161 lines
6.2 KiB
Python
161 lines
6.2 KiB
Python
import base64
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import json
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import logging
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from typing import Literal
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from uuid import UUID
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from pathlib import Path
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def bytes2int(value: bytes, byteorder: Literal['big', 'little'] = 'big', signed: bool = False) -> int:
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"""
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Convert bytes to an integer.
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Args:
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value (bytes): The byte sequence to convert.
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byteorder (Literal['big', 'little'], optional): The byte order for conversion. Defaults to 'big'.
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signed (bool, optional): Indicates if the integer is signed. Defaults to False.
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Returns:
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int: The converted integer.
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"""
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return int.from_bytes(value, byteorder=byteorder, signed=signed)
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class Keybox:
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"""
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The Keybox class handles the storage and management of device IDs and keybox data.
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"""
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def __init__(self):
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"""
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Initializes the Keybox object, setting up a logger and containers for device IDs and keyboxes.
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Attributes:
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logger (Logger): Logger instance for logging messages.
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device_id (list[bytes]): List to store unique device IDs (32 bytes each).
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keybox (dict[bytes, bytes]): Dictionary to map device IDs to their respective keybox data.
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"""
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self.logger = logging.getLogger(self.__class__.__name__)
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# https://github.com/kaltura/kaltura-device-info-android/blob/master/app/src/main/java/com/kaltura/kalturadeviceinfo/MainActivity.java#L203
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self.device_id = []
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self.keybox = {}
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def set_device_id(self, data: bytes) -> None:
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"""
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Set the device ID from the provided data.
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Args:
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data (bytes): The device ID, expected to be 32 bytes long.
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Raises:
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AssertionError: If the data length is not 32 bytes.
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"""
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try:
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size = len(data)
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assert size == 32, f'Invalid keybox length: {size}. Should be 32 bytes'
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if data not in self.device_id:
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self.logger.info('Receive device id: \n\n%s\n', base64.b64encode(data).decode('utf-8'))
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self.device_id.append(data)
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except Exception as e:
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self.logger.debug('Failed to set device id: %s', e)
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def set_keybox(self, data: bytes) -> None:
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"""
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Set the keybox from the provided data.
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Args:
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data (bytes): The keybox data, expected to be either 128 or 132 bytes long.
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Raises:
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AssertionError: If the data length is not 128 or 132 bytes or does not meet other criteria.
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"""
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# https://github.com/wvdumper/dumper/blob/main/Helpers/Keybox.py#L51
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try:
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size = len(data)
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assert size in (128, 132), f'Invalid keybox length: {size}. Should be 128 or 132 bytes'
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if size == 132:
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assert data[128:132] == b"LVL1", 'QSEE style keybox does not end in bytes "LVL1"'
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assert data[120:124] == b"kbox", 'Invalid keybox magic'
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device_id = data[0:32]
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self.set_device_id(data=device_id)
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if device_id not in self.keybox:
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# Fetch keybox info for logging, such as flags and other details
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infos = self.__keybox_info(data)
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self.logger.info('Receive keybox: \n\n%s\n', json.dumps(infos, indent=2))
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# Warn if flags indicate encrypted data, requiring a plain-text device token
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if infos['flags'] > 10:
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self.logger.warning('Received encrypted data. Plaintext device token interception is required')
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self.keybox[device_id] = data
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except Exception as e:
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self.logger.debug('Failed to set keybox: %s', e)
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@staticmethod
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def __keybox_info(data: bytes) -> dict:
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"""
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Extract keybox information from the provided data.
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Args:
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data (bytes): The keybox data.
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Returns:
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dict: A dictionary containing extracted keybox information.
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"""
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# https://github.com/wvdumper/dumper/blob/main/Helpers/Keybox.py#L51
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# Extract key components from the keybox data based on defined byte offsets.
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content = {
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'device_id': data[0:32], # Unique identifier for the device (32 bytes).
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'device_key': data[32:48], # Device-specific cryptographic key (16 bytes).
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'device_token': data[48:120], # AES key used for device token encryption (72 bytes).
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'keybox_tag': data[120:124].decode('utf-8'), # Magic tag indicating keybox format (4 bytes).
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'crc32': bytes2int(data[124:128]), # CRC32 checksum for data integrity verification (4 bytes).
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'level_tag': data[128:132].decode('utf-8') or None, # Optional tag indicating keybox level (4 bytes).
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# TODO: decrypt device_token field
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# Key components extracted from the device token (Bytes 48–119).
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'flags': bytes2int(data[48:52]), # Flags indicating various settings (4 bytes).
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'system_id': bytes2int(data[52:56]), # System identifier for the device (4 bytes).
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# Provisioning ID, encrypted and derived from the unique ID in the system.
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'provisioning_id': UUID(bytes_le=data[56:72]), # Unique ID for provisioning (16 bytes).
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# Encrypted bits containing device key, key hash, and additional flags.
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'encrypted_bits': data[72:120] # Encrypted data relevant to the device (48 bytes).
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}
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# Encode certain fields in base64 and convert UUIDs to string
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return {
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k: base64.b64encode(v).decode('utf-8') if isinstance(v, bytes) else str(v) if isinstance(v, UUID) else v
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for k, v in content.items()
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}
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def export(self, parent: Path) -> bool:
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"""
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Export the keybox data to a file in the specified parent directory.
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Args:
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parent (Path): The parent directory where the keybox data will be saved.
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Returns:
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bool: True if any keybox were exported, otherwise False.
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"""
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keys = self.device_id & self.keybox.keys()
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for k in keys:
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parent.mkdir(parents=True, exist_ok=True)
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path_keybox_bin = parent / 'keybox.bin'
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path_keybox_bin.write_bytes(self.keybox[k])
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self.logger.info('Exported Keybox: %s', path_keybox_bin)
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return len(keys) > 0
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__all__ = ('Keybox',)
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