TinyUmbrella lets you save SHSH blobs for iPhone, iPad, iPod Touch and Apple TV, which actually allow your iDevice to be downgrade-able to an older firmware version. More recently, Saving SHSH blobs also helps in getting untethered jailbreak, most popularly, this is used with tools like Redsn0w (v0.9.7)
TinyUmbrella 4.21.08 is now available for download to save SHSH blobs for iOS 4.3 beta 3 or iOS 4.3b3.
Download TinyUmbrella 4.21.08
Once you ‘upgrade’, apple doesn’t let you downgrade to older iOS firmware. The way apple does this is by taking the firmware version files and ECID and generate a hash that ONLY APPLE can generate. iTunes packages up this hash and sends it to your device. Your device checks the information and verifies the signature making your device look for Authenticity. Apple stops signing older firmwares once a new one is out, henc eolder firmwares stop working.
How Firmware Umbrella fixes it
FirmwareUmbrella sends the same exact request that iTunes sends Apple when requesting the signatures for your device to be restored. It saves SHSH signatures for your device received from the Apple server and let to downgrade OS indefinitely.
TinyTSS is a small java app that acts as your very own signature service. When iTunes verifies thefirmware restore for the devices listed below, it checks if you are allowed to restore to the version you are requesting. With TinyTSS + the shsh blob file(s) you obtained with Umbrella, you will be able to restore to the version of those shsh files forever!
TinyUmbrella = Firmware Umbrella + TinyTSS
TinyUmbrella Supports all iOS 4 devices:
- iPhone 4
- iPhone 3GS, 3G
- iPod Touch 3G, 2G
How to Save SHSH blobs iOS 4.x with Tiny Umbrella
1. Open TinyUmbrella and read TinyUmbrella README. Hit the Save My SHSH button or use advanced options to save SHSH blobs for iPhone 4 iOS 4.1.
2. Click the “Start TSS Server” button, let it quit the iTunes (if running).
3. Now Open iTunes, Holding down the SHIFT (Windows) or Alt/Option (Mac) key and hit the Restore button on iTunes and browse for iOS 4.x firmware you wish to restore to.
4. iTunes should error out with 1004 error. This error confirms we are good.
5. Click the Kick Device Out of Recovery button on TinyUmbrella. and That’s it.