[RCD] Proposed patch against against 1732

David Lublink roundcube.net at spam.bounceme.net
Thu Sep 4 23:01:55 CEST 2008


I received an email today with 232 emails listed in the To: header. Most 
of them had accents in the names so there was about 200 encoding emails 
in the To: header. The method responsable for this is 
decode_mime_string() and is recursive. My server stops recursion at the 
150th level. So the email caused PHP to crash and a blank page to be shown.

I wrote the following patch against revision 1732 which will resolve the 
issue. I changed the recursion for iteration :

Index: program/include/rcube_imap.php
--- program/include/rcube_imap.php	(revision 1732)
+++ program/include/rcube_imap.php	(working copy)
@@ -2416,9 +2416,10 @@
   function decode_mime_string($input, $fallback=null)
     $out = '';
+    $work = $input;
-    $pos = strpos($input, '=?');
-    if ($pos !== false)
+    // Iterate instead of recursing, this way if there are too many values we don't have stack overflows
+    while( strpos($work, '=?') )
       // rfc: all line breaks or other characters not found 
       // in the Base64 Alphabet must be ignored by decoding software
@@ -2436,7 +2437,7 @@
       $rest = substr($input, $end_pos+2);
       $out .= rcube_imap::_decode_mime_string_part($encstr);
-      $out .= rcube_imap::decode_mime_string($rest, $fallback);
+      $work = $rest;
       return $out;

Please include this into trunk of round cube. Additionally, it would be nice if you patched this to the stable version. To patch this to the stable version, you'll want to change rcube_imap.php to rcube_imap.inc before patching. Using patch that comes with gentoo, it patched fine with fuzz.

I tested this patch on trunk and on the stable release 0.1.1. I have noticed that PHP is slow on calling methods statically, so the iteration will be a bit faster than the recursion. :D

Please let me know,


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