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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  *   Copyright 2003 Alan DeKok <aland@freeradius.org>
  21  */
  22 #include "eap_ttls.h"
  23
  24 /*
  25  *    0                   1                   2                   3
  26  *    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
  27  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  28  *   |                           AVP Code                            |
  29  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  30  *   |V M r r r r r r|                  AVP Length                   |
  31  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  32  *   |                        Vendor-ID (opt)                        |
  33  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  34  *   |    Data ...
  35  *   +-+-+-+-+-+-+-+-+
  36  */
  37
  38 /*
  39  *      Verify that the diameter packet is valid.
  40  */
  41 static int diameter_verify(const uint8_t *data, unsigned int data_len)
  42 {
  43         uint32_t attr;
  44         uint32_t length;
  45         unsigned int offset;
  46         unsigned int data_left = data_len;
  47
  48         while (data_left > 0) {
  49                 if (data_len < 12) {
  50                         DEBUG2("  rlm_eap_ttls:  Diameter attribute is too small to contain a Diameter header");
  51                         return 0;
  52                 }
  53
  54                 rad_assert(data_left <= data_len);
  55                 memcpy(&attr, data, sizeof(attr));
  56                 data += 4;
  57                 attr = ntohl(attr);
  58                 if (attr > 255) {
  59                         DEBUG2("  rlm_eap_ttls:  Non-RADIUS attribute in tunneled authentication is not supported");
  60                         return 0;
  61                 }
  62
  63                 memcpy(&length, data , sizeof(length));
  64                 data += 4;
  65                 length = ntohl(length);
  66
  67                 /*
  68                  *      A "vendor" flag, with a vendor ID of zero,
  69                  *      is equivalent to no vendor.  This is stupid.
  70                  */
  71                 offset = 8;
  72                 if ((length & (1 << 31)) != 0) {
  73                         int attribute;
  74                         uint32_t vendor;
  75                         DICT_ATTR *da;
  76
  77                         memcpy(&vendor, data, sizeof(vendor));
  78                         vendor = ntohl(vendor);
  79
  80                         if (vendor > 65535) {
  81                                 DEBUG2("  rlm_eap_ttls: Vendor codes larger than 65535 are not supported");
  82                                 return 0;
  83                         }
  84
  85                         attribute = (vendor << 16) | attr;
  86
  87                         da = dict_attrbyvalue(attribute);
  88
  89                         /*
  90                          *      SHOULD check ((length & (1 << 30)) != 0)
  91                          *      for the mandatory bit.
  92                          */
  93                         if (!da) {
  94                                 DEBUG2("  rlm_eap_ttls: Fatal! Vendor %u, Attribute %u was not found in our dictionary. ",
  95                                        vendor, attr);
  96                                 return 0;
  97                         }
  98
  99                         data += 4; /* skip the vendor field */
 100                         offset += 4; /* offset to value field */
 101                 }
 102
 103                 /*
 104                  *      Ignore the M bit.  We support all RADIUS attributes...
 105                  */
 106
 107                 /*
 108                  *      Get the length.  If it's too big, die.
 109                  */
 110                 length &= 0x00ffffff;
 111
 112                 /*
 113                  *      Too short or too long is bad.
 114                  *
 115                  *      FIXME: EAP-Message
 116                  */
 117                 if (length < offset) {
 118                         DEBUG2("  rlm_eap_ttls: Tunneled attribute %d is too short (%d)to contain anything useful.", attr, length);
 119                         return 0;
 120                 }
 121
 122                 if (length > (MAX_STRING_LEN + 8)) {
 123                         DEBUG2("  rlm_eap_ttls: Tunneled attribute %d is too long (%d) to pack into a RADIUS attribute.", attr, length);
 124                         return 0;
 125                 }
 126
 127                 if (length > data_left) {
 128                         DEBUG2("  rlm_eap_ttls: Tunneled attribute %d is longer than room left in the packet (%d > %d).", attr, length, data_left);
 129                         return 0;
 130                 }
 131
 132                 /*
 133                  *      Check for broken implementations, which don't
 134                  *      pad the AVP to a 4-octet boundary.
 135                  */
 136                 if (data_left == length) break;
 137
 138                 /*
 139                  *      The length does NOT include the padding, so
 140                  *      we've got to account for it here by rounding up
 141                  *      to the nearest 4-byte boundary.
 142                  */
 143                 length += 0x03;
 144                 length &= ~0x03;
 145
 146                 /*
 147                  *      If the rest of the diameter packet is larger than
 148                  *      this attribute, continue.
 149                  *
 150                  *      Otherwise, if the attribute over-flows the end
 151                  *      of the packet, die.
 152                  */
 153                 if (data_left < length) {
 154                         DEBUG2("  rlm_eap_ttls: ERROR! Diameter attribute overflows packet!");
 155                         return 0;
 156                 }
 157
 158                 /*
 159                  *      Check again for equality, now that we're padded
 160                  *      length to a multiple of 4 octets.
 161                  */
 162                 if (data_left == length) break;
 163
 164                 /*
 165                  *      data_left > length, continue.
 166                  */
 167                 data_left -= length;
 168                 data += length - offset;
 169         }
 170
 171         /*
 172          *      We got this far.  It looks OK.
 173          */
 174         return 1;
 175 }
 176
 177
 178 /*
 179  *      Convert diameter attributes to our VALUE_PAIR's
 180  */
 181 static VALUE_PAIR *diameter2vp(SSL *ssl,
 182                                const uint8_t *data, unsigned int data_len)
 183 {
 184         uint32_t        attr;
 185         uint32_t        length;
 186         unsigned int    offset;
 187         int             size;
 188         unsigned int    data_left = data_len;
 189         VALUE_PAIR      *first = NULL;
 190         VALUE_PAIR      **last = &first;
 191         VALUE_PAIR      *vp;
 192
 193         while (data_left > 0) {
 194                 rad_assert(data_left <= data_len);
 195                 memcpy(&attr, data, sizeof(attr));
 196                 data += 4;
 197                 attr = ntohl(attr);
 198
 199                 memcpy(&length, data, sizeof(length));
 200                 data += 4;
 201                 length = ntohl(length);
 202
 203                 /*
 204                  *      Ignore the M bit.  We support all RADIUS attributes...
 205                  */
 206
 207                 /*
 208                  *      A "vendor" flag, with a vendor ID of zero,
 209                  *      is equivalent to no vendor.  This is stupid.
 210                  */
 211                 offset = 8;
 212                 if ((length & (1 << 31)) != 0) {
 213                         uint32_t vendor;
 214
 215                         memcpy(&vendor, data, sizeof(vendor));
 216                         vendor = ntohl(vendor);
 217
 218                         attr |= (vendor << 16);
 219
 220                         data += 4; /* skip the vendor field, it's zero */
 221                         offset += 4; /* offset to value field */
 222                 }
 223
 224                 /*
 225                  *      Get the length.
 226                  */
 227                 length &= 0x00ffffff;
 228
 229                 /*
 230                  *      diameter code + length, and it must fit in
 231                  *      a VALUE_PAIR.
 232                  */
 233                 rad_assert(length <= (offset + MAX_STRING_LEN));
 234
 235                 /*
 236                  *      Get the size of the value portion of the
 237                  *      attribute.
 238                  */
 239                 size = length - offset;
 240
 241                 /*
 242                  *      Create it.
 243                  */
 244                 vp = paircreate(attr, PW_TYPE_OCTETS);
 245                 if (!vp) {
 246                         DEBUG2("  rlm_eap_ttls: Failure in creating VP");
 247                         pairfree(&first);
 248                         return NULL;
 249                 }
 250
 251                 /*
 252                  *      If it's a type from our dictionary, then
 253                  *      we need to put the data in a relevant place.
 254                  */
 255                 switch (vp->type) {
 256                 case PW_TYPE_INTEGER:
 257                 case PW_TYPE_DATE:
 258                         if (size != vp->length) {
 259                                 DEBUG2("  rlm_eap_ttls: Invalid length attribute %d",
 260                                        attr);
 261                                 pairfree(&first);
 262                                 return NULL;
 263                         }
 264                         memcpy(&vp->lvalue, data, vp->length);
 265
 266                         /*
 267                          *      Stored in host byte order: change it.
 268                          */
 269                         vp->lvalue = ntohl(vp->lvalue);
 270                         break;
 271
 272                 case PW_TYPE_IPADDR:
 273                         if (size != vp->length) {
 274                                 DEBUG2("  rlm_eap_ttls: Invalid length attribute %d",
 275                                        attr);
 276                                 pairfree(&first);
 277                                 return NULL;
 278                         }
 279                   memcpy(&vp->lvalue, data, vp->length);
 280
 281                   /*
 282                    *    Stored in network byte order: don't change it.
 283                    */
 284                   break;
 285
 286                   /*
 287                    *    String, octet, etc.  Copy the data from the
 288                    *    value field over verbatim.
 289                    *
 290                    *    FIXME: Ipv6 attributes ?
 291                    *
 292                    */
 293                 default:
 294                         vp->length = size;
 295                         memcpy(vp->strvalue, data, vp->length);
 296                         break;
 297                 }
 298
 299                 /*
 300                  *      User-Password is NUL padded to a multiple
 301                  *      of 16 bytes.  Let's chop it to something
 302                  *      more reasonable.
 303                  *
 304                  *      NOTE: This means that the User-Password
 305                  *      attribute CANNOT EVER have embedded zeros in it!
 306                  */
 307                 switch (vp->attribute) {
 308                 case PW_USER_PASSWORD:
 309                         rad_assert(vp->length <= 128); /* RFC requirements */
 310
 311                         /*
 312                          *      If the password is exactly 16 octets,
 313                          *      it won't be zero-terminated.
 314                          */
 315                         vp->strvalue[vp->length] = '\0';
 316                         vp->length = strlen(vp->strvalue);
 317                         break;
 318
 319                         /*
 320                          *      Ensure that the client is using the
 321                          *      correct challenge.  This weirdness is
 322                          *      to protect against against replay
 323                          *      attacks, where anyone observing the
 324                          *      CHAP exchange could pose as that user,
 325                          *      by simply choosing to use the same
 326                          *      challenge.
 327                          *
 328                          *      By using a challenge based on
 329                          *      information from the current session,
 330                          *      we can guarantee that the client is
 331                          *      not *choosing* a challenge.
 332                          *
 333                          *      We're a little forgiving in that we
 334                          *      have loose checks on the length, and
 335                          *      we do NOT check the Id (first octet of
 336                          *      the response to the challenge)
 337                          *
 338                          *      But if the client gets the challenge correct,
 339                          *      we're not too worried about the Id.
 340                          */
 341                 case PW_CHAP_CHALLENGE:
 342                 case PW_MSCHAP_CHALLENGE:
 343                         if ((vp->length < 8) ||
 344                             (vp->length > 16)) {
 345                                 DEBUG2("  TTLS: Tunneled challenge has invalid length");
 346                                 pairfree(&first);
 347                                 return NULL;
 348
 349                         } else {
 350                                 int i;
 351                                 uint8_t challenge[16];
 352
 353                                 eapttls_gen_challenge(ssl, challenge,
 354                                                       sizeof(challenge));
 355
 356                                 for (i = 0; i < vp->length; i++) {
 357                                         if (challenge[i] != vp->strvalue[i]) {
 358                                                 DEBUG2("  TTLS: Tunneled challenge is incorrect");
 359                                                 pairfree(&first);
 360                                                 return NULL;
 361                                         }
 362                                 }
 363                         }
 364                         break;
 365
 366                 default:
 367                         break;
 368                 } /* switch over checking/re-writing of attributes. */
 369
 370                 /*
 371                  *      Update the list.
 372                  */
 373                 *last = vp;
 374                 last = &(vp->next);
 375
 376                 /*
 377                  *      Catch non-aligned attributes.
 378                  */
 379                 if (data_left == length) break;
 380
 381                 /*
 382                  *      The length does NOT include the padding, so
 383                  *      we've got to account for it here by rounding up
 384                  *      to the nearest 4-byte boundary.
 385                  */
 386                 length += 0x03;
 387                 length &= ~0x03;
 388
 389                 rad_assert(data_left >= length);
 390                 data_left -= length;
 391                 data += length - offset; /* already updated */
 392         }
 393
 394         /*
 395          *      We got this far.  It looks OK.
 396          */
 397         return first;
 398 }
 399
 400 /*
 401  *      Convert VALUE_PAIR's to diameter attributes, and write them
 402  *      to an SSL session.
 403  *
 404  *      The ONLY VALUE_PAIR's which may be passed to this function
 405  *      are ones which can go inside of a RADIUS (i.e. diameter)
 406  *      packet.  So no server-configuration attributes, or the like.
 407  */
 408 static int vp2diameter(tls_session_t *tls_session, VALUE_PAIR *first)
 409 {
 410         /*
 411          *      RADIUS packets are no more than 4k in size, so if
 412          *      we've got more than 4k of data to write, it's very
 413          *      bad.
 414          */
 415         uint8_t         buffer[4096];
 416         uint8_t         *p;
 417         uint32_t        attr;
 418         uint32_t        length;
 419         uint32_t        vendor;
 420         size_t          total;
 421         VALUE_PAIR      *vp;
 422
 423         p = buffer;
 424         total = 0;
 425
 426         for (vp = first; vp != NULL; vp = vp->next) {
 427                 /*
 428                  *      Too much data: die.
 429                  */
 430                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 431                         DEBUG2("  TTLS output buffer is full!");
 432                         return 0;
 433                 }
 434
 435                 /*
 436                  *      Hmm... we don't group multiple EAP-Messages
 437                  *      together.  Maybe we should...
 438                  */
 439
 440                 /*
 441                  *      Length is no more than 253, due to RADIUS
 442                  *      issues.
 443                  */
 444                 length = vp->length;
 445                 vendor = (vp->attribute >> 16) & 0xffff;
 446                 if (vendor != 0) {
 447                         attr = vp->attribute & 0xffff;
 448                         length |= (1 << 31);
 449                 } else {
 450                         attr = vp->attribute;
 451                 }
 452
 453                 /*
 454                  *      Hmm... set the M bit for all attributes?
 455                  */
 456                 length |= (1 << 30);
 457
 458                 attr = ntohl(attr);
 459
 460                 memcpy(p, &attr, sizeof(attr));
 461                 p += 4;
 462                 total += 4;
 463
 464                 length += 8;    /* includes 8 bytes of attr & length */
 465
 466                 if (vendor != 0) {
 467                         length += 4; /* include 4 bytes of vendor */
 468
 469                         length = ntohl(length);
 470                         memcpy(p, &length, sizeof(length));
 471                         p += 4;
 472                         total += 4;
 473
 474                         vendor = ntohl(vendor);
 475                         memcpy(p, &vendor, sizeof(vendor));
 476                         p += 4;
 477                         total += 4;
 478                 } else {
 479                         length = ntohl(length);
 480                         memcpy(p, &length, sizeof(length));
 481                         p += 4;
 482                         total += 4;
 483                 }
 484
 485                 switch (vp->type) {
 486                 case PW_TYPE_INTEGER:
 487                 case PW_TYPE_DATE:
 488                         attr = ntohl(vp->lvalue); /* stored in host order */
 489                         memcpy(p, &attr, sizeof(attr));
 490                         length = 4;
 491                         break;
 492
 493                 case PW_TYPE_IPADDR:
 494                         attr = vp->lvalue; /* stored in network order */
 495                         memcpy(p, &attr, sizeof(attr));
 496                         length = 4;
 497                         break;
 498
 499                 case PW_TYPE_STRING:
 500                 case PW_TYPE_OCTETS:
 501                 default:
 502                         memcpy(p, vp->strvalue, vp->length);
 503                         length = vp->length;
 504                         break;
 505                 }
 506
 507                 /*
 508                  *      Skip to the end of the data.
 509                  */
 510                 p += length;
 511                 total += length;
 512
 513                 /*
 514                  *      Align the data to a multiple of 4 bytes.
 515                  */
 516                 if ((total & 0x03) != 0) {
 517                         unsigned int i;
 518
 519                         length = 4 - (total & 0x03);
 520                         for (i = 0; i < length; i++) {
 521                                 *p = '\0';
 522                                 p++;
 523                                 total++;
 524                         }
 525                 }
 526         } /* loop over the VP's to write. */
 527
 528         /*
 529          *      Write the data in the buffer to the SSL session.
 530          */
 531         if (total > 0) {
 532 #ifndef NDEBUG
 533                 unsigned int i;
 534
 535                 if (debug_flag > 2) {
 536                         for (i = 0; i < total; i++) {
 537                                 if ((i & 0x0f) == 0) printf("  TTLS tunnel data out %04x: ", i);
 538
 539                                 printf("%02x ", buffer[i]);
 540
 541                                 if ((i & 0x0f) == 0x0f) printf("\n");
 542                         }
 543                         if ((total & 0x0f) != 0) printf("\n");
 544                 }
 545 #endif
 546
 547                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 548
 549                 /*
 550                  *      FIXME: Check the return code.
 551                  */
 552                 tls_handshake_send(tls_session);
 553         }
 554
 555         /*
 556          *      Everything's OK.
 557          */
 558         return 1;
 559 }
 560
 561 /*
 562  *      Use a reply packet to determine what to do.
 563  */
 564 static int process_reply(EAP_HANDLER *handler, tls_session_t *tls_session,
 565                          REQUEST *request, RADIUS_PACKET *reply)
 566 {
 567         int rcode = RLM_MODULE_REJECT;
 568         VALUE_PAIR *vp;
 569         ttls_tunnel_t *t = tls_session->opaque;
 570
 571         handler = handler;      /* -Wunused */
 572
 573         /*
 574          *      If the response packet was Access-Accept, then
 575          *      we're OK.  If not, die horribly.
 576          *
 577          *      FIXME: Take MS-CHAP2-Success attribute, and
 578          *      tunnel it back to the client, to authenticate
 579          *      ourselves to the client.
 580          *
 581          *      FIXME: If we have an Access-Challenge, then
 582          *      the Reply-Message is tunneled back to the client.
 583          *
 584          *      FIXME: If we have an EAP-Message, then that message
 585          *      must be tunneled back to the client.
 586          *
 587          *      FIXME: If we have an Access-Challenge with a State
 588          *      attribute, then do we tunnel that to the client, or
 589          *      keep track of it ourselves?
 590          *
 591          *      FIXME: EAP-Messages can only start with 'identity',
 592          *      NOT 'eap start', so we should check for that....
 593          */
 594         switch (reply->code) {
 595         case PW_AUTHENTICATION_ACK:
 596                 DEBUG2("  TTLS: Got tunneled Access-Accept");
 597
 598                 rcode = RLM_MODULE_OK;
 599
 600                 /*
 601                  *      MS-CHAP2-Success means that we do NOT return
 602                  *      an Access-Accept, but instead tunnel that
 603                  *      attribute to the client, and keep going with
 604                  *      the TTLS session.  Once the client accepts
 605                  *      our identity, it will respond with an empty
 606                  *      packet, and we will send EAP-Success.
 607                  */
 608                 vp = NULL;
 609                 pairmove2(&vp, &reply->vps, PW_MSCHAP2_SUCCESS);
 610                 if (vp) {
 611 #if 1
 612                         /*
 613                          *      FIXME: Tunneling MS-CHAP2-Success causes
 614                          *      the only client we have access to, to die.
 615                          *
 616                          *      We don't want that...
 617                          */
 618                         pairfree(&vp);
 619 #else
 620                         DEBUG2("  TTLS: Got MS-CHAP2-Success, tunneling it to the client in a challenge.");
 621                         rcode = RLM_MODULE_HANDLED;
 622                         t->authenticated = TRUE;
 623 #endif
 624                 } else { /* no MS-CHAP2-Success */
 625                         /*
 626                          *      Can only have EAP-Message if there's
 627                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 628                          *
 629                          *      We also do NOT tunnel the EAP-Success
 630                          *      attribute back to the client, as the client
 631                          *      can figure it out, from the non-tunneled
 632                          *      EAP-Success packet.
 633                          */
 634                         pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE);
 635                         pairfree(&vp);
 636                 }
 637
 638                 /*
 639                  *      Handle the ACK, by tunneling any necessary reply
 640                  *      VP's back to the client.
 641                  */
 642                 if (vp) {
 643                         vp2diameter(tls_session, vp);
 644                         pairfree(&vp);
 645                 }
 646
 647                 /*
 648                  *      If we've been told to use the attributes from
 649                  *      the reply, then do so.
 650                  *
 651                  *      WARNING: This may leak information about the
 652                  *      tunneled user!
 653                  */
 654                 if (t->use_tunneled_reply) {
 655                         pairdelete(&reply->vps, PW_PROXY_STATE);
 656                         pairadd(&request->reply->vps, reply->vps);
 657                         reply->vps = NULL;
 658                 }
 659                 break;
 660
 661
 662         case PW_AUTHENTICATION_REJECT:
 663                 DEBUG2("  TTLS: Got tunneled Access-Reject");
 664                 rcode = RLM_MODULE_REJECT;
 665                 break;
 666
 667                 /*
 668                  *      Handle Access-Challenge, but only if we
 669                  *      send tunneled reply data.  This is because
 670                  *      an Access-Challenge means that we MUST tunnel
 671                  *      a Reply-Message to the client.
 672                  */
 673         case PW_ACCESS_CHALLENGE:
 674                 DEBUG2("  TTLS: Got tunneled Access-Challenge");
 675
 676                 /*
 677                  *      Keep the State attribute, if necessary.
 678                  *
 679                  *      Get rid of the old State, too.
 680                  */
 681                 pairfree(&t->state);
 682                 pairmove2(&t->state, &reply->vps, PW_STATE);
 683
 684                 /*
 685                  *      We should really be a bit smarter about this,
 686                  *      and move over only those attributes which
 687                  *      are relevant to the authentication request,
 688                  *      but that's a lot more work, and this "dumb"
 689                  *      method works in 99.9% of the situations.
 690                  */
 691                 vp = NULL;
 692                 pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE);
 693
 694                 /*
 695                  *      There MUST be a Reply-Message in the challenge,
 696                  *      which we tunnel back to the client.
 697                  *
 698                  *      If there isn't one in the reply VP's, then
 699                  *      we MUST create one, with an empty string as
 700                  *      it's value.
 701                  */
 702                 pairmove2(&vp, &reply->vps, PW_REPLY_MESSAGE);
 703
 704                 /*
 705                  *      Handle the ACK, by tunneling any necessary reply
 706                  *      VP's back to the client.
 707                  */
 708                 if (vp) {
 709                         vp2diameter(tls_session, vp);
 710                         pairfree(&vp);
 711                 }
 712                 rcode = RLM_MODULE_HANDLED;
 713                 break;
 714
 715         default:
 716                 DEBUG2("  TTLS: Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 717                 rcode = RLM_MODULE_INVALID;
 718                 break;
 719         }
 720
 721         return rcode;
 722 }
 723
 724
 725 /*
 726  *      Do post-proxy processing,
 727  */
 728 static int eapttls_postproxy(EAP_HANDLER *handler, void *data)
 729 {
 730         int rcode;
 731         tls_session_t *tls_session = (tls_session_t *) data;
 732         REQUEST *fake;
 733
 734         DEBUG2("  TTLS: Passing reply from proxy back into the tunnel.");
 735
 736         /*
 737          *      If there was a fake request associated with the proxied
 738          *      request, do more processing of it.
 739          */
 740         fake = (REQUEST *) request_data_get(handler->request,
 741                                             handler->request->proxy,
 742                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 743
 744         /*
 745          *      Do the callback, if it exists, and if it was a success.
 746          */
 747         if (fake && (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 748                 VALUE_PAIR *vp;
 749                 REQUEST *request = handler->request;
 750
 751                 /*
 752                  *      Terrible hacks.
 753                  */
 754                 rad_assert(fake->packet == NULL);
 755                 fake->packet = request->proxy;
 756                 request->proxy = NULL;
 757
 758                 rad_assert(fake->reply == NULL);
 759                 fake->reply = request->proxy_reply;
 760                 request->proxy_reply = NULL;
 761
 762                 /*
 763                  *      Perform a post-auth stage for the tunneled
 764                  *      session.
 765                  */
 766                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 767                 rcode = rad_postauth(fake);
 768                 DEBUG2("  POST-AUTH %d", rcode);
 769
 770 #ifndef NDEBUG
 771                 if (debug_flag > 0) {
 772                         printf("  TTLS: Final reply from tunneled session code %d\n",
 773                                fake->reply->code);
 774
 775                         for (vp = fake->reply->vps; vp != NULL; vp = vp->next) {
 776                                 putchar('\t');vp_print(stdout, vp);putchar('\n');
 777                         }
 778                 }
 779 #endif
 780
 781                 /*
 782                  *      Terrible hacks.
 783                  */
 784                 request->proxy = fake->packet;
 785                 fake->packet = NULL;
 786                 request->proxy_reply = fake->reply;
 787                 fake->reply = NULL;
 788
 789                 /*
 790                  *      And we're done with this request.
 791                  */
 792
 793                 switch (rcode) {
 794                 case RLM_MODULE_FAIL:
 795                         request_free(&fake);
 796                         eaptls_fail(handler->eap_ds, 0);
 797                         return 0;
 798                         break;
 799
 800                 default:  /* Don't Do Anything */
 801                         DEBUG2(" TTLS: Got reply %d",
 802                                request->proxy_reply->code);
 803                         break;
 804                 }
 805         }
 806         request_free(&fake);    /* robust if fake == NULL */
 807
 808         /*
 809          *      Process the reply from the home server.
 810          */
 811         rcode = process_reply(handler, tls_session, handler->request,
 812                               handler->request->proxy_reply);
 813
 814         /*
 815          *      The proxy code uses the reply from the home server as
 816          *      the basis for the reply to the NAS.  We don't want that,
 817          *      so we toss it, after we've had our way with it.
 818          */
 819         pairfree(&handler->request->proxy_reply->vps);
 820
 821         switch (rcode) {
 822         case RLM_MODULE_REJECT:
 823                 DEBUG2("  TTLS: Reply was rejected");
 824                 break;
 825
 826         case RLM_MODULE_HANDLED:
 827                 DEBUG2("  TTLS: Reply was handled");
 828                 eaptls_request(handler->eap_ds, tls_session);
 829                 return 1;
 830
 831         case RLM_MODULE_OK:
 832                 DEBUG2("  TTLS: Reply was OK");
 833                 eaptls_success(handler->eap_ds, 0);
 834                 eaptls_gen_mppe_keys(&handler->request->reply->vps,
 835                                      tls_session->ssl,
 836                                      "ttls keying material");
 837                 return 1;
 838
 839         default:
 840                 DEBUG2("  TTLS: Reply was unknown.");
 841                 break;
 842         }
 843
 844         eaptls_fail(handler->eap_ds, 0);
 845         return 0;
 846 }
 847
 848
 849 /*
 850  *      Free a request.
 851  */
 852 static void my_request_free(void *data)
 853 {
 854         REQUEST *request = (REQUEST *)data;
 855
 856         request_free(&request);
 857 }
 858
 859
 860 /*
 861  *      Process the "diameter" contents of the tunneled data.
 862  */
 863 int eapttls_process(EAP_HANDLER *handler, tls_session_t *tls_session)
 864 {
 865         int err;
 866         int rcode = PW_AUTHENTICATION_REJECT;
 867         REQUEST *fake;
 868         VALUE_PAIR *vp;
 869         ttls_tunnel_t *t;
 870         const uint8_t *data;
 871         unsigned int data_len;
 872         char buffer[1024];
 873         REQUEST *request = handler->request;
 874
 875         /*
 876          *      Grab the dirty data, and copy it to our buffer.
 877          *
 878          *      I *really* don't like these 'record_t' things...
 879          */
 880         data_len = (tls_session->record_minus)(&tls_session->dirty_in, buffer, sizeof(buffer));
 881         data = buffer;
 882
 883         /*
 884          *      Write the data from the dirty buffer (i.e. packet
 885          *      data) into the buffer which we will give to SSL for
 886          *      decoding.
 887          *
 888          *      Some of this code COULD technically go into the TLS
 889          *      module, in eaptls_process(), where it returns EAPTLS_OK.
 890          *
 891          *      Similarly, the writing of data to the SSL context could
 892          *      go there, too...
 893          */
 894         BIO_write(tls_session->into_ssl, buffer, data_len);
 895         (tls_session->record_init)(&tls_session->clean_out);
 896
 897         /*
 898          *      Read (and decrypt) the tunneled data from the SSL session,
 899          *      and put it into the decrypted data buffer.
 900          */
 901         err = SSL_read(tls_session->ssl, tls_session->clean_out.data,
 902                        sizeof(tls_session->clean_out.data));
 903         if (err < 0) {
 904                 /*
 905                  *      FIXME: Call SSL_get_error() to see what went
 906                  *      wrong.
 907                  */
 908                 radlog(L_INFO, "rlm_eap_ttls: SSL_read Error");
 909                 return PW_AUTHENTICATION_REJECT;
 910         }
 911
 912         t = (ttls_tunnel_t *) tls_session->opaque;
 913
 914         /*
 915          *      If there's no data, maybe this is an ACK to an
 916          *      MS-CHAP2-Success.
 917          */
 918         if (err == 0) {
 919                 if (t->authenticated) {
 920                         DEBUG2("  TTLS: Got ACK, and the user was already authenticated.");
 921                         return PW_AUTHENTICATION_ACK;
 922                 } /* else no session, no data, die. */
 923
 924                 /*
 925                  *      FIXME: Call SSL_get_error() to see what went
 926                  *      wrong.
 927                  */
 928                 radlog(L_INFO, "rlm_eap_ttls: SSL_read Error");
 929                 return PW_AUTHENTICATION_REJECT;
 930         }
 931
 932         data_len = tls_session->clean_out.used = err;
 933         data = tls_session->clean_out.data;
 934
 935 #ifndef NDEBUG
 936         if (debug_flag > 2) {
 937                 unsigned int i;
 938
 939                 for (i = 0; i < data_len; i++) {
 940                         if ((i & 0x0f) == 0) printf("  TTLS tunnel data in %04x: ", i);
 941
 942                         printf("%02x ", data[i]);
 943
 944                         if ((i & 0x0f) == 0x0f) printf("\n");
 945                 }
 946                 if ((data_len & 0x0f) != 0) printf("\n");
 947         }
 948 #endif
 949
 950         if (!diameter_verify(data, data_len)) {
 951                 return PW_AUTHENTICATION_REJECT;
 952         }
 953
 954         /*
 955          *      Allocate a fake REQUEST structe.
 956          */
 957         fake = request_alloc_fake(request);
 958
 959         rad_assert(fake->packet->vps == NULL);
 960
 961         /*
 962          *      Add the tunneled attributes to the fake request.
 963          */
 964         fake->packet->vps = diameter2vp(tls_session->ssl, data, data_len);
 965         if (!fake->packet->vps) {
 966                 return PW_AUTHENTICATION_REJECT;
 967         }
 968
 969         /*
 970          *      Tell the request that it's a fake one.
 971          */
 972         vp = pairmake("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
 973         if (vp) {
 974                 pairadd(&fake->packet->vps, vp);
 975         }
 976
 977 #ifndef NDEBUG
 978         if (debug_flag > 0) {
 979                 printf("  TTLS: Got tunneled request\n");
 980
 981                 for (vp = fake->packet->vps; vp != NULL; vp = vp->next) {
 982                         putchar('\t');vp_print(stdout, vp);putchar('\n');
 983                 }
 984         }
 985 #endif
 986
 987         /*
 988          *      Update other items in the REQUEST data structure.
 989          */
 990         fake->username = pairfind(fake->packet->vps, PW_USER_NAME);
 991         fake->password = pairfind(fake->packet->vps, PW_PASSWORD);
 992
 993         /*
 994          *      No User-Name, try to create one from stored data.
 995          */
 996         if (!fake->username) {
 997                 /*
 998                  *      No User-Name in the stored data, look for
 999                  *      an EAP-Identity, and pull it out of there.
1000                  */
1001                 if (!t->username) {
1002                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE);
1003                         if (vp &&
1004                             (vp->length >= EAP_HEADER_LEN + 2) &&
1005                             (vp->strvalue[0] == PW_EAP_RESPONSE) &&
1006                             (vp->strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1007                             (vp->strvalue[EAP_HEADER_LEN + 1] != 0)) {
1008                                 /*
1009                                  *      Create & remember a User-Name
1010                                  */
1011                                 t->username = pairmake("User-Name", "", T_OP_EQ);
1012                                 rad_assert(t->username != NULL);
1013
1014                                 memcpy(t->username->strvalue, vp->strvalue + 5,
1015                                        vp->length - 5);
1016                                 t->username->length = vp->length - 5;
1017                                 t->username->strvalue[t->username->length] = 0;
1018
1019                                 DEBUG2("  TTLS: Got tunneled identity of %s",
1020                                        t->username->strvalue);
1021
1022                                 /*
1023                                  *      If there's a default EAP type,
1024                                  *      set it here.
1025                                  */
1026                                 if (t->default_eap_type != 0) {
1027                                         DEBUG2("  TTLS: Setting default EAP type for tunneled EAP session.");
1028                                         vp = paircreate(PW_EAP_TYPE,
1029                                                         PW_TYPE_INTEGER);
1030                                         rad_assert(vp != NULL);
1031                                         vp->lvalue = t->default_eap_type;
1032                                         pairadd(&fake->config_items, vp);
1033                                 }
1034
1035                         } else {
1036                                 /*
1037                                  *      Don't reject the request outright,
1038                                  *      as it's permitted to do EAP without
1039                                  *      user-name.
1040                                  */
1041                                 DEBUG2("  rlm_eap_ttls: WARNING! No EAP-Identity found to start EAP conversation.");
1042                         }
1043                 } /* else there WAS a t->username */
1044
1045                 if (t->username) {
1046                         vp = paircopy(t->username);
1047                         pairadd(&fake->packet->vps, vp);
1048                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME);
1049                 }
1050         } /* else the request ALREADY had a User-Name */
1051
1052         /*
1053          *      Add the State attribute, too, if it exists.
1054          */
1055         if (t->state) {
1056                 DEBUG2("  TTLS: Adding old state with %02x %02x",
1057                        t->state->strvalue[0], t->state->strvalue[1]);
1058                 vp = paircopy(t->state);
1059                 if (vp) pairadd(&fake->packet->vps, vp);
1060         }
1061
1062         /*
1063          *      If this is set, we copy SOME of the request attributes
1064          *      from outside of the tunnel to inside of the tunnel.
1065          *
1066          *      We copy ONLY those attributes which do NOT already
1067          *      exist in the tunneled request.
1068          */
1069         if (t->copy_request_to_tunnel) {
1070                 VALUE_PAIR *copy;
1071
1072                 for (vp = request->packet->vps; vp != NULL; vp = vp->next) {
1073                         /*
1074                          *      The attribute is a server-side thingy,
1075                          *      don't copy it.
1076                          */
1077                         if ((vp->attribute > 255) &&
1078                             (((vp->attribute >> 16) & 0xffff) == 0)) {
1079                                 continue;
1080                         }
1081
1082                         /*
1083                          *      The outside attribute is already in the
1084                          *      tunnel, don't copy it.
1085                          *
1086                          *      This works for BOTH attributes which
1087                          *      are originally in the tunneled request,
1088                          *      AND attributes which are copied there
1089                          *      from below.
1090                          */
1091                         if (pairfind(fake->packet->vps, vp->attribute)) {
1092                                 continue;
1093                         }
1094
1095                         /*
1096                          *      Some attributes are handled specially.
1097                          */
1098                         switch (vp->attribute) {
1099                                 /*
1100                                  *      NEVER copy Message-Authenticator,
1101                                  *      EAP-Message, or State.  They're
1102                                  *      only for outside of the tunnel.
1103                                  */
1104                         case PW_USER_NAME:
1105                         case PW_USER_PASSWORD:
1106                         case PW_CHAP_PASSWORD:
1107                         case PW_CHAP_CHALLENGE:
1108                         case PW_PROXY_STATE:
1109                         case PW_MESSAGE_AUTHENTICATOR:
1110                         case PW_EAP_MESSAGE:
1111                         case PW_STATE:
1112                                 continue;
1113                                 break;
1114
1115                                 /*
1116                                  *      By default, copy it over.
1117                                  */
1118                         default:
1119                                 break;
1120                         }
1121
1122                         /*
1123                          *      Don't copy from the head, we've already
1124                          *      checked it.
1125                          */
1126                         copy = paircopy2(vp, vp->attribute);
1127                         pairadd(&fake->packet->vps, copy);
1128                 }
1129         }
1130
1131 #ifndef NDEBUG
1132         if (debug_flag > 0) {
1133           printf("  TTLS: Sending tunneled request\n");
1134
1135           for (vp = fake->packet->vps; vp != NULL; vp = vp->next) {
1136             putchar('\t');vp_print(stdout, vp);putchar('\n');
1137           }
1138         }
1139 #endif
1140
1141         /*
1142          *      Call authentication recursively, which will
1143          *      do PAP, CHAP, MS-CHAP, etc.
1144          */
1145         rad_authenticate(fake);
1146
1147         /*
1148          *      Note that we don't do *anything* with the reply
1149          *      attributes.
1150          */
1151 #ifndef NDEBUG
1152         if (debug_flag > 0) {
1153           printf("  TTLS: Got tunneled reply RADIUS code %d\n",
1154                  fake->reply->code);
1155
1156           for (vp = fake->reply->vps; vp != NULL; vp = vp->next) {
1157             putchar('\t');vp_print(stdout, vp);putchar('\n');
1158           }
1159         }
1160 #endif
1161
1162         /*
1163          *      Decide what to do with the reply.
1164          */
1165         switch (fake->reply->code) {
1166         case 0:                 /* No reply code, must be proxied... */
1167                 vp = pairfind(fake->config_items, PW_PROXY_TO_REALM);
1168                 if (vp) {
1169                         eap_tunnel_data_t *tunnel;
1170                         DEBUG2("  TTLS: Tunneled authentication will be proxied to %s", vp->strvalue);
1171
1172                         /*
1173                          *      Tell the original request that it's going
1174                          *      to be proxied.
1175                          */
1176                         pairmove2(&(request->config_items),
1177                                   &(fake->config_items),
1178                                   PW_PROXY_TO_REALM);
1179
1180                         /*
1181                          *      Seed the proxy packet with the
1182                          *      tunneled request.
1183                          */
1184                         rad_assert(request->proxy == NULL);
1185                         request->proxy = fake->packet;
1186                         fake->packet = NULL;
1187                         rad_free(&fake->reply);
1188                         fake->reply = NULL;
1189
1190                         /*
1191                          *      Set up the callbacks for the tunnel
1192                          */
1193                         tunnel = rad_malloc(sizeof(*tunnel));
1194                         memset(tunnel, 0, sizeof(*tunnel));
1195
1196                         tunnel->tls_session = tls_session;
1197                         tunnel->callback = eapttls_postproxy;
1198
1199                         /*
1200                          *      Associate the callback with the request.
1201                          */
1202                         rcode = request_data_add(request,
1203                                                  request->proxy,
1204                                                  REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1205                                                  tunnel, free);
1206                         rad_assert(rcode == 0);
1207
1208                         /*
1209                          *      rlm_eap.c has taken care of associating
1210                          *      the handler with the fake request.
1211                          *
1212                          *      So we associate the fake request with
1213                          *      this request.
1214                          */
1215                         rcode = request_data_add(request,
1216                                                  request->proxy,
1217                                                  REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1218                                                  fake, my_request_free);
1219                         rad_assert(rcode == 0);
1220                         fake = NULL;
1221
1222                         /*
1223                          *      Didn't authenticate the packet, but
1224                          *      we're proxying it.
1225                          */
1226                         rcode = PW_STATUS_CLIENT;
1227
1228                 } else {
1229                         DEBUG2("  TTLS: No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1230                                request->number);
1231                         rcode = PW_AUTHENTICATION_REJECT;
1232                 }
1233                 break;
1234
1235         default:
1236                 /*
1237                  *      Returns RLM_MODULE_FOO, and we want to return
1238                  *      PW_FOO
1239                  */
1240                 rcode = process_reply(handler, tls_session, request,
1241                                       fake->reply);
1242                 switch (rcode) {
1243                 case RLM_MODULE_REJECT:
1244                         rcode = PW_AUTHENTICATION_REJECT;
1245                         break;
1246
1247                 case RLM_MODULE_HANDLED:
1248                         rcode = PW_ACCESS_CHALLENGE;
1249                         break;
1250
1251                 case RLM_MODULE_OK:
1252                         rcode = PW_AUTHENTICATION_ACK;
1253                         break;
1254
1255                 default:
1256                         rcode = PW_AUTHENTICATION_REJECT;
1257                         break;
1258                 }
1259                 break;
1260         }
1261
1262         request_free(&fake);
1263
1264         return rcode;
1265 }