#!/bin/bash

### defaults
ID_FILE="$HOME/.ssh/id_dsa"
username=$USER
rsa_or_dsa="dsa"

usage_line="$0 -H <host>\nOptions:\n\t-?|-h Display this Output\n\t-l <user>; Default == current user\n\t-f <identity file>; Default == '~/.ssh/id_dsa'\n\t-t <rsa|dsa> ***Only when generating new file; Default == $rsa_or_dsa"
### Start function
USAGE() {
        clear 
        echo -e "Usage: $usage_line"
        echo -e "\nIf you use the '-f' option,\n it will generate the file if it doesn't exist."
        echo -e "\nYou will have to enter the remote password once,\n ...but never again after that.\n"
        exit 2
                }
### End Function

### if no args, complain
[ "$#" -lt "1" ] && USAGE

### set command line options
while getopts ":f:t:H:l:?h" flag; do
        case $flag in
            f )  ID_FILE=$OPTARG ;;
            t ) rsa_or_dsa=$OPTARG ;;
            H ) remote_host=$OPTARG ;;
            l ) username=$OPTARG ;;
            ?|h )  USAGE ;;
        esac
done

### make sure options are set correctly, or complain
if [ -z $remote_host ]; then
        clear
        echo -e "\nYou need to specify a valid hostname or ip-address,\nof the remote host you want to connect to.\n"
        USAGE
        exit 1
elif [ $rsa_or_dsa != "rsa" -a $rsa_or_dsa != "dsa" ]; then
        clear
        echo -e "\nWhoa....the '-t' needs to be either 'rsa', or 'dsa'....not '$rsa_or_dsa', as you put it.\n\n"
        exit 1
fi

### make key files if not already there
[ -e "$ID_FILE" ] || ssh-keygen -t $rsa_or_dsa -f $ID_FILE || exit 1

### read pub file, and complain if it cant be read
pub_key=`cat $ID_FILE.pub`
[ -z "$pub_key" ] && (clear ; echo -e "$ID_FILE.pub could not be read...exiting.\n") && exit 1

### Start Function
SSH_PUT_KEY() {
        ssh $username@$remote_host "[ ! -d \$HOME/.ssh/ ] && mkdir \$HOME/.ssh/ ; echo $pub_key >> \$HOME/.ssh/authorized_keys"
                }
### End Function

### run function
SSH_PUT_KEY