104 lines
2.2 KiB
C
104 lines
2.2 KiB
C
/*
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** This program tests your system to see if you have the lovely
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** security-defeating semantics that an open with O_CREAT|O_EXCL
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** set will successfully open a file named by a symbolic link that
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** points to a non-existent file. Sadly, Posix is mute on what
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** should happen in this situation.
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**
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** Results to date:
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** AIX 3.2 OK
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** BSD family OK
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** BSD/OS 2.1 OK
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** FreeBSD 2.1 OK
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** DEC OSF/1 3.0 OK
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** HP-UX 9.04 FAIL
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** HP-UX 9.05 FAIL
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** HP-UX 9.07 OK
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** HP-UX 10.01 OK
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** HP-UX 10.10 OK
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** HP-UX 10.20 OK
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** Irix 5.3 OK
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** Irix 6.2 OK
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** Irix 6.3 OK
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** Irix 6.4 OK
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** Linux OK
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** NeXT 2.1 OK
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** Solaris 2.x OK
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** SunOS 4.x OK
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** Ultrix 4.3 OK
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*/
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <unistd.h>
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#ifndef lint
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static char id[] = "@(#)$Id: t_exclopen.c,v 8.5 1999/08/28 00:25:28 gshapiro Exp $";
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#endif /* ! lint */
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static char Attacker[128];
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static char Attackee[128];
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static void
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bail(status)
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int status;
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{
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(void) unlink(Attacker);
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(void) unlink(Attackee);
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exit(status);
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}
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int
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main(argc, argv)
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int argc;
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char **argv;
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{
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struct stat st;
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sprintf(Attacker, "/tmp/attacker.%d.%ld", getpid(), time(NULL));
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sprintf(Attackee, "/tmp/attackee.%d.%ld", getpid(), time(NULL));
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if (symlink(Attackee, Attacker) < 0)
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{
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printf("Could not create %s->%s symlink: %d\n",
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Attacker, Attackee, errno);
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bail(1);
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}
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(void) unlink(Attackee);
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if (stat(Attackee, &st) >= 0)
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{
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printf("%s already exists -- remove and try again.\n",
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Attackee);
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bail(1);
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}
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if (open(Attacker, O_WRONLY|O_CREAT|O_EXCL, 0644) < 0)
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{
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int save_errno = errno;
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if (stat(Attackee, &st) >= 0)
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{
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printf("Weird. Open failed but %s was created anyhow (errno = %d)\n",
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Attackee, save_errno);
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bail(1);
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}
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printf("Good show! Exclusive open works properly with symbolic links (errno = %d).\n",
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save_errno);
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bail(0);
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}
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if (stat(Attackee, &st) < 0)
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{
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printf("Weird. Open succeeded but %s was not created\n",
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Attackee);
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bail(2);
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}
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printf("Bad news: you can do an exclusive open through a symbolic link\n");
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printf("\tBe sure you #define BOGUS_O_EXCL in conf.h\n");
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bail(1);
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/* NOTREACHED */
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exit(0);
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}
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