src/modules/rlm_eap/types/rlm_eap_ttls/ttls.c

   1 /*
   2  * rlm_eap_ttls.c  contains the interfaces that are called from eap
   3  *
   4  * Version:     $Id$
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  *   Copyright 2003 Alan DeKok <aland@freeradius.org>
  21  *   Copyright 2006 The FreeRADIUS server project
  22  */
  23
  24 #include <freeradius-devel/ident.h>
  25 RCSID("$Id$")
  26
  27 #include "eap_ttls.h"
  28
  29 /*
  30  *    0                   1                   2                   3
  31  *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  32  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  33  *   |                           AVP Code                            |
  34  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  35  *   |V M r r r r r r|                  AVP Length                   |
  36  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  37  *   |                        Vendor-ID (opt)                        |
  38  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  39  *   |    Data ...
  40  *   +-+-+-+-+-+-+-+-+
  41  */
  42
  43 /*
  44  *      Verify that the diameter packet is valid.
  45  */
  46 static int diameter_verify(REQUEST *request,
  47                            const uint8_t *data, unsigned int data_len)
  48 {
  49         uint32_t attr;
  50         uint32_t length;
  51         unsigned int hdr_len;
  52         unsigned int remaining = data_len;
  53
  54         while (remaining > 0) {
  55                 hdr_len = 12;
  56
  57                 if (remaining < hdr_len) {
  58                   RDEBUG2(" Diameter attribute is too small (%u) to contain a Diameter header", remaining);
  59                         return 0;
  60                 }
  61
  62                 memcpy(&attr, data, sizeof(attr));
  63                 attr = ntohl(attr);
  64                 memcpy(&length, data + 4, sizeof(length));
  65                 length = ntohl(length);
  66
  67                 if ((data[4] & 0x80) != 0) {
  68                         if (remaining < 16) {
  69                                 RDEBUG2(" Diameter attribute is too small to contain a Diameter header with Vendor-Id");
  70                                 return 0;
  71                         }
  72
  73                         hdr_len = 16;
  74                 }
  75
  76                 /*
  77                  *      Get the length.  If it's too big, die.
  78                  */
  79                 length &= 0x00ffffff;
  80
  81                 /*
  82                  *      Too short or too long is bad.
  83                  */
  84                 if (length <= (hdr_len - 4)) {
  85                         RDEBUG2("Tunneled attribute %u is too short (%u < %u) to contain anything useful.", attr, length, hdr_len);
  86                         return 0;
  87                 }
  88
  89                 if (length > remaining) {
  90                         RDEBUG2("Tunneled attribute %u is longer than room remaining in the packet (%u > %u).", attr, length, remaining);
  91                         return 0;
  92                 }
  93
  94                 /*
  95                  *      Check for broken implementations, which don't
  96                  *      pad the AVP to a 4-octet boundary.
  97                  */
  98                 if (remaining == length) break;
  99
 100                 /*
 101                  *      The length does NOT include the padding, so
 102                  *      we've got to account for it here by rounding up
 103                  *      to the nearest 4-byte boundary.
 104                  */
 105                 length += 0x03;
 106                 length &= ~0x03;
 107
 108                 /*
 109                  *      If the rest of the diameter packet is larger than
 110                  *      this attribute, continue.
 111                  *
 112                  *      Otherwise, if the attribute over-flows the end
 113                  *      of the packet, die.
 114                  */
 115                 if (remaining < length) {
 116                         RDEBUG2("ERROR! Diameter attribute overflows packet!");
 117                         return 0;
 118                 }
 119
 120                 /*
 121                  *      remaining > length, continue.
 122                  */
 123                 remaining -= length;
 124                 data += length;
 125         }
 126
 127         /*
 128          *      We got this far.  It looks OK.
 129          */
 130         return 1;
 131 }
 132
 133
 134 /*
 135  *      Convert diameter attributes to our VALUE_PAIR's
 136  */
 137 static VALUE_PAIR *diameter2vp(REQUEST *request, SSL *ssl,
 138                                const uint8_t *data, size_t data_len)
 139 {
 140         uint32_t        attr;
 141         uint32_t        vendor;
 142         uint32_t        length;
 143         size_t          offset;
 144         size_t          size;
 145         size_t          data_left = data_len;
 146         VALUE_PAIR      *first = NULL;
 147         VALUE_PAIR      **last = &first;
 148         VALUE_PAIR      *vp;
 149
 150         while (data_left > 0) {
 151                 rad_assert(data_left <= data_len);
 152                 memcpy(&attr, data, sizeof(attr));
 153                 data += 4;
 154                 attr = ntohl(attr);
 155                 vendor = 0;
 156
 157                 memcpy(&length, data, sizeof(length));
 158                 data += 4;
 159                 length = ntohl(length);
 160
 161                 /*
 162                  *      A "vendor" flag, with a vendor ID of zero,
 163                  *      is equivalent to no vendor.  This is stupid.
 164                  */
 165                 offset = 8;
 166                 if ((length & (1 << 31)) != 0) {
 167                         memcpy(&vendor, data, sizeof(vendor));
 168                         vendor = ntohl(vendor);
 169
 170                         data += 4; /* skip the vendor field, it's zero */
 171                         offset += 4; /* offset to value field */
 172
 173                         if (attr > 65535) goto next_attr;
 174                         if (vendor > FR_MAX_VENDOR) goto next_attr;
 175                 }
 176
 177                 /*
 178                  *      FIXME: Handle the M bit.  For now, we assume that
 179                  *      some other module takes care of any attribute
 180                  *      with the M bit set.
 181                  */
 182
 183                 /*
 184                  *      Get the length.
 185                  */
 186                 length &= 0x00ffffff;
 187
 188                 /*
 189                  *      Get the size of the value portion of the
 190                  *      attribute.
 191                  */
 192                 size = length - offset;
 193
 194                 /*
 195                  *      Vendor attributes can be larger than 255.
 196                  *      Normal attributes cannot be.
 197                  */
 198                 if ((attr > 255) && (vendor == 0)) {
 199                         RDEBUG2("WARNING: Skipping Diameter attribute %u",
 200                                 attr);
 201                         goto next_attr;
 202                 }
 203
 204                 if (size > 253) {
 205                         RDEBUG2("WARNING: diameter2vp skipping long attribute %u, attr");
 206                         goto next_attr;
 207                 }
 208
 209                 /*
 210                  *      RADIUS VSAs are handled as Diameter attributes
 211                  *      with Vendor-Id == 0, and the VSA data packed
 212                  *      into the "String" field as per normal.
 213                  *
 214                  *      EXCEPT for the MS-CHAP attributes.
 215                  */
 216                 if ((vendor == 0) && (attr == PW_VENDOR_SPECIFIC)) {
 217                         ssize_t decoded;
 218                         uint8_t buffer[256];
 219
 220                         buffer[0] = PW_VENDOR_SPECIFIC;
 221                         buffer[1] = size + 2;
 222                         memcpy(buffer + 2, data, size);
 223
 224                         vp = NULL;
 225                         decoded = rad_attr2vp_vsa(NULL, NULL, NULL,
 226                                                   buffer, size + 2, &vp);
 227                         if (decoded < 0) {
 228                                 RDEBUG2("ERROR: diameter2vp failed decoding attr: %s",
 229                                         fr_strerror());
 230                                 goto do_octets;
 231                         }
 232
 233                         if ((size_t) decoded != size + 2) {
 234                                 RDEBUG2("ERROR: diameter2vp failed to entirely decode VSA");
 235                                 pairfree(&vp);
 236                                 goto do_octets;
 237                         }
 238
 239                         *last = vp;
 240                         do {
 241                                 last = &(vp->next);
 242                                 vp = vp->next;
 243                         } while (vp != NULL);
 244
 245                         goto next_attr;
 246                 }
 247
 248                 /*
 249                  *      Create it.  If this fails, it's because we're OOM.
 250                  */
 251         do_octets:
 252                 vp = paircreate(attr, vendor, PW_TYPE_OCTETS);
 253                 if (!vp) {
 254                         RDEBUG2("Failure in creating VP");
 255                         pairfree(&first);
 256                         return NULL;
 257                 }
 258
 259                 /*
 260                  *      If it's a type from our dictionary, then
 261                  *      we need to put the data in a relevant place.
 262                  */
 263                 switch (vp->type) {
 264                 case PW_TYPE_INTEGER:
 265                 case PW_TYPE_DATE:
 266                         if (size != vp->length) {
 267                                 /*
 268                                  *      Bad format.  Create a "raw"
 269                                  *      attribute.
 270                                  */
 271                 raw:
 272                                 vp = paircreate_raw(vp->attribute, vp->vendor,
 273                                                     PW_TYPE_OCTETS, vp);
 274                                 vp->length = size;
 275                                 memcpy(vp->vp_octets, data, vp->length);
 276                                 break;
 277                         }
 278                         memcpy(&vp->vp_integer, data, vp->length);
 279
 280                         /*
 281                          *      Stored in host byte order: change it.
 282                          */
 283                         vp->vp_integer = ntohl(vp->vp_integer);
 284                         break;
 285
 286                 case PW_TYPE_INTEGER64:
 287                         if (size != vp->length) goto raw;
 288                         memcpy(&vp->vp_integer64, data, vp->length);
 289
 290                         /*
 291                          *      Stored in host byte order: change it.
 292                          */
 293                         vp->vp_integer64 = ntohll(vp->vp_integer64);
 294                         break;
 295
 296                 case PW_TYPE_IPADDR:
 297                         if (size != vp->length) {
 298                                 RDEBUG2("Invalid length attribute %d",
 299                                        attr);
 300                                 pairfree(&first);
 301                                 pairfree(&vp);
 302                                 return NULL;
 303                         }
 304                   memcpy(&vp->vp_ipaddr, data, vp->length);
 305
 306                   /*
 307                    *    Stored in network byte order: don't change it.
 308                    */
 309                   break;
 310
 311                 case PW_TYPE_BYTE:
 312                         if (size != vp->length) goto raw;
 313                         vp->vp_integer = data[0];
 314                         break;
 315
 316                 case PW_TYPE_SHORT:
 317                         if (size != vp->length) goto raw;
 318                         vp->vp_integer = (data[0] * 256) + data[1];
 319                         break;
 320
 321                 case PW_TYPE_SIGNED:
 322                         if (size != vp->length) goto raw;
 323                         memcpy(&vp->vp_signed, data, vp->length);
 324                         vp->vp_signed = ntohl(vp->vp_signed);
 325                         break;
 326
 327                 case PW_TYPE_IPV6ADDR:
 328                         if (size != vp->length) goto raw;
 329                         memcpy(&vp->vp_ipv6addr, data, vp->length);
 330                         break;
 331
 332                 case PW_TYPE_IPV6PREFIX:
 333                         if (size != vp->length) goto raw;
 334                         memcpy(&vp->vp_ipv6prefix, data, vp->length);
 335                         break;
 336
 337                         /*
 338                          *      String, octet, etc.  Copy the data from the
 339                          *      value field over verbatim.
 340                          */
 341                 case PW_TYPE_OCTETS:
 342                         if (attr == PW_EAP_MESSAGE) {
 343                                 const uint8_t *eap_message = data;
 344
 345                                 /*
 346                                  *      vp exists the first time around.
 347                                  */
 348                                 while (1) {
 349                                         vp->length = size;
 350                                         if (vp->length > 253) vp->length = 253;
 351                                         memcpy(vp->vp_octets, eap_message,
 352                                                vp->length);
 353
 354                                         size -= vp->length;
 355                                         eap_message += vp->length;
 356
 357                                         *last = vp;
 358                                         last = &(vp->next);
 359
 360                                         if (size == 0) break;
 361
 362                                         vp = paircreate(attr, vendor, PW_TYPE_OCTETS);
 363                                         if (!vp) {
 364                                                 RDEBUG2("Failure in creating VP");
 365                                                 pairfree(&first);
 366                                                 return NULL;
 367                                         }
 368                                 }
 369
 370                                 goto next_attr;
 371                         } /* else it's another kind of attribute */
 372                         /* FALL-THROUGH */
 373
 374                 default:
 375                         vp->length = size;
 376                         memcpy(vp->vp_strvalue, data, vp->length);
 377                         break;
 378                 }
 379
 380                 /*
 381                  *      User-Password is NUL padded to a multiple
 382                  *      of 16 bytes.  Let's chop it to something
 383                  *      more reasonable.
 384                  *
 385                  *      NOTE: This means that the User-Password
 386                  *      attribute CANNOT EVER have embedded zeros in it!
 387                  */
 388                 if ((vp->vendor == 0) && (vp->attribute == PW_USER_PASSWORD)) {
 389                         /*
 390                          *      If the password is exactly 16 octets,
 391                          *      it won't be zero-terminated.
 392                          */
 393                         vp->vp_strvalue[vp->length] = '\0';
 394                         vp->length = strlen(vp->vp_strvalue);
 395                 }
 396
 397                 /*
 398                  *      Ensure that the client is using the
 399                  *      correct challenge.  This weirdness is
 400                  *      to protect against against replay
 401                  *      attacks, where anyone observing the
 402                  *      CHAP exchange could pose as that user,
 403                  *      by simply choosing to use the same
 404                  *      challenge.
 405                  *
 406                  *      By using a challenge based on
 407                  *      information from the current session,
 408                  *      we can guarantee that the client is
 409                  *      not *choosing* a challenge.
 410                  *
 411                  *      We're a little forgiving in that we
 412                  *      have loose checks on the length, and
 413                  *      we do NOT check the Id (first octet of
 414                  *      the response to the challenge)
 415                  *
 416                  *      But if the client gets the challenge correct,
 417                  *      we're not too worried about the Id.
 418                  */
 419                 if (((vp->vendor == 0) && (vp->attribute == PW_CHAP_CHALLENGE)) ||
 420                     ((vp->vendor == VENDORPEC_MICROSOFT) && (vp->attribute == PW_MSCHAP_CHALLENGE))) {
 421                         uint8_t challenge[16];
 422
 423                         if ((vp->length < 8) ||
 424                             (vp->length > 16)) {
 425                                 RDEBUG("Tunneled challenge has invalid length");
 426                                 pairfree(&first);
 427                                 pairfree(&vp);
 428                                 return NULL;
 429                         }
 430
 431                         eapttls_gen_challenge(ssl, challenge,
 432                                               sizeof(challenge));
 433
 434                         if (memcmp(challenge, vp->vp_octets,
 435                                    vp->length) != 0) {
 436                                 RDEBUG("Tunneled challenge is incorrect");
 437                                 pairfree(&first);
 438                                 pairfree(&vp);
 439                                 return NULL;
 440                         }
 441                 }
 442
 443                 /*
 444                  *      Update the list.
 445                  */
 446                 *last = vp;
 447                 last = &(vp->next);
 448
 449         next_attr:
 450                 /*
 451                  *      Catch non-aligned attributes.
 452                  */
 453                 if (data_left == length) break;
 454
 455                 /*
 456                  *      The length does NOT include the padding, so
 457                  *      we've got to account for it here by rounding up
 458                  *      to the nearest 4-byte boundary.
 459                  */
 460                 length += 0x03;
 461                 length &= ~0x03;
 462
 463                 rad_assert(data_left >= length);
 464                 data_left -= length;
 465                 data += length - offset; /* already updated */
 466         }
 467
 468         /*
 469          *      We got this far.  It looks OK.
 470          */
 471         return first;
 472 }
 473
 474 /*
 475  *      Convert VALUE_PAIR's to diameter attributes, and write them
 476  *      to an SSL session.
 477  *
 478  *      The ONLY VALUE_PAIR's which may be passed to this function
 479  *      are ones which can go inside of a RADIUS (i.e. diameter)
 480  *      packet.  So no server-configuration attributes, or the like.
 481  */
 482 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 483 {
 484         /*
 485          *      RADIUS packets are no more than 4k in size, so if
 486          *      we've got more than 4k of data to write, it's very
 487          *      bad.
 488          */
 489         uint8_t         buffer[4096];
 490         uint8_t         *p;
 491         uint32_t        attr;
 492         uint32_t        length;
 493         uint32_t        vendor;
 494         size_t          total;
 495         uint64_t        attr64;
 496         VALUE_PAIR      *vp;
 497
 498         p = buffer;
 499         total = 0;
 500
 501         for (vp = first; vp != NULL; vp = vp->next) {
 502                 /*
 503                  *      Too much data: die.
 504                  */
 505                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 506                         RDEBUG2("output buffer is full!");
 507                         return 0;
 508                 }
 509
 510                 /*
 511                  *      Hmm... we don't group multiple EAP-Messages
 512                  *      together.  Maybe we should...
 513                  */
 514
 515                 /*
 516                  *      Length is no more than 253, due to RADIUS
 517                  *      issues.
 518                  */
 519                 length = vp->length;
 520                 vendor = vp->vendor;
 521                 if (vendor != 0) {
 522                         attr = vp->attribute & 0xffff;
 523                         length |= (1 << 31);
 524                 } else {
 525                         attr = vp->attribute;
 526                 }
 527
 528                 /*
 529                  *      Hmm... set the M bit for all attributes?
 530                  */
 531                 length |= (1 << 30);
 532
 533                 attr = ntohl(attr);
 534
 535                 memcpy(p, &attr, sizeof(attr));
 536                 p += 4;
 537                 total += 4;
 538
 539                 length += 8;    /* includes 8 bytes of attr & length */
 540
 541                 if (vendor != 0) {
 542                         length += 4; /* include 4 bytes of vendor */
 543
 544                         length = ntohl(length);
 545                         memcpy(p, &length, sizeof(length));
 546                         p += 4;
 547                         total += 4;
 548
 549                         vendor = ntohl(vendor);
 550                         memcpy(p, &vendor, sizeof(vendor));
 551                         p += 4;
 552                         total += 4;
 553                 } else {
 554                         length = ntohl(length);
 555                         memcpy(p, &length, sizeof(length));
 556                         p += 4;
 557                         total += 4;
 558                 }
 559
 560                 switch (vp->type) {
 561                 case PW_TYPE_INTEGER:
 562                 case PW_TYPE_DATE:
 563                         attr = htonl(vp->vp_integer); /* stored in host order */
 564                         memcpy(p, &attr, sizeof(attr));
 565                         length = 4;
 566                         break;
 567
 568                 case PW_TYPE_INTEGER64:
 569                         attr64 = htonll(vp->vp_integer64); /* stored in host order */
 570                         memcpy(p, &attr64, sizeof(attr64));
 571                         length = 8;
 572                         break;
 573
 574                 case PW_TYPE_IPADDR:
 575                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 576                         length = 4;
 577                         break;
 578
 579                 case PW_TYPE_STRING:
 580                 case PW_TYPE_OCTETS:
 581                 default:
 582                         memcpy(p, vp->vp_strvalue, vp->length);
 583                         length = vp->length;
 584                         break;
 585                 }
 586
 587                 /*
 588                  *      Skip to the end of the data.
 589                  */
 590                 p += length;
 591                 total += length;
 592
 593                 /*
 594                  *      Align the data to a multiple of 4 bytes.
 595                  */
 596                 if ((total & 0x03) != 0) {
 597                         size_t i;
 598
 599                         length = 4 - (total & 0x03);
 600                         for (i = 0; i < length; i++) {
 601                                 *p = '\0';
 602                                 p++;
 603                                 total++;
 604                         }
 605                 }
 606         } /* loop over the VP's to write. */
 607
 608         /*
 609          *      Write the data in the buffer to the SSL session.
 610          */
 611         if (total > 0) {
 612 #ifndef NDEBUG
 613                 size_t i;
 614
 615                 if ((debug_flag > 2) && fr_log_fp) {
 616                         for (i = 0; i < total; i++) {
 617                                 if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 618
 619                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 620
 621                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 622                         }
 623                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 624                 }
 625 #endif
 626
 627                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 628
 629                 /*
 630                  *      FIXME: Check the return code.
 631                  */
 632                 tls_handshake_send(request, tls_session);
 633         }
 634
 635         /*
 636          *      Everything's OK.
 637          */
 638         return 1;
 639 }
 640
 641 /*
 642  *      Use a reply packet to determine what to do.
 643  */
 644 static int process_reply(EAP_HANDLER *handler, tls_session_t *tls_session,
 645                          REQUEST *request, RADIUS_PACKET *reply)
 646 {
 647         int rcode = RLM_MODULE_REJECT;
 648         VALUE_PAIR *vp;
 649         ttls_tunnel_t *t = tls_session->opaque;
 650
 651         handler = handler;      /* -Wunused */
 652         rad_assert(request != NULL);
 653         rad_assert(handler->request == request);
 654
 655         /*
 656          *      If the response packet was Access-Accept, then
 657          *      we're OK.  If not, die horribly.
 658          *
 659          *      FIXME: Take MS-CHAP2-Success attribute, and
 660          *      tunnel it back to the client, to authenticate
 661          *      ourselves to the client.
 662          *
 663          *      FIXME: If we have an Access-Challenge, then
 664          *      the Reply-Message is tunneled back to the client.
 665          *
 666          *      FIXME: If we have an EAP-Message, then that message
 667          *      must be tunneled back to the client.
 668          *
 669          *      FIXME: If we have an Access-Challenge with a State
 670          *      attribute, then do we tunnel that to the client, or
 671          *      keep track of it ourselves?
 672          *
 673          *      FIXME: EAP-Messages can only start with 'identity',
 674          *      NOT 'eap start', so we should check for that....
 675          */
 676         switch (reply->code) {
 677         case PW_AUTHENTICATION_ACK:
 678                 RDEBUG("Got tunneled Access-Accept");
 679
 680                 rcode = RLM_MODULE_OK;
 681
 682                 /*
 683                  *      MS-CHAP2-Success means that we do NOT return
 684                  *      an Access-Accept, but instead tunnel that
 685                  *      attribute to the client, and keep going with
 686                  *      the TTLS session.  Once the client accepts
 687                  *      our identity, it will respond with an empty
 688                  *      packet, and we will send EAP-Success.
 689                  */
 690                 vp = NULL;
 691                 pairmove2(&vp, &reply->vps, PW_MSCHAP2_SUCCESS, VENDORPEC_MICROSOFT);
 692                 if (vp) {
 693                         RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge.");
 694                         rcode = RLM_MODULE_HANDLED;
 695                         t->authenticated = TRUE;
 696
 697                         /*
 698                          *      Delete MPPE keys & encryption policy.  We don't
 699                          *      want these here.
 700                          */
 701                         pairdelete(&reply->vps, 7, VENDORPEC_MICROSOFT);
 702                         pairdelete(&reply->vps, 8, VENDORPEC_MICROSOFT);
 703                         pairdelete(&reply->vps, 16, VENDORPEC_MICROSOFT);
 704                         pairdelete(&reply->vps, 17, VENDORPEC_MICROSOFT);
 705
 706                         /*
 707                          *      Use the tunneled reply, but not now.
 708                          */
 709                         if (t->use_tunneled_reply) {
 710                                 t->accept_vps = reply->vps;
 711                                 reply->vps = NULL;
 712                         }
 713
 714                 } else { /* no MS-CHAP2-Success */
 715                         /*
 716                          *      Can only have EAP-Message if there's
 717                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 718                          *
 719                          *      We also do NOT tunnel the EAP-Success
 720                          *      attribute back to the client, as the client
 721                          *      can figure it out, from the non-tunneled
 722                          *      EAP-Success packet.
 723                          */
 724                         pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0);
 725                         pairfree(&vp);
 726                 }
 727
 728                 /*
 729                  *      Handle the ACK, by tunneling any necessary reply
 730                  *      VP's back to the client.
 731                  */
 732                 if (vp) {
 733                         vp2diameter(request, tls_session, vp);
 734                         pairfree(&vp);
 735                 }
 736
 737                 /*
 738                  *      If we've been told to use the attributes from
 739                  *      the reply, then do so.
 740                  *
 741                  *      WARNING: This may leak information about the
 742                  *      tunneled user!
 743                  */
 744                 if (t->use_tunneled_reply) {
 745                         pairdelete(&reply->vps, PW_PROXY_STATE, 0);
 746                         pairadd(&request->reply->vps, reply->vps);
 747                         reply->vps = NULL;
 748                 }
 749                 break;
 750
 751
 752         case PW_AUTHENTICATION_REJECT:
 753                 RDEBUG("Got tunneled Access-Reject");
 754                 rcode = RLM_MODULE_REJECT;
 755                 break;
 756
 757                 /*
 758                  *      Handle Access-Challenge, but only if we
 759                  *      send tunneled reply data.  This is because
 760                  *      an Access-Challenge means that we MUST tunnel
 761                  *      a Reply-Message to the client.
 762                  */
 763         case PW_ACCESS_CHALLENGE:
 764                 RDEBUG("Got tunneled Access-Challenge");
 765
 766                 /*
 767                  *      Keep the State attribute, if necessary.
 768                  *
 769                  *      Get rid of the old State, too.
 770                  */
 771                 pairfree(&t->state);
 772                 pairmove2(&t->state, &reply->vps, PW_STATE, 0);
 773
 774                 /*
 775                  *      We should really be a bit smarter about this,
 776                  *      and move over only those attributes which
 777                  *      are relevant to the authentication request,
 778                  *      but that's a lot more work, and this "dumb"
 779                  *      method works in 99.9% of the situations.
 780                  */
 781                 vp = NULL;
 782                 pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0);
 783
 784                 /*
 785                  *      There MUST be a Reply-Message in the challenge,
 786                  *      which we tunnel back to the client.
 787                  *
 788                  *      If there isn't one in the reply VP's, then
 789                  *      we MUST create one, with an empty string as
 790                  *      it's value.
 791                  */
 792                 pairmove2(&vp, &reply->vps, PW_REPLY_MESSAGE, 0);
 793
 794                 /*
 795                  *      Handle the ACK, by tunneling any necessary reply
 796                  *      VP's back to the client.
 797                  */
 798                 if (vp) {
 799                         vp2diameter(request, tls_session, vp);
 800                         pairfree(&vp);
 801                 }
 802                 rcode = RLM_MODULE_HANDLED;
 803                 break;
 804
 805         default:
 806                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 807                 rcode = RLM_MODULE_INVALID;
 808                 break;
 809         }
 810
 811         return rcode;
 812 }
 813
 814
 815 #ifdef WITH_PROXY
 816 /*
 817  *      Do post-proxy processing,
 818  */
 819 static int eapttls_postproxy(EAP_HANDLER *handler, void *data)
 820 {
 821         int rcode;
 822         tls_session_t *tls_session = (tls_session_t *) data;
 823         REQUEST *fake, *request = handler->request;
 824
 825         rad_assert(request != NULL);
 826         RDEBUG("Passing reply from proxy back into the tunnel.");
 827
 828         /*
 829          *      If there was a fake request associated with the proxied
 830          *      request, do more processing of it.
 831          */
 832         fake = (REQUEST *) request_data_get(handler->request,
 833                                             handler->request->proxy,
 834                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 835
 836         /*
 837          *      Do the callback, if it exists, and if it was a success.
 838          */
 839         if (fake &&
 840             handler->request->proxy_reply &&
 841             (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 842                 /*
 843                  *      Terrible hacks.
 844                  */
 845                 rad_assert(fake->packet == NULL);
 846                 fake->packet = request->proxy;
 847                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 848                 request->proxy = NULL;
 849
 850                 rad_assert(fake->reply == NULL);
 851                 fake->reply = request->proxy_reply;
 852                 request->proxy_reply = NULL;
 853
 854                 if ((debug_flag > 0) && fr_log_fp) {
 855                         fprintf(fr_log_fp, "server %s {\n",
 856                                 (fake->server == NULL) ? "" : fake->server);
 857                 }
 858
 859                 /*
 860                  *      Perform a post-auth stage for the tunneled
 861                  *      session.
 862                  */
 863                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 864                 rcode = rad_postauth(fake);
 865                 RDEBUG2("post-auth returns %d", rcode);
 866
 867                 if ((debug_flag > 0) && fr_log_fp) {
 868                         fprintf(fr_log_fp, "} # server %s\n",
 869                                 (fake->server == NULL) ? "" : fake->server);
 870
 871                         RDEBUG("Final reply from tunneled session code %d",
 872                                fake->reply->code);
 873                         debug_pair_list(fake->reply->vps);
 874                 }
 875
 876                 /*
 877                  *      Terrible hacks.
 878                  */
 879                 request->proxy = fake->packet;
 880                 fake->packet = NULL;
 881                 request->proxy_reply = fake->reply;
 882                 fake->reply = NULL;
 883
 884                 /*
 885                  *      And we're done with this request.
 886                  */
 887
 888                 switch (rcode) {
 889                 case RLM_MODULE_FAIL:
 890                         request_free(&fake);
 891                         eaptls_fail(handler, 0);
 892                         return 0;
 893                         break;
 894
 895                 default:  /* Don't Do Anything */
 896                         RDEBUG2("Got reply %d",
 897                                request->proxy_reply->code);
 898                         break;
 899                 }
 900         }
 901         request_free(&fake);    /* robust if fake == NULL */
 902
 903         /*
 904          *      Process the reply from the home server.
 905          */
 906         rcode = process_reply(handler, tls_session, handler->request,
 907                               handler->request->proxy_reply);
 908
 909         /*
 910          *      The proxy code uses the reply from the home server as
 911          *      the basis for the reply to the NAS.  We don't want that,
 912          *      so we toss it, after we've had our way with it.
 913          */
 914         pairfree(&handler->request->proxy_reply->vps);
 915
 916         switch (rcode) {
 917         case RLM_MODULE_REJECT:
 918                 RDEBUG("Reply was rejected");
 919                 break;
 920
 921         case RLM_MODULE_HANDLED:
 922                 RDEBUG("Reply was handled");
 923                 eaptls_request(handler->eap_ds, tls_session);
 924                 return 1;
 925
 926         case RLM_MODULE_OK:
 927                 RDEBUG("Reply was OK");
 928
 929                 /*
 930                  *      Success: Automatically return MPPE keys.
 931                  */
 932                 return eaptls_success(handler, 0);
 933
 934         default:
 935                 RDEBUG("Reply was unknown.");
 936                 break;
 937         }
 938
 939         eaptls_fail(handler, 0);
 940         return 0;
 941 }
 942
 943
 944 /*
 945  *      Free a request.
 946  */
 947 static void my_request_free(void *data)
 948 {
 949         REQUEST *request = (REQUEST *)data;
 950
 951         request_free(&request);
 952 }
 953 #endif  /* WITH_PROXY */
 954
 955 /*
 956  *      Process the "diameter" contents of the tunneled data.
 957  */
 958 int eapttls_process(EAP_HANDLER *handler, tls_session_t *tls_session)
 959 {
 960         int rcode = PW_AUTHENTICATION_REJECT;
 961         REQUEST *fake;
 962         VALUE_PAIR *vp;
 963         ttls_tunnel_t *t;
 964         const uint8_t *data;
 965         size_t data_len;
 966         REQUEST *request = handler->request;
 967
 968         rad_assert(request != NULL);
 969
 970         /*
 971          *      Just look at the buffer directly, without doing
 972          *      record_minus.
 973          */
 974         data_len = tls_session->clean_out.used;
 975         tls_session->clean_out.used = 0;
 976         data = tls_session->clean_out.data;
 977
 978         t = (ttls_tunnel_t *) tls_session->opaque;
 979
 980         /*
 981          *      If there's no data, maybe this is an ACK to an
 982          *      MS-CHAP2-Success.
 983          */
 984         if (data_len == 0) {
 985                 if (t->authenticated) {
 986                         RDEBUG("Got ACK, and the user was already authenticated.");
 987                         return PW_AUTHENTICATION_ACK;
 988                 } /* else no session, no data, die. */
 989
 990                 /*
 991                  *      FIXME: Call SSL_get_error() to see what went
 992                  *      wrong.
 993                  */
 994                 RDEBUG2("SSL_read Error");
 995                 return PW_AUTHENTICATION_REJECT;
 996         }
 997
 998 #ifndef NDEBUG
 999         if ((debug_flag > 2) && fr_log_fp) {
1000                 size_t i;
1001
1002                 for (i = 0; i < data_len; i++) {
1003                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
1004
1005                         fprintf(fr_log_fp, "%02x ", data[i]);
1006
1007                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
1008                 }
1009                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
1010         }
1011 #endif
1012
1013         if (!diameter_verify(request, data, data_len)) {
1014                 return PW_AUTHENTICATION_REJECT;
1015         }
1016
1017         /*
1018          *      Allocate a fake REQUEST structe.
1019          */
1020         fake = request_alloc_fake(request);
1021
1022         rad_assert(fake->packet->vps == NULL);
1023
1024         /*
1025          *      Add the tunneled attributes to the fake request.
1026          */
1027         fake->packet->vps = diameter2vp(request, tls_session->ssl, data, data_len);
1028         if (!fake->packet->vps) {
1029                 request_free(&fake);
1030                 return PW_AUTHENTICATION_REJECT;
1031         }
1032
1033         /*
1034          *      Tell the request that it's a fake one.
1035          */
1036         vp = pairmake("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
1037         if (vp) {
1038                 pairadd(&fake->packet->vps, vp);
1039         }
1040
1041         if ((debug_flag > 0) && fr_log_fp) {
1042                 RDEBUG("Got tunneled request");
1043
1044                 debug_pair_list(fake->packet->vps);
1045         }
1046
1047         /*
1048          *      Update other items in the REQUEST data structure.
1049          */
1050         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0);
1051         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0);
1052
1053         /*
1054          *      No User-Name, try to create one from stored data.
1055          */
1056         if (!fake->username) {
1057                 /*
1058                  *      No User-Name in the stored data, look for
1059                  *      an EAP-Identity, and pull it out of there.
1060                  */
1061                 if (!t->username) {
1062                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0);
1063                         if (vp &&
1064                             (vp->length >= EAP_HEADER_LEN + 2) &&
1065                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1066                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1067                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1068                                 /*
1069                                  *      Create & remember a User-Name
1070                                  */
1071                                 t->username = pairmake("User-Name", "", T_OP_EQ);
1072                                 rad_assert(t->username != NULL);
1073
1074                                 memcpy(t->username->vp_strvalue, vp->vp_strvalue + 5,
1075                                        vp->length - 5);
1076                                 t->username->length = vp->length - 5;
1077                                 t->username->vp_strvalue[t->username->length] = 0;
1078
1079                                 RDEBUG("Got tunneled identity of %s",
1080                                        t->username->vp_strvalue);
1081
1082                                 /*
1083                                  *      If there's a default EAP type,
1084                                  *      set it here.
1085                                  */
1086                                 if (t->default_eap_type != 0) {
1087                                         RDEBUG("Setting default EAP type for tunneled EAP session.");
1088                                         vp = paircreate(PW_EAP_TYPE, 0,
1089                                                         PW_TYPE_INTEGER);
1090                                         rad_assert(vp != NULL);
1091                                         vp->vp_integer = t->default_eap_type;
1092                                         pairadd(&fake->config_items, vp);
1093                                 }
1094
1095                         } else {
1096                                 /*
1097                                  *      Don't reject the request outright,
1098                                  *      as it's permitted to do EAP without
1099                                  *      user-name.
1100                                  */
1101                                 RDEBUG2("WARNING! No EAP-Identity found to start EAP conversation.");
1102                         }
1103                 } /* else there WAS a t->username */
1104
1105                 if (t->username) {
1106                         vp = paircopy(t->username);
1107                         pairadd(&fake->packet->vps, vp);
1108                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0);
1109                 }
1110         } /* else the request ALREADY had a User-Name */
1111
1112         /*
1113          *      Add the State attribute, too, if it exists.
1114          */
1115         if (t->state) {
1116                 vp = paircopy(t->state);
1117                 if (vp) pairadd(&fake->packet->vps, vp);
1118         }
1119
1120         /*
1121          *      If this is set, we copy SOME of the request attributes
1122          *      from outside of the tunnel to inside of the tunnel.
1123          *
1124          *      We copy ONLY those attributes which do NOT already
1125          *      exist in the tunneled request.
1126          */
1127         if (t->copy_request_to_tunnel) {
1128                 VALUE_PAIR *copy;
1129
1130                 for (vp = request->packet->vps; vp != NULL; vp = vp->next) {
1131                         /*
1132                          *      The attribute is a server-side thingy,
1133                          *      don't copy it.
1134                          */
1135                         if ((vp->attribute > 255) &&
1136                             (vp->vendor == 0)) {
1137                                 continue;
1138                         }
1139
1140                         /*
1141                          *      The outside attribute is already in the
1142                          *      tunnel, don't copy it.
1143                          *
1144                          *      This works for BOTH attributes which
1145                          *      are originally in the tunneled request,
1146                          *      AND attributes which are copied there
1147                          *      from below.
1148                          */
1149                         if (pairfind(fake->packet->vps, vp->attribute, vp->vendor)) {
1150                                 continue;
1151                         }
1152
1153                         /*
1154                          *      Some attributes are handled specially.
1155                          */
1156                         switch (vp->attribute) {
1157                                 /*
1158                                  *      NEVER copy Message-Authenticator,
1159                                  *      EAP-Message, or State.  They're
1160                                  *      only for outside of the tunnel.
1161                                  */
1162                         case PW_USER_NAME:
1163                         case PW_USER_PASSWORD:
1164                         case PW_CHAP_PASSWORD:
1165                         case PW_CHAP_CHALLENGE:
1166                         case PW_PROXY_STATE:
1167                         case PW_MESSAGE_AUTHENTICATOR:
1168                         case PW_EAP_MESSAGE:
1169                         case PW_STATE:
1170                                 continue;
1171                                 break;
1172
1173                                 /*
1174                                  *      By default, copy it over.
1175                                  */
1176                         default:
1177                                 break;
1178                         }
1179
1180                         /*
1181                          *      Don't copy from the head, we've already
1182                          *      checked it.
1183                          */
1184                         copy = paircopy2(vp, vp->attribute, vp->vendor);
1185                         pairadd(&fake->packet->vps, copy);
1186                 }
1187         }
1188
1189         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0)) != NULL) {
1190                 fake->server = vp->vp_strvalue;
1191
1192         } else if (t->virtual_server) {
1193                 fake->server = t->virtual_server;
1194
1195         } /* else fake->server == request->server */
1196
1197
1198         if ((debug_flag > 0) && fr_log_fp) {
1199                 RDEBUG("Sending tunneled request");
1200
1201                 debug_pair_list(fake->packet->vps);
1202
1203                 fprintf(fr_log_fp, "server %s {\n",
1204                         (fake->server == NULL) ? "" : fake->server);
1205         }
1206
1207         /*
1208          *      Call authentication recursively, which will
1209          *      do PAP, CHAP, MS-CHAP, etc.
1210          */
1211         rad_virtual_server(fake);
1212
1213         /*
1214          *      Note that we don't do *anything* with the reply
1215          *      attributes.
1216          */
1217         if ((debug_flag > 0) && fr_log_fp) {
1218                 fprintf(fr_log_fp, "} # server %s\n",
1219                         (fake->server == NULL) ? "" : fake->server);
1220
1221                 RDEBUG("Got tunneled reply code %d", fake->reply->code);
1222
1223                 debug_pair_list(fake->reply->vps);
1224         }
1225
1226         /*
1227          *      Decide what to do with the reply.
1228          */
1229         switch (fake->reply->code) {
1230         case 0:                 /* No reply code, must be proxied... */
1231 #ifdef WITH_PROXY
1232           vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0);
1233                 if (vp) {
1234                         eap_tunnel_data_t *tunnel;
1235                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1236
1237                         /*
1238                          *      Tell the original request that it's going
1239                          *      to be proxied.
1240                          */
1241                         pairmove2(&(request->config_items),
1242                                   &(fake->config_items),
1243                                   PW_PROXY_TO_REALM, 0);
1244
1245                         /*
1246                          *      Seed the proxy packet with the
1247                          *      tunneled request.
1248                          */
1249                         rad_assert(request->proxy == NULL);
1250                         request->proxy = fake->packet;
1251                         memset(&request->proxy->src_ipaddr, 0,
1252                                sizeof(request->proxy->src_ipaddr));
1253                         memset(&request->proxy->src_ipaddr, 0,
1254                                sizeof(request->proxy->src_ipaddr));
1255                         request->proxy->src_port = 0;
1256                         request->proxy->dst_port = 0;
1257                         fake->packet = NULL;
1258                         rad_free(&fake->reply);
1259                         fake->reply = NULL;
1260
1261                         /*
1262                          *      Set up the callbacks for the tunnel
1263                          */
1264                         tunnel = rad_malloc(sizeof(*tunnel));
1265                         memset(tunnel, 0, sizeof(*tunnel));
1266
1267                         tunnel->tls_session = tls_session;
1268                         tunnel->callback = eapttls_postproxy;
1269
1270                         /*
1271                          *      Associate the callback with the request.
1272                          */
1273                         rcode = request_data_add(request,
1274                                                  request->proxy,
1275                                                  REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1276                                                  tunnel, free);
1277                         rad_assert(rcode == 0);
1278
1279                         /*
1280                          *      rlm_eap.c has taken care of associating
1281                          *      the handler with the fake request.
1282                          *
1283                          *      So we associate the fake request with
1284                          *      this request.
1285                          */
1286                         rcode = request_data_add(request,
1287                                                  request->proxy,
1288                                                  REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1289                                                  fake, my_request_free);
1290                         rad_assert(rcode == 0);
1291                         fake = NULL;
1292
1293                         /*
1294                          *      Didn't authenticate the packet, but
1295                          *      we're proxying it.
1296                          */
1297                         rcode = PW_STATUS_CLIENT;
1298
1299                 } else
1300 #endif  /* WITH_PROXY */
1301                   {
1302                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1303                                request->number);
1304                         rcode = PW_AUTHENTICATION_REJECT;
1305                 }
1306                 break;
1307
1308         default:
1309                 /*
1310                  *      Returns RLM_MODULE_FOO, and we want to return
1311                  *      PW_FOO
1312                  */
1313                 rcode = process_reply(handler, tls_session, request,
1314                                       fake->reply);
1315                 switch (rcode) {
1316                 case RLM_MODULE_REJECT:
1317                         rcode = PW_AUTHENTICATION_REJECT;
1318                         break;
1319
1320                 case RLM_MODULE_HANDLED:
1321                         rcode = PW_ACCESS_CHALLENGE;
1322                         break;
1323
1324                 case RLM_MODULE_OK:
1325                         rcode = PW_AUTHENTICATION_ACK;
1326                         break;
1327
1328                 default:
1329                         rcode = PW_AUTHENTICATION_REJECT;
1330                         break;
1331                 }
1332                 break;
1333         }
1334
1335         request_free(&fake);
1336
1337         return rcode;
1338 }