From 843993f02b900dd97f413468a482b8d6b19c967d Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Wed, 22 Apr 2020 13:45:29 +0100
Subject: [PATCH] Throw a specific exception for zlib decompression failure

---
 src/network/mcpe/NetworkSession.php           |  3 +-
 .../compression/DecompressionException.php    | 28 +++++++++++++++++++
 src/network/mcpe/compression/Zlib.php         |  8 ++++--
 3 files changed, 36 insertions(+), 3 deletions(-)
 create mode 100644 src/network/mcpe/compression/DecompressionException.php

diff --git a/src/network/mcpe/NetworkSession.php b/src/network/mcpe/NetworkSession.php
index 906dbef54..5da1cf2cf 100644
--- a/src/network/mcpe/NetworkSession.php
+++ b/src/network/mcpe/NetworkSession.php
@@ -35,6 +35,7 @@ use pocketmine\form\Form;
 use pocketmine\math\Vector3;
 use pocketmine\network\BadPacketException;
 use pocketmine\network\mcpe\compression\CompressBatchPromise;
+use pocketmine\network\mcpe\compression\DecompressionException;
 use pocketmine\network\mcpe\compression\Zlib;
 use pocketmine\network\mcpe\encryption\DecryptionException;
 use pocketmine\network\mcpe\encryption\NetworkCipher;
@@ -280,7 +281,7 @@ class NetworkSession{
 		Timings::$playerNetworkReceiveDecompressTimer->startTiming();
 		try{
 			$stream = new PacketBatch(Zlib::decompress($payload));
-		}catch(\ErrorException $e){
+		}catch(DecompressionException $e){
 			$this->logger->debug("Failed to decompress packet: " . base64_encode($payload));
 			//TODO: this isn't incompatible game version if we already established protocol version
 			throw BadPacketException::wrap($e, "Compressed packet batch decode error");
diff --git a/src/network/mcpe/compression/DecompressionException.php b/src/network/mcpe/compression/DecompressionException.php
new file mode 100644
index 000000000..dfaf7e50e
--- /dev/null
+++ b/src/network/mcpe/compression/DecompressionException.php
@@ -0,0 +1,28 @@
+<?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\compression;
+
+final class DecompressionException extends \RuntimeException{
+
+}
\ No newline at end of file
diff --git a/src/network/mcpe/compression/Zlib.php b/src/network/mcpe/compression/Zlib.php
index 7c84adb70..867996f15 100644
--- a/src/network/mcpe/compression/Zlib.php
+++ b/src/network/mcpe/compression/Zlib.php
@@ -40,10 +40,14 @@ final class Zlib{
 	/**
 	 * @param int    $maxDecodedLength default 2MB
 	 *
-	 * @throws \ErrorException
+	 * @throws DecompressionException
 	 */
 	public static function decompress(string $payload, int $maxDecodedLength = 1024 * 1024 * 2) : string{
-		return zlib_decode($payload, $maxDecodedLength);
+		$result = @zlib_decode($payload, $maxDecodedLength);
+		if($result === false){
+			throw new DecompressionException("Failed to decompress data");
+		}
+		return $result;
 	}
 
 	/**