iOS hacker and TinyUmbrella developer Notcom today issued a gentle reminder to all jailbreak community members to take a backup of iOS 5.1 SHSH blobs. Saving iOS 5.0.1 SHSH blobs is highly recommended for those who seeks to jailbreak 5.0.1 firmware in future or those who want to re-jailbreak their iOS device in case of accidental upgrade to iOS 5.1.
With the quiet time between jailbreak and iOS version, make sure you get your SHSHs saved. I’ve been working on the TinyUmbrella rewrite (albeit sparingly due to real life demands). It’s important to make sure you have your 5.0.1 SHSHs tucked away safe. There is no guarantee that we’ll have things this good again.
Why should we save 5.0.1 SHSH Blobs?
Apple released the iOS 5.1 beta 3 (developer build) four weeks back to address the controversial battery drainage issue. To fix this, Apple might release iOS 5.1 software update publicly anytime soon. In addition to rectifying the battery drainage issues on A5 devices, Apple might also patch @pod2g’s untethered iOS 5.0, 5.0.1 jailbreak exploit, leaving you with a tethered jailbreak on A4 devices. Perhaps, some hackers claims that Apple has already fixed the security flaw (in beta 3 of iOS 5.1) being used by pod2g to untether iOS 5.0.1 jailbreak on iPad, iPhone and iPod Touch devices.
iOS 5.0.1 untether Jailbreak Supporting devices
Since A4 or lower devices are pwned with limera1n bootrom exploit, iPhone 3GS, iPhone4 (both GSM and CDMA), iPad1, iPod touch 3G and iPod touch 4G will not loose the jailbreak completely in event of upgrade. These iOS device owners will only lose the untethered jailbreak. However, A5 device owners (iPhone 4S and iPad) may lose the jailbreak (when updated to 5.1) until a new jailbreak exploit is discovered by the hackers.
In order to protect your jailbreak, you will have to save your SHSH blobs for iOS 5.0.1, if you have not already. As we’ve previously stated, these SHSH blobs come in handy when you accidentally update to the latest 5.1 firmware that cannot be jailbroken and want to downgrade to iOS 5.0.1 firmware.
How to save APTickets 5.0.1 SHSH blobs
Saving SHSH blobs is a bit tricky since iOS 5.x have a new APTicket mechanism built-in. Right now, you can use either iFaith 1.4.2 or Redsn0w tool to backup SHSH blobs. If you’re not sure how to save your SHSH blobs, refer to our previous article on how to save SHSH blobs and APTickets using redsn0w.
Redsn0w will stitch 5.0.1 blobs to a custom firmware file and use that file to restore to iOS device. Here, it is important to keep in mind that as of today, redsn0w is not yet compatible with iPad 2 and iPhone 4S (neither iFaith tool). There is no way you can downgrade from iOS 5.1 to 5.0.1 for A5 device. Notcom is already hard at work on the TinyUmbrella rewrite to support both iPhone 4S and iPad 2, but no ETA however.