mirror of https://github.com/dirtbags/moth.git
31 lines
1.0 KiB
Python
31 lines
1.0 KiB
Python
import crypto
|
|
|
|
alpha = b'abcdefghiklmnoprstuw'
|
|
|
|
alice = b'''The next four puzzles are all transposition cyphers like this one. Transposition, like substition, is still used in modern crypto systems. '''
|
|
bob = b'''Transposition cyphers often work with the text arranged into blocks of a certain width, often as determined by the key. Dangling parts are often padded with nulls or random text. terrifying silence '''
|
|
alice = alice.replace(b' ', b'_').lower()
|
|
bob = bob.replace(b' ', b'_').lower()
|
|
|
|
map = [6, 3, 0, 5, 2, 7, 4, 1]
|
|
imap = [2, 7, 4, 1, 6, 3, 0, 5]
|
|
|
|
def transform(text, map):
|
|
assert len(text) % 8 == 0, 'Text must be multiple of 8 in length. '\
|
|
'%d more chars needed.' % (8 - len(text) % 8)
|
|
|
|
out = bytearray()
|
|
i = 0
|
|
while i < len(text):
|
|
for j in range(8):
|
|
out.append( text[i + map[j]] )
|
|
i = i+8
|
|
return bytes(out)
|
|
|
|
encode = lambda t : transform(t, map)
|
|
decode = lambda t : transform(t, imap)
|
|
|
|
crypto.mkIndex(encode, decode, alice, bob, crypto.groups)
|
|
|
|
|