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→MAC header
* to calculate the checksum, a CRC16 of the block (with starting value 0xFFFF) is calculated, and the two bytes of the CRC16 are XORed together to produce the 8bit checksum
* to calculate the checksum, a CRC16 of the block (with starting value 0xFFFF) is calculated, and the two bytes of the CRC16 are XORed together to produce the 8bit checksum
=== MAC header ===
=== AES MAC header ===
{| class="wikitable"
{| class="wikitable"
| 0x00
| 0x00
| 0x10
| 0x10
| [[AES]]-CBC MAC over a 0x20-byte SHA256 hash
| [[AES]] MAC over a 0x20-byte SHA256 hash
|-
|-
| 0x10
| 0x10
|}
|}
This MAC is used to "sign" the DISA/DIFF header. Each time the savegame is updated the hash stored in the DISA/DIFF is updated, therefore the MAC must be updated each time the save is modified as well. SHA256_Update() is used to calculate the hash with the blocks described below.
This AES MAC is used to "sign" the DISA/DIFF header. Each time the savegame is updated the hash stored in the DISA/DIFF is updated, therefore the MAC must be updated each time the save is modified as well. SHA256_Update() is used to calculate the hash with the blocks described below.
==== Savegame Types ====
==== Savegame Types ====
|-
|-
| CTR-9DB0
| CTR-9DB0
| ?
| /dbs extdata images
|}
|}
|-
|-
| 0x4
| 0x4
| ?
| ID, value 0x2 for title.db.
|-
|-
| 0x100
| 0x100
|}
|}
This is likely used for the [[Title_Database|dbs]] images' MAC.
This is used for the [[Title_Database|dbs]] images' MAC.
=== Partitions ===
=== Partitions ===