合天网安实验室CTF练习赛之RE300

int __cdecl main(int argc, char **argv)
{
  if ( argc > 1 && check(argv[1], 0) )
  {
    puts("Access granted");
    sub_8048538(argv[1]);
  }
  else
  {
    puts("Access denied");
  }
  return 0;
}

case 0:
      if ( *argv1 == 'i' )
        goto LABEL_19;
      result = 0;
      break;

LABEL_19:
        result = check(argv1 + 1, 7 * (zero + 1) % 11);

dic = {"3":"n", "9":"r", "4":"d", "1":"e", "0":"i", "5":"a", "6":"g", "7":"s"}

start = "i"
startNum = 0

for x in xrange(1,100):
    key = 7 * (startNum + 1) % 11
    if key == 2 or key == 8 or key == 10:
        print start
        exit(0)

    start += dic[str(key)]
    startNum = key

isengard
[Finished in 0.1s]

root@giantbranch:~# ./rev300 isengard
Access granted
flag{s0me7hing_S0me7hinG_t0lki3n}