Password database extra fields
The primary purpose of a password database lookup is the return the password for a given user. It may however also return other fields which are treated specially:
- [wiki:PasswordDatabase/ExtraFields/User user]: Change the username (eg. lowercase it).
[wiki:PasswordDatabase/ExtraFields/AllowNets allow_nets]: Allow user to log in from only specified IPs.
- [wiki:PasswordDatabase/ExtraFields/Proxy proxy]: Proxy the connection to another IMAP/POP3 server.
- [wiki:PasswordDatabase/ExtraFields/Host host]: Send login referral to client.
[wiki:PasswordDatabase/ExtraFields/NoLogin nologin]: User isn't actually allowed to log in even if the password matches, with optionally a different reason given as the authentication failure message.
[wiki:PasswordDatabase/ExtraFields/NoDelay nodelay]: Don't delay replying to client of the authentication failure.
How to return these extra fields depends on the password database you use. See the [wiki:PasswordDatabase password database] pages how to do it. Some passdbs however don't support returning them at all, such as [wiki:PasswordDatabase/PAM PAM].
The password database may also return fields prefixed with userdb_. These fields are only saved and used later as if they came from the [wiki:UserDatabase user database]'s extra fields. Typically this is done only when using [wiki:UserDatabase/Prefetch prefetch userdb].
Note that boolean fields are true always if the field exists. So nodelay, nodelay=yes, nodelay=no and nodelay=0 all mean that the nodelay field is true. With SQL the field doesn't exist if its value is NULL.
password_query = SELECT userid as user, password, 'Y' as proxy, host \ FROM users WHERE userid = '%u' # NOTE: Dovecot doesn't really support line splitting with '\' currently