From 2c8ad5ee720fea5b1948a8ff0f27d966444ba9d7 Mon Sep 17 00:00:00 2001
From: monnerat <pm@datasphere.ch>
Date: Fri, 12 Oct 2012 01:07:01 +0100
Subject: [PATCH] ASN1: _encode_der(): do not encode optional fields with value
 set to default.

---
 phpseclib/File/ASN1.php | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/phpseclib/File/ASN1.php b/phpseclib/File/ASN1.php
index ad57b392..41d0a502 100644
--- a/phpseclib/File/ASN1.php
+++ b/phpseclib/File/ASN1.php
@@ -728,6 +728,11 @@ class File_ASN1 {
             return $source->element;
         }
 
+		// do not encode optional fields with value set to default
+        if (!empty($mapping['optional']) && isset($mapping['default']) && $source === $mapping['default']) {
+            return '';
+		}
+
         if (isset($idx)) {
             $this->location[] = $idx;
         }