AM:ImportTwlBackup

Revision as of 00:18, 17 October 2016 by Yellows8 (talk | contribs) (→‎Request)

Request

Index Word Description
0 Header code [0x001C0084]
1 Buffer Size (must be >= 0x20000)
2 u8, Operation
3 0x10
4 FSFILE Handle
5 (Buffer Size << 4) | 0xC
6 Buffer Pointer. Input encrypted DSiWare export banner, header, and footer. Also used as a work buffer.

Response

Index Word Description
0 Header code
1 Result code

Operation

Value Description
0-1 Invalid, same as values 4 and 7.
2 and 5 ?
3 and 6 ?
4 and >=7 No importing is done here.

Description

AM module uses AMPXI:DecryptDSiWareData for decrypting each DSiWare section. After decrypting a section via that command, AM module calculates a hash over the decrypted payload data for AMPXI:ValidateDSiWareSectionMAC. The footer hash for this section is then verified by calculating a hash over the cleartext data as well.

After AM module validates the header, AM module then uses AMPXI:ValidateDSiWareMovableSedHash. The footer ECDSA verification is handled by AMPXI:VerifyDSiWareFooter. The decrypted banner is written to inputbuffer+0.