usage of the API

    while true do
        local event, id, msg, dist = api.evt("rednet_message")
            if string.find(msg, "update") then
                msg = string.sub(msg, string.len("update")+2)
                ids = textutils.unserialize(msg)
                if api.isID(id) then
                    mesg = textutils.unserialize(msg)
                end
            elseif string.find(msg, "apply") then
                if api.isID(id) then
                    msg = string.sub(msg, string.len("apply")+2)
                    local _, _, user, pass = string.find(msg, "^(%w+)&pwd=(%w+)$")
                    term.scroll(1)
                    term.setTextColor(colors.yellow)
                    print("Authenticating...")
                    if api.isPermitted(user, pass) then -- using the API here, where it returns an error
                        term.scroll(1)
                        term.setTextColor(colors.lime)
                        print("Authenticated!")
                        api.send(id, encrypt.hash("OK"))
                    else
                        term.scroll(1)
                        term.setTextColor(colors.lime)
                        print("Not authenticated!")
                        api.send(id, encrypt.hash("FAIL"))

                    end

                    sleep(2)
                end
            elseif msg == "ping" then
                term.scroll(1)
                term.setTextColor(colors.yellow)
                print("Got \"ping\" from "..id)
                if not api.isID(id) then
                    api.saveID(id)
                    term.scroll(1)
                    term.setTextColor(colors.lime)
                    print("Saved ID of client")
                end
                api.send(id, "pong")
                term.scroll(1)
                term.setTextColor(colors.lime)
                print("Successfully sended \"pong\"")
            end
    end