PAM_KSU(8) | System Manager's Manual | PAM_KSU(8)

# NAME

`pam_ksu` —
Kerberos 5 SU PAM module

# SYNOPSIS

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

# DESCRIPTION

The Kerberos 5 SU authentication service module for PAM provides functionality 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:

`debug`
  syslog(3) debugging information at `LOG_DEBUG` level.
`use_first_pass`
  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.
`try_first_pass`
  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.

# SEE ALSO

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

May 15, 2002 | NetBSD 9.3