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yuzu/src/core/file_sys/content_archive.cpp
Zach Hilman 4f18c17df7 content_archive: Add update title detection 
This is needed because the title IDs of update NCAs will not use the update title ID. The only sure way to tell is to look for a partition with BKTR crypto.
2018-08-23 18:53:13 -04:00

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// Copyright 2018 yuzu emulator team
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <algorithm>
#include <utility>
#include <boost/optional.hpp>
#include "common/logging/log.h"
#include "core/crypto/aes_util.h"
#include "core/crypto/ctr_encryption_layer.h"
#include "core/file_sys/content_archive.h"
#include "core/file_sys/romfs.h"
#include "core/file_sys/vfs_offset.h"
#include "core/loader/loader.h"
namespace FileSys {
// Media offsets in headers are stored divided by 512. Mult. by this to get real offset.
constexpr u64 MEDIA_OFFSET_MULTIPLIER = 0x200;
constexpr u64 SECTION_HEADER_SIZE = 0x200;
constexpr u64 SECTION_HEADER_OFFSET = 0x400;
constexpr u32 IVFC_MAX_LEVEL = 6;
enum class NCASectionFilesystemType : u8 {
PFS0 = 0x2,
ROMFS = 0x3,
};
struct NCASectionHeaderBlock {
INSERT_PADDING_BYTES(3);
NCASectionFilesystemType filesystem_type;
NCASectionCryptoType crypto_type;
INSERT_PADDING_BYTES(3);
};
static_assert(sizeof(NCASectionHeaderBlock) == 0x8, "NCASectionHeaderBlock has incorrect size.");
struct NCASectionRaw {
NCASectionHeaderBlock header;
std::array<u8, 0x138> block_data;
std::array<u8, 0x8> section_ctr;
INSERT_PADDING_BYTES(0xB8);
};
static_assert(sizeof(NCASectionRaw) == 0x200, "NCASectionRaw has incorrect size.");
struct PFS0Superblock {
NCASectionHeaderBlock header_block;
std::array<u8, 0x20> hash;
u32_le size;
INSERT_PADDING_BYTES(4);
u64_le hash_table_offset;
u64_le hash_table_size;
u64_le pfs0_header_offset;
u64_le pfs0_size;
INSERT_PADDING_BYTES(0x1B0);
};
static_assert(sizeof(PFS0Superblock) == 0x200, "PFS0Superblock has incorrect size.");
struct RomFSSuperblock {
NCASectionHeaderBlock header_block;
IVFCHeader ivfc;
INSERT_PADDING_BYTES(0x118);
};
static_assert(sizeof(RomFSSuperblock) == 0x200, "RomFSSuperblock has incorrect size.");
union NCASectionHeader {
NCASectionRaw raw;
PFS0Superblock pfs0;
RomFSSuperblock romfs;
};
static_assert(sizeof(NCASectionHeader) == 0x200, "NCASectionHeader has incorrect size.");
bool IsValidNCA(const NCAHeader& header) {
// TODO(DarkLordZach): Add NCA2/NCA0 support.
return header.magic == Common::MakeMagic('N', 'C', 'A', '3');
}
u8 NCA::GetCryptoRevision() const {
u8 master_key_id = header.crypto_type;
if (header.crypto_type_2 > master_key_id)
master_key_id = header.crypto_type_2;
if (master_key_id > 0)
--master_key_id;
return master_key_id;
}
boost::optional<Core::Crypto::Key128> NCA::GetKeyAreaKey(NCASectionCryptoType type) const {
const auto master_key_id = GetCryptoRevision();
if (!keys.HasKey(Core::Crypto::S128KeyType::KeyArea, master_key_id, header.key_index))
return boost::none;
std::vector<u8> key_area(header.key_area.begin(), header.key_area.end());
Core::Crypto::AESCipher<Core::Crypto::Key128> cipher(
keys.GetKey(Core::Crypto::S128KeyType::KeyArea, master_key_id, header.key_index),
Core::Crypto::Mode::ECB);
cipher.Transcode(key_area.data(), key_area.size(), key_area.data(), Core::Crypto::Op::Decrypt);
Core::Crypto::Key128 out;
if (type == NCASectionCryptoType::XTS)
std::copy(key_area.begin(), key_area.begin() + 0x10, out.begin());
else if (type == NCASectionCryptoType::CTR)
std::copy(key_area.begin() + 0x20, key_area.begin() + 0x30, out.begin());
else
LOG_CRITICAL(Crypto, "Called GetKeyAreaKey on invalid NCASectionCryptoType type={:02X}",
static_cast<u8>(type));
u128 out_128{};
memcpy(out_128.data(), out.data(), 16);
LOG_DEBUG(Crypto, "called with crypto_rev={:02X}, kak_index={:02X}, key={:016X}{:016X}",
master_key_id, header.key_index, out_128[1], out_128[0]);
return out;
}
boost::optional<Core::Crypto::Key128> NCA::GetTitlekey() {
const auto master_key_id = GetCryptoRevision();
u128 rights_id{};
memcpy(rights_id.data(), header.rights_id.data(), 16);
if (rights_id == u128{}) {
status = Loader::ResultStatus::ErrorInvalidRightsID;
return boost::none;
}
auto titlekey = keys.GetKey(Core::Crypto::S128KeyType::Titlekey, rights_id[1], rights_id[0]);
if (titlekey == Core::Crypto::Key128{}) {
status = Loader::ResultStatus::ErrorMissingTitlekey;
return boost::none;
}
if (!keys.HasKey(Core::Crypto::S128KeyType::Titlekek, master_key_id)) {
status = Loader::ResultStatus::ErrorMissingTitlekek;
return boost::none;
}
Core::Crypto::AESCipher<Core::Crypto::Key128> cipher(
keys.GetKey(Core::Crypto::S128KeyType::Titlekek, master_key_id), Core::Crypto::Mode::ECB);
cipher.Transcode(titlekey.data(), titlekey.size(), titlekey.data(), Core::Crypto::Op::Decrypt);
return titlekey;
}
VirtualFile NCA::Decrypt(NCASectionHeader s_header, VirtualFile in, u64 starting_offset) {
if (!encrypted)
return in;
switch (s_header.raw.header.crypto_type) {
case NCASectionCryptoType::NONE:
LOG_DEBUG(Crypto, "called with mode=NONE");
return in;
case NCASectionCryptoType::CTR:
LOG_DEBUG(Crypto, "called with mode=CTR, starting_offset={:016X}", starting_offset);
{
boost::optional<Core::Crypto::Key128> key = boost::none;
if (has_rights_id) {
status = Loader::ResultStatus::Success;
key = GetTitlekey();
if (key == boost::none) {
if (status == Loader::ResultStatus::Success)
status = Loader::ResultStatus::ErrorMissingTitlekey;
return nullptr;
}
} else {
key = GetKeyAreaKey(NCASectionCryptoType::CTR);
if (key == boost::none) {
status = Loader::ResultStatus::ErrorMissingKeyAreaKey;
return nullptr;
}
}
auto out = std::make_shared<Core::Crypto::CTREncryptionLayer>(
std::move(in), key.value(), starting_offset);
std::vector<u8> iv(16);
for (u8 i = 0; i < 8; ++i)
iv[i] = s_header.raw.section_ctr[0x8 - i - 1];
out->SetIV(iv);
return std::static_pointer_cast<VfsFile>(out);
}
case NCASectionCryptoType::XTS:
// TODO(DarkLordZach): Find a test case for XTS-encrypted NCAs
default:
LOG_ERROR(Crypto, "called with unhandled crypto type={:02X}",
static_cast<u8>(s_header.raw.header.crypto_type));
return nullptr;
}
}
NCA::NCA(VirtualFile file_) : file(std::move(file_)) {
status = Loader::ResultStatus::Success;
if (file == nullptr) {
status = Loader::ResultStatus::ErrorNullFile;
return;
}
if (sizeof(NCAHeader) != file->ReadObject(&header)) {
LOG_ERROR(Loader, "File reader errored out during header read.");
status = Loader::ResultStatus::ErrorBadNCAHeader;
return;
}
encrypted = false;
if (!IsValidNCA(header)) {
if (header.magic == Common::MakeMagic('N', 'C', 'A', '2')) {
status = Loader::ResultStatus::ErrorNCA2;
return;
}
if (header.magic == Common::MakeMagic('N', 'C', 'A', '0')) {
status = Loader::ResultStatus::ErrorNCA0;
return;
}
NCAHeader dec_header{};
Core::Crypto::AESCipher<Core::Crypto::Key256> cipher(
keys.GetKey(Core::Crypto::S256KeyType::Header), Core::Crypto::Mode::XTS);
cipher.XTSTranscode(&header, sizeof(NCAHeader), &dec_header, 0, 0x200,
Core::Crypto::Op::Decrypt);
if (IsValidNCA(dec_header)) {
header = dec_header;
encrypted = true;
} else {
if (dec_header.magic == Common::MakeMagic('N', 'C', 'A', '2')) {
status = Loader::ResultStatus::ErrorNCA2;
return;
}
if (dec_header.magic == Common::MakeMagic('N', 'C', 'A', '0')) {
status = Loader::ResultStatus::ErrorNCA0;
return;
}
if (!keys.HasKey(Core::Crypto::S256KeyType::Header))
status = Loader::ResultStatus::ErrorMissingHeaderKey;
else
status = Loader::ResultStatus::ErrorIncorrectHeaderKey;
return;
}
}
has_rights_id = std::find_if_not(header.rights_id.begin(), header.rights_id.end(),
[](char c) { return c == '\0'; }) != header.rights_id.end();
const std::ptrdiff_t number_sections =
std::count_if(std::begin(header.section_tables), std::end(header.section_tables),
[](NCASectionTableEntry entry) { return entry.media_offset > 0; });
std::vector<NCASectionHeader> sections(number_sections);
const auto length_sections = SECTION_HEADER_SIZE * number_sections;
if (encrypted) {
auto raw = file->ReadBytes(length_sections, SECTION_HEADER_OFFSET);
Core::Crypto::AESCipher<Core::Crypto::Key256> cipher(
keys.GetKey(Core::Crypto::S256KeyType::Header), Core::Crypto::Mode::XTS);
cipher.XTSTranscode(raw.data(), length_sections, sections.data(), 2, SECTION_HEADER_SIZE,
Core::Crypto::Op::Decrypt);
} else {
file->ReadBytes(sections.data(), length_sections, SECTION_HEADER_OFFSET);
}
is_update = std::find_if(sections.begin(), sections.end(), [](const NCASectionHeader& header) {
return header.raw.header.crypto_type == NCASectionCryptoType::BKTR;
}) != sections.end();
for (std::ptrdiff_t i = 0; i < number_sections; ++i) {
auto section = sections[i];
if (section.raw.header.filesystem_type == NCASectionFilesystemType::ROMFS) {
const size_t romfs_offset =
header.section_tables[i].media_offset * MEDIA_OFFSET_MULTIPLIER +
section.romfs.ivfc.levels[IVFC_MAX_LEVEL - 1].offset;
const size_t romfs_size = section.romfs.ivfc.levels[IVFC_MAX_LEVEL - 1].size;
auto dec =
Decrypt(section, std::make_shared<OffsetVfsFile>(file, romfs_size, romfs_offset),
romfs_offset);
if (dec != nullptr) {
files.push_back(std::move(dec));
romfs = files.back();
} else {
if (status != Loader::ResultStatus::Success)
return;
if (has_rights_id)
status = Loader::ResultStatus::ErrorIncorrectTitlekeyOrTitlekek;
else
status = Loader::ResultStatus::ErrorIncorrectKeyAreaKey;
return;
}
} else if (section.raw.header.filesystem_type == NCASectionFilesystemType::PFS0) {
u64 offset = (static_cast<u64>(header.section_tables[i].media_offset) *
MEDIA_OFFSET_MULTIPLIER) +
section.pfs0.pfs0_header_offset;
u64 size = MEDIA_OFFSET_MULTIPLIER * (header.section_tables[i].media_end_offset -
header.section_tables[i].media_offset);
auto dec =
Decrypt(section, std::make_shared<OffsetVfsFile>(file, size, offset), offset);
if (dec != nullptr) {
auto npfs = std::make_shared<PartitionFilesystem>(std::move(dec));
if (npfs->GetStatus() == Loader::ResultStatus::Success) {
dirs.push_back(std::move(npfs));
if (IsDirectoryExeFS(dirs.back()))
exefs = dirs.back();
}
} else {
if (status != Loader::ResultStatus::Success)
return;
if (has_rights_id)
status = Loader::ResultStatus::ErrorIncorrectTitlekeyOrTitlekek;
else
status = Loader::ResultStatus::ErrorIncorrectKeyAreaKey;
return;
}
}
}
status = Loader::ResultStatus::Success;
}
Loader::ResultStatus NCA::GetStatus() const {
return status;
}
std::vector<std::shared_ptr<VfsFile>> NCA::GetFiles() const {
if (status != Loader::ResultStatus::Success)
return {};
return files;
}
std::vector<std::shared_ptr<VfsDirectory>> NCA::GetSubdirectories() const {
if (status != Loader::ResultStatus::Success)
return {};
return dirs;
}
std::string NCA::GetName() const {
return file->GetName();
}
std::shared_ptr<VfsDirectory> NCA::GetParentDirectory() const {
return file->GetContainingDirectory();
}
NCAContentType NCA::GetType() const {
return header.content_type;
}
u64 NCA::GetTitleId() const {
if (status != Loader::ResultStatus::Success)
return {};
return header.title_id;
}
VirtualFile NCA::GetRomFS() const {
return romfs;
}
VirtualDir NCA::GetExeFS() const {
return exefs;
}
VirtualFile NCA::GetBaseFile() const {
return file;
}
bool NCA::IsUpdate() const {
return is_update;
}
bool NCA::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
return false;
}
} // namespace FileSys
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