34 lines
795 B
Markdown
34 lines
795 B
Markdown
|
---
|
||
|
|
title: "Layers — Hex to Base64 Chain"
|
||
|
|
event: "GEMASTIK 2026 Warmup"
|
||
|
|
challenge: "Layers"
|
||
|
|
category: "crypto"
|
||
|
|
points: 500
|
||
|
|
difficulty: "easy"
|
||
|
|
flag: "GEMASTIK19{h3x_lQlu_b4s3_ch41n}"
|
||
|
|
---
|
||
|
|
|
||
|
|
# Layers (500 pts) — Encoding chain
|
||
|
|
|
||
|
|
**File:** `chall.txt` → `5230564e51564e55535573784f58746f4d33686662464673645639694e484d7a58324e6f4e44467566513d3d`
|
||
|
|
|
||
|
|
Dua lapis encoding berturut-turut: **Hex → bytes → Base64 → flag**:
|
||
|
|
|
||
|
|
```python
|
||
|
|
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}`
|