add keybox dump (experimental)

keydive/cdm.py

@@ -15,6 +15,7 @@ from pywidevine.license_protocol_pb2 import (SignedMessage, LicenseRequest, Clie
                                              DrmCertificate, EncryptedClientIdentification)
 
 from keydive.constants import OEM_CRYPTO_API
+from keydive.keybox import Keybox
 
 
 class Cdm:
@@ -23,18 +24,20 @@ class Cdm:
     extracting and storing private keys, and exporting device information.
     """
 
-    def __init__(self):
+    def __init__(self, keybox: bool = False):
         """
         Initializes the Cdm object, setting up a logger and containers for client IDs and private keys.
 
         Attributes:
             client_id (dict[int, ClientIdentification]): Stores client identification info mapped by key modulus.
             private_key (dict[int, RsaKey]): Stores private keys mapped by key modulus.
+            keybox (bool, optional): Initializes a Keybox instance for secure key management.
         """
         self.logger = logging.getLogger(self.__class__.__name__)
         # https://github.com/devine-dl/pywidevine
         self.client_id: dict[int, ClientIdentification] = {}
         self.private_key: dict[int, RsaKey] = {}
+        self.keybox = Keybox() if keybox else None
 
     @staticmethod
     def __client_info(client_id: ClientIdentification) -> dict:
@@ -97,7 +100,7 @@ class Cdm:
             # https://integration.widevine.com/diagnostics
             encrypted_client_id: EncryptedClientIdentification = license_request.encrypted_client_id
             if encrypted_client_id.SerializeToString():
-                self.logger.debug('Receive encrypted client id: \n\n%s\n', json.dumps(self.__encrypted_client_info(encrypted_client_id), indent=2))
+                self.logger.info('Receive encrypted client id: \n\n%s\n', json.dumps(self.__encrypted_client_info(encrypted_client_id), indent=2))
                 self.logger.warning('The client ID of the challenge is encrypted')
             else:
                 client_id: ClientIdentification = license_request.client_id
@@ -124,10 +127,10 @@ class Cdm:
         try:
             key = RSA.import_key(data)
             if key.n not in self.private_key:
-                self.logger.debug('Receive private key: \n\n%s\n', key.exportKey('PEM').decode('utf-8'))
+                self.logger.info('Receive private key: \n\n%s\n', key.exportKey('PEM').decode('utf-8'))
 
                 if name and name not in OEM_CRYPTO_API:
-                    self.logger.warning(f'The function "{name}" does not belong to the referenced functions. Communicate it to the developer to improve the tool.')
+                    self.logger.warning('The function "%s" does not belong to the referenced functions. Communicate it to the developer to improve the tool.', name)
 
             self.private_key[key.n] = key
         except Exception as e:
@@ -157,11 +160,31 @@ class Cdm:
             key = RSA.importKey(public_key)
 
             if key.n not in self.client_id:
-                self.logger.debug('Receive client id: \n\n%s\n', json.dumps(self.__client_info(client_id), indent=2))
+                self.logger.info('Receive client id: \n\n%s\n', json.dumps(self.__client_info(client_id), indent=2))
             self.client_id[key.n] = client_id
         except Exception as e:
             self.logger.debug('Failed to set client ID: %s', e)
 
+    def set_device_id(self, data: bytes) -> None:
+        """
+        Sets the device ID in the keybox if it is enabled.
+
+        Args:
+            data (bytes): The device ID data to be stored in the keybox.
+        """
+        if self.keybox:
+            self.keybox.set_device_id(data=data)
+
+    def set_keybox(self, data: bytes) -> None:
+        """
+        Sets the keybox data.
+
+        Args:
+            data (bytes): The keybox data to be set.
+        """
+        if self.keybox:
+            self.keybox.set_keybox(data=data)
+
     def export(self, parent: Path, wvd: bool = False) -> bool:
         """
         Exports the client ID and private key to disk.
@@ -210,6 +233,9 @@ class Cdm:
                 path_wvd.write_bytes(data=wvd_bin)
                 self.logger.info('Exported WVD: %s', path_wvd)
 
+            if self.keybox and not self.keybox.export(parent=parent):
+                self.logger.warning('The keybox has not been intercepted or decrypted')
+
         return len(keys) > 0
 
 

keydive/core.py

@@ -36,9 +36,10 @@ class Core:
         self.adb = adb
 
         # https://github.com/hyugogirubato/KeyDive/issues/38#issuecomment-2411932679
+        # Flag to skip predefined functions based on the vendor's API level
         self.skip = skip
 
-        # Load the hook script
+        # Load the hook script and prepare for injection
         self.functions = functions
         self.script = self.__prepare_hook_script()
         self.logger.info('Script loaded successfully')
@@ -134,8 +135,10 @@ class Core:
             self.cdm.set_private_key(data=data, name=level['private_key'])
         elif level == 'challenge':
             self.cdm.set_challenge(data=data)
-        elif level == 'client_id':
+        elif level == 'device_id':
-            self.cdm.set_client_id(data=data)
+            self.cdm.set_device_id(data)
+        elif level == 'keybox':
+            self.cdm.set_keybox(data)
 
     def hook_process(self, pid: int, vendor: Vendor, timeout: int = 0) -> bool:
         """

keydive/keybox.py

@@ -0,0 +1,153 @@
+import base64
+import json
+import logging
+
+from typing import Literal
+from uuid import UUID
+
+from pathlib import Path
+
+
+def bytes2int(value: bytes, byteorder: Literal['big', 'little'] = 'big', signed: bool = False) -> int:
+    """
+    Convert bytes to an integer.
+
+    Args:
+        value (bytes): The byte sequence to convert.
+        byteorder (Literal['big', 'little'], optional): The byte order for conversion. Defaults to 'big'.
+        signed (bool, optional): Indicates if the integer is signed. Defaults to False.
+
+    Returns:
+        int: The converted integer.
+    """
+    return int.from_bytes(value, byteorder=byteorder, signed=signed)
+
+
+class Keybox:
+    """
+    The Keybox class handles the storage and management of device IDs and keybox data.
+    """
+
+    def __init__(self):
+        """
+        Initializes the Keybox object, setting up a logger and containers for device IDs and keyboxes.
+
+        Attributes:
+            logger (Logger): Logger instance for logging messages.
+            device_id (list[bytes]): List to store unique device IDs (32 bytes each).
+            keybox (dict[bytes, bytes]): Dictionary to map device IDs to their respective keybox data.
+        """
+        self.logger = logging.getLogger(self.__class__.__name__)
+        # https://github.com/kaltura/kaltura-device-info-android/blob/master/app/src/main/java/com/kaltura/kalturadeviceinfo/MainActivity.java#L203
+        self.device_id = []
+        self.keybox = {}
+
+    def set_device_id(self, data: bytes) -> None:
+        """
+        Set the device ID from the provided data.
+
+        Args:
+            data (bytes): The device ID, expected to be 32 bytes long.
+
+        Raises:
+            AssertionError: If the data length is not 32 bytes.
+        """
+        try:
+            size = len(data)
+            assert size == 32, f'Invalid keybox length: {size}. Should be 32 bytes'
+
+            if data not in self.device_id:
+                self.logger.info('Receive device id: \n\n%s\n', base64.b64encode(data).decode('utf-8'))
+                self.device_id.append(data)
+        except Exception as e:
+            self.logger.debug('Failed to set device id: %s', e)
+
+    def set_keybox(self, data: bytes) -> None:
+        """
+        Set the keybox from the provided data.
+
+        Args:
+            data (bytes): The keybox data, expected to be either 128 or 132 bytes long.
+
+        Raises:
+            AssertionError: If the data length is not 128 or 132 bytes or does not meet other criteria.
+        """
+        # https://github.com/wvdumper/dumper/blob/main/Helpers/Keybox.py#L51
+        try:
+            size = len(data)
+            assert size in (128, 132), f'Invalid keybox length: {size}. Should be 128 or 132 bytes'
+
+            if size == 132:
+                assert data[128:132] == b"LVL1", 'QSEE style keybox does not end in bytes "LVL1"'
+
+            assert data[120:124] == b"kbox", 'Invalid keybox magic'
+
+            device_id = data[0:32]
+            self.set_device_id(data=device_id)
+
+            if device_id not in self.keybox:
+                # https://github.com/wvdumper/dumper/blob/main/Helpers/Keybox.py#L51
+                self.logger.info('Receive keybox: \n\n%s\n', json.dumps(self.__keybox_info(data), indent=2))
+
+            self.keybox[device_id] = data
+        except Exception as e:
+            self.logger.debug('Failed to set keybox: %s', e)
+
+    @staticmethod
+    def __keybox_info(data: bytes) -> dict:
+        """
+        Extract keybox information from the provided data.
+
+        Args:
+            data (bytes): The keybox data.
+
+        Returns:
+            dict: A dictionary containing extracted keybox information.
+        """
+        # Extract key components from the keybox data based on defined byte offsets.
+        content = {
+            'device_id': data[0:32],  # Unique identifier for the device (32 bytes).
+            'device_key': data[32:48],  # Device-specific cryptographic key (16 bytes).
+            'device_token': data[48:120],  # AES key used for device token encryption (72 bytes).
+            'keybox_tag': data[120:124].decode('utf-8'),  # Magic tag indicating keybox format (4 bytes).
+            'crc32': bytes2int(data[124:128]),  # CRC32 checksum for data integrity verification (4 bytes).
+            'level_tag': data[128:132].decode('utf-8') or None,  # Optional tag indicating keybox level (4 bytes).
+
+            # Key components extracted from the device token (Bytes 48–119).
+            'flags': bytes2int(data[48:52]),  # Flags indicating various settings (4 bytes).
+            'system_id': bytes2int(data[52:56]),  # System identifier for the device (4 bytes).
+
+            # Provisioning ID, encrypted and derived from the unique ID in the system.
+            'provisioning_id': UUID(bytes_le=data[56:72]),  # Unique ID for provisioning (16 bytes).
+
+            # Encrypted bits containing device key, key hash, and additional flags.
+            'encrypted_bits': data[72:120]  # Encrypted data relevant to the device (48 bytes).
+        }
+
+        # Encode certain fields in base64 and convert UUIDs to string
+        return {
+            k: base64.b64encode(v).decode('utf-8') if isinstance(v, bytes) else str(v) if isinstance(v, UUID) else v
+            for k, v in content.items()
+        }
+
+    def export(self, parent: Path) -> bool:
+        """
+        Export the keybox data to a file in the specified parent directory.
+
+        Args:
+            parent (Path): The parent directory where the keybox data will be saved.
+
+        Returns:
+            bool: True if any keybox were exported, otherwise False.
+        """
+        keys = self.device_id & self.keybox.keys()
+        for k in keys:
+            parent.mkdir(parents=True, exist_ok=True)
+            path_keybox_bin = parent / 'keybox.bin'
+            path_keybox_bin.write_bytes(self.keybox[k])
+
+            self.logger.info('Exported Keybox: %s', path_keybox_bin)
+        return len(keys) > 0
+
+
+__all__ = ('Keybox',)

keydive/keydive.js

@@ -1,5 +1,5 @@
 /**
- * Date: 2024-10-20
+ * Date: 2024-10-27
  * Description: DRM key extraction for research and educational purposes.
  * Source: https://github.com/hyugogirubato/KeyDive
  */
@@ -253,7 +253,7 @@ const GetDeviceID = (address) => {
             try {
                 const size = Memory.readPointer(this.size).toInt32();
                 const data = Memory.readByteArray(this.data, size);
-                data && send('client_id', data);
+                data && send('device_id', data);
             } catch (e) {
                 print(Level.ERROR, `Failed to dump device ID.`);
             }
@@ -262,10 +262,49 @@ const GetDeviceID = (address) => {
 }
 
 
+const memcpy = (address) => {
+    // libc::memcpy
+    Interceptor.attach(address, {
+        onEnter: function (args) {
+            // Convert size argument from hexadecimal to integer
+            const size = parseInt(args[2], 16);
+
+            // Check if the size matches known keybox sizes (128 or 132 bytes)
+            if ([128, 132].includes(size)) {
+                const data = Memory.readByteArray(args[1], size);
+
+                // Define the target bytes for "kbox"
+                const targetBytes = [0x6b, 0x62, 0x6f, 0x78]; // "kbox" in hex
+
+                // Function to check if target bytes are present
+                function containsTargetBytes(buffer, target) {
+                    const dataArray = Array.from(new Uint8Array(buffer));
+                    for (let i = 0; i <= dataArray.length - target.length; i++) {
+                        if (target.every((byte, index) => dataArray[i + index] === byte)) {
+                            return true;
+                        }
+                    }
+                    return false;
+                }
+
+                // Check if "kbox" is present in the data
+                if (data && containsTargetBytes(data, targetBytes)) {
+                    print(Level.DEBUG, `[*] Keybox: memcpy`);
+                    send('keybox', data);
+                }
+            }
+        },
+        onLeave: function (retval) {
+            // print(Level.DEBUG, `[-] onLeave: memcpy`);
+        }
+    });
+}
+
+
 // @Hooks
 const hookLibrary = (name) => {
     // https://github.com/poxyran/misc/blob/master/frida-enumerate-imports.py
-    const library = getLibrary(name);
+    let library = getLibrary(name);
     if (!library) return false;
 
     let functions;
@@ -281,7 +320,7 @@ const hookLibrary = (name) => {
     }
 
     functions = functions.filter(f => !NATIVE_C_API.includes(f.name));
-    const targets = SKIP ? [] : functions.filter(f => OEM_CRYPTO_API.includes(f.name)).map(f => f.name);
+    let targets = SKIP ? [] : functions.filter(f => OEM_CRYPTO_API.includes(f.name)).map(f => f.name);
     const hooked = [];
 
     functions.forEach(func => {
@@ -295,11 +334,19 @@ const hookLibrary = (name) => {
                 GetCdmClientPropertySet(funcAddr);
             } else if (funcName.includes('PrepareKeyRequest')) {
                 PrepareKeyRequest(funcAddr);
-            } else if (funcName.includes('getOemcryptoDeviceId')) {
+            } else if (funcName.includes('_lcc07') || funcName.includes('_oecc07') || funcName.includes('getOemcryptoDeviceId')) {
                 GetDeviceID(funcAddr);
             } else if (targets.includes(funcName) || (!targets.length && funcName.match(/^[a-z]+$/))) {
                 LoadDeviceRSAKey(funcAddr, funcName);
             } else {
+                /*
+                    1. wvcdm::CdmEngine::GetProvisioningRequest
+                    2. wvcdm::ClientIdentification::GetProvisioningTokenType
+                    3. wvcdm::CryptoSession::GetProvisioningToken
+                       1. wvcdm::CryptoSession::GetTokenFromOemCert
+                       2. wvcdm::CryptoSession::GetTokenFromKeybox
+                 */
+                // print(Level.WARNING, `Hooked (${funcAddr}): ${funcName}`);
                 return;
             }
 
@@ -315,6 +362,18 @@ const hookLibrary = (name) => {
         return false;
     }
 
+    // Keybox (experimental)
+    library = getLibrary('libc.so');
+    targets = getFunctions(library).find(func => func.name === 'memcpy' && func.type === 'function');
+    if (targets) {
+        try {
+            memcpy(targets.address);
+            print(Level.DEBUG, `Hooked (${targets.address}): ${targets.name}`);
+        } catch (e) {
+            print(Level.ERROR, `${e.message} for ${targets.name}`);
+        }
+    }
+
     // https://github.com/hzy132/liboemcryptodisabler/blob/master/customize.sh#L33
     disableLibrary('liboemcrypto.so');
     return true;