Using Ida to crack TraceMe.exe

I find it much easier to hack TraceMe.exe with Ida than OD.

After opening Ida, search directly for "serial number" to get

Double-click to jump to Disassembly window, press F5 to convert to Class C + + code

Signed int __stdcall Dialogfunc (HWND hwnd, int A2, unsigned __int16 A3, int A4)
{
signed int v5; [Email protected]
int V6; [Email protected]
HWND V7; [Email protected]
HWND V8; [Email protected]
HWND V9; [Email protected]
Hicon V10; [Email protected]
Const CHAR STRING2[4]; [SP+8H] [bp-f4h]@1
int V12; [Sp+ch] [bp-f0h]@1
int v13; [SP+10H] [bp-ech]@1
__int16 V14; [SP+14H] [bp-e8h]@1
Char V15; [SP+16H] [bp-e6h]@1
Char V16; [sp+18h] [bp-e4h]@1
__int16 v17; [SP+2CH] [bp-d0h]@1
Char v18; [Sp+2eh] [bp-ceh]@1
Char v19; [sp+30h] [bp-cch]@1
__int16 V20; [SP+44H] [bp-b8h]@1
Char v21; [SP+46H] [bp-b6h]@1
CHAR String; [sp+48h] [bp-b4h]@9
Const CHAR STRING1; [SP+98H] [bp-64h]@9


memcpy (&v16, "you enter more than four characters! ", 0x14u);
v17 = * (_word *) "! ";
V12 = dword_405054;
V18 = aufikgb[22];
V15 = byte_40505e;
memcpy (&v19, "Serial number is wrong, come again!") ", 0x14u);
* (_dword *) String2 = dword_405050;
V20 = * (_word *) "! ";
V14 = word_40505c;
V13 = dword_405058;
V21 = aagmgb[22];
if (a2 = = 16)
{
DestroyWindow (HWND);
return 1;
}
if (a2 = = 272)
{
v10 = Loadicona (HInstance, (LPCSTR) 0x70);
SendMessageA (HWnd, 0x80u, 1u, (LPARAM) V10);
Senddlgitemmessagea (HWnd, 0xc5u, 0x50u, 0);
return 1;
}
if (a2! = 273)
return 0;
if ((signed int) A3 > 1013)
{
if (a3 = = 1014 | | a3 = = 40002)
Dialogboxparama (HInstance, (LPCSTR) 0x67, hWnd, sub_401020, 0);
return 0;
}
if (a3! = 1013)
{
if (a3 = = 2 | | a3 = = 1002)
{
SendMessageA (hWnd, 0x10u, 0, 0);
return 0;
}
return 0;
}
V5 = Getdlgitemtexta (HWnd, &string, 81);//username
Getdlgitemtexta (HWnd, LPSTR, &STRING1, 101);//serial number
if (String && v5 >= 5)//Determine if the input username length is greater than 5
{
Lobyte (v6) = sub_401340 (&string1, &string, V5);//This function generates serial numbers based on user name and is compared with the serial number entered
if (V6)//v6==1, indicating user name and serial number match
{
Lstrcpya (:: String1, String2);
V7 = GetDlgItem (hWnd, 110);
EnableWindow (V7, 0);
V8 = GetDlgItem (hWnd, 1000);
EnableWindow (V8, 0);
V9 = GetDlgItem (hWnd, 1000);
}
Else
{
Lstrcpya (:: String1, &v19);
V9 = GetDlgItem (hWnd, 1000);
}
}
Else
{
Lstrcpya (:: String1, &v16);//username is less than 5, prompting "You must enter more than four characters"
V9 = GetDlgItem (hWnd, 110);
}
SetFocus (V9);
MessageBeep (0);
Dialogboxparama (HInstance, (LPCSTR) 0x79, hWnd, sub_401060, 0);
return 0;
}

BOOL __cdecl sub_401340 (LPCSTR lpString1, LPSTR lpString2, signed int A3)
{
signed int v3; [Email protected]
int v4; [Email protected]
signed int i; [Email protected]


V3 = 3;
V4 = 0;
for (i = 0; v3 < A3; ++i)
{
if (i > 7)
i = 0;
V4 + = (unsigned __int8) byte_405030[i] * (unsigned __int8) lpstring2[v3++];
}
WSPRINTFA (LpString2, "%ld", V4);
Return Lstrcmpa (lpString1, lpString2) = = 0;
}

Byte_405030[] Array in the. Data area:

Char byte_405030[8]={0x0c,0x0a,0x13,0x09,0x0c,0x0b,0x0a,0x08}

If I enter the user name: Tanyo

v4=121*12+111*10=2562

Enter user name Tanyo, serial number 2562 for verification:

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

Using Ida to crack TraceMe.exe