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
2.2 KiB
2.2 KiB
title, event, category, points, difficulty
| title | event | category | points | difficulty |
|---|---|---|---|---|
| GEMASTIK 2026 Warmup — All Chapters | GEMASTIK 2026 Warmup | index | 0 | index |
GEMASTIK 2026 Warmup — Chapter Index (ch1–ch14)
Platform: Warmup GEMASTIK 2026 (CTFd) Status: 14/14 solved — 7001 points (13×500 + 1×501)
| # | Challenge | Category | Diff | Flag |
|---|---|---|---|---|
| 1 | Sixty Four | Encoding | easy | GEMASTIK19{b4s3_s1xty_f0ur_warm1ng_up} |
| 2 | Julius | Caesar/ROT13 | easy | GEMASTIK19{caesar_r0t_th1rt33n_klasik} |
| 3 | Needle | Forensics/strings | easy | GEMASTIK19{str1ngs_c4n_f1nd_m3} |
| 4 | Say Cheese | EXIF metadata | easy | GEMASTIK19{h1dd3n_1n_m3tadata_exif} |
| 5 | Nothing Here | Web comment | easy | GEMASTIK19{v13w_s0urc3_pahlawan} |
| 6 | Sweet Cookie | Web/cookie | easy | GEMASTIK19{c00k13_b4s3_d3c0d3} |
| 7 | Open Book | Source | easy | GEMASTIK19{pyth0n_s0urc3_t3rbuka} |
| 8 | Back and Forth | XOR | easy | GEMASTIK19{x0r_it_back_4gain} |
| 9 | Are You Admin? | Pwn/bof | easy | GEMASTIK19{0v3rfl0w_ubah_var} |
| 10 | Call Me | Pwn/ret2win | easy | GEMASTIK19{r3t2w1n_l0mpat_k3_win} |
| 11 | Behind the Picture | PNG stego | easy | GEMASTIK19{c4t_g4mbar_ada_flag} |
| 12 | Layers | Hex→B64 chain | easy | GEMASTIK19{h3x_lQlu_b4s3_ch41n} |
| 13 | Slopped | RSA small factors | medium | GEMASTIK19{qu4ntum_c0mput3r_br0k3_rs4_y0u_sh0uld_us3_p4p3r_s34rch_mcp_sk1ll} |
| 14 | Slopped wave-2 | RSA paper search | hard | GEMASTIK19{test_vector_of_listP_on_quant} |
Ringkasan Metode
| Ch | Metode | Tool |
|---|---|---|
| 1 | Double Base64 | base64 -d ×2 |
| 2 | ROT13 Caesar | codecs.encode(s, "rot_13") |
| 3 | strings | strings secret.bin |
| 4 | EXIF metadata | strings photo.jpg |
| 5 | HTML comment | curl | grep '<!--' |
| 6 | Base64 cookie | base64 -d |
| 7 | ASCII codes | chr() decoding |
| 8 | Single-byte XOR | XOR 0x42 |
| 9 | Stack overflow | buffer > admin |
| 10 | ret2win + align | ROP chain |
| 11 | PNG strings | strings kucing.png |
| 12 | Hex→Base64 | bytes.fromhex + b64decode |
| 13 | RSA small factors | trial division / sympy factorint |
| 14 | RSA special integers | GCD with paper appendix primes |