Bitsum Community Forum

General Category => Firmware Modification Kit and Embedded Systems => Topic started by: motocrossmann on April 26, 2014, 04:43:32 PM

Title: Modding a security DVR's firmware
Post by: motocrossmann on April 26, 2014, 04:43:32 PM
Using FMK and binwalk, I was able to chop the header and footer off of my Swann DVR's firmware and then mod the Cramfs to update the root password.   When I reassemble it with FMK, and then run binwalk on it, it looks identical to the original with all sections ending/beginning in the sample places.   The contents of the Cramfs do make it a smidge larger, but it still fits into the original "boundaries".   When I go to flash the firmware though, it fails after thinking about it for some time.   I am guessing that there is a checksum somewhere, or some other security feature.   I have no idea how to proceed from here though.   Ideas???
Title: Re: Modding a security DVR's firmware
Post by: Coldblackice on July 13, 2014, 07:15:33 AM
Any progress (or luck!) with this?

I would also guess it's a checksum issue.
Title: Re: Modding a security DVR's firmware
Post by: Jeremy Collake on July 27, 2014, 04:35:41 PM
It does sound like it's probably a checksum / integrity check failure.

Resolution would require further evaluation.

Your best bet is to submit it as an issue at the Google Code site for the FMK.