src/modules/rlm_eap/types/rlm_eap_ttls/ttls.c

   1 /*
   2  * rlm_eap_ttls.c  contains the interfaces that are called from eap
   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 2003 Alan DeKok <aland@freeradius.org>
  21  *   Copyright 2006 The FreeRADIUS server project
  22  */
  23
  24 RCSID("$Id$")
  25
  26 #include "eap_ttls.h"
  27
  28 /*
  29  *    0                   1                   2                   3
  30  *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  31  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  32  *   |                           AVP Code                            |
  33  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  34  *   |V M r r r r r r|                  AVP Length                   |
  35  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  36  *   |                        Vendor-ID (opt)                        |
  37  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  38  *   |    Data ...
  39  *   +-+-+-+-+-+-+-+-+
  40  */
  41
  42 /*
  43  *      Verify that the diameter packet is valid.
  44  */
  45 static int diameter_verify(REQUEST *request, uint8_t const *data, unsigned int data_len)
  46 {
  47         uint32_t attr;
  48         uint32_t length;
  49         unsigned int hdr_len;
  50         unsigned int remaining = data_len;
  51
  52         while (remaining > 0) {
  53                 hdr_len = 12;
  54
  55                 if (remaining < hdr_len) {
  56                   RDEBUG2("Diameter attribute is too small (%u) to contain a Diameter header", remaining);
  57                         return 0;
  58                 }
  59
  60                 memcpy(&attr, data, sizeof(attr));
  61                 attr = ntohl(attr);
  62                 memcpy(&length, data + 4, sizeof(length));
  63                 length = ntohl(length);
  64
  65                 if ((data[4] & 0x80) != 0) {
  66                         if (remaining < 16) {
  67                                 RDEBUG2("Diameter attribute is too small to contain a Diameter header with Vendor-Id");
  68                                 return 0;
  69                         }
  70
  71                         hdr_len = 16;
  72                 }
  73
  74                 /*
  75                  *      Get the length.  If it's too big, die.
  76                  */
  77                 length &= 0x00ffffff;
  78
  79                 /*
  80                  *      Too short or too long is bad.
  81                  */
  82                 if (length <= (hdr_len - 4)) {
  83                         RDEBUG2("Tunneled attribute %u is too short (%u < %u) to contain anything useful.", attr,
  84                                 length, hdr_len);
  85                         return 0;
  86                 }
  87
  88                 if (length > remaining) {
  89                         RDEBUG2("Tunneled attribute %u is longer than room remaining in the packet (%u > %u).", attr,
  90                                 length, remaining);
  91                         return 0;
  92                 }
  93
  94                 /*
  95                  *      Check for broken implementations, which don't
  96                  *      pad the AVP to a 4-octet boundary.
  97                  */
  98                 if (remaining == length) break;
  99
 100                 /*
 101                  *      The length does NOT include the padding, so
 102                  *      we've got to account for it here by rounding up
 103                  *      to the nearest 4-byte boundary.
 104                  */
 105                 length += 0x03;
 106                 length &= ~0x03;
 107
 108                 /*
 109                  *      If the rest of the diameter packet is larger than
 110                  *      this attribute, continue.
 111                  *
 112                  *      Otherwise, if the attribute over-flows the end
 113                  *      of the packet, die.
 114                  */
 115                 if (remaining < length) {
 116                         REDEBUG2("Diameter attribute overflows packet!");
 117                         return 0;
 118                 }
 119
 120                 /*
 121                  *      remaining > length, continue.
 122                  */
 123                 remaining -= length;
 124                 data += length;
 125         }
 126
 127         /*
 128          *      We got this far.  It looks OK.
 129          */
 130         return 1;
 131 }
 132
 133
 134 /*
 135  *      Convert diameter attributes to our VALUE_PAIR's
 136  */
 137 static VALUE_PAIR *diameter2vp(REQUEST *request, REQUEST *fake, SSL *ssl,
 138                                uint8_t const *data, size_t data_len)
 139 {
 140         uint32_t        attr;
 141         uint32_t        vendor;
 142         uint32_t        length;
 143         size_t          offset;
 144         size_t          size;
 145         size_t          data_left = data_len;
 146         char            *p;
 147         VALUE_PAIR      *first = NULL;
 148         VALUE_PAIR      *vp;
 149         RADIUS_PACKET   *packet = fake->packet; /* FIXME: api issues */
 150         vp_cursor_t     out;
 151
 152         fr_cursor_init(&out, &first);
 153
 154         while (data_left > 0) {
 155                 rad_assert(data_left <= data_len);
 156                 memcpy(&attr, data, sizeof(attr));
 157                 data += 4;
 158                 attr = ntohl(attr);
 159                 vendor = 0;
 160
 161                 memcpy(&length, data, sizeof(length));
 162                 data += 4;
 163                 length = ntohl(length);
 164
 165                 /*
 166                  *      A "vendor" flag, with a vendor ID of zero,
 167                  *      is equivalent to no vendor.  This is stupid.
 168                  */
 169                 offset = 8;
 170                 if ((length & (1 << 31)) != 0) {
 171                         memcpy(&vendor, data, sizeof(vendor));
 172                         vendor = ntohl(vendor);
 173
 174                         data += 4; /* skip the vendor field, it's zero */
 175                         offset += 4; /* offset to value field */
 176
 177                         if (attr > 65535) goto next_attr;
 178                         if (vendor > FR_MAX_VENDOR) goto next_attr;
 179                 }
 180
 181                 /*
 182                  *      FIXME: Handle the M bit.  For now, we assume that
 183                  *      some other module takes care of any attribute
 184                  *      with the M bit set.
 185                  */
 186
 187                 /*
 188                  *      Get the length.
 189                  */
 190                 length &= 0x00ffffff;
 191
 192                 /*
 193                  *      Get the size of the value portion of the
 194                  *      attribute.
 195                  */
 196                 size = length - offset;
 197
 198                 /*
 199                  *      Vendor attributes can be larger than 255.
 200                  *      Normal attributes cannot be.
 201                  */
 202                 if ((attr > 255) && (vendor == 0)) {
 203                         RWDEBUG2("Skipping Diameter attribute %u", attr);
 204                         goto next_attr;
 205                 }
 206
 207                 /*
 208                  *      EAP-Message AVPs can be larger than 253 octets.
 209                  *
 210                  *      For now, we rely on the main decoder in
 211                  *      src/lib/radius to decode data into VPs.  This
 212                  *      means putting the data into a RADIUS attribute
 213                  *      format.  It also means that we can't handle
 214                  *      "extended" attributes in the Diameter space.  Oh well...
 215                  */
 216                 if ((size > 253) && !((vendor == 0) && (attr == PW_EAP_MESSAGE))) {
 217                         RWDEBUG2("diameter2vp skipping long attribute %u", attr);
 218                         goto next_attr;
 219                 }
 220
 221                 /*
 222                  *      RADIUS VSAs are handled as Diameter attributes
 223                  *      with Vendor-Id == 0, and the VSA data packed
 224                  *      into the "String" field as per normal.
 225                  *
 226                  *      EXCEPT for the MS-CHAP attributes.
 227                  */
 228                 if ((vendor == 0) && (attr == PW_VENDOR_SPECIFIC)) {
 229                         ssize_t decoded;
 230                         uint8_t buffer[256];
 231
 232                         buffer[0] = PW_VENDOR_SPECIFIC;
 233                         buffer[1] = size + 2;
 234                         memcpy(buffer + 2, data, size);
 235
 236                         vp = NULL;
 237                         decoded = rad_attr2vp(packet, NULL, NULL, NULL,
 238                                               buffer, size + 2, &vp);
 239                         if (decoded < 0) {
 240                                 REDEBUG2("diameter2vp failed decoding attr: %s",
 241                                         fr_strerror());
 242                                 goto do_octets;
 243                         }
 244
 245                         if ((size_t) decoded != size + 2) {
 246                                 REDEBUG2("diameter2vp failed to entirely decode VSA");
 247                                 pairfree(&vp);
 248                                 goto do_octets;
 249                         }
 250
 251                         fr_cursor_insert(&out, vp);
 252
 253                         goto next_attr;
 254                 }
 255
 256                 /*
 257                  *      Create it.  If this fails, it's because we're OOM.
 258                  */
 259         do_octets:
 260                 vp = paircreate(packet, attr, vendor);
 261                 if (!vp) {
 262                         RDEBUG2("Failure in creating VP");
 263                         pairfree(&first);
 264                         return NULL;
 265                 }
 266
 267                 /*
 268                  *      If it's a type from our dictionary, then
 269                  *      we need to put the data in a relevant place.
 270                  *
 271                  *      @todo: Export the lib/radius.c decoder, and use it here!
 272                  */
 273                 switch (vp->da->type) {
 274                 case PW_TYPE_INTEGER:
 275                 case PW_TYPE_DATE:
 276                         if (size != vp->length) {
 277                                 DICT_ATTR const *da;
 278
 279                                 /*
 280                                  *      Bad format.  Create a "raw"
 281                                  *      attribute.
 282                                  */
 283                 raw:
 284                                 if (vp) pairfree(&vp);
 285                                 da = dict_attrunknown(attr, vendor, true);
 286                                 if (!da) return NULL;
 287                                 vp = pairalloc(packet, da);
 288                                 if (!vp) return NULL;
 289                                 pairmemcpy(vp, data, size);
 290                                 break;
 291                         }
 292                         memcpy(&vp->vp_integer, data, vp->length);
 293
 294                         /*
 295                          *      Stored in host byte order: change it.
 296                          */
 297                         vp->vp_integer = ntohl(vp->vp_integer);
 298                         break;
 299
 300                 case PW_TYPE_INTEGER64:
 301                         if (size != vp->length) goto raw;
 302                         memcpy(&vp->vp_integer64, data, vp->length);
 303
 304                         /*
 305                          *      Stored in host byte order: change it.
 306                          */
 307                         vp->vp_integer64 = ntohll(vp->vp_integer64);
 308                         break;
 309
 310                 case PW_TYPE_IPV4_ADDR:
 311                         if (size != vp->length) {
 312                                 RDEBUG2("Invalid length attribute %d",
 313                                        attr);
 314                                 pairfree(&first);
 315                                 pairfree(&vp);
 316                                 return NULL;
 317                         }
 318                         memcpy(&vp->vp_ipaddr, data, vp->length);
 319
 320                         /*
 321                          *      Stored in network byte order: don't change it.
 322                          */
 323                         break;
 324
 325                 case PW_TYPE_BYTE:
 326                         if (size != vp->length) goto raw;
 327                         vp->vp_integer = data[0];
 328                         break;
 329
 330                 case PW_TYPE_SHORT:
 331                         if (size != vp->length) goto raw;
 332                         vp->vp_integer = (data[0] * 256) + data[1];
 333                         break;
 334
 335                 case PW_TYPE_SIGNED:
 336                         if (size != vp->length) goto raw;
 337                         memcpy(&vp->vp_signed, data, vp->length);
 338                         vp->vp_signed = ntohl(vp->vp_signed);
 339                         break;
 340
 341                 case PW_TYPE_IPV6_ADDR:
 342                         if (size != vp->length) goto raw;
 343                         memcpy(&vp->vp_ipv6addr, data, vp->length);
 344                         break;
 345
 346                 case PW_TYPE_IPV6_PREFIX:
 347                         if (size != vp->length) goto raw;
 348                         memcpy(&vp->vp_ipv6prefix, data, vp->length);
 349                         break;
 350
 351                         /*
 352                          *      Ensure it's NUL terminated.
 353                          */
 354                 case PW_TYPE_STRING:
 355                         vp->vp_strvalue = p = talloc_array(vp, char, size + 1);
 356                         vp->type = VT_DATA;
 357                         memcpy(p, data, size);
 358                         p[size] = '\0';
 359                         vp->length = strlen(p);
 360                         break;
 361
 362                         /*
 363                          *      Copy it over verbatim.
 364                          */
 365                 case PW_TYPE_OCTETS:
 366                 default:
 367                         pairmemcpy(vp, data, size);
 368                         break;
 369                 }
 370
 371                 /*
 372                  *      Ensure that the client is using the
 373                  *      correct challenge.  This weirdness is
 374                  *      to protect against against replay
 375                  *      attacks, where anyone observing the
 376                  *      CHAP exchange could pose as that user,
 377                  *      by simply choosing to use the same
 378                  *      challenge.
 379                  *
 380                  *      By using a challenge based on
 381                  *      information from the current session,
 382                  *      we can guarantee that the client is
 383                  *      not *choosing* a challenge.
 384                  *
 385                  *      We're a little forgiving in that we
 386                  *      have loose checks on the length, and
 387                  *      we do NOT check the Id (first octet of
 388                  *      the response to the challenge)
 389                  *
 390                  *      But if the client gets the challenge correct,
 391                  *      we're not too worried about the Id.
 392                  */
 393                 if (((vp->da->vendor == 0) && (vp->da->attr == PW_CHAP_CHALLENGE)) ||
 394                     ((vp->da->vendor == VENDORPEC_MICROSOFT) && (vp->da->attr == PW_MSCHAP_CHALLENGE))) {
 395                         uint8_t challenge[16];
 396
 397                         if ((vp->length < 8) ||
 398                             (vp->length > 16)) {
 399                                 RDEBUG("Tunneled challenge has invalid length");
 400                                 pairfree(&first);
 401                                 pairfree(&vp);
 402                                 return NULL;
 403                         }
 404
 405                         eapttls_gen_challenge(ssl, challenge,
 406                                               sizeof(challenge));
 407
 408                         if (memcmp(challenge, vp->vp_octets,
 409                                    vp->length) != 0) {
 410                                 RDEBUG("Tunneled challenge is incorrect");
 411                                 pairfree(&first);
 412                                 pairfree(&vp);
 413                                 return NULL;
 414                         }
 415                 }
 416
 417                 /*
 418                  *      Update the list.
 419                  */
 420                 fr_cursor_insert(&out, vp);
 421
 422         next_attr:
 423                 /*
 424                  *      Catch non-aligned attributes.
 425                  */
 426                 if (data_left == length) break;
 427
 428                 /*
 429                  *      The length does NOT include the padding, so
 430                  *      we've got to account for it here by rounding up
 431                  *      to the nearest 4-byte boundary.
 432                  */
 433                 length += 0x03;
 434                 length &= ~0x03;
 435
 436                 rad_assert(data_left >= length);
 437                 data_left -= length;
 438                 data += length - offset; /* already updated */
 439         }
 440
 441         /*
 442          *      We got this far.  It looks OK.
 443          */
 444         return first;
 445 }
 446
 447 /*
 448  *      Convert VALUE_PAIR's to diameter attributes, and write them
 449  *      to an SSL session.
 450  *
 451  *      The ONLY VALUE_PAIR's which may be passed to this function
 452  *      are ones which can go inside of a RADIUS (i.e. diameter)
 453  *      packet.  So no server-configuration attributes, or the like.
 454  */
 455 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 456 {
 457         /*
 458          *      RADIUS packets are no more than 4k in size, so if
 459          *      we've got more than 4k of data to write, it's very
 460          *      bad.
 461          */
 462         uint8_t         buffer[4096];
 463         uint8_t         *p;
 464         uint32_t        attr;
 465         uint32_t        length;
 466         uint32_t        vendor;
 467         size_t          total;
 468         uint64_t        attr64;
 469         VALUE_PAIR      *vp;
 470         vp_cursor_t     cursor;
 471
 472         p = buffer;
 473         total = 0;
 474
 475         for (vp = fr_cursor_init(&cursor, &first); vp; vp = fr_cursor_next(&cursor)) {
 476                 /*
 477                  *      Too much data: die.
 478                  */
 479                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 480                         RDEBUG2("output buffer is full!");
 481                         return 0;
 482                 }
 483
 484                 /*
 485                  *      Hmm... we don't group multiple EAP-Messages
 486                  *      together.  Maybe we should...
 487                  */
 488
 489                 length = vp->length;
 490                 vendor = vp->da->vendor;
 491                 if (vendor != 0) {
 492                         attr = vp->da->attr & 0xffff;
 493                         length |= (1 << 31);
 494                 } else {
 495                         attr = vp->da->attr;
 496                 }
 497
 498                 /*
 499                  *      Hmm... set the M bit for all attributes?
 500                  */
 501                 length |= (1 << 30);
 502
 503                 attr = ntohl(attr);
 504
 505                 memcpy(p, &attr, sizeof(attr));
 506                 p += 4;
 507                 total += 4;
 508
 509                 length += 8;    /* includes 8 bytes of attr & length */
 510
 511                 if (vendor != 0) {
 512                         length += 4; /* include 4 bytes of vendor */
 513
 514                         length = ntohl(length);
 515                         memcpy(p, &length, sizeof(length));
 516                         p += 4;
 517                         total += 4;
 518
 519                         vendor = ntohl(vendor);
 520                         memcpy(p, &vendor, sizeof(vendor));
 521                         p += 4;
 522                         total += 4;
 523                 } else {
 524                         length = ntohl(length);
 525                         memcpy(p, &length, sizeof(length));
 526                         p += 4;
 527                         total += 4;
 528                 }
 529
 530                 switch (vp->da->type) {
 531                 case PW_TYPE_INTEGER:
 532                 case PW_TYPE_DATE:
 533                         attr = htonl(vp->vp_integer); /* stored in host order */
 534                         memcpy(p, &attr, sizeof(attr));
 535                         length = 4;
 536                         break;
 537
 538                 case PW_TYPE_INTEGER64:
 539                         attr64 = htonll(vp->vp_integer64); /* stored in host order */
 540                         memcpy(p, &attr64, sizeof(attr64));
 541                         length = 8;
 542                         break;
 543
 544                 case PW_TYPE_IPV4_ADDR:
 545                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 546                         length = 4;
 547                         break;
 548
 549                 case PW_TYPE_STRING:
 550                 case PW_TYPE_OCTETS:
 551                 default:
 552                         memcpy(p, vp->vp_strvalue, vp->length);
 553                         length = vp->length;
 554                         break;
 555                 }
 556
 557                 /*
 558                  *      Skip to the end of the data.
 559                  */
 560                 p += length;
 561                 total += length;
 562
 563                 /*
 564                  *      Align the data to a multiple of 4 bytes.
 565                  */
 566                 if ((total & 0x03) != 0) {
 567                         size_t i;
 568
 569                         length = 4 - (total & 0x03);
 570                         for (i = 0; i < length; i++) {
 571                                 *p = '\0';
 572                                 p++;
 573                                 total++;
 574                         }
 575                 }
 576         } /* loop over the VP's to write. */
 577
 578         /*
 579          *      Write the data in the buffer to the SSL session.
 580          */
 581         if (total > 0) {
 582 #ifndef NDEBUG
 583                 size_t i;
 584
 585                 if ((debug_flag > 2) && fr_log_fp) {
 586                         for (i = 0; i < total; i++) {
 587                                 if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 588
 589                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 590
 591                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 592                         }
 593                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 594                 }
 595 #endif
 596
 597                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 598
 599                 /*
 600                  *      FIXME: Check the return code.
 601                  */
 602                 tls_handshake_send(request, tls_session);
 603         }
 604
 605         /*
 606          *      Everything's OK.
 607          */
 608         return 1;
 609 }
 610
 611 /*
 612  *      Use a reply packet to determine what to do.
 613  */
 614 static rlm_rcode_t CC_HINT(nonnull) process_reply(UNUSED eap_handler_t *handler, tls_session_t *tls_session,
 615                                                   REQUEST *request, RADIUS_PACKET *reply)
 616 {
 617         rlm_rcode_t rcode = RLM_MODULE_REJECT;
 618         VALUE_PAIR *vp;
 619         ttls_tunnel_t *t = tls_session->opaque;
 620
 621         rad_assert(handler->request == request);
 622
 623         /*
 624          *      If the response packet was Access-Accept, then
 625          *      we're OK.  If not, die horribly.
 626          *
 627          *      FIXME: Take MS-CHAP2-Success attribute, and
 628          *      tunnel it back to the client, to authenticate
 629          *      ourselves to the client.
 630          *
 631          *      FIXME: If we have an Access-Challenge, then
 632          *      the Reply-Message is tunneled back to the client.
 633          *
 634          *      FIXME: If we have an EAP-Message, then that message
 635          *      must be tunneled back to the client.
 636          *
 637          *      FIXME: If we have an Access-Challenge with a State
 638          *      attribute, then do we tunnel that to the client, or
 639          *      keep track of it ourselves?
 640          *
 641          *      FIXME: EAP-Messages can only start with 'identity',
 642          *      NOT 'eap start', so we should check for that....
 643          */
 644         switch (reply->code) {
 645         case PW_CODE_ACCESS_ACCEPT:
 646                 RDEBUG("Got tunneled Access-Accept");
 647
 648                 rcode = RLM_MODULE_OK;
 649
 650                 /*
 651                  *      MS-CHAP2-Success means that we do NOT return
 652                  *      an Access-Accept, but instead tunnel that
 653                  *      attribute to the client, and keep going with
 654                  *      the TTLS session.  Once the client accepts
 655                  *      our identity, it will respond with an empty
 656                  *      packet, and we will send EAP-Success.
 657                  */
 658                 vp = NULL;
 659                 pairfilter(tls_session, &vp, &reply->vps, PW_MSCHAP2_SUCCESS, VENDORPEC_MICROSOFT, TAG_ANY);
 660                 if (vp) {
 661                         RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge");
 662                         rcode = RLM_MODULE_HANDLED;
 663                         t->authenticated = true;
 664
 665                         /*
 666                          *      Delete MPPE keys & encryption policy.  We don't
 667                          *      want these here.
 668                          */
 669                         pairdelete(&reply->vps, 7, VENDORPEC_MICROSOFT, TAG_ANY);
 670                         pairdelete(&reply->vps, 8, VENDORPEC_MICROSOFT, TAG_ANY);
 671                         pairdelete(&reply->vps, 16, VENDORPEC_MICROSOFT, TAG_ANY);
 672                         pairdelete(&reply->vps, 17, VENDORPEC_MICROSOFT, TAG_ANY);
 673
 674                         /*
 675                          *      Use the tunneled reply, but not now.
 676                          */
 677                         if (t->use_tunneled_reply) {
 678                                 rad_assert(!t->accept_vps);
 679                                 pairfilter(t, &t->accept_vps, &reply->vps,
 680                                           0, 0, TAG_ANY);
 681                                 rad_assert(!reply->vps);
 682                         }
 683
 684                 } else { /* no MS-CHAP2-Success */
 685                         /*
 686                          *      Can only have EAP-Message if there's
 687                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 688                          *
 689                          *      We also do NOT tunnel the EAP-Success
 690                          *      attribute back to the client, as the client
 691                          *      can figure it out, from the non-tunneled
 692                          *      EAP-Success packet.
 693                          */
 694                         pairfilter(tls_session, &vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 695                         pairfree(&vp);
 696                 }
 697
 698                 /*
 699                  *      Handle the ACK, by tunneling any necessary reply
 700                  *      VP's back to the client.
 701                  */
 702                 if (vp) {
 703                         vp2diameter(request, tls_session, vp);
 704                         pairfree(&vp);
 705                 }
 706
 707                 /*
 708                  *      If we've been told to use the attributes from
 709                  *      the reply, then do so.
 710                  *
 711                  *      WARNING: This may leak information about the
 712                  *      tunneled user!
 713                  */
 714                 if (t->use_tunneled_reply) {
 715                         pairdelete(&reply->vps, PW_PROXY_STATE, 0, TAG_ANY);
 716                         pairfilter(request->reply, &request->reply->vps,
 717                                   &reply->vps, 0, 0, TAG_ANY);
 718                 }
 719                 break;
 720
 721
 722         case PW_CODE_ACCESS_REJECT:
 723                 RDEBUG("Got tunneled Access-Reject");
 724                 rcode = RLM_MODULE_REJECT;
 725                 break;
 726
 727                 /*
 728                  *      Handle Access-Challenge, but only if we
 729                  *      send tunneled reply data.  This is because
 730                  *      an Access-Challenge means that we MUST tunnel
 731                  *      a Reply-Message to the client.
 732                  */
 733         case PW_CODE_ACCESS_CHALLENGE:
 734                 RDEBUG("Got tunneled Access-Challenge");
 735
 736                 /*
 737                  *      Keep the State attribute, if necessary.
 738                  *
 739                  *      Get rid of the old State, too.
 740                  */
 741                 pairfree(&t->state);
 742                 pairfilter(t, &t->state, &reply->vps, PW_STATE, 0, TAG_ANY);
 743
 744                 /*
 745                  *      We should really be a bit smarter about this,
 746                  *      and move over only those attributes which
 747                  *      are relevant to the authentication request,
 748                  *      but that's a lot more work, and this "dumb"
 749                  *      method works in 99.9% of the situations.
 750                  */
 751                 vp = NULL;
 752                 pairfilter(t, &vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 753
 754                 /*
 755                  *      There MUST be a Reply-Message in the challenge,
 756                  *      which we tunnel back to the client.
 757                  *
 758                  *      If there isn't one in the reply VP's, then
 759                  *      we MUST create one, with an empty string as
 760                  *      it's value.
 761                  */
 762                 pairfilter(t, &vp, &reply->vps, PW_REPLY_MESSAGE, 0, TAG_ANY);
 763
 764                 /*
 765                  *      Handle the ACK, by tunneling any necessary reply
 766                  *      VP's back to the client.
 767                  */
 768                 if (vp) {
 769                         vp2diameter(request, tls_session, vp);
 770                         pairfree(&vp);
 771                 }
 772                 rcode = RLM_MODULE_HANDLED;
 773                 break;
 774
 775         default:
 776                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 777                 rcode = RLM_MODULE_INVALID;
 778                 break;
 779         }
 780
 781         return rcode;
 782 }
 783
 784
 785 #ifdef WITH_PROXY
 786 /*
 787  *      Do post-proxy processing,
 788  */
 789 static int CC_HINT(nonnull) eapttls_postproxy(eap_handler_t *handler, void *data)
 790 {
 791         int rcode;
 792         tls_session_t *tls_session = (tls_session_t *) data;
 793         REQUEST *fake, *request = handler->request;
 794
 795         RDEBUG("Passing reply from proxy back into the tunnel");
 796
 797         /*
 798          *      If there was a fake request associated with the proxied
 799          *      request, do more processing of it.
 800          */
 801         fake = (REQUEST *) request_data_get(handler->request,
 802                                             handler->request->proxy,
 803                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 804
 805         /*
 806          *      Do the callback, if it exists, and if it was a success.
 807          */
 808         if (fake && (handler->request->proxy_reply->code == PW_CODE_ACCESS_ACCEPT)) {
 809                 /*
 810                  *      Terrible hacks.
 811                  */
 812                 rad_assert(!fake->packet);
 813                 fake->packet = talloc_steal(fake, request->proxy);
 814                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 815                 request->proxy = NULL;
 816
 817                 rad_assert(!fake->reply);
 818                 fake->reply = talloc_steal(fake, request->proxy_reply);
 819                 request->proxy_reply = NULL;
 820
 821                 if ((debug_flag > 0) && fr_log_fp) {
 822                         fprintf(fr_log_fp, "server %s {\n",
 823                                 (!fake->server) ? "" : fake->server);
 824                 }
 825
 826                 /*
 827                  *      Perform a post-auth stage for the tunneled
 828                  *      session.
 829                  */
 830                 fake->log.lvl &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 831                 rcode = rad_postauth(fake);
 832                 RDEBUG2("post-auth returns %d", rcode);
 833
 834                 if ((debug_flag > 0) && fr_log_fp) {
 835                         fprintf(fr_log_fp, "} # server %s\n",
 836                                 (!fake->server) ? "" : fake->server);
 837
 838                         RDEBUG("Final reply from tunneled session code %d",
 839                                fake->reply->code);
 840                         debug_pair_list(fake->reply->vps);
 841                 }
 842
 843                 /*
 844                  *      Terrible hacks.
 845                  */
 846                 request->proxy = talloc_steal(request, fake->packet);
 847                 fake->packet = NULL;
 848                 request->proxy_reply = talloc_steal(request, fake->reply);
 849                 fake->reply = NULL;
 850
 851                 /*
 852                  *      And we're done with this request.
 853                  */
 854
 855                 switch (rcode) {
 856                 case RLM_MODULE_FAIL:
 857                         talloc_free(fake);
 858                         eaptls_fail(handler, 0);
 859                         return 0;
 860
 861                 default:  /* Don't Do Anything */
 862                         RDEBUG2("Got reply %d",
 863                                request->proxy_reply->code);
 864                         break;
 865                 }
 866         }
 867         talloc_free(fake);      /* robust if !fake */
 868
 869         /*
 870          *      Process the reply from the home server.
 871          */
 872         rcode = process_reply(handler, tls_session, handler->request, handler->request->proxy_reply);
 873
 874         /*
 875          *      The proxy code uses the reply from the home server as
 876          *      the basis for the reply to the NAS.  We don't want that,
 877          *      so we toss it, after we've had our way with it.
 878          */
 879         pairfree(&handler->request->proxy_reply->vps);
 880
 881         switch (rcode) {
 882         case RLM_MODULE_REJECT:
 883                 RDEBUG("Reply was rejected");
 884                 break;
 885
 886         case RLM_MODULE_HANDLED:
 887                 RDEBUG("Reply was handled");
 888                 eaptls_request(handler->eap_ds, tls_session);
 889                 request->proxy_reply->code = PW_CODE_ACCESS_CHALLENGE;
 890                 return 1;
 891
 892         case RLM_MODULE_OK:
 893                 RDEBUG("Reply was OK");
 894
 895                 /*
 896                  *      Success: Automatically return MPPE keys.
 897                  */
 898                 return eaptls_success(handler, 0);
 899
 900         default:
 901                 RDEBUG("Reply was unknown");
 902                 break;
 903         }
 904
 905         eaptls_fail(handler, 0);
 906         return 0;
 907 }
 908
 909 #endif  /* WITH_PROXY */
 910
 911 /*
 912  *      Process the "diameter" contents of the tunneled data.
 913  */
 914 int eapttls_process(eap_handler_t *handler, tls_session_t *tls_session)
 915 {
 916         int code = PW_CODE_ACCESS_REJECT;
 917         rlm_rcode_t rcode;
 918         REQUEST *fake;
 919         VALUE_PAIR *vp;
 920         ttls_tunnel_t *t;
 921         uint8_t const *data;
 922         size_t data_len;
 923         REQUEST *request = handler->request;
 924
 925         /*
 926          *      Just look at the buffer directly, without doing
 927          *      record_minus.
 928          */
 929         data_len = tls_session->clean_out.used;
 930         tls_session->clean_out.used = 0;
 931         data = tls_session->clean_out.data;
 932
 933         t = (ttls_tunnel_t *) tls_session->opaque;
 934
 935         /*
 936          *      If there's no data, maybe this is an ACK to an
 937          *      MS-CHAP2-Success.
 938          */
 939         if (data_len == 0) {
 940                 if (t->authenticated) {
 941                         RDEBUG("Got ACK, and the user was already authenticated");
 942                         return PW_CODE_ACCESS_ACCEPT;
 943                 } /* else no session, no data, die. */
 944
 945                 /*
 946                  *      FIXME: Call SSL_get_error() to see what went
 947                  *      wrong.
 948                  */
 949                 RDEBUG2("SSL_read Error");
 950                 return PW_CODE_ACCESS_REJECT;
 951         }
 952
 953 #ifndef NDEBUG
 954         if ((debug_flag > 2) && fr_log_fp) {
 955                 size_t i;
 956
 957                 for (i = 0; i < data_len; i++) {
 958                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
 959
 960                         fprintf(fr_log_fp, "%02x ", data[i]);
 961
 962                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 963                 }
 964                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 965         }
 966 #endif
 967
 968         if (!diameter_verify(request, data, data_len)) {
 969                 return PW_CODE_ACCESS_REJECT;
 970         }
 971
 972         /*
 973          *      Allocate a fake REQUEST structe.
 974          */
 975         fake = request_alloc_fake(request);
 976
 977         rad_assert(!fake->packet->vps);
 978
 979         /*
 980          *      Add the tunneled attributes to the fake request.
 981          */
 982         fake->packet->vps = diameter2vp(request, fake, tls_session->ssl, data, data_len);
 983         if (!fake->packet->vps) {
 984                 talloc_free(fake);
 985                 return PW_CODE_ACCESS_REJECT;
 986         }
 987
 988         /*
 989          *      Tell the request that it's a fake one.
 990          */
 991         pairmake_packet("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
 992
 993         if ((debug_flag > 0) && fr_log_fp) {
 994                 RDEBUG("Got tunneled request");
 995
 996                 debug_pair_list(fake->packet->vps);
 997         }
 998
 999         /*
1000          *      Update other items in the REQUEST data structure.
1001          */
1002         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1003         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY);
1004
1005         /*
1006          *      No User-Name, try to create one from stored data.
1007          */
1008         if (!fake->username) {
1009                 /*
1010                  *      No User-Name in the stored data, look for
1011                  *      an EAP-Identity, and pull it out of there.
1012                  */
1013                 if (!t->username) {
1014                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
1015                         if (vp &&
1016                             (vp->length >= EAP_HEADER_LEN + 2) &&
1017                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1018                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1019                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1020                                 char *p;
1021
1022                                 /*
1023                                  *      Create & remember a User-Name
1024                                  */
1025                                 t->username = pairmake(t, NULL, "User-Name", NULL, T_OP_EQ);
1026                                 rad_assert(t->username != NULL);
1027                                 t->username->length = vp->length - 5;
1028
1029                                 t->username->vp_strvalue = p = talloc_array(t->username, char,
1030                                                                             t->username->length + 1);
1031                                 memcpy(p, vp->vp_octets + 5, t->username->length);
1032                                 p[t->username->length] = 0;
1033
1034                                 RDEBUG("Got tunneled identity of %s",
1035                                        t->username->vp_strvalue);
1036
1037                                 /*
1038                                  *      If there's a default EAP type,
1039                                  *      set it here.
1040                                  */
1041                                 if (t->default_method != 0) {
1042                                         RDEBUG("Setting default EAP type for tunneled EAP session");
1043                                         vp = paircreate(fake, PW_EAP_TYPE, 0);
1044                                         rad_assert(vp != NULL);
1045                                         vp->vp_integer = t->default_method;
1046                                         pairadd(&fake->config_items, vp);
1047                                 }
1048
1049                         } else {
1050                                 /*
1051                                  *      Don't reject the request outright,
1052                                  *      as it's permitted to do EAP without
1053                                  *      user-name.
1054                                  */
1055                                 RWDEBUG2("No EAP-Identity found to start EAP conversation");
1056                         }
1057                 } /* else there WAS a t->username */
1058
1059                 if (t->username) {
1060                         vp = paircopy(fake->packet, t->username);
1061                         pairadd(&fake->packet->vps, vp);
1062                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1063                 }
1064         } /* else the request ALREADY had a User-Name */
1065
1066         /*
1067          *      Add the State attribute, too, if it exists.
1068          */
1069         if (t->state) {
1070                 vp = paircopy(fake->packet, t->state);
1071                 if (vp) pairadd(&fake->packet->vps, vp);
1072         }
1073
1074         /*
1075          *      If this is set, we copy SOME of the request attributes
1076          *      from outside of the tunnel to inside of the tunnel.
1077          *
1078          *      We copy ONLY those attributes which do NOT already
1079          *      exist in the tunneled request.
1080          */
1081         if (t->copy_request_to_tunnel) {
1082                 VALUE_PAIR *copy;
1083                 vp_cursor_t cursor;
1084
1085                 for (vp = fr_cursor_init(&cursor, &request->packet->vps); vp; vp = fr_cursor_next(&cursor)) {
1086                         /*
1087                          *      The attribute is a server-side thingy,
1088                          *      don't copy it.
1089                          */
1090                         if ((vp->da->attr > 255) &&
1091                             (vp->da->vendor == 0)) {
1092                                 continue;
1093                         }
1094
1095                         /*
1096                          *      The outside attribute is already in the
1097                          *      tunnel, don't copy it.
1098                          *
1099                          *      This works for BOTH attributes which
1100                          *      are originally in the tunneled request,
1101                          *      AND attributes which are copied there
1102                          *      from below.
1103                          */
1104                         if (pairfind(fake->packet->vps, vp->da->attr, vp->da->vendor, TAG_ANY)) {
1105                                 continue;
1106                         }
1107
1108                         /*
1109                          *      Some attributes are handled specially.
1110                          */
1111                         switch (vp->da->attr) {
1112                                 /*
1113                                  *      NEVER copy Message-Authenticator,
1114                                  *      EAP-Message, or State.  They're
1115                                  *      only for outside of the tunnel.
1116                                  */
1117                         case PW_USER_NAME:
1118                         case PW_USER_PASSWORD:
1119                         case PW_CHAP_PASSWORD:
1120                         case PW_CHAP_CHALLENGE:
1121                         case PW_PROXY_STATE:
1122                         case PW_MESSAGE_AUTHENTICATOR:
1123                         case PW_EAP_MESSAGE:
1124                         case PW_STATE:
1125                                 continue;
1126                                 break;
1127
1128                                 /*
1129                                  *      By default, copy it over.
1130                                  */
1131                         default:
1132                                 break;
1133                         }
1134
1135                         /*
1136                          *      Don't copy from the head, we've already
1137                          *      checked it.
1138                          */
1139                         copy = paircopy2(fake->packet, vp, vp->da->attr, vp->da->vendor, TAG_ANY);
1140                         pairadd(&fake->packet->vps, copy);
1141                 }
1142         }
1143
1144         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0, TAG_ANY)) != NULL) {
1145                 fake->server = vp->vp_strvalue;
1146
1147         } else if (t->virtual_server) {
1148                 fake->server = t->virtual_server;
1149
1150         } /* else fake->server == request->server */
1151
1152
1153         if ((debug_flag > 0) && fr_log_fp) {
1154                 RDEBUG("Sending tunneled request");
1155         }
1156
1157         /*
1158          *      Call authentication recursively, which will
1159          *      do PAP, CHAP, MS-CHAP, etc.
1160          */
1161         rad_virtual_server(fake);
1162
1163         /*
1164          *      Decide what to do with the reply.
1165          */
1166         switch (fake->reply->code) {
1167         case 0:                 /* No reply code, must be proxied... */
1168 #ifdef WITH_PROXY
1169                 vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0, TAG_ANY);
1170                 if (vp) {
1171                         eap_tunnel_data_t *tunnel;
1172                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1173
1174                         /*
1175                          *      Tell the original request that it's going
1176                          *      to be proxied.
1177                          */
1178                         pairfilter(request, &request->config_items,
1179                                   &fake->config_items,
1180                                   PW_PROXY_TO_REALM, 0, TAG_ANY);
1181
1182                         /*
1183                          *      Seed the proxy packet with the
1184                          *      tunneled request.
1185                          */
1186                         rad_assert(!request->proxy);
1187                         request->proxy = talloc_steal(request, fake->packet);
1188                         memset(&request->proxy->src_ipaddr, 0,
1189                                sizeof(request->proxy->src_ipaddr));
1190                         memset(&request->proxy->src_ipaddr, 0,
1191                                sizeof(request->proxy->src_ipaddr));
1192                         request->proxy->src_port = 0;
1193                         request->proxy->dst_port = 0;
1194                         fake->packet = NULL;
1195                         rad_free(&fake->reply);
1196                         fake->reply = NULL;
1197
1198                         /*
1199                          *      Set up the callbacks for the tunnel
1200                          */
1201                         tunnel = talloc_zero(request, eap_tunnel_data_t);
1202                         tunnel->tls_session = tls_session;
1203                         tunnel->callback = eapttls_postproxy;
1204
1205                         /*
1206                          *      Associate the callback with the request.
1207                          */
1208                         code = request_data_add(request, request->proxy, REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1209                                                 tunnel, false);
1210                         rad_assert(code == 0);
1211
1212                         /*
1213                          *      rlm_eap.c has taken care of associating
1214                          *      the handler with the fake request.
1215                          *
1216                          *      So we associate the fake request with
1217                          *      this request.
1218                          */
1219                         code = request_data_add(request, request->proxy, REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1220                                                 fake, true);
1221                         rad_assert(code == 0);
1222                         fake = NULL;
1223
1224                         /*
1225                          *      Didn't authenticate the packet, but
1226                          *      we're proxying it.
1227                          */
1228                         code = PW_CODE_STATUS_CLIENT;
1229
1230                 } else
1231 #endif  /* WITH_PROXY */
1232                   {
1233                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1234                                request->number);
1235                         code = PW_CODE_ACCESS_REJECT;
1236                 }
1237                 break;
1238
1239         default:
1240                 /*
1241                  *      Returns RLM_MODULE_FOO, and we want to return PW_FOO
1242                  */
1243                 rcode = process_reply(handler, tls_session, request, fake->reply);
1244                 switch (rcode) {
1245                 case RLM_MODULE_REJECT:
1246                         code = PW_CODE_ACCESS_REJECT;
1247                         break;
1248
1249                 case RLM_MODULE_HANDLED:
1250                         code = PW_CODE_ACCESS_CHALLENGE;
1251                         break;
1252
1253                 case RLM_MODULE_OK:
1254                         code = PW_CODE_ACCESS_ACCEPT;
1255                         break;
1256
1257                 default:
1258                         code = PW_CODE_ACCESS_REJECT;
1259                         break;
1260                 }
1261                 break;
1262         }
1263
1264         talloc_free(fake);
1265
1266         return code;
1267 }