Assembly Language for Beginners

(nextflipdebug2) #1

8.6. “QR9”: RUBIK’S CUBE INSPIRED AMATEUR CRYPTO-ALGORITHM


.text:00541098 add ebx, 8
.text:0054109B cmp edi, 8
.text:0054109E jl short first_loop1_begin
.text:005410A0 lea ebx, [esp+50h+internal_array_64]
.text:005410A4 mov edi, 7 ; EDI is loop1 counter, initial state is 7
.text:005410A9
.text:005410A9 second_loop1_begin: ; CODE XREF: rotate1+57
.text:005410A9 xor esi, esi ; ESI is loop2 counter
.text:005410AB
.text:005410AB second_loop2_begin: ; CODE XREF: rotate1+4E
.text:005410AB mov al, [ebx+esi] ; value from internal array
.text:005410AE push eax
.text:005410AF push ebp ; arg_0
.text:005410B0 push edi
.text:005410B1 push esi
.text:005410B2 call set_bit
.text:005410B7 add esp, 10h
.text:005410BA inc esi ; increment loop2 counter
.text:005410BB cmp esi, 8
.text:005410BE jl short second_loop2_begin
.text:005410C0 dec edi ; decrement loop2 counter
.text:005410C1 add ebx, 8
.text:005410C4 cmp edi, 0FFFFFFFFh
.text:005410C7 jg short second_loop1_begin
.text:005410C9 pop edi
.text:005410CA pop esi
.text:005410CB pop ebp
.text:005410CC pop ebx
.text:005410CD add esp, 40h
.text:005410D0 retn
.text:005410D0 rotate1 endp
.text:005410D0
.text:005410D1 align 10h
.text:005410E0
.text:005410E0 ; =============== S U B R O U T I N E =======================================
.text:005410E0
.text:005410E0
.text:005410E0 rotate2 proc near ; CODE XREF: rotate_all_with_password+7A
.text:005410E0
.text:005410E0 internal_array_64= byte ptr -40h
.text:005410E0 arg_0 = dword ptr 4
.text:005410E0
.text:005410E0 sub esp, 40h
.text:005410E3 push ebx
.text:005410E4 push ebp
.text:005410E5 mov ebp, [esp+48h+arg_0]
.text:005410E9 push esi
.text:005410EA push edi
.text:005410EB xor edi, edi ; loop1 counter
.text:005410ED lea ebx, [esp+50h+internal_array_64]
.text:005410F1
.text:005410F1 loc_5410F1: ; CODE XREF: rotate2+2E
.text:005410F1 xor esi, esi ; loop2 counter
.text:005410F3
.text:005410F3 loc_5410F3: ; CODE XREF: rotate2+25
.text:005410F3 push esi ; loop2
.text:005410F4 push edi ; loop1
.text:005410F5 push ebp ; arg_0
.text:005410F6 call get_bit
.text:005410FB add esp, 0Ch
.text:005410FE mov [ebx+esi], al ; store to internal array
.text:00541101 inc esi ; increment loop1 counter
.text:00541102 cmp esi, 8
.text:00541105 jl short loc_5410F3
.text:00541107 inc edi ; increment loop2 counter
.text:00541108 add ebx, 8
.text:0054110B cmp edi, 8
.text:0054110E jl short loc_5410F1
.text:00541110 lea ebx, [esp+50h+internal_array_64]
.text:00541114 mov edi, 7 ; loop1 counter is initial state 7

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