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 #include "eap_chbind.h"
  29
  30 /*
  31  *    0                   1                   2                   3
  32  *    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
  33  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  34  *   |                           AVP Code                            |
  35  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  36  *   |V M r r r r r r|                  AVP Length                   |
  37  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  38  *   |                        Vendor-ID (opt)                        |
  39  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  40  *   |    Data ...
  41  *   +-+-+-+-+-+-+-+-+
  42  */
  43
  44 /*
  45  *      Verify that the diameter packet is valid.
  46  */
  47 static int diameter_verify(REQUEST *request,
  48                            const uint8_t *data, unsigned int data_len)
  49 {
  50         uint32_t attr;
  51         uint32_t length;
  52         unsigned int hdr_len;
  53         unsigned int remaining = data_len;
  54
  55         while (remaining > 0) {
  56                 hdr_len = 12;
  57
  58                 if (remaining < hdr_len) {
  59                   RDEBUG2(" Diameter attribute is too small (%u) to contain a Diameter header", remaining);
  60                         return 0;
  61                 }
  62
  63                 memcpy(&attr, data, sizeof(attr));
  64                 attr = ntohl(attr);
  65                 memcpy(&length, data + 4, sizeof(length));
  66                 length = ntohl(length);
  67
  68                 if ((data[4] & 0x80) != 0) {
  69                         if (remaining < 16) {
  70                                 RDEBUG2(" Diameter attribute is too small to contain a Diameter header with Vendor-Id");
  71                                 return 0;
  72                         }
  73
  74                         hdr_len = 16;
  75                 }
  76
  77                 /*
  78                  *      Get the length.  If it's too big, die.
  79                  */
  80                 length &= 0x00ffffff;
  81
  82                 /*
  83                  *      Too short or too long is bad.
  84                  */
  85                 if (length <= (hdr_len - 4)) {
  86                         RDEBUG2("Tunneled attribute %u is too short (%u < %u) to contain anything useful.", attr, length, hdr_len);
  87                         return 0;
  88                 }
  89
  90                 if (length > remaining) {
  91                         RDEBUG2("Tunneled attribute %u is longer than room remaining in the packet (%u > %u).", attr, length, remaining);
  92                         return 0;
  93                 }
  94
  95                 /*
  96                  *      Check for broken implementations, which don't
  97                  *      pad the AVP to a 4-octet boundary.
  98                  */
  99                 if (remaining == length) break;
 100
 101                 /*
 102                  *      The length does NOT include the padding, so
 103                  *      we've got to account for it here by rounding up
 104                  *      to the nearest 4-byte boundary.
 105                  */
 106                 length += 0x03;
 107                 length &= ~0x03;
 108
 109                 /*
 110                  *      If the rest of the diameter packet is larger than
 111                  *      this attribute, continue.
 112                  *
 113                  *      Otherwise, if the attribute over-flows the end
 114                  *      of the packet, die.
 115                  */
 116                 if (remaining < length) {
 117                         RDEBUG2E("Diameter attribute overflows packet!");
 118                         return 0;
 119                 }
 120
 121                 /*
 122                  *      remaining > length, continue.
 123                  */
 124                 remaining -= length;
 125                 data += length;
 126         }
 127
 128         /*
 129          *      We got this far.  It looks OK.
 130          */
 131         return 1;
 132 }
 133
 134
 135 /*
 136  *      Convert diameter attributes to our VALUE_PAIR's
 137  */
 138 static VALUE_PAIR *diameter2vp(REQUEST *request, SSL *ssl,
 139                                const uint8_t *data, size_t data_len)
 140 {
 141         uint32_t        attr;
 142         uint32_t        vendor;
 143         uint32_t        length;
 144         size_t          offset;
 145         size_t          size;
 146         size_t          data_left = data_len;
 147         VALUE_PAIR      *first = NULL;
 148         VALUE_PAIR      **last = &first;
 149         VALUE_PAIR      *vp;
 150
 151         while (data_left > 0) {
 152                 rad_assert(data_left <= data_len);
 153                 memcpy(&attr, data, sizeof(attr));
 154                 data += 4;
 155                 attr = ntohl(attr);
 156                 vendor = 0;
 157
 158                 memcpy(&length, data, sizeof(length));
 159                 data += 4;
 160                 length = ntohl(length);
 161
 162                 /*
 163                  *      A "vendor" flag, with a vendor ID of zero,
 164                  *      is equivalent to no vendor.  This is stupid.
 165                  */
 166                 offset = 8;
 167                 if ((length & (1 << 31)) != 0) {
 168                         memcpy(&vendor, data, sizeof(vendor));
 169                         vendor = ntohl(vendor);
 170
 171                         data += 4; /* skip the vendor field, it's zero */
 172                         offset += 4; /* offset to value field */
 173
 174                         if (attr > 65535) goto next_attr;
 175                         if (vendor > FR_MAX_VENDOR) goto next_attr;
 176                 }
 177
 178                 /*
 179                  *      FIXME: Handle the M bit.  For now, we assume that
 180                  *      some other module takes care of any attribute
 181                  *      with the M bit set.
 182                  */
 183
 184                 /*
 185                  *      Get the length.
 186                  */
 187                 length &= 0x00ffffff;
 188
 189                 /*
 190                  *      Get the size of the value portion of the
 191                  *      attribute.
 192                  */
 193                 size = length - offset;
 194
 195                 /*
 196                  *      Vendor attributes can be larger than 255.
 197                  *      Normal attributes cannot be.
 198                  */
 199                 if ((attr > 255) && (vendor == 0)) {
 200                         RDEBUG2W("Skipping Diameter attribute %u",
 201                                 attr);
 202                         goto next_attr;
 203                 }
 204
 205                 /*
 206                  * EAP-Message AVPs can be larger than 253 octets.
 207                  */
 208                 if ((size > 253) && !((vendor == 0) && (attr == PW_EAP_MESSAGE))) {
 209                         RDEBUG2W("diameter2vp skipping long attribute %u", attr);
 210                         goto next_attr;
 211                 }
 212
 213                 /*
 214                  *      RADIUS VSAs are handled as Diameter attributes
 215                  *      with Vendor-Id == 0, and the VSA data packed
 216                  *      into the "String" field as per normal.
 217                  *
 218                  *      EXCEPT for the MS-CHAP attributes.
 219                  */
 220                 if ((vendor == 0) && (attr == PW_VENDOR_SPECIFIC)) {
 221                         ssize_t decoded;
 222                         uint8_t buffer[256];
 223
 224                         buffer[0] = PW_VENDOR_SPECIFIC;
 225                         buffer[1] = size + 2;
 226                         memcpy(buffer + 2, data, size);
 227
 228                         vp = NULL;
 229                         decoded = rad_attr2vp(NULL, NULL, NULL,
 230                                               buffer, size + 2, &vp);
 231                         if (decoded < 0) {
 232                                 RDEBUG2E("diameter2vp failed decoding attr: %s",
 233                                         fr_strerror());
 234                                 goto do_octets;
 235                         }
 236
 237                         if ((size_t) decoded != size + 2) {
 238                                 RDEBUG2E("diameter2vp failed to entirely decode VSA");
 239                                 pairfree(&vp);
 240                                 goto do_octets;
 241                         }
 242
 243                         *last = vp;
 244                         do {
 245                                 last = &(vp->next);
 246                                 vp = vp->next;
 247                         } while (vp != NULL);
 248
 249                         goto next_attr;
 250                 }
 251
 252                 /*
 253                  *      Create it.  If this fails, it's because we're OOM.
 254                  */
 255         do_octets:
 256                 vp = paircreate(attr, vendor);
 257                 if (!vp) {
 258                         RDEBUG2("Failure in creating VP");
 259                         pairfree(&first);
 260                         return NULL;
 261                 }
 262                 if (vendor == VENDORPEC_UKERNA) {
 263                         RDEBUG("Received UKERNA attr %d!", attr);
 264                 }
 265
 266                 /*
 267                  *      If it's a type from our dictionary, then
 268                  *      we need to put the data in a relevant place.
 269                  */
 270                 switch (vp->da->type) {
 271                 case PW_TYPE_INTEGER:
 272                 case PW_TYPE_DATE:
 273                         if (size != vp->length) {
 274                                 const DICT_ATTR *da;
 275
 276                                 /*
 277                                  *      Bad format.  Create a "raw"
 278                                  *      attribute.
 279                                  */
 280                 raw:
 281                                 if (vp) pairfree(&vp);
 282                                 da = dict_attrunknown(attr, vendor, TRUE);
 283                                 if (!da) return NULL;
 284                                 vp = pairalloc(NULL, da);
 285                                 if (size >= 253) size = 253;
 286                                 vp->length = size;
 287                                 memcpy(vp->vp_octets, data, vp->length);
 288                                 break;
 289                         }
 290                         memcpy(&vp->vp_integer, data, vp->length);
 291
 292                         /*
 293                          *      Stored in host byte order: change it.
 294                          */
 295                         vp->vp_integer = ntohl(vp->vp_integer);
 296                         break;
 297
 298                 case PW_TYPE_INTEGER64:
 299                         if (size != vp->length) goto raw;
 300                         memcpy(&vp->vp_integer64, data, vp->length);
 301
 302                         /*
 303                          *      Stored in host byte order: change it.
 304                          */
 305                         vp->vp_integer64 = ntohll(vp->vp_integer64);
 306                         break;
 307
 308                 case PW_TYPE_IPADDR:
 309                         if (size != vp->length) {
 310                                 RDEBUG2("Invalid length attribute %d",
 311                                        attr);
 312                                 pairfree(&first);
 313                                 pairfree(&vp);
 314                                 return NULL;
 315                         }
 316                   memcpy(&vp->vp_ipaddr, data, vp->length);
 317
 318                   /*
 319                    *    Stored in network byte order: don't change it.
 320                    */
 321                   break;
 322
 323                 case PW_TYPE_BYTE:
 324                         if (size != vp->length) goto raw;
 325                         vp->vp_integer = data[0];
 326                         break;
 327
 328                 case PW_TYPE_SHORT:
 329                         if (size != vp->length) goto raw;
 330                         vp->vp_integer = (data[0] * 256) + data[1];
 331                         break;
 332
 333                 case PW_TYPE_SIGNED:
 334                         if (size != vp->length) goto raw;
 335                         memcpy(&vp->vp_signed, data, vp->length);
 336                         vp->vp_signed = ntohl(vp->vp_signed);
 337                         break;
 338
 339                 case PW_TYPE_IPV6ADDR:
 340                         if (size != vp->length) goto raw;
 341                         memcpy(&vp->vp_ipv6addr, data, vp->length);
 342                         break;
 343
 344                 case PW_TYPE_IPV6PREFIX:
 345                         if (size != vp->length) goto raw;
 346                         memcpy(&vp->vp_ipv6prefix, data, vp->length);
 347                         break;
 348
 349                         /*
 350                          *      String, octet, etc.  Copy the data from the
 351                          *      value field over verbatim.
 352                          */
 353                 case PW_TYPE_OCTETS:
 354                         if (attr == PW_EAP_MESSAGE) {
 355                                 const uint8_t *eap_message = data;
 356
 357                                 /*
 358                                  *      vp exists the first time around.
 359                                  */
 360                                 while (1) {
 361                                         vp->length = size;
 362                                         if (vp->length > 253) vp->length = 253;
 363                                         memcpy(vp->vp_octets, eap_message,
 364                                                vp->length);
 365
 366                                         size -= vp->length;
 367                                         eap_message += vp->length;
 368
 369                                         *last = vp;
 370                                         last = &(vp->next);
 371
 372                                         if (size == 0) break;
 373
 374                                         vp = paircreate(attr, vendor);
 375                                         if (!vp) {
 376                                                 RDEBUG2("Failure in creating VP");
 377                                                 pairfree(&first);
 378                                                 return NULL;
 379                                         }
 380                                 }
 381
 382                                 goto next_attr;
 383                         } /* else it's another kind of attribute */
 384                         /* FALL-THROUGH */
 385
 386                 default:
 387                         if (size >= 253) size = 253;
 388                         vp->length = size;
 389                         memcpy(vp->vp_strvalue, data, vp->length);
 390                         break;
 391                 }
 392
 393                 /*
 394                  *      User-Password is NUL padded to a multiple
 395                  *      of 16 bytes.  Let's chop it to something
 396                  *      more reasonable.
 397                  *
 398                  *      NOTE: This means that the User-Password
 399                  *      attribute CANNOT EVER have embedded zeros in it!
 400                  */
 401                 if ((vp->da->vendor == 0) && (vp->da->attr == PW_USER_PASSWORD)) {
 402                         /*
 403                          *      If the password is exactly 16 octets,
 404                          *      it won't be zero-terminated.
 405                          */
 406                         vp->vp_strvalue[vp->length] = '\0';
 407                         vp->length = strlen(vp->vp_strvalue);
 408                 }
 409
 410                 /*
 411                  *      Ensure that the client is using the
 412                  *      correct challenge.  This weirdness is
 413                  *      to protect against against replay
 414                  *      attacks, where anyone observing the
 415                  *      CHAP exchange could pose as that user,
 416                  *      by simply choosing to use the same
 417                  *      challenge.
 418                  *
 419                  *      By using a challenge based on
 420                  *      information from the current session,
 421                  *      we can guarantee that the client is
 422                  *      not *choosing* a challenge.
 423                  *
 424                  *      We're a little forgiving in that we
 425                  *      have loose checks on the length, and
 426                  *      we do NOT check the Id (first octet of
 427                  *      the response to the challenge)
 428                  *
 429                  *      But if the client gets the challenge correct,
 430                  *      we're not too worried about the Id.
 431                  */
 432                 if (((vp->da->vendor == 0) && (vp->da->attr == PW_CHAP_CHALLENGE)) ||
 433                     ((vp->da->vendor == VENDORPEC_MICROSOFT) && (vp->da->attr == PW_MSCHAP_CHALLENGE))) {
 434                         uint8_t challenge[16];
 435
 436                         if ((vp->length < 8) ||
 437                             (vp->length > 16)) {
 438                                 RDEBUG("Tunneled challenge has invalid length");
 439                                 pairfree(&first);
 440                                 pairfree(&vp);
 441                                 return NULL;
 442                         }
 443
 444                         eapttls_gen_challenge(ssl, challenge,
 445                                               sizeof(challenge));
 446
 447                         if (memcmp(challenge, vp->vp_octets,
 448                                    vp->length) != 0) {
 449                                 RDEBUG("Tunneled challenge is incorrect");
 450                                 pairfree(&first);
 451                                 pairfree(&vp);
 452                                 return NULL;
 453                         }
 454                 }
 455
 456                 /*
 457                  *      Update the list.
 458                  */
 459                 *last = vp;
 460                 last = &(vp->next);
 461
 462         next_attr:
 463                 /*
 464                  *      Catch non-aligned attributes.
 465                  */
 466                 if (data_left == length) break;
 467
 468                 /*
 469                  *      The length does NOT include the padding, so
 470                  *      we've got to account for it here by rounding up
 471                  *      to the nearest 4-byte boundary.
 472                  */
 473                 length += 0x03;
 474                 length &= ~0x03;
 475
 476                 rad_assert(data_left >= length);
 477                 data_left -= length;
 478                 data += length - offset; /* already updated */
 479         }
 480
 481         /*
 482          *      We got this far.  It looks OK.
 483          */
 484         return first;
 485 }
 486
 487 /*
 488  *      Convert VALUE_PAIR's to diameter attributes, and write them
 489  *      to an SSL session.
 490  *
 491  *      The ONLY VALUE_PAIR's which may be passed to this function
 492  *      are ones which can go inside of a RADIUS (i.e. diameter)
 493  *      packet.  So no server-configuration attributes, or the like.
 494  */
 495 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 496 {
 497         /*
 498          *      RADIUS packets are no more than 4k in size, so if
 499          *      we've got more than 4k of data to write, it's very
 500          *      bad.
 501          */
 502         uint8_t         buffer[4096];
 503         uint8_t         *p;
 504         uint32_t        attr;
 505         uint32_t        length;
 506         uint32_t        vendor;
 507         size_t          total;
 508         uint64_t        attr64;
 509         VALUE_PAIR      *vp;
 510
 511         p = buffer;
 512         total = 0;
 513
 514         for (vp = first; vp != NULL; vp = vp->next) {
 515                 /*
 516                  *      Too much data: die.
 517                  */
 518                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 519                         RDEBUG2("output buffer is full!");
 520                         return 0;
 521                 }
 522
 523                 /*
 524                  *      Hmm... we don't group multiple EAP-Messages
 525                  *      together.  Maybe we should...
 526                  */
 527
 528                 /*
 529                  *      Length is no more than 253, due to RADIUS
 530                  *      issues.
 531                  */
 532                 length = vp->length;
 533                 vendor = vp->da->vendor;
 534                 if (vendor != 0) {
 535                         attr = vp->da->attr & 0xffff;
 536                         length |= (1 << 31);
 537                 } else {
 538                         attr = vp->da->attr;
 539                 }
 540
 541                 /*
 542                  *      Hmm... set the M bit for all attributes?
 543                  */
 544                 length |= (1 << 30);
 545
 546                 attr = ntohl(attr);
 547
 548                 memcpy(p, &attr, sizeof(attr));
 549                 p += 4;
 550                 total += 4;
 551
 552                 length += 8;    /* includes 8 bytes of attr & length */
 553
 554                 if (vendor != 0) {
 555                         length += 4; /* include 4 bytes of vendor */
 556
 557                         length = ntohl(length);
 558                         memcpy(p, &length, sizeof(length));
 559                         p += 4;
 560                         total += 4;
 561
 562                         vendor = ntohl(vendor);
 563                         memcpy(p, &vendor, sizeof(vendor));
 564                         p += 4;
 565                         total += 4;
 566                 } else {
 567                         length = ntohl(length);
 568                         memcpy(p, &length, sizeof(length));
 569                         p += 4;
 570                         total += 4;
 571                 }
 572
 573                 switch (vp->da->type) {
 574                 case PW_TYPE_INTEGER:
 575                 case PW_TYPE_DATE:
 576                         attr = htonl(vp->vp_integer); /* stored in host order */
 577                         memcpy(p, &attr, sizeof(attr));
 578                         length = 4;
 579                         break;
 580
 581                 case PW_TYPE_INTEGER64:
 582                         attr64 = htonll(vp->vp_integer64); /* stored in host order */
 583                         memcpy(p, &attr64, sizeof(attr64));
 584                         length = 8;
 585                         break;
 586
 587                 case PW_TYPE_IPADDR:
 588                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 589                         length = 4;
 590                         break;
 591
 592                 case PW_TYPE_STRING:
 593                 case PW_TYPE_OCTETS:
 594                 default:
 595                         memcpy(p, vp->vp_strvalue, vp->length);
 596                         length = vp->length;
 597                         break;
 598                 }
 599
 600                 /*
 601                  *      Skip to the end of the data.
 602                  */
 603                 p += length;
 604                 total += length;
 605
 606                 /*
 607                  *      Align the data to a multiple of 4 bytes.
 608                  */
 609                 if ((total & 0x03) != 0) {
 610                         size_t i;
 611
 612                         length = 4 - (total & 0x03);
 613                         for (i = 0; i < length; i++) {
 614                                 *p = '\0';
 615                                 p++;
 616                                 total++;
 617                         }
 618                 }
 619         } /* loop over the VP's to write. */
 620
 621         /*
 622          *      Write the data in the buffer to the SSL session.
 623          */
 624         if (total > 0) {
 625 #ifndef NDEBUG
 626                 size_t i;
 627
 628                 if ((debug_flag > 2) && fr_log_fp) {
 629                         for (i = 0; i < total; i++) {
 630                                 if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 631
 632                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 633
 634                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 635                         }
 636                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 637                 }
 638 #endif
 639
 640                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 641
 642                 /*
 643                  *      FIXME: Check the return code.
 644                  */
 645                 tls_handshake_send(request, tls_session);
 646         }
 647
 648         /*
 649          *      Everything's OK.
 650          */
 651         return 1;
 652 }
 653
 654 /*
 655  *      Use a reply packet to determine what to do.
 656  */
 657 static int process_reply(EAP_HANDLER *handler, tls_session_t *tls_session,
 658                          REQUEST *request, RADIUS_PACKET *reply)
 659 {
 660         int rcode = RLM_MODULE_REJECT;
 661         VALUE_PAIR *vp;
 662         ttls_tunnel_t *t = tls_session->opaque;
 663
 664         handler = handler;      /* -Wunused */
 665         rad_assert(request != NULL);
 666         rad_assert(handler->request == request);
 667
 668         /*
 669          *      If the response packet was Access-Accept, then
 670          *      we're OK.  If not, die horribly.
 671          *
 672          *      FIXME: Take MS-CHAP2-Success attribute, and
 673          *      tunnel it back to the client, to authenticate
 674          *      ourselves to the client.
 675          *
 676          *      FIXME: If we have an Access-Challenge, then
 677          *      the Reply-Message is tunneled back to the client.
 678          *
 679          *      FIXME: If we have an EAP-Message, then that message
 680          *      must be tunneled back to the client.
 681          *
 682          *      FIXME: If we have an Access-Challenge with a State
 683          *      attribute, then do we tunnel that to the client, or
 684          *      keep track of it ourselves?
 685          *
 686          *      FIXME: EAP-Messages can only start with 'identity',
 687          *      NOT 'eap start', so we should check for that....
 688          */
 689         switch (reply->code) {
 690         case PW_AUTHENTICATION_ACK:
 691                 RDEBUG("Got tunneled Access-Accept");
 692
 693                 rcode = RLM_MODULE_OK;
 694
 695                 /*
 696                  *      MS-CHAP2-Success means that we do NOT return
 697                  *      an Access-Accept, but instead tunnel that
 698                  *      attribute to the client, and keep going with
 699                  *      the TTLS session.  Once the client accepts
 700                  *      our identity, it will respond with an empty
 701                  *      packet, and we will send EAP-Success.
 702                  */
 703                 vp = NULL;
 704                 pairmove2(&vp, &reply->vps, PW_MSCHAP2_SUCCESS, VENDORPEC_MICROSOFT, TAG_ANY);
 705                 if (vp) {
 706                         RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge.");
 707                         rcode = RLM_MODULE_HANDLED;
 708                         t->authenticated = TRUE;
 709
 710                         /*
 711                          *      Delete MPPE keys & encryption policy.  We don't
 712                          *      want these here.
 713                          */
 714                         pairdelete(&reply->vps, 7, VENDORPEC_MICROSOFT, TAG_ANY);
 715                         pairdelete(&reply->vps, 8, VENDORPEC_MICROSOFT, TAG_ANY);
 716                         pairdelete(&reply->vps, 16, VENDORPEC_MICROSOFT, TAG_ANY);
 717                         pairdelete(&reply->vps, 17, VENDORPEC_MICROSOFT, TAG_ANY);
 718
 719                         /*
 720                          *      Use the tunneled reply, but not now.
 721                          */
 722                         if (t->use_tunneled_reply) {
 723                                 t->accept_vps = reply->vps;
 724                                 reply->vps = NULL;
 725                         }
 726
 727                 } else { /* no MS-CHAP2-Success */
 728                         /*
 729                          *      Can only have EAP-Message if there's
 730                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 731                          *
 732                          *      We also do NOT tunnel the EAP-Success
 733                          *      attribute back to the client, as the client
 734                          *      can figure it out, from the non-tunneled
 735                          *      EAP-Success packet.
 736                          */
 737                         pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 738                         pairfree(&vp);
 739                 }
 740
 741                 /*
 742                  *      Handle the ACK, by tunneling any necessary reply
 743                  *      VP's back to the client.
 744                  */
 745                 if (vp) {
 746                         vp2diameter(request, tls_session, vp);
 747                         pairfree(&vp);
 748                 }
 749
 750                 /*
 751                  *      If we've been told to use the attributes from
 752                  *      the reply, then do so.
 753                  *
 754                  *      WARNING: This may leak information about the
 755                  *      tunneled user!
 756                  */
 757                 if (t->use_tunneled_reply) {
 758                         pairdelete(&reply->vps, PW_PROXY_STATE, 0, TAG_ANY);
 759                         pairadd(&request->reply->vps, reply->vps);
 760                         reply->vps = NULL;
 761                 }
 762                 break;
 763
 764
 765         case PW_AUTHENTICATION_REJECT:
 766                 RDEBUG("Got tunneled Access-Reject");
 767                 rcode = RLM_MODULE_REJECT;
 768                 break;
 769
 770                 /*
 771                  *      Handle Access-Challenge, but only if we
 772                  *      send tunneled reply data.  This is because
 773                  *      an Access-Challenge means that we MUST tunnel
 774                  *      a Reply-Message to the client.
 775                  */
 776         case PW_ACCESS_CHALLENGE:
 777                 RDEBUG("Got tunneled Access-Challenge");
 778
 779                 /*
 780                  *      Keep the State attribute, if necessary.
 781                  *
 782                  *      Get rid of the old State, too.
 783                  */
 784                 pairfree(&t->state);
 785                 pairmove2(&t->state, &reply->vps, PW_STATE, 0, TAG_ANY);
 786
 787                 /*
 788                  *      We should really be a bit smarter about this,
 789                  *      and move over only those attributes which
 790                  *      are relevant to the authentication request,
 791                  *      but that's a lot more work, and this "dumb"
 792                  *      method works in 99.9% of the situations.
 793                  */
 794                 vp = NULL;
 795                 pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
 796
 797                 /*
 798                  *      There MUST be a Reply-Message in the challenge,
 799                  *      which we tunnel back to the client.
 800                  *
 801                  *      If there isn't one in the reply VP's, then
 802                  *      we MUST create one, with an empty string as
 803                  *      it's value.
 804                  */
 805                 pairmove2(&vp, &reply->vps, PW_REPLY_MESSAGE, 0, TAG_ANY);
 806
 807                 /*
 808                  *      Handle the ACK, by tunneling any necessary reply
 809                  *      VP's back to the client.
 810                  */
 811                 if (vp) {
 812                         vp2diameter(request, tls_session, vp);
 813                         pairfree(&vp);
 814                 }
 815                 rcode = RLM_MODULE_HANDLED;
 816                 break;
 817
 818         default:
 819                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 820                 rcode = RLM_MODULE_INVALID;
 821                 break;
 822         }
 823
 824         return rcode;
 825 }
 826
 827
 828 #ifdef WITH_PROXY
 829 /*
 830  *      Do post-proxy processing,
 831  */
 832 static int eapttls_postproxy(EAP_HANDLER *handler, void *data)
 833 {
 834         int rcode;
 835         tls_session_t *tls_session = (tls_session_t *) data;
 836         REQUEST *fake, *request = handler->request;
 837
 838         rad_assert(request != NULL);
 839         RDEBUG("Passing reply from proxy back into the tunnel.");
 840
 841         /*
 842          *      If there was a fake request associated with the proxied
 843          *      request, do more processing of it.
 844          */
 845         fake = (REQUEST *) request_data_get(handler->request,
 846                                             handler->request->proxy,
 847                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 848
 849         /*
 850          *      Do the callback, if it exists, and if it was a success.
 851          */
 852         if (fake &&
 853             handler->request->proxy_reply &&
 854             (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 855                 /*
 856                  *      Terrible hacks.
 857                  */
 858                 rad_assert(fake->packet == NULL);
 859                 fake->packet = request->proxy;
 860                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 861                 request->proxy = NULL;
 862
 863                 rad_assert(fake->reply == NULL);
 864                 fake->reply = request->proxy_reply;
 865                 request->proxy_reply = NULL;
 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
 872                 /*
 873                  *      Perform a post-auth stage for the tunneled
 874                  *      session.
 875                  */
 876                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 877                 rcode = rad_postauth(fake);
 878                 RDEBUG2("post-auth returns %d", rcode);
 879
 880                 if ((debug_flag > 0) && fr_log_fp) {
 881                         fprintf(fr_log_fp, "} # server %s\n",
 882                                 (fake->server == NULL) ? "" : fake->server);
 883
 884                         RDEBUG("Final reply from tunneled session code %d",
 885                                fake->reply->code);
 886                         debug_pair_list(fake->reply->vps);
 887                 }
 888
 889                 /*
 890                  *      Terrible hacks.
 891                  */
 892                 request->proxy = fake->packet;
 893                 fake->packet = NULL;
 894                 request->proxy_reply = fake->reply;
 895                 fake->reply = NULL;
 896
 897                 /*
 898                  *      And we're done with this request.
 899                  */
 900
 901                 switch (rcode) {
 902                 case RLM_MODULE_FAIL:
 903                         request_free(&fake);
 904                         eaptls_fail(handler, 0);
 905                         return 0;
 906                         break;
 907
 908                 default:  /* Don't Do Anything */
 909                         RDEBUG2("Got reply %d",
 910                                request->proxy_reply->code);
 911                         break;
 912                 }
 913         }
 914         request_free(&fake);    /* robust if fake == NULL */
 915
 916         /*
 917          *      Process the reply from the home server.
 918          */
 919         rcode = process_reply(handler, tls_session, handler->request,
 920                               handler->request->proxy_reply);
 921
 922         /*
 923          *      The proxy code uses the reply from the home server as
 924          *      the basis for the reply to the NAS.  We don't want that,
 925          *      so we toss it, after we've had our way with it.
 926          */
 927         pairfree(&handler->request->proxy_reply->vps);
 928
 929         switch (rcode) {
 930         case RLM_MODULE_REJECT:
 931                 RDEBUG("Reply was rejected");
 932                 break;
 933
 934         case RLM_MODULE_HANDLED:
 935                 RDEBUG("Reply was handled");
 936                 eaptls_request(handler->eap_ds, tls_session);
 937                 return 1;
 938
 939         case RLM_MODULE_OK:
 940                 RDEBUG("Reply was OK");
 941
 942                 /*
 943                  *      Success: Automatically return MPPE keys.
 944                  */
 945                 return eaptls_success(handler, 0);
 946
 947         default:
 948                 RDEBUG("Reply was unknown.");
 949                 break;
 950         }
 951
 952         eaptls_fail(handler, 0);
 953         return 0;
 954 }
 955
 956
 957 /*
 958  *      Free a request.
 959  */
 960 static void my_request_free(void *data)
 961 {
 962         REQUEST *request = (REQUEST *)data;
 963
 964         request_free(&request);
 965 }
 966 #endif  /* WITH_PROXY */
 967
 968 /*
 969  *      Process the "diameter" contents of the tunneled data.
 970  */
 971 int eapttls_process(EAP_HANDLER *handler, tls_session_t *tls_session)
 972 {
 973         int rcode = PW_AUTHENTICATION_REJECT;
 974         REQUEST *fake;
 975         VALUE_PAIR *vp;
 976         ttls_tunnel_t *t;
 977         const uint8_t *data;
 978         size_t data_len;
 979         REQUEST *request = handler->request;
 980         eap_chbind_packet_t *chbind_packet;
 981         size_t chbind_len;
 982
 983         rad_assert(request != NULL);
 984
 985         /*
 986          *      Just look at the buffer directly, without doing
 987          *      record_minus.
 988          */
 989         data_len = tls_session->clean_out.used;
 990         tls_session->clean_out.used = 0;
 991         data = tls_session->clean_out.data;
 992
 993         t = (ttls_tunnel_t *) tls_session->opaque;
 994
 995         /*
 996          *      If there's no data, maybe this is an ACK to an
 997          *      MS-CHAP2-Success.
 998          */
 999         if (data_len == 0) {
1000                 if (t->authenticated) {
1001                         RDEBUG("Got ACK, and the user was already authenticated.");
1002                         return PW_AUTHENTICATION_ACK;
1003                 } /* else no session, no data, die. */
1004
1005                 /*
1006                  *      FIXME: Call SSL_get_error() to see what went
1007                  *      wrong.
1008                  */
1009                 RDEBUG2("SSL_read Error");
1010                 return PW_AUTHENTICATION_REJECT;
1011         }
1012
1013 #ifndef NDEBUG
1014         if ((debug_flag > 2) && fr_log_fp) {
1015                 size_t i;
1016
1017                 for (i = 0; i < data_len; i++) {
1018                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
1019
1020                         fprintf(fr_log_fp, "%02x ", data[i]);
1021
1022                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
1023                 }
1024                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
1025         }
1026 #endif
1027
1028         if (!diameter_verify(request, data, data_len)) {
1029                 return PW_AUTHENTICATION_REJECT;
1030         }
1031
1032         /*
1033          *      Allocate a fake REQUEST structe.
1034          */
1035         fake = request_alloc_fake(request);
1036
1037         rad_assert(fake->packet->vps == NULL);
1038
1039         /*
1040          *      Add the tunneled attributes to the fake request.
1041          */
1042         fake->packet->vps = diameter2vp(request, tls_session->ssl, data, data_len);
1043         if (!fake->packet->vps) {
1044                 request_free(&fake);
1045                 return PW_AUTHENTICATION_REJECT;
1046         }
1047
1048         /*
1049          *      Tell the request that it's a fake one.
1050          */
1051         vp = pairmake("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
1052         if (vp) {
1053                 pairadd(&fake->packet->vps, vp);
1054         }
1055
1056         if ((debug_flag > 0) && fr_log_fp) {
1057                 RDEBUG("Got tunneled request");
1058
1059                 debug_pair_list(fake->packet->vps);
1060         }
1061
1062         /*
1063          *      Update other items in the REQUEST data structure.
1064          */
1065         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1066         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY);
1067
1068         /*
1069          *      No User-Name, try to create one from stored data.
1070          */
1071         if (!fake->username) {
1072                 /*
1073                  *      No User-Name in the stored data, look for
1074                  *      an EAP-Identity, and pull it out of there.
1075                  */
1076                 if (!t->username) {
1077                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0, TAG_ANY);
1078                         if (vp &&
1079                             (vp->length >= EAP_HEADER_LEN + 2) &&
1080                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1081                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1082                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1083                                 /*
1084                                  *      Create & remember a User-Name
1085                                  */
1086                                 t->username = pairmake("User-Name", "", T_OP_EQ);
1087                                 rad_assert(t->username != NULL);
1088
1089                                 memcpy(t->username->vp_strvalue, vp->vp_strvalue + 5,
1090                                        vp->length - 5);
1091                                 t->username->length = vp->length - 5;
1092                                 t->username->vp_strvalue[t->username->length] = 0;
1093
1094                                 RDEBUG("Got tunneled identity of %s",
1095                                        t->username->vp_strvalue);
1096
1097                                 /*
1098                                  *      If there's a default EAP type,
1099                                  *      set it here.
1100                                  */
1101                                 if (t->default_eap_type != 0) {
1102                                         RDEBUG("Setting default EAP type for tunneled EAP session.");
1103                                         vp = paircreate(PW_EAP_TYPE, 0);
1104                                         rad_assert(vp != NULL);
1105                                         vp->vp_integer = t->default_eap_type;
1106                                         pairadd(&fake->config_items, vp);
1107                                 }
1108
1109                         } else {
1110                                 /*
1111                                  *      Don't reject the request outright,
1112                                  *      as it's permitted to do EAP without
1113                                  *      user-name.
1114                                  */
1115                                 RDEBUG2W("No EAP-Identity found to start EAP conversation.");
1116                         }
1117                 } /* else there WAS a t->username */
1118
1119                 if (t->username) {
1120                         vp = paircopy(t->username);
1121                         pairadd(&fake->packet->vps, vp);
1122                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0, TAG_ANY);
1123                 }
1124         } /* else the request ALREADY had a User-Name */
1125
1126         /*
1127          *      Add the State attribute, too, if it exists.
1128          */
1129         if (t->state) {
1130                 vp = paircopy(t->state);
1131                 if (vp) pairadd(&fake->packet->vps, vp);
1132         }
1133
1134         /*
1135          *      If this is set, we copy SOME of the request attributes
1136          *      from outside of the tunnel to inside of the tunnel.
1137          *
1138          *      We copy ONLY those attributes which do NOT already
1139          *      exist in the tunneled request.
1140          */
1141         if (t->copy_request_to_tunnel) {
1142                 VALUE_PAIR *copy;
1143
1144                 for (vp = request->packet->vps; vp != NULL; vp = vp->next) {
1145                         /*
1146                          *      The attribute is a server-side thingy,
1147                          *      don't copy it.
1148                          */
1149                         if ((vp->da->attr > 255) &&
1150                             (vp->da->vendor == 0)) {
1151                                 continue;
1152                         }
1153
1154                         /*
1155                          *      The outside attribute is already in the
1156                          *      tunnel, don't copy it.
1157                          *
1158                          *      This works for BOTH attributes which
1159                          *      are originally in the tunneled request,
1160                          *      AND attributes which are copied there
1161                          *      from below.
1162                          */
1163                         if (pairfind(fake->packet->vps, vp->da->attr, vp->da->vendor, TAG_ANY)) {
1164                                 continue;
1165                         }
1166
1167                         /*
1168                          *      Some attributes are handled specially.
1169                          */
1170                         switch (vp->da->attr) {
1171                                 /*
1172                                  *      NEVER copy Message-Authenticator,
1173                                  *      EAP-Message, or State.  They're
1174                                  *      only for outside of the tunnel.
1175                                  */
1176                         case PW_USER_NAME:
1177                         case PW_USER_PASSWORD:
1178                         case PW_CHAP_PASSWORD:
1179                         case PW_CHAP_CHALLENGE:
1180                         case PW_PROXY_STATE:
1181                         case PW_MESSAGE_AUTHENTICATOR:
1182                         case PW_EAP_MESSAGE:
1183                         case PW_STATE:
1184                                 continue;
1185                                 break;
1186
1187                                 /*
1188                                  *      By default, copy it over.
1189                                  */
1190                         default:
1191                                 break;
1192                         }
1193
1194                         /*
1195                          *      Don't copy from the head, we've already
1196                          *      checked it.
1197                          */
1198                         copy = paircopy2(vp, vp->da->attr, vp->da->vendor, TAG_ANY);
1199                         pairadd(&fake->packet->vps, copy);
1200                 }
1201         }
1202
1203         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0, TAG_ANY)) != NULL) {
1204                 fake->server = vp->vp_strvalue;
1205
1206         } else if (t->virtual_server) {
1207                 fake->server = t->virtual_server;
1208
1209         } /* else fake->server == request->server */
1210
1211
1212         if ((debug_flag > 0) && fr_log_fp) {
1213                 RDEBUG("Sending tunneled request");
1214
1215                 debug_pair_list(fake->packet->vps);
1216
1217                 fprintf(fr_log_fp, "server %s {\n",
1218                         (fake->server == NULL) ? "" : fake->server);
1219         }
1220
1221         /*
1222          *      Process channel binding here.
1223          */
1224         chbind_len = eap_chbind_vp2packet(fake->packet->vps, &chbind_packet);
1225         if (chbind_len > 0) {
1226                 CHBIND_REQ *req = chbind_allocate();
1227                 RDEBUG("received chbind request");
1228                 req->chbind_req_pkt = (uint8_t *)chbind_packet;
1229                 req->chbind_req_len = chbind_len;
1230                 if (fake->username) {
1231                         req->username = fake->username->vp_octets;
1232                         req->username_len = fake->username->length;
1233                 } else {
1234                         req->username = NULL;
1235                         req->username_len = 0;
1236                 }
1237                 chbind_process(request, req);
1238
1239                 /* free the chbind packet; we're done with it */
1240                 free(chbind_packet);
1241
1242                 /* encapsulate response here */
1243                 if (req->chbind_resp_len > 0) {
1244                         RDEBUG("sending chbind response");
1245                         pairadd(&fake->reply->vps,
1246                                 eap_chbind_packet2vp((eap_chbind_packet_t *)req->chbind_resp,
1247                                                      req->chbind_resp_len));
1248                 } else {
1249                         RDEBUG("no chbind response");
1250                 }
1251
1252                 /* clean up chbind req */
1253                 chbind_free(req);
1254         }
1255
1256         /*
1257          *      Call authentication recursively, which will
1258          *      do PAP, CHAP, MS-CHAP, etc.
1259          */
1260         rad_virtual_server(fake);
1261
1262         /*
1263          *      Note that we don't do *anything* with the reply
1264          *      attributes.
1265          */
1266         if ((debug_flag > 0) && fr_log_fp) {
1267                 fprintf(fr_log_fp, "} # server %s\n",
1268                         (fake->server == NULL) ? "" : fake->server);
1269
1270                 RDEBUG("Got tunneled reply code %d", fake->reply->code);
1271
1272                 debug_pair_list(fake->reply->vps);
1273         }
1274
1275         /*
1276          *      Decide what to do with the reply.
1277          */
1278         switch (fake->reply->code) {
1279         case 0:                 /* No reply code, must be proxied... */
1280 #ifdef WITH_PROXY
1281           vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0, TAG_ANY);
1282                 if (vp) {
1283                         eap_tunnel_data_t *tunnel;
1284                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1285
1286                         /*
1287                          *      Tell the original request that it's going
1288                          *      to be proxied.
1289                          */
1290                         pairmove2(&(request->config_items),
1291                                   &(fake->config_items),
1292                                   PW_PROXY_TO_REALM, 0, TAG_ANY);
1293
1294                         /*
1295                          *      Seed the proxy packet with the
1296                          *      tunneled request.
1297                          */
1298                         rad_assert(request->proxy == NULL);
1299                         request->proxy = fake->packet;
1300                         memset(&request->proxy->src_ipaddr, 0,
1301                                sizeof(request->proxy->src_ipaddr));
1302                         memset(&request->proxy->src_ipaddr, 0,
1303                                sizeof(request->proxy->src_ipaddr));
1304                         request->proxy->src_port = 0;
1305                         request->proxy->dst_port = 0;
1306                         fake->packet = NULL;
1307                         rad_free(&fake->reply);
1308                         fake->reply = NULL;
1309
1310                         /*
1311                          *      Set up the callbacks for the tunnel
1312                          */
1313                         tunnel = rad_malloc(sizeof(*tunnel));
1314                         memset(tunnel, 0, sizeof(*tunnel));
1315
1316                         tunnel->tls_session = tls_session;
1317                         tunnel->callback = eapttls_postproxy;
1318
1319                         /*
1320                          *      Associate the callback with the request.
1321                          */
1322                         rcode = request_data_add(request,
1323                                                  request->proxy,
1324                                                  REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1325                                                  tunnel, free);
1326                         rad_assert(rcode == 0);
1327
1328                         /*
1329                          *      rlm_eap.c has taken care of associating
1330                          *      the handler with the fake request.
1331                          *
1332                          *      So we associate the fake request with
1333                          *      this request.
1334                          */
1335                         rcode = request_data_add(request,
1336                                                  request->proxy,
1337                                                  REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1338                                                  fake, my_request_free);
1339                         rad_assert(rcode == 0);
1340                         fake = NULL;
1341
1342                         /*
1343                          *      Didn't authenticate the packet, but
1344                          *      we're proxying it.
1345                          */
1346                         rcode = PW_STATUS_CLIENT;
1347
1348                 } else
1349 #endif  /* WITH_PROXY */
1350                   {
1351                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1352                                request->number);
1353                         rcode = PW_AUTHENTICATION_REJECT;
1354                 }
1355                 break;
1356
1357         default:
1358                 /*
1359                  *      Returns RLM_MODULE_FOO, and we want to return
1360                  *      PW_FOO
1361                  */
1362                 rcode = process_reply(handler, tls_session, request,
1363                                       fake->reply);
1364                 switch (rcode) {
1365                 case RLM_MODULE_REJECT:
1366                         rcode = PW_AUTHENTICATION_REJECT;
1367                         break;
1368
1369                 case RLM_MODULE_HANDLED:
1370                         rcode = PW_ACCESS_CHALLENGE;
1371                         break;
1372
1373                 case RLM_MODULE_OK:
1374                         rcode = PW_AUTHENTICATION_ACK;
1375                         break;
1376
1377                 default:
1378                         rcode = PW_AUTHENTICATION_REJECT;
1379                         break;
1380                 }
1381                 break;
1382         }
1383
1384         request_free(&fake);
1385
1386         return rcode;
1387 }