Myth behind Downgrading iOS 4.0.2 to iOS 4.0.1 without SHSH Blob



Well, it sounds very exciting when we here that it is possible to downgrade from iOS 4.0.2 to iOS 4.0.1 or iOS 4.0 without SHSH blob. Well, all my devices have SHSH Saved. So, it doesn’t make any sense testing it. Because, it will work anyway. So, in my yesterday’s tutorial (Mac / Win), I have mentioned that there is a possibility of downgrading your iOS 4.0.2 running devices to iOS 4.0.1 to iOS 4.0. Well, trying that method will not hurt becuase, anyway you are stuck with iOS 4.0.2 for now. If it works, you can go head and Jailbreak it. If not you can get to your previous state (iOS 4.0.2).

iOS4 Myth behind Downgrading iOS 4.0.2 to iOS 4.0.1 without SHSH Blob

Semaphore, the man behind TinyUmbrella shared his though on Downgrading iOS 4.0.2 to iOS 4.0.1 / iOS 4.0 without SHSH Blob. Well, according to him it is not at all possible.. This is what he says..

Let me get this out first.

  1. This is not a miracle, at least not in the sense you all hope for
  2. SHSHs are STILL required for any iPhone 4, iPhone 3GS, iPad, iPod Touch 3G, and iPod Touch 2G (MC Model)
  3. There is NO way around this… unfortunately this method included.

Let me start by explaining something very important. The buildmanifest is used by iTunes to build much of the TSS request that is used to obtain your SHSH for any given firmware revision. Unfortunately, the BuildNumber has no part to play in the request for SHSH. All that you ended up doing in following these directions is request 4.0.1 SHSH blobs. THAT IS ALL. Since every single one of you that got this to work changed your hosts file to point to Cydia, Cydia responded to the TSS request with an SHSH blob that was ALREADY “on-file”. There was no magic. There was no miracle, apart from the lucky break that your device had been put on Cydia’s SHSH request list at some time in the distant past.

That’s it in a nutshell folks. There was no amazing technique for bypassing Apple’s TSS. There was no amazing exploit that exists in DFU mode allowing for 4.0.2 -> 4.0.1 downgrading. It’s simple; Cydia had your SHSH because at sometime in the past either:

  • Someone saved your SHSH with that device using TinyUmbrella and the default options
  • Someone restored that device with Cydia in the hosts pointing to gs.apple.com
  • Someone jailbroke the device and pressed ‘Make my life easier’

Well, if we keep all this a side, the only thing I can say is to, GIVE IT A TRY & SEE IF IT WORKS FOR YOU. BECAUSE, TRYING IT WILL NOT HURT YOU IN ANYWAY. But, please remember to post your outcome so that, it will help other users.

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  • http://twitter.com/bonbondude Ali Waqas

    blunder

  • Quepasamufasa

    It worked for me. I jailbroke my iphone 3gs 3.1.3 new bootrom before upgrading, then accidently upgraded to ios 4.0.2 and none of the downgrading options worked. After an entire day of trying, only this option let me restore to a 4.0.1, which I had never installed. I am pleased with my jailbroken and unlocked phone

  • rookie_slayer

    many jailbreaker’s concern on de-packaging ipsw. sadly….. i’ve done just in 2 days. Concern on itunes guys. i make several times downgrade/upgrade from/to 4.2 – 3.2.2 – 3.2.1 – 3.2.

    apple new firmwire (4.2) can use as a system failure so shsh blob will be ignored when restored. remember: ITUNES & Ipad 4.2 firmwire (BETA)

    rookie_slayer