Add SFTP auth mechanism to use a password and public key for SFTP

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

apps/files_external/js/public_key.js

@@ -1,7 +1,7 @@
 $(document).ready(function() {
 
 	OCA.External.Settings.mountConfig.whenSelectAuthMechanism(function($tr, authMechanism, scheme, onCompletion) {
-		if (scheme === 'publickey') {
+		if (scheme === 'publickey' && authMechanism === 'publickey::rsa') {
 			var config = $tr.find('.configuration');
 			if ($(config).find('[name="public_key_generate"]').length === 0) {
 				setupTableRow($tr, config);

apps/files_external/lib/AppInfo/Application.php

@@ -29,6 +29,7 @@
 
 namespace OCA\Files_External\AppInfo;
 
+use OCA\Files_External\Lib\Auth\PublicKey\RSAPrivateKey;
 use \OCP\AppFramework\App;
 use OCP\AppFramework\IAppContainer;
 use \OCA\Files_External\Service\BackendService;
@@ -138,6 +139,7 @@ class Application extends App implements IBackendProvider, IAuthMechanismProvide
 
 			// AuthMechanism::SCHEME_PUBLICKEY mechanisms
 			$container->query(RSA::class),
+			$container->query(RSAPrivateKey::class),
 
 			// AuthMechanism::SCHEME_OPENSTACK mechanisms
 			$container->query(OpenStackV2::class),

apps/files_external/lib/Lib/Auth/PublicKey/RSAPrivateKey.php

@@ -0,0 +1,65 @@
+<?php
+/**
+ * @copyright 2018, Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @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 OCA\Files_External\Lib\Auth\PublicKey;
+
+use \OCP\IL10N;
+use \OCA\Files_External\Lib\DefinitionParameter;
+use \OCA\Files_External\Lib\Auth\AuthMechanism;
+use \OCA\Files_External\Lib\StorageConfig;
+use \OCP\IConfig;
+use OCP\IUser;
+use \phpseclib\Crypt\RSA as RSACrypt;
+
+/**
+ * RSA public key authentication
+ */
+class RSAPrivateKey extends AuthMechanism {
+
+	/** @var IConfig */
+	private $config;
+
+	public function __construct(IL10N $l, IConfig $config) {
+		$this->config = $config;
+
+		$this
+			->setIdentifier('publickey::rsa_private')
+			->setScheme(self::SCHEME_PUBLICKEY)
+			->setText($l->t('RSA private key'))
+			->addParameters([
+				new DefinitionParameter('user', $l->t('Username')),
+				(new DefinitionParameter('password', $l->t('Password')))
+					->setFlag(DefinitionParameter::FLAG_OPTIONAL)
+					->setType(DefinitionParameter::VALUE_PASSWORD),
+				new DefinitionParameter('private_key', $l->t('Private key')),
+			]);
+	}
+
+	public function manipulateStorageConfig(StorageConfig &$storage, IUser $user = null) {
+		$auth = new RSACrypt();
+		$auth->setPassword($this->config->getSystemValue('secret', ''));
+		if (!$auth->loadKey($storage->getBackendOption('private_key'))) {
+			throw new \RuntimeException('unable to load private key');
+		}
+		$storage->setBackendOption('public_key_auth', $auth);
+	}
+}

apps/files_external/lib/Lib/Storage/SFTP.php

@@ -47,7 +47,7 @@ class SFTP extends \OC\Files\Storage\Common {
 	private $root;
 	private $port = 22;
 
-	private $auth;
+	private $auth = [];
 
 	/**
 	 * @var \phpseclib\Net\SFTP
@@ -93,10 +93,13 @@ class SFTP extends \OC\Files\Storage\Common {
 		$this->user = $params['user'];
 
 		if (isset($params['public_key_auth'])) {
-			$this->auth = $params['public_key_auth'];
+			$this->auth[] = $params['public_key_auth'];
-		} elseif (isset($params['password'])) {
+		}
-			$this->auth = $params['password'];
+		if (isset($params['password']) && $params['password'] !== '') {
-		} else {
+			$this->auth[] = $params['password'];
+		}
+
+		if ($this->auth === []) {
 			throw new \UnexpectedValueException('no authentication parameters specified');
 		}
 
@@ -132,7 +135,15 @@ class SFTP extends \OC\Files\Storage\Common {
 			$this->writeHostKeys($hostKeys);
 		}
 
-		if (!$this->client->login($this->user, $this->auth)) {
+		$login = false;
+		foreach ($this->auth as $auth) {
+			$login = $this->client->login($this->user, $auth);
+			if ($login === true) {
+				break;
+			}
+		}
+
+		if ($login === false) {
 			throw new \Exception('Login failed');
 		}
 		return $this->client;