--- /dev/null
+from cryptography.hazmat.backends.interfaces import HashBackend
+from cryptography.hazmat.primitives.hashes import HashAlgorithm
+from cryptography.hazmat.primitives.kdf import KeyDerivationFunction
+
+class X963KDF(KeyDerivationFunction):
+ def __init__(self, algorithm: HashAlgorithm, length: int, sharedinfo: bytes | None, backend: HashBackend | None = ...): ...
+ def derive(self, key_material: bytes) -> bytes: ...
+ def verify(self, key_material: bytes, expected_key: bytes) -> None: ...