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\ProcessOpenIdLoginTask;
use pocketmine\network\mcpe\auth\ProcessSelfSignedLoginTask;
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\AuthenticationInfo;
use pocketmine\network\mcpe\protocol\types\login\AuthenticationType;
use pocketmine\network\mcpe\protocol\types\login\clientdata\ClientData;
use pocketmine\network\mcpe\protocol\types\login\clientdata\ClientDataToSkinDataHelper;
use pocketmine\network\mcpe\protocol\types\login\openid\SelfSignedJwtBody;
use pocketmine\network\mcpe\protocol\types\login\openid\XboxAuthJwtBody;
use pocketmine\network\mcpe\protocol\types\login\openid\XboxAuthJwtHeader;
use pocketmine\network\PacketHandlingException;
use pocketmine\player\Player;
use pocketmine\player\PlayerInfo;
use pocketmine\player\XboxLivePlayerInfo;
use pocketmine\Server;
use pocketmine\utils\Utils;
use Ramsey\Uuid\Uuid;
use Ramsey\Uuid\UuidInterface;
use function base64_decode;
use function chr;
use function gettype;
use function is_object;
use function json_decode;
use function md5;
use function ord;
use function substr;
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
    ){}
 
    private static function calculateUuidFromXuid(string $xuid) : UuidInterface{
        $hash = md5("pocket-auth-1-xuid:" . $xuid, binary: true);
        $hash[6] = chr((ord($hash[6]) & 0x0f) | 0x30); // set version to 3
        $hash[8] = chr((ord($hash[8]) & 0x3f) | 0x80); // set variant to RFC 4122
 
        return Uuid::fromBytes($hash);
    }
 
    public function handleLogin(LoginPacket $packet) : bool{
        $authInfo = $this->parseAuthInfo($packet->authInfoJson);
 
        if($authInfo->AuthenticationType === AuthenticationType::FULL->value){
            try{
                [$headerArray, $claimsArray,] = JwtUtils::parse($authInfo->Token);
            }catch(JwtException $e){
                throw PacketHandlingException::wrap($e, "Error parsing authentication token");
            }
            $header = $this->mapXboxTokenHeader($headerArray);
            $claims = $this->mapXboxTokenBody($claimsArray);
 
            $legacyUuid = self::calculateUuidFromXuid($claims->xid);
            $username = $claims->xname;
            $xuid = $claims->xid;
 
            $authRequired = $this->processLoginCommon($packet, $username, $legacyUuid, $xuid);
            if($authRequired === null){
                //plugin cancelled
                return true;
            }
            $this->processOpenIdLogin($authInfo->Token, $header->kid, $packet->clientDataJwt, $authRequired);
 
        }elseif($authInfo->AuthenticationType === AuthenticationType::SELF_SIGNED->value){
            try{
                [, $claimsArray, ] = JwtUtils::parse($authInfo->Token);
            }catch(JwtException $e){
                throw PacketHandlingException::wrap($e, "Error parsing self-signed authentication token");
            }
            $claims = $this->mapSelfSignedTokenBody($claimsArray);
 
            if(!Uuid::isValid($claims->leguuid)){
                throw new PacketHandlingException("Invalid UUID string in self-signed certificate: " . $claims->leguuid);
            }
            $legacyUuid = Uuid::fromString($claims->leguuid);
            $username = $claims->xname;
            $xuid = "";
 
            $selfSignedKey = base64_decode($claims->cpk, strict: true);
            if($selfSignedKey === false){
                throw new PacketHandlingException("Invalid self-signed key");
            }
 
            $authRequired = $this->processLoginCommon($packet, $username, $legacyUuid, $xuid);
            if($authRequired === null){
                //plugin cancelled
                return true;
            }
            $this->processSelfSignedLogin($authInfo->Token, $selfSignedKey, $packet->clientDataJwt, $authRequired);
        }else{
            throw new PacketHandlingException("Unsupported authentication type: $authInfo->AuthenticationType");
        }
 
        return true;
    }
 
    private function processLoginCommon(LoginPacket $packet, string $username, UuidInterface $legacyUuid, string $xuid) : ?bool{
        if(!Player::isValidUserName($username)){
            $this->session->disconnectWithError(KnownTranslationFactory::disconnectionScreen_invalidName());
 
            return null;
        }
 
        $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 null;
        }
 
        if($xuid !== ""){
            $playerInfo = new XboxLivePlayerInfo(
                $xuid,
                $username,
                $legacyUuid,
                $skin,
                $clientData->LanguageCode,
                (array) $clientData
            );
        }else{
            $playerInfo = new PlayerInfo(
                $username,
                $legacyUuid,
                $skin,
                $clientData->LanguageCode,
                (array) $clientData
            );
        }
        ($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 null;
        }
 
        return $ev->isAuthRequired();
    }
 
    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($authInfoJson)){
            throw new PacketHandlingException("Unexpected type for auth info data: " . gettype($authInfoJson) . ", expected object");
        }
 
        $mapper = $this->defaultJsonMapper("Root authentication info JSON");
        try{
            $clientData = $mapper->map($authInfoJson, new AuthenticationInfo());
        }catch(\JsonMapper_Exception $e){
            throw PacketHandlingException::wrap($e);
        }
        return $clientData;
    }
 
    protected function mapXboxTokenHeader(array $headerArray) : XboxAuthJwtHeader{
        $mapper = $this->defaultJsonMapper("OpenID JWT header");
        try{
            $header = $mapper->map($headerArray, new XboxAuthJwtHeader());
        }catch(\JsonMapper_Exception $e){
            throw PacketHandlingException::wrap($e);
        }
        return $header;
    }
 
    protected function mapXboxTokenBody(array $bodyArray) : XboxAuthJwtBody{
        $mapper = $this->defaultJsonMapper("OpenID JWT body");
        try{
            $header = $mapper->map($bodyArray, new XboxAuthJwtBody());
        }catch(\JsonMapper_Exception $e){
            throw PacketHandlingException::wrap($e);
        }
        return $header;
    }
 
    protected function mapSelfSignedTokenBody(array $bodyArray) : SelfSignedJwtBody{
        $mapper = $this->defaultJsonMapper("OpenID JWT body");
        try{
            $header = $mapper->map($bodyArray, new SelfSignedJwtBody());
        }catch(\JsonMapper_Exception $e){
            throw PacketHandlingException::wrap($e);
        }
        return $header;
    }
 
    protected function parseClientData(string $clientDataJwt) : ClientData{
        try{
            [, $clientDataClaims, ] = JwtUtils::parse($clientDataJwt);
        }catch(JwtException $e){
            throw PacketHandlingException::wrap($e);
        }
 
        $mapper = $this->defaultJsonMapper("ClientData JWT body");
        try{
            $clientData = $mapper->map($clientDataClaims, new ClientData());
        }catch(\JsonMapper_Exception $e){
            throw PacketHandlingException::wrap($e);
        }
        return $clientData;
    }
 
    protected function processOpenIdLogin(string $token, string $keyId, string $clientData, bool $authRequired) : void{
        $this->session->setHandler(null); //drop packets received during login verification
 
        $authKeyProvider = $this->server->getAuthKeyProvider();
 
        $authKeyProvider->getKey($keyId)->onCompletion(
            function(array $issuerAndKey) use ($token, $clientData, $authRequired) : void{
                [$issuer, $mojangPublicKeyPem] = $issuerAndKey;
                $this->server->getAsyncPool()->submitTask(new ProcessOpenIdLoginTask($token, $issuer, $mojangPublicKeyPem, $clientData, $authRequired, $this->authCallback));
            },
            fn() => ($this->authCallback)(false, $authRequired, "Unrecognized authentication key ID: $keyId", null)
        );
    }
 
    protected function processSelfSignedLogin(string $token, string $clientPublicKey, string $clientData, bool $authRequired) : void{
        $this->session->setHandler(null); //drop packets received during login verification
 
        $this->server->getAsyncPool()->submitTask(new ProcessSelfSignedLoginTask($token, $clientPublicKey, $clientData, $authRequired, onCompletion: $this->authCallback));
    }
 
    private function defaultJsonMapper(string $logContext) : \JsonMapper{
        $mapper = new \JsonMapper();
        $mapper->bExceptionOnMissingData = true;
        $mapper->undefinedPropertyHandler = $this->warnUndefinedJsonPropertyHandler($logContext);
        $mapper->bStrictObjectTypeChecking = true;
        $mapper->bEnforceMapType = false;
        return $mapper;
    }
 
    private function warnUndefinedJsonPropertyHandler(string $context) : \Closure{
        return function(object $object, string $name, mixed $value) use ($context) : void{
            static $count = 0;
            if($count++ < 10){
                $this->session->getLogger()->warning(
                    "$context: Unexpected JSON property for " . (new \ReflectionClass($object))->getShortName() . ": " . Utils::printable(substr($name, 0, 80))
                );
            }else{
                throw new PacketHandlingException("$context: Too many unexpected JSON properties");
            }
        };
    }
}