avesome-tricks/ssh-agent-in-wsl.md

SSH agent in WSL

There are a plenty of ways to enable the SSH agent in WSL to avoid the password ask at every connect to a remote host.

One of them is the following.

Add these lines to the ~/.profile file

ssh_pid=$(pidof ssh-agent)

# If the agent is not running, start it, and save the environment to a file
if [ "$ssh_pid" = "" ]; then
        ssh_env="$(ssh-agent -s)"
        echo "$ssh_env" | head -n 2 | tee ~/.ssh_agent_env > /dev/null
init=1
fi

# Load the environment from the file
if [ -f ~/.ssh_agent_env ]; then
        eval "$(cat ~/.ssh_agent_env)"
fi

After every start of WSL, add the key to the SSH agent and unlock it with the password. For example when starting the day, after WSL start ssh-add ~/.ssh/id_ed25519

Forward agent

Usualy a good idea to forward the agent. With this if using a jump host, you do not need to reenter the password if connect from a host to another host. Add this or create the ~/.ssh/config file

Host *
	ServerAliveInterval 15
	AddKeysToAgent yes
	ForwardAgent yes

• ServerAlive useful, if the underlying connection closes the TCP sockets, E.G. Cisco EPC3925 or NATted cellular networks. This option sends dummy packet every 15 secs to keep the connection up.
• AddKeysToAgent is an useful function that causes that you do not need to add your keys at boot with ssh-add command. Simply make the first connection, unlock the keys and enjoy it from the next login.

todo

• Add the ability to ask the key password on login
• Store the SSH key between restarts (probably requires external packages)