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 #include <freeradius-devel/ident.h>
  25 RCSID("$Id$")
  26
  27 #include "eap_ttls.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,
  47                            const uint8_t *data, unsigned int data_len)
  48 {
  49         uint32_t attr;
  50         uint32_t length;
  51         unsigned int hdr_len;
  52         unsigned int remaining = data_len;
  53
  54         while (remaining > 0) {
  55                 hdr_len = 12;
  56
  57                 if (remaining < hdr_len) {
  58                   RDEBUG2(" Diameter attribute is too small (%u) to contain a Diameter header", remaining);
  59                         return 0;
  60                 }
  61
  62                 memcpy(&attr, data, sizeof(attr));
  63                 attr = ntohl(attr);
  64                 memcpy(&length, data + 4, sizeof(length));
  65                 length = ntohl(length);
  66
  67                 if ((data[4] & 0x80) != 0) {
  68                         if (remaining < 16) {
  69                                 RDEBUG2(" Diameter attribute is too small to contain a Diameter header with Vendor-Id");
  70                                 return 0;
  71                         }
  72
  73                         hdr_len = 16;
  74                 }
  75
  76                 /*
  77                  *      Get the length.  If it's too big, die.
  78                  */
  79                 length &= 0x00ffffff;
  80
  81                 /*
  82                  *      Too short or too long is bad.
  83                  */
  84                 if (length <= (hdr_len - 4)) {
  85                         RDEBUG2("Tunneled attribute %u is too short (%u < %u) to contain anything useful.", attr, 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, length, remaining);
  91                         return 0;
  92                 }
  93
  94                 /*
  95                  *      Check for broken implementations, which don't
  96                  *      pad the AVP to a 4-octet boundary.
  97                  */
  98                 if (remaining == length) break;
  99
 100                 /*
 101                  *      The length does NOT include the padding, so
 102                  *      we've got to account for it here by rounding up
 103                  *      to the nearest 4-byte boundary.
 104                  */
 105                 length += 0x03;
 106                 length &= ~0x03;
 107
 108                 /*
 109                  *      If the rest of the diameter packet is larger than
 110                  *      this attribute, continue.
 111                  *
 112                  *      Otherwise, if the attribute over-flows the end
 113                  *      of the packet, die.
 114                  */
 115                 if (remaining < length) {
 116                         RDEBUG2E("Diameter attribute overflows packet!");
 117                         return 0;
 118                 }
 119
 120                 /*
 121                  *      remaining > length, continue.
 122                  */
 123                 remaining -= length;
 124                 data += length;
 125         }
 126
 127         /*
 128          *      We got this far.  It looks OK.
 129          */
 130         return 1;
 131 }
 132
 133
 134 /*
 135  *      Convert diameter attributes to our VALUE_PAIR's
 136  */
 137 static VALUE_PAIR *diameter2vp(REQUEST *request, SSL *ssl,
 138                                const uint8_t *data, size_t data_len)
 139 {
 140         uint32_t        attr;
 141         uint32_t        vendor;
 142         uint32_t        length;
 143         size_t          offset;
 144         size_t          size;
 145         size_t          data_left = data_len;
 146         VALUE_PAIR      *first = NULL;
 147         VALUE_PAIR      **last = &first;
 148         VALUE_PAIR      *vp;
 149
 150         while (data_left > 0) {
 151                 rad_assert(data_left <= data_len);
 152                 memcpy(&attr, data, sizeof(attr));
 153                 data += 4;
 154                 attr = ntohl(attr);
 155                 vendor = 0;
 156
 157                 memcpy(&length, data, sizeof(length));
 158                 data += 4;
 159                 length = ntohl(length);
 160
 161                 /*
 162                  *      A "vendor" flag, with a vendor ID of zero,
 163                  *      is equivalent to no vendor.  This is stupid.
 164                  */
 165                 offset = 8;
 166                 if ((length & (1 << 31)) != 0) {
 167                         memcpy(&vendor, data, sizeof(vendor));
 168                         vendor = ntohl(vendor);
 169
 170                         data += 4; /* skip the vendor field, it's zero */
 171                         offset += 4; /* offset to value field */
 172
 173                         if (attr > 65535) goto next_attr;
 174                         if (vendor > FR_MAX_VENDOR) goto next_attr;
 175                 }
 176
 177                 /*
 178                  *      FIXME: Handle the M bit.  For now, we assume that
 179                  *      some other module takes care of any attribute
 180                  *      with the M bit set.
 181                  */
 182
 183                 /*
 184                  *      Get the length.
 185                  */
 186                 length &= 0x00ffffff;
 187
 188                 /*
 189                  *      Get the size of the value portion of the
 190                  *      attribute.
 191                  */
 192                 size = length - offset;
 193
 194                 /*
 195                  *      Vendor attributes can be larger than 255.
 196                  *      Normal attributes cannot be.
 197                  */
 198                 if ((attr > 255) && (vendor == 0)) {
 199                         RDEBUG2W("Skipping Diameter attribute %u",
 200                                 attr);
 201                         goto next_attr;
 202                 }
 203
 204                 /*
 205                  * EAP-Message AVPs can be larger than 253 octets.
 206                  */
 207                 if ((size > 253) && !((vendor == 0) && (attr == PW_EAP_MESSAGE))) {
 208                         RDEBUG2W("diameter2vp skipping long attribute %u", attr);
 209                         goto next_attr;
 210                 }
 211
 212                 /*
 213                  *      RADIUS VSAs are handled as Diameter attributes
 214                  *      with Vendor-Id == 0, and the VSA data packed
 215                  *      into the "String" field as per normal.
 216                  *
 217                  *      EXCEPT for the MS-CHAP attributes.
 218                  */
 219                 if ((vendor == 0) && (attr == PW_VENDOR_SPECIFIC)) {
 220                         ssize_t decoded;
 221                         uint8_t buffer[256];
 222
 223                         buffer[0] = PW_VENDOR_SPECIFIC;
 224                         buffer[1] = size + 2;
 225                         memcpy(buffer + 2, data, size);
 226
 227                         vp = NULL;
 228                         decoded = rad_attr2vp(NULL, NULL, NULL,
 229                                               buffer, size + 2, &vp);
 230                         if (decoded < 0) {
 231                                 RDEBUG2E("diameter2vp failed decoding attr: %s",
 232                                         fr_strerror());
 233                                 goto do_octets;
 234                         }
 235
 236                         if ((size_t) decoded != size + 2) {
 237                                 RDEBUG2E("diameter2vp failed to entirely decode VSA");
 238                                 pairfree(&vp);
 239                                 goto do_octets;
 240                         }
 241
 242                         *last = vp;
 243                         do {
 244                                 last = &(vp->next);
 245                                 vp = vp->next;
 246                         } while (vp != NULL);
 247
 248                         goto next_attr;
 249                 }
 250
 251                 /*
 252                  *      Create it.  If this fails, it's because we're OOM.
 253                  */
 254         do_octets:
 255                 vp = paircreate(attr, vendor);
 256                 if (!vp) {
 257                         RDEBUG2("Failure in creating VP");
 258                         pairfree(&first);
 259                         return NULL;
 260                 }
 261
 262                 /*
 263                  *      If it's a type from our dictionary, then
 264                  *      we need to put the data in a relevant place.
 265                  */
 266                 switch (vp->da->type) {
 267                 case PW_TYPE_INTEGER:
 268                 case PW_TYPE_DATE:
 269                         if (size != vp->length) {
 270                                 const DICT_ATTR *da;
 271
 272                                 /*
 273                                  *      Bad format.  Create a "raw"
 274                                  *      attribute.
 275                                  */
 276                 raw:
 277                                 if (vp) pairfree(&vp);
 278                                 da = dict_attrunknown(attr, vendor, TRUE);
 279                                 if (!da) return NULL;
 280                                 vp = pairalloc(NULL, da);
 281                                 if (size >= 253) size = 253;
 282                                 vp->length = size;
 283                                 memcpy(vp->vp_octets, data, vp->length);
 284                                 break;
 285                         }
 286                         memcpy(&vp->vp_integer, data, vp->length);
 287
 288                         /*
 289                          *      Stored in host byte order: change it.
 290                          */
 291                         vp->vp_integer = ntohl(vp->vp_integer);
 292                         break;
 293
 294                 case PW_TYPE_INTEGER64:
 295                         if (size != vp->length) goto raw;
 296                         memcpy(&vp->vp_integer64, data, vp->length);
 297
 298                         /*
 299                          *      Stored in host byte order: change it.
 300                          */
 301                         vp->vp_integer64 = ntohll(vp->vp_integer64);
 302                         break;
 303
 304                 case PW_TYPE_IPADDR:
 305                         if (size != vp->length) {
 306                                 RDEBUG2("Invalid length attribute %d",
 307                                        attr);
 308                                 pairfree(&first);
 309                                 pairfree(&vp);
 310                                 return NULL;
 311                         }
 312                   memcpy(&vp->vp_ipaddr, data, vp->length);
 313
 314                   /*
 315                    *    Stored in network byte order: don't change it.
 316                    */
 317                   break;
 318
 319                 case PW_TYPE_BYTE:
 320                         if (size != vp->length) goto raw;
 321                         vp->vp_integer = data[0];
 322                         break;
 323
 324                 case PW_TYPE_SHORT:
 325                         if (size != vp->length) goto raw;
 326                         vp->vp_integer = (data[0] * 256) + data[1];
 327                         break;
 328
 329                 case PW_TYPE_SIGNED:
 330                         if (size != vp->length) goto raw;
 331                         memcpy(&vp->vp_signed, data, vp->length);
 332                         vp->vp_signed = ntohl(vp->vp_signed);
 333                         break;
 334
 335                 case PW_TYPE_IPV6ADDR:
 336                         if (size != vp->length) goto raw;
 337                         memcpy(&vp->vp_ipv6addr, data, vp->length);
 338                         break;
 339
 340                 case PW_TYPE_IPV6PREFIX:
 341                         if (size != vp->length) goto raw;
 342                         memcpy(&vp->vp_ipv6prefix, data, vp->length);
 343                         break;
 344
 345                         /*
 346                          *      String, octet, etc.  Copy the data from the
 347                          *      value field over verbatim.
 348                          */
 349                 case PW_TYPE_OCTETS:
 350                         if (attr == PW_EAP_MESSAGE) {
 351                                 const uint8_t *eap_message = data;
 352
 353                                 /*
 354                                  *      vp exists the first time around.
 355                                  */
 356                                 while (1) {
 357                                         vp->length = size;
 358                                         if (vp->length > 253) vp->length = 253;
 359                                         memcpy(vp->vp_octets, eap_message,
 360                                                vp->length);
 361
 362                                         size -= vp->length;
 363                                         eap_message += vp->length;
 364
 365                                         *last = vp;
 366                                         last = &(vp->next);
 367
 368                                         if (size == 0) break;
 369
 370                                         vp = paircreate(attr, vendor);
 371                                         if (!vp) {
 372                                                 RDEBUG2("Failure in creating VP");
 373                                                 pairfree(&first);
 374                                                 return NULL;
 375                                         }
 376                                 }
 377
 378                                 goto next_attr;
 379                         } /* else it's another kind of attribute */
 380                         /* FALL-THROUGH */
 381
 382                 default:
 383                         if (size >= 253) size = 253;
 384                         vp->length = size;
 385                         memcpy(vp->vp_strvalue, data, vp->length);
 386                         break;
 387                 }
 388
 389                 /*
 390                  *      User-Password is NUL padded to a multiple
 391                  *      of 16 bytes.  Let's chop it to something
 392                  *      more reasonable.
 393                  *
 394                  *      NOTE: This means that the User-Password
 395                  *      attribute CANNOT EVER have embedded zeros in it!
 396                  */
 397                 if ((vp->da->vendor == 0) && (vp->da->attr == PW_USER_PASSWORD)) {
 398                         /*
 399                          *      If the password is exactly 16 octets,
 400                          *      it won't be zero-terminated.
 401                          */
 402                         vp->vp_strvalue[vp->length] = '\0';
 403                         vp->length = strlen(vp->vp_strvalue);
 404                 }
 405
 406                 /*
 407                  *      Ensure that the client is using the
 408                  *      correct challenge.  This weirdness is
 409                  *      to protect against against replay
 410                  *      attacks, where anyone observing the
 411                  *      CHAP exchange could pose as that user,
 412                  *      by simply choosing to use the same
 413                  *      challenge.
 414                  *
 415                  *      By using a challenge based on
 416                  *      information from the current session,
 417                  *      we can guarantee that the client is
 418                  *      not *choosing* a challenge.
 419                  *
 420                  *      We're a little forgiving in that we
 421                  *      have loose checks on the length, and
 422                  *      we do NOT check the Id (first octet of
 423                  *      the response to the challenge)
 424                  *
 425                  *      But if the client gets the challenge correct,
 426                  *      we're not too worried about the Id.
 427                  */
 428                 if (((vp->da->vendor == 0) && (vp->da->attr == PW_CHAP_CHALLENGE)) ||
 429                     ((vp->da->vendor == VENDORPEC_MICROSOFT) && (vp->da->attr == PW_MSCHAP_CHALLENGE))) {
 430                         uint8_t challenge[16];
 431
 432                         if ((vp->length < 8) ||
 433                             (vp->length > 16)) {
 434                                 RDEBUG("Tunneled challenge has invalid length");
 435                                 pairfree(&first);
 436                                 pairfree(&vp);
 437                                 return NULL;
 438                         }
 439
 440                         eapttls_gen_challenge(ssl, challenge,
 441                                               sizeof(challenge));
 442
 443                         if (memcmp(challenge, vp->vp_octets,
 444                                    vp->length) != 0) {
 445                                 RDEBUG("Tunneled challenge is incorrect");
 446                                 pairfree(&first);
 447                                 pairfree(&vp);
 448                                 return NULL;
 449                         }
 450                 }
 451
 452                 /*
 453                  *      Update the list.
 454                  */
 455                 *last = vp;
 456                 last = &(vp->next);
 457
 458         next_attr:
 459                 /*
 460                  *      Catch non-aligned attributes.
 461                  */
 462                 if (data_left == length) break;
 463
 464                 /*
 465                  *      The length does NOT include the padding, so
 466                  *      we've got to account for it here by rounding up
 467                  *      to the nearest 4-byte boundary.
 468                  */
 469                 length += 0x03;
 470                 length &= ~0x03;
 471
 472                 rad_assert(data_left >= length);
 473                 data_left -= length;
 474                 data += length - offset; /* already updated */
 475         }
 476
 477         /*
 478          *      We got this far.  It looks OK.
 479          */
 480         return first;
 481 }
 482
 483 /*
 484  *      Convert VALUE_PAIR's to diameter attributes, and write them
 485  *      to an SSL session.
 486  *
 487  *      The ONLY VALUE_PAIR's which may be passed to this function
 488  *      are ones which can go inside of a RADIUS (i.e. diameter)
 489  *      packet.  So no server-configuration attributes, or the like.
 490  */
 491 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 492 {
 493         /*
 494          *      RADIUS packets are no more than 4k in size, so if
 495          *      we've got more than 4k of data to write, it's very
 496          *      bad.
 497          */
 498         uint8_t         buffer[4096];
 499         uint8_t         *p;
 500         uint32_t        attr;
 501         uint32_t        length;
 502         uint32_t        vendor;
 503         size_t          total;
 504         uint64_t        attr64;
 505         VALUE_PAIR      *vp;
 506
 507         p = buffer;
 508         total = 0;
 509
 510         for (vp = first; vp != NULL; vp = vp->next) {
 511                 /*
 512                  *      Too much data: die.
 513                  */
 514                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 515                         RDEBUG2("output buffer is full!");
 516                         return 0;
 517                 }
 518
 519                 /*
 520                  *      Hmm... we don't group multiple EAP-Messages
 521                  *      together.  Maybe we should...
 522                  */
 523
 524                 /*
 525                  *      Length is no more than 253, due to RADIUS
 526                  *      issues.
 527                  */
 528                 length = vp->length;
 529                 vendor = vp->da->vendor;
 530                 if (vendor != 0) {
 531                         attr = vp->da->attr & 0xffff;
 532                         length |= (1 << 31);
 533                 } else {
 534                         attr = vp->da->attr;
 535                 }
 536
 537                 /*
 538                  *      Hmm... set the M bit for all attributes?
 539                  */
 540                 length |= (1 << 30);
 541
 542                 attr = ntohl(attr);
 543
 544                 memcpy(p, &attr, sizeof(attr));
 545                 p += 4;
 546                 total += 4;
 547
 548                 length += 8;    /* includes 8 bytes of attr & length */
 549
 550                 if (vendor != 0) {
 551                         length += 4; /* include 4 bytes of vendor */
 552
 553                         length = ntohl(length);
 554                         memcpy(p, &length, sizeof(length));
 555                         p += 4;
 556                         total += 4;
 557
 558                         vendor = ntohl(vendor);
 559                         memcpy(p, &vendor, sizeof(vendor));
 560                         p += 4;
 561                         total += 4;
 562                 } else {
 563                         length = ntohl(length);
 564                         memcpy(p, &length, sizeof(length));
 565                         p += 4;
 566                         total += 4;
 567                 }
 568
 569                 switch (vp->da->type) {
 570                 case PW_TYPE_INTEGER:
 571                 case PW_TYPE_DATE:
 572                         attr = htonl(vp->vp_integer); /* stored in host order */
 573                         memcpy(p, &attr, sizeof(attr));
 574                         length = 4;
 575                         break;
 576
 577                 case PW_TYPE_INTEGER64:
 578                         attr64 = htonll(vp->vp_integer64); /* stored in host order */
 579                         memcpy(p, &attr64, sizeof(attr64));
 580                         length = 8;
 581                         break;
 582
 583                 case PW_TYPE_IPADDR:
 584                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 585                         length = 4;
 586                         break;
 587
 588                 case PW_TYPE_STRING:
 589                 case PW_TYPE_OCTETS:
 590                 default:
 591                         memcpy(p, vp->vp_strvalue, vp->length);
 592                         length = vp->length;
 593                         break;
 594                 }
 595
 596                 /*
 597                  *      Skip to the end of the data.
 598                  */
 599                 p += length;
 600                 total += length;
 601
 602                 /*
 603                  *      Align the data to a multiple of 4 bytes.
 604                  */
 605                 if ((total & 0x03) != 0) {
 606                         size_t i;
 607
 608                         length = 4 - (total & 0x03);
 609                         for (i = 0; i < length; i++) {
 610                                 *p = '\0';
 611                                 p++;
 612                                 total++;
 613                         }
 614                 }
 615         } /* loop over the VP's to write. */
 616
 617         /*
 618          *      Write the data in the buffer to the SSL session.
 619          */
 620         if (total > 0) {
 621 #ifndef NDEBUG
 622                 size_t i;
 623
 624                 if ((debug_flag > 2) && fr_log_fp) {
 625                         for (i = 0; i < total; i++) {
 626                                 if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 627
 628                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 629
 630                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 631                         }
 632                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 633                 }
 634 #endif
 635
 636                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 637
 638                 /*
 639                  *      FIXME: Check the return code.
 640                  */
 641                 tls_handshake_send(request, tls_session);
 642         }
 643
 644         /*
 645          *      Everything's OK.
 646          */
 647         return 1;
 648 }
 649
 650 /*
 651  *      Use a reply packet to determine what to do.
 652  */
 653 static int process_reply(EAP_HANDLER *handler, tls_session_t *tls_session,
 654                          REQUEST *request, RADIUS_PACKET *reply)
 655 {
 656         int rcode = RLM_MODULE_REJECT;
 657         VALUE_PAIR *vp;
 658         ttls_tunnel_t *t = tls_session->opaque;
 659
 660         handler = handler;      /* -Wunused */
 661         rad_assert(request != NULL);
 662         rad_assert(handler->request == request);
 663
 664         /*
 665          *      If the response packet was Access-Accept, then
 666          *      we're OK.  If not, die horribly.
 667          *
 668          *      FIXME: Take MS-CHAP2-Success attribute, and
 669          *      tunnel it back to the client, to authenticate
 670          *      ourselves to the client.
 671          *
 672          *      FIXME: If we have an Access-Challenge, then
 673          *      the Reply-Message is tunneled back to the client.
 674          *
 675          *      FIXME: If we have an EAP-Message, then that message
 676          *      must be tunneled back to the client.
 677          *
 678          *      FIXME: If we have an Access-Challenge with a State
 679          *      attribute, then do we tunnel that to the client, or
 680          *      keep track of it ourselves?
 681          *
 682          *      FIXME: EAP-Messages can only start with 'identity',
 683          *      NOT 'eap start', so we should check for that....
 684          */
 685         switch (reply->code) {
 686         case PW_AUTHENTICATION_ACK:
 687                 RDEBUG("Got tunneled Access-Accept");
 688
 689                 rcode = RLM_MODULE_OK;
 690
 691                 /*
 692                  *      MS-CHAP2-Success means that we do NOT return
 693                  *      an Access-Accept, but instead tunnel that
 694                  *      attribute to the client, and keep going with
 695                  *      the TTLS session.  Once the client accepts
 696                  *      our identity, it will respond with an empty
 697                  *      packet, and we will send EAP-Success.
 698                  */
 699                 vp = NULL;
 700                 pairmove2(&vp, &reply->vps, PW_MSCHAP2_SUCCESS, VENDORPEC_MICROSOFT, TAG_ANY);
 701                 if (vp) {
 702                         RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge.");
 703                         rcode = RLM_MODULE_HANDLED;
 704                         t->authenticated = TRUE;
 705
 706                         /*
 707                          *      Delete MPPE keys & encryption policy.  We don't
 708                          *      want these here.
 709                          */
 710                         pairdelete(&reply->vps, 7, VENDORPEC_MICROSOFT, TAG_ANY);
 711                         pairdelete(&reply->vps, 8, VENDORPEC_MICROSOFT, TAG_ANY);
 712                         pairdelete(&reply->vps, 16, VENDORPEC_MICROSOFT, TAG_ANY);
 713                         pairdelete(&reply->vps, 17, VENDORPEC_MICROSOFT, TAG_ANY);
 714
 715                         /*
 716                          *      Use the tunneled reply, but not now.
 717                          */
 718                         if (t->use_tunneled_reply) {
 719                                 t->accept_vps = reply->vps;
 720                                 reply->vps = NULL;
 721                         }
 722
 723                 } else { /* no MS-CHAP2-Success */
 724                         /*
 725                          *      Can only have EAP-Message if there's
 726                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 727                          *
 728                          *      We also do NOT tunnel the EAP-Success
 729                          *      attribute back to the client, as the client
 730                          *      can figure it out, from the non-tunneled
 731                          *      EAP-Success packet.
 732                          */
 733                         pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 734                         pairfree(&vp);
 735                 }
 736
 737                 /*
 738                  *      Handle the ACK, by tunneling any necessary reply
 739                  *      VP's back to the client.
 740                  */
 741                 if (vp) {
 742                         vp2diameter(request, tls_session, vp);
 743                         pairfree(&vp);
 744                 }
 745
 746                 /*
 747                  *      If we've been told to use the attributes from
 748                  *      the reply, then do so.
 749                  *
 750                  *      WARNING: This may leak information about the
 751                  *      tunneled user!
 752                  */
 753                 if (t->use_tunneled_reply) {
 754                         pairdelete(&reply->vps, PW_PROXY_STATE, 0, TAG_ANY);
 755                         pairadd(&request->reply->vps, reply->vps);
 756                         reply->vps = NULL;
 757                 }
 758                 break;
 759
 760
 761         case PW_AUTHENTICATION_REJECT:
 762                 RDEBUG("Got tunneled Access-Reject");
 763                 rcode = RLM_MODULE_REJECT;
 764                 break;
 765
 766                 /*
 767                  *      Handle Access-Challenge, but only if we
 768                  *      send tunneled reply data.  This is because
 769                  *      an Access-Challenge means that we MUST tunnel
 770                  *      a Reply-Message to the client.
 771                  */
 772         case PW_ACCESS_CHALLENGE:
 773                 RDEBUG("Got tunneled Access-Challenge");
 774
 775                 /*
 776                  *      Keep the State attribute, if necessary.
 777                  *
 778                  *      Get rid of the old State, too.
 779                  */
 780                 pairfree(&t->state);
 781                 pairmove2(&t->state, &reply->vps, PW_STATE, 0, TAG_ANY);
 782
 783                 /*
 784                  *      We should really be a bit smarter about this,
 785                  *      and move over only those attributes which
 786                  *      are relevant to the authentication request,
 787                  *      but that's a lot more work, and this "dumb"
 788                  *      method works in 99.9% of the situations.
 789                  */
 790                 vp = NULL;
 791                 pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 792
 793                 /*
 794                  *      There MUST be a Reply-Message in the challenge,
 795                  *      which we tunnel back to the client.
 796                  *
 797                  *      If there isn't one in the reply VP's, then
 798                  *      we MUST create one, with an empty string as
 799                  *      it's value.
 800                  */
 801                 pairmove2(&vp, &reply->vps, PW_REPLY_MESSAGE, 0, TAG_ANY);
 802
 803                 /*
 804                  *      Handle the ACK, by tunneling any necessary reply
 805                  *      VP's back to the client.
 806                  */
 807                 if (vp) {
 808                         vp2diameter(request, tls_session, vp);
 809                         pairfree(&vp);
 810                 }
 811                 rcode = RLM_MODULE_HANDLED;
 812                 break;
 813
 814         default:
 815                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 816                 rcode = RLM_MODULE_INVALID;
 817                 break;
 818         }
 819
 820         return rcode;
 821 }
 822
 823
 824 #ifdef WITH_PROXY
 825 /*
 826  *      Do post-proxy processing,
 827  */
 828 static int eapttls_postproxy(EAP_HANDLER *handler, void *data)
 829 {
 830         int rcode;
 831         tls_session_t *tls_session = (tls_session_t *) data;
 832         REQUEST *fake, *request = handler->request;
 833
 834         rad_assert(request != NULL);
 835         RDEBUG("Passing reply from proxy back into the tunnel.");
 836
 837         /*
 838          *      If there was a fake request associated with the proxied
 839          *      request, do more processing of it.
 840          */
 841         fake = (REQUEST *) request_data_get(handler->request,
 842                                             handler->request->proxy,
 843                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 844
 845         /*
 846          *      Do the callback, if it exists, and if it was a success.
 847          */
 848         if (fake &&
 849             handler->request->proxy_reply &&
 850             (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 851                 /*
 852                  *      Terrible hacks.
 853                  */
 854                 rad_assert(fake->packet == NULL);
 855                 fake->packet = request->proxy;
 856                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 857                 request->proxy = NULL;
 858
 859                 rad_assert(fake->reply == NULL);
 860                 fake->reply = request->proxy_reply;
 861                 request->proxy_reply = NULL;
 862
 863                 if ((debug_flag > 0) && fr_log_fp) {
 864                         fprintf(fr_log_fp, "server %s {\n",
 865                                 (fake->server == NULL) ? "" : fake->server);
 866                 }
 867
 868                 /*
 869                  *      Perform a post-auth stage for the tunneled
 870                  *      session.
 871                  */
 872                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 873                 rcode = rad_postauth(fake);
 874                 RDEBUG2("post-auth returns %d", rcode);
 875
 876                 if ((debug_flag > 0) && fr_log_fp) {
 877                         fprintf(fr_log_fp, "} # server %s\n",
 878                                 (fake->server == NULL) ? "" : fake->server);
 879
 880                         RDEBUG("Final reply from tunneled session code %d",
 881                                fake->reply->code);
 882                         debug_pair_list(fake->reply->vps);
 883                 }
 884
 885                 /*
 886                  *      Terrible hacks.
 887                  */
 888                 request->proxy = fake->packet;
 889                 fake->packet = NULL;
 890                 request->proxy_reply = fake->reply;
 891                 fake->reply = NULL;
 892
 893                 /*
 894                  *      And we're done with this request.
 895                  */
 896
 897                 switch (rcode) {
 898                 case RLM_MODULE_FAIL:
 899                         request_free(&fake);
 900                         eaptls_fail(handler, 0);
 901                         return 0;
 902                         break;
 903
 904                 default:  /* Don't Do Anything */
 905                         RDEBUG2("Got reply %d",
 906                                request->proxy_reply->code);
 907                         break;
 908                 }
 909         }
 910         request_free(&fake);    /* robust if fake == NULL */
 911
 912         /*
 913          *      Process the reply from the home server.
 914          */
 915         rcode = process_reply(handler, tls_session, handler->request,
 916                               handler->request->proxy_reply);
 917
 918         /*
 919          *      The proxy code uses the reply from the home server as
 920          *      the basis for the reply to the NAS.  We don't want that,
 921          *      so we toss it, after we've had our way with it.
 922          */
 923         pairfree(&handler->request->proxy_reply->vps);
 924
 925         switch (rcode) {
 926         case RLM_MODULE_REJECT:
 927                 RDEBUG("Reply was rejected");
 928                 break;
 929
 930         case RLM_MODULE_HANDLED:
 931                 RDEBUG("Reply was handled");
 932                 eaptls_request(handler->eap_ds, tls_session);
 933                 return 1;
 934
 935         case RLM_MODULE_OK:
 936                 RDEBUG("Reply was OK");
 937
 938                 /*
 939                  *      Success: Automatically return MPPE keys.
 940                  */
 941                 return eaptls_success(handler, 0);
 942
 943         default:
 944                 RDEBUG("Reply was unknown.");
 945                 break;
 946         }
 947
 948         eaptls_fail(handler, 0);
 949         return 0;
 950 }
 951
 952
 953 /*
 954  *      Free a request.
 955  */
 956 static void my_request_free(void *data)
 957 {
 958         REQUEST *request = (REQUEST *)data;
 959
 960         request_free(&request);
 961 }
 962 #endif  /* WITH_PROXY */
 963
 964 /*
 965  *      Process the "diameter" contents of the tunneled data.
 966  */
 967 int eapttls_process(EAP_HANDLER *handler, tls_session_t *tls_session)
 968 {
 969         int rcode = PW_AUTHENTICATION_REJECT;
 970         REQUEST *fake;
 971         VALUE_PAIR *vp;
 972         ttls_tunnel_t *t;
 973         const uint8_t *data;
 974         size_t data_len;
 975         REQUEST *request = handler->request;
 976         eap_chbind_packet_t *chbind_packet;
 977         size_t chbind_len;
 978
 979         rad_assert(request != NULL);
 980
 981         /*
 982          *      Just look at the buffer directly, without doing
 983          *      record_minus.
 984          */
 985         data_len = tls_session->clean_out.used;
 986         tls_session->clean_out.used = 0;
 987         data = tls_session->clean_out.data;
 988
 989         t = (ttls_tunnel_t *) tls_session->opaque;
 990
 991         /*
 992          *      If there's no data, maybe this is an ACK to an
 993          *      MS-CHAP2-Success.
 994          */
 995         if (data_len == 0) {
 996                 if (t->authenticated) {
 997                         RDEBUG("Got ACK, and the user was already authenticated.");
 998                         return PW_AUTHENTICATION_ACK;
 999                 } /* else no session, no data, die. */
1000
1001                 /*
1002                  *      FIXME: Call SSL_get_error() to see what went
1003                  *      wrong.
1004                  */
1005                 RDEBUG2("SSL_read Error");
1006                 return PW_AUTHENTICATION_REJECT;
1007         }
1008
1009 #ifndef NDEBUG
1010         if ((debug_flag > 2) && fr_log_fp) {
1011                 size_t i;
1012
1013                 for (i = 0; i < data_len; i++) {
1014                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
1015
1016                         fprintf(fr_log_fp, "%02x ", data[i]);
1017
1018                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
1019                 }
1020                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
1021         }
1022 #endif
1023
1024         if (!diameter_verify(request, data, data_len)) {
1025                 return PW_AUTHENTICATION_REJECT;
1026         }
1027
1028         /*
1029          *      Allocate a fake REQUEST structe.
1030          */
1031         fake = request_alloc_fake(request);
1032
1033         rad_assert(fake->packet->vps == NULL);
1034
1035         /*
1036          *      Add the tunneled attributes to the fake request.
1037          */
1038         fake->packet->vps = diameter2vp(request, tls_session->ssl, data, data_len);
1039         if (!fake->packet->vps) {
1040                 request_free(&fake);
1041                 return PW_AUTHENTICATION_REJECT;
1042         }
1043
1044         /*
1045          *      Tell the request that it's a fake one.
1046          */
1047         vp = pairmake("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
1048         if (vp) {
1049                 pairadd(&fake->packet->vps, vp);
1050         }
1051
1052         if ((debug_flag > 0) && fr_log_fp) {
1053                 RDEBUG("Got tunneled request");
1054
1055                 debug_pair_list(fake->packet->vps);
1056         }
1057
1058         /*
1059          *      Update other items in the REQUEST data structure.
1060          */
1061         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1062         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY);
1063
1064         /*
1065          *      No User-Name, try to create one from stored data.
1066          */
1067         if (!fake->username) {
1068                 /*
1069                  *      No User-Name in the stored data, look for
1070                  *      an EAP-Identity, and pull it out of there.
1071                  */
1072                 if (!t->username) {
1073                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
1074                         if (vp &&
1075                             (vp->length >= EAP_HEADER_LEN + 2) &&
1076                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1077                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1078                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1079                                 /*
1080                                  *      Create & remember a User-Name
1081                                  */
1082                                 t->username = pairmake("User-Name", "", T_OP_EQ);
1083                                 rad_assert(t->username != NULL);
1084
1085                                 memcpy(t->username->vp_strvalue, vp->vp_strvalue + 5,
1086                                        vp->length - 5);
1087                                 t->username->length = vp->length - 5;
1088                                 t->username->vp_strvalue[t->username->length] = 0;
1089
1090                                 RDEBUG("Got tunneled identity of %s",
1091                                        t->username->vp_strvalue);
1092
1093                                 /*
1094                                  *      If there's a default EAP type,
1095                                  *      set it here.
1096                                  */
1097                                 if (t->default_eap_type != 0) {
1098                                         RDEBUG("Setting default EAP type for tunneled EAP session.");
1099                                         vp = paircreate(PW_EAP_TYPE, 0);
1100                                         rad_assert(vp != NULL);
1101                                         vp->vp_integer = t->default_eap_type;
1102                                         pairadd(&fake->config_items, vp);
1103                                 }
1104
1105                         } else {
1106                                 /*
1107                                  *      Don't reject the request outright,
1108                                  *      as it's permitted to do EAP without
1109                                  *      user-name.
1110                                  */
1111                                 RDEBUG2W("No EAP-Identity found to start EAP conversation.");
1112                         }
1113                 } /* else there WAS a t->username */
1114
1115                 if (t->username) {
1116                         vp = paircopy(t->username);
1117                         pairadd(&fake->packet->vps, vp);
1118                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1119                 }
1120         } /* else the request ALREADY had a User-Name */
1121
1122         /*
1123          *      Add the State attribute, too, if it exists.
1124          */
1125         if (t->state) {
1126                 vp = paircopy(t->state);
1127                 if (vp) pairadd(&fake->packet->vps, vp);
1128         }
1129
1130         /*
1131          *      If this is set, we copy SOME of the request attributes
1132          *      from outside of the tunnel to inside of the tunnel.
1133          *
1134          *      We copy ONLY those attributes which do NOT already
1135          *      exist in the tunneled request.
1136          */
1137         if (t->copy_request_to_tunnel) {
1138                 VALUE_PAIR *copy;
1139
1140                 for (vp = request->packet->vps; vp != NULL; vp = vp->next) {
1141                         /*
1142                          *      The attribute is a server-side thingy,
1143                          *      don't copy it.
1144                          */
1145                         if ((vp->da->attr > 255) &&
1146                             (vp->da->vendor == 0)) {
1147                                 continue;
1148                         }
1149
1150                         /*
1151                          *      The outside attribute is already in the
1152                          *      tunnel, don't copy it.
1153                          *
1154                          *      This works for BOTH attributes which
1155                          *      are originally in the tunneled request,
1156                          *      AND attributes which are copied there
1157                          *      from below.
1158                          */
1159                         if (pairfind(fake->packet->vps, vp->da->attr, vp->da->vendor, TAG_ANY)) {
1160                                 continue;
1161                         }
1162
1163                         /*
1164                          *      Some attributes are handled specially.
1165                          */
1166                         switch (vp->da->attr) {
1167                                 /*
1168                                  *      NEVER copy Message-Authenticator,
1169                                  *      EAP-Message, or State.  They're
1170                                  *      only for outside of the tunnel.
1171                                  */
1172                         case PW_USER_NAME:
1173                         case PW_USER_PASSWORD:
1174                         case PW_CHAP_PASSWORD:
1175                         case PW_CHAP_CHALLENGE:
1176                         case PW_PROXY_STATE:
1177                         case PW_MESSAGE_AUTHENTICATOR:
1178                         case PW_EAP_MESSAGE:
1179                         case PW_STATE:
1180                                 continue;
1181                                 break;
1182
1183                                 /*
1184                                  *      By default, copy it over.
1185                                  */
1186                         default:
1187                                 break;
1188                         }
1189
1190                         /*
1191                          *      Don't copy from the head, we've already
1192                          *      checked it.
1193                          */
1194                         copy = paircopy2(vp, vp->da->attr, vp->da->vendor, TAG_ANY);
1195                         pairadd(&fake->packet->vps, copy);
1196                 }
1197         }
1198
1199         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0, TAG_ANY)) != NULL) {
1200                 fake->server = vp->vp_strvalue;
1201
1202         } else if (t->virtual_server) {
1203                 fake->server = t->virtual_server;
1204
1205         } /* else fake->server == request->server */
1206
1207
1208         if ((debug_flag > 0) && fr_log_fp) {
1209                 RDEBUG("Sending tunneled request");
1210
1211                 debug_pair_list(fake->packet->vps);
1212
1213                 fprintf(fr_log_fp, "server %s {\n",
1214                         (fake->server == NULL) ? "" : fake->server);
1215         }
1216
1217         /*
1218          *      Process channel binding here.
1219          */
1220         chbind_len = eap_chbind_vp2packet(fake->packet->vps, &chbind_packet);
1221         if (chbind_len > 0) {
1222                 /*CHBIND_REQ *req = chbind_allocate();
1223                 req->chbind_req = chbind_packet;
1224                 req->chbind_req_len = chbind_len;
1225                 if (fake->username) {
1226                         req->username = fake->username->vp_octets;
1227                         req->username_len = fake->username->length;
1228                 } else {
1229                         req->username = NULL;
1230                         req->username_len = 0;
1231                 }
1232                 chbind_process(request, req);
1233                 */
1234
1235                 /* free the chbind packet; we're done with it */
1236                 free(chbind_packet);
1237
1238                 /* encapsulate response here */
1239                 /*pairadd(replyvps, eap_chbind_packet2vp(req->chbind_resp,
1240                                                        req->chbind_resp_len));
1241                 */
1242
1243                 /* clean up chbind req */
1244                 /*chbind_free(req);*/
1245         }
1246
1247         /*
1248          *      Call authentication recursively, which will
1249          *      do PAP, CHAP, MS-CHAP, etc.
1250          */
1251         rad_virtual_server(fake);
1252
1253         /*
1254          *      Note that we don't do *anything* with the reply
1255          *      attributes.
1256          */
1257         if ((debug_flag > 0) && fr_log_fp) {
1258                 fprintf(fr_log_fp, "} # server %s\n",
1259                         (fake->server == NULL) ? "" : fake->server);
1260
1261                 RDEBUG("Got tunneled reply code %d", fake->reply->code);
1262
1263                 debug_pair_list(fake->reply->vps);
1264         }
1265
1266         /*
1267          *      Decide what to do with the reply.
1268          */
1269         switch (fake->reply->code) {
1270         case 0:                 /* No reply code, must be proxied... */
1271 #ifdef WITH_PROXY
1272           vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0, TAG_ANY);
1273                 if (vp) {
1274                         eap_tunnel_data_t *tunnel;
1275                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1276
1277                         /*
1278                          *      Tell the original request that it's going
1279                          *      to be proxied.
1280                          */
1281                         pairmove2(&(request->config_items),
1282                                   &(fake->config_items),
1283                                   PW_PROXY_TO_REALM, 0, TAG_ANY);
1284
1285                         /*
1286                          *      Seed the proxy packet with the
1287                          *      tunneled request.
1288                          */
1289                         rad_assert(request->proxy == NULL);
1290                         request->proxy = fake->packet;
1291                         memset(&request->proxy->src_ipaddr, 0,
1292                                sizeof(request->proxy->src_ipaddr));
1293                         memset(&request->proxy->src_ipaddr, 0,
1294                                sizeof(request->proxy->src_ipaddr));
1295                         request->proxy->src_port = 0;
1296                         request->proxy->dst_port = 0;
1297                         fake->packet = NULL;
1298                         rad_free(&fake->reply);
1299                         fake->reply = NULL;
1300
1301                         /*
1302                          *      Set up the callbacks for the tunnel
1303                          */
1304                         tunnel = rad_malloc(sizeof(*tunnel));
1305                         memset(tunnel, 0, sizeof(*tunnel));
1306
1307                         tunnel->tls_session = tls_session;
1308                         tunnel->callback = eapttls_postproxy;
1309
1310                         /*
1311                          *      Associate the callback with the request.
1312                          */
1313                         rcode = request_data_add(request,
1314                                                  request->proxy,
1315                                                  REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1316                                                  tunnel, free);
1317                         rad_assert(rcode == 0);
1318
1319                         /*
1320                          *      rlm_eap.c has taken care of associating
1321                          *      the handler with the fake request.
1322                          *
1323                          *      So we associate the fake request with
1324                          *      this request.
1325                          */
1326                         rcode = request_data_add(request,
1327                                                  request->proxy,
1328                                                  REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1329                                                  fake, my_request_free);
1330                         rad_assert(rcode == 0);
1331                         fake = NULL;
1332
1333                         /*
1334                          *      Didn't authenticate the packet, but
1335                          *      we're proxying it.
1336                          */
1337                         rcode = PW_STATUS_CLIENT;
1338
1339                 } else
1340 #endif  /* WITH_PROXY */
1341                   {
1342                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1343                                request->number);
1344                         rcode = PW_AUTHENTICATION_REJECT;
1345                 }
1346                 break;
1347
1348         default:
1349                 /*
1350                  *      Returns RLM_MODULE_FOO, and we want to return
1351                  *      PW_FOO
1352                  */
1353                 rcode = process_reply(handler, tls_session, request,
1354                                       fake->reply);
1355                 switch (rcode) {
1356                 case RLM_MODULE_REJECT:
1357                         rcode = PW_AUTHENTICATION_REJECT;
1358                         break;
1359
1360                 case RLM_MODULE_HANDLED:
1361                         rcode = PW_ACCESS_CHALLENGE;
1362                         break;
1363
1364                 case RLM_MODULE_OK:
1365                         rcode = PW_AUTHENTICATION_ACK;
1366                         break;
1367
1368                 default:
1369                         rcode = PW_AUTHENTICATION_REJECT;
1370                         break;
1371                 }
1372                 break;
1373         }
1374
1375         request_free(&fake);
1376
1377         return rcode;
1378 }