Hello,
I'm currently writing my own IMAP client and testing it against Dovecot, and when doing PLAIN AUTH Dovecot sends the "OK Logged in" with an empty tag at the start. I tried reproducing the conversation with netcat, but Dovecot sends a correctly tagged OK at the end of the AUTH so I assume it's timing related. I ended up finding the issue and thought I'd report the fix here. When sending the CAPABILITY command directly after receiving the untagged OK during PREGREET, I sent a trailing '\0' after the '\r\n'. This then
On 15-07-31 at 22:37, Simon Thelen wrote: presumably messed up the tokenizer in dovecot causing it to think that the tag for the AUTHENTICATE command was "". I can't find a spot in the RFC that states what a server should do if it receives a bad tag, so I don't know if dovecot handles it correctly but in any case this was a bug on my part. Sorry for the noise.
-- Simon Thelen