From ccbdb77618ff76078567c33bf61eb3ac2454ebeb Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Tue, 26 Sep 2017 09:49:35 +0100
Subject: [PATCH] Cleaned up LoginPacket handling, don't nuke the buffer

---
 .../network/mcpe/PlayerNetworkSessionAdapter.php   |  2 +-
 .../network/mcpe/protocol/DataPacket.php           |  8 ++++++++
 .../network/mcpe/protocol/LoginPacket.php          | 14 +++++++++-----
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/src/pocketmine/network/mcpe/PlayerNetworkSessionAdapter.php b/src/pocketmine/network/mcpe/PlayerNetworkSessionAdapter.php
index ae753a5d5..fd6e7dd86 100644
--- a/src/pocketmine/network/mcpe/PlayerNetworkSessionAdapter.php
+++ b/src/pocketmine/network/mcpe/PlayerNetworkSessionAdapter.php
@@ -82,7 +82,7 @@ class PlayerNetworkSessionAdapter extends NetworkSession{
 		$timings->startTiming();
 
 		$packet->decode();
-		if(!$packet->feof()){
+		if(!$packet->feof() and !$packet->mayHaveUnreadBytes()){
 			$remains = substr($packet->buffer, $packet->offset);
 			$this->server->getLogger()->debug("Still " . strlen($remains) . " bytes unread in " . $packet->getName() . ": 0x" . bin2hex($remains));
 		}
diff --git a/src/pocketmine/network/mcpe/protocol/DataPacket.php b/src/pocketmine/network/mcpe/protocol/DataPacket.php
index c68c2d447..4a16885b3 100644
--- a/src/pocketmine/network/mcpe/protocol/DataPacket.php
+++ b/src/pocketmine/network/mcpe/protocol/DataPacket.php
@@ -62,6 +62,14 @@ abstract class DataPacket extends BinaryStream{
 		return false;
 	}
 
+	/**
+	 * Returns whether the packet may legally have unread bytes left in the buffer.
+	 * @return bool
+	 */
+	public function mayHaveUnreadBytes() : bool{
+		return false;
+	}
+
 	public function decode(){
 		$this->offset = 0;
 		$this->decodeHeader();
diff --git a/src/pocketmine/network/mcpe/protocol/LoginPacket.php b/src/pocketmine/network/mcpe/protocol/LoginPacket.php
index d6d33ce89..0e9eb77ec 100644
--- a/src/pocketmine/network/mcpe/protocol/LoginPacket.php
+++ b/src/pocketmine/network/mcpe/protocol/LoginPacket.php
@@ -27,6 +27,7 @@ namespace pocketmine\network\mcpe\protocol;
 
 
 use pocketmine\network\mcpe\NetworkSession;
+use pocketmine\utils\BinaryStream;
 use pocketmine\utils\Utils;
 
 class LoginPacket extends DataPacket{
@@ -63,17 +64,20 @@ class LoginPacket extends DataPacket{
 		return true;
 	}
 
+	public function mayHaveUnreadBytes() : bool{
+		return $this->protocol !== null and $this->protocol !== ProtocolInfo::CURRENT_PROTOCOL;
+	}
+
 	protected function decodePayload(){
 		$this->protocol = $this->getInt();
 
 		if($this->protocol !== ProtocolInfo::CURRENT_PROTOCOL){
-			$this->buffer = null;
-			return; //Do not attempt to decode for non-accepted protocols
+			return; //Do not attempt to continue decoding for non-accepted protocols
 		}
 
-		$this->setBuffer($this->getString(), 0);
+		$buffer = new BinaryStream($this->getString());
 
-		$this->chainData = json_decode($this->get($this->getLInt()), true);
+		$this->chainData = json_decode($buffer->get($buffer->getLInt()), true);
 		foreach($this->chainData["chain"] as $chain){
 			$webtoken = Utils::decodeJWT($chain);
 			if(isset($webtoken["extraData"])){
@@ -89,7 +93,7 @@ class LoginPacket extends DataPacket{
 			}
 		}
 
-		$this->clientDataJwt = $this->get($this->getLInt());
+		$this->clientDataJwt = $buffer->get($buffer->getLInt());
 		$this->clientData = Utils::decodeJWT($this->clientDataJwt);
 
 		$this->clientId = $this->clientData["ClientRandomId"] ?? null;