Email system with roaming accounts

Azimath · Jan 19, 2013

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

If I implement this on my friends tekkit server(where we all live pretty close together), I may shoot some video.

Planned features/improvements:
-Save data to disk
-Save data to disk(encrypted or something)
-Misc robustness improvements (I usually let kexus321 try to break it until it does break, then fix what caused it to break)
-clean up a little
-support an inbox using subject lines instead of just "you have x messages"
-support for dynamically discovering DNS and login servers
-create a dynamic mesh network of repeaters to expand usable range (probably going to stay in the planned feature section for a while)
-add other servers that use the login/DNS system to create a larger "internet" system

Suggestions/comments/constructive criticism appreciated
If you use this code, please keep the "Legoman technologies" statement as accreditation

Chaeris · Jan 20, 2013

If we continue going on like that, we'll make video games for computers! (Mario/PacMan/other)

thefun · Jul 7, 2014

does not cause

Azimath · Jul 7, 2014

Could you show what it looks like when you open that program in the computer's edit system? It indicates line 4, which is just term.clear() .

thefun · Jul 7, 2014

I do not know much english

Azimath · Jul 7, 2014

Looks like you havent put the ID number of the DNS and Auth server in the right places. AUTHID and DNSID need to have the number on the same line replaced with the Computer ID of the Authentication and DNS computers. the ID for each computer is displayed on that computer when the program is running.
Code:
local AUTHID = 0
local DNSID = 1
these lines^

thefun · Jul 7, 2014

Do not tell this video

Do not describing the video here

Azimath · Jul 12, 2014

Sorry I've been out. Show/post the top of the code in the computer that is broken, so I can check the configuration.

Email system with roaming accounts

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Email system with roaming accounts

Azimath Master Zepplin Thief

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