Initial Commit

src/web_service/CMakeLists.txt

@@ -0,0 +1,24 @@
+# SPDX-FileCopyrightText: 2018 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+add_library(web_service STATIC
+    announce_room_json.cpp
+    announce_room_json.h
+    precompiled_headers.h
+    telemetry_json.cpp
+    telemetry_json.h
+    verify_login.cpp
+    verify_login.h
+    verify_user_jwt.cpp
+    verify_user_jwt.h
+    web_backend.cpp
+    web_backend.h
+    web_result.h
+)
+
+create_target_directory_groups(web_service)
+target_link_libraries(web_service PRIVATE common network nlohmann_json::nlohmann_json httplib::httplib cpp-jwt::cpp-jwt)
+
+if (YUZU_USE_PRECOMPILED_HEADERS)
+    target_precompile_headers(web_service PRIVATE precompiled_headers.h)
+endif()

src/web_service/announce_room_json.cpp

@@ -0,0 +1,145 @@
+// SPDX-FileCopyrightText: Copyright 2017 Citra Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <future>
+#include <nlohmann/json.hpp>
+#include "common/detached_tasks.h"
+#include "common/logging/log.h"
+#include "web_service/announce_room_json.h"
+#include "web_service/web_backend.h"
+
+namespace AnnounceMultiplayerRoom {
+
+static void to_json(nlohmann::json& json, const Member& member) {
+    if (!member.username.empty()) {
+        json["username"] = member.username;
+    }
+    json["nickname"] = member.nickname;
+    if (!member.avatar_url.empty()) {
+        json["avatarUrl"] = member.avatar_url;
+    }
+    json["gameName"] = member.game.name;
+    json["gameId"] = member.game.id;
+}
+
+static void from_json(const nlohmann::json& json, Member& member) {
+    member.nickname = json.at("nickname").get<std::string>();
+    member.game.name = json.at("gameName").get<std::string>();
+    member.game.id = json.at("gameId").get<u64>();
+    try {
+        member.username = json.at("username").get<std::string>();
+        member.avatar_url = json.at("avatarUrl").get<std::string>();
+    } catch (const nlohmann::detail::out_of_range&) {
+        member.username = member.avatar_url = "";
+        LOG_DEBUG(Network, "Member \'{}\' isn't authenticated", member.nickname);
+    }
+}
+
+static void to_json(nlohmann::json& json, const Room& room) {
+    json["port"] = room.information.port;
+    json["name"] = room.information.name;
+    if (!room.information.description.empty()) {
+        json["description"] = room.information.description;
+    }
+    json["preferredGameName"] = room.information.preferred_game.name;
+    json["preferredGameId"] = room.information.preferred_game.id;
+    json["maxPlayers"] = room.information.member_slots;
+    json["netVersion"] = room.net_version;
+    json["hasPassword"] = room.has_password;
+    if (room.members.size() > 0) {
+        nlohmann::json member_json = room.members;
+        json["players"] = member_json;
+    }
+}
+
+static void from_json(const nlohmann::json& json, Room& room) {
+    room.verify_uid = json.at("externalGuid").get<std::string>();
+    room.ip = json.at("address").get<std::string>();
+    room.information.name = json.at("name").get<std::string>();
+    try {
+        room.information.description = json.at("description").get<std::string>();
+    } catch (const nlohmann::detail::out_of_range&) {
+        room.information.description = "";
+        LOG_DEBUG(Network, "Room \'{}\' doesn't contain a description", room.information.name);
+    }
+    room.information.host_username = json.at("owner").get<std::string>();
+    room.information.port = json.at("port").get<u16>();
+    room.information.preferred_game.name = json.at("preferredGameName").get<std::string>();
+    room.information.preferred_game.id = json.at("preferredGameId").get<u64>();
+    room.information.member_slots = json.at("maxPlayers").get<u32>();
+    room.net_version = json.at("netVersion").get<u32>();
+    room.has_password = json.at("hasPassword").get<bool>();
+    try {
+        room.members = json.at("players").get<std::vector<Member>>();
+    } catch (const nlohmann::detail::out_of_range& e) {
+        LOG_DEBUG(Network, "Out of range {}", e.what());
+    }
+}
+
+} // namespace AnnounceMultiplayerRoom
+
+namespace WebService {
+
+void RoomJson::SetRoomInformation(const std::string& name, const std::string& description,
+                                  const u16 port, const u32 max_player, const u32 net_version,
+                                  const bool has_password,
+                                  const AnnounceMultiplayerRoom::GameInfo& preferred_game) {
+    room.information.name = name;
+    room.information.description = description;
+    room.information.port = port;
+    room.information.member_slots = max_player;
+    room.net_version = net_version;
+    room.has_password = has_password;
+    room.information.preferred_game = preferred_game;
+}
+void RoomJson::AddPlayer(const AnnounceMultiplayerRoom::Member& member) {
+    room.members.push_back(member);
+}
+
+WebService::WebResult RoomJson::Update() {
+    if (room_id.empty()) {
+        LOG_ERROR(WebService, "Room must be registered to be updated");
+        return WebService::WebResult{WebService::WebResult::Code::LibError,
+                                     "Room is not registered", ""};
+    }
+    nlohmann::json json{{"players", room.members}};
+    return client.PostJson(fmt::format("/lobby/{}", room_id), json.dump(), false);
+}
+
+WebService::WebResult RoomJson::Register() {
+    nlohmann::json json = room;
+    auto result = client.PostJson("/lobby", json.dump(), false);
+    if (result.result_code != WebService::WebResult::Code::Success) {
+        return result;
+    }
+    auto reply_json = nlohmann::json::parse(result.returned_data);
+    room = reply_json.get<AnnounceMultiplayerRoom::Room>();
+    room_id = reply_json.at("id").get<std::string>();
+    return WebService::WebResult{WebService::WebResult::Code::Success, "", room.verify_uid};
+}
+
+void RoomJson::ClearPlayers() {
+    room.members.clear();
+}
+
+AnnounceMultiplayerRoom::RoomList RoomJson::GetRoomList() {
+    auto reply = client.GetJson("/lobby", true).returned_data;
+    if (reply.empty()) {
+        return {};
+    }
+    return nlohmann::json::parse(reply).at("rooms").get<AnnounceMultiplayerRoom::RoomList>();
+}
+
+void RoomJson::Delete() {
+    if (room_id.empty()) {
+        LOG_ERROR(WebService, "Room must be registered to be deleted");
+        return;
+    }
+    Common::DetachedTasks::AddTask([host_{this->host}, username_{this->username},
+                                    token_{this->token}, room_id_{this->room_id}]() {
+        // create a new client here because the this->client might be destroyed.
+        Client{host_, username_, token_}.DeleteJson(fmt::format("/lobby/{}", room_id_), "", false);
+    });
+}
+
+} // namespace WebService

src/web_service/announce_room_json.h

@@ -0,0 +1,41 @@
+// SPDX-FileCopyrightText: Copyright 2017 Citra Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <functional>
+#include <string>
+#include "common/announce_multiplayer_room.h"
+#include "web_service/web_backend.h"
+
+namespace WebService {
+
+/**
+ * Implementation of AnnounceMultiplayerRoom::Backend that (de)serializes room information into/from
+ * JSON, and submits/gets it to/from the yuzu web service
+ */
+class RoomJson : public AnnounceMultiplayerRoom::Backend {
+public:
+    RoomJson(const std::string& host_, const std::string& username_, const std::string& token_)
+        : client(host_, username_, token_), host(host_), username(username_), token(token_) {}
+    ~RoomJson() = default;
+    void SetRoomInformation(const std::string& name, const std::string& description, const u16 port,
+                            const u32 max_player, const u32 net_version, const bool has_password,
+                            const AnnounceMultiplayerRoom::GameInfo& preferred_game) override;
+    void AddPlayer(const AnnounceMultiplayerRoom::Member& member) override;
+    WebResult Update() override;
+    WebResult Register() override;
+    void ClearPlayers() override;
+    AnnounceMultiplayerRoom::RoomList GetRoomList() override;
+    void Delete() override;
+
+private:
+    AnnounceMultiplayerRoom::Room room;
+    Client client;
+    std::string host;
+    std::string username;
+    std::string token;
+    std::string room_id;
+};
+
+} // namespace WebService

src/web_service/precompiled_headers.h

@@ -0,0 +1,6 @@
+// SPDX-FileCopyrightText: 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "common/common_precompiled_headers.h"

src/web_service/telemetry_json.cpp

@@ -0,0 +1,130 @@
+// SPDX-FileCopyrightText: 2017 Citra Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <nlohmann/json.hpp>
+#include "common/detached_tasks.h"
+#include "web_service/telemetry_json.h"
+#include "web_service/web_backend.h"
+#include "web_service/web_result.h"
+
+namespace WebService {
+
+namespace Telemetry = Common::Telemetry;
+
+struct TelemetryJson::Impl {
+    Impl(std::string host_, std::string username_, std::string token_)
+        : host{std::move(host_)}, username{std::move(username_)}, token{std::move(token_)} {}
+
+    nlohmann::json& TopSection() {
+        return sections[static_cast<u8>(Telemetry::FieldType::None)];
+    }
+
+    const nlohmann::json& TopSection() const {
+        return sections[static_cast<u8>(Telemetry::FieldType::None)];
+    }
+
+    template <class T>
+    void Serialize(Telemetry::FieldType type, const std::string& name, T value) {
+        sections[static_cast<u8>(type)][name] = value;
+    }
+
+    void SerializeSection(Telemetry::FieldType type, const std::string& name) {
+        TopSection()[name] = sections[static_cast<unsigned>(type)];
+    }
+
+    nlohmann::json output;
+    std::array<nlohmann::json, 7> sections;
+    std::string host;
+    std::string username;
+    std::string token;
+};
+
+TelemetryJson::TelemetryJson(std::string host, std::string username, std::string token)
+    : impl{std::make_unique<Impl>(std::move(host), std::move(username), std::move(token))} {}
+TelemetryJson::~TelemetryJson() = default;
+
+void TelemetryJson::Visit(const Telemetry::Field<bool>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<double>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<float>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<u8>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<u16>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<u32>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<u64>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<s8>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<s16>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<s32>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<s64>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<std::string>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue());
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<const char*>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), std::string(field.GetValue()));
+}
+
+void TelemetryJson::Visit(const Telemetry::Field<std::chrono::microseconds>& field) {
+    impl->Serialize(field.GetType(), field.GetName(), field.GetValue().count());
+}
+
+void TelemetryJson::Complete() {
+    impl->SerializeSection(Telemetry::FieldType::App, "App");
+    impl->SerializeSection(Telemetry::FieldType::Session, "Session");
+    impl->SerializeSection(Telemetry::FieldType::Performance, "Performance");
+    impl->SerializeSection(Telemetry::FieldType::UserConfig, "UserConfig");
+    impl->SerializeSection(Telemetry::FieldType::UserSystem, "UserSystem");
+
+    auto content = impl->TopSection().dump();
+    // Send the telemetry async but don't handle the errors since they were written to the log
+    Common::DetachedTasks::AddTask([host{impl->host}, content]() {
+        Client{host, "", ""}.PostJson("/telemetry", content, true);
+    });
+}
+
+bool TelemetryJson::SubmitTestcase() {
+    impl->SerializeSection(Telemetry::FieldType::App, "App");
+    impl->SerializeSection(Telemetry::FieldType::Session, "Session");
+    impl->SerializeSection(Telemetry::FieldType::UserFeedback, "UserFeedback");
+    impl->SerializeSection(Telemetry::FieldType::UserSystem, "UserSystem");
+    impl->SerializeSection(Telemetry::FieldType::UserConfig, "UserConfig");
+
+    auto content = impl->TopSection().dump();
+    Client client(impl->host, impl->username, impl->token);
+    auto value = client.PostJson("/gamedb/testcase", content, false);
+
+    return value.result_code == WebResult::Code::Success;
+}
+
+} // namespace WebService

src/web_service/telemetry_json.h

@@ -0,0 +1,44 @@
+// SPDX-FileCopyrightText: 2017 Citra Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <chrono>
+#include <string>
+#include "common/telemetry.h"
+
+namespace WebService {
+
+/**
+ * Implementation of VisitorInterface that serialized telemetry into JSON, and submits it to the
+ * yuzu web service
+ */
+class TelemetryJson : public Common::Telemetry::VisitorInterface {
+public:
+    TelemetryJson(std::string host, std::string username, std::string token);
+    ~TelemetryJson() override;
+
+    void Visit(const Common::Telemetry::Field<bool>& field) override;
+    void Visit(const Common::Telemetry::Field<double>& field) override;
+    void Visit(const Common::Telemetry::Field<float>& field) override;
+    void Visit(const Common::Telemetry::Field<u8>& field) override;
+    void Visit(const Common::Telemetry::Field<u16>& field) override;
+    void Visit(const Common::Telemetry::Field<u32>& field) override;
+    void Visit(const Common::Telemetry::Field<u64>& field) override;
+    void Visit(const Common::Telemetry::Field<s8>& field) override;
+    void Visit(const Common::Telemetry::Field<s16>& field) override;
+    void Visit(const Common::Telemetry::Field<s32>& field) override;
+    void Visit(const Common::Telemetry::Field<s64>& field) override;
+    void Visit(const Common::Telemetry::Field<std::string>& field) override;
+    void Visit(const Common::Telemetry::Field<const char*>& field) override;
+    void Visit(const Common::Telemetry::Field<std::chrono::microseconds>& field) override;
+
+    void Complete() override;
+    bool SubmitTestcase() override;
+
+private:
+    struct Impl;
+    std::unique_ptr<Impl> impl;
+};
+
+} // namespace WebService

src/web_service/verify_login.cpp

@@ -0,0 +1,27 @@
+// SPDX-FileCopyrightText: 2017 Citra Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <nlohmann/json.hpp>
+#include "web_service/verify_login.h"
+#include "web_service/web_backend.h"
+#include "web_service/web_result.h"
+
+namespace WebService {
+
+bool VerifyLogin(const std::string& host, const std::string& username, const std::string& token) {
+    Client client(host, username, token);
+    auto reply = client.GetJson("/profile", false).returned_data;
+    if (reply.empty()) {
+        return false;
+    }
+    nlohmann::json json = nlohmann::json::parse(reply);
+    const auto iter = json.find("username");
+
+    if (iter == json.end()) {
+        return username.empty();
+    }
+
+    return *iter == username;
+}
+
+} // namespace WebService

src/web_service/verify_login.h

@@ -0,0 +1,19 @@
+// SPDX-FileCopyrightText: 2017 Citra Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <string>
+
+namespace WebService {
+
+/**
+ * Checks if username and token is valid
+ * @param host the web API URL
+ * @param username yuzu username to use for authentication.
+ * @param token yuzu token to use for authentication.
+ * @returns a bool indicating whether the verification succeeded
+ */
+bool VerifyLogin(const std::string& host, const std::string& username, const std::string& token);
+
+} // namespace WebService

src/web_service/verify_user_jwt.cpp

@@ -0,0 +1,70 @@
+// SPDX-FileCopyrightText: Copyright 2018 Citra Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations" // for deprecated OpenSSL functions
+#endif
+#include <jwt/jwt.hpp>
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic pop
+#endif
+
+#include <system_error>
+#include "common/logging/log.h"
+#include "web_service/verify_user_jwt.h"
+#include "web_service/web_backend.h"
+#include "web_service/web_result.h"
+
+namespace WebService {
+
+static std::string public_key;
+std::string GetPublicKey(const std::string& host) {
+    if (public_key.empty()) {
+        Client client(host, "", ""); // no need for credentials here
+        public_key = client.GetPlain("/jwt/external/key.pem", true).returned_data;
+        if (public_key.empty()) {
+            LOG_ERROR(WebService, "Could not fetch external JWT public key, verification may fail");
+        } else {
+            LOG_INFO(WebService, "Fetched external JWT public key (size={})", public_key.size());
+        }
+    }
+    return public_key;
+}
+
+VerifyUserJWT::VerifyUserJWT(const std::string& host) : pub_key(GetPublicKey(host)) {}
+
+Network::VerifyUser::UserData VerifyUserJWT::LoadUserData(const std::string& verify_uid,
+                                                          const std::string& token) {
+    const std::string audience = fmt::format("external-{}", verify_uid);
+    using namespace jwt::params;
+    std::error_code error;
+
+    // We use the Citra backend so the issuer is citra-core
+    auto decoded =
+        jwt::decode(token, algorithms({"rs256"}), error, secret(pub_key), issuer("citra-core"),
+                    aud(audience), validate_iat(true), validate_jti(true));
+    if (error) {
+        LOG_INFO(WebService, "Verification failed: category={}, code={}, message={}",
+                 error.category().name(), error.value(), error.message());
+        return {};
+    }
+    Network::VerifyUser::UserData user_data{};
+    if (decoded.payload().has_claim("username")) {
+        user_data.username = decoded.payload().get_claim_value<std::string>("username");
+    }
+    if (decoded.payload().has_claim("displayName")) {
+        user_data.display_name = decoded.payload().get_claim_value<std::string>("displayName");
+    }
+    if (decoded.payload().has_claim("avatarUrl")) {
+        user_data.avatar_url = decoded.payload().get_claim_value<std::string>("avatarUrl");
+    }
+    if (decoded.payload().has_claim("roles")) {
+        auto roles = decoded.payload().get_claim_value<std::vector<std::string>>("roles");
+        user_data.moderator = std::find(roles.begin(), roles.end(), "moderator") != roles.end();
+    }
+    return user_data;
+}
+
+} // namespace WebService

src/web_service/verify_user_jwt.h

@@ -0,0 +1,26 @@
+// SPDX-FileCopyrightText: Copyright 2018 Citra Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <fmt/format.h>
+#include "network/verify_user.h"
+#include "web_service/web_backend.h"
+
+namespace WebService {
+
+std::string GetPublicKey(const std::string& host);
+
+class VerifyUserJWT final : public Network::VerifyUser::Backend {
+public:
+    VerifyUserJWT(const std::string& host);
+    ~VerifyUserJWT() = default;
+
+    Network::VerifyUser::UserData LoadUserData(const std::string& verify_uid,
+                                               const std::string& token) override;
+
+private:
+    std::string pub_key;
+};
+
+} // namespace WebService

src/web_service/web_backend.cpp

@@ -0,0 +1,206 @@
+// SPDX-FileCopyrightText: 2017 Citra Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <array>
+#include <mutex>
+#include <string>
+
+#include <fmt/format.h>
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#ifndef __clang__
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+#endif
+#endif
+#include <httplib.h>
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
+
+#include "common/logging/log.h"
+#include "web_service/web_backend.h"
+#include "web_service/web_result.h"
+
+namespace WebService {
+
+constexpr std::array<const char, 1> API_VERSION{'1'};
+
+constexpr std::size_t TIMEOUT_SECONDS = 30;
+
+struct Client::Impl {
+    Impl(std::string host_, std::string username_, std::string token_)
+        : host{std::move(host_)}, username{std::move(username_)}, token{std::move(token_)} {
+        std::scoped_lock lock{jwt_cache.mutex};
+        if (this->username == jwt_cache.username && this->token == jwt_cache.token) {
+            jwt = jwt_cache.jwt;
+        }
+
+        // Normalize host expression
+        if (!this->host.empty() && this->host.back() == '/') {
+            static_cast<void>(this->host.pop_back());
+        }
+    }
+
+    /// A generic function handles POST, GET and DELETE request together
+    WebResult GenericRequest(const std::string& method, const std::string& path,
+                             const std::string& data, bool allow_anonymous,
+                             const std::string& accept) {
+        if (jwt.empty()) {
+            UpdateJWT();
+        }
+
+        if (jwt.empty() && !allow_anonymous) {
+            LOG_ERROR(WebService, "Credentials must be provided for authenticated requests");
+            return WebResult{WebResult::Code::CredentialsMissing, "Credentials needed", ""};
+        }
+
+        auto result = GenericRequest(method, path, data, accept, jwt);
+        if (result.result_string == "401") {
+            // Try again with new JWT
+            UpdateJWT();
+            result = GenericRequest(method, path, data, accept, jwt);
+        }
+
+        return result;
+    }
+
+    /**
+     * A generic function with explicit authentication method specified
+     * JWT is used if the jwt parameter is not empty
+     * username + token is used if jwt is empty but username and token are
+     * not empty anonymous if all of jwt, username and token are empty
+     */
+    WebResult GenericRequest(const std::string& method, const std::string& path,
+                             const std::string& data, const std::string& accept,
+                             const std::string& jwt_ = "", const std::string& username_ = "",
+                             const std::string& token_ = "") {
+        if (cli == nullptr) {
+            cli = std::make_unique<httplib::Client>(host.c_str());
+            cli->set_connection_timeout(TIMEOUT_SECONDS);
+            cli->set_read_timeout(TIMEOUT_SECONDS);
+            cli->set_write_timeout(TIMEOUT_SECONDS);
+        }
+        if (!cli->is_valid()) {
+            LOG_ERROR(WebService, "Invalid URL {}", host + path);
+            return WebResult{WebResult::Code::InvalidURL, "Invalid URL", ""};
+        }
+
+        httplib::Headers params;
+        if (!jwt_.empty()) {
+            params = {
+                {std::string("Authorization"), fmt::format("Bearer {}", jwt_)},
+            };
+        } else if (!username_.empty()) {
+            params = {
+                {std::string("x-username"), username_},
+                {std::string("x-token"), token_},
+            };
+        }
+
+        params.emplace(std::string("api-version"),
+                       std::string(API_VERSION.begin(), API_VERSION.end()));
+        if (method != "GET") {
+            params.emplace(std::string("Content-Type"), std::string("application/json"));
+        }
+
+        httplib::Request request;
+        request.method = method;
+        request.path = path;
+        request.headers = params;
+        request.body = data;
+
+        httplib::Result result = cli->send(request);
+
+        if (!result) {
+            LOG_ERROR(WebService, "{} to {} returned null", method, host + path);
+            return WebResult{WebResult::Code::LibError, "Null response", ""};
+        }
+
+        httplib::Response response = result.value();
+
+        if (response.status >= 400) {
+            LOG_ERROR(WebService, "{} to {} returned error status code: {}", method, host + path,
+                      response.status);
+            return WebResult{WebResult::Code::HttpError, std::to_string(response.status), ""};
+        }
+
+        auto content_type = response.headers.find("content-type");
+
+        if (content_type == response.headers.end()) {
+            LOG_ERROR(WebService, "{} to {} returned no content", method, host + path);
+            return WebResult{WebResult::Code::WrongContent, "", ""};
+        }
+
+        if (content_type->second.find(accept) == std::string::npos) {
+            LOG_ERROR(WebService, "{} to {} returned wrong content: {}", method, host + path,
+                      content_type->second);
+            return WebResult{WebResult::Code::WrongContent, "Wrong content", ""};
+        }
+        return WebResult{WebResult::Code::Success, "", response.body};
+    }
+
+    // Retrieve a new JWT from given username and token
+    void UpdateJWT() {
+        if (username.empty() || token.empty()) {
+            return;
+        }
+
+        auto result = GenericRequest("POST", "/jwt/internal", "", "text/html", "", username, token);
+        if (result.result_code != WebResult::Code::Success) {
+            LOG_ERROR(WebService, "UpdateJWT failed");
+        } else {
+            std::scoped_lock lock{jwt_cache.mutex};
+            jwt_cache.username = username;
+            jwt_cache.token = token;
+            jwt_cache.jwt = jwt = result.returned_data;
+        }
+    }
+
+    std::string host;
+    std::string username;
+    std::string token;
+    std::string jwt;
+    std::unique_ptr<httplib::Client> cli;
+
+    struct JWTCache {
+        std::mutex mutex;
+        std::string username;
+        std::string token;
+        std::string jwt;
+    };
+    static inline JWTCache jwt_cache;
+};
+
+Client::Client(std::string host, std::string username, std::string token)
+    : impl{std::make_unique<Impl>(std::move(host), std::move(username), std::move(token))} {}
+
+Client::~Client() = default;
+
+WebResult Client::PostJson(const std::string& path, const std::string& data, bool allow_anonymous) {
+    return impl->GenericRequest("POST", path, data, allow_anonymous, "application/json");
+}
+
+WebResult Client::GetJson(const std::string& path, bool allow_anonymous) {
+    return impl->GenericRequest("GET", path, "", allow_anonymous, "application/json");
+}
+
+WebResult Client::DeleteJson(const std::string& path, const std::string& data,
+                             bool allow_anonymous) {
+    return impl->GenericRequest("DELETE", path, data, allow_anonymous, "application/json");
+}
+
+WebResult Client::GetPlain(const std::string& path, bool allow_anonymous) {
+    return impl->GenericRequest("GET", path, "", allow_anonymous, "text/plain");
+}
+
+WebResult Client::GetImage(const std::string& path, bool allow_anonymous) {
+    return impl->GenericRequest("GET", path, "", allow_anonymous, "image/png");
+}
+
+WebResult Client::GetExternalJWT(const std::string& audience) {
+    return impl->GenericRequest("POST", fmt::format("/jwt/external/{}", audience), "", false,
+                                "text/html");
+}
+
+} // namespace WebService

src/web_service/web_backend.h

@@ -0,0 +1,72 @@
+// SPDX-FileCopyrightText: 2017 Citra Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <memory>
+#include <string>
+
+namespace WebService {
+
+struct WebResult;
+
+class Client {
+public:
+    Client(std::string host, std::string username, std::string token);
+    ~Client();
+
+    /**
+     * Posts JSON to the specified path.
+     * @param path the URL segment after the host address.
+     * @param data String of JSON data to use for the body of the POST request.
+     * @param allow_anonymous If true, allow anonymous unauthenticated requests.
+     * @return the result of the request.
+     */
+    WebResult PostJson(const std::string& path, const std::string& data, bool allow_anonymous);
+
+    /**
+     * Gets JSON from the specified path.
+     * @param path the URL segment after the host address.
+     * @param allow_anonymous If true, allow anonymous unauthenticated requests.
+     * @return the result of the request.
+     */
+    WebResult GetJson(const std::string& path, bool allow_anonymous);
+
+    /**
+     * Deletes JSON to the specified path.
+     * @param path the URL segment after the host address.
+     * @param data String of JSON data to use for the body of the DELETE request.
+     * @param allow_anonymous If true, allow anonymous unauthenticated requests.
+     * @return the result of the request.
+     */
+    WebResult DeleteJson(const std::string& path, const std::string& data, bool allow_anonymous);
+
+    /**
+     * Gets a plain string from the specified path.
+     * @param path the URL segment after the host address.
+     * @param allow_anonymous If true, allow anonymous unauthenticated requests.
+     * @return the result of the request.
+     */
+    WebResult GetPlain(const std::string& path, bool allow_anonymous);
+
+    /**
+     * Gets an PNG image from the specified path.
+     * @param path the URL segment after the host address.
+     * @param allow_anonymous If true, allow anonymous unauthenticated requests.
+     * @return the result of the request.
+     */
+    WebResult GetImage(const std::string& path, bool allow_anonymous);
+
+    /**
+     * Requests an external JWT for the specific audience provided.
+     * @param audience the audience of the JWT requested.
+     * @return the result of the request.
+     */
+    WebResult GetExternalJWT(const std::string& audience);
+
+private:
+    struct Impl;
+    std::unique_ptr<Impl> impl;
+};
+
+} // namespace WebService

src/web_service/web_result.h

@@ -0,0 +1,24 @@
+// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <string>
+#include "common/common_types.h"
+
+namespace WebService {
+struct WebResult {
+    enum class Code : u32 {
+        Success,
+        InvalidURL,
+        CredentialsMissing,
+        LibError,
+        HttpError,
+        WrongContent,
+        NoWebservice,
+    };
+    Code result_code;
+    std::string result_string;
+    std::string returned_data;
+};
+} // namespace WebService