Welcome to fatboy's strategy guide for current IOS 5.0.1 jailbreakers!
Followers of the Apple scene will know that IOS 5.1 is going to be released in early March, most likely to coincide with the release of the next iPad device, the iPad3. As soon as IOS 5.1 is released Apple will quickly move to close the signing window for IOS 5.0.1. They usually do this within about 24 hours of the release of a new version.
We know that IOS 5.1 will patch the corona and absinthe vulnerabilities which allow the iPad1 and iPad2 to be jailbroken untethered. So, that means you only have a week or two (at the time of posting) to consider your options and decide your strategy for dealing with the release of 5.1!
To understand what the implications are, we need to look at it on a device by device basis:
Whilst iPad1 owners feel the pain of relatively limited amounts of RAM and a slow old single core A4 processor, the one big advantage you have is that your device bootrom is pwnd for life thanks to the limera1n exploit
This means there is always a doorway through which a tethered jailbreak can be deployed onto a new version of IOS. It also means there is a way to defeat Apple’s APTicket security measure introduced in IOS5.x to strengthen SHSH Blobs.
Whilst nothing is confirmed, a tethered jailbreak suitable for iPad1 should surface quite quickly for 5.1 once it is released to the public. An untethered version may take a while to develop, but you can be assured that the dev-teams will be working on it as soon as they have the GM code.
Furthermore, if you have saved SHSH Blobs for 5.0.1, you should be able to use redsn0w or sn0wbreeze to create a custom pre-signed 5.0.1 firmware file so that you can restore your device to IOS 5.0.1 at any time in the future and continue to enjoy the wonders of an untethered jailbreak. Look out for a tutorial on this in the not too distant future…
If you haven’t bothered to save your SHSH Blobs, now is a very good time to do it! These are critical to protecting your future position. You will never be able to downgrade your iPad1 back to 5.0.1 without them. Links are provided at the bottom of the post to assist you.
Lastly, you should be careful of accepting the 5.1 update which will be offered to your device OTA and via iTunes “by accident”. If you have saved blobs you can restore back, but you can probably do without the hassle!
So iPad1 owners have it good. You can stay where you are on 5.0.1, and as long as you take the time to save your 5.0.1 SHSH Blobs you also have the flexibility to try out / experiment with 5.1, and even any tethered jailbreak that gets released for it, knowing that you can restore to 5.0.1 using redsn0w or sn0wbreeze with your blobs at any time.
Whilst iPad2 owners have plenty of RAM and A5 dual-core goodness at their fingertips, our disadvantage is the lack of any known bootrom exploit for our devices.
This means we must always wait for new userland exploits to be found and developed into working jailbreaks for our devices, a process which can take several months following the release of a new version of IOS (already borne out twice in sucession). It also means we currently have no way to defeat Apple’s APTicket security measure introduced in IOS5.x to strengthen SHSH Blobs signatures.
The result, as things stand, is that once Apple closes the signing window on IOS 5.0.1 we will have no way to ever restore our devices to that version again. Because of this you will have no option to try out the public version of IOS 5.1 and then revert back to 5.0.1 if you don’t like it. Once you update your iPad2 to 5.1 you cannot downgrade to 5.0.1 if the signing window is closed. This makes it critical to understand your future strategy!
iPad2 owners don’t have it so good. If you like your iPad2 in all its untethered IOS 5.0.1 jailbroken beauty you need to be very protective of it once 5.1 is released.
You must NOT accept the 5.1 update which will be offered to your device OTA and via iTunes. You can’t afford to make a mistake here. Once you install 5.1 there is no going back to 5.0.1.
Also, you will need to be extra diligent in terms of adding new or updated Cydia tweaks and apps. One false move, perhaps installing a tweak which was designed for the iPhone or IOS 3.x, could render your iPad2 in a state which requires a restore. If that happens you will be restoring to 5.1 and saying goodbye to your jailbreak for a while!
The only safeguard some of you might have is if you have saved SHSH Blobs for 4.3.3 and your iPad2 is not a CDMA model then you can downgrade to 4.3.3 and jailbreak that. It is the APTicket security which cannot be overcome on the iPad2 without a bootrom exploit, but 4.x firmware did not have this feature.
Lastly it’s worth saying, whilst 5.x blobs are currently of no use to iPad2 owners this does not mean you should not save them! You never know what the clever hackers will come up with next, so you should take the time to save them now none the less…
Be prepared and be careful!
No matter what device you own, make sure you have your 5.0.1 SHSH Blobs saved. For iPad1 owners, these provide you enough protection to restore back to 5.0.1 if you ever need to.
If you have an iPad2 device be super vigilant. If you update your device or are forced to restore to 5.1 after the singing window for 5.0.1 is closed, you cannot get back to 5.0.1 as things stand today. Don’t accept the update to 5.1 when offered unless it’s what you want to do. And be very careful when installing new or updated apps from Cydia. Check their compatibility and if in doubt, check in the forums first!
As an anecdote, I experienced a major problem on my iPad2 this week which I was not able to resolve without a restore. If this had happened in a few weeks time I would have lost my 5.0.1 jailbreak for good! - It can happen to anyone! (but don’t have nightmares…)
HOW TO - Save your SHSH Blobs with TinyUmbrella
HOW TO - Use Safe Mode to maintain a stable jailbreak
Hope you enjoyed the post. If you have any questions, please do reply!