Under D-Link DIR-655 hardware version A3 and firmware 1.32NA, the latest released North American DIR-655 firmware, attempting to restore the router's configuration using HTTPS fails. Restoring the router's configuration using HTTP works correctly. I believe this was also broken in firmware 1.21.
Steps to reproduce:
1) Open D-Link DIR-655 System Settings page at [D-Link DIR-655 web server]->Tools->System, i.e., https://[DIR-655 IP address]/Tools/System.shtml (or http:).
2) Save the current router configuration to a file with Save Configuation.
3) From the System Settings page at https://[DIR-655 IP address]/Tools/System.shtml (NOT http:), attempt to restore the saved router configuration using Restore Configuration from File.
4) Note error from router:
The restored configuration file is not correct. You may have restored a file that is not intended for this device, or the restore file is from an incompatible version of this product, or the restored file may be corrupted.
Try the restore again with valid restore configuration file.
Please press the button below to continue configuring the router.
If you open the System Setting page at http://[DIR-655 IP address]/Tools/System.shtml (NOT https:), restoring the router configuration using Restore Configuration from File works correctly. I think this may have been a bug in the router firmware for quite a while.
This bug is not dependent on the router configuration settings involved. It occurs with any router configuration settings, including the Factory Defaults.
This bug is not dependent on the client's browser. It occurs under both Firefox 3.6 and Internet Explorer 8.0.
There is a simple work-around: Use HTTP instead of HTTPS to restore a saved router configuration. But it's silly to have to do that.
Please fix this bug and add HTTPS configuration testing to your internal firmware tests. Thanks.