tests/luaxform: Lua transform tests

This commit adds tests for new Lua transform
- Basic transform operation
- Ensure non-existent Lua scripts are detected
- Ensure Lua scripts without transform functions are detected
- Ensure Lua scripts properly receive optional transform arguments

tests/lua/lua-transform-01/README.md

@@ -0,0 +1 @@
+Lua transform test: returns input buffer in uppercase. The rule will match on the uppercase output

tests/lua/lua-transform-01/test.rules

@@ -0,0 +1 @@
+alert http any any -> any any (msg:"TEST"; http.uri; luaxform:transform.lua;content:"EXEC_POST.PHP";  sid:1; rev:1;)

tests/lua/lua-transform-01/test.yaml

@@ -0,0 +1,14 @@
+requires:
+  min-version: 8
+
+args:
+  - --set default-rule-path=${TEST_DIR}
+  - --set security.lua.allow-rules=true
+
+checks:
+  - filter:
+      count: 1
+      match:
+        event_type: alert
+        alert.signature_id: 1
+        http.url: /exec_post.php

tests/lua/lua-transform-01/transform.lua

@@ -0,0 +1,10 @@
+-- Arguments supported
+local bytes_key = "bytes"
+local offset_key = "offset"
+function transform(input_len, input, argc, args)
+    local bytes = input_len
+    local offset = 0
+
+    local sub = string.sub(input, offset + 1, offset + bytes)
+    return string.upper(sub), bytes
+end

tests/lua/lua-transform-02/README.md

@@ -0,0 +1 @@
+Lua transform: Ensure non-existent lua scripts are detected.

tests/lua/lua-transform-02/test.rules

@@ -0,0 +1 @@
+alert http any any -> any any (msg:"TEST"; http.uri; luaxform:no_filetransform.lua;content:"EXEC_POST.PHP";  sid:1; rev:1;)

tests/lua/lua-transform-02/test.yaml

@@ -0,0 +1,20 @@
+requires:
+  min-version: 8
+
+args:
+  - --set default-rule-path=${TEST_DIR}
+  - --set security.lua.allow-rules=true
+  - --set logging.outputs.1.file.type=json
+  - -T
+
+exit-code: 1
+
+pcap: false
+checks:
+  - filter:
+      count: 1
+      filename: suricata.log
+      match:
+        event_type: engine
+        engine.message.__startswith: "couldn't load file"
+        engine.message.__find: "no_filetransform.lua: No such file or directory"

tests/lua/lua-transform-03/README.md

@@ -0,0 +1 @@
+Lua transform test: ensure lua script has a transform function

tests/lua/lua-transform-03/test.rules

@@ -0,0 +1 @@
+alert http any any -> any any (msg:"TEST"; http.uri; luaxform:transform.lua;content:"EXEC_POST.PHP";  sid:1; rev:1;)

tests/lua/lua-transform-03/test.yaml

@@ -0,0 +1,20 @@
+requires:
+  min-version: 8
+
+args:
+  - --set default-rule-path=${TEST_DIR}
+  - --set security.lua.allow-rules=true
+  - --set logging.outputs.1.file.type=json
+  - -T
+
+pcap: false
+
+exit-code: 1
+
+checks:
+  - filter:
+      count: 1
+      filename: suricata.log
+      match:
+        engine.message.__find: "no transform function in script"
+        event_type: engine

tests/lua/lua-transform-03/transform.lua

@@ -0,0 +1,10 @@
+-- Arguments supported
+local bytes_key = "bytes"
+local offset_key = "offset"
+function no_transform(input_len, input, argc, args)
+    local bytes = input_len
+    local offset = 0
+
+    local sub = string.sub(input, offset + 1, offset + bytes)
+    return string.upper(sub), bytes
+end

tests/lua/lua-transform-04/README.md

@@ -0,0 +1 @@
+Ensure Lua transform receives optional transform function arguments

tests/lua/lua-transform-04/test.rules

@@ -0,0 +1 @@
+alert http any any -> any any (msg:"TEST"; http.uri; luaxform:transform.lua, bytes 0, offset 2;content:"EXEC_POST.PHP";  sid:1; rev:1;)

tests/lua/lua-transform-04/test.yaml

@@ -0,0 +1,18 @@
+requires:
+  min-version: 8
+
+args:
+  - --set default-rule-path=${TEST_DIR}
+  - --set security.lua.allow-rules=true
+
+pcap: ../lua-transform-01/test.pcap
+
+checks:
+
+  - shell:
+      args: grep  "1 item.*  bytes 0" stdout | wc -l | xargs
+      expect: 1
+
+  - shell:
+      args: grep  "2 item.*  offset 2" stdout| wc -l | xargs
+      expect: 1

tests/lua/lua-transform-04/transform.lua

@@ -0,0 +1,13 @@
+-- Arguments supported
+local bytes_key = "bytes"
+local offset_key = "offset"
+function transform(input_len, input, argc, args)
+    offset = 0
+    bytes = input_len
+    for i, item in ipairs(args) do
+        print(i .. " item: " .. item)
+    end
+
+    local sub = string.sub(input, offset + 1, offset + bytes)
+    return string.upper(sub), bytes
+end

tests/lua/lua-transform-05/transform.lua

@@ -1,8 +1,3 @@
-function init (args)
-    local needs = {}
-    return needs
-end
-
 function transform(input_len, input, argc, args)
-    return nil
+    return nil, 0
 end

tests/lua/lua-transform-06/README.md

@@ -0,0 +1 @@
+Lua transform test: transform function returns 1 parameter when 2 are required.

tests/lua/lua-transform-06/test.rules

@@ -0,0 +1 @@
+alert http any any -> any any (msg:"TEST"; http.uri; luaxform:transform.lua;content:"EXEC_POST.PHP";  sid:1; rev:1;)

tests/lua/lua-transform-06/test.yaml

@@ -0,0 +1,16 @@
+requires:
+  min-version: 8
+
+args:
+  - --set default-rule-path=${TEST_DIR}
+  - --set security.lua.allow-rules=true
+
+pcap: ../lua-transform-01/test.pcap
+
+checks:
+  - filter:
+      count: 0
+      match:
+        event_type: alert
+        alert.signature_id: 1
+        http.url: /exec_post.php

tests/lua/lua-transform-06/transform.lua

@@ -0,0 +1,11 @@
+-- Arguments supported
+local bytes_key = "bytes"
+local offset_key = "offset"
+function transform(input_len, input, argc, args)
+    local bytes = input_len
+    local offset = 0
+
+    local sub = string.sub(input, offset + 1, offset + bytes)
+    -- Note -- only one value is returned when 2 are expected: buffer, byte-count
+    return string.upper(sub)
+end

tests/lua/lua-transform-07/README.md

@@ -0,0 +1,2 @@
+Ensure Lua transform receives optional transform function arguments. The Lua transform script
+is also provided as an example in the documentation.

tests/lua/lua-transform-07/test.rules

@@ -0,0 +1 @@
+alert http any any -> any any (msg:"TEST"; http.uri; luaxform:transform.lua, bytes 12, offset 2;content:"XEC_POST.PHP";  sid:1; rev:1;)

tests/lua/lua-transform-07/test.yaml

@@ -0,0 +1,16 @@
+requires:
+  min-version: 8
+
+args:
+  - --set default-rule-path=${TEST_DIR}
+  - --set security.lua.allow-rules=true
+
+pcap: ../lua-transform-01/test.pcap
+
+checks:
+
+  - filter:
+      count: 1
+      match:
+        event_type: alert
+        alert.signature_id: 1

tests/lua/lua-transform-07/transform.lua

@@ -0,0 +1,49 @@
+function init()
+end
+
+local function get_value(item, key)
+   if string.find(item, key) then
+	   local _, value = string.match(item, "(%a+)%s*(%d*)")
+	   if value ~= "" then
+		   return tonumber(value)
+	   end
+   end
+
+   return nil
+end
+
+-- Arguments supported
+local bytes_key = "bytes"
+local offset_key = "offset"
+function transform(input_len, input, argc, args)
+   local bytes = input_len
+   local offset = 0
+
+   -- Look for optional bytes and offset arguments
+   for i, item in ipairs(args) do
+	   local value = get_value(item, bytes_key)
+	   if value ~= nil then
+		   bytes = value
+	   else
+		   value = get_value(item, offset_key)
+		   if value ~= nil then
+			   offset = value
+		   end
+	   end
+   end
+
+   local str_len = #input
+   if offset < 0 or offset > str_len then
+	   print("offset is out of bounds: " .. offset)
+	   return nil
+   end
+
+   local avail_len = str_len - offset
+   if bytes < 0 or bytes > avail_len then
+       print("invalid bytes " ..  bytes .. " or bytes exceeds available  length " .. avail_len)
+	   return nil
+   end
+
+   local sub = string.sub(input, offset + 1, offset + bytes)
+   return string.upper(sub), bytes
+end