The source code being mentioned here is reportedly for iBoot, which is one of the most important parts of iOS. This program takes care of the trusted boot of the operating system on iPhones and other iOS devices.
iBoot is the first program that boots when an iPhone is turned on. For comparisons, you can think of it as the BIOS/UEFI in Windows or Fastboot in Android. This component verifies that iOS is loaded correctly every time and if the kernel is signed by Apple.
The complete authenticity of the leaked code remains yet to be verified. However, it appears to belong to iOS 9.3.x. As per security researchers, parts of this code exist in iOS 11, and it could help hackers to find flaws in iOS 11. While one can’t compile iBoot due to missing files, it is still useful.
As per Motherboard, Jonathan Levin, an iOS and macOS expert, has called it the “biggest leak in history.” Further, he added that the leaked code matches with the portion he reverse engineered himself in the past.
This development can lead to compromising or jailbreaking of iOS-powered devices. Moreover, the code can also allow developers to emulate iOS on non-Apple devices.
“iBoot is the one component Apple has been holding on to, still encrypting its 64-bit image,” Levin added. “And now it’s wide open in source code form.”
It’s worth noting that this source code first appeared last year on Reddit. However, due to low Reddit karma of the user, the post got buried.