I just got a OpenWrt one router that I bought from amazon from a unofficial seller but a known banana pi distributor. I wanted to verify that the router has not been tinkered with. I did the system.upgrade to.the newest version and checked the sha and md5 of the file but is that enough? Does the upgrade overwrite all excisting files or do I need to do a fresh install? Is there another way to ensure the firmware / router is safe and secure?
Yeah? So I dont need to change or check anything then? What happens if i reset the router, does it go back to potential unsecure settings made by the seller?
That is unlikely it should go back to the OpenWRT default but if you upgraded while keeping settings it is not impossible some program has run which infects the image again. Far fetched maybe
But if you are worried I would just install a new image and not keeping settings but that is just me.