代码如下
#include <stdio.h>intmain(){unsignedintrandom;random=rand();// random value!unsignedintkey=0;scanf("%d",&key);if((key^random)==0xdeadbeef){printf("Good!\n");system("/bin/cat flag");return0;}printf("Wrong, maybe you should try 2^32 cases.\n");return0;}rand()并没有真的随机化，manpage里说
If no seed value is provided, the rand() function is automatically seeded with a value of 1.
是用gdb得到这个所谓的随机值，是0x6b8b4567，所以我们输入0x6b8b4567^0xdeadbeef=3039230856就行。