CSRF protection

4 files changed, 40 insertions, 30 deletions

diff --git a/inc/config.php b/inc/config.php
index cd5896fc..3b449b5e 100644
--- a/inc/config.php
+++ b/inc/config.php
@@ -686,6 +686,7 @@
 	$config['error']['404']			= _('Page not found.');
 	$config['error']['modexists']		= _('That mod <a href="?/users/%d">already exists</a>!');
 	$config['error']['invalidtheme']	= _('That theme doesn\'t exist!');
+	$config['error']['csrf']		= _('Invalid security token! Please go back and try again.');
 
 /*
  * =========================
@@ -754,9 +755,6 @@
  *  Mod settings
  * ====================
  */
- 
- 	// Server-side confirm button for actions like deleting posts, for when Javascript is disabled or the DOM isn't loaded.
-	$config['mod']['server-side_confirm'] = true;
 	
 	// Whether or not to lock moderator sessions to the IP address that was logged in with.
 	$config['mod']['lock_ip'] = true;
diff --git a/inc/display.php b/inc/display.php
index 538d5b03..1be066c2 100644
--- a/inc/display.php
+++ b/inc/display.php
@@ -86,11 +86,11 @@ function error($message, $priority = true) {
 function loginForm($error=false, $username=false, $redirect=false) {
 	global $config;
 	
-	die(Element('page.html', Array(
-		'index'=>$config['root'],
-		'title'=>_('Login'),
-		'config'=>$config,
-		'body'=>Element('login.html', Array(
+	die(Element('page.html', array(
+		'index' => $config['root'],
+		'title' => _('Login'),
+		'config' => $config,
+		'body' => Element('login.html', array(
 			'config'=>$config,
 			'error'=>$error,
 			'username'=>utf8tohtml($username),
@@ -205,12 +205,13 @@ function truncate($body, $url, $max_lines = false, $max_chars = false) {
 	return $body;
 }
 
-function confirmLink($text, $title, $confirm, $href) {
-	global $config, $mod;
-	if ($config['mod']['server-side_confirm'])
-		return '<a onclick="if (confirm(\'' . htmlentities(addslashes($confirm)) . '\')) document.location=\'?/' . htmlentities(addslashes($href)) . '\';return false;" title="' . htmlentities($title) . '" href="?/confirm/' . $href . '">' . $text . '</a>';
-	else
-		return '<a onclick="return confirm(\'' . htmlentities(addslashes($confirm)) . '\')" title="' . htmlentities($title) . '" href="?/' . $href . '">' . $text . '</a>';
+function secure_link_confirm($text, $title, $confirm_message, $href) {
+	global $config;
+
+	return '<a onclick="if (confirm(\'' . htmlentities(addslashes($confirm_message)) . '\')) document.location=\'?/' . htmlentities(addslashes($href . '/' . make_secure_link_token($href))) . '\';return false;" title="' . htmlentities($title) . '" href="?/' . $href . '">' . $text . '</a>';
+}
+function secure_link($href) {
+	return $href . '/' . make_secure_link_token($href);
 }
 
 class Post {
@@ -264,15 +265,15 @@ class Post {
 			
 			// Delete
 			if (hasPermission($config['mod']['delete'], $board['uri'], $this->mod))
-				$built .= ' ' . confirmLink($config['mod']['link_delete'], 'Delete', 'Are you sure you want to delete this?', $board['uri'] . '/delete/' . $this->id);
+				$built .= ' ' . secure_link_confirm($config['mod']['link_delete'], 'Delete', 'Are you sure you want to delete this?', $board['uri'] . '/delete/' . $this->id);
 			
 			// Delete all posts by IP
 			if (hasPermission($config['mod']['deletebyip'], $board['uri'], $this->mod))
-				$built .= ' ' . confirmLink($config['mod']['link_deletebyip'], 'Delete all posts by IP', 'Are you sure you want to delete all posts by this IP address?', $board['uri'] . '/deletebyip/' . $this->id);
+				$built .= ' ' . secure_link_confirm($config['mod']['link_deletebyip'], 'Delete all posts by IP', 'Are you sure you want to delete all posts by this IP address?', $board['uri'] . '/deletebyip/' . $this->id);
 			
 			// Delete all posts by IP (global)
 			if (hasPermission($config['mod']['deletebyip_global'], $board['uri'], $this->mod))
-				$built .= ' ' . confirmLink($config['mod']['link_deletebyip_global'], 'Delete all posts by IP across all boards', 'Are you sure you want to delete all posts by this IP address, across all boards?', $board['uri'] . '/deletebyip/' . $this->id . '/global');
+				$built .= ' ' . secure_link_confirm($config['mod']['link_deletebyip_global'], 'Delete all posts by IP across all boards', 'Are you sure you want to delete all posts by this IP address, across all boards?', $board['uri'] . '/deletebyip/' . $this->id . '/global');
 			
 			// Ban
 			if (hasPermission($config['mod']['ban'], $board['uri'], $this->mod))
@@ -362,15 +363,15 @@ class Thread {
 			// Mod controls (on posts)
 			// Delete
 			if (hasPermission($config['mod']['delete'], $board['uri'], $this->mod))
-				$built .= ' ' . confirmLink($config['mod']['link_delete'], 'Delete', 'Are you sure you want to delete this?', $board['uri'] . '/delete/' . $this->id);
+				$built .= ' ' . secure_link_confirm($config['mod']['link_delete'], 'Delete', 'Are you sure you want to delete this?', $board['uri'] . '/delete/' . $this->id);
 			
 			// Delete all posts by IP
 			if (hasPermission($config['mod']['deletebyip'], $board['uri'], $this->mod))
-				$built .= ' ' . confirmLink($config['mod']['link_deletebyip'], 'Delete all posts by IP', 'Are you sure you want to delete all posts by this IP address?', $board['uri'] . '/deletebyip/' . $this->id);
+				$built .= ' ' . secure_link_confirm($config['mod']['link_deletebyip'], 'Delete all posts by IP', 'Are you sure you want to delete all posts by this IP address?', $board['uri'] . '/deletebyip/' . $this->id);
 			
 			// Delete all posts by IP (global)
 			if (hasPermission($config['mod']['deletebyip_global'], $board['uri'], $this->mod))
-				$built .= ' ' . confirmLink($config['mod']['link_deletebyip_global'], 'Delete all posts by IP across all boards', 'Are you sure you want to delete all posts by this IP address, across all boards?', $board['uri'] . '/deletebyip/' . $this->id . '/global');
+				$built .= ' ' . secure_link_confirm($config['mod']['link_deletebyip_global'], 'Delete all posts by IP across all boards', 'Are you sure you want to delete all posts by this IP address, across all boards?', $board['uri'] . '/deletebyip/' . $this->id . '/global');
 			
 			// Ban
 			if (hasPermission($config['mod']['ban'], $board['uri'], $this->mod))
@@ -393,16 +394,16 @@ class Thread {
 			
 			if (hasPermission($config['mod']['bumplock'], $board['uri'], $this->mod))
 				if ($this->bumplocked)
-					$built .= ' <a title="Allow thread to be bumped" href="?/' . $board['uri'] . '/bumpunlock/' . $this->id . '">' . $config['mod']['link_bumpunlock'] . '</a>';
+					$built .= ' <a title="Allow thread to be bumped" href="?/' . secure_link($board['uri'] . '/bumpunlock/' . $this->id) . '">' . $config['mod']['link_bumpunlock'] . '</a>';
 				else
-					$built .= ' <a title="Prevent thread from being bumped" href="?/' . $board['uri'] . '/bumplock/' . $this->id . '">' . $config['mod']['link_bumplock'] . '</a>';
+					$built .= ' <a title="Prevent thread from being bumped" href="?/' . secure_link($board['uri'] . '/bumplock/' . $this->id) . '">' . $config['mod']['link_bumplock'] . '</a>';
 			
 			// Lock
 			if (hasPermission($config['mod']['lock'], $board['uri'], $this->mod))
 				if ($this->locked)
-					$built .= ' <a title="Unlock thread" href="?/' . $board['uri'] . '/unlock/' . $this->id . '">' . $config['mod']['link_unlock'] . '</a>';
+					$built .= ' <a title="Unlock thread" href="?/' . secure_link($board['uri'] . '/unlock/' . $this->id) . '">' . $config['mod']['link_unlock'] . '</a>';
 				else
-					$built .= ' <a title="Lock thread" href="?/' . $board['uri'] . '/lock/' . $this->id . '">' . $config['mod']['link_lock'] . '</a>';
+					$built .= ' <a title="Lock thread" href="?/' . secure_link($board['uri'] . '/lock/' . $this->id) . '">' . $config['mod']['link_lock'] . '</a>';
 			
 			if (hasPermission($config['mod']['move'], $board['uri'], $this->mod))
 				$built .= ' <a title="Move thread to another board" href="?/' . $board['uri'] . '/move/' . $this->id . '">' . $config['mod']['link_move'] . '</a>';
diff --git a/inc/mod/auth.php b/inc/mod/auth.php
index d200c23f..6e2d3d1e 100644
--- a/inc/mod/auth.php
+++ b/inc/mod/auth.php
@@ -150,3 +150,9 @@ function create_pm_header() {
 	return $header;
 }
 
+function make_secure_link_token($uri) {
+	global $mod, $config;
+	return substr(sha1($config['cookies']['salt'] . '-' . $uri . '-' . $mod['id']), 0, 8);
+}
+
+
diff --git a/inc/mod/pages.php b/inc/mod/pages.php
index ad69ae39..19ff8806 100644
--- a/inc/mod/pages.php
+++ b/inc/mod/pages.php
@@ -60,7 +60,7 @@ function mod_login() {
 }
 
 function mod_confirm($request) {
-	mod_page(_('Confirm action'), 'mod/confirm.html', array('request' => $request));
+	mod_page(_('Confirm action'), 'mod/confirm.html', array('request' => $request, 'token' => make_secure_link_token($request)));
 }
 
 function mod_logout() {
@@ -563,7 +563,7 @@ function mod_ban() {
 		error($config['error']['noaccess']);
 	
 	if (!isset($_POST['ip'], $_POST['reason'], $_POST['length'], $_POST['board'])) {
-		mod_page(_('New ban'), 'mod/ban_form.html', array());
+		mod_page(_('New ban'), 'mod/ban_form.html', array('token' => make_secure_link_token('ban')));
 		return;
 	}
 	
@@ -883,10 +883,12 @@ function mod_move($originBoard, $postID) {
 	if (count($boards) <= 1)
 		error(_('Impossible to move thread; there is only one board.'));
 	
-	mod_page(_('Move thread'), 'mod/move.html', array('post' => $postID, 'board' => $originBoard, 'boards' => $boards));
+	$security_token = make_secure_link_token($originBoard . '/move/' . $postID);
+	
+	mod_page(_('Move thread'), 'mod/move.html', array('post' => $postID, 'board' => $originBoard, 'boards' => $boards, 'token' => $security_token));
 }
 
-function mod_ban_post($board, $delete, $post) {
+function mod_ban_post($board, $delete, $post, $token = false) {
 	global $config, $mod;
 	
 	if (!openBoard($board))
@@ -895,6 +897,8 @@ function mod_ban_post($board, $delete, $post) {
 	if (!hasPermission($config['mod']['delete'], $board))
 		error($config['error']['noaccess']);
 	
+	$security_token = make_secure_link_token($board . '/ban' . ($delete ? '&delete' : '') . '/' . $post);
+	
 	$query = prepare(sprintf('SELECT `ip`, `thread` FROM `posts_%s` WHERE `id` = :id', $board));
 	$query->bindValue(':id', $post);
 	$query->execute() or error(db_error($query));
@@ -903,7 +907,7 @@ function mod_ban_post($board, $delete, $post) {
 	
 	$thread = $_post['thread'];
 	$ip = $_post['ip'];
-	
+
 	if (isset($_POST['new_ban'], $_POST['reason'], $_POST['length'], $_POST['board'])) {
 		require_once 'inc/mod/ban.php';
 		
@@ -939,7 +943,8 @@ function mod_ban_post($board, $delete, $post) {
 		'post' => $post,
 		'board' => $board,
 		'delete' => (bool)$delete,
-		'boards' => listBoards()
+		'boards' => listBoards(),
+		'token' => $security_token
 	);
 	
 	mod_page(_('New ban'), 'mod/ban_form.html', $args);