_warn_about_sha1_encoder() — langchain Function Reference

Source Code

libs/langchain/langchain_classic/embeddings/cache.py lines 90–105

def _warn_about_sha1_encoder() -> None:
    """Emit a one-time warning about SHA-1 collision weaknesses."""
    global _warned_about_sha1  # noqa: PLW0603
    if not _warned_about_sha1:
        warnings.warn(
            "Using default key encoder: SHA-1 is *not* collision-resistant. "
            "While acceptable for most cache scenarios, a motivated attacker "
            "can craft two different payloads that map to the same cache key. "
            "If that risk matters in your environment, supply a stronger "
            "encoder (e.g. SHA-256 or BLAKE2) via the `key_encoder` argument. "
            "If you change the key encoder, consider also creating a new cache, "
            "to avoid (the potential for) collisions with existing keys.",
            category=UserWarning,
            stacklevel=2,
        )
        _warned_about_sha1 = True