From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Andrew Steinborn <git@steinborn.me>
Date: Mon, 26 Jul 2021 02:15:17 -0400
Subject: [PATCH] Use Velocity compression and cipher natives


diff --git a/build.gradle.kts b/build.gradle.kts
index 9b9e744d18cf66279f51f950b6ecce31415f9fa8..5d448d8a7cf6626a11791f30ad52baf41a099272 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -37,6 +37,11 @@ dependencies {
     runtimeOnly("org.xerial:sqlite-jdbc:3.45.3.0")
     runtimeOnly("com.mysql:mysql-connector-j:8.3.0")
     runtimeOnly("com.lmax:disruptor:3.4.4") // Paper
+    // Paper start - Use Velocity cipher
+    implementation("com.velocitypowered:velocity-native:3.1.2-SNAPSHOT") {
+        isTransitive = false
+    }
+    // Paper end - Use Velocity cipher
 
     runtimeOnly("org.apache.maven:maven-resolver-provider:3.9.6")
     runtimeOnly("org.apache.maven.resolver:maven-resolver-connector-basic:1.9.18")
diff --git a/src/main/java/net/minecraft/network/CipherDecoder.java b/src/main/java/net/minecraft/network/CipherDecoder.java
index 778beb445eac5769b9e4e07b4d1294c50ae2602b..7b895b6a626da6297f07582e96d98ecfb6c8c951 100644
--- a/src/main/java/net/minecraft/network/CipherDecoder.java
+++ b/src/main/java/net/minecraft/network/CipherDecoder.java
@@ -7,13 +7,29 @@ import java.util.List;
 import javax.crypto.Cipher;
 
 public class CipherDecoder extends MessageToMessageDecoder<ByteBuf> {
-    private final CipherBase cipher;
+    private final com.velocitypowered.natives.encryption.VelocityCipher cipher; // Paper - Use Velocity cipher
 
-    public CipherDecoder(Cipher cipher) {
-        this.cipher = new CipherBase(cipher);
+    public CipherDecoder(com.velocitypowered.natives.encryption.VelocityCipher cipher) {  // Paper - Use Velocity cipher
+        this.cipher = cipher;  // Paper - Use Velocity cipher
     }
 
     protected void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> list) throws Exception {
-        list.add(this.cipher.decipher(channelHandlerContext, byteBuf));
+        // Paper start - Use Velocity cipher
+        ByteBuf compatible = com.velocitypowered.natives.util.MoreByteBufUtils.ensureCompatible(channelHandlerContext.alloc(), cipher, byteBuf);
+        try {
+            cipher.process(compatible);
+            list.add(compatible);
+        } catch (Exception e) {
+            compatible.release(); // compatible will never be used if we throw an exception
+            throw e;
+        }
+        // Paper end - Use Velocity cipher
     }
+
+    // Paper start - Use Velocity cipher
+    @Override
+    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
+        cipher.close();
+    }
+    // Paper end - Use Velocity cipher
 }
diff --git a/src/main/java/net/minecraft/network/CipherEncoder.java b/src/main/java/net/minecraft/network/CipherEncoder.java
index 0f3d502a9680006bcdcd7d272240a2e5c3b46790..ffa1c48585fbbc1d30826d435043527f6183a3ee 100644
--- a/src/main/java/net/minecraft/network/CipherEncoder.java
+++ b/src/main/java/net/minecraft/network/CipherEncoder.java
@@ -4,15 +4,32 @@ import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.MessageToByteEncoder;
 import javax.crypto.Cipher;
+import java.util.List;
 
-public class CipherEncoder extends MessageToByteEncoder<ByteBuf> {
-    private final CipherBase cipher;
+public class CipherEncoder extends io.netty.handler.codec.MessageToMessageEncoder<ByteBuf> { // Paper - Use Velocity cipher; change superclass
+    private final com.velocitypowered.natives.encryption.VelocityCipher cipher; // Paper - Use Velocity cipher
 
-    public CipherEncoder(Cipher cipher) {
-        this.cipher = new CipherBase(cipher);
+    public CipherEncoder(com.velocitypowered.natives.encryption.VelocityCipher cipher) {  // Paper - Use Velocity cipher
+        this.cipher = cipher;  // Paper - Use Velocity cipher
     }
 
-    protected void encode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, ByteBuf byteBuf2) throws Exception {
-        this.cipher.encipher(byteBuf, byteBuf2);
+    protected void encode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> list) throws Exception {
+        // Paper start - Use Velocity cipher
+        ByteBuf compatible = com.velocitypowered.natives.util.MoreByteBufUtils.ensureCompatible(channelHandlerContext.alloc(), cipher, byteBuf);
+        try {
+            cipher.process(compatible);
+            list.add(compatible);
+        } catch (Exception e) {
+            compatible.release(); // compatible will never be used if we throw an exception
+            throw e;
+        }
+        // Paper end - Use Velocity cipher
     }
+
+    // Paper start - Use Velocity cipher
+    @Override
+    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
+        cipher.close();
+    }
+    // Paper end - Use Velocity cipher
 }
diff --git a/src/main/java/net/minecraft/network/CompressionDecoder.java b/src/main/java/net/minecraft/network/CompressionDecoder.java
index 5927c928b27f64bd3973e95d5867b59f67476d41..ba3619b03ea73e4ea55ae2eb79d3b6cd1f48a191 100644
--- a/src/main/java/net/minecraft/network/CompressionDecoder.java
+++ b/src/main/java/net/minecraft/network/CompressionDecoder.java
@@ -13,13 +13,20 @@ public class CompressionDecoder extends ByteToMessageDecoder {
     public static final int MAXIMUM_COMPRESSED_LENGTH = 2097152;
     public static final int MAXIMUM_UNCOMPRESSED_LENGTH = 8388608;
     private final Inflater inflater;
+    private com.velocitypowered.natives.compression.VelocityCompressor compressor; // Paper - Use Velocity cipher
     private int threshold;
     private boolean validateDecompressed;
 
+    // Paper start - Use Velocity cipher
     public CompressionDecoder(int compressionThreshold, boolean rejectsBadPackets) {
+        this(null, compressionThreshold, rejectsBadPackets);
+    }
+    public CompressionDecoder(com.velocitypowered.natives.compression.VelocityCompressor compressor, int compressionThreshold, boolean rejectsBadPackets) {
         this.threshold = compressionThreshold;
         this.validateDecompressed = rejectsBadPackets;
-        this.inflater = new Inflater();
+        this.inflater = compressor == null ? new Inflater() : null;
+        this.compressor = compressor;
+        // Paper end - Use Velocity cipher
     }
 
     protected void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> list) throws Exception {
@@ -38,14 +45,42 @@ public class CompressionDecoder extends ByteToMessageDecoder {
                     }
                 }
 
+                if (inflater != null) { // Paper - Use Velocity cipher; fallback to vanilla inflater
                 this.setupInflaterInput(byteBuf);
                 ByteBuf byteBuf2 = this.inflate(channelHandlerContext, i);
                 this.inflater.reset();
                 list.add(byteBuf2);
+                return; // Paper - Use Velocity cipher
+                } // Paper - use velocity compression
+
+                // Paper start - Use Velocity cipher
+                int claimedUncompressedSize = i; // OBFHELPER
+                ByteBuf compatibleIn = com.velocitypowered.natives.util.MoreByteBufUtils.ensureCompatible(channelHandlerContext.alloc(), this.compressor, byteBuf);
+                ByteBuf uncompressed = com.velocitypowered.natives.util.MoreByteBufUtils.preferredBuffer(channelHandlerContext.alloc(), this.compressor, claimedUncompressedSize);
+                try {
+                    this.compressor.inflate(compatibleIn, uncompressed, claimedUncompressedSize);
+                    list.add(uncompressed);
+                    byteBuf.clear();
+                } catch (Exception e) {
+                    uncompressed.release();
+                    throw e;
+                } finally {
+                    compatibleIn.release();
+                }
+                // Paper end - Use Velocity cipher
             }
         }
     }
 
+    // Paper start - Use Velocity cipher
+    @Override
+    public void handlerRemoved0(ChannelHandlerContext ctx) throws Exception {
+        if (this.compressor != null) {
+            this.compressor.close();
+        }
+    }
+    // Paper end - Use Velocity cipher
+
     private void setupInflaterInput(ByteBuf buf) {
         ByteBuffer byteBuffer;
         if (buf.nioBufferCount() > 0) {
@@ -82,7 +117,7 @@ public class CompressionDecoder extends ByteToMessageDecoder {
         }
     }
 
-    public void setThreshold(int compressionThreshold, boolean rejectsBadPackets) {
+    public void setThreshold(com.velocitypowered.natives.compression.VelocityCompressor compressor, int compressionThreshold, boolean rejectsBadPackets) { // Paper - Use Velocity cipher
         this.threshold = compressionThreshold;
         this.validateDecompressed = rejectsBadPackets;
     }
diff --git a/src/main/java/net/minecraft/network/CompressionEncoder.java b/src/main/java/net/minecraft/network/CompressionEncoder.java
index 34a80d2f34555663ab1b394972957089214cb337..ec30c291188ac3bba7f1c3bc397576d1edb0a57f 100644
--- a/src/main/java/net/minecraft/network/CompressionEncoder.java
+++ b/src/main/java/net/minecraft/network/CompressionEncoder.java
@@ -6,16 +6,31 @@ import io.netty.handler.codec.MessageToByteEncoder;
 import java.util.zip.Deflater;
 
 public class CompressionEncoder extends MessageToByteEncoder<ByteBuf> {
-    private final byte[] encodeBuf = new byte[8192];
+    @javax.annotation.Nullable private final byte[] encodeBuf; // Paper - Use Velocity cipher
+    @javax.annotation.Nullable // Paper - Use Velocity cipher
     private final Deflater deflater;
+    @javax.annotation.Nullable // Paper - Use Velocity cipher
+    private final com.velocitypowered.natives.compression.VelocityCompressor compressor; // Paper - Use Velocity cipher
     private int threshold;
 
+    // Paper start - Use Velocity cipher
     public CompressionEncoder(int compressionThreshold) {
+        this(null, compressionThreshold);
+    }
+    public CompressionEncoder(@javax.annotation.Nullable com.velocitypowered.natives.compression.VelocityCompressor compressor, int compressionThreshold) {
         this.threshold = compressionThreshold;
-        this.deflater = new Deflater();
+        if (compressor == null) {
+            this.encodeBuf = new byte[8192];
+            this.deflater = new Deflater();
+        } else {
+            this.encodeBuf = null;
+            this.deflater = null;
+        }
+        this.compressor = compressor;
+        // Paper end - Use Velocity cipher
     }
 
-    protected void encode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, ByteBuf byteBuf2) {
+    protected void encode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, ByteBuf byteBuf2) throws Exception { // Paper - Use Velocity cipher
         int i = byteBuf.readableBytes();
         if (i > 8388608) {
             throw new IllegalArgumentException("Packet too big (is " + i + ", should be less than 8388608)");
@@ -24,6 +39,7 @@ public class CompressionEncoder extends MessageToByteEncoder<ByteBuf> {
                 VarInt.write(byteBuf2, 0);
                 byteBuf2.writeBytes(byteBuf);
             } else {
+                if (this.deflater != null) { // Paper - Use Velocity cipher
                 byte[] bs = new byte[i];
                 byteBuf.readBytes(bs);
                 VarInt.write(byteBuf2, bs.length);
@@ -36,10 +52,47 @@ public class CompressionEncoder extends MessageToByteEncoder<ByteBuf> {
                 }
 
                 this.deflater.reset();
+                // Paper start - Use Velocity cipher
+                    return;
+                }
+
+                VarInt.write(byteBuf2, i);
+                final ByteBuf compatibleIn = com.velocitypowered.natives.util.MoreByteBufUtils.ensureCompatible(channelHandlerContext.alloc(), this.compressor, byteBuf);
+                try {
+                    this.compressor.deflate(compatibleIn, byteBuf2);
+                } finally {
+                    compatibleIn.release();
+                }
             }
         }
     }
 
+    @Override
+    protected ByteBuf allocateBuffer(ChannelHandlerContext ctx, ByteBuf msg, boolean preferDirect) throws Exception{
+        if (this.compressor != null) {
+            // We allocate bytes to be compressed plus 1 byte. This covers two cases:
+            //
+            // - Compression
+            //    According to https://github.com/ebiggers/libdeflate/blob/master/libdeflate.h#L103,
+            //    if the data compresses well (and we do not have some pathological case) then the maximum
+            //    size the compressed size will ever be is the input size minus one.
+            // - Uncompressed
+            //    This is fairly obvious - we will then have one more than the uncompressed size.
+            final int initialBufferSize = msg.readableBytes() + 1;
+            return com.velocitypowered.natives.util.MoreByteBufUtils.preferredBuffer(ctx.alloc(), this.compressor, initialBufferSize);
+        }
+
+        return super.allocateBuffer(ctx, msg, preferDirect);
+    }
+
+    @Override
+    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
+        if (this.compressor != null) {
+            this.compressor.close();
+            // Paper end - Use Velocity cipher
+        }
+    }
+
     public int getThreshold() {
         return this.threshold;
     }
diff --git a/src/main/java/net/minecraft/network/Connection.java b/src/main/java/net/minecraft/network/Connection.java
index f94458d4270042062b9ae18931cc8179ef1fb420..63066dfde00569833546da01cd580434f8be6593 100644
--- a/src/main/java/net/minecraft/network/Connection.java
+++ b/src/main/java/net/minecraft/network/Connection.java
@@ -763,11 +763,28 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
         return networkmanager;
     }
 
-    public void setEncryptionKey(Cipher decryptionCipher, Cipher encryptionCipher) {
-        this.encrypted = true;
-        this.channel.pipeline().addBefore("splitter", "decrypt", new CipherDecoder(decryptionCipher));
-        this.channel.pipeline().addBefore("prepender", "encrypt", new CipherEncoder(encryptionCipher));
+    // Paper start - Use Velocity cipher
+//    public void setEncryptionKey(Cipher decryptionCipher, Cipher encryptionCipher) {
+//        this.encrypted = true;
+//        this.channel.pipeline().addBefore("splitter", "decrypt", new CipherDecoder(decryptionCipher));
+//        this.channel.pipeline().addBefore("prepender", "encrypt", new CipherEncoder(encryptionCipher));
+//    }
+
+    public void setupEncryption(javax.crypto.SecretKey key) throws net.minecraft.util.CryptException {
+        if (!this.encrypted) {
+            try {
+                com.velocitypowered.natives.encryption.VelocityCipher decryption = com.velocitypowered.natives.util.Natives.cipher.get().forDecryption(key);
+                com.velocitypowered.natives.encryption.VelocityCipher encryption = com.velocitypowered.natives.util.Natives.cipher.get().forEncryption(key);
+
+                this.encrypted = true;
+                this.channel.pipeline().addBefore("splitter", "decrypt", new CipherDecoder(decryption));
+                this.channel.pipeline().addBefore("prepender", "encrypt", new CipherEncoder(encryption));
+            } catch (java.security.GeneralSecurityException e) {
+                throw new net.minecraft.util.CryptException(e);
+            }
+        }
     }
+    // Paper end - Use Velocity cipher
 
     public boolean isEncrypted() {
         return this.encrypted;
@@ -800,12 +817,13 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
 
     public void setupCompression(int compressionThreshold, boolean rejectsBadPackets) {
         if (compressionThreshold >= 0) {
+            com.velocitypowered.natives.compression.VelocityCompressor compressor = com.velocitypowered.natives.util.Natives.compress.get().create(io.papermc.paper.configuration.GlobalConfiguration.get().misc.compressionLevel.or(-1)); // Paper - Use Velocity cipher
             ChannelHandler channelhandler = this.channel.pipeline().get("decompress");
 
             if (channelhandler instanceof CompressionDecoder) {
                 CompressionDecoder packetdecompressor = (CompressionDecoder) channelhandler;
 
-                packetdecompressor.setThreshold(compressionThreshold, rejectsBadPackets);
+                packetdecompressor.setThreshold(compressor, compressionThreshold, rejectsBadPackets); // Paper - Use Velocity cipher
             } else {
                 this.channel.pipeline().addAfter("splitter", "decompress", new CompressionDecoder(compressionThreshold, rejectsBadPackets));
             }
@@ -816,7 +834,7 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
 
                 packetcompressor.setThreshold(compressionThreshold);
             } else {
-                this.channel.pipeline().addAfter("prepender", "compress", new CompressionEncoder(compressionThreshold));
+                this.channel.pipeline().addAfter("prepender", "compress", new CompressionEncoder(compressor, compressionThreshold)); // Paper - Use Velocity cipher
             }
             this.channel.pipeline().fireUserEventTriggered(io.papermc.paper.network.ConnectionEvent.COMPRESSION_THRESHOLD_SET); // Paper - Add Channel initialization listeners
         } else {
diff --git a/src/main/java/net/minecraft/server/network/ServerConnectionListener.java b/src/main/java/net/minecraft/server/network/ServerConnectionListener.java
index a08d9aa6e420f691795df9b627a9cd5b5c0112c5..52f537b7bfbdeaad9d17c0e88a1ed1c8925a833f 100644
--- a/src/main/java/net/minecraft/server/network/ServerConnectionListener.java
+++ b/src/main/java/net/minecraft/server/network/ServerConnectionListener.java
@@ -106,6 +106,11 @@ public class ServerConnectionListener {
                 ServerConnectionListener.LOGGER.info("Using default channel type");
             }
 
+            // Paper start - Use Velocity cipher
+            ServerConnectionListener.LOGGER.info("Paper: Using " + com.velocitypowered.natives.util.Natives.compress.getLoadedVariant() + " compression from Velocity.");
+            ServerConnectionListener.LOGGER.info("Paper: Using " + com.velocitypowered.natives.util.Natives.cipher.getLoadedVariant() + " cipher from Velocity.");
+            // Paper end - Use Velocity cipher
+
             this.channels.add(((ServerBootstrap) ((ServerBootstrap) (new ServerBootstrap()).channel(oclass)).childHandler(new ChannelInitializer<Channel>() {
                 protected void initChannel(Channel channel) {
                     try {
diff --git a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
index cb006ae0e5be2f1d31261bdd36964229ec44416d..b656741eb68adeb04bf995f1045902cb6bd5f2e7 100644
--- a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
@@ -280,12 +280,14 @@ public class ServerLoginPacketListenerImpl implements ServerLoginPacketListener,
             }
 
             SecretKey secretkey = packet.getSecretKey(privatekey);
-            Cipher cipher = Crypt.getCipher(2, secretkey);
-            Cipher cipher1 = Crypt.getCipher(1, secretkey);
+            // Paper start - Use Velocity cipher
+//            Cipher cipher = Crypt.getCipher(2, secretkey);
+//            Cipher cipher1 = Crypt.getCipher(1, secretkey);
+            // Paper end - Use Velocity cipher
 
             s = (new BigInteger(Crypt.digestData("", this.server.getKeyPair().getPublic(), secretkey))).toString(16);
             this.state = ServerLoginPacketListenerImpl.State.AUTHENTICATING;
-            this.connection.setEncryptionKey(cipher, cipher1);
+            this.connection.setupEncryption(secretkey); // Paper - Use Velocity cipher
         } catch (CryptException cryptographyexception) {
             throw new IllegalStateException("Protocol error", cryptographyexception);
         }
