1. 9
  1.  

  2. 1

    It’s in the second and third parts where it picks up the pace (out of 7, this is a substantial amount of work). From the 3rd part:

    However Dark Souls 3 appears to be broken in this regard (a phrase you might want to get used to …). The key material the server sends back is entirely unused. The key used for all future communications is the raw 16 bytes that the game initially sends.

    So what cipher does the game use for all future communications if not RSA? It uses a very obscure ones, that as far as I’m aware only has a single implementation public on the internet - in the original authors GitHub. The cipher is AES-CWC-128, as hinted to by the CWCObject we found when looking through the RTTI types in the previous post.”

    Also if you wanted to use the reference implementation, you might be disappointed! FromSoftware for whatever reason decided to flip the endian of some calculations in the middle of the implementation (at line 498 of cwc.c if your curious). Good job to the guys on the ?ServerName? discord who managed to figure out that nightmare.

    1. 1

      Really nice writeup. The amount of work needed to create the series is huge. I don’t envy the process of reversing protobufs though.