h roaming accounts
Discussion in 'ComputerCraft Programming' started by Azimath, Jan 19, 2013.

 Azimath
Azimath
Master Zepplin Thief
Joined:Jan 22, 2012
Messages:30
Likes Received:6
Ive seen email systems done in the past, but here's the first usable version of mine. I spent a lot of time writing this stuff at 3am, so it probably needs some cleaning up.

It involves a few separate systems: a login server, a DNS-like server, an email server, and an email client.

The login server is similar to the one from the wiki, but with changes to the way it works to make it more secure, and allow the server owner to add/remove accounts on the fly. The code comes with an account for the email server to use by default, so you need to add user accounts. To do so , just start the program and press the 'a' key. It will ask for a name and a password, then confirm adding the user to the list. Removing is just pressing the 'r' key, entering the username, and confirming. You can press 'm' to view the list of users currently in the system.

DANGER: since this is an early version, anything in any of the servers not hardcoded will not persist after a crash/reboot

Code:
pullEvent = os.pullEvent
os.pullEvent = os.pullEventRaw
users = {"mailserver"}
passwords = {"legomail"}
term.clear()
term.setCursorPos(1,1)
print("Legoman technologies authentication server running")
id = os.computerID()
term.setCursorPos(1,2)
print("Computer ID = "..id)

local firstCycle = true
local modemSide = "right"
local valid = false
local DNSID = 2

while true do
  if firstCycle then
    rednet.open(modemSide)
    firstCycle = false
  end
  event, p1, p2, p3 = os.pullEvent()
  term.clear()
  term.setCursorPos(1,1)
  print("Legoman technologies authentication server running")
  id = os.computerID()
  term.setCursorPos(1,2)
  print("Computer ID = "..id)

  if event =="char" then
    if p1 == "m" then
      for i, v in ipairs(users) do
        print(v)
      end
    end
    if p1 == "a" then
      term.setCursorPos(1,10)
      print("Enter name: ")
      name = read()
      print("Enter password: ")
      password = read()
      print("Confim add " .. name .. " Y/N?")
      if read() == "Y" then
        table.insert(users, name)
        table.insert(passwords, password)
        print("Added")
      end
    end
    if p1 == "r" then
      print("Enter name: ")
      name = read()
      print("Confim remove " .. name .. " Y/N?")
      if read() == "Y" then
        for i,v in ipairs(users) do
          if name == v then
            table.remove(users, i)
            table.remove(passwords, i)
          end
        end
      end
    end
  end

  if event == "terminate" then
    term.setCursorPos(1,10)
    print("Enter password: ")
    if read("*") == "unlock" then
      os.pullEvent = pullEvent
      shell.exit()
    end
  end

  if event == "rednet_message" then
    senderId = p1
    message = p2
    term.setCursorPos(1,4)
    term.clearLine()
    print(message)
    for i,v in ipairs(users) do
      if message == v then
      valid = true
      password = passwords[i]
      user = users[i]
      break
      else
      valid = false
      end
    end

    if valid then
    rednet.send(senderId, "Valid")
    print("Valid")
    else
    rednet.send(senderId, "Not Valid")
    print("Not valid")
    end
    sender, passwordRcv, dist = rednet.receive(3)
    print(sender)
    if passwordRcv == password then
      rednet.send(senderId, "Authenticated")
      rednet.send(DNSID, "Add " .. senderId .. " " .. user)
      print("Authenticated")
    else
      rednet.send(senderId, "Failed")
    end
  end
end
There is a variable near the start named DNSID. you need to change that to the id of the next computer, the DNS server.

When someone logs in, the login server tells the DNS server the name and id of the person who logged in, so others can check the names of users and the ids to send things to. It also supports listing the names in the system using the 'm' key. The variable AUTHID needs to be set to the id of the login server for it to accept new entries, and it is a good idea to give the ids table correct ids for the login and DNS server as well. Currently, if it gets multiple commands to add the same name, the one added first will be the one that counts. If you send a remove message, it will delete you from its table as a means of logging out.
Code:
pullEvent = os.pullEvent
os.pullEvent = os.pullEventRaw

names = {"authserver","dnsserver"}
ids = {0,1}


term.clear()
term.setCursorPos(1,1)
print("Legoman technologies DNS server running")
myid = os.computerID()
term.setCursorPos(1,2)
print("Computer ID = " .. myid)

local firstCycle = true
local modemSide = "right"
local AUTHID = 1

while true do
  if firstCycle then
    rednet.open(modemSide)
    firstCycle = false
  end

  event, p1, p2, p3 = os.pullEvent()

  term.clear()
  term.setCursorPos(1,1)
  print("Legoman technologies DNS server running")
  myid = os.computerID()
  term.setCursorPos(1,2)
  print("Computer ID = " .. myid)

  if event == "terminate" then
    term.setCursorPos(1,10)
    print("Enter password: ")
    if read("*") == "unlock" then
      os.pullEvent = pullEvent
      shell.exit()
    end
  end

  if event =="char" then
    if p1 == "m" then
      for i, v in ipairs(names) do
        print(v)
      end
    end
  end
  if event == "rednet_message" then
    senderId = p1
    message = p2
    term.setCursorPos(1,4)
    term.clearLine()
    if  string.match(message, 'Id') == "Id" then
      print("Command: " .. string.match(message, 'Id'))
      idLookup = string.match(message, '%d+') + 0
      term.clearLine()
      print("Param: " .. idLookup)
      for i, v in ipairs(ids) do
        if idLookup == v then
          nameLookup = names[i]
          term.clearLine()
          print("Return: " .. nameLookup)
          rednet.send(senderId, nameLookup)
          break
        end
      end
    end
    if string.match(message, 'Name') == "Name" then
    print("Command: " .. string.match(message, 'Name'))
    nameLookup = string.match(message, '%a+', 5)
      term.clearLine()
      print("Param: " .. nameLookup)
      for i, v in ipairs(names) do
        if nameLookup == v then
          idLookup = ids[i]
          term.clearLine()
          print("Return: " .. idLookup)
          rednet.send(senderId, idLookup.."")
          break
        end
      end
    end
    if string.match(message, 'Add') == "Add" and senderId + 0 == AUTHID then
      print("Command: " .. string.match(message, 'Add'))
      nameAdd = string.match(message, '%a+', 4)
      idAdd = string.match(message, '%d+', 4)
      print("Params: " .. nameAdd .. ", " .. idAdd)
      table.insert(names, nameAdd)
      table.insert(ids, idAdd+0)
    end
    if string.match(message, 'Remove') == "Remove" then
      print("Command: " .. string.match(message, 'Remove'))
      term.clearLine()
      print("Param: " .. senderId)
      for i, v in ipairs(ids) do
        if senderId == v then
          table.remove(ids, i)
          table.remove(names, i)
        end
      end
    end
  end
end
The third and final server in this system is the email server itself. It needs the login and DNS server ids coded into the AUTHID and DNSID variables, respectively. Pressing 'm' lists the recipients of the messages in the system, 'a' adds a user to the list of people who can use email, and 'l' tries to update its id in the DNS server. It works by sending and receiving a variety of messages to and from the clients, and checking who each one is using the reverse DNS function of the DNS server.
Code:
pullEvent = os.pullEvent
os.pullEvent = os.pullEventRaw

users = {"test"}
messages = {"blank"}
recipients = {"test"}


term.clear()
term.setCursorPos(1,1)
print("Legoman technologies email server running")
myid = os.computerID()
term.setCursorPos(1,2)
print("Computer ID = " .. myid)

local firstCycle = true
local modemSide = "right"
local AUTHID = 0
local DNSID = 1
local senderValid = false
local recipientValid = false

function DNSreverse (Id)
  rednet.open(modemSide)
  rednet.send(DNSID, "Id " .. Id)
  local temp, message = rednet.receive(1)
  return message
end

function login()
  rednet.send(AUTHID, "mailserver")
  os.sleep(1)
  rednet.send(AUTHID, "legomail")
end

while true do
  if firstCycle then
    rednet.open(modemSide)
    firstCycle = false
    rednet.send(DNSID, "Remove")
    login()
  end

  event, p1, p2, p3 = os.pullEvent()

  term.clear()
  term.setCursorPos(1,1)
  print("Legoman technologies email server running")
  myid = os.computerID()
  term.setCursorPos(1,2)
  print("Computer ID = " .. myid)

  if event == "terminate" then
    term.setCursorPos(1,10)
    print("Enter password: ")
    if read("*") == "unlock" then
      os.pullEvent = pullEvent
      shell.exit()
    end
  end

  if event =="char" then
    if p1 == "m" then
      for i, v in ipairs(recipients) do
        print(v)
      end
    end
    if p1 == "a" then
      term.setCursorPos(1,10)
      print("Enter name: ")
      name = read()
      print("Confim add " .. name .. " Y/N?")
      if read() == "Y" then
        table.insert(users, name)
        print("Added")
      end
    end
    if p1 == "l" then
      rednet.send(DNSID, "Remove")
      login()
    end
  end

  if event == "rednet_message" then
    senderId = p1
    message = p2
    senderName = DNSreverse(senderId)
    for i, v in ipairs(users) do
      if senderName == v then
        senderValid = true
        print("Sender is valid")
        break
      else
        senderValid = false
      end
    end

    if  string.match(message, 'Send') == "Send" and senderValid then
      print("Command: " .. string.match(message, 'Send'))
      recipient = string.match(message, '%a+', 5)
      mailMessage = string.match(message, '%p.+', 5)
      print("Recipient: " .. recipient)
      --print("Message: " .. mailMessage)
      os.sleep(1)
      for i, v in ipairs(users) do
        print(v)
        if recipient == v then
          recipientValid = true
          print("Recipient is valid")
          break
        else
          recipientValid = false
        end
      end
      if recipientValid then
        table.insert(messages, mailMessage)
        table.insert(recipients, recipient)
        rednet.send(senderId, "Ok")
      end
    end

    if string.match(message, 'Check') == "Check" and senderValid then
      print("Command: " .. string.match(message, 'Check'))
      messageNumber = 0
      for i, v in ipairs(recipients) do
        if senderName == v then
          messageNumber = messageNumber + 1
        end
      end
      rednet.send(senderId, messageNumber .. "")
    end

    if string.match(message, 'Read') == "Read" and senderValid then
      print("Command: " .. string.match(message, 'Read'))
      readNumber = string.match(message, '%d+', 5) + 0
      print("Read number: " .. readNumber)
      messageNumber = 0
      for i, v in ipairs(recipients) do
        if senderName == v then
              messageNumber = messageNumber + 1
        end
        if messageNumber == readNumber then
          print("Message found")
          rednet.send(senderId, messages[i].."")
          break
        end
      end
    end
    if string.match(message, 'Remove') == 'Remove' and senderValid then
      print("Command: " .. string.match(message, 'Remove'))
      removeNumber = string.match(message, '%d+', 7)
      print("Remove number: " .. removeNumber)
      messageNumber = 0
      for i, v in ipairs(recipients) do
        if senderName == v then
              messageNumber = messageNumber + 1
        end
        if messageNumber == removeNumber + 0 then
          table.remove(messages, i)
          table.remove(recipients, i)
          print("Removed")
          break
        end
      end
    end
  end
end
The email client interfaces to all 3 servers, and it will attempt to find the id of the mail and login servers from DNS, so be sure they are both registered in the DNS server. It supports roaming accounts, so you can log in from any computer in rednet range. It can:
1- Check the number of messages in your inbox
2- Read one of the messages (input the number of the message you want read, with the first in the inbox being number one, the second number two, etc)
3- Send a message to a particular user, which give feedback in the form of "Sent" or "error" (which usually means invalid recipient)
4- Remove a message from the inbox, using a number system like reading messages
5-Log out of your account

Code:
pullEvent = os.pullEvent
os.pullEvent = os.pullEventRaw

term.clear()
term.setCursorPos(1,1)
print("Legoman technologies email client running")
myid = os.computerID()
term.setCursorPos(1,2)
print("Computer ID = " .. myid)

local firstCycle = true
local modemSide = "right"
local AUTHID = 0
local DNSID = 1
local loggedin = false

function DNSreverse (Id)
  rednet.open(modemSide)
  rednet.send(DNSID, "Id " .. Id)
  local temp, message = rednet.receive(1)
  return message
end

function DNSforward(servername)
  rednet.open(modemSide)
  rednet.send(DNSID, "Name " .. servername)
  local temp, message = rednet.receive(3)
  return message
end

while true do
  if firstCycle then
    rednet.open(modemSide)
    firstCycle = false
  end

  AUTHID = DNSforward("authserver") + 0
  MAILID = DNSforward("mailserver") + 0
  print("Mail ID: " .. MAILID)
  print("Auth ID: " .. AUTHID)
  print("Welcome! Please log in.")
  print("Username: ")
  username = read()
  print("Password:")
  password = read("*")

  rednet.send(AUTHID + 0, username)
  sender, message = rednet.receive(2)

  if message == "Valid" then
    print("Username ok!")
    rednet.send(AUTHID + 0, password)
  elseif message == "Not Valid" then
    print("Wrong username!")
    loggedin = false
  else
    print("Rednet error!")
  end

  sender, message = rednet.receive(2)

  if message == "Authenticated" then
    loggedin = true
    print("Logged in!")
  else
    print("Login failed!")
  end
  os.sleep(2)

  if loggedin then
    term.clear()
    term.setCursorPos(1,1)
  end

  while loggedin do

    print("Legoman technologies email client! Username: " .. DNSreverse(myid))
    print("What would you like to do?")
    print(" 1 - Check for messages")
    print(" 2 - Read a message")
    print(" 3 - Send a message")
    print(" 4 - Remove a message")
    print(" 5 - Log out")
    print(">")
    input = read()

    if input == "1" then
      print("Checking for messages")
      rednet.send(MAILID, "Check")
      temp, message = rednet.receive(3)
      print("You have: " .. message .. " message(s)")
    end

    if input == "2" then
      print("Enter message number to read: ")
      messageNum = read()
      rednet.send(MAILID, "Read " .. messageNum)
      temp, message = rednet.receive(3)
      print(message)
    end

    if input == "3" then
      print("Enter recipient name: ")
      recipient = read()
      print("Enter message: ")
      toSend = read()
      print("Send message to " .. recipient .. " Y/N?")
      yn = read()
      if yn == "Y" then
        rednet.send(MAILID, "Send " .. recipient .. " !" .. toSend)
        temp, message = rednet.receive(3)
        if message == "Ok" then
          print("Sent!")
        else
          print("Error!")
        end
      end
    end

    if input == "4" then
      print("Enter message number to remove: ")
      messageNum = read()
      os.sleep(1)
      print("Proceed? Y/N?")
      yn = read()
      if yn == "Y" then
        rednet.send(MAILID, "Remove " .. messageNum)
      end
    end

    if input == "5" then
      term.clear()
      term.setCursorPos(1,1)
      print("Goodbye!")
      os.sleep(1)
      rednet.send(DNSID, "Remove")
      loggedin = false
      term.clear()
      term.setCursorPos(1,1)
    end
  end
end