Fix issue

Reviewed-on: #4

tg_server/hash.lua

@@ -0,0 +1,7 @@
+function hash(str)
+    local hash = 0
+    for i = 1, #str do
+        hash = (hash * 31 + string.byte(str, i)) % 65536
+    end
+    return string.format("%04X", hash)
+end

tg_server/tg_server.lua

@@ -1,5 +1,6 @@
 local fullPath = shell.getRunningProgram()
 local dir = fullPath:match("^(.*/)") or ""
+local args = {...}
 
 local config = dofile(dir..'taskguard.cfg')
 
@@ -13,14 +14,7 @@ local function split(str, divider)
     return t
 end
 
-local function hash(str)
+dofile(dir..'hash.lua')
-    local hash = 0
-    for i = 1, #str do
-        hash = (hash * 31 + string.byte(str, i)) % 65536
-    end
-    return string.format("%04X", hash)
-end
-
 
 local function check_for_outdated_sessions()
     local expired = 0
@@ -37,82 +31,119 @@ 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)
-        print("Unknown card "..card_hash)
+    return false
-        return false
-    end
 end
 
-rednet.open(config.modem_side)
+if args[1] == "serve" then
-rednet.host('tg', config.name)
+    rednet.open(config.modem_side)
-print("Server started, waiting for requests...")
+    rednet.host('tg', config.name)
+    print("Server started, waiting for requests...")
+    while true do
+        local id, msg, proto = rednet.receive('tg')
+        check_for_outdated_sessions()
+        msg_parts = split(msg, ',')
+        if msg_parts[1] == 'validate_clearance' then
+            print("Beginning transaction for clearance query with "..id)
+            local target_id = tonumber(msg_parts[2])
+            local requested_clearance = tonumber(msg_parts[3])
+            local has_clearance = false
 
-while true do
+            for i, entry in ipairs(clearances) do
-    local id, msg, proto = rednet.receive('tg')
+                if entry.computer_id == target_id and entry.clearance_level >= requested_clearance then
-    check_for_outdated_sessions()
+                    -- Auth granted
-    msg_parts = split(msg, ',')
+                    rednet.send(id, 'granted', 'tg')
-    if msg_parts[1] == 'validate_clearance' then
+                    print('Finished transaction, granted')
-        print("Beginning transaction for clearance query with "..id)
+                    has_clearance = true
-        local target_id = tonumber(msg_parts[2])
+                end
-        local requested_clearance = tonumber(msg_parts[3])
-        local has_clearance = false
-
-        for i, entry in ipairs(clearances) do
-            if entry.computer_id == target_id and entry.clearance_level >= requested_clearance then
-                -- Auth granted
-                rednet.send(id, 'granted', 'tg')
-                print('Finished transaction, granted')
-                has_clearance = true
             end
-        end
 
-        if has_clearance == false then
+            if has_clearance == false then
-            -- Auth not granted
+                -- Auth not granted
-            rednet.send(id, 'failed', 'tg')
+                rednet.send(id, 'failed', 'tg')
-            print('Finished transaction, failed')
+                print('Finished transaction, failed')
-        end
+            end
-        print("EOP")
+            print("EOP")
-    elseif  msg_parts[1] == 'authenticate' then
+        elseif  msg_parts[1] == 'authenticate' then
-        print("Beginning transaction for authentication with "..id)
+            print("Beginning transaction for authentication with "..id)
-        local card_holder = msg_parts[2]
+            local card_holder = msg_parts[2]
-        local card_clearance = msg_parts[3]
+            local card_clearance = msg_parts[3]
 
-        local is_authentic, card_hash = validate_key(card_holder, card_clearance, msg_parts[4])
+            local is_authentic, card_hash = validate_key(card_holder, card_clearance, msg_parts[4])
 
-        if is_authentic then
+            if is_authentic then
-                table.insert(clearances, { computer_id = tonumber(id), clearance_level = tonumber(card_clearance), time_granted = os.clock() })
+                    table.insert(clearances, { computer_id = tonumber(id), clearance_level = tonumber(card_clearance), time_granted = os.clock() })
+                    rednet.send(id, "authentication successful", "tg")
+                    print("Granted card "..card_hash.." clearance level "..card_clearance)
+            else
+                print("Unknown card "..card_hash)
+                rednet.send(id, "authentication failed", "tg")
+            end
+            print("Transaction finished")
+        elseif msg_parts[1] == 'validate_key' then
+            print("Beginning transaction for single-validation with "..id)
+            local card_holder = msg_parts[2]
+            local card_clearance = msg_parts[3]
+            local minimum_clearance = msg_parts[5]
+
+            if validate_key(card_holder, card_clearance, msg_parts[4]) and tonumber(card_clearance) >= tonumber(minimum_clearance) then
                 rednet.send(id, "authentication successful", "tg")
-                print("Granted card "..card_hash.." clearance level "..card_clearance)
+            else
-        else
+                rednet.send(id, "authentication failed", "tg")
-            print("Unknown card "..card_hash)
+            end
-            rednet.send(id, "authentication failed", "tg")
+            print("Transaction finished")
         end
-        print("Transaction finished")
+    end
-    elseif msg_parts[1] == 'validate_key' then
+elseif args[1] == "add_card" then
-        print("Beginning transaction for single-validation with "..id)
+    if args[2] then
-        local card_holder = msg_parts[2]
+        local new_card = args[2]
-        local card_clearance = msg_parts[3]
+        local new_card_parts = split(new_card, ',')
-        local minimum_clearance = msg_parts[5]
+        local card_holder = new_card_parts[1]
+        local card_hash = hash(new_card)
 
-        if validate_key(card_holder, card_clearance, msg_parts[4]) and tonumber(card_clearance) >= tonumber(minimum_clearance) then
+        local key_file = fs.open(card_hash..'.key', 'w')
-            rednet.send(id, "authentication successful", "tg")
+        key_file.write(new_card..'\n')
-        else
+        key_file.close()
-            rednet.send(id, "authentication failed", "tg")
+
+        local trusted_keys = fs.open(dir..config.key_file, 'a')
+        trusted_keys.write(card_hash)
+        trusted_keys.close()
+
+        print("Created key "..card_hash..".key in root dir")
+    end
+elseif args[1] == "remove_card" then
+    if args[2] then
+        local key_hash = args[2]
+        local trusted_keys = fs.open(dir..config.key_file, 'r')
+        local new_key_table = {}
+        while true do
+            local trusted_hash = trusted_keys.readLine()
+            if trusted_hash ~= key_hash then
+                table.insert(new_key_table, trusted_hash)
+            else
+                print("Removed "..key_hash)
+            end
+            if not trusted_hash then break end -- Stop when EOF reached
         end
-        print("Transaction finished")
+        trusted_keys.close()
+
+        local trusted_keys = fs.open(dir..config.key_file, 'w+')
+        for _, entry in ipairs(new_key_table) do
+            trusted_keys.write(entry .. '\n')
+        end
+        trusted_keys.close()
     end
 end