[IOT安全][原创]ofo小黄车车锁逆向分析笔记

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main函数反汇编结果

int __cdecl main(int argc, const char **argv, const char **envp)
{
  int v3; // r0
  int v8; // r0
  int v10; // r0
  int v11; // r1
  int v12; // r2
  int v13; // r3
  _BYTE *v14; // r0
  unsigned __int8 v15; // r1
  int v16; // r2
  int v17; // r3
  _BYTE *v18; // r0
  int v19; // r1
  int v20; // r2
  int v21; // r3
  int v22; // r0
  int v23; // r0
  int v24; // r1
  int v25; // r2
  int v26; // r3
  char v27; // [sp+8h] [bp-10h]

  strcpy(&v27, "Start.....\n");
  MEMORY[0x40000578] = 1;
  sub_1F7F4();
  if ( sub_1D744(0, 7, 536882692, 0) )
    ((void (*)(void))loc_1D600)();
  sub_1EBB0();
  sub_1FE30();
  v10 = sub_18F94();
  sub_1E47C(v10, v11, v12, v13);
  sub_1F600();
  sub_1F6E8();
  sub_1BEB8();
  sub_1BA44();
  v14 = sub_181F2((_BYTE *)0x200029FC, 0x2Du);
  sub_1F734((int)v14, v15, v16, v17);
  sub_21DD8();
  sub_1D510();
  sub_1F1DC();
  if ( sub_1DF04(3) )
    ((void (*)(void))loc_1D600)();
  __asm { SVC     0x77 ; 'w' }
  sub_1D2DC();
  sub_18CB0();
  nullsub_1();
  if ( MEMORY[0x200020C4] )
    sub_1CCF4();
  sub_2278C();
  sub_205F4(10);
  sub_1B3AE();
  sub_205F4(10);
  sub_1B440();
  sub_205F4(10);
  sub_1FEB8();
  sub_1B3AE();
  sub_205F4(10);
  sub_20FEC(22);
  sub_20FEC(21);
  sub_19976(MEMORY[0x20002019]);
  MEMORY[0x2000209C] = 20;
  MEMORY[0x40007000] = 1;
  v18 = sub_22628();
  sub_1F814((int)v18, v19, v20, v21);
  sub_20C0C();
  sub_21460();
  if ( MEMORY[0x200020C4] == 2 )
    MEMORY[0x2000208C] -= 60;
  while ( 1 )
  {
    do
    {
      if ( MEMORY[0x20002007] == 1 || MEMORY[0x20002007] == 2 )
      {
        MEMORY[0x20002007] = 0;
        sub_1BB38(4393);
        sub_205F4(500);
        sub_1B8D0();
        MEMORY[0x20002D5C] = 0;
      }
      v22 = sub_1BF60();
      if ( v22 )
      {
        sub_1B48C();
        sub_1A448();
        if ( MEMORY[0x20002111] )
        {
          --MEMORY[0x20002111];
          sub_1BA44();
        }
        if ( MEMORY[0x200020C4] )
          ((void (*)(void))loc_19CAC)();
        else
          sub_1C7FC();
        v23 = sub_1ABB8();
        v22 = sub_1AC84(v23, v24, v25, v26);
      }
      sub_21440(v22);
    }
    while ( !MEMORY[0x20002003] );
    if ( MEMORY[0x20002003] == 1 )
      break;
    if ( MEMORY[0x20002003] == 2 && sub_199AC() != 1 )
      goto LABEL_2;
  }
  __asm { SVC     0x45 ; 'E' }
  ((void (__fastcall *)(signed int, _DWORD))loc_1D600)(255, 0);
  __asm { SVC     0x44 ; 'D' }
  ((void (__fastcall *)(signed int, _DWORD))loc_1D600)(177, 0);
  sub_21A18();
  v3 = sub_205F4(20);
  ((void (__fastcall *)(int))loc_1B858)(v3);
LABEL_2:
  __asm { SVC     0x45 ; 'E' }
  ((void (__fastcall *)(signed int, _DWORD))loc_1D600)(255, 0);
  __asm { SVC     0x44 ; 'D' }
  v8 = ((int (__fastcall *)(signed int, _DWORD))loc_1D600)(193, 0);
  ((void (__fastcall *)(int))loc_1B858)(v8);
  return sub_1CC78();
}

在把函数分隔好之后，接下来的工作是函数名称和全局变量名称的补全，这部分极其枯燥，因为最常见的方式（编译SDK例程用bindiff比较）经尝试后走不通，所以只能肉眼识别函数功能。

剩余内容稍后奉上。