/*
* Copyright (c) 1993-1996,1998-2005, 2007-2013
* Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Sponsored in part by the Defense Advanced Research Projects
* Agency (DARPA) and Air Force Research Laboratory, Air Force
* Materiel Command, USAF, under agreement number F39502-99-1-0512.
*/
#include <config.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#ifndef __TANDEM
# include <sys/file.h>
#endif
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
# include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#if TIME_WITH_SYS_TIME
# include <time.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <pwd.h>
#include <grp.h>
#include "sudoers.h"
#include "check.h"
static struct sudo_tty_info tty_info;
static char timestampdir[PATH_MAX];
static char timestampfile[PATH_MAX];
/*
* Fills in timestampdir as well as timestampfile if using tty tickets.
*/
int
build_timestamp(struct passwd *pw)
{
char *dirparent;
struct stat sb;
int len;
debug_decl(build_timestamp, SUDO_DEBUG_AUTH)
/* Stash the tty's device, session ID and ctime for ticket comparison. */
if (def_tty_tickets) {
if (user_ttypath && stat(user_ttypath, &sb) == 0) {
tty_info.dev = sb.st_dev;
tty_info.ino = sb.st_ino;
tty_info.rdev = sb.st_rdev;
tty_info.uid = sb.st_uid;
tty_info.gid = sb.st_gid;
}
tty_info.sid = user_sid;
}
dirparent = def_timestampdir;
timestampfile[0] = '\0';
len = snprintf(timestampdir, sizeof(timestampdir), "%s/%s", dirparent,
user_name);
if (len <= 0 || len >= sizeof(timestampdir))
goto bad;
/*
* Timestamp file may be a file in the directory or NUL to use
* the directory as the timestamp.
*/
if (def_tty_tickets) {
char pidbuf[sizeof("pid") + (((sizeof(pid_t) * 8) + 2) / 3)];
char *p;
if (user_ttypath == NULL) {
/* No tty, use parent pid. */
len = snprintf(pidbuf, sizeof(pidbuf), "pid%u",
(unsigned int)getppid());
if (len <= 0 || len >= sizeof(pidbuf))
goto bad;
p = pidbuf;
} else if ((p = strrchr(user_tty, '/'))) {
p++;
} else {
p = user_tty;
}
if (def_targetpw) {
len = snprintf(timestampfile, sizeof(timestampfile), "%s/%s/%s:%s",
dirparent, user_name, p, runas_pw->pw_name);
} else {
len = snprintf(timestampfile, sizeof(timestampfile), "%s/%s/%s",
dirparent, user_name, p);
}
if (len <= 0 || len >= sizeof(timestampfile))
goto bad;
} else if (def_targetpw) {
len = snprintf(timestampfile, sizeof(timestampfile), "%s/%s/%s",
dirparent, user_name, runas_pw->pw_name);
if (len <= 0 || len >= sizeof(timestampfile))
goto bad;
}
sudo_debug_printf(SUDO_DEBUG_INFO, "using timestamp file %s", timestampfile);
debug_return_int(len);
bad:
log_fatal(0, N_("timestamp path too long: %s"),
*timestampfile ? timestampfile : timestampdir);
/* NOTREACHED */
debug_return_int(-1);
}
/*
* Update the time on the timestamp file/dir or create it if necessary.
*/
bool
update_timestamp(struct passwd *pw)
{
debug_decl(update_timestamp, SUDO_DEBUG_AUTH)
if (timestamp_uid != 0)
set_perms(PERM_TIMESTAMP);
if (*timestampfile) {
/*
* Store tty info in timestamp file
*/
int fd = open(timestampfile, O_WRONLY|O_CREAT, 0600);
if (fd == -1)
log_warning(USE_ERRNO, N_("unable to open %s"), timestampfile);
else {
lock_file(fd, SUDO_LOCK);
if (write(fd, &tty_info, sizeof(tty_info)) != sizeof(tty_info))
log_warning(USE_ERRNO, N_("unable to write to %s"), timestampfile);
close(fd);
}
} else {
if (touch(-1, timestampdir, NULL) == -1) {
if (mkdir(timestampdir, 0700) == -1) {
log_warning(USE_ERRNO, N_("unable to mkdir %s"),
timestampdir);
}
}
}
if (timestamp_uid != 0)
restore_perms();
debug_return_bool(true);
}
/*
* Check the timestamp file and directory and return their status.
*/
static int
timestamp_status_internal(bool removing)
{
struct stat sb;
struct timeval boottime, mtime;
time_t now;
char *dirparent = def_timestampdir;
int status = TS_ERROR; /* assume the worst */
debug_decl(timestamp_status_internal, SUDO_DEBUG_AUTH)
if (timestamp_uid != 0)
set_perms(PERM_TIMESTAMP);
/*
* Sanity check dirparent and make it if it doesn't already exist.
* We start out assuming the worst (that the dir is not sane) and
* if it is ok upgrade the status to ``no timestamp file''.
* Note that we don't check the parent(s) of dirparent for
* sanity since the sudo dir is often just located in /tmp.
*/
if (lstat(dirparent, &sb) == 0) {
if (!S_ISDIR(sb.st_mode))
log_warning(0, N_("%s exists but is not a directory (0%o)"),
dirparent, (unsigned int) sb.st_mode);
else if (sb.st_uid != timestamp_uid)
log_warning(0, N_("%s owned by uid %u, should be uid %u"),
dirparent, (unsigned int) sb.st_uid,
(unsigned int) timestamp_uid);
else if ((sb.st_mode & 0000022))
log_warning(0,
N_("%s writable by non-owner (0%o), should be mode 0700"),
dirparent, (unsigned int) sb.st_mode);
else {
if ((sb.st_mode & 0000777) != 0700)
(void) chmod(dirparent, 0700);
status = TS_MISSING;
}
} else if (errno != ENOENT) {
log_warning(USE_ERRNO, N_("unable to stat %s"), dirparent);
} else {
/* No dirparent, try to make one. */
if (!removing) {
if (mkdir(dirparent, S_IRWXU))
log_warning(USE_ERRNO, N_("unable to mkdir %s"),
dirparent);
else
status = TS_MISSING;
}
}
if (status == TS_ERROR)
goto done;
/*
* Sanity check the user's ticket dir. We start by downgrading
* the status to TS_ERROR. If the ticket dir exists and is sane
* this will be upgraded to TS_OLD. If the dir does not exist,
* it will be upgraded to TS_MISSING.
*/
status = TS_ERROR; /* downgrade status again */
if (lstat(timestampdir, &sb) == 0) {
if (!S_ISDIR(sb.st_mode)) {
if (S_ISREG(sb.st_mode)) {
/* convert from old style */
if (unlink(timestampdir) == 0)
status = TS_MISSING;
} else
log_warning(0, N_("%s exists but is not a directory (0%o)"),
timestampdir, (unsigned int) sb.st_mode);
} else if (sb.st_uid != timestamp_uid)
log_warning(0, N_("%s owned by uid %u, should be uid %u"),
timestampdir, (unsigned int) sb.st_uid,
(unsigned int) timestamp_uid);
else if ((sb.st_mode & 0000022))
log_warning(0,
N_("%s writable by non-owner (0%o), should be mode 0700"),
timestampdir, (unsigned int) sb.st_mode);
else {
if ((sb.st_mode & 0000777) != 0700)
(void) chmod(timestampdir, 0700);
status = TS_OLD; /* do date check later */
}
} else if (errno != ENOENT) {
log_warning(USE_ERRNO, N_("unable to stat %s"), timestampdir);
} else
status = TS_MISSING;
/*
* If there is no user ticket dir, AND we are in tty ticket mode,
* AND we are not just going to remove it, create the user ticket dir.
*/
if (status == TS_MISSING && *timestampfile && !removing) {
if (mkdir(timestampdir, S_IRWXU) == -1) {
status = TS_ERROR;
log_warning(USE_ERRNO, N_("unable to mkdir %s"), timestampdir);
}
}
/*
* Sanity check the tty ticket file if it exists.
*/
if (*timestampfile && status != TS_ERROR) {
if (status != TS_MISSING)
status = TS_NOFILE; /* dir there, file missing */
if (lstat(timestampfile, &sb) == 0) {
if (!S_ISREG(sb.st_mode)) {
status = TS_ERROR;
log_warning(0, N_("%s exists but is not a regular file (0%o)"),
timestampfile, (unsigned int) sb.st_mode);
} else {
/* If bad uid or file mode, complain and kill the bogus file. */
if (sb.st_uid != timestamp_uid) {
log_warning(0,
N_("%s owned by uid %u, should be uid %u"),
timestampfile, (unsigned int) sb.st_uid,
(unsigned int) timestamp_uid);
(void) unlink(timestampfile);
} else if ((sb.st_mode & 0000022)) {
log_warning(0,
N_("%s writable by non-owner (0%o), should be mode 0600"),
timestampfile, (unsigned int) sb.st_mode);
(void) unlink(timestampfile);
} else {
/* If not mode 0600, fix it. */
if ((sb.st_mode & 0000777) != 0600)
(void) chmod(timestampfile, 0600);
/*
* Check for stored tty info. If the file is zero-sized
* it is an old-style timestamp with no tty info in it.
* If removing, we don't care about the contents.
* The actual mtime check is done later.
*/
if (removing) {
status = TS_OLD;
} else if (sb.st_size != 0) {
struct sudo_tty_info info;
int fd = open(timestampfile, O_RDONLY, 0644);
if (fd != -1) {
if (read(fd, &info, sizeof(info)) == sizeof(info) &&
memcmp(&info, &tty_info, sizeof(info)) == 0) {
status = TS_OLD;
}
close(fd);
}
}
}
}
} else if (errno != ENOENT) {
log_warning(USE_ERRNO, N_("unable to stat %s"), timestampfile);
status = TS_ERROR;
}
}
/*
* If the file/dir exists and we are not removing it, check its mtime.
*/
if (status == TS_OLD && !removing) {
mtim_get(&sb, &mtime);
if (timevalisset(&mtime)) {
/* Negative timeouts only expire manually (sudo -k). */
if (def_timestamp_timeout < 0) {
status = TS_CURRENT;
} else {
time(&now);
if (def_timestamp_timeout &&
now - mtime.tv_sec < 60 * def_timestamp_timeout) {
/*
* Check for bogus time on the stampfile. The clock may
* have been set back or user could be trying to spoof us.
*/
if (mtime.tv_sec > now + 60 * def_timestamp_timeout * 2) {
time_t tv_sec = (time_t)mtime.tv_sec;
log_warning(0,
N_("timestamp too far in the future: %20.20s"),
4 + ctime(&tv_sec));
if (*timestampfile)
(void) unlink(timestampfile);
else
(void) rmdir(timestampdir);
status = TS_MISSING;
} else if (get_boottime(&boottime) &&
timevalcmp(&mtime, &boottime, <)) {
status = TS_OLD;
} else {
status = TS_CURRENT;
}
}
}
}
}
done:
if (timestamp_uid != 0)
restore_perms();
debug_return_int(status);
}
int
timestamp_status(struct passwd *pw)
{
return timestamp_status_internal(false);
}
/*
* Remove the timestamp ticket file/dir.
*/
void
remove_timestamp(bool remove)
{
struct timeval tv;
char *path;
int status;
debug_decl(remove_timestamp, SUDO_DEBUG_AUTH)
if (build_timestamp(NULL) == -1)
debug_return;
status = timestamp_status_internal(true);
if (status != TS_MISSING && status != TS_ERROR) {
path = *timestampfile ? timestampfile : timestampdir;
if (remove) {
if (*timestampfile)
status = unlink(timestampfile);
else
status = rmdir(timestampdir);
if (status == -1 && errno != ENOENT) {
log_warning(0,
N_("unable to remove %s, will reset to the Unix epoch"),
path);
remove = false;
}
}
if (!remove) {
timevalclear(&tv);
if (touch(-1, path, &tv) == -1 && errno != ENOENT)
fatal(_("unable to reset %s to the Unix epoch"), path);
}
}
debug_return;
}
/*
* Lecture status is currently implied by the timestamp status but
* may be stored separately in a future release.
*/
bool
set_lectured(void)
{
return true;
}
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