Implement new OpenID authentication system (#6798)

Co-authored-by: Dries C <15795262+dries-c@users.noreply.github.com>

src/network/mcpe/auth/AuthKeyProvider.php

@@ -0,0 +1,164 @@
+<?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\auth;
+
+use pocketmine\network\mcpe\JwtException;
+use pocketmine\network\mcpe\JwtUtils;
+use pocketmine\network\mcpe\protocol\types\login\openid\api\AuthServiceKey;
+use pocketmine\promise\Promise;
+use pocketmine\promise\PromiseResolver;
+use pocketmine\scheduler\AsyncPool;
+use pocketmine\utils\AssumptionFailedError;
+use function array_keys;
+use function count;
+use function implode;
+use function time;
+
+class AuthKeyProvider{
+	private const ALLOWED_REFRESH_INTERVAL = 30 * 60; // 30 minutes
+
+	private ?AuthKeyring $keyring = null;
+
+	/** @phpstan-var PromiseResolver<AuthKeyring> */
+	private ?PromiseResolver $resolver = null;
+
+	private int $lastFetch = 0;
+
+	public function __construct(
+		private readonly \Logger $logger,
+		private readonly AsyncPool $asyncPool,
+		private readonly int $keyRefreshIntervalSeconds = self::ALLOWED_REFRESH_INTERVAL
+	){}
+
+	/**
+	 * Fetches the key for the given key ID.
+	 * The promise will be resolved with an array of [issuer, pemPublicKey].
+	 *
+	 * @phpstan-return Promise<array{string, string}>
+	 */
+	public function getKey(string $keyId) : Promise{
+		/** @phpstan-var PromiseResolver<array{string, string}> $resolver */
+		$resolver = new PromiseResolver();
+
+		if(
+			$this->keyring === null || //we haven't fetched keys yet
+			($this->keyring->getKey($keyId) === null && $this->lastFetch < time() - $this->keyRefreshIntervalSeconds) //we don't recognise this one & keys might be outdated
+		){
+			//only refresh keys when we see one we don't recognise
+			$this->fetchKeys()->onCompletion(
+				onSuccess: fn(AuthKeyring $newKeyring) => $this->resolveKey($resolver, $newKeyring, $keyId),
+				onFailure: $resolver->reject(...)
+			);
+		}else{
+			$this->resolveKey($resolver, $this->keyring, $keyId);
+		}
+
+		return $resolver->getPromise();
+	}
+
+	/**
+	 * @phpstan-param PromiseResolver<array{string, string}> $resolver
+	 */
+	private function resolveKey(PromiseResolver $resolver, AuthKeyring $keyring, string $keyId) : void{
+		$key = $keyring->getKey($keyId);
+		if($key === null){
+			$this->logger->debug("Key $keyId not recognised!");
+			$resolver->reject();
+			return;
+		}
+
+		$this->logger->debug("Key $keyId found in keychain");
+		$resolver->resolve([$keyring->getIssuer(), $key]);
+	}
+
+	/**
+	 * @phpstan-param array<string, AuthServiceKey>|null $keys
+	 * @phpstan-param string[]|null                      $errors
+	 */
+	private function onKeysFetched(?array $keys, string $issuer, ?array $errors) : void{
+		$resolver = $this->resolver;
+		if($resolver === null){
+			throw new AssumptionFailedError("Not expecting this to be called without a resolver present");
+		}
+		if($errors !== null){
+			$this->logger->error("The following errors occurred while fetching new keys:\n\t- " . implode("\n\t-", $errors));
+			//we might've still succeeded in fetching keys even if there were errors, so don't return
+		}
+
+		if($keys === null){
+			$this->logger->critical("Failed to fetch authentication keys from Mojang's API. Xbox players may not be able to authenticate!");
+			$resolver->reject();
+		}else{
+			$pemKeys = [];
+			foreach($keys as $keyModel){
+				if($keyModel->use !== "sig" || $keyModel->kty !== "RSA"){
+					$this->logger->error("Key ID $keyModel->kid doesn't have the expected properties: expected use=sig, kty=RSA, got use=$keyModel->use, kty=$keyModel->kty");
+					continue;
+				}
+				$derKey = JwtUtils::rsaPublicKeyModExpToDer($keyModel->n, $keyModel->e);
+
+				//make sure the key is valid
+				try{
+					JwtUtils::parseDerPublicKey($derKey);
+				}catch(JwtException $e){
+					$this->logger->error("Failed to parse RSA public key for key ID $keyModel->kid: " . $e->getMessage());
+					$this->logger->logException($e);
+					continue;
+				}
+
+				//retain PEM keys instead of OpenSSLAsymmetricKey since these are easier and cheaper to copy between threads
+				$pemKeys[$keyModel->kid] = $derKey;
+			}
+
+			if(count($keys) === 0){
+				$this->logger->critical("No valid authentication keys returned by Mojang's API. Xbox players may not be able to authenticate!");
+				$resolver->reject();
+			}else{
+				$this->logger->info("Successfully fetched " . count($keys) . " new authentication keys from issuer $issuer, key IDs: " . implode(", ", array_keys($pemKeys)));
+				$this->keyring = new AuthKeyring($issuer, $pemKeys);
+				$this->lastFetch = time();
+				$resolver->resolve($this->keyring);
+			}
+		}
+	}
+
+	/**
+	 * @phpstan-return Promise<AuthKeyring>
+	 */
+	private function fetchKeys() : Promise{
+		if($this->resolver !== null){
+			$this->logger->debug("Key refresh was requested, but it's already in progress");
+			return $this->resolver->getPromise();
+		}
+
+		$this->logger->notice("Fetching new authentication keys");
+
+		/** @phpstan-var PromiseResolver<AuthKeyring> $resolver */
+		$resolver = new PromiseResolver();
+		$this->resolver = $resolver;
+		//TODO: extract this so it can be polyfilled for unit testing
+		$this->asyncPool->submitTask(new FetchAuthKeysTask($this->onKeysFetched(...)));
+		return $this->resolver->getPromise();
+	}
+}