The team of hackers working days and nights trying to understand the iPhone's inside outs has achieved a new goal. They are now able to make a call with an AT&T SIM card not attached to the mandatory 2 year contract. The hack can't be used with another Network SIM card, but this is probably a matter of time before they reach this ultimate goal, even though they are now stopped by major roadblocks.
With this new hack, it means that you will be able to use your current AT&T SIM card with you current plan, and even the corporate plan you've been dreaming to have on you iPhone.
Here's what the hackers have to say about their work:
All problems with unlocking lie in the baseband, the radio chipset for the iPhone. The chipset is an S-Gold2, and don't come in the chat and give us links to PapaUtils, we can't use them. Now the iPhone only has one lock, a network personalization lock. This lock means the MCC(US=310) and the MNC(AT&T=410) must match the first six digits of the SIM cards IMSI. This check is done in the baseband firmware itself. I'm not really sure where yet, but that isn't really relevant. The only thing standing in the way of an unlock is the baseband. All the other sim checks are known and can be patched out. We even know the AT command to do the unlock. It's 'AT+CLCK="PN",0,"xxxxxxxx"'. But good luck finding those x's. They are called the NCK, or Network Control Key, and are believed to be unique in everyones phone. Forget brute force(time impractical) and the obvious entries. If you still think bruteforce is a good idea, read this. Further, there is a limit of 3-10 unlock attempts per phone, after which the firmware will "hard-lock" itself to AT&T. So why can't we just patch the firmware? The firmware, located in the ramdisk at /usr/local/standalone/firmware/ICE03.12.06_G.fls, is signed. See here for what is known about the file. The sig is checked in the baseband bootloader. The updater program, bbupdater, only checks a checksum, which can be changed. The update will take, but then the phone won't boot because the sigs don't match.
We worked two solid days on disasseming the radio fw. There are a few backdoors, but none that would lead to an unlock. If you are *good* with disassembling ARM, PM geohot for the idb. We've documented a lot of functions pretty well. Although, this firmware is very difficult to work through. I'm 90% sure the password check happens in the function called pwdcheck, but I haven't found it yet. For all we know there could be a simple algorithm to generate the NCKs that we've missed.
Via Gizmodo
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