Reversing) 기본 C문법 리버싱 (if문, for문)

조건문

int Temp(int a) {
	int b = 1;
	if (a == 1) {
		a++;
	}
	else {
		b++;
	}
	return b;
}

int main(int argc, char* argv[]) {
	Temp(1);
}

VS_disassemble

Olly

 

반복문

int loop(int c) {
	int d = 0;
	for (int i = 0; i <= 0x100; i++) {
		if (i == c)
			break;
		printf("loop : %d\n", d);
		d++;
	}
	return c + d;
}

int main(int argc, char* argv[]) {
	loop(5);
}

int loop(int c) {
00413E10  push        ebp  
00413E11  mov         ebp,esp  
00413E13  sub         esp,0D8h  
00413E19  push        ebx  
00413E1A  push        esi  
00413E1B  push        edi  
00413E1C  lea         edi,[ebp-0D8h]  
00413E22  mov         ecx,36h  
00413E27  mov         eax,0CCCCCCCCh  
00413E2C  rep stos    dword ptr es:[edi]  
00413E2E  mov         ecx,offset _73F1974C_testconsole@cpp (041C003h)  
00413E33  call        @__CheckForDebuggerJustMyCode@4 (0411212h)  
	int d = 0;
00413E38  mov         dword ptr [d],0  
	for (int i = 0; i <= 0x100; i++) {
00413E3F  mov         dword ptr [ebp-14h],0  
00413E46  jmp         loop+41h (0413E51h)  
00413E48  mov         eax,dword ptr [ebp-14h]  
00413E4B  add         eax,1  
00413E4E  mov         dword ptr [ebp-14h],eax  
00413E51  cmp         dword ptr [ebp-14h],100h  
00413E58  jg          loop+70h (0413E80h)  
		if (i == c)
00413E5A  mov         eax,dword ptr [ebp-14h]  
00413E5D  cmp         eax,dword ptr [c]  
00413E60  jne         loop+54h (0413E64h)  
			break;
00413E62  jmp         loop+70h (0413E80h)  
		printf("loop : %d\n", d);
00413E64  mov         eax,dword ptr [d]  
00413E67  push        eax  
00413E68  push        offset string "loop : %d\n" (0417B30h)  
00413E6D  call        _printf (041104Bh)  
00413E72  add         esp,8  
		d++;
00413E75  mov         eax,dword ptr [d]  
00413E78  add         eax,1  
00413E7B  mov         dword ptr [d],eax  
	}
00413E7E  jmp         loop+38h (0413E48h)  
	return c + d;
00413E80  mov         eax,dword ptr [c]  
00413E83  add         eax,dword ptr [d]  
}
00413E86  pop         edi  
00413E87  pop         esi  
00413E88  pop         ebx  
00413E89  add         esp,0D8h  
00413E8F  cmp         ebp,esp  
00413E91  call        __RTC_CheckEsp (041121Ch)  
00413E96  mov         esp,ebp  
00413E98  pop         ebp  
00413E99  ret