From 2709e271f7f04b1ea6b50f3c85c76457e13a5019 Mon Sep 17 00:00:00 2001
From: Sujith H <sharidasan@owncloud.com>
Date: Tue, 20 Jun 2017 19:09:29 +0530
Subject: [PATCH] Proper message shown when private links accessed

When user tries to access private links which are
not accessible, then proper message is delivered
instead of Internal server error message. So is the
case when user is logged in and tries to access
private links not accessible.

Signed-off-by: Sujith H <sharidasan@owncloud.com>
---
 apps/files/lib/Controller/ViewController.php    | 15 ++++++++++++---
 .../tests/Controller/ViewControllerTest.php     |  7 ++++++-
 core/Controller/LoginController.php             | 15 +++++++++++++++
 core/templates/login.php                        |  5 +++++
 tests/Core/Controller/LoginControllerTest.php   | 17 +++++++++++++++++
 5 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/apps/files/lib/Controller/ViewController.php b/apps/files/lib/Controller/ViewController.php
index b13f8e97e24d..d4ecedf0cb73 100644
--- a/apps/files/lib/Controller/ViewController.php
+++ b/apps/files/lib/Controller/ViewController.php
@@ -281,9 +281,12 @@ public function showFile($fileId) {
 		$params = [];
 
 		if (empty($files) && $this->appManager->isEnabledForUser('files_trashbin')) {
-			$baseFolder = $this->rootFolder->get($uid . '/files_trashbin/files/');
-			$files = $baseFolder->getById($fileId);
-			$params['view'] = 'trashbin';
+			// Access files_trashbin if it exists
+			if ( $this->rootFolder->nodeExists($uid . '/files_trashbin/files/')) {
+				$baseFolder = $this->rootFolder->get($uid . '/files_trashbin/files/');
+				$files = $baseFolder->getById($fileId);
+				$params['view'] = 'trashbin';
+			}
 		}
 
 		if (!empty($files)) {
@@ -299,6 +302,12 @@ public function showFile($fileId) {
 			}
 			return new RedirectResponse($this->urlGenerator->linkToRoute('files.view.index', $params));
 		}
+
+		if ( $this->userSession->isLoggedIn() and empty($files)) {
+			$param["error"] = $this->l10n->t("You don't have permissions to access this file/folder - Please contact the owner to share it with you.");
+			return new TemplateResponse("core", 'error', ["errors" => [$param]], 'guest');
+		}
+
 		throw new \OCP\Files\NotFoundException();
 	}
 }
diff --git a/apps/files/tests/Controller/ViewControllerTest.php b/apps/files/tests/Controller/ViewControllerTest.php
index c56e82f1ef48..60b696fb0815 100644
--- a/apps/files/tests/Controller/ViewControllerTest.php
+++ b/apps/files/tests/Controller/ViewControllerTest.php
@@ -428,6 +428,10 @@ public function testShowFileRouteWithTrashedFile($useShowFile) {
 			->with('files_trashbin')
 			->will($this->returnValue(true));
 
+		$this->rootFolder->expects($this->once())
+			->method('nodeExists')
+			->will($this->returnValue(true));
+
 		$parentNode = $this->createMock('\OCP\Files\Folder');
 		$parentNode->expects($this->once())
 			->method('getPath')
@@ -440,7 +444,8 @@ public function testShowFileRouteWithTrashedFile($useShowFile) {
 			->method('get')
 			->with('testuser1/files/')
 			->will($this->returnValue($baseFolderFiles));
-		$this->rootFolder->expects($this->at(1))
+		//The index is pointing to 2, because nodeExists internally calls get method.
+		$this->rootFolder->expects($this->at(2))
 			->method('get')
 			->with('testuser1/files_trashbin/files/')
 			->will($this->returnValue($baseFolderTrash));
diff --git a/core/Controller/LoginController.php b/core/Controller/LoginController.php
index 1d26c002b5b6..8f675b743584 100644
--- a/core/Controller/LoginController.php
+++ b/core/Controller/LoginController.php
@@ -166,6 +166,21 @@ public function showLoginForm($user, $redirect_url, $remember_login) {
 			$parameters['user_autofocus'] = true;
 		}
 
+		/**
+		 * If redirect_url is not empty and remember_login is null and
+		 * user not logged in and check if the string
+		 * webroot+"/index.php/f/" is in redirect_url then
+		 * user is trying to access files for which he needs to login.
+		 */
+
+		if ((!empty($redirect_url)) and ($remember_login === null) and
+			($this->userSession->isLoggedIn() === false) and
+			(strpos($this->urlGenerator->getAbsoluteURL(urldecode($redirect_url)),
+				$this->urlGenerator->getAbsoluteURL('/index.php/f/')) !== false)) {
+
+			$parameters['accessLink'] = true;
+		}
+
 		return new TemplateResponse(
 			$this->appName, 'login', $parameters, 'guest'
 		);
diff --git a/core/templates/login.php b/core/templates/login.php
index 262066569c63..77ae7ce0d274 100644
--- a/core/templates/login.php
+++ b/core/templates/login.php
@@ -66,6 +66,11 @@
 				<?php p($l->t('Wrong password.')); ?>
 			</p>
 		<?php } ?>
+		<?php if (!empty($_['accessLink'])) { ?>
+			<p class="warning">
+				<?php p($l->t("You are trying to access a private link. Please log in first.")) ?>
+			</p>
+		<?php } ?>
 		<?php if ($_['rememberLoginAllowed'] === true) : ?>
 		<div class="remember-login-container">
 			<?php if ($_['rememberLoginState'] === 0) { ?>
diff --git a/tests/Core/Controller/LoginControllerTest.php b/tests/Core/Controller/LoginControllerTest.php
index 7040c8ac4a6b..0690c8a14b92 100644
--- a/tests/Core/Controller/LoginControllerTest.php
+++ b/tests/Core/Controller/LoginControllerTest.php
@@ -137,6 +137,23 @@ public function testShowLoginFormForLoggedInUsers() {
 		$this->assertEquals($expectedResponse, $this->loginController->showLoginForm('', '', ''));
 	}
 
+	public function testResponseForNotLoggedinUser() {
+		$params = [
+			'messages' => Array (),
+			'loginName' => '',
+			'user_autofocus' => true,
+			'redirect_url' => '%2Findex.php%2Ff%2F17',
+			'canResetPassword' => true,
+			'resetPasswordLink' => null,
+			'alt_login' => Array (),
+			'rememberLoginAllowed' => false,
+			'rememberLoginState' => 0
+		];
+
+		$expectedResponse = new TemplateResponse('core', 'login', $params, 'guest');
+		$this->assertEquals($expectedResponse, $this->loginController->showLoginForm('', '%2Findex.php%2Ff%2F17', ''));
+	}
+
 	public function testShowLoginFormWithErrorsInSession() {
 		$this->userSession
 			->expects($this->once())