I just purchased an iphone 3gs from some dude and I want to restore everything back to defaults. He has tons of crap on it and I want to get rid of it all.

It's already unlocked/jb by blackRain, but I can't restore defaults as I just found out there is a restriction Password (and he says he doesn't know it)

So I wanted to restore fresh 3.1.2 but I try to save SHSH on CYdia but the server is down. What can I do? Any way to bypass the restrictions password? or get 3.1.2 back on it getting past apple's check? Thanks in advance!

You've been misinformed on how this works. You cannot currently request a 3.1.2 SHSH -- Apple stopped signing this back in February.

If you do not have a 3.1.2 SHSH on file now, you cannot get one and can only get SHSH blobs for 3.1.3 -- which everyone recommends you do sooner rather than later, since Apple will inevitably stop signing 3.1.3 in the near future as 4.0 has been released.