import random
import codecs
import json
CHAR_REDACTED = '\u2588' # Full block.
CHAR_CONFLICT = '\u2573' # Box drawings light diagonal cross.
## [['an', 'msg', 'is', 'a', 'list', 'of', 'lines,'],
## ['where', 'each', 'line', 'is', 'a', 'list', 'of', 'words.']]
def str2msg(s):
"explode a string into an msg"
return list(map(lambda l:l.split(), s.splitlines()))
def msg2str(ws):
"implode an msg into a string"
return '\n'.join(map(lambda l:' '.join(l), ws))
def mapmsgs(func, *msgs):
"""map func word-per-word on all corresponding words inside [a sequence of] msgs of the same structure. E.g.
>>> mapmsgs(lambda word1,word2:'({}/{})'.format(word1,word2),str2msg("a b\nc d"),str2msg("x y\nz w"))
[['(a/x)', '(b/y)'], ['(c/z)', '(d/w)']]"""
return list(map(lambda s:list(map(lambda v:func(*v), zip(*s))), zip(*msgs)))
def msgget(msg,key,default=None):
return mapmsgs(lambda d:d.get(key,default),msg)
## conversion helpers
def str2bytes(s):
return bytes(s,'utf8')
def bytes2str(b):
return str(b,'utf8','replace')
def bytes2base64(b):
return str(codecs.encode(b,'base64').strip(),'ascii')
def base642bytes(b64):
if b64 is None: return None # Might be missing
return codecs.decode(bytes(b64,'ascii'),'base64')
## "crypto" functions
def makepad(b):
"""Returns a random pad with the same length as b,
encoded to base64.
You think this random function is weak? *Celebrate* that ;)"""
return random._urandom(len(b))
def xor2(c1,c2):
return c1^c2
def integrate2(a,b):
if a is None or a==b: return b
if b is None: return a
return "" # Invoke a conflict [0 is always wrong length ;)]
def integrate(*args):
if not args: return None
if len(args)==1: return args[0]
return integrate2(args[0],integrate(*args[1:]))
return reduce(integrate2,args)
def _redact(s):
plaintext = str2bytes(s)
pad = makepad(plaintext)
return {"cipher":bytes2base64(bytes(map(xor2,plaintext,pad))), "pad":bytes2base64(pad)}
def _unredact(cipher,pad):
if pad is None: # pad is missing
return(CHAR_REDACTED*len(cipher))
if len(cipher)!=len(pad): # Failed the only integrity test ;)
return(CHAR_CONFLICT*len(cipher))
return str(bytes(map(xor2,cipher,pad)),'utf8','replace')
def _disintegrate(value,k=8):
lucky = random.randint(0,k-1)
return [i==lucky and value or None for i in range(k)]
def disintegrate(msg,k=8):
zipped = mapmsgs(lambda p:_disintegrate(p,k),msg)
return [mapmsgs(lambda v:v[i],zipped) for i in range(k)]
def redact(s,k=8):
redaction = mapmsgs(_redact,str2msg(s))
return {
'cipher': msgget(redaction,'cipher'),
'pads': disintegrate(msgget(redaction,'pad'),k)}
def unredact(cipher64,*pads64):
return msg2str(mapmsgs(
_unredact,
mapmsgs(base642bytes,cipher64),
mapmsgs(base642bytes,
mapmsgs(integrate,*pads64))))
def testit():
"Todo: turn this into proper unit tests, anyone?"
plaintext = """Here's the first line,
followed by a second one"""
print('Testing DarkenedAges library')
print('### Redacting prefab plaintext')
redaction = redact(plaintext,2)
for pad in redaction['pads']:
print('# pOTP >>>')
print(pad)
print('# >>> Unredaction')
print(unredact(redaction['cipher'],pad))
print('### >>> integration >>>')
print(unredact(redaction['cipher'],*redaction['pads']))
print('### Simulating incoming [prefab] ciphertext and conflicting pads')
cipher1 = [
['lgPNUJU8', 'qLvBBQ==', '5GfdMat4', 'z8hPe4BlxxdUMXzi4w==', '2IheMA==',
'uZyB', 'wVCtnQ==', 'VnU=', '/pTNipiB55M=', 'XcT1gQ==', 'gxU8', '9MYX',
'io0='],
['0fOyC2/y', 'bg8=', 'bu2T', 'rJH6dWUzpg==', 'B4BTkvtl', '+Ug=', '6wky',
'H78=', 'nx8=', 'TO3/fbE=', 'tqw=', 'S4k8', '+mXOsQ==', 'E3rblIM=',
'bIu6qbrh1g=='],
['sfjl', 'JBxnLbfe0k0n', 'BShgq+QrmdquMA==', 'VYD1hx8=', 'MLk=', 'ig==',
'oasqOoWF', 'Asw=', 'Rof1s/gpQQONcnk=', 'ZW3zOSnTvyg=', 'QlA=',
'6Q0qOw=='],
['9fPa', '2mFZdDltLL4=', '13vdBg==', '+eWH', 'koB24LLGnxs=', 'CedkJ3k=',
'b41+QUU=', 'fRkV', '4/Yc', 'anY6cA==', 'muk=', '9LrH', '5t1uXU0=',
'M1eqTaWs'],
['8Ah2Pq4=', 'ouQ=', 'miJQVgwle6yOcg==', 'PPc=', '6jes', 'kYsY2ynZdg==']]
pad1 = [
['xWusIv5F', '29q4dg==', 'zAa7Rc4K', 'pqY7HvIXqHA1RRWMhA==', None, None,
'lSXD+g==', None, None, None, None, None, None],
['sJDRbhyB', None, None, None, None, 'uDs=', 'jWhA', None, '6Ho=',
'J4OQCp0=', '39g=', 'JuhF', 'kgS41A==', 'fR+t8fE=', None],
['5ZCA', None, None, None, 'Wco=', None, None, None, 'L+mR1ohML2foHA0=',
None, None, None],
['sbuL', 'qhM8EFAOWM0=', 'oxO8cg==', None, '/eYQidGv/nc=', 'epMLVQA=',
None, None, 'i5dv', 'Dh9fFA==', None, 'gNKi', 'lrEPMyg=', None],
[None, None, '+UoxOmBAFcvrFg==', 'Xo4=', None, '4f56t0C6WA==']]
pad2 = [
[None, None, None, None, 'nvo/RQ==', '7ebk', None, 'Pxs=',
'jvG/+ffvzr8=', 'KayU9Q==', '8H1Z', 'nKdz', '5OI='],
[None, 'GmA=', 'GoX2', '/OSQHAtXxw==', 'd+Ej94lL', None, None, 'fsw=',
None, None, None, None, None, None, 'AO7bwt+F+A=='],
[None, 'YXBKZdaztixJ', 'YEYD2Z1b7bPBXg==', 'NvKU5HQ=', None, '6w==',
'085ZT+nx', 'bao=', None, 'FwiAXEih3EA=', 'ICk=', 'r1l+FQ=='],
[None, None, None, 'jY3i', None, None, 'R/kWIDE=', 'O01B', None, None,
'84c=', None, 'kq8PNCM=', 'UCXLPs2F'],
['h2cYGdo=', 'wIE=', None, None, 'nl/J', None]]
for pad in [pad1,pad2]:
print('# pOTP >>>')
#print(json.dumps(pad,indent=4))
print(pad)
print('# >>> Unredaction')
print(unredact(cipher1,pad))
print('### >>> integration >>>')
print(unredact(cipher1,pad1,pad2))
print('')
if __name__=='__main__':
testit()