr", action="count", default=0) - mgroup.add_argument("-6", "--lc4", help="use ElsieFour cipher (6x6 table) (default)", action="store_true") - mgroup.add_argument("-7", "--ls47", help="use LS47 cipher (7x7 table)", action="store_true") + 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") mgroup2 = parser.add_mutually_exclusive_group() mgroup2.add_argument("-ks", "--keystring", metavar="STRING", help="use STRING as key") @@ -301,16 +338,16 @@ if __name__ == '__main__': 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) - mgroup3 = parser.add_mutually_exclusive_group() - mgroup3.add_argument("-nl", "--noncelen", metavar="LENGTH", help="use random nonce of length LENGTH", type=int, default=0) - mgroup3.add_argument("-ns", "--noncestring", metavar="STRING", help="use STRING as nonce") - 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 random nonce and a given key (once with LC4 and once with LS47)", action="store_true") + mgroup4.add_argument("-t", "--test", help="encrypt and decrypt a string with a given key (four cases: random and fixed nonce, 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") @@ -320,7 +357,8 @@ if __name__ == '__main__': 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") + + parser.add_argument("-s", "--signature", help="append SIGNATURE to plaintext when encrypting (default: no signature)") args = parser.parse_args() @@ -372,8 +410,19 @@ if __name__ == '__main__': key = letters + # help 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: key = derive_key(args.keywordstring); + if args.keywordstring: + szkeyword = args.keywordstring + key = derive_key(args.keywordstring) if args.keyfile: args.keystring = open(args.keyfile, 'r').read().rstrip('\r\n') if args.keystring: key = args.keystring; @@ -393,29 +442,38 @@ if __name__ == '__main__': if args.encryptstring: plaintext = args.encryptstring - if args.signature: plaintext += args.signature + if args.signature: + plaintext += args.signature check_plaintext(plaintext) ciphertext = encrypt_with_nonce(plaintext) - if args.verbose: printinfo(True) - print(ciphertext) + if args.verbose: + printinfo(True) + else: + print(ciphertext) elif args.decryptstring: ciphertext = args.decryptstring check_ciphertext(ciphertext) plaintext = decrypt_with_nonce(ciphertext) - if args.verbose: printinfo() if args.signature and args.verbose: - eprint("Warning: the given signature is ignored during decryption") - print(plaintext) + 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('Test: No nonce provided (only its length), so each call will produce a different ciphertext.') - size = 7; test1(size) - size = 6; test1(size) + 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: + else: # you'll never get here (handled via argparse) # if args.verbose: print('Version : ' + version) print('ALPHABET : ' + letters) print('KEY : ' + initialkey) |