I own an iPhone 4S working on iOS 7.03. I got it a couple of years ago as a gift from a friend, however it was locked(I can only assume it was stolen).I took it to a mobile service which charged me 25$ for unlocking the phone by jailbreaking it.Nowadays the version of the phone is sort of lacking and I wish to update to a newer version(at least an iOS 8).Could I get some advice on how to update/jailbreak my phone without the need to take it to a mobile service again, because I do not want to pay the 25$ again.
>>155879
1) You can only ever install the latest version of iOS (and sometimes the second-latest version, if there's been an update recently).
2) You can't jailbreak the latest version of iOS
3) There are no jailbreak/unlocks these days*; phone your carrier and pay the unlocking fee.
* to jailbreak a phone, you exploit a conventional OS running on the application processor. To unlock one, you need to do all that, and then exploit an embedded OS (often formally verified) running on the modem. This is a huge amount of work, and when your sole customers are "people too cheap to pay off their contracts" and "people who steal phones", the payoff isn't exactly fantastic.
>>155888#
I understand.Than what could I do considering the fact that Apple products aren't supported in my country.Should I visit my provider to ask for further assistance?Or there just isn't much to be done and I should start saving for a new phone?
>>155893
If you want it unlocked, you need to speak to whatever provider it's locked to. Obviously, if they believe it's stolen from one of their customers, they'll be disinclined to help you.
iDevice updates are actually a bundle of updates for the various components of the device: the bootloader that shows you the apple and loads the OS, the OS itself, the various recovery modes, the firmwares it injects into the more complicated Lightning devices, the OSes of the security and the motion coprocessors and (crucially for you) the "baseband processor" that provides all the wireless capability.
If you update the phone it'll update the baseband processor, and updating the baseband processor will fix the vulnerability your unlock is using.
If you're planning on updating at all, even to an unjailbroken OS, it'll update the baseband and destroy your unlock.
It's possible to slice up the IPSW bundle and remove the baseband update from it, but I can't remember offhand whether that works on the 4S, or only on the older devices that had an exploitable first-stage bootloader (iPad 1, iPhone 4, iPod Touch 4).
>>155879
I'm an ex Apple engineer. What you're asking for isn't possible to my knowledge. The other guy is right in telling you to contact the carrier it's locked to. A custom IPSW is really your only hope here, but without powerful exploits it's not going to be possible. I worked on the DFU instructions in the 838.3 SecureROM found in your phone. It's rock solid with only a few buffer overflows in a couple areas. Now that exploiting the now that exploiting the bootrom is out of the question, I think you're left with two options. The first is not updating your device. The second is visiting the carrier website and requesting an IEMI unlock.
