Saurik Creates Signature Server for iPhone 3GS Jailbreakers

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Posted September 15, 2009 at 10:21am by iClarified

Saurik has created a signature server to help iPhone 3GS jailbreakers circumvent the new downgrade restrictions.

With the iPhone 3GS, every time you restore the firmware iTunes contacts Apple to verify the restore. Apple can then choose to sign off on the restore or refuse it.

With the release of iPhone 3.1 Apple is now refusing to sign the 3.0 firmware. This means that you cannot downgrade.

So in order to bypass this restriction you need to save the verification information Apple sends back when doing a verified restore. After iTunes sends Apple your ECID (unique-chip-id), if verified the firmware file will be personalized, integrating the ECID, SHSH (signature hash), and CERT blocks into it.

Purplera1n.com was created to save a file that contained just the signature hash for the iBSS file, as that is "sufficient"; however, someone needs to write a tool to use this file.

Saurik's solution saves the entire personalized firmware set required by iTunes to do a restore (full set of SHSH blobs) which will let you do a normal DFU restore in iTunes.

Unfortunately the ability to generate a full set of SHSH blobs via Cydia was only available for a very limited time. As soon as iPhone 3.1 was released Apple stopped signing the 3.0 firmware.

If you were one of the lucky ones and managed to have Cydia save your 3.0 or 3.0.1 ECID SHSHs then Saurik has created a server that duplicates the functionality exposed by Apple's signature server. By changing your hosts file to include 74.208.105.171 gs.apple.com iTunes will now contact Cydia for authorization to restore.

You can find the hosts file here: C:WindowsSystem32driversetchosts (Windows) or /etc/hosts (Mac OS X).

For the majority of users who did not get their ECID SHSHs on file with Cydia for 3.0 there is still hope. The greenpois0n exploit should provide a jailbreak for the 3.1 firmware. At this point it is imperative that you have Cydia save your full set of SHSH blobs for future downgrading.

We will be posting tutorials on how to use these features once they become available.

Saurik's writeup on this matter is far more detailed; however, we wanted to provide a simple overview of the situation. Use the link below to learn more...

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Saurik Creates Signature Server for iPhone 3GS Jailbreakers

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wheedz - September 16, 2009 at 12:36am

I am not well versed with the files that I am supposed to backup for the iphone 3gs. My question- do I have to do that step(saving iBEC and iBSS files) if I will buy iphone 3gs by october or novermber and JB it and unlock it???

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Raul De La Cruz - September 15, 2009 at 5:41pm

I just successfully downgraded back to 3.0 on my 3gs after it bricked on me a few days ago. I never did the 3.1 update and was patient enough for this to come around. Follow the link to Saurik's site. the steps are fairly easy, to be able to get permisson to write to the hosts file, just copy and paste this into a terminal window sudo /Applications/TextEdit.app/Contents/MacOS/TextEdit /etc/hosts then put in your admin password, once you do the file will open up and you can then add 74.208.105.171 gs.apple.com at the end of the file. then save

mulek - September 15, 2009 at 5:56pm

did you previously save your iBEC and iBSS files? I just got myself a 3GS with 3.0.1, but it's not jailbroken. Is there a way to jailbreak it? Maybe restore with this recent Saurik's steps that you wrote, and then JB it with redsn0w? Could it be possible? Or I still have to wait and use my iPhone unjailbroken (which I think is a crippled iPhone because I always use and enjoy my jailbroken 2G)

Raul de La Cruz - September 15, 2009 at 9:06pm

Cydia saved my files on their servers days before apple pulled the plug. i was lucky

Rick - September 15, 2009 at 4:43pm

It seems to me that your average Mac user will not know how to access /etc/hosts, nor will they know how to change permissions in "Get Info" option of the finder to change the hosts file. I do, and it still freaks me out tinkering around in hidden system files. Tutorial needed.

Alex Willoughby - September 15, 2009 at 11:29am

so if your phone is already on 3.1 and you dont have ECID SHSHs on file with Cydia for 3.0 then we should wait for green posion, then once green posion works then we make sure cydia has out ECID SHSHs on file? that right?

santana - September 15, 2009 at 12:55pm

only iphone 3gs that got there information save on cydia could restore all others have to way to there is a way to jail break 3.1 and wend it does come out make sure to save your inf on cydia asp.

Jeff - September 15, 2009 at 11:10am

I have Tried the CYDIA and UPDATE ALL, But never got the option for this. I also tried tapping the word "developing" at the bottom of the Main Screen (Hidden Link) but nothing. I use a 3GS running ver.3.0. Guess I'll have to wait till this mess gets right? And as others Say, MANY thanks for all the Work Saurik has and is Doing!..

Kyle Flanagan - September 15, 2009 at 10:58am

As always, we'll be relying on your tutorials to avoid bricking our iPhone 3G(S). Thank you :)