Bash SSH – Start a System-Wide SSH Agent

bashsshssh-agent

Currently, I have commands to start the SSH agent in my .bashrc file. The trouble is that this only works in a particular terminal – each time I open a terminal, I'm asked for my private key's passphrase.

Is there a way to open the SSH agent so that it can be used for multiple terminals without having to re-enter the passphrase each time?

Best Answer

The agent to use is determined by SSH_AUTH_SOCK environment variable (and the agent process itself - by SSH_AGENT_PID), so you can save those to files in your startup scripts (execute ssh-agent in them as intended user) and pass to login shells in .bashrc script. This will give you not system-wide, but user-wide agent. Also if you use X on this machine, you can add ssh-agent to the terminal which starts X, the variables will be inherited by shells called from X. Your question doesn't specify enough details of your environment to be more specific.

Related Solutions

SSH – How to Get ssh-agent to Work in All Terminals

If you're logging into a graphical session, arrange to start ssh-agent during your session startup. Some distributions already do that for you. If yours doesn't, arrange to run ssh-agent from your session startup script or from your window manager. How do do that depends on your desktop environment and your window manager. For example, if you start your window manager manually, simply replace the call to my_favorite_wm by ssh-agent my_favorite_wm.

Do not start ssh-agent from .bashrc or .zshrc, since these files are executed by each new interactive shell. The place to start ssh-agent is in a session startup file such as .profile or .xsession.

If you want to use the same SSH agent on all processes no matter where you logged in from, you can make it always use the same socket name, instead of using a randomly-named socket. For example, you might put this in your ~/.profile:

export SSH_AUTH_SOCK=~/.ssh/ssh-agent.$HOSTNAME.sock
ssh-add -l 2>/dev/null >/dev/null
if [ $? -ge 2 ]; then
  ssh-agent -a "$SSH_AUTH_SOCK" >/dev/null
fi

SSH – How to Get Asked for SSH Key Passphrase Once and Only When Needed

Don't add anything to any of your shell startup scripts, this is unnecessary hackery.

Instead, add

AddKeysToAgent yes

to your .ssh/config

Like this, ssh-add is run automatically the first time you ssh into another box. You only have to re-enter your key when it expires from ssh-agent or after you reboot.

Best Answer

Related Solutions

SSH – How to Get ssh-agent to Work in All Terminals

SSH – How to Get Asked for SSH Key Passphrase Once and Only When Needed

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