#!/bin/sh

# AUTHOR: Matt Simerson (matt at tnpi.net)
#
# VERSION:
# v1.01 - Jun 24, 2008 - added comments, examples, and docs 
#                      - add prompts for user and key files
# v1.00 - Sep 24, 2007
#
# PURPOSE
# This script installs my SSH public key on a remote server
# I install this script as ~/.ssh/remote.sh and run it like so
# 
# INSTALL
#  1. Install this script in your ~/.ssh directory as agent.sh
#    
#     curl -o .ssh/remote.sh http://www.tnpi.net/computing/ssh_remote.sh.txt
#     chmod 755 .ssh/remote.sh
# 
#  2. run it when you want to install your SSH public key on a remote server
# 
#     ~/.ssh/remote.sh remote.server.com
#
#  3. Send gratitude to author
#
# Examples:
#
# Usage: remote.sh [remote.host.com] [public.key_filename]
#
#  ~/.ssh/remote.sh matts.spry.com spry_rsa.pub
#  Remote username: (matt) 
#  Installing spry_rsa.pub in matts.spry.com:.ssh/authorized_keys
#  Password:
#  done!
#            or
#  
#  ~/.ssh/remote.sh
#  Remote hostname: matts.spry.com   
#  Remote username: (matt) 
#  Installing id_rsa.pub in matts.spry.com:.ssh/authorized_keys ...
#  Password:
#  done!

# you may want to edit these
DEBUG=0
REMOTE_HOST=$1
KEY=$2

# below here is not intended to be user servicable

get_input() {
    _input=

    while : ; do
        read _input

        if [ -x "$_input" ]; then
            err "INVALID, try again."
            continue
        fi
        break
    done
    echo "$_input"
}

get_username() {
    _input=

    echo "Remote username: ($USER) \c"
    read _input
    
    if [ -z "$_input" ]; then
        REMOTE_USER=$USER
    else
        REMOTE_USER="$_input"
    fi
}

get_keyfile() {

    # if a key wasn't specifically entered or doesn't exist, try some defaults 
    if [ ! -f "$HOME/.ssh/$KEY" ]; then
        KEY="id_rsa.pub"
    fi

    if [ ! -f "$HOME/.ssh/$KEY" ]; then
        KEY="id_dsa.pub"
    fi

    if [ ! -f "$HOME/.ssh/$KEY" ]; then
        echo "SSH Public Key filename: \c"
        KEY=`get_input`
    fi

    if [ ! -f "$HOME/.ssh/$KEY" ]; then
        echo "ERR: private key not found"
        echo "     * please create it with \"ssh-keygen\" *"
        exit
    fi
}


get_keyfile

if [ -z $REMOTE_HOST ]; then
    echo "Remote hostname: \c"
    REMOTE_HOST=`get_input`
fi

get_username

REMOTE_CMD='umask 0077; test -d .ssh || mkdir -p ~/.ssh; umask 0022; cat - >> .ssh/authorized_keys'

echo "Installing $KEY in $REMOTE_HOST:.ssh/authorized_keys"
if [ $DEBUG -ne 0 ]; then
    echo "cat $HOME/.ssh/$KEY | ssh $REMOTE_USER@$REMOTE_HOST $REMOTE_CMD"
fi

cat $HOME/.ssh/$KEY | ssh $REMOTE_USER@$REMOTE_HOST $REMOTE_CMD

echo "done!"