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// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
// SPDX-License-Identifier: GPL-3.0-or-later
#pragma once
#include <array>
#include "core/hle/service/nfp/amiibo_types.h"
struct mbedtls_md_context_t;
namespace Service::NFP::AmiiboCrypto {
constexpr std::size_t HMAC_POS_DATA = 0x8;
constexpr std::size_t HMAC_POS_TAG = 0x1B4;
using HmacKey = std::array<u8, 0x10>;
using DrgbOutput = std::array<u8, 0x20>;
struct HashSeed {
union {
std::array<u8, 0x40> raw;
struct {
u16 magic;
std::array<u8, 0xE> padding;
std::array<u8, 0x8> uuid1;
std::array<u8, 0x8> uuid2;
std::array<u8, 0x20> keygen_salt;
} data;
};
};
static_assert(sizeof(HashSeed) == 0x40, "HashSeed is an invalid size");
struct InternalKey {
HmacKey hmac_key;
std::array<char, 0xE> type_string;
u8 reserved;
u8 magic_length;
std::array<u8, 0x10> magic_bytes;
std::array<u8, 0x20> xor_pad;
};
static_assert(sizeof(InternalKey) == 0x50, "InternalKey is an invalid size");
static_assert(std::is_trivially_copyable_v<InternalKey>, "InternalKey must be trivially copyable.");
struct CryptoCtx {
std::array<char, 480> buffer;
bool used;
std::size_t buffer_size;
s16 counter;
};
struct DerivedKeys {
std::array<u8, 0x10> aes_key;
std::array<u8, 0x10> aes_iv;
std::array<u8, 0x10> hmac_key;
};
static_assert(sizeof(DerivedKeys) == 0x30, "DerivedKeys is an invalid size");
/// Converts mii data from nintendo 3ds format to nintendo switch format
Service::Mii::MiiInfo AmiiboRegisterInfoToMii(const AmiiboRegisterInfo& register_info);
/// Validates that the amiibo file is not corrupted
bool IsAmiiboValid(const EncryptedNTAG215File& ntag_file);
/// Converts from encrypted file format to encoded file format
NTAG215File NfcDataToEncodedData(const EncryptedNTAG215File& nfc_data);
/// Converts from encoded file format to encrypted file format
EncryptedNTAG215File EncodedDataToNfcData(const NTAG215File& encoded_data);
/// Returns password needed to allow write access to protected memory
u32 GetTagPassword(const TagUuid& uuid);
// Generates Seed needed for key derivation
HashSeed GetSeed(const NTAG215File& data);
// Middle step on the generation of derived keys
void PreGenerateKey(const InternalKey& key, const HashSeed& seed, u8* output,
std::size_t& outputLen);
// Initializes mbedtls context
void CryptoInit(CryptoCtx& ctx, mbedtls_md_context_t& hmac_ctx, const HmacKey& hmac_key,
const u8* seed, std::size_t seed_size);
// Feeds data to mbedtls context to generate the derived key
void CryptoStep(CryptoCtx& ctx, mbedtls_md_context_t& hmac_ctx, DrgbOutput& output);
// Generates the derived key from amiibo data
DerivedKeys GenerateKey(const InternalKey& key, const NTAG215File& data);
// Encodes or decodes amiibo data
void Cipher(const DerivedKeys& keys, const NTAG215File& in_data, NTAG215File& out_data);
/// Loads both amiibo keys from key_retail.bin
bool LoadKeys(InternalKey& locked_secret, InternalKey& unfixed_info);
/// Decodes encripted amiibo data returns true if output is valid
bool DecodeAmiibo(const EncryptedNTAG215File& encrypted_tag_data, NTAG215File& tag_data);
/// Encodes plain amiibo data returns true if output is valid
bool EncodeAmiibo(const NTAG215File& tag_data, EncryptedNTAG215File& encrypted_tag_data);
} // namespace Service::NFP::AmiiboCrypto
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