# VERYBABYREV
```
fun fact: verybabyrev backwards is verybabyrev
```

- File : [verybabyrev](https://github.com/Pynard/writeups/blob/main/2021/RARCTF/attachements/verybabyrev/verybabyrev)

Here the flag typed is xored xith itself and compared with a string in the code :
```
compare[0] = flag[0] ^ flag[1]
for n > 1 :
compare[n] = compare[n-1] ^ flag[n]
```

We extract the compared string and knowing the first letter ('r') we can xor again each character with its neighbour and decipher the flag.

- File : [solve.py](https://github.com/Pynard/writeups/blob/main/2021/RARCTF/attachements/verybabyrev/solve.py)
```python
import struct

cmp = [
0x45481d1217111313,
0x095f422c260b4145,
0x541b56563d6c5f0b,
0x585c0b3c2945415f,
0x402a6c54095d5f00,
0x4b5f4248276a0606,
0x6c5e5d432c2d4256,
0x6b315e434707412d,
0x5e54491c6e3b0a5a,
0x2828475e05342b1a,
0x060450073b26111f,
0x0a774803050b0d04
]

cmp = b''.join([ struct.pack('