[Dovecot] BUG: Authentication client sent unknown handshake command

[Jean-Yves Moulin]

Hi everybody,

I'm using dovecot-2.2.11 on NetBSD.

After a kernel upgrade, while using the same dovecot binaries (they were working perfectly until today), I'm experiencing this error (more log at the end of my email):

BUG: Authentication client sent unknown handshake command: REQUEST?227672066?18807?2?c717631d60216b2e9ec57a2fa69674b8?session_pid=16343?...

I tried to build a newer version of dovecot (2.2.12) but same issue.

I know this should come from my system and not dovecot, but how can I debug this kind of problem ? I already enabled various debug (auth_verbose, auth_debug, mail_debug) but I need more information.

This issue have already been discussed on dovecot mailing list without solution :-)

Thank you very much.


Best,
jym

Log:

Apr 16 16:29:16 dodo dovecot: imap-login: Debug: SSL: where=0x2002, ret=1: SSL negotiation finished successfully [::1]
Apr 16 16:29:17 dodo dovecot: auth: Debug: client in: AUTH      2       PLAIN   service=imap    secured session=cE/PvSn3qgAAAAAAAAAAAAAAAAAAAAAB        lip=::1 rip=::1 lport=993       rport=65450     resp=<hidden>
Apr 16 16:29:17 dodo dovecot: auth: Debug: cache(mylogin at myhost.org,::1,<cE/PvSn3qgAAAAAAAAAAAAAAAAAAAAAB>): hit: <hidden>
Apr 16 16:29:17 dodo dovecot: auth: Debug: client passdb out: OK        2       user=mylogin at myhost.org
Apr 16 16:29:17 dodo dovecot: auth: Error: BUG: Authentication client sent unknown handshake command: REQUEST?227672066?18807?2?c717631d60216b2e9ec57a2fa69674b8?session_pid=16343?...
Apr 16 16:29:17 dodo dovecot: imap: Error: Authentication server didn't send valid SPID as expected: MECH       PLAIN   plaintext
Apr 16 16:29:17 dodo dovecot: imap: Error: Disconnected from auth server, aborting (client-pid=18807 client-id=2)
Apr 16 16:29:17 dodo dovecot: imap-login: Internal login failure (pid=18807 id=2) (internal failure, 1 successful auths): user=<mylogin at myhost.org>, method=PLAIN, rip=::1, lip=::1, mpid=16343, TLS, session=<cE/PvSn3qgAAAAAAAAAAAAAAAAAAAAAB>
Apr 16 16:29:17 dodo dovecot: imap-login: Debug: SSL alert: close notify [::1]