2015年01月31日 check program for GHOST [長年日記]
_ check program for GHOST
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#define CANARY "in_the_coal_mine"
struct
{
char buffer[1024];
char canary[sizeof (CANARY)];
}
temp =
{
"buffer", CANARY};
int
main (void)
{
struct hostent resbuf;
struct hostent *result;
int herrno;
int retval;
/*** strlen (name) = size_needed - sizeof (*host_addr) - sizeof (*h_addr_ptrs) - 1; ***/
size_t len =
sizeof (temp.buffer) - 16 * sizeof (unsigned char) - 2 * sizeof (char *) -
1;
char name[sizeof (temp.buffer)];
memset (name, '0', len);
name[len] = '\0';
retval =
gethostbyname_r (name, &resbuf, temp.buffer, sizeof (temp.buffer),
&result, &herrno);
if (strcmp (temp.canary, CANARY) != 0)
{
puts ("vulnerable");
exit (EXIT_SUCCESS);
}
if (retval == ERANGE)
{
puts ("not vulnerable");
exit (EXIT_SUCCESS);
}
puts ("should not happen");
exit (EXIT_FAILURE);
}
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