Author: Egor Zaytsev (@groke)

I created a simple service that encrypts flag (and your data) with RC4! I bet you can't the extract flag from there :)

crcrcr-cybrics2020.ctf.su/

Source code: crcrcr.tar.gz

Hint at 20:00 — When I wanna know how Python objects are stored in memory, I can do:

terminal1:
python3
>>> s = b"qweqweqweqwe";
terminal2: gcore `pidof python3`

And then look at resulting core file, get xref to qweqweqeqwe, and try to find out how Python objects are stored in memory.

And I guess I will be happy to find cipher.S (rc4 state) in the coredump