WebService: Verify username and token (#2930)

* WebService: Verify username and token; Log errors in PostJson

* Fixup: added docstrings to the functions

* Webservice: Added Icons to the verification, imrpved error detection in cpr, fixup nits

* fixup: fmt warning

18 files changed, 322 insertions, 38 deletions

diff --git a/dist/icons/checked.png b/dist/icons/checked.png
new file mode 100644
index 000000000..c277e6b40
--- /dev/null
+++ b/dist/icons/checked.png
diff --git a/dist/icons/failed.png b/dist/icons/failed.png
new file mode 100644
index 000000000..ac10f174a
--- /dev/null
+++ b/dist/icons/failed.png
diff --git a/dist/icons/icons.qrc b/dist/icons/icons.qrc
new file mode 100644
index 000000000..f0c44862f
--- /dev/null
+++ b/dist/icons/icons.qrc
@@ -0,0 +1,6 @@
+<RCC>
+  <qresource prefix="icons">
+    <file>checked.png</file>
+    <file>failed.png</file>
+  </qresource>
+</RCC>
diff --git a/src/citra/config.cpp b/src/citra/config.cpp
index a48ef08c7..45c28ad09 100644
--- a/src/citra/config.cpp
+++ b/src/citra/config.cpp
@@ -162,6 +162,8 @@ void Config::ReadValues() {
         sdl2_config->GetBoolean("WebService", "enable_telemetry", true);
     Settings::values.telemetry_endpoint_url = sdl2_config->Get(
         "WebService", "telemetry_endpoint_url", "https://services.citra-emu.org/api/telemetry");
+    Settings::values.verify_endpoint_url = sdl2_config->Get(
+        "WebService", "verify_endpoint_url", "https://services.citra-emu.org/api/profile");
     Settings::values.citra_username = sdl2_config->Get("WebService", "citra_username", "");
     Settings::values.citra_token = sdl2_config->Get("WebService", "citra_token", "");
 }
diff --git a/src/citra/default_ini.h b/src/citra/default_ini.h
index 4b13a2e1b..59faf773f 100644
--- a/src/citra/default_ini.h
+++ b/src/citra/default_ini.h
@@ -185,6 +185,8 @@ gdbstub_port=24689
 enable_telemetry =
 # Endpoint URL for submitting telemetry data
 telemetry_endpoint_url = https://services.citra-emu.org/api/telemetry
+# Endpoint URL to verify the username and token
+verify_endpoint_url = https://services.citra-emu.org/api/profile
 # Username and token for Citra Web Service
 # See https://services.citra-emu.org/ for more info
 citra_username =
diff --git a/src/citra_qt/CMakeLists.txt b/src/citra_qt/CMakeLists.txt
index e0a19fd9e..add7566c2 100644
--- a/src/citra_qt/CMakeLists.txt
+++ b/src/citra_qt/CMakeLists.txt
@@ -79,6 +79,7 @@ set(UIS
             main.ui
             )
 
+file(GLOB_RECURSE ICONS ${CMAKE_SOURCE_DIR}/dist/icons/*)
 file(GLOB_RECURSE THEMES ${CMAKE_SOURCE_DIR}/dist/qt_themes/*)
 
 create_directory_groups(${SRCS} ${HEADERS} ${UIS})
@@ -92,10 +93,10 @@ endif()
 if (APPLE)
     set(MACOSX_ICON "../../dist/citra.icns")
     set_source_files_properties(${MACOSX_ICON} PROPERTIES MACOSX_PACKAGE_LOCATION Resources)
-    add_executable(citra-qt MACOSX_BUNDLE ${SRCS} ${HEADERS} ${UI_HDRS} ${THEMES} ${MACOSX_ICON})
+    add_executable(citra-qt MACOSX_BUNDLE ${SRCS} ${HEADERS} ${UI_HDRS} ${ICONS} ${THEMES} ${MACOSX_ICON})
     set_target_properties(citra-qt PROPERTIES MACOSX_BUNDLE_INFO_PLIST ${CMAKE_CURRENT_SOURCE_DIR}/Info.plist)
 else()
-    add_executable(citra-qt ${SRCS} ${HEADERS} ${UI_HDRS} ${THEMES})
+    add_executable(citra-qt ${SRCS} ${HEADERS} ${UI_HDRS} ${ICONS} ${THEMES})
 endif()
 target_link_libraries(citra-qt PRIVATE audio_core common core input_common network video_core)
 target_link_libraries(citra-qt PRIVATE Boost::boost glad nihstro-headers Qt5::OpenGL Qt5::Widgets)
diff --git a/src/citra_qt/configuration/config.cpp b/src/citra_qt/configuration/config.cpp
index ef114aad3..5261f4c4c 100644
--- a/src/citra_qt/configuration/config.cpp
+++ b/src/citra_qt/configuration/config.cpp
@@ -146,6 +146,10 @@ void Config::ReadValues() {
         qt_config->value("telemetry_endpoint_url", "https://services.citra-emu.org/api/telemetry")
             .toString()
             .toStdString();
+    Settings::values.verify_endpoint_url =
+        qt_config->value("verify_endpoint_url", "https://services.citra-emu.org/api/profile")
+            .toString()
+            .toStdString();
     Settings::values.citra_username = qt_config->value("citra_username").toString().toStdString();
     Settings::values.citra_token = qt_config->value("citra_token").toString().toStdString();
     qt_config->endGroup();
@@ -293,6 +297,8 @@ void Config::SaveValues() {
     qt_config->setValue("enable_telemetry", Settings::values.enable_telemetry);
     qt_config->setValue("telemetry_endpoint_url",
                         QString::fromStdString(Settings::values.telemetry_endpoint_url));
+    qt_config->setValue("verify_endpoint_url",
+                        QString::fromStdString(Settings::values.verify_endpoint_url));
     qt_config->setValue("citra_username", QString::fromStdString(Settings::values.citra_username));
     qt_config->setValue("citra_token", QString::fromStdString(Settings::values.citra_token));
     qt_config->endGroup();
diff --git a/src/citra_qt/configuration/configure_web.cpp b/src/citra_qt/configuration/configure_web.cpp
index 8715fb018..38ce19c0f 100644
--- a/src/citra_qt/configuration/configure_web.cpp
+++ b/src/citra_qt/configuration/configure_web.cpp
@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <QMessageBox>
 #include "citra_qt/configuration/configure_web.h"
 #include "core/settings.h"
 #include "core/telemetry_session.h"
@@ -11,7 +12,9 @@ ConfigureWeb::ConfigureWeb(QWidget* parent)
     : QWidget(parent), ui(std::make_unique<Ui::ConfigureWeb>()) {
     ui->setupUi(this);
     connect(ui->button_regenerate_telemetry_id, &QPushButton::clicked, this,
-            &ConfigureWeb::refreshTelemetryID);
+            &ConfigureWeb::RefreshTelemetryID);
+    connect(ui->button_verify_login, &QPushButton::clicked, this, &ConfigureWeb::VerifyLogin);
+    connect(this, &ConfigureWeb::LoginVerified, this, &ConfigureWeb::OnLoginVerified);
 
     this->setConfiguration();
 }
@@ -34,19 +37,66 @@ void ConfigureWeb::setConfiguration() {
     ui->toggle_telemetry->setChecked(Settings::values.enable_telemetry);
     ui->edit_username->setText(QString::fromStdString(Settings::values.citra_username));
     ui->edit_token->setText(QString::fromStdString(Settings::values.citra_token));
+    // Connect after setting the values, to avoid calling OnLoginChanged now
+    connect(ui->edit_token, &QLineEdit::textChanged, this, &ConfigureWeb::OnLoginChanged);
+    connect(ui->edit_username, &QLineEdit::textChanged, this, &ConfigureWeb::OnLoginChanged);
     ui->label_telemetry_id->setText("Telemetry ID: 0x" +
                                     QString::number(Core::GetTelemetryId(), 16).toUpper());
+    user_verified = true;
 }
 
 void ConfigureWeb::applyConfiguration() {
     Settings::values.enable_telemetry = ui->toggle_telemetry->isChecked();
-    Settings::values.citra_username = ui->edit_username->text().toStdString();
-    Settings::values.citra_token = ui->edit_token->text().toStdString();
+    if (user_verified) {
+        Settings::values.citra_username = ui->edit_username->text().toStdString();
+        Settings::values.citra_token = ui->edit_token->text().toStdString();
+    } else {
+        QMessageBox::warning(this, tr("Username and token not verfied"),
+                             tr("Username and token were not verified. The changes to your "
+                                "username and/or token have not been saved."));
+    }
     Settings::Apply();
 }
 
-void ConfigureWeb::refreshTelemetryID() {
+void ConfigureWeb::RefreshTelemetryID() {
     const u64 new_telemetry_id{Core::RegenerateTelemetryId()};
     ui->label_telemetry_id->setText("Telemetry ID: 0x" +
                                     QString::number(new_telemetry_id, 16).toUpper());
 }
+
+void ConfigureWeb::OnLoginChanged() {
+    if (ui->edit_username->text().isEmpty() && ui->edit_token->text().isEmpty()) {
+        user_verified = true;
+        ui->label_username_verified->setPixmap(QPixmap(":/icons/checked.png"));
+        ui->label_token_verified->setPixmap(QPixmap(":/icons/checked.png"));
+    } else {
+        user_verified = false;
+        ui->label_username_verified->setPixmap(QPixmap(":/icons/failed.png"));
+        ui->label_token_verified->setPixmap(QPixmap(":/icons/failed.png"));
+    }
+}
+
+void ConfigureWeb::VerifyLogin() {
+    verified =
+        Core::VerifyLogin(ui->edit_username->text().toStdString(),
+                          ui->edit_token->text().toStdString(), [&]() { emit LoginVerified(); });
+    ui->button_verify_login->setDisabled(true);
+    ui->button_verify_login->setText(tr("Verifying"));
+}
+
+void ConfigureWeb::OnLoginVerified() {
+    ui->button_verify_login->setEnabled(true);
+    ui->button_verify_login->setText(tr("Verify"));
+    if (verified.get()) {
+        user_verified = true;
+        ui->label_username_verified->setPixmap(QPixmap(":/icons/checked.png"));
+        ui->label_token_verified->setPixmap(QPixmap(":/icons/checked.png"));
+    } else {
+        ui->label_username_verified->setPixmap(QPixmap(":/icons/failed.png"));
+        ui->label_token_verified->setPixmap(QPixmap(":/icons/failed.png"));
+        QMessageBox::critical(
+            this, tr("Verification failed"),
+            tr("Verification failed. Check that you have entered your username and token "
+               "correctly, and that your internet connection is working."));
+    }
+}
diff --git a/src/citra_qt/configuration/configure_web.h b/src/citra_qt/configuration/configure_web.h
index 20bc254b9..ad2d58f6e 100644
--- a/src/citra_qt/configuration/configure_web.h
+++ b/src/citra_qt/configuration/configure_web.h
@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <future>
 #include <memory>
 #include <QWidget>
 
@@ -21,10 +22,19 @@ public:
     void applyConfiguration();
 
 public slots:
-    void refreshTelemetryID();
+    void RefreshTelemetryID();
+    void OnLoginChanged();
+    void VerifyLogin();
+    void OnLoginVerified();
+
+signals:
+    void LoginVerified();
 
 private:
     void setConfiguration();
 
+    bool user_verified = true;
+    std::future<bool> verified;
+
     std::unique_ptr<Ui::ConfigureWeb> ui;
 };
diff --git a/src/citra_qt/configuration/configure_web.ui b/src/citra_qt/configuration/configure_web.ui
index d8d283fad..dd996ab62 100644
--- a/src/citra_qt/configuration/configure_web.ui
+++ b/src/citra_qt/configuration/configure_web.ui
@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>400</width>
-    <height>300</height>
+    <width>926</width>
+    <height>561</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -31,14 +31,30 @@
         </item>
         <item>
          <layout class="QGridLayout" name="gridLayoutCitraUsername">
-          <item row="0" column="0">
-           <widget class="QLabel" name="label_username">
+          <item row="2" column="3">
+           <widget class="QPushButton" name="button_verify_login">
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
+            <property name="layoutDirection">
+             <enum>Qt::RightToLeft</enum>
+            </property>
             <property name="text">
-             <string>Username: </string>
+             <string>Verify</string>
             </property>
            </widget>
           </item>
-          <item row="0" column="1">
+          <item row="2" column="0">
+           <widget class="QLabel" name="web_signup_link">
+            <property name="text">
+             <string>Sign up</string>
+            </property>
+           </widget>
+          </item>
+          <item row="0" column="1" colspan="3">
            <widget class="QLineEdit" name="edit_username">
             <property name="maxLength">
              <number>36</number>
@@ -52,7 +68,22 @@
             </property>
            </widget>
           </item>
-          <item row="1" column="1">
+          <item row="1" column="4">
+           <widget class="QLabel" name="label_token_verified">
+           </widget>
+          </item>
+          <item row="0" column="0">
+           <widget class="QLabel" name="label_username">
+            <property name="text">
+             <string>Username: </string>
+            </property>
+           </widget>
+          </item>
+          <item row="0" column="4">
+           <widget class="QLabel" name="label_username_verified">
+           </widget>
+          </item>
+          <item row="1" column="1" colspan="3">
            <widget class="QLineEdit" name="edit_token">
             <property name="maxLength">
              <number>36</number>
@@ -62,13 +93,6 @@
             </property>
            </widget>
           </item>
-          <item row="2" column="0">
-           <widget class="QLabel" name="web_signup_link">
-            <property name="text">
-             <string>Sign up</string>
-            </property>
-           </widget>
-          </item>
           <item row="2" column="1">
            <widget class="QLabel" name="web_token_info_link">
             <property name="text">
@@ -76,6 +100,19 @@
             </property>
            </widget>
           </item>
+          <item row="2" column="2">
+           <spacer name="horizontalSpacer">
+            <property name="orientation">
+             <enum>Qt::Horizontal</enum>
+            </property>
+            <property name="sizeHint" stdset="0">
+             <size>
+              <width>40</width>
+              <height>20</height>
+             </size>
+            </property>
+           </spacer>
+          </item>
          </layout>
         </item>
        </layout>
@@ -105,17 +142,17 @@
          <layout class="QGridLayout" name="gridLayoutTelemetryId">
           <item row="0" column="0">
            <widget class="QLabel" name="label_telemetry_id">
-             <property name="text">
-              <string>Telemetry ID:</string>
-             </property>
+            <property name="text">
+             <string>Telemetry ID:</string>
+            </property>
            </widget>
           </item>
           <item row="0" column="1">
            <widget class="QPushButton" name="button_regenerate_telemetry_id">
             <property name="sizePolicy">
              <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
-               <horstretch>0</horstretch>
-               <verstretch>0</verstretch>
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
              </sizepolicy>
             </property>
             <property name="layoutDirection">
diff --git a/src/core/settings.h b/src/core/settings.h
index 024f14666..8d78cb424 100644
--- a/src/core/settings.h
+++ b/src/core/settings.h
@@ -133,6 +133,7 @@ struct Values {
     // WebService
     bool enable_telemetry;
     std::string telemetry_endpoint_url;
+    std::string verify_endpoint_url;
     std::string citra_username;
     std::string citra_token;
 } extern values;
diff --git a/src/core/telemetry_session.cpp b/src/core/telemetry_session.cpp
index 104a16cc9..ca517ff44 100644
--- a/src/core/telemetry_session.cpp
+++ b/src/core/telemetry_session.cpp
@@ -15,6 +15,7 @@
 
 #ifdef ENABLE_WEB_SERVICE
 #include "web_service/telemetry_json.h"
+#include "web_service/verify_login.h"
 #endif
 
 namespace Core {
@@ -75,6 +76,17 @@ u64 RegenerateTelemetryId() {
     return new_telemetry_id;
 }
 
+std::future<bool> VerifyLogin(std::string username, std::string token, std::function<void()> func) {
+#ifdef ENABLE_WEB_SERVICE
+    return WebService::VerifyLogin(username, token, Settings::values.verify_endpoint_url, func);
+#else
+    return std::async(std::launch::async, [func{std::move(func)}]() {
+        func();
+        return false;
+    });
+#endif
+}
+
 TelemetrySession::TelemetrySession() {
 #ifdef ENABLE_WEB_SERVICE
     if (Settings::values.enable_telemetry) {
diff --git a/src/core/telemetry_session.h b/src/core/telemetry_session.h
index 65613daae..550c6ea2d 100644
--- a/src/core/telemetry_session.h
+++ b/src/core/telemetry_session.h
@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <future>
 #include <memory>
 #include "common/telemetry.h"
 
@@ -47,4 +48,13 @@ u64 GetTelemetryId();
  */
 u64 RegenerateTelemetryId();
 
+/**
+ * Verifies the username and token.
+ * @param username Citra username to use for authentication.
+ * @param token Citra token to use for authentication.
+ * @param func A function that gets exectued when the verification is finished
+ * @returns Future with bool indicating whether the verification succeeded
+ */
+std::future<bool> VerifyLogin(std::string username, std::string token, std::function<void()> func);
+
 } // namespace Core
diff --git a/src/web_service/CMakeLists.txt b/src/web_service/CMakeLists.txt
index 334d82a8a..c93811892 100644
--- a/src/web_service/CMakeLists.txt
+++ b/src/web_service/CMakeLists.txt
@@ -1,10 +1,12 @@
 set(SRCS
             telemetry_json.cpp
+            verify_login.cpp
             web_backend.cpp
             )
 
 set(HEADERS
             telemetry_json.h
+            verify_login.h
             web_backend.h
             )
 
diff --git a/src/web_service/verify_login.cpp b/src/web_service/verify_login.cpp
new file mode 100644
index 000000000..1bc3b5afe
--- /dev/null
+++ b/src/web_service/verify_login.cpp
@@ -0,0 +1,28 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <json.hpp>
+#include "web_service/verify_login.h"
+#include "web_service/web_backend.h"
+
+namespace WebService {
+
+std::future<bool> VerifyLogin(std::string& username, std::string& token,
+                              const std::string& endpoint_url, std::function<void()> func) {
+    auto get_func = [func, username](const std::string& reply) -> bool {
+        func();
+        if (reply.empty())
+            return false;
+        nlohmann::json json = nlohmann::json::parse(reply);
+        std::string result;
+        try {
+            result = json["username"];
+        } catch (const nlohmann::detail::out_of_range&) {
+        }
+        return result == username;
+    };
+    return GetJson<bool>(get_func, endpoint_url, false, username, token);
+}
+
+} // namespace WebService
diff --git a/src/web_service/verify_login.h b/src/web_service/verify_login.h
new file mode 100644
index 000000000..303f5dbbc
--- /dev/null
+++ b/src/web_service/verify_login.h
@@ -0,0 +1,24 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <functional>
+#include <future>
+#include <string>
+
+namespace WebService {
+
+/**
+ * Checks if username and token is valid
+ * @param username Citra username to use for authentication.
+ * @param token Citra token to use for authentication.
+ * @param endpoint_url URL of the services.citra-emu.org endpoint.
+ * @param func A function that gets exectued when the verification is finished
+ * @returns Future with bool indicating whether the verification succeeded
+ */
+std::future<bool> VerifyLogin(std::string& username, std::string& token,
+                              const std::string& endpoint_url, std::function<void()> func);
+
+} // namespace WebService
diff --git a/src/web_service/web_backend.cpp b/src/web_service/web_backend.cpp
index d28a3f757..b17d82f9c 100644
--- a/src/web_service/web_backend.cpp
+++ b/src/web_service/web_backend.cpp
@@ -18,6 +18,19 @@ static constexpr char API_VERSION[]{"1"};
 
 static std::unique_ptr<cpr::Session> g_session;
 
+void Win32WSAStartup() {
+#ifdef _WIN32
+    // On Windows, CPR/libcurl does not properly initialize Winsock. The below code is used to
+    // initialize Winsock globally, which fixes this problem. Without this, only the first CPR
+    // session will properly be created, and subsequent ones will fail.
+    WSADATA wsa_data;
+    const int wsa_result{WSAStartup(MAKEWORD(2, 2), &wsa_data)};
+    if (wsa_result) {
+        LOG_CRITICAL(WebService, "WSAStartup failed: %d", wsa_result);
+    }
+#endif
+}
+
 void PostJson(const std::string& url, const std::string& data, bool allow_anonymous,
               const std::string& username, const std::string& token) {
     if (url.empty()) {
@@ -31,16 +44,7 @@ void PostJson(const std::string& url, const std::string& data, bool allow_anonym
         return;
     }
 
-#ifdef _WIN32
-    // On Windows, CPR/libcurl does not properly initialize Winsock. The below code is used to
-    // initialize Winsock globally, which fixes this problem. Without this, only the first CPR
-    // session will properly be created, and subsequent ones will fail.
-    WSADATA wsa_data;
-    const int wsa_result{WSAStartup(MAKEWORD(2, 2), &wsa_data)};
-    if (wsa_result) {
-        LOG_CRITICAL(WebService, "WSAStartup failed: %d", wsa_result);
-    }
-#endif
+    Win32WSAStartup();
 
     // Built request header
     cpr::Header header;
@@ -56,8 +60,81 @@ void PostJson(const std::string& url, const std::string& data, bool allow_anonym
     }
 
     // Post JSON asynchronously
-    static cpr::AsyncResponse future;
-    future = cpr::PostAsync(cpr::Url{url.c_str()}, cpr::Body{data.c_str()}, header);
+    static std::future<void> future;
+    future = cpr::PostCallback(
+        [](cpr::Response r) {
+            if (r.error) {
+                LOG_ERROR(WebService, "POST returned cpr error: %u:%s",
+                          static_cast<u32>(r.error.code), r.error.message.c_str());
+                return;
+            }
+            if (r.status_code >= 400) {
+                LOG_ERROR(WebService, "POST returned error status code: %u", r.status_code);
+                return;
+            }
+            if (r.header["content-type"].find("application/json") == std::string::npos) {
+                LOG_ERROR(WebService, "POST returned wrong content: %s",
+                          r.header["content-type"].c_str());
+                return;
+            }
+        },
+        cpr::Url{url}, cpr::Body{data}, header);
+}
+
+template <typename T>
+std::future<T> GetJson(std::function<T(const std::string&)> func, const std::string& url,
+                       bool allow_anonymous, const std::string& username,
+                       const std::string& token) {
+    if (url.empty()) {
+        LOG_ERROR(WebService, "URL is invalid");
+        return std::async(std::launch::async, [func{std::move(func)}]() { return func(""); });
+    }
+
+    const bool are_credentials_provided{!token.empty() && !username.empty()};
+    if (!allow_anonymous && !are_credentials_provided) {
+        LOG_ERROR(WebService, "Credentials must be provided for authenticated requests");
+        return std::async(std::launch::async, [func{std::move(func)}]() { return func(""); });
+    }
+
+    Win32WSAStartup();
+
+    // Built request header
+    cpr::Header header;
+    if (are_credentials_provided) {
+        // Authenticated request if credentials are provided
+        header = {{"Content-Type", "application/json"},
+                  {"x-username", username.c_str()},
+                  {"x-token", token.c_str()},
+                  {"api-version", API_VERSION}};
+    } else {
+        // Otherwise, anonymous request
+        header = cpr::Header{{"Content-Type", "application/json"}, {"api-version", API_VERSION}};
+    }
+
+    // Get JSON asynchronously
+    return cpr::GetCallback(
+        [func{std::move(func)}](cpr::Response r) {
+            if (r.error) {
+                LOG_ERROR(WebService, "GET returned cpr error: %u:%s",
+                          static_cast<u32>(r.error.code), r.error.message.c_str());
+                return func("");
+            }
+            if (r.status_code >= 400) {
+                LOG_ERROR(WebService, "GET returned error code: %u", r.status_code);
+                return func("");
+            }
+            if (r.header["content-type"].find("application/json") == std::string::npos) {
+                LOG_ERROR(WebService, "GET returned wrong content: %s",
+                          r.header["content-type"].c_str());
+                return func("");
+            }
+            return func(r.text);
+        },
+        cpr::Url{url}, header);
 }
 
+template std::future<bool> GetJson(std::function<bool(const std::string&)> func,
+                                   const std::string& url, bool allow_anonymous,
+                                   const std::string& username, const std::string& token);
+
 } // namespace WebService
diff --git a/src/web_service/web_backend.h b/src/web_service/web_backend.h
index d17100398..a63c75d13 100644
--- a/src/web_service/web_backend.h
+++ b/src/web_service/web_backend.h
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <functional>
+#include <future>
 #include <string>
 #include "common/common_types.h"
 
@@ -20,4 +22,18 @@ namespace WebService {
 void PostJson(const std::string& url, const std::string& data, bool allow_anonymous,
               const std::string& username = {}, const std::string& token = {});
 
+/**
+ * Gets JSON from services.citra-emu.org.
+ * @param func A function that gets exectued when the json as a string is received
+ * @param url URL of the services.citra-emu.org endpoint to post data to.
+ * @param allow_anonymous If true, allow anonymous unauthenticated requests.
+ * @param username Citra username to use for authentication.
+ * @param token Citra token to use for authentication.
+ * @return future that holds the return value T of the func
+ */
+template <typename T>
+std::future<T> GetJson(std::function<T(const std::string&)> func, const std::string& url,
+                       bool allow_anonymous, const std::string& username = {},
+                       const std::string& token = {});
+
 } // namespace WebService