pwnable 소스 백업...

#include <stdio.h>
#include <stdlib.h>
#include <alloca.h>
#include <fcntl.h>
unsigned long long key;
int main(void){
        char* args[]={"/bin/sh", 0};
        int fd = open("/dev/urandom", O_RDONLY);
        if( fd==-1 || read(fd, &key, 8) != 8 ){
                printf("Error, tell admin\n");
                return 0;
        }
        close(fd);
        int i;
        fprintf(stdout, "%llu\n", key);
        execve(args[0], args, 0);
        for(i = 0;i<4;i++){
                fprintf(stdin, "\n");
                fflush(stdin);
        }
        sleep(3);
        fprintf(stdin, "%llu\n", key);
        return 0;
}