In The Source View of home page there were a hint:
![](https://abbishal.me/CTF/robots.png)
` `
After we checked the robots.txt file of server and got this:
```User-agent: * Disallow: /cookie.php```
after visiting cookie.php we checked the source view and got this clue:
![](https://abbishal.me/CTF/robots1.png)
Notice:  ``
that's mean our flag was divided into pieces. let' find those pieces.
Remember the first clue on home page: `""`
so we went for check the cookie value. and there found these cookie:
![](http://abbishal.me/CTF/robots3.png)
on every reload of page piece values were increasing by 1 and got some Sha-256 encrypted hash on Our_Fav_Cookie.
there were total 39 Pieces. after collecting them we just google it and decrypted those key then we found this one
> OFQPGS{P00x135_ne3_o35g_cy4p3_70_pu3px}
It's Clear that Flag of this event starts with BSDCTF but there is no BSDCTF and the flag also makes no sense.
After clearly saw the flag we went for Cipher decryption that flag for A→N
After Decoding from web we got our flag:
![](http://abbishal.me/CTF/robots4.png)
> BSDCTF{C00k135_ar3_b35t_pl4c3_70_ch3ck}