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                                 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(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                         vp->type = VT_DATA;
 356                         memcpy(p, data, size);
 357                         p[size] = '\0';
 358                         vp->length = strlen(p);
 359                         break;
 360
 361                         /*
 362                          *      Copy it over verbatim.
 363                          */
 364                 case PW_TYPE_OCTETS:
 365                 default:
 366                         pairmemcpy(vp, data, size);
 367                         break;
 368                 }
 369
 370                 /*
 371                  *      Ensure that the client is using the
 372                  *      correct challenge.  This weirdness is
 373                  *      to protect against against replay
 374                  *      attacks, where anyone observing the
 375                  *      CHAP exchange could pose as that user,
 376                  *      by simply choosing to use the same
 377                  *      challenge.
 378                  *
 379                  *      By using a challenge based on
 380                  *      information from the current session,
 381                  *      we can guarantee that the client is
 382                  *      not *choosing* a challenge.
 383                  *
 384                  *      We're a little forgiving in that we
 385                  *      have loose checks on the length, and
 386                  *      we do NOT check the Id (first octet of
 387                  *      the response to the challenge)
 388                  *
 389                  *      But if the client gets the challenge correct,
 390                  *      we're not too worried about the Id.
 391                  */
 392                 if (((vp->da->vendor == 0) && (vp->da->attr == PW_CHAP_CHALLENGE)) ||
 393                     ((vp->da->vendor == VENDORPEC_MICROSOFT) && (vp->da->attr == PW_MSCHAP_CHALLENGE))) {
 394                         uint8_t challenge[16];
 395
 396                         if ((vp->length < 8) ||
 397                             (vp->length > 16)) {
 398                                 RDEBUG("Tunneled challenge has invalid length");
 399                                 pairfree(&first);
 400                                 pairfree(&vp);
 401                                 return NULL;
 402                         }
 403
 404                         eapttls_gen_challenge(ssl, challenge,
 405                                               sizeof(challenge));
 406
 407                         if (memcmp(challenge, vp->vp_octets,
 408                                    vp->length) != 0) {
 409                                 RDEBUG("Tunneled challenge is incorrect");
 410                                 pairfree(&first);
 411                                 pairfree(&vp);
 412                                 return NULL;
 413                         }
 414                 }
 415
 416                 /*
 417                  *      Update the list.
 418                  */
 419                 pairinsert(&out, vp);
 420
 421         next_attr:
 422                 /*
 423                  *      Catch non-aligned attributes.
 424                  */
 425                 if (data_left == length) break;
 426
 427                 /*
 428                  *      The length does NOT include the padding, so
 429                  *      we've got to account for it here by rounding up
 430                  *      to the nearest 4-byte boundary.
 431                  */
 432                 length += 0x03;
 433                 length &= ~0x03;
 434
 435                 rad_assert(data_left >= length);
 436                 data_left -= length;
 437                 data += length - offset; /* already updated */
 438         }
 439
 440         /*
 441          *      We got this far.  It looks OK.
 442          */
 443         return first;
 444 }
 445
 446 /*
 447  *      Convert VALUE_PAIR's to diameter attributes, and write them
 448  *      to an SSL session.
 449  *
 450  *      The ONLY VALUE_PAIR's which may be passed to this function
 451  *      are ones which can go inside of a RADIUS (i.e. diameter)
 452  *      packet.  So no server-configuration attributes, or the like.
 453  */
 454 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 455 {
 456         /*
 457          *      RADIUS packets are no more than 4k in size, so if
 458          *      we've got more than 4k of data to write, it's very
 459          *      bad.
 460          */
 461         uint8_t         buffer[4096];
 462         uint8_t         *p;
 463         uint32_t        attr;
 464         uint32_t        length;
 465         uint32_t        vendor;
 466         size_t          total;
 467         uint64_t        attr64;
 468         VALUE_PAIR      *vp;
 469         vp_cursor_t     cursor;
 470
 471         p = buffer;
 472         total = 0;
 473
 474         for (vp = paircursor(&cursor, &first); vp; vp = pairnext(&cursor)) {
 475                 /*
 476                  *      Too much data: die.
 477                  */
 478                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 479                         RDEBUG2("output buffer is full!");
 480                         return 0;
 481                 }
 482
 483                 /*
 484                  *      Hmm... we don't group multiple EAP-Messages
 485                  *      together.  Maybe we should...
 486                  */
 487
 488                 length = vp->length;
 489                 vendor = vp->da->vendor;
 490                 if (vendor != 0) {
 491                         attr = vp->da->attr & 0xffff;
 492                         length |= (1 << 31);
 493                 } else {
 494                         attr = vp->da->attr;
 495                 }
 496
 497                 /*
 498                  *      Hmm... set the M bit for all attributes?
 499                  */
 500                 length |= (1 << 30);
 501
 502                 attr = ntohl(attr);
 503
 504                 memcpy(p, &attr, sizeof(attr));
 505                 p += 4;
 506                 total += 4;
 507
 508                 length += 8;    /* includes 8 bytes of attr & length */
 509
 510                 if (vendor != 0) {
 511                         length += 4; /* include 4 bytes of vendor */
 512
 513                         length = ntohl(length);
 514                         memcpy(p, &length, sizeof(length));
 515                         p += 4;
 516                         total += 4;
 517
 518                         vendor = ntohl(vendor);
 519                         memcpy(p, &vendor, sizeof(vendor));
 520                         p += 4;
 521                         total += 4;
 522                 } else {
 523                         length = ntohl(length);
 524                         memcpy(p, &length, sizeof(length));
 525                         p += 4;
 526                         total += 4;
 527                 }
 528
 529                 switch (vp->da->type) {
 530                 case PW_TYPE_INTEGER:
 531                 case PW_TYPE_DATE:
 532                         attr = htonl(vp->vp_integer); /* stored in host order */
 533                         memcpy(p, &attr, sizeof(attr));
 534                         length = 4;
 535                         break;
 536
 537                 case PW_TYPE_INTEGER64:
 538                         attr64 = htonll(vp->vp_integer64); /* stored in host order */
 539                         memcpy(p, &attr64, sizeof(attr64));
 540                         length = 8;
 541                         break;
 542
 543                 case PW_TYPE_IPADDR:
 544                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 545                         length = 4;
 546                         break;
 547
 548                 case PW_TYPE_STRING:
 549                 case PW_TYPE_OCTETS:
 550                 default:
 551                         memcpy(p, vp->vp_strvalue, vp->length);
 552                         length = vp->length;
 553                         break;
 554                 }
 555
 556                 /*
 557                  *      Skip to the end of the data.
 558                  */
 559                 p += length;
 560                 total += length;
 561
 562                 /*
 563                  *      Align the data to a multiple of 4 bytes.
 564                  */
 565                 if ((total & 0x03) != 0) {
 566                         size_t i;
 567
 568                         length = 4 - (total & 0x03);
 569                         for (i = 0; i < length; i++) {
 570                                 *p = '\0';
 571                                 p++;
 572                                 total++;
 573                         }
 574                 }
 575         } /* loop over the VP's to write. */
 576
 577         /*
 578          *      Write the data in the buffer to the SSL session.
 579          */
 580         if (total > 0) {
 581 #ifndef NDEBUG
 582                 size_t i;
 583
 584                 if ((debug_flag > 2) && fr_log_fp) {
 585                         for (i = 0; i < total; i++) {
 586                                 if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 587
 588                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 589
 590                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 591                         }
 592                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 593                 }
 594 #endif
 595
 596                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 597
 598                 /*
 599                  *      FIXME: Check the return code.
 600                  */
 601                 tls_handshake_send(request, tls_session);
 602         }
 603
 604         /*
 605          *      Everything's OK.
 606          */
 607         return 1;
 608 }
 609
 610 /*
 611  *      Use a reply packet to determine what to do.
 612  */
 613 static rlm_rcode_t process_reply(UNUSED eap_handler_t *handler, tls_session_t *tls_session,
 614                                  REQUEST *request, RADIUS_PACKET *reply)
 615 {
 616         rlm_rcode_t rcode = RLM_MODULE_REJECT;
 617         VALUE_PAIR *vp;
 618         ttls_tunnel_t *t = tls_session->opaque;
 619
 620         rad_assert(request != NULL);
 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_AUTHENTICATION_ACK:
 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_AUTHENTICATION_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_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 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         rad_assert(request != NULL);
 796         RDEBUG("Passing reply from proxy back into the tunnel.");
 797
 798         /*
 799          *      If there was a fake request associated with the proxied
 800          *      request, do more processing of it.
 801          */
 802         fake = (REQUEST *) request_data_get(handler->request,
 803                                             handler->request->proxy,
 804                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 805
 806         /*
 807          *      Do the callback, if it exists, and if it was a success.
 808          */
 809         if (fake &&
 810             handler->request->proxy_reply &&
 811             (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 812                 /*
 813                  *      Terrible hacks.
 814                  */
 815                 rad_assert(!fake->packet);
 816                 fake->packet = request->proxy;
 817                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 818                 request->proxy = NULL;
 819
 820                 rad_assert(!fake->reply);
 821                 fake->reply = request->proxy_reply;
 822                 request->proxy_reply = NULL;
 823
 824                 if ((debug_flag > 0) && fr_log_fp) {
 825                         fprintf(fr_log_fp, "server %s {\n",
 826                                 (!fake->server) ? "" : fake->server);
 827                 }
 828
 829                 /*
 830                  *      Perform a post-auth stage for the tunneled
 831                  *      session.
 832                  */
 833                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 834                 rcode = rad_postauth(fake);
 835                 RDEBUG2("post-auth returns %d", rcode);
 836
 837                 if ((debug_flag > 0) && fr_log_fp) {
 838                         fprintf(fr_log_fp, "} # server %s\n",
 839                                 (!fake->server) ? "" : fake->server);
 840
 841                         RDEBUG("Final reply from tunneled session code %d",
 842                                fake->reply->code);
 843                         debug_pair_list(fake->reply->vps);
 844                 }
 845
 846                 /*
 847                  *      Terrible hacks.
 848                  */
 849                 request->proxy = fake->packet;
 850                 fake->packet = NULL;
 851                 request->proxy_reply = fake->reply;
 852                 fake->reply = NULL;
 853
 854                 /*
 855                  *      And we're done with this request.
 856                  */
 857
 858                 switch (rcode) {
 859                 case RLM_MODULE_FAIL:
 860                         request_free(&fake);
 861                         eaptls_fail(handler, 0);
 862                         return 0;
 863                         break;
 864
 865                 default:  /* Don't Do Anything */
 866                         RDEBUG2("Got reply %d",
 867                                request->proxy_reply->code);
 868                         break;
 869                 }
 870         }
 871         request_free(&fake);    /* robust if !fake */
 872
 873         /*
 874          *      Process the reply from the home server.
 875          */
 876         rcode = process_reply(handler, tls_session, handler->request,
 877                               handler->request->proxy_reply);
 878
 879         /*
 880          *      The proxy code uses the reply from the home server as
 881          *      the basis for the reply to the NAS.  We don't want that,
 882          *      so we toss it, after we've had our way with it.
 883          */
 884         pairfree(&handler->request->proxy_reply->vps);
 885
 886         switch (rcode) {
 887         case RLM_MODULE_REJECT:
 888                 RDEBUG("Reply was rejected");
 889                 break;
 890
 891         case RLM_MODULE_HANDLED:
 892                 RDEBUG("Reply was handled");
 893                 eaptls_request(handler->eap_ds, tls_session);
 894                 return 1;
 895
 896         case RLM_MODULE_OK:
 897                 RDEBUG("Reply was OK");
 898
 899                 /*
 900                  *      Success: Automatically return MPPE keys.
 901                  */
 902                 return eaptls_success(handler, 0);
 903
 904         default:
 905                 RDEBUG("Reply was unknown.");
 906                 break;
 907         }
 908
 909         eaptls_fail(handler, 0);
 910         return 0;
 911 }
 912
 913 #endif  /* WITH_PROXY */
 914
 915 /*
 916  *      Process the "diameter" contents of the tunneled data.
 917  */
 918 int eapttls_process(eap_handler_t *handler, tls_session_t *tls_session)
 919 {
 920         int code = PW_AUTHENTICATION_REJECT;
 921         rlm_rcode_t rcode;
 922         REQUEST *fake;
 923         VALUE_PAIR *vp;
 924         ttls_tunnel_t *t;
 925         const uint8_t *data;
 926         size_t data_len;
 927         REQUEST *request = handler->request;
 928
 929         rad_assert(request != NULL);
 930
 931         /*
 932          *      Just look at the buffer directly, without doing
 933          *      record_minus.
 934          */
 935         data_len = tls_session->clean_out.used;
 936         tls_session->clean_out.used = 0;
 937         data = tls_session->clean_out.data;
 938
 939         t = (ttls_tunnel_t *) tls_session->opaque;
 940
 941         /*
 942          *      If there's no data, maybe this is an ACK to an
 943          *      MS-CHAP2-Success.
 944          */
 945         if (data_len == 0) {
 946                 if (t->authenticated) {
 947                         RDEBUG("Got ACK, and the user was already authenticated.");
 948                         return PW_AUTHENTICATION_ACK;
 949                 } /* else no session, no data, die. */
 950
 951                 /*
 952                  *      FIXME: Call SSL_get_error() to see what went
 953                  *      wrong.
 954                  */
 955                 RDEBUG2("SSL_read Error");
 956                 return PW_AUTHENTICATION_REJECT;
 957         }
 958
 959 #ifndef NDEBUG
 960         if ((debug_flag > 2) && fr_log_fp) {
 961                 size_t i;
 962
 963                 for (i = 0; i < data_len; i++) {
 964                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
 965
 966                         fprintf(fr_log_fp, "%02x ", data[i]);
 967
 968                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 969                 }
 970                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 971         }
 972 #endif
 973
 974         if (!diameter_verify(request, data, data_len)) {
 975                 return PW_AUTHENTICATION_REJECT;
 976         }
 977
 978         /*
 979          *      Allocate a fake REQUEST structe.
 980          */
 981         fake = request_alloc_fake(request);
 982
 983         rad_assert(!fake->packet->vps);
 984
 985         /*
 986          *      Add the tunneled attributes to the fake request.
 987          */
 988         fake->packet->vps = diameter2vp(request, fake, tls_session->ssl, data, data_len);
 989         if (!fake->packet->vps) {
 990                 request_free(&fake);
 991                 return PW_AUTHENTICATION_REJECT;
 992         }
 993
 994         /*
 995          *      Tell the request that it's a fake one.
 996          */
 997         pairmake_packet("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
 998
 999         if ((debug_flag > 0) && fr_log_fp) {
1000                 RDEBUG("Got tunneled request");
1001
1002                 debug_pair_list(fake->packet->vps);
1003         }
1004
1005         /*
1006          *      Update other items in the REQUEST data structure.
1007          */
1008         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1009         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY);
1010
1011         /*
1012          *      No User-Name, try to create one from stored data.
1013          */
1014         if (!fake->username) {
1015                 /*
1016                  *      No User-Name in the stored data, look for
1017                  *      an EAP-Identity, and pull it out of there.
1018                  */
1019                 if (!t->username) {
1020                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
1021                         if (vp &&
1022                             (vp->length >= EAP_HEADER_LEN + 2) &&
1023                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1024                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1025                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1026                                 char *p;
1027
1028                                 /*
1029                                  *      Create & remember a User-Name
1030                                  */
1031                                 t->username = pairmake(t, NULL, "User-Name", NULL, T_OP_EQ);
1032                                 rad_assert(t->username != NULL);
1033                                 t->username->length = vp->length - 5;
1034
1035                                 t->username->vp_strvalue = p = talloc_array(t->username, char,
1036                                                                             t->username->length + 1);
1037                                 memcpy(p, vp->vp_octets + 5, t->username->length);
1038                                 p[t->username->length] = 0;
1039
1040                                 RDEBUG("Got tunneled identity of %s",
1041                                        t->username->vp_strvalue);
1042
1043                                 /*
1044                                  *      If there's a default EAP type,
1045                                  *      set it here.
1046                                  */
1047                                 if (t->default_method != 0) {
1048                                         RDEBUG("Setting default EAP type for tunneled EAP session.");
1049                                         vp = paircreate(fake, PW_EAP_TYPE, 0);
1050                                         rad_assert(vp != NULL);
1051                                         vp->vp_integer = t->default_method;
1052                                         pairadd(&fake->config_items, vp);
1053                                 }
1054
1055                         } else {
1056                                 /*
1057                                  *      Don't reject the request outright,
1058                                  *      as it's permitted to do EAP without
1059                                  *      user-name.
1060                                  */
1061                                 RWDEBUG2("No EAP-Identity found to start EAP conversation.");
1062                         }
1063                 } /* else there WAS a t->username */
1064
1065                 if (t->username) {
1066                         vp = paircopy(fake->packet, t->username);
1067                         pairadd(&fake->packet->vps, vp);
1068                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1069                 }
1070         } /* else the request ALREADY had a User-Name */
1071
1072         /*
1073          *      Add the State attribute, too, if it exists.
1074          */
1075         if (t->state) {
1076                 vp = paircopy(fake->packet, t->state);
1077                 if (vp) pairadd(&fake->packet->vps, vp);
1078         }
1079
1080         /*
1081          *      If this is set, we copy SOME of the request attributes
1082          *      from outside of the tunnel to inside of the tunnel.
1083          *
1084          *      We copy ONLY those attributes which do NOT already
1085          *      exist in the tunneled request.
1086          */
1087         if (t->copy_request_to_tunnel) {
1088                 VALUE_PAIR *copy;
1089                 vp_cursor_t cursor;
1090
1091                 for (vp = paircursor(&cursor, &request->packet->vps); vp; vp = pairnext(&cursor)) {
1092                         /*
1093                          *      The attribute is a server-side thingy,
1094                          *      don't copy it.
1095                          */
1096                         if ((vp->da->attr > 255) &&
1097                             (vp->da->vendor == 0)) {
1098                                 continue;
1099                         }
1100
1101                         /*
1102                          *      The outside attribute is already in the
1103                          *      tunnel, don't copy it.
1104                          *
1105                          *      This works for BOTH attributes which
1106                          *      are originally in the tunneled request,
1107                          *      AND attributes which are copied there
1108                          *      from below.
1109                          */
1110                         if (pairfind(fake->packet->vps, vp->da->attr, vp->da->vendor, TAG_ANY)) {
1111                                 continue;
1112                         }
1113
1114                         /*
1115                          *      Some attributes are handled specially.
1116                          */
1117                         switch (vp->da->attr) {
1118                                 /*
1119                                  *      NEVER copy Message-Authenticator,
1120                                  *      EAP-Message, or State.  They're
1121                                  *      only for outside of the tunnel.
1122                                  */
1123                         case PW_USER_NAME:
1124                         case PW_USER_PASSWORD:
1125                         case PW_CHAP_PASSWORD:
1126                         case PW_CHAP_CHALLENGE:
1127                         case PW_PROXY_STATE:
1128                         case PW_MESSAGE_AUTHENTICATOR:
1129                         case PW_EAP_MESSAGE:
1130                         case PW_STATE:
1131                                 continue;
1132                                 break;
1133
1134                                 /*
1135                                  *      By default, copy it over.
1136                                  */
1137                         default:
1138                                 break;
1139                         }
1140
1141                         /*
1142                          *      Don't copy from the head, we've already
1143                          *      checked it.
1144                          */
1145                         copy = paircopy2(fake->packet, vp, vp->da->attr, vp->da->vendor, TAG_ANY);
1146                         pairadd(&fake->packet->vps, copy);
1147                 }
1148         }
1149
1150         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0, TAG_ANY)) != NULL) {
1151                 fake->server = vp->vp_strvalue;
1152
1153         } else if (t->virtual_server) {
1154                 fake->server = t->virtual_server;
1155
1156         } /* else fake->server == request->server */
1157
1158
1159         if ((debug_flag > 0) && fr_log_fp) {
1160                 RDEBUG("Sending tunneled request");
1161
1162                 debug_pair_list(fake->packet->vps);
1163
1164                 fprintf(fr_log_fp, "server %s {\n",
1165                         (!fake->server) ? "" : fake->server);
1166         }
1167
1168         /*
1169          *      Call authentication recursively, which will
1170          *      do PAP, CHAP, MS-CHAP, etc.
1171          */
1172         rad_virtual_server(fake);
1173
1174         /*
1175          *      Note that we don't do *anything* with the reply
1176          *      attributes.
1177          */
1178         if ((debug_flag > 0) && fr_log_fp) {
1179                 fprintf(fr_log_fp, "} # server %s\n",
1180                         (!fake->server) ? "" : fake->server);
1181
1182                 RDEBUG("Got tunneled reply code %d", fake->reply->code);
1183
1184                 debug_pair_list(fake->reply->vps);
1185         }
1186
1187         /*
1188          *      Decide what to do with the reply.
1189          */
1190         switch (fake->reply->code) {
1191         case 0:                 /* No reply code, must be proxied... */
1192 #ifdef WITH_PROXY
1193                 vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0, TAG_ANY);
1194                 if (vp) {
1195                         eap_tunnel_data_t *tunnel;
1196                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1197
1198                         /*
1199                          *      Tell the original request that it's going
1200                          *      to be proxied.
1201                          */
1202                         pairfilter(request, &(request->config_items),
1203                                   &(fake->config_items),
1204                                   PW_PROXY_TO_REALM, 0, TAG_ANY);
1205
1206                         /*
1207                          *      Seed the proxy packet with the
1208                          *      tunneled request.
1209                          */
1210                         rad_assert(!request->proxy);
1211                         request->proxy = fake->packet;
1212                         memset(&request->proxy->src_ipaddr, 0,
1213                                sizeof(request->proxy->src_ipaddr));
1214                         memset(&request->proxy->src_ipaddr, 0,
1215                                sizeof(request->proxy->src_ipaddr));
1216                         request->proxy->src_port = 0;
1217                         request->proxy->dst_port = 0;
1218                         fake->packet = NULL;
1219                         rad_free(&fake->reply);
1220                         fake->reply = NULL;
1221
1222                         /*
1223                          *      Set up the callbacks for the tunnel
1224                          */
1225                         tunnel = talloc_zero(request, eap_tunnel_data_t);
1226                         tunnel->tls_session = tls_session;
1227                         tunnel->callback = eapttls_postproxy;
1228
1229                         /*
1230                          *      Associate the callback with the request.
1231                          */
1232                         code = request_data_add(request, request->proxy, REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1233                                                 tunnel, false);
1234                         rad_assert(code == 0);
1235
1236                         /*
1237                          *      rlm_eap.c has taken care of associating
1238                          *      the handler with the fake request.
1239                          *
1240                          *      So we associate the fake request with
1241                          *      this request.
1242                          */
1243                         talloc_set_destructor(fake, request_opaque_free);
1244                         code = request_data_add(request, request->proxy, REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1245                                                 fake, true);
1246                         rad_assert(code == 0);
1247                         fake = NULL;
1248
1249                         /*
1250                          *      Didn't authenticate the packet, but
1251                          *      we're proxying it.
1252                          */
1253                         code = PW_STATUS_CLIENT;
1254
1255                 } else
1256 #endif  /* WITH_PROXY */
1257                   {
1258                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1259                                request->number);
1260                         code = PW_AUTHENTICATION_REJECT;
1261                 }
1262                 break;
1263
1264         default:
1265                 /*
1266                  *      Returns RLM_MODULE_FOO, and we want to return PW_FOO
1267                  */
1268                 rcode = process_reply(handler, tls_session, request, fake->reply);
1269                 switch (rcode) {
1270                 case RLM_MODULE_REJECT:
1271                         code = PW_AUTHENTICATION_REJECT;
1272                         break;
1273
1274                 case RLM_MODULE_HANDLED:
1275                         code = PW_ACCESS_CHALLENGE;
1276                         break;
1277
1278                 case RLM_MODULE_OK:
1279                         code = PW_AUTHENTICATION_ACK;
1280                         break;
1281
1282                 default:
1283                         code = PW_AUTHENTICATION_REJECT;
1284                         break;
1285                 }
1286                 break;
1287         }
1288
1289         request_free(&fake);
1290
1291         return code;
1292 }