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 > 65535) {
  87                                 RDEBUG2("Vendor codes larger than 65535 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 (attr > 65535) {
 222                                 RDEBUG2("Cannot handle vendor attributes greater than 65535");
 223                                 pairfree(&first);
 224                                 return NULL;
 225                         }
 226
 227                         if (vendor > 65535) {
 228                                 RDEBUG2("Cannot handle vendor Id greater than 65535");
 229                                 pairfree(&first);
 230                                 return NULL;
 231                         }
 232
 233                         data += 4; /* skip the vendor field, it's zero */
 234                         offset += 4; /* offset to value field */
 235                 }
 236
 237                 /*
 238                  *      Vendor attributes can be larger than 255.
 239                  *      Normal attributes cannot be.
 240                  */
 241                 if ((attr > 255) && (vendor == 0)) {
 242                         RDEBUG2("Cannot handle Diameter attributes");
 243                         pairfree(&first);
 244                         return NULL;
 245                 }
 246
 247                 /*
 248                  *      FIXME: Handle the M bit.  For now, we assume that
 249                  *      some other module takes care of any attribute
 250                  *      with the M bit set.
 251                  */
 252
 253                 /*
 254                  *      Get the length.
 255                  */
 256                 length &= 0x00ffffff;
 257
 258                 /*
 259                  *      Get the size of the value portion of the
 260                  *      attribute.
 261                  */
 262                 size = length - offset;
 263
 264                 /*
 265                  *      Create it.
 266                  */
 267                 vp = paircreate(attr, vendor, PW_TYPE_OCTETS);
 268                 if (!vp) {
 269                         RDEBUG2("Failure in creating VP");
 270                         pairfree(&first);
 271                         return NULL;
 272                 }
 273
 274                 /*
 275                  *      If it's a type from our dictionary, then
 276                  *      we need to put the data in a relevant place.
 277                  */
 278                 switch (vp->type) {
 279                 case PW_TYPE_INTEGER:
 280                 case PW_TYPE_DATE:
 281                         if (size != vp->length) {
 282                                 RDEBUG2("Invalid length attribute %d",
 283                                        attr);
 284                                 pairfree(&first);
 285                                 pairfree(&vp);
 286                                 return NULL;
 287                         }
 288                         memcpy(&vp->vp_integer, data, vp->length);
 289
 290                         /*
 291                          *      Stored in host byte order: change it.
 292                          */
 293                         vp->vp_integer = ntohl(vp->vp_integer);
 294                         break;
 295
 296                 case PW_TYPE_IPADDR:
 297                         if (size != vp->length) {
 298                                 RDEBUG2("Invalid length attribute %d",
 299                                        attr);
 300                                 pairfree(&first);
 301                                 pairfree(&vp);
 302                                 return NULL;
 303                         }
 304                   memcpy(&vp->vp_ipaddr, data, vp->length);
 305
 306                   /*
 307                    *    Stored in network byte order: don't change it.
 308                    */
 309                   break;
 310
 311                   /*
 312                    *    String, octet, etc.  Copy the data from the
 313                    *    value field over verbatim.
 314                    *
 315                    *    FIXME: Ipv6 attributes ?
 316                    *
 317                    */
 318                 case PW_TYPE_OCTETS:
 319                         if (attr == PW_EAP_MESSAGE) {
 320                                 const uint8_t *eap_message = data;
 321
 322                                 /*
 323                                  *      vp exists the first time around.
 324                                  */
 325                                 while (1) {
 326                                         vp->length = size;
 327                                         if (vp->length > 253) vp->length = 253;
 328                                         memcpy(vp->vp_octets, eap_message,
 329                                                vp->length);
 330
 331                                         size -= vp->length;
 332                                         eap_message += vp->length;
 333
 334                                         *last = vp;
 335                                         last = &(vp->next);
 336
 337                                         if (size == 0) break;
 338
 339                                         vp = paircreate(attr, vendor, PW_TYPE_OCTETS);
 340                                         if (!vp) {
 341                                                 RDEBUG2("Failure in creating VP");
 342                                                 pairfree(&first);
 343                                                 return NULL;
 344                                         }
 345                                 }
 346
 347                                 goto next_attr;
 348                         } /* else it's another kind of attribute */
 349                         /* FALL-THROUGH */
 350
 351                 default:
 352                         vp->length = size;
 353                         memcpy(vp->vp_strvalue, data, vp->length);
 354                         break;
 355                 }
 356
 357                 /*
 358                  *      User-Password is NUL padded to a multiple
 359                  *      of 16 bytes.  Let's chop it to something
 360                  *      more reasonable.
 361                  *
 362                  *      NOTE: This means that the User-Password
 363                  *      attribute CANNOT EVER have embedded zeros in it!
 364                  */
 365                 switch (vp->attribute) {
 366                 case PW_USER_PASSWORD:
 367                         /*
 368                          *      If the password is exactly 16 octets,
 369                          *      it won't be zero-terminated.
 370                          */
 371                         vp->vp_strvalue[vp->length] = '\0';
 372                         vp->length = strlen(vp->vp_strvalue);
 373                         break;
 374
 375                         /*
 376                          *      Ensure that the client is using the
 377                          *      correct challenge.  This weirdness is
 378                          *      to protect against against replay
 379                          *      attacks, where anyone observing the
 380                          *      CHAP exchange could pose as that user,
 381                          *      by simply choosing to use the same
 382                          *      challenge.
 383                          *
 384                          *      By using a challenge based on
 385                          *      information from the current session,
 386                          *      we can guarantee that the client is
 387                          *      not *choosing* a challenge.
 388                          *
 389                          *      We're a little forgiving in that we
 390                          *      have loose checks on the length, and
 391                          *      we do NOT check the Id (first octet of
 392                          *      the response to the challenge)
 393                          *
 394                          *      But if the client gets the challenge correct,
 395                          *      we're not too worried about the Id.
 396                          */
 397                 case PW_CHAP_CHALLENGE:
 398                 case PW_MSCHAP_CHALLENGE:
 399                         if ((vp->length < 8) ||
 400                             (vp->length > 16)) {
 401                                 RDEBUG("Tunneled challenge has invalid length");
 402                                 pairfree(&first);
 403                                 pairfree(&vp);
 404                                 return NULL;
 405
 406                         } else {
 407                                 uint8_t challenge[16];
 408
 409                                 eapttls_gen_challenge(ssl, challenge,
 410                                                       sizeof(challenge));
 411
 412                                 if (memcmp(challenge, vp->vp_octets,
 413                                            vp->length) != 0) {
 414                                         RDEBUG("Tunneled challenge is incorrect");
 415                                         pairfree(&first);
 416                                         pairfree(&vp);
 417                                         return NULL;
 418                                 }
 419                         }
 420                         break;
 421
 422                 default:
 423                         break;
 424                 } /* switch over checking/re-writing of attributes. */
 425
 426                 /*
 427                  *      Update the list.
 428                  */
 429                 *last = vp;
 430                 last = &(vp->next);
 431
 432         next_attr:
 433                 /*
 434                  *      Catch non-aligned attributes.
 435                  */
 436                 if (data_left == length) break;
 437
 438                 /*
 439                  *      The length does NOT include the padding, so
 440                  *      we've got to account for it here by rounding up
 441                  *      to the nearest 4-byte boundary.
 442                  */
 443                 length += 0x03;
 444                 length &= ~0x03;
 445
 446                 rad_assert(data_left >= length);
 447                 data_left -= length;
 448                 data += length - offset; /* already updated */
 449         }
 450
 451         /*
 452          *      We got this far.  It looks OK.
 453          */
 454         return first;
 455 }
 456
 457 /*
 458  *      Convert VALUE_PAIR's to diameter attributes, and write them
 459  *      to an SSL session.
 460  *
 461  *      The ONLY VALUE_PAIR's which may be passed to this function
 462  *      are ones which can go inside of a RADIUS (i.e. diameter)
 463  *      packet.  So no server-configuration attributes, or the like.
 464  */
 465 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 466 {
 467         /*
 468          *      RADIUS packets are no more than 4k in size, so if
 469          *      we've got more than 4k of data to write, it's very
 470          *      bad.
 471          */
 472         uint8_t         buffer[4096];
 473         uint8_t         *p;
 474         uint32_t        attr;
 475         uint32_t        length;
 476         uint32_t        vendor;
 477         size_t          total;
 478         VALUE_PAIR      *vp;
 479
 480         p = buffer;
 481         total = 0;
 482
 483         for (vp = first; vp != NULL; vp = vp->next) {
 484                 /*
 485                  *      Too much data: die.
 486                  */
 487                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 488                         RDEBUG2("output buffer is full!");
 489                         return 0;
 490                 }
 491
 492                 /*
 493                  *      Hmm... we don't group multiple EAP-Messages
 494                  *      together.  Maybe we should...
 495                  */
 496
 497                 /*
 498                  *      Length is no more than 253, due to RADIUS
 499                  *      issues.
 500                  */
 501                 length = vp->length;
 502                 vendor = (vp->attribute >> 16) & 0xffff;
 503                 if (vendor != 0) {
 504                         attr = vp->attribute & 0xffff;
 505                         length |= (1 << 31);
 506                 } else {
 507                         attr = vp->attribute;
 508                 }
 509
 510                 /*
 511                  *      Hmm... set the M bit for all attributes?
 512                  */
 513                 length |= (1 << 30);
 514
 515                 attr = ntohl(attr);
 516
 517                 memcpy(p, &attr, sizeof(attr));
 518                 p += 4;
 519                 total += 4;
 520
 521                 length += 8;    /* includes 8 bytes of attr & length */
 522
 523                 if (vendor != 0) {
 524                         length += 4; /* include 4 bytes of vendor */
 525
 526                         length = ntohl(length);
 527                         memcpy(p, &length, sizeof(length));
 528                         p += 4;
 529                         total += 4;
 530
 531                         vendor = ntohl(vendor);
 532                         memcpy(p, &vendor, sizeof(vendor));
 533                         p += 4;
 534                         total += 4;
 535                 } else {
 536                         length = ntohl(length);
 537                         memcpy(p, &length, sizeof(length));
 538                         p += 4;
 539                         total += 4;
 540                 }
 541
 542                 switch (vp->type) {
 543                 case PW_TYPE_INTEGER:
 544                 case PW_TYPE_DATE:
 545                         attr = ntohl(vp->vp_integer); /* stored in host order */
 546                         memcpy(p, &attr, sizeof(attr));
 547                         length = 4;
 548                         break;
 549
 550                 case PW_TYPE_IPADDR:
 551                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 552                         length = 4;
 553                         break;
 554
 555                 case PW_TYPE_STRING:
 556                 case PW_TYPE_OCTETS:
 557                 default:
 558                         memcpy(p, vp->vp_strvalue, vp->length);
 559                         length = vp->length;
 560                         break;
 561                 }
 562
 563                 /*
 564                  *      Skip to the end of the data.
 565                  */
 566                 p += length;
 567                 total += length;
 568
 569                 /*
 570                  *      Align the data to a multiple of 4 bytes.
 571                  */
 572                 if ((total & 0x03) != 0) {
 573                         size_t i;
 574
 575                         length = 4 - (total & 0x03);
 576                         for (i = 0; i < length; i++) {
 577                                 *p = '\0';
 578                                 p++;
 579                                 total++;
 580                         }
 581                 }
 582         } /* loop over the VP's to write. */
 583
 584         /*
 585          *      Write the data in the buffer to the SSL session.
 586          */
 587         if (total > 0) {
 588 #ifndef NDEBUG
 589                 size_t i;
 590
 591                 if ((debug_flag > 2) && fr_log_fp) {
 592                         for (i = 0; i < total; i++) {
 593                                 if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 594
 595                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 596
 597                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 598                         }
 599                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 600                 }
 601 #endif
 602
 603                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 604
 605                 /*
 606                  *      FIXME: Check the return code.
 607                  */
 608                 tls_handshake_send(tls_session);
 609         }
 610
 611         /*
 612          *      Everything's OK.
 613          */
 614         return 1;
 615 }
 616
 617 /*
 618  *      Use a reply packet to determine what to do.
 619  */
 620 static int process_reply(EAP_HANDLER *handler, tls_session_t *tls_session,
 621                          REQUEST *request, RADIUS_PACKET *reply)
 622 {
 623         int rcode = RLM_MODULE_REJECT;
 624         VALUE_PAIR *vp;
 625         ttls_tunnel_t *t = tls_session->opaque;
 626
 627         handler = handler;      /* -Wunused */
 628
 629         /*
 630          *      If the response packet was Access-Accept, then
 631          *      we're OK.  If not, die horribly.
 632          *
 633          *      FIXME: Take MS-CHAP2-Success attribute, and
 634          *      tunnel it back to the client, to authenticate
 635          *      ourselves to the client.
 636          *
 637          *      FIXME: If we have an Access-Challenge, then
 638          *      the Reply-Message is tunneled back to the client.
 639          *
 640          *      FIXME: If we have an EAP-Message, then that message
 641          *      must be tunneled back to the client.
 642          *
 643          *      FIXME: If we have an Access-Challenge with a State
 644          *      attribute, then do we tunnel that to the client, or
 645          *      keep track of it ourselves?
 646          *
 647          *      FIXME: EAP-Messages can only start with 'identity',
 648          *      NOT 'eap start', so we should check for that....
 649          */
 650         switch (reply->code) {
 651         case PW_AUTHENTICATION_ACK:
 652                 RDEBUG("Got tunneled Access-Accept");
 653
 654                 rcode = RLM_MODULE_OK;
 655
 656                 /*
 657                  *      MS-CHAP2-Success means that we do NOT return
 658                  *      an Access-Accept, but instead tunnel that
 659                  *      attribute to the client, and keep going with
 660                  *      the TTLS session.  Once the client accepts
 661                  *      our identity, it will respond with an empty
 662                  *      packet, and we will send EAP-Success.
 663                  */
 664                 vp = NULL;
 665                 pairmove2(&vp, &reply->vps, PW_MSCHAP2_SUCCESS, VENDORPEC_MICROSOFT);
 666                 if (vp) {
 667                         RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge.");
 668                         rcode = RLM_MODULE_HANDLED;
 669                         t->authenticated = TRUE;
 670
 671                         /*
 672                          *      Delete MPPE keys & encryption policy.  We don't
 673                          *      want these here.
 674                          */
 675                         pairdelete(&reply->vps, 7, VENDORPEC_MICROSOFT);
 676                         pairdelete(&reply->vps, 8, VENDORPEC_MICROSOFT);
 677                         pairdelete(&reply->vps, 16, VENDORPEC_MICROSOFT);
 678                         pairdelete(&reply->vps, 17, VENDORPEC_MICROSOFT);
 679
 680                         /*
 681                          *      Use the tunneled reply, but not now.
 682                          */
 683                         if (t->use_tunneled_reply) {
 684                                 t->accept_vps = reply->vps;
 685                                 reply->vps = NULL;
 686                         }
 687
 688                 } else { /* no MS-CHAP2-Success */
 689                         /*
 690                          *      Can only have EAP-Message if there's
 691                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 692                          *
 693                          *      We also do NOT tunnel the EAP-Success
 694                          *      attribute back to the client, as the client
 695                          *      can figure it out, from the non-tunneled
 696                          *      EAP-Success packet.
 697                          */
 698                         pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0);
 699                         pairfree(&vp);
 700                 }
 701
 702                 /*
 703                  *      Handle the ACK, by tunneling any necessary reply
 704                  *      VP's back to the client.
 705                  */
 706                 if (vp) {
 707                         vp2diameter(request, tls_session, vp);
 708                         pairfree(&vp);
 709                 }
 710
 711                 /*
 712                  *      If we've been told to use the attributes from
 713                  *      the reply, then do so.
 714                  *
 715                  *      WARNING: This may leak information about the
 716                  *      tunneled user!
 717                  */
 718                 if (t->use_tunneled_reply) {
 719                         pairdelete(&reply->vps, PW_PROXY_STATE, 0);
 720                         pairadd(&request->reply->vps, reply->vps);
 721                         reply->vps = NULL;
 722                 }
 723                 break;
 724
 725
 726         case PW_AUTHENTICATION_REJECT:
 727                 RDEBUG("Got tunneled Access-Reject");
 728                 rcode = RLM_MODULE_REJECT;
 729                 break;
 730
 731                 /*
 732                  *      Handle Access-Challenge, but only if we
 733                  *      send tunneled reply data.  This is because
 734                  *      an Access-Challenge means that we MUST tunnel
 735                  *      a Reply-Message to the client.
 736                  */
 737         case PW_ACCESS_CHALLENGE:
 738                 RDEBUG("Got tunneled Access-Challenge");
 739
 740                 /*
 741                  *      Keep the State attribute, if necessary.
 742                  *
 743                  *      Get rid of the old State, too.
 744                  */
 745                 pairfree(&t->state);
 746                 pairmove2(&t->state, &reply->vps, PW_STATE, 0);
 747
 748                 /*
 749                  *      We should really be a bit smarter about this,
 750                  *      and move over only those attributes which
 751                  *      are relevant to the authentication request,
 752                  *      but that's a lot more work, and this "dumb"
 753                  *      method works in 99.9% of the situations.
 754                  */
 755                 vp = NULL;
 756                 pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE, 0);
 757
 758                 /*
 759                  *      There MUST be a Reply-Message in the challenge,
 760                  *      which we tunnel back to the client.
 761                  *
 762                  *      If there isn't one in the reply VP's, then
 763                  *      we MUST create one, with an empty string as
 764                  *      it's value.
 765                  */
 766                 pairmove2(&vp, &reply->vps, PW_REPLY_MESSAGE, 0);
 767
 768                 /*
 769                  *      Handle the ACK, by tunneling any necessary reply
 770                  *      VP's back to the client.
 771                  */
 772                 if (vp) {
 773                         vp2diameter(request, tls_session, vp);
 774                         pairfree(&vp);
 775                 }
 776                 rcode = RLM_MODULE_HANDLED;
 777                 break;
 778
 779         default:
 780                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 781                 rcode = RLM_MODULE_INVALID;
 782                 break;
 783         }
 784
 785         return rcode;
 786 }
 787
 788
 789 #ifdef WITH_PROXY
 790 /*
 791  *      Do post-proxy processing,
 792  */
 793 static int eapttls_postproxy(EAP_HANDLER *handler, void *data)
 794 {
 795         int rcode;
 796         tls_session_t *tls_session = (tls_session_t *) data;
 797         REQUEST *fake, *request = handler->request;
 798
 799         RDEBUG("Passing reply from proxy back into the tunnel.");
 800
 801         /*
 802          *      If there was a fake request associated with the proxied
 803          *      request, do more processing of it.
 804          */
 805         fake = (REQUEST *) request_data_get(handler->request,
 806                                             handler->request->proxy,
 807                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 808
 809         /*
 810          *      Do the callback, if it exists, and if it was a success.
 811          */
 812         if (fake && (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 813                 /*
 814                  *      Terrible hacks.
 815                  */
 816                 rad_assert(fake->packet == NULL);
 817                 fake->packet = request->proxy;
 818                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 819                 request->proxy = NULL;
 820
 821                 rad_assert(fake->reply == NULL);
 822                 fake->reply = request->proxy_reply;
 823                 request->proxy_reply = NULL;
 824
 825                 if ((debug_flag > 0) && fr_log_fp) {
 826                         fprintf(fr_log_fp, "server %s {\n",
 827                                 (fake->server == NULL) ? "" : fake->server);
 828                 }
 829
 830                 /*
 831                  *      Perform a post-auth stage for the tunneled
 832                  *      session.
 833                  */
 834                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 835                 rcode = rad_postauth(fake);
 836                 RDEBUG2("post-auth returns %d", rcode);
 837
 838                 if ((debug_flag > 0) && fr_log_fp) {
 839                         fprintf(fr_log_fp, "} # server %s\n",
 840                                 (fake->server == NULL) ? "" : fake->server);
 841
 842                         RDEBUG("Final reply from tunneled session code %d",
 843                                fake->reply->code);
 844                         debug_pair_list(fake->reply->vps);
 845                 }
 846
 847                 /*
 848                  *      Terrible hacks.
 849                  */
 850                 request->proxy = fake->packet;
 851                 fake->packet = NULL;
 852                 request->proxy_reply = fake->reply;
 853                 fake->reply = NULL;
 854
 855                 /*
 856                  *      And we're done with this request.
 857                  */
 858
 859                 switch (rcode) {
 860                 case RLM_MODULE_FAIL:
 861                         request_free(&fake);
 862                         eaptls_fail(handler, 0);
 863                         return 0;
 864                         break;
 865
 866                 default:  /* Don't Do Anything */
 867                         RDEBUG2("sGot reply %d",
 868                                request->proxy_reply->code);
 869                         break;
 870                 }
 871         }
 872         request_free(&fake);    /* robust if fake == NULL */
 873
 874         /*
 875          *      Process the reply from the home server.
 876          */
 877         rcode = process_reply(handler, tls_session, handler->request,
 878                               handler->request->proxy_reply);
 879
 880         /*
 881          *      The proxy code uses the reply from the home server as
 882          *      the basis for the reply to the NAS.  We don't want that,
 883          *      so we toss it, after we've had our way with it.
 884          */
 885         pairfree(&handler->request->proxy_reply->vps);
 886
 887         switch (rcode) {
 888         case RLM_MODULE_REJECT:
 889                 RDEBUG("Reply was rejected");
 890                 break;
 891
 892         case RLM_MODULE_HANDLED:
 893                 RDEBUG("Reply was handled");
 894                 eaptls_request(handler->eap_ds, tls_session);
 895                 return 1;
 896
 897         case RLM_MODULE_OK:
 898                 RDEBUG("Reply was OK");
 899
 900                 /*
 901                  *      Success: Automatically return MPPE keys.
 902                  */
 903                 return eaptls_success(handler, 0);
 904
 905         default:
 906                 RDEBUG("Reply was unknown.");
 907                 break;
 908         }
 909
 910         eaptls_fail(handler, 0);
 911         return 0;
 912 }
 913
 914
 915 /*
 916  *      Free a request.
 917  */
 918 static void my_request_free(void *data)
 919 {
 920         REQUEST *request = (REQUEST *)data;
 921
 922         request_free(&request);
 923 }
 924 #endif  /* WITH_PROXY */
 925
 926 /*
 927  *      Process the "diameter" contents of the tunneled data.
 928  */
 929 int eapttls_process(EAP_HANDLER *handler, tls_session_t *tls_session)
 930 {
 931         int rcode = PW_AUTHENTICATION_REJECT;
 932         REQUEST *fake;
 933         VALUE_PAIR *vp;
 934         ttls_tunnel_t *t;
 935         const uint8_t *data;
 936         size_t data_len;
 937         REQUEST *request = handler->request;
 938
 939         /*
 940          *      Just look at the buffer directly, without doing
 941          *      record_minus.
 942          */
 943         data_len = tls_session->clean_out.used;
 944         tls_session->clean_out.used = 0;
 945         data = tls_session->clean_out.data;
 946
 947         t = (ttls_tunnel_t *) tls_session->opaque;
 948
 949         /*
 950          *      If there's no data, maybe this is an ACK to an
 951          *      MS-CHAP2-Success.
 952          */
 953         if (data_len == 0) {
 954                 if (t->authenticated) {
 955                         RDEBUG("Got ACK, and the user was already authenticated.");
 956                         return PW_AUTHENTICATION_ACK;
 957                 } /* else no session, no data, die. */
 958
 959                 /*
 960                  *      FIXME: Call SSL_get_error() to see what went
 961                  *      wrong.
 962                  */
 963                 RDEBUG2("SSL_read Error");
 964                 return PW_AUTHENTICATION_REJECT;
 965         }
 966
 967 #ifndef NDEBUG
 968         if ((debug_flag > 2) && fr_log_fp) {
 969                 size_t i;
 970
 971                 for (i = 0; i < data_len; i++) {
 972                         if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
 973
 974                         fprintf(fr_log_fp, "%02x ", data[i]);
 975
 976                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 977                 }
 978                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 979         }
 980 #endif
 981
 982         if (!diameter_verify(request, data, data_len)) {
 983                 return PW_AUTHENTICATION_REJECT;
 984         }
 985
 986         /*
 987          *      Allocate a fake REQUEST structe.
 988          */
 989         fake = request_alloc_fake(request);
 990
 991         rad_assert(fake->packet->vps == NULL);
 992
 993         /*
 994          *      Add the tunneled attributes to the fake request.
 995          */
 996         fake->packet->vps = diameter2vp(request, tls_session->ssl, data, data_len);
 997         if (!fake->packet->vps) {
 998                 request_free(&fake);
 999                 return PW_AUTHENTICATION_REJECT;
1000         }
1001
1002         /*
1003          *      Tell the request that it's a fake one.
1004          */
1005         vp = pairmake("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
1006         if (vp) {
1007                 pairadd(&fake->packet->vps, vp);
1008         }
1009
1010         if ((debug_flag > 0) && fr_log_fp) {
1011                 RDEBUG("Got tunneled request");
1012
1013                 debug_pair_list(fake->packet->vps);
1014         }
1015
1016         /*
1017          *      Update other items in the REQUEST data structure.
1018          */
1019         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0);
1020         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD, 0);
1021
1022         /*
1023          *      No User-Name, try to create one from stored data.
1024          */
1025         if (!fake->username) {
1026                 /*
1027                  *      No User-Name in the stored data, look for
1028                  *      an EAP-Identity, and pull it out of there.
1029                  */
1030                 if (!t->username) {
1031                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE, 0);
1032                         if (vp &&
1033                             (vp->length >= EAP_HEADER_LEN + 2) &&
1034                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1035                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1036                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1037                                 /*
1038                                  *      Create & remember a User-Name
1039                                  */
1040                                 t->username = pairmake("User-Name", "", T_OP_EQ);
1041                                 rad_assert(t->username != NULL);
1042
1043                                 memcpy(t->username->vp_strvalue, vp->vp_strvalue + 5,
1044                                        vp->length - 5);
1045                                 t->username->length = vp->length - 5;
1046                                 t->username->vp_strvalue[t->username->length] = 0;
1047
1048                                 RDEBUG("Got tunneled identity of %s",
1049                                        t->username->vp_strvalue);
1050
1051                                 /*
1052                                  *      If there's a default EAP type,
1053                                  *      set it here.
1054                                  */
1055                                 if (t->default_eap_type != 0) {
1056                                         RDEBUG("Setting default EAP type for tunneled EAP session.");
1057                                         vp = paircreate(PW_EAP_TYPE, 0,
1058                                                         PW_TYPE_INTEGER);
1059                                         rad_assert(vp != NULL);
1060                                         vp->vp_integer = t->default_eap_type;
1061                                         pairadd(&fake->config_items, vp);
1062                                 }
1063
1064                         } else {
1065                                 /*
1066                                  *      Don't reject the request outright,
1067                                  *      as it's permitted to do EAP without
1068                                  *      user-name.
1069                                  */
1070                                 RDEBUG2("WARNING! No EAP-Identity found to start EAP conversation.");
1071                         }
1072                 } /* else there WAS a t->username */
1073
1074                 if (t->username) {
1075                         vp = paircopy(t->username);
1076                         pairadd(&fake->packet->vps, vp);
1077                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME, 0);
1078                 }
1079         } /* else the request ALREADY had a User-Name */
1080
1081         /*
1082          *      Add the State attribute, too, if it exists.
1083          */
1084         if (t->state) {
1085                 vp = paircopy(t->state);
1086                 if (vp) pairadd(&fake->packet->vps, vp);
1087         }
1088
1089         /*
1090          *      If this is set, we copy SOME of the request attributes
1091          *      from outside of the tunnel to inside of the tunnel.
1092          *
1093          *      We copy ONLY those attributes which do NOT already
1094          *      exist in the tunneled request.
1095          */
1096         if (t->copy_request_to_tunnel) {
1097                 VALUE_PAIR *copy;
1098
1099                 for (vp = request->packet->vps; vp != NULL; vp = vp->next) {
1100                         /*
1101                          *      The attribute is a server-side thingy,
1102                          *      don't copy it.
1103                          */
1104                         if ((vp->attribute > 255) &&
1105                             (((vp->attribute >> 16) & 0xffff) == 0)) {
1106                                 continue;
1107                         }
1108
1109                         /*
1110                          *      The outside attribute is already in the
1111                          *      tunnel, don't copy it.
1112                          *
1113                          *      This works for BOTH attributes which
1114                          *      are originally in the tunneled request,
1115                          *      AND attributes which are copied there
1116                          *      from below.
1117                          */
1118                         if (pairfind(fake->packet->vps, vp->attribute, vp->vendor)) {
1119                                 continue;
1120                         }
1121
1122                         /*
1123                          *      Some attributes are handled specially.
1124                          */
1125                         switch (vp->attribute) {
1126                                 /*
1127                                  *      NEVER copy Message-Authenticator,
1128                                  *      EAP-Message, or State.  They're
1129                                  *      only for outside of the tunnel.
1130                                  */
1131                         case PW_USER_NAME:
1132                         case PW_USER_PASSWORD:
1133                         case PW_CHAP_PASSWORD:
1134                         case PW_CHAP_CHALLENGE:
1135                         case PW_PROXY_STATE:
1136                         case PW_MESSAGE_AUTHENTICATOR:
1137                         case PW_EAP_MESSAGE:
1138                         case PW_STATE:
1139                                 continue;
1140                                 break;
1141
1142                                 /*
1143                                  *      By default, copy it over.
1144                                  */
1145                         default:
1146                                 break;
1147                         }
1148
1149                         /*
1150                          *      Don't copy from the head, we've already
1151                          *      checked it.
1152                          */
1153                         copy = paircopy2(vp, vp->attribute, vp->vendor);
1154                         pairadd(&fake->packet->vps, copy);
1155                 }
1156         }
1157
1158         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER, 0)) != NULL) {
1159                 fake->server = vp->vp_strvalue;
1160
1161         } else if (t->virtual_server) {
1162                 fake->server = t->virtual_server;
1163
1164         } /* else fake->server == request->server */
1165
1166
1167         if ((debug_flag > 0) && fr_log_fp) {
1168                 RDEBUG("Sending tunneled request");
1169
1170                 debug_pair_list(fake->packet->vps);
1171
1172                 fprintf(fr_log_fp, "server %s {\n",
1173                         (fake->server == NULL) ? "" : fake->server);
1174         }
1175
1176         /*
1177          *      Call authentication recursively, which will
1178          *      do PAP, CHAP, MS-CHAP, etc.
1179          */
1180         rad_authenticate(fake);
1181
1182         /*
1183          *      Note that we don't do *anything* with the reply
1184          *      attributes.
1185          */
1186         if ((debug_flag > 0) && fr_log_fp) {
1187                 fprintf(fr_log_fp, "} # server %s\n",
1188                         (fake->server == NULL) ? "" : fake->server);
1189
1190                 RDEBUG("Got tunneled reply code %d", fake->reply->code);
1191
1192                 debug_pair_list(fake->reply->vps);
1193         }
1194
1195         /*
1196          *      Decide what to do with the reply.
1197          */
1198         switch (fake->reply->code) {
1199         case 0:                 /* No reply code, must be proxied... */
1200 #ifdef WITH_PROXY
1201           vp = pairfind(fake->config_items, PW_PROXY_TO_REALM, 0);
1202                 if (vp) {
1203                         eap_tunnel_data_t *tunnel;
1204                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1205
1206                         /*
1207                          *      Tell the original request that it's going
1208                          *      to be proxied.
1209                          */
1210                         pairmove2(&(request->config_items),
1211                                   &(fake->config_items),
1212                                   PW_PROXY_TO_REALM, 0);
1213
1214                         /*
1215                          *      Seed the proxy packet with the
1216                          *      tunneled request.
1217                          */
1218                         rad_assert(request->proxy == NULL);
1219                         request->proxy = fake->packet;
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 }