Commands Reference, Volume 5

tsm Command

Description

The tsm command invokes the terminal state manager, which controls the ports used in the trusted path. The functions are:

Establishing line communication modes and discipline - functions performed by the getty command.
Verifying the user's account and identity, and setting the initial process credentials and environment - functions performed by the login command.
Performing trusted path management if the secure attention key (SAK) is enabled for the port and the system login program is used.

Note: The tsm command is not entered on the command line.

Trusted path management occurs in two phases:

login

This phase is in effect if a user has not successfully logged in. If the secure attention key (SAK) signal is detected, the system restarts getty-login type processing. The next login puts the user into the trusted state, if the port and the user support the trusted state.

shell

This phase occurs after successful user authentication. The command functions according to the user's tpath attribute. The following are valid:

on: Provides standard trusted path management. When the secure attention key (SAK) signal is detected, all processes that access the port, except the tsm process and its siblings (including the trusted shell), are terminated the next time an attempt is made to access the port. The port is reset to its initial state and is marked as trusted, and the trusted shell command (the tsh command) is executed.
notsh: The user session terminates when the secure attention key (SAK) signal is detected.
always: The user is not allowed off the trusted path. The user's shell will always be the trusted shell, tsh.
nosak: The secure attention key (SAK) is disabled for the terminal, and the user's initial program runs.

Security

Access Control: This command should grant execute (x) permission to any user. The command should be setuid to the root user and have the trusted computing base attribute.

Files Accessed:

Mode	File
r	/etc/objrepos/CuAt
r	/usr/lib/objrepos/PdAt
r	/etc/security/login.cfg
r	/etc/security/user

Examples

To provide terminal state management on tty0, add the following line to the /etc/inittab file:

tty0:2:respawn:/usr/sbin/tsm /dev/tty0

This initializes the port /dev/tty0 and sets up the characteristics of the port.

Files

/usr/sbin/tsm	Contains the tsm command.
/etc/security/login.cfg	Contains configuration information.
/etc/security/user	Contains extended user attributes.

Related Information

The getty command, init command, login command, logout command, setgroups command, shell command, su command, tsh command.

For more information about the identification and authentication of users, discretionary access control, the trusted computing base, and auditing, refer to the Security Administration in AIX 5L Version 5.1 System Management Concepts: Operating System and Devices.