| rsame_v3 |
@Ulevel and thank u for crackme |
2026-03-12 20:24 |
| rsame_v3 |
## The mission
Crack RSA-128 signature verifier. Generate valid signatures for any name.
### Step 1: IDA recon
- Opened binary in IDA Pro
- Found main function and RSA library calls
- Spotted modulus: `b4480fc7b2481311435cab0751d0caed`
- Found public exponent: `65537`
### Step 2: Factorization
- Threw modulus into WolframAlpha
- Got factors: `p = 15090658028802823693`, `q = 15879705458532216929`
- Computed private key: `d = 218160655074222574291907173292813830145`
### Step 3: Testing hell
- Tried SHA-256 + RSA - FAILED
- Tried different exponents - FAILED
- **WTF moment:** It was MD5 all along!
### Step 4: Breakthrough
- MD5 hash + RSA sign = VALID signature
- `test` → `69342496f58076bf276607234b44385e` → WORKS!
## Final formula
1. MD5 hash the name
2. RSA sign with private key
3. Output hex
## Usage
```bash
python crackme_keygen.py any_name_here
```
## Result
Working keygen
screenshot: https://imgur.com/a/Hc4BlFR |
2026-03-12 19:06 |