CTF Bleichenbacher Attack - Full: invalid flag (username?)

Question

Hello.

I experienced a problem with the Ctf quest. The flag that I get from "rwc.cs.uni-paderborn.de:10003" in the Bleichenbacher Ctf is deemed invalid by the Jade-Ctf platform. My IMT username technically contains upper case letters, so I tried both that version and the one with only lowercase. That did not help, the flag generated by the uppercase username is invalid too. Is there anything I am missing? The generated flags look right to me and follows the expected format.

Thanks in advance

Edit:

The second Flag works. I did not see it because of a stupid bug of my int to byte conversion part.

Answer 1

There are two flags. The first one is when you successfully do the first step of the attack and choose the "2) Submit first step" option from the server. I think this flag doesn't do anything and is just a confirmation that you do something right. To get the second flag, which should be accepted, you have to do the attack until the end.