Reverse Engineering for Beginners

(avery) #1

CHAPTER 78. DONGLES CHAPTER 78. DONGLES


.data:004016B8 ; "3C"
.data:004016BC dd offset a3e ; "3E"


; these names we gave to the labels:
.data:004016C0 answers1 dd 6B05h ; DATA XREF: sys_info+E7r
.data:004016C4 dd 3D87h
.data:004016C8 answers2 dd 3Ch ; DATA XREF: sys_info+F2r
.data:004016CC dd 832h
.data:004016D0 _C_and_B db 0Ch ; DATA XREF: sys_info+BAr
.data:004016D0 ; sys_info:OKr
.data:004016D1 byte_4016D1 db 0Bh ; DATA XREF: sys_info+FDr
.data:004016D2 db 0


...


.text:0000D652 xor eax, eax
.text:0000D654 mov al, ds:ctl_port
.text:0000D659 mov ecx, _51_52_53[eax4]
.text:0000D660 push ecx
.text:0000D661 call SSQ
.text:0000D666 add esp, 4
.text:0000D669 cmp eax, 0FFFFFFFFh
.text:0000D66E jz short loc_D6D1
.text:0000D670 xor ebx, ebx
.text:0000D672 mov al, _C_and_B
.text:0000D677 test al, al
.text:0000D679 jz short loc_D6C0
.text:0000D67B
.text:0000D67B loc_D67B: ; CODE XREF: sys_info+106j
.text:0000D67B mov eax, _3C_or_3E[ebx
4]
.text:0000D682 push eax
.text:0000D683 call SSQ
.text:0000D688 push offset a4g ; "4G"
.text:0000D68D call SSQ
.text:0000D692 push offset a0123456789 ; "0123456789"
.text:0000D697 call SSQ
.text:0000D69C add esp, 0Ch
.text:0000D69F mov edx, answers1[ebx4]
.text:0000D6A6 cmp eax, edx
.text:0000D6A8 jz short OK
.text:0000D6AA mov ecx, answers2[ebx
4]
.text:0000D6B1 cmp eax, ecx
.text:0000D6B3 jz short OK
.text:0000D6B5 mov al, byte_4016D1[ebx]
.text:0000D6BB inc ebx
.text:0000D6BC test al, al
.text:0000D6BE jnz short loc_D67B
.text:0000D6C0
.text:0000D6C0 loc_D6C0: ; CODE XREF: sys_info+C1j
.text:0000D6C0 inc ds:ctl_port
.text:0000D6C6 xor eax, eax
.text:0000D6C8 mov al, ds:ctl_port
.text:0000D6CD cmp eax, edi
.text:0000D6CF jle short loc_D652
.text:0000D6D1
.text:0000D6D1 loc_D6D1: ; CODE XREF: sys_info+98j
.text:0000D6D1 ; sys_info+B6j
.text:0000D6D1 mov edx, [ebp+var_8]
.text:0000D6D4 inc edx
.text:0000D6D5 mov [ebp+var_8], edx
.text:0000D6D8 cmp edx, 3
.text:0000D6DB jle loc_D641
.text:0000D6E1
.text:0000D6E1 loc_D6E1: ; CODE XREF: sys_info+16j
.text:0000D6E1 ; sys_info+51j ...
.text:0000D6E1 pop ebx
.text:0000D6E2 pop edi
.text:0000D6E3 mov esp, ebp
.text:0000D6E5 pop ebp
.text:0000D6E6 retn

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