Applies to following iDevices:
Since the releases of iPhone 3GS (MC model) Apple start signing the firmware device. It means that Apple must accept the firmware that you want to install on your iPhone 3GS. This means you can only install the most recent version of OS!
The signature (Known as SHSH) is a kind of hash code stores in a file with XML format that generate for your device. Apple uses your device ECID and firmware version in order to create that.
So if you know your ECID and send it to Apple, their servers (known as TSS server) send the code (SHSH) back to you (Remember you just can get) so you can store it somewhere. Firmware Umbrella can do it for you (I will talk about this later on this article).
Now Assume that Apple releases a newer version of OS (e.g 3.1.4). Their TSS server immediately stop singing the older versions and only signs 3.1.4. If you accidentally update your iPhone to newer version you can’t downgrade to any older version because iTunes can’t get SHSH from Apple TSS servers. But the point is that if you previously saved the SHSH for 3.1.3 and give it to iTunes, iTunes will downgrade your device. TinyTSS create a virtual TSS server on you computer, iTunes send request to virtual server then TinyTSS send the saved SHSH back to iTunes. You may know ask me “why should I downgrade? I’m so happy!” The answer is ability to jailbreak! If you update to newer version there is no way to jailbreak it!
Enough talking! Let’s saving SHSH! Follow me!
Prerequisites
- Of course an iPhone 3GS (MC-Model) -What does it mean!?-
- USB cable!
- A PC or MAC
- An active internet connection
- Firmware umbrella (includes TinyTSS)
The Process
STEP 1: Finding ECID
- Disconnect iPhone USB cable
- Turn off the iPhone. Once it is off, press and hold the Home button.
- While holding Home button plug in the USB cable to your iPhone and your computer
- The “Connect to iTunes” logo will appears on the iPhone screen
- Click the Apple logo in the menu bar on your computer. Select About This Mac
- Click More Info
- Find ECID as shown in picture below and write is somewhere
iPhone Connected in recovery mode, you can see device ECID
- Unplug USB cable
- hold down the Power (sleep/wake) button until it shuts off. The iPhone will reboot.
- Windows users should do the same via windows Device Manager!
ECID in windows 7
Congerts! Now you can walk through Step 2!
STEP 2: Getting SHSH
- Unzip the package you previously downloaded
- Open Umbrella (umbrella64.exe : 64bit systems, umbrella.exe : 32bit, umbrella.dmg : MAC)
- Insert your ECID from STEP 1
- Select right firmware version (I recommend to test all)
- Click on Submit button. (Internet connection needed)
Successfuly saved SHSH file
- Normally it saves the SHSH in current location! If not search entire drive to find it.
The next step
Ok, now you have SHSH code. Save it somewhere safe you will force to use it in near future, trust me!
