- 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;