Server_Beta

version = "0.02 Beta"
if not fs.isDir("/apis") then
    fs.delete("/apis/")
    fs.makeDir("/apis/")
    shell.run("pastebin get 9E5UHiqv /apis/AES")
    shell.run("pastebin get QYvNKrXE /apis/Base64")
end
if not fs.exists("/apis/AES") then
    shell.run("pastebin get 9E5UHiqv /apis/AES")
end
if not fs.exists("/apis/Base64") then
    shell.run("pastebin get QYvNKrXE /apis/Base64")
end
os.loadAPI("/apis/AES")
os.loadAPI("/apis/Base64")
modem = nil
for k, v in pairs(peripheral.getNames()) do
    if peripheral.getType(v) == "modem" then
        modem = peripheral.wrap(v)
    end
end
if not modem then
    error("This program requires a modem!")
else
    modem.open(24680)
end
clients = {}
uptime = 0
run = true
timeout = 30
domain = "tron.com"
edomain = domain .. "|"
function sendTo(cid,tmsg,msg)
    modem.transmit(24680,cid,tmsg.." "..msg)
end
function eSendTo(cid,scode,tmsg,msg)
    ctid = nil
    for i = 1, #clients do
        if clients[i]["id"] == cid then
            ctid = i
        end
    end
    if not ctid then
        return "No such client."
    end
    key_used = tostring(cid)..tostring(clients[ctid]["dist"])..tostring(clients[ctid]["ss"])
    local tr = "E"..Base64.encode(AES.encrypt(key_used,tostring(scode).." "..tmsg.." "..msg))
    clients[ctid]["ss"] = clients[ctid]["ss"]+1
    modem.transmit(24680,cid,tr)
    return tr
end
function decode(cid,msg)
    ctid = nil
    for i = 1, #clients do
        if clients[i]["id"] == cid then
            ctid = i
        end
    end
    if not ctid then
        return "No such client."
    end
    ckey = tostring(tostring(cid)..clients[ctid]["dist"]) .. tostring(clients[ctid]["sent"])
    clients[ctid]["sent"] = clients[ctid]["sent"] +1
    clients[ctid]["time"] = uptime
    return AES.decrypt(ckey,Base64.decode(msg))
end
function network()
    tid = os.startTimer(1)
    while run == true do
        e = {os.pullEvent()}
        if e[1] == "timer" and e[2] == tid then
            clientsTimedOut = {}
            tid = os.startTimer(1)
            uptime = uptime+1
            for i = 1, #clients do
                if uptime >= (clients[i]["time"]+timeout) then
                    table.insert(clientsTimedOut,i)
                end
            end
            for i = 1, #clientsTimedOut do
                table.remove(clients,clientsTimedOut[i])
            end
        elseif e[1] == "modem_message" then
            if e[3] == 24680 then
                msg = e[5]
                msgData = {}
                for word in msg:gmatch("%S+") do
                    table.insert(msgData,word)
                end
                if msgData[1] == "PING" then
                    if msgData[2]:lower() == domain:lower() then
                        newClient = {}
                        newClient["time"] = uptime
                        newClient["id"] = e[4]
                        newClient["dist"] = e[6]
                        newClient["sent"] = 1
                        newClient["ss"] = 0
                        table.insert(clients,newClient)
                        sendTo(e[4],"Pong","Pong!")
                    end
                end
                if msg:sub(1,#edomain+1) == "E"..edomain then
                    umsg = decode(e[4],msg:sub(#edomain+2,#msg))
                    if umsg then
                        umd = {}
                        for word in umsg:gmatch("%S+") do
                            table.insert(umd,word)
                        end
                        if umd[1] == "EPING" and umd[2] == "ENCRYPTED" and umd[3] == "PING" then
                            eSendTo(e[4],200,"EPONG","ENCRYPTED PONG")
                        end
                        if umd[1] == "PAGE" then
                            if not umd[2] or umd[2] == "" then
                                umd[2] = "index"
                            end
                            if umd[2] and #umd[2] >= 3 then
                                if umd[2]:sub(#umd[2]-2,#umd[2]) == ".cc" then
                                    umd[2] = umd[2]:sub(1,#umd[2]-3)
                                end
                            end
                            if fs.exists("/www/"..umd[2]) then
                                f = fs.open("/www/"..umd[2],"r")
                                eSendTo(e[4],200,"PDATA",f.readAll())
                                f.close()
                            elseif fs.exists("/www/"..umd[2]..".cc") then
                                f = fs.open("/www/"..umd[2]..".cc","r")
                                eSendTo(e[4],200,"PDATA",f.readAll())
                                f.close()
                            elseif fs.exists("/www/errors/404") then
                                f = fs.open("/www/errors/404","r")
                                eSendTo(e[4],404,"PDATA",f.readAll())
                                f.close()
                            elseif fs.exists("/www/errors/404.cc") then
                                f = fs.open("/www/errors/404.cc","r")
                                eSendTo(e[4],404,"PDATA",f.readAll())
                                f.close()
                            else
                                eSendTo(e[4],404,"PDATA","print('Error 404: Page not found.')")
                            end
                        end
                    end
                end
            end
        end
    end
end
network()