#!/bin/sh

# Concatenate together an authorized_keys file based on files in
# ~/.ssh/{host.d,pubkey.d}.

set -e

WARNING="# Automatically generated by loadsshkeys; edit ~/.ssh/{host.d,pubkey.d}/ files instead."

if [ -e "$HOME/.ssh/authorized_keys" ] && ! cat "$HOME/.ssh/authorized_keys" | grep -q "$WARNING"; then
    if [ "$1" != "-f" ]; then
        echo "loadsshkeys: current authorized_keys file was not generated by this script; not touching it" >&2
        echo "loadsshkeys: use loadsshkeys -f to override" >&2
        exit 1
    else
        cat $HOME/.ssh/authorized_keys > $HOME/tmp/old_authorized_keys
        echo "loadsshkeys: old authorized_keys file backed up to $HOME/tmp/old_authorized_keys"
    fi
fi

keys=$HOME/.ssh/host.d/${USER}_$(hostname -f)
if [ -e "$keys" ]; then
    (
        echo "$WARNING"
        echo
        cat $keys | while read key; do
            cat "$HOME/.ssh/pubkey.d/$key"
        done
    ) > $HOME/.ssh/authorized_keys
fi