Rating:
'''
Full write-up: https://github.com/ginjabenjamin/CTF/tree/master/PicoCTF2017/RE/Level-03-MuchAdoAboutHacking
'''
# cat ans.py
#!/usr/bin/env python
donpedro = 0
achilles = 32
cleopatra = 96
ending = 'tu1|\h+&g\OP7@% :BH7M6m3g='
flag = ''
beatrice = len(ending)
for benedick in ending:
x = ord(benedick)
x = x - achilles
x = x - donpedro
# Assigning Don Pedro here, we can eliminate Don John
donpedro = x
# To reverse the algorithm, we add cleopatra (96) before the modulo operation
x = (x + cleopatra) % cleopatra
# Modulo to handle negative values
benedick = chr((x + achilles) % 192)
flag += benedick
# Reverse our flag string
print flag[::-1]+' '
