Files
sudo/check.c
Todd C. Miller 958ee39a64 Initial revision
1993-06-11 22:03:45 +00:00

277 lines
6.9 KiB
C

/*
* sudo version 1.1 allows users to execute commands as root
* Copyright (C) 1991 The Root Group, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 1, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* If you make modifications to the source, we would be happy to have
* them to include in future releases. Feel free to send them to:
* Jeff Nieusma nieusma@rootgroup.com
* 3959 Arbol CT (303) 447-8093
* Boulder, CO 80301-1752
*
*******************************************************************
*
* check.c
*
* check_user() only returns if the user's timestamp file
* is current or if they enter a correct password.
*
* Jeff Nieusma Thu Mar 21 22:39:07 MST 1991
*/
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <fcntl.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/file.h>
#include <pwd.h>
#include "sudo.h"
char *getpass();
static int check_timestamp();
static void check_passwd();
static void update_timestamp();
static void reminder();
static char *timestampfile_p;
static int timedir_is_good;
/********************************************************************
*
* check_user()
*
* This function only returns if the user can successfully
* verify who s/he is.
*/
void check_user()
{
register int rtn;
umask ( 077 ); /* make sure the timestamp files are private */
if ( setuid (0) ) { /* have to be root to see timestamps */
perror("setuid(0)");
exit(1);
}
rtn = check_timestamp();
if ( setruid (uid) ) { /* don't want to be root longer than necessary */
#ifndef _AIX
perror("setruid(uid)");
exit(1);
#endif
}
if ( rtn && uid ) /* if timestamp is not current... */
check_passwd();
if ( setuid (0) ) { /* have to be root to play with timestamps */
perror("setuid(0)");
exit(1);
}
update_timestamp();
if ( setruid (uid) ) { /* don't want to be root longer than necessary */
#ifndef _AIX
perror("setruid(uid)");
exit(1);
#endif
}
umask ( 022 ); /* want a real umask to exec() the command */
}
/********************************************************************
*
* check_timestamp()
*
* this function checks the timestamp file. If it is within
* TIMEOUT minutes, no password will be required
*/
static int check_timestamp()
{
static char timestampfile[MAXPATHLEN+1];
register char *p;
struct stat statbuf;
register int timestamp_is_old = -1;
time_t now;
sprintf ( timestampfile, "%s/%s", TIMEDIR, user );
timestampfile_p = timestampfile;
timedir_is_good = 1; /* now there's an assumption for ya... */
/* walk through the path one directory at a time */
for ( p=timestampfile+1; p=index(p,'/'); *p++='/' ) {
*p='\0';
if ( stat(timestampfile,&statbuf) < 0) {
if ( strcmp ( timestampfile, TIMEDIR ))
fprintf ( stderr, "Cannot stat() %s\n", timestampfile );
timedir_is_good = 0;
*p='/';
break;
}
}
if ( timedir_is_good ) { /* if all the directories are stat()able */
if ( stat(timestampfile, &statbuf) ) { /* does the file exist? */
if ( uid ) reminder(); /* if not, do the reminder */
timestamp_is_old=1; /* and return (1) */
}
else { /* otherwise, check the time */
now = time ( (time_t *) NULL );
if ( now - statbuf.st_mtime < 60 * TIMEOUT )
timestamp_is_old = 0; /* if file is recent, return(0) */
else
timestamp_is_old = 1; /* else make 'em enter password */
}
}
/* there was a problem stat()ing a directory */
else {
timestamp_is_old = 1; /* user has to enter password */
if ( mkdir (TIMEDIR, 0700 ) ) { /* make the TIMEDIR directory */
perror("check_timestamp: mkdir");
timedir_is_good = 0;
}
else {
timedir_is_good = 1; /* TIMEDIR now exists */
reminder();
}
}
return (timestamp_is_old);
}
/********************************************************************
*
* update_timestamp()
*
* This function changes the timestamp to now
*/
static void update_timestamp()
{
register int fd;
if ( timedir_is_good ) {
unlink ( timestampfile_p );
if (( fd = open (timestampfile_p, O_WRONLY|O_CREAT|O_TRUNC, 0600 )) < 0 )
perror( "update_timestamp: open" );
close (fd);
}
}
/********************************************************************
*
* check_passwd()
*
* This function grabs the user's password and checks with
* the password in /etc/passwd
*/
static void check_passwd()
{
char *crypt();
struct passwd *pw_ent;
char *encrypted; /* this comes from /etc/passwd */
char *pass; /* this is what gets entered */
register int counter=TRIES_FOR_PASSWORD;
if ( (pw_ent = getpwuid( uid )) == NULL ) {
sprintf ( user, "%u", uid );
log_error( GLOBAL_NO_PW_ENT );
inform_user ( GLOBAL_NO_PW_ENT );
exit (1);
}
encrypted = pw_ent -> pw_passwd;
/* you get TRIES_FOR_PASSWORD times to guess your password */
while ( counter > 0 ) {
pass = getpass ( "Password:" );
if ( *pass == (char)NULL ) exit(0);
if ( !strcmp(encrypted, crypt(pass,encrypted)))
return; /* if the passwd is correct return() */
-- counter; /* otherwise, try again */
fprintf ( stderr, "%s\n", INCORRECT_PASSWORD );
}
log_error( PASSWORD_NOT_CORRECT );
inform_user ( PASSWORD_NOT_CORRECT );
exit (1);
}
/********************************************************************
*
* reminder()
*
* this function just prints the the reminder message
*/
static void reminder()
{
#ifdef SHORT_MESSAGE
fprintf(stderr,"\n%s\n%s\n\n%s\n%s\n\n",
#else
fprintf(stderr,"\n%s\n%s\n%s\n\n%s\n%s\n\n%s\n%s\n\n",
" sudo version 1.1, Copyright (C) 1991 The Root Group, Inc.",
" sudo comes with ABSOLUTELY NO WARRANTY. This is free software,",
" and you are welcome to redistribute it under certain conditions.",
#endif
"We trust you have received the usual lecture from the local Systems",
"Administrator. It usually boils down to these two things:",
" #1) Respect the privacy of others.",
" #2) Think before you type."
);
}