ssh tips

Password-less authentication:

generate public and private key e.g. with ssh-keygen -a 100 -t ed25519 -C "a comment" -f name_of_the_file note: previously ssh-keygen -t rsa -b 4096 -C "a comment"
on the machine from which you connect: put private key in ~/.ssh/id_rsa (for rss key) or ~/.ssh/id_dsa (for dsa key), with 0600 permissions
on the machine you connect to: append public key to ~/.ssh/authorized_keys (also with 0600 permission)

Using ssh agent:

Ssh agent remembers password for your private key, so you only have to type it once in a session, not every time it’s used.

Start ssh agent: ssh-agent Add keys: ssh-add List currently loaded keys: ssh-add -l

Cygwin and ssh agent:

Links:

Add this to ~/.bashrc:

## Enable ssh agent
export SSH_AUTH_SOCK=/tmp/.ssh-socket

ssh-add -l \>/dev/null 2\>&1

if [ $? = 2 ]; then
 # Exit status 2 means couldn’t connect to ssh-agent; start one now
 rm -rf /tmp/.ssh*
 ssh-agent -a $SSH_AUTH_SOCK >/tmp/.ssh-script
 . /tmp/.ssh-script
 echo $SSH_AGENT_PID >/tmp/.ssh-agent-pid
fi

function kill-agent {
 pid=`cat /tmp/.ssh-agent-pid`
 kill $pid
}

function addkeys {
 ssh-add ~/.ssh/id_dsa*
}

Set an alias for a hostname

In ~/.ssh/config:

Host dev30
    HostName dev30.kowalczyk.info
    User root
    IdentityFile ~/.ssh/id_dsa_dev30