Most often, users experience problems with iPhone and iPad after updating to new version iOS. Often it is impossible to fix such problems, after which the question of rolling back to previous version firmware. In this guide, we will tell you how the most in a simple way find out what latest version iOS and others operating systems Apple is still signing.

Why find out

Not everyone knows, but roll back the iPhone, iPad or iPod touch on any previous version of iOS is not allowed. Apple stops signing old firmware some time after release latest updates... Apple does this for security reasons, since in new versions of iOS, the company's engineers fix various critical vulnerabilities that pose a real threat to users' personal data. These vulnerabilities remain in older iOS builds.

So it turns out that in order to successfully perform a rollback with a problem iOS version, the user initially needs to find out which firmware it is possible to roll back to. Most quick way the definitions of the firmware still signed by Apple are presented below.

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In this article, we will discuss the question of what kind of firmware Apple signs.

Typically after installation new system problems arise in iPhone operation and iPad. There is no way to fix them for various reasons, and then the question of rolling back to the old version of the system appears. In this guide, we will analyze how to find out which latest version of iOS and other OS is still signed by Apple.

Why is this needed?

Not everyone knows, but iPhone rollback to the previous version is essentially impossible. Apple ceases to make signatures for old irrelevant versions of the system some time after the release of a new one.

This is done for security reasons, as new versions eliminate vulnerabilities that threaten the safety of personal data. In the old build, the vulnerabilities do not disappear anywhere.

So it turns out that for a successful rollback, you need to find out which version of iOS will be received as a result. We have presented the fastest way below.

How do I know if Apple is signing the firmware?

• Open the ipsw.me resource. It's informal but safe

• Select your device name

• Find the model in the list

• See what firmware are available in the section Signed IPSWs
• You can also download the desired one and use it.

This method allows you to determine the available versions of the system and download them in a few clicks. This method is especially relevant for those who are not used to following the company's news, but needed to roll back the system.

What iOS Signs Firmware?

On this moment the situation looks like this.

Sixth and seventh generation iPhones can be rolled back to versions 9.3.5, 10.0.1, 10.0.2.

The same situation with iPhone smartphones 5, 5c, 5s and 4s.

iPhone 4 supports firmware versions - 7.1.2 - unlimited, 7.1.1, 7.1, 7.0.6, 7.0.4, 7.0.3, 7.0.2, 7.0, 6.1.3, 6.1.2, 6.1, 6.0.1 , 6.0, 5.1.1, 5.1, 5.0.1, 5.0, 4.3.5, 4.3.4, 4.3.5, 4.3.4, 4.3.3, 4.3.2, 4.3.1, 4.3, 4.2.10, 4.2 .9, 4.2.8, 4.2.7, 4.2.6, 4.2.5, 4.2.1, 4.1, 4.0.2, 4.0.1, 4.0 - only with SHSH hashes.

iPhone 3GS - 6.1.6, 4.1 - no limits, 6.1.3, 6.1.2, 6.1, 6.0.1, 6.0, 5.1.1, 5.1, 5.0.1, 5.0, 4.3.5, 4.3.4, 4.3. 5, 4.3.4, 4.3.3, 4.3.2, 4.3.1, 4.3, 4.2.1, 4.0.2, 4.0.1, 4.0, 3.1.3, 3.1.2, 3.1, 3.0.1, 3.0 only with SHSH hashes.

iPhone 3G - 4.2.1, 4.1, 3.1.3, 3.1.2, 3.1, 3.0.1, 3.0, 2.2.1, 2.2, 2.1, 2.0.2, 2.0.1, 2 - no restrictions, 4.0.2, 4.0.1, 4.1 - with SHSH hashes.

Rejoice, Apple has started signing old firmwares for iPhone and iPad. This means that your device can become fast again, like in the good old days. But not everything is as good as it might seem at first glance.
Previously, users had a fairly limited time (about a month) to return to the previous firmware if the speed of the new version did not suit them. And there was no possibility at all to roll back several versions.

And then, quite unexpectedly, Apple began to sign almost all firmware, giving users the opportunity to return the smoothness of work on older devices. For example, iPhone 5S could be rolled back to iOS 7, and iPhone 4 to iOS 6.

The only problem that some users have faced is the inability to activate the phone, which is rather strange, given the official signature from Apple.

But the "happiness" did not last long and at the moment the company has stopped signing all firmware, except for the current ones (iOS 11). It is not yet clear whether the possibility of downgrading the firmware was a glitch on the company's servers or not, but the "freebie" is over and we can only rejoice for those who managed to roll back to the old version of iOS.

Most often, users experience problems with iPhone and iPad after updating to a new version of iOS. Often it is impossible to fix such problems, after which the question arises of rolling back to the previous firmware version. In this guide, we will tell you how to find out in the easiest way which latest version of iOS and its other operating systems Apple is still signing.

Why find out

Not everyone knows, but you cannot roll back your iPhone, iPad or iPod touch to any previous version of iOS. Apple stops signing old firmware some time after the latest updates are released. Apple does this for security reasons, since in new versions of iOS, the company's engineers fix various critical vulnerabilities that pose a real threat to users' personal data. These vulnerabilities remain in older iOS builds.

So it turns out that in order to successfully roll back from the problematic version of iOS, the user first needs to find out which firmware it is possible to roll back to. The fastest way to identify firmware still signed by Apple is presented below.

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Everyone once reflashed their device for more new firmware... In most cases, new features are added to the firmware and bugs are fixed, but this does not always happen. V recent times after updates, some users start to "fall off" Wi-Fi, the network is lost or the battery sits down for a couple of hours. Apple releases iOS updates not so often, during this time you can suffer a lot with the problem that has appeared. In such cases, there are two options: wait for the update or roll back to the old iOS.

It is impossible to officially roll back to the previous iOS at the moment. Why and when Apple began to prohibit downgrading to the previous version of iOS, I will try to tell you.

The concept of SHSH (hash) appeared in 2009, along with the release of the iPhone 3GS.

SHSH- digital signature, which signs the firmware file before it is written to the device. The SHSH hash is written out by a special Apple server (gs.apple.com) in response to the identifier of the device being flashed, sent to it by iTunes.

The scheme of interaction between iTunes and Apple servers:

Further, starting with iOS 3.1.1, the signing system was extended to iPod touch 2G and 3G, and since the release of iOS 4.0 SHSH, iPhone 3G also began to subscribe. The iPhone 2G, iPod touch 1G and Apple TV 1G SHSH are not used, so these devices can always be flashed to any available iOS version.

Hackers were able to bypass total control of firmware. It turned out that SHSH with Apple server can be requested not only by iTunes, but also by any other program. So it became possible to make a backup, and with this, in turn, roll back the firmware.

1. Programs that keep SHSH on your PC
2. Programs that save hash on Cydia servers (in the cloud)

Both methods have their pros and cons. For example, programs that store your digital signature on Cydia servers sometimes crash or, due to server overload, the hash simply cannot be saved. But each has its own advantages! For example, saving it on a PC, SHSH will always be available to you, regardless of the health of Cydia servers or the presence of the Internet! Everyone chooses for himself what he likes, what is convenient for him!

Let me present a number of some programs with which you can save SHSH:

Cydia

When jailbreaking to you on iOS device Cydia, a tweak store, is installed immediately. In addition to installing those same tweaks, Cydia will automatically save your firmware hash! Saving occurs when the Internet or Wi-Fi is connected.

Saving is done directly from your iOS device to Cydia's servers. The above shows I have SHSHs stored on my iPod since iOS 3.3.3. A little trick, if the hash is not saved automatically, just hit the Reload button a couple of times.

The only drawback this method preservation digital signature, this is a periodic congestion on the server. For example, after the release of Evasi0n, Cydia did not work stably and the Cydia servers were not up to it.

TinyUmbrella is one of the most famous programs for saving SHSH from your PC, Mac. Main feature of this application is the ability to send your SHSH directly to Cydia servers so that you do not lose the saved certificates on your PC in the future. Same way this program are often used for the firmware downgrade itself. I will tell you about this in future articles!

iFaith (developer iH8sn0w) - A unique program that allows you to save the hash from any iOS device running old version firmware that is not digitally signed by Apple.

When Apple stops signing old firmware versions, there is no way to upload the hash, the iFaith utility allows you to dump SHSH files for any version of iOS and thereby restore to the iOS firmware you need!

Saving takes place on a PC in the location specified by you, so that SHSH will be available to you even when you do not have an Internet connection, but there is a save!

Instructions for use will appear later.

That's all you need to know about downgrading firmware, this page will be updated as new information becomes available !!