Research: Pwnage Patches

If you have IDA Pro and you are at least semi-handy with ARM please contribute :)

Thanks to CPICH for helping out!

The Patches

There are three core patches in Pwnage.

iBoot

There is only 1 patch made to the iBoot, LLB, iBEC, iBSS, and WTF. It simply patches the RSA check to return success when an error occurs.

The patch is simple. This is the default non-patched area:

ROM:00002636                 _fail                                   ; CODE XREF: rsaCheck+3C�j
ROM:00002636                                                         ; rsaCheck+84�j
ROM:00002636                                                         ; rsaCheck+A0�j
ROM:00002636                                                         ; rsaCheck+B4�j
ROM:00002636                                                         ; rsaCheck+F0�j
ROM:00002636                                                         ; rsaCheck+100�j
ROM:00002636                                                         ; rsaCheck+10C�j
ROM:00002636                                                         ; rsaCheck+110�j
ROM:00002636                                                         ; rsaCheck+118�j
ROM:00002636                                                         ; rsaCheck+11C�j ...
ROM:00002636 454 01 20                       MOVS    R0, #1
ROM:00002638 454 40 42                       NEGS    R0, R0

Now, all that they do is change the "40 42" you see at 0x2638 to "00 20" (negs r0,r0->movs r0,#0).

DeviceTree

This simply patches "secure-root-prefix" and "function-disable_keys". It seems that you could bypass this patch by simply patching the iBoot flags to 0xffffffff, but I have personally never verified that the decrypted KBAG was correct, so anyone that is feeling adventurous and wants to verify, please do.

Kernel

Haven't really looked into this too far, but I know that the kernel is patched for codesign as well as a write and execution patch to allow addons such as Mobile Substrate to execute on / at the kernel