GMAC is too fragile, so I made a nonce-based alternative to CW hashes. I use HMAC, so nothing can go wrong. But I am not sure how to use nonces with HMAC...

Challenged provided by Trail of Bits and authored by Xiangan He and Marc Ilunga.

nc duality.nc.jctf.pro 1337

https://s3.cdn.justctf.team/4c55f097-1431-4c2e-99f5-b7e67e8de3cc/duality.tar.gz