FIX: report Unicode tag presence correctly when decoding

pyrit/converter/token_smuggling/ascii_smuggler_converter.py

@@ -95,16 +95,18 @@ def decode_message(self, *, message: str) -> str:
             str: The decoded message.
         """
         decoded_message = ""
+        hidden_tags_found = False
         for char in message:
             code_point = ord(char)
             if 0xE0000 <= code_point <= 0xE007F:
+                hidden_tags_found = True
                 decoded_char = chr(code_point - 0xE0000)
                 if not 0x20 <= ord(decoded_char) <= 0x7E:
                     logger.info(f"Potential unicode tag detected: {decoded_char}")
                 else:
                     decoded_message += decoded_char
 
-        if len(decoded_message) != len(message):
+        if hidden_tags_found:
             logger.info("Hidden Unicode Tags discovered.")
         else:
             logger.info("No hidden Unicode Tag characters discovered.")

tests/unit/converter/test_ascii_smuggler_converter.py

@@ -1,6 +1,8 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT license.
 
+import logging
+
 import pytest
 
 from pyrit.converter import AsciiSmugglerConverter, ConverterResult
@@ -24,6 +26,27 @@ async def test_ascii_smuggler_decode_roundtrip():
     assert decoded.output_text == "hello"
 
 
+async def test_ascii_smuggler_decode_reports_hidden_tags(caplog):
+    encoder = AsciiSmugglerConverter(action="encode")
+    encoded = await encoder.convert_async(prompt="hello", input_type="text")
+
+    caplog.set_level(logging.INFO)
+    decoder = AsciiSmugglerConverter(action="decode")
+    await decoder.convert_async(prompt=encoded.output_text, input_type="text")
+
+    assert "Hidden Unicode Tags discovered." in caplog.messages
+    assert "No hidden Unicode Tag characters discovered." not in caplog.messages
+
+
+async def test_ascii_smuggler_decode_reports_no_hidden_tags_for_plain_text(caplog):
+    caplog.set_level(logging.INFO)
+    decoder = AsciiSmugglerConverter(action="decode")
+    await decoder.convert_async(prompt="hello", input_type="text")
+
+    assert "No hidden Unicode Tag characters discovered." in caplog.messages
+    assert "Hidden Unicode Tags discovered." not in caplog.messages
+
+
 async def test_ascii_smuggler_with_unicode_tags():
     converter = AsciiSmugglerConverter(action="encode", unicode_tags=True)
     result = await converter.convert_async(prompt="hi", input_type="text")