Migrate SFTP_Key external storage to new API

The SFTP backend now supports public key authentication alongside
password authentication.

5 files changed, 126 insertions, 220 deletions

diff --git a/apps/files_external/lib/auth/publickey/rsa.php b/apps/files_external/lib/auth/publickey/rsa.php
new file mode 100644
index 00000000000..b5eecb42712
--- /dev/null
+++ b/apps/files_external/lib/auth/publickey/rsa.php
@@ -0,0 +1,65 @@
+<?php
+/**
+ * @author Robin McCorkell <rmccorkell@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * 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 \phpseclib\Crypt\RSA as RSACrypt;
+
+/**
+ * RSA public key authentication
+ */
+class RSA extends AuthMechanism {
+
+	/** @var IConfig */
+	private $config;
+
+	public function __construct(IL10N $l, IConfig $config) {
+		$this->config = $config;
+
+		$this
+			->setIdentifier('publickey::rsa')
+			->setScheme(self::SCHEME_PUBLICKEY)
+			->setText($l->t('RSA public key'))
+			->addParameters([
+				(new DefinitionParameter('user', $l->t('Username'))),
+				(new DefinitionParameter('public_key', $l->t('Public key'))),
+				(new DefinitionParameter('private_key', 'private_key'))
+					->setType(DefinitionParameter::VALUE_HIDDEN),
+			])
+			->setCustomJs('public_key')
+		;
+	}
+
+	public function manipulateStorageConfig(StorageConfig &$storage) {
+		$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', $auth);
+	}
+
+}
diff --git a/apps/files_external/lib/backend/sftp.php b/apps/files_external/lib/backend/sftp.php
index dd0f5d8e2e0..c0bcd27c54b 100644
--- a/apps/files_external/lib/backend/sftp.php
+++ b/apps/files_external/lib/backend/sftp.php
@@ -43,6 +43,7 @@ class SFTP extends Backend {
 					->setFlag(DefinitionParameter::FLAG_OPTIONAL),
 			])
 			->addAuthScheme(AuthMechanism::SCHEME_PASSWORD)
+			->addAuthScheme(AuthMechanism::SCHEME_PUBLICKEY)
 			->setLegacyAuthMechanism($legacyAuth)
 		;
 	}
diff --git a/apps/files_external/lib/backend/sftp_key.php b/apps/files_external/lib/backend/sftp_key.php
new file mode 100644
index 00000000000..4a7f565eb19
--- /dev/null
+++ b/apps/files_external/lib/backend/sftp_key.php
@@ -0,0 +1,48 @@
+<?php
+/**
+ * @author Robin McCorkell <rmccorkell@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\Files_External\Lib\Backend;
+
+use \OCP\IL10N;
+use \OCA\Files_External\Lib\Backend\Backend;
+use \OCA\Files_External\Lib\DefinitionParameter;
+use \OCA\Files_External\Lib\Auth\AuthMechanism;
+use \OCA\Files_External\Service\BackendService;
+use \OCA\Files_External\Lib\Auth\PublicKey\RSA;
+
+class SFTP_Key extends Backend {
+
+	public function __construct(IL10N $l, RSA $legacyAuth) {
+		$this
+			->setIdentifier('\OC\Files\Storage\SFTP_Key')
+			->setStorageClass('\OC\Files\Storage\SFTP')
+			->setText($l->t('SFTP with secret key login [DEPRECATED]'))
+			->addParameters([
+				(new DefinitionParameter('host', $l->t('Host'))),
+				(new DefinitionParameter('root', $l->t('Remote subfolder')))
+					->setFlag(DefinitionParameter::FLAG_OPTIONAL),
+			])
+			->addAuthScheme(AuthMechanism::SCHEME_PUBLICKEY)
+			->setLegacyAuthMechanism($legacyAuth)
+		;
+	}
+
+}
diff --git a/apps/files_external/lib/sftp.php b/apps/files_external/lib/sftp.php
index 7f921b5342f..921e7283c66 100644
--- a/apps/files_external/lib/sftp.php
+++ b/apps/files_external/lib/sftp.php
@@ -40,10 +40,11 @@ use phpseclib\Net\SFTP\Stream;
 class SFTP extends \OC\Files\Storage\Common {
 	private $host;
 	private $user;
-	private $password;
 	private $root;
 	private $port = 22;
 
+	private $auth;
+
 	/**
 	* @var SFTP
 	*/
@@ -73,8 +74,15 @@ class SFTP extends \OC\Files\Storage\Common {
 		}
 
 		$this->user = $params['user'];
-		$this->password
-			= isset($params['password']) ? $params['password'] : '';
+
+		if (isset($params['public_key_auth'])) {
+			$this->auth = $params['public_key_auth'];
+		} elseif (isset($params['password'])) {
+			$this->auth = $params['password'];
+		} else {
+			throw new \UnexpectedValueException('no authentication parameters specified');
+		}
+
 		$this->root
 			= isset($params['root']) ? $this->cleanPath($params['root']) : '/';
 
@@ -112,7 +120,7 @@ class SFTP extends \OC\Files\Storage\Common {
 			$this->writeHostKeys($hostKeys);
 		}
 
-		if (!$this->client->login($this->user, $this->password)) {
+		if (!$this->client->login($this->user, $this->auth)) {
 			throw new \Exception('Login failed');
 		}
 		return $this->client;
@@ -125,7 +133,6 @@ class SFTP extends \OC\Files\Storage\Common {
 		if (
 			!isset($this->host)
 			|| !isset($this->user)
-			|| !isset($this->password)
 		) {
 			return false;
 		}
diff --git a/apps/files_external/lib/sftp_key.php b/apps/files_external/lib/sftp_key.php
deleted file mode 100644
index a193b323678..00000000000
--- a/apps/files_external/lib/sftp_key.php
+++ /dev/null
@@ -1,215 +0,0 @@
-<?php
-/**
- * @author Lukas Reschke <lukas@owncloud.com>
- * @author Morris Jobke <hey@morrisjobke.de>
- * @author Ross Nicoll <jrn@jrn.me.uk>
- *
- * @copyright Copyright (c) 2015, ownCloud, Inc.
- * @license AGPL-3.0
- *
- * This code is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License, version 3,
- * as published by the Free Software Foundation.
- *
- * 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, version 3,
- * along with this program.  If not, see <http://www.gnu.org/licenses/>
- *
- */
-namespace OC\Files\Storage;
-
-use phpseclib\Crypt\RSA;
-
-class SFTP_Key extends \OC\Files\Storage\SFTP {
-	private $publicKey;
-	private $privateKey;
-
-	/**
-	 * {@inheritdoc}
-	 */
-	public function __construct($params) {
-		parent::__construct($params);
-		$this->publicKey = $params['public_key'];
-		$this->privateKey = $params['private_key'];
-	}
-
-	/**
-	 * Returns the connection.
-	 *
-	 * @return \phpseclib\Net\SFTP connected client instance
-	 * @throws \Exception when the connection failed
-	 */
-	public function getConnection() {
-		if (!is_null($this->client)) {
-			return $this->client;
-		}
-
-		$hostKeys = $this->readHostKeys();
-		$this->client = new \phpseclib\Net\SFTP($this->getHost());
-
-		// The SSH Host Key MUST be verified before login().
-		$currentHostKey = $this->client->getServerPublicHostKey();
-		if (array_key_exists($this->getHost(), $hostKeys)) {
-			if ($hostKeys[$this->getHost()] !== $currentHostKey) {
-				throw new \Exception('Host public key does not match known key');
-			}
-		} else {
-			$hostKeys[$this->getHost()] = $currentHostKey;
-			$this->writeHostKeys($hostKeys);
-		}
-
-		$key = $this->getPrivateKey();
-		if (is_null($key)) {
-			throw new \Exception('Secret key could not be loaded');
-		}
-		if (!$this->client->login($this->getUser(), $key)) {
-			throw new \Exception('Login failed');
-		}
-		return $this->client;
-	}
-
-	/**
-	 * Returns the private key to be used for authentication to the remote server.
-	 *
-	 * @return RSA instance or null in case of a failure to load the key.
-	 */
-	private function getPrivateKey() {
-		$key = new RSA();
-		$key->setPassword(\OC::$server->getConfig()->getSystemValue('secret', ''));
-		if (!$key->loadKey($this->privateKey)) {
-			// Should this exception rather than return null?
-			return null;
-		}
-		return $key;
-	}
-
-	/**
-	 * Throws an exception if the provided host name/address is invalid (cannot be resolved
-	 * and is not an IPv4 address).
-	 *
-	 * @return true; never returns in case of a problem, this return value is used just to
-	 * make unit tests happy.
-	 */
-	public function assertHostAddressValid($hostname) {
-		// TODO: Should handle IPv6 addresses too
-		if (!preg_match('/^\d+\.\d+\.\d+\.\d+$/', $hostname) && gethostbyname($hostname) === $hostname) {
-			// Hostname is not an IPv4 address and cannot be resolved via DNS
-			throw new \InvalidArgumentException('Cannot resolve hostname.');
-		}
-		return true;
-	}
-
-	/**
-	 * Throws an exception if the provided port number is invalid (cannot be resolved
-	 * and is not an IPv4 address).
-	 *
-	 * @return true; never returns in case of a problem, this return value is used just to
-	 * make unit tests happy.
-	 */
-	public function assertPortNumberValid($port) {
-		if (!preg_match('/^\d+$/', $port)) {
-			throw new \InvalidArgumentException('Port number must be a number.');
-		}
-		if ($port < 0 || $port > 65535) {
-			throw new \InvalidArgumentException('Port number must be between 0 and 65535 inclusive.');
-		}
-		return true;
-	}
-
-	/**
-	 * Replaces anything that's not an alphanumeric character or "." in a hostname
-	 * with "_", to make it safe for use as part of a file name.
-	 */
-	protected function sanitizeHostName($name) {
-		return preg_replace('/[^\d\w\._]/', '_', $name);
-	}
-
-	/**
-	 * Replaces anything that's not an alphanumeric character or "_" in a username
-	 * with "_", to make it safe for use as part of a file name.
-	 */
-	protected function sanitizeUserName($name) {
-		return preg_replace('/[^\d\w_]/', '_', $name);
-	}
-
-	public function test() {
-
-		// FIXME: Use as expression in empty once PHP 5.4 support is dropped
-		$host = $this->getHost();
-		if (empty($host)) {
-			\OC::$server->getLogger()->warning('Hostname has not been specified');
-			return false;
-		}
-		// FIXME: Use as expression in empty once PHP 5.4 support is dropped
-		$user = $this->getUser();
-		if (empty($user)) {
-			\OC::$server->getLogger()->warning('Username has not been specified');
-			return false;
-		}
-		if (!isset($this->privateKey)) {
-			\OC::$server->getLogger()->warning('Private key was missing from the request');
-			return false;
-		}
-
-		// Sanity check the host
-		$hostParts = explode(':', $this->getHost());
-		try {
-			if (count($hostParts) == 1) {
-				$hostname = $hostParts[0];
-				$this->assertHostAddressValid($hostname);
-			} else if (count($hostParts) == 2) {
-				$hostname = $hostParts[0];
-				$this->assertHostAddressValid($hostname);
-				$this->assertPortNumberValid($hostParts[1]);
-			} else {
-				throw new \Exception('Host connection string is invalid.');
-			}
-		} catch(\Exception $e) {
-			\OC::$server->getLogger()->warning($e->getMessage());
-			return false;
-		}
-
-		// Validate the key
-		$key = $this->getPrivateKey();
-		if (is_null($key)) {
-			\OC::$server->getLogger()->warning('Secret key could not be loaded');
-			return false;
-		}
-
-		try {
-			if ($this->getConnection()->nlist() === false) {
-				return false;
-			}
-		} catch(\Exception $e) {
-			// We should be throwing a more specific error, so we're not just catching
-			// Exception here
-			\OC::$server->getLogger()->warning($e->getMessage());
-			return false;
-		}
-
-		// Save the key somewhere it can easily be extracted later
-		if (\OC::$server->getUserSession()->getUser()) {
-			$view = new \OC\Files\View('/'.\OC::$server->getUserSession()->getUser()->getUId().'/files_external/sftp_keys');
-			if (!$view->is_dir('')) {
-				if (!$view->mkdir('')) {
-					\OC::$server->getLogger()->warning('Could not create secret key directory.');
-					return false;
-				}
-			}
-			$key_filename = $this->sanitizeUserName($this->getUser()).'@'.$this->sanitizeHostName($hostname).'.pub';
-			$key_file = $view->fopen($key_filename, "w");
-			if ($key_file) {
-				fwrite($key_file, $this->publicKey);
-				fclose($key_file);
-			} else {
-				\OC::$server->getLogger()->warning('Could not write secret key file.');
-			}
-		}
-
-		return true;
-	}
-}