42 SnowCrash Level09 - Walkthrough 👾

Introduction:

In level 09, we are provided with a token encoded as a list of hexadecimal values. Our objective is to decode this token using a Python script.

Steps:

1. Understanding the Token Encoding:
   We have a token represented as a list of hexadecimal values:

   data = [0x66, 0x34, 0x6b, 0x6d, 0x6d, 0x36, 0x70, 0x7c, 0x3d, 0x82, 0x7f, 0x70,
     0x82, 0x6e, 0x83, 0x82, 0x44, 0x42, 0x83, 0x44, 0x75, 0x7b, 0x7f, 0x8c,
     0x89]

   Each value in the list corresponds to a ASCII character in the buffer.

2. Decoding the Token:
   We use a Python script to decode the token by subtracting the index from each character’s ASCII value:

   flag = "".join([chr(data[i] - i) for i in range(len(data))])
   print(flag)

   This script will output the decoded flag.

3. Executing the Script:
   We save the script in a file, let’s say decode_flag.py, and then execute it or just run the following command:

   python3 -c 'data = [0x66, 0x34, 0x6b, 0x6d, 0x6d, 0x36, 0x70, 0x7c, 0x3d, 0x82, 0x7f, 0x70,
   0x82, 0x6e, 0x83, 0x82, 0x44, 0x42, 0x83, 0x44, 0x75, 0x7b, 0x7f, 0x8c,
   0x89];flag = "".join([ chr(data[i] - i) for i in range(len(data)) ]);print(flag)

Conclusion

By decoding the token using the provided Python script, we successfully obtained the flag for level 09.