I've been hesitating to jailbreak my wife's 3GS (with the old boot rom) that is now at 3.1.2 since I don't have the SHSH blobs and if I mess up I end up going to 3.1.3 and can't get back from the baseband update.

But I know that I should be getting the blobs backed up so that when the next release comes out, I can at least restore back to 3.1.3

suggestions? Can I somehow use firmware umbrella to get them without having jailbroken her phone? Or do I jump off without a net and just go?

(I have jailbroken my 3.1.2 3GS also with the old boot rom with PWNAGE and all is fine, I guess I could use that custom restore image, no?)


thanks

Yes, you can backup 3.1.3 SHSH without jailbreak. All you need is the ECID (from recovery or DFU mode) and umbrella from firmware umbrella.