FEAT Moonshot Attack Module: Insert Punctuation Attack (#475)

u7780339 · web-flow · commit d4a0e79a7fe1 · 2025-02-25T06:32:28.000-08:00
diff --git a/pyrit/prompt_converter/insert_punctuation_converter.py b/pyrit/prompt_converter/insert_punctuation_converter.py
@@ -0,0 +1,155 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT license.
+
+import random
+import re
+import string
+from typing import List, Optional
+
+from pyrit.models import PromptDataType
+from pyrit.prompt_converter import ConverterResult, PromptConverter
+
+
+class InsertPunctuationConverter(PromptConverter):
+    """
+    Inserts punctuation into a prompt to test robustness.
+    Punctuation insertion: inserting single punctuations in string.punctuation.
+    Words in a prompt: a word does not contain any punctuation and space.
+    "a1b2c3" is a word; "a1 2" are 2 words; "a1,b,3" are 3 words.
+    """
+
+    default_punctuation_list = [",", ".", "!", "?", ":", ";", "-"]
+
+    def __init__(self, word_swap_ratio: float = 0.2, between_words: bool = True) -> None:
+        """
+        Initialize the converter with optional and word swap ratio.
+        Args:
+            word_swap_ratio (float): Percentage of words to perturb. Defaults to 0.2.
+            between_words (bool): If True, insert punctuation only between words.
+                                  If False, insert punctuation within words. Defaults to True.
+        """
+        # Swap ratio cannot be 0 or larger than 1
+        if not 0 < word_swap_ratio <= 1:
+            raise ValueError("word_swap_ratio must be between 0 to 1, as (0, 1].")
+
+        self._word_swap_ratio = word_swap_ratio
+        self._between_words = between_words
+
+    def _is_valid_punctuation(self, punctuation_list: List[str]) -> bool:
+        """
+        Check if all items in the list are valid punctuation characters in string.punctuation.
+        Space, letters, numbers, double punctuations are all invalid.
+        Args:
+            punctuation_list (List[str]): List of punctuations to validate.
+        Returns:
+            bool: valid list and valid punctuations
+        """
+        return all(str in string.punctuation for str in punctuation_list)
+
+    async def convert_async(
+        self, *, prompt: str, input_type: PromptDataType = "text", punctuation_list: Optional[List[str]] = None
+    ) -> ConverterResult:
+        """
+        Convert the given prompt by inserting punctuation.
+        Args:
+            prompt (str): The text to convert.
+            input_type (PromptDataType): The type of input data.
+            punctuation_list (Optional[List[str]]): List of punctuations to use for insertion.
+        Returns:
+            ConverterResult: A ConverterResult containing a interation of modified prompts.
+        """
+        if not self.input_supported(input_type):
+            raise ValueError("Input type not supported")
+
+        # Initialize default punctuation list
+        # If not specified, defaults to default_punctuation_list
+        if punctuation_list is None:
+            punctuation_list = self.default_punctuation_list
+        elif not self._is_valid_punctuation(punctuation_list):
+            raise ValueError(
+                f"Invalid punctuations: {punctuation_list}."
+                f" Only single characters from {string.punctuation} are allowed."
+            )
+
+        modified_prompt = self._insert_punctuation(prompt, punctuation_list)
+        return ConverterResult(output_text=modified_prompt, output_type="text")
+
+    def _insert_punctuation(self, prompt: str, punctuation_list: List[str]) -> str:
+        """
+        Insert punctuation into the prompt.
+        Args:
+            prompt (str): The text to modify.
+            punctuation_list (List[str]): List of punctuations for insertion.
+        Returns:
+            str: The modified prompt with inserted punctuation from helper method.
+        """
+        # Words list contains single spaces, single word without punctuations, single punctuations
+        words = re.findall(r"\w+|[^\w\s]|\s", prompt)
+        # Maintains indices for actual "words", i.e. letters and numbers not divided by punctuations
+        word_indices = [i for i in range(0, len(words)) if not re.match(r"\W", words[i])]
+        # Calculate the number of insertions
+        num_insertions = max(
+            1, round(len(word_indices) * self._word_swap_ratio)
+        )  # Ensure at least one punctuation is inserted
+
+        # If there's no actual word without punctuations in the list, insert random punctuation at position 0
+        if not word_indices:
+            return random.choice(punctuation_list) + prompt
+
+        if self._between_words:
+            return self._insert_between_words(words, word_indices, num_insertions, punctuation_list)
+        else:
+            return self._insert_within_words(prompt, num_insertions, punctuation_list)
+
+    def _insert_between_words(
+        self, words: List[str], word_indices: List[int], num_insertions: int, punctuation_list: List[str]
+    ) -> str:
+        """
+        Insert punctuation between words in the prompt.
+        Args:
+            words (List[str]): List of words and punctuations.
+            word_indices (List[int]): Indices of the actual words without punctuations in words list.
+            num_insertions (int): Number of punctuations to insert.
+            punctuation_list (List[str]): punctuations for insertion.
+
+        Returns:
+            str: The modified prompt with inserted punctuation.
+        """
+        insert_indices = random.sample(word_indices, num_insertions)
+        # Randomly choose num_insertions indices from actual word indices.
+        INSERT_BEFORE = 0
+        INSERT_AFTER = 1
+        for index in insert_indices:
+            if random.randint(INSERT_BEFORE, INSERT_AFTER) == INSERT_AFTER:
+                words[index] += random.choice(punctuation_list)
+            else:
+                words[index] = random.choice(punctuation_list) + words[index]
+        # Join the words list and return a modified prompt
+        return "".join(words).strip()
+
+    def _insert_within_words(self, prompt: str, num_insertions: int, punctuation_list: List[str]) -> str:
+        """
+        Insert punctuation at any indices in the prompt, can insert into a word.
+        Args:
+            promp str: The prompt string
+            num_insertions (int): Number of punctuations to insert.
+            punctuation_list (List[str]): punctuations for insertion.
+        Returns:
+            str: The modified prompt with inserted punctuation.
+        """
+        # List of chars in the prompt string
+        prompt_list = list(prompt)
+        # Store random indices of prompt_list into insert_indices
+        # If the prompt has only 0 or 1 chars, insert at the end of the prompt
+        insert_indices = (
+            [1] if len(prompt_list) <= num_insertions else random.sample(range(0, len(prompt_list) - 1), num_insertions)
+        )
+
+        for index in insert_indices:
+            # Insert into prompt_list at the insert_indices with random punctuation from the punctuation_list
+            prompt_list.insert(index, random.choice(punctuation_list))
+
+        return "".join(prompt_list).strip()
+
+    def input_supported(self, input_type: PromptDataType) -> bool:
+        return input_type == "text"
diff --git a/tests/converter/test_insert_punctuation_converter.py b/tests/converter/test_insert_punctuation_converter.py
@@ -0,0 +1,79 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT license.
+
+import re
+
+import pytest
+
+from pyrit.prompt_converter.insert_punctuation_converter import (
+    InsertPunctuationConverter,
+)
+
+
+# Test for correctness
+# Long prompt, short prompt, weird spacing and punctuation, non-wordy prompt, short and empty prompt
+@pytest.mark.parametrize(
+    "input_prompt,between_words,punctuation_list,word_swap_ratio,expected_punctuation_count",
+    [
+        ("Despite the rain, we decided to go hiking; it was a refreshing experience.", True, [",", "!", "]"], 1, 16),
+        ("Quick!", False, [",", "~", "]"], 1, 2),
+        ("   Hello,   world!   ", True, [",", "[", "]"], 0.3, 3),
+        ("....", True, [",", "[", ">"], 0.2, 5),
+        ("Numbers are also words, 1234 not intuitive, not symbols $@.", True, [",", "[", "]"], 0.6, 10),
+        ("", True, [",", "$", "]"], 0.9, 1),
+        ("a b", False, [",", "^", "]"], 1, 2),
+        ("I can't wait!!!", False, [",", "/", "]"], 0.4, 6),
+    ],
+)
+@pytest.mark.asyncio
+async def test_word_swap_ratio(
+    input_prompt, between_words, punctuation_list, word_swap_ratio, expected_punctuation_count
+):
+    converter = InsertPunctuationConverter(word_swap_ratio=word_swap_ratio, between_words=between_words)
+    result = await converter.convert_async(prompt=input_prompt, punctuation_list=punctuation_list)
+    modified_prompt = result.output_text
+    assert (
+        punctuation_count := len(re.findall(r"[^\w\s]", modified_prompt))
+    ) == expected_punctuation_count, (
+        f"Expect {expected_punctuation_count} punctuations found in prompt: {punctuation_count}"
+    )
+
+
+# Test default swap ratio = 0.2
+@pytest.mark.parametrize(
+    "input_prompt, expected_punctuation_count",
+    [("count 1 2 3 4 5 6 7 8 9 and 10.", 3), ("Aha!", 2)],
+)
+@pytest.mark.asyncio
+async def test_default_swap(input_prompt, expected_punctuation_count):
+    converter = InsertPunctuationConverter()
+    result = await converter.convert_async(prompt=input_prompt)
+    modified_prompt = result.output_text
+    assert (
+        punctuation_count := len(re.findall(r"[^\w\s]", modified_prompt))
+    ) == expected_punctuation_count, (
+        f"Expect {expected_punctuation_count} punctuations found in prompt: {punctuation_count}"
+    )
+
+
+# Test value error raising for invalid swap ratio
+@pytest.mark.parametrize(
+    "word_swap_ratio",
+    [-0.1, 1.5],
+)
+@pytest.mark.asyncio
+async def test_invalid_word_swap_ratio(word_swap_ratio):
+    with pytest.raises(ValueError):
+        InsertPunctuationConverter(word_swap_ratio=word_swap_ratio)
+
+
+# Test value error raising for invalid punctuations
+@pytest.mark.parametrize(
+    "punctuation_list",
+    ["~~", " ", "1", "a", "//"],
+)
+@pytest.mark.asyncio
+async def test_invalid_punctuation_list(punctuation_list):
+    with pytest.raises(ValueError):
+        converter = InsertPunctuationConverter()
+        await converter.convert_async(prompt="prompt", punctuation_list=[punctuation_list])
