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