import hashlib import hmac from typing import Any, List, Sequence def _check_bytes(value: Any, name: str) -> bytes: if isinstance(value, (str, dict)) or not hasattr(value, "__len__"): raise TypeError("%s must be a list of integers from 0 to 255" % name) for b in value: if type(b) is not int or b < 0 or b > 255: raise ValueError("%s must be a list of integers from 0 to 255" % name) return bytes(value) def hmac_sha256(key: Sequence[int], message: Sequence[int]) -> List[int]: """HMAC-SHA256 (RFC 2104) from the standard library's hmac module. The byte values are checked here so a bad value fails with the same words as in TypeScript and Rust. """ k = _check_bytes(key, "key") m = _check_bytes(message, "message") return list(hmac.new(k, m, hashlib.sha256).digest())