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         fr_cursor_init(&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(packet, 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                         fr_cursor_insert(&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
 268                 /*
 269                  *      If it's a type from our dictionary, then
 270                  *      we need to put the data in a relevant place.
 271                  *
 272                  *      @todo: Export the lib/radius.c decoder, and use it here!
 273                  */
 274                 switch (vp->da->type) {
 275                 case PW_TYPE_INTEGER:
 276                 case PW_TYPE_DATE:
 277                         if (size != vp->length) {
 278                                 DICT_ATTR const *da;
 279
 280                                 /*
 281                                  *      Bad format.  Create a "raw"
 282                                  *      attribute.
 283                                  */
 284                 raw:
 285                                 if (vp) pairfree(&vp);
 286                                 da = dict_attrunknown(attr, vendor, true);
 287                                 if (!da) return NULL;
 288                                 vp = pairalloc(packet, da);
 289                                 if (!vp) return NULL;
 290                                 pairmemcpy(vp, data, size);
 291                                 break;
 292                         }
 293                         memcpy(&vp->vp_integer, data, vp->length);
 294
 295                         /*
 296                          *      Stored in host byte order: change it.
 297                          */
 298                         vp->vp_integer = ntohl(vp->vp_integer);
 299                         break;
 300
 301                 case PW_TYPE_INTEGER64:
 302                         if (size != vp->length) goto raw;
 303                         memcpy(&vp->vp_integer64, data, vp->length);
 304
 305                         /*
 306                          *      Stored in host byte order: change it.
 307                          */
 308                         vp->vp_integer64 = ntohll(vp->vp_integer64);
 309                         break;
 310
 311                 case PW_TYPE_IPV4_ADDR:
 312                         if (size != vp->length) {
 313                                 RDEBUG2("Invalid length attribute %d",
 314                                        attr);
 315                                 pairfree(&first);
 316                                 pairfree(&vp);
 317                                 return NULL;
 318                         }
 319                         memcpy(&vp->vp_ipaddr, data, vp->length);
 320
 321                         /*
 322                          *      Stored in network byte order: don't change it.
 323                          */
 324                         break;
 325
 326                 case PW_TYPE_BYTE:
 327                         if (size != vp->length) goto raw;
 328                         vp->vp_integer = data[0];
 329                         break;
 330
 331                 case PW_TYPE_SHORT:
 332                         if (size != vp->length) goto raw;
 333                         vp->vp_integer = (data[0] * 256) + data[1];
 334                         break;
 335
 336                 case PW_TYPE_SIGNED:
 337                         if (size != vp->length) goto raw;
 338                         memcpy(&vp->vp_signed, data, vp->length);
 339                         vp->vp_signed = ntohl(vp->vp_signed);
 340                         break;
 341
 342                 case PW_TYPE_IPV6_ADDR:
 343                         if (size != vp->length) goto raw;
 344                         memcpy(&vp->vp_ipv6addr, data, vp->length);
 345                         break;
 346
 347                 case PW_TYPE_IPV6_PREFIX:
 348                         if (size != vp->length) goto raw;
 349                         memcpy(&vp->vp_ipv6prefix, data, vp->length);
 350                         break;
 351
 352                         /*
 353                          *      Ensure it's NUL terminated.
 354                          */
 355                 case PW_TYPE_STRING:
 356                         vp->vp_strvalue = p = talloc_array(vp, char, size + 1);
 357                         vp->type = VT_DATA;
 358                         memcpy(p, data, size);
 359                         p[size] = '\0';
 360                         vp->length = strlen(p);
 361                         break;
 362
 363                         /*
 364                          *      Copy it over verbatim.
 365                          */
 366                 case PW_TYPE_OCTETS:
 367                 default:
 368                         pairmemcpy(vp, data, size);
 369                         break;
 370                 }
 371
 372                 /*
 373                  *      Ensure that the client is using the
 374                  *      correct challenge.  This weirdness is
 375                  *      to protect against against replay
 376                  *      attacks, where anyone observing the
 377                  *      CHAP exchange could pose as that user,
 378                  *      by simply choosing to use the same
 379                  *      challenge.
 380                  *
 381                  *      By using a challenge based on
 382                  *      information from the current session,
 383                  *      we can guarantee that the client is
 384                  *      not *choosing* a challenge.
 385                  *
 386                  *      We're a little forgiving in that we
 387                  *      have loose checks on the length, and
 388                  *      we do NOT check the Id (first octet of
 389                  *      the response to the challenge)
 390                  *
 391                  *      But if the client gets the challenge correct,
 392                  *      we're not too worried about the Id.
 393                  */
 394                 if (((vp->da->vendor == 0) && (vp->da->attr == PW_CHAP_CHALLENGE)) ||
 395                     ((vp->da->vendor == VENDORPEC_MICROSOFT) && (vp->da->attr == PW_MSCHAP_CHALLENGE))) {
 396                         uint8_t challenge[16];
 397
 398                         if ((vp->length < 8) ||
 399                             (vp->length > 16)) {
 400                                 RDEBUG("Tunneled challenge has invalid length");
 401                                 pairfree(&first);
 402                                 pairfree(&vp);
 403                                 return NULL;
 404                         }
 405
 406                         eapttls_gen_challenge(ssl, challenge,
 407                                               sizeof(challenge));
 408
 409                         if (memcmp(challenge, vp->vp_octets,
 410                                    vp->length) != 0) {
 411                                 RDEBUG("Tunneled challenge is incorrect");
 412                                 pairfree(&first);
 413                                 pairfree(&vp);
 414                                 return NULL;
 415                         }
 416                 }
 417
 418                 /*
 419                  *      Update the list.
 420                  */
 421                 fr_cursor_insert(&out, vp);
 422
 423         next_attr:
 424                 /*
 425                  *      Catch non-aligned attributes.
 426                  */
 427                 if (data_left == length) break;
 428
 429                 /*
 430                  *      The length does NOT include the padding, so
 431                  *      we've got to account for it here by rounding up
 432                  *      to the nearest 4-byte boundary.
 433                  */
 434                 length += 0x03;
 435                 length &= ~0x03;
 436
 437                 rad_assert(data_left >= length);
 438                 data_left -= length;
 439                 data += length - offset; /* already updated */
 440         }
 441
 442         /*
 443          *      We got this far.  It looks OK.
 444          */
 445         return first;
 446 }
 447
 448 /*
 449  *      Convert VALUE_PAIR's to diameter attributes, and write them
 450  *      to an SSL session.
 451  *
 452  *      The ONLY VALUE_PAIR's which may be passed to this function
 453  *      are ones which can go inside of a RADIUS (i.e. diameter)
 454  *      packet.  So no server-configuration attributes, or the like.
 455  */
 456 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 457 {
 458         /*
 459          *      RADIUS packets are no more than 4k in size, so if
 460          *      we've got more than 4k of data to write, it's very
 461          *      bad.
 462          */
 463         uint8_t         buffer[4096];
 464         uint8_t         *p;
 465         uint32_t        attr;
 466         uint32_t        length;
 467         uint32_t        vendor;
 468         size_t          total;
 469         uint64_t        attr64;
 470         VALUE_PAIR      *vp;
 471         vp_cursor_t     cursor;
 472
 473         p = buffer;
 474         total = 0;
 475
 476         for (vp = fr_cursor_init(&cursor, &first); vp; vp = fr_cursor_next(&cursor)) {
 477                 /*
 478                  *      Too much data: die.
 479                  */
 480                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 481                         RDEBUG2("output buffer is full!");
 482                         return 0;
 483                 }
 484
 485                 /*
 486                  *      Hmm... we don't group multiple EAP-Messages
 487                  *      together.  Maybe we should...
 488                  */
 489
 490                 length = vp->length;
 491                 vendor = vp->da->vendor;
 492                 if (vendor != 0) {
 493                         attr = vp->da->attr & 0xffff;
 494                         length |= (1 << 31);
 495                 } else {
 496                         attr = vp->da->attr;
 497                 }
 498
 499                 /*
 500                  *      Hmm... set the M bit for all attributes?
 501                  */
 502                 length |= (1 << 30);
 503
 504                 attr = ntohl(attr);
 505
 506                 memcpy(p, &attr, sizeof(attr));
 507                 p += 4;
 508                 total += 4;
 509
 510                 length += 8;    /* includes 8 bytes of attr & length */
 511
 512                 if (vendor != 0) {
 513                         length += 4; /* include 4 bytes of vendor */
 514
 515                         length = ntohl(length);
 516                         memcpy(p, &length, sizeof(length));
 517                         p += 4;
 518                         total += 4;
 519
 520                         vendor = ntohl(vendor);
 521                         memcpy(p, &vendor, sizeof(vendor));
 522                         p += 4;
 523                         total += 4;
 524                 } else {
 525                         length = ntohl(length);
 526                         memcpy(p, &length, sizeof(length));
 527                         p += 4;
 528                         total += 4;
 529                 }
 530
 531                 switch (vp->da->type) {
 532                 case PW_TYPE_INTEGER:
 533                 case PW_TYPE_DATE:
 534                         attr = htonl(vp->vp_integer); /* stored in host order */
 535                         memcpy(p, &attr, sizeof(attr));
 536                         length = 4;
 537                         break;
 538
 539                 case PW_TYPE_INTEGER64:
 540                         attr64 = htonll(vp->vp_integer64); /* stored in host order */
 541                         memcpy(p, &attr64, sizeof(attr64));
 542                         length = 8;
 543                         break;
 544
 545                 case PW_TYPE_IPV4_ADDR:
 546                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 547                         length = 4;
 548                         break;
 549
 550                 case PW_TYPE_STRING:
 551                 case PW_TYPE_OCTETS:
 552                 default:
 553                         memcpy(p, vp->vp_strvalue, vp->length);
 554                         length = vp->length;
 555                         break;
 556                 }
 557
 558                 /*
 559                  *      Skip to the end of the data.
 560                  */
 561                 p += length;
 562                 total += length;
 563
 564                 /*
 565                  *      Align the data to a multiple of 4 bytes.
 566                  */
 567                 if ((total & 0x03) != 0) {
 568                         size_t i;
 569
 570                         length = 4 - (total & 0x03);
 571                         for (i = 0; i < length; i++) {
 572                                 *p = '\0';
 573                                 p++;
 574                                 total++;
 575                         }
 576                 }
 577         } /* loop over the VP's to write. */
 578
 579         /*
 580          *      Write the data in the buffer to the SSL session.
 581          */
 582         if (total > 0) {
 583 #ifndef NDEBUG
 584                 size_t i;
 585
 586                 if ((debug_flag > 2) && fr_log_fp) {
 587                         for (i = 0; i < total; i++) {
 588                                 if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 589
 590                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 591
 592                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 593                         }
 594                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 595                 }
 596 #endif
 597
 598                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 599
 600                 /*
 601                  *      FIXME: Check the return code.
 602                  */
 603                 tls_handshake_send(request, tls_session);
 604         }
 605
 606         /*
 607          *      Everything's OK.
 608          */
 609         return 1;
 610 }
 611
 612 /*
 613  *      Use a reply packet to determine what to do.
 614  */
 615 static rlm_rcode_t CC_HINT(nonnull) process_reply(UNUSED eap_handler_t *handler, tls_session_t *tls_session,
 616                                                   REQUEST *request, RADIUS_PACKET *reply)
 617 {
 618         rlm_rcode_t rcode = RLM_MODULE_REJECT;
 619         VALUE_PAIR *vp;
 620         ttls_tunnel_t *t = tls_session->opaque;
 621
 622         rad_assert(handler->request == request);
 623
 624         /*
 625          *      If the response packet was Access-Accept, then
 626          *      we're OK.  If not, die horribly.
 627          *
 628          *      FIXME: Take MS-CHAP2-Success attribute, and
 629          *      tunnel it back to the client, to authenticate
 630          *      ourselves to the client.
 631          *
 632          *      FIXME: If we have an Access-Challenge, then
 633          *      the Reply-Message is tunneled back to the client.
 634          *
 635          *      FIXME: If we have an EAP-Message, then that message
 636          *      must be tunneled back to the client.
 637          *
 638          *      FIXME: If we have an Access-Challenge with a State
 639          *      attribute, then do we tunnel that to the client, or
 640          *      keep track of it ourselves?
 641          *
 642          *      FIXME: EAP-Messages can only start with 'identity',
 643          *      NOT 'eap start', so we should check for that....
 644          */
 645         switch (reply->code) {
 646         case PW_CODE_ACCESS_ACCEPT:
 647                 RDEBUG("Got tunneled Access-Accept");
 648
 649                 rcode = RLM_MODULE_OK;
 650
 651                 /*
 652                  *      MS-CHAP2-Success means that we do NOT return
 653                  *      an Access-Accept, but instead tunnel that
 654                  *      attribute to the client, and keep going with
 655                  *      the TTLS session.  Once the client accepts
 656                  *      our identity, it will respond with an empty
 657                  *      packet, and we will send EAP-Success.
 658                  */
 659                 vp = NULL;
 660                 pairfilter(tls_session, &vp, &reply->vps, PW_MSCHAP2_SUCCESS, VENDORPEC_MICROSOFT, TAG_ANY);
 661                 if (vp) {
 662                         RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge");
 663                         rcode = RLM_MODULE_HANDLED;
 664                         t->authenticated = true;
 665
 666                         /*
 667                          *      Delete MPPE keys & encryption policy.  We don't
 668                          *      want these here.
 669                          */
 670                         pairdelete(&reply->vps, 7, VENDORPEC_MICROSOFT, TAG_ANY);
 671                         pairdelete(&reply->vps, 8, VENDORPEC_MICROSOFT, TAG_ANY);
 672                         pairdelete(&reply->vps, 16, VENDORPEC_MICROSOFT, TAG_ANY);
 673                         pairdelete(&reply->vps, 17, VENDORPEC_MICROSOFT, TAG_ANY);
 674
 675                         /*
 676                          *      Use the tunneled reply, but not now.
 677                          */
 678                         if (t->use_tunneled_reply) {
 679                                 rad_assert(!t->accept_vps);
 680                                 pairfilter(t, &t->accept_vps, &reply->vps,
 681                                           0, 0, TAG_ANY);
 682                                 rad_assert(!reply->vps);
 683                         }
 684
 685                 } else { /* no MS-CHAP2-Success */
 686                         /*
 687                          *      Can only have EAP-Message if there's
 688                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 689                          *
 690                          *      We also do NOT tunnel the EAP-Success
 691                          *      attribute back to the client, as the client
 692                          *      can figure it out, from the non-tunneled
 693                          *      EAP-Success packet.
 694                          */
 695                         pairfilter(tls_session, &vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 696                         pairfree(&vp);
 697                 }
 698
 699                 /* move channel binding responses; we need to send them */
 700                 pairfilter(tls_session, &vp, &reply->vps, PW_UKERNA_CHBIND, VENDORPEC_UKERNA, TAG_ANY);
 701                 if (pairfind(vp, PW_UKERNA_CHBIND, VENDORPEC_UKERNA, TAG_ANY) != NULL) {
 702                         t->authenticated = true;
 703                         /*
 704                          *      Use the tunneled reply, but not now.
 705                          */
 706                         if (t->use_tunneled_reply) {
 707                                 rad_assert(!t->accept_vps);
 708                                 pairfilter(t, &t->accept_vps, &reply->vps,
 709                                           0, 0, TAG_ANY);
 710                                 rad_assert(!reply->vps);
 711                         }
 712                         rcode = RLM_MODULE_HANDLED;
 713                 }
 714
 715                 /*
 716                  *      Handle the ACK, by tunneling any necessary reply
 717                  *      VP's back to the client.
 718                  */
 719                 if (vp) {
 720                         RDEBUG("sending tunneled reply attributes");
 721                         debug_pair_list(vp);
 722                         RDEBUG("end tunneled reply attributes");
 723                         vp2diameter(request, tls_session, vp);
 724                         pairfree(&vp);
 725                 }
 726
 727                 /*
 728                  *      If we've been told to use the attributes from
 729                  *      the reply, then do so.
 730                  *
 731                  *      WARNING: This may leak information about the
 732                  *      tunneled user!
 733                  */
 734                 if (t->use_tunneled_reply) {
 735                         pairdelete(&reply->vps, PW_PROXY_STATE, 0, TAG_ANY);
 736                         pairfilter(request->reply, &request->reply->vps,
 737                                   &reply->vps, 0, 0, TAG_ANY);
 738                 }
 739                 break;
 740
 741
 742         case PW_CODE_ACCESS_REJECT:
 743                 RDEBUG("Got tunneled Access-Reject");
 744                 rcode = RLM_MODULE_REJECT;
 745                 break;
 746
 747                 /*
 748                  *      Handle Access-Challenge, but only if we
 749                  *      send tunneled reply data.  This is because
 750                  *      an Access-Challenge means that we MUST tunnel
 751                  *      a Reply-Message to the client.
 752                  */
 753         case PW_CODE_ACCESS_CHALLENGE:
 754                 RDEBUG("Got tunneled Access-Challenge");
 755
 756                 /*
 757                  *      Keep the State attribute, if necessary.
 758                  *
 759                  *      Get rid of the old State, too.
 760                  */
 761                 pairfree(&t->state);
 762                 pairfilter(t, &t->state, &reply->vps, PW_STATE, 0, TAG_ANY);
 763
 764                 /*
 765                  *      We should really be a bit smarter about this,
 766                  *      and move over only those attributes which
 767                  *      are relevant to the authentication request,
 768                  *      but that's a lot more work, and this "dumb"
 769                  *      method works in 99.9% of the situations.
 770                  */
 771                 vp = NULL;
 772                 pairfilter(t, &vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 773
 774                 /*
 775                  *      There MUST be a Reply-Message in the challenge,
 776                  *      which we tunnel back to the client.
 777                  *
 778                  *      If there isn't one in the reply VP's, then
 779                  *      we MUST create one, with an empty string as
 780                  *      it's value.
 781                  */
 782                 pairfilter(t, &vp, &reply->vps, PW_REPLY_MESSAGE, 0, TAG_ANY);
 783
 784                 /* also move chbind messages, if any */
 785                 pairfilter(t, &vp, &reply->vps, PW_UKERNA_CHBIND, VENDORPEC_UKERNA,
 786                           TAG_ANY);
 787
 788                 /*
 789                  *      Handle the ACK, by tunneling any necessary reply
 790                  *      VP's back to the client.
 791                  */
 792                 if (vp) {
 793                         vp2diameter(request, tls_session, vp);
 794                         pairfree(&vp);
 795                 }
 796                 rcode = RLM_MODULE_HANDLED;
 797                 break;
 798
 799         default:
 800                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 801                 rcode = RLM_MODULE_INVALID;
 802                 break;
 803         }
 804
 805         return rcode;
 806 }
 807
 808
 809 #ifdef WITH_PROXY
 810 /*
 811  *      Do post-proxy processing,
 812  */
 813 static int CC_HINT(nonnull) eapttls_postproxy(eap_handler_t *handler, void *data)
 814 {
 815         int rcode;
 816         tls_session_t *tls_session = (tls_session_t *) data;
 817         REQUEST *fake, *request = handler->request;
 818
 819         RDEBUG("Passing reply from proxy back into the tunnel");
 820
 821         /*
 822          *      If there was a fake request associated with the proxied
 823          *      request, do more processing of it.
 824          */
 825         fake = (REQUEST *) request_data_get(handler->request,
 826                                             handler->request->proxy,
 827                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 828
 829         /*
 830          *      Do the callback, if it exists, and if it was a success.
 831          */
 832         if (fake && (handler->request->proxy_reply->code == PW_CODE_ACCESS_ACCEPT)) {
 833                 /*
 834                  *      Terrible hacks.
 835                  */
 836                 rad_assert(!fake->packet);
 837                 fake->packet = talloc_steal(fake, request->proxy);
 838                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 839                 request->proxy = NULL;
 840
 841                 rad_assert(!fake->reply);
 842                 fake->reply = talloc_steal(fake, request->proxy_reply);
 843                 request->proxy_reply = NULL;
 844
 845                 if ((debug_flag > 0) && fr_log_fp) {
 846                         fprintf(fr_log_fp, "server %s {\n",
 847                                 (!fake->server) ? "" : fake->server);
 848                 }
 849
 850                 /*
 851                  *      Perform a post-auth stage for the tunneled
 852                  *      session.
 853                  */
 854                 fake->log.lvl &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 855                 rcode = rad_postauth(fake);
 856                 RDEBUG2("post-auth returns %d", rcode);
 857
 858                 if ((debug_flag > 0) && fr_log_fp) {
 859                         fprintf(fr_log_fp, "} # server %s\n",
 860                                 (!fake->server) ? "" : fake->server);
 861
 862                         RDEBUG("Final reply from tunneled session code %d",
 863                                fake->reply->code);
 864                         debug_pair_list(fake->reply->vps);
 865                 }
 866
 867                 /*
 868                  *      Terrible hacks.
 869                  */
 870                 request->proxy = talloc_steal(request, fake->packet);
 871                 fake->packet = NULL;
 872                 request->proxy_reply = talloc_steal(request, fake->reply);
 873                 fake->reply = NULL;
 874
 875                 /*
 876                  *      And we're done with this request.
 877                  */
 878
 879                 switch (rcode) {
 880                 case RLM_MODULE_FAIL:
 881                         talloc_free(fake);
 882                         eaptls_fail(handler, 0);
 883                         return 0;
 884
 885                 default:  /* Don't Do Anything */
 886                         RDEBUG2("Got reply %d",
 887                                request->proxy_reply->code);
 888                         break;
 889                 }
 890         }
 891         talloc_free(fake);      /* robust if !fake */
 892
 893         /*
 894          *      Process the reply from the home server.
 895          */
 896         rcode = process_reply(handler, tls_session, handler->request, handler->request->proxy_reply);
 897
 898         /*
 899          *      The proxy code uses the reply from the home server as
 900          *      the basis for the reply to the NAS.  We don't want that,
 901          *      so we toss it, after we've had our way with it.
 902          */
 903         pairfree(&handler->request->proxy_reply->vps);
 904
 905         switch (rcode) {
 906         case RLM_MODULE_REJECT:
 907                 RDEBUG("Reply was rejected");
 908                 break;
 909
 910         case RLM_MODULE_HANDLED:
 911                 RDEBUG("Reply was handled");
 912                 eaptls_request(handler->eap_ds, tls_session);
 913                 request->proxy_reply->code = PW_CODE_ACCESS_CHALLENGE;
 914                 return 1;
 915
 916         case RLM_MODULE_OK:
 917                 RDEBUG("Reply was OK");
 918
 919                 /*
 920                  *      Success: Automatically return MPPE keys.
 921                  */
 922                 return eaptls_success(handler, 0);
 923
 924         default:
 925                 RDEBUG("Reply was unknown");
 926                 break;
 927         }
 928
 929         eaptls_fail(handler, 0);
 930         return 0;
 931 }
 932
 933 #endif  /* WITH_PROXY */
 934
 935 /*
 936  *      Process the "diameter" contents of the tunneled data.
 937  */
 938 int eapttls_process(eap_handler_t *handler, tls_session_t *tls_session)
 939 {
 940         PW_CODE code = PW_CODE_ACCESS_REJECT;
 941         rlm_rcode_t rcode;
 942         REQUEST *fake;
 943         VALUE_PAIR *vp;
 944         ttls_tunnel_t *t;
 945         uint8_t const *data;
 946         size_t data_len;
 947         REQUEST *request = handler->request;
 948         chbind_packet_t *chbind;
 949
 950         /*
 951          *      Just look at the buffer directly, without doing
 952          *      record_minus.
 953          */
 954         data_len = tls_session->clean_out.used;
 955         tls_session->clean_out.used = 0;
 956         data = tls_session->clean_out.data;
 957
 958         t = (ttls_tunnel_t *) tls_session->opaque;
 959
 960         /*
 961          *      If there's no data, maybe this is an ACK to an
 962          *      MS-CHAP2-Success.
 963          */
 964         if (data_len == 0) {
 965                 if (t->authenticated) {
 966                         RDEBUG("Got ACK, and the user was already authenticated");
 967                         return PW_CODE_ACCESS_ACCEPT;
 968                 } /* else no session, no data, die. */
 969
 970                 /*
 971                  *      FIXME: Call SSL_get_error() to see what went
 972                  *      wrong.
 973                  */
 974                 RDEBUG2("SSL_read Error");
 975                 return PW_CODE_ACCESS_REJECT;
 976         }
 977
 978 #ifndef NDEBUG
 979         if ((debug_flag > 2) && fr_log_fp) {
 980                 size_t i;
 981
 982                 for (i = 0; i < data_len; i++) {
 983                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
 984
 985                         fprintf(fr_log_fp, "%02x ", data[i]);
 986
 987                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 988                 }
 989                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 990         }
 991 #endif
 992
 993         if (!diameter_verify(request, data, data_len)) {
 994                 return PW_CODE_ACCESS_REJECT;
 995         }
 996
 997         /*
 998          *      Allocate a fake REQUEST structe.
 999          */
1000         fake = request_alloc_fake(request);
1001
1002         rad_assert(!fake->packet->vps);
1003
1004         /*
1005          *      Add the tunneled attributes to the fake request.
1006          */
1007         fake->packet->vps = diameter2vp(request, fake, tls_session->ssl, data, data_len);
1008         if (!fake->packet->vps) {
1009                 talloc_free(fake);
1010                 return PW_CODE_ACCESS_REJECT;
1011         }
1012
1013         /*
1014          *      Tell the request that it's a fake one.
1015          */
1016         pairmake_packet("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
1017
1018         if ((debug_flag > 0) && fr_log_fp) {
1019                 RDEBUG("Got tunneled request");
1020
1021                 debug_pair_list(fake->packet->vps);
1022         }
1023
1024         /*
1025          *      Update other items in the REQUEST data structure.
1026          */
1027         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1028         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY);
1029
1030         /*
1031          *      No User-Name, try to create one from stored data.
1032          */
1033         if (!fake->username) {
1034                 /*
1035                  *      No User-Name in the stored data, look for
1036                  *      an EAP-Identity, and pull it out of there.
1037                  */
1038                 if (!t->username) {
1039                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
1040                         if (vp &&
1041                             (vp->length >= EAP_HEADER_LEN + 2) &&
1042                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1043                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1044                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1045                                 char *p;
1046
1047                                 /*
1048                                  *      Create & remember a User-Name
1049                                  */
1050                                 t->username = pairmake(t, NULL, "User-Name", NULL, T_OP_EQ);
1051                                 rad_assert(t->username != NULL);
1052                                 t->username->length = vp->length - 5;
1053
1054                                 t->username->vp_strvalue = p = talloc_array(t->username, char,
1055                                                                             t->username->length + 1);
1056                                 memcpy(p, vp->vp_octets + 5, t->username->length);
1057                                 p[t->username->length] = 0;
1058
1059                                 RDEBUG("Got tunneled identity of %s",
1060                                        t->username->vp_strvalue);
1061
1062                                 /*
1063                                  *      If there's a default EAP type,
1064                                  *      set it here.
1065                                  */
1066                                 if (t->default_method != 0) {
1067                                         RDEBUG("Setting default EAP type for tunneled EAP session");
1068                                         vp = paircreate(fake, PW_EAP_TYPE, 0);
1069                                         rad_assert(vp != NULL);
1070                                         vp->vp_integer = t->default_method;
1071                                         pairadd(&fake->config_items, vp);
1072                                 }
1073
1074                         } else {
1075                                 /*
1076                                  *      Don't reject the request outright,
1077                                  *      as it's permitted to do EAP without
1078                                  *      user-name.
1079                                  */
1080                                 RWDEBUG2("No EAP-Identity found to start EAP conversation");
1081                         }
1082                 } /* else there WAS a t->username */
1083
1084                 if (t->username) {
1085                         vp = paircopy(fake->packet, t->username);
1086                         pairadd(&fake->packet->vps, vp);
1087                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1088                 }
1089         } /* else the request ALREADY had a User-Name */
1090
1091         /*
1092          *      Add the State attribute, too, if it exists.
1093          */
1094         if (t->state) {
1095                 vp = paircopy(fake->packet, t->state);
1096                 if (vp) pairadd(&fake->packet->vps, vp);
1097         }
1098
1099         /*
1100          *      If this is set, we copy SOME of the request attributes
1101          *      from outside of the tunnel to inside of the tunnel.
1102          *
1103          *      We copy ONLY those attributes which do NOT already
1104          *      exist in the tunneled request.
1105          */
1106         if (t->copy_request_to_tunnel) {
1107                 VALUE_PAIR *copy;
1108                 vp_cursor_t cursor;
1109
1110                 for (vp = fr_cursor_init(&cursor, &request->packet->vps); vp; vp = fr_cursor_next(&cursor)) {
1111                         /*
1112                          *      The attribute is a server-side thingy,
1113                          *      don't copy it.
1114                          */
1115                         if ((vp->da->attr > 255) &&
1116                             (vp->da->vendor == 0)) {
1117                                 continue;
1118                         }
1119
1120                         /*
1121                          *      The outside attribute is already in the
1122                          *      tunnel, don't copy it.
1123                          *
1124                          *      This works for BOTH attributes which
1125                          *      are originally in the tunneled request,
1126                          *      AND attributes which are copied there
1127                          *      from below.
1128                          */
1129                         if (pairfind(fake->packet->vps, vp->da->attr, vp->da->vendor, TAG_ANY)) {
1130                                 continue;
1131                         }
1132
1133                         /*
1134                          *      Some attributes are handled specially.
1135                          */
1136                         switch (vp->da->attr) {
1137                                 /*
1138                                  *      NEVER copy Message-Authenticator,
1139                                  *      EAP-Message, or State.  They're
1140                                  *      only for outside of the tunnel.
1141                                  */
1142                         case PW_USER_NAME:
1143                         case PW_USER_PASSWORD:
1144                         case PW_CHAP_PASSWORD:
1145                         case PW_CHAP_CHALLENGE:
1146                         case PW_PROXY_STATE:
1147                         case PW_MESSAGE_AUTHENTICATOR:
1148                         case PW_EAP_MESSAGE:
1149                         case PW_STATE:
1150                                 continue;
1151                                 break;
1152
1153                                 /*
1154                                  *      By default, copy it over.
1155                                  */
1156                         default:
1157                                 break;
1158                         }
1159
1160                         /*
1161                          *      Don't copy from the head, we've already
1162                          *      checked it.
1163                          */
1164                         copy = paircopy2(fake->packet, vp, vp->da->attr, vp->da->vendor, TAG_ANY);
1165                         pairadd(&fake->packet->vps, copy);
1166                 }
1167         }
1168
1169         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0, TAG_ANY)) != NULL) {
1170                 fake->server = vp->vp_strvalue;
1171
1172         } else if (t->virtual_server) {
1173                 fake->server = t->virtual_server;
1174
1175         } /* else fake->server == request->server */
1176
1177
1178         if ((debug_flag > 0) && fr_log_fp) {
1179                 RDEBUG("Sending tunneled request");
1180         }
1181
1182         /*
1183          *      Process channel binding.
1184          */
1185         chbind = eap_chbind_vp2packet(fake, fake->packet->vps);
1186         if (chbind) {
1187                 PW_CODE chbind_code;
1188                 CHBIND_REQ *req = talloc_zero(fake, CHBIND_REQ);
1189
1190                 RDEBUG("received chbind request");
1191                 req->request = chbind;
1192                 if (fake->username) {
1193                         req->username = fake->username;
1194                 } else {
1195                         req->username = NULL;
1196                 }
1197                 chbind_code = chbind_process(request, req);
1198
1199                 /* free the chbind packet; we're done with it */
1200                 free(chbind);
1201
1202                 /* encapsulate response here */
1203                 if (req->response) {
1204                         RDEBUG("sending chbind response");
1205                         pairadd(&fake->reply->vps,
1206                                 eap_chbind_packet2vp(fake, req->response));
1207                 } else {
1208                         RDEBUG("no chbind response");
1209                 }
1210
1211                 /* clean up chbind req */
1212                 talloc_free(req);
1213
1214                 if (chbind_code != PW_CODE_ACCESS_ACCEPT) {
1215                         return chbind_code;
1216                 }
1217         }
1218
1219         /*
1220          *      Call authentication recursively, which will
1221          *      do PAP, CHAP, MS-CHAP, etc.
1222          */
1223         rad_virtual_server(fake);
1224
1225         /*
1226          *      Decide what to do with the reply.
1227          */
1228         switch (fake->reply->code) {
1229         case 0:                 /* No reply code, must be proxied... */
1230 #ifdef WITH_PROXY
1231                 vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0, TAG_ANY);
1232                 if (vp) {
1233                         eap_tunnel_data_t *tunnel;
1234                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1235
1236                         /*
1237                          *      Tell the original request that it's going
1238                          *      to be proxied.
1239                          */
1240                         pairfilter(request, &request->config_items,
1241                                   &fake->config_items,
1242                                   PW_PROXY_TO_REALM, 0, TAG_ANY);
1243
1244                         /*
1245                          *      Seed the proxy packet with the
1246                          *      tunneled request.
1247                          */
1248                         rad_assert(!request->proxy);
1249                         request->proxy = talloc_steal(request, fake->packet);
1250                         memset(&request->proxy->src_ipaddr, 0,
1251                                sizeof(request->proxy->src_ipaddr));
1252                         memset(&request->proxy->src_ipaddr, 0,
1253                                sizeof(request->proxy->src_ipaddr));
1254                         request->proxy->src_port = 0;
1255                         request->proxy->dst_port = 0;
1256                         fake->packet = NULL;
1257                         rad_free(&fake->reply);
1258                         fake->reply = NULL;
1259
1260                         /*
1261                          *      Set up the callbacks for the tunnel
1262                          */
1263                         tunnel = talloc_zero(request, eap_tunnel_data_t);
1264                         tunnel->tls_session = tls_session;
1265                         tunnel->callback = eapttls_postproxy;
1266
1267                         /*
1268                          *      Associate the callback with the request.
1269                          */
1270                         code = request_data_add(request, request->proxy, REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1271                                                 tunnel, false);
1272                         rad_assert(code == 0);
1273
1274                         /*
1275                          *      rlm_eap.c has taken care of associating
1276                          *      the handler with the fake request.
1277                          *
1278                          *      So we associate the fake request with
1279                          *      this request.
1280                          */
1281                         code = request_data_add(request, request->proxy, REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1282                                                 fake, true);
1283                         rad_assert(code == 0);
1284                         fake = NULL;
1285
1286                         /*
1287                          *      Didn't authenticate the packet, but
1288                          *      we're proxying it.
1289                          */
1290                         code = PW_CODE_STATUS_CLIENT;
1291
1292                 } else
1293 #endif  /* WITH_PROXY */
1294                   {
1295                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1296                                request->number);
1297                         code = PW_CODE_ACCESS_REJECT;
1298                 }
1299                 break;
1300
1301         default:
1302                 /*
1303                  *      Returns RLM_MODULE_FOO, and we want to return PW_FOO
1304                  */
1305                 rcode = process_reply(handler, tls_session, request, fake->reply);
1306                 switch (rcode) {
1307                 case RLM_MODULE_REJECT:
1308                         code = PW_CODE_ACCESS_REJECT;
1309                         break;
1310
1311                 case RLM_MODULE_HANDLED:
1312                         code = PW_CODE_ACCESS_CHALLENGE;
1313                         break;
1314
1315                 case RLM_MODULE_OK:
1316                         code = PW_CODE_ACCESS_ACCEPT;
1317                         break;
1318
1319                 default:
1320                         code = PW_CODE_ACCESS_REJECT;
1321                         break;
1322                 }
1323                 break;
1324         }
1325
1326         talloc_free(fake);
1327
1328         return code;
1329 }