Is the feature request related to a problem?
To be able to easily access to the NCCH header from generic tools (like SceneGate), it would be better if it's a node as part of the NCCH NodeContainerFormat, instead of just a property.

Describe the solution you'd like
Similar to NitroRom for NDS, put the format of NcchHeader as a node of the NodeContainerFormat generated by Binary2Ncch.

Describe alternatives you've considered
None.

Additional context
None.

Is your feature request related to a problem? Please describe.
As mentioned in #12, generating a new CIA binary with modified content will not work properly. (Maybe it works in emulator by luck, but not on a real console).

Describe the solution you'd like
When using NodeContainer2BinaryCia, it should create a new TMD by reading the original file to get information like the content info and content chunks and use it to create a new TMD.

Proposed plan of implementation (same or different PRs):

• Create two new properties in the TitleMetadata class and read them when using Binary2TitleMetadata, the sign type and the sign size.
• When using NodeContainer2BinaryCia, instead of writing the binary of the "title" child, it would create and write a new one by using the TitleMetadata properties and by reading some information from the original binary (content info records).

Describe alternatives you've considered
I thought of making more properties to the TitleMetadata class, but that would be hard to make since some relies on hashes and the content info records are long.

Additional context
I have some working code that goes with my proposed plan of implementation. If this is okay, then I'll make a pull request.

Is your feature request related to a problem? Please describe.
In order to generate a valid CIA, we need to update the TMD and write it back [#13].

Describe the solution you'd like

• Implement a converter to write into binary format the TMD (TitleMetadata): TitleMetadata2Binary. Skip the work related to signatures.
• Add integration tests so the generation works: it should skip checking the bytes related to signatures.

Describe alternatives you've considered
Implement it inside the CIA converter but for maintainability and future, a new converter we can re-use would be better.

The file Ncch2Binary.cs (line 39 to 41)
mentions that it expects nodes that are in "header_data", this is a leftover of when I tried to make all the header data nodes.
Small thing, but I forgot to remove it.

Description
Implement a converter to pack/write nodes into the binary format NCCH.

Describe the solution you'd like
Create a new class Ncch2Binary that implements IConverter<NodeContainerFormat, BinaryFormat>. The input NodeContainerFormat should have a specific folder hierarchy, like a node with the format NcchHeader.

Proposed plan of implementation (same or different PRs):

• Read the remaining of the NCHH header in Binary2Ncch (the TODOs).
• Implement integration test.
• Implement Ncch2Binary converter.

Describe alternatives you've considered
The current approach of having the header as part of the property class instead of as a specific node. However, it would be harder for generic tools to display the header and being a separate node can simplify potential future converters into yaml or binary.

Additional context
Tests should be implemented in NcchConverterTests and they should verify that we generate back and forward the exactly same binary. We would need to add one new test that does something like this:

using var nodes = containerConverter.Convert(original);
using var actualBinary = binaryConverter.Convert(nodes);
Assert.That(original.Stream.Compare(actualBinary.Stream), Is.True, "Streams are not identical");

Validate the different signatures avaiable in the NCCH and other containers. The public key should be provided via a class in a external file.

Documentation explaining how to get the public key should be available.

This should make possible to validate original dumps.

Implement the NCCH encryption and decryption (AES).

The list of keys should come from a new class (key database). It should not be in the repository. The user must always provide these keys.

Documentation explaining how to obtain the keys from your own 3DS should be available.

This would make possible to read direct dumps from original games.