# -*- coding: utf-8 -*-

from ..util.byteutil import ByteUtil


class DerivedMessageSecrets:
    SIZE = 80
    CIPHER_KEY_LENGTH = 32
    MAC_KEY_LENGTH = 32
    IV_LENGTH = 16

    def __init__(self, okm):
        keys = ByteUtil.split(okm,
                              self.__class__.CIPHER_KEY_LENGTH,
                              self.__class__.MAC_KEY_LENGTH,
                              self.__class__.IV_LENGTH)
        self.cipherKey = keys[0]  # AES
        self.macKey = keys[1]  # sha256
        self.iv = keys[2]

    def getCipherKey(self):
        return self.cipherKey

    def getMacKey(self):
        return self.macKey

    def getIv(self):
        return self.iv