Date check added for HTTP signatures

[friendica.git] / src / BaseModule.php

diff --git a/src/BaseModule.php b/src/BaseModule.php
index 3ad4a4f055a7be33ebba9b3a1dfe42556ca7f11c..6c14d6ba77aa6b6838c90316cdd30773f2a9460d 100644 (file)
--- a/src/BaseModule.php
+++ b/src/BaseModule.php
@@ -2,6 +2,10 @@
 
 namespace Friendica;
 
+use Friendica\Core\L10n;
+use Friendica\Core\Logger;
+use Friendica\Core\System;
+
 /**
  * All modules in Friendica should extend BaseModule, although not all modules
  * need to extend all the methods described here
@@ -21,7 +25,16 @@ abstract class BaseModule extends BaseObject
         */
        public static function init()
        {
+       }
 
+       /**
+        * @brief Module GET method to display raw content from technical endpoints
+        *
+        * Extend this method if the module is supposed to return communication data,
+        * e.g. from protocol implementations.
+        */
+       public static function rawContent()
+       {
        }
 
        /**
@@ -48,7 +61,8 @@ abstract class BaseModule extends BaseObject
         */
        public static function post()
        {
-               // goaway('module');
+               // $a = self::getApp();
+               // $a->internalRedirect('module');
        }
 
        /**
@@ -60,4 +74,84 @@ abstract class BaseModule extends BaseObject
        {
 
        }
+
+       /*
+        * Functions used to protect against Cross-Site Request Forgery
+        * The security token has to base on at least one value that an attacker can't know - here it's the session ID and the private key.
+        * In this implementation, a security token is reusable (if the user submits a form, goes back and resubmits the form, maybe with small changes;
+        * or if the security token is used for ajax-calls that happen several times), but only valid for a certain amout of time (3hours).
+        * The "typename" seperates the security tokens of different types of forms. This could be relevant in the following case:
+        *    A security token is used to protekt a link from CSRF (e.g. the "delete this profile"-link).
+        *    If the new page contains by any chance external elements, then the used security token is exposed by the referrer.
+        *    Actually, important actions should not be triggered by Links / GET-Requests at all, but somethimes they still are,
+        *    so this mechanism brings in some damage control (the attacker would be able to forge a request to a form of this type, but not to forms of other types).
+        */
+       public static function getFormSecurityToken($typename = '')
+       {
+               $a = \get_app();
+
+               $timestamp = time();
+               $sec_hash = hash('whirlpool', $a->user['guid'] . $a->user['prvkey'] . session_id() . $timestamp . $typename);
+
+               return $timestamp . '.' . $sec_hash;
+       }
+
+       public static function checkFormSecurityToken($typename = '', $formname = 'form_security_token')
+       {
+               $hash = null;
+
+               if (!empty($_REQUEST[$formname])) {
+                       /// @TODO Careful, not secured!
+                       $hash = $_REQUEST[$formname];
+               }
+
+               if (!empty($_SERVER['HTTP_X_CSRF_TOKEN'])) {
+                       /// @TODO Careful, not secured!
+                       $hash = $_SERVER['HTTP_X_CSRF_TOKEN'];
+               }
+
+               if (empty($hash)) {
+                       return false;
+               }
+
+               $max_livetime = 10800; // 3 hours
+
+               $a = \get_app();
+
+               $x = explode('.', $hash);
+               if (time() > (IntVal($x[0]) + $max_livetime)) {
+                       return false;
+               }
+
+               $sec_hash = hash('whirlpool', $a->user['guid'] . $a->user['prvkey'] . session_id() . $x[0] . $typename);
+
+               return ($sec_hash == $x[1]);
+       }
+
+       public static function getFormSecurityStandardErrorMessage()
+       {
+               return L10n::t("The form security token was not correct. This probably happened because the form has been opened for too long \x28>3 hours\x29 before submitting it.") . EOL;
+       }
+
+       public static function checkFormSecurityTokenRedirectOnError($err_redirect, $typename = '', $formname = 'form_security_token')
+       {
+               if (!self::checkFormSecurityToken($typename, $formname)) {
+                       $a = \get_app();
+                       Logger::log('checkFormSecurityToken failed: user ' . $a->user['guid'] . ' - form element ' . $typename);
+                       Logger::log('checkFormSecurityToken failed: _REQUEST data: ' . print_r($_REQUEST, true), Logger::DATA);
+                       notice(self::getFormSecurityStandardErrorMessage());
+                       $a->internalRedirect($err_redirect);
+               }
+       }
+
+       public static function checkFormSecurityTokenForbiddenOnError($typename = '', $formname = 'form_security_token')
+       {
+               if (!self::checkFormSecurityToken($typename, $formname)) {
+                       $a = \get_app();
+                       Logger::log('checkFormSecurityToken failed: user ' . $a->user['guid'] . ' - form element ' . $typename);
+                       Logger::log('checkFormSecurityToken failed: _REQUEST data: ' . print_r($_REQUEST, true), Logger::DATA);
+                       header('HTTP/1.1 403 Forbidden');
+                       killme();
+               }
+       }
 }