[Dovecot] Authentication cache, failure to login after changed password

[Tom Sommer]

Timo Sirainen wrote:
> On Mon, 2009-01-05 at 14:33 +0100, Tom Sommer wrote:
>   
>> Sorry to bump this, but I can still reproduce it - I have enabled 
>> auth_debug now to attempt to provide some more details.
>>     
>
> Actually enable auth_debug_passwords=yes. It then also logs what's seen
> in the cache entries.
>   
dovecot: Jan 20 09:01:18 Info: auth(default): 
cache(user at example.com,127.0.0.1): miss
dovecot: Jan 20 09:01:18 Info: auth-worker(default): 
sql(user at example.com,127.0.0.1): query: SELECT username as user, 
plainpassword as password, nopassword FROM cyrususers WHERE username = 
'user at example.com' AND password = PASSWORD('SECRET') AND active = 1
dovecot: Jan 20 09:01:18 Info: auth-worker(default): 
sql(user at example.com,127.0.0.1): unknown user
dovecot: Jan 20 09:01:20 Info: auth(default): client out: FAIL  1       
user=user at example.com
dovecot: Jan 20 09:01:20 Info: imap-login: Disconnected (auth failed, 1 
attempts): user=<user at example.com>, method=PLAIN, rip=127.0.0.1, 
lip=127.0.0.2
dovecot: Jan 20 09:01:32 Info: auth(default): 
cache(user at example.com,127.0.0.1): hit:
dovecot: Jan 20 09:01:32 Info: auth(default): 
cache(user at example.com,127.0.0.1): User unknown
dovecot: Jan 20 09:01:34 Info: auth(default): client out: FAIL  1       
user=user at example.com

It appears the user missed the cache, a SQL lookup is performed (which 
returns 1 record, I tested the query directly) - however for some reason 
the lookup is set as Unknown User, a state which it then keeps. 
Obviously I can adjust this with auth_cache_negative_ttl, but I presumed 
the default value was always 0

Setting auth_cache_negative_ttl = 0 now and awaiting results

--
Tom Sommer