use DateTime/DateTimeZone classes

both classes are available since php 5.2.0

no longer modifies global state,
also good side effect is that format is no longer locale dependant

Author: glensc

lib/Saml/AuthRequest.php

@@ -56,10 +56,8 @@ protected function _generateUniqueID()
      */
     protected function _getTimestamp()
     {
-        $defaultTimezone = date_default_timezone_get();
-        date_default_timezone_set('UTC');
-        $timestamp = strftime("%Y-%m-%dT%H:%M:%SZ");
-        date_default_timezone_set($defaultTimezone);
+        $date = new DateTime('now', new DateTimeZone('UTC'));
+        $timestamp = $date->format("Y-m-d\Th:i:s\Z");
         return $timestamp;
     }
 }

lib/Saml/Metadata.php

@@ -30,10 +30,9 @@ public function getXml()
      */
     protected function _getMetadataValidTimestamp()
     {
-        $timeZone = date_default_timezone_get();
-        date_default_timezone_set('UTC');
-        $time = strftime("%Y-%m-%dT%H:%M:%SZ", time() + self::VALIDITY_SECONDS);
-        date_default_timezone_set($timeZone);
+        $timestamp = time() + self::VALIDITY_SECONDS;
+        $date = new DateTime("@$timestamp", new DateTimeZone('UTC'));
+        $time = $date->format("Y-m-d\Th:i:s\Z");
         return $time;
     }
 }

lib/Saml2/Utils.php

@@ -658,10 +658,8 @@ public static function generateUniqueID()
      */
     public static function parseTime2SAML($time)
     {
-        $defaultTimezone = date_default_timezone_get();
-        date_default_timezone_set('UTC');
-        $timestamp = strftime("%Y-%m-%dT%H:%M:%SZ", $time);
-        date_default_timezone_set($defaultTimezone);
+        $date = new DateTime("@$time", new DateTimeZone('UTC'));
+        $timestamp = $date->format("Y-m-d\Th:i:s\Z");
         return $timestamp;
     }
 
@@ -1151,7 +1149,7 @@ public static function decryptElement(DOMElement $encryptedData, XMLSecurityKey
                 OneLogin_Saml2_ValidationError::INVALID_XML_FORMAT
             );
         }
- 
+
         $decryptedElement = $newDoc->firstChild->firstChild;
         if ($decryptedElement === null) {
             throw new OneLogin_Saml2_ValidationError(

tests/src/OneLogin/Saml2/UtilsTest.php

@@ -697,7 +697,7 @@ public function testParseTime2SAML()
             OneLogin_Saml2_Utils::parseTime2SAML('invalidtime');
             $this->fail('Exception was not raised');
         } catch (Exception $e) {
-            $this->assertContains('strftime() expects parameter 2 to be', $e->getMessage());
+            $this->assertContains('Failed to parse time string', $e->getMessage());
         }
     }