Difference between revisions of "NCA"

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Line 119: Line 119:
 
| 0x8
 
| 0x8
 
|  
 
|  
| Start of the fs-specific header data.
+
| FS-specific superblock.
 
|}
 
|}
  
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The total size is 0x200-bytes.
 
The total size is 0x200-bytes.
  
==Logo section==
+
==PFS0 superblock==
 +
{| class="wikitable" border="1"
 +
|-
 +
! Offset
 +
! Size
 +
! Description
 +
|-
 +
| 0x8
 +
| 0x20
 +
| SHA256 hash
 +
|-
 +
| 0x28
 +
| 0x4
 +
| ?
 +
|-
 +
| 0x2C
 +
| 0x4
 +
| ?
 +
|-
 +
| 0x38
 +
| 0x8?
 +
| Size of hash-table.
 +
|-
 +
| 0x40
 +
| 0x8?
 +
| Offset relative to section-start where the PFS0 header is located.
 +
|-
 +
| 0x48
 +
| 0x8
 +
| Actual byte-size of the PFS0 filesystem relative to the PFS0 header.
 +
|-
 +
| 0x50
 +
| 0xF4
 +
| Normally zeros.
 +
|-
 +
| 0x144
 +
| ?
 +
| 0x1?
 +
|-
 +
| 0x148
 +
| 0xB8
 +
| Normally zeros.
 +
|}
 +
 
 +
This documents the structure of Section Header Block +0 for PFS0.
 +
 
 +
==RomFS superblock==
 +
{| class="wikitable" border="1"
 +
|-
 +
! Offset
 +
! Size
 +
! Description
 +
|-
 +
| 0x8
 +
|
 +
| IVFC header
 +
|}
 +
 
 +
This documents the structure of Section Header Block +0 for RomFS.
 +
 
 +
=Logo section=
 
This is a PFS0. See [[NCA_Content_FS|here]] for the mounted-FS logo contents.
 
This is a PFS0. See [[NCA_Content_FS|here]] for the mounted-FS logo contents.
  
==ExeFS section ==
+
=ExeFS section =
 
This is a PFS0.
 
This is a PFS0.
  

Revision as of 03:44, 18 July 2017

The entire raw NCAs are encrypted.

The only known area which is not encrypted in the raw NCA is the logo section, when the NCA includes that section. Everything else documented on this page is for the plaintext version of that data.

Header

Offset Size Description
0x0 0x100 RSA-2048 signature over the 0x200-bytes starting at offset 0x200 using fixed key.
0x100 0x100 RSA-2048 signature over the 0x200-bytes starting at offset 0x200 using key from NPDM, or zeroes if not a program.
0x200 0x4 Magicnum "NCA3"
0x204 0x3 ?
0x207 0x1 Key index
0x208 0x8 Size of the entire NCA.
0x210 0x8 titleID
0x230 0x10 Rights ID (Ticket)
0x240 0x10*0x4(0x40) Table for each section, see below.
0x280 0x20*0x4(0x80) Table of SHA256 hashes, over each 0x200-byte Section Header Block.
0x300 0x10*0x4(0x40) Key area

The header is 0x400-bytes, at NCA+0.

Section Table Entry

Offset Size Description
0x0 0x4 Media offset
0x4 0x4 Media end-offset
0x8 0x4 Unknown
0xC 0x4 Unknown

Entry size is 0x10-bytes.

Media offset is absoluteoffset/{mediasize}, where mediasize is hard-coded to 0x200.

Section Header Block

Offset Size Description
0x0 0x1 ?
0x1 0x1 ?
0x2 0x1 ?
0x3 0x1 ?
0x4 0x1 Crypto type. 0 and >4 are invalid. 1 = none(plaintext from raw NCA). 2 = other crypto. 3 = regular crypto. 4 = unknown.
0x5 0x1 Padding?
0x8 FS-specific superblock.

The Section Header Block for each section is at absoluteoffset+0x400+(sectionid*0x200), where sectionid corresponds to the index used with the entry/hash tables.

The total size is 0x200-bytes.

PFS0 superblock

Offset Size Description
0x8 0x20 SHA256 hash
0x28 0x4 ?
0x2C 0x4 ?
0x38 0x8? Size of hash-table.
0x40 0x8? Offset relative to section-start where the PFS0 header is located.
0x48 0x8 Actual byte-size of the PFS0 filesystem relative to the PFS0 header.
0x50 0xF4 Normally zeros.
0x144 ? 0x1?
0x148 0xB8 Normally zeros.

This documents the structure of Section Header Block +0 for PFS0.

RomFS superblock

Offset Size Description
0x8 IVFC header

This documents the structure of Section Header Block +0 for RomFS.

Logo section

This is a PFS0. See here for the mounted-FS logo contents.

ExeFS section

This is a PFS0.

See here for mounted-FS ExeFS contents.

PFS0

Offset Size Description
0x0 X Table of hashes.
X Y Zeros for alignment to {alignment size}.
X+Y Start of the PFS0 header.

This is the FS which has magicnum "PFS0" at header+0.