Get SHSH from iTunes backup?
Is there a way I can get my old SHSH from an iTunes backup? I've got a week 24 3GS running jailed iOS 4 right now.
Before someone asks, "OMG why you do that?!?" The reason this happened is I previously had a jailbroken iOS 4 3GS, but when I tried to install a fix for notifications in Cydia, I got stuck in a reboot loop and I had to restore my phone, and the only firmware that would work was the jailed iOS 4. I didn't know anything about SHSH files until after the restore (I don't keep up with this stuff.)
So my buddy told me he thinks there is a way to get an SHSH to downgrade the phone from an old iTunes backup, but he didn't know how to do it, and I can't find it with Google. Is he correct or mistaken?