Moved skin uploading to the global api

common/src/main/java/org/geysermc/floodgate/util/BedrockData.java

@@ -37,7 +37,7 @@ import lombok.Getter;
 @Getter
 @AllArgsConstructor(access = AccessLevel.PRIVATE)
 public final class BedrockData implements Cloneable {
-    public static final int EXPECTED_LENGTH = 10;
+    public static final int EXPECTED_LENGTH = 12;
 
     private final String version;
     private final String username;
@@ -50,19 +50,24 @@ public final class BedrockData implements Cloneable {
     private final LinkedPlayer linkedPlayer;
     private final boolean fromProxy;
 
+    private final int subscribeId;
+    private final String verifyCode;
+
     private final int dataLength;
 
     public static BedrockData of(String version, String username, String xuid, int deviceOs,
                                  String languageCode, int uiProfile, int inputMode, String ip,
-                                 LinkedPlayer linkedPlayer, boolean fromProxy) {
+                                 LinkedPlayer linkedPlayer, boolean fromProxy, int subscribeId,
+                                 String verifyCode) {
         return new BedrockData(version, username, xuid, deviceOs, languageCode, inputMode,
-                uiProfile, ip, linkedPlayer, fromProxy, EXPECTED_LENGTH);
+                uiProfile, ip, linkedPlayer, fromProxy, subscribeId, verifyCode, EXPECTED_LENGTH);
     }
 
     public static BedrockData of(String version, String username, String xuid, int deviceOs,
-                                 String languageCode, int uiProfile, int inputMode, String ip) {
+                                 String languageCode, int uiProfile, int inputMode, String ip,
-        return of(version, username, xuid, deviceOs, languageCode,
+                                 int subscribeId, String verifyCode) {
-                uiProfile, inputMode, ip, null, false);
+        return of(version, username, xuid, deviceOs, languageCode, uiProfile, inputMode, ip, null,
+                false, subscribeId, verifyCode);
     }
 
     public static BedrockData fromString(String data) {
@@ -75,13 +80,14 @@ public final class BedrockData implements Cloneable {
         // The format is the same as the order of the fields in this class
         return new BedrockData(
                 split[0], split[1], split[2], Integer.parseInt(split[3]), split[4],
-                Integer.parseInt(split[5]), Integer.parseInt(split[6]), split[7],
+                Integer.parseInt(split[5]), Integer.parseInt(split[6]), split[7], linkedPlayer,
-                linkedPlayer, "1".equals(split[8]), split.length
+                "1".equals(split[9]), Integer.parseInt(split[10]), split[11], split.length
         );
     }
 
     private static BedrockData emptyData(int dataLength) {
-        return new BedrockData(null, null, null, -1, null, -1, -1, null, null, false, dataLength);
+        return new BedrockData(null, null, null, -1, null, -1, -1, null, null, false, -1, null,
+                dataLength);
     }
 
     public boolean hasPlayerLink() {
@@ -94,7 +100,8 @@ public final class BedrockData implements Cloneable {
         return version + '\0' + username + '\0' + xuid + '\0' + deviceOs + '\0' +
                 languageCode + '\0' + uiProfile + '\0' + inputMode + '\0' + ip + '\0' +
                 (fromProxy ? 1 : 0) + '\0' +
-                (linkedPlayer != null ? linkedPlayer.toString() : "null");
+                (linkedPlayer != null ? linkedPlayer.toString() : "null") + '\0' +
+                subscribeId + '\0' + verifyCode;
     }
 
     @Override

common/src/main/java/org/geysermc/floodgate/util/RawSkin.java

@@ -1,106 +0,0 @@
-/*
- * Copyright (c) 2019-2020 GeyserMC. http://geysermc.org
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @author GeyserMC
- * @link https://github.com/GeyserMC/Geyser
- */
-
-package org.geysermc.floodgate.util;
-
-import lombok.AllArgsConstructor;
-
-import java.nio.ByteBuffer;
-import java.util.Base64;
-
-import static java.lang.String.format;
-
-@AllArgsConstructor
-public final class RawSkin {
-    public int width;
-    public int height;
-    public byte[] data;
-    public boolean alex;
-
-    private RawSkin() {
-    }
-
-    public static RawSkin decode(byte[] data, int offset) throws InvalidFormatException {
-        if (data == null || offset < 0 || data.length <= offset) {
-            return null;
-        }
-        if (offset == 0) {
-            return decode(data);
-        }
-
-        byte[] rawSkin = new byte[data.length - offset];
-        System.arraycopy(data, offset, rawSkin, 0, rawSkin.length);
-        return decode(rawSkin);
-    }
-
-    public static RawSkin decode(byte[] data) throws InvalidFormatException {
-        // offset is an amount of bytes before the Base64 starts
-        if (data == null) {
-            return null;
-        }
-
-        int maxEncodedLength = Base64Utils.getEncodedLength(64 * 64 * 4 + 9);
-        // if the RawSkin is longer then the max Java Edition skin length
-        if (data.length > maxEncodedLength) {
-            throw new InvalidFormatException(format(
-                    "Encoded data cannot be longer then %s bytes! Got %s",
-                    maxEncodedLength, data.length
-            ));
-        }
-
-        // if the encoded data doesn't even contain the width, height (8 bytes, 2 ints) and isAlex
-        if (data.length < Base64Utils.getEncodedLength(9)) {
-            throw new InvalidFormatException("Encoded data must be at least 16 bytes long!");
-        }
-
-        data = Base64.getDecoder().decode(data);
-
-        ByteBuffer buffer = ByteBuffer.wrap(data);
-
-        RawSkin skin = new RawSkin();
-        skin.width = buffer.getInt();
-        skin.height = buffer.getInt();
-        if (buffer.remaining() - 1 != (skin.width * skin.height * 4)) {
-            throw new InvalidFormatException(format(
-                    "Expected skin length to be %s, got %s",
-                    (skin.width * skin.height * 4), buffer.remaining()
-            ));
-        }
-        skin.data = new byte[buffer.remaining() - 1];
-        buffer.get(skin.data);
-        skin.alex = buffer.get() == 1;
-        return skin;
-    }
-
-    public byte[] encode() {
-        // 2 x int + 1 = 9 bytes
-        ByteBuffer buffer = ByteBuffer.allocate(9 + data.length);
-        buffer.putInt(width);
-        buffer.putInt(height);
-        buffer.put(data);
-        buffer.put((byte) (alex ? 1 : 0));
-        return Base64.getEncoder().encode(buffer.array());
-    }
-}

common/src/main/java/org/geysermc/floodgate/util/WebsocketEventType.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2019-2021 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.floodgate.util;
+
+public enum WebsocketEventType {
+    SUBSCRIBER_CREATED,
+    SUBSCRIBERS_COUNT,
+    ADDED_TO_QUEUE,
+    SKIN_UPLOADED,
+    CREATOR_DISCONNECTED;
+
+    public static final WebsocketEventType[] VALUES = values();
+
+    public static WebsocketEventType getById(int id) {
+        return VALUES.length > id ? VALUES[id] : null;
+    }
+}

connector/pom.xml

@@ -22,6 +22,11 @@
             <version>2.9.8</version>
             <scope>compile</scope>
         </dependency>
+        <dependency>
+            <groupId>org.java-websocket</groupId>
+            <artifactId>Java-Websocket</artifactId>
+            <version>1.5.1</version>
+        </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.datatype</groupId>
             <artifactId>jackson-datatype-jsr310</artifactId>

connector/src/main/java/org/geysermc/connector/GeyserConnector.java

@@ -56,6 +56,7 @@ import org.geysermc.connector.network.translators.world.WorldManager;
 import org.geysermc.connector.network.translators.world.block.BlockTranslator;
 import org.geysermc.connector.network.translators.world.block.entity.BlockEntityTranslator;
 import org.geysermc.connector.network.translators.world.block.entity.SkullBlockEntityTranslator;
+import org.geysermc.connector.skin.FloodgateSkinUploader;
 import org.geysermc.connector.utils.DimensionUtils;
 import org.geysermc.connector.utils.LanguageUtils;
 import org.geysermc.connector.utils.LocaleUtils;
@@ -108,6 +109,7 @@ public class GeyserConnector {
     private AuthType authType;
 
     private FloodgateCipher cipher;
+    private FloodgateSkinUploader skinUploader;
 
     private boolean shuttingDown = false;
 
@@ -203,6 +205,7 @@ public class GeyserConnector {
                 cipher = new AesCipher(new Base64Topping());
                 cipher.init(key);
                 logger.info(LanguageUtils.getLocaleStringLog("geyser.auth.floodgate.loaded_key"));
+                skinUploader = new FloodgateSkinUploader(this).start();
             } catch (Exception exception) {
                 logger.severe(LanguageUtils.getLocaleStringLog("geyser.auth.floodgate.bad_key"), exception);
             }

connector/src/main/java/org/geysermc/connector/network/session/GeyserSession.java

@@ -67,10 +67,10 @@ import lombok.Getter;
 import lombok.NonNull;
 import lombok.Setter;
 import org.geysermc.connector.GeyserConnector;
-import org.geysermc.connector.entity.Tickable;
 import org.geysermc.connector.command.CommandSender;
 import org.geysermc.connector.common.AuthType;
 import org.geysermc.connector.entity.Entity;
+import org.geysermc.connector.entity.Tickable;
 import org.geysermc.connector.entity.player.SessionPlayerEntity;
 import org.geysermc.connector.entity.player.SkullPlayerEntity;
 import org.geysermc.connector.inventory.PlayerInventory;
@@ -85,6 +85,7 @@ import org.geysermc.connector.network.translators.chat.MessageTranslator;
 import org.geysermc.connector.network.translators.collision.CollisionManager;
 import org.geysermc.connector.network.translators.inventory.EnchantmentInventoryTranslator;
 import org.geysermc.connector.network.translators.item.ItemRegistry;
+import org.geysermc.connector.skin.FloodgateSkinUploader;
 import org.geysermc.connector.skin.SkinManager;
 import org.geysermc.connector.utils.*;
 import org.geysermc.cumulus.Form;
@@ -553,7 +554,9 @@ public class GeyserSession implements CommandSender {
                     byte[] encryptedData;
 
                     try {
+                        FloodgateSkinUploader skinUploader = connector.getSkinUploader();
                         FloodgateCipher cipher = connector.getCipher();
+
                         encryptedData = cipher.encryptFromString(BedrockData.of(
                                 clientData.getGameVersion(),
                                 authData.getName(),
@@ -562,7 +565,9 @@ public class GeyserSession implements CommandSender {
                                 clientData.getLanguageCode(),
                                 clientData.getUiProfile().ordinal(),
                                 clientData.getCurrentInputMode().ordinal(),
-                                upstream.getSession().getAddress().getAddress().getHostAddress()
+                                upstream.getSession().getAddress().getAddress().getHostAddress(),
+                                skinUploader.getId(),
+                                skinUploader.getVerifyCode()
                         ).toString());
                     } catch (Exception e) {
                         connector.getLogger().error(LanguageUtils.getLocaleStringLog("geyser.auth.floodgate.encrypt_fail"), e);
@@ -570,13 +575,7 @@ public class GeyserSession implements CommandSender {
                         return;
                     }
 
-                    byte[] rawSkin = clientData.getAndTransformImage("Skin").encode();
+                    String finalDataString = new String(encryptedData, StandardCharsets.UTF_8);
-                    byte[] finalData = new byte[encryptedData.length + rawSkin.length + 1];
-                    System.arraycopy(encryptedData, 0, finalData, 0, encryptedData.length);
-                    finalData[encryptedData.length] = 0x21; // splitter
-                    System.arraycopy(rawSkin, 0, finalData, encryptedData.length + 1, rawSkin.length);
-
-                    String finalDataString = new String(finalData, StandardCharsets.UTF_8);
 
                     HandshakePacket handshakePacket = event.getPacket();
                     event.setPacket(new HandshakePacket(
@@ -639,6 +638,10 @@ public class GeyserSession implements CommandSender {
                         if (connector.getAuthType() == AuthType.OFFLINE || playerEntity.getUuid().getMostSignificantBits() == 0) {
                             SkinManager.handleBedrockSkin(playerEntity, clientData);
                         }
+
+                        // We'll send the skin upload a bit after the handshake packet (aka this packet),
+                        // because otherwise the global server returns the data too fast.
+                        getAuthData().upload(connector);
                     }
 
                     PacketTranslatorRegistry.JAVA_TRANSLATOR.translate(event.getPacket().getClass(), event.getPacket(), GeyserSession.this);

connector/src/main/java/org/geysermc/connector/network/session/auth/AuthData.java

@@ -25,16 +25,26 @@
 
 package org.geysermc.connector.network.session.auth;
 
-import lombok.AllArgsConstructor;
+import com.fasterxml.jackson.databind.JsonNode;
 import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import org.geysermc.connector.GeyserConnector;
 
 import java.util.UUID;
 
-@Getter
+@RequiredArgsConstructor
-@AllArgsConstructor
 public class AuthData {
+    @Getter private final String name;
+    @Getter private final UUID UUID;
+    @Getter private final String xboxUUID;
 
-    private String name;
+    private final JsonNode certChainData;
-    private UUID UUID;
+    private final String clientData;
-    private String xboxUUID;
+
+    public void upload(GeyserConnector connector) {
+        // we can't upload the skin in LoginEncryptionUtil since the global server would return
+        // the skin too fast, that's why we upload it after we know for sure that the target server
+        // is ready to handle the result of the global server
+        connector.getSkinUploader().uploadSkin(certChainData, clientData);
+    }
 }

connector/src/main/java/org/geysermc/connector/network/session/auth/BedrockClientData.java

@@ -34,10 +34,8 @@ import lombok.Getter;
 import org.geysermc.connector.skin.SkinProvider;
 import org.geysermc.floodgate.util.DeviceOs;
 import org.geysermc.floodgate.util.InputMode;
-import org.geysermc.floodgate.util.RawSkin;
 import org.geysermc.floodgate.util.UiProfile;
 
-import java.awt.image.BufferedImage;
 import java.util.Base64;
 import java.util.UUID;
 
@@ -115,77 +113,12 @@ public final class BedrockClientData {
     @JsonProperty(value = "ThirdPartyNameOnly")
     private boolean thirdPartyNameOnly;
 
-    private static RawSkin getLegacyImage(byte[] imageData, boolean alex) {
-        if (imageData == null) {
-            return null;
-        }
-
-        // width * height * 4 (rgba)
-        switch (imageData.length) {
-            case 8192:
-                return new RawSkin(64, 32, imageData, alex);
-            case 16384:
-                return new RawSkin(64, 64, imageData, alex);
-            case 32768:
-                return new RawSkin(64, 128, imageData, alex);
-            case 65536:
-                return new RawSkin(128, 128, imageData, alex);
-            default:
-                throw new IllegalArgumentException("Unknown legacy skin size");
-        }
-    }
-
     public void setJsonData(JsonNode data) {
         if (this.jsonData == null && data != null) {
             this.jsonData = data;
         }
     }
 
-    /**
-     * Taken from https://github.com/NukkitX/Nukkit/blob/master/src/main/java/cn/nukkit/network/protocol/LoginPacket.java<br>
-     * Internally only used for Skins, but can be used for Capes too
-     */
-    public RawSkin getImage(String name) {
-        if (jsonData == null || !jsonData.has(name + "Data")) {
-            return null;
-        }
-
-        boolean alex = false;
-        if (name.equals("Skin")) {
-            alex = isAlex();
-        }
-
-        byte[] image = Base64.getDecoder().decode(jsonData.get(name + "Data").asText());
-        if (jsonData.has(name + "ImageWidth") && jsonData.has(name + "ImageHeight")) {
-            return new RawSkin(
-                    jsonData.get(name + "ImageWidth").asInt(),
-                    jsonData.get(name + "ImageHeight").asInt(),
-                    image, alex
-            );
-        }
-        return getLegacyImage(image, alex);
-    }
-
-    public RawSkin getAndTransformImage(String name) {
-        RawSkin skin = getImage(name);
-        if (skin != null && (skin.width > 64 || skin.height > 64)) {
-            BufferedImage scaledImage =
-                    SkinProvider.imageDataToBufferedImage(skin.data, skin.width, skin.height);
-
-            int max = Math.max(skin.width, skin.height);
-            while (max > 64) {
-                max /= 2;
-                scaledImage = SkinProvider.scale(scaledImage);
-            }
-
-            byte[] skinData = SkinProvider.bufferedImageToImageData(scaledImage);
-            skin.width = scaledImage.getWidth();
-            skin.height = scaledImage.getHeight();
-            skin.data = skinData;
-        }
-        return skin;
-    }
-
     public boolean isAlex() {
         try {
             byte[] bytes = Base64.getDecoder().decode(geometryName.getBytes(Charsets.UTF_8));

connector/src/main/java/org/geysermc/connector/skin/FloodgateSkinUploader.java

@@ -0,0 +1,205 @@
+/*
+ * Copyright (c) 2019-2021 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.connector.skin;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import lombok.Getter;
+import org.geysermc.connector.GeyserConnector;
+import org.geysermc.connector.GeyserLogger;
+import org.geysermc.connector.network.session.GeyserSession;
+import org.geysermc.connector.utils.Constants;
+import org.geysermc.connector.utils.PluginMessageUtils;
+import org.geysermc.floodgate.util.WebsocketEventType;
+import org.java_websocket.client.WebSocketClient;
+import org.java_websocket.handshake.ServerHandshake;
+
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.TimeUnit;
+
+import static org.geysermc.connector.utils.PluginMessageUtils.getSkinChannel;
+
+public final class FloodgateSkinUploader {
+    private final ObjectMapper JACKSON = new ObjectMapper();
+    private final List<String> skinQueue = new ArrayList<>();
+
+    private final GeyserLogger logger;
+    private final WebSocketClient client;
+
+    @Getter private int id;
+    @Getter private String verifyCode;
+    @Getter private int subscribersCount;
+
+    public FloodgateSkinUploader(GeyserConnector connector) {
+        this.logger = connector.getLogger();
+        this.client = new WebSocketClient(Constants.SKIN_UPLOAD_URI) {
+            @Override
+            public void onOpen(ServerHandshake handshake) {
+                setConnectionLostTimeout(11);
+
+                Iterator<String> queueIterator = skinQueue.iterator();
+                while (isOpen() && queueIterator.hasNext()) {
+                    send(queueIterator.next());
+                    queueIterator.remove();
+                }
+            }
+
+            @Override
+            public void onMessage(String message) {
+                System.out.println(message);
+                // The reason why I don't like Jackson
+                try {
+                    JsonNode node = JACKSON.readTree(message);
+                    if (node.has("error")) {
+                        logger.error("Got an error: " + node.get("error").asText());
+                        return;
+                    }
+
+                    int typeId = node.get("event_id").asInt();
+                    WebsocketEventType type = WebsocketEventType.getById(typeId);
+                    if (type == null) {
+                        logger.warning(String.format(
+                                "Got (unknown) type %s. Ensure that Geyser is on the latest version and report this issue!",
+                                typeId));
+                        return;
+                    }
+
+                    switch (type) {
+                        case SUBSCRIBER_CREATED:
+                            id = node.get("id").asInt();
+                            verifyCode = node.get("verify_code").asText();
+                            break;
+                        case SUBSCRIBERS_COUNT:
+                            subscribersCount = node.get("subscribers_count").asInt();
+                            break;
+                        case SKIN_UPLOADED:
+                            // if Geyser is the only subscriber we have send it to the server manually
+                            if (subscribersCount != 1) {
+                                break;
+                            }
+
+                            String xuid = node.get("xuid").asText();
+                            String value = node.get("value").asText();
+                            String signature = node.get("signature").asText();
+                            ;
+
+                            GeyserSession session = connector.getPlayerByXuid(xuid);
+                            if (session != null) {
+                                byte[] bytes = (value + '\0' + signature)
+                                        .getBytes(StandardCharsets.UTF_8);
+                                PluginMessageUtils.sendMessage(session, getSkinChannel(), bytes);
+                            }
+                            break;
+                    }
+                } catch (Exception e) {
+                    logger.error("Error while receiving a message", e);
+                }
+            }
+
+            @Override
+            public void onClose(int code, String reason, boolean remote) {
+                if (reason != null && !reason.isEmpty()) {
+                    // The reason why I don't like Jackson
+                    try {
+                        JsonNode node = JACKSON.readTree(reason);
+                        // info means that the uploader itself did nothing wrong
+                        if (node.has("info")) {
+                            String info = node.get("info").asText();
+                            logger.debug("Got disconnected from the skin uploader: " + info);
+                        }
+                        // error means that the uploader did something wrong
+                        if (node.has("error")) {
+                            String error = node.get("error").asText();
+                            logger.info("Got disconnected from the skin uploader: " + error);
+                        }
+                        // it can't be something else then info or error, so we won't handle anything other than that.
+                        // try to reconnect (which will make a new id and verify token) after a few seconds
+                        reconnectLater(connector);
+                    } catch (Exception e) {
+                        logger.error("Error while handling onClose", e);
+                    }
+                }
+            }
+
+            @Override
+            public void onError(Exception ex) {
+                logger.error("Got an error", ex);
+            }
+        };
+    }
+
+    public void uploadSkin(JsonNode chainData, String clientData) {
+        if (chainData == null || !chainData.isArray() || clientData == null) {
+            return;
+        }
+
+        ObjectNode node = JACKSON.createObjectNode();
+        node.set("chain_data", chainData);
+        node.put("client_data", clientData);
+
+        // The reason why I don't like Jackson
+        String jsonString;
+        try {
+            jsonString = JACKSON.writeValueAsString(node);
+        } catch (Exception e) {
+            logger.error("Failed to upload skin", e);
+            return;
+        }
+
+        if (client.isOpen()) {
+            client.send(jsonString);
+            return;
+        }
+        skinQueue.add(jsonString);
+    }
+
+    private void reconnectLater(GeyserConnector connector) {
+        long additionalTime = ThreadLocalRandom.current().nextInt(7);
+        connector.getGeneralThreadPool().schedule(() -> {
+            try {
+                if (!client.connectBlocking()) {
+                    reconnectLater(connector);
+                }
+            } catch (InterruptedException ignored) {
+                reconnectLater(connector);
+            }
+        }, 8 + additionalTime, TimeUnit.SECONDS);
+    }
+
+    public FloodgateSkinUploader start() {
+        client.connect();
+        return this;
+    }
+
+    public void stop() {
+        client.close();
+    }
+}

connector/src/main/java/org/geysermc/connector/utils/Constants.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2019-2021 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.connector.utils;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+
+public final class Constants {
+    public static final URI SKIN_UPLOAD_URI;
+
+    static {
+        URI skinUploadUri = null;
+        try {
+            skinUploadUri = new URI("wss://api.geysermc.org/ws");
+        } catch (URISyntaxException e) {
+            e.printStackTrace();
+        }
+        SKIN_UPLOAD_URI = skinUploadUri;
+    }
+}

connector/src/main/java/org/geysermc/connector/utils/LoginEncryptionUtils.java

@@ -118,7 +118,8 @@ public class LoginEncryptionUtils {
             session.setAuthenticationData(new AuthData(
                     extraData.get("displayName").asText(),
                     UUID.fromString(extraData.get("identity").asText()),
-                    extraData.get("XUID").asText()
+                    extraData.get("XUID").asText(),
+                    certChainData, clientData
             ));
 
             if (payload.get("identityPublicKey").getNodeType() != JsonNodeType.STRING) {

connector/src/main/java/org/geysermc/connector/utils/PluginMessageUtils.java

@@ -25,12 +25,15 @@
 
 package org.geysermc.connector.utils;
 
+import com.github.steveice10.mc.protocol.packet.ingame.server.ServerPluginMessagePacket;
 import com.google.common.base.Charsets;
 import org.geysermc.connector.GeyserConnector;
+import org.geysermc.connector.network.session.GeyserSession;
 
 import java.nio.ByteBuffer;
 
 public class PluginMessageUtils {
+    private static final String SKIN_CHANNEL = "floodgate:skin";
     private static final byte[] GEYSER_BRAND_DATA;
     private static final byte[] FLOODGATE_REGISTER_DATA;
 
@@ -42,7 +45,7 @@ public class PluginMessageUtils {
                         .put(data)
                         .array();
 
-        FLOODGATE_REGISTER_DATA = "floodgate:skin\0floodgate:form".getBytes(Charsets.UTF_8);
+        FLOODGATE_REGISTER_DATA = (SKIN_CHANNEL + "\0floodgate:form").getBytes(Charsets.UTF_8);
     }
 
     /**
@@ -63,6 +66,22 @@ public class PluginMessageUtils {
         return FLOODGATE_REGISTER_DATA;
     }
 
+    /**
+     * Returns the skin channel used in Floodgate
+     */
+    public static String getSkinChannel() {
+        return SKIN_CHANNEL;
+    }
+
+    public static void sendMessage(GeyserSession session, String channel, byte[] data) {
+        byte[] finalData =
+                ByteBuffer.allocate(data.length + getVarIntLength(data.length))
+                        .put(writeVarInt(data.length))
+                        .put(data)
+                        .array();
+        session.sendDownstreamPacket(new ServerPluginMessagePacket(channel, finalData));
+    }
+
     private static byte[] writeVarInt(int value) {
         byte[] data = new byte[getVarIntLength(value)];
         int index = 0;