PW Crack 5

Tags: General Skills, password_cracking, hashing
Author: LT ‘syreal’ Jones

Description

Can you crack the password to get the flag?
Download the password checker here and you’ll need the encrypted flag and the hash in the same directory too. Here’s a dictionary with all possible passwords based on the password conventions we’ve seen so far.

Hints

1. Opening a file in Python is crucial to using the provided dictionary.
2. You may need to trim the whitespace from the dictionary word before hashing. Look up the Python string function, strip
3. The str_xor function does not need to be reverse engineered for this challenge.

   Approach

   This is pretty similar to PW Crack 4 ```python import hashlib def hash_pw(pw_str): pw_bytes = bytearray() pw_bytes.extend(pw_str.encode()) m = hashlib.md5() m.update(pw_bytes) return m.digest() correct_pw_hash = open(‘level5.hash.bin’, ‘rb’).read()

dictionary = open(“dictionary.txt”, “r”).readlines() for word in dictionary: word = word.strip() if hash_pw(word) == correct_pw_hash: print(word) ``` The first bit is the same, just change “level4.hash.bin” to “level5.hash.bin”.
The next bit reads the entire dictionary’s lines, then loops through each word in the dictionary. There might be trailing whitespaces which is bad because the whitespace would be hashed too so to deal with this, we’ll strip the word of whitespaces. strip removes trailing whitespaces. Then we just check to see if the hashed word is the same as the correct hashed password and if so, print the word.
Run level5.py with the password obtained from the script.

Flag

picoCTF{h45h_sl1ng1ng_36e992a6}