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NAME

       auditd.conf - audit daemon configuration file

DESCRIPTION

       The  file  /etc/audit/auditd.conf  contains  configuration  information
       specific to the audit daemon.   It  should  contain  one  configuration
       keyword  per  line,  an  equal  sign,  and then followed by appropriate
       configuration  information.  The  keywords  recognized  are:  log_file,
       log_format, log_group, priority_boost, flush, freq, num_logs , disp_qos
       , dispatcher, name_format ,  name,  max_log_file,  max_log_file_action,
       space_left,   action_mail_acct,   space_left_action,  admin_space_left,
       admin_space_left_action,      disk_full_action,      disk_error_action,
       tcp_listen_port,  tcp_listen_queue,  use_libwrap  ,  tcp_client_ports ,
       tcp_client_max_idle, enable_krb5,  krb5_principal,  and  krb5_key_file.
       These keywords are described below.

       log_file
              This  keyword specifies the full path name to the log file where
              audit records will be stored. It must be a regular file.

       log_format
              The log format describes how the information should be stored on
              disk.  There  are  2 options: raw and nolog.  If set to RAW, the
              audit records will be stored in a format exactly as  the  kernel
              sends  it.  If  this  option  is  set  to  NOLOG  then all audit
              information is discarded instead of writing to disk.  This  mode
              does not affect data sent to the audit event dispatcher.

       log_group
              This  keyword  specifies  the  group  that is applied to the log
              file’s permissions. The default is root. The group name  can  be
              either numeric or spelled out.

       priority_boost
              This  is  a  non-negative number that tells the audit daemon how
              much of a priority boost it should take. The default  is  4.  No
              change is 0.

       flush  Valid  values are none, incremental, data,  and sync.  If set to
              none, no special effort is made to flush the  audit  records  to
              disk.  If set to incremental, Then the freq parameter is used to
              determine how often an explicit flush to disk  is  issued.   The
              data parameter tells the audit damon to keep the data portion of
              the disk file sync’d at all times. The  sync  option  tells  the
              audit  daemon  to  keep both the data and meta-data fully sync’d
              with every write to disk.

       freq   This is a non-negative number that tells  the  audit  damon  how
              many  records  to write before issuing an explicit flush to disk
              command. this value is only valid when the flush keyword is  set
              to incremental.

       num_logs
              This keyword specifies the number of log files to keep if rotate
              is given as the max_log_file_action.  If the number is < 2, logs
              are not rotated. This number must be 99 or less.  The default is
              0 - which means no rotation. As you increase the number  of  log
              files  being  rotated, you may need to adjust the kernel backlog
              setting upwards since it takes more time to  rotate  the  files.
              This is typically done in /etc/audit/audit.rules.

       disp_qos
              This  option controls whether you want blocking/lossless or non-
              blocking/lossy communication between the audit  daemon  and  the
              dispatcher.  There is a 128k buffer between the audit daemon and
              dispatcher. This is good  enogh  for  most  uses.  If  lossy  is
              chosen,  incoming  events  going to the dispatcher are discarded
              when this queue is full. (Events are still written  to  disk  if
              log_format  is not nolog.) Otherwise the auditd daemon will wait
              for the queue to have an empty spot before logging to disk.  The
              risk  is  that  while  the  daemon is waiting for network IO, an
              event is not being recorded to disk. Valid values are: lossy and
              lossless. Lossy is the default value.

       dispatcher
              The  dispatcher is a program that is started by the audit daemon
              when it starts up. It will pass a copy of all  audit  events  to
              that  application’s  stdin.  Make sure you trust the application
              that you add to this line since it runs with root privileges.

       name_format
              This option controls how computer node names are  inserted  into
              the  audit  event  stream.  It  has the following choices: none,
              hostname, fqd, numeric, and user.  None means that  no  computer
              name  is  inserted  into  the audit event.  hostname is the name
              returned by the gethostname syscall. The fqd means that it takes
              the  hostname  and  resolves  it  with dns for a fully qualified
              domain name of that machine.  Numeric is similar to  fqd  except
              it  resolves  the  IP  address of the machine.  User is an admin
              defined string from the name option. The default value is  none.

       name   This  is the admin defined string that identifies the machine if
              user is given as the name_format option.

       max_log_file
              This keyword specifies the maximum file size in megabytes.  When
              this  limit  is  reached, it will trigger a configurable action.
              The value given must be numeric.

       max_log_file_action
              This parameter tells the system what action  to  take  when  the
              system  has  detected  that  the  max  file  size limit has been
              reached. Valid values are ignore, syslog,  suspend,  rotate  and
              keep_logs.   If  set  to  ignore, the audit daemon does nothing.
              syslog means that it will issue a warning  to  syslog.   suspend
              will cause the audit daemon to stop writing records to the disk.
              The daemon will still be alive. The rotate option will cause the
              audit  daemon  to  rotate the logs. It should be noted that logs
              with higher numbers are older than logs with lower numbers. This
              is  the  same  convention  used  by  the  logrotate utility. The
              keep_logs option is similar to rotate except it does not use the
              num_logs   setting.   This   prevents   audit  logs  from  being
              overwritten.

       action_mail_acct
              This option should contain a valid email address or  alias.  The
              default  address  is  root. If the email address is not local to
              the  machine,  you  must  make  sure  you  have  email  properly
              configured  on  your  machine  and  network.  Also,  this option
              requires that /usr/lib/sendmail exists on the machine.

       space_left
              This is a numeric value in megabytes that tells the audit daemon
              when  to  perform  a  configurable  action because the system is
              starting to run low on disk space.

       space_left_action
              This parameter tells the system what action  to  take  when  the
              system  has  detected  that  it  is  starting to get low on disk
              space.  Valid values are ignore, syslog, email,  exec,  suspend,
              single,  and  halt.   If  set  to  ignore, the audit daemon does
              nothing.  syslog means that it will issue a warning  to  syslog.
              Email  means  that  it  will send a warning to the email account
              specified in action_mail_acct as well as sending the message  to
              syslog.   exec  /path-to-script  will  execute  the  script. You
              cannot pass parameters to the script.  suspend  will  cause  the
              audit  daemon  to  stop  writing records to the disk. The daemon
              will still be alive. The single  option  will  cause  the  audit
              daemon  to  put  the  computer system in single user mode.  halt
              option will cause the audit  daemon  to  shutdown  the  computer
              system.

       admin_space_left
              This is a numeric value in megabytes that tells the audit daemon
              when to perform a configurable  action  because  the  system  is
              running  low  on  disk space. This should be considered the last
              chance to do something before running out  of  disk  space.  The
              numeric value for this parameter should be lower than the number
              for space_left.

       admin_space_left_action
              This parameter tells the system what action  to  take  when  the
              system  has detected that it is low on disk space.  Valid values
              are ignore, syslog, email, exec, suspend, single, and halt.   If
              set to ignore, the audit daemon does nothing.  Syslog means that
              it will issue a warning to syslog.  Email  means  that  it  will
              send   a   warning   to   the   email   account   specified   in
              action_mail_acct as well as sending the message to syslog.  exec
              /path-to-script   will  execute  the  script.  You  cannot  pass
              parameters to the script.  Suspend will cause the  audit  daemon
              to  stop  writing  records to the disk. The daemon will still be
              alive. The single option will cause the audit daemon to put  the
              computer system in single user mode.  halt

       disk_full_action
              This  parameter  tells  the  system what action to take when the
              system has detected that the partition to which  log  files  are
              written  has become full. Valid values are ignore, syslog, exec,
              suspend, single, and halt.  If set to ignore, the  audit  daemon
              does  nothing.   Syslog  means  that  it will issue a warning to
              syslog.  exec  /path-to-script  will  execute  the  script.  You
              cannot  pass  parameters  to the script.  Suspend will cause the
              audit daemon to stop writing records to  the  disk.  The  daemon
              will  still  be  alive.  The  single option will cause the audit
              daemon to put the computer system in  single  user  mode.   halt
              option  will  cause  the  audit  daemon to shutdown the computer
              system.

       disk_error_action
              This parameter tells the system what  action  to  take  whenever
              there  is an error detected when writing audit events to disk or
              rotating logs. Valid values are ignore, syslog,  exec,  suspend,
              single,  and  halt.   If  set  to  ignore, the audit daemon does
              nothing.  Syslog means that it will issue a warning  to  syslog.
              exec  /path-to-script  will  execute the script. You cannot pass
              parameters to the script.  Suspend will cause the  audit  daemon
              to  stop  writing  records to the disk. The daemon will still be
              alive. The single option will cause the audit daemon to put  the
              computer system in single user mode.  halt option will cause the
              audit daemon to shutdown the computer system.

       tcp_listen_port
              This is  a  numeric  value  in  the  range  1..65535  which,  if
              specified, causes auditd to listen on the corresponding TCP port
              for audit records from remote systems. The audit daemon  may  be
              linked  with  tcp_wrappers. You may want to controll access with
              an entry in the hosts.allow and deny files.

       tcp_listen_queue
              This is  a  numeric  value  which  indicates  how  many  pending
              (requested but unaccepted) connections are allowed.  The default
              is 5.  Setting this  too  small  may  cause  connections  to  be
              rejected  if  too  many hosts start up at exactly the same time,
              such as after a power failure.

       use_libwrap
              This setting determines whether or not to  use  tcp_wrappers  to
              discern  connection  attempts  that  are  from allowed machines.
              Legal values are either yes, or no The default value is yes.

       tcp_client_ports
              This parameter may be a  single  numeric  value  or  two  values
              separated  by  a  dash  (no spaces allowed).  It indicates which
              client ports are  allowed  for  incoming  connections.   If  not
              specified,  any  port  is allowed.  Allowed values are 1..65535.
              For example, to require  the  client  use  a  priviledged  port,
              specify 1-1023 for this parameter. You will also need to set the
              local_port option in the audisp-remote.conf  file.  Making  sure
              that  clients  send from a privileged port is a security feature
              to prevent log injection attacks by untrusted users.

       tcp_client_max_idle
              This parameter indicates the number of seconds that a client may
              be idle (i.e. no data from them at all) before auditd complains.
              This is used to close inactive connections if the client machine
              has  a  problem where it cannot shutdown the connection cleanly.
              Note that this is a global setting, and must be higher than  any
              individual  client  heartbeat_timeout  setting,  preferably by a
              factor of two.  The default is zero, which disables this  check.

       enable_krb5
              If  set to "yes", Kerberos 5 will be used for authentication and
              encryption.  The default is "no".

       krb5_principal
              This is the principal for this server.  The default is "auditd".
              Given  this  default,  the server will look for a key named like
              auditd/hostname@EXAMPLE.COM stored  in  /etc/audit/audit.key  to
              authenticate  itself,  where  hostname is the canonical name for
              the server’s host, as  returned  by  a  DNS  lookup  of  its  IP
              address.

       krb5_key_file
              Location  of the key for this client’s principal.  Note that the
              key file must be owned by root and mode 0400.   The  default  is
              /etc/audit/audit.key

NOTES

       In  a CAPP environment, the audit trail is considered so important that
       access to system resources must be denied if an audit trail  cannot  be
       created. In this environment, it would be suggested that /var/log/audit
       be on its own partition. This is to  ensure  that  space  detection  is
       accurate and that no other process comes along and consumes part of it.

       The flush parameter should be set to sync or data.

       Max_log_file and num_logs need to be adjusted so that you get  complete
       use of your partition. It should be noted that the more files that have
       to be rotated, the longer it takes  to  get  back  to  receiving  audit
       events. Max_log_file_action should be set to keep_logs.

       Space_left  should  be set to a number that gives the admin enough time
       to react to any alert message and perform some maintenance to  free  up
       disk space. This would typically involve running the aureport -t report
       and moving the oldest logs to an archive area. The value of  space_left
       is  site  dependant since the rate at which events are generated varies
       with each deployment. The space_left_action is recommended to be set to
       email.  If  you  need something like an snmp trap, you can use the exec
       option to send one.

       Admin_space_left should be set to the amount of disk space on the audit
       partition    needed    for    admin    actions    to    be    recorded.
       Admin_space_left_action would be set to  single  so  that  use  of  the
       machine is restricted to just the console.

       The  disk_full_action  is  triggered  when  no  more room exists on the
       partition.  All  access  should  be  terminated  since  no  more  audit
       capability exists. This can be set to either single or halt.

       The  disk_error_action  should  be  set  to  syslog,  single,  or  halt
       depending  on  your  local  policies  regarding  handling  of  hardware
       malfunctions.

       Specifying  a  single allowed client port may make it difficult for the
       client to restart their audit  subsystem,  as  it  will  be  unable  to
       recreate  a connection with the same host addresses and ports until the
       connection closure TIME_WAIT state times out.

FILES

       /etc/audit/auditd.conf
              Audit daemon configuration file

SEE ALSO

       auditd(8), audisp-remote.conf(5).

AUTHOR

       Steve Grubb