#include "config.h"
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/sysctl.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
#ifdef HAVE_STRING_H
# include <string.h>
#else
# ifdef HAVE_STRINGS_H
# include <strings.h>
# endif
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifdef HAVE_ERR_H
# include <err.h>
#else
# include "emul/err.h"
#endif
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <time.h>
#include <pwd.h>
#include <grp.h>
#include "sudo.h"
#ifndef lint
static const char rcsid[] = "$Sudo: check.c,v 1.226 2004/09/08 15:48:23 millert Exp $";
#endif
#ifdef __APPLE_MEMBERD__
#include <membership.h>
#endif
#define TS_CURRENT 0
#define TS_OLD 1
#define TS_MISSING 2
#define TS_NOFILE 3
#define TS_ERROR 4
static void build_timestamp __P((char **, char **));
static int timestamp_status __P((char *, char *, char *, int));
static char *expand_prompt __P((char *, char *, char *));
static void lecture __P((int));
static void update_timestamp __P((char *, char *));
void
check_user(override)
int override;
{
char *timestampdir = NULL;
char *timestampfile = NULL;
char *prompt;
int status;
if (user_uid == 0 || user_uid == runas_pw->pw_uid || user_is_exempt())
return;
build_timestamp(×tampdir, ×tampfile);
status = timestamp_status(timestampdir, timestampfile, user_name, TRUE);
if (override || status != TS_CURRENT) {
lecture(status);
prompt = expand_prompt(user_prompt ? user_prompt : def_passprompt,
user_name, user_shost);
verify_user(auth_pw, prompt);
}
if (status != TS_ERROR)
update_timestamp(timestampdir, timestampfile);
free(timestampdir);
if (timestampfile)
free(timestampfile);
}
static void
lecture(status)
int status;
{
FILE *fp;
char buf[BUFSIZ];
ssize_t nread;
if (def_lecture == never ||
(def_lecture == once && status != TS_MISSING && status != TS_ERROR))
return;
if (def_lecture_file && (fp = fopen(def_lecture_file, "r")) != NULL) {
while ((nread = fread(buf, sizeof(char), sizeof(buf), fp)) != 0)
fwrite(buf, nread, 1, stderr);
} else {
(void) fputs("\n\
WARNING: Improper use of the sudo command could lead to data loss\n\
or the deletion of important system files. Please double-check your\n\
typing when using sudo. Type \"man sudo\" for more information.\n\
\n\
To proceed, enter your password, or type Ctrl-C to abort.\n\n",
stderr);
}
}
static void
update_timestamp(timestampdir, timestampfile)
char *timestampdir;
char *timestampfile;
{
if (timestamp_uid != 0)
set_perms(PERM_TIMESTAMP);
if (touch(-1, timestampfile ? timestampfile : timestampdir, NULL) == -1) {
if (timestampfile) {
int fd = open(timestampfile, O_WRONLY|O_CREAT|O_TRUNC, 0600);
if (fd == -1)
log_error(NO_EXIT|USE_ERRNO, "Can't open %s", timestampfile);
else
close(fd);
} else {
if (mkdir(timestampdir, 0700) == -1)
log_error(NO_EXIT|USE_ERRNO, "Can't mkdir %s", timestampdir);
}
}
if (timestamp_uid != 0)
set_perms(PERM_ROOT);
}
static char *
expand_prompt(old_prompt, user, host)
char *old_prompt;
char *user;
char *host;
{
size_t len, n;
int subst;
char *p, *np, *new_prompt, *endp;
subst = 0;
for (p = old_prompt, len = strlen(old_prompt); *p; p++) {
if (p[0] =='%') {
switch (p[1]) {
case 'h':
p++;
len += strlen(user_shost) - 2;
subst = 1;
break;
case 'H':
p++;
len += strlen(user_host) - 2;
subst = 1;
break;
case 'u':
p++;
len += strlen(user_name) - 2;
subst = 1;
break;
case 'U':
p++;
len += strlen(*user_runas) - 2;
subst = 1;
break;
case '%':
p++;
len--;
subst = 1;
break;
default:
break;
}
}
}
if (subst) {
new_prompt = (char *) emalloc(++len);
endp = new_prompt + len;
for (p = old_prompt, np = new_prompt; *p; p++) {
if (p[0] =='%') {
switch (p[1]) {
case 'h':
p++;
n = strlcpy(np, user_shost, np - endp);
if (n >= np - endp)
goto oflow;
np += n;
continue;
case 'H':
p++;
n = strlcpy(np, user_host, np - endp);
if (n >= np - endp)
goto oflow;
np += n;
continue;
case 'u':
p++;
n = strlcpy(np, user_name, np - endp);
if (n >= np - endp)
goto oflow;
np += n;
continue;
case 'U':
p++;
n = strlcpy(np, *user_runas, np - endp);
if (n >= np - endp)
goto oflow;
np += n;
continue;
case '%':
p++;
break;
default:
break;
}
}
*np++ = *p;
if (np >= endp)
goto oflow;
}
*np = '\0';
} else
new_prompt = old_prompt;
return(new_prompt);
oflow:
errx(1, "internal error, expand_prompt() overflow");
}
int
user_is_exempt()
{
struct group *grp;
char **gr_mem;
#ifdef __APPLE_MEMBERD__
struct passwd *pw = getpwuid(getuid());
uuid_t uu, gu;
int ismember = 0;
#endif
if (!def_exempt_group)
return(FALSE);
if (!(grp = getgrnam(def_exempt_group)))
return(FALSE);
if (user_gid == grp->gr_gid)
return(TRUE);
#ifdef __APPLE_MEMBERD__
if ( 0 == mbr_uid_to_uuid(pw->pw_uid,uu) && 0 == mbr_gid_to_uuid(grp->gr_gid,gu) && 0 == mbr_check_membership(uu,gu,&ismember) ) {
if (1 == ismember) return(TRUE);
}
#else
for (gr_mem = grp->gr_mem; *gr_mem; gr_mem++) {
if (strcmp(user_name, *gr_mem) == 0)
return(TRUE);
}
#endif
return(FALSE);
}
static void
build_timestamp(timestampdir, timestampfile)
char **timestampdir;
char **timestampfile;
{
char *dirparent;
int len;
dirparent = def_timestampdir;
len = easprintf(timestampdir, "%s/%s", dirparent, user_name);
if (len >= PATH_MAX)
log_error(0, "timestamp path too long: %s", *timestampdir);
if (def_tty_tickets) {
char *p;
if ((p = strrchr(user_tty, '/')))
p++;
else
p = user_tty;
if (def_targetpw)
len = easprintf(timestampfile, "%s/%s/%s:%s", dirparent, user_name,
p, *user_runas);
else
len = easprintf(timestampfile, "%s/%s/%s", dirparent, user_name, p);
if (len >= PATH_MAX)
log_error(0, "timestamp path too long: %s", *timestampfile);
} else if (def_targetpw) {
len = easprintf(timestampfile, "%s/%s/%s", dirparent, user_name,
*user_runas);
if (len >= PATH_MAX)
log_error(0, "timestamp path too long: %s", *timestampfile);
} else
*timestampfile = NULL;
}
static int
timestamp_status(timestampdir, timestampfile, user, make_dirs)
char *timestampdir;
char *timestampfile;
char *user;
int make_dirs;
{
struct stat sb;
time_t now;
char *dirparent = def_timestampdir;
int status = TS_ERROR;
if (timestamp_uid != 0)
set_perms(PERM_TIMESTAMP);
if (lstat(dirparent, &sb) == 0) {
if (!S_ISDIR(sb.st_mode))
log_error(NO_EXIT, "%s exists but is not a directory (0%o)",
dirparent, sb.st_mode);
else if (sb.st_uid != timestamp_uid)
log_error(NO_EXIT, "%s owned by uid %lu, should be uid %lu",
dirparent, (unsigned long) sb.st_uid,
(unsigned long) timestamp_uid);
else if ((sb.st_mode & 0000022))
log_error(NO_EXIT,
"%s writable by non-owner (0%o), should be mode 0700",
dirparent, sb.st_mode);
else {
if ((sb.st_mode & 0000777) != 0700)
(void) chmod(dirparent, 0700);
status = TS_MISSING;
}
} else if (errno != ENOENT) {
log_error(NO_EXIT|USE_ERRNO, "can't stat %s", dirparent);
} else {
if (make_dirs) {
if (mkdir(dirparent, S_IRWXU))
log_error(NO_EXIT|USE_ERRNO, "can't mkdir %s",
dirparent);
else
status = TS_MISSING;
}
}
if (status == TS_ERROR) {
if (timestamp_uid != 0)
set_perms(PERM_ROOT);
return(status);
}
status = TS_ERROR;
if (lstat(timestampdir, &sb) == 0) {
if (!S_ISDIR(sb.st_mode)) {
if (S_ISREG(sb.st_mode)) {
if (unlink(timestampdir) == 0)
status = TS_MISSING;
} else
log_error(NO_EXIT, "%s exists but is not a directory (0%o)",
timestampdir, sb.st_mode);
} else if (sb.st_uid != timestamp_uid)
log_error(NO_EXIT, "%s owned by uid %lu, should be uid %lu",
timestampdir, (unsigned long) sb.st_uid,
(unsigned long) timestamp_uid);
else if ((sb.st_mode & 0000022))
log_error(NO_EXIT,
"%s writable by non-owner (0%o), should be mode 0700",
timestampdir, sb.st_mode);
else {
if ((sb.st_mode & 0000777) != 0700)
(void) chmod(timestampdir, 0700);
status = TS_OLD;
}
} else if (errno != ENOENT) {
log_error(NO_EXIT|USE_ERRNO, "can't stat %s", timestampdir);
} else
status = TS_MISSING;
if (status == TS_MISSING && timestampfile && make_dirs) {
if (mkdir(timestampdir, S_IRWXU) == -1) {
status = TS_ERROR;
log_error(NO_EXIT|USE_ERRNO, "can't mkdir %s", timestampdir);
}
}
if (timestampfile && status != TS_ERROR) {
if (status != TS_MISSING)
status = TS_NOFILE;
if (lstat(timestampfile, &sb) == 0) {
if (!S_ISREG(sb.st_mode)) {
status = TS_ERROR;
log_error(NO_EXIT, "%s exists but is not a regular file (0%o)",
timestampfile, sb.st_mode);
} else {
if (sb.st_uid != timestamp_uid) {
log_error(NO_EXIT,
"%s owned by uid %lu, should be uid %lu",
timestampfile, (unsigned long) sb.st_uid,
(unsigned long) timestamp_uid);
(void) unlink(timestampfile);
} else if ((sb.st_mode & 0000022)) {
log_error(NO_EXIT,
"%s writable by non-owner (0%o), should be mode 0600",
timestampfile, sb.st_mode);
(void) unlink(timestampfile);
} else {
if ((sb.st_mode & 0000777) != 0600)
(void) chmod(timestampfile, 0600);
status = TS_OLD;
}
}
} else if (errno != ENOENT) {
log_error(NO_EXIT|USE_ERRNO, "can't stat %s", timestampfile);
status = TS_ERROR;
}
}
if (status == TS_OLD) {
if (def_timestamp_timeout < 0 && sb.st_mtime != 0)
status = TS_CURRENT;
else {
now = time(NULL);
if (def_timestamp_timeout &&
now - sb.st_mtime < 60 * def_timestamp_timeout) {
if (sb.st_mtime > now + 60 * def_timestamp_timeout * 2) {
log_error(NO_EXIT,
"timestamp too far in the future: %20.20s",
4 + ctime(&sb.st_mtime));
if (timestampfile)
(void) unlink(timestampfile);
else
(void) rmdir(timestampdir);
status = TS_MISSING;
} else if (sb.st_mtime < timeofboot()) {
status = TS_OLD;
} else
status = TS_CURRENT;
}
}
}
if (timestamp_uid != 0)
set_perms(PERM_ROOT);
return(status);
}
void
remove_timestamp(remove)
int remove;
{
struct timespec ts;
char *timestampdir, *timestampfile, *path;
int status;
build_timestamp(×tampdir, ×tampfile);
status = timestamp_status(timestampdir, timestampfile, user_name, FALSE);
if (status == TS_OLD || status == TS_CURRENT) {
path = timestampfile ? timestampfile : timestampdir;
if (remove) {
if (timestampfile)
status = unlink(timestampfile);
else
status = rmdir(timestampdir);
if (status == -1 && errno != ENOENT) {
log_error(NO_EXIT, "can't remove %s (%s), will reset to Epoch",
path, strerror(errno));
remove = FALSE;
}
} else {
timespecclear(&ts);
if (touch(-1, path, &ts) == -1)
err(1, "can't reset %s to Epoch", path);
}
}
free(timestampdir);
if (timestampfile)
free(timestampfile);
}
int
timeofboot()
{
struct timeval boottime;
time_t timeofboot = 0;
int mib[2];
size_t size;
mib[0] = CTL_KERN;
mib[1] = KERN_BOOTTIME;
size = sizeof(boottime);
if (sysctl(mib, 2, &boottime, &size, NULL, 0) != -1 && boottime.tv_sec != 0) {
timeofboot = boottime.tv_sec;
}
return timeofboot;
}