Patch for the Drupal Varnish module (7.x-1.0-beta2) to fix authentication.

varnish_authentication_fix.patch

diff --git a/varnish.module b/varnish.module
index 80e7af2..248a564 100644
--- a/varnish.module
+++ b/varnish.module
@@ -260,7 +260,7 @@ function _varnish_terminal_run($commands) {
       if ($status['code'] == 107) { // Require authentication
         $secret = variable_get('varnish_control_key', '');
         $challenge = substr($status['msg'], 0, 32);
-        $pack = $challenge . "\x0A" . $secret . "\x0A" . $challenge . "\x0A";
+        $pack = $challenge . "\x0A" . $secret . $challenge . "\x0A";
         $key = hash('sha256', $pack);
         socket_write($client, "auth $key\n");
         $status = _varnish_read_socket($client);