Keep without password ssh key for one session

.bashrc

SSH_ENV="$HOME/.ssh/environment"

function start_agent {
    echo "Initialising new SSH agent..."
    (umask 066; /usr/bin/ssh-agent > "${SSH_ENV}")
    . "${SSH_ENV}" > /dev/null
    /usr/bin/ssh-add -t 36000; # Lifetime only for 10 hours
}

# Source SSH settings, if applicable

if [ -f "${SSH_ENV}" ]; then
    . "${SSH_ENV}" > /dev/null
    ps -ef | grep ${SSH_AGENT_PID} | grep ssh-agent$ > /dev/null || {
        start_agent;
    }
else
    start_agent;
fi