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Merge pull request #4348 from B3n30/native_firm_keys

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Load keys from save mode native firm
This commit is contained in:
Weiyi Wang 2018-10-28 10:24:29 -04:00 committed by GitHub
commit 67888f92e5
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 238 additions and 26 deletions
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1
src/common/common_paths.h
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@ -51,3 +51,4 @@
#define SHARED_FONT "shared_font.bin"
#define AES_KEYS "aes_keys.txt"
#define BOOTROM9 "boot9.bin"
#define SECRET_SECTOR "sector0x96.bin"

263
src/core/hw/aes/key.cpp
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@ -6,11 +6,15 @@
#include <exception>
#include <optional>
#include <sstream>
#include <cryptopp/aes.h>
#include <cryptopp/modes.h>
#include <fmt/format.h>
#include "common/common_paths.h"
#include "common/file_util.h"
#include "common/logging/log.h"
#include "common/string_util.h"
#include "core/file_sys/archive_ncch.h"
#include "core/hle/service/fs/archive.h"
#include "core/hw/aes/arithmetic128.h"
#include "core/hw/aes/key.h"
@ -19,7 +23,14 @@ namespace AES {
namespace {
std::optional<AESKey> generator_constant;
// The generator constant was calculated using the 0x39 KeyX and KeyY retrieved from a 3DS and the
// normal key dumped from a Wii U solving the equation:
// NormalKey = (((KeyX ROL 2) XOR KeyY) + constant) ROL 87
// On a real 3DS the generation for the normal key is hardware based, and thus the constant can't
// get dumped . generated normal keys are also not accesible on a 3DS. The used formula for
// calculating the constant is a software implementation of what the hardware generator does.
constexpr AESKey generator_constant = {{0x1F, 0xF9, 0xE9, 0xAA, 0xC5, 0xFE, 0x04, 0x08, 0x02, 0x45,
0x91, 0xDC, 0x5D, 0x52, 0x76, 0x8A}};
struct KeyDesc {
char key_type;
@ -28,6 +39,19 @@ struct KeyDesc {
bool same_as_before;
};
AESKey HexToKey(const std::string& hex) {
if (hex.size() < 32) {
throw std::invalid_argument("hex string is too short");
}
AESKey key;
for (std::size_t i = 0; i < key.size(); ++i) {
key[i] = static_cast<u8>(std::stoi(hex.substr(i * 2, 2), 0, 16));
}
return key;
}
struct KeySlot {
std::optional<AESKey> x;
std::optional<AESKey> y;
@ -48,8 +72,8 @@ struct KeySlot {
}
void GenerateNormalKey() {
if (x && y && generator_constant) {
normal = Lrot128(Add128(Xor128(Lrot128(*x, 2), *y), *generator_constant), 87);
if (x && y) {
normal = Lrot128(Add128(Xor128(Lrot128(*x, 2), *y), generator_constant), 87);
} else {
normal = {};
}
@ -65,17 +89,46 @@ struct KeySlot {
std::array<KeySlot, KeySlotID::MaxKeySlotID> key_slots;
std::array<std::optional<AESKey>, 6> common_key_y_slots;
AESKey HexToKey(const std::string& hex) {
if (hex.size() < 32) {
throw std::invalid_argument("hex string is too short");
}
enum class FirmwareType : u32 {
ARM9 = 0, // uses NDMA
ARM11 = 1, // uses XDMA
};
AESKey key;
for (std::size_t i = 0; i < key.size(); ++i) {
key[i] = static_cast<u8>(std::stoi(hex.substr(i * 2, 2), 0, 16));
}
struct FirmwareSectionHeader {
u32_le offset;
u32_le phys_address;
u32_le size;
enum_le<FirmwareType> firmware_type;
std::array<u8, 0x20> hash; // SHA-256 hash
};
return key;
struct FIRM_Header {
u32_le magic; // FIRM
u32_le boot_priority; // Usually 0
u32_le arm11_entrypoint;
u32_le arm9_entrypoint;
INSERT_PADDING_BYTES(0x30); // Reserved
std::array<FirmwareSectionHeader, 4> section_headers; // 1st ARM11?, 3rd ARM9
std::array<u8, 0x100> signature; // RSA-2048 signature of the FIRM header's hash
};
struct ARM9_Header {
AESKey enc_key_x;
AESKey key_y;
AESKey CTR;
std::array<u8, 8> size; // in ASCII
INSERT_PADDING_BYTES(8); // Unknown
std::array<u8, 16> control_block;
std::array<u8, 16> hardware_debug_info;
std::array<u8, 16> enc_key_x_slot_16;
};
std::string KeyToString(AESKey& key) {
std::string s;
for (auto pos : key) {
s += fmt::format("{:02X}", pos);
}
return s;
}
void LoadBootromKeys() {
@ -130,11 +183,8 @@ void LoadBootromKeys() {
}
}
std::string s;
for (auto pos : new_key) {
s += fmt::format("{:02X}", pos);
}
LOG_DEBUG(HW_AES, "Loaded Slot{:#02x} Key{}: {}", key.slot_id, key.key_type, s);
LOG_DEBUG(HW_AES, "Loaded Slot{:#02x} Key{}: {}", key.slot_id, key.key_type,
KeyToString(new_key));
switch (key.key_type) {
case 'X':
@ -153,6 +203,174 @@ void LoadBootromKeys() {
}
}
void LoadNativeFirmKeysOld3DS() {
// Use the save mode native firm instead of the normal mode since there are only 2 version of it
// and thus we can use fixed offsets
constexpr u64 save_mode_native_firm_id = 0x00040138'00000003;
// TODO(B3N30): Add the 0x25 KeyX that gets initalized by native_firm
FileSys::NCCHArchive archive(save_mode_native_firm_id, Service::FS::MediaType::NAND);
std::array<char, 8> exefs_filepath = {'.', 'f', 'i', 'r', 'm', 0, 0, 0};
FileSys::Path file_path = FileSys::MakeNCCHFilePath(
FileSys::NCCHFileOpenType::NCCHData, 0, FileSys::NCCHFilePathType::ExeFS, exefs_filepath);
FileSys::Mode open_mode = {};
open_mode.read_flag.Assign(1);
auto file_result = archive.OpenFile(file_path, open_mode);
if (file_result.Failed())
return;
auto firm = std::move(file_result).Unwrap();
const std::size_t size = firm->GetSize();
if (size != 843776) {
LOG_ERROR(HW_AES, "save mode native firm has wrong size {}", size);
return;
}
std::vector<u8> firm_buffer(size);
firm->Read(0, firm_buffer.size(), firm_buffer.data());
firm->Close();
AESKey key;
constexpr std::size_t SLOT_0x31_KEY_Y_OFFSET = 817672;
std::memcpy(key.data(), firm_buffer.data() + SLOT_0x31_KEY_Y_OFFSET, sizeof(key));
key_slots.at(0x31).SetKeyY(key);
LOG_DEBUG(HW_AES, "Loaded Slot0x31 KeyY: {}", KeyToString(key));
auto LoadCommonKey = [&firm_buffer](std::size_t key_slot) -> AESKey {
constexpr std::size_t START_OFFSET = 836533;
constexpr std::size_t OFFSET = 0x14; // 0x10 bytes for key + 4 bytes between keys
AESKey key;
std::memcpy(key.data(), firm_buffer.data() + START_OFFSET + OFFSET * key_slot, sizeof(key));
return key;
};
for (std::size_t key_slot{0}; key_slot < 6; ++key_slot) {
AESKey key = LoadCommonKey(key_slot);
common_key_y_slots[key_slot] = key;
LOG_DEBUG(HW_AES, "Loaded common key{}: {}", key_slot, KeyToString(key));
}
}
void LoadNativeFirmKeysNew3DS() {
// The first 0x10 bytes of the secret_sector are used as a key to decrypt a KeyX from the
// native_firm
const std::string filepath =
FileUtil::GetUserPath(FileUtil::UserPath::SysDataDir) + SECRET_SECTOR;
auto secret = FileUtil::IOFile(filepath, "rb");
if (!secret) {
return;
}
ASSERT(secret.GetSize() > 0x10);
AESKey secret_key;
secret.ReadArray(secret_key.data(), secret_key.size());
// Use the save mode native firm instead of the normal mode since there are only 1 version of it
// and thus we can use fixed offsets
constexpr u64 save_mode_native_firm_id = 0x00040138'20000003;
// TODO(B3N30): Add the 0x25 KeyX that gets initalized by native_firm
// TODO(B3N30): Add the 0x18 - 0x1F KeyX that gets initalized by native_firm. This probably
// requires the normal native firm with version > 9.6.0-X
FileSys::NCCHArchive archive(save_mode_native_firm_id, Service::FS::MediaType::NAND);
std::array<char, 8> exefs_filepath = {'.', 'f', 'i', 'r', 'm', 0, 0, 0};
FileSys::Path file_path = FileSys::MakeNCCHFilePath(
FileSys::NCCHFileOpenType::NCCHData, 0, FileSys::NCCHFilePathType::ExeFS, exefs_filepath);
FileSys::Mode open_mode = {};
open_mode.read_flag.Assign(1);
auto file_result = archive.OpenFile(file_path, open_mode);
if (file_result.Failed())
return;
auto firm = std::move(file_result).Unwrap();
std::vector<u8> firm_buffer(firm->GetSize());
firm->Read(0, firm_buffer.size(), firm_buffer.data());
firm->Close();
FIRM_Header header;
std::memcpy(&header, firm_buffer.data(), sizeof(header));
auto MakeMagic = [](char a, char b, char c, char d) -> u32 {
return a | b << 8 | c << 16 | d << 24;
};
if (MakeMagic('F', 'I', 'R', 'M') != header.magic) {
LOG_ERROR(HW_AES, "N3DS SAVE MODE Native Firm has wrong header {}", header.magic);
return;
}
u32 arm9_offset(0);
u32 arm9_size(0);
for (auto section_header : header.section_headers) {
if (section_header.firmware_type == FirmwareType::ARM9) {
arm9_offset = section_header.offset;
arm9_size = section_header.size;
break;
}
}
if (arm9_offset != 0x66800) {
LOG_ERROR(HW_AES, "ARM9 binary at wrong offset: {}", arm9_offset);
return;
}
if (arm9_size != 0x8BA00) {
LOG_ERROR(HW_AES, "ARM9 binary has wrong size: {}", arm9_size);
return;
}
ARM9_Header arm9_header;
std::memcpy(&arm9_header, firm_buffer.data() + arm9_offset, sizeof(arm9_header));
AESKey keyX_slot0x15;
CryptoPP::ECB_Mode<CryptoPP::AES>::Decryption d;
d.SetKey(secret_key.data(), secret_key.size());
d.ProcessData(keyX_slot0x15.data(), arm9_header.enc_key_x.data(), arm9_header.enc_key_x.size());
key_slots.at(0x15).SetKeyX(keyX_slot0x15);
key_slots.at(0x15).SetKeyY(arm9_header.key_y);
auto normal_key_slot0x15 = key_slots.at(0x15).normal;
if (!normal_key_slot0x15) {
LOG_ERROR(HW_AES, "Failed to get normal key for slot id 0x15");
return;
}
constexpr u32 ARM9_BINARY_OFFSET = 0x800; // From the beginning of the ARM9 section
std::vector<u8> enc_arm9_binary;
enc_arm9_binary.resize(arm9_size - ARM9_BINARY_OFFSET);
ASSERT(enc_arm9_binary.size() + arm9_offset + ARM9_BINARY_OFFSET < firm_buffer.size());
std::memcpy(enc_arm9_binary.data(), firm_buffer.data() + arm9_offset + ARM9_BINARY_OFFSET,
enc_arm9_binary.size());
std::vector<u8> arm9_binary;
arm9_binary.resize(enc_arm9_binary.size());
CryptoPP::CTR_Mode<CryptoPP::AES>::Decryption d2;
d2.SetKeyWithIV(normal_key_slot0x15->data(), normal_key_slot0x15->size(),
arm9_header.CTR.data(), arm9_header.CTR.size());
d2.ProcessData(arm9_binary.data(), enc_arm9_binary.data(), enc_arm9_binary.size());
AESKey key;
constexpr std::size_t SLOT_0x31_KEY_Y_OFFSET = 517368;
std::memcpy(key.data(), arm9_binary.data() + SLOT_0x31_KEY_Y_OFFSET, sizeof(key));
key_slots.at(0x31).SetKeyY(key);
LOG_DEBUG(HW_AES, "Loaded Slot0x31 KeyY: {}", KeyToString(key));
auto LoadCommonKey = [&arm9_binary](std::size_t key_slot) -> AESKey {
constexpr std::size_t START_OFFSET = 541065;
constexpr std::size_t OFFSET = 0x14; // 0x10 bytes for key + 4 bytes between keys
AESKey key;
std::memcpy(key.data(), arm9_binary.data() + START_OFFSET + OFFSET * key_slot, sizeof(key));
return key;
};
for (std::size_t key_slot{0}; key_slot < 6; ++key_slot) {
AESKey key = LoadCommonKey(key_slot);
common_key_y_slots[key_slot] = key;
LOG_DEBUG(HW_AES, "Loaded common key{}: {}", key_slot, KeyToString(key));
}
}
void LoadPresetKeys() {
const std::string filepath = FileUtil::GetUserPath(FileUtil::UserPath::SysDataDir) + AES_KEYS;
FileUtil::CreateFullPath(filepath); // Create path if not already created
@ -181,11 +399,6 @@ void LoadPresetKeys() {
continue;
}
if (name == "generator") {
generator_constant = key;
continue;
}
std::size_t common_key_index;
if (std::sscanf(name.c_str(), "common%zd", &common_key_index) == 1) {
if (common_key_index >= common_key_y_slots.size()) {
@ -232,14 +445,12 @@ void InitKeys() {
if (initialized)
return;
LoadBootromKeys();
LoadNativeFirmKeysOld3DS();
LoadNativeFirmKeysNew3DS();
LoadPresetKeys();
initialized = true;
}
void SetGeneratorConstant(const AESKey& key) {
generator_constant = key;
}
void SetKeyX(std::size_t slot_id, const AESKey& key) {
key_slots.at(slot_id).SetKeyX(key);
}