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         paircursor(&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(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                         pairinsert(&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                                 const DICT_ATTR *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(NULL, da);
 288                                 pairmemcpy(vp, data, size);
 289                                 break;
 290                         }
 291                         memcpy(&vp->vp_integer, data, vp->length);
 292
 293                         /*
 294                          *      Stored in host byte order: change it.
 295                          */
 296                         vp->vp_integer = ntohl(vp->vp_integer);
 297                         break;
 298
 299                 case PW_TYPE_INTEGER64:
 300                         if (size != vp->length) goto raw;
 301                         memcpy(&vp->vp_integer64, data, vp->length);
 302
 303                         /*
 304                          *      Stored in host byte order: change it.
 305                          */
 306                         vp->vp_integer64 = ntohll(vp->vp_integer64);
 307                         break;
 308
 309                 case PW_TYPE_IPADDR:
 310                         if (size != vp->length) {
 311                                 RDEBUG2("Invalid length attribute %d",
 312                                        attr);
 313                                 pairfree(&first);
 314                                 pairfree(&vp);
 315                                 return NULL;
 316                         }
 317                         memcpy(&vp->vp_ipaddr, data, vp->length);
 318
 319                         /*
 320                          *      Stored in network byte order: don't change it.
 321                          */
 322                         break;
 323
 324                 case PW_TYPE_BYTE:
 325                         if (size != vp->length) goto raw;
 326                         vp->vp_integer = data[0];
 327                         break;
 328
 329                 case PW_TYPE_SHORT:
 330                         if (size != vp->length) goto raw;
 331                         vp->vp_integer = (data[0] * 256) + data[1];
 332                         break;
 333
 334                 case PW_TYPE_SIGNED:
 335                         if (size != vp->length) goto raw;
 336                         memcpy(&vp->vp_signed, data, vp->length);
 337                         vp->vp_signed = ntohl(vp->vp_signed);
 338                         break;
 339
 340                 case PW_TYPE_IPV6ADDR:
 341                         if (size != vp->length) goto raw;
 342                         memcpy(&vp->vp_ipv6addr, data, vp->length);
 343                         break;
 344
 345                 case PW_TYPE_IPV6PREFIX:
 346                         if (size != vp->length) goto raw;
 347                         memcpy(&vp->vp_ipv6prefix, data, vp->length);
 348                         break;
 349
 350                         /*
 351                          *      Ensure it's NUL terminated.
 352                          */
 353                 case PW_TYPE_STRING:
 354                         vp->vp_strvalue = p = talloc_array(vp, char, size + 1);
 355                         memcpy(p, data, size);
 356                         p[size] = '\0';
 357                         vp->length = strlen(p);
 358                         break;
 359
 360                         /*
 361                          *      Copy it over verbatim.
 362                          */
 363                 case PW_TYPE_OCTETS:
 364                 default:
 365                         pairmemcpy(vp, data, size);
 366                         break;
 367                 }
 368
 369                 /*
 370                  *      Ensure that the client is using the
 371                  *      correct challenge.  This weirdness is
 372                  *      to protect against against replay
 373                  *      attacks, where anyone observing the
 374                  *      CHAP exchange could pose as that user,
 375                  *      by simply choosing to use the same
 376                  *      challenge.
 377                  *
 378                  *      By using a challenge based on
 379                  *      information from the current session,
 380                  *      we can guarantee that the client is
 381                  *      not *choosing* a challenge.
 382                  *
 383                  *      We're a little forgiving in that we
 384                  *      have loose checks on the length, and
 385                  *      we do NOT check the Id (first octet of
 386                  *      the response to the challenge)
 387                  *
 388                  *      But if the client gets the challenge correct,
 389                  *      we're not too worried about the Id.
 390                  */
 391                 if (((vp->da->vendor == 0) && (vp->da->attr == PW_CHAP_CHALLENGE)) ||
 392                     ((vp->da->vendor == VENDORPEC_MICROSOFT) && (vp->da->attr == PW_MSCHAP_CHALLENGE))) {
 393                         uint8_t challenge[16];
 394
 395                         if ((vp->length < 8) ||
 396                             (vp->length > 16)) {
 397                                 RDEBUG("Tunneled challenge has invalid length");
 398                                 pairfree(&first);
 399                                 pairfree(&vp);
 400                                 return NULL;
 401                         }
 402
 403                         eapttls_gen_challenge(ssl, challenge,
 404                                               sizeof(challenge));
 405
 406                         if (memcmp(challenge, vp->vp_octets,
 407                                    vp->length) != 0) {
 408                                 RDEBUG("Tunneled challenge is incorrect");
 409                                 pairfree(&first);
 410                                 pairfree(&vp);
 411                                 return NULL;
 412                         }
 413                 }
 414
 415                 /*
 416                  *      Update the list.
 417                  */
 418                 pairinsert(&out, vp);
 419
 420         next_attr:
 421                 /*
 422                  *      Catch non-aligned attributes.
 423                  */
 424                 if (data_left == length) break;
 425
 426                 /*
 427                  *      The length does NOT include the padding, so
 428                  *      we've got to account for it here by rounding up
 429                  *      to the nearest 4-byte boundary.
 430                  */
 431                 length += 0x03;
 432                 length &= ~0x03;
 433
 434                 rad_assert(data_left >= length);
 435                 data_left -= length;
 436                 data += length - offset; /* already updated */
 437         }
 438
 439         /*
 440          *      We got this far.  It looks OK.
 441          */
 442         return first;
 443 }
 444
 445 /*
 446  *      Convert VALUE_PAIR's to diameter attributes, and write them
 447  *      to an SSL session.
 448  *
 449  *      The ONLY VALUE_PAIR's which may be passed to this function
 450  *      are ones which can go inside of a RADIUS (i.e. diameter)
 451  *      packet.  So no server-configuration attributes, or the like.
 452  */
 453 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 454 {
 455         /*
 456          *      RADIUS packets are no more than 4k in size, so if
 457          *      we've got more than 4k of data to write, it's very
 458          *      bad.
 459          */
 460         uint8_t         buffer[4096];
 461         uint8_t         *p;
 462         uint32_t        attr;
 463         uint32_t        length;
 464         uint32_t        vendor;
 465         size_t          total;
 466         uint64_t        attr64;
 467         VALUE_PAIR      *vp;
 468         vp_cursor_t     cursor;
 469
 470         p = buffer;
 471         total = 0;
 472
 473         for (vp = paircursor(&cursor, &first); vp; vp = pairnext(&cursor)) {
 474                 /*
 475                  *      Too much data: die.
 476                  */
 477                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 478                         RDEBUG2("output buffer is full!");
 479                         return 0;
 480                 }
 481
 482                 /*
 483                  *      Hmm... we don't group multiple EAP-Messages
 484                  *      together.  Maybe we should...
 485                  */
 486
 487                 length = vp->length;
 488                 vendor = vp->da->vendor;
 489                 if (vendor != 0) {
 490                         attr = vp->da->attr & 0xffff;
 491                         length |= (1 << 31);
 492                 } else {
 493                         attr = vp->da->attr;
 494                 }
 495
 496                 /*
 497                  *      Hmm... set the M bit for all attributes?
 498                  */
 499                 length |= (1 << 30);
 500
 501                 attr = ntohl(attr);
 502
 503                 memcpy(p, &attr, sizeof(attr));
 504                 p += 4;
 505                 total += 4;
 506
 507                 length += 8;    /* includes 8 bytes of attr & length */
 508
 509                 if (vendor != 0) {
 510                         length += 4; /* include 4 bytes of vendor */
 511
 512                         length = ntohl(length);
 513                         memcpy(p, &length, sizeof(length));
 514                         p += 4;
 515                         total += 4;
 516
 517                         vendor = ntohl(vendor);
 518                         memcpy(p, &vendor, sizeof(vendor));
 519                         p += 4;
 520                         total += 4;
 521                 } else {
 522                         length = ntohl(length);
 523                         memcpy(p, &length, sizeof(length));
 524                         p += 4;
 525                         total += 4;
 526                 }
 527
 528                 switch (vp->da->type) {
 529                 case PW_TYPE_INTEGER:
 530                 case PW_TYPE_DATE:
 531                         attr = htonl(vp->vp_integer); /* stored in host order */
 532                         memcpy(p, &attr, sizeof(attr));
 533                         length = 4;
 534                         break;
 535
 536                 case PW_TYPE_INTEGER64:
 537                         attr64 = htonll(vp->vp_integer64); /* stored in host order */
 538                         memcpy(p, &attr64, sizeof(attr64));
 539                         length = 8;
 540                         break;
 541
 542                 case PW_TYPE_IPADDR:
 543                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 544                         length = 4;
 545                         break;
 546
 547                 case PW_TYPE_STRING:
 548                 case PW_TYPE_OCTETS:
 549                 default:
 550                         memcpy(p, vp->vp_strvalue, vp->length);
 551                         length = vp->length;
 552                         break;
 553                 }
 554
 555                 /*
 556                  *      Skip to the end of the data.
 557                  */
 558                 p += length;
 559                 total += length;
 560
 561                 /*
 562                  *      Align the data to a multiple of 4 bytes.
 563                  */
 564                 if ((total & 0x03) != 0) {
 565                         size_t i;
 566
 567                         length = 4 - (total & 0x03);
 568                         for (i = 0; i < length; i++) {
 569                                 *p = '\0';
 570                                 p++;
 571                                 total++;
 572                         }
 573                 }
 574         } /* loop over the VP's to write. */
 575
 576         /*
 577          *      Write the data in the buffer to the SSL session.
 578          */
 579         if (total > 0) {
 580 #ifndef NDEBUG
 581                 size_t i;
 582
 583                 if ((debug_flag > 2) && fr_log_fp) {
 584                         for (i = 0; i < total; i++) {
 585                                 if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 586
 587                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 588
 589                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 590                         }
 591                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 592                 }
 593 #endif
 594
 595                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 596
 597                 /*
 598                  *      FIXME: Check the return code.
 599                  */
 600                 tls_handshake_send(request, tls_session);
 601         }
 602
 603         /*
 604          *      Everything's OK.
 605          */
 606         return 1;
 607 }
 608
 609 /*
 610  *      Use a reply packet to determine what to do.
 611  */
 612 static int process_reply(UNUSED eap_handler_t *handler, tls_session_t *tls_session,
 613                          REQUEST *request, RADIUS_PACKET *reply)
 614 {
 615         int rcode = RLM_MODULE_REJECT;
 616         VALUE_PAIR *vp;
 617         ttls_tunnel_t *t = tls_session->opaque;
 618
 619         rad_assert(request != NULL);
 620         rad_assert(handler->request == request);
 621
 622         /*
 623          *      If the response packet was Access-Accept, then
 624          *      we're OK.  If not, die horribly.
 625          *
 626          *      FIXME: Take MS-CHAP2-Success attribute, and
 627          *      tunnel it back to the client, to authenticate
 628          *      ourselves to the client.
 629          *
 630          *      FIXME: If we have an Access-Challenge, then
 631          *      the Reply-Message is tunneled back to the client.
 632          *
 633          *      FIXME: If we have an EAP-Message, then that message
 634          *      must be tunneled back to the client.
 635          *
 636          *      FIXME: If we have an Access-Challenge with a State
 637          *      attribute, then do we tunnel that to the client, or
 638          *      keep track of it ourselves?
 639          *
 640          *      FIXME: EAP-Messages can only start with 'identity',
 641          *      NOT 'eap start', so we should check for that....
 642          */
 643         switch (reply->code) {
 644         case PW_AUTHENTICATION_ACK:
 645                 RDEBUG("Got tunneled Access-Accept");
 646
 647                 rcode = RLM_MODULE_OK;
 648
 649                 /*
 650                  *      MS-CHAP2-Success means that we do NOT return
 651                  *      an Access-Accept, but instead tunnel that
 652                  *      attribute to the client, and keep going with
 653                  *      the TTLS session.  Once the client accepts
 654                  *      our identity, it will respond with an empty
 655                  *      packet, and we will send EAP-Success.
 656                  */
 657                 vp = NULL;
 658                 pairfilter(tls_session, &vp, &reply->vps, PW_MSCHAP2_SUCCESS, VENDORPEC_MICROSOFT, TAG_ANY);
 659                 if (vp) {
 660                         RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge.");
 661                         rcode = RLM_MODULE_HANDLED;
 662                         t->authenticated = true;
 663
 664                         /*
 665                          *      Delete MPPE keys & encryption policy.  We don't
 666                          *      want these here.
 667                          */
 668                         pairdelete(&reply->vps, 7, VENDORPEC_MICROSOFT, TAG_ANY);
 669                         pairdelete(&reply->vps, 8, VENDORPEC_MICROSOFT, TAG_ANY);
 670                         pairdelete(&reply->vps, 16, VENDORPEC_MICROSOFT, TAG_ANY);
 671                         pairdelete(&reply->vps, 17, VENDORPEC_MICROSOFT, TAG_ANY);
 672
 673                         /*
 674                          *      Use the tunneled reply, but not now.
 675                          */
 676                         if (t->use_tunneled_reply) {
 677                                 rad_assert(!t->accept_vps);
 678                                 pairfilter(t, &t->accept_vps, &reply->vps,
 679                                           0, 0, TAG_ANY);
 680                                 rad_assert(!reply->vps);
 681                         }
 682
 683                 } else { /* no MS-CHAP2-Success */
 684                         /*
 685                          *      Can only have EAP-Message if there's
 686                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 687                          *
 688                          *      We also do NOT tunnel the EAP-Success
 689                          *      attribute back to the client, as the client
 690                          *      can figure it out, from the non-tunneled
 691                          *      EAP-Success packet.
 692                          */
 693                         pairfilter(tls_session, &vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 694                         pairfree(&vp);
 695                 }
 696
 697                 /*
 698                  *      Handle the ACK, by tunneling any necessary reply
 699                  *      VP's back to the client.
 700                  */
 701                 if (vp) {
 702                         vp2diameter(request, tls_session, vp);
 703                         pairfree(&vp);
 704                 }
 705
 706                 /*
 707                  *      If we've been told to use the attributes from
 708                  *      the reply, then do so.
 709                  *
 710                  *      WARNING: This may leak information about the
 711                  *      tunneled user!
 712                  */
 713                 if (t->use_tunneled_reply) {
 714                         pairdelete(&reply->vps, PW_PROXY_STATE, 0, TAG_ANY);
 715                         pairfilter(request->reply, &request->reply->vps,
 716                                   &reply->vps, 0, 0, TAG_ANY);
 717                 }
 718                 break;
 719
 720
 721         case PW_AUTHENTICATION_REJECT:
 722                 RDEBUG("Got tunneled Access-Reject");
 723                 rcode = RLM_MODULE_REJECT;
 724                 break;
 725
 726                 /*
 727                  *      Handle Access-Challenge, but only if we
 728                  *      send tunneled reply data.  This is because
 729                  *      an Access-Challenge means that we MUST tunnel
 730                  *      a Reply-Message to the client.
 731                  */
 732         case PW_ACCESS_CHALLENGE:
 733                 RDEBUG("Got tunneled Access-Challenge");
 734
 735                 /*
 736                  *      Keep the State attribute, if necessary.
 737                  *
 738                  *      Get rid of the old State, too.
 739                  */
 740                 pairfree(&t->state);
 741                 pairfilter(t, &t->state, &reply->vps, PW_STATE, 0, TAG_ANY);
 742
 743                 /*
 744                  *      We should really be a bit smarter about this,
 745                  *      and move over only those attributes which
 746                  *      are relevant to the authentication request,
 747                  *      but that's a lot more work, and this "dumb"
 748                  *      method works in 99.9% of the situations.
 749                  */
 750                 vp = NULL;
 751                 pairfilter(t, &vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 752
 753                 /*
 754                  *      There MUST be a Reply-Message in the challenge,
 755                  *      which we tunnel back to the client.
 756                  *
 757                  *      If there isn't one in the reply VP's, then
 758                  *      we MUST create one, with an empty string as
 759                  *      it's value.
 760                  */
 761                 pairfilter(t, &vp, &reply->vps, PW_REPLY_MESSAGE, 0, TAG_ANY);
 762
 763                 /*
 764                  *      Handle the ACK, by tunneling any necessary reply
 765                  *      VP's back to the client.
 766                  */
 767                 if (vp) {
 768                         vp2diameter(request, tls_session, vp);
 769                         pairfree(&vp);
 770                 }
 771                 rcode = RLM_MODULE_HANDLED;
 772                 break;
 773
 774         default:
 775                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 776                 rcode = RLM_MODULE_INVALID;
 777                 break;
 778         }
 779
 780         return rcode;
 781 }
 782
 783
 784 #ifdef WITH_PROXY
 785 /*
 786  *      Do post-proxy processing,
 787  */
 788 static int eapttls_postproxy(eap_handler_t *handler, void *data)
 789 {
 790         int rcode;
 791         tls_session_t *tls_session = (tls_session_t *) data;
 792         REQUEST *fake, *request = handler->request;
 793
 794         rad_assert(request != NULL);
 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 &&
 809             handler->request->proxy_reply &&
 810             (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 811                 /*
 812                  *      Terrible hacks.
 813                  */
 814                 rad_assert(!fake->packet);
 815                 fake->packet = request->proxy;
 816                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 817                 request->proxy = NULL;
 818
 819                 rad_assert(!fake->reply);
 820                 fake->reply = request->proxy_reply;
 821                 request->proxy_reply = NULL;
 822
 823                 if ((debug_flag > 0) && fr_log_fp) {
 824                         fprintf(fr_log_fp, "server %s {\n",
 825                                 (!fake->server) ? "" : fake->server);
 826                 }
 827
 828                 /*
 829                  *      Perform a post-auth stage for the tunneled
 830                  *      session.
 831                  */
 832                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 833                 rcode = rad_postauth(fake);
 834                 RDEBUG2("post-auth returns %d", rcode);
 835
 836                 if ((debug_flag > 0) && fr_log_fp) {
 837                         fprintf(fr_log_fp, "} # server %s\n",
 838                                 (!fake->server) ? "" : fake->server);
 839
 840                         RDEBUG("Final reply from tunneled session code %d",
 841                                fake->reply->code);
 842                         debug_pair_list(fake->reply->vps);
 843                 }
 844
 845                 /*
 846                  *      Terrible hacks.
 847                  */
 848                 request->proxy = fake->packet;
 849                 fake->packet = NULL;
 850                 request->proxy_reply = fake->reply;
 851                 fake->reply = NULL;
 852
 853                 /*
 854                  *      And we're done with this request.
 855                  */
 856
 857                 switch (rcode) {
 858                 case RLM_MODULE_FAIL:
 859                         request_free(&fake);
 860                         eaptls_fail(handler, 0);
 861                         return 0;
 862                         break;
 863
 864                 default:  /* Don't Do Anything */
 865                         RDEBUG2("Got reply %d",
 866                                request->proxy_reply->code);
 867                         break;
 868                 }
 869         }
 870         request_free(&fake);    /* robust if !fake */
 871
 872         /*
 873          *      Process the reply from the home server.
 874          */
 875         rcode = process_reply(handler, tls_session, handler->request,
 876                               handler->request->proxy_reply);
 877
 878         /*
 879          *      The proxy code uses the reply from the home server as
 880          *      the basis for the reply to the NAS.  We don't want that,
 881          *      so we toss it, after we've had our way with it.
 882          */
 883         pairfree(&handler->request->proxy_reply->vps);
 884
 885         switch (rcode) {
 886         case RLM_MODULE_REJECT:
 887                 RDEBUG("Reply was rejected");
 888                 break;
 889
 890         case RLM_MODULE_HANDLED:
 891                 RDEBUG("Reply was handled");
 892                 eaptls_request(handler->eap_ds, tls_session);
 893                 return 1;
 894
 895         case RLM_MODULE_OK:
 896                 RDEBUG("Reply was OK");
 897
 898                 /*
 899                  *      Success: Automatically return MPPE keys.
 900                  */
 901                 return eaptls_success(handler, 0);
 902
 903         default:
 904                 RDEBUG("Reply was unknown.");
 905                 break;
 906         }
 907
 908         eaptls_fail(handler, 0);
 909         return 0;
 910 }
 911
 912
 913 /*
 914  *      Free a request.
 915  */
 916 static void my_request_free(void *data)
 917 {
 918         REQUEST *request = (REQUEST *)data;
 919
 920         request_free(&request);
 921 }
 922 #endif  /* WITH_PROXY */
 923
 924 /*
 925  *      Process the "diameter" contents of the tunneled data.
 926  */
 927 int eapttls_process(eap_handler_t *handler, tls_session_t *tls_session)
 928 {
 929         int rcode = PW_AUTHENTICATION_REJECT;
 930         REQUEST *fake;
 931         VALUE_PAIR *vp;
 932         ttls_tunnel_t *t;
 933         const uint8_t *data;
 934         size_t data_len;
 935         REQUEST *request = handler->request;
 936
 937         rad_assert(request != NULL);
 938
 939         /*
 940          *      Just look at the buffer directly, without doing
 941          *      record_minus.
 942          */
 943         data_len = tls_session->clean_out.used;
 944         tls_session->clean_out.used = 0;
 945         data = tls_session->clean_out.data;
 946
 947         t = (ttls_tunnel_t *) tls_session->opaque;
 948
 949         /*
 950          *      If there's no data, maybe this is an ACK to an
 951          *      MS-CHAP2-Success.
 952          */
 953         if (data_len == 0) {
 954                 if (t->authenticated) {
 955                         RDEBUG("Got ACK, and the user was already authenticated.");
 956                         return PW_AUTHENTICATION_ACK;
 957                 } /* else no session, no data, die. */
 958
 959                 /*
 960                  *      FIXME: Call SSL_get_error() to see what went
 961                  *      wrong.
 962                  */
 963                 RDEBUG2("SSL_read Error");
 964                 return PW_AUTHENTICATION_REJECT;
 965         }
 966
 967 #ifndef NDEBUG
 968         if ((debug_flag > 2) && fr_log_fp) {
 969                 size_t i;
 970
 971                 for (i = 0; i < data_len; i++) {
 972                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
 973
 974                         fprintf(fr_log_fp, "%02x ", data[i]);
 975
 976                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 977                 }
 978                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 979         }
 980 #endif
 981
 982         if (!diameter_verify(request, data, data_len)) {
 983                 return PW_AUTHENTICATION_REJECT;
 984         }
 985
 986         /*
 987          *      Allocate a fake REQUEST structe.
 988          */
 989         fake = request_alloc_fake(request);
 990
 991         rad_assert(!fake->packet->vps);
 992
 993         /*
 994          *      Add the tunneled attributes to the fake request.
 995          */
 996         fake->packet->vps = diameter2vp(request, fake, tls_session->ssl, data, data_len);
 997         if (!fake->packet->vps) {
 998                 request_free(&fake);
 999                 return PW_AUTHENTICATION_REJECT;
1000         }
1001
1002         /*
1003          *      Tell the request that it's a fake one.
1004          */
1005         pairmake_packet("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
1006
1007         if ((debug_flag > 0) && fr_log_fp) {
1008                 RDEBUG("Got tunneled request");
1009
1010                 debug_pair_list(fake->packet->vps);
1011         }
1012
1013         /*
1014          *      Update other items in the REQUEST data structure.
1015          */
1016         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1017         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY);
1018
1019         /*
1020          *      No User-Name, try to create one from stored data.
1021          */
1022         if (!fake->username) {
1023                 /*
1024                  *      No User-Name in the stored data, look for
1025                  *      an EAP-Identity, and pull it out of there.
1026                  */
1027                 if (!t->username) {
1028                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
1029                         if (vp &&
1030                             (vp->length >= EAP_HEADER_LEN + 2) &&
1031                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1032                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1033                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1034                                 char *p;
1035
1036                                 /*
1037                                  *      Create & remember a User-Name
1038                                  */
1039                                 t->username = pairmake(t, NULL, "User-Name", NULL, T_OP_EQ);
1040                                 rad_assert(t->username != NULL);
1041                                 t->username->length = vp->length - 5;
1042
1043                                 t->username->vp_strvalue = p = talloc_array(t->username, char,
1044                                                                             t->username->length + 1);
1045                                 memcpy(p, vp->vp_octets + 5, t->username->length);
1046                                 p[t->username->length] = 0;
1047
1048                                 RDEBUG("Got tunneled identity of %s",
1049                                        t->username->vp_strvalue);
1050
1051                                 /*
1052                                  *      If there's a default EAP type,
1053                                  *      set it here.
1054                                  */
1055                                 if (t->default_method != 0) {
1056                                         RDEBUG("Setting default EAP type for tunneled EAP session.");
1057                                         vp = paircreate(fake, PW_EAP_TYPE, 0);
1058                                         rad_assert(vp != NULL);
1059                                         vp->vp_integer = t->default_method;
1060                                         pairadd(&fake->config_items, vp);
1061                                 }
1062
1063                         } else {
1064                                 /*
1065                                  *      Don't reject the request outright,
1066                                  *      as it's permitted to do EAP without
1067                                  *      user-name.
1068                                  */
1069                                 RWDEBUG2("No EAP-Identity found to start EAP conversation.");
1070                         }
1071                 } /* else there WAS a t->username */
1072
1073                 if (t->username) {
1074                         vp = paircopy(fake->packet, t->username);
1075                         pairadd(&fake->packet->vps, vp);
1076                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1077                 }
1078         } /* else the request ALREADY had a User-Name */
1079
1080         /*
1081          *      Add the State attribute, too, if it exists.
1082          */
1083         if (t->state) {
1084                 vp = paircopy(fake->packet, t->state);
1085                 if (vp) pairadd(&fake->packet->vps, vp);
1086         }
1087
1088         /*
1089          *      If this is set, we copy SOME of the request attributes
1090          *      from outside of the tunnel to inside of the tunnel.
1091          *
1092          *      We copy ONLY those attributes which do NOT already
1093          *      exist in the tunneled request.
1094          */
1095         if (t->copy_request_to_tunnel) {
1096                 VALUE_PAIR *copy;
1097                 vp_cursor_t cursor;
1098
1099                 for (vp = paircursor(&cursor, &request->packet->vps); vp; vp = pairnext(&cursor)) {
1100                         /*
1101                          *      The attribute is a server-side thingy,
1102                          *      don't copy it.
1103                          */
1104                         if ((vp->da->attr > 255) &&
1105                             (vp->da->vendor == 0)) {
1106                                 continue;
1107                         }
1108
1109                         /*
1110                          *      The outside attribute is already in the
1111                          *      tunnel, don't copy it.
1112                          *
1113                          *      This works for BOTH attributes which
1114                          *      are originally in the tunneled request,
1115                          *      AND attributes which are copied there
1116                          *      from below.
1117                          */
1118                         if (pairfind(fake->packet->vps, vp->da->attr, vp->da->vendor, TAG_ANY)) {
1119                                 continue;
1120                         }
1121
1122                         /*
1123                          *      Some attributes are handled specially.
1124                          */
1125                         switch (vp->da->attr) {
1126                                 /*
1127                                  *      NEVER copy Message-Authenticator,
1128                                  *      EAP-Message, or State.  They're
1129                                  *      only for outside of the tunnel.
1130                                  */
1131                         case PW_USER_NAME:
1132                         case PW_USER_PASSWORD:
1133                         case PW_CHAP_PASSWORD:
1134                         case PW_CHAP_CHALLENGE:
1135                         case PW_PROXY_STATE:
1136                         case PW_MESSAGE_AUTHENTICATOR:
1137                         case PW_EAP_MESSAGE:
1138                         case PW_STATE:
1139                                 continue;
1140                                 break;
1141
1142                                 /*
1143                                  *      By default, copy it over.
1144                                  */
1145                         default:
1146                                 break;
1147                         }
1148
1149                         /*
1150                          *      Don't copy from the head, we've already
1151                          *      checked it.
1152                          */
1153                         copy = paircopy2(fake->packet, vp, vp->da->attr, vp->da->vendor, TAG_ANY);
1154                         pairadd(&fake->packet->vps, copy);
1155                 }
1156         }
1157
1158         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0, TAG_ANY)) != NULL) {
1159                 fake->server = vp->vp_strvalue;
1160
1161         } else if (t->virtual_server) {
1162                 fake->server = t->virtual_server;
1163
1164         } /* else fake->server == request->server */
1165
1166
1167         if ((debug_flag > 0) && fr_log_fp) {
1168                 RDEBUG("Sending tunneled request");
1169
1170                 debug_pair_list(fake->packet->vps);
1171
1172                 fprintf(fr_log_fp, "server %s {\n",
1173                         (!fake->server) ? "" : fake->server);
1174         }
1175
1176         /*
1177          *      Call authentication recursively, which will
1178          *      do PAP, CHAP, MS-CHAP, etc.
1179          */
1180         rad_virtual_server(fake);
1181
1182         /*
1183          *      Note that we don't do *anything* with the reply
1184          *      attributes.
1185          */
1186         if ((debug_flag > 0) && fr_log_fp) {
1187                 fprintf(fr_log_fp, "} # server %s\n",
1188                         (!fake->server) ? "" : fake->server);
1189
1190                 RDEBUG("Got tunneled reply code %d", fake->reply->code);
1191
1192                 debug_pair_list(fake->reply->vps);
1193         }
1194
1195         /*
1196          *      Decide what to do with the reply.
1197          */
1198         switch (fake->reply->code) {
1199         case 0:                 /* No reply code, must be proxied... */
1200 #ifdef WITH_PROXY
1201                 vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0, TAG_ANY);
1202                 if (vp) {
1203                         eap_tunnel_data_t *tunnel;
1204                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1205
1206                         /*
1207                          *      Tell the original request that it's going
1208                          *      to be proxied.
1209                          */
1210                         pairfilter(request, &(request->config_items),
1211                                   &(fake->config_items),
1212                                   PW_PROXY_TO_REALM, 0, TAG_ANY);
1213
1214                         /*
1215                          *      Seed the proxy packet with the
1216                          *      tunneled request.
1217                          */
1218                         rad_assert(!request->proxy);
1219                         request->proxy = fake->packet;
1220                         memset(&request->proxy->src_ipaddr, 0,
1221                                sizeof(request->proxy->src_ipaddr));
1222                         memset(&request->proxy->src_ipaddr, 0,
1223                                sizeof(request->proxy->src_ipaddr));
1224                         request->proxy->src_port = 0;
1225                         request->proxy->dst_port = 0;
1226                         fake->packet = NULL;
1227                         rad_free(&fake->reply);
1228                         fake->reply = NULL;
1229
1230                         /*
1231                          *      Set up the callbacks for the tunnel
1232                          */
1233                         tunnel = talloc_zero(request, eap_tunnel_data_t);
1234                         tunnel->tls_session = tls_session;
1235                         tunnel->callback = eapttls_postproxy;
1236
1237                         /*
1238                          *      Associate the callback with the request.
1239                          */
1240                         rcode = request_data_add(request,
1241                                                  request->proxy,
1242                                                  REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1243                                                  tunnel, NULL);
1244                         rad_assert(rcode == 0);
1245
1246                         /*
1247                          *      rlm_eap.c has taken care of associating
1248                          *      the handler with the fake request.
1249                          *
1250                          *      So we associate the fake request with
1251                          *      this request.
1252                          */
1253                         rcode = request_data_add(request,
1254                                                  request->proxy,
1255                                                  REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1256                                                  fake, my_request_free);
1257                         rad_assert(rcode == 0);
1258                         fake = NULL;
1259
1260                         /*
1261                          *      Didn't authenticate the packet, but
1262                          *      we're proxying it.
1263                          */
1264                         rcode = PW_STATUS_CLIENT;
1265
1266                 } else
1267 #endif  /* WITH_PROXY */
1268                   {
1269                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1270                                request->number);
1271                         rcode = PW_AUTHENTICATION_REJECT;
1272                 }
1273                 break;
1274
1275         default:
1276                 /*
1277                  *      Returns RLM_MODULE_FOO, and we want to return
1278                  *      PW_FOO
1279                  */
1280                 rcode = process_reply(handler, tls_session, request,
1281                                       fake->reply);
1282                 switch (rcode) {
1283                 case RLM_MODULE_REJECT:
1284                         rcode = PW_AUTHENTICATION_REJECT;
1285                         break;
1286
1287                 case RLM_MODULE_HANDLED:
1288                         rcode = PW_ACCESS_CHALLENGE;
1289                         break;
1290
1291                 case RLM_MODULE_OK:
1292                         rcode = PW_AUTHENTICATION_ACK;
1293                         break;
1294
1295                 default:
1296                         rcode = PW_AUTHENTICATION_REJECT;
1297                         break;
1298                 }
1299                 break;
1300         }
1301
1302         request_free(&fake);
1303
1304         return rcode;
1305 }