Doing an Ssh-Add Upon Ssh/Slogin If Key Is Not in Ssh-Agent?
When I'm Running Gnome, Ssh-Agent Will Run Ssh-Add Upon Slogin/Ssh If the Identity Is Not Loaded. I Want to Mimic This Behavior on Remote Shells, but...
When I'm running Gnome, ssh-agent will run ssh-add upon slogin/ssh if the identity is not loaded. I want to mimic this behavior on remote shells, but everything I find suggests to run ssh-add upon login. I only want to run ssh-add if I subsequently run slogin/ssh on the remote shell, not every time I login.
4 Answers
I worked out a solution for this via the bash shell.
Add to .bashrc:
check-ssh-add() {
if [ "$DESKTOP_SESSION" == "" ]; then
if [[ `ssh-add -l` != *id_?sa* ]]; then
ssh-add -t 5h ## 5 hour ssh-agent expiration
fi
fi
}
slogin() {
check-ssh-add
/usr/bin/slogin $@
}
ssh() {
check-ssh-add
/usr/bin/ssh $@
}
scp() {
check-ssh-add
/usr/bin/scp $@
}
sftp() {
check-ssh-add
/usr/bin/sftp $@
}
There's actually an even simpler way. ssh-add -l returns true (0) if there are keys and false (1) otherwise, so your first function can be replaced with this:
check-ssh-add() {
if ! ssh-add -l >/dev/null; then
ssh-add -t 5h
fi
}
Even simpler in the «this is an interactive session» part add
ssh-add -l &> /dev/null || ssh-add ~/.ssh/my_id
Newer versions of OpenSSH can add the key to the agent on first use, if you enable AddKeysToAgent yes in your ~/.ssh/config.
(I've learned this from . I'm not sure what the proper StackOverflow etiquette is for coping answers across various StackExchange sites.)
Elena Rostova holds a Master's degree in Public Health Journalism. She covers groundbreaking medical research, holistic wellness trends, mental health awareness, and nutritional science.
