Add wirelessCode/wireless.lua

wirelessCode/wireless.lua

@@ -0,0 +1,118 @@
+local key = ""
+local wirelessChannel = 44385
+
+local wirelessModem = assert(peripheral.wrap("top"))
+
+wirelessModem.open(wirelessChannel)
+
+local random = require("ccryptolib.random")
+local aead = require("ccryptolib.aead")
+
+local seed = ""
+-- this isnt exactly secure, but its fine, probably..
+for i=1,64 do
+  seed = seed .. string.char(math.random(0, 255))
+end
+
+random.init(seed)
+
+local function encrypt(message)
+  local nonce = random.random(12)
+  local ciphertext, tag = aead.encrypt(key, nonce, message, "")
+
+  return nonce..tag..ciphertext
+end
+
+local function decrypt(message)
+  local ciphertextLength = #message-12-16
+
+  if ciphertextLength < 0 then
+    printError("message too short, this may be caused by other traffic on the same port")
+    return
+  end
+
+  if ciphertextLength >= 32768 then
+    printError("message too large, this may be caused by other traffic on the same port")
+    return
+  end
+
+  local nonce, tag, endPos = string.unpack("c12c16", message)
+  local ciphertext = message:sub(endPos)
+
+  local decryptedMessage = aead.decrypt(key, nonce, tag, ciphertext, "") -- this is nil if auth failed
+
+  if not decryptedMessage then
+    printError("message auth invalid")
+    return
+  end
+
+  return decryptedMessage
+end
+
+local function sendWireless(tbl)
+  local str = textutils.serialize(tbl)
+
+  if not str then
+    printError("failed to serialize message")
+    return
+  end
+
+  local enc = encrypt(str)
+
+  if not enc then
+    printError("failed to encrypt serialized message")
+    return
+  end
+
+  wirelessModem.transmit(wirelessChannel, wirelessChannel, enc)
+end
+
+local function recvWireless()
+  while true do
+    local event, side, channel, replyChannel, message, distance = os.pullEvent("modem_message")
+    if side == peripheral.getName(wirelessModem) and channel == wirelessChannel then
+      local dec = decrypt(message)
+      if dec then
+        local unser = textutils.unserialize(dec)
+        if unser then
+          return unser
+        else
+          printError("failed to unserialize")
+        end
+      end
+    end
+  end
+end
+
+return {
+  broadcast = function(data, protocol)
+    local message_wrapper = {
+      nMessageID = math.random(1, 2147483647), -- we dont store messageid here because we shouldnt get our messages back
+      nRecipient = rednet.CHANNEL_BROADCAST,
+      nSender = os.getComputerID(),
+      message = data,
+      sProtocol = protocol,
+    }
+
+    sendWireless(message_wrapper)
+  end,
+  receive = function(protocol, timeout) -- computer ids not implemented
+    local ret = {}
+    parallel.waitForAny(function()
+      while true do
+        local msg = recvWireless()
+
+        if type(msg) == "table" then
+          ret = {msg.nMessageID, msg.message, msg.sProtocol}
+          return
+        end
+      end
+    end, function() -- this sucks as well
+      while not timeout do sleep(1) end
+      sleep(timeout)
+      ret = {}
+    end)
+
+    return table.unpack(ret)
+  end
+}