Ticket

Tickets are found in many encrypted files used by the Wii (e.g. WAD Files or Wiidiscs). They contain the encrypted AES "title key" and the Title ID of the data and are signed by a certificate from a certificate chain (which usually is the same for all titles and stored somewhere on the NAND). So far only tickets with RSA-2048 signatures have been seen. (Discs will only work with those signatures because the size of partition ticket is always 0x2a4)

File structure

Start	End	Length	Description
0x0000	0x0004	4	Signature type (always 0x10001 for RSA-2048)
0x0004	0x0104	256	Signature by a certificate's key (everything after this field is covered by this signature)
0x0104	0x0140	60	Padding (Always 0)
0x0140	0x0180	64	Signature issuer
0x0180	0x01bf	63	Unknown (0, unless it is a VC game)
0x01bf	0x01cf	16	Encrypted title key
0x01cf	0x01dc	16	Unknown
0x01dc	0x01e4	8	Title ID / Initialization Vector (IV) used for AES-CBC encryption
0x01e4	0x01f1	13	Unknown
0x01f1	0x01f2	1	Common Key index (1 = Korean Common key, 0 = "normal" Common key)
0x01f2	0x0222	48	Unknown. Is all 0 for non-VC, for VC, all 0 except last byte is 1.
0x0222	0x0242	32	Always 0xFF (?)
0x0242	0x0244	2	Padding (Always 0)
0x0244	0x0248	4	Enable time limit (1 = Enabled, 0 = Disabled)
0x0248	0x024a	4	Time limit (Seconds)
0x024a	0x02a4	90	Padding (Always 0)

To get the title key decrypt the 16 bytes at offset 0x1bf with the Common Key using the Title ID (offset 0x1dc) as the initialization vector (the last 8 bytes of the IV should be zero).