Add your public key to authorized_keys on a remote host

authify.sh

#!/bin/bash
# Add yourself to the list of authorized ssh users on a host
host=$1
tmpfile=`mktemp /tmp/authorized_keys.XXXXXX` || exit 1

notice() {
    echo -e "\033[33m# $1\033[0m"
}

notice "Adding you to authorized_keys for $host"
notice "You will be prompted for your password multiple times"
notice "Checking for .ssh dir..."
if ssh $host ls .ssh > /dev/null; then
    notice "Found"
    notice "Attempting to retrieve existing authorized_keys file..."
    scp -pq $host:.ssh/authorized_keys $tmpfile
    notice "Done"
else
    notice "Missing"
    notice "Creating .ssh dir..."
    ssh $host mkdir -m 700 .ssh
    notice "Done"
    touch $tmpfile
fi
cat ~/.ssh/id_rsa.pub >> $tmpfile
chmod 600 $tmpfile
notice "Uploading new authorized_keys file..."
scp -pq $tmpfile $host:.ssh/authorized_keys
notice "Done"