nstool/README.md
2021-11-14 07:11:34 +08:00

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# Nintendo Switch Tool (NSTool) ![DeviceTag](https://img.shields.io/badge/Device-SWITCH-e60012.svg)
General purpose reading/extraction tool for Nintendo Switch file formats.
## Supported File Formats
* PartitionFs (`PFS0`) (.pfs0)
* Sha256PartitionFs (`HFS0`) (.hfs0)
* RomFs (.romfs)
* Nintendo Submission Package (.nsp)
* Nintendo Content Archive (.nca)
* NX GameCard Image (.xci)
* Meta (`META`) (.npdm)
* Nintendo Application Control Property (.nacp)
* Content Metadata (.cnmt)
* ES Certificate (.cert)
* ES Ticket (v2 only) (.tik)
* Nintendo Shared Object (`NSO0`) (.nso)
* Nintendo Relocatable Object (`NRO0`) (.nro)
* Initial Program Bundle (`INI1`) (.ini)
* Initial Program (`KIP1`) (.kip)
# Usage
## General usage
The default mode of NSTool is to show general information about a file.
To display general information the usage is as follows:
```
nstool some_file.bin
```
However not all information is shown in this mode; file-layout, key data and properties set to default values are omitted.
## Alternative output modes
To output file-layout information, use the `--showlayout` option:
```
nstool --showlayout some_file.bin
```
To output key data generation and selection, use the `--showkeys` option:
```
nstool --showkeys some_file.bin
```
To output all information, enable the verbose output mode with the `-v` or `--verbose` option:
```
nstool -v some_file.bin
```
## Specify File Type
NSTool will in most cases correctly identify the file type. However you can override this and manually specify the file type with the `-t` or `--intype` option:
```
nstool -t cnmt some_file.bin
```
In that example `cnmt` was selected, NSTool would process the file as `Content Metadata`. See below for a list of supported file type codes:
| Code | Description |
| ----------- | --------------- |
| gc, xci | NX GameCard Image |
| nsp | Nintendo Submission Package |
| pfs | PartitionFs |
| hfs | Sha256PartitionFs |
| romfs | RomFs |
| nca | Nintendo Content Archive |
| meta, npdm | Meta (.npdm) |
| cnmt | Content Metadata |
| nso | Nintendo Shared Object |
| nro | Nintendo Relocatable Object |
| ini | Initial Program Bundle |
| kip | Initial Program |
| nacp | Nintendo Application Control Property |
| cert | ES Certificate |
| tik | ES Ticket |
| aset, asset | Homebrew NRO Asset Binary |
## Validate Input File
Some file types have signatures/hashes/fields that can be validated by NSTool, but this mode isn't enabled by default.
To validate files with NSTool, enable the verify mode with the `-y` or `--verify` option:
```
nstool -y some_file.bin
```
See the below table for file types that support optional validation:
| File Type | Validation | Comments |
| --------- | ---------- | -------- |
| ES Certificate | Signature | If certificate is part of a certificate chain it will validate it as part of that chain. `Root` signed certificates are verified with user supplied `Root` public key. |
| ES Ticket | Signature | If the user specifies a certificate chain with `--cert` option, the ticket will be verified against that certificate chain. |
| NX GameCard Image | XCI Header Signature, HFS0 Hashes | XCI header signature is verified with user supplied `XCI Header` public key. |
| META | AccessControlInfo fields, AccessControlInfoDesc signature | AccessControlInfo fields are validated against the AccessControlInfoDesc. AccessControlInfoDesc signature is verfied with the appropriate user supplied `ACID` public key. |
| NCA | Header Signature[0], Header Signature[1] | Header Signature[0] is verified with the appropriate user supplied `NCA Header` public key. Header Signature[1] is verified only in Program titles, by retrieving the with public key from the AccessControlInfoDesc stored in the `code` partition. |
* As of Nintendo Switch Firmware 9.0.0, Nintendo retroactively added key generations for some public keys, including `NCA Header` and `ACID` public keys, so the various generations for these public keys will have to be supplied by the user.
* As of NSTool v1.6.0 the public key(s) for `Root Certificate`, `XCI Header`, `ACID` and `NCA Header` are built-in, and will be used if the user does not supply the public key in a key file.
## DevKit Mode
Files generated for `Production` use different (for the most part) encryption/signing keys than files generated for `Development`. NSTool will select `Production` encryption/signing keys by default.
When handling files intended for developer consoles (e.g. systemupdaters, devtools, test builds, etc), you should enable developer mode with the `-d`, `--dev` option:
```
nstool -d some_file.bin
```
## Extract Files
Some file types have some internal file system that can be displayed or extracted
## Encrypted Files
Some Nintendo Switch files are partially or completely encrypted. These require the user to supply the encryption keys to NSTool so that it can process them. Follow the below advice for what keys are required and how to supply them to NSTool.
### NX GameCard Image
The `GameCard ExtendedHeader` is encrypted with one of 8 keys, specified by the `KekIndex` in the `GameCard Header`.
It isn't required to extract game data, it just contains metadata.
Only two keys are currently defined:
| KeyIndex | Name | Description |
| ----------- | --------------- | ----------- |
| 00 | Production | Usually selected for prod images. Some dev images use this key index. |
| 01 | Development | Usually selected for dev images. This was changed from key index 00 at some point. |
In order to read the XCI Extended Header, the header key(s) must be defined in `prod.keys`/`dev.keys` (Prod and dev share the same keydata).
```
xci_header_key_00 = <32 char AES128 key here>
xci_header_key_01 = <32 char AES128 key here>
```
### Nintendo Content Archive
Nintendo Content Archive (NCA) files have both an encrypted header and content. The encrypted header determines the layout/format/encryption method of the content, which contains the game data.
In order to read the NCA header, the header key must be defined in `prod.keys`/`dev.keys`.
This can be explicitly:
```
nca_header_key = <64 char AES128-XTS key-data here>
```
Or allow NSTool to derive it from key sources:
```
master_key_00 = <32 char AES128 key-data here>
aes_kek_generation_source = <32 char AES128 key-data here>
aes_key_generation_source = <32 char AES128 key-data here>
nca_header_kek_source = <32 char AES128 key-data here>
nca_header_key_source = <64 char AES128 key-data here>
```
In order to read the NCA content, the content key must be determined. Unlike the header key which is fixed, each NCA will have a unique content key.
Content keys are either:
1) "Internal", where they are encrypted the NCA Header KeyArea
2) "External", where they are encrypted in an external Ticket file (.tik) (external content keys are sometimes called title keys)
#### Internal Content Key
Decrypting the content key from the NCA Header Key Area requires the appropriate `nca_key_area_key` to be defined in `prod.keys`/`dev.keys`.
However for security reasons Nintendo revises this key periodically, and within each key revision there are 3 separate keys for different categories of applications.
It's best to define as many of these as possible, to reduce the number of times you need to edit the keyfiles.
So for a given key revision these key area keys can be defined explicitly (`##` represents the key revision in hexadecimal):
```
nca_key_area_key_application_## = <32 char AES128 key-data here>
nca_key_area_key_ocean_## = <32 char AES128 key-data here>
nca_key_area_key_system_## = <32 char AES128 key-data here>
```
Or allow NSTool to derive them from key sources: (`##` represents the key revision in hexadecimal):
```
master_key_## = <32 char AES128 key-data here>
aes_kek_generation_source = <32 char AES128 key-data here>
aes_key_generation_source = <32 char AES128 key-data here>
nca_key_area_key_application_source = <32 char AES128 key-data here>
nca_key_area_key_ocean_source = <32 char AES128 key-data here>
nca_key_area_key_system_source = <32 char AES128 key-data here>
```
#### External Content Key
For NCAs that use an external content key, the user must supplied the key to NSTool.
Most NCAs that use an external content key will be bundled with a ticket file (*.tik) that contains the content key in an encrypted form.
The ticket can be supplied by the user using the `--tik` option:
```
nstool --tik <32 char rightsid>.tik <32 char contentid>.nca
```
This however requires the the appropriate commonkey to be defined in `prod.keys`/`dev.keys` to decrypt the content key in the ticket. However for security reasons Nintendo revises this key periodically. So it's best to define as many of these as possible, to reduce the number of times you need to edit the keyfiles.
So for a given key revision the common key can be defined explicitly (`##` represents the key revision in hexadecimal):
```
ticket_commonkey_## = <32 char AES128 key-data here>
```
Or allow NSTool to derive them from key sources: (`##` represents the key revision in hexadecimal):
```
master_key_## = <32 char AES128 key-data here>
ticket_commonkey_source = <32 char AES128 key-data here>
```
Alternatively you can supply the raw encrypted content key (also called a title key) directly with the `--titlekey` option:
```
nstool --titlekey <32 char AES128 key-data here> <32 char contentid>.nca
```
It is also possible to supply the decrypted content key directly with the `--contentkey` option:
```
nstool --contentkey <32 char AES128 key-data here> <32 char contentid>.nca
```
##### Scene Tickets
Please note that "Scene" tickets have been known to have errors. If you have issues using the `--tik` option, try passing the raw encrypted titlekey directly with the `--titlekey` option. The titlekey can be found by reading the ticket with NSTool:
```
nstool <32 char rightsid>.tik
```
##### Personalised Tickets
If the ticket is personalised (encrypted with console unique RSA key), NSTool will not support it. You will need to use extract the title key with another tool and pass the encrypted title key directly with the `--titlekey` option.
# External Keys
NSTool doesn't embed any keys that are copyright protected. However keys can be imported via various keyset files.
See [SWITCH_KEYS.md](/SWITCH_KEYS.md) for more info.
# Building
See [BUILDING.md](/BUILDING.md).