1 files changed, 125 insertions, 0 deletions
diff --git a/lib/private/OCS/DiscoveryService.php b/lib/private/OCS/DiscoveryService.php
new file mode 100644
index 00000000000..a7945681183
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+++ b/lib/private/OCS/DiscoveryService.php
@@ -0,0 +1,125 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017 Bjoern Schiessle <bjoern@schiessle.org>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+
+namespace OC\OCS;
+
+use OCP\AppFramework\Http;
+use OCP\Http\Client\IClient;
+use OCP\Http\Client\IClientService;
+use OCP\ICache;
+use OCP\ICacheFactory;
+use OCP\OCS\IDiscoveryService;
+
+class DiscoveryService implements IDiscoveryService {
+
+	/** @var ICache */
+	private $cache;
+
+	/** @var IClient */
+	private $client;
+
+	/**
+	 * @param ICacheFactory $cacheFactory
+	 * @param IClientService $clientService
+	 */
+	public function __construct(ICacheFactory $cacheFactory,
+								IClientService $clientService
+	) {
+		$this->cache = $cacheFactory->create('ocs-discovery');
+		$this->client = $clientService->newClient();
+	}
+
+
+	/**
+	 * Discover OCS end-points
+	 *
+	 * If no valid discovery data is found the defaults are returned
+	 *
+	 * @param string $remote
+	 * @param string $service the service you want to discover
+	 * @return array
+	 */
+	public function discover($remote, $service) {
+		// Check the cache first
+		$cacheData = $this->cache->get($remote . '#' . $service);
+		if($cacheData) {
+			return json_decode($cacheData, true);
+		}
+
+		$discoveredServices = [];
+
+		// query the remote server for available services
+		try {
+			$response = $this->client->get($remote . '/ocs-provider/', [
+				'timeout' => 10,
+				'connect_timeout' => 10,
+			]);
+			if($response->getStatusCode() === Http::STATUS_OK) {
+				$decodedServices = json_decode($response->getBody(), true);
+				$discoveredServices = $this->getEndpoints($decodedServices, $service);
+			}
+		} catch (\Exception $e) {
+			// if we couldn't discover the service or any end-points we return a empty array
+			return [];
+		}
+
+		// Write into cache
+		$this->cache->set($remote . '#' . $service, json_encode($discoveredServices));
+		return $discoveredServices;
+	}
+
+	/**
+	 * get requested end-points from the requested service
+	 *
+	 * @param $decodedServices
+	 * @param $service
+	 * @return array
+	 */
+	private function getEndpoints($decodedServices, $service) {
+
+		$discoveredServices = [];
+
+		if(is_array($decodedServices) &&
+			isset($decodedServices['services'][$service]['endpoints'])
+		) {
+			foreach ($decodedServices['services'][$service]['endpoints'] as $endpoint => $url) {
+				if($this->isSafeUrl($url)) {
+					$discoveredServices[$endpoint] = $url;
+				}
+			}
+		}
+
+		return $discoveredServices;
+	}
+
+	/**
+	 * Returns whether the specified URL includes only safe characters, if not
+	 * returns false
+	 *
+	 * @param string $url
+	 * @return bool
+	 */
+	private function isSafeUrl($url) {
+		return (bool)preg_match('/^[\/\.A-Za-z0-9]+$/', $url);
+	}
+
+}