From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Spottedleaf Date: Sat, 1 Jan 2022 05:19:37 -0800 Subject: [PATCH] Validate usernames diff --git a/src/main/java/com/destroystokyo/paper/PaperConfig.java b/src/main/java/com/destroystokyo/paper/PaperConfig.java index d5aa95846e7f52108a03e3731023527281b21d73..1d3cc8836d2ccbec4a8660f86501be35c76e8b0b 100644 --- a/src/main/java/com/destroystokyo/paper/PaperConfig.java +++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java @@ -493,6 +493,12 @@ public class PaperConfig { set("settings.unsupported-settings.allow-tnt-duplication", null); } + public static boolean performUsernameValidation; + private static void performUsernameValidation() { + performUsernameValidation = getBoolean("settings.unsupported-settings.perform-username-validation", true); + } + + public static int playerAutoSaveRate = -1; public static int maxPlayerAutoSavePerTick = 10; private static void playerAutoSaveRate() { diff --git a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java index 33a29890435d6065a2cc4f8e8bf8209c01d5d114..bb70d2b4d284727aa5dc88dd99534d09c2e38657 100644 --- a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java +++ b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java @@ -65,6 +65,7 @@ public class ServerLoginPacketListenerImpl implements ServerLoginPacketListener private ServerPlayer delayedAcceptPlayer; public String hostname = ""; // CraftBukkit - add field private int velocityLoginMessageId = -1; // Paper - Velocity support + public boolean iKnowThisMayNotBeTheBestIdeaButPleaseDisableUsernameValidation = false; // Paper - username validation overriding public ServerLoginPacketListenerImpl(MinecraftServer server, Connection connection) { this.state = ServerLoginPacketListenerImpl.State.HELLO; @@ -230,10 +231,38 @@ public class ServerLoginPacketListenerImpl implements ServerLoginPacketListener // Paper end } + // Paper start - validate usernames + public static boolean validateUsername(String in) { + if (in == null || in.isEmpty() || in.length() > 16) { + return false; + } + + for (int i = 0, len = in.length(); i < len; ++i) { + char c = in.charAt(i); + + if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || (c == '_' || c == '.')) { + continue; + } + + return false; + } + + return true; + } + // Paper end - validate usernames + @Override public void handleHello(ServerboundHelloPacket packet) { Validate.validState(this.state == ServerLoginPacketListenerImpl.State.HELLO, "Unexpected hello packet", new Object[0]); this.gameProfile = packet.getGameProfile(); + // Paper start - validate usernames + if (com.destroystokyo.paper.PaperConfig.isProxyOnlineMode() && com.destroystokyo.paper.PaperConfig.performUsernameValidation) { + if (!this.iKnowThisMayNotBeTheBestIdeaButPleaseDisableUsernameValidation && !validateUsername(this.gameProfile.getName())) { + ServerLoginPacketListenerImpl.this.disconnect("Failed to verify username!"); + return; + } + } + // Paper end - validate usernames if (this.server.usesAuthentication() && !this.connection.isMemoryConnection()) { this.state = ServerLoginPacketListenerImpl.State.KEY; this.connection.send(new ClientboundHelloPacket("", this.server.getKeyPair().getPublic().getEncoded(), this.nonce)); diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java index fe9810c3b908339ca050ed832c2e67d62cc97b0b..cd08f9b16c065be8f0eacaeba51d3e72d332daf9 100644 --- a/src/main/java/net/minecraft/server/players/PlayerList.java +++ b/src/main/java/net/minecraft/server/players/PlayerList.java @@ -707,7 +707,7 @@ public abstract class PlayerList { for (int i = 0; i < this.players.size(); ++i) { entityplayer = (ServerPlayer) this.players.get(i); - if (entityplayer.getUUID().equals(uuid)) { + if (entityplayer.getUUID().equals(uuid) || (com.destroystokyo.paper.PaperConfig.isProxyOnlineMode() && entityplayer.getGameProfile().getName().equalsIgnoreCase(gameprofile.getName()))) { // Paper - validate usernames list.add(entityplayer); } }