Scott Haseley a65ddfdc81 Beefed up consoletest for new ASST2.1. In its former incarnation, there
is an easy hack to pass the test. This new version checks a little more
of the write() spec and prevents the known exploitation.
2017-02-18 23:11:29 -05:00

112 lines
3.2 KiB
C

/*
* Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
* The President and Fellows of Harvard College.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* consoletest.c
*
* Tests whether console can be written to.
*
* This should run correctly when open and write syscalls are correctly
* implemented.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <errno.h>
#include <err.h>
#include <test161/test161.h>
// 23 Mar 2012 : GWA : BUFFER_COUNT must be even.
#define STDOUT 1
#define BUFFER_SIZE 1024
#define NSEC_PER_MSEC 1000000ULL
#define MSEC_PER_SEC 1000ULL
static void *
invalid_addr(int max) {
return (void *)((0x70000000) - (random() % max));
}
static void
init_random() {
time_t sec;
unsigned long ns;
unsigned long long ms;
__time(&sec, &ns);
ms = (unsigned long long)sec * MSEC_PER_SEC;
ms += (ns / NSEC_PER_MSEC);
srandom((unsigned long)ms);
}
int
main(int argc, char **argv)
{
// 23 Mar 2012 : GWA : Assume argument passing is *not* supported.
(void) argc;
(void) argv;
int how_many, rv, i, len;
char buffer[BUFFER_SIZE];
init_random();
len = snsecprintf(BUFFER_SIZE, buffer, SECRET, "Able was i ere i saw elbA", "/testbin/consoletest");
how_many = (random() % 20) + 5;
for (i = 0; i < how_many; i++) {
rv = write(1, invalid_addr(0x1000000), len+1);
if (rv != -1) {
tprintf("Error: writing to invalid address!\n");
} else if (errno != EFAULT) {
tprintf("Error: Expected EFAULT, got %d\n", errno);
}
}
// Insert a '\0' somewhere in the secured string to thwart kprintf attack.
how_many = (random() % (len - 10)) + 5;
for (i = BUFFER_SIZE-1; i > how_many; i--) {
buffer[i] = buffer[i-1];
}
buffer[how_many] = '\0';
++len;
write(1, buffer, len);
write(1, "\n", 1);
return 0;
}