asepharyana
7a6e717c28
- Deleted all previous dummy docs (defcon-quals-2024, infra/cloudflare-525, debugging/websocket-timeout, template, docs/*, notes/*, research/*) - Added 14 Gemastik warmup writeups covering encoding, stego, web, pwn, crypto - ch13: RSA small factors; ch14: RSA special integers via paper-search (GCD with paper appendix primes) - All flags recovered and documented with solution methods
795 B
795 B
title, event, challenge, category, points, difficulty, flag
| title | event | challenge | category | points | difficulty | flag |
|---|---|---|---|---|---|---|
| Layers — Hex to Base64 Chain | GEMASTIK 2026 Warmup | Layers | crypto | 500 | easy | GEMASTIK19{h3x_lQlu_b4s3_ch41n} |
Layers (500 pts) — Encoding chain
File: chall.txt → 5230564e51564e55535573784f58746f4d33686662464673645639694e484d7a58324e6f4e44467566513d3d
Dua lapis encoding berturut-turut: Hex → bytes → Base64 → flag:
import base64
s = "5230564e51564e55535573784f58746f4d33686662464673645639694e484d7a58324e6f4e44467566513d3d"
# Layer 1: hex decode
b = bytes.fromhex(s)
# b = b'R0VNQVNUSUsxOXtoM3hfbFFsdV9iNHMzX2NoNDFufQ=='
# Layer 2: base64 decode
flag = base64.b64decode(b).decode()
print(flag)
# GEMASTIK19{h3x_lQlu_b4s3_ch41n}
Flag
GEMASTIK19{h3x_lQlu_b4s3_ch41n}