diff --git a/tg_server/tg_server.lua b/tg_server/tg_server.lua
index 1cb5ec2..313c647 100644
--- a/tg_server/tg_server.lua
+++ b/tg_server/tg_server.lua
@@ -31,24 +31,21 @@ end
 local function validate_key(card_holder, card_clearance, random_chars)
     local card_hash = hash(card_holder..','..card_clearance..','..random_chars)
     local key_file = fs.open(dir..config.key_file, 'r')
-    local card_authentic = false
 
     while true do
         local trusted_hash = key_file.readLine()
         if trusted_hash == card_hash then
             print("Valid card "..card_hash)
-            card_authentic = true
+            key_file.close()
             return true, card_hash
         end
-        if not line then break end -- Stop when EOF reached
+        if not trusted_hash then break end -- Stop when EOF reached
     end
 
     key_file.close()
     
-    if card_authentic == false then
-        print("Unknown card "..card_hash)
-        return false
-    end
+    print("Unknown card "..card_hash)
+    return false
 end
 
 if args[1] == "serve" then