8.5. DONGLES
seg000:001186A0 54 60 06 3E clrlwi %r0, %r3, 24
seg000:001186A4 28 00 00 01 cmplwi %r0, 1
seg000:001186A8 94 21 FF B0 stwu %sp, -0x50(%sp)
seg000:001186AC 40 82 00 0C bne loc_1186B8
seg000:001186B0 38 60 00 01 li %r3, 1
seg000:001186B4 48 00 00 6C b exit
seg000:001186B8
seg000:001186B8 loc_1186B8: # CODE XREF: check2+28j
seg000:001186B8 48 00 03 D5 bl sub_118A8C
seg000:001186BC 60 00 00 00 nop
seg000:001186C0 3B C0 00 00 li %r30, 0
seg000:001186C4
seg000:001186C4 skip: # CODE XREF: check2+94j
seg000:001186C4 57 C0 06 3F clrlwi. %r0, %r30, 24
seg000:001186C8 41 82 00 18 beq loc_1186E0
seg000:001186CC 38 61 00 38 addi %r3, %sp, 0x50+var_18
seg000:001186D0 80 9F 00 00 lwz %r4, dword_24B704
seg000:001186D4 48 00 C0 55 bl .RBEFINDNEXT
seg000:001186D8 60 00 00 00 nop
seg000:001186DC 48 00 00 1C b loc_1186F8
seg000:001186E0
seg000:001186E0 loc_1186E0: # CODE XREF: check2+44j
seg000:001186E0 80 BF 00 00 lwz %r5, dword_24B704
seg000:001186E4 38 81 00 38 addi %r4, %sp, 0x50+var_18
seg000:001186E8 38 60 08 C2 li %r3, 0x1234
seg000:001186EC 48 00 BF 99 bl .RBEFINDFIRST
seg000:001186F0 60 00 00 00 nop
seg000:001186F4 3B C0 00 01 li %r30, 1
seg000:001186F8
seg000:001186F8 loc_1186F8: # CODE XREF: check2+58j
seg000:001186F8 54 60 04 3F clrlwi. %r0, %r3, 16
seg000:001186FC 41 82 00 0C beq must_jump
seg000:00118700 38 60 00 00 li %r3, 0 # error
seg000:00118704 48 00 00 1C b exit
seg000:00118708
seg000:00118708 must_jump: # CODE XREF: check2+78j
seg000:00118708 7F A3 EB 78 mr %r3, %r29
seg000:0011870C 48 00 00 31 bl check3
seg000:00118710 60 00 00 00 nop
seg000:00118714 54 60 06 3F clrlwi. %r0, %r3, 24
seg000:00118718 41 82 FF AC beq skip
seg000:0011871C 38 60 00 01 li %r3, 1
seg000:00118720
seg000:00118720 exit: # CODE XREF: check2+30j
seg000:00118720 # check2+80j
seg000:00118720 80 01 00 58 lwz %r0, 0x50+arg_8(%sp)
seg000:00118724 38 21 00 50 addi %sp, %sp, 0x50
seg000:00118728 83 E1 FF FC lwz %r31, var_4(%sp)
seg000:0011872C 7C 08 03 A6 mtlr %r0
seg000:00118730 83 C1 FF F8 lwz %r30, var_8(%sp)
seg000:00118734 83 A1 FF F4 lwz %r29, var_C(%sp)
seg000:00118738 4E 80 00 20 blr
seg000:00118738 # End of function check2
We are lucky again: some function names are left in the executable (debug symbols section?
Hard to say while we are not very familiar with the file format, maybe it is some kind of PE exports? (6.5.2
on page 760)),
like.RBEFINDNEXT()and.RBEFINDFIRST().
Eventuallythesefunctionscallotherfunctionswithnameslike.GetNextDeviceViaUSB(),.USBSendPKT(),
so these are clearly dealing with an USB device.
There is even a function named.GetNextEve3Device()—sounds familiar, there was a Sentinel Eve3 don-
gle for ADB port (present on Macs) in 1990s.
Let’s first take a look on how the r3 register is set before return, while ignoring everything else.
We know that a “good” r3 value has to be non-zero, zero r3 leads the execution flow to the message box
with an error message.
There are twoli %r3, 1instructions present in the function and oneli %r3, 0(Load Immediate, i.e.,