early-access version 1255

src/core/hle/service/bcat/backend/backend.cpp

@@ -0,0 +1,136 @@
+// Copyright 2019 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/hex_util.h"
+#include "common/logging/log.h"
+#include "core/core.h"
+#include "core/hle/lock.h"
+#include "core/hle/service/bcat/backend/backend.h"
+
+namespace Service::BCAT {
+
+ProgressServiceBackend::ProgressServiceBackend(Kernel::KernelCore& kernel,
+                                               std::string_view event_name) {
+    event = Kernel::WritableEvent::CreateEventPair(
+        kernel, std::string("ProgressServiceBackend:UpdateEvent:").append(event_name));
+}
+
+std::shared_ptr<Kernel::ReadableEvent> ProgressServiceBackend::GetEvent() const {
+    return event.readable;
+}
+
+DeliveryCacheProgressImpl& ProgressServiceBackend::GetImpl() {
+    return impl;
+}
+
+void ProgressServiceBackend::SetNeedHLELock(bool need) {
+    need_hle_lock = need;
+}
+
+void ProgressServiceBackend::SetTotalSize(u64 size) {
+    impl.total_bytes = size;
+    SignalUpdate();
+}
+
+void ProgressServiceBackend::StartConnecting() {
+    impl.status = DeliveryCacheProgressImpl::Status::Connecting;
+    SignalUpdate();
+}
+
+void ProgressServiceBackend::StartProcessingDataList() {
+    impl.status = DeliveryCacheProgressImpl::Status::ProcessingDataList;
+    SignalUpdate();
+}
+
+void ProgressServiceBackend::StartDownloadingFile(std::string_view dir_name,
+                                                  std::string_view file_name, u64 file_size) {
+    impl.status = DeliveryCacheProgressImpl::Status::Downloading;
+    impl.current_downloaded_bytes = 0;
+    impl.current_total_bytes = file_size;
+    std::memcpy(impl.current_directory.data(), dir_name.data(),
+                std::min<u64>(dir_name.size(), 0x31ull));
+    std::memcpy(impl.current_file.data(), file_name.data(),
+                std::min<u64>(file_name.size(), 0x31ull));
+    SignalUpdate();
+}
+
+void ProgressServiceBackend::UpdateFileProgress(u64 downloaded) {
+    impl.current_downloaded_bytes = downloaded;
+    SignalUpdate();
+}
+
+void ProgressServiceBackend::FinishDownloadingFile() {
+    impl.total_downloaded_bytes += impl.current_total_bytes;
+    SignalUpdate();
+}
+
+void ProgressServiceBackend::CommitDirectory(std::string_view dir_name) {
+    impl.status = DeliveryCacheProgressImpl::Status::Committing;
+    impl.current_file.fill(0);
+    impl.current_downloaded_bytes = 0;
+    impl.current_total_bytes = 0;
+    std::memcpy(impl.current_directory.data(), dir_name.data(),
+                std::min<u64>(dir_name.size(), 0x31ull));
+    SignalUpdate();
+}
+
+void ProgressServiceBackend::FinishDownload(ResultCode result) {
+    impl.total_downloaded_bytes = impl.total_bytes;
+    impl.status = DeliveryCacheProgressImpl::Status::Done;
+    impl.result = result;
+    SignalUpdate();
+}
+
+void ProgressServiceBackend::SignalUpdate() const {
+    if (need_hle_lock) {
+        std::lock_guard lock(HLE::g_hle_lock);
+        event.writable->Signal();
+    } else {
+        event.writable->Signal();
+    }
+}
+
+Backend::Backend(DirectoryGetter getter) : dir_getter(std::move(getter)) {}
+
+Backend::~Backend() = default;
+
+NullBackend::NullBackend(DirectoryGetter getter) : Backend(std::move(getter)) {}
+
+NullBackend::~NullBackend() = default;
+
+bool NullBackend::Synchronize(TitleIDVersion title, ProgressServiceBackend& progress) {
+    LOG_DEBUG(Service_BCAT, "called, title_id={:016X}, build_id={:016X}", title.title_id,
+              title.build_id);
+
+    progress.FinishDownload(RESULT_SUCCESS);
+    return true;
+}
+
+bool NullBackend::SynchronizeDirectory(TitleIDVersion title, std::string name,
+                                       ProgressServiceBackend& progress) {
+    LOG_DEBUG(Service_BCAT, "called, title_id={:016X}, build_id={:016X}, name={}", title.title_id,
+              title.build_id, name);
+
+    progress.FinishDownload(RESULT_SUCCESS);
+    return true;
+}
+
+bool NullBackend::Clear(u64 title_id) {
+    LOG_DEBUG(Service_BCAT, "called, title_id={:016X}", title_id);
+
+    return true;
+}
+
+void NullBackend::SetPassphrase(u64 title_id, const Passphrase& passphrase) {
+    LOG_DEBUG(Service_BCAT, "called, title_id={:016X}, passphrase={}", title_id,
+              Common::HexToString(passphrase));
+}
+
+std::optional<std::vector<u8>> NullBackend::GetLaunchParameter(TitleIDVersion title) {
+    LOG_DEBUG(Service_BCAT, "called, title_id={:016X}, build_id={:016X}", title.title_id,
+              title.build_id);
+    return std::nullopt;
+}
+
+} // namespace Service::BCAT

src/core/hle/service/bcat/backend/backend.h

@@ -0,0 +1,158 @@
+// Copyright 2019 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <functional>
+#include <optional>
+#include <string>
+#include <string_view>
+
+#include "common/common_types.h"
+#include "core/file_sys/vfs_types.h"
+#include "core/hle/kernel/readable_event.h"
+#include "core/hle/kernel/writable_event.h"
+#include "core/hle/result.h"
+
+namespace Core {
+class System;
+}
+
+namespace Kernel {
+class KernelCore;
+}
+
+namespace Service::BCAT {
+
+struct DeliveryCacheProgressImpl;
+
+using DirectoryGetter = std::function<FileSys::VirtualDir(u64)>;
+using Passphrase = std::array<u8, 0x20>;
+
+struct TitleIDVersion {
+    u64 title_id;
+    u64 build_id;
+};
+
+using DirectoryName = std::array<char, 0x20>;
+using FileName = std::array<char, 0x20>;
+
+struct DeliveryCacheProgressImpl {
+    enum class Status : s32 {
+        None = 0x0,
+        Queued = 0x1,
+        Connecting = 0x2,
+        ProcessingDataList = 0x3,
+        Downloading = 0x4,
+        Committing = 0x5,
+        Done = 0x9,
+    };
+
+    Status status;
+    ResultCode result = RESULT_SUCCESS;
+    DirectoryName current_directory;
+    FileName current_file;
+    s64 current_downloaded_bytes; ///< Bytes downloaded on current file.
+    s64 current_total_bytes;      ///< Bytes total on current file.
+    s64 total_downloaded_bytes;   ///< Bytes downloaded on overall download.
+    s64 total_bytes;              ///< Bytes total on overall download.
+    INSERT_PADDING_BYTES(
+        0x198); ///< Appears to be unused in official code, possibly reserved for future use.
+};
+static_assert(sizeof(DeliveryCacheProgressImpl) == 0x200,
+              "DeliveryCacheProgressImpl has incorrect size.");
+
+// A class to manage the signalling to the game about BCAT download progress.
+// Some of this class is implemented in module.cpp to avoid exposing the implementation structure.
+class ProgressServiceBackend {
+    friend class IBcatService;
+
+public:
+    // Clients should call this with true if any of the functions are going to be called from a
+    // non-HLE thread and this class need to lock the hle mutex. (default is false)
+    void SetNeedHLELock(bool need);
+
+    // Sets the number of bytes total in the entire download.
+    void SetTotalSize(u64 size);
+
+    // Notifies the application that the backend has started connecting to the server.
+    void StartConnecting();
+    // Notifies the application that the backend has begun accumulating and processing metadata.
+    void StartProcessingDataList();
+
+    // Notifies the application that a file is starting to be downloaded.
+    void StartDownloadingFile(std::string_view dir_name, std::string_view file_name, u64 file_size);
+    // Updates the progress of the current file to the size passed.
+    void UpdateFileProgress(u64 downloaded);
+    // Notifies the application that the current file has completed download.
+    void FinishDownloadingFile();
+
+    // Notifies the application that all files in this directory have completed and are being
+    // finalized.
+    void CommitDirectory(std::string_view dir_name);
+
+    // Notifies the application that the operation completed with result code result.
+    void FinishDownload(ResultCode result);
+
+private:
+    explicit ProgressServiceBackend(Kernel::KernelCore& kernel, std::string_view event_name);
+
+    std::shared_ptr<Kernel::ReadableEvent> GetEvent() const;
+    DeliveryCacheProgressImpl& GetImpl();
+
+    void SignalUpdate() const;
+
+    DeliveryCacheProgressImpl impl{};
+    Kernel::EventPair event;
+    bool need_hle_lock = false;
+};
+
+// A class representing an abstract backend for BCAT functionality.
+class Backend {
+public:
+    explicit Backend(DirectoryGetter getter);
+    virtual ~Backend();
+
+    // Called when the backend is needed to synchronize the data for the game with title ID and
+    // version in title. A ProgressServiceBackend object is provided to alert the application of
+    // status.
+    virtual bool Synchronize(TitleIDVersion title, ProgressServiceBackend& progress) = 0;
+    // Very similar to Synchronize, but only for the directory provided. Backends should not alter
+    // the data for any other directories.
+    virtual bool SynchronizeDirectory(TitleIDVersion title, std::string name,
+                                      ProgressServiceBackend& progress) = 0;
+
+    // Removes all cached data associated with title id provided.
+    virtual bool Clear(u64 title_id) = 0;
+
+    // Sets the BCAT Passphrase to be used with the associated title ID.
+    virtual void SetPassphrase(u64 title_id, const Passphrase& passphrase) = 0;
+
+    // Gets the launch parameter used by AM associated with the title ID and version provided.
+    virtual std::optional<std::vector<u8>> GetLaunchParameter(TitleIDVersion title) = 0;
+
+protected:
+    DirectoryGetter dir_getter;
+};
+
+// A backend of BCAT that provides no operation.
+class NullBackend : public Backend {
+public:
+    explicit NullBackend(DirectoryGetter getter);
+    ~NullBackend() override;
+
+    bool Synchronize(TitleIDVersion title, ProgressServiceBackend& progress) override;
+    bool SynchronizeDirectory(TitleIDVersion title, std::string name,
+                              ProgressServiceBackend& progress) override;
+
+    bool Clear(u64 title_id) override;
+
+    void SetPassphrase(u64 title_id, const Passphrase& passphrase) override;
+
+    std::optional<std::vector<u8>> GetLaunchParameter(TitleIDVersion title) override;
+};
+
+std::unique_ptr<Backend> CreateBackendFromSettings(Core::System& system, DirectoryGetter getter);
+
+} // namespace Service::BCAT

src/core/hle/service/bcat/backend/boxcat.cpp

@@ -0,0 +1,521 @@
+// Copyright 2019 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <fmt/ostream.h>
+#include <httplib.h>
+#include <mbedtls/sha256.h>
+#include <nlohmann/json.hpp>
+#include "common/hex_util.h"
+#include "common/logging/backend.h"
+#include "common/logging/log.h"
+#include "core/core.h"
+#include "core/file_sys/vfs.h"
+#include "core/file_sys/vfs_libzip.h"
+#include "core/file_sys/vfs_vector.h"
+#include "core/frontend/applets/error.h"
+#include "core/hle/service/am/applets/applets.h"
+#include "core/hle/service/bcat/backend/boxcat.h"
+#include "core/settings.h"
+
+namespace Service::BCAT {
+namespace {
+
+// Prevents conflicts with windows macro called CreateFile
+FileSys::VirtualFile VfsCreateFileWrap(FileSys::VirtualDir dir, std::string_view name) {
+    return dir->CreateFile(name);
+}
+
+// Prevents conflicts with windows macro called DeleteFile
+bool VfsDeleteFileWrap(FileSys::VirtualDir dir, std::string_view name) {
+    return dir->DeleteFile(name);
+}
+
+constexpr ResultCode ERROR_GENERAL_BCAT_FAILURE{ErrorModule::BCAT, 1};
+
+constexpr char BOXCAT_HOSTNAME[] = "api.yuzu-emu.org";
+
+// Formatted using fmt with arg[0] = hex title id
+constexpr char BOXCAT_PATHNAME_DATA[] = "/game-assets/{:016X}/boxcat";
+constexpr char BOXCAT_PATHNAME_LAUNCHPARAM[] = "/game-assets/{:016X}/launchparam";
+
+constexpr char BOXCAT_PATHNAME_EVENTS[] = "/game-assets/boxcat/events";
+
+constexpr char BOXCAT_API_VERSION[] = "1";
+constexpr char BOXCAT_CLIENT_TYPE[] = "yuzu";
+
+// HTTP status codes for Boxcat
+enum class ResponseStatus {
+    Ok = 200,               ///< Operation completed successfully.
+    BadClientVersion = 301, ///< The Boxcat-Client-Version doesn't match the server.
+    NoUpdate = 304,         ///< The digest provided would match the new data, no need to update.
+    NoMatchTitleId = 404,   ///< The title ID provided doesn't have a boxcat implementation.
+    NoMatchBuildId = 406,   ///< The build ID provided is blacklisted (potentially because of format
+                            ///< issues or whatnot) and has no data.
+};
+
+enum class DownloadResult {
+    Success = 0,
+    NoResponse,
+    GeneralWebError,
+    NoMatchTitleId,
+    NoMatchBuildId,
+    InvalidContentType,
+    GeneralFSError,
+    BadClientVersion,
+};
+
+constexpr std::array<const char*, 8> DOWNLOAD_RESULT_LOG_MESSAGES{
+    "Success",
+    "There was no response from the server.",
+    "There was a general web error code returned from the server.",
+    "The title ID of the current game doesn't have a boxcat implementation. If you believe an "
+    "implementation should be added, contact yuzu support.",
+    "The build ID of the current version of the game is marked as incompatible with the current "
+    "BCAT distribution. Try upgrading or downgrading your game version or contacting yuzu support.",
+    "The content type of the web response was invalid.",
+    "There was a general filesystem error while saving the zip file.",
+    "The server is either too new or too old to serve the request. Try using the latest version of "
+    "an official release of yuzu.",
+};
+
+std::ostream& operator<<(std::ostream& os, DownloadResult result) {
+    return os << DOWNLOAD_RESULT_LOG_MESSAGES.at(static_cast<std::size_t>(result));
+}
+
+constexpr u32 PORT = 443;
+constexpr u32 TIMEOUT_SECONDS = 30;
+[[maybe_unused]] constexpr u64 VFS_COPY_BLOCK_SIZE = 1ULL << 24; // 4MB
+
+std::string GetBINFilePath(u64 title_id) {
+    return fmt::format("{}bcat/{:016X}/launchparam.bin",
+                       Common::FS::GetUserPath(Common::FS::UserPath::CacheDir), title_id);
+}
+
+std::string GetZIPFilePath(u64 title_id) {
+    return fmt::format("{}bcat/{:016X}/data.zip",
+                       Common::FS::GetUserPath(Common::FS::UserPath::CacheDir), title_id);
+}
+
+// If the error is something the user should know about (build ID mismatch, bad client version),
+// display an error.
+void HandleDownloadDisplayResult(const AM::Applets::AppletManager& applet_manager,
+                                 DownloadResult res) {
+    if (res == DownloadResult::Success || res == DownloadResult::NoResponse ||
+        res == DownloadResult::GeneralWebError || res == DownloadResult::GeneralFSError ||
+        res == DownloadResult::NoMatchTitleId || res == DownloadResult::InvalidContentType) {
+        return;
+    }
+
+    const auto& frontend{applet_manager.GetAppletFrontendSet()};
+    frontend.error->ShowCustomErrorText(
+        RESULT_UNKNOWN, "There was an error while attempting to use Boxcat.",
+        DOWNLOAD_RESULT_LOG_MESSAGES[static_cast<std::size_t>(res)], [] {});
+}
+
+bool VfsRawCopyProgress(FileSys::VirtualFile src, FileSys::VirtualFile dest,
+                        std::string_view dir_name, ProgressServiceBackend& progress,
+                        std::size_t block_size = 0x1000) {
+    if (src == nullptr || dest == nullptr || !src->IsReadable() || !dest->IsWritable())
+        return false;
+    if (!dest->Resize(src->GetSize()))
+        return false;
+
+    progress.StartDownloadingFile(dir_name, src->GetName(), src->GetSize());
+
+    std::vector<u8> temp(std::min(block_size, src->GetSize()));
+    for (std::size_t i = 0; i < src->GetSize(); i += block_size) {
+        const auto read = std::min(block_size, src->GetSize() - i);
+
+        if (src->Read(temp.data(), read, i) != read) {
+            return false;
+        }
+
+        if (dest->Write(temp.data(), read, i) != read) {
+            return false;
+        }
+
+        progress.UpdateFileProgress(i);
+    }
+
+    progress.FinishDownloadingFile();
+
+    return true;
+}
+
+bool VfsRawCopyDProgressSingle(FileSys::VirtualDir src, FileSys::VirtualDir dest,
+                               ProgressServiceBackend& progress, std::size_t block_size = 0x1000) {
+    if (src == nullptr || dest == nullptr || !src->IsReadable() || !dest->IsWritable())
+        return false;
+
+    for (const auto& file : src->GetFiles()) {
+        const auto out_file = VfsCreateFileWrap(dest, file->GetName());
+        if (!VfsRawCopyProgress(file, out_file, src->GetName(), progress, block_size)) {
+            return false;
+        }
+    }
+    progress.CommitDirectory(src->GetName());
+
+    return true;
+}
+
+bool VfsRawCopyDProgress(FileSys::VirtualDir src, FileSys::VirtualDir dest,
+                         ProgressServiceBackend& progress, std::size_t block_size = 0x1000) {
+    if (src == nullptr || dest == nullptr || !src->IsReadable() || !dest->IsWritable())
+        return false;
+
+    for (const auto& dir : src->GetSubdirectories()) {
+        const auto out = dest->CreateSubdirectory(dir->GetName());
+        if (!VfsRawCopyDProgressSingle(dir, out, progress, block_size)) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+} // Anonymous namespace
+
+class Boxcat::Client {
+public:
+    Client(std::string path, u64 title_id, u64 build_id)
+        : path(std::move(path)), title_id(title_id), build_id(build_id) {}
+
+    DownloadResult DownloadDataZip() {
+        return DownloadInternal(fmt::format(BOXCAT_PATHNAME_DATA, title_id), TIMEOUT_SECONDS,
+                                "application/zip");
+    }
+
+    DownloadResult DownloadLaunchParam() {
+        return DownloadInternal(fmt::format(BOXCAT_PATHNAME_LAUNCHPARAM, title_id),
+                                TIMEOUT_SECONDS / 3, "application/octet-stream");
+    }
+
+private:
+    DownloadResult DownloadInternal(const std::string& resolved_path, u32 timeout_seconds,
+                                    const std::string& content_type_name) {
+        if (client == nullptr) {
+            client = std::make_unique<httplib::SSLClient>(BOXCAT_HOSTNAME, PORT);
+            client->set_connection_timeout(timeout_seconds);
+            client->set_read_timeout(timeout_seconds);
+            client->set_write_timeout(timeout_seconds);
+        }
+
+        httplib::Headers headers{
+            {std::string("Game-Assets-API-Version"), std::string(BOXCAT_API_VERSION)},
+            {std::string("Boxcat-Client-Type"), std::string(BOXCAT_CLIENT_TYPE)},
+            {std::string("Game-Build-Id"), fmt::format("{:016X}", build_id)},
+        };
+
+        if (Common::FS::Exists(path)) {
+            Common::FS::IOFile file{path, "rb"};
+            if (file.IsOpen()) {
+                std::vector<u8> bytes(file.GetSize());
+                file.ReadBytes(bytes.data(), bytes.size());
+                const auto digest = DigestFile(bytes);
+                headers.insert({std::string("If-None-Match"), Common::HexToString(digest, false)});
+            }
+        }
+
+        const auto response = client->Get(resolved_path.c_str(), headers);
+        if (response == nullptr)
+            return DownloadResult::NoResponse;
+
+        if (response->status == static_cast<int>(ResponseStatus::NoUpdate))
+            return DownloadResult::Success;
+        if (response->status == static_cast<int>(ResponseStatus::BadClientVersion))
+            return DownloadResult::BadClientVersion;
+        if (response->status == static_cast<int>(ResponseStatus::NoMatchTitleId))
+            return DownloadResult::NoMatchTitleId;
+        if (response->status == static_cast<int>(ResponseStatus::NoMatchBuildId))
+            return DownloadResult::NoMatchBuildId;
+        if (response->status != static_cast<int>(ResponseStatus::Ok))
+            return DownloadResult::GeneralWebError;
+
+        const auto content_type = response->headers.find("content-type");
+        if (content_type == response->headers.end() ||
+            content_type->second.find(content_type_name) == std::string::npos) {
+            return DownloadResult::InvalidContentType;
+        }
+
+        Common::FS::CreateFullPath(path);
+        Common::FS::IOFile file{path, "wb"};
+        if (!file.IsOpen())
+            return DownloadResult::GeneralFSError;
+        if (!file.Resize(response->body.size()))
+            return DownloadResult::GeneralFSError;
+        if (file.WriteBytes(response->body.data(), response->body.size()) != response->body.size())
+            return DownloadResult::GeneralFSError;
+
+        return DownloadResult::Success;
+    }
+
+    using Digest = std::array<u8, 0x20>;
+    static Digest DigestFile(std::vector<u8> bytes) {
+        Digest out{};
+        mbedtls_sha256_ret(bytes.data(), bytes.size(), out.data(), 0);
+        return out;
+    }
+
+    std::unique_ptr<httplib::SSLClient> client;
+    std::string path;
+    u64 title_id;
+    u64 build_id;
+};
+
+Boxcat::Boxcat(AM::Applets::AppletManager& applet_manager_, DirectoryGetter getter)
+    : Backend(std::move(getter)), applet_manager{applet_manager_} {}
+
+Boxcat::~Boxcat() = default;
+
+void SynchronizeInternal(AM::Applets::AppletManager& applet_manager, DirectoryGetter dir_getter,
+                         TitleIDVersion title, ProgressServiceBackend& progress,
+                         std::optional<std::string> dir_name = {}) {
+    progress.SetNeedHLELock(true);
+
+    if (Settings::values.bcat_boxcat_local) {
+        LOG_INFO(Service_BCAT, "Boxcat using local data by override, skipping download.");
+        const auto dir = dir_getter(title.title_id);
+        if (dir)
+            progress.SetTotalSize(dir->GetSize());
+        progress.FinishDownload(RESULT_SUCCESS);
+        return;
+    }
+
+    const auto zip_path{GetZIPFilePath(title.title_id)};
+    Boxcat::Client client{zip_path, title.title_id, title.build_id};
+
+    progress.StartConnecting();
+
+    const auto res = client.DownloadDataZip();
+    if (res != DownloadResult::Success) {
+        LOG_ERROR(Service_BCAT, "Boxcat synchronization failed with error '{}'!", res);
+
+        if (res == DownloadResult::NoMatchBuildId || res == DownloadResult::NoMatchTitleId) {
+            Common::FS::Delete(zip_path);
+        }
+
+        HandleDownloadDisplayResult(applet_manager, res);
+        progress.FinishDownload(ERROR_GENERAL_BCAT_FAILURE);
+        return;
+    }
+
+    progress.StartProcessingDataList();
+
+    Common::FS::IOFile zip{zip_path, "rb"};
+    const auto size = zip.GetSize();
+    std::vector<u8> bytes(size);
+    if (!zip.IsOpen() || size == 0 || zip.ReadBytes(bytes.data(), bytes.size()) != bytes.size()) {
+        LOG_ERROR(Service_BCAT, "Boxcat failed to read ZIP file at path '{}'!", zip_path);
+        progress.FinishDownload(ERROR_GENERAL_BCAT_FAILURE);
+        return;
+    }
+
+    const auto extracted = FileSys::ExtractZIP(std::make_shared<FileSys::VectorVfsFile>(bytes));
+    if (extracted == nullptr) {
+        LOG_ERROR(Service_BCAT, "Boxcat failed to extract ZIP file!");
+        progress.FinishDownload(ERROR_GENERAL_BCAT_FAILURE);
+        return;
+    }
+
+    if (dir_name == std::nullopt) {
+        progress.SetTotalSize(extracted->GetSize());
+
+        const auto target_dir = dir_getter(title.title_id);
+        if (target_dir == nullptr || !VfsRawCopyDProgress(extracted, target_dir, progress)) {
+            LOG_ERROR(Service_BCAT, "Boxcat failed to copy extracted ZIP to target directory!");
+            progress.FinishDownload(ERROR_GENERAL_BCAT_FAILURE);
+            return;
+        }
+    } else {
+        const auto target_dir = dir_getter(title.title_id);
+        if (target_dir == nullptr) {
+            LOG_ERROR(Service_BCAT, "Boxcat failed to get directory for title ID!");
+            progress.FinishDownload(ERROR_GENERAL_BCAT_FAILURE);
+            return;
+        }
+
+        const auto target_sub = target_dir->GetSubdirectory(*dir_name);
+        const auto source_sub = extracted->GetSubdirectory(*dir_name);
+
+        progress.SetTotalSize(source_sub->GetSize());
+
+        std::vector<std::string> filenames;
+        {
+            const auto files = target_sub->GetFiles();
+            std::transform(files.begin(), files.end(), std::back_inserter(filenames),
+                           [](const auto& vfile) { return vfile->GetName(); });
+        }
+
+        for (const auto& filename : filenames) {
+            VfsDeleteFileWrap(target_sub, filename);
+        }
+
+        if (target_sub == nullptr || source_sub == nullptr ||
+            !VfsRawCopyDProgressSingle(source_sub, target_sub, progress)) {
+            LOG_ERROR(Service_BCAT, "Boxcat failed to copy extracted ZIP to target directory!");
+            progress.FinishDownload(ERROR_GENERAL_BCAT_FAILURE);
+            return;
+        }
+    }
+
+    progress.FinishDownload(RESULT_SUCCESS);
+}
+
+bool Boxcat::Synchronize(TitleIDVersion title, ProgressServiceBackend& progress) {
+    is_syncing.exchange(true);
+
+    std::thread([this, title, &progress] {
+        SynchronizeInternal(applet_manager, dir_getter, title, progress);
+    }).detach();
+
+    return true;
+}
+
+bool Boxcat::SynchronizeDirectory(TitleIDVersion title, std::string name,
+                                  ProgressServiceBackend& progress) {
+    is_syncing.exchange(true);
+
+    std::thread([this, title, name, &progress] {
+        SynchronizeInternal(applet_manager, dir_getter, title, progress, name);
+    }).detach();
+
+    return true;
+}
+
+bool Boxcat::Clear(u64 title_id) {
+    if (Settings::values.bcat_boxcat_local) {
+        LOG_INFO(Service_BCAT, "Boxcat using local data by override, skipping clear.");
+        return true;
+    }
+
+    const auto dir = dir_getter(title_id);
+
+    std::vector<std::string> dirnames;
+
+    for (const auto& subdir : dir->GetSubdirectories())
+        dirnames.push_back(subdir->GetName());
+
+    for (const auto& subdir : dirnames) {
+        if (!dir->DeleteSubdirectoryRecursive(subdir))
+            return false;
+    }
+
+    return true;
+}
+
+void Boxcat::SetPassphrase(u64 title_id, const Passphrase& passphrase) {
+    LOG_DEBUG(Service_BCAT, "called, title_id={:016X}, passphrase={}", title_id,
+              Common::HexToString(passphrase));
+}
+
+std::optional<std::vector<u8>> Boxcat::GetLaunchParameter(TitleIDVersion title) {
+    const auto path{GetBINFilePath(title.title_id)};
+
+    if (Settings::values.bcat_boxcat_local) {
+        LOG_INFO(Service_BCAT, "Boxcat using local data by override, skipping download.");
+    } else {
+        Boxcat::Client client{path, title.title_id, title.build_id};
+
+        const auto res = client.DownloadLaunchParam();
+        if (res != DownloadResult::Success) {
+            LOG_ERROR(Service_BCAT, "Boxcat synchronization failed with error '{}'!", res);
+
+            if (res == DownloadResult::NoMatchBuildId || res == DownloadResult::NoMatchTitleId) {
+                Common::FS::Delete(path);
+            }
+
+            HandleDownloadDisplayResult(applet_manager, res);
+            return std::nullopt;
+        }
+    }
+
+    Common::FS::IOFile bin{path, "rb"};
+    const auto size = bin.GetSize();
+    std::vector<u8> bytes(size);
+    if (!bin.IsOpen() || size == 0 || bin.ReadBytes(bytes.data(), bytes.size()) != bytes.size()) {
+        LOG_ERROR(Service_BCAT, "Boxcat failed to read launch parameter binary at path '{}'!",
+                  path);
+        return std::nullopt;
+    }
+
+    return bytes;
+}
+
+Boxcat::StatusResult Boxcat::GetStatus(std::optional<std::string>& global,
+                                       std::map<std::string, EventStatus>& games) {
+    httplib::SSLClient client{BOXCAT_HOSTNAME, static_cast<int>(PORT)};
+    client.set_connection_timeout(static_cast<int>(TIMEOUT_SECONDS));
+    client.set_read_timeout(static_cast<int>(TIMEOUT_SECONDS));
+    client.set_write_timeout(static_cast<int>(TIMEOUT_SECONDS));
+
+    httplib::Headers headers{
+        {std::string("Game-Assets-API-Version"), std::string(BOXCAT_API_VERSION)},
+        {std::string("Boxcat-Client-Type"), std::string(BOXCAT_CLIENT_TYPE)},
+    };
+
+    if (!client.is_valid()) {
+        LOG_ERROR(Service_BCAT, "Client is invalid, going offline!");
+        return StatusResult::Offline;
+    }
+
+    if (!client.is_socket_open()) {
+        LOG_ERROR(Service_BCAT, "Failed to open socket, going offline!");
+        return StatusResult::Offline;
+    }
+
+    const auto response = client.Get(BOXCAT_PATHNAME_EVENTS, headers);
+    if (response == nullptr)
+        return StatusResult::Offline;
+
+    if (response->status == static_cast<int>(ResponseStatus::BadClientVersion))
+        return StatusResult::BadClientVersion;
+
+    try {
+        nlohmann::json json = nlohmann::json::parse(response->body);
+
+        if (!json["online"].get<bool>())
+            return StatusResult::Offline;
+
+        if (json["global"].is_null())
+            global = std::nullopt;
+        else
+            global = json["global"].get<std::string>();
+
+        if (json["games"].is_array()) {
+            for (const auto& object : json["games"]) {
+                if (object.is_object() && object.find("name") != object.end()) {
+                    EventStatus detail{};
+                    if (object["header"].is_string()) {
+                        detail.header = object["header"].get<std::string>();
+                    } else {
+                        detail.header = std::nullopt;
+                    }
+
+                    if (object["footer"].is_string()) {
+                        detail.footer = object["footer"].get<std::string>();
+                    } else {
+                        detail.footer = std::nullopt;
+                    }
+
+                    if (object["events"].is_array()) {
+                        for (const auto& event : object["events"]) {
+                            if (!event.is_string())
+                                continue;
+                            detail.events.push_back(event.get<std::string>());
+                        }
+                    }
+
+                    games.insert_or_assign(object["name"], std::move(detail));
+                }
+            }
+        }
+
+        return StatusResult::Success;
+    } catch (const nlohmann::json::parse_error& error) {
+        LOG_ERROR(Service_BCAT, "{}", error.what());
+        return StatusResult::ParseError;
+    }
+}
+
+} // namespace Service::BCAT

src/core/hle/service/bcat/backend/boxcat.h

@@ -0,0 +1,64 @@
+// Copyright 2019 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <atomic>
+#include <map>
+#include <optional>
+#include "core/hle/service/bcat/backend/backend.h"
+
+namespace Service::AM::Applets {
+class AppletManager;
+}
+
+namespace Service::BCAT {
+
+struct EventStatus {
+    std::optional<std::string> header;
+    std::optional<std::string> footer;
+    std::vector<std::string> events;
+};
+
+/// Boxcat is yuzu's custom backend implementation of Nintendo's BCAT service. It is free to use and
+/// doesn't require a switch or nintendo account. The content is controlled by the yuzu team.
+class Boxcat final : public Backend {
+    friend void SynchronizeInternal(AM::Applets::AppletManager& applet_manager,
+                                    DirectoryGetter dir_getter, TitleIDVersion title,
+                                    ProgressServiceBackend& progress,
+                                    std::optional<std::string> dir_name);
+
+public:
+    explicit Boxcat(AM::Applets::AppletManager& applet_manager_, DirectoryGetter getter);
+    ~Boxcat() override;
+
+    bool Synchronize(TitleIDVersion title, ProgressServiceBackend& progress) override;
+    bool SynchronizeDirectory(TitleIDVersion title, std::string name,
+                              ProgressServiceBackend& progress) override;
+
+    bool Clear(u64 title_id) override;
+
+    void SetPassphrase(u64 title_id, const Passphrase& passphrase) override;
+
+    std::optional<std::vector<u8>> GetLaunchParameter(TitleIDVersion title) override;
+
+    enum class StatusResult {
+        Success,
+        Offline,
+        ParseError,
+        BadClientVersion,
+    };
+
+    static StatusResult GetStatus(std::optional<std::string>& global,
+                                  std::map<std::string, EventStatus>& games);
+
+private:
+    std::atomic_bool is_syncing{false};
+
+    class Client;
+    std::unique_ptr<Client> client;
+    AM::Applets::AppletManager& applet_manager;
+};
+
+} // namespace Service::BCAT

src/core/hle/service/bcat/bcat.cpp

@@ -0,0 +1,25 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/hle/service/bcat/bcat.h"
+
+namespace Service::BCAT {
+
+BCAT::BCAT(Core::System& system, std::shared_ptr<Module> module,
+           FileSystem::FileSystemController& fsc, const char* name)
+    : Interface(system, std::move(module), fsc, name) {
+    // clang-format off
+    static const FunctionInfo functions[] = {
+        {0, &BCAT::CreateBcatService, "CreateBcatService"},
+        {1, &BCAT::CreateDeliveryCacheStorageService, "CreateDeliveryCacheStorageService"},
+        {2, &BCAT::CreateDeliveryCacheStorageServiceWithApplicationId, "CreateDeliveryCacheStorageServiceWithApplicationId"},
+        {3, nullptr, "CreateDeliveryCacheProgressService"},
+        {4, nullptr, "CreateDeliveryCacheProgressServiceWithApplicationId"},
+    };
+    // clang-format on
+    RegisterHandlers(functions);
+}
+
+BCAT::~BCAT() = default;
+} // namespace Service::BCAT

src/core/hle/service/bcat/bcat.h

@@ -0,0 +1,22 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/hle/service/bcat/module.h"
+
+namespace Core {
+class System;
+}
+
+namespace Service::BCAT {
+
+class BCAT final : public Module::Interface {
+public:
+    explicit BCAT(Core::System& system, std::shared_ptr<Module> module,
+                  FileSystem::FileSystemController& fsc, const char* name);
+    ~BCAT() override;
+};
+
+} // namespace Service::BCAT

src/core/hle/service/bcat/module.cpp

@@ -0,0 +1,604 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cctype>
+#include <mbedtls/md5.h>
+#include "backend/boxcat.h"
+#include "common/hex_util.h"
+#include "common/logging/log.h"
+#include "common/string_util.h"
+#include "core/core.h"
+#include "core/file_sys/vfs.h"
+#include "core/hle/ipc_helpers.h"
+#include "core/hle/kernel/process.h"
+#include "core/hle/kernel/readable_event.h"
+#include "core/hle/kernel/writable_event.h"
+#include "core/hle/service/bcat/backend/backend.h"
+#include "core/hle/service/bcat/bcat.h"
+#include "core/hle/service/bcat/module.h"
+#include "core/hle/service/filesystem/filesystem.h"
+#include "core/settings.h"
+
+namespace Service::BCAT {
+
+constexpr ResultCode ERROR_INVALID_ARGUMENT{ErrorModule::BCAT, 1};
+constexpr ResultCode ERROR_FAILED_OPEN_ENTITY{ErrorModule::BCAT, 2};
+constexpr ResultCode ERROR_ENTITY_ALREADY_OPEN{ErrorModule::BCAT, 6};
+constexpr ResultCode ERROR_NO_OPEN_ENTITY{ErrorModule::BCAT, 7};
+
+// The command to clear the delivery cache just calls fs IFileSystem DeleteFile on all of the files
+// and if any of them have a non-zero result it just forwards that result. This is the FS error code
+// for permission denied, which is the closest approximation of this scenario.
+constexpr ResultCode ERROR_FAILED_CLEAR_CACHE{ErrorModule::FS, 6400};
+
+using BCATDigest = std::array<u8, 0x10>;
+
+namespace {
+
+u64 GetCurrentBuildID(const Core::System::CurrentBuildProcessID& id) {
+    u64 out{};
+    std::memcpy(&out, id.data(), sizeof(u64));
+    return out;
+}
+
+// The digest is only used to determine if a file is unique compared to others of the same name.
+// Since the algorithm isn't ever checked in game, MD5 is safe.
+BCATDigest DigestFile(const FileSys::VirtualFile& file) {
+    BCATDigest out{};
+    const auto bytes = file->ReadAllBytes();
+    mbedtls_md5_ret(bytes.data(), bytes.size(), out.data());
+    return out;
+}
+
+// For a name to be valid it must be non-empty, must have a null terminating character as the final
+// char, can only contain numbers, letters, underscores and a hyphen if directory and a period if
+// file.
+bool VerifyNameValidInternal(Kernel::HLERequestContext& ctx, std::array<char, 0x20> name,
+                             char match_char) {
+    const auto null_chars = std::count(name.begin(), name.end(), 0);
+    const auto bad_chars = std::count_if(name.begin(), name.end(), [match_char](char c) {
+        return !std::isalnum(static_cast<u8>(c)) && c != '_' && c != match_char && c != '\0';
+    });
+    if (null_chars == 0x20 || null_chars == 0 || bad_chars != 0 || name[0x1F] != '\0') {
+        LOG_ERROR(Service_BCAT, "Name passed was invalid!");
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ERROR_INVALID_ARGUMENT);
+        return false;
+    }
+
+    return true;
+}
+
+bool VerifyNameValidDir(Kernel::HLERequestContext& ctx, DirectoryName name) {
+    return VerifyNameValidInternal(ctx, name, '-');
+}
+
+bool VerifyNameValidFile(Kernel::HLERequestContext& ctx, FileName name) {
+    return VerifyNameValidInternal(ctx, name, '.');
+}
+
+} // Anonymous namespace
+
+struct DeliveryCacheDirectoryEntry {
+    FileName name;
+    u64 size;
+    BCATDigest digest;
+};
+
+class IDeliveryCacheProgressService final : public ServiceFramework<IDeliveryCacheProgressService> {
+public:
+    explicit IDeliveryCacheProgressService(Core::System& system_,
+                                           std::shared_ptr<Kernel::ReadableEvent> event_,
+                                           const DeliveryCacheProgressImpl& impl_)
+        : ServiceFramework{system_, "IDeliveryCacheProgressService"}, event{std::move(event_)},
+          impl{impl_} {
+        // clang-format off
+        static const FunctionInfo functions[] = {
+            {0, &IDeliveryCacheProgressService::GetEvent, "GetEvent"},
+            {1, &IDeliveryCacheProgressService::GetImpl, "GetImpl"},
+        };
+        // clang-format on
+
+        RegisterHandlers(functions);
+    }
+
+private:
+    void GetEvent(Kernel::HLERequestContext& ctx) {
+        LOG_DEBUG(Service_BCAT, "called");
+
+        IPC::ResponseBuilder rb{ctx, 2, 1};
+        rb.Push(RESULT_SUCCESS);
+        rb.PushCopyObjects(event);
+    }
+
+    void GetImpl(Kernel::HLERequestContext& ctx) {
+        LOG_DEBUG(Service_BCAT, "called");
+
+        ctx.WriteBuffer(impl);
+
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(RESULT_SUCCESS);
+    }
+
+    std::shared_ptr<Kernel::ReadableEvent> event;
+    const DeliveryCacheProgressImpl& impl;
+};
+
+class IBcatService final : public ServiceFramework<IBcatService> {
+public:
+    explicit IBcatService(Core::System& system_, Backend& backend_)
+        : ServiceFramework{system_, "IBcatService"}, backend{backend_},
+          progress{{
+              ProgressServiceBackend{system_.Kernel(), "Normal"},
+              ProgressServiceBackend{system_.Kernel(), "Directory"},
+          }} {
+        // clang-format off
+        static const FunctionInfo functions[] = {
+            {10100, &IBcatService::RequestSyncDeliveryCache, "RequestSyncDeliveryCache"},
+            {10101, &IBcatService::RequestSyncDeliveryCacheWithDirectoryName, "RequestSyncDeliveryCacheWithDirectoryName"},
+            {10200, nullptr, "CancelSyncDeliveryCacheRequest"},
+            {20100, nullptr, "RequestSyncDeliveryCacheWithApplicationId"},
+            {20101, nullptr, "RequestSyncDeliveryCacheWithApplicationIdAndDirectoryName"},
+            {20300, nullptr, "GetDeliveryCacheStorageUpdateNotifier"},
+            {20301, nullptr, "RequestSuspendDeliveryTask"},
+            {20400, nullptr, "RegisterSystemApplicationDeliveryTask"},
+            {20401, nullptr, "UnregisterSystemApplicationDeliveryTask"},
+            {20410, nullptr, "SetSystemApplicationDeliveryTaskTimer"},
+            {30100, &IBcatService::SetPassphrase, "SetPassphrase"},
+            {30101, nullptr, "Unknown"},
+            {30102, nullptr, "Unknown2"},
+            {30200, nullptr, "RegisterBackgroundDeliveryTask"},
+            {30201, nullptr, "UnregisterBackgroundDeliveryTask"},
+            {30202, nullptr, "BlockDeliveryTask"},
+            {30203, nullptr, "UnblockDeliveryTask"},
+            {30210, nullptr, "SetDeliveryTaskTimer"},
+            {30300, nullptr, "RegisterSystemApplicationDeliveryTasks"},
+            {90100, nullptr, "EnumerateBackgroundDeliveryTask"},
+            {90200, nullptr, "GetDeliveryList"},
+            {90201, &IBcatService::ClearDeliveryCacheStorage, "ClearDeliveryCacheStorage"},
+            {90202, nullptr, "ClearDeliveryTaskSubscriptionStatus"},
+            {90300, nullptr, "GetPushNotificationLog"},
+        };
+        // clang-format on
+        RegisterHandlers(functions);
+    }
+
+private:
+    enum class SyncType {
+        Normal,
+        Directory,
+        Count,
+    };
+
+    std::shared_ptr<IDeliveryCacheProgressService> CreateProgressService(SyncType type) {
+        auto& backend{progress.at(static_cast<std::size_t>(type))};
+        return std::make_shared<IDeliveryCacheProgressService>(system, backend.GetEvent(),
+                                                               backend.GetImpl());
+    }
+
+    void RequestSyncDeliveryCache(Kernel::HLERequestContext& ctx) {
+        LOG_DEBUG(Service_BCAT, "called");
+
+        backend.Synchronize({system.CurrentProcess()->GetTitleID(),
+                             GetCurrentBuildID(system.GetCurrentProcessBuildID())},
+                            progress.at(static_cast<std::size_t>(SyncType::Normal)));
+
+        IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+        rb.Push(RESULT_SUCCESS);
+        rb.PushIpcInterface(CreateProgressService(SyncType::Normal));
+    }
+
+    void RequestSyncDeliveryCacheWithDirectoryName(Kernel::HLERequestContext& ctx) {
+        IPC::RequestParser rp{ctx};
+        const auto name_raw = rp.PopRaw<DirectoryName>();
+        const auto name =
+            Common::StringFromFixedZeroTerminatedBuffer(name_raw.data(), name_raw.size());
+
+        LOG_DEBUG(Service_BCAT, "called, name={}", name);
+
+        backend.SynchronizeDirectory({system.CurrentProcess()->GetTitleID(),
+                                      GetCurrentBuildID(system.GetCurrentProcessBuildID())},
+                                     name,
+                                     progress.at(static_cast<std::size_t>(SyncType::Directory)));
+
+        IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+        rb.Push(RESULT_SUCCESS);
+        rb.PushIpcInterface(CreateProgressService(SyncType::Directory));
+    }
+
+    void SetPassphrase(Kernel::HLERequestContext& ctx) {
+        IPC::RequestParser rp{ctx};
+        const auto title_id = rp.PopRaw<u64>();
+
+        const auto passphrase_raw = ctx.ReadBuffer();
+
+        LOG_DEBUG(Service_BCAT, "called, title_id={:016X}, passphrase={}", title_id,
+                  Common::HexToString(passphrase_raw));
+
+        if (title_id == 0) {
+            LOG_ERROR(Service_BCAT, "Invalid title ID!");
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_INVALID_ARGUMENT);
+        }
+
+        if (passphrase_raw.size() > 0x40) {
+            LOG_ERROR(Service_BCAT, "Passphrase too large!");
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_INVALID_ARGUMENT);
+            return;
+        }
+
+        Passphrase passphrase{};
+        std::memcpy(passphrase.data(), passphrase_raw.data(),
+                    std::min(passphrase.size(), passphrase_raw.size()));
+
+        backend.SetPassphrase(title_id, passphrase);
+
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(RESULT_SUCCESS);
+    }
+
+    void ClearDeliveryCacheStorage(Kernel::HLERequestContext& ctx) {
+        IPC::RequestParser rp{ctx};
+        const auto title_id = rp.PopRaw<u64>();
+
+        LOG_DEBUG(Service_BCAT, "called, title_id={:016X}", title_id);
+
+        if (title_id == 0) {
+            LOG_ERROR(Service_BCAT, "Invalid title ID!");
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_INVALID_ARGUMENT);
+            return;
+        }
+
+        if (!backend.Clear(title_id)) {
+            LOG_ERROR(Service_BCAT, "Could not clear the directory successfully!");
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_FAILED_CLEAR_CACHE);
+            return;
+        }
+
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(RESULT_SUCCESS);
+    }
+
+    Backend& backend;
+
+    std::array<ProgressServiceBackend, static_cast<std::size_t>(SyncType::Count)> progress;
+};
+
+void Module::Interface::CreateBcatService(Kernel::HLERequestContext& ctx) {
+    LOG_DEBUG(Service_BCAT, "called");
+
+    IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+    rb.Push(RESULT_SUCCESS);
+    rb.PushIpcInterface<IBcatService>(system, *backend);
+}
+
+class IDeliveryCacheFileService final : public ServiceFramework<IDeliveryCacheFileService> {
+public:
+    explicit IDeliveryCacheFileService(Core::System& system_, FileSys::VirtualDir root_)
+        : ServiceFramework{system_, "IDeliveryCacheFileService"}, root(std::move(root_)) {
+        // clang-format off
+        static const FunctionInfo functions[] = {
+            {0, &IDeliveryCacheFileService::Open, "Open"},
+            {1, &IDeliveryCacheFileService::Read, "Read"},
+            {2, &IDeliveryCacheFileService::GetSize, "GetSize"},
+            {3, &IDeliveryCacheFileService::GetDigest, "GetDigest"},
+        };
+        // clang-format on
+
+        RegisterHandlers(functions);
+    }
+
+private:
+    void Open(Kernel::HLERequestContext& ctx) {
+        IPC::RequestParser rp{ctx};
+        const auto dir_name_raw = rp.PopRaw<DirectoryName>();
+        const auto file_name_raw = rp.PopRaw<FileName>();
+
+        const auto dir_name =
+            Common::StringFromFixedZeroTerminatedBuffer(dir_name_raw.data(), dir_name_raw.size());
+        const auto file_name =
+            Common::StringFromFixedZeroTerminatedBuffer(file_name_raw.data(), file_name_raw.size());
+
+        LOG_DEBUG(Service_BCAT, "called, dir_name={}, file_name={}", dir_name, file_name);
+
+        if (!VerifyNameValidDir(ctx, dir_name_raw) || !VerifyNameValidFile(ctx, file_name_raw))
+            return;
+
+        if (current_file != nullptr) {
+            LOG_ERROR(Service_BCAT, "A file has already been opened on this interface!");
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_ENTITY_ALREADY_OPEN);
+            return;
+        }
+
+        const auto dir = root->GetSubdirectory(dir_name);
+
+        if (dir == nullptr) {
+            LOG_ERROR(Service_BCAT, "The directory of name={} couldn't be opened!", dir_name);
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_FAILED_OPEN_ENTITY);
+            return;
+        }
+
+        current_file = dir->GetFile(file_name);
+
+        if (current_file == nullptr) {
+            LOG_ERROR(Service_BCAT, "The file of name={} couldn't be opened!", file_name);
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_FAILED_OPEN_ENTITY);
+            return;
+        }
+
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(RESULT_SUCCESS);
+    }
+
+    void Read(Kernel::HLERequestContext& ctx) {
+        IPC::RequestParser rp{ctx};
+        const auto offset{rp.PopRaw<u64>()};
+
+        auto size = ctx.GetWriteBufferSize();
+
+        LOG_DEBUG(Service_BCAT, "called, offset={:016X}, size={:016X}", offset, size);
+
+        if (current_file == nullptr) {
+            LOG_ERROR(Service_BCAT, "There is no file currently open!");
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_NO_OPEN_ENTITY);
+        }
+
+        size = std::min<u64>(current_file->GetSize() - offset, size);
+        const auto buffer = current_file->ReadBytes(size, offset);
+        ctx.WriteBuffer(buffer);
+
+        IPC::ResponseBuilder rb{ctx, 4};
+        rb.Push(RESULT_SUCCESS);
+        rb.Push<u64>(buffer.size());
+    }
+
+    void GetSize(Kernel::HLERequestContext& ctx) {
+        LOG_DEBUG(Service_BCAT, "called");
+
+        if (current_file == nullptr) {
+            LOG_ERROR(Service_BCAT, "There is no file currently open!");
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_NO_OPEN_ENTITY);
+        }
+
+        IPC::ResponseBuilder rb{ctx, 4};
+        rb.Push(RESULT_SUCCESS);
+        rb.Push<u64>(current_file->GetSize());
+    }
+
+    void GetDigest(Kernel::HLERequestContext& ctx) {
+        LOG_DEBUG(Service_BCAT, "called");
+
+        if (current_file == nullptr) {
+            LOG_ERROR(Service_BCAT, "There is no file currently open!");
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_NO_OPEN_ENTITY);
+        }
+
+        IPC::ResponseBuilder rb{ctx, 6};
+        rb.Push(RESULT_SUCCESS);
+        rb.PushRaw(DigestFile(current_file));
+    }
+
+    FileSys::VirtualDir root;
+    FileSys::VirtualFile current_file;
+};
+
+class IDeliveryCacheDirectoryService final
+    : public ServiceFramework<IDeliveryCacheDirectoryService> {
+public:
+    explicit IDeliveryCacheDirectoryService(Core::System& system_, FileSys::VirtualDir root_)
+        : ServiceFramework{system_, "IDeliveryCacheDirectoryService"}, root(std::move(root_)) {
+        // clang-format off
+        static const FunctionInfo functions[] = {
+            {0, &IDeliveryCacheDirectoryService::Open, "Open"},
+            {1, &IDeliveryCacheDirectoryService::Read, "Read"},
+            {2, &IDeliveryCacheDirectoryService::GetCount, "GetCount"},
+        };
+        // clang-format on
+
+        RegisterHandlers(functions);
+    }
+
+private:
+    void Open(Kernel::HLERequestContext& ctx) {
+        IPC::RequestParser rp{ctx};
+        const auto name_raw = rp.PopRaw<DirectoryName>();
+        const auto name =
+            Common::StringFromFixedZeroTerminatedBuffer(name_raw.data(), name_raw.size());
+
+        LOG_DEBUG(Service_BCAT, "called, name={}", name);
+
+        if (!VerifyNameValidDir(ctx, name_raw))
+            return;
+
+        if (current_dir != nullptr) {
+            LOG_ERROR(Service_BCAT, "A file has already been opened on this interface!");
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_ENTITY_ALREADY_OPEN);
+            return;
+        }
+
+        current_dir = root->GetSubdirectory(name);
+
+        if (current_dir == nullptr) {
+            LOG_ERROR(Service_BCAT, "Failed to open the directory name={}!", name);
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_FAILED_OPEN_ENTITY);
+            return;
+        }
+
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(RESULT_SUCCESS);
+    }
+
+    void Read(Kernel::HLERequestContext& ctx) {
+        auto write_size = ctx.GetWriteBufferSize() / sizeof(DeliveryCacheDirectoryEntry);
+
+        LOG_DEBUG(Service_BCAT, "called, write_size={:016X}", write_size);
+
+        if (current_dir == nullptr) {
+            LOG_ERROR(Service_BCAT, "There is no open directory!");
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_NO_OPEN_ENTITY);
+            return;
+        }
+
+        const auto files = current_dir->GetFiles();
+        write_size = std::min<u64>(write_size, files.size());
+        std::vector<DeliveryCacheDirectoryEntry> entries(write_size);
+        std::transform(
+            files.begin(), files.begin() + write_size, entries.begin(), [](const auto& file) {
+                FileName name{};
+                std::memcpy(name.data(), file->GetName().data(),
+                            std::min(file->GetName().size(), name.size()));
+                return DeliveryCacheDirectoryEntry{name, file->GetSize(), DigestFile(file)};
+            });
+
+        ctx.WriteBuffer(entries);
+
+        IPC::ResponseBuilder rb{ctx, 3};
+        rb.Push(RESULT_SUCCESS);
+        rb.Push(static_cast<u32>(write_size * sizeof(DeliveryCacheDirectoryEntry)));
+    }
+
+    void GetCount(Kernel::HLERequestContext& ctx) {
+        LOG_DEBUG(Service_BCAT, "called");
+
+        if (current_dir == nullptr) {
+            LOG_ERROR(Service_BCAT, "There is no open directory!");
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(ERROR_NO_OPEN_ENTITY);
+            return;
+        }
+
+        const auto files = current_dir->GetFiles();
+
+        IPC::ResponseBuilder rb{ctx, 3};
+        rb.Push(RESULT_SUCCESS);
+        rb.Push(static_cast<u32>(files.size()));
+    }
+
+    FileSys::VirtualDir root;
+    FileSys::VirtualDir current_dir;
+};
+
+class IDeliveryCacheStorageService final : public ServiceFramework<IDeliveryCacheStorageService> {
+public:
+    explicit IDeliveryCacheStorageService(Core::System& system_, FileSys::VirtualDir root_)
+        : ServiceFramework{system_, "IDeliveryCacheStorageService"}, root(std::move(root_)) {
+        // clang-format off
+        static const FunctionInfo functions[] = {
+            {0, &IDeliveryCacheStorageService::CreateFileService, "CreateFileService"},
+            {1, &IDeliveryCacheStorageService::CreateDirectoryService, "CreateDirectoryService"},
+            {10, &IDeliveryCacheStorageService::EnumerateDeliveryCacheDirectory, "EnumerateDeliveryCacheDirectory"},
+        };
+        // clang-format on
+
+        RegisterHandlers(functions);
+
+        for (const auto& subdir : root->GetSubdirectories()) {
+            DirectoryName name{};
+            std::memcpy(name.data(), subdir->GetName().data(),
+                        std::min(sizeof(DirectoryName) - 1, subdir->GetName().size()));
+            entries.push_back(name);
+        }
+    }
+
+private:
+    void CreateFileService(Kernel::HLERequestContext& ctx) {
+        LOG_DEBUG(Service_BCAT, "called");
+
+        IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+        rb.Push(RESULT_SUCCESS);
+        rb.PushIpcInterface<IDeliveryCacheFileService>(system, root);
+    }
+
+    void CreateDirectoryService(Kernel::HLERequestContext& ctx) {
+        LOG_DEBUG(Service_BCAT, "called");
+
+        IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+        rb.Push(RESULT_SUCCESS);
+        rb.PushIpcInterface<IDeliveryCacheDirectoryService>(system, root);
+    }
+
+    void EnumerateDeliveryCacheDirectory(Kernel::HLERequestContext& ctx) {
+        auto size = ctx.GetWriteBufferSize() / sizeof(DirectoryName);
+
+        LOG_DEBUG(Service_BCAT, "called, size={:016X}", size);
+
+        size = std::min<u64>(size, entries.size() - next_read_index);
+        ctx.WriteBuffer(entries.data() + next_read_index, size * sizeof(DirectoryName));
+        next_read_index += size;
+
+        IPC::ResponseBuilder rb{ctx, 3};
+        rb.Push(RESULT_SUCCESS);
+        rb.Push(static_cast<u32>(size));
+    }
+
+    FileSys::VirtualDir root;
+    std::vector<DirectoryName> entries;
+    u64 next_read_index = 0;
+};
+
+void Module::Interface::CreateDeliveryCacheStorageService(Kernel::HLERequestContext& ctx) {
+    LOG_DEBUG(Service_BCAT, "called");
+
+    const auto title_id = system.CurrentProcess()->GetTitleID();
+    IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+    rb.Push(RESULT_SUCCESS);
+    rb.PushIpcInterface<IDeliveryCacheStorageService>(system, fsc.GetBCATDirectory(title_id));
+}
+
+void Module::Interface::CreateDeliveryCacheStorageServiceWithApplicationId(
+    Kernel::HLERequestContext& ctx) {
+    IPC::RequestParser rp{ctx};
+    const auto title_id = rp.PopRaw<u64>();
+
+    LOG_DEBUG(Service_BCAT, "called, title_id={:016X}", title_id);
+
+    IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+    rb.Push(RESULT_SUCCESS);
+    rb.PushIpcInterface<IDeliveryCacheStorageService>(system, fsc.GetBCATDirectory(title_id));
+}
+
+std::unique_ptr<Backend> CreateBackendFromSettings([[maybe_unused]] Core::System& system,
+                                                   DirectoryGetter getter) {
+#ifdef YUZU_ENABLE_BOXCAT
+    if (Settings::values.bcat_backend == "boxcat") {
+        return std::make_unique<Boxcat>(system.GetAppletManager(), std::move(getter));
+    }
+#endif
+
+    return std::make_unique<NullBackend>(std::move(getter));
+}
+
+Module::Interface::Interface(Core::System& system_, std::shared_ptr<Module> module_,
+                             FileSystem::FileSystemController& fsc_, const char* name)
+    : ServiceFramework{system_, name}, fsc{fsc_}, module{std::move(module_)},
+      backend{CreateBackendFromSettings(system_,
+                                        [&fsc_](u64 tid) { return fsc_.GetBCATDirectory(tid); })} {}
+
+Module::Interface::~Interface() = default;
+
+void InstallInterfaces(Core::System& system) {
+    auto module = std::make_shared<Module>();
+    std::make_shared<BCAT>(system, module, system.GetFileSystemController(), "bcat:a")
+        ->InstallAsService(system.ServiceManager());
+    std::make_shared<BCAT>(system, module, system.GetFileSystemController(), "bcat:m")
+        ->InstallAsService(system.ServiceManager());
+    std::make_shared<BCAT>(system, module, system.GetFileSystemController(), "bcat:u")
+        ->InstallAsService(system.ServiceManager());
+    std::make_shared<BCAT>(system, module, system.GetFileSystemController(), "bcat:s")
+        ->InstallAsService(system.ServiceManager());
+}
+
+} // namespace Service::BCAT

src/core/hle/service/bcat/module.h

@@ -0,0 +1,48 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/hle/service/service.h"
+
+namespace Core {
+class System;
+}
+
+namespace Service {
+
+namespace FileSystem {
+class FileSystemController;
+} // namespace FileSystem
+
+namespace BCAT {
+
+class Backend;
+
+class Module final {
+public:
+    class Interface : public ServiceFramework<Interface> {
+    public:
+        explicit Interface(Core::System& system_, std::shared_ptr<Module> module_,
+                           FileSystem::FileSystemController& fsc_, const char* name);
+        ~Interface() override;
+
+        void CreateBcatService(Kernel::HLERequestContext& ctx);
+        void CreateDeliveryCacheStorageService(Kernel::HLERequestContext& ctx);
+        void CreateDeliveryCacheStorageServiceWithApplicationId(Kernel::HLERequestContext& ctx);
+
+    protected:
+        FileSystem::FileSystemController& fsc;
+
+        std::shared_ptr<Module> module;
+        std::unique_ptr<Backend> backend;
+    };
+};
+
+/// Registers all BCAT services with the specified service manager.
+void InstallInterfaces(Core::System& system);
+
+} // namespace BCAT
+
+} // namespace Service