Apple freezes the digital signatures of iOS 5.0.1
As usual, Apple has done so after a few days to capture digital signatures necessary to install the penultimate mobile operating system. This implies of course that is no longer possible to install the 5.0.1 firmware in the traditional manner, i.e. through the normal recovery process in iTunes.
So, if you need to restore iOS 5.0.1, you need the certificates SHSH of your device for that version. Following our guide, you can still have iPhone OS 5.0.1 on your device even though Apple has locked digital signatures. However, we would like to point out that the recovery method using the SHSH blob can be run only on Apple devices with the previous chip A5. So, owners of iPhone 4S and iPad 2 with iOS 5.0.1 can no longer recover even if they saved the SHSH.
How to downgrade iPhone OS to version 5.0.1
The new version of the mobile operating system has already been jailbroken, albeit tethered and only for some devices (which do not include the iPhone 4S and iPad 2). However, if you are interested in the jailbreak, the best choice right now is to stay with iOS 5.0.1. If you have already installed the latest version, here is how to downgrade it.
Apple has not yet locked the keys to sign the firmware 5.0.1, so there is no need to have previously saved the certificate SHSH your device on the penultimate version. As soon as such keys are removed, you cannot restore iOS 5.0.1 using traditional methods developed by Apple. The only alternative, therefore, remains the one that uses the SHSH blob.
The downgrade of the method allows restoring iOS 5.0.1 only if, when you had that version of the operating system on your device, you have done to save the certificate SHSH. However, the method described here cannot be applied to iPhone 4S or iPad 2 because, although you have the SHSH blob in your hands, there is still no way to use it in the process of installing the firmware.
To downgrade using certificates SHSH you need iFaith (the links for download are listed at end of article) and the iOS 5.0.1 firmware on your device formed IPSW, available from our download page. Do the following:
- Open iFaith and choose the “Build IPSW*signed w/Blobs”
- Look for the path on your computer where you saved the certificate SHSH of iOS 5.0.1. Select the file also IPSW you downloaded
- iFaith will kick off the automatic procedure, after which you will create the custom firmware
- Set your device into DFU mode by following closely the steps shown by iFaith
- Open iTunes and hold down SHIFT, click on Restore. Select the custom firmware created by iFaith and wait until the processing is completed.