server

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--Copyright 2018 by Dusk the Dutch Angel Dragon
-----------------------------------------------
sides = {"top", "back", "left", "right", "bottom"}
allowedID = {}
username = {}
password = {}
modem = "null"

--Define Functions
function init()
 print("Initalizing Server...")
 print("Initalizing modem...")
 for i=1, #sides do
  if peripheral.getType(sides[i]) == "modem" then
   modem = sides[i]
   print("Modem found on "..sides[i].. " side.")
   rednet.open(modem)
   break
  elseif i == #sides and modem == "null" then
   error("Fatal Error: No Modem found.")
  end
 end

 username = loadTable("uname")
 password = loadTable("pword")
 allowedID = loadTable("whitelist")
end

function checkTable(table, chkv)
 for i=1, #table do
  if table[i] == chkv then
   return i
  elseif i == #table and table[i] ~= chkv then
   return "nomatch"
  end
 end
end

function loadTable(file)
 --Load table contents
 if fs.exists(file) then
  f = fs.open(file, "r")
  d = f.readAll()
  f.close()
  return(textutils.unserialise(d))
 else
  print("File not found: "..file)
  sleep(0.1)
  return {}
 end
end

function saveTable(file, table)
 --Save table contents
 f = fs.open(file, "w")
 f.write(textutils.serialise(table))
 f.close()
end

function filterResponse(filterID)
 rid = -1
 while rid ~= filterID do
  rid, msg = rednet.receive()
 end
 return msg
end

function checkWhitelist(compID)
 for i=1, #allowedID do
  if allowedID[i] == compID then
   return true
  elseif i == #allowedID and allowedID[i] ~= compID then
   return false
  end
 end
end

--Main Code
init()
while true do
 term.clear()
 term.setCursorPos(1,1)
 print("Choose an Option:")
 print("1: Start Server")
 print("2: Add User")
 print("3: Remove User")
 print("4: Add Whitelist ID")
 print("5: Revoke Whitelist ID")
 print("6: Exit Program")
 print("")
 write("Your Choice: ")
 x = read()
--------------------------------------------------
 if tonumber(x) == 1 then
  --Server Code
  print("Server started...")
  while true do
   id, msg = rednet.receive()
   if checkWhitelist(id) then
    sleep(0.1)
    rednet.send(id, "ready")
    subUname = filterResponse(id)
    subPword = filterResponse(id)
    chkUname = checkTable(username,subUname)
    if password[chkUname] == subPword then
     rednet.send(id, "auth")
    else
     rednet.send(id, "nauth")
    end
   else
    rednet.send(id,"400")
   end
  end
--------------------------------------------------
 elseif tonumber(x) == 2 then
  write("Username?: ")
  uname = read()
  print("")
  write("Password?: ")
  pword = read()
  print("")
  print("Creating user...")
  table.insert(username, uname)
  table.insert(password, pword)
  print("User created, saving tables...")
  saveTable("uname", username)
  saveTable("pword", password)
  print("Tables saved successfully!")
 elseif tonumber(x) == 3 then
  write("Username of user to delete?: ")
  uname = read()
  for i=1, #username do
   if username[i] == uname then
    table.remove(username, i)
    table.remove(password, i)
    print("User removed, saving tables...")
    saveTable("uname", username)
    saveTable("pword", password)
    print("Tables saved successfully!")
   elseif i == #username and uname ~= username[i] then
    print("Error: User not found.")
   end
  end
  --
 elseif tonumber(x) == 4 then
  write("Computer ID to whitelist?: ")
  compID = tonumber(read())
  table.insert(allowedID, compID)
  saveTable("whitelist", allowedID)
  print("Computer whitelisted successfully!")
  --
 elseif tonumber(x) == 5 then
  write("Computer ID to dewhitelist?: ")
  compID = tonumber(read())
  for i=1, #allowedID do
   if allowedID[i] == compID then
    table.remove(allowedID, i)
    saveTable("whitelist", allowedID)
    print("Computer dewhitelisted successfully!")
   elseif i == #allowedID and allowedID[i] ~= compID then
    print("Error: Computer ID not found.")
   end
  end
  --
 elseif tonumber(x) == 6 then
  print("Exiting...")
  error()
 end
 sleep(1)
end