The DSiWare exported from a 3DS is located at "sdmc:/Nintendo 3DS/<ID0>/<ID1>/Nintendo DSiWare". Filenames are same format as DSi: "<TitleID-Low>.bin". The below sizes include the 0x20-byte block metadata.
DSiWare exported from 3DS use console-unique keyslots initialized by movable.sed. Each section is encrypted with AES-CBC.
The content sections are ordered the same way as DSi: TMD, SRL from content0, <content1-7 for format v2>, public.sav, and banner.sav when banner.sav exists. When the DSiWare export type is 7-11, the 12th content section is the private.sav, if it exists.(ContentX here is the .app data from TWL-NAND /title)
DSiWare Export Types
| Value
|
Format version
|
Description
|
| 0-6
|
|
Invalid
|
| 7-11
|
v2
|
12 content sections
|
| 12
|
v2
|
4 content sections
|
| 13
|
v1
|
4 content sections
|
| 14
|
v2
|
11 content sections
|
For NATIVE_FIRM versions where this DSiWare export type field is unused, format version v1 is used with 4 content sections. Otherwise when this field is used, see the above table.
Block Metadata
| Offset
|
Size
|
Description
|
| 0x0
|
0x10
|
AES MAC over a SHA-256 hash
|
| 0x10
|
0x10
|
IV, generated by the RNG.
|
Each section begins with the payload encrypted data, followed by this block metadata. The SHA-256 hash used for the MAC is calculated over the cleartext payload. This hash used for generating the MAC is also stored in the footer.
| Offset
|
Size
|
Description
|
| 0x0
|
X
|
SHA-256 hashes over the banner, header, and content sections. When a content section doesn't exist, the corresponding hash here is uninitialized.
|
| 0x0 + X
|
0x3C
|
ECDSA signature over the previous hashes, signed by the APCert.
|
| 0x3C + X
|
0x180
|
ECDSA "APXXXXXXXXXXXXXXXX" cert signed by the CTCert, where X is random lowercase ASCII hex data.
|
| 0x1BC + X
|
0x180
|
ECDSA CTCert
|
| 0x33C + X
|
0x4
|
Uninitialized padding.
|
These hashes are the same hashes used for generating each section's MAC stored in the metadata block. X = 0x40 + totalcontentsections*0x20.
File Structure v1
| Offset
|
Size
|
Description
|
| 0x0
|
0x4020
|
Banner section
|
| 0x4020
|
0xC0
|
Header section
|
| 0x40E0
|
0x340 + 0x20 + X, where X is the total size of the hashes stored in the footer.
|
Footer section
|
| 0x40E0 + footer_size
|
|
Content sections
|
| Offset
|
Size
|
Description
|
| 0x0
|
0x4
|
Magic number 0x54444633, "3FDT".
|
| 0x4
|
0x2
|
Byte-swapped groupID from the TWL TMD.
|
| 0x6
|
0x2
|
Byte-swapped title version from the TWL TMD.
|
| 0x8
|
0x20
|
SHA-256 hash calculated over the encrypted movable.sed.
|
| 0x28
|
0x10
|
Encrypted AES block from encrypting an all-zero 0x10-byte block with AES-CBC, where the IV is all-zero.
|
| 0x38
|
0x8
|
Byte-swapped titleID from the TWL TMD.
|
| 0x40
|
0x8
|
?
|
| 0x48
|
0x10
|
u32 payload sizes for the 4 content sections.
|
| 0x58
|
0x4
|
?
|
| 0x5C
|
0x3E
|
Data from the TWL TMD reserved section. Only the first 0x20-bytes from the TWL TMD is written here, the rest is uninitialized.
|
| 0x9A
|
0x6
|
Padding?
|
File Structure v2
| Offset
|
Size
|
Description
|
| 0x0
|
0x4020
|
Banner section
|
| 0x4020
|
0x110
|
Header section
|
| 0x4130
|
0x340 + 0x20 + X, where X is the total size of the hashes stored in the footer.
|
Footer section
|
| 0x4130 + footer_size
|
|
Content sections
|
| Offset
|
Size
|
Description
|
| 0x0
|
0x4
|
Magic number 0x54444633, "3FDT".
|
| 0x4
|
0x2
|
Byte-swapped groupID from the TWL TMD.
|
| 0x6
|
0x2
|
Byte-swapped title version from the TWL TMD.
|
| 0x8
|
0x20
|
SHA-256 hash calculated over the encrypted movable.sed.
|
| 0x28
|
0x10
|
Encrypted AES block from encrypting an all-zero 0x10-byte block with AES-CBC, where the IV is all-zero.
|
| 0x38
|
0x8
|
Byte-swapped titleID from the TWL TMD.
|
| 0x40
|
0x8
|
?
|
| 0x48
|
0x2C
|
u32 payload sizes for the 11 content sections.
|
| 0x74
|
0x30
|
?
|
| 0xA4
|
0x3E
|
Data from the TWL TMD reserved section. Only the first 0x20-bytes from the TWL TMD is written here, the rest is uninitialized.
|
| 0xE2
|
0x0E
|
Padding?
|