src/lib/radius.c

   1 /*
   2  * radius.c     Functions to send/receive radius packets.
   3  *
   4  * Version:     $Id$
   5  *
   6  *   This library is free software; you can redistribute it and/or
   7  *   modify it under the terms of the GNU Lesser General Public
   8  *   License as published by the Free Software Foundation; either
   9  *   version 2.1 of the License, or (at your option) any later version.
  10  *
  11  *   This library 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 GNU
  14  *   Lesser General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU Lesser General Public
  17  *   License along with this library; if not, write to the Free Software
  18  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * Copyright 2000-2003,2006  The FreeRADIUS server project
  21  */
  22
  23 #include        <freeradius-devel/ident.h>
  24 RCSID("$Id$")
  25
  26 #include        <freeradius-devel/libradius.h>
  27 #include        <freeradius-devel/md5.h>
  28
  29 #include        <fcntl.h>
  30 #include        <ctype.h>
  31
  32 #ifdef WITH_UDPFROMTO
  33 #include        <freeradius-devel/udpfromto.h>
  34 #endif
  35
  36 #ifdef HAVE_MALLOC_H
  37 #include        <malloc.h>
  38 #endif
  39
  40 /*
  41  *  The RFC says 4096 octets max, and most packets are less than 256.
  42  */
  43 #define MAX_PACKET_LEN 4096
  44
  45 /*
  46  *      The maximum number of attributes which we allow in an incoming
  47  *      request.  If there are more attributes than this, the request
  48  *      is rejected.
  49  *
  50  *      This helps to minimize the potential for a DoS, when an
  51  *      attacker spoofs Access-Request packets, which don't have a
  52  *      Message-Authenticator attribute.  This means that the packet
  53  *      is unsigned, and the attacker can use resources on the server,
  54  *      even if the end request is rejected.
  55  */
  56 int fr_max_attributes = 0;
  57 FILE *fr_log_fp = NULL;
  58
  59 typedef struct radius_packet_t {
  60   uint8_t       code;
  61   uint8_t       id;
  62   uint8_t       length[2];
  63   uint8_t       vector[AUTH_VECTOR_LEN];
  64   uint8_t       data[1];
  65 } radius_packet_t;
  66
  67 static fr_randctx fr_rand_pool; /* across multiple calls */
  68 static int fr_rand_initialized = 0;
  69 static unsigned int salt_offset = 0;
  70
  71 const char *fr_packet_codes[FR_MAX_PACKET_CODE] = {
  72   "",
  73   "Access-Request",
  74   "Access-Accept",
  75   "Access-Reject",
  76   "Accounting-Request",
  77   "Accounting-Response",
  78   "Accounting-Status",
  79   "Password-Request",
  80   "Password-Accept",
  81   "Password-Reject",
  82   "Accounting-Message",
  83   "Access-Challenge",
  84   "Status-Server",
  85   "Status-Client",
  86   "14",
  87   "15",
  88   "16",
  89   "17",
  90   "18",
  91   "19",
  92   "20",
  93   "Resource-Free-Request",
  94   "Resource-Free-Response",
  95   "Resource-Query-Request",
  96   "Resource-Query-Response",
  97   "Alternate-Resource-Reclaim-Request",
  98   "NAS-Reboot-Request",
  99   "NAS-Reboot-Response",
 100   "28",
 101   "Next-Passcode",
 102   "New-Pin",
 103   "Terminate-Session",
 104   "Password-Expired",
 105   "Event-Request",
 106   "Event-Response",
 107   "35",
 108   "36",
 109   "37",
 110   "38",
 111   "39",
 112   "Disconnect-Request",
 113   "Disconnect-ACK",
 114   "Disconnect-NAK",
 115   "CoA-Request",
 116   "CoA-ACK",
 117   "CoA-NAK",
 118   "46",
 119   "47",
 120   "48",
 121   "49",
 122   "IP-Address-Allocate",
 123   "IP-Address-Release"
 124 };
 125
 126
 127 void fr_printf_log(const char *fmt, ...)
 128 {
 129         va_list ap;
 130
 131         va_start(ap, fmt);
 132         if ((fr_debug_flag == 0) || !fr_log_fp) {
 133                 va_end(ap);
 134                 return;
 135         }
 136
 137         vfprintf(fr_log_fp, fmt, ap);
 138         va_end(ap);
 139
 140         return;
 141 }
 142
 143 static void print_hex(RADIUS_PACKET *packet)
 144 {
 145         int i;
 146
 147         if (!packet->data) return;
 148
 149         printf("  Code:\t\t%u\n", packet->data[0]);
 150         printf("  Id:\t\t%u\n", packet->data[1]);
 151         printf("  Length:\t%u\n", ((packet->data[2] << 8) |
 152                                    (packet->data[3])));
 153         printf("  Vector:\t");
 154         for (i = 4; i < 20; i++) {
 155                 printf("%02x", packet->data[i]);
 156         }
 157         printf("\n");
 158
 159         if (packet->data_len > 20) {
 160                 int total;
 161                 const uint8_t *ptr;
 162                 printf("  Data:");
 163
 164                 total = packet->data_len - 20;
 165                 ptr = packet->data + 20;
 166
 167                 while (total > 0) {
 168                         int attrlen;
 169
 170                         printf("\t\t");
 171                         if (total < 2) { /* too short */
 172                                 printf("%02x\n", *ptr);
 173                                 break;
 174                         }
 175
 176                         if (ptr[1] > total) { /* too long */
 177                                 for (i = 0; i < total; i++) {
 178                                         printf("%02x ", ptr[i]);
 179                                 }
 180                                 break;
 181                         }
 182
 183                         printf("%02x  %02x  ", ptr[0], ptr[1]);
 184                         attrlen = ptr[1] - 2;
 185                         ptr += 2;
 186                         total -= 2;
 187
 188                         for (i = 0; i < attrlen; i++) {
 189                                 if ((i > 0) && ((i & 0x0f) == 0x00))
 190                                         printf("\t\t\t");
 191                                 printf("%02x ", ptr[i]);
 192                                 if ((i & 0x0f) == 0x0f) printf("\n");
 193                         }
 194
 195                         if ((attrlen & 0x0f) != 0x00) printf("\n");
 196
 197                         ptr += attrlen;
 198                         total -= attrlen;
 199                 }
 200         }
 201         fflush(stdout);
 202 }
 203
 204
 205 /*
 206  *      Wrapper for sendto which handles sendfromto, IPv6, and all
 207  *      possible combinations.
 208  */
 209 static int rad_sendto(int sockfd, void *data, size_t data_len, int flags,
 210                       fr_ipaddr_t *src_ipaddr, int src_port,
 211                       fr_ipaddr_t *dst_ipaddr, int dst_port)
 212 {
 213         struct sockaddr_storage dst;
 214         socklen_t               sizeof_dst;
 215
 216 #ifdef WITH_UDPFROMTO
 217         struct sockaddr_storage src;
 218         socklen_t               sizeof_src;
 219
 220         fr_ipaddr2sockaddr(src_ipaddr, src_port, &src, &sizeof_src);
 221 #else
 222         src_port = src_port;    /* -Wunused */
 223 #endif
 224
 225         if (!fr_ipaddr2sockaddr(dst_ipaddr, dst_port, &dst, &sizeof_dst)) {
 226                 return -1;
 227         }
 228
 229 #ifdef WITH_UDPFROMTO
 230         /*
 231          *      Only IPv4 is supported for udpfromto.
 232          *
 233          *      And if they don't specify a source IP address, don't
 234          *      use udpfromto.
 235          */
 236         if ((dst_ipaddr->af == AF_INET) ||
 237             (src_ipaddr->af != AF_UNSPEC)) {
 238                 return sendfromto(sockfd, data, data_len, flags,
 239                                   (struct sockaddr *)&src, sizeof_src,
 240                                   (struct sockaddr *)&dst, sizeof_dst);
 241         }
 242 #else
 243         src_ipaddr = src_ipaddr; /* -Wunused */
 244 #endif
 245
 246         /*
 247          *      No udpfromto, OR an IPv6 socket, fail gracefully.
 248          */
 249         return sendto(sockfd, data, data_len, flags,
 250                       (struct sockaddr *) &dst, sizeof_dst);
 251 }
 252
 253
 254 void rad_recv_discard(int sockfd)
 255 {
 256         uint8_t                 header[4];
 257         struct sockaddr_storage src;
 258         socklen_t               sizeof_src = sizeof(src);
 259
 260         recvfrom(sockfd, header, sizeof(header), 0,
 261                  (struct sockaddr *)&src, &sizeof_src);
 262 }
 263
 264
 265 ssize_t rad_recv_header(int sockfd, fr_ipaddr_t *src_ipaddr, int *src_port,
 266                         int *code)
 267 {
 268         ssize_t                 data_len, packet_len;
 269         uint8_t                 header[4];
 270         struct sockaddr_storage src;
 271         socklen_t               sizeof_src = sizeof(src);
 272
 273         data_len = recvfrom(sockfd, header, sizeof(header), MSG_PEEK,
 274                             (struct sockaddr *)&src, &sizeof_src);
 275         if (data_len < 0) {
 276                 if ((errno == EAGAIN) || (errno == EINTR)) return 0;
 277                 return -1;
 278         }
 279
 280         /*
 281          *      Too little data is available, discard the packet.
 282          */
 283         if (data_len < 4) {
 284                 recvfrom(sockfd, header, sizeof(header), 0,
 285                          (struct sockaddr *)&src, &sizeof_src);
 286                 return 1;
 287
 288         } else {                /* we got 4 bytes of data. */
 289                 /*
 290                  *      See how long the packet says it is.
 291                  */
 292                 packet_len = (header[2] * 256) + header[3];
 293
 294                 /*
 295                  *      The length in the packet says it's less than
 296                  *      a RADIUS header length: discard it.
 297                  */
 298                 if (packet_len < AUTH_HDR_LEN) {
 299                         recvfrom(sockfd, header, sizeof(header), 0,
 300                                  (struct sockaddr *)&src, &sizeof_src);
 301                         return 1;
 302
 303                         /*
 304                          *      Enforce RFC requirements, for sanity.
 305                          *      Anything after 4k will be discarded.
 306                          */
 307                 } else if (packet_len > MAX_PACKET_LEN) {
 308                         recvfrom(sockfd, header, sizeof(header), 0,
 309                                  (struct sockaddr *)&src, &sizeof_src);
 310                         return 1;
 311                 }
 312         }
 313
 314         /*
 315          *      Convert AF.  If unknown, discard packet.
 316          */
 317         if (!fr_sockaddr2ipaddr(&src, sizeof_src, src_ipaddr, src_port)) {
 318                 recvfrom(sockfd, header, sizeof(header), 0,
 319                          (struct sockaddr *)&src, &sizeof_src);
 320                 return 1;
 321         }
 322
 323         *code = header[0];
 324
 325         /*
 326          *      The packet says it's this long, but the actual UDP
 327          *      size could still be smaller.
 328          */
 329         return packet_len;
 330 }
 331
 332
 333 /*
 334  *      wrapper for recvfrom, which handles recvfromto, IPv6, and all
 335  *      possible combinations.
 336  */
 337 static ssize_t rad_recvfrom(int sockfd, uint8_t **pbuf, int flags,
 338                             fr_ipaddr_t *src_ipaddr, uint16_t *src_port,
 339                             fr_ipaddr_t *dst_ipaddr, uint16_t *dst_port)
 340 {
 341         struct sockaddr_storage src;
 342         struct sockaddr_storage dst;
 343         socklen_t               sizeof_src = sizeof(src);
 344         socklen_t               sizeof_dst = sizeof(dst);
 345         ssize_t                 data_len;
 346         uint8_t                 header[4];
 347         void                    *buf;
 348         size_t                  len;
 349         int                     port;
 350
 351         memset(&src, 0, sizeof_src);
 352         memset(&dst, 0, sizeof_dst);
 353
 354         /*
 355          *      Get address family, etc. first, so we know if we
 356          *      need to do udpfromto.
 357          *
 358          *      FIXME: udpfromto also does this, but it's not
 359          *      a critical problem.
 360          */
 361         if (getsockname(sockfd, (struct sockaddr *)&dst,
 362                         &sizeof_dst) < 0) return -1;
 363
 364         /*
 365          *      Read the length of the packet, from the packet.
 366          *      This lets us allocate the buffer to use for
 367          *      reading the rest of the packet.
 368          */
 369         data_len = recvfrom(sockfd, header, sizeof(header), MSG_PEEK,
 370                             (struct sockaddr *)&src, &sizeof_src);
 371         if (data_len < 0) {
 372                 if ((errno == EAGAIN) || (errno == EINTR)) return 0;
 373                 return -1;
 374         }
 375
 376         /*
 377          *      Too little data is available, discard the packet.
 378          */
 379         if (data_len < 4) {
 380                 recvfrom(sockfd, header, sizeof(header), flags,
 381                          (struct sockaddr *)&src, &sizeof_src);
 382                 return 0;
 383
 384         } else {                /* we got 4 bytes of data. */
 385                 /*
 386                  *      See how long the packet says it is.
 387                  */
 388                 len = (header[2] * 256) + header[3];
 389
 390                 /*
 391                  *      The length in the packet says it's less than
 392                  *      a RADIUS header length: discard it.
 393                  */
 394                 if (len < AUTH_HDR_LEN) {
 395                         recvfrom(sockfd, header, sizeof(header), flags,
 396                                  (struct sockaddr *)&src, &sizeof_src);
 397                         return 0;
 398
 399                         /*
 400                          *      Enforce RFC requirements, for sanity.
 401                          *      Anything after 4k will be discarded.
 402                          */
 403                 } else if (len > MAX_PACKET_LEN) {
 404                         recvfrom(sockfd, header, sizeof(header), flags,
 405                                  (struct sockaddr *)&src, &sizeof_src);
 406                         return len;
 407                 }
 408         }
 409
 410         buf = malloc(len);
 411         if (!buf) return -1;
 412
 413         /*
 414          *      Receive the packet.  The OS will discard any data in the
 415          *      packet after "len" bytes.
 416          */
 417 #ifdef WITH_UDPFROMTO
 418         if (dst.ss_family == AF_INET) {
 419                 data_len = recvfromto(sockfd, buf, len, flags,
 420                                       (struct sockaddr *)&src, &sizeof_src,
 421                                       (struct sockaddr *)&dst, &sizeof_dst);
 422         } else
 423 #endif
 424                 /*
 425                  *      No udpfromto, OR an IPv6 socket.  Fail gracefully.
 426                  */
 427                 data_len = recvfrom(sockfd, buf, len, flags,
 428                                     (struct sockaddr *)&src, &sizeof_src);
 429         if (data_len < 0) {
 430                 free(buf);
 431                 return data_len;
 432         }
 433
 434         if (!fr_sockaddr2ipaddr(&src, sizeof_src, src_ipaddr, &port)) {
 435                 free(buf);
 436                 return -1;      /* Unknown address family, Die Die Die! */
 437         }
 438         *src_port = port;
 439
 440         fr_sockaddr2ipaddr(&dst, sizeof_dst, dst_ipaddr, &port);
 441         *dst_port = port;
 442
 443         /*
 444          *      Different address families should never happen.
 445          */
 446         if (src.ss_family != dst.ss_family) {
 447                 free(buf);
 448                 return -1;
 449         }
 450
 451         /*
 452          *      Tell the caller about the data
 453          */
 454         *pbuf = buf;
 455
 456         return data_len;
 457 }
 458
 459
 460 #define AUTH_PASS_LEN (AUTH_VECTOR_LEN)
 461 /*************************************************************************
 462  *
 463  *      Function: make_secret
 464  *
 465  *      Purpose: Build an encrypted secret value to return in a reply
 466  *               packet.  The secret is hidden by xoring with a MD5 digest
 467  *               created from the shared secret and the authentication
 468  *               vector.  We put them into MD5 in the reverse order from
 469  *               that used when encrypting passwords to RADIUS.
 470  *
 471  *************************************************************************/
 472 static void make_secret(uint8_t *digest, const uint8_t *vector,
 473                         const char *secret, const uint8_t *value)
 474 {
 475         FR_MD5_CTX context;
 476         int             i;
 477
 478         fr_MD5Init(&context);
 479         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
 480         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
 481         fr_MD5Final(digest, &context);
 482
 483         for ( i = 0; i < AUTH_VECTOR_LEN; i++ ) {
 484                 digest[i] ^= value[i];
 485         }
 486 }
 487
 488 #define MAX_PASS_LEN (128)
 489 static void make_passwd(uint8_t *output, size_t *outlen,
 490                         const uint8_t *input, size_t inlen,
 491                         const char *secret, const uint8_t *vector)
 492 {
 493         FR_MD5_CTX context, old;
 494         uint8_t digest[AUTH_VECTOR_LEN];
 495         uint8_t passwd[MAX_PASS_LEN];
 496         int     i, n;
 497         int     len;
 498
 499         /*
 500          *      If the length is zero, round it up.
 501          */
 502         len = inlen;
 503
 504         if (len > MAX_PASS_LEN) len = MAX_PASS_LEN;
 505
 506         memcpy(passwd, input, len);
 507         memset(passwd + len, 0, sizeof(passwd) - len);
 508
 509         if (len == 0) {
 510                 len = AUTH_PASS_LEN;
 511         }
 512
 513         else if ((len & 0x0f) != 0) {
 514                 len += 0x0f;
 515                 len &= ~0x0f;
 516         }
 517         *outlen = len;
 518
 519         fr_MD5Init(&context);
 520         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
 521         old = context;
 522
 523         /*
 524          *      Do first pass.
 525          */
 526         fr_MD5Update(&context, vector, AUTH_PASS_LEN);
 527
 528         for (n = 0; n < len; n += AUTH_PASS_LEN) {
 529                 if (n > 0) {
 530                         context = old;
 531                         fr_MD5Update(&context,
 532                                        passwd + n - AUTH_PASS_LEN,
 533                                        AUTH_PASS_LEN);
 534                 }
 535
 536                 fr_MD5Final(digest, &context);
 537                 for (i = 0; i < AUTH_PASS_LEN; i++) {
 538                         passwd[i + n] ^= digest[i];
 539                 }
 540         }
 541
 542         memcpy(output, passwd, len);
 543 }
 544
 545 static void make_tunnel_passwd(uint8_t *output, size_t *outlen,
 546                                const uint8_t *input, size_t inlen, size_t room,
 547                                const char *secret, const uint8_t *vector)
 548 {
 549         FR_MD5_CTX context, old;
 550         uint8_t digest[AUTH_VECTOR_LEN];
 551         uint8_t passwd[MAX_STRING_LEN + AUTH_VECTOR_LEN];
 552         int     i, n;
 553         int     len;
 554
 555         /*
 556          *      Be paranoid.
 557          */
 558         if (room > 253) room = 253;
 559
 560         /*
 561          *      Account for 2 bytes of the salt, and round the room
 562          *      available down to the nearest multiple of 16.  Then,
 563          *      subtract one from that to account for the length byte,
 564          *      and the resulting number is the upper bound on the data
 565          *      to copy.
 566          *
 567          *      We could short-cut this calculation just be forcing
 568          *      inlen to be no more than 239.  It would work for all
 569          *      VSA's, as we don't pack multiple VSA's into one
 570          *      attribute.
 571          *
 572          *      However, this calculation is more general, if a little
 573          *      complex.  And it will work in the future for all possible
 574          *      kinds of weird attribute packing.
 575          */
 576         room -= 2;
 577         room -= (room & 0x0f);
 578         room--;
 579
 580         if (inlen > room) inlen = room;
 581
 582         /*
 583          *      Length of the encrypted data is password length plus
 584          *      one byte for the length of the password.
 585          */
 586         len = inlen + 1;
 587         if ((len & 0x0f) != 0) {
 588                 len += 0x0f;
 589                 len &= ~0x0f;
 590         }
 591         *outlen = len + 2;      /* account for the salt */
 592
 593         /*
 594          *      Copy the password over.
 595          */
 596         memcpy(passwd + 3, input, inlen);
 597         memset(passwd + 3 + inlen, 0, sizeof(passwd) - 3 - inlen);
 598
 599         /*
 600          *      Generate salt.  The RFC's say:
 601          *
 602          *      The high bit of salt[0] must be set, each salt in a
 603          *      packet should be unique, and they should be random
 604          *
 605          *      So, we set the high bit, add in a counter, and then
 606          *      add in some CSPRNG data.  should be OK..
 607          */
 608         passwd[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
 609                      (fr_rand() & 0x07));
 610         passwd[1] = fr_rand();
 611         passwd[2] = inlen;      /* length of the password string */
 612
 613         fr_MD5Init(&context);
 614         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
 615         old = context;
 616
 617         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
 618         fr_MD5Update(&context, &passwd[0], 2);
 619
 620         for (n = 0; n < len; n += AUTH_PASS_LEN) {
 621                 if (n > 0) {
 622                         context = old;
 623                         fr_MD5Update(&context,
 624                                        passwd + 2 + n - AUTH_PASS_LEN,
 625                                        AUTH_PASS_LEN);
 626                 }
 627
 628                 fr_MD5Final(digest, &context);
 629                 for (i = 0; i < AUTH_PASS_LEN; i++) {
 630                         passwd[i + 2 + n] ^= digest[i];
 631                 }
 632         }
 633         memcpy(output, passwd, len + 2);
 634 }
 635
 636 /*
 637  *      Returns the end of the data.
 638  */
 639 static uint8_t *vp2data(const RADIUS_PACKET *packet,
 640                         const RADIUS_PACKET *original,
 641                         const char *secret, const VALUE_PAIR *vp, uint8_t *ptr,
 642                         size_t room)
 643 {
 644         uint32_t lvalue;
 645         size_t len;
 646         const uint8_t *data;
 647         uint8_t array[4];
 648
 649         /*
 650          *      Set up the default sources for the data.
 651          */
 652         data = vp->vp_octets;
 653         len = vp->length;
 654
 655         switch(vp->type) {
 656         case PW_TYPE_STRING:
 657         case PW_TYPE_OCTETS:
 658         case PW_TYPE_IFID:
 659         case PW_TYPE_IPV6ADDR:
 660         case PW_TYPE_IPV6PREFIX:
 661         case PW_TYPE_ABINARY:
 662                 /* nothing more to do */
 663                 break;
 664
 665         case PW_TYPE_BYTE:
 666                 len = 1;        /* just in case */
 667                 array[0] = vp->vp_integer & 0xff;
 668                 data = array;
 669                 break;
 670
 671         case PW_TYPE_SHORT:
 672                 len = 2;        /* just in case */
 673                 array[0] = (vp->vp_integer >> 8) & 0xff;
 674                 array[1] = vp->vp_integer & 0xff;
 675                 data = array;
 676                 break;
 677
 678         case PW_TYPE_INTEGER:
 679                 len = 4;        /* just in case */
 680                 lvalue = htonl(vp->vp_integer);
 681                 memcpy(array, &lvalue, sizeof(lvalue));
 682                 data = array;
 683                 break;
 684
 685         case PW_TYPE_IPADDR:
 686                 data = (const uint8_t *) &vp->vp_ipaddr;
 687                 len = 4;        /* just in case */
 688                 break;
 689
 690                 /*
 691                  *  There are no tagged date attributes.
 692                  */
 693         case PW_TYPE_DATE:
 694                 lvalue = htonl(vp->vp_date);
 695                 data = (const uint8_t *) &lvalue;
 696                 len = 4;        /* just in case */
 697                 break;
 698
 699         case PW_TYPE_SIGNED:
 700         {
 701                 int32_t slvalue;
 702
 703                 len = 4;        /* just in case */
 704                 slvalue = htonl(vp->vp_signed);
 705                 memcpy(array, &slvalue, sizeof(slvalue));
 706                 break;
 707         }
 708
 709         case PW_TYPE_TLV:
 710                 data = vp->vp_tlv;
 711                 if (!data) {
 712                         fr_strerror_printf("ERROR: Cannot encode NULL TLV");
 713                         return NULL;
 714                 }
 715                 if (vp->length > room) return 0; /* can't chop TLVs to fit */
 716                 break;
 717
 718         default:                /* unknown type: ignore it */
 719                 fr_strerror_printf("ERROR: Unknown attribute type %d", vp->type);
 720                 return NULL;
 721         }
 722
 723         /*
 724          *      Bound the data to the calling size
 725          */
 726         if (len > room) len = room;
 727
 728         /*
 729          *      Encrypt the various password styles
 730          *
 731          *      Attributes with encrypted values MUST be less than
 732          *      128 bytes long.
 733          */
 734         switch (vp->flags.encrypt) {
 735         case FLAG_ENCRYPT_USER_PASSWORD:
 736                 make_passwd(ptr, &len, data, len,
 737                             secret, packet->vector);
 738                 break;
 739
 740         case FLAG_ENCRYPT_TUNNEL_PASSWORD:
 741                 /*
 742                  *      Check if there's enough room.  If there isn't,
 743                  *      we discard the attribute.
 744                  *
 745                  *      This is ONLY a problem if we have multiple VSA's
 746                  *      in one Vendor-Specific, though.
 747                  */
 748                 if (room < 18) return ptr;
 749
 750                 switch (packet->code) {
 751                 case PW_AUTHENTICATION_ACK:
 752                 case PW_AUTHENTICATION_REJECT:
 753                 case PW_ACCESS_CHALLENGE:
 754                 default:
 755                         if (!original) {
 756                                 fr_strerror_printf("ERROR: No request packet, cannot encrypt %s attribute in the vp.", vp->name);
 757                                 return NULL;
 758                         }
 759                         make_tunnel_passwd(ptr, &len, data, len, room,
 760                                            secret, original->vector);
 761                         break;
 762                 case PW_ACCOUNTING_REQUEST:
 763                 case PW_DISCONNECT_REQUEST:
 764                 case PW_COA_REQUEST:
 765                         make_tunnel_passwd(ptr, &len, data, len, room,
 766                                            secret, packet->vector);
 767                         break;
 768                 }
 769                 break;
 770
 771                 /*
 772                  *      The code above ensures that this attribute
 773                  *      always fits.
 774                  */
 775         case FLAG_ENCRYPT_ASCEND_SECRET:
 776                 make_secret(ptr, packet->vector, secret, data);
 777                 len = AUTH_VECTOR_LEN;
 778                 break;
 779
 780
 781         default:
 782                 /*
 783                  *      Just copy the data over
 784                  */
 785                 memcpy(ptr, data, len);
 786                 break;
 787         } /* switch over encryption flags */
 788
 789         return ptr + len;
 790 }
 791
 792
 793 /*
 794  *      Parse a data structure into a RADIUS attribute.
 795  */
 796 int rad_vp2attr(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
 797                 const char *secret, const VALUE_PAIR *vp, uint8_t *start,
 798                 size_t room)
 799 {
 800         int             vendorcode;
 801         int             len, total_length;
 802         uint32_t        lvalue;
 803         uint8_t         *ptr, *length_ptr, *vsa_length_ptr, *tlv_length_ptr;
 804         uint8_t         *end, *sub_length_ptr; /* evil */
 805
 806         ptr = start;
 807         vendorcode = total_length = 0;
 808         length_ptr = vsa_length_ptr = tlv_length_ptr = sub_length_ptr = NULL;
 809
 810         /*
 811          *      For interoperability, always put vendor attributes
 812          *      into their own VSA.
 813          */
 814         if ((vendorcode = vp->vendor) == 0) {
 815                 if (room < 2) return 0;
 816                 room -= 2;
 817
 818                 *(ptr++) = vp->attribute & 0xff;
 819                 length_ptr = ptr;
 820                 *(ptr++) = 2;
 821                 total_length += 2;
 822
 823         } else {
 824                 int vsa_tlen = 1;
 825                 int vsa_llen = 1;
 826                 int vsa_offset = 0;
 827                 DICT_VENDOR *dv = dict_vendorbyvalue(vendorcode);
 828
 829                 /*
 830                  *      This must be an RFC-format attribute.  If it
 831                  *      wasn't, then the "decode" function would have
 832                  *      made a Vendor-Specific attribute (i.e. type
 833                  *      26), and we would have "vendorcode == 0" here.
 834                  */
 835                 if (dv) {
 836                         vsa_tlen = dv->type;
 837                         vsa_llen = dv->length;
 838                         if (dv->flags) vsa_offset = 1;
 839                 }
 840
 841                 if (room < (6 + vsa_tlen + vsa_llen + vsa_offset)) return 0;
 842                 room -= 6 + vsa_tlen + vsa_llen + vsa_offset;
 843
 844                 /*
 845                  *      Build a VSA header.
 846                  */
 847                 *ptr++ = PW_VENDOR_SPECIFIC;
 848                 vsa_length_ptr = ptr;
 849                 *ptr++ = 6;
 850                 lvalue = htonl(vendorcode);
 851                 memcpy(ptr, &lvalue, 4);
 852                 ptr += 4;
 853                 total_length += 6;
 854
 855                 switch (vsa_tlen) {
 856                 case 1:
 857                         ptr[0] = (vp->attribute & 0xFF);
 858                         break;
 859
 860                 case 2:
 861                         ptr[0] = ((vp->attribute >> 8) & 0xFF);
 862                         ptr[1] = (vp->attribute & 0xFF);
 863                         break;
 864
 865                 case 4:
 866                         ptr[0] = 0;
 867                         ptr[1] = 0;
 868                         ptr[2] = ((vp->attribute >> 8) & 0xFF);
 869                         ptr[3] = (vp->attribute & 0xFF);
 870                         break;
 871
 872                 default:
 873                         return 0; /* silently discard it */
 874                 }
 875                 ptr += vsa_tlen;
 876
 877                 switch (vsa_llen) {
 878                 case 0:
 879                         length_ptr = vsa_length_ptr;
 880                         vsa_length_ptr = NULL;
 881                         break;
 882                 case 1:
 883                         ptr[0] = 0;
 884                         length_ptr = ptr;
 885                         break;
 886                 case 2:
 887                         ptr[0] = 0;
 888                         ptr[1] = 0;
 889                         length_ptr = ptr + 1;
 890                         break;
 891
 892                 default:
 893                         return 0; /* silently discard it */
 894                 }
 895                 ptr += vsa_llen;
 896
 897                 /*
 898                  *      Allow for some continuation.
 899                  */
 900                 if (vsa_offset) {
 901                         ptr[0] = 0x00;
 902                         ptr++;
 903
 904                         /*
 905                          *      Ignore TLVs that don't have data, OR
 906                          *      have too much data to fit in the
 907                          *      packet, OR have too much data to fit
 908                          *      in the attribute
 909                          *
 910                          *      This shouldn't happen in normal
 911                          *      operation, as the code assumes that
 912                          *      the "tlv" type shouldn't be used.
 913                          */
 914                         if (vp->flags.has_tlv &&
 915                             (!vp->vp_tlv || (vp->length > room) ||
 916
 917                              /*
 918                               *         6 + 1 (vsa_tlen) + 1 (vsa_llen)
 919                               *         + 1 (vsa_offset).
 920                               */
 921                              (vp->length > (255 - 9)))) return 0;
 922
 923
 924                         /*
 925                          *      sub-TLV's can only be in one format.
 926                          */
 927                         if (vp->flags.is_tlv) {
 928                                 if (room < 2) return 0;
 929                                 room -= 2;
 930
 931                                 *(ptr++) = (vp->attribute & 0xff00) >> 8;
 932                                 tlv_length_ptr = ptr;
 933                                 *(ptr++) = 2;
 934                                 vsa_offset += 2;
 935
 936                                 /*
 937                                  *      WiMAX is like sticking knitting
 938                                  *      needles up your nose, and claiming
 939                                  *      you like it.
 940                                  */
 941                                 if ((vp->attribute & 0xff0000) != 0) {
 942                                         *(ptr++) = (vp->attribute >> 16) & 0xff;
 943                                         sub_length_ptr = ptr;
 944                                         *(ptr++) = 2;
 945                                         vsa_offset += 2;
 946                                         *tlv_length_ptr += 2;
 947                                 }
 948                         }
 949                 }
 950
 951                 total_length += vsa_tlen + vsa_llen + vsa_offset;
 952                 if (vsa_length_ptr) *vsa_length_ptr += vsa_tlen + vsa_llen + vsa_offset;
 953                 *length_ptr += vsa_tlen + vsa_llen + vsa_offset;
 954         }
 955
 956         /*
 957          *      Insert tags for string attributes.  They go BEFORE
 958          *      the string.
 959          */
 960         if (vp->flags.has_tag && (vp->type == PW_TYPE_STRING) &&
 961             (TAG_VALID(vp->flags.tag) ||
 962              (vp->flags.encrypt == FLAG_ENCRYPT_TUNNEL_PASSWORD))) {
 963                 if (room < (1 + vp->length)) return 0;
 964
 965                 ptr[0] = vp->flags.tag;
 966                 end = vp2data(packet, original, secret, vp, ptr + 1,
 967                               (end - ptr) - 1);
 968         } else {
 969                 if (room < vp->length) return 0;
 970                 end = vp2data(packet, original, secret, vp, ptr,
 971                               (end - ptr));
 972         }
 973         if (!end) return -1;
 974
 975         /*
 976          *      Insert tags for integer attributes.  They go at the START
 977          *      of the integer, and over-write the first byte.
 978          */
 979         if (vp->flags.has_tag && (vp->type == PW_TYPE_INTEGER)) {
 980                 ptr[0] = vp->flags.tag;
 981         }
 982
 983         /*
 984          *      RFC 2865 section 5 says that zero-length attributes
 985          *      MUST NOT be sent.
 986          *
 987          *      ... and the WiMAX forum ignores this... because of
 988          *      one vendor.  Don't they have anything better to do
 989          *      with their time?
 990          */
 991         if ((end == ptr) &&
 992             (vp->attribute != PW_CHARGEABLE_USER_IDENTITY)) return 0;
 993
 994         len = (end - ptr);
 995
 996         /*
 997          *      Update the various lengths.
 998          */
 999         *length_ptr += len;
1000         if (vsa_length_ptr) *vsa_length_ptr += len;
1001         if (tlv_length_ptr) *tlv_length_ptr += len;
1002         if (sub_length_ptr) *sub_length_ptr += len;
1003         ptr += len;
1004         total_length += len;
1005
1006         return total_length;    /* of attribute */
1007 }
1008
1009 /*
1010  *  Swap 123a -> 0321
1011  */
1012 #define REORDER(x) ((x & 0xff00) << 8) | ((x & 0xff0000) >> 8) | ((x & 0xff000000 >> 24))
1013
1014 static int rad_encode_wimax(const RADIUS_PACKET *packet,
1015                             const RADIUS_PACKET *original,
1016                             const char *secret, VALUE_PAIR *reply,
1017                             uint8_t *start, size_t room)
1018 {
1019         int len, total_len = 0;
1020         uint8_t *wimax = NULL;
1021         uint8_t *ptr = start;
1022         uint32_t maxattr;
1023         VALUE_PAIR *vp = reply;
1024
1025         /*
1026          *      Swap the order of the WiMAX hacks, to make later
1027          *      comparisons easier.
1028          */
1029         maxattr = REORDER(vp->attribute);
1030
1031 redo:
1032         len = rad_vp2attr(packet, original, secret, vp, ptr,
1033                           (start + room) - ptr);
1034         if (len <= 0) return total_len;
1035
1036         /*
1037          *      After adding an attribute with the simplest encoding,
1038          *      check to see if we can append it to the previous one.
1039          */
1040         if (wimax) {
1041                 if ((wimax[1] + (ptr[1] - 6)) <= 255) {
1042                         unsigned int hack;
1043
1044                         hack = ptr[7] - 3;
1045                         memmove(ptr, ptr + 9, hack);
1046                         wimax[1] += hack;
1047                         wimax[7] += hack;
1048                         len -= 9;
1049
1050                         /*
1051                          *      See if we can nest sub-TLVs, too, in
1052                          *      order to shorten the encoding.
1053                          */
1054
1055                 } else {
1056                         wimax[8] = 0x80; /* set continuation */
1057                         wimax = ptr;
1058                 }
1059         } else {
1060                 wimax = ptr;
1061         }
1062
1063         total_len += len;
1064         ptr += len;
1065
1066         vp->flags.encoded = 1;
1067         vp = vp->next;
1068
1069         /*
1070          *      Look at the NEXT tlv.  Ensure that we encode
1071          *      attributes into a common VSA *only* if they are for
1072          *      the same WiMAX VSA, AND if the TLVs are in numerically
1073          *      increasing order.
1074          */
1075         if (vp && vp->flags.is_tlv && (reply->vendor == vp->vendor) &&
1076             ((reply->attribute & 0xff) == (vp->attribute & 0xff))) {
1077                 uint32_t attr;
1078
1079                 attr = REORDER(vp->attribute);
1080                 if (attr >= maxattr) {
1081                         maxattr = attr;
1082                         goto redo;
1083                 }
1084         }
1085
1086         return total_len;
1087 }
1088
1089
1090 /*
1091  *      Encode a packet.
1092  */
1093 int rad_encode(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1094                const char *secret)
1095 {
1096         radius_packet_t *hdr;
1097         uint8_t         *ptr;
1098         uint16_t        total_length;
1099         int             len;
1100         VALUE_PAIR      *reply;
1101         const char      *what;
1102         char            ip_buffer[128];
1103
1104         /*
1105          *      A 4K packet, aligned on 64-bits.
1106          */
1107         uint64_t        data[MAX_PACKET_LEN / sizeof(uint64_t)];
1108
1109         if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1110                 what = fr_packet_codes[packet->code];
1111         } else {
1112                 what = "Reply";
1113         }
1114
1115         DEBUG("Sending %s of id %d to %s port %d\n",
1116               what, packet->id,
1117               inet_ntop(packet->dst_ipaddr.af,
1118                         &packet->dst_ipaddr.ipaddr,
1119                         ip_buffer, sizeof(ip_buffer)),
1120               packet->dst_port);
1121
1122         /*
1123          *      Double-check some things based on packet code.
1124          */
1125         switch (packet->code) {
1126         case PW_AUTHENTICATION_ACK:
1127         case PW_AUTHENTICATION_REJECT:
1128         case PW_ACCESS_CHALLENGE:
1129                 if (!original) {
1130                         fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1131                         return -1;
1132                 }
1133                 break;
1134
1135                 /*
1136                  *      These packet vectors start off as all zero.
1137                  */
1138         case PW_ACCOUNTING_REQUEST:
1139         case PW_DISCONNECT_REQUEST:
1140         case PW_COA_REQUEST:
1141                 memset(packet->vector, 0, sizeof(packet->vector));
1142                 break;
1143
1144         default:
1145                 break;
1146         }
1147
1148         /*
1149          *      Use memory on the stack, until we know how
1150          *      large the packet will be.
1151          */
1152         hdr = (radius_packet_t *) data;
1153
1154         /*
1155          *      Build standard header
1156          */
1157         hdr->code = packet->code;
1158         hdr->id = packet->id;
1159
1160         memcpy(hdr->vector, packet->vector, sizeof(hdr->vector));
1161
1162         total_length = AUTH_HDR_LEN;
1163
1164         /*
1165          *      Load up the configuration values for the user
1166          */
1167         ptr = hdr->data;
1168         packet->offset = 0;
1169
1170         /*
1171          *      FIXME: Loop twice over the reply list.  The first time,
1172          *      calculate the total length of data.  The second time,
1173          *      allocate the memory, and fill in the VP's.
1174          *
1175          *      Hmm... this may be slower than just doing a small
1176          *      memcpy.
1177          */
1178
1179         /*
1180          *      Loop over the reply attributes for the packet.
1181          */
1182         for (reply = packet->vps; reply; reply = reply->next) {
1183                 /*
1184                  *      Ignore non-wire attributes
1185                  */
1186                 if ((reply->vendor == 0) &&
1187                     ((reply->attribute & 0xFFFF) > 0xff)) {
1188 #ifndef NDEBUG
1189                         /*
1190                          *      Permit the admin to send BADLY formatted
1191                          *      attributes with a debug build.
1192                          */
1193                         if (reply->attribute == PW_RAW_ATTRIBUTE) {
1194                                 memcpy(ptr, reply->vp_octets, reply->length);
1195                                 len = reply->length;
1196                                 goto next;
1197                         }
1198 #endif
1199                         continue;
1200                 }
1201
1202                 /*
1203                  *      Set the Message-Authenticator to the correct
1204                  *      length and initial value.
1205                  */
1206                 if (reply->attribute == PW_MESSAGE_AUTHENTICATOR) {
1207                         reply->length = AUTH_VECTOR_LEN;
1208                         memset(reply->vp_strvalue, 0, AUTH_VECTOR_LEN);
1209
1210                         /*
1211                          *      Cache the offset to the
1212                          *      Message-Authenticator
1213                          */
1214                         packet->offset = total_length;
1215                 }
1216
1217                 /*
1218                  *      Print out ONLY the attributes which
1219                  *      we're sending over the wire, and print
1220                  *      them out BEFORE they're encrypted.
1221                  */
1222                 debug_pair(reply);
1223
1224                 /*
1225                  *      Skip attributes that are encoded.
1226                  */
1227                 if (reply->flags.encoded) continue;
1228
1229                 if (reply->flags.is_tlv) {
1230                         len = rad_encode_wimax(packet, original, secret,
1231                                                reply, ptr,
1232                                                ((uint8_t *) data) + sizeof(data) - ptr);
1233                 } else {
1234
1235                         len = rad_vp2attr(packet, original, secret, reply, ptr,
1236                                           ((uint8_t *) data) + sizeof(data) - ptr);
1237                 }
1238
1239                 if (len < 0) return -1;
1240
1241         next:
1242                 ptr += len;
1243                 total_length += len;
1244         } /* done looping over all attributes */
1245
1246         /*
1247          *      Fill in the rest of the fields, and copy the data over
1248          *      from the local stack to the newly allocated memory.
1249          *
1250          *      Yes, all this 'memcpy' is slow, but it means
1251          *      that we only allocate the minimum amount of
1252          *      memory for a request.
1253          */
1254         packet->data_len = total_length;
1255         packet->data = (uint8_t *) malloc(packet->data_len);
1256         if (!packet->data) {
1257                 fr_strerror_printf("Out of memory");
1258                 return -1;
1259         }
1260
1261         memcpy(packet->data, hdr, packet->data_len);
1262         hdr = (radius_packet_t *) packet->data;
1263
1264         total_length = htons(total_length);
1265         memcpy(hdr->length, &total_length, sizeof(total_length));
1266
1267         return 0;
1268 }
1269
1270
1271 /*
1272  *      Sign a previously encoded packet.
1273  */
1274 int rad_sign(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1275              const char *secret)
1276 {
1277         radius_packet_t *hdr = (radius_packet_t *)packet->data;
1278
1279         /*
1280          *      It wasn't assigned an Id, this is bad!
1281          */
1282         if (packet->id < 0) {
1283                 fr_strerror_printf("ERROR: RADIUS packets must be assigned an Id.");
1284                 return -1;
1285         }
1286
1287         if (!packet->data || (packet->data_len < AUTH_HDR_LEN) ||
1288             (packet->offset < 0)) {
1289                 fr_strerror_printf("ERROR: You must call rad_encode() before rad_sign()");
1290                 return -1;
1291         }
1292
1293         /*
1294          *      If there's a Message-Authenticator, update it
1295          *      now, BEFORE updating the authentication vector.
1296          */
1297         if (packet->offset > 0) {
1298                 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
1299
1300                 switch (packet->code) {
1301                 case PW_ACCOUNTING_REQUEST:
1302                 case PW_ACCOUNTING_RESPONSE:
1303                 case PW_DISCONNECT_REQUEST:
1304                 case PW_DISCONNECT_ACK:
1305                 case PW_DISCONNECT_NAK:
1306                 case PW_COA_REQUEST:
1307                 case PW_COA_ACK:
1308                 case PW_COA_NAK:
1309                         memset(hdr->vector, 0, AUTH_VECTOR_LEN);
1310                         break;
1311
1312                 case PW_AUTHENTICATION_ACK:
1313                 case PW_AUTHENTICATION_REJECT:
1314                 case PW_ACCESS_CHALLENGE:
1315                         if (!original) {
1316                                 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1317                                 return -1;
1318                         }
1319                         memcpy(hdr->vector, original->vector,
1320                                AUTH_VECTOR_LEN);
1321                         break;
1322
1323                 default:        /* others have vector already set to zero */
1324                         break;
1325
1326                 }
1327
1328                 /*
1329                  *      Set the authentication vector to zero,
1330                  *      calculate the signature, and put it
1331                  *      into the Message-Authenticator
1332                  *      attribute.
1333                  */
1334                 fr_hmac_md5(packet->data, packet->data_len,
1335                             (const uint8_t *) secret, strlen(secret),
1336                             calc_auth_vector);
1337                 memcpy(packet->data + packet->offset + 2,
1338                        calc_auth_vector, AUTH_VECTOR_LEN);
1339
1340                 /*
1341                  *      Copy the original request vector back
1342                  *      to the raw packet.
1343                  */
1344                 memcpy(hdr->vector, packet->vector, AUTH_VECTOR_LEN);
1345         }
1346
1347         /*
1348          *      Switch over the packet code, deciding how to
1349          *      sign the packet.
1350          */
1351         switch (packet->code) {
1352                 /*
1353                  *      Request packets are not signed, bur
1354                  *      have a random authentication vector.
1355                  */
1356         case PW_AUTHENTICATION_REQUEST:
1357         case PW_STATUS_SERVER:
1358                 break;
1359
1360                 /*
1361                  *      Reply packets are signed with the
1362                  *      authentication vector of the request.
1363                  */
1364         default:
1365                 {
1366                         uint8_t digest[16];
1367
1368                         FR_MD5_CTX      context;
1369                         fr_MD5Init(&context);
1370                         fr_MD5Update(&context, packet->data, packet->data_len);
1371                         fr_MD5Update(&context, (const uint8_t *) secret,
1372                                      strlen(secret));
1373                         fr_MD5Final(digest, &context);
1374
1375                         memcpy(hdr->vector, digest, AUTH_VECTOR_LEN);
1376                         memcpy(packet->vector, digest, AUTH_VECTOR_LEN);
1377                         break;
1378                 }
1379         }/* switch over packet codes */
1380
1381         return 0;
1382 }
1383
1384 /*
1385  *      Reply to the request.  Also attach
1386  *      reply attribute value pairs and any user message provided.
1387  */
1388 int rad_send(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1389              const char *secret)
1390 {
1391         VALUE_PAIR              *reply;
1392         const char              *what;
1393         char                    ip_buffer[128];
1394
1395         /*
1396          *      Maybe it's a fake packet.  Don't send it.
1397          */
1398         if (!packet || (packet->sockfd < 0)) {
1399                 return 0;
1400         }
1401
1402         if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1403                 what = fr_packet_codes[packet->code];
1404         } else {
1405                 what = "Reply";
1406         }
1407
1408         /*
1409          *  First time through, allocate room for the packet
1410          */
1411         if (!packet->data) {
1412                 /*
1413                  *      Encode the packet.
1414                  */
1415                 if (rad_encode(packet, original, secret) < 0) {
1416                         return -1;
1417                 }
1418
1419                 /*
1420                  *      Re-sign it, including updating the
1421                  *      Message-Authenticator.
1422                  */
1423                 if (rad_sign(packet, original, secret) < 0) {
1424                         return -1;
1425                 }
1426
1427                 /*
1428                  *      If packet->data points to data, then we print out
1429                  *      the VP list again only for debugging.
1430                  */
1431         } else if (fr_debug_flag) {
1432                 DEBUG("Sending %s of id %d to %s port %d\n", what, packet->id,
1433                       inet_ntop(packet->dst_ipaddr.af,
1434                                 &packet->dst_ipaddr.ipaddr,
1435                                 ip_buffer, sizeof(ip_buffer)),
1436                       packet->dst_port);
1437
1438                 for (reply = packet->vps; reply; reply = reply->next) {
1439                         if ((reply->vendor == 0) &&
1440                             ((reply->attribute & 0xFFFF) > 0xff)) continue;
1441                         debug_pair(reply);
1442                 }
1443         }
1444
1445         /*
1446          *      And send it on it's way.
1447          */
1448         return rad_sendto(packet->sockfd, packet->data, packet->data_len, 0,
1449                           &packet->src_ipaddr, packet->src_port,
1450                           &packet->dst_ipaddr, packet->dst_port);
1451 }
1452
1453 /*
1454  *      Do a comparison of two authentication digests by comparing
1455  *      the FULL digest.  Otehrwise, the server can be subject to
1456  *      timing attacks that allow attackers find a valid message
1457  *      authenticator.
1458  *
1459  *      http://www.cs.rice.edu/~dwallach/pub/crosby-timing2009.pdf
1460  */
1461 static int digest_cmp(const uint8_t *a, const uint8_t *b, size_t length)
1462 {
1463         int result = 0;
1464         size_t i;
1465
1466         for (i = 0; i < length; i++) {
1467                 result |= a[i] ^ b[i];
1468         }
1469
1470         return result;          /* 0 is OK, !0 is !OK, just like memcmp */
1471 }
1472
1473
1474 /*
1475  *      Validates the requesting client NAS.  Calculates the
1476  *      signature based on the clients private key.
1477  */
1478 static int calc_acctdigest(RADIUS_PACKET *packet, const char *secret)
1479 {
1480         uint8_t         digest[AUTH_VECTOR_LEN];
1481         FR_MD5_CTX              context;
1482
1483         /*
1484          *      Zero out the auth_vector in the received packet.
1485          *      Then append the shared secret to the received packet,
1486          *      and calculate the MD5 sum. This must be the same
1487          *      as the original MD5 sum (packet->vector).
1488          */
1489         memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
1490
1491         /*
1492          *  MD5(packet + secret);
1493          */
1494         fr_MD5Init(&context);
1495         fr_MD5Update(&context, packet->data, packet->data_len);
1496         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1497         fr_MD5Final(digest, &context);
1498
1499         /*
1500          *      Return 0 if OK, 2 if not OK.
1501          */
1502         if (digest_cmp(digest, packet->vector, AUTH_VECTOR_LEN) != 0) return 2;
1503         return 0;
1504 }
1505
1506
1507 /*
1508  *      Validates the requesting client NAS.  Calculates the
1509  *      signature based on the clients private key.
1510  */
1511 static int calc_replydigest(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1512                             const char *secret)
1513 {
1514         uint8_t         calc_digest[AUTH_VECTOR_LEN];
1515         FR_MD5_CTX              context;
1516
1517         /*
1518          *      Very bad!
1519          */
1520         if (original == NULL) {
1521                 return 3;
1522         }
1523
1524         /*
1525          *  Copy the original vector in place.
1526          */
1527         memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
1528
1529         /*
1530          *  MD5(packet + secret);
1531          */
1532         fr_MD5Init(&context);
1533         fr_MD5Update(&context, packet->data, packet->data_len);
1534         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1535         fr_MD5Final(calc_digest, &context);
1536
1537         /*
1538          *  Copy the packet's vector back to the packet.
1539          */
1540         memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
1541
1542         /*
1543          *      Return 0 if OK, 2 if not OK.
1544          */
1545         if (digest_cmp(packet->vector, calc_digest, AUTH_VECTOR_LEN) != 0) return 2;
1546         return 0;
1547 }
1548
1549
1550 /*
1551  *      See if the data pointed to by PTR is a valid RADIUS packet.
1552  *
1553  *      packet is not 'const * const' because we may update data_len,
1554  *      if there's more data in the UDP packet than in the RADIUS packet.
1555  */
1556 int rad_packet_ok(RADIUS_PACKET *packet, int flags)
1557 {
1558         uint8_t                 *attr;
1559         int                     totallen;
1560         int                     count;
1561         radius_packet_t         *hdr;
1562         char                    host_ipaddr[128];
1563         int                     require_ma = 0;
1564         int                     seen_ma = 0;
1565         int                     num_attributes;
1566
1567         /*
1568          *      Check for packets smaller than the packet header.
1569          *
1570          *      RFC 2865, Section 3., subsection 'length' says:
1571          *
1572          *      "The minimum length is 20 ..."
1573          */
1574         if (packet->data_len < AUTH_HDR_LEN) {
1575                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (received %d < minimum %d)",
1576                            inet_ntop(packet->src_ipaddr.af,
1577                                      &packet->src_ipaddr.ipaddr,
1578                                      host_ipaddr, sizeof(host_ipaddr)),
1579                                    (int) packet->data_len, AUTH_HDR_LEN);
1580                 return 0;
1581         }
1582
1583         /*
1584          *      RFC 2865, Section 3., subsection 'length' says:
1585          *
1586          *      " ... and maximum length is 4096."
1587          */
1588         if (packet->data_len > MAX_PACKET_LEN) {
1589                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (received %d > maximum %d)",
1590                            inet_ntop(packet->src_ipaddr.af,
1591                                      &packet->src_ipaddr.ipaddr,
1592                                      host_ipaddr, sizeof(host_ipaddr)),
1593                                    (int) packet->data_len, MAX_PACKET_LEN);
1594                 return 0;
1595         }
1596
1597         /*
1598          *      Check for packets with mismatched size.
1599          *      i.e. We've received 128 bytes, and the packet header
1600          *      says it's 256 bytes long.
1601          */
1602         totallen = (packet->data[2] << 8) | packet->data[3];
1603         hdr = (radius_packet_t *)packet->data;
1604
1605         /*
1606          *      Code of 0 is not understood.
1607          *      Code of 16 or greate is not understood.
1608          */
1609         if ((hdr->code == 0) ||
1610             (hdr->code >= FR_MAX_PACKET_CODE)) {
1611                 fr_strerror_printf("WARNING: Bad RADIUS packet from host %s: unknown packet code%d ",
1612                            inet_ntop(packet->src_ipaddr.af,
1613                                      &packet->src_ipaddr.ipaddr,
1614                                      host_ipaddr, sizeof(host_ipaddr)),
1615                            hdr->code);
1616                 return 0;
1617         }
1618
1619         /*
1620          *      Message-Authenticator is required in Status-Server
1621          *      packets, otherwise they can be trivially forged.
1622          */
1623         if (hdr->code == PW_STATUS_SERVER) require_ma = 1;
1624
1625         /*
1626          *      It's also required if the caller asks for it.
1627          */
1628         if (flags) require_ma = 1;
1629
1630         /*
1631          *      Repeat the length checks.  This time, instead of
1632          *      looking at the data we received, look at the value
1633          *      of the 'length' field inside of the packet.
1634          *
1635          *      Check for packets smaller than the packet header.
1636          *
1637          *      RFC 2865, Section 3., subsection 'length' says:
1638          *
1639          *      "The minimum length is 20 ..."
1640          */
1641         if (totallen < AUTH_HDR_LEN) {
1642                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (length %d < minimum %d)",
1643                            inet_ntop(packet->src_ipaddr.af,
1644                                      &packet->src_ipaddr.ipaddr,
1645                                      host_ipaddr, sizeof(host_ipaddr)),
1646                            totallen, AUTH_HDR_LEN);
1647                 return 0;
1648         }
1649
1650         /*
1651          *      And again, for the value of the 'length' field.
1652          *
1653          *      RFC 2865, Section 3., subsection 'length' says:
1654          *
1655          *      " ... and maximum length is 4096."
1656          */
1657         if (totallen > MAX_PACKET_LEN) {
1658                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (length %d > maximum %d)",
1659                            inet_ntop(packet->src_ipaddr.af,
1660                                      &packet->src_ipaddr.ipaddr,
1661                                      host_ipaddr, sizeof(host_ipaddr)),
1662                            totallen, MAX_PACKET_LEN);
1663                 return 0;
1664         }
1665
1666         /*
1667          *      RFC 2865, Section 3., subsection 'length' says:
1668          *
1669          *      "If the packet is shorter than the Length field
1670          *      indicates, it MUST be silently discarded."
1671          *
1672          *      i.e. No response to the NAS.
1673          */
1674         if (packet->data_len < totallen) {
1675                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: received %d octets, packet length says %d",
1676                            inet_ntop(packet->src_ipaddr.af,
1677                                      &packet->src_ipaddr.ipaddr,
1678                                      host_ipaddr, sizeof(host_ipaddr)),
1679                                    (int) packet->data_len, totallen);
1680                 return 0;
1681         }
1682
1683         /*
1684          *      RFC 2865, Section 3., subsection 'length' says:
1685          *
1686          *      "Octets outside the range of the Length field MUST be
1687          *      treated as padding and ignored on reception."
1688          */
1689         if (packet->data_len > totallen) {
1690                 /*
1691                  *      We're shortening the packet below, but just
1692                  *      to be paranoid, zero out the extra data.
1693                  */
1694                 memset(packet->data + totallen, 0, packet->data_len - totallen);
1695                 packet->data_len = totallen;
1696         }
1697
1698         /*
1699          *      Walk through the packet's attributes, ensuring that
1700          *      they add up EXACTLY to the size of the packet.
1701          *
1702          *      If they don't, then the attributes either under-fill
1703          *      or over-fill the packet.  Any parsing of the packet
1704          *      is impossible, and will result in unknown side effects.
1705          *
1706          *      This would ONLY happen with buggy RADIUS implementations,
1707          *      or with an intentional attack.  Either way, we do NOT want
1708          *      to be vulnerable to this problem.
1709          */
1710         attr = hdr->data;
1711         count = totallen - AUTH_HDR_LEN;
1712         num_attributes = 0;
1713
1714         while (count > 0) {
1715                 /*
1716                  *      Attribute number zero is NOT defined.
1717                  */
1718                 if (attr[0] == 0) {
1719                         fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Invalid attribute 0",
1720                                    inet_ntop(packet->src_ipaddr.af,
1721                                              &packet->src_ipaddr.ipaddr,
1722                                              host_ipaddr, sizeof(host_ipaddr)));
1723                         return 0;
1724                 }
1725
1726                 /*
1727                  *      Attributes are at LEAST as long as the ID & length
1728                  *      fields.  Anything shorter is an invalid attribute.
1729                  */
1730                 if (attr[1] < 2) {
1731                         fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %d too short",
1732                                    inet_ntop(packet->src_ipaddr.af,
1733                                              &packet->src_ipaddr.ipaddr,
1734                                              host_ipaddr, sizeof(host_ipaddr)),
1735                                    attr[0]);
1736                         return 0;
1737                 }
1738
1739                 /*
1740                  *      Sanity check the attributes for length.
1741                  */
1742                 switch (attr[0]) {
1743                 default:        /* don't do anything by default */
1744                         break;
1745
1746                         /*
1747                          *      If there's an EAP-Message, we require
1748                          *      a Message-Authenticator.
1749                          */
1750                 case PW_EAP_MESSAGE:
1751                         require_ma = 1;
1752                         break;
1753
1754                 case PW_MESSAGE_AUTHENTICATOR:
1755                         if (attr[1] != 2 + AUTH_VECTOR_LEN) {
1756                                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Message-Authenticator has invalid length %d",
1757                                            inet_ntop(packet->src_ipaddr.af,
1758                                                      &packet->src_ipaddr.ipaddr,
1759                                                      host_ipaddr, sizeof(host_ipaddr)),
1760                                            attr[1] - 2);
1761                                 return 0;
1762                         }
1763                         seen_ma = 1;
1764                         break;
1765                 }
1766
1767                 /*
1768                  *      FIXME: Look up the base 255 attributes in the
1769                  *      dictionary, and switch over their type.  For
1770                  *      integer/date/ip, the attribute length SHOULD
1771                  *      be 6.
1772                  */
1773                 count -= attr[1];       /* grab the attribute length */
1774                 attr += attr[1];
1775                 num_attributes++;       /* seen one more attribute */
1776         }
1777
1778         /*
1779          *      If the attributes add up to a packet, it's allowed.
1780          *
1781          *      If not, we complain, and throw the packet away.
1782          */
1783         if (count != 0) {
1784                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: packet attributes do NOT exactly fill the packet",
1785                            inet_ntop(packet->src_ipaddr.af,
1786                                      &packet->src_ipaddr.ipaddr,
1787                                      host_ipaddr, sizeof(host_ipaddr)));
1788                 return 0;
1789         }
1790
1791         /*
1792          *      If we're configured to look for a maximum number of
1793          *      attributes, and we've seen more than that maximum,
1794          *      then throw the packet away, as a possible DoS.
1795          */
1796         if ((fr_max_attributes > 0) &&
1797             (num_attributes > fr_max_attributes)) {
1798                 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
1799                            inet_ntop(packet->src_ipaddr.af,
1800                                      &packet->src_ipaddr.ipaddr,
1801                                      host_ipaddr, sizeof(host_ipaddr)),
1802                            num_attributes, fr_max_attributes);
1803                 return 0;
1804         }
1805
1806         /*
1807          *      http://www.freeradius.org/rfc/rfc2869.html#EAP-Message
1808          *
1809          *      A packet with an EAP-Message attribute MUST also have
1810          *      a Message-Authenticator attribute.
1811          *
1812          *      A Message-Authenticator all by itself is OK, though.
1813          *
1814          *      Similarly, Status-Server packets MUST contain
1815          *      Message-Authenticator attributes.
1816          */
1817         if (require_ma && ! seen_ma) {
1818                 fr_strerror_printf("WARNING: Insecure packet from host %s:  Packet does not contain required Message-Authenticator attribute",
1819                            inet_ntop(packet->src_ipaddr.af,
1820                                      &packet->src_ipaddr.ipaddr,
1821                                      host_ipaddr, sizeof(host_ipaddr)));
1822                 return 0;
1823         }
1824
1825         /*
1826          *      Fill RADIUS header fields
1827          */
1828         packet->code = hdr->code;
1829         packet->id = hdr->id;
1830         memcpy(packet->vector, hdr->vector, AUTH_VECTOR_LEN);
1831
1832         return 1;
1833 }
1834
1835
1836 /*
1837  *      Receive UDP client requests, and fill in
1838  *      the basics of a RADIUS_PACKET structure.
1839  */
1840 RADIUS_PACKET *rad_recv(int fd, int flags)
1841 {
1842         int sock_flags = 0;
1843         RADIUS_PACKET           *packet;
1844
1845         /*
1846          *      Allocate the new request data structure
1847          */
1848         if ((packet = malloc(sizeof(*packet))) == NULL) {
1849                 fr_strerror_printf("out of memory");
1850                 return NULL;
1851         }
1852         memset(packet, 0, sizeof(*packet));
1853
1854         if (flags & 0x02) {
1855                 sock_flags = MSG_PEEK;
1856                 flags &= ~0x02;
1857         }
1858
1859         packet->data_len = rad_recvfrom(fd, &packet->data, sock_flags,
1860                                         &packet->src_ipaddr, &packet->src_port,
1861                                         &packet->dst_ipaddr, &packet->dst_port);
1862
1863         /*
1864          *      Check for socket errors.
1865          */
1866         if (packet->data_len < 0) {
1867                 fr_strerror_printf("Error receiving packet: %s", strerror(errno));
1868                 /* packet->data is NULL */
1869                 free(packet);
1870                 return NULL;
1871         }
1872
1873         /*
1874          *      If the packet is too big, then rad_recvfrom did NOT
1875          *      allocate memory.  Instead, it just discarded the
1876          *      packet.
1877          */
1878         if (packet->data_len > MAX_PACKET_LEN) {
1879                 fr_strerror_printf("Discarding packet: Larger than RFC limitation of 4096 bytes.");
1880                 /* packet->data is NULL */
1881                 free(packet);
1882                 return NULL;
1883         }
1884
1885         /*
1886          *      Read no data.  Continue.
1887          *      This check is AFTER the MAX_PACKET_LEN check above, because
1888          *      if the packet is larger than MAX_PACKET_LEN, we also have
1889          *      packet->data == NULL
1890          */
1891         if ((packet->data_len == 0) || !packet->data) {
1892                 fr_strerror_printf("Empty packet: Socket is not ready.");
1893                 free(packet);
1894                 return NULL;
1895         }
1896
1897         /*
1898          *      See if it's a well-formed RADIUS packet.
1899          */
1900         if (!rad_packet_ok(packet, flags)) {
1901                 rad_free(&packet);
1902                 return NULL;
1903         }
1904
1905         /*
1906          *      Remember which socket we read the packet from.
1907          */
1908         packet->sockfd = fd;
1909
1910         /*
1911          *      FIXME: Do even more filtering by only permitting
1912          *      certain IP's.  The problem is that we don't know
1913          *      how to do this properly for all possible clients...
1914          */
1915
1916         /*
1917          *      Explicitely set the VP list to empty.
1918          */
1919         packet->vps = NULL;
1920
1921         if (fr_debug_flag) {
1922                 char host_ipaddr[128];
1923
1924                 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1925                         DEBUG("rad_recv: %s packet from host %s port %d",
1926                               fr_packet_codes[packet->code],
1927                               inet_ntop(packet->src_ipaddr.af,
1928                                         &packet->src_ipaddr.ipaddr,
1929                                         host_ipaddr, sizeof(host_ipaddr)),
1930                               packet->src_port);
1931                 } else {
1932                         DEBUG("rad_recv: Packet from host %s port %d code=%d",
1933                               inet_ntop(packet->src_ipaddr.af,
1934                                         &packet->src_ipaddr.ipaddr,
1935                                         host_ipaddr, sizeof(host_ipaddr)),
1936                               packet->src_port,
1937                               packet->code);
1938                 }
1939                 DEBUG(", id=%d, length=%d\n",
1940                       packet->id, (int) packet->data_len);
1941         }
1942
1943         return packet;
1944 }
1945
1946
1947 /*
1948  *      Verify the signature of a packet.
1949  */
1950 int rad_verify(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1951                const char *secret)
1952 {
1953         uint8_t                 *ptr;
1954         int                     length;
1955         int                     attrlen;
1956
1957         if (!packet || !packet->data) return -1;
1958
1959         /*
1960          *      Before we allocate memory for the attributes, do more
1961          *      sanity checking.
1962          */
1963         ptr = packet->data + AUTH_HDR_LEN;
1964         length = packet->data_len - AUTH_HDR_LEN;
1965         while (length > 0) {
1966                 uint8_t msg_auth_vector[AUTH_VECTOR_LEN];
1967                 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
1968
1969                 attrlen = ptr[1];
1970
1971                 switch (ptr[0]) {
1972                 default:        /* don't do anything. */
1973                         break;
1974
1975                         /*
1976                          *      Note that more than one Message-Authenticator
1977                          *      attribute is invalid.
1978                          */
1979                 case PW_MESSAGE_AUTHENTICATOR:
1980                         memcpy(msg_auth_vector, &ptr[2], sizeof(msg_auth_vector));
1981                         memset(&ptr[2], 0, AUTH_VECTOR_LEN);
1982
1983                         switch (packet->code) {
1984                         default:
1985                                 break;
1986
1987                         case PW_ACCOUNTING_REQUEST:
1988                         case PW_ACCOUNTING_RESPONSE:
1989                         case PW_DISCONNECT_REQUEST:
1990                         case PW_DISCONNECT_ACK:
1991                         case PW_DISCONNECT_NAK:
1992                         case PW_COA_REQUEST:
1993                         case PW_COA_ACK:
1994                         case PW_COA_NAK:
1995                                 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
1996                                 break;
1997
1998                         case PW_AUTHENTICATION_ACK:
1999                         case PW_AUTHENTICATION_REJECT:
2000                         case PW_ACCESS_CHALLENGE:
2001                                 if (!original) {
2002                                         fr_strerror_printf("ERROR: Cannot validate Message-Authenticator in response packet without a request packet.");
2003                                         return -1;
2004                                 }
2005                                 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
2006                                 break;
2007                         }
2008
2009                         fr_hmac_md5(packet->data, packet->data_len,
2010                                     (const uint8_t *) secret, strlen(secret),
2011                                     calc_auth_vector);
2012                         if (digest_cmp(calc_auth_vector, msg_auth_vector,
2013                                    sizeof(calc_auth_vector)) != 0) {
2014                                 char buffer[32];
2015                                 fr_strerror_printf("Received packet from %s with invalid Message-Authenticator!  (Shared secret is incorrect.)",
2016                                            inet_ntop(packet->src_ipaddr.af,
2017                                                      &packet->src_ipaddr.ipaddr,
2018                                                      buffer, sizeof(buffer)));
2019                                 /* Silently drop packet, according to RFC 3579 */
2020                                 return -1;
2021                         } /* else the message authenticator was good */
2022
2023                         /*
2024                          *      Reinitialize Authenticators.
2025                          */
2026                         memcpy(&ptr[2], msg_auth_vector, AUTH_VECTOR_LEN);
2027                         memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
2028                         break;
2029                 } /* switch over the attributes */
2030
2031                 ptr += attrlen;
2032                 length -= attrlen;
2033         } /* loop over the packet, sanity checking the attributes */
2034
2035         /*
2036          *      It looks like a RADIUS packet, but we can't validate
2037          *      the signature.
2038          */
2039         if ((packet->code == 0) || (packet->code >= FR_MAX_PACKET_CODE)) {
2040                 char buffer[32];
2041                 fr_strerror_printf("Received Unknown packet code %d "
2042                            "from client %s port %d: Cannot validate signature.",
2043                            packet->code,
2044                            inet_ntop(packet->src_ipaddr.af,
2045                                      &packet->src_ipaddr.ipaddr,
2046                                      buffer, sizeof(buffer)),
2047                            packet->src_port);
2048                 return -1;
2049         }
2050
2051         /*
2052          *      Calculate and/or verify digest.
2053          */
2054         switch(packet->code) {
2055                 int rcode;
2056                 char buffer[32];
2057
2058                 case PW_AUTHENTICATION_REQUEST:
2059                 case PW_STATUS_SERVER:
2060                         /*
2061                          *      The authentication vector is random
2062                          *      nonsense, invented by the client.
2063                          */
2064                         break;
2065
2066                 case PW_COA_REQUEST:
2067                 case PW_DISCONNECT_REQUEST:
2068                 case PW_ACCOUNTING_REQUEST:
2069                         if (calc_acctdigest(packet, secret) > 1) {
2070                                 fr_strerror_printf("Received %s packet "
2071                                            "from %s with invalid signature!  (Shared secret is incorrect.)",
2072                                            fr_packet_codes[packet->code],
2073                                            inet_ntop(packet->src_ipaddr.af,
2074                                                      &packet->src_ipaddr.ipaddr,
2075                                                      buffer, sizeof(buffer)));
2076                                 return -1;
2077                         }
2078                         break;
2079
2080                         /* Verify the reply digest */
2081                 case PW_AUTHENTICATION_ACK:
2082                 case PW_AUTHENTICATION_REJECT:
2083                 case PW_ACCESS_CHALLENGE:
2084                 case PW_ACCOUNTING_RESPONSE:
2085                 case PW_DISCONNECT_ACK:
2086                 case PW_DISCONNECT_NAK:
2087                 case PW_COA_ACK:
2088                 case PW_COA_NAK:
2089                         rcode = calc_replydigest(packet, original, secret);
2090                         if (rcode > 1) {
2091                                 fr_strerror_printf("Received %s packet "
2092                                            "from client %s port %d with invalid signature (err=%d)!  (Shared secret is incorrect.)",
2093                                            fr_packet_codes[packet->code],
2094                                            inet_ntop(packet->src_ipaddr.af,
2095                                                      &packet->src_ipaddr.ipaddr,
2096                                                      buffer, sizeof(buffer)),
2097                                            packet->src_port,
2098                                            rcode);
2099                                 return -1;
2100                         }
2101                         break;
2102
2103                 default:
2104                         fr_strerror_printf("Received Unknown packet code %d "
2105                                    "from client %s port %d: Cannot validate signature",
2106                                    packet->code,
2107                                    inet_ntop(packet->src_ipaddr.af,
2108                                              &packet->src_ipaddr.ipaddr,
2109                                                      buffer, sizeof(buffer)),
2110                                    packet->src_port);
2111                         return -1;
2112         }
2113
2114         return 0;
2115 }
2116
2117
2118 static VALUE_PAIR *data2vp(const RADIUS_PACKET *packet,
2119                            const RADIUS_PACKET *original,
2120                            const char *secret, size_t length,
2121                            const uint8_t *data, VALUE_PAIR *vp)
2122 {
2123         int offset = 0;
2124
2125         /*
2126          *      If length is greater than 253, something is SERIOUSLY
2127          *      wrong.
2128          */
2129         if (length > 253) length = 253; /* paranoia (pair-anoia?) */
2130
2131         vp->length = length;
2132         vp->operator = T_OP_EQ;
2133         vp->next = NULL;
2134
2135         /*
2136          *      Handle tags.
2137          */
2138         if (vp->flags.has_tag) {
2139                 if (TAG_VALID(data[0]) ||
2140                     (vp->flags.encrypt == FLAG_ENCRYPT_TUNNEL_PASSWORD)) {
2141                         /*
2142                          *      Tunnel passwords REQUIRE a tag, even
2143                          *      if don't have a valid tag.
2144                          */
2145                         vp->flags.tag = data[0];
2146
2147                         if ((vp->type == PW_TYPE_STRING) ||
2148                             (vp->type == PW_TYPE_OCTETS)) offset = 1;
2149                 }
2150         }
2151
2152         /*
2153          *      Copy the data to be decrypted
2154          */
2155         memcpy(&vp->vp_octets[0], data + offset, length - offset);
2156         vp->length -= offset;
2157
2158         /*
2159          *      Decrypt the attribute.
2160          */
2161         switch (vp->flags.encrypt) {
2162                 /*
2163                  *  User-Password
2164                  */
2165         case FLAG_ENCRYPT_USER_PASSWORD:
2166                 if (original) {
2167                         rad_pwdecode((char *)vp->vp_strvalue,
2168                                      vp->length, secret,
2169                                      original->vector);
2170                 } else {
2171                         rad_pwdecode((char *)vp->vp_strvalue,
2172                                      vp->length, secret,
2173                                      packet->vector);
2174                 }
2175                 if (vp->attribute == PW_USER_PASSWORD) {
2176                         vp->length = strlen(vp->vp_strvalue);
2177                 }
2178                 break;
2179
2180                 /*
2181                  *      Tunnel-Password's may go ONLY
2182                  *      in response packets.
2183                  */
2184         case FLAG_ENCRYPT_TUNNEL_PASSWORD:
2185                 if (!original) goto raw;
2186
2187                 if (rad_tunnel_pwdecode(vp->vp_octets, &vp->length,
2188                                         secret, original->vector) < 0) {
2189                         goto raw;
2190                 }
2191                 break;
2192
2193                 /*
2194                  *  Ascend-Send-Secret
2195                  *  Ascend-Receive-Secret
2196                  */
2197         case FLAG_ENCRYPT_ASCEND_SECRET:
2198                 if (!original) {
2199                         goto raw;
2200                 } else {
2201                         uint8_t my_digest[AUTH_VECTOR_LEN];
2202                         make_secret(my_digest,
2203                                     original->vector,
2204                                     secret, data);
2205                         memcpy(vp->vp_strvalue, my_digest,
2206                                AUTH_VECTOR_LEN );
2207                         vp->vp_strvalue[AUTH_VECTOR_LEN] = '\0';
2208                         vp->length = strlen(vp->vp_strvalue);
2209                 }
2210                 break;
2211
2212         default:
2213                 break;
2214         } /* switch over encryption flags */
2215
2216
2217         switch (vp->type) {
2218         case PW_TYPE_STRING:
2219         case PW_TYPE_OCTETS:
2220         case PW_TYPE_ABINARY:
2221                 /* nothing more to do */
2222                 break;
2223
2224         case PW_TYPE_BYTE:
2225                 if (vp->length != 1) goto raw;
2226
2227                 vp->vp_integer = vp->vp_octets[0];
2228                 break;
2229
2230
2231         case PW_TYPE_SHORT:
2232                 if (vp->length != 2) goto raw;
2233
2234                 vp->vp_integer = (vp->vp_octets[0] << 8) | vp->vp_octets[1];
2235                 break;
2236
2237         case PW_TYPE_INTEGER:
2238                 if (vp->length != 4) goto raw;
2239
2240                 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2241                 vp->vp_integer = ntohl(vp->vp_integer);
2242
2243                 if (vp->flags.has_tag) vp->vp_integer &= 0x00ffffff;
2244
2245                 /*
2246                  *      Try to get named VALUEs
2247                  */
2248                 {
2249                         DICT_VALUE *dval;
2250                         dval = dict_valbyattr(vp->attribute, vp->vendor,
2251                                               vp->vp_integer);
2252                         if (dval) {
2253                                 strlcpy(vp->vp_strvalue,
2254                                         dval->name,
2255                                         sizeof(vp->vp_strvalue));
2256                         }
2257                 }
2258                 break;
2259
2260         case PW_TYPE_DATE:
2261                 if (vp->length != 4) goto raw;
2262
2263                 memcpy(&vp->vp_date, vp->vp_octets, 4);
2264                 vp->vp_date = ntohl(vp->vp_date);
2265                 break;
2266
2267
2268         case PW_TYPE_IPADDR:
2269                 if (vp->length != 4) goto raw;
2270
2271                 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2272                 break;
2273
2274                 /*
2275                  *      IPv6 interface ID is 8 octets long.
2276                  */
2277         case PW_TYPE_IFID:
2278                 if (vp->length != 8) goto raw;
2279                 /* vp->vp_ifid == vp->vp_octets */
2280                 break;
2281
2282                 /*
2283                  *      IPv6 addresses are 16 octets long
2284                  */
2285         case PW_TYPE_IPV6ADDR:
2286                 if (vp->length != 16) goto raw;
2287                 /* vp->vp_ipv6addr == vp->vp_octets */
2288                 break;
2289
2290                 /*
2291                  *      IPv6 prefixes are 2 to 18 octets long.
2292                  *
2293                  *      RFC 3162: The first octet is unused.
2294                  *      The second is the length of the prefix
2295                  *      the rest are the prefix data.
2296                  *
2297                  *      The prefix length can have value 0 to 128.
2298                  */
2299         case PW_TYPE_IPV6PREFIX:
2300                 if (vp->length < 2 || vp->length > 18) goto raw;
2301                 if (vp->vp_octets[1] > 128) goto raw;
2302
2303                 /*
2304                  *      FIXME: double-check that
2305                  *      (vp->vp_octets[1] >> 3) matches vp->length + 2
2306                  */
2307                 if (vp->length < 18) {
2308                         memset(vp->vp_octets + vp->length, 0,
2309                                18 - vp->length);
2310                 }
2311                 break;
2312
2313         case PW_TYPE_SIGNED:
2314                 if (vp->length != 4) goto raw;
2315
2316                 /*
2317                  *      Overload vp_integer for ntohl, which takes
2318                  *      uint32_t, not int32_t
2319                  */
2320                 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2321                 vp->vp_integer = ntohl(vp->vp_integer);
2322                 memcpy(&vp->vp_signed, &vp->vp_integer, 4);
2323                 break;
2324
2325         case PW_TYPE_TLV:
2326                 vp->length = length;
2327                 vp->vp_tlv = malloc(length);
2328                 if (!vp->vp_tlv) {
2329                         pairfree(&vp);
2330                         fr_strerror_printf("No memory");
2331                         return NULL;
2332                 }
2333                 memcpy(vp->vp_tlv, data, length);
2334                 break;
2335
2336         case PW_TYPE_COMBO_IP:
2337                 if (vp->length == 4) {
2338                         vp->type = PW_TYPE_IPADDR;
2339                         memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2340                         break;
2341
2342                 } else if (vp->length == 16) {
2343                         vp->type = PW_TYPE_IPV6ADDR;
2344                         /* vp->vp_ipv6addr == vp->vp_octets */
2345                         break;
2346
2347                 }
2348                 /* FALL-THROUGH */
2349
2350         default:
2351         raw:
2352                 vp->type = PW_TYPE_OCTETS;
2353                 vp->length = length;
2354                 memcpy(vp->vp_octets, data, length);
2355
2356
2357                 /*
2358                  *      Ensure there's no encryption or tag stuff,
2359                  *      we just pass the attribute as-is.
2360                  */
2361                 memset(&vp->flags, 0, sizeof(vp->flags));
2362         }
2363
2364         return vp;
2365 }
2366
2367 static void rad_sortvp(VALUE_PAIR **head)
2368 {
2369         int swapped;
2370         VALUE_PAIR *vp, **tail;
2371
2372         /*
2373          *      Walk over the VP's, sorting them in order.  Did I
2374          *      mention that I hate WiMAX continuations?
2375          *
2376          *      And bubble sort!  WTF is up with that?
2377          */
2378         do {
2379                 swapped = 0;
2380                 tail = head;
2381                 while (*tail) {
2382                         vp = *tail;
2383                         if (!vp->next) break;
2384
2385                         if (vp->attribute > vp->next->attribute) {
2386                                 *tail = vp->next;
2387                                 vp->next = (*tail)->next;
2388                                 (*tail)->next = vp;
2389                                 swapped = 1;
2390                         }
2391                         tail = &(vp->next);
2392                 }
2393         } while (swapped);
2394 }
2395
2396
2397 /*
2398  *      Walk the packet, looking for continuations of this attribute.
2399  *
2400  *      This is (worst-case) O(N^2) in the number of RADIUS
2401  *      attributes.  That happens only when perverse clients create
2402  *      continued attributes, AND separate the fragmented portions
2403  *      with a lot of other attributes.
2404  *
2405  *      Sane clients should put the fragments next to each other, in
2406  *      which case this is O(N), in the number of fragments.
2407  */
2408 static uint8_t *rad_coalesce(unsigned int attribute, int vendor,
2409                              size_t length, uint8_t *data,
2410                              size_t packet_length, size_t *ptlv_length)
2411
2412 {
2413         uint32_t lvalue;
2414         size_t tlv_length = length;
2415         uint8_t *ptr, *tlv, *tlv_data;
2416
2417         for (ptr = data + length;
2418              ptr != (data + packet_length);
2419              ptr += ptr[1]) {
2420                 /* FIXME: Check that there are 6 bytes of data here... */
2421                 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2422                     (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2423                     (ptr[2] != 0) || (ptr[3] != 0) ||  /* our requirement */
2424                     (ptr[4] != ((vendor >> 8) & 0xff)) ||
2425                     (ptr[5] != (vendor & 0xff))) {
2426                         continue;
2427                 }
2428
2429                 memcpy(&lvalue, ptr + 2, 4); /* Vendor Id */
2430                 lvalue = ntohl(lvalue);
2431                 lvalue <<= 16;
2432                 lvalue |= ptr[2 + 4]; /* add in VSA number */
2433                 if (lvalue != attribute) continue;
2434
2435                 /*
2436                  *      If the vendor-length is too small, it's badly
2437                  *      formed, so we stop.
2438                  */
2439                 if ((ptr[2 + 4 + 1]) < 3) break;
2440
2441                 tlv_length += ptr[2 + 4 + 1] - 3;
2442                 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2443         }
2444
2445         tlv = tlv_data = malloc(tlv_length);
2446         if (!tlv_data) return NULL;
2447
2448         memcpy(tlv, data, length);
2449         tlv += length;
2450
2451         /*
2452          *      Now we walk the list again, copying the data over to
2453          *      our newly created memory.
2454          */
2455         for (ptr = data + length;
2456              ptr != (data + packet_length);
2457              ptr += ptr[1]) {
2458                 int this_length;
2459
2460                 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2461                     (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2462                     (ptr[2] != 0) || (ptr[3] != 0)) { /* our requirement */
2463                         continue;
2464                 }
2465
2466                 memcpy(&lvalue, ptr + 2, 4);
2467                 lvalue = ntohl(lvalue);
2468                 lvalue <<= 16;
2469                 lvalue |= ptr[2 + 4];
2470                 if (lvalue != attribute) continue;
2471
2472                 /*
2473                  *      If the vendor-length is too small, it's badly
2474                  *      formed, so we stop.
2475                  */
2476                 if ((ptr[2 + 4 + 1]) < 3) break;
2477
2478                 this_length = ptr[2 + 4 + 1] - 3;
2479                 memcpy(tlv, ptr + 2 + 4 + 3, this_length);
2480                 tlv += this_length;
2481
2482                 ptr[2 + 4] = 0; /* What a hack! */
2483                 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2484         }
2485
2486         *ptlv_length = tlv_length;
2487         return tlv_data;
2488 }
2489
2490 /*
2491  *      Walk over Evil WIMAX Hell, creating attributes.
2492  *
2493  *      Won't someone think of the children?  What if they read this code?
2494  */
2495 static VALUE_PAIR *recurse_evil(const RADIUS_PACKET *packet,
2496                                 const RADIUS_PACKET *original,
2497                                 const char *secret,
2498                                 int attribute, int vendor,
2499                                 uint8_t *ptr, size_t len)
2500 {
2501         VALUE_PAIR *head = NULL;
2502         VALUE_PAIR **tail = &head;
2503         VALUE_PAIR *vp;
2504         uint8_t *y;             /* why do I need to do this? */
2505
2506         /*
2507          *      Sanity check the attribute.
2508          */
2509         for (y = ptr; y < (ptr + len); y += y[1]) {
2510                 if ((y[0] == 0) || ((y + 2) > (ptr + len)) ||
2511                     (y[1] < 2) || ((y + y[1]) > (ptr + len))) {
2512                         return NULL;
2513                 }
2514         }
2515
2516         for (y = ptr; y < (ptr + len); y += y[1]) {
2517                 vp = paircreate(attribute | (ptr[0] << 16), vendor,
2518                                 PW_TYPE_OCTETS);
2519                 if (!vp) {
2520                 error:
2521                         pairfree(&head);
2522                         return NULL;
2523                 }
2524
2525                 if (!data2vp(packet, original, secret,
2526                              y[1] - 2, y + 2, vp)) {
2527                         goto error;
2528                 }
2529
2530                 *tail = vp;
2531                 tail = &(vp->next);
2532         }
2533
2534         return head;
2535 }
2536
2537 /*
2538  *      Start at the *data* portion of a continued attribute.  search
2539  *      through the rest of the attributes to find a matching one, and
2540  *      add it's contents to our contents.
2541  */
2542 static VALUE_PAIR *rad_continuation2vp(const RADIUS_PACKET *packet,
2543                                        const RADIUS_PACKET *original,
2544                                        const char *secret, int attribute,
2545                                        int vendor,
2546                                        int length, /* CANNOT be zero */
2547                                        uint8_t *data, size_t packet_length,
2548                                        int flag, DICT_ATTR *da)
2549 {
2550         size_t tlv_length, left;
2551         uint8_t *ptr;
2552         uint8_t *tlv_data;
2553         VALUE_PAIR *vp, *head, **tail;
2554         DICT_ATTR *tlv_da;
2555
2556         /*
2557          *      Ensure we have data that hasn't been split across
2558          *      multiple attributes.
2559          */
2560         if (flag) {
2561                 tlv_data = rad_coalesce(attribute, vendor, length,
2562                                         data, packet_length, &tlv_length);
2563                 if (!tlv_data) return NULL;
2564         } else {
2565                 tlv_data = data;
2566                 tlv_length = length;
2567         }
2568
2569         /*
2570          *      Non-TLV types cannot be continued across multiple
2571          *      attributes.  This is true even of keys that are
2572          *      encrypted with the tunnel-password method.  The spec
2573          *      says that they can be continued... but also that the
2574          *      keys are 160 bits, which means that they CANNOT be
2575          *      continued.  <sigh>
2576          *
2577          *      Note that we don't check "flag" here.  The calling
2578          *      code ensures that
2579          */
2580         if (!da || (da->type != PW_TYPE_TLV)) {
2581         not_well_formed:
2582                 if (tlv_data == data) { /* true if we had 'goto' */
2583                         tlv_data = malloc(tlv_length);
2584                         if (!tlv_data) return NULL;
2585                         memcpy(tlv_data, data, tlv_length);
2586                 }
2587
2588                 vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2589                 if (!vp) return NULL;
2590
2591                 vp->type = PW_TYPE_TLV;
2592                 vp->flags.encrypt = FLAG_ENCRYPT_NONE;
2593                 vp->flags.has_tag = 0;
2594                 vp->flags.is_tlv = 0;
2595                 vp->vp_tlv = tlv_data;
2596                 vp->length = tlv_length;
2597                 return vp;
2598         } /* else it WAS a TLV, go decode the sub-tlv's */
2599
2600         /*
2601          *      Now (sigh) we walk over the TLV, seeing if it is
2602          *      well-formed.
2603          */
2604         left = tlv_length;
2605         for (ptr = tlv_data;
2606              ptr != (tlv_data + tlv_length);
2607              ptr += ptr[1]) {
2608                 if ((left < 2) ||
2609                     (ptr[1] < 2) ||
2610                     (ptr[1] > left)) {
2611                         goto not_well_formed;
2612                 }
2613
2614                 left -= ptr[1];
2615         }
2616
2617         /*
2618          *      Now we walk over the TLV *again*, creating sub-tlv's.
2619          */
2620         head = NULL;
2621         tail = &head;
2622
2623         for (ptr = tlv_data;
2624              ptr != (tlv_data + tlv_length);
2625              ptr += ptr[1]) {
2626
2627                 tlv_da = dict_attrbyvalue(attribute | (ptr[0] << 8), vendor);
2628                 if (tlv_da && (tlv_da->type == PW_TYPE_TLV)) {
2629                         vp = recurse_evil(packet, original, secret,
2630                                           attribute | (ptr[0] << 8),
2631                                           vendor, ptr + 2, ptr[1] - 2);
2632
2633                         if (!vp) {
2634                                 pairfree(&head);
2635                                 goto not_well_formed;
2636                         }
2637                 } else {
2638                         vp = paircreate(attribute | (ptr[0] << 8), vendor,
2639                                         PW_TYPE_OCTETS);
2640                         if (!vp) {
2641                                 pairfree(&head);
2642                                 goto not_well_formed;
2643                         }
2644
2645                         if (!data2vp(packet, original, secret,
2646                                      ptr[1] - 2, ptr + 2, vp)) {
2647                                 pairfree(&head);
2648                                 goto not_well_formed;
2649                         }
2650                 }
2651
2652                 *tail = vp;
2653
2654                 while (*tail) tail = &((*tail)->next);
2655         }
2656
2657         /*
2658          *      TLV's MAY be continued, but sometimes they're not.
2659          */
2660         if (tlv_data != data) free(tlv_data);
2661
2662         if (head->next) rad_sortvp(&head);
2663
2664         return head;
2665 }
2666
2667
2668 /*
2669  *      Parse a RADIUS attribute into a data structure.
2670  */
2671 VALUE_PAIR *rad_attr2vp(const RADIUS_PACKET *packet,
2672                         const RADIUS_PACKET *original,
2673                         const char *secret, int attribute, int vendor,
2674                         int length, const uint8_t *data)
2675 {
2676         VALUE_PAIR *vp;
2677
2678         vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2679         if (!vp) return NULL;
2680
2681         return data2vp(packet, original, secret, length, data, vp);
2682 }
2683
2684
2685 /*
2686  *      Calculate/check digest, and decode radius attributes.
2687  *      Returns:
2688  *      -1 on decoding error
2689  *      0 on success
2690  */
2691 int rad_decode(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2692                const char *secret)
2693 {
2694         uint32_t                lvalue;
2695         uint32_t                vendorcode;
2696         VALUE_PAIR              **tail;
2697         VALUE_PAIR              *pair;
2698         uint8_t                 *ptr, *vsa_ptr;
2699         int                     packet_length;
2700         int                     attribute;
2701         int                     attrlen;
2702         int                     vendorlen;
2703         radius_packet_t         *hdr;
2704         int                     vsa_tlen, vsa_llen, vsa_offset;
2705         DICT_VENDOR             *dv = NULL;
2706         int                     num_attributes = 0;
2707
2708         /*
2709          *      Extract attribute-value pairs
2710          */
2711         hdr = (radius_packet_t *)packet->data;
2712         ptr = hdr->data;
2713         packet_length = packet->data_len - AUTH_HDR_LEN;
2714
2715         /*
2716          *      There may be VP's already in the packet.  Don't
2717          *      destroy them.
2718          */
2719         for (tail = &packet->vps; *tail != NULL; tail = &((*tail)->next)) {
2720                 /* nothing */
2721         }
2722
2723         vendorcode = 0;
2724         vendorlen  = 0;
2725         vsa_tlen = vsa_llen = 1;
2726         vsa_offset = 0;
2727
2728         /*
2729          *      We have to read at least two bytes.
2730          *
2731          *      rad_recv() above ensures that this is OK.
2732          */
2733         while (packet_length > 0) {
2734                 attribute = -1;
2735                 attrlen = -1;
2736
2737                 /*
2738                  *      Normal attribute, handle it like normal.
2739                  */
2740                 if (vendorcode == 0) {
2741                         /*
2742                          *      No room to read attr/length,
2743                          *      or bad attribute, or attribute is
2744                          *      too short, or attribute is too long,
2745                          *      stop processing the packet.
2746                          */
2747                         if ((packet_length < 2) ||
2748                             (ptr[0] == 0) ||  (ptr[1] < 2) ||
2749                             (ptr[1] > packet_length)) break;
2750
2751                         attribute = *ptr++;
2752                         attrlen   = *ptr++;
2753
2754                         attrlen -= 2;
2755                         packet_length  -= 2;
2756
2757                         if (attribute != PW_VENDOR_SPECIFIC) goto create_pair;
2758
2759                         /*
2760                          *      No vendor code, or ONLY vendor code.
2761                          */
2762                         if (attrlen <= 4) goto create_pair;
2763
2764                         vendorlen = 0;
2765                 }
2766
2767                 /*
2768                  *      Handle Vendor-Specific
2769                  */
2770                 if (vendorlen == 0) {
2771                         uint8_t *subptr;
2772                         int sublen;
2773                         int myvendor;
2774
2775                         /*
2776                          *      attrlen was checked above.
2777                          */
2778                         memcpy(&lvalue, ptr, 4);
2779                         myvendor = ntohl(lvalue);
2780
2781                         /*
2782                          *      Zero isn't allowed.
2783                          */
2784                         if (myvendor == 0) goto create_pair;
2785
2786                         /*
2787                          *      This is an implementation issue.
2788                          *      We currently pack vendor into the upper
2789                          *      16 bits of a 32-bit attribute number,
2790                          *      so we can't handle vendor numbers larger
2791                          *      than 16 bits.
2792                          */
2793                         if (myvendor > 65535) goto create_pair;
2794
2795                         vsa_tlen = vsa_llen = 1;
2796                         vsa_offset = 0;
2797                         dv = dict_vendorbyvalue(myvendor);
2798                         if (dv) {
2799                                 vsa_tlen = dv->type;
2800                                 vsa_llen = dv->length;
2801                                 if (dv->flags) vsa_offset = 1;
2802                         }
2803
2804                         /*
2805                          *      Sweep through the list of VSA's,
2806                          *      seeing if they exactly fill the
2807                          *      outer Vendor-Specific attribute.
2808                          *
2809                          *      If not, create a raw Vendor-Specific.
2810                          */
2811                         subptr = ptr + 4;
2812                         sublen = attrlen - 4;
2813
2814                         /*
2815                          *      See if we can parse it.
2816                          */
2817                         do {
2818                                 int myattr = 0;
2819
2820                                 /*
2821                                  *      Not enough room for one more
2822                                  *      attribute.  Die!
2823                                  */
2824                                 if (sublen < (vsa_tlen + vsa_llen + vsa_offset)) goto create_pair;
2825
2826                                 /*
2827                                  *      Ensure that the attribute number
2828                                  *      is OK.
2829                                  */
2830                                 switch (vsa_tlen) {
2831                                 case 1:
2832                                         myattr = subptr[0];
2833                                         break;
2834
2835                                 case 2:
2836                                         myattr = (subptr[0] << 8) | subptr[1];
2837                                         break;
2838
2839                                 case 4:
2840                                         if ((subptr[0] != 0) ||
2841                                             (subptr[1] != 0)) goto create_pair;
2842
2843                                         myattr = (subptr[2] << 8) | subptr[3];
2844                                         break;
2845
2846                                         /*
2847                                          *      Our dictionary is broken.
2848                                          */
2849                                 default:
2850                                         goto create_pair;
2851                                 }
2852
2853                                 switch (vsa_llen) {
2854                                 case 0:
2855                                         attribute = myattr;
2856                                         ptr += 4 + vsa_tlen;
2857                                         attrlen -= (4 + vsa_tlen);
2858                                         packet_length -= 4 + vsa_tlen;
2859                                         goto create_pair;
2860
2861                                 case 1:
2862                                         if (subptr[vsa_tlen] < (vsa_tlen + vsa_llen + vsa_offset))
2863                                                 goto create_pair;
2864
2865                                         if (subptr[vsa_tlen] > sublen)
2866                                                 goto create_pair;
2867
2868                                         /*
2869                                          *      WiMAX: 0bCrrrrrrr
2870                                          *      Reserved bits MUST be
2871                                          *      zero.
2872                                          */
2873                                         if (vsa_offset &&
2874                                             ((subptr[vsa_tlen + vsa_llen] & 0x7f) != 0))
2875                                                 goto create_pair;
2876
2877                                         sublen -= subptr[vsa_tlen];
2878                                         subptr += subptr[vsa_tlen];
2879                                         break;
2880
2881                                 case 2:
2882                                         if (subptr[vsa_tlen] != 0) goto create_pair;
2883                                         if (subptr[vsa_tlen + 1] < (vsa_tlen + vsa_llen))
2884                                                 goto create_pair;
2885                                         if (subptr[vsa_tlen + 1] > sublen)
2886                                                 goto create_pair;
2887                                         sublen -= subptr[vsa_tlen + 1];
2888                                         subptr += subptr[vsa_tlen + 1];
2889                                         break;
2890
2891                                         /*
2892                                          *      Our dictionaries are
2893                                          *      broken.
2894                                          */
2895                                 default:
2896                                         goto create_pair;
2897                                 }
2898                         } while (sublen > 0);
2899
2900                         vendorcode = myvendor;
2901                         vendorlen = attrlen - 4;
2902                         packet_length -= 4;
2903
2904                         ptr += 4;
2905                 }
2906
2907                 /*
2908                  *      attrlen is the length of this attribute.
2909                  *      total_len is the length of the encompassing
2910                  *      attribute.
2911                  */
2912                 switch (vsa_tlen) {
2913                 case 1:
2914                         attribute = ptr[0];
2915                         break;
2916
2917                 case 2:
2918                         attribute = (ptr[0] << 8) | ptr[1];
2919                         break;
2920
2921                 default:        /* can't hit this. */
2922                         return -1;
2923                 }
2924                 vsa_ptr = ptr;
2925                 ptr += vsa_tlen;
2926
2927                 switch (vsa_llen) {
2928                 case 1:
2929                         attrlen = ptr[0] - (vsa_tlen + vsa_llen + vsa_offset);
2930                         break;
2931
2932                 case 2:
2933                         attrlen = ptr[1] - (vsa_tlen + vsa_llen);
2934                         break;
2935
2936                 default:        /* can't hit this. */
2937                         return -1;
2938                 }
2939
2940                 ptr += vsa_llen + vsa_offset;
2941                 vendorlen -= vsa_tlen + vsa_llen + vsa_offset + attrlen;
2942                 packet_length -= (vsa_tlen + vsa_llen + vsa_offset);
2943
2944                 /*
2945                  *      Ignore VSAs that have no data.
2946                  */
2947                 if (attrlen == 0) goto next;
2948
2949                 /*
2950                  *      WiMAX attributes of type 0 are ignored.  They
2951                  *      are a secret flag to us that the attribute has
2952                  *      already been dealt with.
2953                  */
2954                 if ((vendorcode == VENDORPEC_WIMAX) && (attribute == 0)) {
2955                         goto next;
2956                 }
2957
2958                 if (vsa_offset) {
2959                         DICT_ATTR *da;
2960
2961                         da = dict_attrbyvalue(attribute, vendorcode);
2962
2963                         /*
2964                          *      If it's NOT continued, AND we know
2965                          *      about it, AND it's not a TLV, we can
2966                          *      create a normal pair.
2967                          */
2968                         if (((vsa_ptr[2] & 0x80) == 0) &&
2969                             da && (da->type != PW_TYPE_TLV)) goto create_pair;
2970
2971                         /*
2972                          *      Else it IS continued, or it's a TLV.
2973                          *      Go do a lot of work to find the stuff.
2974                          */
2975                         pair = rad_continuation2vp(packet, original, secret,
2976                                                    attribute, vendorcode,
2977                                                    attrlen, ptr,
2978                                                    packet_length,
2979                                                    ((vsa_ptr[2] & 0x80) != 0),
2980                                                    da);
2981                         goto created_pair;
2982                 }
2983
2984                 /*
2985                  *      Create the attribute, setting the default type
2986                  *      to 'octets'.  If the type in the dictionary
2987                  *      is different, then the dictionary type will
2988                  *      over-ride this one.
2989                  *
2990                  *      If the attribute has no data, then discard it.
2991                  *
2992                  *      Unless it's CUI.  Damn you, CUI!
2993                  */
2994         create_pair:
2995                 if (!attrlen &&
2996                     (attribute != PW_CHARGEABLE_USER_IDENTITY)) goto next;
2997
2998                 pair = rad_attr2vp(packet, original, secret,
2999                                    attribute, vendorcode, attrlen, ptr);
3000                 if (!pair) {
3001                         pairfree(&packet->vps);
3002                         fr_strerror_printf("out of memory");
3003                         return -1;
3004                 }
3005
3006         created_pair:
3007                 *tail = pair;
3008                 while (pair) {
3009                         num_attributes++;
3010                         debug_pair(pair);
3011                         tail = &pair->next;
3012                         pair = pair->next;
3013                 }
3014
3015                 /*
3016                  *      VSA's may not have been counted properly in
3017                  *      rad_packet_ok() above, as it is hard to count
3018                  *      then without using the dictionary.  We
3019                  *      therefore enforce the limits here, too.
3020                  */
3021                 if ((fr_max_attributes > 0) &&
3022                     (num_attributes > fr_max_attributes)) {
3023                         char host_ipaddr[128];
3024
3025                         pairfree(&packet->vps);
3026                         fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
3027                                    inet_ntop(packet->src_ipaddr.af,
3028                                              &packet->src_ipaddr.ipaddr,
3029                                              host_ipaddr, sizeof(host_ipaddr)),
3030                                    num_attributes, fr_max_attributes);
3031                         return -1;
3032                 }
3033
3034         next:
3035                 if (vendorlen == 0) vendorcode = 0;
3036                 ptr += attrlen;
3037                 packet_length -= attrlen;
3038         }
3039
3040         /*
3041          *      Merge information from the outside world into our
3042          *      random pool.
3043          */
3044         fr_rand_seed(packet->data, AUTH_HDR_LEN);
3045
3046         return 0;
3047 }
3048
3049
3050 /*
3051  *      Encode password.
3052  *
3053  *      We assume that the passwd buffer passed is big enough.
3054  *      RFC2138 says the password is max 128 chars, so the size
3055  *      of the passwd buffer must be at least 129 characters.
3056  *      Preferably it's just MAX_STRING_LEN.
3057  *
3058  *      int *pwlen is updated to the new length of the encrypted
3059  *      password - a multiple of 16 bytes.
3060  */
3061 int rad_pwencode(char *passwd, size_t *pwlen, const char *secret,
3062                  const uint8_t *vector)
3063 {
3064         FR_MD5_CTX context, old;
3065         uint8_t digest[AUTH_VECTOR_LEN];
3066         int     i, n, secretlen;
3067         int     len;
3068
3069         /*
3070          *      RFC maximum is 128 bytes.
3071          *
3072          *      If length is zero, pad it out with zeros.
3073          *
3074          *      If the length isn't aligned to 16 bytes,
3075          *      zero out the extra data.
3076          */
3077         len = *pwlen;
3078
3079         if (len > 128) len = 128;
3080
3081         if (len == 0) {
3082                 memset(passwd, 0, AUTH_PASS_LEN);
3083                 len = AUTH_PASS_LEN;
3084         } else if ((len % AUTH_PASS_LEN) != 0) {
3085                 memset(&passwd[len], 0, AUTH_PASS_LEN - (len % AUTH_PASS_LEN));
3086                 len += AUTH_PASS_LEN - (len % AUTH_PASS_LEN);
3087         }
3088         *pwlen = len;
3089
3090         /*
3091          *      Use the secret to setup the decryption digest
3092          */
3093         secretlen = strlen(secret);
3094
3095         fr_MD5Init(&context);
3096         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3097         old = context;          /* save intermediate work */
3098
3099         /*
3100          *      Encrypt it in place.  Don't bother checking
3101          *      len, as we've ensured above that it's OK.
3102          */
3103         for (n = 0; n < len; n += AUTH_PASS_LEN) {
3104                 if (n == 0) {
3105                         fr_MD5Update(&context, vector, AUTH_PASS_LEN);
3106                         fr_MD5Final(digest, &context);
3107                 } else {
3108                         context = old;
3109                         fr_MD5Update(&context,
3110                                      (uint8_t *) passwd + n - AUTH_PASS_LEN,
3111                                      AUTH_PASS_LEN);
3112                         fr_MD5Final(digest, &context);
3113                 }
3114
3115                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3116                         passwd[i + n] ^= digest[i];
3117                 }
3118         }
3119
3120         return 0;
3121 }
3122
3123 /*
3124  *      Decode password.
3125  */
3126 int rad_pwdecode(char *passwd, size_t pwlen, const char *secret,
3127                  const uint8_t *vector)
3128 {
3129         FR_MD5_CTX context, old;
3130         uint8_t digest[AUTH_VECTOR_LEN];
3131         int     i;
3132         size_t  n, secretlen;
3133
3134         /*
3135          *      The RFC's say that the maximum is 128.
3136          *      The buffer we're putting it into above is 254, so
3137          *      we don't need to do any length checking.
3138          */
3139         if (pwlen > 128) pwlen = 128;
3140
3141         /*
3142          *      Catch idiots.
3143          */
3144         if (pwlen == 0) goto done;
3145
3146         /*
3147          *      Use the secret to setup the decryption digest
3148          */
3149         secretlen = strlen(secret);
3150
3151         fr_MD5Init(&context);
3152         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3153         old = context;          /* save intermediate work */
3154
3155         /*
3156          *      The inverse of the code above.
3157          */
3158         for (n = 0; n < pwlen; n += AUTH_PASS_LEN) {
3159                 if (n == 0) {
3160                         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3161                         fr_MD5Final(digest, &context);
3162
3163                         context = old;
3164                         if (pwlen > AUTH_PASS_LEN) {
3165                                 fr_MD5Update(&context, (uint8_t *) passwd,
3166                                              AUTH_PASS_LEN);
3167                         }
3168                 } else {
3169                         fr_MD5Final(digest, &context);
3170
3171                         context = old;
3172                         if (pwlen > (n + AUTH_PASS_LEN)) {
3173                                 fr_MD5Update(&context, (uint8_t *) passwd + n,
3174                                              AUTH_PASS_LEN);
3175                         }
3176                 }
3177
3178                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3179                         passwd[i + n] ^= digest[i];
3180                 }
3181         }
3182
3183  done:
3184         passwd[pwlen] = '\0';
3185         return strlen(passwd);
3186 }
3187
3188
3189 /*
3190  *      Encode Tunnel-Password attributes when sending them out on the wire.
3191  *
3192  *      int *pwlen is updated to the new length of the encrypted
3193  *      password - a multiple of 16 bytes.
3194  *
3195  *      This is per RFC-2868 which adds a two char SALT to the initial intermediate
3196  *      value MD5 hash.
3197  */
3198 int rad_tunnel_pwencode(char *passwd, size_t *pwlen, const char *secret,
3199                         const uint8_t *vector)
3200 {
3201         uint8_t buffer[AUTH_VECTOR_LEN + MAX_STRING_LEN + 3];
3202         unsigned char   digest[AUTH_VECTOR_LEN];
3203         char*   salt;
3204         int     i, n, secretlen;
3205         unsigned len, n2;
3206
3207         len = *pwlen;
3208
3209         if (len > 127) len = 127;
3210
3211         /*
3212          * Shift the password 3 positions right to place a salt and original
3213          * length, tag will be added automatically on packet send
3214          */
3215         for (n=len ; n>=0 ; n--) passwd[n+3] = passwd[n];
3216         salt = passwd;
3217         passwd += 2;
3218         /*
3219          * save original password length as first password character;
3220          */
3221         *passwd = len;
3222         len += 1;
3223
3224
3225         /*
3226          *      Generate salt.  The RFC's say:
3227          *
3228          *      The high bit of salt[0] must be set, each salt in a
3229          *      packet should be unique, and they should be random
3230          *
3231          *      So, we set the high bit, add in a counter, and then
3232          *      add in some CSPRNG data.  should be OK..
3233          */
3234         salt[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
3235                    (fr_rand() & 0x07));
3236         salt[1] = fr_rand();
3237
3238         /*
3239          *      Padd password to multiple of AUTH_PASS_LEN bytes.
3240          */
3241         n = len % AUTH_PASS_LEN;
3242         if (n) {
3243                 n = AUTH_PASS_LEN - n;
3244                 for (; n > 0; n--, len++)
3245                         passwd[len] = 0;
3246         }
3247         /* set new password length */
3248         *pwlen = len + 2;
3249
3250         /*
3251          *      Use the secret to setup the decryption digest
3252          */
3253         secretlen = strlen(secret);
3254         memcpy(buffer, secret, secretlen);
3255
3256         for (n2 = 0; n2 < len; n2+=AUTH_PASS_LEN) {
3257                 if (!n2) {
3258                         memcpy(buffer + secretlen, vector, AUTH_VECTOR_LEN);
3259                         memcpy(buffer + secretlen + AUTH_VECTOR_LEN, salt, 2);
3260                         fr_md5_calc(digest, buffer, secretlen + AUTH_VECTOR_LEN + 2);
3261                 } else {
3262                         memcpy(buffer + secretlen, passwd + n2 - AUTH_PASS_LEN, AUTH_PASS_LEN);
3263                         fr_md5_calc(digest, buffer, secretlen + AUTH_PASS_LEN);
3264                 }
3265
3266                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3267                         passwd[i + n2] ^= digest[i];
3268                 }
3269         }
3270         passwd[n2] = 0;
3271         return 0;
3272 }
3273
3274 /*
3275  *      Decode Tunnel-Password encrypted attributes.
3276  *
3277  *      Defined in RFC-2868, this uses a two char SALT along with the
3278  *      initial intermediate value, to differentiate it from the
3279  *      above.
3280  */
3281 int rad_tunnel_pwdecode(uint8_t *passwd, size_t *pwlen, const char *secret,
3282                         const uint8_t *vector)
3283 {
3284         FR_MD5_CTX  context, old;
3285         uint8_t         digest[AUTH_VECTOR_LEN];
3286         int             secretlen;
3287         unsigned        i, n, len, reallen;
3288
3289         len = *pwlen;
3290
3291         /*
3292          *      We need at least a salt.
3293          */
3294         if (len < 2) {
3295                 fr_strerror_printf("tunnel password is too short");
3296                 return -1;
3297         }
3298
3299         /*
3300          *      There's a salt, but no password.  Or, there's a salt
3301          *      and a 'data_len' octet.  It's wrong, but at least we
3302          *      can figure out what it means: the password is empty.
3303          *
3304          *      Note that this means we ignore the 'data_len' field,
3305          *      if the attribute length tells us that there's no
3306          *      more data.  So the 'data_len' field may be wrong,
3307          *      but that's ok...
3308          */
3309         if (len <= 3) {
3310                 passwd[0] = 0;
3311                 *pwlen = 0;
3312                 return 0;
3313         }
3314
3315         len -= 2;               /* discount the salt */
3316
3317         /*
3318          *      Use the secret to setup the decryption digest
3319          */
3320         secretlen = strlen(secret);
3321
3322         fr_MD5Init(&context);
3323         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3324         old = context;          /* save intermediate work */
3325
3326         /*
3327          *      Set up the initial key:
3328          *
3329          *       b(1) = MD5(secret + vector + salt)
3330          */
3331         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3332         fr_MD5Update(&context, passwd, 2);
3333
3334         reallen = 0;
3335         for (n = 0; n < len; n += AUTH_PASS_LEN) {
3336                 int base = 0;
3337
3338                 if (n == 0) {
3339                         fr_MD5Final(digest, &context);
3340
3341                         context = old;
3342
3343                         /*
3344                          *      A quick check: decrypt the first octet
3345                          *      of the password, which is the
3346                          *      'data_len' field.  Ensure it's sane.
3347                          */
3348                         reallen = passwd[2] ^ digest[0];
3349                         if (reallen >= len) {
3350                                 fr_strerror_printf("tunnel password is too long for the attribute");
3351                                 return -1;
3352                         }
3353
3354                         fr_MD5Update(&context, passwd + 2, AUTH_PASS_LEN);
3355
3356                         base = 1;
3357                 } else {
3358                         fr_MD5Final(digest, &context);
3359
3360                         context = old;
3361                         fr_MD5Update(&context, passwd + n + 2, AUTH_PASS_LEN);
3362                 }
3363
3364                 for (i = base; i < AUTH_PASS_LEN; i++) {
3365                         passwd[n + i - 1] = passwd[n + i + 2] ^ digest[i];
3366                 }
3367         }
3368
3369         /*
3370          *      See make_tunnel_password, above.
3371          */
3372         if (reallen > 239) reallen = 239;
3373
3374         *pwlen = reallen;
3375         passwd[reallen] = 0;
3376
3377         return reallen;
3378 }
3379
3380 /*
3381  *      Encode a CHAP password
3382  *
3383  *      FIXME: might not work with Ascend because
3384  *      we use vp->length, and Ascend gear likes
3385  *      to send an extra '\0' in the string!
3386  */
3387 int rad_chap_encode(RADIUS_PACKET *packet, uint8_t *output, int id,
3388                     VALUE_PAIR *password)
3389 {
3390         int             i;
3391         uint8_t         *ptr;
3392         uint8_t         string[MAX_STRING_LEN * 2 + 1];
3393         VALUE_PAIR      *challenge;
3394
3395         /*
3396          *      Sanity check the input parameters
3397          */
3398         if ((packet == NULL) || (password == NULL)) {
3399                 return -1;
3400         }
3401
3402         /*
3403          *      Note that the password VP can be EITHER
3404          *      a User-Password attribute (from a check-item list),
3405          *      or a CHAP-Password attribute (the client asking
3406          *      the library to encode it).
3407          */
3408
3409         i = 0;
3410         ptr = string;
3411         *ptr++ = id;
3412
3413         i++;
3414         memcpy(ptr, password->vp_strvalue, password->length);
3415         ptr += password->length;
3416         i += password->length;
3417
3418         /*
3419          *      Use Chap-Challenge pair if present,
3420          *      Request-Authenticator otherwise.
3421          */
3422         challenge = pairfind(packet->vps, PW_CHAP_CHALLENGE, 0);
3423         if (challenge) {
3424                 memcpy(ptr, challenge->vp_strvalue, challenge->length);
3425                 i += challenge->length;
3426         } else {
3427                 memcpy(ptr, packet->vector, AUTH_VECTOR_LEN);
3428                 i += AUTH_VECTOR_LEN;
3429         }
3430
3431         *output = id;
3432         fr_md5_calc((uint8_t *)output + 1, (uint8_t *)string, i);
3433
3434         return 0;
3435 }
3436
3437
3438 /*
3439  *      Seed the random number generator.
3440  *
3441  *      May be called any number of times.
3442  */
3443 void fr_rand_seed(const void *data, size_t size)
3444 {
3445         uint32_t hash;
3446
3447         /*
3448          *      Ensure that the pool is initialized.
3449          */
3450         if (!fr_rand_initialized) {
3451                 int fd;
3452
3453                 memset(&fr_rand_pool, 0, sizeof(fr_rand_pool));
3454
3455                 fd = open("/dev/urandom", O_RDONLY);
3456                 if (fd >= 0) {
3457                         size_t total;
3458                         ssize_t this;
3459
3460                         total = this = 0;
3461                         while (total < sizeof(fr_rand_pool.randrsl)) {
3462                                 this = read(fd, fr_rand_pool.randrsl,
3463                                             sizeof(fr_rand_pool.randrsl) - total);
3464                                 if ((this < 0) && (errno != EINTR)) break;
3465                                 if (this > 0) total += this;
3466                         }
3467                         close(fd);
3468                 } else {
3469                         fr_rand_pool.randrsl[0] = fd;
3470                         fr_rand_pool.randrsl[1] = time(NULL);
3471                         fr_rand_pool.randrsl[2] = errno;
3472                 }
3473
3474                 fr_randinit(&fr_rand_pool, 1);
3475                 fr_rand_pool.randcnt = 0;
3476                 fr_rand_initialized = 1;
3477         }
3478
3479         if (!data) return;
3480
3481         /*
3482          *      Hash the user data
3483          */
3484         hash = fr_rand();
3485         if (!hash) hash = fr_rand();
3486         hash = fr_hash_update(data, size, hash);
3487
3488         fr_rand_pool.randmem[fr_rand_pool.randcnt] ^= hash;
3489 }
3490
3491
3492 /*
3493  *      Return a 32-bit random number.
3494  */
3495 uint32_t fr_rand(void)
3496 {
3497         uint32_t num;
3498
3499         /*
3500          *      Ensure that the pool is initialized.
3501          */
3502         if (!fr_rand_initialized) {
3503                 fr_rand_seed(NULL, 0);
3504         }
3505
3506         num = fr_rand_pool.randrsl[fr_rand_pool.randcnt++];
3507         if (fr_rand_pool.randcnt >= 256) {
3508                 fr_rand_pool.randcnt = 0;
3509                 fr_isaac(&fr_rand_pool);
3510         }
3511
3512         return num;
3513 }
3514
3515
3516 /*
3517  *      Allocate a new RADIUS_PACKET
3518  */
3519 RADIUS_PACKET *rad_alloc(int newvector)
3520 {
3521         RADIUS_PACKET   *rp;
3522
3523         if ((rp = malloc(sizeof(RADIUS_PACKET))) == NULL) {
3524                 fr_strerror_printf("out of memory");
3525                 return NULL;
3526         }
3527         memset(rp, 0, sizeof(*rp));
3528         rp->id = -1;
3529         rp->offset = -1;
3530
3531         if (newvector) {
3532                 int i;
3533                 uint32_t hash, base;
3534
3535                 /*
3536                  *      Don't expose the actual contents of the random
3537                  *      pool.
3538                  */
3539                 base = fr_rand();
3540                 for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(uint32_t)) {
3541                         hash = fr_rand() ^ base;
3542                         memcpy(rp->vector + i, &hash, sizeof(hash));
3543                 }
3544         }
3545         fr_rand();              /* stir the pool again */
3546
3547         return rp;
3548 }
3549
3550 RADIUS_PACKET *rad_alloc_reply(RADIUS_PACKET *packet)
3551 {
3552         RADIUS_PACKET *reply;
3553
3554         if (!packet) return NULL;
3555
3556         reply = rad_alloc(0);
3557         if (!reply) return NULL;
3558
3559         /*
3560          *      Initialize the fields from the request.
3561          */
3562         reply->sockfd = packet->sockfd;
3563         reply->dst_ipaddr = packet->src_ipaddr;
3564         reply->src_ipaddr = packet->dst_ipaddr;
3565         reply->dst_port = packet->src_port;
3566         reply->src_port = packet->dst_port;
3567         reply->id = packet->id;
3568         reply->code = 0; /* UNKNOWN code */
3569         memcpy(reply->vector, packet->vector,
3570                sizeof(reply->vector));
3571         reply->vps = NULL;
3572         reply->data = NULL;
3573         reply->data_len = 0;
3574
3575         return reply;
3576 }
3577
3578
3579 /*
3580  *      Free a RADIUS_PACKET
3581  */
3582 void rad_free(RADIUS_PACKET **radius_packet_ptr)
3583 {
3584         RADIUS_PACKET *radius_packet;
3585
3586         if (!radius_packet_ptr || !*radius_packet_ptr) return;
3587         radius_packet = *radius_packet_ptr;
3588
3589         free(radius_packet->data);
3590
3591         pairfree(&radius_packet->vps);
3592
3593         free(radius_packet);
3594
3595         *radius_packet_ptr = NULL;
3596 }