Method _hmac

authlib/jose/rfc7518/jwe_encs.py:43–47

(self, ciphertext, aad, iv, key)

        self.hash_alg = getattr(hashlib, f"sha{hash_type}")

    def _hmac(self, ciphertext, aad, iv, key):
        al = encode_int(len(aad) * 8, 64)
        msg = aad + iv + ciphertext + al
        d = hmac.new(key, msg, self.hash_alg).digest()
        return d[: self.key_len]

    def encrypt(self, msg, aad, iv, key):
        """Key Encryption with AES_CBC_HMAC_SHA2.