A user logged in with a captial "L" for his username:
Jul 7 12:30:31 postamt dovecot: auth(default): cache(Loser,10.47.64.227): miss Jul 7 12:30:31 postamt dovecot: auth(default): shadow(Loser,10.47.64.227): lookup Jul 7 12:30:31 postamt dovecot: auth(default): shadow(Loser,10.47.64.227): unknown user Jul 7 12:30:31 postamt dovecot: auth(default): cache(Loser,10.47.64.227): miss Jul 7 12:30:31 postamt dovecot: auth-worker(default): pam(Loser,10.47.64.227): lookup service=dovecot Jul 7 12:30:31 postamt dovecot: auth-worker(default): pam(Loser,10.47.64.227): #1/1 style=1 msg=Password: Jul 7 12:30:33 postamt dovecot: auth-worker(default): pam(Loser,10.47.64.227): unknown user
Then I told him that he's supposed to use an "l" instead of "L" but:
Jul 7 12:42:01 postamt dovecot: imap-login: Login: user=<loser>, method=PLAIN, rip=10.47.64.227, lip=141.42.4.250, TLS Jul 7 12:42:02 postamt dovecot: auth(default): client in: ... Jul 7 12:42:02 postamt dovecot: auth(default): cache(Loser,10.47.64.227): hit: Jul 7 12:42:02 postamt dovecot: auth(default): cache(Loser,10.47.64.227): User unknown Jul 7 12:42:02 postamt dovecot: auth(default): cache(Loser,10.47.64.227): hit: Jul 7 12:42:02 postamt dovecot: auth(default): cache(Loser,10.47.64.227): User unknown Jul 7 12:43:50 postamt dovecot: imap-login: Disconnected (auth failed, 1 attempts): user=<Loser>, method=PLAIN, rip=10.47.64.227, lip=141.42.4.250, TLS: Disconnected
I think the auth cache may work case-insensitive, thus making the "User invalid" response for "Loser" also valid for "loser" (which is the valid and correct username!)
-- Ralf Hildebrandt Geschäftsbereich IT | Abteilung Netzwerk Charité - Universitätsmedizin Berlin Campus Benjamin Franklin Hindenburgdamm 30 | D-12203 Berlin Tel. +49 30 450 570 155 | Fax: +49 30 450 570 962 ralf.hildebrandt@charite.de | http://www.charite.de