Reverse Engineering for Beginners

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CHAPTER 79. “QR9”: RUBIK’S CUBE INSPIRED AMATEUR CRYPTO-ALGORITHM CHAPTER 79. “QR9”: RUBIK’S CUBE INSPIRED AMATEUR CRYPTO-ALGORITHM


.text:005412A3 pop edi
.text:005412A4 pop esi
.text:005412A5 pop ebp
.text:005412A6 pop ebx
.text:005412A7 retn
.text:005412A7 crypt endp
.text:005412A7
.text:005412A8 align 10h
.text:005412B0
.text:005412B0 ; =============== S U B R O U T I N E =======================================
.text:005412B0
.text:005412B0
.text:005412B0 ; int __cdecl decrypt(int, int, void Src)
.text:005412B0 decrypt proc near ; CODE XREF: decrypt_file+99
.text:005412B0
.text:005412B0 arg_0 = dword ptr 4
.text:005412B0 arg_4 = dword ptr 8
.text:005412B0 Src = dword ptr 0Ch
.text:005412B0
.text:005412B0 mov eax, [esp+Src]
.text:005412B4 push ebx
.text:005412B5 push ebp
.text:005412B6 push esi
.text:005412B7 push edi
.text:005412B8 push eax ; Src
.text:005412B9 call strdup
.text:005412BE push eax ; Str
.text:005412BF mov [esp+18h+Src], eax
.text:005412C3 call
strrev
.text:005412C8 mov ebx, [esp+18h+arg_0]
.text:005412CC add esp, 8
.text:005412CF xor ebp, ebp
.text:005412D1
.text:005412D1 loc_5412D1: ; CODE XREF: decrypt+58
.text:005412D1 mov ecx, 10h
.text:005412D6 mov esi, ebx
.text:005412D8 mov edi, offset cube64
.text:005412DD push 3
.text:005412DF rep movsd
.text:005412E1 mov ecx, [esp+14h+Src]
.text:005412E5 push ecx
.text:005412E6 call rotate_all_with_password
.text:005412EB mov eax, [esp+18h+arg_4]
.text:005412EF mov edi, ebx
.text:005412F1 add ebp, 40h
.text:005412F4 add esp, 8
.text:005412F7 mov ecx, 10h
.text:005412FC mov esi, offset cube64
.text:00541301 add ebx, 40h
.text:00541304 cmp ebp, eax
.text:00541306 rep movsd
.text:00541308 jl short loc_5412D1
.text:0054130A mov edx, [esp+10h+Src]
.text:0054130E push edx ; Memory
.text:0054130F call _free
.text:00541314 add esp, 4
.text:00541317 pop edi
.text:00541318 pop esi
.text:00541319 pop ebp
.text:0054131A pop ebx
.text:0054131B retn
.text:0054131B decrypt endp
.text:0054131B
.text:0054131C align 10h
.text:00541320
.text:00541320 ; =============== S U B R O U T I N E =======================================
.text:00541320
.text:00541320
.text:00541320 ; int __cdecl crypt_file(int Str, char
Filename, int password)
.text:00541320 crypt_file proc near ; CODE XREF: _main+42

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