Title metadata
Title metadata, or TMD for short, is a format used to store information about a title (DSiWare, etc.) and all its installed contents, including which contents they consist of and their SHA-1 hashes. The format between Wii and DSi Title metadata appears to be identical; this includes endianness, so byteswaps are often needed on the DSi.
Many operations are done in terms of 64-byte blocks, which means you will often see padding out to the nearest 64-byte boundary at the end of a field.
Example of a Nintendo DSi TMD: http://nus.cdn.t.shop.nintendowifi.net/ccs/download/0003000f484e4c4a/tmd ("HNLJ", or Japanese Version Data.)
The certificate chain at the end of the file seems to always/usually have a size in bytes of 1,792 and a SHA-256 of 03CE2468F00D1AAEA52D7193A2312B0FE87ECE72D43381C3B6BD4C57E700CDD7.
Structure
Header
| Start | Length | Description |
|---|---|---|
| 0x000 | 4 | Signature type |
| 0x004 | 256 | Signature |
| 0x104 | 60 | Padding modulo 64 |
| 0x140 | 64 | Issuer |
| 0x180 | 1 | Version |
| 0x181 | 1 | ca_crl_version |
| 0x182 | 1 | signer_crl_version |
| 0x183 | 1 | Padding modulo 4 |
| 0x184 | 8 | System Version; probably always 0 |
| 0x18C | 8 | Title ID |
| 0x194 | 4 | Title type |
| 0x198 | 2 | Group ID |
| 0x19A | 62 | reserved |
| 0x1D8 | 4 | Access rights |
| 0x1DC | 2 | Title version |
| 0x1DE | 2 | Number of contents (nbr_cont) |
| 0x1E0 | 2 | boot index |
| 0x1E2 | 2 | Padding modulo 64 |
| 0x1E4 | 36*nbr_cont | Contents |
Content
| Start | Length | Description |
|---|---|---|
| 0x00 | 4 | Content ID |
| 0x04 | 2 | Index |
| 0x06 | 2 | Type |
| 0x08 | 8 | Size |
| 0x10 | 20 | SHA1 hash |
Certificates
| Start | Length | Description |
|---|---|---|
| 0x000 | 4 | Signature type |
| 0x004 | 256 | Signature |
| 0x104 | 32 | Issuer |
| 0x124 | 4 | Tag |
| 0x128 | 64 | Name |
| 0x168 | Key |