czw., 3 sty 2019 o 17:52 Olivier Houchard <ohouch...@haproxy.com> napisał(a): > Ah I think I figured it out. > OpenSSL added anti-replay protection when using early data, and it messes up > with the session handling. > With the updated attached patch, I get early data to work again. Is it better > for you ?
Now it works. However, I am a bit concerned about disabling something that sounds like an important safeguard. Reading this https://www.openssl.org/docs/man1.1.1/man3/SSL_SESSION_get_max_early_data.html#REPLAY-PROTECTION suggests that it is really not a wise thing to do. And again, s_server works differently. It does not use SSL_OP_NO_ANTI_REPLAY but the resumption, with early data, works, once. Then you get new session that you can resume again if you wish, but also once. You cannot resume the same session twice. With your patch I can resume single session as many times as I wish. Coupled with early data this is exactly something that TLS 1.3 RFC warns against. This probably is due to haproxy using external session management. I'll try to dig more into this on weekend, now that I know where to look. -- Janusz Dziemidowicz