Linux Security Cookbook

6.11. Terminating an SSH Agent on Logout

Problem

When you log out, you want the ssh-agent process to be terminated automatically.

Solution

For bash:

               ~/.bash_profile:
trap 'test -n "$SSH_AGENT_PID" && eval `/usr/bin/ssh-agent -k`' 0

For csh or tcsh:

               ~/.logout:
if ( "$SSH_AGENT_PID" != "" ) then
        eval `/usr/bin/ssh-agent -k`
endif

Discussion

SSH agents you invoke yourself don’t die automatically when you log out: you must kill them explicitly. When you run an agent, it defines the environment variable SSH_AGENT_PID. [Recipe 6.9] Simply test for its existence and kill the agent with the -k option.

See Also

ssh-agent(1).