pyctr.type.cdn module

Module for interacting with contents in CDN layout.

exception pyctr.type.cdn.CDNError

Bases: PyCTRError

Generic error for CDN operations.

class pyctr.type.cdn.CDNSection(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: IntEnum

Ticket = -2

Contains the title key used to decrypt the contents, as well as a content index describing which contents are enabled (mostly used for DLC).

TitleMetadata = -1

Contains information about all the possible contents.

Application = 0

Main application CXI.

Manual = 1

Manual CFA. It has a RomFS with a single “Manual.bcma” file inside.

DownloadPlayChild = 2

Download Play Child CFA. It has a RomFS with CIA files that are sent to other Nintendo 3DS systems using Download Play. Most games only contain one.

class pyctr.type.cdn.CDNRegion(section, iv)

Bases: NamedTuple

Parameters:

• section (Union[int, CDNSection]) –

• iv (bytes) –

section: int | CDNSection

Index of the section.

iv: bytes

Initialization vector. Only used for encrypted contents.

class pyctr.type.cdn.CDNReader(file, *, fs=None, case_insensitive=False, crypto=None, dev=False, seed=None, titlekey=None, decrypted_titlekey=None, common_key_index=0, load_contents=True)

Bases: object

Reads the contents of files in a CDN file layout.

Only NCCH contents are supported. SRL (DSiWare) contents are currently ignored.

Note that a custom CryptoEngine object is only used for encryption on the CDN contents. Each NCCHReader must use their own object, as it can only store keys for a single NCCH container. To use a custom one, set load_contents to False, then load each section manually with open_raw_section.

Parameters:

• file (FilePath) – A path to a tmd file. All the contents should be in the same directory.

• case_insensitive (bool) – Use case-insensitive paths for the RomFS of each NCCH container.

• crypto (CryptoEngine) – A custom CryptoEngine object to be used. Defaults to None, which causes a new one to be created. This is only used to decrypt the CIA, not the NCCH contents.

• dev (bool) – Use devunit keys.

• seed (bytes) – Seed to use. This is a quick way to add a seed using add_seed().

• titlekey (bytes) – Encrypted titlekey to use. Used over the ticket file if specified.

• decrypted_titlekey (bytes) – Decrypted titlekey to use. Used over the encrypted titlekey or ticket if specified.

• common_key_index (int) – Common key index to decrypt the titlekey with. Only used if titlekey is specified. Defaults to 0 for an eShop application.

• load_contents (bool) – Load each partition with NCCHReader.

• fs (Optional[FS]) –

closed: bool

True if the reader is closed.

fs

available_sections: List[CDNSection | int]

A list of sections available, including contents, ticket, and title metadata.

contents: Dict[int, NCCHReader]

A dict of NCCHReader objects for each active NCCH content.

content_info: List[ContentChunkRecord]

A list of ContentChunkRecord objects for each content found in the directory at the time of object initialization.

tmd: TitleMetadataReader

The TitleMetadataReader object with information from the TMD section.

close()

Close the reader.

open_raw_section(section)

Open a raw CDN content for reading with on-the-fly decryption.

Parameters:

section (Union[int, CDNSection]) – The content to open.

Returns:

A file-like object that reads from the content.

Return type:

io.BufferedIOBase | CBCFileIO