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 offset;
  53         unsigned int data_left = data_len;
  54
  55         while (data_left > 0) {
  56                 if (data_len < 12) {
  57                         RDEBUG2(" Diameter attribute is too small to contain a Diameter header");
  58                         return 0;
  59                 }
  60
  61                 rad_assert(data_left <= data_len);
  62                 memcpy(&attr, data, sizeof(attr));
  63                 data += 4;
  64                 attr = ntohl(attr);
  65                 if (attr > 255) {
  66                         RDEBUG2(" Non-RADIUS attribute in tunneled authentication is not supported");
  67                         return 0;
  68                 }
  69
  70                 memcpy(&length, data , sizeof(length));
  71                 data += 4;
  72                 length = ntohl(length);
  73
  74                 /*
  75                  *      A "vendor" flag, with a vendor ID of zero,
  76                  *      is equivalent to no vendor.  This is stupid.
  77                  */
  78                 offset = 8;
  79                 if ((length & (1 << 31)) != 0) {
  80                         uint32_t vendor;
  81                         DICT_ATTR *da;
  82
  83                         memcpy(&vendor, data, sizeof(vendor));
  84                         vendor = ntohl(vendor);
  85
  86                         if (vendor > FR_MAX_VENDOR) {
  87                                 RDEBUG2("Vendor codes larger than 2^24 are not supported");
  88                                 return 0;
  89                         }
  90
  91                         da = dict_attrbyvalue(attr, vendor);
  92
  93                         /*
  94                          *      SHOULD check ((length & (1 << 30)) != 0)
  95                          *      for the mandatory bit.
  96                          */
  97                         if (!da) {
  98                                 RDEBUG2("Fatal! Vendor %u, Attribute %u was not found in our dictionary. ",
  99                                        vendor, attr);
 100                                 return 0;
 101                         }
 102
 103                         data += 4; /* skip the vendor field */
 104                         offset += 4; /* offset to value field */
 105                 }
 106
 107                 /*
 108                  *      Ignore the M bit.  We support all RADIUS attributes...
 109                  */
 110
 111                 /*
 112                  *      Get the length.  If it's too big, die.
 113                  */
 114                 length &= 0x00ffffff;
 115
 116                 /*
 117                  *      Too short or too long is bad.
 118                  */
 119                 if (length < offset) {
 120                         RDEBUG2("Tunneled attribute %d is too short (%d)to contain anything useful.", attr, length);
 121                         return 0;
 122                 }
 123
 124                 /*
 125                  *      EAP Messages cane be longer than MAX_STRING_LEN.
 126                  *      Other attributes cannot be.
 127                  */
 128                 if ((attr != PW_EAP_MESSAGE) &&
 129                     (length > (MAX_STRING_LEN + 8))) {
 130                         RDEBUG2("Tunneled attribute %d is too long (%d) to pack into a RADIUS attribute.", attr, length);
 131                         return 0;
 132                 }
 133
 134                 if (length > data_left) {
 135                         RDEBUG2("Tunneled attribute %d is longer than room left in the packet (%d > %d).", attr, length, data_left);
 136                         return 0;
 137                 }
 138
 139                 /*
 140                  *      Check for broken implementations, which don't
 141                  *      pad the AVP to a 4-octet boundary.
 142                  */
 143                 if (data_left == length) break;
 144
 145                 /*
 146                  *      The length does NOT include the padding, so
 147                  *      we've got to account for it here by rounding up
 148                  *      to the nearest 4-byte boundary.
 149                  */
 150                 length += 0x03;
 151                 length &= ~0x03;
 152
 153                 /*
 154                  *      If the rest of the diameter packet is larger than
 155                  *      this attribute, continue.
 156                  *
 157                  *      Otherwise, if the attribute over-flows the end
 158                  *      of the packet, die.
 159                  */
 160                 if (data_left < length) {
 161                         RDEBUG2("ERROR! Diameter attribute overflows packet!");
 162                         return 0;
 163                 }
 164
 165                 /*
 166                  *      Check again for equality, now that we're padded
 167                  *      length to a multiple of 4 octets.
 168                  */
 169                 if (data_left == length) break;
 170
 171                 /*
 172                  *      data_left > length, continue.
 173                  */
 174                 data_left -= length;
 175                 data += length - offset;
 176         }
 177
 178         /*
 179          *      We got this far.  It looks OK.
 180          */
 181         return 1;
 182 }
 183
 184
 185 /*
 186  *      Convert diameter attributes to our VALUE_PAIR's
 187  */
 188 static VALUE_PAIR *diameter2vp(REQUEST *request, SSL *ssl,
 189                                const uint8_t *data, size_t data_len)
 190 {
 191         uint32_t        attr;
 192         uint32_t        vendor;
 193         uint32_t        length;
 194         size_t          offset;
 195         size_t          size;
 196         size_t          data_left = data_len;
 197         VALUE_PAIR      *first = NULL;
 198         VALUE_PAIR      **last = &first;
 199         VALUE_PAIR      *vp;
 200
 201         while (data_left > 0) {
 202                 rad_assert(data_left <= data_len);
 203                 memcpy(&attr, data, sizeof(attr));
 204                 data += 4;
 205                 attr = ntohl(attr);
 206                 vendor = 0;
 207
 208                 memcpy(&length, data, sizeof(length));
 209                 data += 4;
 210                 length = ntohl(length);
 211
 212                 /*
 213                  *      A "vendor" flag, with a vendor ID of zero,
 214                  *      is equivalent to no vendor.  This is stupid.
 215                  */
 216                 offset = 8;
 217                 if ((length & (1 << 31)) != 0) {
 218                         memcpy(&vendor, data, sizeof(vendor));
 219                         vendor = ntohl(vendor);
 220
 221                         if (vendor > FR_MAX_VENDOR) {
 222                                 RDEBUG2("Cannot handle vendor Id greater than 2^&24");
 223                                 pairfree(&first);
 224                                 return NULL;
 225                         }
 226
 227                         data += 4; /* skip the vendor field, it's zero */
 228                         offset += 4; /* offset to value field */
 229                 }
 230
 231                 /*
 232                  *      Vendor attributes can be larger than 255.
 233                  *      Normal attributes cannot be.
 234                  */
 235                 if ((attr > 255) && (vendor == 0)) {
 236                         RDEBUG2("Cannot handle Diameter attributes");
 237                         pairfree(&first);
 238                         return NULL;
 239                 }
 240
 241                 /*
 242                  *      FIXME: Handle the M bit.  For now, we assume that
 243                  *      some other module takes care of any attribute
 244                  *      with the M bit set.
 245                  */
 246
 247                 /*
 248                  *      Get the length.
 249                  */
 250                 length &= 0x00ffffff;
 251
 252                 /*
 253                  *      Get the size of the value portion of the
 254                  *      attribute.
 255                  */
 256                 size = length - offset;
 257
 258                 /*
 259                  *      Create it.
 260                  */
 261                 vp = paircreate(attr, vendor, PW_TYPE_OCTETS);
 262                 if (!vp) {
 263                         RDEBUG2("Failure in creating VP");
 264                         pairfree(&first);
 265                         return NULL;
 266                 }
 267                 if (vendor == VENDORPEC_UKERNA) {
 268                         RDEBUG("Received UKERNA attr %d!", attr);
 269                 }
 270
 271                 /*
 272                  *      If it's a type from our dictionary, then
 273                  *      we need to put the data in a relevant place.
 274                  */
 275                 switch (vp->type) {
 276                 case PW_TYPE_INTEGER:
 277                 case PW_TYPE_DATE:
 278                         if (size != vp->length) {
 279                                 RDEBUG2("Invalid length attribute %d",
 280                                        attr);
 281                                 pairfree(&first);
 282                                 pairfree(&vp);
 283                                 return NULL;
 284                         }
 285                         memcpy(&vp->vp_integer, data, vp->length);
 286
 287                         /*
 288                          *      Stored in host byte order: change it.
 289                          */
 290                         vp->vp_integer = ntohl(vp->vp_integer);
 291                         break;
 292
 293                 case PW_TYPE_INTEGER64:
 294                         if (size != vp->length) {
 295                                 RDEBUG2("Invalid length attribute %d",
 296                                        attr);
 297                                 pairfree(&first);
 298                                 pairfree(&vp);
 299                                 return NULL;
 300                         }
 301                         memcpy(&vp->vp_integer64, data, vp->length);
 302
 303                         /*
 304                          *      Stored in host byte order: change it.
 305                          */
 306                         vp->vp_integer64 = ntohll(vp->vp_integer64);
 307                         break;
 308
 309                 case PW_TYPE_IPADDR:
 310                         if (size != vp->length) {
 311                                 RDEBUG2("Invalid length attribute %d",
 312                                        attr);
 313                                 pairfree(&first);
 314                                 pairfree(&vp);
 315                                 return NULL;
 316                         }
 317                   memcpy(&vp->vp_ipaddr, data, vp->length);
 318
 319                   /*
 320                    *    Stored in network byte order: don't change it.
 321                    */
 322                   break;
 323
 324                   /*
 325                    *    String, octet, etc.  Copy the data from the
 326                    *    value field over verbatim.
 327                    *
 328                    *    FIXME: Ipv6 attributes ?
 329                    *
 330                    */
 331                 case PW_TYPE_OCTETS:
 332                         if (attr == PW_EAP_MESSAGE) {
 333                                 const uint8_t *eap_message = data;
 334
 335                                 /*
 336                                  *      vp exists the first time around.
 337                                  */
 338                                 while (1) {
 339                                         vp->length = size;
 340                                         if (vp->length > 253) vp->length = 253;
 341                                         memcpy(vp->vp_octets, eap_message,
 342                                                vp->length);
 343
 344                                         size -= vp->length;
 345                                         eap_message += vp->length;
 346
 347                                         *last = vp;
 348                                         last = &(vp->next);
 349
 350                                         if (size == 0) break;
 351
 352                                         vp = paircreate(attr, vendor, PW_TYPE_OCTETS);
 353                                         if (!vp) {
 354                                                 RDEBUG2("Failure in creating VP");
 355                                                 pairfree(&first);
 356                                                 return NULL;
 357                                         }
 358                                 }
 359
 360                                 goto next_attr;
 361                         } /* else it's another kind of attribute */
 362                         /* FALL-THROUGH */
 363
 364                 default:
 365                         vp->length = size;
 366                         memcpy(vp->vp_strvalue, data, vp->length);
 367                         break;
 368                 }
 369
 370                 /*
 371                  *      User-Password is NUL padded to a multiple
 372                  *      of 16 bytes.  Let's chop it to something
 373                  *      more reasonable.
 374                  *
 375                  *      NOTE: This means that the User-Password
 376                  *      attribute CANNOT EVER have embedded zeros in it!
 377                  */
 378                 switch (vp->attribute) {
 379                 case PW_USER_PASSWORD:
 380                         /*
 381                          *      If the password is exactly 16 octets,
 382                          *      it won't be zero-terminated.
 383                          */
 384                         vp->vp_strvalue[vp->length] = '\0';
 385                         vp->length = strlen(vp->vp_strvalue);
 386                         break;
 387
 388                         /*
 389                          *      Ensure that the client is using the
 390                          *      correct challenge.  This weirdness is
 391                          *      to protect against against replay
 392                          *      attacks, where anyone observing the
 393                          *      CHAP exchange could pose as that user,
 394                          *      by simply choosing to use the same
 395                          *      challenge.
 396                          *
 397                          *      By using a challenge based on
 398                          *      information from the current session,
 399                          *      we can guarantee that the client is
 400                          *      not *choosing* a challenge.
 401                          *
 402                          *      We're a little forgiving in that we
 403                          *      have loose checks on the length, and
 404                          *      we do NOT check the Id (first octet of
 405                          *      the response to the challenge)
 406                          *
 407                          *      But if the client gets the challenge correct,
 408                          *      we're not too worried about the Id.
 409                          */
 410                 case PW_CHAP_CHALLENGE:
 411                 case PW_MSCHAP_CHALLENGE:
 412                         if ((vp->length < 8) ||
 413                             (vp->length > 16)) {
 414                                 RDEBUG("Tunneled challenge has invalid length");
 415                                 pairfree(&first);
 416                                 pairfree(&vp);
 417                                 return NULL;
 418
 419                         } else {
 420                                 uint8_t challenge[16];
 421
 422                                 eapttls_gen_challenge(ssl, challenge,
 423                                                       sizeof(challenge));
 424
 425                                 if (memcmp(challenge, vp->vp_octets,
 426                                            vp->length) != 0) {
 427                                         RDEBUG("Tunneled challenge is incorrect");
 428                                         pairfree(&first);
 429                                         pairfree(&vp);
 430                                         return NULL;
 431                                 }
 432                         }
 433                         break;
 434
 435                 default:
 436                         break;
 437                 } /* switch over checking/re-writing of attributes. */
 438
 439                 /*
 440                  *      Update the list.
 441                  */
 442                 *last = vp;
 443                 last = &(vp->next);
 444
 445         next_attr:
 446                 /*
 447                  *      Catch non-aligned attributes.
 448                  */
 449                 if (data_left == length) break;
 450
 451                 /*
 452                  *      The length does NOT include the padding, so
 453                  *      we've got to account for it here by rounding up
 454                  *      to the nearest 4-byte boundary.
 455                  */
 456                 length += 0x03;
 457                 length &= ~0x03;
 458
 459                 rad_assert(data_left >= length);
 460                 data_left -= length;
 461                 data += length - offset; /* already updated */
 462         }
 463
 464         /*
 465          *      We got this far.  It looks OK.
 466          */
 467         return first;
 468 }
 469
 470 /*
 471  *      Convert VALUE_PAIR's to diameter attributes, and write them
 472  *      to an SSL session.
 473  *
 474  *      The ONLY VALUE_PAIR's which may be passed to this function
 475  *      are ones which can go inside of a RADIUS (i.e. diameter)
 476  *      packet.  So no server-configuration attributes, or the like.
 477  */
 478 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 479 {
 480         /*
 481          *      RADIUS packets are no more than 4k in size, so if
 482          *      we've got more than 4k of data to write, it's very
 483          *      bad.
 484          */
 485         uint8_t         buffer[4096];
 486         uint8_t         *p;
 487         uint32_t        attr;
 488         uint32_t        length;
 489         uint32_t        vendor;
 490         size_t          total;
 491         uint64_t        attr64;
 492         VALUE_PAIR      *vp;
 493
 494         p = buffer;
 495         total = 0;
 496
 497         for (vp = first; vp != NULL; vp = vp->next) {
 498                 /*
 499                  *      Too much data: die.
 500                  */
 501                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 502                         RDEBUG2("output buffer is full!");
 503                         return 0;
 504                 }
 505
 506                 /*
 507                  *      Hmm... we don't group multiple EAP-Messages
 508                  *      together.  Maybe we should...
 509                  */
 510
 511                 /*
 512                  *      Length is no more than 253, due to RADIUS
 513                  *      issues.
 514                  */
 515                 length = vp->length;
 516                 vendor = vp->vendor;
 517                 if (vendor != 0) {
 518                         attr = vp->attribute & 0xffff;
 519                         length |= (1 << 31);
 520                 } else {
 521                         attr = vp->attribute;
 522                 }
 523
 524                 /*
 525                  *      Hmm... set the M bit for all attributes?
 526                  */
 527                 length |= (1 << 30);
 528
 529                 attr = ntohl(attr);
 530
 531                 memcpy(p, &attr, sizeof(attr));
 532                 p += 4;
 533                 total += 4;
 534
 535                 length += 8;    /* includes 8 bytes of attr & length */
 536
 537                 if (vendor != 0) {
 538                         length += 4; /* include 4 bytes of vendor */
 539
 540                         length = ntohl(length);
 541                         memcpy(p, &length, sizeof(length));
 542                         p += 4;
 543                         total += 4;
 544
 545                         vendor = ntohl(vendor);
 546                         memcpy(p, &vendor, sizeof(vendor));
 547                         p += 4;
 548                         total += 4;
 549                 } else {
 550                         length = ntohl(length);
 551                         memcpy(p, &length, sizeof(length));
 552                         p += 4;
 553                         total += 4;
 554                 }
 555
 556                 switch (vp->type) {
 557                 case PW_TYPE_INTEGER:
 558                 case PW_TYPE_DATE:
 559                         attr = htonl(vp->vp_integer); /* stored in host order */
 560                         memcpy(p, &attr, sizeof(attr));
 561                         length = 4;
 562                         break;
 563
 564                 case PW_TYPE_INTEGER64:
 565                         attr64 = htonll(vp->vp_integer64); /* stored in host order */
 566                         memcpy(p, &attr64, sizeof(attr64));
 567                         length = 8;
 568                         break;
 569
 570                 case PW_TYPE_IPADDR:
 571                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 572                         length = 4;
 573                         break;
 574
 575                 case PW_TYPE_STRING:
 576                 case PW_TYPE_OCTETS:
 577                 default:
 578                         memcpy(p, vp->vp_strvalue, vp->length);
 579                         length = vp->length;
 580                         break;
 581                 }
 582
 583                 /*
 584                  *      Skip to the end of the data.
 585                  */
 586                 p += length;
 587                 total += length;
 588
 589                 /*
 590                  *      Align the data to a multiple of 4 bytes.
 591                  */
 592                 if ((total & 0x03) != 0) {
 593                         size_t i;
 594
 595                         length = 4 - (total & 0x03);
 596                         for (i = 0; i < length; i++) {
 597                                 *p = '\0';
 598                                 p++;
 599                                 total++;
 600                         }
 601                 }
 602         } /* loop over the VP's to write. */
 603
 604         /*
 605          *      Write the data in the buffer to the SSL session.
 606          */
 607         if (total > 0) {
 608 #ifndef NDEBUG
 609                 size_t i;
 610
 611                 if ((debug_flag > 2) && fr_log_fp) {
 612                         for (i = 0; i < total; i++) {
 613                                 if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 614
 615                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 616
 617                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 618                         }
 619                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 620                 }
 621 #endif
 622
 623                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 624
 625                 /*
 626                  *      FIXME: Check the return code.
 627                  */
 628                 tls_handshake_send(request, tls_session);
 629         }
 630
 631         /*
 632          *      Everything's OK.
 633          */
 634         return 1;
 635 }
 636
 637 /*
 638  *      Use a reply packet to determine what to do.
 639  */
 640 static int process_reply(EAP_HANDLER *handler, tls_session_t *tls_session,
 641                          REQUEST *request, RADIUS_PACKET *reply)
 642 {
 643         int rcode = RLM_MODULE_REJECT;
 644         VALUE_PAIR *vp;
 645         ttls_tunnel_t *t = tls_session->opaque;
 646
 647         handler = handler;      /* -Wunused */
 648         rad_assert(request != NULL);
 649         rad_assert(handler->request == request);
 650
 651         /*
 652          *      If the response packet was Access-Accept, then
 653          *      we're OK.  If not, die horribly.
 654          *
 655          *      FIXME: Take MS-CHAP2-Success attribute, and
 656          *      tunnel it back to the client, to authenticate
 657          *      ourselves to the client.
 658          *
 659          *      FIXME: If we have an Access-Challenge, then
 660          *      the Reply-Message is tunneled back to the client.
 661          *
 662          *      FIXME: If we have an EAP-Message, then that message
 663          *      must be tunneled back to the client.
 664          *
 665          *      FIXME: If we have an Access-Challenge with a State
 666          *      attribute, then do we tunnel that to the client, or
 667          *      keep track of it ourselves?
 668          *
 669          *      FIXME: EAP-Messages can only start with 'identity',
 670          *      NOT 'eap start', so we should check for that....
 671          */
 672         switch (reply->code) {
 673         case PW_AUTHENTICATION_ACK:
 674                 RDEBUG("Got tunneled Access-Accept");
 675
 676                 rcode = RLM_MODULE_OK;
 677
 678                 /*
 679                  *      MS-CHAP2-Success means that we do NOT return
 680                  *      an Access-Accept, but instead tunnel that
 681                  *      attribute to the client, and keep going with
 682                  *      the TTLS session.  Once the client accepts
 683                  *      our identity, it will respond with an empty
 684                  *      packet, and we will send EAP-Success.
 685                  */
 686                 vp = NULL;
 687                 pairmove2(&vp, &reply->vps, PW_MSCHAP2_SUCCESS, VENDORPEC_MICROSOFT);
 688                 if (vp) {
 689                         RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge.");
 690                         rcode = RLM_MODULE_HANDLED;
 691                         t->authenticated = TRUE;
 692
 693                         /*
 694                          *      Delete MPPE keys & encryption policy.  We don't
 695                          *      want these here.
 696                          */
 697                         pairdelete(&reply->vps, 7, VENDORPEC_MICROSOFT);
 698                         pairdelete(&reply->vps, 8, VENDORPEC_MICROSOFT);
 699                         pairdelete(&reply->vps, 16, VENDORPEC_MICROSOFT);
 700                         pairdelete(&reply->vps, 17, VENDORPEC_MICROSOFT);
 701
 702                         /*
 703                          *      Use the tunneled reply, but not now.
 704                          */
 705                         if (t->use_tunneled_reply) {
 706                                 t->accept_vps = reply->vps;
 707                                 reply->vps = NULL;
 708                         }
 709
 710                 } else { /* no MS-CHAP2-Success */
 711                         /*
 712                          *      Can only have EAP-Message if there's
 713                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 714                          *
 715                          *      We also do NOT tunnel the EAP-Success
 716                          *      attribute back to the client, as the client
 717                          *      can figure it out, from the non-tunneled
 718                          *      EAP-Success packet.
 719                          */
 720                         pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0);
 721                         pairfree(&vp);
 722                 }
 723
 724                 /* move channel binding responses; we need to send them */
 725                 pairmove2(&vp, &reply->vps, PW_UKERNA_CHBIND, VENDORPEC_UKERNA);
 726
 727                 /*
 728                  *      Handle the ACK, by tunneling any necessary reply
 729                  *      VP's back to the client.
 730                  */
 731                 if (vp) {
 732                         RDEBUG("sending tunneled reply attributes");
 733                         debug_pair_list(vp);
 734                         RDEBUG("end tunneled reply attributes");
 735                         vp2diameter(request, tls_session, vp);
 736                         pairfree(&vp);
 737                 }
 738
 739                 /*
 740                  *      If we've been told to use the attributes from
 741                  *      the reply, then do so.
 742                  *
 743                  *      WARNING: This may leak information about the
 744                  *      tunneled user!
 745                  */
 746                 if (t->use_tunneled_reply) {
 747                         pairdelete(&reply->vps, PW_PROXY_STATE, 0);
 748                         pairadd(&request->reply->vps, reply->vps);
 749                         reply->vps = NULL;
 750                 }
 751                 break;
 752
 753
 754         case PW_AUTHENTICATION_REJECT:
 755                 RDEBUG("Got tunneled Access-Reject");
 756                 rcode = RLM_MODULE_REJECT;
 757                 break;
 758
 759                 /*
 760                  *      Handle Access-Challenge, but only if we
 761                  *      send tunneled reply data.  This is because
 762                  *      an Access-Challenge means that we MUST tunnel
 763                  *      a Reply-Message to the client.
 764                  */
 765         case PW_ACCESS_CHALLENGE:
 766                 RDEBUG("Got tunneled Access-Challenge");
 767
 768                 /*
 769                  *      Keep the State attribute, if necessary.
 770                  *
 771                  *      Get rid of the old State, too.
 772                  */
 773                 pairfree(&t->state);
 774                 pairmove2(&t->state, &reply->vps, PW_STATE, 0);
 775
 776                 /*
 777                  *      We should really be a bit smarter about this,
 778                  *      and move over only those attributes which
 779                  *      are relevant to the authentication request,
 780                  *      but that's a lot more work, and this "dumb"
 781                  *      method works in 99.9% of the situations.
 782                  */
 783                 vp = NULL;
 784                 pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0);
 785
 786                 /*
 787                  *      There MUST be a Reply-Message in the challenge,
 788                  *      which we tunnel back to the client.
 789                  *
 790                  *      If there isn't one in the reply VP's, then
 791                  *      we MUST create one, with an empty string as
 792                  *      it's value.
 793                  */
 794                 pairmove2(&vp, &reply->vps, PW_REPLY_MESSAGE, 0);
 795
 796                 /* also move chbind messages, if any */
 797                 pairmove2(&vp, &reply->vps, PW_UKERNA_CHBIND, VENDORPEC_UKERNA);
 798
 799                 /*
 800                  *      Handle the ACK, by tunneling any necessary reply
 801                  *      VP's back to the client.
 802                  */
 803                 if (vp) {
 804                         vp2diameter(request, tls_session, vp);
 805                         pairfree(&vp);
 806                 }
 807                 rcode = RLM_MODULE_HANDLED;
 808                 break;
 809
 810         default:
 811                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 812                 rcode = RLM_MODULE_INVALID;
 813                 break;
 814         }
 815
 816         return rcode;
 817 }
 818
 819
 820 #ifdef WITH_PROXY
 821 /*
 822  *      Do post-proxy processing,
 823  */
 824 static int eapttls_postproxy(EAP_HANDLER *handler, void *data)
 825 {
 826         int rcode;
 827         tls_session_t *tls_session = (tls_session_t *) data;
 828         REQUEST *fake, *request = handler->request;
 829
 830         rad_assert(request != NULL);
 831         RDEBUG("Passing reply from proxy back into the tunnel.");
 832
 833         /*
 834          *      If there was a fake request associated with the proxied
 835          *      request, do more processing of it.
 836          */
 837         fake = (REQUEST *) request_data_get(handler->request,
 838                                             handler->request->proxy,
 839                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 840
 841         /*
 842          *      Do the callback, if it exists, and if it was a success.
 843          */
 844         if (fake && (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 845                 /*
 846                  *      Terrible hacks.
 847                  */
 848                 rad_assert(fake->packet == NULL);
 849                 fake->packet = request->proxy;
 850                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 851                 request->proxy = NULL;
 852
 853                 rad_assert(fake->reply == NULL);
 854                 fake->reply = request->proxy_reply;
 855                 request->proxy_reply = NULL;
 856
 857                 if ((debug_flag > 0) && fr_log_fp) {
 858                         fprintf(fr_log_fp, "server %s {\n",
 859                                 (fake->server == NULL) ? "" : fake->server);
 860                 }
 861
 862                 /*
 863                  *      Perform a post-auth stage for the tunneled
 864                  *      session.
 865                  */
 866                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 867                 rcode = rad_postauth(fake);
 868                 RDEBUG2("post-auth returns %d", rcode);
 869
 870                 if ((debug_flag > 0) && fr_log_fp) {
 871                         fprintf(fr_log_fp, "} # server %s\n",
 872                                 (fake->server == NULL) ? "" : fake->server);
 873
 874                         RDEBUG("Final reply from tunneled session code %d",
 875                                fake->reply->code);
 876                         debug_pair_list(fake->reply->vps);
 877                 }
 878
 879                 /*
 880                  *      Terrible hacks.
 881                  */
 882                 request->proxy = fake->packet;
 883                 fake->packet = NULL;
 884                 request->proxy_reply = fake->reply;
 885                 fake->reply = NULL;
 886
 887                 /*
 888                  *      And we're done with this request.
 889                  */
 890
 891                 switch (rcode) {
 892                 case RLM_MODULE_FAIL:
 893                         request_free(&fake);
 894                         eaptls_fail(handler, 0);
 895                         return 0;
 896                         break;
 897
 898                 default:  /* Don't Do Anything */
 899                         RDEBUG2("Got reply %d",
 900                                request->proxy_reply->code);
 901                         break;
 902                 }
 903         }
 904         request_free(&fake);    /* robust if fake == NULL */
 905
 906         /*
 907          *      Process the reply from the home server.
 908          */
 909         rcode = process_reply(handler, tls_session, handler->request,
 910                               handler->request->proxy_reply);
 911
 912         /*
 913          *      The proxy code uses the reply from the home server as
 914          *      the basis for the reply to the NAS.  We don't want that,
 915          *      so we toss it, after we've had our way with it.
 916          */
 917         pairfree(&handler->request->proxy_reply->vps);
 918
 919         switch (rcode) {
 920         case RLM_MODULE_REJECT:
 921                 RDEBUG("Reply was rejected");
 922                 break;
 923
 924         case RLM_MODULE_HANDLED:
 925                 RDEBUG("Reply was handled");
 926                 eaptls_request(handler->eap_ds, tls_session);
 927                 return 1;
 928
 929         case RLM_MODULE_OK:
 930                 RDEBUG("Reply was OK");
 931
 932                 /*
 933                  *      Success: Automatically return MPPE keys.
 934                  */
 935                 return eaptls_success(handler, 0);
 936
 937         default:
 938                 RDEBUG("Reply was unknown.");
 939                 break;
 940         }
 941
 942         eaptls_fail(handler, 0);
 943         return 0;
 944 }
 945
 946
 947 /*
 948  *      Free a request.
 949  */
 950 static void my_request_free(void *data)
 951 {
 952         REQUEST *request = (REQUEST *)data;
 953
 954         request_free(&request);
 955 }
 956 #endif  /* WITH_PROXY */
 957
 958 /*
 959  *      Process the "diameter" contents of the tunneled data.
 960  */
 961 int eapttls_process(EAP_HANDLER *handler, tls_session_t *tls_session)
 962 {
 963         int rcode = PW_AUTHENTICATION_REJECT;
 964         REQUEST *fake;
 965         VALUE_PAIR *vp;
 966         ttls_tunnel_t *t;
 967         const uint8_t *data;
 968         size_t data_len;
 969         REQUEST *request = handler->request;
 970         eap_chbind_packet_t *chbind_packet;
 971         size_t chbind_len;
 972
 973         rad_assert(request != NULL);
 974
 975         /*
 976          *      Just look at the buffer directly, without doing
 977          *      record_minus.
 978          */
 979         data_len = tls_session->clean_out.used;
 980         tls_session->clean_out.used = 0;
 981         data = tls_session->clean_out.data;
 982
 983         t = (ttls_tunnel_t *) tls_session->opaque;
 984
 985         /*
 986          *      If there's no data, maybe this is an ACK to an
 987          *      MS-CHAP2-Success.
 988          */
 989         if (data_len == 0) {
 990                 if (t->authenticated) {
 991                         RDEBUG("Got ACK, and the user was already authenticated.");
 992                         return PW_AUTHENTICATION_ACK;
 993                 } /* else no session, no data, die. */
 994
 995                 /*
 996                  *      FIXME: Call SSL_get_error() to see what went
 997                  *      wrong.
 998                  */
 999                 RDEBUG2("SSL_read Error");
1000                 return PW_AUTHENTICATION_REJECT;
1001         }
1002
1003 #ifndef NDEBUG
1004         if ((debug_flag > 2) && fr_log_fp) {
1005                 size_t i;
1006
1007                 for (i = 0; i < data_len; i++) {
1008                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
1009
1010                         fprintf(fr_log_fp, "%02x ", data[i]);
1011
1012                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
1013                 }
1014                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
1015         }
1016 #endif
1017
1018         if (!diameter_verify(request, data, data_len)) {
1019                 return PW_AUTHENTICATION_REJECT;
1020         }
1021
1022         /*
1023          *      Allocate a fake REQUEST structe.
1024          */
1025         fake = request_alloc_fake(request);
1026
1027         rad_assert(fake->packet->vps == NULL);
1028
1029         /*
1030          *      Add the tunneled attributes to the fake request.
1031          */
1032         fake->packet->vps = diameter2vp(request, tls_session->ssl, data, data_len);
1033         if (!fake->packet->vps) {
1034                 request_free(&fake);
1035                 return PW_AUTHENTICATION_REJECT;
1036         }
1037
1038         /*
1039          *      Tell the request that it's a fake one.
1040          */
1041         vp = pairmake("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
1042         if (vp) {
1043                 pairadd(&fake->packet->vps, vp);
1044         }
1045
1046         if ((debug_flag > 0) && fr_log_fp) {
1047                 RDEBUG("Got tunneled request");
1048
1049                 debug_pair_list(fake->packet->vps);
1050         }
1051
1052         /*
1053          *      Update other items in the REQUEST data structure.
1054          */
1055         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0);
1056         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0);
1057
1058         /*
1059          *      No User-Name, try to create one from stored data.
1060          */
1061         if (!fake->username) {
1062                 /*
1063                  *      No User-Name in the stored data, look for
1064                  *      an EAP-Identity, and pull it out of there.
1065                  */
1066                 if (!t->username) {
1067                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0);
1068                         if (vp &&
1069                             (vp->length >= EAP_HEADER_LEN + 2) &&
1070                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1071                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1072                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1073                                 /*
1074                                  *      Create & remember a User-Name
1075                                  */
1076                                 t->username = pairmake("User-Name", "", T_OP_EQ);
1077                                 rad_assert(t->username != NULL);
1078
1079                                 memcpy(t->username->vp_strvalue, vp->vp_strvalue + 5,
1080                                        vp->length - 5);
1081                                 t->username->length = vp->length - 5;
1082                                 t->username->vp_strvalue[t->username->length] = 0;
1083
1084                                 RDEBUG("Got tunneled identity of %s",
1085                                        t->username->vp_strvalue);
1086
1087                                 /*
1088                                  *      If there's a default EAP type,
1089                                  *      set it here.
1090                                  */
1091                                 if (t->default_eap_type != 0) {
1092                                         RDEBUG("Setting default EAP type for tunneled EAP session.");
1093                                         vp = paircreate(PW_EAP_TYPE, 0,
1094                                                         PW_TYPE_INTEGER);
1095                                         rad_assert(vp != NULL);
1096                                         vp->vp_integer = t->default_eap_type;
1097                                         pairadd(&fake->config_items, vp);
1098                                 }
1099
1100                         } else {
1101                                 /*
1102                                  *      Don't reject the request outright,
1103                                  *      as it's permitted to do EAP without
1104                                  *      user-name.
1105                                  */
1106                                 RDEBUG2("WARNING! No EAP-Identity found to start EAP conversation.");
1107                         }
1108                 } /* else there WAS a t->username */
1109
1110                 if (t->username) {
1111                         vp = paircopy(t->username);
1112                         pairadd(&fake->packet->vps, vp);
1113                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0);
1114                 }
1115         } /* else the request ALREADY had a User-Name */
1116
1117         /*
1118          *      Add the State attribute, too, if it exists.
1119          */
1120         if (t->state) {
1121                 vp = paircopy(t->state);
1122                 if (vp) pairadd(&fake->packet->vps, vp);
1123         }
1124
1125         /*
1126          *      If this is set, we copy SOME of the request attributes
1127          *      from outside of the tunnel to inside of the tunnel.
1128          *
1129          *      We copy ONLY those attributes which do NOT already
1130          *      exist in the tunneled request.
1131          */
1132         if (t->copy_request_to_tunnel) {
1133                 VALUE_PAIR *copy;
1134
1135                 for (vp = request->packet->vps; vp != NULL; vp = vp->next) {
1136                         /*
1137                          *      The attribute is a server-side thingy,
1138                          *      don't copy it.
1139                          */
1140                         if ((vp->attribute > 255) &&
1141                             (vp->vendor == 0)) {
1142                                 continue;
1143                         }
1144
1145                         /*
1146                          *      The outside attribute is already in the
1147                          *      tunnel, don't copy it.
1148                          *
1149                          *      This works for BOTH attributes which
1150                          *      are originally in the tunneled request,
1151                          *      AND attributes which are copied there
1152                          *      from below.
1153                          */
1154                         if (pairfind(fake->packet->vps, vp->attribute, vp->vendor)) {
1155                                 continue;
1156                         }
1157
1158                         /*
1159                          *      Some attributes are handled specially.
1160                          */
1161                         switch (vp->attribute) {
1162                                 /*
1163                                  *      NEVER copy Message-Authenticator,
1164                                  *      EAP-Message, or State.  They're
1165                                  *      only for outside of the tunnel.
1166                                  */
1167                         case PW_USER_NAME:
1168                         case PW_USER_PASSWORD:
1169                         case PW_CHAP_PASSWORD:
1170                         case PW_CHAP_CHALLENGE:
1171                         case PW_PROXY_STATE:
1172                         case PW_MESSAGE_AUTHENTICATOR:
1173                         case PW_EAP_MESSAGE:
1174                         case PW_STATE:
1175                                 continue;
1176                                 break;
1177
1178                                 /*
1179                                  *      By default, copy it over.
1180                                  */
1181                         default:
1182                                 break;
1183                         }
1184
1185                         /*
1186                          *      Don't copy from the head, we've already
1187                          *      checked it.
1188                          */
1189                         copy = paircopy2(vp, vp->attribute, vp->vendor);
1190                         pairadd(&fake->packet->vps, copy);
1191                 }
1192         }
1193
1194         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0)) != NULL) {
1195                 fake->server = vp->vp_strvalue;
1196
1197         } else if (t->virtual_server) {
1198                 fake->server = t->virtual_server;
1199
1200         } /* else fake->server == request->server */
1201
1202
1203         if ((debug_flag > 0) && fr_log_fp) {
1204                 RDEBUG("Sending tunneled request");
1205
1206                 debug_pair_list(fake->packet->vps);
1207
1208                 fprintf(fr_log_fp, "server %s {\n",
1209                         (fake->server == NULL) ? "" : fake->server);
1210         }
1211
1212         /*
1213          *      Process channel binding here.
1214          */
1215         chbind_len = eap_chbind_vp2packet(fake->packet->vps, &chbind_packet);
1216         if (chbind_len > 0) {
1217                 int chbind_rcode;
1218                 CHBIND_REQ *req = chbind_allocate();
1219
1220                 RDEBUG("received chbind request");
1221                 req->chbind_req_pkt = (uint8_t *)chbind_packet;
1222                 req->chbind_req_len = chbind_len;
1223                 if (fake->username) {
1224                         req->username = fake->username->vp_octets;
1225                         req->username_len = fake->username->length;
1226                 } else {
1227                         req->username = NULL;
1228                         req->username_len = 0;
1229                 }
1230                 chbind_rcode = chbind_process(request, req);
1231
1232                 /* free the chbind packet; we're done with it */
1233                 free(chbind_packet);
1234
1235                 /* encapsulate response here */
1236                 if (req->chbind_resp_len > 0) {
1237                         RDEBUG("sending chbind response");
1238                         pairadd(&fake->reply->vps,
1239                                  eap_chbind_packet2vp((eap_chbind_packet_t *)req->chbind_resp,
1240                                                       req->chbind_resp_len));
1241                 } else {
1242                         RDEBUG("no chbind response");
1243                 }
1244
1245                 /* clean up chbind req */
1246                 chbind_free(req);
1247
1248                 if (chbind_rcode != PW_AUTHENTICATION_ACK)
1249                         return chbind_rcode;
1250         }
1251
1252         /*
1253          *      Call authentication recursively, which will
1254          *      do PAP, CHAP, MS-CHAP, etc.
1255          */
1256         rad_authenticate(fake);
1257
1258         /*
1259          *      Note that we don't do *anything* with the reply
1260          *      attributes.
1261          */
1262         if ((debug_flag > 0) && fr_log_fp) {
1263                 fprintf(fr_log_fp, "} # server %s\n",
1264                         (fake->server == NULL) ? "" : fake->server);
1265
1266                 RDEBUG("Got tunneled reply code %d", fake->reply->code);
1267
1268                 debug_pair_list(fake->reply->vps);
1269         }
1270
1271         /*
1272          *      Decide what to do with the reply.
1273          */
1274         switch (fake->reply->code) {
1275         case 0:                 /* No reply code, must be proxied... */
1276 #ifdef WITH_PROXY
1277           vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0);
1278                 if (vp) {
1279                         eap_tunnel_data_t *tunnel;
1280                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1281
1282                         /*
1283                          *      Tell the original request that it's going
1284                          *      to be proxied.
1285                          */
1286                         pairmove2(&(request->config_items),
1287                                   &(fake->config_items),
1288                                   PW_PROXY_TO_REALM, 0);
1289
1290                         /*
1291                          *      Seed the proxy packet with the
1292                          *      tunneled request.
1293                          */
1294                         rad_assert(request->proxy == NULL);
1295                         request->proxy = fake->packet;
1296                         memset(&request->proxy->src_ipaddr, 0,
1297                                sizeof(request->proxy->src_ipaddr));
1298                         memset(&request->proxy->src_ipaddr, 0,
1299                                sizeof(request->proxy->src_ipaddr));
1300                         request->proxy->src_port = 0;
1301                         request->proxy->dst_port = 0;
1302                         fake->packet = NULL;
1303                         rad_free(&fake->reply);
1304                         fake->reply = NULL;
1305
1306                         /*
1307                          *      Set up the callbacks for the tunnel
1308                          */
1309                         tunnel = rad_malloc(sizeof(*tunnel));
1310                         memset(tunnel, 0, sizeof(*tunnel));
1311
1312                         tunnel->tls_session = tls_session;
1313                         tunnel->callback = eapttls_postproxy;
1314
1315                         /*
1316                          *      Associate the callback with the request.
1317                          */
1318                         rcode = request_data_add(request,
1319                                                  request->proxy,
1320                                                  REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1321                                                  tunnel, free);
1322                         rad_assert(rcode == 0);
1323
1324                         /*
1325                          *      rlm_eap.c has taken care of associating
1326                          *      the handler with the fake request.
1327                          *
1328                          *      So we associate the fake request with
1329                          *      this request.
1330                          */
1331                         rcode = request_data_add(request,
1332                                                  request->proxy,
1333                                                  REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1334                                                  fake, my_request_free);
1335                         rad_assert(rcode == 0);
1336                         fake = NULL;
1337
1338                         /*
1339                          *      Didn't authenticate the packet, but
1340                          *      we're proxying it.
1341                          */
1342                         rcode = PW_STATUS_CLIENT;
1343
1344                 } else
1345 #endif  /* WITH_PROXY */
1346                   {
1347                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1348                                request->number);
1349                         rcode = PW_AUTHENTICATION_REJECT;
1350                 }
1351                 break;
1352
1353         default:
1354                 /*
1355                  *      Returns RLM_MODULE_FOO, and we want to return
1356                  *      PW_FOO
1357                  */
1358                 rcode = process_reply(handler, tls_session, request,
1359                                       fake->reply);
1360                 switch (rcode) {
1361                 case RLM_MODULE_REJECT:
1362                         rcode = PW_AUTHENTICATION_REJECT;
1363                         break;
1364
1365                 case RLM_MODULE_HANDLED:
1366                         rcode = PW_ACCESS_CHALLENGE;
1367                         break;
1368
1369                 case RLM_MODULE_OK:
1370                         rcode = PW_AUTHENTICATION_ACK;
1371                         break;
1372
1373                 default:
1374                         rcode = PW_AUTHENTICATION_REJECT;
1375                         break;
1376                 }
1377                 break;
1378         }
1379
1380         request_free(&fake);
1381
1382         return rcode;
1383 }