picoCTF crackme-py Write Up

Details:

Points: 30

Jeopardy style CTF

Category: Reverse Engineering

Write up:

At the top of the python file you can see:

# Hiding this really important number in an obscure piece of code is brilliant!
# AND it's encrypted!
# We want our biggest client to know his information is safe with us.
bezos_cc_secret = "A:4@r%uL`M-^M0c0AbcM-MFE055a4ce`eN"

# Reference alphabet
alphabet = "!\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ"+ \
            "[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~"



def decode_secret(secret):
    """ROT47 decode

    NOTE: encode and decode are the same operation in the ROT cipher family.
    """

And then the file calls another function, to solve this I simply changed what function the program calls:

decode_secret(bezos_cc_secret)

And this then produced:

picoCTF{1|\/|_4_p34|\|ut_dd2c4616}