PAM_KSU(8) MidnightBSD System Manager’s Manual PAM_KSU(8)


pam_ksu — Kerberos 5 SU PAM module


[service-name] module-type control-flag pam_ksu [options]


The Kerberos 5 SU authentication service module for PAM, pam_ksu for only one PAM category: authentication. In terms of the module-type parameter, this is the ‘‘auth’’ feature. The module is specifically designed to be used with the su(1) utility.

Kerberos 5 SU Authentication Module
The Kerberos 5 SU authentication component provides functions to verify the identity of a user (pam_sm_authenticate()), and determine whether or not the user is authorized to obtain the privileges of the target account. If the target account is ‘‘root’’, then the Kerberos 5 principal used for authentication and authorization will be the ‘‘root’’ instance of the current user, e.g. ‘‘user/root@REAL.M’’. Otherwise, the principal will simply be the current user’s default principal, e.g. ‘‘user@REAL.M’’.

The user is prompted for a password if necessary. Authorization is performed by comparing the Kerberos 5 principal with those listed in the .k5login file in the target account’s home directory (e.g. /root/.k5login for root).

The following options may be passed to the authentication module:


syslog(3) debugging information at LOG_DEBUG level.


If the authentication module is not the first in the stack, and a previous module obtained the user’s password, that password is used to authenticate the user. If this fails, the authentication module returns failure without prompting the user for a password. This option has no effect if the authentication module is the first in the stack, or if no previous modules obtained the user’s password.


This option is similar to the use_first_pass option, except that if the previously obtained password fails, the user is prompted for another password.


su(1), syslog(3), pam.conf(5), pam(8)

MidnightBSD 0.3 May 15, 2002 MidnightBSD 0.3