LoginPacketHandler.php

<?php
 
/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 *
 *
 */
 
declare(strict_types=1);
 
namespace pocketmine\network\mcpe\handler;
 
use pocketmine\entity\InvalidSkinException;
use pocketmine\event\player\PlayerPreLoginEvent;
use pocketmine\lang\KnownTranslationFactory;
use pocketmine\lang\Translatable;
use pocketmine\network\mcpe\auth\ProcessLoginTask;
use pocketmine\network\mcpe\JwtException;
use pocketmine\network\mcpe\JwtUtils;
use pocketmine\network\mcpe\NetworkSession;
use pocketmine\network\mcpe\protocol\LoginPacket;
use pocketmine\network\mcpe\protocol\types\login\AuthenticationData;
use pocketmine\network\mcpe\protocol\types\login\AuthenticationInfo;
use pocketmine\network\mcpe\protocol\types\login\AuthenticationType;
use pocketmine\network\mcpe\protocol\types\login\ClientData;
use pocketmine\network\mcpe\protocol\types\login\ClientDataToSkinDataHelper;
use pocketmine\network\mcpe\protocol\types\login\JwtChain;
use pocketmine\network\PacketHandlingException;
use pocketmine\player\Player;
use pocketmine\player\PlayerInfo;
use pocketmine\player\XboxLivePlayerInfo;
use pocketmine\Server;
use Ramsey\Uuid\Uuid;
use function gettype;
use function is_array;
use function is_object;
use function json_decode;
use const JSON_THROW_ON_ERROR;
 
class LoginPacketHandler extends PacketHandler{
    public function __construct(
        private Server $server,
        private NetworkSession $session,
        private \Closure $playerInfoConsumer,
        private \Closure $authCallback
    ){}
 
    public function handleLogin(LoginPacket $packet) : bool{
        $authInfo = $this->parseAuthInfo($packet->authInfoJson);
        $jwtChain = $this->parseJwtChain($authInfo->Certificate);
        $extraData = $this->fetchAuthData($jwtChain);
 
        if(!Player::isValidUserName($extraData->displayName)){
            $this->session->disconnectWithError(KnownTranslationFactory::disconnectionScreen_invalidName());
 
            return true;
        }
 
        $clientData = $this->parseClientData($packet->clientDataJwt);
 
        try{
            $skin = $this->session->getTypeConverter()->getSkinAdapter()->fromSkinData(ClientDataToSkinDataHelper::fromClientData($clientData));
        }catch(\InvalidArgumentException | InvalidSkinException $e){
            $this->session->disconnectWithError(
                reason: "Invalid skin: " . $e->getMessage(),
                disconnectScreenMessage: KnownTranslationFactory::disconnectionScreen_invalidSkin()
            );
 
            return true;
        }
 
        if(!Uuid::isValid($extraData->identity)){
            throw new PacketHandlingException("Invalid login UUID");
        }
        $uuid = Uuid::fromString($extraData->identity);
        $arrClientData = (array) $clientData;
        $arrClientData["TitleID"] = $extraData->titleId;
 
        if($extraData->XUID !== ""){
            $playerInfo = new XboxLivePlayerInfo(
                $extraData->XUID,
                $extraData->displayName,
                $uuid,
                $skin,
                $clientData->LanguageCode,
                $arrClientData
            );
        }else{
            $playerInfo = new PlayerInfo(
                $extraData->displayName,
                $uuid,
                $skin,
                $clientData->LanguageCode,
                $arrClientData
            );
        }
        ($this->playerInfoConsumer)($playerInfo);
 
        $ev = new PlayerPreLoginEvent(
            $playerInfo,
            $this->session->getIp(),
            $this->session->getPort(),
            $this->server->requiresAuthentication()
        );
        if($this->server->getNetwork()->getValidConnectionCount() > $this->server->getMaxPlayers()){
            $ev->setKickFlag(PlayerPreLoginEvent::KICK_FLAG_SERVER_FULL, KnownTranslationFactory::disconnectionScreen_serverFull());
        }
        if(!$this->server->isWhitelisted($playerInfo->getUsername())){
            $ev->setKickFlag(PlayerPreLoginEvent::KICK_FLAG_SERVER_WHITELISTED, KnownTranslationFactory::pocketmine_disconnect_whitelisted());
        }
 
        $banMessage = null;
        if(($banEntry = $this->server->getNameBans()->getEntry($playerInfo->getUsername())) !== null){
            $banReason = $banEntry->getReason();
            $banMessage = $banReason === "" ? KnownTranslationFactory::pocketmine_disconnect_ban_noReason() : KnownTranslationFactory::pocketmine_disconnect_ban($banReason);
        }elseif(($banEntry = $this->server->getIPBans()->getEntry($this->session->getIp())) !== null){
            $banReason = $banEntry->getReason();
            $banMessage = KnownTranslationFactory::pocketmine_disconnect_ban($banReason !== "" ? $banReason : KnownTranslationFactory::pocketmine_disconnect_ban_ip());
        }
        if($banMessage !== null){
            $ev->setKickFlag(PlayerPreLoginEvent::KICK_FLAG_BANNED, $banMessage);
        }
 
        $ev->call();
        if(!$ev->isAllowed()){
            $this->session->disconnect($ev->getFinalDisconnectReason(), $ev->getFinalDisconnectScreenMessage());
            return true;
        }
 
        $this->processLogin($authInfo->Token, AuthenticationType::from($authInfo->AuthenticationType), $jwtChain->chain, $packet->clientDataJwt, $ev->isAuthRequired());
 
        return true;
    }
 
    protected function parseAuthInfo(string $authInfo) : AuthenticationInfo{
        try{
            $authInfoJson = json_decode($authInfo, associative: false, flags: JSON_THROW_ON_ERROR);
        }catch(\JsonException $e){
            throw PacketHandlingException::wrap($e);
        }
        if(!is_object($authInfoJson)){
            throw new \RuntimeException("Unexpected type for auth info data: " . gettype($authInfoJson) . ", expected object");
        }
 
        $mapper = new \JsonMapper();
        $mapper->bExceptionOnMissingData = true;
        $mapper->bExceptionOnUndefinedProperty = true;
        $mapper->bStrictObjectTypeChecking = true;
        try{
            $clientData = $mapper->map($authInfoJson, new AuthenticationInfo());
        }catch(\JsonMapper_Exception $e){
            throw PacketHandlingException::wrap($e);
        }
        return $clientData;
    }
 
    protected function parseJwtChain(string $chainDataJwt) : JwtChain{
        try{
            $jwtChainJson = json_decode($chainDataJwt, associative: false, flags: JSON_THROW_ON_ERROR);
        }catch(\JsonException $e){
            throw PacketHandlingException::wrap($e);
        }
        if(!is_object($jwtChainJson)){
            throw new \RuntimeException("Unexpected type for JWT chain data: " . gettype($jwtChainJson) . ", expected object");
        }
 
        $mapper = new \JsonMapper();
        $mapper->bExceptionOnMissingData = true;
        $mapper->bExceptionOnUndefinedProperty = true;
        $mapper->bStrictObjectTypeChecking = true;
        try{
            $clientData = $mapper->map($jwtChainJson, new JwtChain());
        }catch(\JsonMapper_Exception $e){
            throw PacketHandlingException::wrap($e);
        }
        return $clientData;
    }
 
    protected function fetchAuthData(JwtChain $chain) : AuthenticationData{
        $extraData = null;
        foreach($chain->chain as $jwt){
            //validate every chain element
            try{
                [, $claims, ] = JwtUtils::parse($jwt);
            }catch(JwtException $e){
                throw PacketHandlingException::wrap($e);
            }
            if(isset($claims["extraData"])){
                if($extraData !== null){
                    throw new PacketHandlingException("Found 'extraData' more than once in chainData");
                }
 
                if(!is_array($claims["extraData"])){
                    throw new PacketHandlingException("'extraData' key should be an array");
                }
                $mapper = new \JsonMapper();
                $mapper->bEnforceMapType = false; //TODO: we don't really need this as an array, but right now we don't have enough models
                $mapper->bExceptionOnMissingData = true;
                $mapper->bExceptionOnUndefinedProperty = true;
                $mapper->bStrictObjectTypeChecking = true;
                try{
                    $extraData = $mapper->map($claims["extraData"], new AuthenticationData());
                }catch(\JsonMapper_Exception $e){
                    throw PacketHandlingException::wrap($e);
                }
            }
        }
        if($extraData === null){
            throw new PacketHandlingException("'extraData' not found in chain data");
        }
        return $extraData;
    }
 
    protected function parseClientData(string $clientDataJwt) : ClientData{
        try{
            [, $clientDataClaims, ] = JwtUtils::parse($clientDataJwt);
        }catch(JwtException $e){
            throw PacketHandlingException::wrap($e);
        }
 
        $mapper = new \JsonMapper();
        $mapper->bEnforceMapType = false; //TODO: we don't really need this as an array, but right now we don't have enough models
        $mapper->bExceptionOnMissingData = true;
        $mapper->bExceptionOnUndefinedProperty = true;
        $mapper->bStrictObjectTypeChecking = true;
        try{
            $clientData = $mapper->map($clientDataClaims, new ClientData());
        }catch(\JsonMapper_Exception $e){
            throw PacketHandlingException::wrap($e);
        }
        return $clientData;
    }
 
    protected function processLogin(string $token, AuthenticationType $authType, ?array $legacyCertificate, string $clientData, bool $authRequired) : void{
        if($legacyCertificate === null){
            throw new PacketHandlingException("Legacy certificate cannot be null");
        }
        $this->server->getAsyncPool()->submitTask(new ProcessLoginTask($legacyCertificate, $clientData, $authRequired, $this->authCallback));
        $this->session->setHandler(null); //drop packets received during login verification
    }
}