A library to read some formats used by Nintendo Switch operating system.
Mostly based on code in LibHac
Encrypted & container format for games and updates
Decryption & integrity verification are supported, though the header signature is not yet checked.
No support for BKTR patching and AES-XTS encryption (which NCAs even use it?).
Filesystem used for ExeFS, metadata storage.
Filesystem used to store game assets.
Note that while the RomFs itself is supported, no support is provided for BKTR patching, so currently it is not possible to read RomFs from updates.
CNMT are used to store metadata about titles and applications, prior to the downloading of the content.
The parsed CNMT is fully represented with nice rusty structs and enums.
NACP are used to store metadata about titles and applications, after the downloading of the content. They include a lot of information about what the application can and can't do.
All this information is available as rust structs.
Tickets are used to store metadata about the rights of a user to access a title.
There is support of extracting the rights ID and the title key from the ticket, if it is not personalized (Personalized stuff requires decryption of RSA messages and is not supported yet).
NSP are actually just a PartitionFs with NCAs and stuff inside.
There is a SwitchFs struct, which allows to load NCAs from a filesystem.
It parses all the metadata files (CNMTs and NACPs) and makes them available as a list of titles and applications.
The code handling the above formats is actually agnostic of the storage it is operating on.
It uses ReadableStorage trait to represent raw byte storage, allowing read(offset, size) operations on it. There is also ReadableBlockStorage, which constraints operations to only work with full blocks, which is useful for crypto and integrity verification stuff.
Finally, there is a ReadableFileSystem, along with ReadableFile, ReadableDirectory trait, which allow to represent some filesystem.
You can open sections of NCAs as ReadableFileSystem, without caring about the actual file system in use.
The API surface is definitely not final & stable yet, I am willing to make changes that would make it nicer.
There are plans to make some CLI tool, but what exist now is very bare-bones.
Licensed under either of
- Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.