cpukit/telnetd/check_passwd.c

0001 /*
0002  * Authorship
0003  * ----------
0004  * This software was created by
0005  *     Till Straumann <strauman@slac.stanford.edu>, 2003-2007
0006  *     Stanford Linear Accelerator Center, Stanford University.
0007  *
0008  * Acknowledgement of sponsorship
0009  * ------------------------------
0010  * This software was produced by
0011  *     the Stanford Linear Accelerator Center, Stanford University,
0012  *     under Contract DE-AC03-76SFO0515 with the Department of Energy.
0013  *
0014  * Government disclaimer of liability
0015  * ----------------------------------
0016  * Neither the United States nor the United States Department of Energy,
0017  * nor any of their employees, makes any warranty, express or implied, or
0018  * assumes any legal liability or responsibility for the accuracy,
0019  * completeness, or usefulness of any data, apparatus, product, or process
0020  * disclosed, or represents that its use would not infringe privately owned
0021  * rights.
0022  *
0023  * Stanford disclaimer of liability
0024  * --------------------------------
0025  * Stanford University makes no representations or warranties, express or
0026  * implied, nor assumes any liability for the use of this software.
0027  *
0028  * Stanford disclaimer of copyright
0029  * --------------------------------
0030  * Stanford University, owner of the copyright, hereby disclaims its
0031  * copyright and all other rights in this software.  Hence, anyone may
0032  * freely use it for any purpose without restriction.
0033  *
0034  * Maintenance of notices
0035  * ----------------------
0036  * In the interest of clarity regarding the origin and status of this
0037  * SLAC software, this and all the preceding Stanford University notices
0038  * are to remain affixed to any copy or derivative of this software made
0039  * or distributed by the recipient and are to be affixed to any copy of
0040  * software made or distributed by the recipient that contains a copy or
0041  * derivative of this software.
0042  *
0043  * ------------------ SLAC Software Notices, Set 4 OTT.002a, 2004 FEB 03
0044  *
0045  * Copyright (c) 2009 embedded brains GmbH & Co. KG
0046  *
0047  * The license and distribution terms for this file may be
0048  * found in the file LICENSE in this distribution or at
0049  * http://www.rtems.org/license/LICENSE.
0050  */
0051
0052 #ifdef HAVE_CONFIG_H
0053 #include "config.h"
0054 #endif
0055
0056 #include <termios.h>
0057 #include <errno.h>
0058 #include <stdio.h>
0059 #include <unistd.h>
0060 #include <stdlib.h>
0061 #include <string.h>
0062 #include <syslog.h>
0063
0064 #include <rtems/telnetd.h>
0065
0066 #include "des.h"
0067 #include <rtems/passwd.h>
0068
0069 /**
0070  * @brief Standard Telnet login check that uses DES to encrypt the passphrase.
0071  *
0072  * Takes a @a passphrase, encrypts it and compares it to the encrypted
0073  * passphrase in the @c TELNETD_PASSWD environment variable.  No password is
0074  * required if @c TELNETD_PASSWD is unset.  The argument @a user is ignored.
0075  */
0076 bool rtems_telnetd_login_check(
0077   const char *user,
0078   const char *passphrase
0079 )
0080 {
0081   char *pw = getenv( "TELNETD_PASSWD");
0082   char cryptbuf [21];
0083   char salt [3];
0084
0085   if (pw == NULL || strlen( pw) == 0) {
0086     #ifdef TELNETD_DEFAULT_PASSWD
0087       pw = TELNETD_DEFAULT_PASSWD;
0088     #else
0089       return true;
0090     #endif
0091   }
0092
0093   strncpy( salt, pw, 2);
0094   salt [2] = '\0';
0095
0096   return strcmp(
0097     __des_crypt_r( passphrase, salt, cryptbuf, sizeof( cryptbuf)),
0098     pw
0099   ) == 0;
0100 }