_validate_path() — langchain Function Reference

Source Code

libs/partners/anthropic/langchain_anthropic/middleware/anthropic_tools.py lines 96–131

def _validate_path(path: str, *, allowed_prefixes: Sequence[str] | None = None) -> str:
    """Validate and normalize file path for security.

    Args:
        path: The path to validate.
        allowed_prefixes: Optional list of allowed path prefixes.

    Returns:
        Normalized canonical path.

    Raises:
        ValueError: If path contains traversal sequences or violates prefix rules.
    """
    # Reject paths with traversal attempts
    if ".." in path or path.startswith("~"):
        msg = f"Path traversal not allowed: {path}"
        raise ValueError(msg)

    # Normalize path (resolve ., //, etc.)
    normalized = os.path.normpath(path)

    # Convert to forward slashes for consistency
    normalized = normalized.replace("\\", "/")

    # Ensure path starts with /
    if not normalized.startswith("/"):
        normalized = f"/{normalized}"

    # Check allowed prefixes if specified
    if allowed_prefixes is not None and not any(
        normalized.startswith(prefix) for prefix in allowed_prefixes
    ):
        msg = f"Path must start with one of {allowed_prefixes}: {path}"
        raise ValueError(msg)

    return normalized