insanity

文件

file: 428f6e6f75754fca8964d35b16a4b709

sha1: 2e21f5d3bd8f2af3a1bc2cc8397b75e9e0077dff

file 命令

> file 428f6e6f75754fca8964d35b16a4b709
428f6e6f75754fca8964d35b16a4b709: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux.so.2, for GNU/Linux 2.6.26, BuildID[sha1]=5b8ef7c72fce77481f4edd6802bbdb7c6100dc6e, not stripped

运行

> ./428f6e6f75754fca8964d35b16a4b709
Reticulating splines, please wait..
There aren't enough bits in my memory to represent how hard you fail.

strings 命令

> strings 428f6e6f75754fca8964d35b16a4b709| grep flag
9447{This_is_a_flag}

IDA Pro 分析

main 函数

int __cdecl main(int argc, const char **argv, const char **envp)
{
  unsigned int v3; // eax
  unsigned int v4; // eax

  puts("Reticulating splines, please wait..");
  sleep(5u);
  v3 = time(0);
  srand(v3);
  v4 = rand();
  puts((&strs)[v4 % 0xA]);
  return 0;
}

flag

9447{This_is_a_flag}