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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * Copyright 2000-2003,2006  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 <freeradius-devel/ident.h>
  26 RCSID("$Id$")
  27
  28 #include <freeradius-devel/radiusd.h>
  29 #include <freeradius-devel/modules.h>
  30
  31 #include "rlm_eap.h"
  32
  33 static const CONF_PARSER module_config[] = {
  34         { "default_eap_type", PW_TYPE_STRING_PTR,
  35           offsetof(rlm_eap_t, default_eap_type_name), NULL, "md5" },
  36         { "timer_expire", PW_TYPE_INTEGER,
  37           offsetof(rlm_eap_t, timer_limit), NULL, "60"},
  38         { "ignore_unknown_eap_types", PW_TYPE_BOOLEAN,
  39           offsetof(rlm_eap_t, ignore_unknown_eap_types), NULL, "no" },
  40         { "cisco_accounting_username_bug", PW_TYPE_BOOLEAN,
  41           offsetof(rlm_eap_t, cisco_accounting_username_bug), NULL, "no" },
  42
  43         { NULL, -1, 0, NULL, NULL }           /* end the list */
  44 };
  45
  46 /*
  47  * delete all the allocated space by eap module
  48  */
  49 static int eap_detach(void *instance)
  50 {
  51         rlm_eap_t *inst;
  52         int i;
  53
  54         inst = (rlm_eap_t *)instance;
  55
  56         rbtree_free(inst->session_tree);
  57         inst->session_tree = NULL;
  58         eaplist_free(inst);
  59
  60         for (i = 0; i < PW_EAP_MAX_TYPES; i++) {
  61                 if (inst->types[i]) eaptype_free(inst->types[i]);
  62                 inst->types[i] = NULL;
  63         }
  64
  65         pthread_mutex_destroy(&(inst->session_mutex));
  66
  67         free(inst);
  68
  69         return 0;
  70 }
  71
  72
  73 /*
  74  *      Compare two handlers.
  75  */
  76 static int eap_handler_cmp(const void *a, const void *b)
  77 {
  78         int rcode;
  79         const EAP_HANDLER *one = a;
  80         const EAP_HANDLER *two = b;
  81
  82         if (one->eap_id < two->eap_id) return -1;
  83         if (one->eap_id > two->eap_id) return +1;
  84
  85         rcode = fr_ipaddr_cmp(&one->src_ipaddr, &two->src_ipaddr);
  86         if (rcode != 0) return rcode;
  87
  88         return memcmp(one->state, two->state, sizeof(one->state));
  89 }
  90
  91
  92 /*
  93  * read the config section and load all the eap authentication types present.
  94  */
  95 static int eap_instantiate(CONF_SECTION *cs, void **instance)
  96 {
  97         int             i, eap_type;
  98         int             num_types;
  99         CONF_SECTION    *scs;
 100         rlm_eap_t       *inst;
 101
 102         inst = (rlm_eap_t *) malloc(sizeof(*inst));
 103         if (!inst) {
 104                 return -1;
 105         }
 106         memset(inst, 0, sizeof(*inst));
 107         if (cf_section_parse(cs, inst, module_config) < 0) {
 108                 eap_detach(inst);
 109                 return -1;
 110         }
 111
 112         /*
 113          *      Create our own random pool.
 114          */
 115         for (i = 0; i < 256; i++) {
 116                 inst->rand_pool.randrsl[i] = fr_rand();
 117         }
 118         fr_randinit(&inst->rand_pool, 1);
 119
 120         /* Load all the configured EAP-Types */
 121         num_types = 0;
 122         for(scs=cf_subsection_find_next(cs, NULL, NULL);
 123                 scs != NULL;
 124                 scs=cf_subsection_find_next(cs, scs, NULL)) {
 125
 126                 const char      *auth_type;
 127
 128                 auth_type = cf_section_name1(scs);
 129
 130                 if (!auth_type)  continue;
 131
 132                 eap_type = eaptype_name2type(auth_type);
 133                 if (eap_type < 0) {
 134                         radlog(L_ERR|L_CONS, "rlm_eap: Unknown EAP type %s",
 135                                auth_type);
 136                         eap_detach(inst);
 137                         return -1;
 138                 }
 139
 140 #ifndef HAVE_OPENSSL_SSL_H
 141                 /*
 142                  *      This allows the default configuration to be
 143                  *      shipped with EAP-TLS, etc. enabled.  If the
 144                  *      system doesn't have OpenSSL, they will be
 145                  *      ignored.
 146                  *
 147                  *      If the system does have OpenSSL, then this
 148                  *      code will not be used.  The administrator will
 149                  *      then have to delete the tls,
 150                  *      etc. configurations from eap.conf in order to
 151                  *      have EAP without the TLS types.
 152                  */
 153                 if ((eap_type == PW_EAP_TLS) ||
 154                     (eap_type == PW_EAP_TTLS) ||
 155                     (eap_type == PW_EAP_PEAP)) {
 156                         DEBUG2("rlm_eap: Ignoring EAP-Type/%s because we do not have OpenSSL support.", auth_type);
 157                         continue;
 158                 }
 159 #endif
 160
 161                 /*
 162                  *      If we're asked to load TTLS or PEAP, ensure
 163                  *      that we've first loaded TLS.
 164                  */
 165                 if (((eap_type == PW_EAP_TTLS) ||
 166                      (eap_type == PW_EAP_PEAP)) &&
 167                     (inst->types[PW_EAP_TLS] == NULL)) {
 168                         radlog(L_ERR, "rlm_eap: Unable to load EAP-Type/%s, as EAP-Type/TLS is required first.",
 169                                auth_type);
 170                         return -1;
 171                 }
 172
 173                 /*
 174                  *      Load the type.
 175                  */
 176                 if (eaptype_load(&inst->types[eap_type], eap_type, scs) < 0) {
 177                         eap_detach(inst);
 178                         return -1;
 179                 }
 180
 181                 num_types++;    /* successfully loaded one more types */
 182         }
 183
 184         if (num_types == 0) {
 185                 radlog(L_ERR|L_CONS, "rlm_eap: No EAP type configured, module cannot do anything.");
 186                 eap_detach(inst);
 187                 return -1;
 188         }
 189
 190         /*
 191          *      Ensure that the default EAP type is loaded.
 192          */
 193         eap_type = eaptype_name2type(inst->default_eap_type_name);
 194         if (eap_type < 0) {
 195                 radlog(L_ERR|L_CONS, "rlm_eap: Unknown default EAP type %s",
 196                        inst->default_eap_type_name);
 197                 eap_detach(inst);
 198                 return -1;
 199         }
 200
 201         if (inst->types[eap_type] == NULL) {
 202                 radlog(L_ERR|L_CONS, "rlm_eap: No such sub-type for default EAP type %s",
 203                        inst->default_eap_type_name);
 204                 eap_detach(inst);
 205                 return -1;
 206         }
 207         inst->default_eap_type = eap_type; /* save the numerical type */
 208
 209         /*
 210          *      List of sessions are set to NULL by the memset
 211          *      of 'inst', above.
 212          */
 213
 214         /*
 215          *      Lookup sessions in the tree.  We don't free them in
 216          *      the tree, as that's taken care of elsewhere...
 217          */
 218         inst->session_tree = rbtree_create(eap_handler_cmp, NULL, 0);
 219         if (!inst->session_tree) {
 220                 radlog(L_ERR|L_CONS, "rlm_eap: Cannot initialize tree");
 221                 eap_detach(inst);
 222                 return -1;
 223         }
 224
 225         pthread_mutex_init(&(inst->session_mutex), NULL);
 226
 227         *instance = inst;
 228         return 0;
 229 }
 230
 231
 232 /*
 233  *      For backwards compatibility.
 234  */
 235 static int eap_authenticate(void *instance, REQUEST *request)
 236 {
 237         rlm_eap_t       *inst;
 238         EAP_HANDLER     *handler;
 239         eap_packet_t    *eap_packet;
 240         int             rcode;
 241
 242         inst = (rlm_eap_t *) instance;
 243
 244         /*
 245          *      Get the eap packet  to start with
 246          */
 247         eap_packet = eap_vp2packet(request->packet->vps);
 248         if (eap_packet == NULL) {
 249                 radlog(L_ERR, "rlm_eap: Malformed EAP Message");
 250                 return RLM_MODULE_FAIL;
 251         }
 252
 253         /*
 254          *      Create the eap handler.  The eap_packet will end up being
 255          *      "swallowed" into the handler, so we can't access it after
 256          *      this call.
 257          */
 258         handler = eap_handler(inst, &eap_packet, request);
 259         if (handler == NULL) {
 260                 DEBUG2("  rlm_eap: Failed in handler");
 261                 return RLM_MODULE_INVALID;
 262         }
 263
 264         /*
 265          *      Select the appropriate eap_type or default to the
 266          *      configured one
 267          */
 268         rcode = eaptype_select(inst, handler);
 269
 270         /*
 271          *      If it failed, die.
 272          */
 273         if (rcode == EAP_INVALID) {
 274                 eap_fail(handler);
 275                 eap_handler_free(handler);
 276                 DEBUG2("  rlm_eap: Failed in EAP select");
 277                 return RLM_MODULE_INVALID;
 278         }
 279
 280         /*
 281          *      If we're doing horrible tunneling work, remember it.
 282          */
 283         if ((request->options & RAD_REQUEST_OPTION_PROXY_EAP) != 0) {
 284                 DEBUG2("  Not-EAP proxy set.  Not composing EAP");
 285                 /*
 286                  *      Add the handle to the proxied list, so that we
 287                  *      can retrieve it in the post-proxy stage, and
 288                  *      send a response.
 289                  */
 290                 rcode = request_data_add(request,
 291                                          inst, REQUEST_DATA_EAP_HANDLER,
 292                                          handler,
 293                                          (void *) eap_handler_free);
 294                 rad_assert(rcode == 0);
 295
 296                 return RLM_MODULE_HANDLED;
 297         }
 298
 299
 300         /*
 301          *      Maybe the request was marked to be proxied.  If so,
 302          *      proxy it.
 303          */
 304         if (request->proxy != NULL) {
 305                 VALUE_PAIR *vp = NULL;
 306
 307                 rad_assert(request->proxy_reply == NULL);
 308
 309                 /*
 310                  *      Add the handle to the proxied list, so that we
 311                  *      can retrieve it in the post-proxy stage, and
 312                  *      send a response.
 313                  */
 314                 rcode = request_data_add(request,
 315                                          inst, REQUEST_DATA_EAP_HANDLER,
 316                                          handler,
 317                                          (void *) eap_handler_free);
 318                 rad_assert(rcode == 0);
 319
 320                 /*
 321                  *      Some simple sanity checks.  These should really
 322                  *      be handled by the radius library...
 323                  */
 324                 vp = pairfind(request->proxy->vps, PW_EAP_MESSAGE);
 325                 if (vp) {
 326                         vp = pairfind(request->proxy->vps, PW_MESSAGE_AUTHENTICATOR);
 327                         if (!vp) {
 328                                 vp = pairmake("Message-Authenticator",
 329                                               "0x00", T_OP_EQ);
 330                                 rad_assert(vp != NULL);
 331                                 pairadd(&(request->proxy->vps), vp);
 332                         }
 333                 }
 334
 335                 /*
 336                  *      Delete the "proxied to" attribute, as it's
 337                  *      set to 127.0.0.1 for tunneled requests, and
 338                  *      we don't want to tell the world that...
 339                  */
 340                 pairdelete(&request->proxy->vps, PW_FREERADIUS_PROXIED_TO);
 341
 342                 DEBUG2("  Tunneled session will be proxied.  Not doing EAP.");
 343                 return RLM_MODULE_HANDLED;
 344         }
 345
 346         /*
 347          *      We are done, wrap the EAP-request in RADIUS to send
 348          *      with all other required radius attributes
 349          */
 350         rcode = eap_compose(handler);
 351
 352         /*
 353          *      Add to the list only if it is EAP-Request, OR if
 354          *      it's LEAP, and a response.
 355          */
 356         if (((handler->eap_ds->request->code == PW_EAP_REQUEST) &&
 357             (handler->eap_ds->request->type.type >= PW_EAP_MD5)) ||
 358
 359                 /*
 360                  *      LEAP is a little different.  At Stage 4,
 361                  *      it sends an EAP-Success message, but we still
 362                  *      need to keep the State attribute & session
 363                  *      data structure around for the AP Challenge.
 364                  *
 365                  *      At stage 6, LEAP sends an EAP-Response, which
 366                  *      isn't put into the list.
 367                  */
 368             ((handler->eap_ds->response->code == PW_EAP_RESPONSE) &&
 369              (handler->eap_ds->response->type.type == PW_EAP_LEAP) &&
 370              (handler->eap_ds->request->code == PW_EAP_SUCCESS) &&
 371              (handler->eap_ds->request->type.type == 0))) {
 372
 373                 if (!eaplist_add(inst, handler)) {
 374                         eap_fail(handler);
 375                         eap_handler_free(handler);
 376                         return RLM_MODULE_FAIL;
 377                 }
 378
 379         } else {
 380                 DEBUG2("  rlm_eap: Freeing handler");
 381                 /* handler is not required any more, free it now */
 382                 eap_handler_free(handler);
 383         }
 384
 385         /*
 386          *      If it's an Access-Accept, RFC 2869, Section 2.3.1
 387          *      says that we MUST include a User-Name attribute in the
 388          *      Access-Accept.
 389          */
 390         if ((request->reply->code == PW_AUTHENTICATION_ACK) &&
 391             request->username) {
 392                 VALUE_PAIR *vp;
 393
 394                 /*
 395                  *      Doesn't exist, add it in.
 396                  */
 397                 vp = pairfind(request->reply->vps, PW_USER_NAME);
 398                 if (!vp) {
 399                         vp = pairmake("User-Name", request->username->vp_strvalue,
 400                                       T_OP_EQ);
 401                         rad_assert(vp != NULL);
 402                         pairadd(&(request->reply->vps), vp);
 403                 }
 404
 405                 /*
 406                  *      Cisco AP1230 has a bug and needs a zero
 407                  *      terminated string in Access-Accept.
 408                  */
 409                 if ((inst->cisco_accounting_username_bug) &&
 410                     (vp->length < (int) sizeof(vp->vp_strvalue))) {
 411                         vp->vp_strvalue[vp->length] = '\0';
 412                         vp->length++;
 413                 }
 414         }
 415
 416         return rcode;
 417 }
 418
 419 /*
 420  * EAP authorization DEPENDS on other rlm authorizations,
 421  * to check for user existance & get their configured values.
 422  * It Handles EAP-START Messages, User-Name initilization.
 423  */
 424 static int eap_authorize(void *instance, REQUEST *request)
 425 {
 426         rlm_eap_t       *inst;
 427         int             status;
 428         VALUE_PAIR      *vp;
 429
 430         inst = (rlm_eap_t *)instance;
 431
 432         /*
 433          *      We don't do authorization again, once we've seen the
 434          *      proxy reply (or the proxied packet)
 435          */
 436         if (request->proxy != NULL)
 437                 return RLM_MODULE_NOOP;
 438
 439         /*
 440          *      For EAP_START, send Access-Challenge with EAP Identity
 441          *      request.  even when we have to proxy this request
 442          *
 443          *      RFC 2869, Section 2.3.1 notes that the "domain" of the
 444          *      user, (i.e. where to proxy him) comes from the EAP-Identity,
 445          *      so we CANNOT proxy the user, until we know his identity.
 446          *
 447          *      We therefore send an EAP Identity request.
 448          */
 449         status = eap_start(inst, request);
 450         switch(status) {
 451         case EAP_NOOP:
 452                 return RLM_MODULE_NOOP;
 453         case EAP_FAIL:
 454                 return RLM_MODULE_FAIL;
 455         case EAP_FOUND:
 456                 return RLM_MODULE_HANDLED;
 457         case EAP_OK:
 458         case EAP_NOTFOUND:
 459         default:
 460                 break;
 461         }
 462
 463         /*
 464          *      RFC 2869, Section 2.3.1.  If a NAS sends an EAP-Identity,
 465          *      it MUST copy the identity into the User-Name attribute.
 466          *
 467          *      But we don't worry about that too much.  We depend on
 468          *      each EAP sub-module to look for handler->request->username,
 469          *      and to get excited if it doesn't appear.
 470          */
 471
 472         vp = pairfind(request->config_items, PW_AUTH_TYPE);
 473         if ((!vp) ||
 474             (vp->vp_integer != PW_AUTHTYPE_REJECT)) {
 475                 vp = pairmake("Auth-Type", "EAP", T_OP_EQ);
 476                 if (!vp) {
 477                         return RLM_MODULE_FAIL;
 478                 }
 479                 pairadd(&request->config_items, vp);
 480         }
 481
 482         if (status == EAP_OK) return RLM_MODULE_OK;
 483
 484         return RLM_MODULE_UPDATED;
 485 }
 486
 487 /*
 488  *      If we're proxying EAP, then there may be magic we need
 489  *      to do.
 490  */
 491 static int eap_post_proxy(void *inst, REQUEST *request)
 492 {
 493         size_t          i;
 494         size_t          len;
 495         VALUE_PAIR      *vp;
 496         EAP_HANDLER     *handler;
 497
 498         /*
 499          *      If there was a handler associated with this request,
 500          *      then it's a tunneled request which was proxied...
 501          */
 502         handler = request_data_get(request, inst, REQUEST_DATA_EAP_HANDLER);
 503         if (handler != NULL) {
 504                 int             rcode;
 505                 eap_tunnel_data_t *data;
 506
 507                 /*
 508                  *      Grab the tunnel callbacks from the request.
 509                  */
 510                 data = (eap_tunnel_data_t *) request_data_get(request,
 511                                                               request->proxy,
 512                                                               REQUEST_DATA_EAP_TUNNEL_CALLBACK);
 513                 if (!data) {
 514                         radlog(L_ERR, "rlm_eap: Failed to retrieve callback for tunneled session!");
 515                         eap_handler_free(handler);
 516                         return RLM_MODULE_FAIL;
 517                 }
 518
 519                 /*
 520                  *      Do the callback...
 521                  */
 522                 rcode = data->callback(handler, data->tls_session);
 523                 free(data);
 524                 if (rcode == 0) {
 525                         eap_fail(handler);
 526                         eap_handler_free(handler);
 527                         return RLM_MODULE_REJECT;
 528                 }
 529
 530                 /*
 531                  *      We are done, wrap the EAP-request in RADIUS to send
 532                  *      with all other required radius attributes
 533                  */
 534                 rcode = eap_compose(handler);
 535
 536                 /*
 537                  *      Add to the list only if it is EAP-Request, OR if
 538                  *      it's LEAP, and a response.
 539                  */
 540                 if ((handler->eap_ds->request->code == PW_EAP_REQUEST) &&
 541                     (handler->eap_ds->request->type.type >= PW_EAP_MD5)) {
 542                         eaplist_add(inst, handler);
 543
 544                 } else {        /* couldn't have been LEAP, there's no tunnel */
 545                         DEBUG2("  rlm_eap: Freeing handler");
 546                         /* handler is not required any more, free it now */
 547                         eap_handler_free(handler);
 548                 }
 549
 550                 /*
 551                  *      If it's an Access-Accept, RFC 2869, Section 2.3.1
 552                  *      says that we MUST include a User-Name attribute in the
 553                  *      Access-Accept.
 554                  */
 555                 if ((request->reply->code == PW_AUTHENTICATION_ACK) &&
 556                     request->username) {
 557                         /*
 558                          *      Doesn't exist, add it in.
 559                          */
 560                         vp = pairfind(request->reply->vps, PW_USER_NAME);
 561                         if (!vp) {
 562                                 vp = pairmake("User-Name", request->username->vp_strvalue,
 563                                               T_OP_EQ);
 564                                 rad_assert(vp != NULL);
 565                                 pairadd(&(request->reply->vps), vp);
 566                         }
 567                 }
 568
 569                 return RLM_MODULE_OK;
 570         }
 571
 572
 573         /*
 574          *      There may be more than one Cisco-AVPair.
 575          *      Ensure we find the one with the LEAP attribute.
 576          */
 577         vp = request->proxy_reply->vps;
 578         for (;;) {
 579                 /*
 580                  *      Hmm... there's got to be a better way to
 581                  *      discover codes for vendor attributes.
 582                  *
 583                  *      This is vendor Cisco (9), Cisco-AVPair
 584                  *      attribute (1)
 585                  */
 586                 vp = pairfind(vp, (9 << 16)  | 1);
 587                 if (!vp) {
 588                         return RLM_MODULE_NOOP;
 589                 }
 590
 591                 /*
 592                  *      If it's "leap:session-key", then stop.
 593                  *
 594                  *      The format is VERY specific!
 595                  */
 596                 if (strncasecmp(vp->vp_strvalue, "leap:session-key=", 17) == 0) {
 597                         break;
 598                 }
 599
 600                 /*
 601                  *      Not this AV-pair.  Go to the next one.
 602                  */
 603                 vp = vp->next;
 604         }
 605
 606         /*
 607          *      The format is very specific.
 608          */
 609         if (vp->length != 17 + 34) {
 610                 DEBUG2("  rlm_eap: Cisco-AVPair with leap:session-key has incorrect length %d: Expected %d",
 611                        vp->length, 17 + 34);
 612                 return RLM_MODULE_NOOP;
 613         }
 614
 615         /*
 616          *      Decrypt the session key, using the proxy data.
 617          */
 618         i = 34;                 /* starts off with 34 octets */
 619         len = rad_tunnel_pwdecode(vp->vp_octets + 17, &i,
 620                                   request->home_server->secret,
 621                                   request->proxy->vector);
 622
 623         /*
 624          *      FIXME: Assert that i == 16.
 625          */
 626
 627         /*
 628          *      Encrypt the session key again, using the request data.
 629          */
 630         rad_tunnel_pwencode(vp->vp_strvalue + 17, &len,
 631                             request->client->secret,
 632                             request->packet->vector);
 633
 634         return RLM_MODULE_UPDATED;
 635 }
 636
 637
 638 /*
 639  *      The module name should be the only globally exported symbol.
 640  *      That is, everything else should be 'static'.
 641  */
 642 module_t rlm_eap = {
 643         RLM_MODULE_INIT,
 644         "eap",
 645         RLM_TYPE_CHECK_CONFIG_SAFE,     /* type */
 646         eap_instantiate,                /* instantiation */
 647         eap_detach,                     /* detach */
 648         {
 649                 eap_authenticate,       /* authentication */
 650                 eap_authorize,          /* authorization */
 651                 NULL,                   /* preaccounting */
 652                 NULL,                   /* accounting */
 653                 NULL,                   /* checksimul */
 654                 NULL,                   /* pre-proxy */
 655                 eap_post_proxy,         /* post-proxy */
 656                 NULL                    /* post-auth */
 657         },
 658 };