Bug 1328 add function to check token

git-svn-id: http://piwigo.org/svn/trunk@4492 68402e56-0260-453c-a942-63ccdbb3a9ee

1 files changed, 22 insertions, 0 deletions

diff --git a/admin/include/functions.php b/admin/include/functions.php
index 20cb6e534..0e5a2b5d8 100644
--- a/admin/include/functions.php
+++ b/admin/include/functions.php
@@ -23,6 +23,28 @@
 
 include(PHPWG_ROOT_PATH.'admin/include/functions_metadata.php');
 
+/**
+ * check token comming from form posted or get params to prevent csrf attacks
+ * if pwg_token is empty action doesn't require token
+ * else pwg_token is compare to server token
+ *
+ * @return void access denied if token given is not equal to server token 
+ */
+function check_token()
+{
+  global $conf;
+
+  $token = hash_hmac('md5', session_id(), $conf['secret_key']);
+
+  if (!empty($_POST['pwg_token']) && ($_POST['pwg_token'] != $token))
+  {
+    access_denied();    
+  }
+  elseif (!empty($_GET['pwg_token']) && ($_GET['pwg_token'] != $token))
+  {
+    access_denied();    
+  }
+}
 
 // The function delete_site deletes a site and call the function
 // delete_categories for each primary category of the site