Weird Code

Description

Level: 2 Score 15 Category coding

I've found a weird piece of code in the internet. That looks strange....but there is a flag inside. I believe that! Help me, plz.

Link: SecurityValley/PublicCTFChallenges/coding/weird_code

Analysis

1. We are given what seems to be a disassambled code.

2. Its not Assembly

3. Searching around we can find that this is a python byte code using dis module

4. Python dis Module

5. k\\PbYUHDAM[[VJlVAMVk[VWQE seems to be encrypted password

Solution

After fiddling around with dis.dis() I came to solution which looks like this. A standard XOR (as well seen in previous challenges)

import dis

def enc():
    flag = "k\\PbYUHDAM[[VJlVAMVk[VWQE"
    key = "8934"
    out = ""
    for i in range(len(flag)):
        out += chr(ord(flag[i]) ^ ord(key[i % len(key)]))
    
    print(out)

print(dis.dis(enc)) # Debug

# enc() # Uncomment for flag