+++ /dev/null
-/*
- * Copyright (c) 1993-1996,1998-2005, 2007-2010
- * 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/param.h>
-#include <sys/time.h>
-#include <sys/stat.h>
-#ifdef __linux__
-# include <sys/vfs.h>
-#endif
-#if defined(__sun) && defined(__SVR4)
-# include <sys/statvfs.h>
-#endif
-#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 "sudo.h"
-
-/* Status codes for timestamp_status() */
-#define TS_CURRENT 0
-#define TS_OLD 1
-#define TS_MISSING 2
-#define TS_NOFILE 3
-#define TS_ERROR 4
-
-/* Flags for timestamp_status() */
-#define TS_MAKE_DIRS 1
-#define TS_REMOVE 2
-
-/*
- * Info stored in tty ticket from stat(2) to help with tty matching.
- */
-static struct tty_info {
- dev_t dev; /* ID of device tty resides on */
- dev_t rdev; /* tty device ID */
- ino_t ino; /* tty inode number */
- struct timeval ctime; /* tty inode change time */
-} tty_info;
-
-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 *));
-static int tty_is_devpts __P((const char *));
-
-/*
- * This function only returns if the user can successfully
- * verify who he/she is.
- */
-void
-check_user(validated, mode)
- int validated;
- int mode;
-{
- char *timestampdir = NULL;
- char *timestampfile = NULL;
- char *prompt;
- struct stat sb;
- int status;
-
- /* Stash the tty's ctime for tty ticket comparison. */
- if (def_tty_tickets && 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;
- if (tty_is_devpts(user_ttypath))
- ctim_get(&sb, &tty_info.ctime);
- }
-
- /* Always prompt for a password when -k was specified with the command. */
- if (ISSET(mode, MODE_INVALIDATE)) {
- SET(validated, FLAG_CHECK_USER);
- } else {
- /*
- * Don't prompt for the root passwd or if the user is exempt.
- * If the user is not changing uid/gid, no need for a password.
- */
- if (user_uid == 0 || (user_uid == runas_pw->pw_uid &&
- (!runas_gr || user_in_group(sudo_user.pw, runas_gr->gr_name))) ||
- user_is_exempt())
- return;
- }
-
- build_timestamp(×tampdir, ×tampfile);
- status = timestamp_status(timestampdir, timestampfile, user_name,
- TS_MAKE_DIRS);
-
- if (status != TS_CURRENT || ISSET(validated, FLAG_CHECK_USER)) {
- /* Bail out if we are non-interactive and a password is required */
- if (ISSET(mode, MODE_NONINTERACTIVE))
- errorx(1, "sorry, a password is required to run %s", getprogname());
-
- /* If user specified -A, make sure we have an askpass helper. */
- if (ISSET(tgetpass_flags, TGP_ASKPASS)) {
- if (user_askpass == NULL)
- log_error(NO_MAIL,
- "no askpass program specified, try setting SUDO_ASKPASS");
- } else if (!ISSET(tgetpass_flags, TGP_STDIN)) {
- /* If no tty but DISPLAY is set, use askpass if we have it. */
- if (!user_ttypath && !tty_present()) {
- if (user_askpass && user_display && *user_display != '\0') {
- SET(tgetpass_flags, TGP_ASKPASS);
- } else if (!def_visiblepw) {
- log_error(NO_MAIL,
- "no tty present and no askpass program specified");
- }
- }
- }
-
- if (!ISSET(tgetpass_flags, TGP_ASKPASS))
- lecture(status);
-
- /* Expand any escapes in the prompt. */
- prompt = expand_prompt(user_prompt ? user_prompt : def_passprompt,
- user_name, user_shost);
-
- verify_user(auth_pw, prompt);
- }
- /* Only update timestamp if user was validated. */
- if (ISSET(validated, VALIDATE_OK) && !ISSET(mode, MODE_INVALIDATE) && status != TS_ERROR)
- update_timestamp(timestampdir, timestampfile);
- efree(timestampdir);
- efree(timestampfile);
-}
-
-/*
- * Standard sudo lecture.
- */
-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);
- fclose(fp);
- } else {
- (void) fputs("\n\
-We trust you have received the usual lecture from the local System\n\
-Administrator. It usually boils down to these three things:\n\
-\n\
- #1) Respect the privacy of others.\n\
- #2) Think before you type.\n\
- #3) With great power comes great responsibility.\n\n",
- stderr);
- }
-}
-
-/*
- * Update the time on the timestamp file/dir or create it if necessary.
- */
-static void
-update_timestamp(timestampdir, timestampfile)
- char *timestampdir;
- char *timestampfile;
-{
- /* If using tty timestamps but we have no tty there is nothing to do. */
- if (timestampfile && !user_ttypath)
- return;
-
- 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_error(NO_EXIT|USE_ERRNO, "Can't open %s", timestampfile);
- else {
- lock_file(fd, SUDO_LOCK);
- write(fd, &tty_info, sizeof(tty_info));
- close(fd);
- }
- } else {
- if (touch(-1, timestampdir, NULL) == -1) {
- if (mkdir(timestampdir, 0700) == -1)
- log_error(NO_EXIT|USE_ERRNO, "Can't mkdir %s", timestampdir);
- }
- }
- if (timestamp_uid != 0)
- set_perms(PERM_ROOT);
-}
-
-/*
- * Expand %h and %u escapes in the prompt and pass back the dynamically
- * allocated result. Returns the same string if there are no escapes.
- */
-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;
-
- /* How much space do we need to malloc for the prompt? */
- 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 'p':
- p++;
- if (def_rootpw)
- len += 2;
- else if (def_targetpw || def_runaspw)
- len += strlen(runas_pw->pw_name) - 2;
- else
- len += strlen(user_name) - 2;
- subst = 1;
- break;
- case 'u':
- p++;
- len += strlen(user_name) - 2;
- subst = 1;
- break;
- case 'U':
- p++;
- len += strlen(runas_pw->pw_name) - 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 'p':
- p++;
- if (def_rootpw)
- n = strlcpy(np, "root", np - endp);
- else if (def_targetpw || def_runaspw)
- n = strlcpy(np, runas_pw->pw_name, np - endp);
- else
- n = strlcpy(np, user_name, 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, runas_pw->pw_name, np - endp);
- if (n >= np - endp)
- goto oflow;
- np += n;
- continue;
- case '%':
- /* convert %% -> % */
- p++;
- break;
- default:
- /* no conversion */
- break;
- }
- }
- *np++ = *p;
- if (np >= endp)
- goto oflow;
- }
- *np = '\0';
- } else
- new_prompt = old_prompt;
-
- return(new_prompt);
-
-oflow:
- /* We pre-allocate enough space, so this should never happen. */
- errorx(1, "internal error, expand_prompt() overflow");
-}
-
-/*
- * Checks if the user is exempt from supplying a password.
- */
-int
-user_is_exempt()
-{
- if (!def_exempt_group)
- return(FALSE);
- return(user_in_group(sudo_user.pw, def_exempt_group));
-}
-
-/*
- * Fills in timestampdir as well as timestampfile if using tty tickets.
- */
-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);
-
- /*
- * Timestamp file may be a file in the directory or NUL to use
- * the directory as the timestamp.
- */
- 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, runas_pw->pw_name);
- 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,
- runas_pw->pw_name);
- if (len >= PATH_MAX)
- log_error(0, "timestamp path too long: %s", *timestampfile);
- } else
- *timestampfile = NULL;
-}
-
-/*
- * Check the timestamp file and directory and return their status.
- */
-static int
-timestamp_status(timestampdir, timestampfile, user, flags)
- char *timestampdir;
- char *timestampfile;
- char *user;
- int flags;
-{
- struct stat sb;
- struct timeval boottime, mtime;
- time_t now;
- char *dirparent = def_timestampdir;
- int status = TS_ERROR; /* assume the worst */
-
- 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_error(NO_EXIT, "%s exists but is not a directory (0%o)",
- dirparent, (unsigned int) 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, (unsigned int) 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 {
- /* No dirparent, try to make one. */
- if (ISSET(flags, TS_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);
- }
-
- /*
- * 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_error(NO_EXIT, "%s exists but is not a directory (0%o)",
- timestampdir, (unsigned int) 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, (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_error(NO_EXIT|USE_ERRNO, "can't stat %s", timestampdir);
- } else
- status = TS_MISSING;
-
- /*
- * If there is no user ticket dir, AND we are in tty ticket mode,
- * AND the TS_MAKE_DIRS flag is set, create the user ticket dir.
- */
- if (status == TS_MISSING && timestampfile && ISSET(flags, TS_MAKE_DIRS)) {
- if (mkdir(timestampdir, S_IRWXU) == -1) {
- status = TS_ERROR;
- log_error(NO_EXIT|USE_ERRNO, "can't 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 (!user_ttypath)
- goto done; /* no tty, always prompt */
- 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, (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_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, (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 (ISSET(flags, TS_REMOVE)) {
- status = TS_OLD;
- } else if (sb.st_size != 0) {
- struct 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_error(NO_EXIT|USE_ERRNO, "can't stat %s", timestampfile);
- status = TS_ERROR;
- }
- }
-
- /*
- * If the file/dir exists and we are not removing it, check its mtime.
- */
- if (status == TS_OLD && !ISSET(flags, TS_REMOVE)) {
- mtim_get(&sb, &mtime);
- /* Negative timeouts only expire manually (sudo -k). */
- if (def_timestamp_timeout < 0 && mtime.tv_sec != 0)
- status = TS_CURRENT;
- else {
- now = time(NULL);
- 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 someone 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_error(NO_EXIT,
- "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)
- set_perms(PERM_ROOT);
- return(status);
-}
-
-/*
- * Remove the timestamp ticket file/dir.
- */
-void
-remove_timestamp(remove)
- int remove;
-{
- struct timeval tv;
- char *timestampdir, *timestampfile, *path;
- int status;
-
- build_timestamp(×tampdir, ×tampfile);
- status = timestamp_status(timestampdir, timestampfile, user_name,
- TS_REMOVE);
- 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 {
- timevalclear(&tv);
- if (touch(-1, path, &tv) == -1 && errno != ENOENT)
- error(1, "can't reset %s to Epoch", path);
- }
- }
-
- efree(timestampdir);
- efree(timestampfile);
-}
-
-/*
- * Returns TRUE if tty lives on a devpts or /devices filesystem, else FALSE.
- * Unlike most filesystems, the ctime of devpts nodes is not updated when
- * the device node is written to, only when the inode's status changes,
- * typically via the chmod, chown, link, rename, or utimes system calls.
- * Since the ctime is "stable" in this case, we can stash it the tty ticket
- * file and use it to determine whether the tty ticket file is stale.
- */
-static int
-tty_is_devpts(tty)
- const char *tty;
-{
- int retval = FALSE;
-#ifdef __linux__
- struct statfs sfs;
-
-#ifndef DEVPTS_SUPER_MAGIC
-# define DEVPTS_SUPER_MAGIC 0x1cd1
-#endif
-
- if (statfs(tty, &sfs) == 0) {
- if (sfs.f_type == DEVPTS_SUPER_MAGIC)
- retval = TRUE;
- }
-#elif defined(__sun) && defined(__SVR4)
- struct statvfs sfs;
-
- if (statvfs(tty, &sfs) == 0) {
- if (strcmp(sfs.f_fstr, "devices") == 0)
- retval = TRUE;
- }
-#endif /* __linux__ */
- return retval;
-}
projects / debian / sudo / blobdiff