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                                 const DICT_ATTR *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 int process_reply(UNUSED eap_handler_t *handler, tls_session_t *tls_session,
 618                          REQUEST *request, RADIUS_PACKET *reply)
 619 {
 620         int 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                 pairmove2(&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                                 t->accept_vps = reply->vps;
 711                                 reply->vps = NULL;
 712                         }
 713                         rcode = RLM_MODULE_HANDLED;
 714                 }
 715
 716                 /*
 717                  *      Handle the ACK, by tunneling any necessary reply
 718                  *      VP's back to the client.
 719                  */
 720                 if (vp) {
 721                         RDEBUG("sending tunneled reply attributes");
 722                         debug_pair_list(vp);
 723                         RDEBUG("end tunneled reply attributes");
 724                         vp2diameter(request, tls_session, vp);
 725                         pairfree(&vp);
 726                 }
 727
 728                 /*
 729                  *      If we've been told to use the attributes from
 730                  *      the reply, then do so.
 731                  *
 732                  *      WARNING: This may leak information about the
 733                  *      tunneled user!
 734                  */
 735                 if (t->use_tunneled_reply) {
 736                         pairdelete(&reply->vps, PW_PROXY_STATE, 0, TAG_ANY);
 737                         pairfilter(request->reply, &request->reply->vps,
 738                                   &reply->vps, 0, 0, TAG_ANY);
 739                 }
 740                 break;
 741
 742
 743         case PW_AUTHENTICATION_REJECT:
 744                 RDEBUG("Got tunneled Access-Reject");
 745                 rcode = RLM_MODULE_REJECT;
 746                 break;
 747
 748                 /*
 749                  *      Handle Access-Challenge, but only if we
 750                  *      send tunneled reply data.  This is because
 751                  *      an Access-Challenge means that we MUST tunnel
 752                  *      a Reply-Message to the client.
 753                  */
 754         case PW_ACCESS_CHALLENGE:
 755                 RDEBUG("Got tunneled Access-Challenge");
 756
 757                 /*
 758                  *      Keep the State attribute, if necessary.
 759                  *
 760                  *      Get rid of the old State, too.
 761                  */
 762                 pairfree(&t->state);
 763                 pairfilter(t, &t->state, &reply->vps, PW_STATE, 0, TAG_ANY);
 764
 765                 /*
 766                  *      We should really be a bit smarter about this,
 767                  *      and move over only those attributes which
 768                  *      are relevant to the authentication request,
 769                  *      but that's a lot more work, and this "dumb"
 770                  *      method works in 99.9% of the situations.
 771                  */
 772                 vp = NULL;
 773                 pairfilter(t, &vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 774
 775                 /*
 776                  *      There MUST be a Reply-Message in the challenge,
 777                  *      which we tunnel back to the client.
 778                  *
 779                  *      If there isn't one in the reply VP's, then
 780                  *      we MUST create one, with an empty string as
 781                  *      it's value.
 782                  */
 783                 pairfilter(t, &vp, &reply->vps, PW_REPLY_MESSAGE, 0, TAG_ANY);
 784
 785                 /* also move chbind messages, if any */
 786                 pairmove2(&vp, &reply->vps, PW_UKERNA_CHBIND, VENDORPEC_UKERNA,
 787                           TAG_ANY);
 788
 789                 /*
 790                  *      Handle the ACK, by tunneling any necessary reply
 791                  *      VP's back to the client.
 792                  */
 793                 if (vp) {
 794                         vp2diameter(request, tls_session, vp);
 795                         pairfree(&vp);
 796                 }
 797                 rcode = RLM_MODULE_HANDLED;
 798                 break;
 799
 800         default:
 801                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 802                 rcode = RLM_MODULE_INVALID;
 803                 break;
 804         }
 805
 806         return rcode;
 807 }
 808
 809
 810 #ifdef WITH_PROXY
 811 /*
 812  *      Do post-proxy processing,
 813  */
 814 static int eapttls_postproxy(eap_handler_t *handler, void *data)
 815 {
 816         int rcode;
 817         tls_session_t *tls_session = (tls_session_t *) data;
 818         REQUEST *fake, *request = handler->request;
 819
 820         rad_assert(request != NULL);
 821         RDEBUG("Passing reply from proxy back into the tunnel.");
 822
 823         /*
 824          *      If there was a fake request associated with the proxied
 825          *      request, do more processing of it.
 826          */
 827         fake = (REQUEST *) request_data_get(handler->request,
 828                                             handler->request->proxy,
 829                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 830
 831         /*
 832          *      Do the callback, if it exists, and if it was a success.
 833          */
 834         if (fake &&
 835             handler->request->proxy_reply &&
 836             (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 837                 /*
 838                  *      Terrible hacks.
 839                  */
 840                 rad_assert(!fake->packet);
 841                 fake->packet = request->proxy;
 842                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 843                 request->proxy = NULL;
 844
 845                 rad_assert(!fake->reply);
 846                 fake->reply = request->proxy_reply;
 847                 request->proxy_reply = NULL;
 848
 849                 if ((debug_flag > 0) && fr_log_fp) {
 850                         fprintf(fr_log_fp, "server %s {\n",
 851                                 (!fake->server) ? "" : fake->server);
 852                 }
 853
 854                 /*
 855                  *      Perform a post-auth stage for the tunneled
 856                  *      session.
 857                  */
 858                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 859                 rcode = rad_postauth(fake);
 860                 RDEBUG2("post-auth returns %d", rcode);
 861
 862                 if ((debug_flag > 0) && fr_log_fp) {
 863                         fprintf(fr_log_fp, "} # server %s\n",
 864                                 (!fake->server) ? "" : fake->server);
 865
 866                         RDEBUG("Final reply from tunneled session code %d",
 867                                fake->reply->code);
 868                         debug_pair_list(fake->reply->vps);
 869                 }
 870
 871                 /*
 872                  *      Terrible hacks.
 873                  */
 874                 request->proxy = fake->packet;
 875                 fake->packet = NULL;
 876                 request->proxy_reply = fake->reply;
 877                 fake->reply = NULL;
 878
 879                 /*
 880                  *      And we're done with this request.
 881                  */
 882
 883                 switch (rcode) {
 884                 case RLM_MODULE_FAIL:
 885                         request_free(&fake);
 886                         eaptls_fail(handler, 0);
 887                         return 0;
 888                         break;
 889
 890                 default:  /* Don't Do Anything */
 891                         RDEBUG2("Got reply %d",
 892                                request->proxy_reply->code);
 893                         break;
 894                 }
 895         }
 896         request_free(&fake);    /* robust if !fake */
 897
 898         /*
 899          *      Process the reply from the home server.
 900          */
 901         rcode = process_reply(handler, tls_session, handler->request,
 902                               handler->request->proxy_reply);
 903
 904         /*
 905          *      The proxy code uses the reply from the home server as
 906          *      the basis for the reply to the NAS.  We don't want that,
 907          *      so we toss it, after we've had our way with it.
 908          */
 909         pairfree(&handler->request->proxy_reply->vps);
 910
 911         switch (rcode) {
 912         case RLM_MODULE_REJECT:
 913                 RDEBUG("Reply was rejected");
 914                 break;
 915
 916         case RLM_MODULE_HANDLED:
 917                 RDEBUG("Reply was handled");
 918                 eaptls_request(handler->eap_ds, tls_session);
 919                 return 1;
 920
 921         case RLM_MODULE_OK:
 922                 RDEBUG("Reply was OK");
 923
 924                 /*
 925                  *      Success: Automatically return MPPE keys.
 926                  */
 927                 return eaptls_success(handler, 0);
 928
 929         default:
 930                 RDEBUG("Reply was unknown.");
 931                 break;
 932         }
 933
 934         eaptls_fail(handler, 0);
 935         return 0;
 936 }
 937
 938
 939 /*
 940  *      Free a request.
 941  */
 942 static void my_request_free(void *data)
 943 {
 944         REQUEST *request = (REQUEST *)data;
 945
 946         request_free(&request);
 947 }
 948 #endif  /* WITH_PROXY */
 949
 950 /*
 951  *      Process the "diameter" contents of the tunneled data.
 952  */
 953 int eapttls_process(eap_handler_t *handler, tls_session_t *tls_session)
 954 {
 955         int rcode = PW_AUTHENTICATION_REJECT;
 956         REQUEST *fake;
 957         VALUE_PAIR *vp;
 958         ttls_tunnel_t *t;
 959         const uint8_t *data;
 960         size_t data_len;
 961         REQUEST *request = handler->request;
 962         eap_chbind_packet_t *chbind_packet;
 963         size_t chbind_len;
 964
 965         rad_assert(request != NULL);
 966
 967         /*
 968          *      Just look at the buffer directly, without doing
 969          *      record_minus.
 970          */
 971         data_len = tls_session->clean_out.used;
 972         tls_session->clean_out.used = 0;
 973         data = tls_session->clean_out.data;
 974
 975         t = (ttls_tunnel_t *) tls_session->opaque;
 976
 977         /*
 978          *      If there's no data, maybe this is an ACK to an
 979          *      MS-CHAP2-Success.
 980          */
 981         if (data_len == 0) {
 982                 if (t->authenticated) {
 983                         RDEBUG("Got ACK, and the user was already authenticated.");
 984                         return PW_AUTHENTICATION_ACK;
 985                 } /* else no session, no data, die. */
 986
 987                 /*
 988                  *      FIXME: Call SSL_get_error() to see what went
 989                  *      wrong.
 990                  */
 991                 RDEBUG2("SSL_read Error");
 992                 return PW_AUTHENTICATION_REJECT;
 993         }
 994
 995 #ifndef NDEBUG
 996         if ((debug_flag > 2) && fr_log_fp) {
 997                 size_t i;
 998
 999                 for (i = 0; i < data_len; i++) {
1000                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
1001
1002                         fprintf(fr_log_fp, "%02x ", data[i]);
1003
1004                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
1005                 }
1006                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
1007         }
1008 #endif
1009
1010         if (!diameter_verify(request, data, data_len)) {
1011                 return PW_AUTHENTICATION_REJECT;
1012         }
1013
1014         /*
1015          *      Allocate a fake REQUEST structe.
1016          */
1017         fake = request_alloc_fake(request);
1018
1019         rad_assert(!fake->packet->vps);
1020
1021         /*
1022          *      Add the tunneled attributes to the fake request.
1023          */
1024         fake->packet->vps = diameter2vp(request, fake, tls_session->ssl, data, data_len);
1025         if (!fake->packet->vps) {
1026                 request_free(&fake);
1027                 return PW_AUTHENTICATION_REJECT;
1028         }
1029
1030         /*
1031          *      Tell the request that it's a fake one.
1032          */
1033         pairmake_packet("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
1034
1035         if ((debug_flag > 0) && fr_log_fp) {
1036                 RDEBUG("Got tunneled request");
1037
1038                 debug_pair_list(fake->packet->vps);
1039         }
1040
1041         /*
1042          *      Update other items in the REQUEST data structure.
1043          */
1044         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1045         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY);
1046
1047         /*
1048          *      No User-Name, try to create one from stored data.
1049          */
1050         if (!fake->username) {
1051                 /*
1052                  *      No User-Name in the stored data, look for
1053                  *      an EAP-Identity, and pull it out of there.
1054                  */
1055                 if (!t->username) {
1056                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
1057                         if (vp &&
1058                             (vp->length >= EAP_HEADER_LEN + 2) &&
1059                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1060                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1061                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1062                                 char *p;
1063
1064                                 /*
1065                                  *      Create & remember a User-Name
1066                                  */
1067                                 t->username = pairmake(t, NULL, "User-Name", NULL, T_OP_EQ);
1068                                 rad_assert(t->username != NULL);
1069                                 t->username->length = vp->length - 5;
1070
1071                                 t->username->vp_strvalue = p = talloc_array(t->username, char,
1072                                                                             t->username->length + 1);
1073                                 memcpy(p, vp->vp_octets + 5, t->username->length);
1074                                 p[t->username->length] = 0;
1075
1076                                 RDEBUG("Got tunneled identity of %s",
1077                                        t->username->vp_strvalue);
1078
1079                                 /*
1080                                  *      If there's a default EAP type,
1081                                  *      set it here.
1082                                  */
1083                                 if (t->default_method != 0) {
1084                                         RDEBUG("Setting default EAP type for tunneled EAP session.");
1085                                         vp = paircreate(fake, PW_EAP_TYPE, 0);
1086                                         rad_assert(vp != NULL);
1087                                         vp->vp_integer = t->default_method;
1088                                         pairadd(&fake->config_items, vp);
1089                                 }
1090
1091                         } else {
1092                                 /*
1093                                  *      Don't reject the request outright,
1094                                  *      as it's permitted to do EAP without
1095                                  *      user-name.
1096                                  */
1097                                 RWDEBUG2("No EAP-Identity found to start EAP conversation.");
1098                         }
1099                 } /* else there WAS a t->username */
1100
1101                 if (t->username) {
1102                         vp = paircopy(fake->packet, t->username);
1103                         pairadd(&fake->packet->vps, vp);
1104                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1105                 }
1106         } /* else the request ALREADY had a User-Name */
1107
1108         /*
1109          *      Add the State attribute, too, if it exists.
1110          */
1111         if (t->state) {
1112                 vp = paircopy(fake->packet, t->state);
1113                 if (vp) pairadd(&fake->packet->vps, vp);
1114         }
1115
1116         /*
1117          *      If this is set, we copy SOME of the request attributes
1118          *      from outside of the tunnel to inside of the tunnel.
1119          *
1120          *      We copy ONLY those attributes which do NOT already
1121          *      exist in the tunneled request.
1122          */
1123         if (t->copy_request_to_tunnel) {
1124                 VALUE_PAIR *copy;
1125                 vp_cursor_t cursor;
1126
1127                 for (vp = paircursor(&cursor, &request->packet->vps); vp; vp = pairnext(&cursor)) {
1128                         /*
1129                          *      The attribute is a server-side thingy,
1130                          *      don't copy it.
1131                          */
1132                         if ((vp->da->attr > 255) &&
1133                             (vp->da->vendor == 0)) {
1134                                 continue;
1135                         }
1136
1137                         /*
1138                          *      The outside attribute is already in the
1139                          *      tunnel, don't copy it.
1140                          *
1141                          *      This works for BOTH attributes which
1142                          *      are originally in the tunneled request,
1143                          *      AND attributes which are copied there
1144                          *      from below.
1145                          */
1146                         if (pairfind(fake->packet->vps, vp->da->attr, vp->da->vendor, TAG_ANY)) {
1147                                 continue;
1148                         }
1149
1150                         /*
1151                          *      Some attributes are handled specially.
1152                          */
1153                         switch (vp->da->attr) {
1154                                 /*
1155                                  *      NEVER copy Message-Authenticator,
1156                                  *      EAP-Message, or State.  They're
1157                                  *      only for outside of the tunnel.
1158                                  */
1159                         case PW_USER_NAME:
1160                         case PW_USER_PASSWORD:
1161                         case PW_CHAP_PASSWORD:
1162                         case PW_CHAP_CHALLENGE:
1163                         case PW_PROXY_STATE:
1164                         case PW_MESSAGE_AUTHENTICATOR:
1165                         case PW_EAP_MESSAGE:
1166                         case PW_STATE:
1167                                 continue;
1168                                 break;
1169
1170                                 /*
1171                                  *      By default, copy it over.
1172                                  */
1173                         default:
1174                                 break;
1175                         }
1176
1177                         /*
1178                          *      Don't copy from the head, we've already
1179                          *      checked it.
1180                          */
1181                         copy = paircopy2(fake->packet, vp, vp->da->attr, vp->da->vendor, TAG_ANY);
1182                         pairadd(&fake->packet->vps, copy);
1183                 }
1184         }
1185
1186         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0, TAG_ANY)) != NULL) {
1187                 fake->server = vp->vp_strvalue;
1188
1189         } else if (t->virtual_server) {
1190                 fake->server = t->virtual_server;
1191
1192         } /* else fake->server == request->server */
1193
1194
1195         if ((debug_flag > 0) && fr_log_fp) {
1196                 RDEBUG("Sending tunneled request");
1197
1198                 debug_pair_list(fake->packet->vps);
1199
1200                 fprintf(fr_log_fp, "server %s {\n",
1201                         (!fake->server) ? "" : fake->server);
1202         }
1203
1204         /*
1205          *      Process channel binding here.
1206          */
1207         chbind_len = eap_chbind_vp2packet(fake->packet->vps, &chbind_packet);
1208         if (chbind_len > 0) {
1209                 int chbind_rcode;
1210                 CHBIND_REQ *req = chbind_allocate();
1211
1212                 RDEBUG("received chbind request");
1213                 req->chbind_req_pkt = (uint8_t *)chbind_packet;
1214                 req->chbind_req_len = chbind_len;
1215                 if (fake->username) {
1216                         req->username = fake->username->vp_octets;
1217                         req->username_len = fake->username->length;
1218                 } else {
1219                         req->username = NULL;
1220                         req->username_len = 0;
1221                 }
1222                 chbind_rcode = chbind_process(request, req);
1223
1224                 /* free the chbind packet; we're done with it */
1225                 free(chbind_packet);
1226
1227                 /* encapsulate response here */
1228                 if (req->chbind_resp_len > 0) {
1229                         RDEBUG("sending chbind response");
1230                         pairadd(&fake->reply->vps,
1231                                  eap_chbind_packet2vp((eap_chbind_packet_t *)req->chbind_resp,
1232                                                       req->chbind_resp_len));
1233                 } else {
1234                         RDEBUG("no chbind response");
1235                 }
1236
1237                 /* clean up chbind req */
1238                 chbind_free(req);
1239
1240                 if (chbind_rcode != PW_AUTHENTICATION_ACK)
1241                         return chbind_rcode;
1242         }
1243
1244         /*
1245          *      Call authentication recursively, which will
1246          *      do PAP, CHAP, MS-CHAP, etc.
1247          */
1248         rad_virtual_server(fake);
1249
1250         /*
1251          *      Note that we don't do *anything* with the reply
1252          *      attributes.
1253          */
1254         if ((debug_flag > 0) && fr_log_fp) {
1255                 fprintf(fr_log_fp, "} # server %s\n",
1256                         (!fake->server) ? "" : fake->server);
1257
1258                 RDEBUG("Got tunneled reply code %d", fake->reply->code);
1259
1260                 debug_pair_list(fake->reply->vps);
1261         }
1262
1263         /*
1264          *      Decide what to do with the reply.
1265          */
1266         switch (fake->reply->code) {
1267         case 0:                 /* No reply code, must be proxied... */
1268 #ifdef WITH_PROXY
1269                 vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0, TAG_ANY);
1270                 if (vp) {
1271                         eap_tunnel_data_t *tunnel;
1272                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1273
1274                         /*
1275                          *      Tell the original request that it's going
1276                          *      to be proxied.
1277                          */
1278                         pairfilter(request, &(request->config_items),
1279                                   &(fake->config_items),
1280                                   PW_PROXY_TO_REALM, 0, TAG_ANY);
1281
1282                         /*
1283                          *      Seed the proxy packet with the
1284                          *      tunneled request.
1285                          */
1286                         rad_assert(!request->proxy);
1287                         request->proxy = fake->packet;
1288                         memset(&request->proxy->src_ipaddr, 0,
1289                                sizeof(request->proxy->src_ipaddr));
1290                         memset(&request->proxy->src_ipaddr, 0,
1291                                sizeof(request->proxy->src_ipaddr));
1292                         request->proxy->src_port = 0;
1293                         request->proxy->dst_port = 0;
1294                         fake->packet = NULL;
1295                         rad_free(&fake->reply);
1296                         fake->reply = NULL;
1297
1298                         /*
1299                          *      Set up the callbacks for the tunnel
1300                          */
1301                         tunnel = talloc_zero(request, eap_tunnel_data_t);
1302                         tunnel->tls_session = tls_session;
1303                         tunnel->callback = eapttls_postproxy;
1304
1305                         /*
1306                          *      Associate the callback with the request.
1307                          */
1308                         rcode = request_data_add(request,
1309                                                  request->proxy,
1310                                                  REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1311                                                  tunnel, NULL);
1312                         rad_assert(rcode == 0);
1313
1314                         /*
1315                          *      rlm_eap.c has taken care of associating
1316                          *      the handler with the fake request.
1317                          *
1318                          *      So we associate the fake request with
1319                          *      this request.
1320                          */
1321                         rcode = request_data_add(request,
1322                                                  request->proxy,
1323                                                  REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1324                                                  fake, my_request_free);
1325                         rad_assert(rcode == 0);
1326                         fake = NULL;
1327
1328                         /*
1329                          *      Didn't authenticate the packet, but
1330                          *      we're proxying it.
1331                          */
1332                         rcode = PW_STATUS_CLIENT;
1333
1334                 } else
1335 #endif  /* WITH_PROXY */
1336                   {
1337                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1338                                request->number);
1339                         rcode = PW_AUTHENTICATION_REJECT;
1340                 }
1341                 break;
1342
1343         default:
1344                 /*
1345                  *      Returns RLM_MODULE_FOO, and we want to return
1346                  *      PW_FOO
1347                  */
1348                 rcode = process_reply(handler, tls_session, request,
1349                                       fake->reply);
1350                 switch (rcode) {
1351                 case RLM_MODULE_REJECT:
1352                         rcode = PW_AUTHENTICATION_REJECT;
1353                         break;
1354
1355                 case RLM_MODULE_HANDLED:
1356                         rcode = PW_ACCESS_CHALLENGE;
1357                         break;
1358
1359                 case RLM_MODULE_OK:
1360                         rcode = PW_AUTHENTICATION_ACK;
1361                         break;
1362
1363                 default:
1364                         rcode = PW_AUTHENTICATION_REJECT;
1365                         break;
1366                 }
1367                 break;
1368         }
1369
1370         request_free(&fake);
1371
1372         return rcode;
1373 }