Ticket #4137: 4137-functions-new.patch

functions.php

@@ -692 +692 @@
         return $array;
 }
 
+function wp_limited_curl($url) {
+        /* This function is a wrapper for curl
+         * that limits the amount of data we
+         * fetch from a URI to avoid DOS problems
+         * with wp_remote_fopen()
+         */
+
+        $ch = curl_init($url);
+        global $total;
+        global $output;
+        $total = 0;
+        $output = "";
+
+        function read_body($ch, $string) {
+                $length = strlen($string);
+                global $total;
+                global $output;
+                $total += $length;
+                $output .= $string;
+                if ($total > 30720) return -1;
+                return $length;
+        }
+
+        curl_setopt($ch, CURLOPT_WRITEFUNCTION, 'read_body');
+        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 1);
+        curl_setopt($ch, CURLOPT_TIMEOUT, 30);
+        curl_setopt($ch, CURLOPT_BUFFERSIZE, 4096);
+        curl_setopt($ch, CURLOPT_RANGE, "0-30720");
+        curl_exec($ch);
+        curl_close($ch);
+
+        return $output;
+}
+
 function wp_remote_fopen( $uri ) {
-        $timeout = 10;
+        $bytes_limit = 30720;  /* limit on size of source documen bytes, see 
+                                * Errata for pingback specification.
+                                * http://www.hixie.ch/specs/pingback/pingback
+                                */
+        $timeout = 10; 
         $parsed_url = @parse_url($uri);
 
         if ( !$parsed_url || !is_array($parsed_url) )
@@ -709 +747 @@
 
                 //stream_set_timeout($fp, $timeout); // Requires php 4.3
                 $linea = '';
-                while( $remote_read = fread($fp, 4096) )
+                $bytes = 0;
+                while( $remote_read = fread($fp, 4096) && $bytes < $bytes_limit )
+                        $bytes = $bytes + 4096;
                         $linea .= $remote_read;
                 fclose($fp);
                 return $linea;
         } else if ( function_exists('curl_init') ) {
-                $handle = curl_init();
-                curl_setopt ($handle, CURLOPT_URL, $uri);
-                curl_setopt ($handle, CURLOPT_CONNECTTIMEOUT, 1);
-                curl_setopt ($handle, CURLOPT_RETURNTRANSFER, 1);
-                curl_setopt ($handle, CURLOPT_TIMEOUT, $timeout);
-                $buffer = curl_exec($handle);
-                curl_close($handle);
-                return $buffer;
+                return wp_limited_curl($uri);
         } else {
                 return false;
         }