From f1f271abbeb409f53c8624cad20274a13b78c0f2 Mon Sep 17 00:00:00 2001
From: BodgeMaster <>
Date: Sat, 26 Nov 2022 15:19:02 +0100
Subject: [PATCH] Enforce command/condition whitelist

---
 lambdaV.py | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/lambdaV.py b/lambdaV.py
index 0d7c107..e2c7db9 100644
--- a/lambdaV.py
+++ b/lambdaV.py
@@ -304,9 +304,13 @@ def parse_condition(condition_code, allowed_conditions):
     else:
         debug_message("  Unknown condition: "+condition_code)
         return [condition, inverted, "Unknown condition: "+condition_code]
+
+    if not condition_code in allowed_conditions:
+        return [condition, inverted, "Condition is not allowed here: "+condition_code]
+
     return [condition, inverted, ""]
 
-# returns [[functions], [arguments], -1, ""] or [[], [], error_position, "error message"]
+# returns [[functions], [arguments], -1, "", "formatted code"] or [[], [], error_position, "error message", "formatted code"]
 def parse_code(code, allowed_commands, allowed_conditions, unformatted_code=True):
     if unformatted_code:
         code = format_code(code)
@@ -328,15 +332,22 @@ def parse_code(code, allowed_commands, allowed_conditions, unformatted_code=True
             debug_message("Next command is: "+next_command)
 
             parsed_code[1].append(())
-            #TODO: add function to to the function list
             if next_command == "step":
                 parsed_code[0].append(command_step)
+                if not next_command in allowed_commands:
+                    return [[], [], parse_position, "Command is not allowed here: "+next_command, code]
             elif next_command == "left":
                 parsed_code[0].append(command_left)
+                if not next_command in allowed_commands:
+                    return [[], [], parse_position, "Command is not allowed here: "+next_command, code]
             elif next_command == "right":
                 parsed_code[0].append(command_right)
+                if not next_command in allowed_commands:
+                    return [[], [], parse_position, "Command is not allowed here: "+next_command, code]
             elif next_command == "take":
                 parsed_code[0].append(command_take)
+                if not next_command in allowed_commands:
+                    return [[], [], parse_position, "Command is not allowed here: "+next_command, code]
             elif next_command == "repeat":
                 return [[], [], next_space, "Syntax error: Number of repetitions missing", code]
             elif next_command == "while":
@@ -354,6 +365,10 @@ def parse_code(code, allowed_commands, allowed_conditions, unformatted_code=True
             control_structure = code[parse_position:next_condition]
             if control_structure == "repeat":
                 debug_message("  Type: repeat loop")
+                # This is checked here because otherwise it would throw a bogus error message for unknown control structures.
+                if not control_structure in allowed_commands:
+                    return [[], [], parse_position, "Command is not allowed here: "+control_structure, code]
+
                 parse_position = next_condition
                 repetitions_length = get_length_of_condition(code[parse_position:])
                 if repetitions_length == -2:
@@ -387,6 +402,10 @@ def parse_code(code, allowed_commands, allowed_conditions, unformatted_code=True
                 continue
             elif control_structure == "if":
                 debug_message("  Type: if statement")
+                # This is checked here because otherwise it would throw a bogus error message for unknown control structures.
+                if not control_structure in allowed_commands:
+                    return [[], [], parse_position, "Command is not allowed here: "+control_structure, code]
+
                 parse_position = next_condition
                 condition_length = get_length_of_condition(code[parse_position:])
                 if condition_length == -2:
@@ -432,6 +451,10 @@ def parse_code(code, allowed_commands, allowed_conditions, unformatted_code=True
                 continue
             elif control_structure == "while":
                 debug_message("  Type: while loop")
+                # This is checked here because otherwise it would throw a bogus error message for unknown control structures.
+                if not control_structure in allowed_commands:
+                    return [[], [], parse_position, "Command is not allowed here: "+control_structure, code]
+
                 parse_position = next_condition
                 condition_length = get_length_of_condition(code[parse_position:])
                 if condition_length == -2: