#!/bin/bash
PROGNAME=`basename $0`
DEFAULT_PATH="/usr/local/bin/"
AUX_SCRIPT_PATH="/usr/local/bin/"
LOCAL=`hostname`
KEYTYPE=rsa

# ============================= Functions ============================

############################## Debugging Functions ######################
function BUGPAUSE 
{
echo " "
echo "-----------------------------------------------------------"
echo "                    MANUAL BUG CHECK!"
echo "      Is the program doing what you expect?  Please "
echo "   review preceeding output for correctness.  Thank you."
echo "-----------------------------------------------------------"
echo " "
echo "Args so far:"
echo "KEYTYPE: $KEYTYPE "
echo "DEFAULT_PATH: $DEFAULT_PATH "
echo "AUX_SCRIPT_PATH: $AUX_SCRIPT_PATH"
echo "GETHOST: $GETHOST "
echo " "
ask "Continue? [Y/n]" y
if [ $? -ne 0 ]; then
        {
        exit 100
        }
fi
}

			


####
####
#
# Error Handler.
#
####
####

function ERROR 
{
	echo " "
	echo " "
	echo "----------------"
	echo "| ABEND: Code $1 |"
	echo "--------------------------------------------------------------------------"
	echo "| Bummer!  An error occurred!"
	echo "| Don't you just hate it when..."
	echo "|${2}?"
	echo "|_________________________________________________________________________"
}

	



####
####
#
# -  SYNTAX  -------- Bet you cannot guess what this does.  
#
####
####

function SYNTAX 
{
	MORE "Do you wish to view the Syntax for `VERSION`" y
	echo "SYNTAX: Program $PROGNAME"
	echo " "

	
	MORE "Do you wish to continue?" y
	echo "NOTES: "
	echo " "

	
	MORE "Do you wish to continue?" y
	echo "NOTES:"
	echo " "
	echo "**** End of help.  Don't you wish there was more? ****"
	echo "Strike a key to exit help."
	read DUMMY
	return
}
	
####
####
#
# MORE
#
####
####

function MORE()
{
ask "$1 [y/n]" $2
if [ $? -eq 0 ]; then
        return
else
        exit 0
fi
}


####
####
#
# -  CHECKCMD  --------- Locates the system cammands used by this script.-------
# This makes sure the commands we need exist.  If a command is missing,
# this function will cause the script to abort.
#
####
####

function CHECKCMD 
{
# Check for required *NIX executable commands.
echo "---->In CHECKCMD...."
	for i in id seq echo hostname touch cp mv rm rsync do_massdo ask; do
		which $i; 
		if [ $? -ne 0 ]; then 
			ERROR 1 "the command $i is missing from the system: Error in CHECKCMD"
			exit 1
		fi;  
	done

## Check for individual specifically required files
	if [ -f ${AUX_SCRIPT_PATH}do_ssh_hosts  ]; then
		echo "${AUX_SCRIPT_PATH}do_ssh_hosts found.  Proceeding."
	else
		ERROR 2 "the ${AUX_SCRIPT_PATH}do_ssh_hosts file is missing: Error 2 in CHECKCMD"
		exit 2
	fi
	
	if [ -f ${DEFAULT_PATH}do_massdo  ]; then
		echo "${DEFAULT_PATH}do_massdo found.  Proceeding."
	else
		ERROR 3 "the ${DEFAULT_PATH}do_massdo file is missing: Error 3 in CHECKCMD"
		exit 3
	fi
}

####
####
#
# CHECK_HOST  ----Aborts the program if the hostname keyfile is missing.
#
####
####
function CHECK_HOST()
{
AUTHORIZED_BACKUP_HOST=`cat /root/bin/authorized_hostkey`
if [ $AUTHORIZED_BACKUP_HOST = `hostname` ]; then
	{
	echo "Host $AUTHORIZED_BACKUP_HOST validated."
	}
else
	{
	ERROR 20 "you try to run Snapback on an unauthorized backup host: Error 20 in CHECK_HOST"
	exit 20
	}
fi
}






####
####
#
# - R_U_ROOT  ----- Aborts the program if the person running it is not root.
#
####
####

function R_U_ROOT
{
ID=`id -u`
if [ $ID -ne 0 ]; then
	{
	echo "$PROGNAME is a potentially dangerous program."
	echo "Therefore it is only to be run by the root user."
	echo "You appear to be running it as `id -nu`."
	echo "Please try again as root or have the system administrator run"
	echo "$PROGNAME for you."
	ERROR 10 "you forget to log in as root first: Error 10 in R_U_ROOT"
	exit 10
	}
fi
}



####
####
#
# - GETARGS  ----------- Converts command-line args to appropriate parameters.  Otherwise, 
# it prompts for the necessary arguments.
#
####
####

function GETARGS
{
echo "IN GETARGS...."
if [ -z $1 ]; then
	{
	ask "Do you wish a DSA key? (default is RSA) [y/N]" n
	if [ $? -eq 0 ]; then
		KEYTYPE=dsa
	else
		KEYTYPE=rsa
	fi
	}
else
	{
	case "$1" in
		dsa|DSA|-d|-D|d|D|-dsa|-DSA|--dsa|--DSA)
			KEYTYPE=dsa
		;;
		
		*)
			KEYTYPE=rsa
		;;
	esac
	}
fi
}


####
####
#
# Reports the version for this program.
#
####
####

function VERSION
{
echo "$PROGNAME Version 11192k3-a, NEWSCRIPT Version 11132k3-a"
}




####
####
#
# SSH2 Key Generation and Acquisition.
#
####
####
function SSH_KEY_GENERATION
{
echo "===================================="
echo " SSH2 KEY GENERATION AND AQUISITION"
echo "===================================="
i=0
for GETHOST in `cat ${AUX_SCRIPT_PATH}do_ssh_hosts`; do
	{
	clear
	i=`expr $i + 1`
	echo "Iteration #: $i: Processing: $GETHOST"
	ask "Do you REALLY want to generate a new key for $GETHOST [y/N]?" n
	if [ $? -eq 0 ]; then
		{
		echo "Generating key..."
		ssh $GETHOST ssh-keygen -t $KEYTYPE
		}
	else
		echo "Will use existing key from $GETHOST."
	fi
	echo "Acquiring public key from $GETHOST..."
	scp $GETHOST:~/.ssh/id_${KEYTYPE}.pub ~/.ssh/$GETHOST.id_${KEYTYPE}_pub
	}
done
}



####
####
#
# MASTER_KEY_FILE_COMPILATION
#
####
####
function COMPILE_MASTERKEYS
{
echo "==============================="
echo "    COMPILING MASTER KEYS"
echo "==============================="
echo "Nuking old masterkey file of name $MASTER_AUTHKEYS2"
rm ~/.ssh/$MASTER_AUTHKEYS2
for FILE in `echo *.id_${KEYTYPE}_pub`; do
	{
	cat ~/.ssh/$FILE >>~/.ssh/$MASTER_AUTHKEYS2
	if [ $? -ne 0 ]; then
		ERROR 50 "compilation of $MASTER_AUTHKEYS2 fails: Error 50 in COMPILE_MASTERHOSTS()"
		exit 50
	fi
	}
done
}



####
####
#
# DISSEMINATE_NEW_MASTERKEYS_FILES
#
####
####
function DISSEMINATE_MASTERKEYS
{
echo "================================================================="
echo "			  DISSEMINATING MASTER KEYS"
echo " Populating cluster with new masterkeys file for user `whoami`."
echo "      Optionally removing existing known_hosts file. . ."
echo "================================================================="
echo "This will disseminate copies of the $MASTER_AUTHKEYS2 file to each"
echo "node specified in the ${AUX_SCRIPT_PATH}do_ssh_hosts file"
i=0
ask "Do you wish to proceed? [Y/n]" y
if [ $? -eq 0 ]; then
	{
	for GETHOST in `cat ${AUX_SCRIPT_PATH}do_ssh_hosts`; do
		{
		clear
		i=`expr $i + 1`
		echo "Iteration #: $i: Sending master keys to $GETHOST:"
		scp ~/.ssh/$MASTER_AUTHKEYS2 $GETHOST:~/.ssh/authorized_keys2
		echo "This will remove the existing .ssh/known_hosts."
		ask "Do you wish to proceed [Y/n]?" y
		if [ $? -eq 0 ]; then
			{
			echo "Removing .ssh/known_hosts on $GETHOST."
			ssh $GETHOST rm ~/.ssh/known_hosts
			}
		else
			echo "I am not touching .ssh/known_hosts on $GETHOST."
		fi
		
		echo "======>>> RESTARTING SSH on $GETHOST. <<<======"
		ssh $GETHOST "test -f /etc/debian_version"
		if [ $? -eq 0  ]; then
			{
			echo " "
			echo "======================================"
			echo "DEBIAN SSH DAEMON RESTART in PROGRESS!"
			echo "======================================"
			ssh root@$GETHOST /etc/init.d/ssh restart
			if [ $? -ne 0 ]; then
				ERROR 60 "we couldn't restart ssh on $GETHOST (Error 60 in DISSEMINATE_MASTERKEYS()"
			fi
			}
		else
			{
			echo " "
			echo "========================================="
			echo "RPM-based SSH DAEMON RESTART in PROGRESS!"
			echo "========================================="
			ssh root@$GETHOST /etc/init.d/sshd restart
			if [ $? -ne 0 ]; then
				ERROR 61 "we couldn't restart sshd on $GETHOST (error 61 in DISSEMINATE_MASTERKEYS()"
			fi
			}
		fi
		
		ask "Continue with the next host [Y/n]?" y
		if [ $? -eq 0 ]; then
			echo "Proceeding...."
		else
			{
			echo "Aborting per your request at host $GETHOST."
			exit 62
			}
		fi
		}	
	done
	}
else
	{
	echo "Cancelling Dissemination of Master Keys at your request."
	echo "NO master keys file was replicated."
	exit 63
	}
fi
}


####
####
#
# ACQUAINTING--REGISTERING HOSTS WITH EACH OTHER.
#
####
####
function ACQUAINT
{
echo "====================================================================="
echo "                             ACQUAINT"
echo "Many thanks to Peter Cordes for his suggestion that I use ssh-keyscan"
echo "to automate what was once an annoyingly manual procedure."
echo " "
echo "This process will \"register\" each host with all the others so that "
echo "it becomes possible to log in to them without being prompted to add "
echo "each host to the known_hosts file."
echo " "
echo "This process will update both /etc/ssh/ssh_known_hosts"
echo "and the local ~/.ssh/known_hosts on each machine."
echo "====================================================================="
echo " "
ask "Shall I proceed with the updates to /etc/ssh/ssh_known_hosts [Y/n]" y
if [ $? -eq 0 ]; then
	{
	do_massdo "ssh-keyscan -t dsa,rsa -f ${AUX_SCRIPT_PATH}do_ssh_hosts | sort -u > /etc/ssh/ssh_known_hosts2"
	do_massdo "ssh-keyscan -t $KEYTYPE -f ${AUX_SCRIPT_PATH}do_ssh_hosts | sort -u > ~/.ssh/known_hosts"
	}
fi
}


#======================================= No more functions. ==========

#############################################################################
#################################        ####################################
#################################  MAIN  ####################################
#################################        ####################################
#############################################################################

case "$1" in
	v|V|-v|-V|--version|--VERSION|--Version|-version|-Version|-VERSION--ver|--Ver|--VER|-ver|-Ver|-VER)
		VERSION
		exit 0
	;;
	h|H|-h|-H|--help|--HELP|--Help|HELP|help|Help|-help|-HELP|-Help)
		SYNTAX
		exit 0
	;;
esac

#CHECK_HOST
R_U_ROOT
VERSION
CHECKCMD
GETARGS $1


echo "IN MAIN-------->>>>>>>"

echo "What would you like to name the masterkeys template file?"
read MASTER_AUTHKEYS2
cd ~/.ssh
touch ~/.ssh/$MASTER_AUTHKEYS2
echo "We are working with ~/.ssh/$MASTER_AUTHKEYS2."

SSH_KEY_GENERATION
COMPILE_MASTERKEYS
DISSEMINATE_MASTERKEYS
ACQUAINT

echo "End run--------------<<<<<<<".