from cryptography.hazmat.backends.interfaces import HMACBackend from cryptography.hazmat.primitives.hashes import HashAlgorithm from cryptography.hazmat.primitives.kdf import KeyDerivationFunction class HKDF(KeyDerivationFunction): def __init__( self, algorithm: HashAlgorithm, length: int, salt: bytes | None, info: bytes | None, backend: HMACBackend | None = ... ): ... def derive(self, key_material: bytes) -> bytes: ... def verify(self, key_material: bytes, expected_key: bytes) -> None: ... class HKDFExpand(KeyDerivationFunction): def __init__(self, algorithm: HashAlgorithm, length: int, info: bytes | None, backend: HMACBackend | None = ...): ... def derive(self, key_material: bytes) -> bytes: ... def verify(self, key_material: bytes, expected_key: bytes) -> None: ...