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/net/minecraft/server/network/ServerLoginPacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java index 0c4fb4a7d4fcdc6d724beb13a16bd729a3c525cd..20ba13c06edf125ba216d1ca8794868abcd8f916 100644 --- a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java +++ b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java @@ -63,6 +63,7 @@ public class ServerLoginPacketListenerImpl implements ServerLoginPacketListener, public GameProfile authenticatedProfile; // Paper - public private final String serverId; private ServerPlayer player; // CraftBukkit + public boolean iKnowThisMayNotBeTheBestIdeaButPleaseDisableUsernameValidation = false; // Paper - username validation overriding public ServerLoginPacketListenerImpl(MinecraftServer server, Connection connection) { this.state = ServerLoginPacketListenerImpl.State.HELLO; @@ -134,10 +135,38 @@ public class ServerLoginPacketListenerImpl implements ServerLoginPacketListener, return this.requestedUsername != null ? this.requestedUsername + " (" + s + ")" : s; } + // 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]); Validate.validState(Player.isValidUsername(packet.name()), "Invalid characters in username", new Object[0]); + // Paper start - validate usernames -- TODO: Do we need this? + if (io.papermc.paper.configuration.GlobalConfiguration.get().proxies.isProxyOnlineMode() && io.papermc.paper.configuration.GlobalConfiguration.get().unsupportedSettings.performUsernameValidation) { + if (!this.iKnowThisMayNotBeTheBestIdeaButPleaseDisableUsernameValidation && !validateUsername(packet.name())) { + ServerLoginPacketListenerImpl.this.disconnect("Failed to verify username!"); + return; + } + } + // Paper end - validate usernames this.requestedUsername = packet.name(); GameProfile gameprofile = this.server.getSingleplayerProfile(); diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java index c92545e3cd199c7e123f65d42ca8976d2da27509..1e15c3576b6b506335c66a4ca0a47f3aa178c72a 100644 --- a/src/main/java/net/minecraft/server/players/PlayerList.java +++ b/src/main/java/net/minecraft/server/players/PlayerList.java @@ -679,7 +679,7 @@ 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) || (io.papermc.paper.configuration.GlobalConfiguration.get().proxies.isProxyOnlineMode() && entityplayer.getGameProfile().getName().equalsIgnoreCase(gameprofile.getName()))) { // Paper - validate usernames list.add(entityplayer); } }