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

   1 /*
   2  * rlm_eap_ttls.c  contains the interfaces that are called from eap
   3  *
   4  * Version:     $Id$
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  *   Copyright 2003 Alan DeKok <aland@freeradius.org>
  21  *   Copyright 2006 The FreeRADIUS server project
  22  */
  23
  24 #include <freeradius-devel/ident.h>
  25 RCSID("$Id$")
  26
  27 #include "eap_ttls.h"
  28
  29 /*
  30  *    0                   1                   2                   3
  31  *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  32  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  33  *   |                           AVP Code                            |
  34  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  35  *   |V M r r r r r r|                  AVP Length                   |
  36  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  37  *   |                        Vendor-ID (opt)                        |
  38  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  39  *   |    Data ...
  40  *   +-+-+-+-+-+-+-+-+
  41  */
  42
  43 /*
  44  *      Verify that the diameter packet is valid.
  45  */
  46 static int diameter_verify(REQUEST *request,
  47                            const uint8_t *data, unsigned int data_len)
  48 {
  49         uint32_t attr;
  50         uint32_t length;
  51         unsigned int offset;
  52         unsigned int data_left = data_len;
  53
  54         while (data_left > 0) {
  55                 if (data_len < 12) {
  56                         RDEBUG2(" Diameter attribute is too small to contain a Diameter header");
  57                         return 0;
  58                 }
  59
  60                 rad_assert(data_left <= data_len);
  61                 memcpy(&attr, data, sizeof(attr));
  62                 data += 4;
  63                 attr = ntohl(attr);
  64                 if (attr > 255) {
  65                         RDEBUG2(" Non-RADIUS attribute in tunneled authentication is not supported");
  66                         return 0;
  67                 }
  68
  69                 memcpy(&length, data , sizeof(length));
  70                 data += 4;
  71                 length = ntohl(length);
  72
  73                 /*
  74                  *      A "vendor" flag, with a vendor ID of zero,
  75                  *      is equivalent to no vendor.  This is stupid.
  76                  */
  77                 offset = 8;
  78                 if ((length & (1 << 31)) != 0) {
  79                         uint32_t vendor;
  80                         DICT_ATTR *da;
  81
  82                         memcpy(&vendor, data, sizeof(vendor));
  83                         vendor = ntohl(vendor);
  84
  85                         if (vendor > FR_MAX_VENDOR) {
  86                                 RDEBUG2("Vendor codes larger than 2^24 are not supported");
  87                                 return 0;
  88                         }
  89
  90                         da = dict_attrbyvalue(attr, vendor);
  91
  92                         /*
  93                          *      SHOULD check ((length & (1 << 30)) != 0)
  94                          *      for the mandatory bit.
  95                          */
  96                         if (!da) {
  97                                 RDEBUG2("Fatal! Vendor %u, Attribute %u was not found in our dictionary. ",
  98                                        vendor, attr);
  99                                 return 0;
 100                         }
 101
 102                         data += 4; /* skip the vendor field */
 103                         offset += 4; /* offset to value field */
 104                 }
 105
 106                 /*
 107                  *      Ignore the M bit.  We support all RADIUS attributes...
 108                  */
 109
 110                 /*
 111                  *      Get the length.  If it's too big, die.
 112                  */
 113                 length &= 0x00ffffff;
 114
 115                 /*
 116                  *      Too short or too long is bad.
 117                  */
 118                 if (length < offset) {
 119                         RDEBUG2("Tunneled attribute %d is too short (%d)to contain anything useful.", attr, length);
 120                         return 0;
 121                 }
 122
 123                 /*
 124                  *      EAP Messages cane be longer than MAX_STRING_LEN.
 125                  *      Other attributes cannot be.
 126                  */
 127                 if ((attr != PW_EAP_MESSAGE) &&
 128                     (length > (MAX_STRING_LEN + 8))) {
 129                         RDEBUG2("Tunneled attribute %d is too long (%d) to pack into a RADIUS attribute.", attr, length);
 130                         return 0;
 131                 }
 132
 133                 if (length > data_left) {
 134                         RDEBUG2("Tunneled attribute %d is longer than room left in the packet (%d > %d).", attr, length, data_left);
 135                         return 0;
 136                 }
 137
 138                 /*
 139                  *      Check for broken implementations, which don't
 140                  *      pad the AVP to a 4-octet boundary.
 141                  */
 142                 if (data_left == length) break;
 143
 144                 /*
 145                  *      The length does NOT include the padding, so
 146                  *      we've got to account for it here by rounding up
 147                  *      to the nearest 4-byte boundary.
 148                  */
 149                 length += 0x03;
 150                 length &= ~0x03;
 151
 152                 /*
 153                  *      If the rest of the diameter packet is larger than
 154                  *      this attribute, continue.
 155                  *
 156                  *      Otherwise, if the attribute over-flows the end
 157                  *      of the packet, die.
 158                  */
 159                 if (data_left < length) {
 160                         RDEBUG2("ERROR! Diameter attribute overflows packet!");
 161                         return 0;
 162                 }
 163
 164                 /*
 165                  *      Check again for equality, now that we're padded
 166                  *      length to a multiple of 4 octets.
 167                  */
 168                 if (data_left == length) break;
 169
 170                 /*
 171                  *      data_left > length, continue.
 172                  */
 173                 data_left -= length;
 174                 data += length - offset;
 175         }
 176
 177         /*
 178          *      We got this far.  It looks OK.
 179          */
 180         return 1;
 181 }
 182
 183
 184 /*
 185  *      Convert diameter attributes to our VALUE_PAIR's
 186  */
 187 static VALUE_PAIR *diameter2vp(REQUEST *request, SSL *ssl,
 188                                const uint8_t *data, size_t data_len)
 189 {
 190         uint32_t        attr;
 191         uint32_t        vendor;
 192         uint32_t        length;
 193         size_t          offset;
 194         size_t          size;
 195         size_t          data_left = data_len;
 196         VALUE_PAIR      *first = NULL;
 197         VALUE_PAIR      **last = &first;
 198         VALUE_PAIR      *vp;
 199
 200         while (data_left > 0) {
 201                 rad_assert(data_left <= data_len);
 202                 memcpy(&attr, data, sizeof(attr));
 203                 data += 4;
 204                 attr = ntohl(attr);
 205                 vendor = 0;
 206
 207                 memcpy(&length, data, sizeof(length));
 208                 data += 4;
 209                 length = ntohl(length);
 210
 211                 /*
 212                  *      A "vendor" flag, with a vendor ID of zero,
 213                  *      is equivalent to no vendor.  This is stupid.
 214                  */
 215                 offset = 8;
 216                 if ((length & (1 << 31)) != 0) {
 217                         memcpy(&vendor, data, sizeof(vendor));
 218                         vendor = ntohl(vendor);
 219
 220                         if (vendor > FR_MAX_VENDOR) {
 221                                 RDEBUG2("Cannot handle vendor Id greater than 2^&24");
 222                                 pairfree(&first);
 223                                 return NULL;
 224                         }
 225
 226                         data += 4; /* skip the vendor field, it's zero */
 227                         offset += 4; /* offset to value field */
 228                 }
 229
 230                 /*
 231                  *      Vendor attributes can be larger than 255.
 232                  *      Normal attributes cannot be.
 233                  */
 234                 if ((attr > 255) && (vendor == 0)) {
 235                         RDEBUG2("Cannot handle Diameter attributes");
 236                         pairfree(&first);
 237                         return NULL;
 238                 }
 239
 240                 /*
 241                  *      FIXME: Handle the M bit.  For now, we assume that
 242                  *      some other module takes care of any attribute
 243                  *      with the M bit set.
 244                  */
 245
 246                 /*
 247                  *      Get the length.
 248                  */
 249                 length &= 0x00ffffff;
 250
 251                 /*
 252                  *      Get the size of the value portion of the
 253                  *      attribute.
 254                  */
 255                 size = length - offset;
 256
 257                 /*
 258                  *      Create it.
 259                  */
 260                 vp = paircreate(attr, vendor, PW_TYPE_OCTETS);
 261                 if (!vp) {
 262                         RDEBUG2("Failure in creating VP");
 263                         pairfree(&first);
 264                         return NULL;
 265                 }
 266
 267                 /*
 268                  *      If it's a type from our dictionary, then
 269                  *      we need to put the data in a relevant place.
 270                  */
 271                 switch (vp->type) {
 272                 case PW_TYPE_INTEGER:
 273                 case PW_TYPE_DATE:
 274                         if (size != vp->length) {
 275                                 RDEBUG2("Invalid length attribute %d",
 276                                        attr);
 277                                 pairfree(&first);
 278                                 pairfree(&vp);
 279                                 return NULL;
 280                         }
 281                         memcpy(&vp->vp_integer, data, vp->length);
 282
 283                         /*
 284                          *      Stored in host byte order: change it.
 285                          */
 286                         vp->vp_integer = ntohl(vp->vp_integer);
 287                         break;
 288
 289                 case PW_TYPE_IPADDR:
 290                         if (size != vp->length) {
 291                                 RDEBUG2("Invalid length attribute %d",
 292                                        attr);
 293                                 pairfree(&first);
 294                                 pairfree(&vp);
 295                                 return NULL;
 296                         }
 297                   memcpy(&vp->vp_ipaddr, data, vp->length);
 298
 299                   /*
 300                    *    Stored in network byte order: don't change it.
 301                    */
 302                   break;
 303
 304                   /*
 305                    *    String, octet, etc.  Copy the data from the
 306                    *    value field over verbatim.
 307                    *
 308                    *    FIXME: Ipv6 attributes ?
 309                    *
 310                    */
 311                 case PW_TYPE_OCTETS:
 312                         if (attr == PW_EAP_MESSAGE) {
 313                                 const uint8_t *eap_message = data;
 314
 315                                 /*
 316                                  *      vp exists the first time around.
 317                                  */
 318                                 while (1) {
 319                                         vp->length = size;
 320                                         if (vp->length > 253) vp->length = 253;
 321                                         memcpy(vp->vp_octets, eap_message,
 322                                                vp->length);
 323
 324                                         size -= vp->length;
 325                                         eap_message += vp->length;
 326
 327                                         *last = vp;
 328                                         last = &(vp->next);
 329
 330                                         if (size == 0) break;
 331
 332                                         vp = paircreate(attr, vendor, PW_TYPE_OCTETS);
 333                                         if (!vp) {
 334                                                 RDEBUG2("Failure in creating VP");
 335                                                 pairfree(&first);
 336                                                 return NULL;
 337                                         }
 338                                 }
 339
 340                                 goto next_attr;
 341                         } /* else it's another kind of attribute */
 342                         /* FALL-THROUGH */
 343
 344                 default:
 345                         vp->length = size;
 346                         memcpy(vp->vp_strvalue, data, vp->length);
 347                         break;
 348                 }
 349
 350                 /*
 351                  *      User-Password is NUL padded to a multiple
 352                  *      of 16 bytes.  Let's chop it to something
 353                  *      more reasonable.
 354                  *
 355                  *      NOTE: This means that the User-Password
 356                  *      attribute CANNOT EVER have embedded zeros in it!
 357                  */
 358                 switch (vp->attribute) {
 359                 case PW_USER_PASSWORD:
 360                         /*
 361                          *      If the password is exactly 16 octets,
 362                          *      it won't be zero-terminated.
 363                          */
 364                         vp->vp_strvalue[vp->length] = '\0';
 365                         vp->length = strlen(vp->vp_strvalue);
 366                         break;
 367
 368                         /*
 369                          *      Ensure that the client is using the
 370                          *      correct challenge.  This weirdness is
 371                          *      to protect against against replay
 372                          *      attacks, where anyone observing the
 373                          *      CHAP exchange could pose as that user,
 374                          *      by simply choosing to use the same
 375                          *      challenge.
 376                          *
 377                          *      By using a challenge based on
 378                          *      information from the current session,
 379                          *      we can guarantee that the client is
 380                          *      not *choosing* a challenge.
 381                          *
 382                          *      We're a little forgiving in that we
 383                          *      have loose checks on the length, and
 384                          *      we do NOT check the Id (first octet of
 385                          *      the response to the challenge)
 386                          *
 387                          *      But if the client gets the challenge correct,
 388                          *      we're not too worried about the Id.
 389                          */
 390                 case PW_CHAP_CHALLENGE:
 391                 case PW_MSCHAP_CHALLENGE:
 392                         if ((vp->length < 8) ||
 393                             (vp->length > 16)) {
 394                                 RDEBUG("Tunneled challenge has invalid length");
 395                                 pairfree(&first);
 396                                 pairfree(&vp);
 397                                 return NULL;
 398
 399                         } else {
 400                                 uint8_t challenge[16];
 401
 402                                 eapttls_gen_challenge(ssl, challenge,
 403                                                       sizeof(challenge));
 404
 405                                 if (memcmp(challenge, vp->vp_octets,
 406                                            vp->length) != 0) {
 407                                         RDEBUG("Tunneled challenge is incorrect");
 408                                         pairfree(&first);
 409                                         pairfree(&vp);
 410                                         return NULL;
 411                                 }
 412                         }
 413                         break;
 414
 415                 default:
 416                         break;
 417                 } /* switch over checking/re-writing of attributes. */
 418
 419                 /*
 420                  *      Update the list.
 421                  */
 422                 *last = vp;
 423                 last = &(vp->next);
 424
 425         next_attr:
 426                 /*
 427                  *      Catch non-aligned attributes.
 428                  */
 429                 if (data_left == length) break;
 430
 431                 /*
 432                  *      The length does NOT include the padding, so
 433                  *      we've got to account for it here by rounding up
 434                  *      to the nearest 4-byte boundary.
 435                  */
 436                 length += 0x03;
 437                 length &= ~0x03;
 438
 439                 rad_assert(data_left >= length);
 440                 data_left -= length;
 441                 data += length - offset; /* already updated */
 442         }
 443
 444         /*
 445          *      We got this far.  It looks OK.
 446          */
 447         return first;
 448 }
 449
 450 /*
 451  *      Convert VALUE_PAIR's to diameter attributes, and write them
 452  *      to an SSL session.
 453  *
 454  *      The ONLY VALUE_PAIR's which may be passed to this function
 455  *      are ones which can go inside of a RADIUS (i.e. diameter)
 456  *      packet.  So no server-configuration attributes, or the like.
 457  */
 458 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 459 {
 460         /*
 461          *      RADIUS packets are no more than 4k in size, so if
 462          *      we've got more than 4k of data to write, it's very
 463          *      bad.
 464          */
 465         uint8_t         buffer[4096];
 466         uint8_t         *p;
 467         uint32_t        attr;
 468         uint32_t        length;
 469         uint32_t        vendor;
 470         size_t          total;
 471         VALUE_PAIR      *vp;
 472
 473         p = buffer;
 474         total = 0;
 475
 476         for (vp = first; vp != NULL; vp = vp->next) {
 477                 /*
 478                  *      Too much data: die.
 479                  */
 480                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 481                         RDEBUG2("output buffer is full!");
 482                         return 0;
 483                 }
 484
 485                 /*
 486                  *      Hmm... we don't group multiple EAP-Messages
 487                  *      together.  Maybe we should...
 488                  */
 489
 490                 /*
 491                  *      Length is no more than 253, due to RADIUS
 492                  *      issues.
 493                  */
 494                 length = vp->length;
 495                 vendor = vp->vendor;
 496                 if (vendor != 0) {
 497                         attr = vp->attribute & 0xffff;
 498                         length |= (1 << 31);
 499                 } else {
 500                         attr = vp->attribute;
 501                 }
 502
 503                 /*
 504                  *      Hmm... set the M bit for all attributes?
 505                  */
 506                 length |= (1 << 30);
 507
 508                 attr = ntohl(attr);
 509
 510                 memcpy(p, &attr, sizeof(attr));
 511                 p += 4;
 512                 total += 4;
 513
 514                 length += 8;    /* includes 8 bytes of attr & length */
 515
 516                 if (vendor != 0) {
 517                         length += 4; /* include 4 bytes of vendor */
 518
 519                         length = ntohl(length);
 520                         memcpy(p, &length, sizeof(length));
 521                         p += 4;
 522                         total += 4;
 523
 524                         vendor = ntohl(vendor);
 525                         memcpy(p, &vendor, sizeof(vendor));
 526                         p += 4;
 527                         total += 4;
 528                 } else {
 529                         length = ntohl(length);
 530                         memcpy(p, &length, sizeof(length));
 531                         p += 4;
 532                         total += 4;
 533                 }
 534
 535                 switch (vp->type) {
 536                 case PW_TYPE_INTEGER:
 537                 case PW_TYPE_DATE:
 538                         attr = ntohl(vp->vp_integer); /* stored in host order */
 539                         memcpy(p, &attr, sizeof(attr));
 540                         length = 4;
 541                         break;
 542
 543                 case PW_TYPE_IPADDR:
 544                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 545                         length = 4;
 546                         break;
 547
 548                 case PW_TYPE_STRING:
 549                 case PW_TYPE_OCTETS:
 550                 default:
 551                         memcpy(p, vp->vp_strvalue, vp->length);
 552                         length = vp->length;
 553                         break;
 554                 }
 555
 556                 /*
 557                  *      Skip to the end of the data.
 558                  */
 559                 p += length;
 560                 total += length;
 561
 562                 /*
 563                  *      Align the data to a multiple of 4 bytes.
 564                  */
 565                 if ((total & 0x03) != 0) {
 566                         size_t i;
 567
 568                         length = 4 - (total & 0x03);
 569                         for (i = 0; i < length; i++) {
 570                                 *p = '\0';
 571                                 p++;
 572                                 total++;
 573                         }
 574                 }
 575         } /* loop over the VP's to write. */
 576
 577         /*
 578          *      Write the data in the buffer to the SSL session.
 579          */
 580         if (total > 0) {
 581 #ifndef NDEBUG
 582                 size_t i;
 583
 584                 if ((debug_flag > 2) && fr_log_fp) {
 585                         for (i = 0; i < total; i++) {
 586                                 if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 587
 588                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 589
 590                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 591                         }
 592                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 593                 }
 594 #endif
 595
 596                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 597
 598                 /*
 599                  *      FIXME: Check the return code.
 600                  */
 601                 tls_handshake_send(request, tls_session);
 602         }
 603
 604         /*
 605          *      Everything's OK.
 606          */
 607         return 1;
 608 }
 609
 610 /*
 611  *      Use a reply packet to determine what to do.
 612  */
 613 static int process_reply(EAP_HANDLER *handler, tls_session_t *tls_session,
 614                          REQUEST *request, RADIUS_PACKET *reply)
 615 {
 616         int rcode = RLM_MODULE_REJECT;
 617         VALUE_PAIR *vp;
 618         ttls_tunnel_t *t = tls_session->opaque;
 619
 620         handler = handler;      /* -Wunused */
 621
 622         /*
 623          *      If the response packet was Access-Accept, then
 624          *      we're OK.  If not, die horribly.
 625          *
 626          *      FIXME: Take MS-CHAP2-Success attribute, and
 627          *      tunnel it back to the client, to authenticate
 628          *      ourselves to the client.
 629          *
 630          *      FIXME: If we have an Access-Challenge, then
 631          *      the Reply-Message is tunneled back to the client.
 632          *
 633          *      FIXME: If we have an EAP-Message, then that message
 634          *      must be tunneled back to the client.
 635          *
 636          *      FIXME: If we have an Access-Challenge with a State
 637          *      attribute, then do we tunnel that to the client, or
 638          *      keep track of it ourselves?
 639          *
 640          *      FIXME: EAP-Messages can only start with 'identity',
 641          *      NOT 'eap start', so we should check for that....
 642          */
 643         switch (reply->code) {
 644         case PW_AUTHENTICATION_ACK:
 645                 RDEBUG("Got tunneled Access-Accept");
 646
 647                 rcode = RLM_MODULE_OK;
 648
 649                 /*
 650                  *      MS-CHAP2-Success means that we do NOT return
 651                  *      an Access-Accept, but instead tunnel that
 652                  *      attribute to the client, and keep going with
 653                  *      the TTLS session.  Once the client accepts
 654                  *      our identity, it will respond with an empty
 655                  *      packet, and we will send EAP-Success.
 656                  */
 657                 vp = NULL;
 658                 pairmove2(&vp, &reply->vps, PW_MSCHAP2_SUCCESS, VENDORPEC_MICROSOFT);
 659                 if (vp) {
 660                         RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge.");
 661                         rcode = RLM_MODULE_HANDLED;
 662                         t->authenticated = TRUE;
 663
 664                         /*
 665                          *      Delete MPPE keys & encryption policy.  We don't
 666                          *      want these here.
 667                          */
 668                         pairdelete(&reply->vps, 7, VENDORPEC_MICROSOFT);
 669                         pairdelete(&reply->vps, 8, VENDORPEC_MICROSOFT);
 670                         pairdelete(&reply->vps, 16, VENDORPEC_MICROSOFT);
 671                         pairdelete(&reply->vps, 17, VENDORPEC_MICROSOFT);
 672
 673                         /*
 674                          *      Use the tunneled reply, but not now.
 675                          */
 676                         if (t->use_tunneled_reply) {
 677                                 t->accept_vps = reply->vps;
 678                                 reply->vps = NULL;
 679                         }
 680
 681                 } else { /* no MS-CHAP2-Success */
 682                         /*
 683                          *      Can only have EAP-Message if there's
 684                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 685                          *
 686                          *      We also do NOT tunnel the EAP-Success
 687                          *      attribute back to the client, as the client
 688                          *      can figure it out, from the non-tunneled
 689                          *      EAP-Success packet.
 690                          */
 691                         pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0);
 692                         pairfree(&vp);
 693                 }
 694
 695                 /*
 696                  *      Handle the ACK, by tunneling any necessary reply
 697                  *      VP's back to the client.
 698                  */
 699                 if (vp) {
 700                         vp2diameter(request, tls_session, vp);
 701                         pairfree(&vp);
 702                 }
 703
 704                 /*
 705                  *      If we've been told to use the attributes from
 706                  *      the reply, then do so.
 707                  *
 708                  *      WARNING: This may leak information about the
 709                  *      tunneled user!
 710                  */
 711                 if (t->use_tunneled_reply) {
 712                         pairdelete(&reply->vps, PW_PROXY_STATE, 0);
 713                         pairadd(&request->reply->vps, reply->vps);
 714                         reply->vps = NULL;
 715                 }
 716                 break;
 717
 718
 719         case PW_AUTHENTICATION_REJECT:
 720                 RDEBUG("Got tunneled Access-Reject");
 721                 rcode = RLM_MODULE_REJECT;
 722                 break;
 723
 724                 /*
 725                  *      Handle Access-Challenge, but only if we
 726                  *      send tunneled reply data.  This is because
 727                  *      an Access-Challenge means that we MUST tunnel
 728                  *      a Reply-Message to the client.
 729                  */
 730         case PW_ACCESS_CHALLENGE:
 731                 RDEBUG("Got tunneled Access-Challenge");
 732
 733                 /*
 734                  *      Keep the State attribute, if necessary.
 735                  *
 736                  *      Get rid of the old State, too.
 737                  */
 738                 pairfree(&t->state);
 739                 pairmove2(&t->state, &reply->vps, PW_STATE, 0);
 740
 741                 /*
 742                  *      We should really be a bit smarter about this,
 743                  *      and move over only those attributes which
 744                  *      are relevant to the authentication request,
 745                  *      but that's a lot more work, and this "dumb"
 746                  *      method works in 99.9% of the situations.
 747                  */
 748                 vp = NULL;
 749                 pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0);
 750
 751                 /*
 752                  *      There MUST be a Reply-Message in the challenge,
 753                  *      which we tunnel back to the client.
 754                  *
 755                  *      If there isn't one in the reply VP's, then
 756                  *      we MUST create one, with an empty string as
 757                  *      it's value.
 758                  */
 759                 pairmove2(&vp, &reply->vps, PW_REPLY_MESSAGE, 0);
 760
 761                 /*
 762                  *      Handle the ACK, by tunneling any necessary reply
 763                  *      VP's back to the client.
 764                  */
 765                 if (vp) {
 766                         vp2diameter(request, tls_session, vp);
 767                         pairfree(&vp);
 768                 }
 769                 rcode = RLM_MODULE_HANDLED;
 770                 break;
 771
 772         default:
 773                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 774                 rcode = RLM_MODULE_INVALID;
 775                 break;
 776         }
 777
 778         return rcode;
 779 }
 780
 781
 782 #ifdef WITH_PROXY
 783 /*
 784  *      Do post-proxy processing,
 785  */
 786 static int eapttls_postproxy(EAP_HANDLER *handler, void *data)
 787 {
 788         int rcode;
 789         tls_session_t *tls_session = (tls_session_t *) data;
 790         REQUEST *fake, *request = handler->request;
 791
 792         RDEBUG("Passing reply from proxy back into the tunnel.");
 793
 794         /*
 795          *      If there was a fake request associated with the proxied
 796          *      request, do more processing of it.
 797          */
 798         fake = (REQUEST *) request_data_get(handler->request,
 799                                             handler->request->proxy,
 800                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 801
 802         /*
 803          *      Do the callback, if it exists, and if it was a success.
 804          */
 805         if (fake && (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 806                 /*
 807                  *      Terrible hacks.
 808                  */
 809                 rad_assert(fake->packet == NULL);
 810                 fake->packet = request->proxy;
 811                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 812                 request->proxy = NULL;
 813
 814                 rad_assert(fake->reply == NULL);
 815                 fake->reply = request->proxy_reply;
 816                 request->proxy_reply = NULL;
 817
 818                 if ((debug_flag > 0) && fr_log_fp) {
 819                         fprintf(fr_log_fp, "server %s {\n",
 820                                 (fake->server == NULL) ? "" : fake->server);
 821                 }
 822
 823                 /*
 824                  *      Perform a post-auth stage for the tunneled
 825                  *      session.
 826                  */
 827                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 828                 rcode = rad_postauth(fake);
 829                 RDEBUG2("post-auth returns %d", rcode);
 830
 831                 if ((debug_flag > 0) && fr_log_fp) {
 832                         fprintf(fr_log_fp, "} # server %s\n",
 833                                 (fake->server == NULL) ? "" : fake->server);
 834
 835                         RDEBUG("Final reply from tunneled session code %d",
 836                                fake->reply->code);
 837                         debug_pair_list(fake->reply->vps);
 838                 }
 839
 840                 /*
 841                  *      Terrible hacks.
 842                  */
 843                 request->proxy = fake->packet;
 844                 fake->packet = NULL;
 845                 request->proxy_reply = fake->reply;
 846                 fake->reply = NULL;
 847
 848                 /*
 849                  *      And we're done with this request.
 850                  */
 851
 852                 switch (rcode) {
 853                 case RLM_MODULE_FAIL:
 854                         request_free(&fake);
 855                         eaptls_fail(handler, 0);
 856                         return 0;
 857                         break;
 858
 859                 default:  /* Don't Do Anything */
 860                         RDEBUG2("Got reply %d",
 861                                request->proxy_reply->code);
 862                         break;
 863                 }
 864         }
 865         request_free(&fake);    /* robust if fake == NULL */
 866
 867         /*
 868          *      Process the reply from the home server.
 869          */
 870         rcode = process_reply(handler, tls_session, handler->request,
 871                               handler->request->proxy_reply);
 872
 873         /*
 874          *      The proxy code uses the reply from the home server as
 875          *      the basis for the reply to the NAS.  We don't want that,
 876          *      so we toss it, after we've had our way with it.
 877          */
 878         pairfree(&handler->request->proxy_reply->vps);
 879
 880         switch (rcode) {
 881         case RLM_MODULE_REJECT:
 882                 RDEBUG("Reply was rejected");
 883                 break;
 884
 885         case RLM_MODULE_HANDLED:
 886                 RDEBUG("Reply was handled");
 887                 eaptls_request(handler->eap_ds, tls_session);
 888                 return 1;
 889
 890         case RLM_MODULE_OK:
 891                 RDEBUG("Reply was OK");
 892
 893                 /*
 894                  *      Success: Automatically return MPPE keys.
 895                  */
 896                 return eaptls_success(handler, 0);
 897
 898         default:
 899                 RDEBUG("Reply was unknown.");
 900                 break;
 901         }
 902
 903         eaptls_fail(handler, 0);
 904         return 0;
 905 }
 906
 907
 908 /*
 909  *      Free a request.
 910  */
 911 static void my_request_free(void *data)
 912 {
 913         REQUEST *request = (REQUEST *)data;
 914
 915         request_free(&request);
 916 }
 917 #endif  /* WITH_PROXY */
 918
 919 /*
 920  *      Process the "diameter" contents of the tunneled data.
 921  */
 922 int eapttls_process(EAP_HANDLER *handler, tls_session_t *tls_session)
 923 {
 924         int rcode = PW_AUTHENTICATION_REJECT;
 925         REQUEST *fake;
 926         VALUE_PAIR *vp;
 927         ttls_tunnel_t *t;
 928         const uint8_t *data;
 929         size_t data_len;
 930         REQUEST *request = handler->request;
 931
 932         /*
 933          *      Just look at the buffer directly, without doing
 934          *      record_minus.
 935          */
 936         data_len = tls_session->clean_out.used;
 937         tls_session->clean_out.used = 0;
 938         data = tls_session->clean_out.data;
 939
 940         t = (ttls_tunnel_t *) tls_session->opaque;
 941
 942         /*
 943          *      If there's no data, maybe this is an ACK to an
 944          *      MS-CHAP2-Success.
 945          */
 946         if (data_len == 0) {
 947                 if (t->authenticated) {
 948                         RDEBUG("Got ACK, and the user was already authenticated.");
 949                         return PW_AUTHENTICATION_ACK;
 950                 } /* else no session, no data, die. */
 951
 952                 /*
 953                  *      FIXME: Call SSL_get_error() to see what went
 954                  *      wrong.
 955                  */
 956                 RDEBUG2("SSL_read Error");
 957                 return PW_AUTHENTICATION_REJECT;
 958         }
 959
 960 #ifndef NDEBUG
 961         if ((debug_flag > 2) && fr_log_fp) {
 962                 size_t i;
 963
 964                 for (i = 0; i < data_len; i++) {
 965                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
 966
 967                         fprintf(fr_log_fp, "%02x ", data[i]);
 968
 969                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 970                 }
 971                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 972         }
 973 #endif
 974
 975         if (!diameter_verify(request, data, data_len)) {
 976                 return PW_AUTHENTICATION_REJECT;
 977         }
 978
 979         /*
 980          *      Allocate a fake REQUEST structe.
 981          */
 982         fake = request_alloc_fake(request);
 983
 984         rad_assert(fake->packet->vps == NULL);
 985
 986         /*
 987          *      Add the tunneled attributes to the fake request.
 988          */
 989         fake->packet->vps = diameter2vp(request, tls_session->ssl, data, data_len);
 990         if (!fake->packet->vps) {
 991                 request_free(&fake);
 992                 return PW_AUTHENTICATION_REJECT;
 993         }
 994
 995         /*
 996          *      Tell the request that it's a fake one.
 997          */
 998         vp = pairmake("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
 999         if (vp) {
1000                 pairadd(&fake->packet->vps, vp);
1001         }
1002
1003         if ((debug_flag > 0) && fr_log_fp) {
1004                 RDEBUG("Got tunneled request");
1005
1006                 debug_pair_list(fake->packet->vps);
1007         }
1008
1009         /*
1010          *      Update other items in the REQUEST data structure.
1011          */
1012         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0);
1013         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0);
1014
1015         /*
1016          *      No User-Name, try to create one from stored data.
1017          */
1018         if (!fake->username) {
1019                 /*
1020                  *      No User-Name in the stored data, look for
1021                  *      an EAP-Identity, and pull it out of there.
1022                  */
1023                 if (!t->username) {
1024                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0);
1025                         if (vp &&
1026                             (vp->length >= EAP_HEADER_LEN + 2) &&
1027                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1028                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1029                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1030                                 /*
1031                                  *      Create & remember a User-Name
1032                                  */
1033                                 t->username = pairmake("User-Name", "", T_OP_EQ);
1034                                 rad_assert(t->username != NULL);
1035
1036                                 memcpy(t->username->vp_strvalue, vp->vp_strvalue + 5,
1037                                        vp->length - 5);
1038                                 t->username->length = vp->length - 5;
1039                                 t->username->vp_strvalue[t->username->length] = 0;
1040
1041                                 RDEBUG("Got tunneled identity of %s",
1042                                        t->username->vp_strvalue);
1043
1044                                 /*
1045                                  *      If there's a default EAP type,
1046                                  *      set it here.
1047                                  */
1048                                 if (t->default_eap_type != 0) {
1049                                         RDEBUG("Setting default EAP type for tunneled EAP session.");
1050                                         vp = paircreate(PW_EAP_TYPE, 0,
1051                                                         PW_TYPE_INTEGER);
1052                                         rad_assert(vp != NULL);
1053                                         vp->vp_integer = t->default_eap_type;
1054                                         pairadd(&fake->config_items, vp);
1055                                 }
1056
1057                         } else {
1058                                 /*
1059                                  *      Don't reject the request outright,
1060                                  *      as it's permitted to do EAP without
1061                                  *      user-name.
1062                                  */
1063                                 RDEBUG2("WARNING! No EAP-Identity found to start EAP conversation.");
1064                         }
1065                 } /* else there WAS a t->username */
1066
1067                 if (t->username) {
1068                         vp = paircopy(t->username);
1069                         pairadd(&fake->packet->vps, vp);
1070                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0);
1071                 }
1072         } /* else the request ALREADY had a User-Name */
1073
1074         /*
1075          *      Add the State attribute, too, if it exists.
1076          */
1077         if (t->state) {
1078                 vp = paircopy(t->state);
1079                 if (vp) pairadd(&fake->packet->vps, vp);
1080         }
1081
1082         /*
1083          *      If this is set, we copy SOME of the request attributes
1084          *      from outside of the tunnel to inside of the tunnel.
1085          *
1086          *      We copy ONLY those attributes which do NOT already
1087          *      exist in the tunneled request.
1088          */
1089         if (t->copy_request_to_tunnel) {
1090                 VALUE_PAIR *copy;
1091
1092                 for (vp = request->packet->vps; vp != NULL; vp = vp->next) {
1093                         /*
1094                          *      The attribute is a server-side thingy,
1095                          *      don't copy it.
1096                          */
1097                         if ((vp->attribute > 255) &&
1098                             (vp->vendor == 0)) {
1099                                 continue;
1100                         }
1101
1102                         /*
1103                          *      The outside attribute is already in the
1104                          *      tunnel, don't copy it.
1105                          *
1106                          *      This works for BOTH attributes which
1107                          *      are originally in the tunneled request,
1108                          *      AND attributes which are copied there
1109                          *      from below.
1110                          */
1111                         if (pairfind(fake->packet->vps, vp->attribute, vp->vendor)) {
1112                                 continue;
1113                         }
1114
1115                         /*
1116                          *      Some attributes are handled specially.
1117                          */
1118                         switch (vp->attribute) {
1119                                 /*
1120                                  *      NEVER copy Message-Authenticator,
1121                                  *      EAP-Message, or State.  They're
1122                                  *      only for outside of the tunnel.
1123                                  */
1124                         case PW_USER_NAME:
1125                         case PW_USER_PASSWORD:
1126                         case PW_CHAP_PASSWORD:
1127                         case PW_CHAP_CHALLENGE:
1128                         case PW_PROXY_STATE:
1129                         case PW_MESSAGE_AUTHENTICATOR:
1130                         case PW_EAP_MESSAGE:
1131                         case PW_STATE:
1132                                 continue;
1133                                 break;
1134
1135                                 /*
1136                                  *      By default, copy it over.
1137                                  */
1138                         default:
1139                                 break;
1140                         }
1141
1142                         /*
1143                          *      Don't copy from the head, we've already
1144                          *      checked it.
1145                          */
1146                         copy = paircopy2(vp, vp->attribute, vp->vendor);
1147                         pairadd(&fake->packet->vps, copy);
1148                 }
1149         }
1150
1151         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0)) != NULL) {
1152                 fake->server = vp->vp_strvalue;
1153
1154         } else if (t->virtual_server) {
1155                 fake->server = t->virtual_server;
1156
1157         } /* else fake->server == request->server */
1158
1159
1160         if ((debug_flag > 0) && fr_log_fp) {
1161                 RDEBUG("Sending tunneled request");
1162
1163                 debug_pair_list(fake->packet->vps);
1164
1165                 fprintf(fr_log_fp, "server %s {\n",
1166                         (fake->server == NULL) ? "" : fake->server);
1167         }
1168
1169         /*
1170          *      Call authentication recursively, which will
1171          *      do PAP, CHAP, MS-CHAP, etc.
1172          */
1173         rad_authenticate(fake);
1174
1175         /*
1176          *      Note that we don't do *anything* with the reply
1177          *      attributes.
1178          */
1179         if ((debug_flag > 0) && fr_log_fp) {
1180                 fprintf(fr_log_fp, "} # server %s\n",
1181                         (fake->server == NULL) ? "" : fake->server);
1182
1183                 RDEBUG("Got tunneled reply code %d", fake->reply->code);
1184
1185                 debug_pair_list(fake->reply->vps);
1186         }
1187
1188         /*
1189          *      Decide what to do with the reply.
1190          */
1191         switch (fake->reply->code) {
1192         case 0:                 /* No reply code, must be proxied... */
1193 #ifdef WITH_PROXY
1194           vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0);
1195                 if (vp) {
1196                         eap_tunnel_data_t *tunnel;
1197                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1198
1199                         /*
1200                          *      Tell the original request that it's going
1201                          *      to be proxied.
1202                          */
1203                         pairmove2(&(request->config_items),
1204                                   &(fake->config_items),
1205                                   PW_PROXY_TO_REALM, 0);
1206
1207                         /*
1208                          *      Seed the proxy packet with the
1209                          *      tunneled request.
1210                          */
1211                         rad_assert(request->proxy == NULL);
1212                         request->proxy = fake->packet;
1213                         memset(&request->proxy->src_ipaddr, 0,
1214                                sizeof(request->proxy->src_ipaddr));
1215                         memset(&request->proxy->src_ipaddr, 0,
1216                                sizeof(request->proxy->src_ipaddr));
1217                         request->proxy->src_port = 0;
1218                         request->proxy->dst_port = 0;
1219                         fake->packet = NULL;
1220                         rad_free(&fake->reply);
1221                         fake->reply = NULL;
1222
1223                         /*
1224                          *      Set up the callbacks for the tunnel
1225                          */
1226                         tunnel = rad_malloc(sizeof(*tunnel));
1227                         memset(tunnel, 0, sizeof(*tunnel));
1228
1229                         tunnel->tls_session = tls_session;
1230                         tunnel->callback = eapttls_postproxy;
1231
1232                         /*
1233                          *      Associate the callback with the request.
1234                          */
1235                         rcode = request_data_add(request,
1236                                                  request->proxy,
1237                                                  REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1238                                                  tunnel, free);
1239                         rad_assert(rcode == 0);
1240
1241                         /*
1242                          *      rlm_eap.c has taken care of associating
1243                          *      the handler with the fake request.
1244                          *
1245                          *      So we associate the fake request with
1246                          *      this request.
1247                          */
1248                         rcode = request_data_add(request,
1249                                                  request->proxy,
1250                                                  REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1251                                                  fake, my_request_free);
1252                         rad_assert(rcode == 0);
1253                         fake = NULL;
1254
1255                         /*
1256                          *      Didn't authenticate the packet, but
1257                          *      we're proxying it.
1258                          */
1259                         rcode = PW_STATUS_CLIENT;
1260
1261                 } else
1262 #endif  /* WITH_PROXY */
1263                   {
1264                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1265                                request->number);
1266                         rcode = PW_AUTHENTICATION_REJECT;
1267                 }
1268                 break;
1269
1270         default:
1271                 /*
1272                  *      Returns RLM_MODULE_FOO, and we want to return
1273                  *      PW_FOO
1274                  */
1275                 rcode = process_reply(handler, tls_session, request,
1276                                       fake->reply);
1277                 switch (rcode) {
1278                 case RLM_MODULE_REJECT:
1279                         rcode = PW_AUTHENTICATION_REJECT;
1280                         break;
1281
1282                 case RLM_MODULE_HANDLED:
1283                         rcode = PW_ACCESS_CHALLENGE;
1284                         break;
1285
1286                 case RLM_MODULE_OK:
1287                         rcode = PW_AUTHENTICATION_ACK;
1288                         break;
1289
1290                 default:
1291                         rcode = PW_AUTHENTICATION_REJECT;
1292                         break;
1293                 }
1294                 break;
1295         }
1296
1297         request_free(&fake);
1298
1299         return rcode;
1300 }