config File

Purpose

Contains audit system configuration information.

Description

The /etc/security/audit/config file is an ASCII stanza file that contains audit system configuration information. This file contains five stanzas: start, bin, stream, classes, and users.

start Stanza

The start stanza contains the attributes used by the audit start command to initialize the audit system. The format follows:

start:
 binmode = off | on | panic
 streammode = off | on

The attributes are defined as follows:

Note: If neither collection mode is defined or if both modes are in the off state, only subsystem configuration is done.

bin Stanza

The bin stanza contains the attributes used by the auditbin daemon to set up bin mode auditing. The format follows:

bin:
  trail = PathName
  bin1 = PathName
  bin2 = PathName
  binsize = DecimalString
  cmds = PathName
  bytethreshold = DecimalString
  eventthreshold = DecimalString

Bin mode parameters are defined as follows:

stream Stanza

The stream stanza contains the attributes that the audit start command uses to set up initial stream mode auditing. The format follows:

cmds = PathName  

The PathName parameter identifies the file that contains the stream commands that are executed at the initialization of the audit system. These commands can use shell piping and redirection, but no substitution of path names is performed on $trail or $bin strings.

classes Stanza

The classes stanza defines audit classes (sets of audit events) to the system.

Each audit class name must be less than 16 characters and be unique on the system. Each class definition must be contained in a single line, with a new line acting as a delimiter between classes. The system supports up to 32 audit classes, with ALL as the last class. The audit events in the class must be defined in the /etc/security/audit/events file.

classes:
        auditclass = auditevent, ...auditevent        

users Stanza

The users stanza defines audit classes (sets of events) for each user. The classes are defined to the operating system kernel.

The format is as follows:

users:
    UserName = auditclass, ... auditclass        

Each UserName attribute must be the login name of a system user or the string default, and each auditclass parameter should be defined in the classes stanza.

To establish the audit activities for a user, use the chuser command with the auditclasses attribute.

Security

Access Control: This file should grant read (r) access to the root user and members of the audit group and write (w) access only to the root user.

Examples

1. To define audit classes, add a line to the classes stanza of the /etc/security/audit/config file for each set of events that you want to assign to a class:

   classes:
     general = USER_SU,PASSWORD_Change,FILE_Unlink,
       FILE_Link,FILE_Remove
     system = USER_Change,GROUP_Change,USER_Create,
       GROUP_Create
     init = USER_Login, USER_Logout

   These specific audit events and audit classes are described in "Setting Up Auditing" in AIX Version 4.3 System Management Guide: Operating System and Devices.

2. To establish the audit activities for each user, use the chuser command with the auditclasses attribute for each user for whom you want to define audit classes (sets of audit events):

   
   chuser "auditclasses=general,init,system" dave
   chuser "auditclasses=general,init" mary

   These chuser commands create the following lines in the users stanza of the /etc/security/audit/config file:

   users:
    dave=general,init,system
    mary=general,init  

   This configuration includes dave, the administrator of the system, and mary, an employee who updates information.

3. To enable the auditing system, turn on bin data collection, and turn off initial stream data collection, add the following to the start stanza of the /etc/security/audit/config file:

   start:
     binmode = on
     streammode = off

4. To enable the auditbin daemon to set up bin collection, add attributes to the bin stanza of the /etc/security/audit/config file:

   bin:
     trail = /audit/trail
     bin1 = /audit/bin1
     bin2 = /audit/bin2
     binsize = 25000
     cmds = /etc/security/audit/bincmds

   The attribute values in the preceding stanza enable the audit system to collect bin files of data and store the records in a long-term audit trail.

5. To enable the auditbin daemon to set up stream collection, add lines to the start and stream stanzas of the /etc/security/audit/config file:

   start:
     streammode = on
   stream:
     cmds = /etc/security/audit/streamcmds

Implementation Specifics

This file is part of Base Operating System (BOS) Runtime.

Files

Related Information

The audit command, auditbin daemon, chuser command.

The auditproc subroutine.

Security Administration, Setting Up Auditing, Auditing Overview in AIX Version 4.3 System Management Guide: Operating System and Devices.