3.2 User Database

A User Database is a storage system where GNU Anubis keeps user credentials, i.e. data necessary for authenticating and authorizing users. The exact way of storing these data is described further in this manual. In this section we treat user database as an abstraction layer.

The user database consists of records. Each record keeps information about a particular user. A record consists of four fields. A field may contain some value, or be empty, in which case we say that it has null value.

The fields are:

SMTP AUTHID

SMTP authentication ID of the user.

AUTH PASSWORD

SMTP password.

ACCOUNT

System user name.

CONFIG

Path to the configuration file.

The first two fields are mandatory and must always have non-null values. No two records in the database may have the same value of SMTP AUTHID field. When anubis is trying to authenticate a user, it first looks up in the database a record with the value of SMTP AUTHID field matching AUTHID given by the user. If no such entry is found, authentication fails. Otherwise, anubis goes on and compares the password supplied by the user with that from AUTH PASSWORD field. If they match, authentication succeeds and anubis passes to authorization state.

In this state, it first determines the user ID (UID) to switch to. If the ACCOUNT field is not null, its value is used as account login name. If it is null, anubis will use privileges of the default not privileged user, specified by user-notprivileged statement in the global configuration file (see section user-notprivileged).

The final step is to parse the user configuration file. If CONFIG field is not null, its value is the absolute pathname of the user configuration file. Otherwise, anubis searches for file ‘~/.anubisrc’ (where ‘~’ denotes home directory for the system account obtained on the previous step) and if such a file exists, loads it.

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