1 files changed, 104 insertions, 0 deletions
diff --git a/lib/private/OCM/OCMDiscoveryService.php b/lib/private/OCM/OCMDiscoveryService.php
new file mode 100644
index 00000000000..a151bbc753c
--- /dev/null
+++ b/lib/private/OCM/OCMDiscoveryService.php
@@ -0,0 +1,104 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2023 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OC\OCM;
+
+use GuzzleHttp\Exception\ConnectException;
+use JsonException;
+use OCP\AppFramework\Http;
+use OCP\Http\Client\IClientService;
+use OCP\ICache;
+use OCP\ICacheFactory;
+use OCP\IConfig;
+use OCP\OCM\Exceptions\OCMProviderException;
+use OCP\OCM\ICapabilityAwareOCMProvider;
+use OCP\OCM\IOCMDiscoveryService;
+use Psr\Log\LoggerInterface;
+
+/**
+ * @since 28.0.0
+ */
+class OCMDiscoveryService implements IOCMDiscoveryService {
+	private ICache $cache;
+
+	public function __construct(
+		ICacheFactory $cacheFactory,
+		private IClientService $clientService,
+		private IConfig $config,
+		private ICapabilityAwareOCMProvider $provider,
+		private LoggerInterface $logger,
+	) {
+		$this->cache = $cacheFactory->createDistributed('ocm-discovery');
+	}
+
+
+	/**
+	 * @param string $remote
+	 * @param bool $skipCache
+	 *
+	 * @return ICapabilityAwareOCMProvider
+	 * @throws OCMProviderException
+	 */
+	public function discover(string $remote, bool $skipCache = false): ICapabilityAwareOCMProvider {
+		$remote = rtrim($remote, '/');
+		if (!str_starts_with($remote, 'http://') && !str_starts_with($remote, 'https://')) {
+			// if scheme not specified, we test both;
+			try {
+				return $this->discover('https://' . $remote, $skipCache);
+			} catch (OCMProviderException|ConnectException) {
+				return $this->discover('http://' . $remote, $skipCache);
+			}
+		}
+
+		if (!$skipCache) {
+			try {
+				$cached = $this->cache->get($remote);
+				if ($cached === false) {
+					throw new OCMProviderException('Previous discovery failed.');
+				}
+
+				$this->provider->import(json_decode($cached ?? '', true, 8, JSON_THROW_ON_ERROR) ?? []);
+				return $this->provider;
+			} catch (JsonException|OCMProviderException $e) {
+				// we ignore cache on issues
+			}
+		}
+
+		$client = $this->clientService->newClient();
+		try {
+			$options = [
+				'timeout' => 10,
+				'connect_timeout' => 10,
+			];
+			if ($this->config->getSystemValueBool('sharing.federation.allowSelfSignedCertificates') === true) {
+				$options['verify'] = false;
+			}
+			$response = $client->get($remote . '/ocm-provider/', $options);
+
+			if ($response->getStatusCode() === Http::STATUS_OK) {
+				$body = $response->getBody();
+				// update provider with data returned by the request
+				$this->provider->import(json_decode($body, true, 8, JSON_THROW_ON_ERROR) ?? []);
+				$this->cache->set($remote, $body, 60 * 60 * 24);
+			}
+		} catch (JsonException|OCMProviderException $e) {
+			$this->cache->set($remote, false, 5 * 60);
+			throw new OCMProviderException('data returned by remote seems invalid - ' . ($body ?? ''));
+		} catch (\Exception $e) {
+			$this->cache->set($remote, false, 5 * 60);
+			$this->logger->warning('error while discovering ocm provider', [
+				'exception' => $e,
+				'remote' => $remote
+			]);
+			throw new OCMProviderException('error while requesting remote ocm provider');
+		}
+
+		return $this->provider;
+	}
+}