search

hannesm / ocaml-otr

Off-the-record (OTR) messaging protocol, purely in OCaml
BSD 2-Clause "Simplified" License
40 stars 3 forks source link

"invalid mac" when talking to coy #12

Open cfcs opened 7 years ago

cfcs commented 7 years ago

opam version 0.3.3 of otr with jackline craps out with coyim using otr3 in some cases craps out with the message [invalid mac] and goes into and endless loop of invalid ciphertexts being received (presumably coyim trying to resend).

Links are to confirmed combinations of git commits where this occurs.

someone (like, me, I guess) should tests these against each other sometime.

hannesm commented 7 years ago

that's weird. do you have a trace? who is generating the [invalid mac] message? otr generates a `Warning "invalid mac" upon failure to verify the mac, which jackline reports as OTR warning: invalid mac... if there are any square brackets ([]) in the output, it must be the other side.. also would be worth to investigate what changed in coy so that this is happening now...

cfcs commented 7 years ago

It has only happened a few times, usually there are no problems. I do not have a trace, I can try to get one in case it happens again. There were definitely square brackets around it. I think it's a bit confusing with these errors whether they came from "us" or "them" (it's not immediately clear in the UI). The Coyim build I referenced is fairly old (half year), so I don't think it's a sudden change, but yes, worth digging into some day when someone has time. Just noting it here for the future.