Merge pull request #1598 from Kaydax/authlib

Add support for authlibinjector

launcher/Application.cpp

@@ -818,6 +818,7 @@ Application::Application(int &argc, char **argv) : QApplication(argc, argv)
         m_metacache->addBase("translations", QDir("translations").absolutePath());
         m_metacache->addBase("icons", QDir("cache/icons").absolutePath());
         m_metacache->addBase("meta", QDir("meta").absolutePath());
+        m_metacache->addBase("authlibinjector", QDir("cache/authlibinjector").absolutePath());
         m_metacache->Load();
         qDebug() << "<> Cache initialized.";
     }

launcher/CMakeLists.txt

@@ -205,11 +205,15 @@ set(MINECRAFT_SOURCES
     minecraft/auth/flows/AuthFlow.h
     minecraft/auth/flows/Mojang.cpp
     minecraft/auth/flows/Mojang.h
+    minecraft/auth/flows/AuthlibInjector.cpp
+    minecraft/auth/flows/AuthlibInjector.h
     minecraft/auth/flows/MSA.cpp
     minecraft/auth/flows/MSA.h
     minecraft/auth/flows/Offline.cpp
     minecraft/auth/flows/Offline.h
 
+    minecraft/auth/steps/AuthlibInjectorStep.cpp
+    minecraft/auth/steps/AuthlibInjectorStep.h
     minecraft/auth/steps/OfflineStep.cpp
     minecraft/auth/steps/OfflineStep.h
     minecraft/auth/steps/EntitlementsStep.cpp
@@ -249,6 +253,8 @@ set(MINECRAFT_SOURCES
 
     minecraft/launch/ClaimAccount.cpp
     minecraft/launch/ClaimAccount.h
+    minecraft/launch/ConfigureAuthlibInjector.cpp
+    minecraft/launch/ConfigureAuthlibInjector.h
     minecraft/launch/CreateGameFolders.cpp
     minecraft/launch/CreateGameFolders.h
     minecraft/launch/ModMinecraftJar.cpp

launcher/minecraft/MinecraftInstance.cpp

@@ -60,6 +60,7 @@
 #include "launch/steps/QuitAfterGameStop.h"
 
 #include "minecraft/launch/LauncherPartLaunch.h"
+#include "minecraft/launch/ConfigureAuthlibInjector.h"
 #include "minecraft/launch/DirectJavaLaunch.h"
 #include "minecraft/launch/ModMinecraftJar.h"
 #include "minecraft/launch/ClaimAccount.h"
@@ -388,6 +389,11 @@ QStringList MinecraftInstance::javaArguments()
 {
     QStringList args;
 
+    if (!m_authlibinjector_javaagent->isNull())
+    {
+        args.append(QString("-javaagent:%1").arg(*m_authlibinjector_javaagent));
+    }
+
     // custom args go first. we want to override them if we have our own here.
     args.append(extraArguments());
 
@@ -990,6 +996,12 @@ shared_qobject_ptr<LaunchTask> MinecraftInstance::createLaunchTask(AuthSessionPt
         process->appendStep(step);
     }
 
+    *m_authlibinjector_javaagent = QString();
+    if (!session->authlib_injector_base_url.isNull())
+    {
+        process->appendStep(new ConfigureAuthlibInjector(pptr, session->authlib_injector_base_url, m_authlibinjector_javaagent));
+    }
+
     // if we aren't in offline mode,.
     if(session->status != AuthSession::PlayableOffline)
     {

launcher/minecraft/MinecraftInstance.h

@@ -173,6 +173,7 @@ protected: // data
     mutable std::shared_ptr<TexturePackFolderModel> m_texture_pack_list;
     mutable std::shared_ptr<WorldList> m_world_list;
     mutable std::shared_ptr<GameOptions> m_game_options;
+    mutable std::shared_ptr<QString> m_authlibinjector_javaagent = std::make_shared<QString>();
 };
 
 typedef std::shared_ptr<MinecraftInstance> MinecraftInstancePtr;

launcher/minecraft/auth/AccountData.cpp

@@ -350,6 +350,8 @@ bool AccountData::resumeStateFromV3(QJsonObject data) {
         type = AccountType::MSA;
     } else if (typeS == "Mojang") {
         type = AccountType::Mojang;
+    } else if (typeS == "Authlib-Injector") {
+        type = AccountType::AuthlibInjector;
     } else if (typeS == "Offline") {
         type = AccountType::Offline;
     } else {
@@ -362,6 +364,10 @@ bool AccountData::resumeStateFromV3(QJsonObject data) {
         canMigrateToMSA = data.value("canMigrateToMSA").toBool(false);
     }
 
+    if(type == AccountType::AuthlibInjector) {
+        authlibInjectorBaseUrl = data.value("authlibInjectorUrl").toString();
+    }
+
     if(type == AccountType::MSA) {
         auto clientIDV = data.value("msa-client-id");
         if (clientIDV.isString()) {
@@ -405,8 +411,10 @@ QJsonObject AccountData::saveState() const {
         tokenToJSONV3(output, userToken, "utoken");
         tokenToJSONV3(output, xboxApiToken, "xrp-main");
         tokenToJSONV3(output, mojangservicesToken, "xrp-mc");
-    }
-    else if (type == AccountType::Offline) {
+    } else if (type == AccountType::AuthlibInjector) {
+        output["type"] = "Authlib-Injector";
+        output["authlibInjectorUrl"] = authlibInjectorBaseUrl;
+    } else if (type == AccountType::Offline) {
         output["type"] = "Offline";
     }
 
@@ -428,14 +436,14 @@ QString AccountData::accessToken() const {
 }
 
 QString AccountData::clientToken() const {
-    if(type != AccountType::Mojang) {
+    if(type != AccountType::Mojang && type != AccountType::AuthlibInjector) {
         return QString();
     }
     return yggdrasilToken.extra["clientToken"].toString();
 }
 
 void AccountData::setClientToken(QString clientToken) {
-    if(type != AccountType::Mojang) {
+    if(type != AccountType::Mojang && type != AccountType::AuthlibInjector) {
         return;
     }
     yggdrasilToken.extra["clientToken"] = clientToken;
@@ -449,7 +457,7 @@ void AccountData::generateClientTokenIfMissing() {
 }
 
 void AccountData::invalidateClientToken() {
-    if(type != AccountType::Mojang) {
+    if(type != AccountType::Mojang && type != AccountType::AuthlibInjector) {
         return;
     }
     yggdrasilToken.extra["clientToken"] = QUuid::createUuid().toString().remove(QRegularExpression("[{-}]"));
@@ -470,6 +478,7 @@ QString AccountData::profileName() const {
 
 QString AccountData::accountDisplayString() const {
     switch(type) {
+        case AccountType::AuthlibInjector: 
         case AccountType::Mojang: {
             return userName();
         }

launcher/minecraft/auth/AccountData.h

@@ -74,6 +74,7 @@ struct MinecraftProfile {
 enum class AccountType {
     MSA,
     Mojang,
+    AuthlibInjector,
     Offline
 };
 
@@ -115,6 +116,9 @@ struct AccountData {
     QString lastError() const;
 
     AccountType type = AccountType::MSA;
+    QString authlibInjectorBaseUrl;
+    QString authlibInjectorApiLocation;
+
     bool legacy = false;
     bool canMigrateToMSA = false;
 

launcher/minecraft/auth/AuthSession.h

@@ -38,8 +38,12 @@ struct AuthSession
     QString player_name;
     // profile ID
     QString uuid;
-    // 'legacy' or 'mojang', depending on account type
+    // 'legacy' or 'mojang' or 'authlib-injector', depending on account type
     QString user_type;
+
+    // If not using authlib injector, this is blank.
+    QString authlib_injector_base_url;
+
     // Did the auth server reply?
     bool auth_server_online = false;
     // Did the user request online mode?

launcher/minecraft/auth/MinecraftAccount.cpp

@@ -50,7 +50,9 @@
 
 #include "flows/MSA.h"
 #include "flows/Mojang.h"
+#include "flows/AuthlibInjector.h"
 #include "flows/Offline.h"
+#include "minecraft/auth/AccountData.h"
 
 MinecraftAccount::MinecraftAccount(QObject* parent) : QObject(parent) {
     data.internalId = QUuid::createUuid().toString().remove(QRegularExpression("[{}-]"));
@@ -82,6 +84,16 @@ MinecraftAccountPtr MinecraftAccount::createFromUsername(const QString &username
     return account;
 }
 
+MinecraftAccountPtr MinecraftAccount::createAuthlibInjectorFromUsername(const QString &username, QString baseUrl)
+{
+    MinecraftAccountPtr account = createFromUsername(username);
+    account->data.type = AccountType::AuthlibInjector;
+    account->data.authlibInjectorBaseUrl = baseUrl;
+    account->data.minecraftEntitlement.ownsMinecraft = true;
+    account->data.minecraftEntitlement.canPlayMinecraft = true;
+    return account;
+}
+
 MinecraftAccountPtr MinecraftAccount::createBlankMSA()
 {
     MinecraftAccountPtr account(new MinecraftAccount());
@@ -132,7 +144,14 @@ QPixmap MinecraftAccount::getFace() const {
 shared_qobject_ptr<AccountTask> MinecraftAccount::login(QString password) {
     Q_ASSERT(m_currentTask.get() == nullptr);
 
-    m_currentTask.reset(new MojangLogin(&data, password));
+    if (data.type == AccountType::Mojang)
+    {
+        m_currentTask.reset(new MojangLogin(&data, password));
+    }
+    else if (data.type == AccountType::AuthlibInjector)
+    {
+        m_currentTask.reset(new AuthlibInjectorLogin(&data, password));
+    }
     connect(m_currentTask.get(), SIGNAL(succeeded()), SLOT(authSucceeded()));
     connect(m_currentTask.get(), SIGNAL(failed(QString)), SLOT(authFailed(QString)));
     connect(m_currentTask.get(), &Task::aborted, this, [this]{ authFailed(tr("Aborted")); });
@@ -173,6 +192,9 @@ shared_qobject_ptr<AccountTask> MinecraftAccount::refresh() {
     else if(data.type == AccountType::Offline) {
         m_currentTask.reset(new OfflineRefresh(&data));
     }
+    else if(data.type == AccountType::AuthlibInjector) {
+        m_currentTask.reset(new AuthlibInjectorRefresh(&data));
+    }
     else {
         m_currentTask.reset(new MojangRefresh(&data));
     }
@@ -300,8 +322,9 @@ void MinecraftAccount::fillSession(AuthSessionPtr session)
     session->player_name = data.profileName();
     // profile ID
     session->uuid = data.profileId();
-    // 'legacy' or 'mojang', depending on account type
+    // 'legacy' or 'mojang', or 'authlib-injector' depending on account type
     session->user_type = typeString();
+    session->authlib_injector_base_url = data.authlibInjectorBaseUrl;
     if (!session->access_token.isEmpty())
     {
         session->session = "token:" + data.accessToken() + ":" + data.profileId();

launcher/minecraft/auth/MinecraftAccount.h

@@ -91,6 +91,8 @@ public: /* construction */
 
     static MinecraftAccountPtr createFromUsername(const QString &username);
 
+    static MinecraftAccountPtr createAuthlibInjectorFromUsername(const QString &username, QString baseUrl);
+
     static MinecraftAccountPtr createBlankMSA();
 
     static MinecraftAccountPtr createOffline(const QString &username);
@@ -177,6 +179,10 @@ public: /* queries */
                 return "msa";
             }
             break;
+            case AccountType::AuthlibInjector: {
+              return "authlib-injector";
+            }
+            break;
             case AccountType::Offline: {
                 return "offline";
             }

launcher/minecraft/auth/Yggdrasil.cpp

@@ -27,6 +27,25 @@
 
 #include "Application.h"
 
+
+QString Yggdrasil::getBaseUrl()
+{
+    switch (m_data->type)
+    {
+        case AccountType::Mojang: {
+          return "https://authserver.mojang.com";
+        }
+        case AccountType::AuthlibInjector: {
+            return m_data->authlibInjectorApiLocation + "/authserver";
+        }
+        // Silence warnings about unhandled enum values for values we know shouldn't be handled.
+        case AccountType::MSA:
+        case AccountType::Offline:
+        break;
+    }
+    return "";
+}
+
 Yggdrasil::Yggdrasil(AccountData *data, QObject *parent)
     : AccountTask(data, parent)
 {
@@ -84,7 +103,7 @@ void Yggdrasil::refresh() {
     req.insert("requestUser", false);
     QJsonDocument doc(req);
 
-    QUrl reqUrl("https://authserver.mojang.com/refresh");
+    QUrl reqUrl = getBaseUrl() + "/refresh";
     QByteArray requestData = doc.toJson();
 
     sendRequest(reqUrl, requestData);
@@ -129,7 +148,8 @@ void Yggdrasil::login(QString password) {
 
     QJsonDocument doc(req);
 
-    QUrl reqUrl("https://authserver.mojang.com/authenticate");
+    QUrl reqUrl = getBaseUrl() + "/authenticate";
+    qDebug() << "baseurl = " << getBaseUrl() << "requrl = " << reqUrl;
     QNetworkRequest netRequest(reqUrl);
     QByteArray requestData = doc.toJson();
 

launcher/minecraft/auth/Yggdrasil.h

@@ -90,6 +90,7 @@ public slots:
 
 private:
     void sendRequest(QUrl endpoint, QByteArray content);
+    QString getBaseUrl();
 
 protected:
     QNetworkReply *m_netReply = nullptr;

launcher/minecraft/auth/flows/AuthlibInjector.cpp

@@ -0,0 +1,29 @@
+#include "AuthlibInjector.h"
+
+#include "minecraft/auth/steps/AuthlibInjectorStep.h"
+#include "minecraft/auth/steps/MinecraftProfileStepMojang.h"
+#include "minecraft/auth/steps/YggdrasilStep.h"
+#include "minecraft/auth/steps/MinecraftProfileStep.h"
+#include "minecraft/auth/steps/MigrationEligibilityStep.h"
+#include "minecraft/auth/steps/GetSkinStep.h"
+
+AuthlibInjectorRefresh::AuthlibInjectorRefresh(
+    AccountData *data,
+    QObject *parent
+) : AuthFlow(data, parent) {
+    m_steps.append(new AuthlibInjectorStep(m_data));
+    m_steps.append(new YggdrasilStep(m_data, QString()));
+    m_steps.append(new MinecraftProfileStepMojang(m_data));
+    m_steps.append(new GetSkinStep(m_data));
+}
+
+AuthlibInjectorLogin::AuthlibInjectorLogin(
+    AccountData *data,
+    QString password,
+    QObject *parent
+): AuthFlow(data, parent), m_password(password) {
+    m_steps.append(new AuthlibInjectorStep(m_data));
+    m_steps.append(new YggdrasilStep(m_data, m_password));
+    m_steps.append(new MinecraftProfileStepMojang(m_data));
+    m_steps.append(new GetSkinStep(m_data));
+}

launcher/minecraft/auth/flows/AuthlibInjector.h

@@ -0,0 +1,26 @@
+#pragma once
+#include "AuthFlow.h"
+
+class AuthlibInjectorRefresh : public AuthFlow
+{
+    Q_OBJECT
+public:
+    explicit AuthlibInjectorRefresh(
+        AccountData *data,
+        QObject *parent = 0
+    );
+};
+
+class AuthlibInjectorLogin : public AuthFlow
+{
+    Q_OBJECT
+public:
+    explicit AuthlibInjectorLogin(
+        AccountData *data,
+        QString password,
+        QObject *parent = 0
+    );
+
+private:
+    QString m_password;
+};

launcher/minecraft/auth/steps/AuthlibInjectorStep.cpp

@@ -0,0 +1,58 @@
+#include "AuthlibInjectorStep.h"
+#include "Application.h"
+
+#include <iostream>
+
+#include <QNetworkRequest>
+#include <QUuid>
+
+AuthlibInjectorStep::AuthlibInjectorStep(AccountData* data) : AuthStep(data) {
+}
+
+AuthlibInjectorStep::~AuthlibInjectorStep() noexcept = default;
+
+QString AuthlibInjectorStep::describe() {
+    return tr("Fetching authlib injector API URL");
+}
+
+
+void AuthlibInjectorStep::perform() {
+    // Default to the same as the base URL
+    QUrl url;
+    url.setScheme("https");
+    url.setAuthority(m_data->authlibInjectorBaseUrl);
+    qDebug() << url << url.toString() << url.isLocalFile();
+    m_data->authlibInjectorApiLocation = url.toString();
+    QNetworkRequest request = QNetworkRequest(url);
+    m_reply.reset( APPLICATION->network()->get(request));
+    connect(m_reply.get(), &QNetworkReply::finished, this, &AuthlibInjectorStep::onRequestDone);
+    qDebug() << "Fetching authlib injector API URL";
+}
+
+void AuthlibInjectorStep::rehydrate() {
+    // NOOP, for now. We only save bools and there's nothing to check.
+}
+
+void AuthlibInjectorStep::onRequestDone() {
+    if (m_reply->hasRawHeader("x-authlib-injector-api-location"))
+    {
+        QString authlibInjectorApiLocationHeader = m_reply->rawHeader("x-authlib-injector-api-location");
+        QUrl url = authlibInjectorApiLocationHeader;
+        if (!url.isValid())
+        {
+            qDebug() << "Invalid Authlib Injector API URL specified by server: " << authlibInjectorApiLocationHeader;
+            emit finished(AccountTaskState::STATE_FAILED_HARD, tr("Invalid authlib injector API URL"));
+        }
+        else
+        {
+            m_data->authlibInjectorApiLocation = authlibInjectorApiLocationHeader;
+            qDebug() << "Authlib injector API URL: " << m_data->authlibInjectorApiLocation;
+            emit finished(AccountTaskState::STATE_WORKING, tr("Fetched authlib injector API URL"));
+        }
+    }
+    else
+    {
+        qDebug() << "Authlib injector API URL not found";
+        emit finished(AccountTaskState::STATE_WORKING, tr("Authlib injector API URL not found, defaulting to the supplied base URL"));
+    }
+}

launcher/minecraft/auth/steps/AuthlibInjectorStep.h

@@ -0,0 +1,24 @@
+#pragma once
+#include <QObject>
+
+#include "QObjectPtr.h"
+#include "minecraft/auth/AuthStep.h"
+
+
+class AuthlibInjectorStep : public AuthStep {
+    Q_OBJECT
+
+public:
+    explicit AuthlibInjectorStep(AccountData *data);
+    virtual ~AuthlibInjectorStep() noexcept;
+
+    void perform() override;
+    void rehydrate() override;
+
+    QString describe() override;
+
+private slots:
+    void onRequestDone();
+private:
+    std::unique_ptr<QNetworkReply> m_reply;
+};

launcher/minecraft/auth/steps/MinecraftProfileStep.cpp

@@ -7,7 +7,21 @@
 #include "net/NetUtils.h"
 
 MinecraftProfileStep::MinecraftProfileStep(AccountData* data) : AuthStep(data) {
-
+    switch (m_data->type)
+    {
+        case AccountType::Mojang: {
+            baseUrl = "https://api.minecraftservices.com";
+            break;
+        }
+        case AccountType::AuthlibInjector: {
+            baseUrl = m_data->authlibInjectorApiLocation + "/minecraftservices";
+            break;
+        }
+        // Silence warnings about unhandled enum values for values we know shouldn't be handled.
+        case AccountType::MSA:
+        case AccountType::Offline:
+        break;
+    }
 }
 
 MinecraftProfileStep::~MinecraftProfileStep() noexcept = default;
@@ -18,7 +32,7 @@ QString MinecraftProfileStep::describe() {
 
 
 void MinecraftProfileStep::perform() {
-    auto url = QUrl("https://api.minecraftservices.com/minecraft/profile");
+    QUrl url = baseUrl + "/minecraft/profile";
     QNetworkRequest request = QNetworkRequest(url);
     request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
     request.setRawHeader("Authorization", QString("Bearer %1").arg(m_data->yggdrasilToken.token).toUtf8());

launcher/minecraft/auth/steps/MinecraftProfileStep.h

@@ -19,4 +19,7 @@ public:
 
 private slots:
     void onRequestDone(QNetworkReply::NetworkError, QByteArray, QList<QNetworkReply::RawHeaderPair>);
+
+private:
+    QString baseUrl;
 };

launcher/minecraft/auth/steps/MinecraftProfileStepMojang.cpp

@@ -6,8 +6,24 @@
 #include "minecraft/auth/Parsers.h"
 #include "net/NetUtils.h"
 
-MinecraftProfileStepMojang::MinecraftProfileStepMojang(AccountData* data) : AuthStep(data) {
+MinecraftProfileStepMojang::MinecraftProfileStepMojang(AccountData* data) : AuthStep(data) {}
 
+QString MinecraftProfileStepMojang::getBaseUrl()
+{
+    switch (m_data->type)
+    {
+        case AccountType::Mojang: {
+          return "https://sessionserver.mojang.com";
+        }
+        case AccountType::AuthlibInjector: {
+            return m_data->authlibInjectorApiLocation + "/sessionserver";
+        }
+        // Silence warnings about unhandled enum values for values we know shouldn't be handled.
+        case AccountType::MSA:
+        case AccountType::Offline:
+        break;
+    }
+    return "";
 }
 
 MinecraftProfileStepMojang::~MinecraftProfileStepMojang() noexcept = default;
@@ -24,7 +40,7 @@ void MinecraftProfileStepMojang::perform() {
     }
 
     // use session server instead of profile due to profile endpoint being locked for locked Mojang accounts
-    QUrl url = QUrl("https://sessionserver.mojang.com/session/minecraft/profile/" + m_data->minecraftProfile.id);
+    QUrl url = getBaseUrl() + "/session/minecraft/profile/" + m_data->minecraftProfile.id;
     QNetworkRequest req = QNetworkRequest(url);
     AuthRequest *request = new AuthRequest(this);
     connect(request, &AuthRequest::finished, this, &MinecraftProfileStepMojang::onRequestDone);

launcher/minecraft/auth/steps/MinecraftProfileStepMojang.h

@@ -19,4 +19,7 @@ public:
 
 private slots:
     void onRequestDone(QNetworkReply::NetworkError, QByteArray, QList<QNetworkReply::RawHeaderPair>);
+
+private:
+    QString getBaseUrl();
 };

launcher/minecraft/auth/steps/YggdrasilStep.cpp

@@ -1,5 +1,6 @@
 #include "YggdrasilStep.h"
 
+#include "minecraft/auth/AccountData.h"
 #include "minecraft/auth/AuthRequest.h"
 #include "minecraft/auth/Parsers.h"
 #include "minecraft/auth/Yggdrasil.h"
@@ -15,7 +16,14 @@ YggdrasilStep::YggdrasilStep(AccountData* data, QString password) : AuthStep(dat
 YggdrasilStep::~YggdrasilStep() noexcept = default;
 
 QString YggdrasilStep::describe() {
-    return tr("Logging in with Mojang account.");
+  switch(m_data->type) {
+    case(AccountType::Mojang):
+      return tr("Logging in with Mojang account.");
+    case AccountType::AuthlibInjector:
+      return tr("Logging in with %1 account.").arg(m_data->authlibInjectorBaseUrl);
+    default:
+      break;
+  }
 }
 
 void YggdrasilStep::rehydrate() {
@@ -32,7 +40,9 @@ void YggdrasilStep::perform() {
 }
 
 void YggdrasilStep::onAuthSucceeded() {
-    emit finished(AccountTaskState::STATE_WORKING, tr("Logged in with Mojang"));
+    emit m_data->type == AccountType::Mojang 
+                         ? finished(AccountTaskState::STATE_WORKING, tr("Logged in with Mojang"))
+                         : finished(AccountTaskState::STATE_WORKING, tr("Logged in with %1").arg(m_data->authlibInjectorBaseUrl));
 }
 
 void YggdrasilStep::onAuthFailed() {
@@ -41,12 +51,32 @@ void YggdrasilStep::onAuthFailed() {
     // m_aborted = m_yggdrasil->m_aborted;
 
     auto state = m_yggdrasil->taskState();
-    QString errorMessage = tr("Mojang user authentication failed.");
+    QString errorMessage = m_data->type == AccountType::Mojang
+                                           ? tr("Mojang user authentication failed.")
+                                           : tr("%1 user authentication failed").arg(m_data->authlibInjectorBaseUrl);
 
     // NOTE: soft error in the first step means 'offline'
     if(state == AccountTaskState::STATE_FAILED_SOFT) {
         state = AccountTaskState::STATE_OFFLINE;
-        errorMessage = tr("Mojang user authentication ended with a network error.");
+        switch(m_data->type) {
+          case AccountType::Mojang:
+          {
+            errorMessage = tr("Mojang user authentication ended with a network error.");
+            break;
+          }
+          case AccountType::AuthlibInjector:
+          {
+            if(m_data->authlibInjectorBaseUrl.isEmpty())
+            {
+              errorMessage = tr("User authentication ended with a network error, did specify a url?");
+            } else {
+              errorMessage = tr("%1 user authentication ended with a network error").arg(m_data->authlibInjectorBaseUrl);
+            }
+            break;
+          }
+          default:
+            break;
+        }
     }
     emit finished(state, errorMessage);
 }

launcher/minecraft/launch/ConfigureAuthlibInjector.cpp

@@ -0,0 +1,80 @@
+#include "ConfigureAuthlibInjector.h"
+#include <launch/LaunchTask.h>
+#include <QDir>
+#include <QFileInfo>
+#include <QJsonDocument>
+#include <Qt>
+
+#include "Application.h"
+#include "minecraft/auth/AccountList.h"
+#include "net/ChecksumValidator.h"
+#include "net/Download.h"
+#include "net/HttpMetaCache.h"
+#include "net/NetAction.h"
+
+ConfigureAuthlibInjector::ConfigureAuthlibInjector(LaunchTask* parent,
+                                                   QString authlibinjector_base_url,
+                                                   std::shared_ptr<QString> javaagent_arg)
+    : LaunchStep(parent), m_javaagent_arg{ javaagent_arg }, m_authlibinjector_base_url{ authlibinjector_base_url }
+{}
+
+void ConfigureAuthlibInjector::executeTask()
+{
+    auto downloadFailed = [this] (QString reason) {
+        return emitFailed(QString("Download failed: %1").arg(reason));
+    };
+    auto entry = APPLICATION->metacache()->resolveEntry("authlibinjector", "latest.json");
+
+    entry->setStale(true);
+    m_job = std::make_unique<NetJob>("Download authlibinjector latest.json", APPLICATION->network());
+    auto latestJsonDl =
+        Net::Download::makeCached(QUrl("https://authlib-injector.yushi.moe/artifact/latest.json"), entry, Net::Download::Option::NoOptions);
+    m_job->addNetAction(latestJsonDl);
+    connect(m_job.get(), &NetJob::succeeded, this, [this, entry, downloadFailed] {
+        QFile authlibInjectorLatestJson = entry->getFullPath();
+        authlibInjectorLatestJson.open(QIODevice::ReadOnly);
+        if (!authlibInjectorLatestJson.isOpen())
+            return emitFailed(QString("Failed to open authlib-injector info json: %1").arg(authlibInjectorLatestJson.errorString()));
+
+        QJsonParseError json_parse_error;
+        QJsonDocument doc = QJsonDocument::fromJson(authlibInjectorLatestJson.readAll(), &json_parse_error);
+        if (json_parse_error.error != QJsonParseError::NoError)
+            return emitFailed(QString("Failed to parse authlib-injector info json: %1").arg(json_parse_error.errorString()));
+
+        if (!doc.isObject())
+            return emitFailed(QString("Failed to parse authlib-injector info json: not a json object"));
+        QJsonObject obj = doc.object();
+
+        QString authlibInjectorJarUrl = obj["download_url"].toString();
+        if (authlibInjectorJarUrl.isNull())
+            return emitFailed(QString("Failed to parse authlib-injector info json: download url missing"));
+
+        QString sha256Sum = obj["checksums"].toObject()["sha256"].toString();
+        if (sha256Sum.isNull())
+            return emitFailed("Failed to parse authlib-injector info json: sha256 checksum missing");
+
+        auto sha256SumRaw = QByteArray::fromHex(sha256Sum.toLatin1());
+
+        QString filename = QFileInfo(authlibInjectorJarUrl).fileName();
+        auto javaAgentEntry = APPLICATION->metacache()->resolveEntry("authlibinjector", filename);
+        m_job = std::make_unique<NetJob>("Download authlibinjector java agent", APPLICATION->network());
+        auto javaAgentDl = Net::Download::makeCached(QUrl(authlibInjectorJarUrl), javaAgentEntry, Net::Download::Option::MakeEternal);
+        javaAgentDl->addValidator(new Net::ChecksumValidator(QCryptographicHash::Sha256, sha256SumRaw));
+        m_job->addNetAction(javaAgentDl);
+        connect(m_job.get(), &NetJob::succeeded, this, [this, javaAgentEntry] {
+            auto path = javaAgentEntry->getFullPath();
+            qDebug() << path;
+            *m_javaagent_arg = QString("%1=%2").arg(path).arg(m_authlibinjector_base_url);
+            emitSucceeded();
+        });
+        connect(m_job.get(), &NetJob::failed, this, downloadFailed);
+        m_job->start();
+    },
+    // This slot can't run instantly because it needs to wait for the netjob's code to stop running
+    // Since it will destroy the old netjob by reassigning the unique_ptr
+    Qt::QueuedConnection);
+    connect(m_job.get(), &NetJob::failed, this, downloadFailed);
+    m_job->start();
+}
+
+void ConfigureAuthlibInjector::finalize() {}

launcher/minecraft/launch/ConfigureAuthlibInjector.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <launch/LaunchStep.h>
+#include <minecraft/auth/MinecraftAccount.h>
+#include "net/NetJob.h"
+
+class ConfigureAuthlibInjector: public LaunchStep
+{
+    Q_OBJECT
+public:
+    explicit ConfigureAuthlibInjector(LaunchTask *parent, QString authlibinjector_base_url, std::shared_ptr<QString> javaagent_arg);
+    virtual ~ConfigureAuthlibInjector() {};
+
+    void executeTask() override;
+    void finalize() override;
+    bool canAbort() const override
+    {
+        return false;
+    }
+private:
+    std::unique_ptr<NetJob> m_job;
+    std::shared_ptr<QString> m_javaagent_arg;
+    QString m_authlibinjector_base_url;
+};

launcher/ui/dialogs/LoginDialog.cpp

@@ -20,9 +20,10 @@
 
 #include <QtWidgets/QPushButton>
 
-LoginDialog::LoginDialog(QWidget *parent) : QDialog(parent), ui(new Ui::LoginDialog)
+LoginDialog::LoginDialog(QWidget *parent, AccountType type) : QDialog(parent), ui(new Ui::LoginDialog), m_accountType{type}
 {
     ui->setupUi(this);
+    ui->authlibInjectorBaseTextBox->setVisible(m_accountType == AccountType::AuthlibInjector);
     ui->progressBar->setVisible(false);
     ui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(false);
 
@@ -42,7 +43,14 @@ void LoginDialog::accept()
     ui->progressBar->setVisible(true);
 
     // Setup the login task and start it
-    m_account = MinecraftAccount::createFromUsername(ui->userTextBox->text());
+    if (m_accountType == AccountType::Mojang)
+    {
+        m_account = MinecraftAccount::createFromUsername(ui->userTextBox->text());
+    }
+    else if (m_accountType == AccountType::AuthlibInjector)
+    {
+        m_account = MinecraftAccount::createAuthlibInjectorFromUsername(ui->userTextBox->text(), ui->authlibInjectorBaseTextBox->text());
+    }
     m_loginTask = m_account->login(ui->passTextBox->text());
     connect(m_loginTask.get(), &Task::failed, this, &LoginDialog::onTaskFailed);
     connect(m_loginTask.get(), &Task::succeeded, this, &LoginDialog::onTaskSucceeded);
@@ -106,10 +114,9 @@ void LoginDialog::onTaskProgress(qint64 current, qint64 total)
     ui->progressBar->setValue(current);
 }
 
-// Public interface
-MinecraftAccountPtr LoginDialog::newAccount(QWidget *parent, QString msg)
+MinecraftAccountPtr LoginDialog::newAccount(QWidget *parent, QString msg, AccountType type)
 {
-    LoginDialog dlg(parent);
+    LoginDialog dlg(parent, type);
     dlg.ui->label->setText(msg);
     if (dlg.exec() == QDialog::Accepted)
     {

launcher/ui/dialogs/LoginDialog.h

@@ -18,6 +18,7 @@
 #include <QtWidgets/QDialog>
 #include <QtCore/QEventLoop>
 
+#include "minecraft/auth/AccountData.h"
 #include "minecraft/auth/MinecraftAccount.h"
 #include "tasks/Task.h"
 
@@ -33,10 +34,13 @@ class LoginDialog : public QDialog
 public:
     ~LoginDialog();
 
-    static MinecraftAccountPtr newAccount(QWidget *parent, QString message);
+    /*
+     * @param type: Mojang or Authlib
+     */
+    static MinecraftAccountPtr newAccount(QWidget *parent, QString message, AccountType type = AccountType::Mojang);
 
 private:
-    explicit LoginDialog(QWidget *parent = 0);
+    explicit LoginDialog(QWidget *parent = 0, AccountType type = AccountType::Mojang);
 
     void setUserInputsEnabled(bool enable);
 
@@ -56,4 +60,5 @@ private:
     Ui::LoginDialog *ui;
     MinecraftAccountPtr m_account;
     Task::Ptr m_loginTask;
+    AccountType m_accountType;
 };

launcher/ui/dialogs/LoginDialog.ui

@@ -33,6 +33,13 @@
      </property>
     </widget>
    </item>
+   <item>
+    <widget class="QLineEdit" name="authlibInjectorBaseTextBox">
+     <property name="placeholderText">
+      <string>AuthlibInjector base URL (e.g. ely.by)</string>
+     </property>
+    </widget>
+   </item>
    <item>
     <widget class="QLineEdit" name="userTextBox">
      <property name="placeholderText">

launcher/ui/pages/global/AccountListPage.cpp

@@ -157,6 +157,36 @@ void AccountListPage::on_actionAddMojang_triggered()
     }
 }
 
+void AccountListPage::on_actionAddAuthlibInjector_triggered()
+{
+    if (!m_accounts->drmCheck()) {
+        QMessageBox::warning(
+            this,
+            tr("Error"),
+            tr(
+                "You must add a Microsoft or Mojang account that owns Minecraft before you can add an Authlib Injector account."
+                "<br><br>"
+                "If you have lost your account you can contact Microsoft for support."
+            )
+        );
+        return;
+    }
+
+    MinecraftAccountPtr account = LoginDialog::newAccount(
+        this,
+        tr("Please enter the AuthlibInjector base URL, and enter your account email and password to add your account."),
+        AccountType::AuthlibInjector
+    );
+
+    if (account)
+    {
+        m_accounts->addAccount(account);
+        if (m_accounts->count() == 1) {
+            m_accounts->setDefaultAccount(account);
+        }
+    }
+}
+
 void AccountListPage::on_actionAddMicrosoft_triggered()
 {
     if(BuildConfig.BUILD_PLATFORM == "osx64") {

launcher/ui/pages/global/AccountListPage.h

@@ -83,6 +83,7 @@ public:
 
 public slots:
     void on_actionAddMojang_triggered();
+    void on_actionAddAuthlibInjector_triggered();
     void on_actionAddMicrosoft_triggered();
     void on_actionAddOffline_triggered();
     void on_actionRemove_triggered();

launcher/ui/pages/global/AccountListPage.ui

@@ -54,6 +54,7 @@
    </attribute>
    <addaction name="actionAddMicrosoft"/>
    <addaction name="actionAddMojang"/>
+   <addaction name="actionAddAuthlibInjector"/>
    <addaction name="actionAddOffline"/>
    <addaction name="actionRefresh"/>
    <addaction name="actionRemove"/>
@@ -68,6 +69,11 @@
     <string>Add &amp;Mojang</string>
    </property>
   </action>
+  <action name="actionAddAuthlibInjector">
+   <property name="text">
+    <string>Add Authlib-&amp;Injector</string>
+   </property>
+  </action>
   <action name="actionRemove">
    <property name="text">
     <string>Remo&amp;ve</string>