[Dovecot] NTLM authentication does not work

[Timo Sirainen]

On Mon, 2010-08-30 at 12:21 -0500, Alexander Cherniak wrote:
> Windbind seems to work:
>  [root at aCentOs2 dovecot]# wbinfo -a wAlex%pass
>  plaintext password authentication succeeded
>  challenge/response password authentication succeeded
> 
> Same is true for ntlm_auth helper:
>  [root at aCentOs2 dovecot]# /usr/bin/ntlm_auth --username=wAlex --password=pass
>  NT_STATUS_OK: Success (0x0)

I don't much know of NTLM, but..

> But I couldn't get into Dovecot (with or without auth_use_winbind option):
> . login wAlex pass
> . NO [ALERT] Unsupported authentication mechanism.
..
> auth_mechanisms = ntlm

This error happens because you enabled NTLM mechanism, but disabled
PLAIN mechanism (LOGIN command uses PLAIN mechanism). If you want both
to work, use:

auth_mechanisms = plain ntlm

And note that winbind authentication only works for NTLM mechanism, not
for anything else. Maybe you need to figure out some other passdb to use
like LDAP or maybe some PAM plugin?..