findmy.util.crypto
==================

.. py:module:: findmy.util.crypto

.. autoapi-nested-parse::

   Pure-python NIST P-224 Elliptic Curve cryptography. Used for some Apple algorithms.



Attributes
----------

.. autoapisummary::

   findmy.util.crypto.P224_N


Functions
---------

.. autoapisummary::

   findmy.util.crypto.encrypt_password
   findmy.util.crypto.decrypt_spd_aes_cbc
   findmy.util.crypto.x963_kdf
   findmy.util.crypto.bytes_to_int
   findmy.util.crypto.derive_ps_key


Module Contents
---------------

.. py:data:: P224_N
   :value: 26959946667150639794667015087019625940457807714424391721682722368061


.. py:function:: encrypt_password(password: str, salt: bytes, iterations: int, protocol: str) -> bytes

   Encrypt password using PBKDF2-HMAC.


.. py:function:: decrypt_spd_aes_cbc(session_key: bytes, data: bytes) -> bytes

   Decrypt SPD data using SRP session key.


.. py:function:: x963_kdf(value: bytes, si: bytes, length: int) -> bytes

   Single pass of X9.63 KDF with SHA1.


.. py:function:: bytes_to_int(value: bytes) -> int

   Convert bytes in big-endian format to int.


.. py:function:: derive_ps_key(privkey: bytes, sk: bytes) -> bytes

   Derive a primary or secondary key used by an accessory.

   :param privkey: Private key generated during pairing
   :param sk: Current secret key for this time period.
              Use SKN to derive the primary key, SKS for secondary.