Added function to crypto.py for encrypting a title key

src/libWiiPy/__init__.py

@@ -6,6 +6,7 @@
 from .commonkeys import *
 from .content import *
 from .ticket import *
+from .crypto import *
 from .title import *
 from .tmd import *
 from .wad import *

src/libWiiPy/crypto.py

@@ -1,8 +1,10 @@
 # "crypto.py" from libWiiPy by NinjaCheetah & Contributors
 # https://github.com/NinjaCheetah/libWiiPy
+import binascii
 
 import struct
 from .commonkeys import get_common_key
+
 from Crypto.Cipher import AES
 
 
@@ -17,7 +19,7 @@ def decrypt_title_key(title_key_enc, common_key_index, title_id) -> bytes:
     title_key_enc : bytes
         The encrypted Title Key.
     common_key_index : int
-        The index of the common key to be returned.
+        The index of the common key used to encrypt the Title Key.
     title_id : bytes
         The title ID of the title that the key is for.
 
@@ -29,7 +31,8 @@ def decrypt_title_key(title_key_enc, common_key_index, title_id) -> bytes:
     # Load the correct common key for the title.
     common_key = get_common_key(common_key_index)
     # Calculate the IV by adding 8 bytes to the end of the Title ID.
-    title_key_iv = title_id + (b'\x00' * 8)
+    title_key_iv = binascii.unhexlify(title_id)
+    title_key_iv = title_key_iv + (b'\x00' * 8)
     # Create a new AES object with the values provided.
     aes = AES.new(common_key, AES.MODE_CBC, title_key_iv)
     # Decrypt the Title Key using the AES object.
@@ -37,6 +40,38 @@ def decrypt_title_key(title_key_enc, common_key_index, title_id) -> bytes:
     return title_key
 
 
+def encrypt_title_key(title_key_dec, common_key_index, title_id) -> bytes:
+    """
+    Encrypts the provided Title Key with the selected common key.
+
+    Requires the index of the common key to use, and the Title ID of the title that the Title Key is for.
+
+    Parameters
+    ----------
+    title_key_dec : bytes
+        The decrypted Title Key.
+    common_key_index : int
+        The index of the common key used to encrypt the Title Key.
+    title_id : bytes
+        The title ID of the title that the key is for.
+
+    Returns
+    -------
+    bytes
+        An encrypted Title Key.
+    """
+    # Load the correct common key for the title.
+    common_key = get_common_key(common_key_index)
+    # Calculate the IV by adding 8 bytes to the end of the Title ID.
+    title_key_iv = binascii.unhexlify(title_id)
+    title_key_iv = title_key_iv + (b'\x00' * 8)
+    # Create a new AES object with the values provided.
+    aes = AES.new(common_key, AES.MODE_CBC, title_key_iv)
+    # Encrypt Title Key using the AES object.
+    title_key = aes.encrypt(title_key_dec)
+    return title_key
+
+
 def decrypt_content(content_enc, title_key, content_index, content_length) -> bytes:
     """
     Gets the decrypted version of the encrypted content.

src/libWiiPy/ticket.py

@@ -99,10 +99,9 @@ class Ticket:
             self.console_id = int.from_bytes(ticket_data.read(4))
             # Title ID.
             ticket_data.seek(0x1DC)
-            self.title_id = ticket_data.read(8)
+            self.title_id = binascii.hexlify(ticket_data.read(8))
             # Title ID (as a string).
-            title_id_hex = binascii.hexlify(self.title_id)
-            self.title_id_str = str(title_id_hex.decode())
+            self.title_id_str = str(self.title_id.decode())
             # Unknown data 1.
             ticket_data.seek(0x1E4)
             self.unknown1 = ticket_data.read(2)
@@ -172,7 +171,7 @@ class Ticket:
             # Console ID.
             ticket_data.write(int.to_bytes(self.console_id, 4))
             # Title ID.
-            ticket_data.write(self.title_id)
+            ticket_data.write(binascii.unhexlify(self.title_id))
             # Unknown data 1.
             ticket_data.write(self.unknown1)
             # Title version.