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 hdr_len;
  52         unsigned int data_left = data_len;
  53
  54         while (data_left > 0) {
  55                 hdr_len = 12;
  56
  57                 if (data_len < 12) {
  58                         RDEBUG2(" Diameter attribute is too small to contain a Diameter header");
  59                         return 0;
  60                 }
  61
  62                 memcpy(&attr, data, 4);
  63                 attr = htonl(attr);
  64                 memcpy(&length, data + 4, 4);
  65                 length = ntohl(length);
  66
  67                 if ((data[4] & 0x80) != 0) {
  68                         if (data_len < 16) {
  69                                 RDEBUG2(" Diameter attribute is too small to contain a Diameter header with Vendor-Id");
  70                                 return 0;
  71                         }
  72
  73                         hdr_len = 16;
  74                 }
  75
  76                 length &= 0x00ffffff;
  77
  78                 /*
  79                  *      Too short or too long is bad.
  80                  */
  81                 if (length <= (hdr_len - 4)) {
  82                         RDEBUG2("Tunneled attribute %u is too short (%u < %u) to contain anything useful.", attr, length, hdr_len);
  83                         return 0;
  84                 }
  85
  86                 if (length > data_left) {
  87                         RDEBUG2("Tunneled attribute %u is longer than room left in the packet (%u > %u).", attr, length, data_left);
  88                         return 0;
  89                 }
  90
  91                 /*
  92                  *      Check for broken implementations, which don't
  93                  *      pad the AVP to a 4-octet boundary.
  94                  */
  95                 if (data_left == length) break;
  96
  97                 /*
  98                  *      The length does NOT include the padding, so
  99                  *      we've got to account for it here by rounding up
 100                  *      to the nearest 4-byte boundary.
 101                  */
 102                 length += 0x03;
 103                 length &= ~0x03;
 104
 105                 /*
 106                  *      If the rest of the diameter packet is larger than
 107                  *      this attribute, continue.
 108                  *
 109                  *      Otherwise, if the attribute over-flows the end
 110                  *      of the packet, die.
 111                  */
 112                 if (data_left < length) {
 113                         RDEBUG2("ERROR! Diameter attribute overflows packet!");
 114                         return 0;
 115                 }
 116
 117                 /*
 118                  *      data_left > length, continue.
 119                  */
 120                 data_left -= length;
 121                 data += length;
 122         }
 123
 124         /*
 125          *      We got this far.  It looks OK.
 126          */
 127         return 1;
 128 }
 129
 130
 131 /*
 132  *      Convert diameter attributes to our VALUE_PAIR's
 133  */
 134 static VALUE_PAIR *diameter2vp(REQUEST *request, SSL *ssl,
 135                                const uint8_t *data, size_t data_len)
 136 {
 137         uint32_t        attr;
 138         uint32_t        length;
 139         size_t          offset;
 140         size_t          size;
 141         size_t          data_left = data_len;
 142         VALUE_PAIR      *first = NULL;
 143         VALUE_PAIR      **last = &first;
 144         VALUE_PAIR      *vp;
 145
 146         while (data_left > 0) {
 147                 rad_assert(data_left <= data_len);
 148                 memcpy(&attr, data, sizeof(attr));
 149                 data += 4;
 150                 attr = ntohl(attr);
 151
 152                 memcpy(&length, data, sizeof(length));
 153                 data += 4;
 154                 length = ntohl(length);
 155
 156                 /*
 157                  *      A "vendor" flag, with a vendor ID of zero,
 158                  *      is equivalent to no vendor.  This is stupid.
 159                  */
 160                 offset = 8;
 161                 if ((length & (1 << 31)) != 0) {
 162                         uint32_t vendor;
 163
 164                         memcpy(&vendor, data, sizeof(vendor));
 165                         vendor = ntohl(vendor);
 166
 167                         data += 4; /* skip the vendor field, it's zero */
 168                         offset += 4; /* offset to value field */
 169                         length &= 0x00ffffff;
 170
 171                         if (attr > 65535) goto next_attr;
 172                         if (vendor > 65535) goto next_attr;
 173
 174                         attr |= (vendor << 16);
 175                 }
 176
 177                 /*
 178                  *      Get the length.
 179                  */
 180                 length &= 0x00ffffff;
 181
 182                 /*
 183                  *      FIXME: Handle the M bit.  For now, we assume that
 184                  *      some other module takes care of any attribute
 185                  *      with the M bit set.
 186                  */
 187
 188                 /*
 189                  *      Get the size of the value portion of the
 190                  *      attribute.
 191                  */
 192                 size = length - offset;
 193
 194                 /*
 195                  *      Vendor attributes can be larger than 255.
 196                  *      Normal attributes cannot be.
 197                  */
 198                 if ((attr > 255) && (VENDOR(attr) == 0)) {
 199                         RDEBUG2("WARNING: Skipping Diameter attribute %u",
 200                                 attr);
 201                         goto next_attr;
 202                 }
 203
 204                 if (size > 253) {
 205                         RDEBUG2("WARNING: diameter2vp skipping long attribute %u, attr");
 206                         goto next_attr;
 207                 }
 208
 209                 /*
 210                  *      Create it.  If this fails, it's because we're OOM.
 211                  */
 212                 vp = paircreate(attr, PW_TYPE_OCTETS);
 213                 if (!vp) {
 214                         RDEBUG2("diameter2vp: Failed creating attribute %u", attr);
 215                         pairfree(&first);
 216                         return NULL;
 217                 }
 218
 219                 /*
 220                  *      If it's a type from our dictionary, then
 221                  *      we need to put the data in a relevant place.
 222                  */
 223                 switch (vp->type) {
 224                 case PW_TYPE_INTEGER:
 225                 case PW_TYPE_DATE:
 226                         if (size != vp->length) {
 227                                 /*
 228                                  *      Bad format.  Create a "raw"
 229                                  *      attribute.
 230                                  */
 231                 raw:
 232                                 vp = paircreate_raw(vp->attribute,
 233                                                     PW_TYPE_OCTETS, vp);
 234                                 vp->length = size;
 235                                 memcpy(vp->vp_octets, data, vp->length);
 236                                 break;
 237                         }
 238                         memcpy(&vp->vp_integer, data, vp->length);
 239
 240                         /*
 241                          *      Stored in host byte order: change it.
 242                          */
 243                         vp->vp_integer = ntohl(vp->vp_integer);
 244                         break;
 245
 246                 case PW_TYPE_IPADDR:
 247                         if (size != vp->length) goto raw;
 248                         memcpy(&vp->vp_ipaddr, data, vp->length);
 249
 250                         /*
 251                          *      Stored in network byte order: don't change it.
 252                          */
 253                         break;
 254
 255                 case PW_TYPE_BYTE:
 256                         if (size != vp->length) goto raw;
 257                         vp->vp_integer = data[0];
 258                         break;
 259
 260                 case PW_TYPE_SHORT:
 261                         if (size != vp->length) goto raw;
 262                         vp->vp_integer = (data[0] * 256) + data[1];
 263                         break;
 264
 265                 case PW_TYPE_SIGNED:
 266                         if (size != vp->length) goto raw;
 267                         memcpy(&vp->vp_signed, data, vp->length);
 268                         vp->vp_signed = ntohl(vp->vp_signed);
 269                         break;
 270
 271                 case PW_TYPE_IPV6ADDR:
 272                         if (size != vp->length) goto raw;
 273                         memcpy(&vp->vp_ipv6addr, data, vp->length);
 274                         break;
 275
 276                 case PW_TYPE_IPV6PREFIX:
 277                         if (size != vp->length) goto raw;
 278                         memcpy(&vp->vp_ipv6prefix, data, vp->length);
 279                         break;
 280
 281                         /*
 282                          *      String, octet, etc.  Copy the data from the
 283                          *      value field over verbatim.
 284                          *
 285                          *      FIXME: Ipv6 attributes ?
 286                          *
 287                          */
 288                 case PW_TYPE_OCTETS:
 289                         if (attr == PW_EAP_MESSAGE) {
 290                                 const uint8_t *eap_message = data;
 291
 292                                 /*
 293                                  *      vp exists the first time around.
 294                                  */
 295                                 while (1) {
 296                                         vp->length = size;
 297                                         if (vp->length > 253) vp->length = 253;
 298                                         memcpy(vp->vp_octets, eap_message,
 299                                                vp->length);
 300
 301                                         size -= vp->length;
 302                                         eap_message += vp->length;
 303
 304                                         *last = vp;
 305                                         last = &(vp->next);
 306
 307                                         if (size == 0) break;
 308
 309                                         vp = paircreate(attr, PW_TYPE_OCTETS);
 310                                         if (!vp) {
 311                                                 RDEBUG2("Failed creating EAP-Message");
 312                                                 pairfree(&first);
 313                                                 return NULL;
 314                                         }
 315                                 }
 316
 317                                 goto next_attr;
 318                         } /* else it's another kind of attribute */
 319                         /* FALL-THROUGH */
 320
 321                 default:
 322                         vp->length = size;
 323                         memcpy(vp->vp_octets, data, vp->length);
 324                         break;
 325                 }
 326
 327                 /*
 328                  *      User-Password is NUL padded to a multiple
 329                  *      of 16 bytes.  Let's chop it to something
 330                  *      more reasonable.
 331                  *
 332                  *      NOTE: This means that the User-Password
 333                  *      attribute CANNOT EVER have embedded zeros in it!
 334                  */
 335                 switch (vp->attribute) {
 336                 case PW_USER_PASSWORD:
 337                         /*
 338                          *      If the password is exactly 16 octets,
 339                          *      it won't be zero-terminated.
 340                          */
 341                         vp->vp_strvalue[vp->length] = '\0';
 342                         vp->length = strlen(vp->vp_strvalue);
 343                         break;
 344
 345                         /*
 346                          *      Ensure that the client is using the
 347                          *      correct challenge.  This weirdness is
 348                          *      to protect against against replay
 349                          *      attacks, where anyone observing the
 350                          *      CHAP exchange could pose as that user,
 351                          *      by simply choosing to use the same
 352                          *      challenge.
 353                          *
 354                          *      By using a challenge based on
 355                          *      information from the current session,
 356                          *      we can guarantee that the client is
 357                          *      not *choosing* a challenge.
 358                          *
 359                          *      We're a little forgiving in that we
 360                          *      have loose checks on the length, and
 361                          *      we do NOT check the Id (first octet of
 362                          *      the response to the challenge)
 363                          *
 364                          *      But if the client gets the challenge correct,
 365                          *      we're not too worried about the Id.
 366                          */
 367                 case PW_CHAP_CHALLENGE:
 368                 case PW_MSCHAP_CHALLENGE:
 369                         if ((vp->length < 8) ||
 370                             (vp->length > 16)) {
 371                                 RDEBUG("Tunneled challenge has invalid length");
 372                                 pairfree(&first);
 373                                 pairfree(&vp);
 374                                 return NULL;
 375
 376                         } else {
 377                                 uint8_t challenge[16];
 378
 379                                 eapttls_gen_challenge(ssl, challenge,
 380                                                       sizeof(challenge));
 381
 382                                 if (memcmp(challenge, vp->vp_octets,
 383                                            vp->length) != 0) {
 384                                         RDEBUG("Tunneled challenge is incorrect");
 385                                         pairfree(&first);
 386                                         pairfree(&vp);
 387                                         return NULL;
 388                                 }
 389                         }
 390                         break;
 391
 392                 default:
 393                         break;
 394                 } /* switch over checking/re-writing of attributes. */
 395
 396                 /*
 397                  *      Update the list.
 398                  */
 399                 *last = vp;
 400                 last = &(vp->next);
 401
 402         next_attr:
 403                 /*
 404                  *      Catch non-aligned attributes.
 405                  */
 406                 if (data_left == length) break;
 407
 408                 /*
 409                  *      The length does NOT include the padding, so
 410                  *      we've got to account for it here by rounding up
 411                  *      to the nearest 4-byte boundary.
 412                  */
 413                 length += 0x03;
 414                 length &= ~0x03;
 415
 416                 rad_assert(data_left >= length);
 417                 data_left -= length;
 418                 data += length - offset; /* already updated */
 419         }
 420
 421         /*
 422          *      We got this far.  It looks OK.
 423          */
 424         return first;
 425 }
 426
 427 /*
 428  *      Convert VALUE_PAIR's to diameter attributes, and write them
 429  *      to an SSL session.
 430  *
 431  *      The ONLY VALUE_PAIR's which may be passed to this function
 432  *      are ones which can go inside of a RADIUS (i.e. diameter)
 433  *      packet.  So no server-configuration attributes, or the like.
 434  */
 435 static int vp2diameter(REQUEST *request, tls_session_t *tls_session, VALUE_PAIR *first)
 436 {
 437         /*
 438          *      RADIUS packets are no more than 4k in size, so if
 439          *      we've got more than 4k of data to write, it's very
 440          *      bad.
 441          */
 442         uint8_t         buffer[4096];
 443         uint8_t         *p;
 444         uint32_t        attr;
 445         uint32_t        length;
 446         uint32_t        vendor;
 447         size_t          total;
 448         VALUE_PAIR      *vp;
 449
 450         p = buffer;
 451         total = 0;
 452
 453         for (vp = first; vp != NULL; vp = vp->next) {
 454                 /*
 455                  *      Too much data: die.
 456                  */
 457                 if ((total + vp->length + 12) >= sizeof(buffer)) {
 458                         RDEBUG2("output buffer is full!");
 459                         return 0;
 460                 }
 461
 462                 /*
 463                  *      Hmm... we don't group multiple EAP-Messages
 464                  *      together.  Maybe we should...
 465                  */
 466
 467                 /*
 468                  *      Length is no more than 253, due to RADIUS
 469                  *      issues.
 470                  */
 471                 length = vp->length;
 472                 vendor = (vp->attribute >> 16) & 0xffff;
 473                 if (vendor != 0) {
 474                         attr = vp->attribute & 0xffff;
 475                         length |= (1 << 31);
 476                 } else {
 477                         attr = vp->attribute;
 478                 }
 479
 480                 /*
 481                  *      Hmm... set the M bit for all attributes?
 482                  */
 483                 length |= (1 << 30);
 484
 485                 attr = ntohl(attr);
 486
 487                 memcpy(p, &attr, sizeof(attr));
 488                 p += 4;
 489                 total += 4;
 490
 491                 length += 8;    /* includes 8 bytes of attr & length */
 492
 493                 if (vendor != 0) {
 494                         length += 4; /* include 4 bytes of vendor */
 495
 496                         length = ntohl(length);
 497                         memcpy(p, &length, sizeof(length));
 498                         p += 4;
 499                         total += 4;
 500
 501                         vendor = ntohl(vendor);
 502                         memcpy(p, &vendor, sizeof(vendor));
 503                         p += 4;
 504                         total += 4;
 505                 } else {
 506                         length = ntohl(length);
 507                         memcpy(p, &length, sizeof(length));
 508                         p += 4;
 509                         total += 4;
 510                 }
 511
 512                 switch (vp->type) {
 513                 case PW_TYPE_INTEGER:
 514                 case PW_TYPE_DATE:
 515                         attr = ntohl(vp->vp_integer); /* stored in host order */
 516                         memcpy(p, &attr, sizeof(attr));
 517                         length = 4;
 518                         break;
 519
 520                 case PW_TYPE_IPADDR:
 521                         memcpy(p, &vp->vp_ipaddr, 4); /* network order */
 522                         length = 4;
 523                         break;
 524
 525                 case PW_TYPE_STRING:
 526                 case PW_TYPE_OCTETS:
 527                 default:
 528                         memcpy(p, vp->vp_strvalue, vp->length);
 529                         length = vp->length;
 530                         break;
 531                 }
 532
 533                 /*
 534                  *      Skip to the end of the data.
 535                  */
 536                 p += length;
 537                 total += length;
 538
 539                 /*
 540                  *      Align the data to a multiple of 4 bytes.
 541                  */
 542                 if ((total & 0x03) != 0) {
 543                         size_t i;
 544
 545                         length = 4 - (total & 0x03);
 546                         for (i = 0; i < length; i++) {
 547                                 *p = '\0';
 548                                 p++;
 549                                 total++;
 550                         }
 551                 }
 552         } /* loop over the VP's to write. */
 553
 554         /*
 555          *      Write the data in the buffer to the SSL session.
 556          */
 557         if (total > 0) {
 558 #ifndef NDEBUG
 559                 size_t i;
 560
 561                 if ((debug_flag > 2) && fr_log_fp) {
 562                         for (i = 0; i < total; i++) {
 563                           if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data out %04x: ", (int) i);
 564
 565                                 fprintf(fr_log_fp, "%02x ", buffer[i]);
 566
 567                                 if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 568                         }
 569                         if ((total & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 570                 }
 571 #endif
 572
 573                 (tls_session->record_plus)(&tls_session->clean_in, buffer, total);
 574
 575                 /*
 576                  *      FIXME: Check the return code.
 577                  */
 578                 tls_handshake_send(request, tls_session);
 579         }
 580
 581         /*
 582          *      Everything's OK.
 583          */
 584         return 1;
 585 }
 586
 587 /*
 588  *      Use a reply packet to determine what to do.
 589  */
 590 static int process_reply(EAP_HANDLER *handler, tls_session_t *tls_session,
 591                          REQUEST *request, RADIUS_PACKET *reply)
 592 {
 593         int rcode = RLM_MODULE_REJECT;
 594         VALUE_PAIR *vp;
 595         ttls_tunnel_t *t = tls_session->opaque;
 596
 597         handler = handler;      /* -Wunused */
 598
 599         /*
 600          *      If the response packet was Access-Accept, then
 601          *      we're OK.  If not, die horribly.
 602          *
 603          *      FIXME: Take MS-CHAP2-Success attribute, and
 604          *      tunnel it back to the client, to authenticate
 605          *      ourselves to the client.
 606          *
 607          *      FIXME: If we have an Access-Challenge, then
 608          *      the Reply-Message is tunneled back to the client.
 609          *
 610          *      FIXME: If we have an EAP-Message, then that message
 611          *      must be tunneled back to the client.
 612          *
 613          *      FIXME: If we have an Access-Challenge with a State
 614          *      attribute, then do we tunnel that to the client, or
 615          *      keep track of it ourselves?
 616          *
 617          *      FIXME: EAP-Messages can only start with 'identity',
 618          *      NOT 'eap start', so we should check for that....
 619          */
 620         switch (reply->code) {
 621         case PW_AUTHENTICATION_ACK:
 622                 RDEBUG("Got tunneled Access-Accept");
 623
 624                 rcode = RLM_MODULE_OK;
 625
 626                 /*
 627                  *      MS-CHAP2-Success means that we do NOT return
 628                  *      an Access-Accept, but instead tunnel that
 629                  *      attribute to the client, and keep going with
 630                  *      the TTLS session.  Once the client accepts
 631                  *      our identity, it will respond with an empty
 632                  *      packet, and we will send EAP-Success.
 633                  */
 634                 vp = NULL;
 635                 pairmove2(&vp, &reply->vps, PW_MSCHAP2_SUCCESS);
 636                 if (vp) {
 637                         RDEBUG("Got MS-CHAP2-Success, tunneling it to the client in a challenge.");
 638                         rcode = RLM_MODULE_HANDLED;
 639                         t->authenticated = TRUE;
 640
 641                         /*
 642                          *      Delete MPPE keys & encryption policy.  We don't
 643                          *      want these here.
 644                          */
 645                         pairdelete(&reply->vps, ((311 << 16) | 7));
 646                         pairdelete(&reply->vps, ((311 << 16) | 8));
 647                         pairdelete(&reply->vps, ((311 << 16) | 16));
 648                         pairdelete(&reply->vps, ((311 << 16) | 17));
 649
 650                         /*
 651                          *      Use the tunneled reply, but not now.
 652                          */
 653                         if (t->use_tunneled_reply) {
 654                                 t->accept_vps = reply->vps;
 655                                 reply->vps = NULL;
 656                         }
 657
 658                 } else { /* no MS-CHAP2-Success */
 659                         /*
 660                          *      Can only have EAP-Message if there's
 661                          *      no MS-CHAP2-Success.  (FIXME: EAP-MSCHAP?)
 662                          *
 663                          *      We also do NOT tunnel the EAP-Success
 664                          *      attribute back to the client, as the client
 665                          *      can figure it out, from the non-tunneled
 666                          *      EAP-Success packet.
 667                          */
 668                         pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE);
 669                         pairfree(&vp);
 670                 }
 671
 672                 /*
 673                  *      Handle the ACK, by tunneling any necessary reply
 674                  *      VP's back to the client.
 675                  */
 676                 if (vp) {
 677                         vp2diameter(request, tls_session, vp);
 678                         pairfree(&vp);
 679                 }
 680
 681                 /*
 682                  *      If we've been told to use the attributes from
 683                  *      the reply, then do so.
 684                  *
 685                  *      WARNING: This may leak information about the
 686                  *      tunneled user!
 687                  */
 688                 if (t->use_tunneled_reply) {
 689                         pairdelete(&reply->vps, PW_PROXY_STATE);
 690                         pairadd(&request->reply->vps, reply->vps);
 691                         reply->vps = NULL;
 692                 }
 693                 break;
 694
 695
 696         case PW_AUTHENTICATION_REJECT:
 697                 RDEBUG("Got tunneled Access-Reject");
 698                 rcode = RLM_MODULE_REJECT;
 699                 break;
 700
 701                 /*
 702                  *      Handle Access-Challenge, but only if we
 703                  *      send tunneled reply data.  This is because
 704                  *      an Access-Challenge means that we MUST tunnel
 705                  *      a Reply-Message to the client.
 706                  */
 707         case PW_ACCESS_CHALLENGE:
 708                 RDEBUG("Got tunneled Access-Challenge");
 709
 710                 /*
 711                  *      Keep the State attribute, if necessary.
 712                  *
 713                  *      Get rid of the old State, too.
 714                  */
 715                 pairfree(&t->state);
 716                 pairmove2(&t->state, &reply->vps, PW_STATE);
 717
 718                 /*
 719                  *      We should really be a bit smarter about this,
 720                  *      and move over only those attributes which
 721                  *      are relevant to the authentication request,
 722                  *      but that's a lot more work, and this "dumb"
 723                  *      method works in 99.9% of the situations.
 724                  */
 725                 vp = NULL;
 726                 pairmove2(&vp, &reply->vps, PW_EAP_MESSAGE);
 727
 728                 /*
 729                  *      There MUST be a Reply-Message in the challenge,
 730                  *      which we tunnel back to the client.
 731                  *
 732                  *      If there isn't one in the reply VP's, then
 733                  *      we MUST create one, with an empty string as
 734                  *      it's value.
 735                  */
 736                 pairmove2(&vp, &reply->vps, PW_REPLY_MESSAGE);
 737
 738                 /*
 739                  *      Handle the ACK, by tunneling any necessary reply
 740                  *      VP's back to the client.
 741                  */
 742                 if (vp) {
 743                         vp2diameter(request, tls_session, vp);
 744                         pairfree(&vp);
 745                 }
 746                 rcode = RLM_MODULE_HANDLED;
 747                 break;
 748
 749         default:
 750                 RDEBUG("Unknown RADIUS packet type %d: rejecting tunneled user", reply->code);
 751                 rcode = RLM_MODULE_INVALID;
 752                 break;
 753         }
 754
 755         return rcode;
 756 }
 757
 758
 759 #ifdef WITH_PROXY
 760 /*
 761  *      Do post-proxy processing,
 762  */
 763 static int eapttls_postproxy(EAP_HANDLER *handler, void *data)
 764 {
 765         int rcode;
 766         tls_session_t *tls_session = (tls_session_t *) data;
 767         REQUEST *fake, *request = handler->request;
 768
 769         RDEBUG("Passing reply from proxy back into the tunnel.");
 770
 771         /*
 772          *      If there was a fake request associated with the proxied
 773          *      request, do more processing of it.
 774          */
 775         fake = (REQUEST *) request_data_get(handler->request,
 776                                             handler->request->proxy,
 777                                             REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK);
 778
 779         /*
 780          *      Do the callback, if it exists, and if it was a success.
 781          */
 782         if (fake &&
 783             handler->request->proxy_reply &&
 784             (handler->request->proxy_reply->code == PW_AUTHENTICATION_ACK)) {
 785                 /*
 786                  *      Terrible hacks.
 787                  */
 788                 rad_assert(fake->packet == NULL);
 789                 fake->packet = request->proxy;
 790                 fake->packet->src_ipaddr = request->packet->src_ipaddr;
 791                 request->proxy = NULL;
 792
 793                 rad_assert(fake->reply == NULL);
 794                 fake->reply = request->proxy_reply;
 795                 request->proxy_reply = NULL;
 796
 797                 if ((debug_flag > 0) && fr_log_fp) {
 798                         fprintf(fr_log_fp, "server %s {\n",
 799                                 (fake->server == NULL) ? "" : fake->server);
 800                 }
 801
 802                 /*
 803                  *      Perform a post-auth stage for the tunneled
 804                  *      session.
 805                  */
 806                 fake->options &= ~RAD_REQUEST_OPTION_PROXY_EAP;
 807                 rcode = rad_postauth(fake);
 808                 RDEBUG2("post-auth returns %d", rcode);
 809
 810                 if ((debug_flag > 0) && fr_log_fp) {
 811                         fprintf(fr_log_fp, "} # server %s\n",
 812                                 (fake->server == NULL) ? "" : fake->server);
 813
 814                         RDEBUG("Final reply from tunneled session code %d",
 815                                fake->reply->code);
 816                         debug_pair_list(fake->reply->vps);
 817                 }
 818
 819                 /*
 820                  *      Terrible hacks.
 821                  */
 822                 request->proxy = fake->packet;
 823                 fake->packet = NULL;
 824                 request->proxy_reply = fake->reply;
 825                 fake->reply = NULL;
 826
 827                 /*
 828                  *      And we're done with this request.
 829                  */
 830
 831                 switch (rcode) {
 832                 case RLM_MODULE_FAIL:
 833                         request_free(&fake);
 834                         eaptls_fail(handler, 0);
 835                         return 0;
 836                         break;
 837
 838                 default:  /* Don't Do Anything */
 839                         RDEBUG2("Got reply %d",
 840                                request->proxy_reply->code);
 841                         break;
 842                 }
 843         }
 844         request_free(&fake);    /* robust if fake == NULL */
 845
 846         /*
 847          *      Process the reply from the home server.
 848          */
 849         rcode = process_reply(handler, tls_session, handler->request,
 850                               handler->request->proxy_reply);
 851
 852         /*
 853          *      The proxy code uses the reply from the home server as
 854          *      the basis for the reply to the NAS.  We don't want that,
 855          *      so we toss it, after we've had our way with it.
 856          */
 857         pairfree(&handler->request->proxy_reply->vps);
 858
 859         switch (rcode) {
 860         case RLM_MODULE_REJECT:
 861                 RDEBUG("Reply was rejected");
 862                 break;
 863
 864         case RLM_MODULE_HANDLED:
 865                 RDEBUG("Reply was handled");
 866                 eaptls_request(handler->eap_ds, tls_session);
 867                 return 1;
 868
 869         case RLM_MODULE_OK:
 870                 RDEBUG("Reply was OK");
 871
 872                 /*
 873                  *      Success: Automatically return MPPE keys.
 874                  */
 875                 return eaptls_success(handler, 0);
 876
 877         default:
 878                 RDEBUG("Reply was unknown.");
 879                 break;
 880         }
 881
 882         eaptls_fail(handler, 0);
 883         return 0;
 884 }
 885
 886
 887 /*
 888  *      Free a request.
 889  */
 890 static void my_request_free(void *data)
 891 {
 892         REQUEST *request = (REQUEST *)data;
 893
 894         request_free(&request);
 895 }
 896 #endif  /* WITH_PROXY */
 897
 898 /*
 899  *      Process the "diameter" contents of the tunneled data.
 900  */
 901 int eapttls_process(EAP_HANDLER *handler, tls_session_t *tls_session)
 902 {
 903         int rcode = PW_AUTHENTICATION_REJECT;
 904         REQUEST *fake;
 905         VALUE_PAIR *vp;
 906         ttls_tunnel_t *t;
 907         const uint8_t *data;
 908         size_t data_len;
 909         REQUEST *request = handler->request;
 910
 911         /*
 912          *      Just look at the buffer directly, without doing
 913          *      record_minus.
 914          */
 915         data_len = tls_session->clean_out.used;
 916         tls_session->clean_out.used = 0;
 917         data = tls_session->clean_out.data;
 918
 919         t = (ttls_tunnel_t *) tls_session->opaque;
 920
 921         /*
 922          *      If there's no data, maybe this is an ACK to an
 923          *      MS-CHAP2-Success.
 924          */
 925         if (data_len == 0) {
 926                 if (t->authenticated) {
 927                         RDEBUG("Got ACK, and the user was already authenticated.");
 928                         return PW_AUTHENTICATION_ACK;
 929                 } /* else no session, no data, die. */
 930
 931                 /*
 932                  *      FIXME: Call SSL_get_error() to see what went
 933                  *      wrong.
 934                  */
 935                 RDEBUG2("SSL_read Error");
 936                 return PW_AUTHENTICATION_REJECT;
 937         }
 938
 939 #ifndef NDEBUG
 940         if ((debug_flag > 2) && fr_log_fp) {
 941                 size_t i;
 942
 943                 for (i = 0; i < data_len; i++) {
 944                   if ((i & 0x0f) == 0) fprintf(fr_log_fp, "  TTLS tunnel data in %04x: ", (int) i);
 945
 946                         fprintf(fr_log_fp, "%02x ", data[i]);
 947
 948                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 949                 }
 950                 if ((data_len & 0x0f) != 0) fprintf(fr_log_fp, "\n");
 951         }
 952 #endif
 953
 954         if (!diameter_verify(request, data, data_len)) {
 955                 return PW_AUTHENTICATION_REJECT;
 956         }
 957
 958         /*
 959          *      Allocate a fake REQUEST structe.
 960          */
 961         fake = request_alloc_fake(request);
 962
 963         rad_assert(fake->packet->vps == NULL);
 964
 965         /*
 966          *      Add the tunneled attributes to the fake request.
 967          */
 968         fake->packet->vps = diameter2vp(request, tls_session->ssl, data, data_len);
 969         if (!fake->packet->vps) {
 970                 request_free(&fake);
 971                 return PW_AUTHENTICATION_REJECT;
 972         }
 973
 974         /*
 975          *      Tell the request that it's a fake one.
 976          */
 977         vp = pairmake("Freeradius-Proxied-To", "127.0.0.1", T_OP_EQ);
 978         if (vp) {
 979                 pairadd(&fake->packet->vps, vp);
 980         }
 981
 982         if ((debug_flag > 0) && fr_log_fp) {
 983                 RDEBUG("Got tunneled request");
 984
 985                 debug_pair_list(fake->packet->vps);
 986         }
 987
 988         /*
 989          *      Update other items in the REQUEST data structure.
 990          */
 991         fake->username = pairfind(fake->packet->vps, PW_USER_NAME);
 992         fake->password = pairfind(fake->packet->vps, PW_USER_PASSWORD);
 993
 994         /*
 995          *      No User-Name, try to create one from stored data.
 996          */
 997         if (!fake->username) {
 998                 /*
 999                  *      No User-Name in the stored data, look for
1000                  *      an EAP-Identity, and pull it out of there.
1001                  */
1002                 if (!t->username) {
1003                         vp = pairfind(fake->packet->vps, PW_EAP_MESSAGE);
1004                         if (vp &&
1005                             (vp->length >= EAP_HEADER_LEN + 2) &&
1006                             (vp->vp_strvalue[0] == PW_EAP_RESPONSE) &&
1007                             (vp->vp_strvalue[EAP_HEADER_LEN] == PW_EAP_IDENTITY) &&
1008                             (vp->vp_strvalue[EAP_HEADER_LEN + 1] != 0)) {
1009                                 /*
1010                                  *      Create & remember a User-Name
1011                                  */
1012                                 t->username = pairmake("User-Name", "", T_OP_EQ);
1013                                 rad_assert(t->username != NULL);
1014
1015                                 memcpy(t->username->vp_strvalue, vp->vp_strvalue + 5,
1016                                        vp->length - 5);
1017                                 t->username->length = vp->length - 5;
1018                                 t->username->vp_strvalue[t->username->length] = 0;
1019
1020                                 RDEBUG("Got tunneled identity of %s",
1021                                        t->username->vp_strvalue);
1022
1023                                 /*
1024                                  *      If there's a default EAP type,
1025                                  *      set it here.
1026                                  */
1027                                 if (t->default_eap_type != 0) {
1028                                         RDEBUG("Setting default EAP type for tunneled EAP session.");
1029                                         vp = paircreate(PW_EAP_TYPE,
1030                                                         PW_TYPE_INTEGER);
1031                                         rad_assert(vp != NULL);
1032                                         vp->vp_integer = t->default_eap_type;
1033                                         pairadd(&fake->config_items, vp);
1034                                 }
1035
1036                         } else {
1037                                 /*
1038                                  *      Don't reject the request outright,
1039                                  *      as it's permitted to do EAP without
1040                                  *      user-name.
1041                                  */
1042                                 RDEBUG2("WARNING! No EAP-Identity found to start EAP conversation.");
1043                         }
1044                 } /* else there WAS a t->username */
1045
1046                 if (t->username) {
1047                         vp = paircopy(t->username);
1048                         pairadd(&fake->packet->vps, vp);
1049                         fake->username = pairfind(fake->packet->vps, PW_USER_NAME);
1050                 }
1051         } /* else the request ALREADY had a User-Name */
1052
1053         /*
1054          *      Add the State attribute, too, if it exists.
1055          */
1056         if (t->state) {
1057                 vp = paircopy(t->state);
1058                 if (vp) pairadd(&fake->packet->vps, vp);
1059         }
1060
1061         /*
1062          *      If this is set, we copy SOME of the request attributes
1063          *      from outside of the tunnel to inside of the tunnel.
1064          *
1065          *      We copy ONLY those attributes which do NOT already
1066          *      exist in the tunneled request.
1067          */
1068         if (t->copy_request_to_tunnel) {
1069                 VALUE_PAIR *copy;
1070
1071                 for (vp = request->packet->vps; vp != NULL; vp = vp->next) {
1072                         /*
1073                          *      The attribute is a server-side thingy,
1074                          *      don't copy it.
1075                          */
1076                         if ((vp->attribute > 255) &&
1077                             (((vp->attribute >> 16) & 0xffff) == 0)) {
1078                                 continue;
1079                         }
1080
1081                         /*
1082                          *      The outside attribute is already in the
1083                          *      tunnel, don't copy it.
1084                          *
1085                          *      This works for BOTH attributes which
1086                          *      are originally in the tunneled request,
1087                          *      AND attributes which are copied there
1088                          *      from below.
1089                          */
1090                         if (pairfind(fake->packet->vps, vp->attribute)) {
1091                                 continue;
1092                         }
1093
1094                         /*
1095                          *      Some attributes are handled specially.
1096                          */
1097                         switch (vp->attribute) {
1098                                 /*
1099                                  *      NEVER copy Message-Authenticator,
1100                                  *      EAP-Message, or State.  They're
1101                                  *      only for outside of the tunnel.
1102                                  */
1103                         case PW_USER_NAME:
1104                         case PW_USER_PASSWORD:
1105                         case PW_CHAP_PASSWORD:
1106                         case PW_CHAP_CHALLENGE:
1107                         case PW_PROXY_STATE:
1108                         case PW_MESSAGE_AUTHENTICATOR:
1109                         case PW_EAP_MESSAGE:
1110                         case PW_STATE:
1111                                 continue;
1112                                 break;
1113
1114                                 /*
1115                                  *      By default, copy it over.
1116                                  */
1117                         default:
1118                                 break;
1119                         }
1120
1121                         /*
1122                          *      Don't copy from the head, we've already
1123                          *      checked it.
1124                          */
1125                         copy = paircopy2(vp, vp->attribute);
1126                         pairadd(&fake->packet->vps, copy);
1127                 }
1128         }
1129
1130         if ((vp = pairfind(request->config_items, PW_VIRTUAL_SERVER)) != NULL) {
1131                 fake->server = vp->vp_strvalue;
1132
1133         } else if (t->virtual_server) {
1134                 fake->server = t->virtual_server;
1135
1136         } /* else fake->server == request->server */
1137
1138
1139         if ((debug_flag > 0) && fr_log_fp) {
1140                 RDEBUG("Sending tunneled request");
1141
1142                 debug_pair_list(fake->packet->vps);
1143
1144                 fprintf(fr_log_fp, "server %s {\n",
1145                         (fake->server == NULL) ? "" : fake->server);
1146         }
1147
1148         /*
1149          *      Call authentication recursively, which will
1150          *      do PAP, CHAP, MS-CHAP, etc.
1151          */
1152         rad_authenticate(fake);
1153
1154         /*
1155          *      Note that we don't do *anything* with the reply
1156          *      attributes.
1157          */
1158         if ((debug_flag > 0) && fr_log_fp) {
1159                 fprintf(fr_log_fp, "} # server %s\n",
1160                         (fake->server == NULL) ? "" : fake->server);
1161
1162                 RDEBUG("Got tunneled reply code %d", fake->reply->code);
1163
1164                 debug_pair_list(fake->reply->vps);
1165         }
1166
1167         /*
1168          *      Decide what to do with the reply.
1169          */
1170         switch (fake->reply->code) {
1171         case 0:                 /* No reply code, must be proxied... */
1172 #ifdef WITH_PROXY
1173                 vp = pairfind(fake->config_items, PW_PROXY_TO_REALM);
1174                 if (vp) {
1175                         eap_tunnel_data_t *tunnel;
1176                         RDEBUG("Tunneled authentication will be proxied to %s", vp->vp_strvalue);
1177
1178                         /*
1179                          *      Tell the original request that it's going
1180                          *      to be proxied.
1181                          */
1182                         pairmove2(&(request->config_items),
1183                                   &(fake->config_items),
1184                                   PW_PROXY_TO_REALM);
1185
1186                         /*
1187                          *      Seed the proxy packet with the
1188                          *      tunneled request.
1189                          */
1190                         rad_assert(request->proxy == NULL);
1191                         request->proxy = fake->packet;
1192                         memset(&request->proxy->src_ipaddr, 0,
1193                                sizeof(request->proxy->src_ipaddr));
1194                         memset(&request->proxy->src_ipaddr, 0,
1195                                sizeof(request->proxy->src_ipaddr));
1196                         request->proxy->src_port = 0;
1197                         request->proxy->dst_port = 0;
1198                         fake->packet = NULL;
1199                         rad_free(&fake->reply);
1200                         fake->reply = NULL;
1201
1202                         /*
1203                          *      Set up the callbacks for the tunnel
1204                          */
1205                         tunnel = rad_malloc(sizeof(*tunnel));
1206                         memset(tunnel, 0, sizeof(*tunnel));
1207
1208                         tunnel->tls_session = tls_session;
1209                         tunnel->callback = eapttls_postproxy;
1210
1211                         /*
1212                          *      Associate the callback with the request.
1213                          */
1214                         rcode = request_data_add(request,
1215                                                  request->proxy,
1216                                                  REQUEST_DATA_EAP_TUNNEL_CALLBACK,
1217                                                  tunnel, free);
1218                         rad_assert(rcode == 0);
1219
1220                         /*
1221                          *      rlm_eap.c has taken care of associating
1222                          *      the handler with the fake request.
1223                          *
1224                          *      So we associate the fake request with
1225                          *      this request.
1226                          */
1227                         rcode = request_data_add(request,
1228                                                  request->proxy,
1229                                                  REQUEST_DATA_EAP_MSCHAP_TUNNEL_CALLBACK,
1230                                                  fake, my_request_free);
1231                         rad_assert(rcode == 0);
1232                         fake = NULL;
1233
1234                         /*
1235                          *      Didn't authenticate the packet, but
1236                          *      we're proxying it.
1237                          */
1238                         rcode = PW_STATUS_CLIENT;
1239
1240                 } else
1241 #endif  /* WITH_PROXY */
1242                   {
1243                         RDEBUG("No tunneled reply was found for request %d , and the request was not proxied: rejecting the user.",
1244                                request->number);
1245                         rcode = PW_AUTHENTICATION_REJECT;
1246                 }
1247                 break;
1248
1249         default:
1250                 /*
1251                  *      Returns RLM_MODULE_FOO, and we want to return
1252                  *      PW_FOO
1253                  */
1254                 rcode = process_reply(handler, tls_session, request,
1255                                       fake->reply);
1256                 switch (rcode) {
1257                 case RLM_MODULE_REJECT:
1258                         rcode = PW_AUTHENTICATION_REJECT;
1259                         break;
1260
1261                 case RLM_MODULE_HANDLED:
1262                         rcode = PW_ACCESS_CHALLENGE;
1263                         break;
1264
1265                 case RLM_MODULE_OK:
1266                         rcode = PW_AUTHENTICATION_ACK;
1267                         break;
1268
1269                 default:
1270                         rcode = PW_AUTHENTICATION_REJECT;
1271                         break;
1272                 }
1273                 break;
1274         }
1275
1276         request_free(&fake);
1277
1278         return rcode;
1279 }