#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>

void hackit()
{
	char *q = getenv("QUERY_STRING");
	int fd = open("hacklog.txt", O_WRONLY|O_APPEND);

	printf("You got it!\n");
	q = strchr(q, '.');
	if (!q) exit(0);

	printf("Writing to hacklog.txt:\n%s\n", q);
	write(fd, q, strlen(q)); write(fd, "\n", 2);
	exit(0);
}

void readit(char * r)
{
	char *q = getenv("QUERY_STRING");
	int i;

	if (!q) q="";
	for (i=0; q[0] && q[1]; i++, q+=2) {
		char tmp[3] = { q[0], q[1], 0 };
		r[i] = strtol(tmp, NULL, 16);
	}
	r[i] = 0;
}

int main()
{
	char result[16];

	if ( chroot(".") ) return 1;
	if ( setresgid(65534, 65534, 65534) ) return 1;
	if ( setresuid(65534, 65534, 65534) ) return 1;

	readit(result);
	printf("Content-type: text/plain\n\n");
	printf("%p\n", hackit); fflush(stdout);
	return 0;
}