nstool/lib/nx/NcaHeader.h

#pragma once
#include <vector>
#include <string>
#include <fnd/types.h>
#include <fnd/memory_blob.h>
#include <crypto/aes.h>
#include <crypto/sha.h>
#include <nx/ISerialiseableBinary.h>

class NcaHeader : public ISerialiseableBinary
{
public:
	struct sSection
	{
		u32 start_blk;
		u32 end_blk;
		u64 offset;
		u64 size;
		u8 key_type;
		crypto::sha::sSha256Hash hash;
	};

	static const size_t kDefaultBlockSize = 0x200;

	NcaHeader();
	NcaHeader(const NcaHeader& other);
	NcaHeader(const u8* bytes);

	bool operator==(const NcaHeader& other);
	void operator=(const NcaHeader& other);

	// to be used after export
	const u8* getBytes() const;
	size_t getSize() const;

	// export/import binary
	void exportBinary();
	void importBinary(const u8* bytes);
	void importBinary(const u8* bytes, size_t len);

	// variables
	u64 getNcaSize() const;
	void setNcaSize(u64 size);
	u64 getProgramId() const;
	void setProgramId(u64 program_id);
	u32 getUnk() const;
	const std::vector<sSection>& getSections() const;
	void addSection(const sSection& section);
	const std::vector<crypto::aes::sAes128Key>& getAesKeys() const;
	void addKey(const crypto::aes::sAes128Key& key);

private:
	const std::string kModuleName = "NCA_HEADER";
	const std::string kNcaSig = "NCA2";
	static const size_t kSectionNum = 4;
	static const size_t kAesKeyNum = 4;

#pragma pack (push, 1)

	struct sNcaHeader
	{
	private:
		u8 signature_[4];
		u8 reserved_0[2];
		u16 block_size_;
		u64 nca_size_;
		u64 program_id_;
		u8 reserved_1[4];
		u32 unk_0_;
		u8 reserved_2[0x20];
		struct sNcaSection
		{
		private:
			u32 start_; // block units
			u32 end_; // block units
			u8 key_type_;
			u8 reserved[7];
		public:
			u32 start() const { return le_word(start_); }
			void set_start(u32 offset) { start_ = le_word(offset); }

			u32 end() const { return le_word(end_); }
			void set_end(u32 offset) { end_ = le_word(offset); }

			u8 key_type() const { return key_type_; }
			void set_key_type(u8 key_type) { key_type_ = key_type; }
		} section_[kSectionNum];
		crypto::sha::sSha256Hash section_hash_[kSectionNum];
		crypto::aes::sAes128Key aes_keys_[kAesKeyNum];
	public:
		const char* signature() const { return (const char*)signature_; }
		void set_signature(const char* signature) { memcpy(signature_, signature, 4); }

		u16 block_size() const { return le_hword(block_size_); }
		void set_block_size(u16 block_size) { block_size_ = le_hword(block_size); }

		u64 nca_size() const { return le_dword(nca_size_); }
		void set_nca_size(u64 nca_size) { nca_size_ = le_dword(nca_size); }

		u64 program_id() const { return le_dword(program_id_); }
		void set_program_id(u64 program_id) { program_id_ = le_dword(program_id); }

		u32 unk0() const { return le_word(unk_0_); }
		void set_unk0(u32 val) { unk_0_ = le_word(val); }

		const sNcaSection& section(u8 index) const { return section_[index%kSectionNum]; }
		sNcaSection& section(u8 index) { return section_[index%kSectionNum]; }

		const crypto::sha::sSha256Hash& section_hash(u8 index) const { return section_hash_[index%kSectionNum]; }
		crypto::sha::sSha256Hash& section_hash(u8 index) { return section_hash_[index%kSectionNum]; }

		const crypto::aes::sAes128Key& aes_key(u8 index) const { return aes_keys_[index%kAesKeyNum]; }
		crypto::aes::sAes128Key& aes_key(u8 index) { return aes_keys_[index%kAesKeyNum]; }
	};
#pragma pack (pop)

	// binary
	fnd::MemoryBlob mBinaryBlob;

	// data
	u16 mBlockSize;
	u64 mNcaSize;
	u64 mProgramId;
	u32 mUnk0;
	std::vector<sSection> mSections;
	std::vector<crypto::aes::sAes128Key> mAesKeys;

	void clearVariables();
	u64 blockNumToSize(u32 block_num) const;
	u32 sizeToBlockNum(u64 real_size) const;
};