#51 init mac component from config key

reactor-plc/config.lua

@@ -17,6 +17,11 @@ config.PLC_CHANNEL = 16241
 config.TRUSTED_RANGE = 0
 -- time in seconds (>= 2) before assuming a remote device is no longer active
 config.COMMS_TIMEOUT = 5
+-- facility authentication key (do NOT use one of your passwords)
+-- this enables verifying that messages are authentic
+-- all devices on the same network must use the same key
+-- message authentication codes require computing a hash on each message, so this can slow things down
+-- config.AUTH_KEY = "SCADAfacility123"
 
 -- log path
 config.LOG_PATH = "/log.txt"

reactor-plc/startup.lua

@@ -80,6 +80,11 @@ local function main()
     -- mount connected devices
     ppm.mount_all()
 
+    -- message authentication init
+    if type(config.AUTH_KEY) == "string" then
+        network.init_mac(config.AUTH_KEY)
+    end
+
     -- shared memory across threads
     ---@class plc_shared_memory
     local __shared_memory = {