"SfR Fresh" - the SfR Freeware/Shareware Archive 
Member "dovecot-1.0.15/doc/wiki/AuthDatabase.Passwd.txt" of archive dovecot-1.0.15.tar.gz:
As a special service "SfR Fresh" has tried to format the requested source page into HTML format using source code syntax highlighting with prefixed line numbers.
Alternatively you can here view or download the uninterpreted source code file.
That can be also achieved for any archive member file by clicking within an archive contents listing on the first character of the file(path) respectively on the according byte size field.
1
2
3 Passwd
4 ======
5
6
7 User is looked up using 'getpwnam()' call, which usually looks into '/etc/passwd' file, but depending on NSS [None] configuration it may also look up the user from eg. LDAP database.
8 Most commonly used as a user database. Many systems use shadow passwords nowadays so it doesn't usually work as a password database. BSDs are an exception to this, they still set the password field even with shadow passwords.
9 The lookup is by default done in the primary dovecot-auth process, so if NSS is configured to do the lookups from an external server, it slows down all the other authentications while waiting for the reply. To avoid that, you can use 'blocking=yes' argument to do the lookups in auth worker processes:
10
11 ---%<-------------------------------------------------------------------------
12 # NOTE: v1.0.rc23 and later only
13 userdb passwd {
14 args = blocking=yes
15 }
16 ---%<-------------------------------------------------------------------------
17
18 The "blocking" name can be a bit confusing. It doesn't mean that the lookup blocks the whole dovecot-auth, exactly the opposite.
19
20
21 Field overriding and extra fields
22 =================================
23
24
25 v1.1+ only: It's possible to override fields from passwd and add >>extra fields<< with templates. For example:
26
27 ---%<-------------------------------------------------------------------------
28 userdb passwd {
29 args = home=/var/mail/%u mail=maildir:/var/mail/%u/Maildir
30 }
31 ---%<-------------------------------------------------------------------------
32
33 This uses the UID and GID fields from passwd, but home directory is overridden. Also the default >>mail_location<< setting is overridden.
34
35
36 nss_ldap
37 ========
38
39
40 nss_ldap can in some cases return wrong user's information and cause users to log in as each others. With 1.0.rc23 and later you can fix this by using the 'blocking=yes' setting as described above.
41 There's a nss_ldap bug about this in RedHat's Bugzilla [None].
42 A typical PAM + nss_ldap configuration looks like:
43
44 ---%<-------------------------------------------------------------------------
45 # NOTE: v1.0.rc23 and later only
46 userdb passwd {
47 args = blocking=yes
48 }
49 passdb pam {
50 args = dovecot
51 }
52 ---%<-------------------------------------------------------------------------
53
54 (This file was created from the wiki on 2007-12-11 04:42)