The warn.conf file contains configuration information specifying how users will be warned by the ktkt_warnd daemon about ticket expiration. In addition, this file can be used to auto-renew the user's Ticket-Granting Ticket (TGT) instead of warning the user. Credential expiration warnings and auto-renew results are sent, by means of syslog, to auth.notice.
Each Kerberos client host must have a warn.conf file in order for users on that host to get Kerberos warnings from the client. Entries in the warn.conf file must have the following format:
principal [renew[:opt1,...optN]] syslog|terminal time
principal [renew[:opt1,...optN]] mail time [email address]
principal Specifies the principal name to be warned. The asterisk (*) wildcard can be used to specify groups of principals.
renew Automatically renew the credentials (TGT) until renewable lifetime expires. This is equivalent to the user running kinit -R.
The renew options include:
Log the result of the renew attempt on success using the specified method (syslog|terminal|mail).
Log the result of the renew attempt on failure using the specified method (syslog|terminal|mail). Some renew failure conditions are: TGT renewable lifetime has expired, the KDCs are unavailable, or the cred cache file has been removed.
Same as specifing both log-success and log-failure.
Note - If no log options are given, no logging is done.
syslog Sends the warnings to the system's syslog. Depending on the /etc/syslog.conf file, syslog entries are written to the /var/adm/messages file and/or displayed on the terminal.
terminal Sends the warnings to display on the terminal.
mail Sends the warnings as email to the address specified by email_address.
time Specifies how much time before the TGT expires when a warning should be sent. The default time value is seconds, but you can specify h (hours) and m (minutes) after the number to specify other time values.
email_address Specifies the email address at which to send the warnings. This field must be specified only with the mail field.
Example 1: Specifying Warnings
The following warn.conf entry
* syslog 5m
specifies that warnings will be sent to the syslog five minutes before the expiration of the TGT for all principals. The form of the message is:
jdb@ACME.COM: your kerberos credentials expire in 5 minutes
Example 2: Specifying Renewal
The following warn.conf entry:
* renew:log terminal 30m
...specifies that renew results will be sent to the user's terminal 30 minutes before the expiration of the TGT for all principals. The form of the message (on renew success) is:
myname@ACME.COM: your kerberos credentials have been renewed
/usr/lib/krb5/ktkt_warnd Kerberos warning daemon
See attributes(5) for descriptions of the following attributes:
|ATTRIBUTE TYPE||ATTRIBUTE VALUE|
kinit(1), kdestroy(1), ktkt_warnd(1M), syslog.conf(4), utmpx(4), attributes(5), kerberos(5), pam_krb5(5)
The auto-renew of the TGT is attempted only if the user is logged-in, as determined by examining utmpx(4).