Code that checks for mod7 in Windows95 product key check function in setupx.dll

95mod7check.c

//reversed by x64mayhem for educational purpose only.

bool __cdecl16far MOD7check(char *param_1,undefined2 param_2)
{
  int IndexCounter;
  int SUM;
  char character;
  
  IndexCounter = 0;
  SUM = 0;
  while( true ) {
    character = *param_1;
    if ((character < '0') || ('9' < character)) break;
                    /* Convert Char to Int ?? */
    SUM = SUM + character + -48;
    IndexCounter = IndexCounter + 1;
    param_1 = param_1 + 1;
    if (6 < IndexCounter) {
      return SUM % 7 == 0;
    }
  }
  return false;
}