From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Spottedleaf <Spottedleaf@users.noreply.github.com> 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 baedae23865ea80c6546d1f6f439e1d7712258b9..e9cd90b6bb2f57d605323add43f12962bd7cb843 100644 --- a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java +++ b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java @@ -85,6 +85,7 @@ public class ServerLoginPacketListenerImpl implements ServerLoginPacketListener, private final String serverId; private final boolean transferred; private ServerPlayer player; // CraftBukkit + public boolean iKnowThisMayNotBeTheBestIdeaButPleaseDisableUsernameValidation = false; // Paper - username validation overriding public ServerLoginPacketListenerImpl(MinecraftServer server, Connection connection, boolean transferred) { this.state = ServerLoginPacketListenerImpl.State.HELLO; @@ -166,7 +167,13 @@ public class ServerLoginPacketListenerImpl implements ServerLoginPacketListener, @Override public void handleHello(ServerboundHelloPacket packet) { Validate.validState(this.state == ServerLoginPacketListenerImpl.State.HELLO, "Unexpected hello packet", new Object[0]); - Validate.validState(StringUtil.isValidPlayerName(packet.name()), "Invalid characters in username", new Object[0]); + // Paper start - Validate usernames + if (io.papermc.paper.configuration.GlobalConfiguration.get().proxies.isProxyOnlineMode() + && io.papermc.paper.configuration.GlobalConfiguration.get().unsupportedSettings.performUsernameValidation + && !this.iKnowThisMayNotBeTheBestIdeaButPleaseDisableUsernameValidation) { + Validate.validState(StringUtil.isReasonablePlayerName(packet.name()), "Invalid characters in username", new Object[0]); + } + // 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 bc5088b4b8a60dcd87eb9a7e0858a5c45bd9a7d4..2b104326f718bdfa263554c60ead798659ab5fa0 100644 --- a/src/main/java/net/minecraft/server/players/PlayerList.java +++ b/src/main/java/net/minecraft/server/players/PlayerList.java @@ -670,7 +670,7 @@ 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); } } diff --git a/src/main/java/net/minecraft/util/StringUtil.java b/src/main/java/net/minecraft/util/StringUtil.java index d3fc549a08993376c76c4ebebb788fea3f4ddf69..0bd191acb9596d3aa21c337230d26f09d26f6888 100644 --- a/src/main/java/net/minecraft/util/StringUtil.java +++ b/src/main/java/net/minecraft/util/StringUtil.java @@ -67,6 +67,25 @@ public class StringUtil { return name.length() <= 16 && name.chars().filter(c -> c <= 32 || c >= 127).findAny().isEmpty(); } + // Paper start - Username validation + public static boolean isReasonablePlayerName(final String name) { + if (name.isEmpty() || name.length() > 16) { + return false; + } + + for (int i = 0, len = name.length(); i < len; ++i) { + final char c = name.charAt(i); + if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || (c == '_' || c == '.')) { + continue; + } + + return false; + } + + return true; + } + // Paper end - Username validation + public static String filterText(String string) { return filterText(string, false); }