login_passwd/login.c

   1 /*      $OpenBSD: login.c,v 1.18 2018/06/13 15:02:09 reyk Exp $ */
   2
   3 /*-
   4  * Copyright (c) 1995 Berkeley Software Design, Inc. All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by Berkeley Software Design,
  17  *      Inc.
  18  * 4. The name of Berkeley Software Design, Inc.  may not be used to endorse
  19  *    or promote products derived from this software without specific prior
  20  *    written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN, INC. ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN, INC. BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      BSDI $From: login_passwd.c,v 1.11 1997/08/08 18:58:24 prb Exp $
  35  */
  36
  37 #include "common.h"
  38
  39 FILE *back = NULL;
  40
  41 int
  42 main(int argc, char **argv)
  43 {
  44         int opt, mode = 0, ret, lastchance = 0;
  45         char *username, *password = NULL;
  46         char pbuf[1024];
  47         char response[1024];
  48         int arg_login = 0, arg_notickets = 0;
  49         char invokinguser[LOGIN_NAME_MAX];
  50         char *wheel = NULL, *class = NULL;
  51 #ifdef PASSWD
  52         struct passwd *pwd, *pwd_save;
  53 #endif
  54
  55         invokinguser[0] = '\0';
  56
  57         setpriority(PRIO_PROCESS, 0, 0);
  58
  59         openlog(NULL, LOG_ODELAY, LOG_AUTH);
  60
  61         while ((opt = getopt(argc, argv, "ds:v:")) != -1) {
  62                 switch (opt) {
  63                 case 'd':
  64                         back = stdout;
  65                         break;
  66                 case 's':       /* service */
  67                         if (strcmp(optarg, "login") == 0)
  68                                 mode = MODE_LOGIN;
  69                         else if (strcmp(optarg, "challenge") == 0)
  70                                 mode = MODE_CHALLENGE;
  71                         else if (strcmp(optarg, "response") == 0)
  72                                 mode = MODE_RESPONSE;
  73                         else {
  74                                 syslog(LOG_ERR, "%s: invalid service", optarg);
  75                                 exit(1);
  76                         }
  77                         break;
  78                 case 'v':
  79                         if (strncmp(optarg, "wheel=", 6) == 0)
  80                                 wheel = optarg + 6;
  81                         else if (strncmp(optarg, "lastchance=", 11) == 0)
  82                                 lastchance = (strcmp(optarg + 11, "yes") == 0);
  83                         else if (strcmp(optarg, "login=yes") == 0)
  84                                 arg_login = 1;
  85                         else if (strcmp(optarg, "notickets=yes") == 0)
  86                                 arg_notickets = 1;
  87                         else if (strncmp(optarg, "invokinguser=", 13) == 0)
  88                                 snprintf(invokinguser, sizeof(invokinguser),
  89                                     "%s", &optarg[13]);
  90                         /* Silently ignore unsupported variables */
  91                         break;
  92                 default:
  93                         syslog(LOG_ERR, "usage error1");
  94                         exit(1);
  95                 }
  96         }
  97
  98         switch (argc - optind) {
  99         case 2:
 100                 class = argv[optind + 1];
 101                 /*FALLTHROUGH*/
 102         case 1:
 103                 username = argv[optind];
 104                 break;
 105         default:
 106                 syslog(LOG_ERR, "usage error2");
 107                 exit(1);
 108         }
 109
 110 #ifdef PASSWD
 111         /* get the password hash before pledge(2) or it will return '*' */
 112         pwd = getpwnam_shadow(username);
 113         if (pwd == NULL || (pwd_save = pw_dup(pwd)) == NULL)
 114                 exit(1);
 115 #endif
 116
 117         if ((arg_login) && (!arg_notickets)) {
 118                 if (pledge("stdio rpath tty id getpw dns inet flock cpath wpath chown", NULL) == -1) {
 119                         syslog(LOG_ERR, "pledge: %m");
 120                         exit(1);
 121                 }
 122         } else {
 123                 if (pledge("stdio rpath tty id getpw dns inet flock", NULL) == -1) {
 124                         syslog(LOG_ERR, "pledge: %m");
 125                         exit(1);
 126                 }
 127         }
 128
 129         if (back == NULL && (back = fdopen(3, "r+")) == NULL) {
 130                 syslog(LOG_ERR, "reopening back channel: %m");
 131                 exit(1);
 132         }
 133
 134         /*
 135          * Read password, either as from the terminal or if the
 136          * response mode is active from the caller program.
 137          *
 138          * XXX  This is completely ungrokkable, and should be rewritten.
 139          */
 140         switch (mode) {
 141         case MODE_RESPONSE: {
 142                 int count;
 143                 mode = 0;
 144                 count = -1;
 145                 while (++count < sizeof(response) &&
 146                     read(3, &response[count], 1) == 1) {
 147                         if (response[count] == '\0' && ++mode == 2)
 148                                 break;
 149                         if (response[count] == '\0' && mode == 1) {
 150                                 password = response + count + 1;
 151                         }
 152                 }
 153                 if (mode < 2) {
 154                         syslog(LOG_ERR, "protocol error on back channel");
 155                         exit(1);
 156                 }
 157                 break;
 158         }
 159
 160         case MODE_LOGIN:
 161                 password = readpassphrase("Password:", pbuf, sizeof(pbuf), RPP_ECHO_OFF);
 162                 break;
 163         case MODE_CHALLENGE:
 164                 fprintf(back, BI_SILENT "\n");
 165                 exit(0);
 166                 break;
 167         default:
 168                 syslog(LOG_ERR, "%d: unknown mode", mode);
 169                 exit(1);
 170                 break;
 171         }
 172
 173         ret = AUTH_FAILED;
 174         ret = krb5_login(username, invokinguser, password, arg_login,
 175                          !arg_notickets, class);
 176 #ifdef PASSWD
 177         if (ret != AUTH_OK)
 178                 ret = pwd_login(username, password, wheel, lastchance, class, pwd_save);
 179         free (pwd_save);
 180 #endif
 181
 182         if (password != NULL)
 183                 explicit_bzero(password, strlen(password));
 184         if (ret != AUTH_OK)
 185                 fprintf(back, BI_REJECT "\n");
 186
 187         closelog();
 188
 189         exit(0);
 190 }