lib/libpam/modules/pam_tacplus/pam_tacplus.c

   1 /*-
   2  * Copyright 1998 Juniper Networks, Inc.
   3  * All rights reserved.
   4  * Copyright (c) 2001 Networks Associates Technology, Inc.
   5  * All rights reserved.
   6  *
   7  * Portions of this software were developed for the FreeBSD Project by
   8  * ThinkSec AS and NAI Labs, the Security Research Division of Network
   9  * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
  10  * ("CBOSS"), as part of the DARPA CHATS research program.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. The name of the author may not be used to endorse or promote
  21  *    products derived from this software without specific prior written
  22  *    permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * $FreeBSD: src/lib/libpam/modules/pam_tacplus/pam_tacplus.c,v 1.2.6.1 2002/07/03 21:41:31 des Exp $
  37  * $DragonFly: src/lib/libpam/modules/pam_tacplus/Attic/pam_tacplus.c,v 1.2 2003/06/17 04:26:51 dillon Exp $
  38  */
  39
  40 #include <sys/param.h>
  41
  42 #include <pwd.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45 #include <syslog.h>
  46 #include <taclib.h>
  47 #include <unistd.h>
  48
  49 #define PAM_SM_AUTH
  50 #define PAM_SM_ACCOUNT
  51 #define PAM_SM_SESSION
  52 #define PAM_SM_PASSWORD
  53
  54 #include <security/pam_appl.h>
  55 #include <security/pam_modules.h>
  56 #include <security/pam_mod_misc.h>
  57
  58 enum { PAM_OPT_CONF=PAM_OPT_STD_MAX, PAM_OPT_TEMPLATE_USER };
  59
  60 static struct opttab other_options[] = {
  61         { "conf",               PAM_OPT_CONF },
  62         { "template_user",      PAM_OPT_TEMPLATE_USER },
  63         { NULL, 0 }
  64 };
  65
  66 typedef int (*set_func)(struct tac_handle *, const char *);
  67
  68 static int       do_item(pam_handle_t *, struct tac_handle *, int,
  69                     set_func, const char *);
  70 static char     *get_msg(struct tac_handle *);
  71 static int       set_msg(struct tac_handle *, const char *);
  72
  73 static int
  74 do_item(pam_handle_t *pamh, struct tac_handle *tach, int item,
  75     set_func func, const char *funcname)
  76 {
  77         int retval;
  78         const void *value;
  79
  80         retval = pam_get_item(pamh, item, &value);
  81         if (retval != PAM_SUCCESS)
  82             return retval;
  83         if (value != NULL && (*func)(tach, (const char *)value) == -1) {
  84                 syslog(LOG_CRIT, "%s: %s", funcname, tac_strerror(tach));
  85                 tac_close(tach);
  86                 return PAM_SERVICE_ERR;
  87         }
  88         return PAM_SUCCESS;
  89 }
  90
  91 static char *
  92 get_msg(struct tac_handle *tach)
  93 {
  94         char *msg;
  95
  96         msg = tac_get_msg(tach);
  97         if (msg == NULL) {
  98                 syslog(LOG_CRIT, "tac_get_msg: %s", tac_strerror(tach));
  99                 tac_close(tach);
 100                 return NULL;
 101         }
 102         return msg;
 103 }
 104
 105 static int
 106 set_msg(struct tac_handle *tach, const char *msg)
 107 {
 108         if (tac_set_msg(tach, msg) == -1) {
 109                 syslog(LOG_CRIT, "tac_set_msg: %s", tac_strerror(tach));
 110                 tac_close(tach);
 111                 return -1;
 112         }
 113         return 0;
 114 }
 115
 116 PAM_EXTERN int
 117 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, int argc,
 118     const char **argv)
 119 {
 120         struct options options;
 121         int retval;
 122         struct tac_handle *tach;
 123         char *conf_file;
 124         char *template_user;
 125
 126         pam_std_option(&options, other_options, argc, argv);
 127
 128         PAM_LOG("Options processed");
 129
 130         conf_file = NULL;
 131         pam_test_option(&options, PAM_OPT_CONF, &conf_file);
 132         template_user = NULL;
 133         pam_test_option(&options, PAM_OPT_TEMPLATE_USER, &template_user);
 134
 135         tach = tac_open();
 136         if (tach == NULL) {
 137                 syslog(LOG_CRIT, "tac_open failed");
 138                 PAM_RETURN(PAM_SERVICE_ERR);
 139         }
 140         if (tac_config(tach, conf_file) == -1) {
 141                 syslog(LOG_ALERT, "tac_config: %s", tac_strerror(tach));
 142                 tac_close(tach);
 143                 PAM_RETURN(PAM_SERVICE_ERR);
 144         }
 145         if (tac_create_authen(tach, TAC_AUTHEN_LOGIN, TAC_AUTHEN_TYPE_ASCII,
 146             TAC_AUTHEN_SVC_LOGIN) == -1) {
 147                 syslog(LOG_CRIT, "tac_create_authen: %s", tac_strerror(tach));
 148                 tac_close(tach);
 149                 PAM_RETURN(PAM_SERVICE_ERR);
 150         }
 151
 152         PAM_LOG("Done tac_open() ... tac_close()");
 153
 154         retval = do_item(pamh, tach, PAM_USER, tac_set_user, "tac_set_user");
 155         if (retval != PAM_SUCCESS)
 156                 PAM_RETURN(retval);
 157
 158         PAM_LOG("Done user");
 159
 160         retval = do_item(pamh, tach, PAM_TTY, tac_set_port, "tac_set_port");
 161         if (retval != PAM_SUCCESS)
 162                 PAM_RETURN(retval);
 163
 164         PAM_LOG("Done tty");
 165
 166         retval = do_item(pamh, tach, PAM_RHOST, tac_set_rem_addr,
 167             "tac_set_rem_addr");
 168         if (retval != PAM_SUCCESS)
 169                 PAM_RETURN(retval);
 170
 171         for ( ; ; ) {
 172                 char *srvr_msg;
 173                 size_t msg_len;
 174                 const char *user_msg;
 175                 char *data_msg;
 176                 int sflags;
 177                 int status;
 178
 179                 sflags = tac_send_authen(tach);
 180                 if (sflags == -1) {
 181                         syslog(LOG_CRIT, "tac_send_authen: %s",
 182                             tac_strerror(tach));
 183                         tac_close(tach);
 184                         PAM_RETURN(PAM_AUTHINFO_UNAVAIL);
 185                 }
 186                 status = TAC_AUTHEN_STATUS(sflags);
 187                 if (!TAC_AUTHEN_NOECHO(sflags))
 188                         pam_set_option(&options, PAM_OPT_ECHO_PASS);
 189                 switch (status) {
 190
 191                 case TAC_AUTHEN_STATUS_PASS:
 192                         tac_close(tach);
 193                         if (template_user != NULL) {
 194                                 const void *item;
 195                                 const char *user;
 196
 197                                 PAM_LOG("Trying template user: %s",
 198                                     template_user);
 199
 200                                 /*
 201                                  * If the given user name doesn't exist in
 202                                  * the local password database, change it
 203                                  * to the value given in the "template_user"
 204                                  * option.
 205                                  */
 206                                 retval = pam_get_item(pamh, PAM_USER, &item);
 207                                 if (retval != PAM_SUCCESS)
 208                                         PAM_RETURN(retval);
 209                                 user = (const char *)item;
 210                                 if (getpwnam(user) == NULL) {
 211                                         pam_set_item(pamh, PAM_USER,
 212                                             template_user);
 213                                         PAM_LOG("Using template user");
 214                                 }
 215                         }
 216                         PAM_RETURN(PAM_SUCCESS);
 217
 218                 case TAC_AUTHEN_STATUS_FAIL:
 219                         tac_close(tach);
 220                         PAM_VERBOSE_ERROR("TACACS+ authentication failed");
 221                         PAM_RETURN(PAM_AUTH_ERR);
 222
 223                 case TAC_AUTHEN_STATUS_GETUSER:
 224                 case TAC_AUTHEN_STATUS_GETPASS:
 225                         if ((srvr_msg = get_msg(tach)) == NULL)
 226                                 PAM_RETURN(PAM_SERVICE_ERR);
 227                         if (status == TAC_AUTHEN_STATUS_GETUSER)
 228                                 retval = pam_get_user(pamh, &user_msg,
 229                                     srvr_msg[0] != '\0' ? srvr_msg : NULL);
 230                         else if (status == TAC_AUTHEN_STATUS_GETPASS)
 231                                 retval = pam_get_pass(pamh, &user_msg,
 232                                     srvr_msg[0] != '\0' ? srvr_msg :
 233                                     "Password:", &options);
 234                         free(srvr_msg);
 235                         if (retval != PAM_SUCCESS) {
 236                                 /* XXX - send a TACACS+ abort packet */
 237                                 tac_close(tach);
 238                                 PAM_RETURN(retval);
 239                         }
 240                         if (set_msg(tach, user_msg) == -1)
 241                                 PAM_RETURN(PAM_SERVICE_ERR);
 242                         break;
 243
 244                 case TAC_AUTHEN_STATUS_GETDATA:
 245                         if ((srvr_msg = get_msg(tach)) == NULL)
 246                                 PAM_RETURN(PAM_SERVICE_ERR);
 247                         retval = pam_prompt(pamh,
 248                             pam_test_option(&options, PAM_OPT_ECHO_PASS, NULL)
 249                                 ? PAM_PROMPT_ECHO_ON : PAM_PROMPT_ECHO_OFF,
 250                             srvr_msg[0] != '\0' ? srvr_msg : "Data:",
 251                             &data_msg);
 252                         free(srvr_msg);
 253                         if (retval != PAM_SUCCESS) {
 254                                 /* XXX - send a TACACS+ abort packet */
 255                                 tac_close(tach);
 256                                 PAM_RETURN(retval);
 257                         }
 258                         retval = set_msg(tach, data_msg);
 259                         memset(data_msg, 0, strlen(data_msg));
 260                         free(data_msg);
 261                         if (retval == -1)
 262                                 PAM_RETURN(PAM_SERVICE_ERR);
 263                         break;
 264
 265                 case TAC_AUTHEN_STATUS_ERROR:
 266                         srvr_msg = (char *)tac_get_data(tach, &msg_len);
 267                         if (srvr_msg != NULL && msg_len != 0) {
 268                                 syslog(LOG_CRIT, "tac_send_authen:"
 269                                     " server detected error: %s", srvr_msg);
 270                                 free(srvr_msg);
 271                         }
 272                         else
 273                                 syslog(LOG_CRIT,
 274                                     "tac_send_authen: server detected error");
 275                         tac_close(tach);
 276                         PAM_RETURN(PAM_AUTHINFO_UNAVAIL);
 277                         break;
 278
 279                 case TAC_AUTHEN_STATUS_RESTART:
 280                 case TAC_AUTHEN_STATUS_FOLLOW:
 281                 default:
 282                         syslog(LOG_CRIT,
 283                             "tac_send_authen: unexpected status %#x", status);
 284                         tac_close(tach);
 285                         PAM_RETURN(PAM_AUTHINFO_UNAVAIL);
 286                 }
 287         }
 288 }
 289
 290 PAM_EXTERN int
 291 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, int argc, const char **argv)
 292 {
 293         struct options options;
 294
 295         pam_std_option(&options, NULL, argc, argv);
 296
 297         PAM_LOG("Options processed");
 298
 299         PAM_RETURN(PAM_IGNORE);
 300 }
 301
 302 PAM_EXTERN int
 303 pam_sm_acct_mgmt(pam_handle_t *pamh __unused, int flags __unused, int argc ,const char **argv)
 304 {
 305         struct options options;
 306
 307         pam_std_option(&options, NULL, argc, argv);
 308
 309         PAM_LOG("Options processed");
 310
 311         PAM_RETURN(PAM_IGNORE);
 312 }
 313
 314 PAM_EXTERN int
 315 pam_sm_chauthtok(pam_handle_t *pamh __unused, int flags __unused, int argc, const char **argv)
 316 {
 317         struct options options;
 318
 319         pam_std_option(&options, NULL, argc, argv);
 320
 321         PAM_LOG("Options processed");
 322
 323         PAM_RETURN(PAM_IGNORE);
 324 }
 325
 326 PAM_EXTERN int
 327 pam_sm_open_session(pam_handle_t *pamh __unused, int flags __unused, int argc, const char **argv)
 328 {
 329         struct options options;
 330
 331         pam_std_option(&options, NULL, argc, argv);
 332
 333         PAM_LOG("Options processed");
 334
 335         PAM_RETURN(PAM_IGNORE);
 336 }
 337
 338 PAM_EXTERN int
 339 pam_sm_close_session(pam_handle_t *pamh __unused, int flags __unused, int argc, const char **argv)
 340 {
 341         struct options options;
 342
 343         pam_std_option(&options, NULL, argc, argv);
 344
 345         PAM_LOG("Options processed");
 346
 347         PAM_RETURN(PAM_IGNORE);
 348 }
 349
 350 PAM_MODULE_ENTRY("pam_tacplus");