#   cryptomator-utils: Python utilities for inspecting Cryptomator drives
#   Copyright (C) 2024-2025  Lee Yingtong Li (RunasSudo)
#
#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU Affero General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU Affero General Public License for more details.
#
#   You should have received a copy of the GNU Affero General Public License
#   along with this program.  If not, see <https://www.gnu.org/licenses/>.

from cryptography.hazmat.primitives.ciphers.aead import AESSIV
from cryptography.hazmat.primitives.ciphers.algorithms import AES
from cryptography.hazmat.primitives.cmac import CMAC

import struct

def aes_siv_encrypt(primary_master_key, hmac_master_key, plaintext, associated_data):
	"""
	Encrypt the given bytes using AES-SIV
	"""
	
	siv_and_ciphertext = AESSIV(hmac_master_key + primary_master_key).encrypt(plaintext, associated_data)
	return siv_and_ciphertext

def aes_siv_decrypt(primary_master_key, hmac_master_key, siv_and_ciphertext, associated_data):
	"""
	Decrypt the given AES-SIV ciphertext
	"""
	
	return AESSIV(hmac_master_key + primary_master_key).decrypt(siv_and_ciphertext, associated_data)