- Sorry, but I haven't got any good name for this commit

- This commit has been on my computer for like 6 months untouched

21 files changed, 1657 insertions, 0 deletions

diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/DGInterface.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/DGInterface.java
new file mode 100755
index 00000000..c88a3cbf
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/DGInterface.java
@@ -0,0 +1,31 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher;
+
+import net.minecraft.client.resources.IResourceManager;
+import net.minecraftforge.fml.common.event.FMLInitializationEvent;
+import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;
+
+import java.io.File;
+
+public interface DGInterface {
+    void init(File resourceDir);
+    void unload();
+    void onResourceReload(IResourceManager a);
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/DungeonsGuideReloadListener.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/DungeonsGuideReloadListener.java
new file mode 100644
index 00000000..7252a9db
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/DungeonsGuideReloadListener.java
@@ -0,0 +1,24 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher;
+
+public interface DungeonsGuideReloadListener {
+    public void unloadReference();
+    public void onLoad(DGInterface dgInterface);
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/Main.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/Main.java
new file mode 100755
index 00000000..c279d812
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/Main.java
@@ -0,0 +1,296 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher;
+
+import kr.syeyoung.dungeonsguide.launcher.exceptions.AuthServerException;
+import kr.syeyoung.dungeonsguide.launcher.authentication.Authenticator;
+import kr.syeyoung.dungeonsguide.launcher.branch.ModDownloader;
+import kr.syeyoung.dungeonsguide.launcher.exceptions.NoSuitableLoaderFoundException;
+import kr.syeyoung.dungeonsguide.launcher.exceptions.PrivacyPolicyRequiredException;
+import kr.syeyoung.dungeonsguide.launcher.exceptions.ReferenceLeakedException;
+import kr.syeyoung.dungeonsguide.launcher.exceptions.TokenExpiredException;
+import kr.syeyoung.dungeonsguide.launcher.gui.GuiLoadingError;
+import kr.syeyoung.dungeonsguide.launcher.loader.IDGLoader;
+import kr.syeyoung.dungeonsguide.launcher.loader.JarLoader;
+import kr.syeyoung.dungeonsguide.launcher.loader.LocalLoader;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.gui.GuiErrorScreen;
+import net.minecraft.client.gui.GuiMainMenu;
+import net.minecraft.client.gui.GuiScreen;
+import net.minecraft.client.resources.IReloadableResourceManager;
+import net.minecraftforge.client.event.GuiOpenEvent;
+import net.minecraftforge.common.MinecraftForge;
+import net.minecraftforge.common.config.Configuration;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.common.Mod.EventHandler;
+import net.minecraftforge.fml.common.ProgressManager;
+import net.minecraftforge.fml.common.event.FMLInitializationEvent;
+import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;
+import net.minecraftforge.fml.common.eventhandler.EventPriority;
+import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
+
+import java.io.*;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+
+@Mod(modid = Main.MOD_ID, version = Main.VERSION)
+public class Main
+{
+    public static final String MOD_ID = "dungeons_guide_wrapper";
+    public static final String VERSION = "1.0";
+    public static final String DOMAIN = "http://testmachine:8080/panel/api";
+
+    private static Main main;
+
+    private File configDir;
+
+    private DGInterface dgInterface;
+    private Authenticator authenticator = new Authenticator();
+    private ModDownloader modDownloader = new ModDownloader(authenticator);
+
+    private List<DungeonsGuideReloadListener> listeners = new ArrayList<>();
+
+    public void addDGReloadListener(DungeonsGuideReloadListener dungeonsGuideReloadListener) {
+        listeners.add(Objects.requireNonNull(dungeonsGuideReloadListener));
+    }
+    public void removeDGReloadListener(DungeonsGuideReloadListener dungeonsGuideReloadListener) {
+        listeners.remove(dungeonsGuideReloadListener);
+    }
+
+    private IDGLoader currentLoader;
+
+    private Throwable lastError;
+    private boolean isMcLoaded;
+
+
+
+
+    @EventHandler
+    public void initEvent(FMLInitializationEvent initializationEvent)
+    {
+        MinecraftForge.EVENT_BUS.register(this);
+        if (dgInterface != null) {
+            try {
+                dgInterface.init(configDir);
+
+                for (DungeonsGuideReloadListener listener : listeners) {
+                    listener.onLoad(dgInterface);
+                }
+            } catch (Exception e) {
+                e.printStackTrace();
+                lastError = e;
+                tryOpenError();
+            }
+        }
+    }
+
+    public void unload() throws ReferenceLeakedException {
+        if (currentLoader != null && !currentLoader.isUnloadable()) {
+            throw new UnsupportedOperationException("Current version is not unloadable");
+        }
+        dgInterface = null;
+        for (DungeonsGuideReloadListener listener : listeners) {
+            listener.unloadReference();
+        }
+        if (currentLoader != null) {
+            currentLoader.unloadJar();
+        }
+        currentLoader = null;
+    }
+    public void load(IDGLoader newLoader) throws ClassNotFoundException, InstantiationException, IllegalAccessException {
+        if (dgInterface != null) throw new IllegalStateException("DG is loaded");
+        newLoader.loadJar(authenticator);
+        dgInterface = newLoader.getInstance();
+        currentLoader = newLoader;
+
+        dgInterface.init(configDir);
+
+        for (DungeonsGuideReloadListener listener : listeners) {
+            listener.onLoad(dgInterface);
+        }
+    }
+    private void partialLoad(IDGLoader newLoader) throws ClassNotFoundException, InstantiationException, IllegalAccessException {
+        if (dgInterface != null) throw new IllegalStateException("DG is loaded");
+        newLoader.loadJar(authenticator);
+        dgInterface = newLoader.getInstance();
+        currentLoader = newLoader;
+    }
+
+    public void reload(IDGLoader newLoader) {
+        try {
+            unload();
+            load(newLoader);
+        } catch (Exception e) {
+            e.printStackTrace();
+            lastError = e;
+            dgInterface = null;
+            currentLoader = null;
+            tryOpenError();
+        }
+    }
+
+    public void tryOpenError() {
+        if (isMcLoaded) Minecraft.getMinecraft().displayGuiScreen(obtainErrorGUI());
+    }
+
+    public GuiScreen obtainErrorGUI() {
+        if (lastError instanceof PrivacyPolicyRequiredException) {
+
+        } else if (lastError instanceof TokenExpiredException) {
+
+        } else if (lastError instanceof NoSuitableLoaderFoundException) {
+
+        } else if (lastError instanceof ReferenceLeakedException) {
+
+        } else if (lastError instanceof AuthServerException) {
+
+        } else if (lastError != null){
+            return new GuiLoadingError(lastError, () -> {lastError = null;});
+        }
+        if (lastError != null)
+            lastError.printStackTrace();
+        // when gets called init and stuff remove thing
+        return null;
+    }
+
+    @SubscribeEvent(priority = EventPriority.LOWEST)
+    public void onGuiOpen(GuiOpenEvent guiOpenEvent) {
+        if (guiOpenEvent.gui instanceof GuiMainMenu) {
+            isMcLoaded = true;
+        }
+        if (lastError != null && guiOpenEvent.gui instanceof GuiMainMenu) {
+            guiOpenEvent.gui = obtainErrorGUI();
+        }
+    }
+
+    public String getLoaderName(Configuration configuration) {
+        String loader = System.getProperty("dg.loader");
+        if (loader == null) {
+            loader = configuration.get("loader", "modsource", "auto").getString();
+        }
+        if (loader == null) loader = "auto";
+        return loader;
+    }
+
+
+    public IDGLoader obtainLoader(Configuration configuration) {
+        String loader = getLoaderName(configuration);
+
+        if ("local".equals(loader) ||
+                (loader.equals("auto") && this.getClass().getResourceAsStream("/kr/syeyoung/dungeonsguide/DungeonsGuide.class") == null)) {
+            return new LocalLoader();
+        } else if ("jar".equals(loader) ||
+                (loader.equals("auto") && this.getClass().getResourceAsStream("/mod.jar") == null)) {
+            return new JarLoader();
+        } else if (loader.equals("auto") ){
+                // remote load
+            throw new UnsupportedOperationException(""); // yet
+        } else {
+            throw new NoSuitableLoaderFoundException(System.getProperty("dg.loader"), configuration.get("loader", "modsource", "auto").getString());
+        }
+    }
+
+    @EventHandler
+    public void preInit(FMLPreInitializationEvent preInitializationEvent) {
+        main = this;
+        configDir = preInitializationEvent.getModConfigurationDirectory();
+        ProgressManager.ProgressBar bar = null;
+        try {
+            bar = ProgressManager.push("DungeonsGuide",2);
+            bar.step("Authenticating...");
+            authenticator.repeatAuthenticate(5);
+
+            File f = new File(preInitializationEvent.getModConfigurationDirectory(), "loader.cfg");
+            Configuration configuration = new Configuration(f);
+            bar.step("Instantiating...");
+
+            partialLoad(obtainLoader(configuration));
+
+            configuration.save();
+        } catch (Throwable t) {
+            t.printStackTrace();
+            lastError = t;
+            dgInterface = null;
+            currentLoader = null;
+            tryOpenError();
+        } finally {
+            if (bar != null) {
+                while(bar.getStep() < bar.getSteps()) bar.step("");
+                ProgressManager.pop(bar);
+            }
+        }
+
+        ((IReloadableResourceManager) Minecraft.getMinecraft().getResourceManager()).registerReloadListener(a -> {
+            if (dgInterface != null) dgInterface.onResourceReload(a);
+        });
+//        try {
+//            token = authenticator.authenticateAndDownload(this.getClass().getResourceAsStream("/kr/syeyoung/dungeonsguide/DungeonsGuide.class") == null ? System.getProperty("dg.version") == null ? "nlatest" : System.getProperty("dg.version") : null);
+//            if (token != null) {
+//                main = this;
+//                URL.setURLStreamHandlerFactory(new DGStreamHandlerFactory(authenticator));
+//                LaunchClassLoader classLoader = (LaunchClassLoader) Main.class.getClassLoader();
+//                classLoader.addURL(new URL("z:///"));
+//
+//                try {
+//                    progressBar.step("Initializing");
+//                    this.dgInterface = new DungeonsGuide(authenticator);
+//                    this.dgInterface.pre(preInitializationEvent);
+//                    while (progressBar.getStep() < progressBar.getSteps())
+//                        progressBar.step("random-"+progressBar.getStep());
+//                    ProgressManager.pop(progressBar);
+//                    isLoaded = true;
+//                } catch (Throwable e) {
+//                    cause = e;
+//                    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
+//                    PrintStream printStream = new PrintStream(byteArrayOutputStream);
+//                    e.printStackTrace(printStream);
+//                    stacktrace = new String(byteArrayOutputStream.toByteArray());
+//
+//                    while (progressBar.getStep() < progressBar.getSteps())
+//                        progressBar.step("random-"+progressBar.getStep());
+//                    ProgressManager.pop(progressBar);
+//
+//                    e.printStackTrace();
+//                }
+//            }
+//        } catch (IOException  | AuthenticationException | NoSuchAlgorithmException | CertificateException | KeyStoreException | KeyManagementException | InvalidKeySpecException | SignatureException e) {
+//            cause = e;
+//            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
+//            PrintStream printStream = new PrintStream(byteArrayOutputStream);
+//            e.printStackTrace(printStream);
+//            stacktrace = new String(byteArrayOutputStream.toByteArray());
+//
+//            while (progressBar.getStep() < progressBar.getSteps())
+//                progressBar.step("random-"+progressBar.getStep());
+//            ProgressManager.pop(progressBar);
+//
+//            e.printStackTrace();
+//        }
+    }
+
+    public void setLastError(Throwable t) {
+        lastError = t;
+        tryOpenError();
+    }
+
+    public static Main getMain() {
+        return main;
+    }
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/authentication/Authenticator.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/authentication/Authenticator.java
new file mode 100755
index 00000000..627a058f
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/authentication/Authenticator.java
@@ -0,0 +1,252 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.authentication;
+
+import com.mojang.authlib.exceptions.AuthenticationException;
+import com.mojang.authlib.minecraft.MinecraftSessionService;
+import kr.syeyoung.dungeonsguide.launcher.Main;
+import kr.syeyoung.dungeonsguide.launcher.exceptions.AuthServerException;
+import kr.syeyoung.dungeonsguide.launcher.exceptions.PrivacyPolicyRequiredException;
+import kr.syeyoung.dungeonsguide.launcher.exceptions.TokenExpiredException;
+import lombok.Getter;
+import net.minecraft.client.Minecraft;
+import net.minecraft.util.Session;
+import org.apache.commons.codec.binary.Base64;
+import org.apache.commons.io.IOUtils;
+import org.json.JSONObject;
+import sun.reflect.Reflection;
+
+import javax.crypto.*;
+import javax.net.ssl.*;
+import java.io.*;
+import java.math.BigInteger;
+import java.net.*;
+import java.security.*;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.X509EncodedKeySpec;
+import java.time.Instant;
+import java.util.UUID;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+
+public class Authenticator {
+    private String token;
+    private Instant validThru;
+    @Getter
+    private TokenStatus tokenStatus = TokenStatus.UNAUTHENTICATED;
+
+    private final SecureRandom secureRandom = new SecureRandom();
+
+    private Lock authenticationLock = new ReentrantLock();
+
+    static {
+        Reflection.registerFieldsToFilter(Authenticator.class, "token"); // Please do not touch this field. I know there is a way to block it completely, but I won't do it here.
+    }
+
+    public String getRawToken() {
+        return token;
+    }
+    public String getUnexpiredToken() {
+        if (tokenStatus != TokenStatus.AUTHENTICATED) throw new IllegalStateException("Token is not available");
+        long expiry = getJwtPayload(token).getLong("exp");
+        if (System.currentTimeMillis() >= expiry-2000 || tokenStatus == TokenStatus.EXPIRED) {
+            tokenStatus = TokenStatus.EXPIRED;
+            try {
+                repeatAuthenticate(5);
+            } catch (Throwable t) {
+                Main.getMain().setLastError(t);
+                throw new TokenExpiredException(t);
+            }
+        }
+        return token;
+    }
+
+
+    private byte[] generateSharedSecret() {
+        byte[] bts = new byte[32];
+        secureRandom.nextBytes(bts);
+        return bts;
+    }
+
+    public String repeatAuthenticate(int tries) {
+        int cnt = 0;
+        while(true) {
+            try {
+                reauthenticate();
+                break;
+            } catch (IOException | AuthenticationException | NoSuchAlgorithmException e) {
+                e.printStackTrace();
+                if (cnt == tries) throw new RuntimeException(e);
+                try {
+                    Thread.sleep((long) Math.max(Math.pow(2, tries)* 100, 1000 * 10));
+                } catch (InterruptedException ex) {}
+            }
+            cnt++;
+        }
+        return token;
+    }
+    public String reauthenticate() throws IOException, AuthenticationException, NoSuchAlgorithmException {
+        try {
+            authenticationLock.lock();
+
+            MinecraftSessionService yggdrasilMinecraftSessionService = Minecraft.getMinecraft().getSessionService();
+            Session session = Minecraft.getMinecraft().getSession();
+
+            tokenStatus = TokenStatus.UNAUTHENTICATED;
+            token = null;
+            token = requestAuth(session.getProfile().getId(), session.getProfile().getName());
+            JSONObject d = getJwtPayload(token);
+
+            byte[] sharedSecret = generateSharedSecret();
+
+
+            String hash = calculateServerHash(sharedSecret,
+                    Base64.decodeBase64(d.getString("publicKey")));
+
+            byte[] encodedSharedSecret;
+            try {
+                Cipher cipher = Cipher.getInstance("RSA");
+                cipher.init(Cipher.ENCRYPT_MODE, KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(Base64.decodeBase64(d.getString("publicKey")))));
+                encodedSharedSecret = cipher.doFinal(sharedSecret);
+            } catch (NoSuchPaddingException | IllegalBlockSizeException | BadPaddingException |
+                     InvalidKeySpecException |
+                     InvalidKeyException e) {
+                throw new RuntimeException(e);
+            }
+
+            yggdrasilMinecraftSessionService.joinServer(session.getProfile(), session.getToken(), hash); // Sent to "MOJANG" Server.
+            JSONObject furtherStuff = verifyAuth(token, encodedSharedSecret);
+            token = furtherStuff.getString("jwt");
+            if ("TOS_PRIVACY_POLICY_ACCEPT_REQUIRED".equals(furtherStuff.getString("result"))) {
+                tokenStatus = TokenStatus.PP_REQUIRED;
+                throw new PrivacyPolicyRequiredException();
+            }
+            tokenStatus = TokenStatus.AUTHENTICATED;
+            return this.token;
+        } finally {
+            authenticationLock.unlock();
+        }
+    }
+
+    public String acceptLatestTOS() throws IOException {
+        try {
+            authenticationLock.lock();
+            if (tokenStatus != TokenStatus.PP_REQUIRED) throw new IllegalStateException("Already accepted TOS");
+            JSONObject furtherStuff = acceptPrivacyPolicy(token);
+            token = furtherStuff.getString("jwt");
+            if ("TOS_PRIVACY_POLICY_ACCEPT_REQUIRED".equals(furtherStuff.getString("result"))) {
+                tokenStatus = TokenStatus.PP_REQUIRED;
+                throw new PrivacyPolicyRequiredException();
+            }
+            tokenStatus = TokenStatus.AUTHENTICATED;
+            return this.token;
+        } finally {
+            authenticationLock.unlock();
+        }
+    }
+
+    public JSONObject getJwtPayload(String jwt) {
+        String midPart = jwt.split("\\.")[1].replace("+", "-").replace("/", "_");
+        String base64Decode = new String(Base64.decodeBase64(midPart)); // padding
+        return new JSONObject(base64Decode);
+    }
+
+    private String requestAuth(UUID uuid, String nickname) throws IOException {
+        HttpURLConnection urlConnection = request("POST", "/auth/v2/requestAuth");
+        urlConnection.setRequestProperty("Content-Type", "application/json");
+
+        urlConnection.getOutputStream().write(("{\"uuid\":\""+uuid.toString()+"\",\"nickname\":\""+nickname+"\"}").getBytes());
+        try (InputStream is = obtainInputStream(urlConnection)) {
+            String payload = String.join("\n", IOUtils.readLines(is));
+            if (urlConnection.getResponseCode() != 200)
+                System.out.println("/auth/requestAuth :: Received " + urlConnection.getResponseCode() + " along with\n" + payload);
+
+            JSONObject json = new JSONObject(payload);
+
+            if ("Success".equals(json.getString("status"))) {
+                return json.getString("data");
+            } else {
+                throw new AuthServerException(json);
+            }
+        }
+    }
+    private JSONObject verifyAuth(String tempToken, byte[] secret) throws IOException {
+        HttpURLConnection urlConnection = request("POST", "/auth/v2/authenticate");
+
+        urlConnection.getOutputStream().write(("{\"jwt\":\""+tempToken+"\",\"sharedSecret\":\""+Base64.encodeBase64URLSafeString(secret)+"}").getBytes());
+        try (InputStream is = obtainInputStream(urlConnection)) {
+            String payload = String.join("\n", IOUtils.readLines(is));
+            if (urlConnection.getResponseCode() != 200)
+                System.out.println("/auth/authenticate :: Received " + urlConnection.getResponseCode() + " along with\n" + payload);
+
+            JSONObject jsonObject = new JSONObject(payload);
+            if (!"Success".equals(jsonObject.getString("status"))) {
+                throw new AuthServerException(jsonObject);
+            }
+            return jsonObject.getJSONObject("data");
+        }
+    }
+    private JSONObject acceptPrivacyPolicy(String tempToken) throws IOException {
+        HttpURLConnection urlConnection =  request("POST", "/auth/v2/acceptPrivacyPolicy");
+
+        urlConnection.getOutputStream().write(tempToken.getBytes());
+        try (InputStream is = obtainInputStream(urlConnection)) {
+            String payload = String.join("\n", IOUtils.readLines(is));
+            if (urlConnection.getResponseCode() != 200)
+                System.out.println("/auth/authenticate :: Received " + urlConnection.getResponseCode() + " along with\n" + payload);
+
+            JSONObject jsonObject = new JSONObject(payload);
+            if (!"Success".equals(jsonObject.getString("status"))) {
+                throw new AuthServerException(jsonObject);
+            }
+            return jsonObject.getJSONObject("data");
+        }
+    }
+
+
+    private String calculateServerHash(byte[] a, byte[] b) throws NoSuchAlgorithmException {
+        MessageDigest c = MessageDigest.getInstance("SHA-1");
+        c.update("".getBytes());
+        c.update(a);
+        c.update(b);
+        byte[] d = c.digest();
+        return new BigInteger(d).toString(16);
+    }
+
+    public InputStream obtainInputStream(HttpURLConnection huc) {
+        InputStream inputStream = null;
+        try {
+            inputStream = huc.getInputStream();
+        } catch (Exception e) {
+            inputStream = huc.getErrorStream();
+        }
+        return inputStream;
+    }
+    public HttpURLConnection request(String method, String url) throws IOException {
+        HttpURLConnection urlConnection = (HttpURLConnection) new URL(Main.DOMAIN+url).openConnection();
+        urlConnection.setRequestMethod(method);
+        urlConnection.setRequestProperty("User-Agent", "DungeonsGuide/1.0");
+        urlConnection.setDoInput(true);
+        urlConnection.setDoOutput(true);
+        urlConnection.setAllowUserInteraction(true);
+        if (tokenStatus == TokenStatus.AUTHENTICATED)
+            urlConnection.setRequestProperty("Authorization", "Bearer "+getUnexpiredToken());
+        return urlConnection;
+    }
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/authentication/TokenStatus.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/authentication/TokenStatus.java
new file mode 100644
index 00000000..a83818b8
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/authentication/TokenStatus.java
@@ -0,0 +1,27 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.authentication;
+
+public enum TokenStatus {
+    UNAUTHENTICATED,
+    BANNED,
+    PP_REQUIRED,
+    AUTHENTICATED,
+    EXPIRED
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/branch/ModDownloader.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/branch/ModDownloader.java
new file mode 100644
index 00000000..45eacee5
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/branch/ModDownloader.java
@@ -0,0 +1,302 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.branch;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParser;
+import kr.syeyoung.dungeonsguide.launcher.authentication.Authenticator;
+import lombok.Getter;
+import net.minecraftforge.fml.common.ProgressManager;
+import org.apache.commons.codec.binary.Base64;
+import org.apache.commons.io.IOUtils;
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+import javax.crypto.*;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+import javax.net.ssl.HttpsURLConnection;
+import java.io.*;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.security.*;
+import java.security.cert.CertificateException;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.X509EncodedKeySpec;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.UUID;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+public class ModDownloader {
+    private Authenticator authenticator;
+
+    @Getter
+    private List<UpdateBranch> accessibleBranches = null;
+
+    public ModDownloader(Authenticator authenticator) {
+        this.authenticator = authenticator;
+    }
+
+    public List<UpdateBranch> fetchAccessibleBranches() throws IOException {
+        HttpURLConnection urlConnection = authenticator.request("GET", "/updates/");
+        try (InputStream is = authenticator.obtainInputStream(urlConnection)) {
+            String payload = String.join("\n", IOUtils.readLines(is));
+
+            JSONArray jsonArray = new JSONArray(payload);
+            List<UpdateBranch> branches = new ArrayList<>();
+            for (Object o : jsonArray) {
+                if (o instanceof JSONObject) {
+                    JSONObject branch = (JSONObject) o;
+                    UpdateBranch updateBranch = new UpdateBranch();
+                    updateBranch.setId(branch.getLong("id"));
+                    updateBranch.setName(branch.getString("name"));
+                    updateBranch.setMetadata(branch.getJSONObject("metadata").getJSONObject("metadataSchema"));
+                    branches.add(updateBranch);
+                }
+            }
+            return this.accessibleBranches = branches;
+        }
+    }
+
+    public List<Update> fetchUpdates(Long branch, int page) throws IOException {
+        HttpURLConnection urlConnection = authenticator.request("GET", "/updates/"+branch+"/");
+        try (InputStream is = authenticator.obtainInputStream(urlConnection)) {
+            String payload = String.join("\n", IOUtils.readLines(is));
+
+            JSONArray jsonArray = new JSONArray(payload);
+            List<Update> updates = new ArrayList<>();
+            for (Object o : jsonArray) {
+                if (o instanceof JSONObject) {
+                    JSONObject json = (JSONObject) o;
+                    Update update = new Update();
+                    update.setId(json.getLong("id"));
+                    update.setBranchId(json.getLong("branchId"));
+                    update.setName(json.getString("versionName"));
+                    update.setUpdateLog(json.getString("updateLog"));
+                    update.setMetadata(json.getJSONObject("metadata"));
+                    for (Object assets : json.getJSONObject("assets").getJSONArray("assets")) {
+                        if (assets instanceof JSONObject) {
+                            JSONObject a_json = (JSONObject) assets;
+                            Update.Asset asset = new Update.Asset();
+                            asset.setName(a_json.getString("name"));
+                            asset.setSize(a_json.getLong("size"));
+                            asset.setObjectId(a_json.getString("objectId"));
+                            asset.setAssetId(UUID.fromString(a_json.getString("assetID")));
+                            update.getAssets().add(asset);
+                        }
+                    }
+                    updates.add(update);
+                }
+            }
+            return updates;
+        }
+    }
+
+    /*
+        pls Close after done
+     */
+    public InputStream fetchAsset(Update update, UUID assetId) throws IOException {
+        HttpURLConnection urlConnection = authenticator.request("GET", "/updates/"+update.getBranchId()+"/"+update.getId()+"/"+assetId.toString());
+        try (InputStream is = authenticator.obtainInputStream(urlConnection)) {
+            String payload = String.join("\n", IOUtils.readLines(is));
+            JSONObject object = new JSONObject(payload);
+
+            HttpURLConnection connection = (HttpURLConnection) new URL(object.getString("url")).openConnection();
+            connection.setRequestMethod(object.getString("method"));
+            urlConnection.setRequestProperty("User-Agent", "DungeonsGuide/1.0");
+            urlConnection.setDoInput(true);
+            urlConnection.setDoOutput(true);
+            urlConnection.setAllowUserInteraction(true);
+            return authenticator.obtainInputStream(connection);
+        }
+    }
+
+
+
+
+
+
+    private ProgressManager.ProgressBar progressBar;
+
+    private PublicKey dgPublicKey;
+    private PublicKey getDGPublicKey() throws NoSuchAlgorithmException, InvalidKeySpecException {
+        if (dgPublicKey != null) return dgPublicKey;
+        X509EncodedKeySpec spec = new X509EncodedKeySpec(Base64.decodeBase64("MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAxO89qtwG67jNucQ9Y44c" +
+                "IUs/B+5BeJPs7G+RG2gfs4/2+tzF/c1FLDc33M7yKw8aKk99vsBUY9Oo8gxxiEPB" +
+                "JitP/qfon2THp94oM77ZTpHlmFoqbZMcKGZVI8yfvEL4laTM8Hw+qh5poQwtpEbK" +
+                "Xo47AkxygxJasUnykER2+aSTZ6kWU2D4xiNtFA6lzqN+/oA+NaYfPS0amAvyVlHR" +
+                "n/8IuGkxb5RrlqVssQstFnxsJuv88qdGSEqlcKq2tLeg9hb8eCnl2OFzvXmgbVER" +
+                "0JaV+4Z02fVG1IlR3Xo1mSit7yIU6++3usRCjx2yfXpnGGJUW5pe6YETjNew3ax+" +
+                "FAZ4GePWCdmS7FvBnbbABKo5pE06ZTfDUTCjQlAJQiUgoF6ntMJvQAXPu48Vr8q/" +
+                "mTcuZWVnI6CDgyE7nNq3WNoq3397sBzxRohMxuqzl3T19zkfPKF05iV2Ju1HQMW5" +
+                "I119bYrmVD240aGESZc20Sx/9g1BFpNzQbM5PGUlWJ0dhLjl2ge4ip2hHciY3OEY" +
+                "p2Qy2k+xEdenpKdL+WMRimCQoO9gWe2Tp4NmP5dppDXZgPjXqjZpnGs0Uxs+fXqW" +
+                "cwlg3MbX3rFl9so/fhVf4p9oXZK3ve7z5D6XSSDRYECvsKIa08WAxJ/U6n204E/4" +
+                "xUF+3ZgFPdzZGn2PU7SsnOsCAwEAAQ=="));
+        return dgPublicKey = KeyFactory.getInstance("RSA").generatePublic(spec);
+    }
+
+
+
+
+    private KeyPair rsaKey;
+    private KeyPair getKeyPair()  {
+        KeyPairGenerator a = null;
+        try {
+            a = KeyPairGenerator.getInstance("RSA");
+        } catch (NoSuchAlgorithmException b) { }
+        a.initialize(1024);
+        this.rsaKey = a.generateKeyPair();
+        return this.rsaKey;
+    }
+
+
+    private final HashMap<String, byte[]> loadedResources = new HashMap<String, byte[]>();
+
+    public HashMap<String, byte[]> getResources() {
+        return loadedResources;
+    }
+
+    private void downloadSafe(String dgToken, String url, boolean isValidateSignature) throws IOException, NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException, InvalidAlgorithmParameterException, CertificateException, KeyStoreException, KeyManagementException, SignatureException, InvalidKeySpecException {
+        HttpsURLConnection dgConnection = (HttpsURLConnection) new URL(url).openConnection();
+        dgConnection.setRequestProperty("User-Agent", "DungeonsGuide/1.0");
+        dgConnection.setRequestProperty("Content-Type", "application/json");
+        dgConnection.setRequestMethod("GET");
+        dgConnection.setRequestProperty("Authorization", dgToken);
+        dgConnection.setDoInput(true);
+        dgConnection.setDoOutput(true);
+
+        InputStream inputStream = dgConnection.getInputStream();
+        byte[] lengthBytes = new byte[4];
+        inputStream.read(lengthBytes);
+        int length = ((lengthBytes[0] & 0xFF) << 24) |
+                ((lengthBytes[1] & 0xFF) << 16) |
+                ((lengthBytes[2] & 0xFF) << 8) |
+                ((lengthBytes[3] & 0xFF));
+        while (inputStream.available() < length) ;
+        byte[] keyPayload = new byte[length];
+        inputStream.read(keyPayload);
+
+        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
+        cipher.init(Cipher.DECRYPT_MODE, this.rsaKey.getPrivate());
+        byte[] h = cipher.doFinal(keyPayload);
+
+        cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+        SecretKeySpec keySpec = new SecretKeySpec(h, "AES");
+        IvParameterSpec ivSpec = new IvParameterSpec(h);
+        cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
+        CipherInputStream cipherInputStream = new CipherInputStream(inputStream, cipher);
+
+        cipherInputStream.read(lengthBytes);
+        length = ((lengthBytes[0] & 0xFF) << 24) |
+                ((lengthBytes[1] & 0xFF) << 16) |
+                ((lengthBytes[2] & 0xFF) << 8) |
+                ((lengthBytes[3] & 0xFF));
+
+        int totalLen = length;
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        byte[] buff = new byte[256];
+        while (totalLen > 0) {
+            int len = cipherInputStream.read(buff, 0, Math.min(buff.length,  totalLen));
+            totalLen -= len;
+            bos.write(buff, 0, len);
+        }
+        byte[] body = bos.toByteArray();
+
+        byte[] signed = null;
+        if (isValidateSignature) {
+            progressBar.step("Validating Signature");
+            cipherInputStream.read(lengthBytes,0 , 4);
+            length = ((lengthBytes[0] & 0xFF) << 24) |
+                    ((lengthBytes[1] & 0xFF) << 16) |
+                    ((lengthBytes[2] & 0xFF) << 8) |
+                    ((lengthBytes[3] & 0xFF));
+
+            totalLen = length;
+            bos = new ByteArrayOutputStream();
+            while (totalLen > 0) {
+                int len = cipherInputStream.read(buff, 0, Math.min(buff.length,  totalLen));
+                totalLen -= len;
+                bos.write(buff, 0, len);
+            }
+            signed = bos.toByteArray();
+
+            Signature sign = Signature.getInstance("SHA512withRSA");
+            sign.initVerify(getDGPublicKey());
+            sign.update(body);
+            boolean truth = sign.verify(signed);
+            if (!truth) throw new SignatureException("DG SIGNATURE FORGED");
+        }
+
+        ZipInputStream zipInputStream = new ZipInputStream(new ByteArrayInputStream(body));
+        ZipEntry zipEntry;
+        while ((zipEntry=zipInputStream.getNextEntry()) != null) {
+            byte[] buffer = new byte[256];
+            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
+            int p = 0;
+            while((p = zipInputStream.read(buffer)) > 0) {
+                byteArrayOutputStream.write(buffer, 0, p);
+            }
+            this.loadedResources.put(zipEntry.getName(), byteArrayOutputStream.toByteArray());
+        }
+        dgConnection.disconnect();
+    }
+
+    public JsonElement getJsonSecured(String u) throws IOException, NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException, InvalidAlgorithmParameterException, CertificateException, KeyStoreException, KeyManagementException {
+        HttpsURLConnection httpsURLConnection = (HttpsURLConnection) new URL(u).openConnection();
+        httpsURLConnection.setRequestProperty("User-Agent", "DungeonsGuide/1.0");
+        httpsURLConnection.setRequestProperty("Content-Type", "application/json");
+        httpsURLConnection.setRequestMethod("GET");
+        httpsURLConnection.setRequestProperty("Authorization", authenticator.getUnexpiredToken());
+        httpsURLConnection.setDoInput(true);
+        httpsURLConnection.setDoOutput(true);
+
+        InputStream inputStream = httpsURLConnection.getInputStream();
+        byte[] lengthPayload = new byte[4];
+        inputStream.read(lengthPayload);
+        int length = ((lengthPayload[0] & 0xFF) << 24) |
+                ((lengthPayload[1] & 0xFF) << 16) |
+                ((lengthPayload[2] & 0xFF) << 8) |
+                ((lengthPayload[3] & 0xFF));
+        while (inputStream.available() < length) ;
+        byte[] keyPayload = new byte[length];
+        inputStream.read(keyPayload);
+
+        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
+        cipher.init(Cipher.DECRYPT_MODE, this.rsaKey.getPrivate());
+        byte[] AESKey = cipher.doFinal(keyPayload);
+
+        cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+        SecretKeySpec secretKeySpec = new SecretKeySpec(AESKey, "AES");
+        IvParameterSpec ivParameterSpec = new IvParameterSpec(AESKey);
+        cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivParameterSpec);
+        CipherInputStream cipherInputStream = new CipherInputStream(inputStream, cipher);
+        cipherInputStream.read(lengthPayload);
+        length = ((lengthPayload[0] & 0xFF) << 24) |
+                ((lengthPayload[1] & 0xFF) << 16) |
+                ((lengthPayload[2] & 0xFF) << 8) |
+                ((lengthPayload[3] & 0xFF));
+        JsonElement l = new JsonParser().parse(new InputStreamReader(cipherInputStream));
+        httpsURLConnection.disconnect();
+        return l;
+    }
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/branch/Update.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/branch/Update.java
new file mode 100644
index 00000000..565ac5aa
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/branch/Update.java
@@ -0,0 +1,46 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.branch;
+
+import lombok.Data;
+import org.json.JSONObject;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+@Data
+public class Update {
+    private long id;
+    private long branchId;
+    private String name;
+    private String updateLog;
+    private JSONObject metadata;
+    private Instant releaseDate;
+    private List<Asset> assets = new ArrayList<>();
+
+    @Data
+    public static class Asset {
+        private String name;
+        private long size;
+        private String objectId;
+        private UUID assetId;
+    }
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/branch/UpdateBranch.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/branch/UpdateBranch.java
new file mode 100644
index 00000000..f0b05ee4
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/branch/UpdateBranch.java
@@ -0,0 +1,29 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.branch;
+
+import lombok.Data;
+import org.json.JSONObject;
+
+@Data
+public class UpdateBranch {
+    private Long id;
+    private String name;
+    private JSONObject metadata;
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/AuthServerException.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/AuthServerException.java
new file mode 100644
index 00000000..22b851a8
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/AuthServerException.java
@@ -0,0 +1,27 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.exceptions;
+
+import lombok.AllArgsConstructor;
+import org.json.JSONObject;
+
+@AllArgsConstructor
+public class AuthServerException extends RuntimeException {
+    private JSONObject payload;
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/NoSuitableLoaderFoundException.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/NoSuitableLoaderFoundException.java
new file mode 100644
index 00000000..e5f50754
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/NoSuitableLoaderFoundException.java
@@ -0,0 +1,27 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.exceptions;
+
+import lombok.AllArgsConstructor;
+
+@AllArgsConstructor
+public class NoSuitableLoaderFoundException extends RuntimeException {
+    private String jvmFlag;
+    private String configuration;
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/PrivacyPolicyRequiredException.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/PrivacyPolicyRequiredException.java
new file mode 100644
index 00000000..006e03ca
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/PrivacyPolicyRequiredException.java
@@ -0,0 +1,22 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.exceptions;
+
+public class PrivacyPolicyRequiredException extends RuntimeException{
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/ReferenceLeakedException.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/ReferenceLeakedException.java
new file mode 100644
index 00000000..3a88b862
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/ReferenceLeakedException.java
@@ -0,0 +1,22 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.exceptions;
+
+public class ReferenceLeakedException extends Exception {
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/TokenExpiredException.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/TokenExpiredException.java
new file mode 100644
index 00000000..2c115e2f
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/exceptions/TokenExpiredException.java
@@ -0,0 +1,26 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.exceptions;
+
+public class TokenExpiredException extends RuntimeException{
+
+    public TokenExpiredException(Throwable parent) {
+        super(parent);
+    }
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/gui/GuiLoadingError.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/gui/GuiLoadingError.java
new file mode 100644
index 00000000..f7cc5972
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/gui/GuiLoadingError.java
@@ -0,0 +1,141 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.gui;
+
+import kr.syeyoung.dungeonsguide.launcher.util.QRCodeGenerator;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.gui.*;
+import net.minecraft.client.renderer.GlStateManager;
+import net.minecraft.client.renderer.Tessellator;
+import net.minecraft.client.renderer.WorldRenderer;
+import net.minecraft.client.renderer.texture.DynamicTexture;
+import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
+import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.fml.common.FMLCommonHandler;
+import org.lwjgl.opengl.GL11;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.Base64;
+import java.util.zip.GZIPOutputStream;
+
+public class GuiLoadingError extends GuiScreen {
+    private String stacktrace;
+    private Throwable throwable;
+
+    private DynamicTexture texture;
+    private ResourceLocation location;
+    private BufferedImage qrCode;
+    private Runnable clear;
+
+    public GuiLoadingError(Throwable t, Runnable clear) {
+        this.throwable = t;
+        StringWriter sw = new StringWriter();
+        PrintWriter pw = new PrintWriter(sw);
+        t.printStackTrace(pw);
+        stacktrace = sw.toString();
+
+
+        try {
+            qrCode = QRCodeGenerator.generateQRCode(stacktrace.getBytes());
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        texture = new DynamicTexture(qrCode.getWidth(), qrCode.getHeight());
+        location = Minecraft.getMinecraft().getTextureManager().getDynamicTextureLocation("dg/errorqr", texture);
+
+        qrCode.getRGB(0,0,qrCode.getWidth(), qrCode.getHeight(), texture.getTextureData(), 0, qrCode.getWidth());
+
+        texture.updateDynamicTexture();
+        this.clear = clear;
+    }
+
+    @Override
+    public void initGui() {
+        ScaledResolution sr = new ScaledResolution(Minecraft.getMinecraft());
+        this.buttonList.add(new GuiButton(0, sr.getScaledWidth()/2-100,sr.getScaledHeight()-40 ,"Close Minecraft"));
+        this.buttonList.add(new GuiButton(1, sr.getScaledWidth()/2-100,sr.getScaledHeight()-70 ,"Play Without DG"));
+        clear.run();
+    }
+
+    @Override
+    protected void actionPerformed(GuiButton button) throws IOException {
+        super.actionPerformed(button);
+        if (button.id == 0) {
+            FMLCommonHandler.instance().exitJava(-1,true);
+        } else if (button.id == 1) {
+            Minecraft.getMinecraft().displayGuiScreen(null);
+        }
+    }
+
+    @Override
+    public void drawScreen(int mouseX, int mouseY, float partialTicks) {
+        super.drawBackground(1);
+
+        ScaledResolution sr = new ScaledResolution(Minecraft.getMinecraft());
+        FontRenderer fontRenderer = Minecraft.getMinecraft().fontRendererObj;
+        fontRenderer.drawString("DungeonsGuide has ran into unknown error while loading itself", (sr.getScaledWidth()-fontRenderer.getStringWidth("DungeonsGuide has ran into unknown error while loading itself"))/2,40,0xFFFF0000);
+        fontRenderer.drawString("Please contact DungeonsGuide support with this screen", (sr.getScaledWidth()-fontRenderer.getStringWidth("Please contact DungeonsGuide support with this screen"))/2, (int) (40+fontRenderer.FONT_HEIGHT*1.5),0xFFFF0000);
+
+        int tenth = sr.getScaledWidth() / 10;
+
+        Gui.drawRect(tenth, 70,sr.getScaledWidth()-tenth, sr.getScaledHeight()-80, 0xFF5B5B5B);
+        String[] split = stacktrace.split("\n");
+        clip(sr, tenth, 70,sr.getScaledWidth()-2*tenth, sr.getScaledHeight()-150);
+        GL11.glEnable(GL11.GL_SCISSOR_TEST);
+        for (int i = 0; i < split.length; i++) {
+            fontRenderer.drawString(split[i].replace("\t", "    "), tenth+2,i*fontRenderer.FONT_HEIGHT + 72, 0xFFFFFFFF);
+        }
+        GL11.glDisable(GL11.GL_SCISSOR_TEST);
+
+
+        GlStateManager.pushMatrix();
+        GlStateManager.scale(1.0/sr.getScaleFactor(), 1.0/sr.getScaleFactor(), 1);
+        GlStateManager.translate(0, Minecraft.getMinecraft().displayHeight - qrCode.getHeight() * 3, 0);
+        Tessellator tessellator = Tessellator.getInstance();
+        WorldRenderer worldrenderer = tessellator.getWorldRenderer();
+        float f = 0.0F;
+        Minecraft.getMinecraft().getTextureManager().bindTexture(this.location);
+        GlStateManager.enableBlend();
+        GlStateManager.tryBlendFuncSeparate(1, 771, 0, 1);
+        GlStateManager.disableAlpha();
+        worldrenderer.begin(7, DefaultVertexFormats.POSITION_TEX);
+        worldrenderer.pos(0, qrCode.getHeight()*3, 0).tex(0.0D, 1.0D).endVertex();
+        worldrenderer.pos(qrCode.getWidth()*3, qrCode.getHeight()*3, 0).tex(1.0D, 1.0D).endVertex();
+        worldrenderer.pos(qrCode.getWidth()*3, 0, 0).tex(1.0D, 0.0D).endVertex();
+        worldrenderer.pos(0, 0, 0).tex(0.0D, 0.0D).endVertex();
+        tessellator.draw();
+        GlStateManager.enableAlpha();
+        GlStateManager.disableBlend();
+        GlStateManager.popMatrix();
+
+        super.drawScreen(mouseX, mouseY, partialTicks);
+    }
+
+    public static void clip(ScaledResolution resolution, int x, int y, int width, int height) {
+        if (width < 0 || height < 0) return;
+
+        int scale = resolution.getScaleFactor();
+        GL11.glScissor((x ) * scale, Minecraft.getMinecraft().displayHeight - (y + height) * scale, (width) * scale, height * scale);
+    }
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/loader/IDGLoader.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/loader/IDGLoader.java
new file mode 100644
index 00000000..ceff437e
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/loader/IDGLoader.java
@@ -0,0 +1,36 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.loader;
+
+import kr.syeyoung.dungeonsguide.launcher.DGInterface;
+import kr.syeyoung.dungeonsguide.launcher.authentication.Authenticator;
+import kr.syeyoung.dungeonsguide.launcher.exceptions.ReferenceLeakedException;
+import net.minecraftforge.common.config.Configuration;
+
+public interface IDGLoader {
+    void loadJar(Authenticator authenticator) throws InstantiationException, IllegalAccessException, ClassNotFoundException;
+    DGInterface getInstance();
+    void unloadJar() throws ReferenceLeakedException;
+
+    boolean isUnloadable();
+
+    boolean isLoaded();
+
+    String strategyName();
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/loader/JarLoader.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/loader/JarLoader.java
new file mode 100644
index 00000000..2012412a
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/loader/JarLoader.java
@@ -0,0 +1,128 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.loader;
+
+import kr.syeyoung.dungeonsguide.launcher.DGInterface;
+import kr.syeyoung.dungeonsguide.launcher.Main;
+import kr.syeyoung.dungeonsguide.launcher.authentication.Authenticator;
+import kr.syeyoung.dungeonsguide.launcher.exceptions.ReferenceLeakedException;
+
+import java.lang.ref.PhantomReference;
+import java.lang.ref.Reference;
+import java.lang.ref.ReferenceQueue;
+import java.lang.ref.WeakReference;
+import java.net.URL;
+import java.net.URLClassLoader;
+
+public class JarLoader implements IDGLoader {
+    private DGInterface dgInterface;
+    private ReferenceQueue<ClassLoader> refQueue = new ReferenceQueue<>();
+    private PhantomReference<ClassLoader> phantomReference;
+
+    private boolean loaded;
+
+    public static class JarClassLoader extends URLClassLoader {
+        public JarClassLoader(URL[] urls, ClassLoader parent) {
+            super(urls, parent);
+        }
+
+        @Override
+        protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
+
+            synchronized (getClassLoadingLock(name)) {
+                // First, check if the class has already been loaded
+                Class<?> c = findLoadedClass(name);
+                if (c == null) {
+                    long t0 = System.nanoTime();
+
+                    if (c == null) {
+                        // If still not found, then invoke findClass in order
+                        // to find the class.
+                        long t1 = System.nanoTime();
+                        c = findClass(name);
+
+                        // this is the defining class loader; record the stats
+                        sun.misc.PerfCounter.getParentDelegationTime().addTime(t1 - t0);
+                        sun.misc.PerfCounter.getFindClassTime().addElapsedTimeFrom(t1);
+                        sun.misc.PerfCounter.getFindClasses().increment();
+                    }
+                    try {
+                        if (getParent() != null && c == null) {
+                            c = getParent().loadClass(name);
+                        }
+                    } catch (ClassNotFoundException e) {
+                        // ClassNotFoundException thrown if class not found
+                        // from the non-null parent class loader
+                    }
+                }
+                if (resolve) {
+                    resolveClass(c);
+                }
+                return c;
+            }
+        }
+
+        public Class<?> loadClassResolve(String name, boolean resolve) throws ClassNotFoundException {
+            return this.loadClass(name, resolve);
+        }
+    }
+
+    @Override
+    public void loadJar(Authenticator authenticator) throws ClassNotFoundException, InstantiationException, IllegalAccessException {
+        if (dgInterface != null) throw new IllegalStateException("Already loaded");
+
+        JarClassLoader classLoader = new JarClassLoader(new URL[] {
+                Main.class.getResource("/mod.jar")
+        }, this.getClass().getClassLoader());
+
+        dgInterface = (DGInterface) classLoader.loadClassResolve("kr.syeyoung.dungeonsguide.DungeonsGuide", true).newInstance();
+        phantomReference = new PhantomReference<>(classLoader, refQueue);
+    }
+
+    @Override
+    public DGInterface getInstance() {
+        return dgInterface;
+    }
+
+    @Override
+    public void unloadJar() throws ReferenceLeakedException {
+        dgInterface.unload();
+        dgInterface = null;
+        System.gc();// pls do
+        Reference<? extends ClassLoader> t = refQueue.poll();
+        if (t == null) throw new ReferenceLeakedException(); // Why do you have to be that strict? Well, to tell them to actually listen on DungeonsGuideReloadListener. If it starts causing issues then I will remove check cus it's not really loaded (classes are loaded by child classloader)
+        t.clear();
+        phantomReference = null;
+    }
+
+    @Override
+    public boolean isUnloadable() {
+        return true;
+    }
+
+    @Override
+    public boolean isLoaded() {
+        return dgInterface != null;
+    }
+
+    @Override
+    public String strategyName() {
+        return "jar";
+    }
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/loader/LocalLoader.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/loader/LocalLoader.java
new file mode 100644
index 00000000..67c43ad5
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/loader/LocalLoader.java
@@ -0,0 +1,58 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.loader;
+
+import kr.syeyoung.dungeonsguide.launcher.DGInterface;
+import kr.syeyoung.dungeonsguide.launcher.authentication.Authenticator;
+import kr.syeyoung.dungeonsguide.launcher.exceptions.ReferenceLeakedException;
+
+public class LocalLoader implements IDGLoader {
+    private DGInterface dgInterface;
+
+    @Override
+    public void loadJar(Authenticator authenticator) throws ClassNotFoundException, InstantiationException, IllegalAccessException {
+        if (dgInterface != null) throw new IllegalStateException("Already loaded");
+        dgInterface =  (DGInterface) Class.forName("kr.syeyoung.dungeonsguide.DungeonsGuide").newInstance();
+    }
+
+    @Override
+    public DGInterface getInstance() {
+        return dgInterface;
+    }
+
+    @Override
+    public void unloadJar() throws ReferenceLeakedException {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean isUnloadable() {
+        return false;
+    }
+
+    @Override
+    public boolean isLoaded() {
+        return dgInterface != null;
+    }
+
+    @Override
+    public String strategyName() {
+        return "local";
+    }
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/url/DGConnection.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/url/DGConnection.java
new file mode 100755
index 00000000..649dfdc5
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/url/DGConnection.java
@@ -0,0 +1,47 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.url;
+
+import kr.syeyoung.dungeonsguide.launcher.authentication.Authenticator;
+
+import java.io.*;
+import java.net.URL;
+import java.net.URLConnection;
+
+public class DGConnection extends URLConnection {
+    private final Authenticator authenticator;
+    protected DGConnection(URL url, Authenticator a) {
+        super(url);
+        connected = false;
+        this.authenticator = a;
+    }
+
+    @Override
+    public void connect() throws IOException {
+    }
+    @Override
+    public InputStream getInputStream() throws IOException {
+            if (authenticator != null) {
+                String path = url.getPath().substring(1);
+//                if (!authenticator.getResources().containsKey(path)) throw new FileNotFoundException();
+//                return new ByteArrayInputStream(authenticator.getResources().get(path));
+            }
+        throw new FileNotFoundException();
+    }
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/url/DGStreamHandler.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/url/DGStreamHandler.java
new file mode 100755
index 00000000..82ddff18
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/url/DGStreamHandler.java
@@ -0,0 +1,36 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.url;
+
+import kr.syeyoung.dungeonsguide.launcher.authentication.Authenticator;
+import lombok.AllArgsConstructor;
+
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.net.URLStreamHandler;
+
+@AllArgsConstructor
+public class DGStreamHandler extends URLStreamHandler {
+    private final Authenticator auth;
+    @Override
+    protected URLConnection openConnection(URL url) throws IOException {
+        return new DGConnection(url, this.auth);
+    }
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/url/DGStreamHandlerFactory.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/url/DGStreamHandlerFactory.java
new file mode 100755
index 00000000..a7b50046
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/url/DGStreamHandlerFactory.java
@@ -0,0 +1,37 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.url;
+
+import kr.syeyoung.dungeonsguide.launcher.authentication.Authenticator;
+import lombok.AllArgsConstructor;
+
+import java.net.URLStreamHandler;
+import java.net.URLStreamHandlerFactory;
+
+@AllArgsConstructor
+public class DGStreamHandlerFactory implements URLStreamHandlerFactory {
+    private final Authenticator auth;
+    @Override
+    public URLStreamHandler createURLStreamHandler(String protocol) {
+        if ("z".equals(protocol)) {
+            return new DGStreamHandler(this.auth);
+        }
+        return null;
+    }
+}
diff --git a/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/util/QRCodeGenerator.java b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/util/QRCodeGenerator.java
new file mode 100644
index 00000000..d0c3306a
--- /dev/null
+++ b/loader/src/main/java/kr/syeyoung/dungeonsguide/launcher/util/QRCodeGenerator.java
@@ -0,0 +1,43 @@
+/*
+ * Dungeons Guide - The most intelligent Hypixel Skyblock Dungeons Mod
+ * Copyright (C) 2021  cyoung06
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package kr.syeyoung.dungeonsguide.launcher.util;
+
+import io.nayuki.qrcodegen.QrCode;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.zip.GZIPOutputStream;
+
+public class QRCodeGenerator {
+    public static BufferedImage generateQRCode(byte[] bytes) throws IOException {
+        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
+        GZIPOutputStream gzipOutputStream = new GZIPOutputStream(byteArrayOutputStream);
+        gzipOutputStream.write(bytes);
+        gzipOutputStream.flush();
+        gzipOutputStream.close();
+
+
+        byte[] array = byteArrayOutputStream.toByteArray();
+
+        QrCode qrCode = QrCode.encodeBinary(array, QrCode.Ecc.LOW);
+        return qrCode.toImage(1, 0);
+    }
+}