Challenge archive: zh3r0 CTF V2 2021 - b00tleg

Challenge: b00tleg
Event: zh3r0 CTF - 2021 (V2)
Year: 2021
Category: Cryptography
Authors: deuterium
Mode: interactive
Article: https://deut-erium.github.io/challenges/zh3r0-2021/b00tleg/
Text: https://deut-erium.github.io/challenges/zh3r0-2021/b00tleg/challenge.txt
JSON: https://deut-erium.github.io/challenges/zh3r0-2021/b00tleg/challenge.json

Original description:
Source? Gotta comply to Indian CTFs' crypto standards

Notes:
- This was a black-box challenge: players did not receive the source. The local organizer practice copy includes the level answers and is listed separately as a spoiler. Only its final reward was replaced with a dummy flag; the original source remains linked for reference.
- The original remote service is retired. Browser practice runs locally with the public dummy reward practice{local_dummy_reward}, not an event flag or authoritative score. No TCP endpoint is provided.

Browser practice: https://deut-erium.github.io/challenges/zh3r0-2021/b00tleg/#browser-practice
Runtime: b00tleg
Variants: default (first is default)
Mode describes the original interactive I/O. Start practice from the article, not a TCP client.

Challenge files (primary):
No player handout is available in this archive.

Licenses (local copies):
No local license record is available for this entry.

SPOILERS - organizer files and solutions
Spoilers: organizer files and upstream source, archive, or solution links may reveal answers. Modified downloads are identified below.
- organizer-practice.py (organizer-practice.py; organizer-source)
  URL: https://deut-erium.github.io/assets/challenges/zh3r0-2021-b00tleg/organizer-practice.py
  Bytes: 4180
  SHA-256: 21ebf905b9af68e8215883456a7f4a344a5577859ea4b6a526223a60a6ef7208
  Upstream provenance: https://raw.githubusercontent.com/zh3r0/zh3r0-ctf/7fd08591b088215d58aefdc3b0f64c4a9de80f5d/V2/crypto/b00tleg/admin/challenge.py
  Modification: Only the final event reward was replaced with a public dummy reward. Level answers remain.
  Upstream bytes: 4215
  Upstream SHA-256: 3df9b05402271aeda470885e31f9041854cb514bb652fd6a1a18607c5154dace
Source: https://github.com/zh3r0/zh3r0-ctf/blob/7fd08591b088215d58aefdc3b0f64c4a9de80f5d/V2/crypto/b00tleg/readme.md#L5
Archive: https://github.com/zh3r0/zh3r0-ctf/tree/7fd08591b088215d58aefdc3b0f64c4a9de80f5d/V2/crypto/b00tleg