使用IDA破解TraceMe.exe

我发现用IDA破解TraceMe.exe比ODeasy多了。

打开IDA 后。直接搜索“序列号”。得到

双击跳转到反汇编窗体，按F5转换为类C++代码

signed int __stdcall DialogFunc(HWND hWnd, int a2, unsigned __int16 a3, int a4)

{

  signed int v5; // ebx@9

  int v6; // eax@11

  HWND v7; // eax@12

  HWND v8; // eax@12

  HWND v9; // eax@12

  HICON v10; // eax@20

  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, "你输入字符要大于四个。", 0x14u);

  v17 = *(_WORD *)"！";

  v12 = dword_405054;

  v18 = aUFIKGb[22];

  v15 = byte_40505E;

  memcpy(&v19, "序列号错误。再来一次！", 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, 110, 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, 110, &String, 81);//username

  GetDlgItemTextA(hWnd, 1000, (LPSTR)&String1, 101);//序列号

  if ( String && v5 >= 5 )//推断输入的username长度是不是大于5

  {

    LOBYTE(v6) = sub_401340(&String1, &String, v5);//此函数依据username生成序列号。并与输入的序列号进行比較

    if ( v6 )//v6==1，表示username和序列号匹配

    {

      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长度小于5。提示“你输入字符要大于四个”

    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; // ecx@1

  int v4; // esi@1

  signed int i; // eax@1





  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[]数组在.data区：

char byte_405030[8]={0x0C,0x0A,0x13,0x09,0x0C,0x0B,0x0A,0x08}

假如我输入username为：tanyo

v4=121*12+111*10=2562

输入usernametanyo，序列号2562进行验证：