#!/bin/bash
NF="\e[0m"
FB="\e[1m"
CG="\e[38;5;40m"
CR="\e[38;5;9m"
CY="\033[38;5;226m"
USER=$(getent passwd 1000 | cut -d: -f1)
PC=$(uname -n | awk '{print $1}')

guardband() {
if [ $? -ne 0 ]; then
echo -e "${CR}Script Exited with an Error.${NF}"
exit 1
fi
}

verifycdn(){
CDN="https://cdn.franscorack.com"
echo -e "${CY}Verifying CDN availability...${NF}"
if ! wget --spider "$CDN" 2>/dev/null; then
    echo -e "${CR}Error: Cannot reach CDN for checksum verification - ${FB}Are you connected on the Internet ? / Is the CDN down ?${NF}"
    echo -e "${CR}Key-renewal script can only be ran if $CDN is reachable. Script Halted. ${NF}"
    return 1
    else
    echo -e "${CG}CDN available for checksum downloads - ${FB}Proceeding...${NF}"
    serversidePUB=$(wget https://cdn.franscorack.com/chksum/sshprov/pub -q -O -)
    serversidePRIV=$(wget https://cdn.franscorack.com/chksum/sshprov/priv -q -O -)
    sleep 2
fi
}

rootcheck(){
if [ -f /root/.ssh/id_ed25519 ]; then
rootPRIV=$(sha256sum /root/.ssh/id_ed25519 | awk '{print $1}')
else
rootPRIV=0
fi
if [ -f /root/.ssh/authorized_keys ]; then
rootPUB=$(sha256sum /root/.ssh/authorized_keys | awk '{print $1}')
else
rootPUB=0
fi
echo Root User Check:
if [ "$rootPRIV" = "$serversidePRIV" ]
then
    echo -e "${CG}Private Keys Checksum against Server - ${FB}OK${NF} ${CG}- No action needed${NF}"
    chmod 700 /root/.ssh
    chmod 600 /root/.ssh/id_ed25519
    else
    echo -e "${CR}Private Keys Checksum against Server - ${FB}MISMATCH${NF} ${CR}- Provisioning... ${NF}"
    sleep 2
    if [ -f /root/.ssh/id_ed25519 ]; then
    rm /root/.ssh/id_ed25519
    fi
    cp --no-preserve=mode,ownership /.SSH/automated/priv/servers/id_ed25519 /root/.ssh/id_ed25519
    echo -e ${CY}'key data from server -> local store'${NF}
    chmod 700 /root/.ssh
    chmod 600 /root/.ssh/id_ed25519
    echo -e ${CY}'chmod -> local store'${NF}
    systemctl restart sshd
    echo -e ${CY}'sshd restart'${NF}
    sleep 3
    rootPRIV2=$(sha256sum /root/.ssh/id_ed25519 | awk '{print $1}')
    if [ "$rootPRIV2" = "$serversidePRIV" ]
    then
        echo -e "${CG}${FB}CHECKSUM OK - PROVISION SUCCESS${NF}"
        else
        echo -e "${CR}${FB}CHECKSUM MISMATCH - MANUAL INTERVENTION REQUIRED${NF}"
        return 1
    fi
fi
if [ "$rootPUB" = "$serversidePUB" ]
then
    echo -e "${CG}Public Keys Checksum against Server - ${FB}OK${NF} ${CG}- No action needed${NF}"
    chmod 700 /root/.ssh
    chmod 600 /root/.ssh/authorized_keys
    else
    echo -e "${CR}Public Keys Checksum against Server - ${FB}MISMATCH${NF} ${CR}- Provisioning... ${NF}"
    sleep 2
    if [ -f /root/.ssh/authorized_keys ]; then
    rm /root/.ssh/authorized_keys
    fi
    cp --no-preserve=mode,ownership /.SSH/automated/pub/servers/id_ed25519.pub /root/.ssh/authorized_keys
    echo -e ${CY}'key data from server -> local store'${NF}
    chmod 700 /root/.ssh
    chmod 600 /root/.ssh/authorized_keys
    echo -e ${CY}'chmod -> local store'${NF}
    systemctl restart sshd
    echo -e ${CY}'sshd restart'${NF}
    sleep 3
    rootPUB2=$(sha256sum /root/.ssh/authorized_keys | awk '{print $1}')
    if [ "$rootPUB2" = "$serversidePUB" ]
    then
        echo -e "${CG}${FB}CHECKSUM OK - PROVISION SUCCESS${NF}"
        else
        echo -e "${CR}${FB}CHECKSUM MISMATCH - MANUAL INTERVENTION REQUIRED${NF}"
        return 1
    fi
fi
}

admincheck(){
if [ -f /home/$USER/.ssh/id_ed25519 ]; then
adminPRIV=$(sha256sum /home/$USER/.ssh/id_ed25519 | awk '{print $1}')
else
adminPRIV=0
fi
if [ -f /home/$USER/.ssh/authorized_keys ]; then
adminPUB=$(sha256sum /home/$USER/.ssh/authorized_keys | awk '{print $1}')
else
adminPUB=0
fi
echo Admin User Check:
if [ "$adminPRIV" = "$serversidePRIV" ]
then
    echo -e "${CG}Private Keys Checksum against Server - ${FB}OK${NF} ${CG}- No action needed${NF}"
    chmod 700 /home/$USER/.ssh
    chmod 600 /home/$USER/.ssh/id_ed25519
    chown $USER -R /home/$USER/.ssh
    else
    echo -e "${CR}Private Keys Checksum against Server - ${FB}MISMATCH${NF} ${CR}- Provisioning... ${NF}"
    sleep 2
    if [ -f /home/$USER/.ssh/id_ed25519 ]; then
    rm /home/$USER/.ssh/id_ed25519
    fi
    cp --no-preserve=mode,ownership /.SSH/automated/priv/servers/id_ed25519 /home/$USER/.ssh/id_ed25519
    echo -e ${CY}'key data from server -> local store'${NF}
    chmod 700 /home/$USER/.ssh
    chmod 600 /home/$USER/.ssh/id_ed25519
    chown $USER -R /home/$USER/.ssh
    echo -e ${CY}'chmod -> local store'${NF}
    systemctl restart sshd
    echo -e ${CY}'sshd restart'${NF}
    sleep 3
    adminPRIV2=$(sha256sum /home/$USER/.ssh/id_ed25519 | awk '{print $1}')
    if [ "$adminPRIV2" = "$serversidePRIV" ]
    then
        echo -e "${CG}${FB}CHECKSUM OK - PROVISION SUCCESS${NF}"
        else
        echo -e "${CR}${FB}CHECKSUM MISMATCH - MANUAL INTERVENTION REQUIRED${NF}"
        return 1
    fi
fi
if [ "$adminPUB" = "$serversidePUB" ]
then
    echo -e "${CG}Public Keys Checksum against Server - ${FB}OK${NF} ${CG}- No action needed${NF}"
    chmod 700 /home/$USER/.ssh
    chmod 600 /home/$USER/.ssh/authorized_keys
    chown $USER -R /home/$USER/.ssh
    else
    echo -e "${CR}Public Keys Checksum against Server - ${FB}MISMATCH${NF} ${CR}- Provisioning... ${NF}"
    sleep 2
    if [ -f /home/$USER/.ssh/authorized_keys ]; then
    rm /home/$USER/.ssh/authorized_keys
    fi
    cp --no-preserve=mode,ownership /.SSH/automated/pub/servers/id_ed25519.pub /home/$USER/.ssh/authorized_keys
    echo -e ${CY}'key data from server -> local store'${NF}
    chmod 700 /home/$USER/.ssh
    chmod 600 /home/$USER/.ssh/authorized_keys
    chown $USER -R /home/$USER/.ssh
    echo -e ${CY}'chmod -> local store'${NF}
    systemctl restart sshd
    echo -e ${CY}'sshd restart'${NF}
    sleep 3
    adminPUB2=$(sha256sum /home/$USER/.ssh/authorized_keys | awk '{print $1}')
    if [ "$adminPUB2" = "$serversidePUB" ]
    then
        echo -e "${CG}${FB}CHECKSUM OK - PROVISION SUCCESS${NF}"
        else
        echo -e "${CR}${FB}CHECKSUM MISMATCH - MANUAL INTERVENTION REQUIRED${NF}"
        return 1
    fi
fi
}

if [ "$UID" -ne 0 ]; then
    echo -e "${CR}This script must be run as root.${NF}"
    exit 1
fi
echo -e ${CY}Warning: running this script resets known_hosts file. Abort this script using CTRL+C if you want to avoid that.${NF}
sleep 3
if [ -f /home/$USER/.ssh/known_hosts ]; then
rm /home/$USER/.ssh/known_hosts
fi
if [ -f /root/.ssh/known_hosts ]; then
rm /root/.ssh/known_hosts
fi
if [ "$PC" = "pve01" ]
then
verifycdn
guardband
rootcheck
guardband
else
verifycdn
guardband
rootcheck
guardband
admincheck
guardband
fi
sleep 2
echo -e "${CG}Script execution completed.${NF}"