Mag card door V1.0

So i found the mag card readers we have, and decided to play with them and a bit of crypto to make a door that requires a magnetic card to be swiped.

Here's how it works:

1. An admin card is swiped, which has a hardcoded password (stored as a hash in the computer).
2. The computer accepts the card if it is an admin card and prompts the user to insert a card.
3. The computer writes a random 15 character password to the card, and stores an SHA1 hashed version in its memory, creating a door card.
4. When a door card is swiped, the door opens for 3 seconds (under optimal TPS, if this matters).

Here's the hardware needed:

1. A door closed by redstone.
2. A computer, advanced or regular.
3. A monitor and mag card reader connected by wired modems to the computer

Optionally, you can have readers away from the monitor to have more than one reader open the door. Only the first reader connected will work to make cards. This is because the computer gets a "mag_swipe" event from any reader connected, and checks the card against the stored hashes. However it needs to wrap the peripheral to actually write, plus the monitor nearby gives confirmation of a valid admin card. The monitor display text needs fixing to line wrap properly, but whatever.

Hardware pics:


Main area


Door open


Inside of door (lever keeps door closed if down, overriding cards)


Some wiring/peripherals


Another view of wiring.

Heres the code:

Code:

os.loadAPI("SHA")
os.pullEvent = os.pullEventRaw
 
redstone.setBundledOutput("left", colors.white)
math.randomseed(os.time())
 
term.clear()
term.setCursorPos(1,1)
print("Legoman Technologies door lock V1.0")
print("Thank you to tomas1666 for his SHA1 code")
 
modem = peripheral.wrap("top")
 
if modem == nil then
  error("Modem not on top")
end
 
if modem.isPresentRemote("mag card reader_0") then
  reader = peripheral.wrap("mag card reader_0")
  print("Card reader connected")
else
  error("Mag-card reader not found")
end
 
if modem.isPresentRemote("monitor_0") then
  monitor = peripheral.wrap("monitor_0")
  print("Monitor connected")
else
  error("Monitor not found")
end
 
hashedPw = "Put the hashed admin password here"
cardsFilePath = "Cards"
cards = {""}
chars = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z","0","1","2","3","4","5","6","7","8","9", "@", "#", "$", "%", "&", "?"}
newpass = ""
cardNum = 0
 
if fs.exists(cardsFilePath) then
  cardsFile = fs.open(cardsFilePath, "r")
  cards = textutils.unserialize(cardsFile.readAll())
  cardsFile.close()
end
 
while true do
  admin = false
 
  monitor.clear()
  monitor.setCursorPos(1,1)
  monitor.write("Welcome to Legoman Industries! Please insert a card!")
  reader.setInsertCardLight(true)
 
 
  event, p1,p2,p3 = os.pullEvent()
 
  if event == "mag_swipe" then
    if SHA.SHA1_2(p1) == hashedPw then
      admin = true
    end
    for x = 1, #cards do
      if SHA.SHA1_2(p1) == cards[x] then
        reader.setInsertCardLight(false)
        redstone.setBundledOutput("left", 0)
        os.sleep(3)
        redstone.setBundledOutput("left", colors.white)
        reader.setInsertCardLight(true)
        break
      end
    end   
  end
  if admin == true then
    reader.setInsertCardLight(false)
    monitor.clear()
    monitor.setCursorPos(1,1)
    monitor.write("Admin granted! Insert blank card!")
    for z = 1,15 do
      case = math.random(1,2) -- randomly choose case (caps or lower)
      a = math.random(1,#chars) -- randomly choose a character from the "char" array
      if case == 1 then
        x=string.upper(chars[a]) -- uppercase if case = 1
      elseif case == 2 then
        x=string.lower(chars[a]) -- lowercase if case = 2
      end
      newpass = newpass..x
    end
    reader.setInsertCardLight(true)
    cardNum = #cards
    print(reader.beginWrite(newpass, cardNum..""))
    table.insert(cards, SHA.SHA1_2(newpass))
   
    while reader.isWaiting() do
    end
   
    reader.setInsertCardLight(false)
    monitor.clear()
    monitor.setCursorPos(1,1)
    monitor.write("New card created!")
    newpass = ""
  end
 
  os.sleep(1)
 
  cardsFile = fs.open(cardsFilePath, "w")
  cardsFile.write(textutils.serialize(cards))
  cardsFile.close()
 
 
end

I'll probably edit this post tomorrow when i have time, and fix the text on the screen to look better.

 

Well edit post is broken, and i wanted to note that there's a computercraft bug where you may need to reconnect the peripherals from time to time by right clicking on the defective peripheral's modem twice.

 

If i had the time, Id make the door solid and do one of those crazy piston contraptions. Keeps the mobs out at least. It doesn't do much for our base against players due to the numerous jet-pack exits in our ceilings.

 

You use the bundled cable functions in the redstone API. It works the same way redpower bundled cable does.

 

The reason I've done anything impractical.
After some server trouble wiped the code from the computer (I could get it from the post), and the pistons disappeared, and the wired cable kept bugging out, Ive stopped using the computer system, and gone to a TC drawbridge and lever thing to close the "lobby" (where my enhanced portal is) off from the rest of my base.

 

That sounds pretty cool. It sounds like it would be pretty hard for you to revoke a lost/stolen card's permissions it sounds like (since some of us like to pretend we have agents/employees/subjugates that need to go in and out all the time and might lose a card). I would have mine running to a master server if I hadn't been playing star-made so much recently. My base isn't complex enough (It consists of a power wing, an automation wing, and a manual crafting/monitoring room) for me to want to implement a multilevel permission system (yet), especially since I usually fly out the "jetpack entrance" rather than mucking about with the door .