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 #include "eap_chbind.h"
  28
  29 /*
  30  *    0            1               2               3
  31  *    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
  32  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  33  *   |                     AVP Code                         |
  34  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  35  *   |V M r r r r r r|            AVP Length               |
  36  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  37  *   |                  Vendor-ID (opt)                 |
  38  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  39  *   |    Data ...
  40  *   +-+-+-+-+-+-+-+-+
  41  */
  42
  43 /*
  44  *      Verify that the diameter packet is valid.
  45  */
  46 static int diameter_verify(REQUEST *request, uint8_t const *data, unsigned int data_len)
  47 {
  48         uint32_t attr;
  49         uint32_t length;
  50         unsigned int hdr_len;
  51         unsigned int remaining = data_len;
  52
  53         while (remaining > 0) {
  54                 hdr_len = 12;
  55
  56                 if (remaining < hdr_len) {
  57                   RDEBUG2(" Diameter attribute is too small (%u) to contain a Diameter header", remaining);
  58                         return 0;
  59                 }
  60
  61                 memcpy(&attr, data, sizeof(attr));
  62                 attr = ntohl(attr);
  63                 memcpy(&length, data + 4, sizeof(length));
  64                 length = ntohl(length);
  65
  66                 if ((data[4] & 0x80) != 0) {
  67                         if (remaining < 16) {
  68                                 RDEBUG2(" Diameter attribute is too small to contain a Diameter header with Vendor-Id");
  69                                 return 0;
  70                         }
  71
  72                         hdr_len = 16;
  73                 }
  74
  75                 /*
  76                  *      Get the length.  If it's too big, die.
  77                  */
  78                 length &= 0x00ffffff;
  79
  80                 /*
  81                  *      Too short or too long is bad.
  82                  */
  83                 if (length <= (hdr_len - 4)) {
  84                         RDEBUG2("Tunneled attribute %u is too short (%u < %u) to contain anything useful.", attr,
  85                                 length, hdr_len);
  86                         return 0;
  87                 }
  88
  89                 if (length > remaining) {
  90                         RDEBUG2("Tunneled attribute %u is longer than room remaining in the packet (%u > %u).", attr,
  91                                 length, remaining);
  92                         return 0;
  93                 }
  94
  95                 /*
  96                  *      Check for broken implementations, which don't
  97                  *      pad the AVP to a 4-octet boundary.
  98                  */
  99                 if (remaining == length) break;
 100
 101                 /*
 102                  *      The length does NOT include the padding, so
 103                  *      we've got to account for it here by rounding up
 104                  *      to the nearest 4-byte boundary.
 105                  */
 106                 length += 0x03;
 107                 length &= ~0x03;
 108
 109                 /*
 110                  *      If the rest of the diameter packet is larger than
 111                  *      this attribute, continue.
 112                  *
 113                  *      Otherwise, if the attribute over-flows the end
 114                  *      of the packet, die.
 115                  */
 116                 if (remaining < length) {
 117                         REDEBUG2("Diameter attribute overflows packet!");
 118                         return 0;
 119                 }
 120
 121                 /*
 122                  *      remaining > length, continue.
 123                  */
 124                 remaining -= length;
 125                 data += length;
 126         }
 127
 128         /*
 129          *      We got this far.  It looks OK.
 130          */
 131         return 1;
 132 }
 133
 134
 135 /*
 136  *      Convert diameter attributes to our VALUE_PAIR's
 137  */
 138 static VALUE_PAIR *diameter2vp(REQUEST *request, REQUEST *fake, SSL *ssl,
 139                                uint8_t const *data, size_t data_len)
 140 {
 141         uint32_t        attr;
 142         uint32_t        vendor;
 143         uint32_t        length;
 144         size_t          offset;
 145         size_t          size;
 146         size_t          data_left = data_len;
 147         char            *p;
 148         VALUE_PAIR      *first = NULL;
 149         VALUE_PAIR      *vp;
 150         RADIUS_PACKET   *packet = fake->packet; /* FIXME: api issues */
 151         vp_cursor_t     out;
 152
 153         paircursor(&out, &first);
 154
 155         while (data_left > 0) {
 156                 rad_assert(data_left <= data_len);
 157                 memcpy(&attr, data, sizeof(attr));
 158                 data += 4;
 159                 attr = ntohl(attr);
 160                 vendor = 0;
 161
 162                 memcpy(&length, data, sizeof(length));
 163                 data += 4;
 164                 length = ntohl(length);
 165
 166                 /*
 167                  *      A "vendor" flag, with a vendor ID of zero,
 168                  *      is equivalent to no vendor.  This is stupid.
 169                  */
 170                 offset = 8;
 171                 if ((length & (1 << 31)) != 0) {
 172                         memcpy(&vendor, data, sizeof(vendor));
 173                         vendor = ntohl(vendor);
 174
 175                         data += 4; /* skip the vendor field, it's zero */
 176                         offset += 4; /* offset to value field */
 177
 178                         if (attr > 65535) goto next_attr;
 179                         if (vendor > FR_MAX_VENDOR) goto next_attr;
 180                 }
 181
 182                 /*
 183                  *      FIXME: Handle the M bit.  For now, we assume that
 184                  *      some other module takes care of any attribute
 185                  *      with the M bit set.
 186                  */
 187
 188                 /*
 189                  *      Get the length.
 190                  */
 191                 length &= 0x00ffffff;
 192
 193                 /*
 194                  *      Get the size of the value portion of the
 195                  *      attribute.
 196                  */
 197                 size = length - offset;
 198
 199                 /*
 200                  *      Vendor attributes can be larger than 255.
 201                  *      Normal attributes cannot be.
 202                  */
 203                 if ((attr > 255) && (vendor == 0)) {
 204                         RWDEBUG2("Skipping Diameter attribute %u", attr);
 205                         goto next_attr;
 206                 }
 207
 208                 /*
 209                  *      EAP-Message AVPs can be larger than 253 octets.
 210                  *
 211                  *      For now, we rely on the main decoder in
 212                  *      src/lib/radius to decode data into VPs.  This
 213                  *      means putting the data into a RADIUS attribute
 214                  *      format.  It also means that we can't handle
 215                  *      "extended" attributes in the Diameter space.  Oh well...
 216                  */
 217                 if ((size > 253) && !((vendor == 0) && (attr == PW_EAP_MESSAGE))) {
 218                         RWDEBUG2("diameter2vp skipping long attribute %u", attr);
 219                         goto next_attr;
 220                 }
 221
 222                 /*
 223                  *      RADIUS VSAs are handled as Diameter attributes
 224                  *      with Vendor-Id == 0, and the VSA data packed
 225                  *      into the "String" field as per normal.
 226                  *
 227                  *      EXCEPT for the MS-CHAP attributes.
 228                  */
 229                 if ((vendor == 0) && (attr == PW_VENDOR_SPECIFIC)) {
 230                         ssize_t decoded;
 231                         uint8_t buffer[256];
 232
 233                         buffer[0] = PW_VENDOR_SPECIFIC;
 234                         buffer[1] = size + 2;
 235                         memcpy(buffer + 2, data, size);
 236
 237                         vp = NULL;
 238                         decoded = rad_attr2vp(NULL, NULL, NULL,
 239                                               buffer, size + 2, &vp);
 240                         if (decoded < 0) {
 241                                 REDEBUG2("diameter2vp failed decoding attr: %s",
 242                                         fr_strerror());
 243                                 goto do_octets;
 244                         }
 245
 246                         if ((size_t) decoded != size + 2) {
 247                                 REDEBUG2("diameter2vp failed to entirely decode VSA");
 248                                 pairfree(&vp);
 249                                 goto do_octets;
 250                         }
 251
 252                         pairinsert(&out, vp);
 253
 254                         goto next_attr;
 255                 }
 256
 257                 /*
 258                  *      Create it.  If this fails, it's because we're OOM.
 259                  */
 260         do_octets:
 261                 vp = paircreate(packet, attr, vendor);
 262                 if (!vp) {
 263                         RDEBUG2("Failure in creating VP");
 264                         pairfree(&first);
 265                         return NULL;
 266                 }
 267                 if (vendor == VENDORPEC_UKERNA) {
 268                         RDEBUG("Received UKERNA attr %d!", attr);
 269                 }
 270
 271                 /*
 272                  *      If it's a type from our dictionary, then
 273                  *      we need to put the data in a relevant place.
 274                  *
 275                  *      @todo: Export the lib/radius.c decoder, and use it here!
 276                  */
 277                 switch (vp->da->type) {
 278                 case PW_TYPE_INTEGER:
 279                 case PW_TYPE_DATE:
 280                         if (size != vp->length) {
 281                                 DICT_ATTR const *da;
 282
 283                                 /*
 284                                  *      Bad format.  Create a "raw"
 285                                  *      attribute.
 286                                  */
 287                 raw:
 288                                 if (vp) pairfree(&vp);
 289                                 da = dict_attrunknown(attr, vendor, true);
 290                                 if (!da) return NULL;
 291                                 vp = pairalloc(NULL, da);
 292                                 pairmemcpy(vp, data, size);
 293                                 break;
 294                         }
 295                         memcpy(&vp->vp_integer, data, vp->length);
 296
 297                         /*
 298                          *      Stored in host byte order: change it.
 299                          */
 300                         vp->vp_integer = ntohl(vp->vp_integer);
 301                         break;
 302
 303                 case PW_TYPE_INTEGER64:
 304                         if (size != vp->length) goto raw;
 305                         memcpy(&vp->vp_integer64, data, vp->length);
 306
 307                         /*
 308                          *      Stored in host byte order: change it.
 309                          */
 310                         vp->vp_integer64 = ntohll(vp->vp_integer64);
 311                         break;
 312
 313                 case PW_TYPE_IPADDR:
 314                         if (size != vp->length) {
 315                                 RDEBUG2("Invalid length attribute %d",
 316                                        attr);
 317                                 pairfree(&first);
 318                                 pairfree(&vp);
 319                                 return NULL;
 320                         }
 321                         memcpy(&vp->vp_ipaddr, data, vp->length);
 322
 323                         /*
 324                          *      Stored in network byte order: don't change it.
 325                          */
 326                         break;
 327
 328                 case PW_TYPE_BYTE:
 329                         if (size != vp->length) goto raw;
 330                         vp->vp_integer = data[0];
 331                         break;
 332
 333                 case PW_TYPE_SHORT:
 334                         if (size != vp->length) goto raw;
 335                         vp->vp_integer = (data[0] * 256) + data[1];
 336                         break;
 337
 338                 case PW_TYPE_SIGNED:
 339                         if (size != vp->length) goto raw;
 340                         memcpy(&vp->vp_signed, data, vp->length);
 341                         vp->vp_signed = ntohl(vp->vp_signed);
 342                         break;
 343
 344                 case PW_TYPE_IPV6ADDR:
 345                         if (size != vp->length) goto raw;
 346                         memcpy(&vp->vp_ipv6addr, data, vp->length);
 347                         break;
 348
 349                 case PW_TYPE_IPV6PREFIX:
 350                         if (size != vp->length) goto raw;
 351                         memcpy(&vp->vp_ipv6prefix, data, vp->length);
 352                         break;
 353
 354                         /*
 355                          *      Ensure it's NUL terminated.
 356                          */
 357                 case PW_TYPE_STRING:
 358                         vp->vp_strvalue = p = talloc_array(vp, char, size + 1);
 359                         vp->type = VT_DATA;
 360                         memcpy(p, data, size);
 361                         p[size] = '\0';
 362                         vp->length = strlen(p);
 363                         break;
 364
 365                         /*
 366                          *      Copy it over verbatim.
 367                          */
 368                 case PW_TYPE_OCTETS:
 369                 default:
 370                         pairmemcpy(vp, data, size);
 371                         break;
 372                 }
 373
 374                 /*
 375                  *      Ensure that the client is using the
 376                  *      correct challenge.  This weirdness is
 377                  *      to protect against against replay
 378                  *      attacks, where anyone observing the
 379                  *      CHAP exchange could pose as that user,
 380                  *      by simply choosing to use the same
 381                  *      challenge.
 382                  *
 383                  *      By using a challenge based on
 384                  *      information from the current session,
 385                  *      we can guarantee that the client is
 386                  *      not *choosing* a challenge.
 387                  *
 388                  *      We're a little forgiving in that we
 389                  *      have loose checks on the length, and
 390                  *      we do NOT check the Id (first octet of
 391                  *      the response to the challenge)
 392                  *
 393                  *      But if the client gets the challenge correct,
 394                  *      we're not too worried about the Id.
 395                  */
 396                 if (((vp->da->vendor == 0) && (vp->da->attr == PW_CHAP_CHALLENGE)) ||
 397                     ((vp->da->vendor == VENDORPEC_MICROSOFT) && (vp->da->attr == PW_MSCHAP_CHALLENGE))) {
 398                         uint8_t challenge[16];
 399
 400                         if ((vp->length < 8) ||
 401                             (vp->length > 16)) {
 402                                 RDEBUG("Tunneled challenge has invalid length");
 403                                 pairfree(&first);
 404                                 pairfree(&vp);
 405                                 return NULL;
 406                         }
 407
 408                         eapttls_gen_challenge(ssl, challenge,
 409                                               sizeof(challenge));
 410
 411                         if (memcmp(challenge, vp->vp_octets,
 412                                    vp->length) != 0) {
 413                                 RDEBUG("Tunneled challenge is incorrect");
 414                                 pairfree(&first);
 415                                 pairfree(&vp);
 416                                 return NULL;
 417                         }
 418                 }
 419
 420                 /*
 421                  *      Update the list.
 422                  */
 423                 pairinsert(&out, vp);
 424
 425         next_attr:
 426                 /*
 427                  *      Catch non-aligned attributes.
 428                  */
 429                 if (data_left == length) break;
 430
 431                 /*
 432                  *      The length does NOT include the padding, so
 433                  *      we've got to account for it here by rounding up
 434                  *      to the nearest 4-byte boundary.
 435                  */
 436                 length += 0x03;
 437                 length &= ~0x03;
 438
 439                 rad_assert(data_left >= length);
 440                 data_left -= length;
 441                 data += length - offset; /* already updated */
 442         }
 443
 444         /*
 445          *      We got this far.  It looks OK.
 446          */
 447         return first;
 448 }
 449
 450 /*
 451  *      Convert VALUE_PAIR's to diameter attributes, and write them
 452  *      to an SSL session.
 453  *
 454  *      The ONLY VALUE_PAIR's which may be passed to this function
 455  *      are ones which can go inside of a RADIUS (i.e. diameter)
 456  *      packet.  So no server-configuration attributes, or the like.
 457  */
 458 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 459 {
 460         /*
 461          *      RADIUS packets are no more than 4k in size, so if
 462          *      we've got more than 4k of data to write, it's very
 463          *      bad.
 464          */
 465         uint8_t         buffer[4096];
 466         uint8_t         *p;
 467         uint32_t        attr;
 468         uint32_t        length;
 469         uint32_t        vendor;
 470         size_t          total;
 471         uint64_t        attr64;
 472         VALUE_PAIR      *vp;
 473         vp_cursor_t     cursor;
 474
 475         p = buffer;
 476         total = 0;
 477
 478         for (vp = paircursor(&cursor, &first); vp; vp = pairnext(&cursor)) {
 479                 /*
 480                  *      Too much data: die.
 481                  */
 482                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 483                         RDEBUG2("output buffer is full!");
 484                         return 0;
 485                 }
 486
 487                 /*
 488                  *      Hmm... we don't group multiple EAP-Messages
 489                  *      together.  Maybe we should...
 490                  */
 491
 492                 length = vp->length;
 493                 vendor = vp->da->vendor;
 494                 if (vendor != 0) {
 495                         attr = vp->da->attr & 0xffff;
 496                         length |= (1 << 31);
 497                 } else {
 498                         attr = vp->da->attr;
 499                 }
 500
 501                 /*
 502                  *      Hmm... set the M bit for all attributes?
 503                  */
 504                 length |= (1 << 30);
 505
 506                 attr = ntohl(attr);
 507
 508                 memcpy(p, &attr, sizeof(attr));
 509                 p += 4;
 510                 total += 4;
 511
 512                 length += 8;    /* includes 8 bytes of attr & length */
 513
 514                 if (vendor != 0) {
 515                         length += 4; /* include 4 bytes of vendor */
 516
 517                         length = ntohl(length);
 518                         memcpy(p, &length, sizeof(length));
 519                         p += 4;
 520                         total += 4;
 521
 522                         vendor = ntohl(vendor);
 523                         memcpy(p, &vendor, sizeof(vendor));
 524                         p += 4;
 525                         total += 4;
 526                 } else {
 527                         length = ntohl(length);
 528                         memcpy(p, &length, sizeof(length));
 529                         p += 4;
 530                         total += 4;
 531                 }
 532
 533                 switch (vp->da->type) {
 534                 case PW_TYPE_INTEGER:
 535                 case PW_TYPE_DATE:
 536                         attr = htonl(vp->vp_integer); /* stored in host order */
 537                         memcpy(p, &attr, sizeof(attr));
 538                         length = 4;
 539                         break;
 540
 541                 case PW_TYPE_INTEGER64:
 542                         attr64 = htonll(vp->vp_integer64); /* stored in host order */
 543                         memcpy(p, &attr64, sizeof(attr64));
 544                         length = 8;
 545                         break;
 546
 547                 case PW_TYPE_IPADDR:
 548                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 549                         length = 4;
 550                         break;
 551
 552                 case PW_TYPE_STRING:
 553                 case PW_TYPE_OCTETS:
 554                 default:
 555                         memcpy(p, vp->vp_strvalue, vp->length);
 556                         length = vp->length;
 557                         break;
 558                 }
 559
 560                 /*
 561                  *      Skip to the end of the data.
 562                  */
 563                 p += length;
 564                 total += length;
 565
 566                 /*
 567                  *      Align the data to a multiple of 4 bytes.
 568                  */
 569                 if ((total & 0x03) != 0) {
 570                         size_t i;
 571
 572                         length = 4 - (total & 0x03);
 573                         for (i = 0; i < length; i++) {
 574                                 *p = '\0';
 575                                 p++;
 576                                 total++;
 577                         }
 578                 }
 579         } /* loop over the VP's to write. */
 580
 581         /*
 582          *      Write the data in the buffer to the SSL session.
 583          */
 584         if (total > 0) {
 585 #ifndef NDEBUG
 586                 size_t i;
 587
 588                 if ((debug_flag > 2) && fr_log_fp) {
 589                         for (i = 0; i < total; i++) {
 590                                 if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 591
 592                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 593
 594                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 595                         }
 596                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 597                 }
 598 #endif
 599
 600                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 601
 602                 /*
 603                  *      FIXME: Check the return code.
 604                  */
 605                 tls_handshake_send(request, tls_session);
 606         }
 607
 608         /*
 609          *      Everything's OK.
 610          */
 611         return 1;
 612 }
 613
 614 /*
 615  *      Use a reply packet to determine what to do.
 616  */
 617 static rlm_rcode_t process_reply(UNUSED eap_handler_t *handler, tls_session_t *tls_session,
 618                                  REQUEST *request, RADIUS_PACKET *reply)
 619 {
 620         rlm_rcode_t rcode = RLM_MODULE_REJECT;
 621         VALUE_PAIR *vp;
 622         ttls_tunnel_t *t = tls_session->opaque;
 623
 624         rad_assert(request != NULL);
 625         rad_assert(handler->request == request);
 626
 627         /*
 628          *      If the response packet was Access-Accept, then
 629          *      we're OK.  If not, die horribly.
 630          *
 631          *      FIXME: Take MS-CHAP2-Success attribute, and
 632          *      tunnel it back to the client, to authenticate
 633          *      ourselves to the client.
 634          *
 635          *      FIXME: If we have an Access-Challenge, then
 636          *      the Reply-Message is tunneled back to the client.
 637          *
 638          *      FIXME: If we have an EAP-Message, then that message
 639          *      must be tunneled back to the client.
 640          *
 641          *      FIXME: If we have an Access-Challenge with a State
 642          *      attribute, then do we tunnel that to the client, or
 643          *      keep track of it ourselves?
 644          *
 645          *      FIXME: EAP-Messages can only start with 'identity',
 646          *      NOT 'eap start', so we should check for that....
 647          */
 648         switch (reply->code) {
 649         case PW_AUTHENTICATION_ACK:
 650                 RDEBUG("Got tunneled Access-Accept");
 651
 652                 rcode = RLM_MODULE_OK;
 653
 654                 /*
 655                  *      MS-CHAP2-Success means that we do NOT return
 656                  *      an Access-Accept, but instead tunnel that
 657                  *      attribute to the client, and keep going with
 658                  *      the TTLS session.  Once the client accepts
 659                  *      our identity, it will respond with an empty
 660                  *      packet, and we will send EAP-Success.
 661                  */
 662                 vp = NULL;
 663                 pairfilter(tls_session, &vp, &reply->vps, PW_MSCHAP2_SUCCESS, VENDORPEC_MICROSOFT, TAG_ANY);
 664                 if (vp) {
 665                         RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge.");
 666                         rcode = RLM_MODULE_HANDLED;
 667                         t->authenticated = true;
 668
 669                         /*
 670                          *      Delete MPPE keys & encryption policy.  We don't
 671                          *      want these here.
 672                          */
 673                         pairdelete(&reply->vps, 7, VENDORPEC_MICROSOFT, TAG_ANY);
 674                         pairdelete(&reply->vps, 8, VENDORPEC_MICROSOFT, TAG_ANY);
 675                         pairdelete(&reply->vps, 16, VENDORPEC_MICROSOFT, TAG_ANY);
 676                         pairdelete(&reply->vps, 17, VENDORPEC_MICROSOFT, TAG_ANY);
 677
 678                         /*
 679                          *      Use the tunneled reply, but not now.
 680                          */
 681                         if (t->use_tunneled_reply) {
 682                                 rad_assert(!t->accept_vps);
 683                                 pairfilter(t, &t->accept_vps, &reply->vps,
 684                                           0, 0, TAG_ANY);
 685                                 rad_assert(!reply->vps);
 686                         }
 687
 688                 } else { /* no MS-CHAP2-Success */
 689                         /*
 690                          *      Can only have EAP-Message if there's
 691                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 692                          *
 693                          *      We also do NOT tunnel the EAP-Success
 694                          *      attribute back to the client, as the client
 695                          *      can figure it out, from the non-tunneled
 696                          *      EAP-Success packet.
 697                          */
 698                         pairfilter(tls_session, &vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 699                         pairfree(&vp);
 700                 }
 701
 702                 /* move channel binding responses; we need to send them */
 703                 pairfilter(tls_session, &vp, &reply->vps, PW_UKERNA_CHBIND, VENDORPEC_UKERNA, TAG_ANY);
 704                 if (pairfind(vp, PW_UKERNA_CHBIND, VENDORPEC_UKERNA, TAG_ANY) != NULL) {
 705                         t->authenticated = true;
 706                         /*
 707                          *      Use the tunneled reply, but not now.
 708                          */
 709                         if (t->use_tunneled_reply) {
 710                                 rad_assert(!t->accept_vps);
 711                                 pairfilter(t, &t->accept_vps, &reply->vps,
 712                                           0, 0, TAG_ANY);
 713                                 rad_assert(!reply->vps);
 714                         }
 715                         rcode = RLM_MODULE_HANDLED;
 716                 }
 717
 718                 /*
 719                  *      Handle the ACK, by tunneling any necessary reply
 720                  *      VP's back to the client.
 721                  */
 722                 if (vp) {
 723                         RDEBUG("sending tunneled reply attributes");
 724                         debug_pair_list(vp);
 725                         RDEBUG("end tunneled reply attributes");
 726                         vp2diameter(request, tls_session, vp);
 727                         pairfree(&vp);
 728                 }
 729
 730                 /*
 731                  *      If we've been told to use the attributes from
 732                  *      the reply, then do so.
 733                  *
 734                  *      WARNING: This may leak information about the
 735                  *      tunneled user!
 736                  */
 737                 if (t->use_tunneled_reply) {
 738                         pairdelete(&reply->vps, PW_PROXY_STATE, 0, TAG_ANY);
 739                         pairfilter(request->reply, &request->reply->vps,
 740                                   &reply->vps, 0, 0, TAG_ANY);
 741                 }
 742                 break;
 743
 744
 745         case PW_AUTHENTICATION_REJECT:
 746                 RDEBUG("Got tunneled Access-Reject");
 747                 rcode = RLM_MODULE_REJECT;
 748                 break;
 749
 750                 /*
 751                  *      Handle Access-Challenge, but only if we
 752                  *      send tunneled reply data.  This is because
 753                  *      an Access-Challenge means that we MUST tunnel
 754                  *      a Reply-Message to the client.
 755                  */
 756         case PW_ACCESS_CHALLENGE:
 757                 RDEBUG("Got tunneled Access-Challenge");
 758
 759                 /*
 760                  *      Keep the State attribute, if necessary.
 761                  *
 762                  *      Get rid of the old State, too.
 763                  */
 764                 pairfree(&t->state);
 765                 pairfilter(t, &t->state, &reply->vps, PW_STATE, 0, TAG_ANY);
 766
 767                 /*
 768                  *      We should really be a bit smarter about this,
 769                  *      and move over only those attributes which
 770                  *      are relevant to the authentication request,
 771                  *      but that's a lot more work, and this "dumb"
 772                  *      method works in 99.9% of the situations.
 773                  */
 774                 vp = NULL;
 775                 pairfilter(t, &vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 776
 777                 /*
 778                  *      There MUST be a Reply-Message in the challenge,
 779                  *      which we tunnel back to the client.
 780                  *
 781                  *      If there isn't one in the reply VP's, then
 782                  *      we MUST create one, with an empty string as
 783                  *      it's value.
 784                  */
 785                 pairfilter(t, &vp, &reply->vps, PW_REPLY_MESSAGE, 0, TAG_ANY);
 786
 787                 /* also move chbind messages, if any */
 788                 pairfilter(t, &vp, &reply->vps, PW_UKERNA_CHBIND, VENDORPEC_UKERNA,
 789                           TAG_ANY);
 790
 791                 /*
 792                  *      Handle the ACK, by tunneling any necessary reply
 793                  *      VP's back to the client.
 794                  */
 795                 if (vp) {
 796                         vp2diameter(request, tls_session, vp);
 797                         pairfree(&vp);
 798                 }
 799                 rcode = RLM_MODULE_HANDLED;
 800                 break;
 801
 802         default:
 803                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 804                 rcode = RLM_MODULE_INVALID;
 805                 break;
 806         }
 807
 808         return rcode;
 809 }
 810
 811
 812 #ifdef WITH_PROXY
 813 /*
 814  *      Do post-proxy processing,
 815  */
 816 static int eapttls_postproxy(eap_handler_t *handler, void *data)
 817 {
 818         int rcode;
 819         tls_session_t *tls_session = (tls_session_t *) data;
 820         REQUEST *fake, *request = handler->request;
 821
 822         rad_assert(request != NULL);
 823         RDEBUG("Passing reply from proxy back into the tunnel.");
 824
 825         /*
 826          *      If there was a fake request associated with the proxied
 827          *      request, do more processing of it.
 828          */
 829         fake = (REQUEST *) request_data_get(handler->request,
 830                                             handler->request->proxy,
 831                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 832
 833         /*
 834          *      Do the callback, if it exists, and if it was a success.
 835          */
 836         if (fake &&
 837             handler->request->proxy_reply &&
 838             (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 839                 /*
 840                  *      Terrible hacks.
 841                  */
 842                 rad_assert(!fake->packet);
 843                 fake->packet = request->proxy;
 844                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 845                 request->proxy = NULL;
 846
 847                 rad_assert(!fake->reply);
 848                 fake->reply = request->proxy_reply;
 849                 request->proxy_reply = NULL;
 850
 851                 if ((debug_flag > 0) && fr_log_fp) {
 852                         fprintf(fr_log_fp, "server %s {\n",
 853                                 (!fake->server) ? "" : fake->server);
 854                 }
 855
 856                 /*
 857                  *      Perform a post-auth stage for the tunneled
 858                  *      session.
 859                  */
 860                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 861                 rcode = rad_postauth(fake);
 862                 RDEBUG2("post-auth returns %d", rcode);
 863
 864                 if ((debug_flag > 0) && fr_log_fp) {
 865                         fprintf(fr_log_fp, "} # server %s\n",
 866                                 (!fake->server) ? "" : fake->server);
 867
 868                         RDEBUG("Final reply from tunneled session code %d",
 869                                fake->reply->code);
 870                         debug_pair_list(fake->reply->vps);
 871                 }
 872
 873                 /*
 874                  *      Terrible hacks.
 875                  */
 876                 request->proxy = fake->packet;
 877                 fake->packet = NULL;
 878                 request->proxy_reply = fake->reply;
 879                 fake->reply = NULL;
 880
 881                 /*
 882                  *      And we're done with this request.
 883                  */
 884
 885                 switch (rcode) {
 886                 case RLM_MODULE_FAIL:
 887                         request_free(&fake);
 888                         eaptls_fail(handler, 0);
 889                         return 0;
 890                         break;
 891
 892                 default:  /* Don't Do Anything */
 893                         RDEBUG2("Got reply %d",
 894                                request->proxy_reply->code);
 895                         break;
 896                 }
 897         }
 898         request_free(&fake);    /* robust if !fake */
 899
 900         /*
 901          *      Process the reply from the home server.
 902          */
 903         rcode = process_reply(handler, tls_session, handler->request,
 904                               handler->request->proxy_reply);
 905
 906         /*
 907          *      The proxy code uses the reply from the home server as
 908          *      the basis for the reply to the NAS.  We don't want that,
 909          *      so we toss it, after we've had our way with it.
 910          */
 911         pairfree(&handler->request->proxy_reply->vps);
 912
 913         switch (rcode) {
 914         case RLM_MODULE_REJECT:
 915                 RDEBUG("Reply was rejected");
 916                 break;
 917
 918         case RLM_MODULE_HANDLED:
 919                 RDEBUG("Reply was handled");
 920                 eaptls_request(handler->eap_ds, tls_session);
 921                 return 1;
 922
 923         case RLM_MODULE_OK:
 924                 RDEBUG("Reply was OK");
 925
 926                 /*
 927                  *      Success: Automatically return MPPE keys.
 928                  */
 929                 return eaptls_success(handler, 0);
 930
 931         default:
 932                 RDEBUG("Reply was unknown.");
 933                 break;
 934         }
 935
 936         eaptls_fail(handler, 0);
 937         return 0;
 938 }
 939
 940 #endif  /* WITH_PROXY */
 941
 942 /*
 943  *      Process the "diameter" contents of the tunneled data.
 944  */
 945 int eapttls_process(eap_handler_t *handler, tls_session_t *tls_session)
 946 {
 947         int code = PW_AUTHENTICATION_REJECT;
 948         rlm_rcode_t rcode;
 949         REQUEST *fake;
 950         VALUE_PAIR *vp;
 951         ttls_tunnel_t *t;
 952         uint8_t const *data;
 953         size_t data_len;
 954         REQUEST *request = handler->request;
 955         eap_chbind_packet_t *chbind_packet;
 956         size_t chbind_len;
 957
 958         rad_assert(request != NULL);
 959
 960         /*
 961          *      Just look at the buffer directly, without doing
 962          *      record_minus.
 963          */
 964         data_len = tls_session->clean_out.used;
 965         tls_session->clean_out.used = 0;
 966         data = tls_session->clean_out.data;
 967
 968         t = (ttls_tunnel_t *) tls_session->opaque;
 969
 970         /*
 971          *      If there's no data, maybe this is an ACK to an
 972          *      MS-CHAP2-Success.
 973          */
 974         if (data_len == 0) {
 975                 if (t->authenticated) {
 976                         RDEBUG("Got ACK, and the user was already authenticated.");
 977                         return PW_AUTHENTICATION_ACK;
 978                 } /* else no session, no data, die. */
 979
 980                 /*
 981                  *      FIXME: Call SSL_get_error() to see what went
 982                  *      wrong.
 983                  */
 984                 RDEBUG2("SSL_read Error");
 985                 return PW_AUTHENTICATION_REJECT;
 986         }
 987
 988 #ifndef NDEBUG
 989         if ((debug_flag > 2) && fr_log_fp) {
 990                 size_t i;
 991
 992                 for (i = 0; i < data_len; i++) {
 993                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
 994
 995                         fprintf(fr_log_fp, "%02x ", data[i]);
 996
 997                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 998                 }
 999                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
1000         }
1001 #endif
1002
1003         if (!diameter_verify(request, data, data_len)) {
1004                 return PW_AUTHENTICATION_REJECT;
1005         }
1006
1007         /*
1008          *      Allocate a fake REQUEST structe.
1009          */
1010         fake = request_alloc_fake(request);
1011
1012         rad_assert(!fake->packet->vps);
1013
1014         /*
1015          *      Add the tunneled attributes to the fake request.
1016          */
1017         fake->packet->vps = diameter2vp(request, fake, tls_session->ssl, data, data_len);
1018         if (!fake->packet->vps) {
1019                 request_free(&fake);
1020                 return PW_AUTHENTICATION_REJECT;
1021         }
1022
1023         /*
1024          *      Tell the request that it's a fake one.
1025          */
1026         pairmake_packet("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
1027
1028         if ((debug_flag > 0) && fr_log_fp) {
1029                 RDEBUG("Got tunneled request");
1030
1031                 debug_pair_list(fake->packet->vps);
1032         }
1033
1034         /*
1035          *      Update other items in the REQUEST data structure.
1036          */
1037         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1038         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY);
1039
1040         /*
1041          *      No User-Name, try to create one from stored data.
1042          */
1043         if (!fake->username) {
1044                 /*
1045                  *      No User-Name in the stored data, look for
1046                  *      an EAP-Identity, and pull it out of there.
1047                  */
1048                 if (!t->username) {
1049                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
1050                         if (vp &&
1051                             (vp->length >= EAP_HEADER_LEN + 2) &&
1052                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1053                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1054                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1055                                 char *p;
1056
1057                                 /*
1058                                  *      Create & remember a User-Name
1059                                  */
1060                                 t->username = pairmake(t, NULL, "User-Name", NULL, T_OP_EQ);
1061                                 rad_assert(t->username != NULL);
1062                                 t->username->length = vp->length - 5;
1063
1064                                 t->username->vp_strvalue = p = talloc_array(t->username, char,
1065                                                                             t->username->length + 1);
1066                                 memcpy(p, vp->vp_octets + 5, t->username->length);
1067                                 p[t->username->length] = 0;
1068
1069                                 RDEBUG("Got tunneled identity of %s",
1070                                        t->username->vp_strvalue);
1071
1072                                 /*
1073                                  *      If there's a default EAP type,
1074                                  *      set it here.
1075                                  */
1076                                 if (t->default_method != 0) {
1077                                         RDEBUG("Setting default EAP type for tunneled EAP session.");
1078                                         vp = paircreate(fake, PW_EAP_TYPE, 0);
1079                                         rad_assert(vp != NULL);
1080                                         vp->vp_integer = t->default_method;
1081                                         pairadd(&fake->config_items, vp);
1082                                 }
1083
1084                         } else {
1085                                 /*
1086                                  *      Don't reject the request outright,
1087                                  *      as it's permitted to do EAP without
1088                                  *      user-name.
1089                                  */
1090                                 RWDEBUG2("No EAP-Identity found to start EAP conversation.");
1091                         }
1092                 } /* else there WAS a t->username */
1093
1094                 if (t->username) {
1095                         vp = paircopy(fake->packet, t->username);
1096                         pairadd(&fake->packet->vps, vp);
1097                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1098                 }
1099         } /* else the request ALREADY had a User-Name */
1100
1101         /*
1102          *      Add the State attribute, too, if it exists.
1103          */
1104         if (t->state) {
1105                 vp = paircopy(fake->packet, t->state);
1106                 if (vp) pairadd(&fake->packet->vps, vp);
1107         }
1108
1109         /*
1110          *      If this is set, we copy SOME of the request attributes
1111          *      from outside of the tunnel to inside of the tunnel.
1112          *
1113          *      We copy ONLY those attributes which do NOT already
1114          *      exist in the tunneled request.
1115          */
1116         if (t->copy_request_to_tunnel) {
1117                 VALUE_PAIR *copy;
1118                 vp_cursor_t cursor;
1119
1120                 for (vp = paircursor(&cursor, &request->packet->vps); vp; vp = pairnext(&cursor)) {
1121                         /*
1122                          *      The attribute is a server-side thingy,
1123                          *      don't copy it.
1124                          */
1125                         if ((vp->da->attr > 255) &&
1126                             (vp->da->vendor == 0)) {
1127                                 continue;
1128                         }
1129
1130                         /*
1131                          *      The outside attribute is already in the
1132                          *      tunnel, don't copy it.
1133                          *
1134                          *      This works for BOTH attributes which
1135                          *      are originally in the tunneled request,
1136                          *      AND attributes which are copied there
1137                          *      from below.
1138                          */
1139                         if (pairfind(fake->packet->vps, vp->da->attr, vp->da->vendor, TAG_ANY)) {
1140                                 continue;
1141                         }
1142
1143                         /*
1144                          *      Some attributes are handled specially.
1145                          */
1146                         switch (vp->da->attr) {
1147                                 /*
1148                                  *      NEVER copy Message-Authenticator,
1149                                  *      EAP-Message, or State.  They're
1150                                  *      only for outside of the tunnel.
1151                                  */
1152                         case PW_USER_NAME:
1153                         case PW_USER_PASSWORD:
1154                         case PW_CHAP_PASSWORD:
1155                         case PW_CHAP_CHALLENGE:
1156                         case PW_PROXY_STATE:
1157                         case PW_MESSAGE_AUTHENTICATOR:
1158                         case PW_EAP_MESSAGE:
1159                         case PW_STATE:
1160                                 continue;
1161                                 break;
1162
1163                                 /*
1164                                  *      By default, copy it over.
1165                                  */
1166                         default:
1167                                 break;
1168                         }
1169
1170                         /*
1171                          *      Don't copy from the head, we've already
1172                          *      checked it.
1173                          */
1174                         copy = paircopy2(fake->packet, vp, vp->da->attr, vp->da->vendor, TAG_ANY);
1175                         pairadd(&fake->packet->vps, copy);
1176                 }
1177         }
1178
1179         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0, TAG_ANY)) != NULL) {
1180                 fake->server = vp->vp_strvalue;
1181
1182         } else if (t->virtual_server) {
1183                 fake->server = t->virtual_server;
1184
1185         } /* else fake->server == request->server */
1186
1187
1188         if ((debug_flag > 0) && fr_log_fp) {
1189                 RDEBUG("Sending tunneled request");
1190
1191                 debug_pair_list(fake->packet->vps);
1192
1193                 fprintf(fr_log_fp, "server %s {\n",
1194                         (!fake->server) ? "" : fake->server);
1195         }
1196
1197         /*
1198          *      Process channel binding here.
1199          */
1200         chbind_len = eap_chbind_vp2packet(fake->packet->vps, &chbind_packet);
1201         if (chbind_len > 0) {
1202                 int chbind_rcode;
1203                 CHBIND_REQ *req = chbind_allocate();
1204
1205                 RDEBUG("received chbind request");
1206                 req->chbind_req_pkt = (uint8_t *)chbind_packet;
1207                 req->chbind_req_len = chbind_len;
1208                 if (fake->username) {
1209                         req->username = fake->username->vp_octets;
1210                         req->username_len = fake->username->length;
1211                 } else {
1212                         req->username = NULL;
1213                         req->username_len = 0;
1214                 }
1215                 chbind_rcode = chbind_process(request, req);
1216
1217                 /* free the chbind packet; we're done with it */
1218                 free(chbind_packet);
1219
1220                 /* encapsulate response here */
1221                 if (req->chbind_resp_len > 0) {
1222                         RDEBUG("sending chbind response");
1223                         pairadd(&fake->reply->vps,
1224                                 eap_chbind_packet2vp(fake, (eap_chbind_packet_t *)req->chbind_resp,
1225                                                       req->chbind_resp_len));
1226                 } else {
1227                         RDEBUG("no chbind response");
1228                 }
1229
1230                 /* clean up chbind req */
1231                 chbind_free(req);
1232
1233                 if (chbind_rcode != PW_AUTHENTICATION_ACK)
1234                         return chbind_rcode;
1235         }
1236
1237         /*
1238          *      Call authentication recursively, which will
1239          *      do PAP, CHAP, MS-CHAP, etc.
1240          */
1241         rad_virtual_server(fake);
1242
1243         /*
1244          *      Note that we don't do *anything* with the reply
1245          *      attributes.
1246          */
1247         if ((debug_flag > 0) && fr_log_fp) {
1248                 fprintf(fr_log_fp, "} # server %s\n",
1249                         (!fake->server) ? "" : fake->server);
1250
1251                 RDEBUG("Got tunneled reply code %d", fake->reply->code);
1252
1253                 debug_pair_list(fake->reply->vps);
1254         }
1255
1256         /*
1257          *      Decide what to do with the reply.
1258          */
1259         switch (fake->reply->code) {
1260         case 0:                 /* No reply code, must be proxied... */
1261 #ifdef WITH_PROXY
1262                 vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0, TAG_ANY);
1263                 if (vp) {
1264                         eap_tunnel_data_t *tunnel;
1265                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1266
1267                         /*
1268                          *      Tell the original request that it's going
1269                          *      to be proxied.
1270                          */
1271                         pairfilter(request, &(request->config_items),
1272                                   &(fake->config_items),
1273                                   PW_PROXY_TO_REALM, 0, TAG_ANY);
1274
1275                         /*
1276                          *      Seed the proxy packet with the
1277                          *      tunneled request.
1278                          */
1279                         rad_assert(!request->proxy);
1280                         request->proxy = fake->packet;
1281                         memset(&request->proxy->src_ipaddr, 0,
1282                                sizeof(request->proxy->src_ipaddr));
1283                         memset(&request->proxy->src_ipaddr, 0,
1284                                sizeof(request->proxy->src_ipaddr));
1285                         request->proxy->src_port = 0;
1286                         request->proxy->dst_port = 0;
1287                         fake->packet = NULL;
1288                         rad_free(&fake->reply);
1289                         fake->reply = NULL;
1290
1291                         /*
1292                          *      Set up the callbacks for the tunnel
1293                          */
1294                         tunnel = talloc_zero(request, eap_tunnel_data_t);
1295                         tunnel->tls_session = tls_session;
1296                         tunnel->callback = eapttls_postproxy;
1297
1298                         /*
1299                          *      Associate the callback with the request.
1300                          */
1301                         code = request_data_add(request, request->proxy, REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1302                                                 tunnel, false);
1303                         rad_assert(code == 0);
1304
1305                         /*
1306                          *      rlm_eap.c has taken care of associating
1307                          *      the handler with the fake request.
1308                          *
1309                          *      So we associate the fake request with
1310                          *      this request.
1311                          */
1312                         talloc_set_destructor(fake, request_opaque_free);
1313                         code = request_data_add(request, request->proxy, REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1314                                                 fake, true);
1315                         rad_assert(code == 0);
1316                         fake = NULL;
1317
1318                         /*
1319                          *      Didn't authenticate the packet, but
1320                          *      we're proxying it.
1321                          */
1322                         code = PW_STATUS_CLIENT;
1323
1324                 } else
1325 #endif  /* WITH_PROXY */
1326                   {
1327                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1328                                request->number);
1329                         code = PW_AUTHENTICATION_REJECT;
1330                 }
1331                 break;
1332
1333         default:
1334                 /*
1335                  *      Returns RLM_MODULE_FOO, and we want to return PW_FOO
1336                  */
1337                 rcode = process_reply(handler, tls_session, request, fake->reply);
1338                 switch (rcode) {
1339                 case RLM_MODULE_REJECT:
1340                         code = PW_AUTHENTICATION_REJECT;
1341                         break;
1342
1343                 case RLM_MODULE_HANDLED:
1344                         code = PW_ACCESS_CHALLENGE;
1345                         break;
1346
1347                 case RLM_MODULE_OK:
1348                         code = PW_AUTHENTICATION_ACK;
1349                         break;
1350
1351                 default:
1352                         code = PW_AUTHENTICATION_REJECT;
1353                         break;
1354                 }
1355                 break;
1356         }
1357
1358         request_free(&fake);
1359
1360         return code;
1361 }