src/modules/rlm_eap/rlm_eap.c

   1 /*
   2  * rlm_eap.c  contains handles that are called from modules.
   3  *
   4  * Version:     $Id$
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  * Copyright 2000-2003  The FreeRADIUS server project
  21  * Copyright 2001  hereUare Communications, Inc. <raghud@hereuare.com>
  22  * Copyright 2003  Alan DeKok <aland@freeradius.org>
  23  */
  24
  25 #include "autoconf.h"
  26 #include "rlm_eap.h"
  27 #include "modules.h"
  28
  29 static const char rcsid[] = "$Id$";
  30
  31 static const CONF_PARSER module_config[] = {
  32         { "default_eap_type", PW_TYPE_STRING_PTR,
  33           offsetof(rlm_eap_t, default_eap_type_name), NULL, "md5" },
  34         { "timer_expire", PW_TYPE_INTEGER,
  35           offsetof(rlm_eap_t, timer_limit), NULL, "60"},
  36         { "ignore_unknown_eap_types", PW_TYPE_BOOLEAN,
  37           offsetof(rlm_eap_t, ignore_unknown_eap_types), NULL, "no" },
  38         { "cisco_accounting_username_bug", PW_TYPE_BOOLEAN,
  39           offsetof(rlm_eap_t, cisco_accounting_username_bug), NULL, "no" },
  40
  41         { NULL, -1, 0, NULL, NULL }           /* end the list */
  42 };
  43
  44 static int eap_init(void)
  45 {
  46         return 0;
  47 }
  48
  49
  50 /*
  51  * delete all the allocated space by eap module
  52  */
  53 static int eap_detach(void *instance)
  54 {
  55         rlm_eap_t *inst;
  56         int i;
  57
  58         inst = (rlm_eap_t *)instance;
  59
  60         eaplist_free(inst);
  61
  62         for (i = 0; i < PW_EAP_MAX_TYPES; i++) {
  63                 if (inst->types[i]) eaptype_free(inst->types[i]);
  64                 inst->types[i] = NULL;
  65         }
  66
  67 #ifdef HAVE_PTHREAD_H
  68         pthread_mutex_destroy(&(inst->session_mutex));
  69         pthread_mutex_destroy(&(inst->module_mutex));
  70 #endif
  71
  72         if (inst->default_eap_type_name) free(inst->default_eap_type_name);
  73         free(inst);
  74
  75         return 0;
  76 }
  77
  78
  79 /*
  80  * read the config section and load all the eap authentication types present.
  81  */
  82 static int eap_instantiate(CONF_SECTION *cs, void **instance)
  83 {
  84         int             eap_type;
  85         int             num_types;
  86         CONF_SECTION    *scs;
  87         rlm_eap_t       *inst;
  88
  89         inst = (rlm_eap_t *) malloc(sizeof(*inst));
  90         if (!inst) {
  91                 return -1;
  92         }
  93         memset(inst, 0, sizeof(*inst));
  94         if (cf_section_parse(cs, inst, module_config) < 0) {
  95                 eap_detach(inst);
  96                 return -1;
  97         }
  98
  99         /* Load all the configured EAP-Types */
 100         num_types = 0;
 101         for(scs=cf_subsection_find_next(cs, NULL, NULL);
 102                 scs != NULL;
 103                 scs=cf_subsection_find_next(cs, scs, NULL)) {
 104
 105                 char    *auth_type;
 106
 107                 auth_type = cf_section_name1(scs);
 108
 109                 if (!auth_type)  continue;
 110
 111                 eap_type = eaptype_name2type(auth_type);
 112                 if (eap_type < 0) {
 113                         radlog(L_ERR|L_CONS, "rlm_eap: Unknown EAP type %s",
 114                                auth_type);
 115                         eap_detach(inst);
 116                         return -1;
 117                 }
 118
 119                 /*
 120                  *      If we're asked to load TTLS or PEAP, ensure
 121                  *      that we've first loaded TLS.
 122                  */
 123                 if (((eap_type == PW_EAP_TTLS) ||
 124                      (eap_type == PW_EAP_PEAP)) &&
 125                     (inst->types[PW_EAP_TLS] == NULL)) {
 126                         radlog(L_ERR, "rlm_eap: Unable to load EAP-Type/%s, as EAP-Type/TLS is required first.",
 127                                auth_type);
 128                         return -1;
 129                 }
 130
 131                 /*
 132                  *      Load the type.
 133                  */
 134                 if (eaptype_load(&inst->types[eap_type], eap_type, scs) < 0) {
 135                         eap_detach(inst);
 136                         return -1;
 137                 }
 138
 139                 num_types++;    /* successfully loaded one more types */
 140         }
 141
 142         if (num_types == 0) {
 143                 radlog(L_ERR|L_CONS, "rlm_eap: No EAP type configured, module cannot do anything.");
 144                 eap_detach(inst);
 145                 return -1;
 146         }
 147
 148         /*
 149          *      Ensure that the default EAP type is loaded.
 150          */
 151         eap_type = eaptype_name2type(inst->default_eap_type_name);
 152         if (eap_type < 0) {
 153                 radlog(L_ERR|L_CONS, "rlm_eap: Unknown default EAP type %s",
 154                        inst->default_eap_type_name);
 155                 eap_detach(inst);
 156                 return -1;
 157         }
 158
 159         if (inst->types[eap_type] == NULL) {
 160                 radlog(L_ERR|L_CONS, "rlm_eap: No such sub-type for default EAP type %s",
 161                        inst->default_eap_type_name);
 162                 eap_detach(inst);
 163                 return -1;
 164         }
 165         inst->default_eap_type = eap_type; /* save the numerical type */
 166
 167         /*
 168          *      List of sessions are set to NULL by the memset
 169          *      of 'inst', above.
 170          */
 171
 172         /* Generate a state key, specific to eap */
 173         generate_key();
 174
 175 #ifdef HAVE_PTHREAD_H
 176         pthread_mutex_init(&(inst->session_mutex), NULL);
 177         pthread_mutex_init(&(inst->module_mutex), NULL);
 178 #endif
 179
 180         *instance = inst;
 181         return 0;
 182 }
 183
 184 /*
 185  *      Dumb wrapper.
 186  *      FIXME: this should be done more intelligently...
 187  */
 188 static void my_handler_free(void *data)
 189 {
 190   EAP_HANDLER *handler = (EAP_HANDLER *) data;
 191   eap_handler_free(&handler);
 192 }
 193
 194 /*
 195  *      For backwards compatibility.
 196  */
 197 static int eap_authenticate(void *instance, REQUEST *request)
 198 {
 199         rlm_eap_t       *inst;
 200         EAP_HANDLER     *handler;
 201         eap_packet_t    *eap_packet;
 202         int             rcode;
 203 #ifdef HAVE_PTHREAD_H
 204         int             locked = FALSE;
 205 #endif
 206
 207         inst = (rlm_eap_t *) instance;
 208
 209         /*
 210          *      Get the eap packet  to start with
 211          */
 212         eap_packet = eap_attribute(request->packet->vps);
 213         if (eap_packet == NULL) {
 214                 radlog(L_ERR, "rlm_eap: Malformed EAP Message");
 215                 return RLM_MODULE_FAIL;
 216         }
 217
 218         /*
 219          *      Create the eap handler.  The eap_packet will end up being
 220          *      "swallowed" into the handler, so we can't access it after
 221          *      this call.
 222          */
 223         handler = eap_handler(inst, &eap_packet, request);
 224         if (handler == NULL) {
 225                 DEBUG2("  rlm_eap: Failed in handler");
 226                 return RLM_MODULE_INVALID;
 227         }
 228
 229         /*
 230          *      If it's a recursive request, then disallow
 231          *      TLS, TTLS, and PEAP, inside of the TLS tunnel.
 232          */
 233         if ((request->options & RAD_REQUEST_OPTION_FAKE_REQUEST) != 0) {
 234                 switch(handler->eap_ds->response->type.type) {
 235                 case PW_EAP_TLS:
 236                 case PW_EAP_TTLS:
 237                 case PW_EAP_PEAP:
 238                         DEBUG2(" rlm_eap: Unable to tunnel TLS inside of TLS");
 239                         eap_fail(handler);
 240                         eap_handler_free(&handler);
 241                         return RLM_MODULE_INVALID;
 242                         break;
 243
 244                 default:        /* It may be OK, allow it to proceed */
 245                         break;
 246
 247                 }
 248         }
 249
 250 #ifdef HAVE_PTHREAD_H
 251         else {                  /* it's a normal request from a NAS */
 252                 /*
 253                  *      The OpenSSL code isn't strictly thread-safe,
 254                  *      as we've got to provide callback functions.
 255                  *
 256                  *      Rather than doing that, we just ensure that the
 257                  *      sub-modules are locked via a mutex.
 258                  *
 259                  *      Don't lock it if we're calling ourselves recursively,
 260                  *      we've already got the lock.
 261                  */
 262                 pthread_mutex_lock(&(inst->module_mutex));
 263                 locked = TRUE;  /* for recursive calls to the module */
 264         }
 265 #endif
 266
 267         /*
 268          *      Select the appropriate eap_type or default to the
 269          *      configured one
 270          */
 271         rcode = eaptype_select(inst, handler);
 272
 273 #ifdef HAVE_PTHREAD_H
 274         if (locked) pthread_mutex_unlock(&(inst->module_mutex));
 275 #endif
 276
 277         /*
 278          *      If it failed, die.
 279          */
 280         if (rcode == EAP_INVALID) {
 281                 eap_fail(handler);
 282                 eap_handler_free(&handler);
 283                 DEBUG2("  rlm_eap: Failed in EAP select");
 284                 return RLM_MODULE_INVALID;
 285         }
 286
 287         /*
 288          *      Maybe the request was marked to be proxied.  If so,
 289          *      proxy it.
 290          */
 291         if (request->proxy != NULL) {
 292                 VALUE_PAIR *vp;
 293
 294                 rad_assert(request->proxy_reply == NULL);
 295
 296                 /*
 297                  *      Add the handle to the proxied list, so that we
 298                  *      can retrieve it in the post-proxy stage, and
 299                  *      send a response.
 300                  */
 301                 rcode = request_data_add(request,
 302                                          instance, REQUEST_DATA_EAP_HANDLER,
 303                                          handler, my_handler_free);
 304                 rad_assert(rcode == 0);
 305
 306                 /*
 307                  *      Some simple sanity checks.  These should really
 308                  *      be handled by the radius library...
 309                  */
 310                 vp = pairfind(request->proxy->vps, PW_EAP_MESSAGE);
 311                 if (vp) {
 312                         vp = pairfind(request->proxy->vps, PW_MESSAGE_AUTHENTICATOR);
 313                         if (!vp) {
 314                                 vp = pairmake("Message-Authenticator",
 315                                               "0x00", T_OP_EQ);
 316                                 rad_assert(vp != NULL);
 317                                 pairadd(&(request->proxy->vps), vp);
 318                         }
 319                 }
 320
 321                 /*
 322                  *      Delete the "proxied to" attribute, as it's
 323                  *      set to 127.0.0.1 for tunneled requests, and
 324                  *      we don't want to tell the world that...
 325                  */
 326                 pairdelete(&request->proxy->vps, PW_FREERADIUS_PROXIED_TO);
 327
 328                 return RLM_MODULE_HANDLED;
 329         }
 330
 331
 332         /*
 333          *      We are done, wrap the EAP-request in RADIUS to send
 334          *      with all other required radius attributes
 335          */
 336         rcode = eap_compose(handler);
 337
 338         /*
 339          *      Add to the list only if it is EAP-Request, OR if
 340          *      it's LEAP, and a response.
 341          */
 342         if ((handler->eap_ds->request->code == PW_EAP_REQUEST) &&
 343             (handler->eap_ds->request->type.type >= PW_EAP_MD5)) {
 344                 eaplist_add(inst, handler);
 345
 346                 /*
 347                  *      LEAP is a little different.  At Stage 4,
 348                  *      it sends an EAP-Success message, but we still
 349                  *      need to keep the State attribute & session
 350                  *      data structure around for the AP Challenge.
 351                  *
 352                  *      At stage 6, LEAP sends an EAP-Response, which
 353                  *      isn't put into the list.
 354                  */
 355         } else if ((handler->eap_ds->response->code == PW_EAP_RESPONSE) &&
 356                    (handler->eap_ds->response->type.type == PW_EAP_LEAP) &&
 357                    (handler->eap_ds->request->code == PW_EAP_SUCCESS) &&
 358                    (handler->eap_ds->request->type.type == 0)) {
 359
 360                 eaplist_add(inst, handler);
 361
 362         } else {
 363                 DEBUG2("  rlm_eap: Freeing handler");
 364                 /* handler is not required any more, free it now */
 365                 eap_handler_free(&handler);
 366         }
 367
 368         /*
 369          *      If it's an Access-Accept, RFC 2869, Section 2.3.1
 370          *      says that we MUST include a User-Name attribute in the
 371          *      Access-Accept.
 372          */
 373         if ((request->reply->code == PW_AUTHENTICATION_ACK) &&
 374             request->username) {
 375                 VALUE_PAIR *vp;
 376
 377                 /*
 378                  *      Doesn't exist, add it in.
 379                  */
 380                 vp = pairfind(request->reply->vps, PW_USER_NAME);
 381                 if (!vp) {
 382                         vp = pairmake("User-Name", request->username->strvalue,
 383                                       T_OP_EQ);
 384                         rad_assert(vp != NULL);
 385                         pairadd(&(request->reply->vps), vp);
 386                 }
 387
 388                 /*
 389                  *      Cisco AP1230 has a bug and needs a zero
 390                  *      terminated string in Access-Accept.
 391                  */
 392                 if ((inst->cisco_accounting_username_bug) &&
 393                     (vp->length < (int) sizeof(vp->strvalue))) {
 394                         vp->strvalue[vp->length] = '\0';
 395                         vp->length++;
 396                 }
 397         }
 398
 399         return rcode;
 400 }
 401
 402 /*
 403  * EAP authorization DEPENDS on other rlm authorizations,
 404  * to check for user existance & get their configured values.
 405  * It Handles EAP-START Messages, User-Name initilization.
 406  */
 407 static int eap_authorize(void *instance, REQUEST *request)
 408 {
 409         rlm_eap_t       *inst;
 410         int             status;
 411         VALUE_PAIR      *vp;
 412
 413         inst = (rlm_eap_t *)instance;
 414
 415         /*
 416          *      We don't do authorization again, once we've seen the
 417          *      proxy reply (or the proxied packet)
 418          */
 419         if (request->proxy != NULL)
 420                 return RLM_MODULE_NOOP;
 421
 422         /*
 423          *      For EAP_START, send Access-Challenge with EAP Identity
 424          *      request.  even when we have to proxy this request
 425          *
 426          *      RFC 2869, Section 2.3.1 notes that the "domain" of the
 427          *      user, (i.e. where to proxy him) comes from the EAP-Identity,
 428          *      so we CANNOT proxy the user, until we know his identity.
 429          *
 430          *      We therefore send an EAP Identity request.
 431          */
 432         status = eap_start(inst, request);
 433         switch(status) {
 434         case EAP_NOOP:
 435                 return RLM_MODULE_NOOP;
 436         case EAP_FAIL:
 437                 return RLM_MODULE_FAIL;
 438         case EAP_FOUND:
 439                 return RLM_MODULE_HANDLED;
 440         case EAP_NOTFOUND:
 441         default:
 442                 break;
 443         }
 444
 445         /*
 446          *      RFC 2869, Section 2.3.1.  If a NAS sends an EAP-Identity,
 447          *      it MUST copy the identity into the User-Name attribute.
 448          *
 449          *      But we don't worry about that too much.  We depend on
 450          *      each EAP sub-module to look for handler->request->username,
 451          *      and to get excited if it doesn't appear.
 452          */
 453
 454         vp = pairfind(request->config_items, PW_AUTH_TYPE);
 455         if ((!vp) ||
 456             (vp->lvalue != PW_AUTHTYPE_REJECT)) {
 457                 vp = pairmake("Auth-Type", "EAP", T_OP_EQ);
 458                 if (!vp) {
 459                         return RLM_MODULE_FAIL;
 460                 }
 461                 pairadd(&request->config_items, vp);
 462         }
 463
 464         return RLM_MODULE_UPDATED;
 465 }
 466
 467 /*
 468  *      If we're proxying EAP, then there may be magic we need
 469  *      to do.
 470  */
 471 static int eap_post_proxy(void *inst, REQUEST *request)
 472 {
 473         int             i, len;
 474         VALUE_PAIR      *vp;
 475         EAP_HANDLER     *handler;
 476
 477         /*
 478          *      If there was a handler associated with this request,
 479          *      then it's a tunneled request which was proxied...
 480          */
 481         handler = request_data_get(request, inst, REQUEST_DATA_EAP_HANDLER);
 482         if (handler != NULL) {
 483                 int             rcode;
 484                 eap_tunnel_data_t *data;
 485
 486                 /*
 487                  *      Grab the tunnel callbacks from the request.
 488                  */
 489                 data = (eap_tunnel_data_t *) request_data_get(request,
 490                                                               request->proxy,
 491                                                               REQUEST_DATA_EAP_TUNNEL_CALLBACK);
 492                 if (!data) {
 493                         radlog(L_ERR, "rlm_eap: Failed to retrieve callback for tunneled session!");
 494                         eap_handler_free(&handler);
 495                         return RLM_MODULE_FAIL;
 496                 }
 497
 498                 /*
 499                  *      Do the callback...
 500                  */
 501                 rcode = data->callback(handler, data->tls_session);
 502                 free(data);
 503                 if (rcode == 0) {
 504                         eap_handler_free(&handler);
 505                         return RLM_MODULE_REJECT;
 506                 }
 507
 508                 /*
 509                  *      We are done, wrap the EAP-request in RADIUS to send
 510                  *      with all other required radius attributes
 511                  */
 512                 rcode = eap_compose(handler);
 513
 514                 /*
 515                  *      Add to the list only if it is EAP-Request, OR if
 516                  *      it's LEAP, and a response.
 517                  */
 518                 if ((handler->eap_ds->request->code == PW_EAP_REQUEST) &&
 519                     (handler->eap_ds->request->type.type >= PW_EAP_MD5)) {
 520                         eaplist_add(inst, handler);
 521
 522                 } else {        /* couldn't have been LEAP, there's no tunnel */
 523                         DEBUG2("  rlm_eap: Freeing handler");
 524                         /* handler is not required any more, free it now */
 525                         eap_handler_free(&handler);
 526                 }
 527
 528                 /*
 529                  *      If it's an Access-Accept, RFC 2869, Section 2.3.1
 530                  *      says that we MUST include a User-Name attribute in the
 531                  *      Access-Accept.
 532                  */
 533                 if ((request->reply->code == PW_AUTHENTICATION_ACK) &&
 534                     request->username) {
 535                         /*
 536                          *      Doesn't exist, add it in.
 537                          */
 538                         vp = pairfind(request->reply->vps, PW_USER_NAME);
 539                         if (!vp) {
 540                                 vp = pairmake("User-Name", request->username->strvalue,
 541                                               T_OP_EQ);
 542                                 rad_assert(vp != NULL);
 543                                 pairadd(&(request->reply->vps), vp);
 544                         }
 545                 }
 546
 547                 return RLM_MODULE_OK;
 548         }
 549
 550
 551         /*
 552          *      There may be more than one Cisco-AVPair.
 553          *      Ensure we find the one with the LEAP attribute.
 554          */
 555         vp = request->proxy_reply->vps;
 556         for (;;) {
 557                 /*
 558                  *      Hmm... there's got to be a better way to
 559                  *      discover codes for vendor attributes.
 560                  *
 561                  *      This is vendor Cisco (9), Cisco-AVPair
 562                  *      attribute (1)
 563                  */
 564                 vp = pairfind(vp, (9 << 16)  | 1);
 565                 if (!vp) {
 566                         return RLM_MODULE_NOOP;
 567                 }
 568
 569                 /*
 570                  *      If it's "leap:session-key", then stop.
 571                  *
 572                  *      The format is VERY specific!
 573                  */
 574                 if (strncasecmp(vp->strvalue, "leap:session-key=", 17) == 0) {
 575                         break;
 576                 }
 577
 578                 /*
 579                  *      Not this AV-pair.  Go to the next one.
 580                  */
 581                 vp = vp->next;
 582         }
 583
 584         /*
 585          *      The format is very specific.
 586          */
 587         if (vp->length != 17 + 34) {
 588                 DEBUG2("  rlm_eap: Cisco-AVPair with leap:session-key has incorrect length %d: Expected %d",
 589                        vp->length, 17 + 34);
 590                 return RLM_MODULE_NOOP;
 591         }
 592
 593         /*
 594          *      Decrypt the session key, using the proxy data.
 595          */
 596         i = 34;                 /* starts off with 34 octets */
 597         len = rad_tunnel_pwdecode(vp->strvalue + 17, &i,
 598                                   request->proxysecret,
 599                                   request->proxy->vector);
 600
 601         /*
 602          *      FIXME: Assert that i == 16.
 603          */
 604
 605         /*
 606          *      Encrypt the session key again, using the request data.
 607          */
 608         rad_tunnel_pwencode(vp->strvalue + 17, &len,
 609                             request->secret,
 610                             request->packet->vector);
 611
 612         return RLM_MODULE_UPDATED;
 613 }
 614
 615
 616 /*
 617  *      The module name should be the only globally exported symbol.
 618  *      That is, everything else should be 'static'.
 619  */
 620 module_t rlm_eap = {
 621         "eap",
 622         RLM_TYPE_THREAD_SAFE,           /* type */
 623         eap_init,                       /* initialization */
 624         eap_instantiate,                /* instantiation */
 625         {
 626                 eap_authenticate,       /* authentication */
 627                 eap_authorize,          /* authorization */
 628                 NULL,                   /* preaccounting */
 629                 NULL,                   /* accounting */
 630                 NULL,                   /* checksimul */
 631                 NULL,                   /* pre-proxy */
 632                 eap_post_proxy,         /* post-proxy */
 633                 NULL                    /* post-auth */
 634         },
 635         eap_detach,                     /* detach */
 636         NULL,                           /* destroy */
 637 };