a new approach to display the error message

5 files changed, 105 insertions, 41 deletions

diff --git a/lib/private/encryption/exceptions/decryptionfailedexception.php b/lib/private/encryption/exceptions/decryptionfailedexception.php
index 406ae12968e..7e9fa21eaef 100644
--- a/lib/private/encryption/exceptions/decryptionfailedexception.php
+++ b/lib/private/encryption/exceptions/decryptionfailedexception.php
@@ -27,4 +27,15 @@ use OCP\Encryption\Exceptions\GenericEncryptionException;
 
 class DecryptionFailedException extends GenericEncryptionException {
 
+	/**
+	 * @param string $message
+	 * @param int $code
+	 * @param \Exception $previous
+	 * @param string $hint
+	 */
+	public function __construct($message = '', $code = 0, \Exception $previous = null, $hint = '') {
+		parent::__construct($message, $code, $previous, $hint);
+
+}
+
 }
diff --git a/lib/private/files.php b/lib/private/files.php
index 97f9d8163b1..6a739fc844c 100644
--- a/lib/private/files.php
+++ b/lib/private/files.php
@@ -129,52 +129,60 @@ class OC_Files {
 			$zip = new ZipStreamer(false);
 		}
 		OC_Util::obEnd();
-		if ($zip or \OC\Files\Filesystem::isReadable($filename)) {
-			self::sendHeaders($filename, $name, $zip);
-		} elseif (!\OC\Files\Filesystem::file_exists($filename)) {
-			header("HTTP/1.0 404 Not Found");
-			$tmpl = new OC_Template('', '404', 'guest');
-			$tmpl->printPage();
-		} else {
-			header("HTTP/1.0 403 Forbidden");
-			die('403 Forbidden');
-		}
-		if($only_header) {
-			return ;
-		}
-		if ($zip) {
-			$executionTime = intval(ini_get('max_execution_time'));
-			set_time_limit(0);
-			if ($get_type === self::ZIP_FILES) {
-				foreach ($files as $file) {
-					$file = $dir . '/' . $file;
-					if (\OC\Files\Filesystem::is_file($file)) {
-						$fh = \OC\Files\Filesystem::fopen($file, 'r');
-						$zip->addFileFromStream($fh, basename($file));
-						fclose($fh);
-					} elseif (\OC\Files\Filesystem::is_dir($file)) {
-						self::zipAddDir($file, $zip);
+
+		try {
+
+			if ($zip or \OC\Files\Filesystem::isReadable($filename)) {
+				self::sendHeaders($filename, $name, $zip);
+			} elseif (!\OC\Files\Filesystem::file_exists($filename)) {
+				header("HTTP/1.0 404 Not Found");
+				$tmpl = new OC_Template('', '404', 'guest');
+				$tmpl->printPage();
+			} else {
+				header("HTTP/1.0 403 Forbidden");
+				die('403 Forbidden');
+			}
+			if ($only_header) {
+				return;
+			}
+			if ($zip) {
+				$executionTime = intval(ini_get('max_execution_time'));
+				set_time_limit(0);
+				if ($get_type === self::ZIP_FILES) {
+					foreach ($files as $file) {
+						$file = $dir . '/' . $file;
+						if (\OC\Files\Filesystem::is_file($file)) {
+							$fh = \OC\Files\Filesystem::fopen($file, 'r');
+							$zip->addFileFromStream($fh, basename($file));
+							fclose($fh);
+						} elseif (\OC\Files\Filesystem::is_dir($file)) {
+							self::zipAddDir($file, $zip);
+						}
 					}
+				} elseif ($get_type === self::ZIP_DIR) {
+					$file = $dir . '/' . $files;
+					self::zipAddDir($file, $zip);
 				}
-			} elseif ($get_type === self::ZIP_DIR) {
-				$file = $dir . '/' . $files;
-				self::zipAddDir($file, $zip);
-			}
-			$zip->finalize();
-			set_time_limit($executionTime);
-		} else {
-			if ($xsendfile) {
-				$view = \OC\Files\Filesystem::getView();
-				/** @var $storage \OC\Files\Storage\Storage */
-				list($storage) = $view->resolvePath($filename);
-				if ($storage->isLocal()) {
-					self::addSendfileHeader($filename);
+				$zip->finalize();
+				set_time_limit($executionTime);
+			} else {
+				if ($xsendfile) {
+					$view = \OC\Files\Filesystem::getView();
+					/** @var $storage \OC\Files\Storage\Storage */
+					list($storage) = $view->resolvePath($filename);
+					if ($storage->isLocal()) {
+						self::addSendfileHeader($filename);
+					} else {
+						\OC\Files\Filesystem::readfile($filename);
+					}
 				} else {
 					\OC\Files\Filesystem::readfile($filename);
 				}
-			} else {
-				\OC\Files\Filesystem::readfile($filename);
 			}
+		} catch (\Exception $ex) {
+			$l = \OC::$server->getL10N('core');
+			$hint = method_exists($ex, 'getHint') ? $ex->getHint() : '';
+			\OC_Template::printErrorPage($l->t('Can\'t read file'), $hint);
 		}
 	}
 
diff --git a/lib/private/files/storage/wrapper/encryption.php b/lib/private/files/storage/wrapper/encryption.php
index f7759d91497..1683ff1350f 100644
--- a/lib/private/files/storage/wrapper/encryption.php
+++ b/lib/private/files/storage/wrapper/encryption.php
@@ -253,6 +253,30 @@ class Encryption extends Wrapper {
 	}
 
 	/**
+	 * check if a file can be read
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function isReadable($path) {
+
+		$isReadable = true;
+
+		$metaData = $this->getMetaData($path);
+		if (
+			!$this->is_dir($path) &&
+			isset($metaData['encrypted']) &&
+			$metaData['encrypted'] === true
+		) {
+			$fullPath = $this->getFullPath($path);
+			$module = $this->getEncryptionModule($path);
+			$isReadable = $module->isReadable($fullPath, $this->uid);
+		}
+
+		return $this->storage->isReadable($path) && $isReadable;
+	}
+
+	/**
 	 * see http://php.net/manual/en/function.copy.php
 	 *
 	 * @param string $path1
diff --git a/lib/public/encryption/exceptions/genericencryptionexception.php b/lib/public/encryption/exceptions/genericencryptionexception.php
index be96450d431..e97f00c88bf 100644
--- a/lib/public/encryption/exceptions/genericencryptionexception.php
+++ b/lib/public/encryption/exceptions/genericencryptionexception.php
@@ -30,17 +30,26 @@ namespace OCP\Encryption\Exceptions;
  */
 class GenericEncryptionException extends \Exception {
 
+	/** @var string */
+	protected $hint;
+
 	/**
 	 * @param string $message
 	 * @param int $code
 	 * @param \Exception $previous
 	 * @since 8.1.0
 	 */
-	public function __construct($message = '', $code = 0, \Exception $previous = null) {
+	public function __construct($message = '', $code = 0, \Exception $previous = null, $hint = '') {
 		if (empty($message)) {
 			$message = 'Unspecified encryption exception';
 		}
 		parent::__construct($message, $code, $previous);
+
+		$this->hint = $hint;
+	}
+
+	public function getHint() {
+		return $this->hint;
 	}
 
 }
diff --git a/lib/public/encryption/iencryptionmodule.php b/lib/public/encryption/iencryptionmodule.php
index 0dda042d759..975e57744e9 100644
--- a/lib/public/encryption/iencryptionmodule.php
+++ b/lib/public/encryption/iencryptionmodule.php
@@ -119,4 +119,16 @@ interface IEncryptionModule {
 	 * @since 8.1.0
 	 */
 	public function getUnencryptedBlockSize();
+
+	/**
+	 * check if the encryption module is able to read the file,
+	 * e.g. if all encryption keys exists
+	 *
+	 * @param string $path
+	 * @param string $uid user for whom we want to check if he can read the file
+	 * @return boolean
+	 * @since 8.1.0
+	 */
+	public function isReadable($path, $uid);
+
 }