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Difference between revisions of "Bluefreeze"
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| + | [[iFaith]] has a protection that you don't use it on the wrong firmware to protect you. '''Bluefreeze''' modifies the firmware version (and firmware checksum) in the iFaith certificate file, so that this check gets disabled. By doing so, you can install any firmware version on your device, even without having saved the [[SHSH]] files. The problem by doing so is that you actually install a firmware without signatures. |
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| − | '''Bluefreeze''' is a tethered downgrade solution by a group called the Private Dev Team. It claims to allow the downgrade of a device to [[iOS]] 4.3, 4.3.5, or 5.0 from 5.0.1 without [[SHSH]] blobs saved via [[TinyUmbrella]] or [[iFaith]]. iDevices that are supported are iPhone 3GS, iPod touch 3G, and all [[S5L8930|A4]] devices. |
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| + | Having an unsigned firmware installed won't let you boot of course. But using the limera1n exploit (DFU mode, then using redsn0w) you can still boot your device up. The problem is only that you have to repeat this every time, so it's not a real downgrade you would want for having an untethered jailbreak. |
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| − | == Download == |
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| − | * [http://www.mediafire.com/?02y3bl3by41aaa3 Windows] |
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| + | And also after boot, once you put the device to sleep, the kernel will notice LLB is invalid and reboot again. So you have to do all the procedure again. You can install a [[Cydia.app|Cydia]] tweak called ''Prevent Sleep'' to avoid the device going to sleep. |
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| − | == Usage == |
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| − | * Step 1: Use [[iFaith]] to get an iOS 5.0.1 [[SHSH]] blob |
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| − | + | This way a "downgrade" to [[iOS]] 4.3, 4.3.5, or 5.0 from 5.0.1 is poassible. Supported devices are iPhone 3GS, iPod touch 3G, and all [[S5L8930|A4]] devices. |
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| − | <ios>5.0.1 (9A405)</ios> -> <ios>5.0 (9A433)</ios> |
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| − | <ipsw_md5>c13c14abcde18bbdb7d70c8563f56ac1</ipsw_md5> -> <ipsw_md5>989b8327acab76e7632443a0e179250c</ipsw_md5> |
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| − | * Step 3: Save the modified file, and use it to build an iOS 5.0 custom firmware. Even though the firmware has fake shsh blobs on it, iTunes will still accept it. (iREB will be used to bypass error 16XX) |
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| − | * Step 4: Since there are no shsh blobs present the device will boot up into DFU mode. A bootrom exploit, known as Limera1n, will be used to bypass Apple's blob checker per se. (Tool used: redsn0w) |
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| − | * Step 5: Device will boot up, and one will have a tethered downgrade. |
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| − | == |
+ | == Purpose == |
| + | With this method you can install a firmware for which you don't have [[SHSH]] saved for some tests, for examle if you're a software developer and need to do some tests on a specific version. |
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| − | It is highly suggested that you jailbreak your device after you accomplish this process and install a Cydia tweak known as Prevent Sleep. If you do not do so you run the risk of having your device randomly go into DFU mode. (if this tweak is installed this issue will go away). |
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| + | |||
| + | == Download == |
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| + | * [http://www.mediafire.com/?02y3bl3by41aaa3 Windows] |
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== External Links == |
== External Links == |
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Revision as of 23:00, 15 December 2011
iFaith has a protection that you don't use it on the wrong firmware to protect you. Bluefreeze modifies the firmware version (and firmware checksum) in the iFaith certificate file, so that this check gets disabled. By doing so, you can install any firmware version on your device, even without having saved the SHSH files. The problem by doing so is that you actually install a firmware without signatures.
Having an unsigned firmware installed won't let you boot of course. But using the limera1n exploit (DFU mode, then using redsn0w) you can still boot your device up. The problem is only that you have to repeat this every time, so it's not a real downgrade you would want for having an untethered jailbreak.
And also after boot, once you put the device to sleep, the kernel will notice LLB is invalid and reboot again. So you have to do all the procedure again. You can install a Cydia tweak called Prevent Sleep to avoid the device going to sleep.
This way a "downgrade" to iOS 4.3, 4.3.5, or 5.0 from 5.0.1 is poassible. Supported devices are iPhone 3GS, iPod touch 3G, and all A4 devices.
Purpose
With this method you can install a firmware for which you don't have SHSH saved for some tests, for examle if you're a software developer and need to do some tests on a specific version.
