Allow specifying a key for encrypted resource packs (#5297)

resources/resource_packs.yml

@@ -10,3 +10,4 @@ resource_stack:
   # - natural.zip
   # - vanilla.zip
   #If you want to force clients to use vanilla resources, you must place a vanilla resource pack in your resources folder and add it to the stack here.
+  #To specify a resource encryption key, put the key in the <resource>.key file alongside the resource pack. Example: vanilla.zip.key

src/network/mcpe/handler/ResourcePacksPacketHandler.php

@@ -65,9 +65,19 @@ class ResourcePacksPacketHandler extends PacketHandler{
 	){}
 
 	public function setUp() : void{
-		$resourcePackEntries = array_map(static function(ResourcePack $pack) : ResourcePackInfoEntry{
+		$resourcePackEntries = array_map(function(ResourcePack $pack) : ResourcePackInfoEntry{
 			//TODO: more stuff
-			return new ResourcePackInfoEntry($pack->getPackId(), $pack->getPackVersion(), $pack->getPackSize(), "", "", "", false);
+			$encryptionKey = $this->resourcePackManager->getPackEncryptionKey($pack->getPackId());
+
+			return new ResourcePackInfoEntry(
+				$pack->getPackId(),
+				$pack->getPackVersion(),
+				$pack->getPackSize(),
+				$encryptionKey ?? "",
+				"",
+				$pack->getPackId(),
+				false
+			);
 		}, $this->resourcePackManager->getResourceStack());
 		//TODO: support forcing server packs
 		$this->session->sendDataPacket(ResourcePacksInfoPacket::create($resourcePackEntries, [], $this->resourcePackManager->resourcePacksRequired(), false, false));

src/resourcepacks/ResourcePackManager.php

@@ -23,12 +23,14 @@ declare(strict_types=1);
 
 namespace pocketmine\resourcepacks;
 
+use pocketmine\errorhandler\ErrorToExceptionHandler;
 use pocketmine\utils\Config;
 use Webmozart\PathUtil\Path;
 use function array_keys;
 use function copy;
 use function count;
 use function file_exists;
+use function file_get_contents;
 use function gettype;
 use function is_array;
 use function is_dir;
@@ -49,6 +51,12 @@ class ResourcePackManager{
 	/** @var ResourcePack[] */
 	private array $uuidList = [];
 
+	/**
+	 * @var string[]
+	 * @phpstan-var array<string, string>
+	 */
+	private array $encryptionKeys = [];
+
 	/**
 	 * @param string  $path Path to resource-packs directory.
 	 */
@@ -106,6 +114,17 @@ class ResourcePackManager{
 				if($newPack instanceof ResourcePack){
 					$this->resourcePacks[] = $newPack;
 					$this->uuidList[strtolower($newPack->getPackId())] = $newPack;
+
+					$keyPath = Path::join($this->path, $pack . ".key");
+					if(file_exists($keyPath)){
+						try{
+							$this->encryptionKeys[strtolower($newPack->getPackId())] = ErrorToExceptionHandler::trapAndRemoveFalse(
+								fn() => file_get_contents($keyPath)
+							);
+						}catch(\ErrorException $e){
+							throw new ResourcePackException("Could not read encryption key file: " . $e->getMessage(), 0, $e);
+						}
+					}
 				}else{
 					throw new ResourcePackException("Format not recognized");
 				}
@@ -153,4 +172,11 @@ class ResourcePackManager{
 	public function getPackIdList() : array{
 		return array_keys($this->uuidList);
 	}
+
+	/**
+	 * Returns the key with which the pack was encrypted, or null if the pack has no key.
+	 */
+	public function getPackEncryptionKey(string $id) : ?string{
+		return $this->encryptionKeys[strtolower($id)] ?? null;
+	}
 }