Some ideas about 1.19.2 support

[BruceChenQAQ]

Some previous discussions: #2084

The processing path for chat signatures in 1.19.1:

// net/minecraft/client/MinecraftClient.java
private void openChatScreen(String text);
👇
// net/minecraft/client/gui/screen/ChatScreen.java
public boolean keyPressed(int keyCode, int scanCode, int modifiers);
👇
public boolean sendMessage(String chatText, boolean addToHistory);
......
if (chatText.startsWith("/"))
	this.client.player.sendCommand(chatText.substring(1), text);
else
	this.client.player.sendChatMessage(chatText, text);
👇
// net/minecraft/client/network/ClientPlayerEntity.java
public void sendChatMessage(String message, @Nullable Text preview);
👇
// net/minecraft/client/network/ClientPlayerEntity.java
private void sendChatMessagePacket(String string, @Nullable Text text) {
	DecoratedContents decoratedContents = this.method_45081(string, text);
	MessageMetadata messageMetadata = this.createMessageMetadata();
	LastSeenMessageList.Acknowledgment acknowledgment = this.networkHandler.consumeAcknowledgment();
	MessageSignatureData messageSignatureData = this.signChatMessage(messageMetadata, decoratedContents, acknowledgment.lastSeen());
	this.networkHandler.sendPacket(new ChatMessageC2SPacket(decoratedContents.plain(), messageMetadata.timestamp(), messageMetadata.salt(), messageSignatureData, decoratedContents.isDecorated(), acknowledgment));
}
/* 
sending "1" in game:

decoratedContents = {DecoratedContents@20193} "DecoratedContents[plain=1, decorated=literal{1}]"
 plain = "1"
 decorated = {MutableText@20208} "literal{1}"

messageMetadata = {MessageMetadata@20201} "MessageMetadata[profileId=e3cdae64-fbb7-3d76-b2a1-ad5f0de24f4e, timeStamp=2022-07-31T04:20:54.515543900Z, salt=-6378869263287041412]"
 sender = {UUID@18135} "e3cdae64-fbb7-3d76-b2a1-ad5f0de24f4e"
 timestamp = {Instant@20205} "2022-07-31T04:20:54.515543900Z"
 salt = -6378869263287041412

acknowledgment = {LastSeenMessageList$Acknowledgment@20211} "Acknowledgment[lastSeen=LastSeenMessageList[entries=[]], lastReceived=Optional.empty]"
 lastSeen = {LastSeenMessageList@20214} "LastSeenMessageList[entries=[]]"
 lastReceived = {Optional@18119} "Optional.empty"
*/

---

👉
// net/minecraft/client/network/ClientPlayerEntity.java
private MessageSignatureData signChatMessage(MessageMetadata metadata, DecoratedContents content, LastSeenMessageList lastSeenMessages) {
	try {
		Signer signer = this.client.getProfileKeys().getSigner();
		if (signer != null) {
			return this.networkHandler.getMessagePacker().pack(signer, metadata, content, lastSeenMessages).signature();
		}
	} catch (Exception var5) {
		field_39078.error((String)"Failed to sign chat message: '{}'", (Object)content.plain(), (Object)var5);
	}
	return MessageSignatureData.EMPTY;
}
👇
// net/minecraft/client/util/ProfileKeys.java
this.signerFuture = completableFuture.thenApply((optionalKeyPair) -> {
	return optionalKeyPair.map((keyPair) -> {
		return Signer.create(keyPair.privateKey(), "SHA256withRSA");
	});
});
public Signer getSigner() {
	return (Signer)((Optional)this.signerFuture.join()).orElse((Object)null);
}
👇
// net/minecraft/network/message/MessageChain.java
private SignedMessage unpack(Signature signature, MessageMetadata metadata, DecoratedContents contents, LastSeenMessageList lastSeenMessages) {
	SignedMessage signedMessage = createMessage(signature, this.precedingSignature, metadata, contents, lastSeenMessages);
	this.precedingSignature = signature.signature;
	return signedMessage;
}

private static SignedMessage createMessage(Signature signature, @Nullable MessageSignatureData precedingSignature, MessageMetadata metadata, DecoratedContents contents, LastSeenMessageList lastSeenMessage) {
	MessageHeader messageHeader = new MessageHeader(precedingSignature, metadata.sender());
	MessageBody messageBody = new MessageBody(contents, metadata.timestamp(), metadata.salt(), lastSeenMessage);
	return new SignedMessage(messageHeader, signature.signature, messageBody, Optional.empty(), class_7649.field_39942);
}

public interface Unpacker {
	Unpacker field_39951 = (signature, messageMetadata, decoratedContents, lastSeenMessageList) -> {
		return SignedMessage.method_45098(messageMetadata, decoratedContents);
	};
	SignedMessage unpack(Signature signature, MessageMetadata metadata, DecoratedContents decoratedContents, LastSeenMessageList lastSeenMessages);
}

public interface Packer {
	Signature pack(Signer signer, MessageMetadata metadata, DecoratedContents contents, LastSeenMessageList lastSeenMessages);
}
👇
// net/minecraft/network/message/SignedMessage.java
public static SignedMessage method_45098(MessageMetadata messageMetadata, DecoratedContents decoratedContents) {
	MessageBody messageBody = new MessageBody(decoratedContents, messageMetadata.timestamp(), messageMetadata.salt(), LastSeenMessageList.EMPTY);
	MessageHeader messageHeader = new MessageHeader((MessageSignatureData)null, messageMetadata.sender());
	return new SignedMessage(messageHeader, MessageSignatureData.EMPTY, messageBody, Optional.empty(), class_7649.field_39942);
}
👉
// net/minecraft/class_7649.java
private static enum class_7650 {
	PASS_THROUGH,
	FULLY_FILTERED,
	PARTIALLY_FILTERED;
}
static {
	field_39941 = new class_7649(new BitSet(0), class_7649.class_7650.FULLY_FILTERED);
	field_39942 = new class_7649(new BitSet(0), class_7649.class_7650.PASS_THROUGH);
}
👉
// net/minecraft/network/message/MessageBody.java
public MessageBody(DecoratedContents decoratedContents, Instant instant, long l, LastSeenMessageList lastSeenMessageList) {
	this.content = decoratedContents;
	this.timestamp = instant;
	this.salt = l;
	this.lastSeenMessages = lastSeenMessageList;
}
👉
// net/minecraft/network/message/MessageHeader.java
public MessageHeader(@Nullable MessageSignatureData messageSignatureData, UUID uUID) {
	this.precedingSignature = messageSignatureData;
	this.sender = uUID;
}
👉
// net/minecraft/network/message/SignedMessage.java
public SignedMessage(MessageHeader messageHeader, MessageSignatureData messageSignatureData, MessageBody messageBody, Optional<Text> optional, class_7649 arg) {
	this.signedHeader = messageHeader;
	this.headerSignature = messageSignatureData;
	this.signedBody = messageBody;
	this.unsignedContent = optional;
	this.filterMask = arg;
}

---

👇
// net/minecraft/network/packet/c2s/play/ChatMessageC2SPacket.java
public ChatMessageC2SPacket(String string, Instant timestamp, long salt, MessageSignatureData signature, boolean signedPreview, LastSeenMessageList.Acknowledgment acknowledgment) {
	this.chatMessage = string;
	this.timestamp = timestamp;
	this.salt = salt;
	this.signature = signature;
	this.signedPreview = signedPreview;
	this.acknowledgment = acknowledgment;
}
public void write(PacketByteBuf buf) {
	buf.writeString(this.chatMessage, 256);
	buf.writeInstant(this.timestamp);
	buf.writeLong(this.salt);
	this.signature.write(buf);
	buf.writeBoolean(this.signedPreview);
	this.acknowledgment.write(buf);
}
👉 signature.write
// net/minecraft/network/message/MessageSignatureData.java
public record MessageSignatureData(byte[] data);
public void write(PacketByteBuf buf) {
	buf.writeByteArray(this.data);
}
👉 writeByteArray
public PacketByteBuf writeByteArray(byte[] array) {
	this.writeVarInt(array.length);
	this.writeBytes(array);
	return this;
}
👉 acknowledgment.write
// net/minecraft/network/message/LastSeenMessageList.java
public static record Acknowledgment(LastSeenMessageList lastSeen, Optional<Entry> lastReceived);
public void write(PacketByteBuf buf) {
	this.lastSeen.write(buf);
	buf.writeOptional(this.lastReceived, (buf2, lastReceived) -> {
		lastReceived.write(buf2);
	});
}
👉 writeOptional
public <T> void writeOptional(Optional<T> value, PacketWriter<T> writer) {
	if (value.isPresent()) {
		this.writeBoolean(true);
		writer.accept(this, value.get());
	} else {
		this.writeBoolean(false);
	}
}
👉 lastSeen.write
// net/minecraft/network/message/LastSeenMessageList.java
public record LastSeenMessageList(List<Entry> entries);
public void write(PacketByteBuf buf) {
	buf.writeCollection(this.entries, (buf2, entries) -> {
		entries.write(buf2);
	});
}
👉 lastReceived.write
// net/minecraft/network/message/LastSeenMessageList.java
public static record Entry(UUID profileId, MessageSignatureData lastSignature);
public void write(PacketByteBuf buf) {
	buf.writeUuid(this.profileId);
	this.lastSignature.write(buf);
}
👉 writeUuid
public PacketByteBuf writeUuid(UUID uuid) {
	this.writeLong(uuid.getMostSignificantBits());
	this.writeLong(uuid.getLeastSignificantBits());
	return this;
}
👉 lastSignature.write
// net/minecraft/network/message/MessageSignatureData.java
public record MessageSignatureData(byte[] data);
public void write(PacketByteBuf buf) {
	buf.writeByteArray(this.data);
}
👇
// net/minecraft/client/network/ClientPlayNetworkHandler.java
public void sendPacket(Packet<?> packet)

[BruceChenQAQ]

image from https://gist.github.com/kennytv/ed783dd244ca0321bbd882c347892874#signed-command-arguments

[milutinke]

Has 1.19.1 been implemented?
Or we still need to do it?
I was busy with writing the whole of documentation from scratch.
Off, still no page on the wiki.vg

[BruceChenQAQ]

I've been busy with other tasks lately, and I'll probably continue to work on the 1.19.1/2 adaptation in a week or so.

By the way, after the de-obfuscation project is updated and the documentation in wiki.vg is more complete, it will be easier to do the adaptation work.

[BruceChenQAQ]

• ChatMessageS2CPacket
  https://pokechu22.github.io/Burger/1.19.2.html#packets:play_clientbound_33

// ChatMessageS2CPacket.write
message.write(buf);
// ChatMessageS2CPacket.write -> message.write
this.signedHeader.write(buf);
// ChatMessageS2CPacket.write -> message.write -> signedHeader.write
if (this.precedingSignature != null)
  writeBoolean(true);
  precedingSignature.write(buf2);
else
  writeBoolean(false);
writeUuid(this.sender);


// ChatMessageS2CPacket.write -> message.write
headerSignature.write(buf);
// ChatMessageS2CPacket.write -> message.write -> headerSignature.write
writeVarInt(this.data.length);
writeBytes(this.data);

// ChatMessageS2CPacket.write -> message.write
signedBody.write(buf);
// ChatMessageS2CPacket.write -> message.write -> signedBody.write
DecoratedContents.write(buf, this.content);
// ChatMessageS2CPacket.write -> message.write -> signedBody.write -> DecoratedContents.write
buf.writeString(contents.plain(), 256);
Text text = contents.isDecorated() ? contents.decorated() : null;
if (text != null)
  this.writeBoolean(true);
  this.writeString(Text.Serializer.toJson(text), MAX_TEXT_LENGTH); // MAX_TEXT_LENGTH = 262144
else
  this.writeBoolean(false);

// ChatMessageS2CPacket.write -> message.write -> signedBody.write
buf.writeInstant(this.timestamp);
buf.writeLong(this.salt);

// ChatMessageS2CPacket.write -> message.write -> signedBody.write
this.lastSeenMessages.write(buf);
// ChatMessageS2CPacket.write -> message.write -> signedBody.write -> LastSeenMessageList.write
this.writeVarInt(this.entries.size());
foreach (var entry in this.entries)
  entrie.write(buf2);
// ChatMessageS2CPacket.write -> message.write -> signedBody.write -> LastSeenMessageList.write -> Entry.write
buf.writeUuid(this.profileId);
lastSignature.write(buf);
// ChatMessageS2CPacket.write -> message.write -> signedBody.write -> LastSeenMessageList.write -> Entry.write -> MessageSignatureData.write
writeVarInt(this.data.length);
writeBytes(this.data);

// ChatMessageS2CPacket.write -> message.write
if (this.unsignedContent != null)
  this.writeBoolean(true);
  this.writeString(Text.Serializer.toJson(this.unsignedContent), MAX_TEXT_LENGTH);
else
  this.writeBoolean(false);

// ChatMessageS2CPacket.write -> message.write
class_7649.method_45091(buf, this.filterMask);
// ChatMessageS2CPacket.write -> message.write -> class_7649.method_45091
packetByteBuf.writeEnumConstant(filterMask.field_39945); // writeVarIntEnum
if (filterMask.field_39945 == class_7649.class_7650.PARTIALLY_FILTERED) {
    packetByteBuf.writeBitSet(arg.field_39944);
}
// ChatMessageS2CPacket.write -> message.write -> class_7649.method_45091 -> writeBitSet
writeVarInt(bitSet.toLongArray().length);
writeLongArray(bitSet.toLongArray()); 

// ChatMessageS2CPacket.write
serializedParameters.write(buf);
// ChatMessageS2CPacket.write -> serializedParameters.write
writeVarInt(this.typeId);
writeString(Text.Serializer.toJson(this.name), MAX_TEXT_LENGTH);
if (this.targetName != null)
  writeBoolean(true);
  writeString(Text.Serializer.toJson(this.targetName), MAX_TEXT_LENGTH);
else
  writeBoolean(false);