src/main/tls.c

   1 /*
   2  * tls.c
   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 2001  hereUare Communications, Inc. <raghud@hereuare.com>
  21  * Copyright 2003  Alan DeKok <aland@freeradius.org>
  22  * Copyright 2006  The FreeRADIUS server project
  23  */
  24
  25 #include <freeradius-devel/ident.h>
  26 RCSID("$Id$")
  27
  28 #include <freeradius-devel/autoconf.h>
  29 #include <freeradius-devel/radiusd.h>
  30 #include <freeradius-devel/tls.h>
  31 #include <freeradius-devel/rad_assert.h>
  32
  33 #ifdef HAVE_SYS_STAT_H
  34 #include <sys/stat.h>
  35 #endif
  36
  37 #ifdef WITH_TLS
  38 #ifdef HAVE_OPENSSL_RAND_H
  39 #include <openssl/rand.h>
  40 #endif
  41
  42 #ifdef HAVE_OPENSSL_OCSP_H
  43 #include <openssl/ocsp.h>
  44 #endif
  45
  46 #ifdef HAVE_PTHREAD_H
  47 #define PTHREAD_MUTEX_LOCK pthread_mutex_lock
  48 #define PTHREAD_MUTEX_UNLOCK pthread_mutex_unlock
  49 #else
  50 #define PTHREAD_MUTEX_LOCK(_x)
  51 #define PTHREAD_MUTEX_UNLOCK(_x)
  52 #endif
  53
  54
  55 /* record */
  56 static void             record_init(record_t *buf);
  57 static void             record_close(record_t *buf);
  58 static unsigned int     record_plus(record_t *buf, const void *ptr,
  59                                     unsigned int size);
  60 static unsigned int     record_minus(record_t *buf, void *ptr,
  61                                      unsigned int size);
  62
  63 tls_session_t *tls_new_session(SSL_CTX *ssl_ctx, int client_cert)
  64 {
  65         tls_session_t *state = NULL;
  66         SSL *new_tls = NULL;
  67
  68         client_cert = client_cert; /* -Wunused.  See bug #350 */
  69
  70         if ((new_tls = SSL_new(ssl_ctx)) == NULL) {
  71                 radlog(L_ERR, "SSL: Error creating new SSL: %s",
  72                        ERR_error_string(ERR_get_error(), NULL));
  73                 return NULL;
  74         }
  75
  76         /* We use the SSL's "app_data" to indicate a call-back */
  77         SSL_set_app_data(new_tls, NULL);
  78
  79         state = (tls_session_t *)malloc(sizeof(*state));
  80         memset(state, 0, sizeof(*state));
  81         session_init(state);
  82
  83         state->ctx = ssl_ctx;
  84         state->ssl = new_tls;
  85
  86         /*
  87          *      Initialize callbacks
  88          */
  89         state->record_init = record_init;
  90         state->record_close = record_close;
  91         state->record_plus = record_plus;
  92         state->record_minus = record_minus;
  93
  94         /*
  95          *      Create & hook the BIOs to handle the dirty side of the
  96          *      SSL.  This is *very important* as we want to handle
  97          *      the transmission part.  Now the only IO interface
  98          *      that SSL is aware of, is our defined BIO buffers.
  99          *
 100          *      This means that all SSL IO is done to/from memory,
 101          *      and we can update those BIOs from the packets we've
 102          *      received.
 103          */
 104         state->into_ssl = BIO_new(BIO_s_mem());
 105         state->from_ssl = BIO_new(BIO_s_mem());
 106         SSL_set_bio(state->ssl, state->into_ssl, state->from_ssl);
 107
 108         /*
 109          *      Add the message callback to identify what type of
 110          *      message/handshake is passed
 111          */
 112         SSL_set_msg_callback(new_tls, cbtls_msg);
 113         SSL_set_msg_callback_arg(new_tls, state);
 114         SSL_set_info_callback(new_tls, cbtls_info);
 115
 116         /*
 117          *      In Server mode we only accept.
 118          */
 119         SSL_set_accept_state(state->ssl);
 120
 121         return state;
 122 }
 123
 124 /*
 125  *      Print out some text describing the error.
 126  */
 127 static int int_ssl_check(REQUEST *request, SSL *s, int ret, const char *text)
 128 {
 129         int e;
 130         unsigned long l;
 131
 132         if ((l = ERR_get_error()) != 0) {
 133                 const char *p = ERR_error_string(l, NULL);
 134                 VALUE_PAIR *vp;
 135
 136                 radlog(L_ERR, "SSL error %s", p);
 137
 138                 if (request) {
 139                         vp = pairmake("Module-Failure-Message", p, T_OP_ADD);
 140                         if (vp) pairadd(&request->packet->vps, vp);
 141                 }
 142         }
 143         e = SSL_get_error(s, ret);
 144
 145         switch(e) {
 146                 /*
 147                  *      These seem to be harmless and already "dealt
 148                  *      with" by our non-blocking environment. NB:
 149                  *      "ZERO_RETURN" is the clean "error"
 150                  *      indicating a successfully closed SSL
 151                  *      tunnel. We let this happen because our IO
 152                  *      loop should not appear to have broken on
 153                  *      this condition - and outside the IO loop, the
 154                  *      "shutdown" state is checked.
 155                  *
 156                  *      Don't print anything if we ignore the error.
 157                  */
 158         case SSL_ERROR_NONE:
 159         case SSL_ERROR_WANT_READ:
 160         case SSL_ERROR_WANT_WRITE:
 161         case SSL_ERROR_WANT_X509_LOOKUP:
 162         case SSL_ERROR_ZERO_RETURN:
 163                 break;
 164
 165                 /*
 166                  *      These seem to be indications of a genuine
 167                  *      error that should result in the SSL tunnel
 168                  *      being regarded as "dead".
 169                  */
 170         case SSL_ERROR_SYSCALL:
 171                 radlog(L_ERR, "SSL: %s failed in a system call (%d), TLS session fails.",
 172                        text, ret);
 173                 return 0;
 174
 175         case SSL_ERROR_SSL:
 176                 radlog(L_ERR, "SSL: %s failed inside of TLS (%d), TLS session fails.",
 177                        text, ret);
 178                 return 0;
 179
 180         default:
 181                 /*
 182                  *      For any other errors that (a) exist, and (b)
 183                  *      crop up - we need to interpret what to do with
 184                  *      them - so "politely inform" the caller that
 185                  *      the code needs updating here.
 186                  */
 187                 radlog(L_ERR, "SSL: FATAL SSL error ..... %d\n", e);
 188                 return 0;
 189         }
 190
 191         return 1;
 192 }
 193
 194 /*
 195  * We are the server, we always get the dirty data
 196  * (Handshake data is also considered as dirty data)
 197  * During handshake, since SSL API handles itself,
 198  * After clean-up, dirty_out will be filled with
 199  * the data required for handshaking. So we check
 200  * if dirty_out is empty then we simply send it back.
 201  * As of now, if handshake is successful, then we keep going,
 202  * otherwise we fail.
 203  *
 204  * Fill the Bio with the dirty data to clean it
 205  * Get the cleaned data from SSL, if it is not Handshake data
 206  */
 207 int tls_handshake_recv(REQUEST *request, tls_session_t *ssn)
 208 {
 209         int err;
 210
 211         BIO_write(ssn->into_ssl, ssn->dirty_in.data, ssn->dirty_in.used);
 212
 213         err = SSL_read(ssn->ssl, ssn->clean_out.data + ssn->clean_out.used,
 214                        sizeof(ssn->clean_out.data) - ssn->clean_out.used);
 215         if (err > 0) {
 216                 ssn->clean_out.used += err;
 217                 record_init(&ssn->dirty_in);
 218                 return 1;
 219         }
 220
 221         if (!int_ssl_check(request, ssn->ssl, err, "SSL_read")) {
 222                 return 0;
 223         }
 224
 225         /* Some Extra STATE information for easy debugging */
 226         if (SSL_is_init_finished(ssn->ssl)) {
 227                 DEBUG2("SSL Connection Established\n");
 228         }
 229         if (SSL_in_init(ssn->ssl)) {
 230                 DEBUG2("In SSL Handshake Phase\n");
 231         }
 232         if (SSL_in_before(ssn->ssl)) {
 233                 DEBUG2("Before SSL Handshake Phase\n");
 234         }
 235         if (SSL_in_accept_init(ssn->ssl)) {
 236                 DEBUG2("In SSL Accept mode \n");
 237         }
 238         if (SSL_in_connect_init(ssn->ssl)) {
 239                 DEBUG2("In SSL Connect mode \n");
 240         }
 241
 242         err = BIO_ctrl_pending(ssn->from_ssl);
 243         if (err > 0) {
 244                 err = BIO_read(ssn->from_ssl, ssn->dirty_out.data,
 245                                sizeof(ssn->dirty_out.data));
 246                 if (err > 0) {
 247                         ssn->dirty_out.used = err;
 248
 249                 } else if (BIO_should_retry(ssn->from_ssl)) {
 250                         record_init(&ssn->dirty_in);
 251                         DEBUG2("  tls: Asking for more data in tunnel");
 252                         return 1;
 253
 254                 } else {
 255                         int_ssl_check(request, ssn->ssl, err, "BIO_read");
 256                         record_init(&ssn->dirty_in);
 257                         return 0;
 258                 }
 259         } else {
 260                 DEBUG2("SSL Application Data");
 261                 /* Its clean application data, do whatever we want */
 262                 record_init(&ssn->clean_out);
 263         }
 264
 265         /* We are done with dirty_in, reinitialize it */
 266         record_init(&ssn->dirty_in);
 267         return 1;
 268 }
 269
 270 /*
 271  *      Take clear-text user data, and encrypt it into the output buffer,
 272  *      to send to the client at the other end of the SSL connection.
 273  */
 274 int tls_handshake_send(REQUEST *request, tls_session_t *ssn)
 275 {
 276         int err;
 277
 278         /*
 279          *      If there's un-encrypted data in 'clean_in', then write
 280          *      that data to the SSL session, and then call the BIO function
 281          *      to get that encrypted data from the SSL session, into
 282          *      a buffer which we can then package into an EAP packet.
 283          *
 284          *      Based on Server's logic this clean_in is expected to
 285          *      contain the data to send to the client.
 286          */
 287         if (ssn->clean_in.used > 0) {
 288                 int written;
 289
 290                 written = SSL_write(ssn->ssl, ssn->clean_in.data, ssn->clean_in.used);
 291                 record_minus(&ssn->clean_in, NULL, written);
 292
 293                 /* Get the dirty data from Bio to send it */
 294                 err = BIO_read(ssn->from_ssl, ssn->dirty_out.data,
 295                                sizeof(ssn->dirty_out.data));
 296                 if (err > 0) {
 297                         ssn->dirty_out.used = err;
 298                 } else {
 299                         int_ssl_check(request, ssn->ssl, err, "handshake_send");
 300                 }
 301         }
 302
 303         return 1;
 304 }
 305
 306 void session_init(tls_session_t *ssn)
 307 {
 308         ssn->ssl = NULL;
 309         ssn->into_ssl = ssn->from_ssl = NULL;
 310         record_init(&ssn->clean_in);
 311         record_init(&ssn->clean_out);
 312         record_init(&ssn->dirty_in);
 313         record_init(&ssn->dirty_out);
 314
 315         memset(&ssn->info, 0, sizeof(ssn->info));
 316
 317         ssn->offset = 0;
 318         ssn->fragment = 0;
 319         ssn->tls_msg_len = 0;
 320         ssn->length_flag = 0;
 321         ssn->opaque = NULL;
 322         ssn->free_opaque = NULL;
 323 }
 324
 325 void session_close(tls_session_t *ssn)
 326 {
 327         if (ssn->ssl->session) {
 328                 VALUE_PAIR *vp;
 329
 330                 vp = SSL_SESSION_get_ex_data(ssn->ssl->session,
 331                                              FR_TLS_EX_INDEX_VPS);
 332                 if (vp) pairfree(&vp);
 333         }
 334
 335         SSL_set_quiet_shutdown(ssn->ssl, 1);
 336         SSL_shutdown(ssn->ssl);
 337
 338         if(ssn->ssl)
 339                 SSL_free(ssn->ssl);
 340 #if 0
 341 /*
 342  * WARNING: SSL_free seems to decrement the reference counts already,
 343  *      so doing this might crash the application.
 344  */
 345         if(ssn->into_ssl)
 346                 BIO_free(ssn->into_ssl);
 347         if(ssn->from_ssl)
 348                 BIO_free(ssn->from_ssl);
 349 #endif
 350         record_close(&ssn->clean_in);
 351         record_close(&ssn->clean_out);
 352         record_close(&ssn->dirty_in);
 353         record_close(&ssn->dirty_out);
 354         session_init(ssn);
 355 }
 356
 357 void session_free(void *ssn)
 358 {
 359         tls_session_t *sess = (tls_session_t *)ssn;
 360
 361         if (!ssn) return;
 362
 363         /*
 364          *      Free any opaque TTLS or PEAP data.
 365          */
 366         if ((sess->opaque) && (sess->free_opaque)) {
 367                 sess->free_opaque(sess->opaque);
 368                 sess->opaque = NULL;
 369         }
 370
 371         session_close(sess);
 372
 373         free(sess);
 374 }
 375
 376 static void record_init(record_t *rec)
 377 {
 378         rec->used = 0;
 379 }
 380
 381 static void record_close(record_t *rec)
 382 {
 383         rec->used = 0;
 384 }
 385
 386
 387 /*
 388  *      Copy data to the intermediate buffer, before we send
 389  *      it somewhere.
 390  */
 391 static unsigned int record_plus(record_t *rec, const void *ptr,
 392                                 unsigned int size)
 393 {
 394         unsigned int added = MAX_RECORD_SIZE - rec->used;
 395
 396         if(added > size)
 397                 added = size;
 398         if(added == 0)
 399                 return 0;
 400         memcpy(rec->data + rec->used, ptr, added);
 401         rec->used += added;
 402         return added;
 403 }
 404
 405 /*
 406  *      Take data from the buffer, and give it to the caller.
 407  */
 408 static unsigned int record_minus(record_t *rec, void *ptr,
 409                                  unsigned int size)
 410 {
 411         unsigned int taken = rec->used;
 412
 413         if(taken > size)
 414                 taken = size;
 415         if(taken == 0)
 416                 return 0;
 417         if(ptr)
 418                 memcpy(ptr, rec->data, taken);
 419         rec->used -= taken;
 420
 421         /*
 422          *      This is pretty bad...
 423          */
 424         if(rec->used > 0)
 425                 memmove(rec->data, rec->data + taken, rec->used);
 426         return taken;
 427 }
 428
 429 void tls_session_information(tls_session_t *tls_session)
 430 {
 431         const char *str_write_p, *str_version, *str_content_type = "";
 432         const char *str_details1 = "", *str_details2= "";
 433         REQUEST *request;
 434
 435         /*
 436          *      Don't print this out in the normal course of
 437          *      operations.
 438          */
 439         if (debug_flag == 0) {
 440                 return;
 441         }
 442
 443         str_write_p = tls_session->info.origin ? ">>>" : "<<<";
 444
 445         switch (tls_session->info.version)
 446         {
 447         case SSL2_VERSION:
 448                 str_version = "SSL 2.0";
 449                 break;
 450         case SSL3_VERSION:
 451                 str_version = "SSL 3.0 ";
 452                 break;
 453         case TLS1_VERSION:
 454                 str_version = "TLS 1.0 ";
 455                 break;
 456         default:
 457                 str_version = "Unknown TLS version";
 458                 break;
 459         }
 460
 461         if (tls_session->info.version == SSL3_VERSION ||
 462             tls_session->info.version == TLS1_VERSION) {
 463                 switch (tls_session->info.content_type) {
 464                 case SSL3_RT_CHANGE_CIPHER_SPEC:
 465                         str_content_type = "ChangeCipherSpec";
 466                         break;
 467                 case SSL3_RT_ALERT:
 468                         str_content_type = "Alert";
 469                         break;
 470                 case SSL3_RT_HANDSHAKE:
 471                         str_content_type = "Handshake";
 472                         break;
 473                 case SSL3_RT_APPLICATION_DATA:
 474                         str_content_type = "ApplicationData";
 475                         break;
 476                 default:
 477                         str_content_type = "UnknownContentType";
 478                         break;
 479                 }
 480
 481                 if (tls_session->info.content_type == SSL3_RT_ALERT) {
 482                         str_details1 = ", ???";
 483
 484                         if (tls_session->info.record_len == 2) {
 485
 486                                 switch (tls_session->info.alert_level) {
 487                                 case SSL3_AL_WARNING:
 488                                         str_details1 = ", warning";
 489                                         break;
 490                                 case SSL3_AL_FATAL:
 491                                         str_details1 = ", fatal";
 492                                         break;
 493                                 }
 494
 495                                 str_details2 = " ???";
 496                                 switch (tls_session->info.alert_description) {
 497                                 case SSL3_AD_CLOSE_NOTIFY:
 498                                         str_details2 = " close_notify";
 499                                         break;
 500                                 case SSL3_AD_UNEXPECTED_MESSAGE:
 501                                         str_details2 = " unexpected_message";
 502                                         break;
 503                                 case SSL3_AD_BAD_RECORD_MAC:
 504                                         str_details2 = " bad_record_mac";
 505                                         break;
 506                                 case TLS1_AD_DECRYPTION_FAILED:
 507                                         str_details2 = " decryption_failed";
 508                                         break;
 509                                 case TLS1_AD_RECORD_OVERFLOW:
 510                                         str_details2 = " record_overflow";
 511                                         break;
 512                                 case SSL3_AD_DECOMPRESSION_FAILURE:
 513                                         str_details2 = " decompression_failure";
 514                                         break;
 515                                 case SSL3_AD_HANDSHAKE_FAILURE:
 516                                         str_details2 = " handshake_failure";
 517                                         break;
 518                                 case SSL3_AD_BAD_CERTIFICATE:
 519                                         str_details2 = " bad_certificate";
 520                                         break;
 521                                 case SSL3_AD_UNSUPPORTED_CERTIFICATE:
 522                                         str_details2 = " unsupported_certificate";
 523                                         break;
 524                                 case SSL3_AD_CERTIFICATE_REVOKED:
 525                                         str_details2 = " certificate_revoked";
 526                                         break;
 527                                 case SSL3_AD_CERTIFICATE_EXPIRED:
 528                                         str_details2 = " certificate_expired";
 529                                         break;
 530                                 case SSL3_AD_CERTIFICATE_UNKNOWN:
 531                                         str_details2 = " certificate_unknown";
 532                                         break;
 533                                 case SSL3_AD_ILLEGAL_PARAMETER:
 534                                         str_details2 = " illegal_parameter";
 535                                         break;
 536                                 case TLS1_AD_UNKNOWN_CA:
 537                                         str_details2 = " unknown_ca";
 538                                         break;
 539                                 case TLS1_AD_ACCESS_DENIED:
 540                                         str_details2 = " access_denied";
 541                                         break;
 542                                 case TLS1_AD_DECODE_ERROR:
 543                                         str_details2 = " decode_error";
 544                                         break;
 545                                 case TLS1_AD_DECRYPT_ERROR:
 546                                         str_details2 = " decrypt_error";
 547                                         break;
 548                                 case TLS1_AD_EXPORT_RESTRICTION:
 549                                         str_details2 = " export_restriction";
 550                                         break;
 551                                 case TLS1_AD_PROTOCOL_VERSION:
 552                                         str_details2 = " protocol_version";
 553                                         break;
 554                                 case TLS1_AD_INSUFFICIENT_SECURITY:
 555                                         str_details2 = " insufficient_security";
 556                                         break;
 557                                 case TLS1_AD_INTERNAL_ERROR:
 558                                         str_details2 = " internal_error";
 559                                         break;
 560                                 case TLS1_AD_USER_CANCELLED:
 561                                         str_details2 = " user_canceled";
 562                                         break;
 563                                 case TLS1_AD_NO_RENEGOTIATION:
 564                                         str_details2 = " no_renegotiation";
 565                                         break;
 566                                 }
 567                         }
 568                 }
 569
 570                 if (tls_session->info.content_type == SSL3_RT_HANDSHAKE) {
 571                         str_details1 = "???";
 572
 573                         if (tls_session->info.record_len > 0)
 574                         switch (tls_session->info.handshake_type)
 575                         {
 576                         case SSL3_MT_HELLO_REQUEST:
 577                                 str_details1 = ", HelloRequest";
 578                                 break;
 579                         case SSL3_MT_CLIENT_HELLO:
 580                                 str_details1 = ", ClientHello";
 581                                 break;
 582                         case SSL3_MT_SERVER_HELLO:
 583                                 str_details1 = ", ServerHello";
 584                                 break;
 585                         case SSL3_MT_CERTIFICATE:
 586                                 str_details1 = ", Certificate";
 587                                 break;
 588                         case SSL3_MT_SERVER_KEY_EXCHANGE:
 589                                 str_details1 = ", ServerKeyExchange";
 590                                 break;
 591                         case SSL3_MT_CERTIFICATE_REQUEST:
 592                                 str_details1 = ", CertificateRequest";
 593                                 break;
 594                         case SSL3_MT_SERVER_DONE:
 595                                 str_details1 = ", ServerHelloDone";
 596                                 break;
 597                         case SSL3_MT_CERTIFICATE_VERIFY:
 598                                 str_details1 = ", CertificateVerify";
 599                                 break;
 600                         case SSL3_MT_CLIENT_KEY_EXCHANGE:
 601                                 str_details1 = ", ClientKeyExchange";
 602                                 break;
 603                         case SSL3_MT_FINISHED:
 604                                 str_details1 = ", Finished";
 605                                 break;
 606                         }
 607                 }
 608         }
 609
 610         snprintf(tls_session->info.info_description,
 611                  sizeof(tls_session->info.info_description),
 612                  "%s %s%s [length %04lx]%s%s\n",
 613                  str_write_p, str_version, str_content_type,
 614                  (unsigned long)tls_session->info.record_len,
 615                  str_details1, str_details2);
 616
 617         request = SSL_get_ex_data(tls_session->ssl, FR_TLS_EX_INDEX_REQUEST);
 618
 619         RDEBUG2("%s\n", tls_session->info.info_description);
 620 }
 621
 622 static CONF_PARSER cache_config[] = {
 623         { "enable", PW_TYPE_BOOLEAN,
 624           offsetof(fr_tls_server_conf_t, session_cache_enable), NULL, "no" },
 625         { "lifetime", PW_TYPE_INTEGER,
 626           offsetof(fr_tls_server_conf_t, session_timeout), NULL, "24" },
 627         { "max_entries", PW_TYPE_INTEGER,
 628           offsetof(fr_tls_server_conf_t, session_cache_size), NULL, "255" },
 629         { "name", PW_TYPE_STRING_PTR,
 630           offsetof(fr_tls_server_conf_t, session_id_name), NULL, NULL},
 631         { NULL, -1, 0, NULL, NULL }           /* end the list */
 632 };
 633
 634 static CONF_PARSER verify_config[] = {
 635         { "tmpdir", PW_TYPE_STRING_PTR,
 636           offsetof(fr_tls_server_conf_t, verify_tmp_dir), NULL, NULL},
 637         { "client", PW_TYPE_STRING_PTR,
 638           offsetof(fr_tls_server_conf_t, verify_client_cert_cmd), NULL, NULL},
 639         { NULL, -1, 0, NULL, NULL }           /* end the list */
 640 };
 641
 642 #ifdef HAVE_OPENSSL_OCSP_H
 643 static CONF_PARSER ocsp_config[] = {
 644         { "enable", PW_TYPE_BOOLEAN,
 645           offsetof(fr_tls_server_conf_t, ocsp_enable), NULL, "no"},
 646         { "override_cert_url", PW_TYPE_BOOLEAN,
 647           offsetof(fr_tls_server_conf_t, ocsp_override_url), NULL, "no"},
 648         { "url", PW_TYPE_STRING_PTR,
 649           offsetof(fr_tls_server_conf_t, ocsp_url), NULL, NULL },
 650         { NULL, -1, 0, NULL, NULL }           /* end the list */
 651 };
 652 #endif
 653
 654 static CONF_PARSER tls_server_config[] = {
 655         { "rsa_key_exchange", PW_TYPE_BOOLEAN,
 656           offsetof(fr_tls_server_conf_t, rsa_key), NULL, "no" },
 657         { "dh_key_exchange", PW_TYPE_BOOLEAN,
 658           offsetof(fr_tls_server_conf_t, dh_key), NULL, "yes" },
 659         { "rsa_key_length", PW_TYPE_INTEGER,
 660           offsetof(fr_tls_server_conf_t, rsa_key_length), NULL, "512" },
 661         { "dh_key_length", PW_TYPE_INTEGER,
 662           offsetof(fr_tls_server_conf_t, dh_key_length), NULL, "512" },
 663         { "verify_depth", PW_TYPE_INTEGER,
 664           offsetof(fr_tls_server_conf_t, verify_depth), NULL, "0" },
 665         { "CA_path", PW_TYPE_FILENAME,
 666           offsetof(fr_tls_server_conf_t, ca_path), NULL, NULL },
 667         { "pem_file_type", PW_TYPE_BOOLEAN,
 668           offsetof(fr_tls_server_conf_t, file_type), NULL, "yes" },
 669         { "private_key_file", PW_TYPE_FILENAME,
 670           offsetof(fr_tls_server_conf_t, private_key_file), NULL, NULL },
 671         { "certificate_file", PW_TYPE_FILENAME,
 672           offsetof(fr_tls_server_conf_t, certificate_file), NULL, NULL },
 673         { "CA_file", PW_TYPE_FILENAME,
 674           offsetof(fr_tls_server_conf_t, ca_file), NULL, NULL },
 675         { "private_key_password", PW_TYPE_STRING_PTR,
 676           offsetof(fr_tls_server_conf_t, private_key_password), NULL, NULL },
 677         { "dh_file", PW_TYPE_STRING_PTR,
 678           offsetof(fr_tls_server_conf_t, dh_file), NULL, NULL },
 679         { "random_file", PW_TYPE_STRING_PTR,
 680           offsetof(fr_tls_server_conf_t, random_file), NULL, NULL },
 681         { "fragment_size", PW_TYPE_INTEGER,
 682           offsetof(fr_tls_server_conf_t, fragment_size), NULL, "1024" },
 683         { "include_length", PW_TYPE_BOOLEAN,
 684           offsetof(fr_tls_server_conf_t, include_length), NULL, "yes" },
 685         { "check_crl", PW_TYPE_BOOLEAN,
 686           offsetof(fr_tls_server_conf_t, check_crl), NULL, "no"},
 687         { "allow_expired_crl", PW_TYPE_BOOLEAN,
 688           offsetof(fr_tls_server_conf_t, allow_expired_crl), NULL, NULL},
 689         { "check_cert_cn", PW_TYPE_STRING_PTR,
 690           offsetof(fr_tls_server_conf_t, check_cert_cn), NULL, NULL},
 691         { "cipher_list", PW_TYPE_STRING_PTR,
 692           offsetof(fr_tls_server_conf_t, cipher_list), NULL, NULL},
 693         { "check_cert_issuer", PW_TYPE_STRING_PTR,
 694           offsetof(fr_tls_server_conf_t, check_cert_issuer), NULL, NULL},
 695         { "make_cert_command", PW_TYPE_STRING_PTR,
 696           offsetof(fr_tls_server_conf_t, make_cert_command), NULL, NULL},
 697
 698         { "cache", PW_TYPE_SUBSECTION, 0, NULL, (const void *) cache_config },
 699
 700         { "verify", PW_TYPE_SUBSECTION, 0, NULL, (const void *) verify_config },
 701
 702 #ifdef HAVE_OPENSSL_OCSP_H
 703         { "ocsp", PW_TYPE_SUBSECTION, 0, NULL, (const void *) ocsp_config },
 704 #endif
 705
 706         { NULL, -1, 0, NULL, NULL }           /* end the list */
 707 };
 708
 709 /*
 710  *      TODO: Check for the type of key exchange * like conf->dh_key
 711  */
 712 static int load_dh_params(SSL_CTX *ctx, char *file)
 713 {
 714         DH *dh = NULL;
 715         BIO *bio;
 716
 717         if ((bio = BIO_new_file(file, "r")) == NULL) {
 718                 radlog(L_ERR, "rlm_eap_tls: Unable to open DH file - %s", file);
 719                 return -1;
 720         }
 721
 722         dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
 723         BIO_free(bio);
 724         if (!dh) {
 725                 DEBUG2("WARNING: rlm_eap_tls: Unable to set DH parameters.  DH cipher suites may not work!");
 726                 DEBUG2("WARNING: Fix this by running the OpenSSL command listed in eap.conf");
 727                 return 0;
 728         }
 729
 730         if (SSL_CTX_set_tmp_dh(ctx, dh) < 0) {
 731                 radlog(L_ERR, "rlm_eap_tls: Unable to set DH parameters");
 732                 DH_free(dh);
 733                 return -1;
 734         }
 735
 736         DH_free(dh);
 737         return 0;
 738 }
 739
 740
 741 /*
 742  *      Generate ephemeral RSA keys.
 743  */
 744 static int generate_eph_rsa_key(SSL_CTX *ctx)
 745 {
 746         RSA *rsa;
 747
 748         rsa = RSA_generate_key(512, RSA_F4, NULL, NULL);
 749
 750         if (!SSL_CTX_set_tmp_rsa(ctx, rsa)) {
 751                 radlog(L_ERR, "rlm_eap_tls: Couldn't set ephemeral RSA key");
 752                 return -1;
 753         }
 754
 755         RSA_free(rsa);
 756         return 0;
 757 }
 758
 759
 760 /*
 761  *      These functions don't do anything other than print debugging
 762  *      messages.
 763  *
 764  *      FIXME: Write sessions to some long-term storage, so that
 765  *             session resumption can still occur after the server
 766  *             restarts.
 767  */
 768 #define MAX_SESSION_SIZE (256)
 769
 770 static void cbtls_remove_session(UNUSED SSL_CTX *ctx, SSL_SESSION *sess)
 771 {
 772         size_t size;
 773         char buffer[2 * MAX_SESSION_SIZE + 1];
 774
 775         size = sess->session_id_length;
 776         if (size > MAX_SESSION_SIZE) size = MAX_SESSION_SIZE;
 777
 778         fr_bin2hex(sess->session_id, buffer, size);
 779
 780         DEBUG2("  SSL: Removing session %s from the cache", buffer);
 781         SSL_SESSION_free(sess);
 782
 783         return;
 784 }
 785
 786 static int cbtls_new_session(UNUSED SSL *s, SSL_SESSION *sess)
 787 {
 788         size_t size;
 789         char buffer[2 * MAX_SESSION_SIZE + 1];
 790
 791         size = sess->session_id_length;
 792         if (size > MAX_SESSION_SIZE) size = MAX_SESSION_SIZE;
 793
 794         fr_bin2hex(sess->session_id, buffer, size);
 795
 796         DEBUG2("  SSL: adding session %s to cache", buffer);
 797
 798         return 1;
 799 }
 800
 801 static SSL_SESSION *cbtls_get_session(UNUSED SSL *s,
 802                                       unsigned char *data, int len,
 803                                       UNUSED int *copy)
 804 {
 805         size_t size;
 806         char buffer[2 * MAX_SESSION_SIZE + 1];
 807
 808         size = len;
 809         if (size > MAX_SESSION_SIZE) size = MAX_SESSION_SIZE;
 810
 811         fr_bin2hex(data, buffer, size);
 812
 813         DEBUG2("  SSL: Client requested nonexistent cached session %s",
 814                buffer);
 815
 816         return NULL;
 817 }
 818
 819 #ifdef HAVE_OPENSSL_OCSP_H
 820 /*
 821  * This function extracts the OCSP Responder URL
 822  * from an existing x509 certificate.
 823  */
 824 static int ocsp_parse_cert_url(X509 *cert, char **phost, char **pport,
 825                                char **ppath, int *pssl)
 826 {
 827         int i;
 828
 829         AUTHORITY_INFO_ACCESS *aia;
 830         ACCESS_DESCRIPTION *ad;
 831
 832         aia = X509_get_ext_d2i(cert, NID_info_access, NULL, NULL);
 833
 834         for (i = 0; i < sk_ACCESS_DESCRIPTION_num(aia); i++) {
 835                 ad = sk_ACCESS_DESCRIPTION_value(aia, 0);
 836                 if (OBJ_obj2nid(ad->method) == NID_ad_OCSP) {
 837                         if (ad->location->type == GEN_URI) {
 838                                 if(OCSP_parse_url(ad->location->d.ia5->data,
 839                                         phost, pport, ppath, pssl))
 840                                         return 1;
 841                         }
 842                 }
 843         }
 844         return 0;
 845 }
 846
 847 /*
 848  * This function sends a OCSP request to a defined OCSP responder
 849  * and checks the OCSP response for correctness.
 850  */
 851 static int ocsp_check(X509_STORE *store, X509 *issuer_cert, X509 *client_cert,
 852                       fr_tls_server_conf_t *conf)
 853 {
 854         OCSP_CERTID *certid;
 855         OCSP_REQUEST *req;
 856         OCSP_RESPONSE *resp;
 857         OCSP_BASICRESP *bresp = NULL;
 858         char *host = NULL;
 859         char *port = NULL;
 860         char *path = NULL;
 861         int use_ssl = -1;
 862         BIO *cbio;
 863         int ocsp_ok;
 864         int status;
 865
 866         /*
 867          * Create OCSP Request
 868          */
 869         certid = OCSP_cert_to_id(NULL, client_cert, issuer_cert);
 870         req = OCSP_REQUEST_new();
 871         OCSP_request_add0_id(req, certid);
 872         OCSP_request_add1_nonce(req, NULL, 8);
 873
 874         /*
 875          * Send OCSP Request and get OCSP Response
 876          */
 877
 878         /* Get OCSP responder URL */
 879         if(conf->ocsp_override_url) {
 880                 OCSP_parse_url(conf->ocsp_url, &host, &port, &path, &use_ssl);
 881         }
 882         else {
 883                 ocsp_parse_cert_url(client_cert, &host, &port, &path, &use_ssl);
 884         }
 885
 886         DEBUG2("[ocsp] --> Responder URL = http://%s:%s%s", host, port, path);
 887
 888         /* Setup BIO socket to OCSP responder */
 889         cbio = BIO_new_connect(host);
 890         BIO_set_conn_port(cbio, port);
 891         BIO_do_connect(cbio);
 892
 893         /* Send OCSP request and wait for response */
 894         resp = OCSP_sendreq_bio(cbio, path, req);
 895         if(resp==0) {
 896                 radlog(L_ERR, "Error: Couldn't get OCSP response");
 897                 ocsp_ok = 0;
 898                 goto ocsp_end;
 899         }
 900
 901         /* Verify OCSP response */
 902         status = OCSP_response_status(resp);
 903         if(status != OCSP_RESPONSE_STATUS_SUCCESSFUL) {
 904                 radlog(L_ERR, "Error: OCSP response status: %s", OCSP_response_status_str(status));
 905                 ocsp_ok = 0;
 906                 goto ocsp_end;
 907         }
 908         bresp = OCSP_response_get1_basic(resp);
 909         if(OCSP_check_nonce(req, bresp)!=1) {
 910                 radlog(L_ERR, "Error: OCSP response has wrong nonce value");
 911                 ocsp_ok = 0;
 912                 goto ocsp_end;
 913         }
 914         if(OCSP_basic_verify(bresp, NULL, store, 0)!=1){
 915                 radlog(L_ERR, "Error: Couldn't verify OCSP basic response");
 916                 ocsp_ok = 0;
 917                 goto ocsp_end;
 918         }
 919
 920         ocsp_ok = 1;
 921
 922 ocsp_end:
 923         /* Free OCSP Stuff */
 924         OCSP_REQUEST_free(req);
 925         OCSP_RESPONSE_free(resp);
 926         free(host);
 927         free(port);
 928         free(path);
 929         BIO_free_all(cbio);
 930         OCSP_BASICRESP_free(bresp);
 931
 932         if (ocsp_ok) {
 933                 DEBUG2("[ocsp] --> Certificate is valid!");
 934         } else {
 935                 DEBUG2("[ocsp] --> Certificate has been expired/revoked!");
 936         }
 937
 938         return ocsp_ok;
 939 }
 940 #endif  /* HAVE_OPENSSL_OCSP_H */
 941
 942 /*
 943  *      For creating certificate attributes.
 944  */
 945 static const char *cert_attr_names[5][2] = {
 946   { "TLS-Client-Cert-Serial",           "TLS-Cert-Serial" },
 947   { "TLS-Client-Cert-Expiration",       "TLS-Cert-Expiration" },
 948   { "TLS-Client-Cert-Subject",          "TLS-Cert-Subject" },
 949   { "TLS-Client-Cert-Issuer",           "TLS-Cert-Issuer" },
 950   { "TLS-Client-Cert-Common-Name",      "TLS-Cert-Common-Name" }
 951 };
 952
 953 #define EAPTLS_SERIAL           (0)
 954 #define EAPTLS_EXPIRATION       (1)
 955 #define EAPTLS_SUBJECT          (2)
 956 #define EAPTLS_ISSUER           (3)
 957 #define EAPTLS_CN               (4)
 958
 959 /*
 960  *      Before trusting a certificate, you must make sure that the
 961  *      certificate is 'valid'. There are several steps that your
 962  *      application can take in determining if a certificate is
 963  *      valid. Commonly used steps are:
 964  *
 965  *      1.Verifying the certificate's signature, and verifying that
 966  *      the certificate has been issued by a trusted Certificate
 967  *      Authority.
 968  *
 969  *      2.Verifying that the certificate is valid for the present date
 970  *      (i.e. it is being presented within its validity dates).
 971  *
 972  *      3.Verifying that the certificate has not been revoked by its
 973  *      issuing Certificate Authority, by checking with respect to a
 974  *      Certificate Revocation List (CRL).
 975  *
 976  *      4.Verifying that the credentials presented by the certificate
 977  *      fulfill additional requirements specific to the application,
 978  *      such as with respect to access control lists or with respect
 979  *      to OCSP (Online Certificate Status Processing).
 980  *
 981  *      NOTE: This callback will be called multiple times based on the
 982  *      depth of the root certificate chain
 983  */
 984 int cbtls_verify(int ok, X509_STORE_CTX *ctx)
 985 {
 986         char subject[1024]; /* Used for the subject name */
 987         char issuer[1024]; /* Used for the issuer name */
 988         char common_name[1024];
 989         char cn_str[1024];
 990         char buf[64];
 991         X509 *client_cert;
 992         X509 *issuer_cert;
 993         SSL *ssl;
 994         int err, depth, lookup;
 995         fr_tls_server_conf_t *conf;
 996         int my_ok = ok;
 997         REQUEST *request;
 998         ASN1_INTEGER *sn = NULL;
 999         ASN1_TIME *asn_time = NULL;
1000         VALUE_PAIR **certs;
1001         char **identity;
1002 #ifdef HAVE_OPENSSL_OCSP_H
1003         X509_STORE *ocsp_store = NULL;
1004 #endif
1005
1006         client_cert = X509_STORE_CTX_get_current_cert(ctx);
1007         err = X509_STORE_CTX_get_error(ctx);
1008         depth = X509_STORE_CTX_get_error_depth(ctx);
1009
1010         lookup = depth;
1011
1012         /*
1013          *      Log client/issuing cert.  If there's an error, log
1014          *      issuing cert.
1015          */
1016         if ((lookup > 1) && !my_ok) lookup = 1;
1017
1018         /*
1019          * Retrieve the pointer to the SSL of the connection currently treated
1020          * and the application specific data stored into the SSL object.
1021          */
1022         ssl = X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx());
1023         conf = (fr_tls_server_conf_t *)SSL_get_ex_data(ssl, FR_TLS_EX_INDEX_CONF);
1024         if (!conf) return 1;
1025
1026         request = (REQUEST *)SSL_get_ex_data(ssl, FR_TLS_EX_INDEX_REQUEST);
1027
1028         if (!request) return 1; /* FIXME: outbound TLS */
1029
1030         rad_assert(request != NULL);
1031         certs = (VALUE_PAIR **)SSL_get_ex_data(ssl, FR_TLS_EX_INDEX_CERTS);
1032         rad_assert(certs != NULL);
1033         identity = (char **)SSL_get_ex_data(ssl, FR_TLS_EX_INDEX_IDENTITY);
1034 #ifdef HAVE_OPENSSL_OCSP_H
1035         ocsp_store = (X509_STORE *)SSL_get_ex_data(ssl, FR_TLS_EX_INDEX_STORE);
1036 #endif
1037
1038
1039         /*
1040          *      Get the Serial Number
1041          */
1042         buf[0] = '\0';
1043         sn = X509_get_serialNumber(client_cert);
1044
1045         /*
1046          *      For this next bit, we create the attributes *only* if
1047          *      we're at the client or issuing certificate.
1048          */
1049         if ((lookup <= 1) && sn && (sn->length < (sizeof(buf) / 2))) {
1050                 char *p = buf;
1051                 int i;
1052
1053                 for (i = 0; i < sn->length; i++) {
1054                         sprintf(p, "%02x", (unsigned int)sn->data[i]);
1055                         p += 2;
1056                 }
1057                 pairadd(certs,
1058                         pairmake(cert_attr_names[EAPTLS_SERIAL][lookup], buf, T_OP_SET));
1059         }
1060
1061
1062         /*
1063          *      Get the Expiration Date
1064          */
1065         buf[0] = '\0';
1066         asn_time = X509_get_notAfter(client_cert);
1067         if ((lookup <= 1) && asn_time && (asn_time->length < MAX_STRING_LEN)) {
1068                 memcpy(buf, (char*) asn_time->data, asn_time->length);
1069                 buf[asn_time->length] = '\0';
1070                 pairadd(certs,
1071                         pairmake(cert_attr_names[EAPTLS_EXPIRATION][lookup], buf, T_OP_SET));
1072         }
1073
1074         /*
1075          *      Get the Subject & Issuer
1076          */
1077         subject[0] = issuer[0] = '\0';
1078         X509_NAME_oneline(X509_get_subject_name(client_cert), subject,
1079                           sizeof(subject));
1080         subject[sizeof(subject) - 1] = '\0';
1081         if ((lookup <= 1) && subject[0] && (strlen(subject) < MAX_STRING_LEN)) {
1082                 pairadd(certs,
1083                         pairmake(cert_attr_names[EAPTLS_SUBJECT][lookup], subject, T_OP_SET));
1084         }
1085
1086         X509_NAME_oneline(X509_get_issuer_name(ctx->current_cert), issuer,
1087                           sizeof(issuer));
1088         issuer[sizeof(issuer) - 1] = '\0';
1089         if ((lookup <= 1) && issuer[0] && (strlen(issuer) < MAX_STRING_LEN)) {
1090                 pairadd(certs,
1091                         pairmake(cert_attr_names[EAPTLS_ISSUER][lookup], issuer, T_OP_SET));
1092         }
1093
1094         /*
1095          *      Get the Common Name
1096          */
1097         X509_NAME_get_text_by_NID(X509_get_subject_name(client_cert),
1098                                   NID_commonName, common_name, sizeof(common_name));
1099         common_name[sizeof(common_name) - 1] = '\0';
1100         if ((lookup <= 1) && common_name[0] && (strlen(common_name) < MAX_STRING_LEN)) {
1101                 pairadd(certs,
1102                         pairmake(cert_attr_names[EAPTLS_CN][lookup], common_name, T_OP_SET));
1103         }
1104
1105         /*
1106          *      If the CRL has expired, that might still be OK.
1107          */
1108         if (!my_ok &&
1109             (conf->allow_expired_crl) &&
1110             (err == X509_V_ERR_CRL_HAS_EXPIRED)) {
1111                 my_ok = 1;
1112                 X509_STORE_CTX_set_error( ctx, 0 );
1113         }
1114
1115         if (!my_ok) {
1116                 const char *p = X509_verify_cert_error_string(err);
1117                 radlog(L_ERR,"--> verify error:num=%d:%s\n",err, p);
1118                 radius_pairmake(request, &request->packet->vps,
1119                                 "Module-Failure-Message", p, T_OP_SET);
1120                 return my_ok;
1121         }
1122
1123         switch (ctx->error) {
1124
1125         case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
1126                 radlog(L_ERR, "issuer= %s\n", issuer);
1127                 break;
1128         case X509_V_ERR_CERT_NOT_YET_VALID:
1129         case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
1130                 radlog(L_ERR, "notBefore=");
1131 #if 0
1132                 ASN1_TIME_print(bio_err, X509_get_notBefore(ctx->current_cert));
1133 #endif
1134                 break;
1135         case X509_V_ERR_CERT_HAS_EXPIRED:
1136         case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
1137                 radlog(L_ERR, "notAfter=");
1138 #if 0
1139                 ASN1_TIME_print(bio_err, X509_get_notAfter(ctx->current_cert));
1140 #endif
1141                 break;
1142         }
1143
1144         /*
1145          *      If we're at the actual client cert, apply additional
1146          *      checks.
1147          */
1148         if (depth == 0) {
1149                 /*
1150                  *      If the conf tells us to, check cert issuer
1151                  *      against the specified value and fail
1152                  *      verification if they don't match.
1153                  */
1154                 if (conf->check_cert_issuer &&
1155                     (strcmp(issuer, conf->check_cert_issuer) != 0)) {
1156                         radlog(L_AUTH, "rlm_eap_tls: Certificate issuer (%s) does not match specified value (%s)!", issuer, conf->check_cert_issuer);
1157                         my_ok = 0;
1158                 }
1159
1160                 /*
1161                  *      If the conf tells us to, check the CN in the
1162                  *      cert against xlat'ed value, but only if the
1163                  *      previous checks passed.
1164                  */
1165                 if (my_ok && conf->check_cert_cn) {
1166                         if (!radius_xlat(cn_str, sizeof(cn_str), conf->check_cert_cn, request, NULL)) {
1167                                 radlog(L_ERR, "rlm_eap_tls (%s): xlat failed.",
1168                                        conf->check_cert_cn);
1169                                 /* if this fails, fail the verification */
1170                                 my_ok = 0;
1171                         } else {
1172                                 RDEBUG2("checking certificate CN (%s) with xlat'ed value (%s)", common_name, cn_str);
1173                                 if (strcmp(cn_str, common_name) != 0) {
1174                                         radlog(L_AUTH, "rlm_eap_tls: Certificate CN (%s) does not match specified value (%s)!", common_name, cn_str);
1175                                         my_ok = 0;
1176                                 }
1177                         }
1178                 } /* check_cert_cn */
1179
1180 #ifdef HAVE_OPENSSL_OCSP_H
1181                 if (my_ok && conf->ocsp_enable){
1182                         RDEBUG2("--> Starting OCSP Request");
1183                         if(X509_STORE_CTX_get1_issuer(&issuer_cert, ctx, client_cert)!=1) {
1184                                 radlog(L_ERR, "Error: Couldn't get issuer_cert for %s", common_name);
1185                         }
1186                         my_ok = ocsp_check(ocsp_store, issuer_cert, client_cert, conf);
1187                 }
1188 #endif
1189
1190                 while (conf->verify_client_cert_cmd) {
1191                         char filename[256];
1192                         int fd;
1193                         FILE *fp;
1194
1195                         snprintf(filename, sizeof(filename), "%s/%s.client.XXXXXXXX",
1196                                  conf->verify_tmp_dir, progname);
1197                         fd = mkstemp(filename);
1198                         if (fd < 0) {
1199                                 RDEBUG("Failed creating file in %s: %s",
1200                                        conf->verify_tmp_dir, strerror(errno));
1201                                 break;
1202                         }
1203
1204                         fp = fdopen(fd, "w");
1205                         if (!fp) {
1206                                 RDEBUG("Failed opening file %s: %s",
1207                                        filename, strerror(errno));
1208                                 break;
1209                         }
1210
1211                         if (!PEM_write_X509(fp, client_cert)) {
1212                                 fclose(fp);
1213                                 RDEBUG("Failed writing certificate to file");
1214                                 goto do_unlink;
1215                         }
1216                         fclose(fp);
1217
1218                         if (!radius_pairmake(request, &request->packet->vps,
1219                                              "TLS-Client-Cert-Filename",
1220                                              filename, T_OP_SET)) {
1221                                 RDEBUG("Failed creating TLS-Client-Cert-Filename");
1222
1223                                 goto do_unlink;
1224                         }
1225
1226                         RDEBUG("Verifying client certificate: %s",
1227                                conf->verify_client_cert_cmd);
1228                         if (radius_exec_program(conf->verify_client_cert_cmd,
1229                                                 request, 1, NULL, 0,
1230                                                 request->packet->vps,
1231                                                 NULL, 1) != 0) {
1232                                 radlog(L_AUTH, "rlm_eap_tls: Certificate CN (%s) fails external verification!", common_name);
1233                                 my_ok = 0;
1234                         } else {
1235                                 RDEBUG("Client certificate CN %s passed external validation", common_name);
1236                         }
1237
1238                 do_unlink:
1239                         unlink(filename);
1240                         break;
1241                 }
1242
1243
1244         } /* depth == 0 */
1245
1246         if (debug_flag > 0) {
1247                 RDEBUG2("chain-depth=%d, ", depth);
1248                 RDEBUG2("error=%d", err);
1249
1250                 RDEBUG2("--> User-Name = %s", *identity);
1251                 RDEBUG2("--> BUF-Name = %s", common_name);
1252                 RDEBUG2("--> subject = %s", subject);
1253                 RDEBUG2("--> issuer  = %s", issuer);
1254                 RDEBUG2("--> verify return:%d", my_ok);
1255         }
1256         return my_ok;
1257 }
1258
1259
1260 #ifdef HAVE_OPENSSL_OCSP_H
1261 /*
1262  *      Create Global X509 revocation store and use it to verify
1263  *      OCSP responses
1264  *
1265  *      - Load the trusted CAs
1266  *      - Load the trusted issuer certificates
1267  */
1268 static X509_STORE *init_revocation_store(fr_tls_server_conf_t *conf)
1269 {
1270         X509_STORE *store = NULL;
1271
1272         store = X509_STORE_new();
1273
1274         /* Load the CAs we trust */
1275         if (conf->ca_file || conf->ca_path)
1276                 if(!X509_STORE_load_locations(store, conf->ca_file, conf->ca_path)) {
1277                         radlog(L_ERR, "rlm_eap: X509_STORE error %s", ERR_error_string(ERR_get_error(), NULL));
1278                         radlog(L_ERR, "rlm_eap_tls: Error reading Trusted root CA list %s",conf->ca_file );
1279                         return NULL;
1280                 }
1281
1282 #ifdef X509_V_FLAG_CRL_CHECK
1283         if (conf->check_crl)
1284                 X509_STORE_set_flags(store, X509_V_FLAG_CRL_CHECK);
1285 #endif
1286         return store;
1287 }
1288 #endif  /* HAVE_OPENSSL_OCSP_H */
1289
1290 /*
1291  *      Create Global context SSL and use it in every new session
1292  *
1293  *      - Load the trusted CAs
1294  *      - Load the Private key & the certificate
1295  *      - Set the Context options & Verify options
1296  */
1297 static SSL_CTX *init_tls_ctx(fr_tls_server_conf_t *conf)
1298 {
1299         SSL_METHOD *meth;
1300         SSL_CTX *ctx;
1301         X509_STORE *certstore;
1302         int verify_mode = SSL_VERIFY_NONE;
1303         int ctx_options = 0;
1304         int type;
1305
1306         /*
1307          *      Add all the default ciphers and message digests
1308          *      Create our context.
1309          */
1310         SSL_library_init();
1311         SSL_load_error_strings();
1312
1313         /*
1314          *      SHA256 is in all versions of OpenSSL, but isn't
1315          *      initialized by default.  It's needed for WiMAX
1316          *      certificates.
1317          */
1318 #ifdef HAVE_OPENSSL_EVP_SHA256
1319         EVP_add_digest(EVP_sha256());
1320 #endif
1321
1322         meth = TLSv1_method();
1323         ctx = SSL_CTX_new(meth);
1324
1325         /*
1326          * Identify the type of certificates that needs to be loaded
1327          */
1328         if (conf->file_type) {
1329                 type = SSL_FILETYPE_PEM;
1330         } else {
1331                 type = SSL_FILETYPE_ASN1;
1332         }
1333
1334         /*
1335          * Set the password to load private key
1336          */
1337         if (conf->private_key_password) {
1338 #ifdef __APPLE__
1339                 /*
1340                  * We don't want to put the private key password in eap.conf, so  check
1341                  * for our special string which indicates we should get the password
1342                  * programmatically.
1343                  */
1344                 const char* special_string = "Apple:UseCertAdmin";
1345                 if (strncmp(conf->private_key_password,
1346                                         special_string,
1347                                         strlen(special_string)) == 0)
1348                 {
1349                         char cmd[256];
1350                         const long max_password_len = 128;
1351                         snprintf(cmd, sizeof(cmd) - 1,
1352                                          "/usr/sbin/certadmin --get-private-key-passphrase \"%s\"",
1353                                          conf->private_key_file);
1354
1355                         DEBUG2("rlm_eap: Getting private key passphrase using command \"%s\"", cmd);
1356
1357                         FILE* cmd_pipe = popen(cmd, "r");
1358                         if (!cmd_pipe) {
1359                                 radlog(L_ERR, "rlm_eap: %s command failed.      Unable to get private_key_password", cmd);
1360                                 radlog(L_ERR, "rlm_eap: Error reading private_key_file %s", conf->private_key_file);
1361                                 return NULL;
1362                         }
1363
1364                         free(conf->private_key_password);
1365                         conf->private_key_password = malloc(max_password_len * sizeof(char));
1366                         if (!conf->private_key_password) {
1367                                 radlog(L_ERR, "rlm_eap: Can't malloc space for private_key_password");
1368                                 radlog(L_ERR, "rlm_eap: Error reading private_key_file %s", conf->private_key_file);
1369                                 pclose(cmd_pipe);
1370                                 return NULL;
1371                         }
1372
1373                         fgets(conf->private_key_password, max_password_len, cmd_pipe);
1374                         pclose(cmd_pipe);
1375
1376                         /* Get rid of newline at end of password. */
1377                         conf->private_key_password[strlen(conf->private_key_password) - 1] = '\0';
1378                         DEBUG2("rlm_eap:  Password from command = \"%s\"", conf->private_key_password);
1379                 }
1380 #endif
1381                 SSL_CTX_set_default_passwd_cb_userdata(ctx, conf->private_key_password);
1382                 SSL_CTX_set_default_passwd_cb(ctx, cbtls_password);
1383         }
1384
1385         /*
1386          *      Load our keys and certificates
1387          *
1388          *      If certificates are of type PEM then we can make use
1389          *      of cert chain authentication using openssl api call
1390          *      SSL_CTX_use_certificate_chain_file.  Please see how
1391          *      the cert chain needs to be given in PEM from
1392          *      openSSL.org
1393          */
1394         if (type == SSL_FILETYPE_PEM) {
1395                 if (!(SSL_CTX_use_certificate_chain_file(ctx, conf->certificate_file))) {
1396                         radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
1397                         radlog(L_ERR, "rlm_eap_tls: Error reading certificate file %s", conf->certificate_file);
1398                         return NULL;
1399                 }
1400
1401         } else if (!(SSL_CTX_use_certificate_file(ctx, conf->certificate_file, type))) {
1402                 radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
1403                 radlog(L_ERR, "rlm_eap_tls: Error reading certificate file %s", conf->certificate_file);
1404                 return NULL;
1405         }
1406
1407         /* Load the CAs we trust */
1408         if (conf->ca_file || conf->ca_path) {
1409                 if (!SSL_CTX_load_verify_locations(ctx, conf->ca_file, conf->ca_path)) {
1410                         radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
1411                         radlog(L_ERR, "rlm_eap_tls: Error reading Trusted root CA list %s",conf->ca_file );
1412                         return NULL;
1413                 }
1414         }
1415         if (conf->ca_file && *conf->ca_file) SSL_CTX_set_client_CA_list(ctx, SSL_load_client_CA_file(conf->ca_file));
1416         if (!(SSL_CTX_use_PrivateKey_file(ctx, conf->private_key_file, type))) {
1417                 radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
1418                 radlog(L_ERR, "rlm_eap_tls: Error reading private key file %s", conf->private_key_file);
1419                 return NULL;
1420         }
1421
1422         /*
1423          * Check if the loaded private key is the right one
1424          */
1425         if (!SSL_CTX_check_private_key(ctx)) {
1426                 radlog(L_ERR, "rlm_eap_tls: Private key does not match the certificate public key");
1427                 return NULL;
1428         }
1429
1430         /*
1431          *      Set ctx_options
1432          */
1433         ctx_options |= SSL_OP_NO_SSLv2;
1434         ctx_options |= SSL_OP_NO_SSLv3;
1435 #ifdef SSL_OP_NO_TICKET
1436         ctx_options |= SSL_OP_NO_TICKET ;
1437 #endif
1438
1439         /*
1440          *      SSL_OP_SINGLE_DH_USE must be used in order to prevent
1441          *      small subgroup attacks and forward secrecy. Always
1442          *      using
1443          *
1444          *      SSL_OP_SINGLE_DH_USE has an impact on the computer
1445          *      time needed during negotiation, but it is not very
1446          *      large.
1447          */
1448         ctx_options |= SSL_OP_SINGLE_DH_USE;
1449
1450         /*
1451          *      SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS to work around issues
1452          *      in Windows Vista client.
1453          *      http://www.openssl.org/~bodo/tls-cbc.txt
1454          *      http://www.nabble.com/(RADIATOR)-Radiator-Version-3.16-released-t2600070.html
1455          */
1456         ctx_options |= SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS;
1457
1458         SSL_CTX_set_options(ctx, ctx_options);
1459
1460         /*
1461          *      TODO: Set the RSA & DH
1462          *      SSL_CTX_set_tmp_rsa_callback(ctx, cbtls_rsa);
1463          *      SSL_CTX_set_tmp_dh_callback(ctx, cbtls_dh);
1464          */
1465
1466         /*
1467          *      set the message callback to identify the type of
1468          *      message.  For every new session, there can be a
1469          *      different callback argument.
1470          *
1471          *      SSL_CTX_set_msg_callback(ctx, cbtls_msg);
1472          */
1473
1474         /* Set Info callback */
1475         SSL_CTX_set_info_callback(ctx, cbtls_info);
1476
1477         /*
1478          *      Callbacks, etc. for session resumption.
1479          */
1480         if (conf->session_cache_enable) {
1481                 SSL_CTX_sess_set_new_cb(ctx, cbtls_new_session);
1482                 SSL_CTX_sess_set_get_cb(ctx, cbtls_get_session);
1483                 SSL_CTX_sess_set_remove_cb(ctx, cbtls_remove_session);
1484
1485                 SSL_CTX_set_quiet_shutdown(ctx, 1);
1486         }
1487
1488         /*
1489          *      Check the certificates for revocation.
1490          */
1491 #ifdef X509_V_FLAG_CRL_CHECK
1492         if (conf->check_crl) {
1493           certstore = SSL_CTX_get_cert_store(ctx);
1494           if (certstore == NULL) {
1495             radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
1496             radlog(L_ERR, "rlm_eap_tls: Error reading Certificate Store");
1497             return NULL;
1498           }
1499           X509_STORE_set_flags(certstore, X509_V_FLAG_CRL_CHECK);
1500         }
1501 #endif
1502
1503         /*
1504          *      Set verify modes
1505          *      Always verify the peer certificate
1506          */
1507         verify_mode |= SSL_VERIFY_PEER;
1508         verify_mode |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
1509         verify_mode |= SSL_VERIFY_CLIENT_ONCE;
1510         SSL_CTX_set_verify(ctx, verify_mode, cbtls_verify);
1511
1512         if (conf->verify_depth) {
1513                 SSL_CTX_set_verify_depth(ctx, conf->verify_depth);
1514         }
1515
1516         /* Load randomness */
1517         if (!(RAND_load_file(conf->random_file, 1024*1024))) {
1518                 radlog(L_ERR, "rlm_eap: SSL error %s", ERR_error_string(ERR_get_error(), NULL));
1519                 radlog(L_ERR, "rlm_eap_tls: Error loading randomness");
1520                 return NULL;
1521         }
1522
1523         /*
1524          * Set the cipher list if we were told to
1525          */
1526         if (conf->cipher_list) {
1527                 if (!SSL_CTX_set_cipher_list(ctx, conf->cipher_list)) {
1528                         radlog(L_ERR, "rlm_eap_tls: Error setting cipher list");
1529                         return NULL;
1530                 }
1531         }
1532
1533         /*
1534          *      Setup session caching
1535          */
1536         if (conf->session_cache_enable) {
1537                 /*
1538                  *      Create a unique context Id per EAP-TLS configuration.
1539                  */
1540                 if (conf->session_id_name) {
1541                         snprintf(conf->session_context_id,
1542                                  sizeof(conf->session_context_id),
1543                                  "FreeRADIUS EAP-TLS %s",
1544                                  conf->session_id_name);
1545                 } else {
1546                         snprintf(conf->session_context_id,
1547                                  sizeof(conf->session_context_id),
1548                                  "FreeRADIUS EAP-TLS %p", conf);
1549                 }
1550
1551                 /*
1552                  *      Cache it, and DON'T auto-clear it.
1553                  */
1554                 SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_SERVER | SSL_SESS_CACHE_NO_AUTO_CLEAR);
1555
1556                 SSL_CTX_set_session_id_context(ctx,
1557                                                (unsigned char *) conf->session_context_id,
1558                                                (unsigned int) strlen(conf->session_context_id));
1559
1560                 /*
1561                  *      Our timeout is in hours, this is in seconds.
1562                  */
1563                 SSL_CTX_set_timeout(ctx, conf->session_timeout * 3600);
1564
1565                 /*
1566                  *      Set the maximum number of entries in the
1567                  *      session cache.
1568                  */
1569                 SSL_CTX_sess_set_cache_size(ctx, conf->session_cache_size);
1570
1571         } else {
1572                 SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
1573         }
1574
1575         return ctx;
1576 }
1577
1578
1579 void tls_server_conf_free(fr_tls_server_conf_t *conf)
1580 {
1581         if (!conf) return;
1582
1583         if (conf->cs) cf_section_parse_free(conf->cs, conf);
1584
1585         if (conf->ctx) SSL_CTX_free(conf->ctx);
1586
1587 #ifdef HAVE_OPENSSL_OCSP_H
1588         if (conf->ocsp_store) X509_STORE_free(conf->ocsp_store);
1589         conf->ocsp_store = NULL;
1590 #endif
1591
1592         memset(conf, 0, sizeof(*conf));
1593         free(conf);
1594 }
1595
1596
1597 fr_tls_server_conf_t *tls_server_conf_parse(CONF_SECTION *cs)
1598 {
1599         fr_tls_server_conf_t *conf;
1600
1601         conf = malloc(sizeof(*conf));
1602         if (!conf) {
1603                 radlog(L_ERR, "Out of memory");
1604                 return NULL;
1605         }
1606         memset(conf, 0, sizeof(*conf));
1607
1608         if (cf_section_parse(cs, conf, tls_server_config) < 0) {
1609         error:
1610                 tls_server_conf_free(conf);
1611                 return NULL;
1612         }
1613
1614         /*
1615          *      Save people from their own stupidity.
1616          */
1617         if (conf->fragment_size < 100) conf->fragment_size = 100;
1618
1619         /*
1620          *      This magic makes the administrators life HUGELY easier
1621          *      on initial deployments.
1622          *
1623          *      If the server starts up in debugging mode, AND the
1624          *      bootstrap command is configured, AND it exists, AND
1625          *      there is no server certificate
1626          */
1627         if (conf->make_cert_command && (debug_flag >= 2)) {
1628                 struct stat buf;
1629
1630                 if ((stat(conf->make_cert_command, &buf) == 0) &&
1631                     (stat(conf->certificate_file, &buf) < 0) &&
1632                     (errno == ENOENT) &&
1633                     (radius_exec_program(conf->make_cert_command, NULL, 1,
1634                                          NULL, 0, NULL, NULL, 0) != 0)) {
1635                         goto error;
1636                 }
1637         }
1638
1639         if (!conf->private_key_file) {
1640                 radlog(L_ERR, "TLS Server requires a private key file");
1641                 goto error;
1642         }
1643
1644         if (!conf->private_key_password) {
1645                 radlog(L_ERR, "TLS Server requires a private key password");
1646                 goto error;
1647         }
1648
1649         if (!conf->certificate_file) {
1650                 radlog(L_ERR, "TLS Server requires a certificate file");
1651                 goto error;
1652         }
1653
1654         /*
1655          *      Initialize TLS
1656          */
1657         conf->ctx = init_tls_ctx(conf);
1658         if (conf->ctx == NULL) {
1659                 goto error;
1660         }
1661
1662 #ifdef HAVE_OPENSSL_OCSP_H
1663         /*
1664          *      Initialize OCSP Revocation Store
1665          */
1666         if (conf->ocsp_enable) {
1667                 conf->ocsp_store = init_revocation_store(conf);
1668                 if (conf->ocsp_store == NULL) goto error;
1669         }
1670 #endif HAVE_OPENSSL_OCSP_H
1671
1672         if (load_dh_params(conf->ctx, conf->dh_file) < 0) {
1673                 goto error;
1674         }
1675
1676         if (generate_eph_rsa_key(conf->ctx) < 0) {
1677                 goto error;
1678         }
1679
1680         if (conf->verify_tmp_dir) {
1681                 if (chmod(conf->verify_tmp_dir, S_IRWXU) < 0) {
1682                         radlog(L_ERR, "Failed changing permissions on %s: %s", conf->verify_tmp_dir, strerror(errno));
1683                         goto error;
1684                 }
1685         }
1686
1687         if (conf->verify_client_cert_cmd && !conf->verify_tmp_dir) {
1688                 radlog(L_ERR, "You MUST set the verify directory in order to use verify_client_cmd");
1689                 goto error;
1690         }
1691
1692         return conf;
1693 }
1694 #endif  /* WITH_TLS */
1695