NCA extraction

[roblabla]

Parse and extract nca sections.

[todo]

Better format

linkle/src/format/nca.rs

Lines 141 to 151 in 935fed2

	sdk_version: u32, // TODO: Better format
	xts_key: AesXtsKey,
	ctr_key: Aes128Key,
	rights_id: Option<[u8; 0x10]>,
	sections: [Option<SectionJson>; 4]
	}
	#[derive(Debug)]
	pub struct Nca<R> {
	stream: R,
	json: NcaJson

---

This comment was generated by todo based on a TODO comment in 935fed2 in #34. cc @roblabla.

[todo]

Check if NCA is already decrypted

linkle/src/format/nca.rs

Lines 170 to 180 in 935fed2

	// TODO: Check if NCA is already decrypted
	let header_key = pki.header_key().as_ref().ok_or(Error::MissingKey("header_key", Backtrace::new()))?;
	header_key.decrypt(&header[..0x400], &mut decrypted_header[..0x400], 0, 0x200)?;
	let raw_nca = *RawNca::from_bytes(&decrypted_header).expect("RawNca to be of the right size");
	match &raw_nca.magic {
	b"NCA3" => {
	header_key.decrypt(&header, &mut decrypted_header, 0, 0x200)?;
	},
	b"NCA2" => {

---

This comment was generated by todo based on a TODO comment in 935fed2 in #34. cc @roblabla.

[todo]

NCA: Verify header with RSA2048 PSS

We want to make sure the NCAs have a valid signature before decrypting. Maybe put it behind a flag that accepts invalidly signed NCAs?

---

linkle/src/format/nca.rs

Lines 206 to 216 in 935fed2

	// TODO: NCA: Verify header with RSA2048 PSS
	// BODY: We want to make sure the NCAs have a valid signature before
	// BODY: decrypting. Maybe put it behind a flag that accepts invalidly
	// BODY: signed NCAs?
	// Crypto is stupid. First, we need to get the max of crypto_type and crypto_type2.
	// Then, nintendo uses both 0 and 1 as master key 0, and then everything is shifted by one.
	// So we sub by 1.
	let master_key_revision = max(header.crypto_type2, header.crypto_type).saturating_sub(1);
	// Handle Rights ID.

---

This comment was generated by todo based on a TODO comment in 935fed2 in #34. cc @roblabla.

[todo]

NCA0 => return

linkle/src/format/nca.rs

Lines 222 to 232 in 935fed2

	// TODO: NCA0 => return
	(
	key_area_key.derive_xts_key(&header.encrypted_xts_key)?,
	key_area_key.derive_key(&header.encrypted_ctr_key)?,
	)
	} else {
	// TODO: Implement RightsID crypto.
	unimplemented!("Rights ID");
	};
	// Parse sections

---

This comment was generated by todo based on a TODO comment in 935fed2 in #34. cc @roblabla.

[todo]

Implement RightsID crypto.

linkle/src/format/nca.rs

Lines 228 to 238 in 935fed2

	// TODO: Implement RightsID crypto.
	unimplemented!("Rights ID");
	};
	// Parse sections
	let mut sections = [None, None, None, None];
	for (idx, (section, fs)) in header.section_entries.iter().zip(header.fs_headers.iter()).enumerate() {
	// Check if section is present
	if section.media_start_offset != 0 {
	if has_rights_id {
	unimplemented!("Rights ID");

---

This comment was generated by todo based on a TODO comment in 935fed2 in #34. cc @roblabla.

[todo]

Store the SDK version in a more human readable format.

linkle/src/format/nca.rs

Lines 277 to 287 in 935fed2

	// TODO: Store the SDK version in a more human readable format.
	sdk_version: header.sdk_version,
	xts_key: decrypted_keys.0,
	ctr_key: decrypted_keys.1,
	// TODO: Implement rights id.
	rights_id: None,
	sections: sections,
	}
	};
	Ok(nca)

---

This comment was generated by todo based on a TODO comment in 935fed2 in #34. cc @roblabla.

[todo]

Implement rights id.

linkle/src/format/nca.rs

Lines 281 to 291 in 935fed2

	// TODO: Implement rights id.
	rights_id: None,
	sections: sections,
	}
	};
	Ok(nca)
	}
	}
	impl<R: Read + TryClone + Seek> Nca<R> {

---

This comment was generated by todo based on a TODO comment in 935fed2 in #34. cc @roblabla.

[todo]

Nca::raw_section should reopen the file, not dup2 the handle.

linkle/src/format/nca.rs

Lines 294 to 304 in 935fed2

	// TODO: Nca::raw_section should reopen the file, not dup2 the handle.
	let mut stream = self.stream.try_clone()?;
	stream.seek(std::io::SeekFrom::Start(section.start_offset()))?;
	Ok(CryptoStream {
	stream: ReadRange::new(stream, section.start_offset(), section.size()),
	// Keep a 1-block large buffer of data in case of partial reads.
	buffer: [0; 0x10],
	state: CryptoStreamState {
	ctr_key: self.json.ctr_key,
	xts_key: self.json.xts_key,

---

This comment was generated by todo based on a TODO comment in 935fed2 in #34. cc @roblabla.

[todo]

Make VerificationStream actually verify the data it reads.

based on the hash table located with the help of the superblock. It will need a different implementation for PFS0 and RomFs (and maybe Bktr?).

---

linkle/src/format/nca.rs

Lines 457 to 467 in 935fed2

	// TODO: Make VerificationStream actually verify the data it reads.
	// BODY: VerificationStream should verify the body based on the hash table
	// BODY: located with the help of the superblock. It will need a different
	// BODY: implementation for PFS0 and RomFs (and maybe Bktr?).
	pub struct VerificationStream<R> {
	stream: R,
	start_at: u64,
	}
	impl<R: Read + Seek> Read for VerificationStream<R> {
	fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {

---

This comment was generated by todo based on a TODO comment in 935fed2 in #34. cc @roblabla.

[todo]

Figure out why this is necessary.

linkle/src/lib.rs

Lines 1 to 4 in 935fed2

	// TODO: Figure out why this is necessary.
	#[macro_use]
	extern crate static_assertions;

---

This comment was generated by todo based on a TODO comment in 935fed2 in #34. cc @roblabla.

[todo]

Document

linkle/src/utils.rs

Lines 5 to 15 in 935fed2

	// TODO: Document
	#[macro_export]
	macro_rules! enum_with_val {
	($(#[$meta:meta])* $vis:vis struct $ident:ident($ty:ty) {
	$($variant:ident = $num:expr),* $(,)*
	}) => {
	$(#[$meta])*
	#[derive(PartialEq, Eq)]
	$vis struct $ident($ty);
	impl $ident {
	$(#[allow(non_upper_case_globals)] $vis const $variant: $ident = $ident($num);)*

---

This comment was generated by todo based on a TODO comment in 935fed2 in #34. cc @roblabla.

[todo]

NCA0 => return

linkle/src/format/nca.rs

Lines 222 to 232 in 9ba46f8

	// TODO: NCA0 => return
	(
	key_area_key.derive_xts_key(&header.encrypted_xts_key)?,
	key_area_key.derive_key(&header.encrypted_ctr_key)?,
	)
	} else {
	// TODO: Implement RightsID crypto.
	unimplemented!("Rights ID");
	};
	// Parse sections

---

This comment was generated by todo based on a TODO comment in 9ba46f8 in #34. cc @roblabla.

[todo]

NCA0 => return

linkle/src/format/nca.rs

Lines 264 to 274 in 2d2206b

	// TODO: NCA0 => return
	(
	key_area_key.derive_xts_key(&header.encrypted_xts_key)?,
	key_area_key.derive_key(&header.encrypted_ctr_key)?,
	)
	} else {
	// TODO: Implement RightsID crypto.
	unimplemented!("Rights ID");
	};
	// Parse sections

---

This comment was generated by todo based on a TODO comment in 2d2206b in #34. cc @roblabla.

[todo]

Bubble up the error.

linkle/src/format/nca.rs

Lines 627 to 637 in 2d2206b

	// TODO: Bubble up the error.
	self.state.decrypt(&mut self.buffer).unwrap();
	buf[from..].copy_from_slice(&self.buffer[..leftovers]);
	self.state.offset += leftovers as u64;
	}
	Ok(previous_leftovers_written + read)
	}
	}
	impl<W: Write + Seek> Write for CryptoStream<W> {

---

This comment was generated by todo based on a TODO comment in 2d2206b in #34. cc @roblabla.

[todo]

Bubble up the error.

linkle/src/format/nca.rs

Lines 649 to 659 in 2d2206b

	// TODO: Bubble up the error.
	self.state.encrypt(&mut self.buffer).unwrap();
	self.stream.write_all(&self.buffer)?;
	self.state.decrypt(&mut self.buffer).unwrap();
	if to != 16 {
	self.stream.seek(io::SeekFrom::Current(-16))?;
	} else {
	self.buffer = [0; 16];
	}

---

This comment was generated by todo based on a TODO comment in 2d2206b in #34. cc @roblabla.

[todo]

Now, verify the buffer.

linkle/src/format/nca.rs

Lines 741 to 751 in 2d2206b

	// TODO: Now, verify the buffer.
	}
	}
	fn write_hash<W: Write + Seek>(section: &SectionJson, cur_off: u64, stream: &mut ReadRange<W>, block: &[u8]) -> io::Result<()> {
	match section.fstype {
	FsType::Pfs0 { hash_table_offset, .. } => {
	let hash = Sha256::digest(block);
	let hash_pos = hash_table_offset + 0x20 * (cur_off / 4096);
	stream.as_inner_mut().seek(io::SeekFrom::Start(hash_pos)).unwrap();
	stream.as_inner_mut().write_all(hash.as_slice()).unwrap();

---

This comment was generated by todo based on a TODO comment in 2d2206b in #34. cc @roblabla.