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-rw-r--r--src/core/crypto/aes_util.cpp7
-rw-r--r--src/core/crypto/ctr_encryption_layer.cpp8
-rw-r--r--src/core/crypto/key_manager.cpp172
-rw-r--r--src/core/crypto/key_manager.h68
-rw-r--r--src/core/crypto/xts_encryption_layer.cpp58
-rw-r--r--src/core/crypto/xts_encryption_layer.h25
6 files changed, 288 insertions, 50 deletions
diff --git a/src/core/crypto/aes_util.cpp b/src/core/crypto/aes_util.cpp
index a9876c83e..72e4bed67 100644
--- a/src/core/crypto/aes_util.cpp
+++ b/src/core/crypto/aes_util.cpp
@@ -99,10 +99,7 @@ void AESCipher<Key, KeySize>::Transcode(const u8* src, size_t size, u8* dest, Op
template <typename Key, size_t KeySize>
void AESCipher<Key, KeySize>::XTSTranscode(const u8* src, size_t size, u8* dest, size_t sector_id,
size_t sector_size, Op op) {
- if (size % sector_size > 0) {
- LOG_CRITICAL(Crypto, "Data size must be a multiple of sector size.");
- return;
- }
+ ASSERT_MSG(size % sector_size == 0, "XTS decryption size must be a multiple of sector size.");
for (size_t i = 0; i < size; i += sector_size) {
SetIV(CalculateNintendoTweak(sector_id++));
@@ -112,4 +109,4 @@ void AESCipher<Key, KeySize>::XTSTranscode(const u8* src, size_t size, u8* dest,
template class AESCipher<Key128>;
template class AESCipher<Key256>;
-} // namespace Core::Crypto \ No newline at end of file
+} // namespace Core::Crypto
diff --git a/src/core/crypto/ctr_encryption_layer.cpp b/src/core/crypto/ctr_encryption_layer.cpp
index 106db02b3..3ea60dbd0 100644
--- a/src/core/crypto/ctr_encryption_layer.cpp
+++ b/src/core/crypto/ctr_encryption_layer.cpp
@@ -20,10 +20,8 @@ size_t CTREncryptionLayer::Read(u8* data, size_t length, size_t offset) const {
if (sector_offset == 0) {
UpdateIV(base_offset + offset);
std::vector<u8> raw = base->ReadBytes(length, offset);
- if (raw.size() != length)
- return Read(data, raw.size(), offset);
- cipher.Transcode(raw.data(), length, data, Op::Decrypt);
- return length;
+ cipher.Transcode(raw.data(), raw.size(), data, Op::Decrypt);
+ return raw.size();
}
// offset does not fall on block boundary (0x10)
@@ -34,7 +32,7 @@ size_t CTREncryptionLayer::Read(u8* data, size_t length, size_t offset) const {
if (length + sector_offset < 0x10) {
std::memcpy(data, block.data() + sector_offset, std::min<u64>(length, read));
- return read;
+ return std::min<u64>(length, read);
}
std::memcpy(data, block.data() + sector_offset, read);
return read + Read(data + read, length - read, offset + read);
diff --git a/src/core/crypto/key_manager.cpp b/src/core/crypto/key_manager.cpp
index db8b22c85..0b6c07de8 100644
--- a/src/core/crypto/key_manager.cpp
+++ b/src/core/crypto/key_manager.cpp
@@ -12,11 +12,112 @@
#include "common/file_util.h"
#include "common/hex_util.h"
#include "common/logging/log.h"
+#include "core/crypto/aes_util.h"
#include "core/crypto/key_manager.h"
#include "core/settings.h"
namespace Core::Crypto {
+Key128 GenerateKeyEncryptionKey(Key128 source, Key128 master, Key128 kek_seed, Key128 key_seed) {
+ Key128 out{};
+
+ AESCipher<Key128> cipher1(master, Mode::ECB);
+ cipher1.Transcode(kek_seed.data(), kek_seed.size(), out.data(), Op::Decrypt);
+ AESCipher<Key128> cipher2(out, Mode::ECB);
+ cipher2.Transcode(source.data(), source.size(), out.data(), Op::Decrypt);
+
+ if (key_seed != Key128{}) {
+ AESCipher<Key128> cipher3(out, Mode::ECB);
+ cipher3.Transcode(key_seed.data(), key_seed.size(), out.data(), Op::Decrypt);
+ }
+
+ return out;
+}
+
+boost::optional<Key128> DeriveSDSeed() {
+ const FileUtil::IOFile save_43(FileUtil::GetUserPath(FileUtil::UserPath::NANDDir) +
+ "/system/save/8000000000000043",
+ "rb+");
+ if (!save_43.IsOpen())
+ return boost::none;
+ const FileUtil::IOFile sd_private(
+ FileUtil::GetUserPath(FileUtil::UserPath::SDMCDir) + "/Nintendo/Contents/private", "rb+");
+ if (!sd_private.IsOpen())
+ return boost::none;
+
+ sd_private.Seek(0, SEEK_SET);
+ std::array<u8, 0x10> private_seed{};
+ if (sd_private.ReadBytes(private_seed.data(), private_seed.size()) != 0x10)
+ return boost::none;
+
+ std::array<u8, 0x10> buffer{};
+ size_t offset = 0;
+ for (; offset + 0x10 < save_43.GetSize(); ++offset) {
+ save_43.Seek(offset, SEEK_SET);
+ save_43.ReadBytes(buffer.data(), buffer.size());
+ if (buffer == private_seed)
+ break;
+ }
+
+ if (offset + 0x10 >= save_43.GetSize())
+ return boost::none;
+
+ Key128 seed{};
+ save_43.Seek(offset + 0x10, SEEK_SET);
+ save_43.ReadBytes(seed.data(), seed.size());
+ return seed;
+}
+
+Loader::ResultStatus DeriveSDKeys(std::array<Key256, 2>& sd_keys, const KeyManager& keys) {
+ if (!keys.HasKey(S128KeyType::Source, static_cast<u64>(SourceKeyType::SDKEK)))
+ return Loader::ResultStatus::ErrorMissingSDKEKSource;
+ if (!keys.HasKey(S128KeyType::Source, static_cast<u64>(SourceKeyType::AESKEKGeneration)))
+ return Loader::ResultStatus::ErrorMissingAESKEKGenerationSource;
+ if (!keys.HasKey(S128KeyType::Source, static_cast<u64>(SourceKeyType::AESKeyGeneration)))
+ return Loader::ResultStatus::ErrorMissingAESKeyGenerationSource;
+
+ const auto sd_kek_source =
+ keys.GetKey(S128KeyType::Source, static_cast<u64>(SourceKeyType::SDKEK));
+ const auto aes_kek_gen =
+ keys.GetKey(S128KeyType::Source, static_cast<u64>(SourceKeyType::AESKEKGeneration));
+ const auto aes_key_gen =
+ keys.GetKey(S128KeyType::Source, static_cast<u64>(SourceKeyType::AESKeyGeneration));
+ const auto master_00 = keys.GetKey(S128KeyType::Master);
+ const auto sd_kek =
+ GenerateKeyEncryptionKey(sd_kek_source, master_00, aes_kek_gen, aes_key_gen);
+
+ if (!keys.HasKey(S128KeyType::SDSeed))
+ return Loader::ResultStatus::ErrorMissingSDSeed;
+ const auto sd_seed = keys.GetKey(S128KeyType::SDSeed);
+
+ if (!keys.HasKey(S256KeyType::SDKeySource, static_cast<u64>(SDKeyType::Save)))
+ return Loader::ResultStatus::ErrorMissingSDSaveKeySource;
+ if (!keys.HasKey(S256KeyType::SDKeySource, static_cast<u64>(SDKeyType::NCA)))
+ return Loader::ResultStatus::ErrorMissingSDNCAKeySource;
+
+ std::array<Key256, 2> sd_key_sources{
+ keys.GetKey(S256KeyType::SDKeySource, static_cast<u64>(SDKeyType::Save)),
+ keys.GetKey(S256KeyType::SDKeySource, static_cast<u64>(SDKeyType::NCA)),
+ };
+
+ // Combine sources and seed
+ for (auto& source : sd_key_sources) {
+ for (size_t i = 0; i < source.size(); ++i)
+ source[i] ^= sd_seed[i & 0xF];
+ }
+
+ AESCipher<Key128> cipher(sd_kek, Mode::ECB);
+ // The transform manipulates sd_keys as part of the Transcode, so the return/output is
+ // unnecessary. This does not alter sd_keys_sources.
+ std::transform(sd_key_sources.begin(), sd_key_sources.end(), sd_keys.begin(),
+ sd_key_sources.begin(), [&cipher](const Key256& source, Key256& out) {
+ cipher.Transcode(source.data(), source.size(), out.data(), Op::Decrypt);
+ return source; ///< Return unaltered source to satisfy output requirement.
+ });
+
+ return Loader::ResultStatus::Success;
+}
+
KeyManager::KeyManager() {
// Initialize keys
const std::string hactool_keys_dir = FileUtil::GetHactoolConfigurationPath();
@@ -24,12 +125,15 @@ KeyManager::KeyManager() {
if (Settings::values.use_dev_keys) {
dev_mode = true;
AttemptLoadKeyFile(yuzu_keys_dir, hactool_keys_dir, "dev.keys", false);
+ AttemptLoadKeyFile(yuzu_keys_dir, yuzu_keys_dir, "dev.keys_autogenerated", false);
} else {
dev_mode = false;
AttemptLoadKeyFile(yuzu_keys_dir, hactool_keys_dir, "prod.keys", false);
+ AttemptLoadKeyFile(yuzu_keys_dir, yuzu_keys_dir, "prod.keys_autogenerated", false);
}
AttemptLoadKeyFile(yuzu_keys_dir, hactool_keys_dir, "title.keys", true);
+ AttemptLoadKeyFile(yuzu_keys_dir, yuzu_keys_dir, "title.keys_autogenerated", true);
}
void KeyManager::LoadFromFile(const std::string& filename, bool is_title_keys) {
@@ -56,17 +160,17 @@ void KeyManager::LoadFromFile(const std::string& filename, bool is_title_keys) {
u128 rights_id{};
std::memcpy(rights_id.data(), rights_id_raw.data(), rights_id_raw.size());
Key128 key = Common::HexStringToArray<16>(out[1]);
- SetKey(S128KeyType::Titlekey, key, rights_id[1], rights_id[0]);
+ s128_keys[{S128KeyType::Titlekey, rights_id[1], rights_id[0]}] = key;
} else {
std::transform(out[0].begin(), out[0].end(), out[0].begin(), ::tolower);
if (s128_file_id.find(out[0]) != s128_file_id.end()) {
const auto index = s128_file_id.at(out[0]);
Key128 key = Common::HexStringToArray<16>(out[1]);
- SetKey(index.type, key, index.field1, index.field2);
+ s128_keys[{index.type, index.field1, index.field2}] = key;
} else if (s256_file_id.find(out[0]) != s256_file_id.end()) {
const auto index = s256_file_id.at(out[0]);
Key256 key = Common::HexStringToArray<32>(out[1]);
- SetKey(index.type, key, index.field1, index.field2);
+ s256_keys[{index.type, index.field1, index.field2}] = key;
}
}
}
@@ -100,11 +204,50 @@ Key256 KeyManager::GetKey(S256KeyType id, u64 field1, u64 field2) const {
return s256_keys.at({id, field1, field2});
}
+template <size_t Size>
+void KeyManager::WriteKeyToFile(bool title_key, std::string_view keyname,
+ const std::array<u8, Size>& key) {
+ const std::string yuzu_keys_dir = FileUtil::GetUserPath(FileUtil::UserPath::KeysDir);
+ std::string filename = "title.keys_autogenerated";
+ if (!title_key)
+ filename = dev_mode ? "dev.keys_autogenerated" : "prod.keys_autogenerated";
+ const auto add_info_text = !FileUtil::Exists(yuzu_keys_dir + DIR_SEP + filename);
+ FileUtil::CreateFullPath(yuzu_keys_dir + DIR_SEP + filename);
+ std::ofstream file(yuzu_keys_dir + DIR_SEP + filename, std::ios::app);
+ if (!file.is_open())
+ return;
+ if (add_info_text) {
+ file
+ << "# This file is autogenerated by Yuzu\n"
+ << "# It serves to store keys that were automatically generated from the normal keys\n"
+ << "# If you are experiencing issues involving keys, it may help to delete this file\n";
+ }
+
+ file << fmt::format("\n{} = {}", keyname, Common::HexArrayToString(key));
+ AttemptLoadKeyFile(yuzu_keys_dir, yuzu_keys_dir, filename, title_key);
+}
+
void KeyManager::SetKey(S128KeyType id, Key128 key, u64 field1, u64 field2) {
+ const auto iter = std::find_if(
+ s128_file_id.begin(), s128_file_id.end(),
+ [&id, &field1, &field2](const std::pair<std::string, KeyIndex<S128KeyType>> elem) {
+ return std::tie(elem.second.type, elem.second.field1, elem.second.field2) ==
+ std::tie(id, field1, field2);
+ });
+ if (iter != s128_file_id.end())
+ WriteKeyToFile(id == S128KeyType::Titlekey, iter->first, key);
s128_keys[{id, field1, field2}] = key;
}
void KeyManager::SetKey(S256KeyType id, Key256 key, u64 field1, u64 field2) {
+ const auto iter = std::find_if(
+ s256_file_id.begin(), s256_file_id.end(),
+ [&id, &field1, &field2](const std::pair<std::string, KeyIndex<S256KeyType>> elem) {
+ return std::tie(elem.second.type, elem.second.field1, elem.second.field2) ==
+ std::tie(id, field1, field2);
+ });
+ if (iter != s256_file_id.end())
+ WriteKeyToFile(false, iter->first, key);
s256_keys[{id, field1, field2}] = key;
}
@@ -125,7 +268,16 @@ bool KeyManager::KeyFileExists(bool title) {
FileUtil::Exists(yuzu_keys_dir + DIR_SEP + "prod.keys");
}
-const std::unordered_map<std::string, KeyIndex<S128KeyType>> KeyManager::s128_file_id = {
+void KeyManager::DeriveSDSeedLazy() {
+ if (HasKey(S128KeyType::SDSeed))
+ return;
+
+ const auto res = DeriveSDSeed();
+ if (res != boost::none)
+ SetKey(S128KeyType::SDSeed, res.get());
+}
+
+const boost::container::flat_map<std::string, KeyIndex<S128KeyType>> KeyManager::s128_file_id = {
{"master_key_00", {S128KeyType::Master, 0, 0}},
{"master_key_01", {S128KeyType::Master, 1, 0}},
{"master_key_02", {S128KeyType::Master, 2, 0}},
@@ -167,11 +319,17 @@ const std::unordered_map<std::string, KeyIndex<S128KeyType>> KeyManager::s128_fi
{"key_area_key_system_02", {S128KeyType::KeyArea, 2, static_cast<u64>(KeyAreaKeyType::System)}},
{"key_area_key_system_03", {S128KeyType::KeyArea, 3, static_cast<u64>(KeyAreaKeyType::System)}},
{"key_area_key_system_04", {S128KeyType::KeyArea, 4, static_cast<u64>(KeyAreaKeyType::System)}},
+ {"sd_card_kek_source", {S128KeyType::Source, static_cast<u64>(SourceKeyType::SDKEK), 0}},
+ {"aes_kek_generation_source",
+ {S128KeyType::Source, static_cast<u64>(SourceKeyType::AESKEKGeneration), 0}},
+ {"aes_key_generation_source",
+ {S128KeyType::Source, static_cast<u64>(SourceKeyType::AESKeyGeneration), 0}},
+ {"sd_seed", {S128KeyType::SDSeed, 0, 0}},
};
-const std::unordered_map<std::string, KeyIndex<S256KeyType>> KeyManager::s256_file_id = {
+const boost::container::flat_map<std::string, KeyIndex<S256KeyType>> KeyManager::s256_file_id = {
{"header_key", {S256KeyType::Header, 0, 0}},
- {"sd_card_save_key", {S256KeyType::SDSave, 0, 0}},
- {"sd_card_nca_key", {S256KeyType::SDNCA, 0, 0}},
+ {"sd_card_save_key_source", {S256KeyType::SDKeySource, static_cast<u64>(SDKeyType::Save), 0}},
+ {"sd_card_nca_key_source", {S256KeyType::SDKeySource, static_cast<u64>(SDKeyType::NCA), 0}},
};
} // namespace Core::Crypto
diff --git a/src/core/crypto/key_manager.h b/src/core/crypto/key_manager.h
index 0c62d4421..7ca3e6cbc 100644
--- a/src/core/crypto/key_manager.h
+++ b/src/core/crypto/key_manager.h
@@ -6,11 +6,13 @@
#include <array>
#include <string>
+#include <string_view>
#include <type_traits>
-#include <unordered_map>
#include <vector>
+#include <boost/container/flat_map.hpp>
#include <fmt/format.h>
#include "common/common_types.h"
+#include "core/loader/loader.h"
namespace Core::Crypto {
@@ -22,9 +24,8 @@ static_assert(sizeof(Key128) == 16, "Key128 must be 128 bytes big.");
static_assert(sizeof(Key256) == 32, "Key128 must be 128 bytes big.");
enum class S256KeyType : u64 {
- Header, //
- SDSave, //
- SDNCA, //
+ Header, //
+ SDKeySource, // f1=SDKeyType
};
enum class S128KeyType : u64 {
@@ -36,6 +37,7 @@ enum class S128KeyType : u64 {
KeyArea, // f1=crypto revision f2=type {app, ocean, system}
SDSeed, //
Titlekey, // f1=rights id LSB f2=rights id MSB
+ Source, // f1=source type, f2= sub id
};
enum class KeyAreaKeyType : u8 {
@@ -44,6 +46,17 @@ enum class KeyAreaKeyType : u8 {
System,
};
+enum class SourceKeyType : u8 {
+ SDKEK,
+ AESKEKGeneration,
+ AESKeyGeneration,
+};
+
+enum class SDKeyType : u8 {
+ Save,
+ NCA,
+};
+
template <typename KeyType>
struct KeyIndex {
KeyType type;
@@ -59,34 +72,12 @@ struct KeyIndex {
}
};
-// The following two (== and hash) are so KeyIndex can be a key in unordered_map
-
+// boost flat_map requires operator< for O(log(n)) lookups.
template <typename KeyType>
-bool operator==(const KeyIndex<KeyType>& lhs, const KeyIndex<KeyType>& rhs) {
- return std::tie(lhs.type, lhs.field1, lhs.field2) == std::tie(rhs.type, rhs.field1, rhs.field2);
+bool operator<(const KeyIndex<KeyType>& lhs, const KeyIndex<KeyType>& rhs) {
+ return std::tie(lhs.type, lhs.field1, lhs.field2) < std::tie(rhs.type, rhs.field1, rhs.field2);
}
-template <typename KeyType>
-bool operator!=(const KeyIndex<KeyType>& lhs, const KeyIndex<KeyType>& rhs) {
- return !operator==(lhs, rhs);
-}
-
-} // namespace Core::Crypto
-
-namespace std {
-template <typename KeyType>
-struct hash<Core::Crypto::KeyIndex<KeyType>> {
- size_t operator()(const Core::Crypto::KeyIndex<KeyType>& k) const {
- using std::hash;
-
- return ((hash<u64>()(static_cast<u64>(k.type)) ^ (hash<u64>()(k.field1) << 1)) >> 1) ^
- (hash<u64>()(k.field2) << 1);
- }
-};
-} // namespace std
-
-namespace Core::Crypto {
-
class KeyManager {
public:
KeyManager();
@@ -102,16 +93,27 @@ public:
static bool KeyFileExists(bool title);
+ // Call before using the sd seed to attempt to derive it if it dosen't exist. Needs system save
+ // 8*43 and the private file to exist.
+ void DeriveSDSeedLazy();
+
private:
- std::unordered_map<KeyIndex<S128KeyType>, Key128> s128_keys;
- std::unordered_map<KeyIndex<S256KeyType>, Key256> s256_keys;
+ boost::container::flat_map<KeyIndex<S128KeyType>, Key128> s128_keys;
+ boost::container::flat_map<KeyIndex<S256KeyType>, Key256> s256_keys;
bool dev_mode;
void LoadFromFile(const std::string& filename, bool is_title_keys);
void AttemptLoadKeyFile(const std::string& dir1, const std::string& dir2,
const std::string& filename, bool title);
+ template <size_t Size>
+ void WriteKeyToFile(bool title_key, std::string_view keyname, const std::array<u8, Size>& key);
- static const std::unordered_map<std::string, KeyIndex<S128KeyType>> s128_file_id;
- static const std::unordered_map<std::string, KeyIndex<S256KeyType>> s256_file_id;
+ static const boost::container::flat_map<std::string, KeyIndex<S128KeyType>> s128_file_id;
+ static const boost::container::flat_map<std::string, KeyIndex<S256KeyType>> s256_file_id;
};
+
+Key128 GenerateKeyEncryptionKey(Key128 source, Key128 master, Key128 kek_seed, Key128 key_seed);
+boost::optional<Key128> DeriveSDSeed();
+Loader::ResultStatus DeriveSDKeys(std::array<Key256, 2>& sd_keys, const KeyManager& keys);
+
} // namespace Core::Crypto
diff --git a/src/core/crypto/xts_encryption_layer.cpp b/src/core/crypto/xts_encryption_layer.cpp
new file mode 100644
index 000000000..c10832cfe
--- /dev/null
+++ b/src/core/crypto/xts_encryption_layer.cpp
@@ -0,0 +1,58 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <cstring>
+#include "common/assert.h"
+#include "core/crypto/xts_encryption_layer.h"
+
+namespace Core::Crypto {
+
+constexpr u64 XTS_SECTOR_SIZE = 0x4000;
+
+XTSEncryptionLayer::XTSEncryptionLayer(FileSys::VirtualFile base_, Key256 key_)
+ : EncryptionLayer(std::move(base_)), cipher(key_, Mode::XTS) {}
+
+size_t XTSEncryptionLayer::Read(u8* data, size_t length, size_t offset) const {
+ if (length == 0)
+ return 0;
+
+ const auto sector_offset = offset & 0x3FFF;
+ if (sector_offset == 0) {
+ if (length % XTS_SECTOR_SIZE == 0) {
+ std::vector<u8> raw = base->ReadBytes(length, offset);
+ cipher.XTSTranscode(raw.data(), raw.size(), data, offset / XTS_SECTOR_SIZE,
+ XTS_SECTOR_SIZE, Op::Decrypt);
+ return raw.size();
+ }
+ if (length > XTS_SECTOR_SIZE) {
+ const auto rem = length % XTS_SECTOR_SIZE;
+ const auto read = length - rem;
+ return Read(data, read, offset) + Read(data + read, rem, offset + read);
+ }
+ std::vector<u8> buffer = base->ReadBytes(XTS_SECTOR_SIZE, offset);
+ if (buffer.size() < XTS_SECTOR_SIZE)
+ buffer.resize(XTS_SECTOR_SIZE);
+ cipher.XTSTranscode(buffer.data(), buffer.size(), buffer.data(), offset / XTS_SECTOR_SIZE,
+ XTS_SECTOR_SIZE, Op::Decrypt);
+ std::memcpy(data, buffer.data(), std::min(buffer.size(), length));
+ return std::min(buffer.size(), length);
+ }
+
+ // offset does not fall on block boundary (0x4000)
+ std::vector<u8> block = base->ReadBytes(0x4000, offset - sector_offset);
+ if (block.size() < XTS_SECTOR_SIZE)
+ block.resize(XTS_SECTOR_SIZE);
+ cipher.XTSTranscode(block.data(), block.size(), block.data(),
+ (offset - sector_offset) / XTS_SECTOR_SIZE, XTS_SECTOR_SIZE, Op::Decrypt);
+ const size_t read = XTS_SECTOR_SIZE - sector_offset;
+
+ if (length + sector_offset < XTS_SECTOR_SIZE) {
+ std::memcpy(data, block.data() + sector_offset, std::min<u64>(length, read));
+ return std::min<u64>(length, read);
+ }
+ std::memcpy(data, block.data() + sector_offset, read);
+ return read + Read(data + read, length - read, offset + read);
+}
+} // namespace Core::Crypto
diff --git a/src/core/crypto/xts_encryption_layer.h b/src/core/crypto/xts_encryption_layer.h
new file mode 100644
index 000000000..7a1f1dc64
--- /dev/null
+++ b/src/core/crypto/xts_encryption_layer.h
@@ -0,0 +1,25 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/crypto/aes_util.h"
+#include "core/crypto/encryption_layer.h"
+#include "core/crypto/key_manager.h"
+
+namespace Core::Crypto {
+
+// Sits on top of a VirtualFile and provides XTS-mode AES decription.
+class XTSEncryptionLayer : public EncryptionLayer {
+public:
+ XTSEncryptionLayer(FileSys::VirtualFile base, Key256 key);
+
+ size_t Read(u8* data, size_t length, size_t offset) const override;
+
+private:
+ // Must be mutable as operations modify cipher contexts.
+ mutable AESCipher<Key256> cipher;
+};
+
+} // namespace Core::Crypto