Getting your iPhone enter DFU (Device Firmware Update) mode can be tricky, as it involves carefully timed pressing and holding of multiple buttons. Imagine the situation when your Apple device have broken Power and/or Home buttons which do not work as expected, and the need to get your device in DFU mode arises.

Thankfully, the leading jailbreaking utility redsn0w offers a solution to create DFU .IPSW firmware restore file for users who are not able to get the DFU mode using the button combination.

The cat-and-mouse game between jailbreakers and Apple is getting tough for hackers with every new release of Apple iOS, as it plugs existing loopholes which they exploit. Anyone trying to restore Apple iOS 5.1.1 on iPhone 4 and 4S will face iTunes errors like 3194 and 1600 while trying to flash an sn0wbreeze customized IPSW file, even when having saved SHSH blobs and using TinyUmbrella TSS server. The solution to this problem is to have the custom .IPSW firmware file stitched with previously saved SHSH digital signatures, follow the detailed instructions ahead to get this done using sn0wbreeze.

What is TinyUmbrella ?

TinyUmbrella is an utility for Windows and MAC which allows users to save SHSH Blobs or Digital Signatures for Apple Devices (iPhone, iPad and Apple TV) locally, this allows restores to older firmware's which are no longer officially supported by Apple. TinyUmbrella works the magic by running locally as a proxy to iTunes, intercepting and faking the communication while iTunes thinks it is communicating with Apple servers for authenticating the firmware restore as permitted irrespective of what Apple Servers allow and disallow. This feature becomes indispensable for users relying on "Software unlocks" which are supported on older firmwares and basebands, as Apple restricts restores to these exploited versions forcing users to newer versions of iOS.

What is SHSH Blobs ?

These are backup files of firmware digital signatures which are needed to restore an Apple device, Apple generates these based on hardware keys of the device and the hash of the firmware - which makes them unique for every device. It is to be noted that Apple only issues signatures for the currently-available, current iOS version. What TinyUmbrella does is to save these digital signatures locally for later use, when Apple does not allow them.

How to save SHSH Blobs using TinyUmbrella ?

Simply download the TinyUmbrella utility (links provided at the end of this blog post), and connect your device. Once detected click the "Save SHSH button" and it's done, if having errors look at our TinyUnmbrella troubleshooting guide.

The DFU (Device Firmware Update) mode is needed to update/upgrade/restore an Apple iDevice, however if you want to flash a custom .IPSW file you must enter a Pwned DFU mode i.e. a special DFU mode which had exploited limera1n jailbroken core to allow operations not permitted by the normal Apple DFU core.

Here is a simple to follow, visual tutorial on how to enter the Pwned DFU mode on an Apple device using ever handy redsn0w jailbreaking tool.

TinyUmbrella is an indispensable tool in the war between jailbreaking community and Apple, the software allows users to save their iDevice SHSH files making it possible to later downgrade or restore a firmware (.IPSW) even when Apple has blocked that forcing users to upgrade to a newer version.

If you are having issues trying to use TinyUmbrella and error shown is "Cannot Start TSS Service" and the status shows "TinyUmbrella's TSS server is not running" with option to start the server disabled, here is a quick and easy solution to the problem.

Developer of popular TinyUmbrella tool is working on a new utility allowing users to customize Apple iOS Firmware .IPSW files, according to the tweet by the developer the new utility TinyPwn will make is possible for users to make scriptable modification of the ipsw firmware files via a simple custom API on Windows, Mac and Linux.