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                         DEBUG2("  TTLS: Got MS-CHAP2-Success, tunneling it to the client in a challenge.");
 612                         rcode = RLM_MODULE_HANDLED;
 613                         t->authenticated = TRUE;
 614                 } else { /* no MS-CHAP2-Success */
 615                         /*
 616                          *      Can only have EAP-Message if there's
 617                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 618                          *
 619                          *      We also do NOT tunnel the EAP-Success
 620                          *      attribute back to the client, as the client
 621                          *      can figure it out, from the non-tunneled
 622                          *      EAP-Success packet.
 623                          */
 624                         pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE);
 625                         pairfree(&vp);
 626                 }
 627
 628                 /*
 629                  *      Handle the ACK, by tunneling any necessary reply
 630                  *      VP's back to the client.
 631                  */
 632                 if (vp) {
 633                         vp2diameter(tls_session, vp);
 634                         pairfree(&vp);
 635                 }
 636
 637                 /*
 638                  *      If we've been told to use the attributes from
 639                  *      the reply, then do so.
 640                  *
 641                  *      WARNING: This may leak information about the
 642                  *      tunneled user!
 643                  */
 644                 if (t->use_tunneled_reply) {
 645                         pairdelete(&reply->vps, PW_PROXY_STATE);
 646                         pairadd(&request->reply->vps, reply->vps);
 647                         reply->vps = NULL;
 648                 }
 649                 break;
 650
 651
 652         case PW_AUTHENTICATION_REJECT:
 653                 DEBUG2("  TTLS: Got tunneled Access-Reject");
 654                 rcode = RLM_MODULE_REJECT;
 655                 break;
 656
 657                 /*
 658                  *      Handle Access-Challenge, but only if we
 659                  *      send tunneled reply data.  This is because
 660                  *      an Access-Challenge means that we MUST tunnel
 661                  *      a Reply-Message to the client.
 662                  */
 663         case PW_ACCESS_CHALLENGE:
 664                 DEBUG2("  TTLS: Got tunneled Access-Challenge");
 665
 666                 /*
 667                  *      Keep the State attribute, if necessary.
 668                  *
 669                  *      Get rid of the old State, too.
 670                  */
 671                 pairfree(&t->state);
 672                 pairmove2(&t->state, &reply->vps, PW_STATE);
 673
 674                 /*
 675                  *      We should really be a bit smarter about this,
 676                  *      and move over only those attributes which
 677                  *      are relevant to the authentication request,
 678                  *      but that's a lot more work, and this "dumb"
 679                  *      method works in 99.9% of the situations.
 680                  */
 681                 vp = NULL;
 682                 pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE);
 683
 684                 /*
 685                  *      There MUST be a Reply-Message in the challenge,
 686                  *      which we tunnel back to the client.
 687                  *
 688                  *      If there isn't one in the reply VP's, then
 689                  *      we MUST create one, with an empty string as
 690                  *      it's value.
 691                  */
 692                 pairmove2(&vp, &reply->vps, PW_REPLY_MESSAGE);
 693
 694                 /*
 695                  *      Handle the ACK, by tunneling any necessary reply
 696                  *      VP's back to the client.
 697                  */
 698                 if (vp) {
 699                         vp2diameter(tls_session, vp);
 700                         pairfree(&vp);
 701                 }
 702                 rcode = RLM_MODULE_HANDLED;
 703                 break;
 704
 705         default:
 706                 DEBUG2("  TTLS: Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 707                 rcode = RLM_MODULE_INVALID;
 708                 break;
 709         }
 710
 711         return rcode;
 712 }
 713
 714
 715 /*
 716  *      Do post-proxy processing,
 717  */
 718 static int eapttls_postproxy(EAP_HANDLER *handler, void *data)
 719 {
 720         int rcode;
 721         tls_session_t *tls_session = (tls_session_t *) data;
 722         REQUEST *fake;
 723
 724         DEBUG2("  TTLS: Passing reply from proxy back into the tunnel.");
 725
 726         /*
 727          *      If there was a fake request associated with the proxied
 728          *      request, do more processing of it.
 729          */
 730         fake = (REQUEST *) request_data_get(handler->request,
 731                                             handler->request->proxy,
 732                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 733
 734         /*
 735          *      Do the callback, if it exists, and if it was a success.
 736          */
 737         if (fake && (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 738                 VALUE_PAIR *vp;
 739                 REQUEST *request = handler->request;
 740
 741                 /*
 742                  *      Terrible hacks.
 743                  */
 744                 rad_assert(fake->packet == NULL);
 745                 fake->packet = request->proxy;
 746                 request->proxy = NULL;
 747
 748                 rad_assert(fake->reply == NULL);
 749                 fake->reply = request->proxy_reply;
 750                 request->proxy_reply = NULL;
 751
 752                 /*
 753                  *      Perform a post-auth stage for the tunneled
 754                  *      session.
 755                  */
 756                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 757                 rcode = rad_postauth(fake);
 758                 DEBUG2("  POST-AUTH %d", rcode);
 759
 760 #ifndef NDEBUG
 761                 if (debug_flag > 0) {
 762                         printf("  TTLS: Final reply from tunneled session code %d\n",
 763                                fake->reply->code);
 764
 765                         for (vp = fake->reply->vps; vp != NULL; vp = vp->next) {
 766                                 putchar('\t');vp_print(stdout, vp);putchar('\n');
 767                         }
 768                 }
 769 #endif
 770
 771                 /*
 772                  *      Terrible hacks.
 773                  */
 774                 request->proxy = fake->packet;
 775                 fake->packet = NULL;
 776                 request->proxy_reply = fake->reply;
 777                 fake->reply = NULL;
 778
 779                 /*
 780                  *      And we're done with this request.
 781                  */
 782
 783                 switch (rcode) {
 784                 case RLM_MODULE_FAIL:
 785                         request_free(&fake);
 786                         eaptls_fail(handler->eap_ds, 0);
 787                         return 0;
 788                         break;
 789
 790                 default:  /* Don't Do Anything */
 791                         DEBUG2(" TTLS: Got reply %d",
 792                                request->proxy_reply->code);
 793                         break;
 794                 }
 795         }
 796         request_free(&fake);    /* robust if fake == NULL */
 797
 798         /*
 799          *      Process the reply from the home server.
 800          */
 801         rcode = process_reply(handler, tls_session, handler->request,
 802                               handler->request->proxy_reply);
 803
 804         /*
 805          *      The proxy code uses the reply from the home server as
 806          *      the basis for the reply to the NAS.  We don't want that,
 807          *      so we toss it, after we've had our way with it.
 808          */
 809         pairfree(&handler->request->proxy_reply->vps);
 810
 811         switch (rcode) {
 812         case RLM_MODULE_REJECT:
 813                 DEBUG2("  TTLS: Reply was rejected");
 814                 break;
 815
 816         case RLM_MODULE_HANDLED:
 817                 DEBUG2("  TTLS: Reply was handled");
 818                 eaptls_request(handler->eap_ds, tls_session);
 819                 return 1;
 820
 821         case RLM_MODULE_OK:
 822                 DEBUG2("  TTLS: Reply was OK");
 823                 eaptls_success(handler->eap_ds, 0);
 824                 eaptls_gen_mppe_keys(&handler->request->reply->vps,
 825                                      tls_session->ssl,
 826                                      "ttls keying material");
 827                 return 1;
 828
 829         default:
 830                 DEBUG2("  TTLS: Reply was unknown.");
 831                 break;
 832         }
 833
 834         eaptls_fail(handler->eap_ds, 0);
 835         return 0;
 836 }
 837
 838
 839 /*
 840  *      Free a request.
 841  */
 842 static void my_request_free(void *data)
 843 {
 844         REQUEST *request = (REQUEST *)data;
 845
 846         request_free(&request);
 847 }
 848
 849
 850 /*
 851  *      Process the "diameter" contents of the tunneled data.
 852  */
 853 int eapttls_process(EAP_HANDLER *handler, tls_session_t *tls_session)
 854 {
 855         int err;
 856         int rcode = PW_AUTHENTICATION_REJECT;
 857         REQUEST *fake;
 858         VALUE_PAIR *vp;
 859         ttls_tunnel_t *t;
 860         const uint8_t *data;
 861         unsigned int data_len;
 862         char buffer[1024];
 863         REQUEST *request = handler->request;
 864
 865         /*
 866          *      Grab the dirty data, and copy it to our buffer.
 867          *
 868          *      I *really* don't like these 'record_t' things...
 869          */
 870         data_len = (tls_session->record_minus)(&tls_session->dirty_in, buffer, sizeof(buffer));
 871         data = buffer;
 872
 873         /*
 874          *      Write the data from the dirty buffer (i.e. packet
 875          *      data) into the buffer which we will give to SSL for
 876          *      decoding.
 877          *
 878          *      Some of this code COULD technically go into the TLS
 879          *      module, in eaptls_process(), where it returns EAPTLS_OK.
 880          *
 881          *      Similarly, the writing of data to the SSL context could
 882          *      go there, too...
 883          */
 884         BIO_write(tls_session->into_ssl, buffer, data_len);
 885         (tls_session->record_init)(&tls_session->clean_out);
 886
 887         /*
 888          *      Read (and decrypt) the tunneled data from the SSL session,
 889          *      and put it into the decrypted data buffer.
 890          */
 891         err = SSL_read(tls_session->ssl, tls_session->clean_out.data,
 892                        sizeof(tls_session->clean_out.data));
 893         if (err < 0) {
 894                 /*
 895                  *      FIXME: Call SSL_get_error() to see what went
 896                  *      wrong.
 897                  */
 898                 radlog(L_INFO, "rlm_eap_ttls: SSL_read Error");
 899                 return PW_AUTHENTICATION_REJECT;
 900         }
 901
 902         t = (ttls_tunnel_t *) tls_session->opaque;
 903
 904         /*
 905          *      If there's no data, maybe this is an ACK to an
 906          *      MS-CHAP2-Success.
 907          */
 908         if (err == 0) {
 909                 if (t->authenticated) {
 910                         DEBUG2("  TTLS: Got ACK, and the user was already authenticated.");
 911                         return PW_AUTHENTICATION_ACK;
 912                 } /* else no session, no data, die. */
 913
 914                 /*
 915                  *      FIXME: Call SSL_get_error() to see what went
 916                  *      wrong.
 917                  */
 918                 radlog(L_INFO, "rlm_eap_ttls: SSL_read Error");
 919                 return PW_AUTHENTICATION_REJECT;
 920         }
 921
 922         data_len = tls_session->clean_out.used = err;
 923         data = tls_session->clean_out.data;
 924
 925 #ifndef NDEBUG
 926         if (debug_flag > 2) {
 927                 unsigned int i;
 928
 929                 for (i = 0; i < data_len; i++) {
 930                         if ((i & 0x0f) == 0) printf("  TTLS tunnel data in %04x: ", i);
 931
 932                         printf("%02x ", data[i]);
 933
 934                         if ((i & 0x0f) == 0x0f) printf("\n");
 935                 }
 936                 if ((data_len & 0x0f) != 0) printf("\n");
 937         }
 938 #endif
 939
 940         if (!diameter_verify(data, data_len)) {
 941                 return PW_AUTHENTICATION_REJECT;
 942         }
 943
 944         /*
 945          *      Allocate a fake REQUEST structe.
 946          */
 947         fake = request_alloc_fake(request);
 948
 949         rad_assert(fake->packet->vps == NULL);
 950
 951         /*
 952          *      Add the tunneled attributes to the fake request.
 953          */
 954         fake->packet->vps = diameter2vp(tls_session->ssl, data, data_len);
 955         if (!fake->packet->vps) {
 956                 return PW_AUTHENTICATION_REJECT;
 957         }
 958
 959         /*
 960          *      Tell the request that it's a fake one.
 961          */
 962         vp = pairmake("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
 963         if (vp) {
 964                 pairadd(&fake->packet->vps, vp);
 965         }
 966
 967 #ifndef NDEBUG
 968         if (debug_flag > 0) {
 969                 printf("  TTLS: Got tunneled request\n");
 970
 971                 for (vp = fake->packet->vps; vp != NULL; vp = vp->next) {
 972                         putchar('\t');vp_print(stdout, vp);putchar('\n');
 973                 }
 974         }
 975 #endif
 976
 977         /*
 978          *      Update other items in the REQUEST data structure.
 979          */
 980         fake->username = pairfind(fake->packet->vps, PW_USER_NAME);
 981         fake->password = pairfind(fake->packet->vps, PW_PASSWORD);
 982
 983         /*
 984          *      No User-Name, try to create one from stored data.
 985          */
 986         if (!fake->username) {
 987                 /*
 988                  *      No User-Name in the stored data, look for
 989                  *      an EAP-Identity, and pull it out of there.
 990                  */
 991                 if (!t->username) {
 992                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE);
 993                         if (vp &&
 994                             (vp->length >= EAP_HEADER_LEN + 2) &&
 995                             (vp->strvalue[0] == PW_EAP_RESPONSE) &&
 996                             (vp->strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
 997                             (vp->strvalue[EAP_HEADER_LEN + 1] != 0)) {
 998                                 /*
 999                                  *      Create & remember a User-Name
1000                                  */
1001                                 t->username = pairmake("User-Name", "", T_OP_EQ);
1002                                 rad_assert(t->username != NULL);
1003
1004                                 memcpy(t->username->strvalue, vp->strvalue + 5,
1005                                        vp->length - 5);
1006                                 t->username->length = vp->length - 5;
1007                                 t->username->strvalue[t->username->length] = 0;
1008
1009                                 DEBUG2("  TTLS: Got tunneled identity of %s",
1010                                        t->username->strvalue);
1011
1012                                 /*
1013                                  *      If there's a default EAP type,
1014                                  *      set it here.
1015                                  */
1016                                 if (t->default_eap_type != 0) {
1017                                         DEBUG2("  TTLS: Setting default EAP type for tunneled EAP session.");
1018                                         vp = paircreate(PW_EAP_TYPE,
1019                                                         PW_TYPE_INTEGER);
1020                                         rad_assert(vp != NULL);
1021                                         vp->lvalue = t->default_eap_type;
1022                                         pairadd(&fake->config_items, vp);
1023                                 }
1024
1025                         } else {
1026                                 /*
1027                                  *      Don't reject the request outright,
1028                                  *      as it's permitted to do EAP without
1029                                  *      user-name.
1030                                  */
1031                                 DEBUG2("  rlm_eap_ttls: WARNING! No EAP-Identity found to start EAP conversation.");
1032                         }
1033                 } /* else there WAS a t->username */
1034
1035                 if (t->username) {
1036                         vp = paircopy(t->username);
1037                         pairadd(&fake->packet->vps, vp);
1038                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME);
1039                 }
1040         } /* else the request ALREADY had a User-Name */
1041
1042         /*
1043          *      Add the State attribute, too, if it exists.
1044          */
1045         if (t->state) {
1046                 DEBUG2("  TTLS: Adding old state with %02x %02x",
1047                        t->state->strvalue[0], t->state->strvalue[1]);
1048                 vp = paircopy(t->state);
1049                 if (vp) pairadd(&fake->packet->vps, vp);
1050         }
1051
1052         /*
1053          *      If this is set, we copy SOME of the request attributes
1054          *      from outside of the tunnel to inside of the tunnel.
1055          *
1056          *      We copy ONLY those attributes which do NOT already
1057          *      exist in the tunneled request.
1058          */
1059         if (t->copy_request_to_tunnel) {
1060                 VALUE_PAIR *copy;
1061
1062                 for (vp = request->packet->vps; vp != NULL; vp = vp->next) {
1063                         /*
1064                          *      The attribute is a server-side thingy,
1065                          *      don't copy it.
1066                          */
1067                         if ((vp->attribute > 255) &&
1068                             (((vp->attribute >> 16) & 0xffff) == 0)) {
1069                                 continue;
1070                         }
1071
1072                         /*
1073                          *      The outside attribute is already in the
1074                          *      tunnel, don't copy it.
1075                          *
1076                          *      This works for BOTH attributes which
1077                          *      are originally in the tunneled request,
1078                          *      AND attributes which are copied there
1079                          *      from below.
1080                          */
1081                         if (pairfind(fake->packet->vps, vp->attribute)) {
1082                                 continue;
1083                         }
1084
1085                         /*
1086                          *      Some attributes are handled specially.
1087                          */
1088                         switch (vp->attribute) {
1089                                 /*
1090                                  *      NEVER copy Message-Authenticator,
1091                                  *      EAP-Message, or State.  They're
1092                                  *      only for outside of the tunnel.
1093                                  */
1094                         case PW_USER_NAME:
1095                         case PW_USER_PASSWORD:
1096                         case PW_CHAP_PASSWORD:
1097                         case PW_CHAP_CHALLENGE:
1098                         case PW_PROXY_STATE:
1099                         case PW_MESSAGE_AUTHENTICATOR:
1100                         case PW_EAP_MESSAGE:
1101                         case PW_STATE:
1102                                 continue;
1103                                 break;
1104
1105                                 /*
1106                                  *      By default, copy it over.
1107                                  */
1108                         default:
1109                                 break;
1110                         }
1111
1112                         /*
1113                          *      Don't copy from the head, we've already
1114                          *      checked it.
1115                          */
1116                         copy = paircopy2(vp, vp->attribute);
1117                         pairadd(&fake->packet->vps, copy);
1118                 }
1119         }
1120
1121 #ifndef NDEBUG
1122         if (debug_flag > 0) {
1123           printf("  TTLS: Sending tunneled request\n");
1124
1125           for (vp = fake->packet->vps; vp != NULL; vp = vp->next) {
1126             putchar('\t');vp_print(stdout, vp);putchar('\n');
1127           }
1128         }
1129 #endif
1130
1131         /*
1132          *      Call authentication recursively, which will
1133          *      do PAP, CHAP, MS-CHAP, etc.
1134          */
1135         rad_authenticate(fake);
1136
1137         /*
1138          *      Note that we don't do *anything* with the reply
1139          *      attributes.
1140          */
1141 #ifndef NDEBUG
1142         if (debug_flag > 0) {
1143           printf("  TTLS: Got tunneled reply RADIUS code %d\n",
1144                  fake->reply->code);
1145
1146           for (vp = fake->reply->vps; vp != NULL; vp = vp->next) {
1147             putchar('\t');vp_print(stdout, vp);putchar('\n');
1148           }
1149         }
1150 #endif
1151
1152         /*
1153          *      Decide what to do with the reply.
1154          */
1155         switch (fake->reply->code) {
1156         case 0:                 /* No reply code, must be proxied... */
1157                 vp = pairfind(fake->config_items, PW_PROXY_TO_REALM);
1158                 if (vp) {
1159                         eap_tunnel_data_t *tunnel;
1160                         DEBUG2("  TTLS: Tunneled authentication will be proxied to %s", vp->strvalue);
1161
1162                         /*
1163                          *      Tell the original request that it's going
1164                          *      to be proxied.
1165                          */
1166                         pairmove2(&(request->config_items),
1167                                   &(fake->config_items),
1168                                   PW_PROXY_TO_REALM);
1169
1170                         /*
1171                          *      Seed the proxy packet with the
1172                          *      tunneled request.
1173                          */
1174                         rad_assert(request->proxy == NULL);
1175                         request->proxy = fake->packet;
1176                         fake->packet = NULL;
1177                         rad_free(&fake->reply);
1178                         fake->reply = NULL;
1179
1180                         /*
1181                          *      Set up the callbacks for the tunnel
1182                          */
1183                         tunnel = rad_malloc(sizeof(*tunnel));
1184                         memset(tunnel, 0, sizeof(*tunnel));
1185
1186                         tunnel->tls_session = tls_session;
1187                         tunnel->callback = eapttls_postproxy;
1188
1189                         /*
1190                          *      Associate the callback with the request.
1191                          */
1192                         rcode = request_data_add(request,
1193                                                  request->proxy,
1194                                                  REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1195                                                  tunnel, free);
1196                         rad_assert(rcode == 0);
1197
1198                         /*
1199                          *      rlm_eap.c has taken care of associating
1200                          *      the handler with the fake request.
1201                          *
1202                          *      So we associate the fake request with
1203                          *      this request.
1204                          */
1205                         rcode = request_data_add(request,
1206                                                  request->proxy,
1207                                                  REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1208                                                  fake, my_request_free);
1209                         rad_assert(rcode == 0);
1210                         fake = NULL;
1211
1212                         /*
1213                          *      Didn't authenticate the packet, but
1214                          *      we're proxying it.
1215                          */
1216                         rcode = PW_STATUS_CLIENT;
1217
1218                 } else {
1219                         DEBUG2("  TTLS: No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1220                                request->number);
1221                         rcode = PW_AUTHENTICATION_REJECT;
1222                 }
1223                 break;
1224
1225         default:
1226                 /*
1227                  *      Returns RLM_MODULE_FOO, and we want to return
1228                  *      PW_FOO
1229                  */
1230                 rcode = process_reply(handler, tls_session, request,
1231                                       fake->reply);
1232                 switch (rcode) {
1233                 case RLM_MODULE_REJECT:
1234                         rcode = PW_AUTHENTICATION_REJECT;
1235                         break;
1236
1237                 case RLM_MODULE_HANDLED:
1238                         rcode = PW_ACCESS_CHALLENGE;
1239                         break;
1240
1241                 case RLM_MODULE_OK:
1242                         rcode = PW_AUTHENTICATION_ACK;
1243                         break;
1244
1245                 default:
1246                         rcode = PW_AUTHENTICATION_REJECT;
1247                         break;
1248                 }
1249                 break;
1250         }
1251
1252         request_free(&fake);
1253
1254         return rcode;
1255 }