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NCSD: Difference between revisions

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|  0x118
|  0x118
|  8
|  8
|  Partitions crypt type  
|  Partitions crypt type (each byte corresponds to a partition in the partition table)
|-
|-
|  0x120
|  0x120
Line 102: Line 102:
|  Partition ID table  
|  Partition ID table  
|-
|-
|  0x1C0
|  0x1D0
|  0x30
|  0x20
|  Reserved
|  Reserved
|-
|-
Line 136: Line 136:
|}
|}


=== NCSD Signature ===
The RSA public key used for gamecard NCSD is stored in [[Memory_layout|ITCM]]. The separate public key used for NAND NCSD is stored in Process9 .(ro)data instead of ITCM, and in [[Bootloader|boot ROM]].
For the boot ROM check, sighax may be used to fake-sign NAND headers.  Process9's check will fail, however, unless patched.


=== Partition Flags ===
=== Partition Flags ===
Line 197: Line 201:
|-
|-
|  0x208
|  0x208
|  0xDF8
|  0xF8
|  Reserved1
|  Reserved
|-
|  0x300
|  4
|  Filled size of cartridge
|-
|  0x304
|  0xC
|  Reserved
|-
|  0x310
|  2
|  Title version
|-
|  0x312
|  2
|  Card revision
|-
|  0x314
|  0xC
|  Reserved
|-
|  0x320
|  8
|  Title ID of [[CVer]] in included update partition
|-
|  0x328
|  2
|  Version number of [[CVer]] in included update partition
|-
|  0x32A
|  0xCD6
|  Reserved
|-
|-
|  0x1000
|  0x1000
|  0x200
|  InitialData
|}
=== InitialData ===
This data is returned by [[Gamecards|16-byte cartridge command]] 0x82.
{| class="wikitable" border="1"
|-
!  OFFSET
!  SIZE
!  DESCRIPTION
|-
|  0x00
|  0x10
|  0x10
|  Card seed keyY (first u64 is Media ID (same as first NCCH partitionId))
|  Seed (keyY used to decrypt the title key - keyX is keyslot 0x3B for production cards, or a key of all zeroes for development cards), consisting of the title ID (little-endian) followed by reserved data (normally all-zero)
|-
|-
|  0x1010
|  0x10
|  0x10
|  Encrypted card seed (AES-CCM, keyslot 0x3B for retail cards, see [[CTRCARD_Registers|CTRCARD_SECSEED]])
|  0x10
|  TitleKey (AES-CCM encrypted)
|-
|-
|  0x1020
|  0x20
|  0x10
|  0x10
|  Card seed AES-MAC
|  AES-CCM MAC
|-
|-
|  0x1030
|  0x30
|  0xC
|  0xC
|  Card seed nonce
|  AES-CCM nonce
|-
|-
|  0x103C
|  0x3C
|  0xC4
|  0xC4
|  Reserved
|  Reserved (normally all-zero)
|-
|-
|  0x1100
|  0x100
|  0x100
|  Copy of first NCCH header (excluding RSA signature)
|  0x100
|  NcchHeader (copy of the first NCCH header, excluding the RSA signature)
|}
|}


Line 238: Line 289:
|  0x1400
|  0x1400
|  0x10
|  0x10
|  TitleKey
|  TitleKeyData
|-
|-
|  0x1410
|  0x1410
|  0xF0
|  0x1BF0
|  CardDeviceReserved2
|  CardDeviceReserved2
|-
|  0x3000
|  0x1000
|  TestData
|}
TitleKeyData contains the decrypted version of the title key found in the InitialData. This field appears to be what development--and maybe production?--cards read to know what card encryption seed to use in the CTR protocol.
The CardDeviceReserved areas have random-looking data whose purpose is unknown, other than perhaps to hide the TitleKey.
Note that a particular flashcard vendor, namely Gateway, puts what many refer to as "private headers" at CardDeviceReserved1 in place of actual development card information. This header consists of:
{| class="wikitable" border="1"
|-
!  OFFSET
!  SIZE
!  DESCRIPTION
|-
|  0x0
|  0x40
|  Unique cartridge ID; only the first 0x10 bytes are meaningful, the rest are 0xff; obtainable using encrypted [[Gamecards|16-byte cartridge command]] 0xc6; the first 0x10 bytes can also be obtained in userland via [[Process_Services_PXI|pxi:ps9::GetRomId]]
|-
|  0x40
|  0x4
|  Cartridge ID1; obtainable using 8-byte cartridge command 0x90 or 16-byte cartridge command 0xa2
|-
|  0x44
|  0x4
|  Cartridge ID2; obtainable using 8-byte cartridge command 0xa0 or 16-byte cartridge command 0xa4
|-
|  0x48
|  0x8
|  Padding (all-0xff)
|}
The legitimacy of the unique cartridge ID can be validated by online services.
Some dumping tools, notably GodMode9 as of 2024-05-26, erroneously always write 0x00000000 into the position of the Cartridge ID2. This is presumably because the cartridge ID2 is always zero for retail carts.
=== TestData ===
The test data is the same one encountered in development DS/DSi cartridges. Its layout is as follows:
{| class="wikitable" border="1"
|-
!  OFFSET
!  SIZE
!  DESCRIPTION
|-
|  0x0
|  0x8
|  The bytes FF 00 FF 00 AA 55 AA 55.
|-
|  0x8
|  0x1F8
|  An ascending byte sequence equal to the offset mod 256 (08 09 0A ... FE FF 00 01 ... FF).
|-
|  0x200
|  0x200
|  A descending byte sequence equal to 255 minus the offset mod 256 (FF FE FD ... 00 FF DE ... 00).
|-
|  0x400
|  0x200
|  Filled with 00 (0b00000000) bytes.
|-
|  0x600
|  0x200
|  Filled with FF (0b11111111) bytes.
|-
|  0x800
|  0x200
|  Filled with 0F (0b00001111) bytes.
|-
|  0xA00
|  0x200
|  Filled with F0 (0b11110000) bytes.
|-
|  0xC00
|  0x200
|  Filled with 55 (0b01010101) bytes.
|-
|  0xE00
|  0x1FF
|  Filled with AA (0b10101010) bytes.
|-
|  0xFFF
|  0x1
|  The final byte is 00 (0b00000000).
|}
|}


Note that a particular flashcard vendor puts what many refer to as "private headers" here in place of actual development card information. This header is constituted by a cartridge-unique Id obtained from [[Process_Services_PXI|pxi:ps9::GetRomId]] and the title-unique cart ID (identical for all carts of the same title; can be retrieved using the NTR gamecard protocol command 0x90 or through the CTR protocol commands 0x90 or 0xA2).
Production cards always return FF when attempting to read 0x1200-0x3FFF. They probably actually have the same data as development cards, but there's no way to read it.


== Tools ==
== Tools ==
Retrieved from "https://www.3dbrew.org/wiki/NCSD"