1.19 compatibility

[TuxCoding]

Microsoft/Mojang changed a lot of the authentication protocol. This requires a lot of work and testing. As protocol changes are very recent, not a lot of research was done about the internal changes. Furthermore, the login authentication is a critical area, so requires careful code design and tests. As I don't have much time for a hobby project, because of personal issues, expect some delay.

Status:

Spigot

ProtocolLib

Won't work - not tested, but strongly appears so from the code.

ProtocolSupport

Could work - not tested

Proxy-side

The supported proxies allows for enabling onlinemode using an API call. Therefore breaking changes are very unlikely.

BungeeCord

Fixed in 6665c03

Now always requires the latest version, because BungeeCord is backwards compatible.

Velocity

No changes required from FastLogin.

[Tander]

Can provide some info:

with ProtocolLib build 559 - getting this error, autologin doesn't work

[23:17:22 WARN]: [ProtocolLib] Loaded class com.github.games647.fastlogin.bukkit.listener.protocollib.ProtocolLibListener from FastLogin v1.11-SNAPSHOT-6665c03 which is not a depend or softdepend of this plugin.
[23:17:22 ERROR]: [FastLogin] Unhandled exception occurred in onAsyncPacket() for FastLogin
com.comphenix.protocol.reflect.FieldAccessException: No field with type com.mojang.authlib.GameProfile exists in class PacketLoginInStart.
	at com.comphenix.protocol.reflect.StructureModifier.readInternal(StructureModifier.java:216) ~[ProtocolLib.jar:5.0.0-SNAPSHOT-b559]
	at com.comphenix.protocol.reflect.StructureModifier.read(StructureModifier.java:195) ~[ProtocolLib.jar:5.0.0-SNAPSHOT-b559]
	at com.github.games647.fastlogin.bukkit.listener.protocollib.ProtocolLibListener.onLogin(ProtocolLibListener.java:126) ~[FastLoginBukkit.jar:?]
	at com.github.games647.fastlogin.bukkit.listener.protocollib.ProtocolLibListener.onPacketReceiving(ProtocolLibListener.java:96) ~[FastLoginBukkit.jar:?]
	at com.comphenix.protocol.async.AsyncListenerHandler.processPacket(AsyncListenerHandler.java:642) [ProtocolLib.jar:5.0.0-SNAPSHOT-b559]
	at com.comphenix.protocol.async.AsyncListenerHandler.listenerLoop(AsyncListenerHandler.java:596) [ProtocolLib.jar:5.0.0-SNAPSHOT-b559]
	at com.comphenix.protocol.async.AsyncListenerHandler.access$200(AsyncListenerHandler.java:48) [ProtocolLib.jar:5.0.0-SNAPSHOT-b559]
	at com.comphenix.protocol.async.AsyncListenerHandler$2.run(AsyncListenerHandler.java:229) [ProtocolLib.jar:5.0.0-SNAPSHOT-b559]
	at com.comphenix.protocol.async.AsyncListenerHandler$3.run(AsyncListenerHandler.java:300) [ProtocolLib.jar:5.0.0-SNAPSHOT-b559]
	at org.bukkit.craftbukkit.v1_19_R1.scheduler.CraftTask.run(CraftTask.java:82) [spigot-1.19-R0.1-SNAPSHOT.jar:3507-Spigot-fa893f0-c3f219e]
	at org.bukkit.craftbukkit.v1_19_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:54) [spigot-1.19-R0.1-SNAPSHOT.jar:3507-Spigot-fa893f0-c3f219e]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:?]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:?]
	at java.lang.Thread.run(Unknown Source) [?:?]

with ProtocolSupport build 673 it just doesn't output any errors, and autologin doesn't work too

P.S.: Hope 1.19 compatibility will be implemented soon

[gavenda]

ProtocolLib recently added wrappers for ProfileKeyData which is now being used by 1.19 login:

dmulloy2/ProtocolLib@84a0b5f#diff-3f954902d97423b8e2d9515f479ff251c366fb2444b6461d7d42b3b6850b41e5

[comonier]

Waterfall ? I have no problem using Bungeecord on 1.18.2 but always have problems using waterfall.... now, Bungeecord did not updates to 1.19 yet, so i am using waterfall but fastlogin cant communicate with proxy

that issue not happens on bungeecord [when it was 1.18.2] only when i change to waterfall [i guess]

[TuxCoding]

@comonier This always means there is an issue with the plugin not responding on the proxy. Please check your proxy logs. You are likely running a FastLogin that isn't compatible with your proxy version. Newer FastLogin version require the last proxy.

[TuxCoding]

@gavenda

ProtocolLib recently added wrappers for ProfileKeyData which is now being used by 1.19 login:

dmulloy2/ProtocolLib@84a0b5f#diff-3f954902d97423b8e2d9515f479ff251c366fb2444b6461d7d42b3b6850b41e5

Thanks for noticing that. However, the signature data is more important at the moment. The verification of profile keys is introduced as optional feature by Mojang and we could do the same. The client -> served online mode acknowledgement is now cryptographic signed too. This signature field is encapsulated behind an Either field. This is a lot trickier to get to and as far as I know not available in ProtocolLib as of now.

Furthermore the Mojang verification logic still has to be implemented by FastLogin. Most of it is already is implemented. However it still lacks some test cases.

[gavenda]

@gavenda

ProtocolLib recently added wrappers for ProfileKeyData which is now being used by 1.19 login:
dmulloy2/ProtocolLib@84a0b5f#diff-3f954902d97423b8e2d9515f479ff251c366fb2444b6461d7d42b3b6850b41e5

Thanks for noticing that. However, the signature data is more important at the moment. The verification of profile keys is introduced as optional feature by Mojang and we could do the same. The client -> served online mode acknowledgement is now cryptographic signed too. This signature field is encapsulated behind an Either field. This is a lot trickier to get to and as far as I know not available in ProtocolLib as of now.

Furthermore the Mojang verification logic still has to be implemented by FastLogin. Most of it is already is implemented. However it still lacks some test cases.

I basically have a fork of your codebase ported over Kotlin right here and offline mode with premium login already works. But the code isn't backwards compatible and just runs assuming you're on 1.19.

I just experimented with it and somehow made it work. I stored the public key data if it exists (or sent by client) in a session and used that to fake a login packet.

Related code:
https://github.com/gavenda/yawa/blob/3fb25d7e011dbb220480c41cd3e5e3d6cda3d7a6/yawa/src/main/kotlin/work/gavenda/yawa/login/LoginListener.kt#L58

https://github.com/gavenda/yawa/blob/3fb25d7e011dbb220480c41cd3e5e3d6cda3d7a6/yawa/src/main/kotlin/work/gavenda/yawa/login/LoginEncryptionTask.kt#L172-L192

It should be comfortable with you since its really just a miniature port of this plugin.

[TuxCoding]

@gavenda Maybe I'm missing it, but where do you verify the nonce/verify token? That's the part I'm talking about earlier. It's necessary to prevent relay attacks.

[gavenda]

I'm missing on that as well, the nonce token somehow became missing on ENCRYPTION_BEGIN, reading index 1 just throws an index out of bounds. It seems like they're using the public key data for signing somehow (starting 1.19 ?). I just skipped the verification part in my end but it will be critical for this plugin.

I can try to experiment a bit more and see if the public key data can be used to verify something on our end.