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
 630                 for (i = 0; i < AUTH_PASS_LEN; i++) {
 631                         passwd[i + 2 + n] ^= digest[i];
 632                 }
 633         }
 634         memcpy(output, passwd, len + 2);
 635 }
 636
 637 /*
 638  *      Returns the end of the data.
 639  */
 640 static int vp2data(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
 641                    const char *secret, const VALUE_PAIR *vp, uint8_t *start,
 642                    size_t room)
 643 {
 644         uint32_t lvalue;
 645         size_t len;
 646         const uint8_t *data;
 647         uint8_t *ptr = start;
 648         uint8_t array[4];
 649
 650         /*
 651          *      Set up the default sources for the data.
 652          */
 653         data = vp->vp_octets;
 654         len = vp->length;
 655
 656         switch(vp->type) {
 657         case PW_TYPE_STRING:
 658         case PW_TYPE_OCTETS:
 659         case PW_TYPE_IFID:
 660         case PW_TYPE_IPV6ADDR:
 661         case PW_TYPE_IPV6PREFIX:
 662         case PW_TYPE_ABINARY:
 663                 /* nothing more to do */
 664                 break;
 665
 666         case PW_TYPE_BYTE:
 667                 len = 1;        /* just in case */
 668                 array[0] = vp->vp_integer & 0xff;
 669                 data = array;
 670                 break;
 671
 672         case PW_TYPE_SHORT:
 673                 len = 2;        /* just in case */
 674                 array[0] = (vp->vp_integer >> 8) & 0xff;
 675                 array[1] = vp->vp_integer & 0xff;
 676                 data = array;
 677                 break;
 678
 679         case PW_TYPE_INTEGER:
 680                 len = 4;        /* just in case */
 681                 lvalue = htonl(vp->vp_integer);
 682                 memcpy(array, &lvalue, sizeof(lvalue));
 683                 data = array;
 684                 break;
 685
 686         case PW_TYPE_IPADDR:
 687                 data = (const uint8_t *) &vp->vp_ipaddr;
 688                 len = 4;        /* just in case */
 689                 break;
 690
 691                 /*
 692                  *  There are no tagged date attributes.
 693                  */
 694         case PW_TYPE_DATE:
 695                 lvalue = htonl(vp->vp_date);
 696                 data = (const uint8_t *) &lvalue;
 697                 len = 4;        /* just in case */
 698                 break;
 699
 700         case PW_TYPE_SIGNED:
 701         {
 702                 int32_t slvalue;
 703
 704                 len = 4;        /* just in case */
 705                 slvalue = htonl(vp->vp_signed);
 706                 memcpy(array, &slvalue, sizeof(slvalue));
 707                 break;
 708         }
 709
 710         case PW_TYPE_TLV:
 711                 data = vp->vp_tlv;
 712                 if (!data) {
 713                         fr_strerror_printf("ERROR: Cannot encode NULL TLV");
 714                         return -1;
 715                 }
 716                 if (vp->length > room) return 0; /* can't chop TLVs to fit */
 717                 break;
 718
 719         default:                /* unknown type: ignore it */
 720                 fr_strerror_printf("ERROR: Unknown attribute type %d", vp->type);
 721                 return -1;
 722         }
 723
 724         /*
 725          *      Bound the data to the calling size
 726          */
 727         if (len > room) len = room;
 728
 729         /*
 730          *      Encrypt the various password styles
 731          *
 732          *      Attributes with encrypted values MUST be less than
 733          *      128 bytes long.
 734          */
 735         switch (vp->flags.encrypt) {
 736         case FLAG_ENCRYPT_USER_PASSWORD:
 737                 make_passwd(ptr, &len, data, len,
 738                             secret, packet->vector);
 739                 break;
 740
 741         case FLAG_ENCRYPT_TUNNEL_PASSWORD:
 742                 lvalue = 0;
 743                 if (vp->flags.has_tag) lvalue = 1;
 744
 745                 /*
 746                  *      Check if there's enough room.  If there isn't,
 747                  *      we discard the attribute.
 748                  *
 749                  *      This is ONLY a problem if we have multiple VSA's
 750                  *      in one Vendor-Specific, though.
 751                  */
 752                 if (room < (18 + lvalue)) return 0;
 753
 754                 switch (packet->code) {
 755                 case PW_AUTHENTICATION_ACK:
 756                 case PW_AUTHENTICATION_REJECT:
 757                 case PW_ACCESS_CHALLENGE:
 758                 default:
 759                         if (!original) {
 760                                 fr_strerror_printf("ERROR: No request packet, cannot encrypt %s attribute in the vp.", vp->name);
 761                                 return -1;
 762                         }
 763
 764                         if (lvalue) ptr[0] = vp->flags.tag;
 765                         make_tunnel_passwd(ptr + lvalue, &len, data, len,
 766                                            room - lvalue,
 767                                            secret, original->vector);
 768                         break;
 769                 case PW_ACCOUNTING_REQUEST:
 770                 case PW_DISCONNECT_REQUEST:
 771                 case PW_COA_REQUEST:
 772                         ptr[0] = vp->flags.tag;
 773                         make_tunnel_passwd(ptr + 1, &len, data, len - 1, room,
 774                                            secret, packet->vector);
 775                         break;
 776                 }
 777                 break;
 778
 779                 /*
 780                  *      The code above ensures that this attribute
 781                  *      always fits.
 782                  */
 783         case FLAG_ENCRYPT_ASCEND_SECRET:
 784                 make_secret(ptr, packet->vector, secret, data);
 785                 len = AUTH_VECTOR_LEN;
 786                 break;
 787
 788
 789         default:
 790                 if (vp->flags.has_tag && TAG_VALID(vp->flags.tag)) {
 791                         if (vp->type == PW_TYPE_STRING) {
 792                                 if (len > (room - 1)) len = room - 1;
 793                                 ptr[0] = vp->flags.tag;
 794                                 ptr++;
 795                         } else if (vp->type == PW_TYPE_INTEGER) {
 796                                 array[0] = vp->flags.tag;
 797                         } /* else it can't be any other type */
 798                 }
 799                 memcpy(ptr, data, len);
 800                 break;
 801         } /* switch over encryption flags */
 802
 803         return len + (ptr - start);;
 804 }
 805
 806
 807 static int rad_vp2rfc(const RADIUS_PACKET *packet,
 808                       const RADIUS_PACKET *original,
 809                       const char *secret, const VALUE_PAIR *vp,
 810                       unsigned int attribute, uint8_t *ptr, size_t room)
 811 {
 812         int len;
 813
 814         if (room < 2) return 0;
 815
 816         ptr[0] = attribute & 0xff; /* NOT vp->attribute */
 817         ptr[1] = 2;
 818
 819         len = vp2data(packet, original, secret, vp, ptr + 2, room - 2);
 820         if (len < 0) return len;
 821
 822         ptr[1] += len;
 823
 824         return ptr[1];
 825 }
 826
 827 extern int fr_wimax_max_tlv;
 828 extern int fr_wimax_shift[];
 829 extern int fr_wimax_mask[];
 830
 831 static int tlv2data(const RADIUS_PACKET *packet,
 832                     const RADIUS_PACKET *original,
 833                     const char *secret, const VALUE_PAIR *vp,
 834                     uint8_t *ptr, size_t room, int nest)
 835 {
 836         int len;
 837
 838         if (nest > fr_wimax_max_tlv) return -1;
 839
 840         if (room < 2) return 0;
 841         room -= 2;
 842
 843         ptr[0] = (vp->attribute >> fr_wimax_shift[nest]) & fr_wimax_mask[nest];
 844         ptr[1] = 2;
 845
 846         /*
 847          *      No more nested TLVs: pack the data.
 848          */
 849         if ((nest == fr_wimax_max_tlv) ||
 850             ((vp->attribute >> fr_wimax_shift[nest + 1]) == 0)) {
 851                 len = vp2data(packet, original, secret, vp, ptr + 2, room);
 852         } else {
 853                 len = tlv2data(packet, original, secret, vp, ptr + 2, room,
 854                                nest + 1);
 855         }
 856         if (len <= 0) return len;
 857
 858         ptr[1] += len;
 859
 860         return ptr[1];
 861 }
 862
 863 static int wimax2data(const RADIUS_PACKET *packet,
 864                       const RADIUS_PACKET *original,
 865                       const char *secret, const VALUE_PAIR *vp,
 866                       uint8_t *start, size_t room, uint8_t *ptr)
 867 {
 868         int len;
 869
 870         /*
 871          *      Offsets to Vendor-Specific length, and to length of
 872          *      WiMAX attribute.
 873          */
 874 #define VS_OFF (1)
 875 #define WM_OFF (7)
 876
 877         if (room < 1) return 0;
 878         room--;
 879
 880         /*
 881          *      Account for continuation bytes.  The caller has
 882          *      already accounting for the continuation byte in the
 883          *      Vendor-Specific "length" field.
 884          */
 885         start[WM_OFF]++;
 886         *(ptr++) = 0;
 887
 888         /*
 889          *      Chop everything to fit in one attribute.
 890          */
 891         if (room > (255 - 9)) room = (255 - 9);
 892
 893         /*
 894          *      The attribute contains TLVs that we have NOT decoded
 895          *      properly, OR it contains TLV that the user has encoded
 896          *      manually.  If it has no data, OR it's too long,
 897          *      discard it.  We're not going to walk through its
 898          *      contents trying to figure out how to chop it across
 899          *      multiple continuations.
 900          */
 901         if (vp->flags.has_tlv && (!vp->vp_tlv || (vp->length > room))) {
 902                 return 0;
 903         }
 904
 905         /*
 906          *      The attribute is a top-level integer, ipaddr, etc.
 907          *      Encode it.
 908          */
 909         if (!vp->flags.is_tlv) {
 910                 len = vp2data(packet, original, secret, vp, ptr, room);
 911         } else {
 912                 len = tlv2data(packet, original, secret, vp, ptr, room, 1);
 913         }
 914
 915         if (len <= 0) return len;
 916
 917         start[VS_OFF] += len;
 918         start[WM_OFF] += len;
 919
 920         return start[VS_OFF];
 921 }
 922
 923
 924 /*
 925  *      Parse a data structure into a RADIUS attribute.
 926  */
 927 int rad_vp2attr(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
 928                 const char *secret, const VALUE_PAIR *vp, uint8_t *start,
 929                 size_t room)
 930 {
 931         int len;
 932         uint32_t lvalue;
 933         uint8_t *ptr;
 934         DICT_VENDOR *dv;
 935
 936         /*
 937          *      RFC format attributes take the fast path.
 938          */
 939         if (vp->vendor == 0) {
 940                 len = rad_vp2rfc(packet, original, secret, vp,
 941                                  vp->attribute, start, room);
 942                 if (len < 0) return -1;
 943
 944                 /*
 945                  *      RFC 2865 section 5 says that zero-length
 946                  *      attributes MUST NOT be sent.
 947                  *
 948                  *      ... and the WiMAX forum ignores
 949                  *      this... because of one vendor.  Don't they
 950                  *      have anything better to do with their time?
 951                  */
 952                 if ((len == 0) &&
 953                     (vp->attribute != PW_CHARGEABLE_USER_IDENTITY)) return 0;
 954
 955                 return len;
 956
 957         }
 958
 959         /*
 960          *      Not enough room for:
 961          *              attr, len, vendor-id, vsa, vsalen
 962          */
 963         if (room < 8) return 0;
 964
 965         /*
 966          *      Build the Vendor-Specific header
 967          */
 968         ptr = start;
 969         *ptr++ = PW_VENDOR_SPECIFIC;
 970         *ptr++ = 6;
 971         room -= 6;
 972         lvalue = htonl(vp->vendor);
 973         memcpy(ptr, &lvalue, 4);
 974         ptr += 4;
 975
 976         /*
 977          *      Unknown vendors, and type=1,length=1,no-continuation
 978          *      are RFC format attributes.
 979          */
 980         dv = dict_vendorbyvalue(vp->vendor);
 981         if (!dv ||
 982             ((dv->type == 1) && (dv->length = 1) && !dv->flags)) {
 983                 len = rad_vp2rfc(packet, original, secret, vp,
 984                                  vp->attribute, ptr, room);
 985                 if (len <= 0) return len;
 986
 987                 start[1] += len;
 988                 return start[1];
 989         }
 990
 991         if (room < (dv->type + dv->length + dv->flags)) return 0;
 992         room -= (dv->type + dv->length + dv->flags);
 993         start[1] += (dv->type + dv->length + dv->flags);
 994
 995         switch (dv->type) {
 996                 case 1:
 997                         ptr[0] = (vp->attribute & 0xFF);
 998                         break;
 999
1000                 case 2:
1001                         ptr[0] = ((vp->attribute >> 8) & 0xFF);
1002                         ptr[1] = (vp->attribute & 0xFF);
1003                         break;
1004
1005                 case 4:
1006                         ptr[0] = 0;
1007                         ptr[1] = ((vp->attribute >> 16) & 0xFF);
1008                         ptr[2] = ((vp->attribute >> 8) & 0xFF);
1009                         ptr[3] = (vp->attribute & 0xFF);
1010                         break;
1011
1012                 default:
1013                         return 0; /* silently discard it */
1014         }
1015         ptr += dv->type;
1016
1017         switch (dv->length) {
1018         case 0:
1019                 break;
1020         case 1:
1021                 ptr[0] = dv->type + 1;
1022                 break;
1023         case 2:
1024                 ptr[0] = 0;
1025                 ptr[1] = dv->type + 2;
1026                 break;
1027
1028         default:
1029                 return 0; /* silently discard it */
1030         }
1031         ptr += dv->length;
1032
1033         /*
1034          *      WiMAX attributes take their own path through the
1035          *      system.
1036          */
1037         if (dv->flags) return wimax2data(packet, original, secret, vp,
1038                                          start, room, ptr);
1039
1040         len = vp2data(packet, original, secret, vp, ptr, room);
1041         if (len <= 0) return len;
1042
1043         if (dv->length != 0) ptr[-1] += len;
1044
1045         start[1] += len;
1046
1047         return start[1];
1048 }
1049
1050 /*
1051  *  Swap 123a -> 0321
1052  */
1053 #define REORDER(x) ((x & 0xff00) << 8) | ((x & 0xff0000) >> 8) | ((x & 0xff000000 >> 24))
1054
1055
1056 /*
1057  *      Encode a WiMAX sub-TLV.  It must NOT be called for WiMAX
1058  *      attributes that are of type integer, string, etc.
1059  */
1060 static int rad_encode_wimax(const RADIUS_PACKET *packet,
1061                             const RADIUS_PACKET *original,
1062                             const char *secret, VALUE_PAIR *reply,
1063                             uint8_t *start, size_t room)
1064 {
1065         int len, redo;
1066         uint32_t lvalue;
1067         uint8_t *ptr = start, *vsa = start;
1068         uint32_t maxattr;
1069         VALUE_PAIR *vp = reply;
1070
1071         /*
1072          *      Swap the order of the WiMAX hacks, to make later
1073          *      comparisons easier.
1074          */
1075         maxattr = REORDER(vp->attribute);
1076
1077         /*
1078          *      Build the Vendor-Specific header
1079          */
1080         ptr = start;
1081         redo = 0;
1082
1083 redo_vsa:
1084         vsa = ptr;
1085
1086         if (room < 9) return 0;
1087         *ptr++ = PW_VENDOR_SPECIFIC;
1088         *ptr++ = 9;
1089         room -= 9;
1090         lvalue = htonl(vp->vendor);
1091         memcpy(ptr, &lvalue, 4);
1092         ptr += 4;
1093         *(ptr++) = vp->attribute & 0xff;
1094         *(ptr++) = 3;
1095         *(ptr++) = 0;           /* continuation */
1096         room -= 9;
1097
1098 redo_tlv:
1099         len = tlv2data(packet, original, secret, vp, ptr, room, 1);
1100         if (len < 0) return len;
1101
1102         /*
1103          *      Not enough room.  Do a continuation.
1104          */
1105         if ((len == 0) || ((vsa[VS_OFF] + len) > 255)) {
1106                 if (redo) return (start - vsa);
1107
1108                 vsa[8] = 0x80;
1109                 redo = 1;
1110                 goto redo_vsa;
1111         }
1112         redo = 0;
1113
1114         ptr += len;
1115         vsa[VS_OFF] += len;
1116         vsa[WM_OFF] += len;
1117
1118         vp->flags.encoded = 1;
1119         vp = vp->next;
1120
1121         /*
1122          *      Look at the NEXT tlv.  Ensure that we encode
1123          *      attributes into a common VSA *only* if they are for
1124          *      the same WiMAX VSA, AND if the TLVs are in numerically
1125          *      increasing order.
1126          */
1127         if (vp && vp->flags.is_tlv && (reply->vendor == vp->vendor) &&
1128             ((reply->attribute & 0xff) == (vp->attribute & 0xff))) {
1129                 uint32_t attr;
1130
1131                 attr = REORDER(vp->attribute);
1132                 if (attr >= maxattr) {
1133                         maxattr = attr;
1134                         goto redo_tlv;
1135                 }
1136         }
1137
1138         return ptr - start;
1139 }
1140
1141
1142 /*
1143  *      Encode a packet.
1144  */
1145 int rad_encode(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1146                const char *secret)
1147 {
1148         radius_packet_t *hdr;
1149         uint8_t         *ptr;
1150         uint16_t        total_length;
1151         int             len;
1152         VALUE_PAIR      *reply;
1153         const char      *what;
1154         char            ip_buffer[128];
1155
1156         /*
1157          *      A 4K packet, aligned on 64-bits.
1158          */
1159         uint64_t        data[MAX_PACKET_LEN / sizeof(uint64_t)];
1160
1161         if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1162                 what = fr_packet_codes[packet->code];
1163         } else {
1164                 what = "Reply";
1165         }
1166
1167         DEBUG("Sending %s of id %d to %s port %d\n",
1168               what, packet->id,
1169               inet_ntop(packet->dst_ipaddr.af,
1170                         &packet->dst_ipaddr.ipaddr,
1171                         ip_buffer, sizeof(ip_buffer)),
1172               packet->dst_port);
1173
1174         /*
1175          *      Double-check some things based on packet code.
1176          */
1177         switch (packet->code) {
1178         case PW_AUTHENTICATION_ACK:
1179         case PW_AUTHENTICATION_REJECT:
1180         case PW_ACCESS_CHALLENGE:
1181                 if (!original) {
1182                         fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1183                         return -1;
1184                 }
1185                 break;
1186
1187                 /*
1188                  *      These packet vectors start off as all zero.
1189                  */
1190         case PW_ACCOUNTING_REQUEST:
1191         case PW_DISCONNECT_REQUEST:
1192         case PW_COA_REQUEST:
1193                 memset(packet->vector, 0, sizeof(packet->vector));
1194                 break;
1195
1196         default:
1197                 break;
1198         }
1199
1200         /*
1201          *      Use memory on the stack, until we know how
1202          *      large the packet will be.
1203          */
1204         hdr = (radius_packet_t *) data;
1205
1206         /*
1207          *      Build standard header
1208          */
1209         hdr->code = packet->code;
1210         hdr->id = packet->id;
1211
1212         memcpy(hdr->vector, packet->vector, sizeof(hdr->vector));
1213
1214         total_length = AUTH_HDR_LEN;
1215
1216         /*
1217          *      Load up the configuration values for the user
1218          */
1219         ptr = hdr->data;
1220         packet->offset = 0;
1221
1222         /*
1223          *      FIXME: Loop twice over the reply list.  The first time,
1224          *      calculate the total length of data.  The second time,
1225          *      allocate the memory, and fill in the VP's.
1226          *
1227          *      Hmm... this may be slower than just doing a small
1228          *      memcpy.
1229          */
1230
1231         /*
1232          *      Loop over the reply attributes for the packet.
1233          */
1234         for (reply = packet->vps; reply; reply = reply->next) {
1235                 /*
1236                  *      Ignore non-wire attributes
1237                  */
1238                 if ((reply->vendor == 0) &&
1239                     ((reply->attribute & 0xFFFF) > 0xff)) {
1240 #ifndef NDEBUG
1241                         /*
1242                          *      Permit the admin to send BADLY formatted
1243                          *      attributes with a debug build.
1244                          */
1245                         if (reply->attribute == PW_RAW_ATTRIBUTE) {
1246                                 memcpy(ptr, reply->vp_octets, reply->length);
1247                                 len = reply->length;
1248                                 goto next;
1249                         }
1250 #endif
1251                         continue;
1252                 }
1253
1254                 /*
1255                  *      Set the Message-Authenticator to the correct
1256                  *      length and initial value.
1257                  */
1258                 if (reply->attribute == PW_MESSAGE_AUTHENTICATOR) {
1259                         reply->length = AUTH_VECTOR_LEN;
1260                         memset(reply->vp_strvalue, 0, AUTH_VECTOR_LEN);
1261
1262                         /*
1263                          *      Cache the offset to the
1264                          *      Message-Authenticator
1265                          */
1266                         packet->offset = total_length;
1267                 }
1268
1269                 /*
1270                  *      Print out ONLY the attributes which
1271                  *      we're sending over the wire, and print
1272                  *      them out BEFORE they're encrypted.
1273                  */
1274                 debug_pair(reply);
1275
1276                 /*
1277                  *      Skip attributes that are encoded.
1278                  */
1279                 if (reply->flags.encoded) continue;
1280
1281                 if (reply->flags.is_tlv) {
1282                         len = rad_encode_wimax(packet, original, secret,
1283                                                reply, ptr,
1284                                                ((uint8_t *) data) + sizeof(data) - ptr);
1285                 } else {
1286
1287                         len = rad_vp2attr(packet, original, secret, reply, ptr,
1288                                           ((uint8_t *) data) + sizeof(data) - ptr);
1289                 }
1290
1291                 if (len < 0) return -1;
1292
1293         next:
1294                 ptr += len;
1295                 total_length += len;
1296         } /* done looping over all attributes */
1297
1298         /*
1299          *      Fill in the rest of the fields, and copy the data over
1300          *      from the local stack to the newly allocated memory.
1301          *
1302          *      Yes, all this 'memcpy' is slow, but it means
1303          *      that we only allocate the minimum amount of
1304          *      memory for a request.
1305          */
1306         packet->data_len = total_length;
1307         packet->data = (uint8_t *) malloc(packet->data_len);
1308         if (!packet->data) {
1309                 fr_strerror_printf("Out of memory");
1310                 return -1;
1311         }
1312
1313         memcpy(packet->data, hdr, packet->data_len);
1314         hdr = (radius_packet_t *) packet->data;
1315
1316         total_length = htons(total_length);
1317         memcpy(hdr->length, &total_length, sizeof(total_length));
1318
1319         return 0;
1320 }
1321
1322
1323 /*
1324  *      Sign a previously encoded packet.
1325  */
1326 int rad_sign(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1327              const char *secret)
1328 {
1329         radius_packet_t *hdr = (radius_packet_t *)packet->data;
1330
1331         /*
1332          *      It wasn't assigned an Id, this is bad!
1333          */
1334         if (packet->id < 0) {
1335                 fr_strerror_printf("ERROR: RADIUS packets must be assigned an Id.");
1336                 return -1;
1337         }
1338
1339         if (!packet->data || (packet->data_len < AUTH_HDR_LEN) ||
1340             (packet->offset < 0)) {
1341                 fr_strerror_printf("ERROR: You must call rad_encode() before rad_sign()");
1342                 return -1;
1343         }
1344
1345         /*
1346          *      If there's a Message-Authenticator, update it
1347          *      now, BEFORE updating the authentication vector.
1348          */
1349         if (packet->offset > 0) {
1350                 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
1351
1352                 switch (packet->code) {
1353                 case PW_ACCOUNTING_REQUEST:
1354                 case PW_ACCOUNTING_RESPONSE:
1355                 case PW_DISCONNECT_REQUEST:
1356                 case PW_DISCONNECT_ACK:
1357                 case PW_DISCONNECT_NAK:
1358                 case PW_COA_REQUEST:
1359                 case PW_COA_ACK:
1360                 case PW_COA_NAK:
1361                         memset(hdr->vector, 0, AUTH_VECTOR_LEN);
1362                         break;
1363
1364                 case PW_AUTHENTICATION_ACK:
1365                 case PW_AUTHENTICATION_REJECT:
1366                 case PW_ACCESS_CHALLENGE:
1367                         if (!original) {
1368                                 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1369                                 return -1;
1370                         }
1371                         memcpy(hdr->vector, original->vector,
1372                                AUTH_VECTOR_LEN);
1373                         break;
1374
1375                 default:        /* others have vector already set to zero */
1376                         break;
1377
1378                 }
1379
1380                 /*
1381                  *      Set the authentication vector to zero,
1382                  *      calculate the signature, and put it
1383                  *      into the Message-Authenticator
1384                  *      attribute.
1385                  */
1386                 fr_hmac_md5(packet->data, packet->data_len,
1387                             (const uint8_t *) secret, strlen(secret),
1388                             calc_auth_vector);
1389                 memcpy(packet->data + packet->offset + 2,
1390                        calc_auth_vector, AUTH_VECTOR_LEN);
1391
1392                 /*
1393                  *      Copy the original request vector back
1394                  *      to the raw packet.
1395                  */
1396                 memcpy(hdr->vector, packet->vector, AUTH_VECTOR_LEN);
1397         }
1398
1399         /*
1400          *      Switch over the packet code, deciding how to
1401          *      sign the packet.
1402          */
1403         switch (packet->code) {
1404                 /*
1405                  *      Request packets are not signed, bur
1406                  *      have a random authentication vector.
1407                  */
1408         case PW_AUTHENTICATION_REQUEST:
1409         case PW_STATUS_SERVER:
1410                 break;
1411
1412                 /*
1413                  *      Reply packets are signed with the
1414                  *      authentication vector of the request.
1415                  */
1416         default:
1417                 {
1418                         uint8_t digest[16];
1419
1420                         FR_MD5_CTX      context;
1421                         fr_MD5Init(&context);
1422                         fr_MD5Update(&context, packet->data, packet->data_len);
1423                         fr_MD5Update(&context, (const uint8_t *) secret,
1424                                      strlen(secret));
1425                         fr_MD5Final(digest, &context);
1426
1427                         memcpy(hdr->vector, digest, AUTH_VECTOR_LEN);
1428                         memcpy(packet->vector, digest, AUTH_VECTOR_LEN);
1429                         break;
1430                 }
1431         }/* switch over packet codes */
1432
1433         return 0;
1434 }
1435
1436 /*
1437  *      Reply to the request.  Also attach
1438  *      reply attribute value pairs and any user message provided.
1439  */
1440 int rad_send(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1441              const char *secret)
1442 {
1443         VALUE_PAIR              *reply;
1444         const char              *what;
1445         char                    ip_buffer[128];
1446
1447         /*
1448          *      Maybe it's a fake packet.  Don't send it.
1449          */
1450         if (!packet || (packet->sockfd < 0)) {
1451                 return 0;
1452         }
1453
1454         if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1455                 what = fr_packet_codes[packet->code];
1456         } else {
1457                 what = "Reply";
1458         }
1459
1460         /*
1461          *  First time through, allocate room for the packet
1462          */
1463         if (!packet->data) {
1464                 /*
1465                  *      Encode the packet.
1466                  */
1467                 if (rad_encode(packet, original, secret) < 0) {
1468                         return -1;
1469                 }
1470
1471                 /*
1472                  *      Re-sign it, including updating the
1473                  *      Message-Authenticator.
1474                  */
1475                 if (rad_sign(packet, original, secret) < 0) {
1476                         return -1;
1477                 }
1478
1479                 /*
1480                  *      If packet->data points to data, then we print out
1481                  *      the VP list again only for debugging.
1482                  */
1483         } else if (fr_debug_flag) {
1484                 DEBUG("Sending %s of id %d to %s port %d\n", what, packet->id,
1485                       inet_ntop(packet->dst_ipaddr.af,
1486                                 &packet->dst_ipaddr.ipaddr,
1487                                 ip_buffer, sizeof(ip_buffer)),
1488                       packet->dst_port);
1489
1490                 for (reply = packet->vps; reply; reply = reply->next) {
1491                         if ((reply->vendor == 0) &&
1492                             ((reply->attribute & 0xFFFF) > 0xff)) continue;
1493                         debug_pair(reply);
1494                 }
1495         }
1496
1497         /*
1498          *      And send it on it's way.
1499          */
1500         return rad_sendto(packet->sockfd, packet->data, packet->data_len, 0,
1501                           &packet->src_ipaddr, packet->src_port,
1502                           &packet->dst_ipaddr, packet->dst_port);
1503 }
1504
1505 /*
1506  *      Do a comparison of two authentication digests by comparing
1507  *      the FULL digest.  Otehrwise, the server can be subject to
1508  *      timing attacks that allow attackers find a valid message
1509  *      authenticator.
1510  *
1511  *      http://www.cs.rice.edu/~dwallach/pub/crosby-timing2009.pdf
1512  */
1513 static int digest_cmp(const uint8_t *a, const uint8_t *b, size_t length)
1514 {
1515         int result = 0;
1516         size_t i;
1517
1518         for (i = 0; i < length; i++) {
1519                 result |= a[i] ^ b[i];
1520         }
1521
1522         return result;          /* 0 is OK, !0 is !OK, just like memcmp */
1523 }
1524
1525
1526 /*
1527  *      Validates the requesting client NAS.  Calculates the
1528  *      signature based on the clients private key.
1529  */
1530 static int calc_acctdigest(RADIUS_PACKET *packet, const char *secret)
1531 {
1532         uint8_t         digest[AUTH_VECTOR_LEN];
1533         FR_MD5_CTX              context;
1534
1535         /*
1536          *      Zero out the auth_vector in the received packet.
1537          *      Then append the shared secret to the received packet,
1538          *      and calculate the MD5 sum. This must be the same
1539          *      as the original MD5 sum (packet->vector).
1540          */
1541         memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
1542
1543         /*
1544          *  MD5(packet + secret);
1545          */
1546         fr_MD5Init(&context);
1547         fr_MD5Update(&context, packet->data, packet->data_len);
1548         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1549         fr_MD5Final(digest, &context);
1550
1551         /*
1552          *      Return 0 if OK, 2 if not OK.
1553          */
1554         if (digest_cmp(digest, packet->vector, AUTH_VECTOR_LEN) != 0) return 2;
1555         return 0;
1556 }
1557
1558
1559 /*
1560  *      Validates the requesting client NAS.  Calculates the
1561  *      signature based on the clients private key.
1562  */
1563 static int calc_replydigest(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1564                             const char *secret)
1565 {
1566         uint8_t         calc_digest[AUTH_VECTOR_LEN];
1567         FR_MD5_CTX              context;
1568
1569         /*
1570          *      Very bad!
1571          */
1572         if (original == NULL) {
1573                 return 3;
1574         }
1575
1576         /*
1577          *  Copy the original vector in place.
1578          */
1579         memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
1580
1581         /*
1582          *  MD5(packet + secret);
1583          */
1584         fr_MD5Init(&context);
1585         fr_MD5Update(&context, packet->data, packet->data_len);
1586         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1587         fr_MD5Final(calc_digest, &context);
1588
1589         /*
1590          *  Copy the packet's vector back to the packet.
1591          */
1592         memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
1593
1594         /*
1595          *      Return 0 if OK, 2 if not OK.
1596          */
1597         if (digest_cmp(packet->vector, calc_digest, AUTH_VECTOR_LEN) != 0) return 2;
1598         return 0;
1599 }
1600
1601
1602 /*
1603  *      See if the data pointed to by PTR is a valid RADIUS packet.
1604  *
1605  *      packet is not 'const * const' because we may update data_len,
1606  *      if there's more data in the UDP packet than in the RADIUS packet.
1607  */
1608 int rad_packet_ok(RADIUS_PACKET *packet, int flags)
1609 {
1610         uint8_t                 *attr;
1611         int                     totallen;
1612         int                     count;
1613         radius_packet_t         *hdr;
1614         char                    host_ipaddr[128];
1615         int                     require_ma = 0;
1616         int                     seen_ma = 0;
1617         int                     num_attributes;
1618
1619         /*
1620          *      Check for packets smaller than the packet header.
1621          *
1622          *      RFC 2865, Section 3., subsection 'length' says:
1623          *
1624          *      "The minimum length is 20 ..."
1625          */
1626         if (packet->data_len < AUTH_HDR_LEN) {
1627                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (received %d < minimum %d)",
1628                            inet_ntop(packet->src_ipaddr.af,
1629                                      &packet->src_ipaddr.ipaddr,
1630                                      host_ipaddr, sizeof(host_ipaddr)),
1631                                    (int) packet->data_len, AUTH_HDR_LEN);
1632                 return 0;
1633         }
1634
1635         /*
1636          *      RFC 2865, Section 3., subsection 'length' says:
1637          *
1638          *      " ... and maximum length is 4096."
1639          */
1640         if (packet->data_len > MAX_PACKET_LEN) {
1641                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (received %d > maximum %d)",
1642                            inet_ntop(packet->src_ipaddr.af,
1643                                      &packet->src_ipaddr.ipaddr,
1644                                      host_ipaddr, sizeof(host_ipaddr)),
1645                                    (int) packet->data_len, MAX_PACKET_LEN);
1646                 return 0;
1647         }
1648
1649         /*
1650          *      Check for packets with mismatched size.
1651          *      i.e. We've received 128 bytes, and the packet header
1652          *      says it's 256 bytes long.
1653          */
1654         totallen = (packet->data[2] << 8) | packet->data[3];
1655         hdr = (radius_packet_t *)packet->data;
1656
1657         /*
1658          *      Code of 0 is not understood.
1659          *      Code of 16 or greate is not understood.
1660          */
1661         if ((hdr->code == 0) ||
1662             (hdr->code >= FR_MAX_PACKET_CODE)) {
1663                 fr_strerror_printf("WARNING: Bad RADIUS packet from host %s: unknown packet code%d ",
1664                            inet_ntop(packet->src_ipaddr.af,
1665                                      &packet->src_ipaddr.ipaddr,
1666                                      host_ipaddr, sizeof(host_ipaddr)),
1667                            hdr->code);
1668                 return 0;
1669         }
1670
1671         /*
1672          *      Message-Authenticator is required in Status-Server
1673          *      packets, otherwise they can be trivially forged.
1674          */
1675         if (hdr->code == PW_STATUS_SERVER) require_ma = 1;
1676
1677         /*
1678          *      It's also required if the caller asks for it.
1679          */
1680         if (flags) require_ma = 1;
1681
1682         /*
1683          *      Repeat the length checks.  This time, instead of
1684          *      looking at the data we received, look at the value
1685          *      of the 'length' field inside of the packet.
1686          *
1687          *      Check for packets smaller than the packet header.
1688          *
1689          *      RFC 2865, Section 3., subsection 'length' says:
1690          *
1691          *      "The minimum length is 20 ..."
1692          */
1693         if (totallen < AUTH_HDR_LEN) {
1694                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (length %d < minimum %d)",
1695                            inet_ntop(packet->src_ipaddr.af,
1696                                      &packet->src_ipaddr.ipaddr,
1697                                      host_ipaddr, sizeof(host_ipaddr)),
1698                            totallen, AUTH_HDR_LEN);
1699                 return 0;
1700         }
1701
1702         /*
1703          *      And again, for the value of the 'length' field.
1704          *
1705          *      RFC 2865, Section 3., subsection 'length' says:
1706          *
1707          *      " ... and maximum length is 4096."
1708          */
1709         if (totallen > MAX_PACKET_LEN) {
1710                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (length %d > maximum %d)",
1711                            inet_ntop(packet->src_ipaddr.af,
1712                                      &packet->src_ipaddr.ipaddr,
1713                                      host_ipaddr, sizeof(host_ipaddr)),
1714                            totallen, MAX_PACKET_LEN);
1715                 return 0;
1716         }
1717
1718         /*
1719          *      RFC 2865, Section 3., subsection 'length' says:
1720          *
1721          *      "If the packet is shorter than the Length field
1722          *      indicates, it MUST be silently discarded."
1723          *
1724          *      i.e. No response to the NAS.
1725          */
1726         if (packet->data_len < totallen) {
1727                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: received %d octets, packet length says %d",
1728                            inet_ntop(packet->src_ipaddr.af,
1729                                      &packet->src_ipaddr.ipaddr,
1730                                      host_ipaddr, sizeof(host_ipaddr)),
1731                                    (int) packet->data_len, totallen);
1732                 return 0;
1733         }
1734
1735         /*
1736          *      RFC 2865, Section 3., subsection 'length' says:
1737          *
1738          *      "Octets outside the range of the Length field MUST be
1739          *      treated as padding and ignored on reception."
1740          */
1741         if (packet->data_len > totallen) {
1742                 /*
1743                  *      We're shortening the packet below, but just
1744                  *      to be paranoid, zero out the extra data.
1745                  */
1746                 memset(packet->data + totallen, 0, packet->data_len - totallen);
1747                 packet->data_len = totallen;
1748         }
1749
1750         /*
1751          *      Walk through the packet's attributes, ensuring that
1752          *      they add up EXACTLY to the size of the packet.
1753          *
1754          *      If they don't, then the attributes either under-fill
1755          *      or over-fill the packet.  Any parsing of the packet
1756          *      is impossible, and will result in unknown side effects.
1757          *
1758          *      This would ONLY happen with buggy RADIUS implementations,
1759          *      or with an intentional attack.  Either way, we do NOT want
1760          *      to be vulnerable to this problem.
1761          */
1762         attr = hdr->data;
1763         count = totallen - AUTH_HDR_LEN;
1764         num_attributes = 0;
1765
1766         while (count > 0) {
1767                 /*
1768                  *      Attribute number zero is NOT defined.
1769                  */
1770                 if (attr[0] == 0) {
1771                         fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Invalid attribute 0",
1772                                    inet_ntop(packet->src_ipaddr.af,
1773                                              &packet->src_ipaddr.ipaddr,
1774                                              host_ipaddr, sizeof(host_ipaddr)));
1775                         return 0;
1776                 }
1777
1778                 /*
1779                  *      Attributes are at LEAST as long as the ID & length
1780                  *      fields.  Anything shorter is an invalid attribute.
1781                  */
1782                 if (attr[1] < 2) {
1783                         fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %d too short",
1784                                    inet_ntop(packet->src_ipaddr.af,
1785                                              &packet->src_ipaddr.ipaddr,
1786                                              host_ipaddr, sizeof(host_ipaddr)),
1787                                    attr[0]);
1788                         return 0;
1789                 }
1790
1791                 /*
1792                  *      Sanity check the attributes for length.
1793                  */
1794                 switch (attr[0]) {
1795                 default:        /* don't do anything by default */
1796                         break;
1797
1798                         /*
1799                          *      If there's an EAP-Message, we require
1800                          *      a Message-Authenticator.
1801                          */
1802                 case PW_EAP_MESSAGE:
1803                         require_ma = 1;
1804                         break;
1805
1806                 case PW_MESSAGE_AUTHENTICATOR:
1807                         if (attr[1] != 2 + AUTH_VECTOR_LEN) {
1808                                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Message-Authenticator has invalid length %d",
1809                                            inet_ntop(packet->src_ipaddr.af,
1810                                                      &packet->src_ipaddr.ipaddr,
1811                                                      host_ipaddr, sizeof(host_ipaddr)),
1812                                            attr[1] - 2);
1813                                 return 0;
1814                         }
1815                         seen_ma = 1;
1816                         break;
1817                 }
1818
1819                 /*
1820                  *      FIXME: Look up the base 255 attributes in the
1821                  *      dictionary, and switch over their type.  For
1822                  *      integer/date/ip, the attribute length SHOULD
1823                  *      be 6.
1824                  */
1825                 count -= attr[1];       /* grab the attribute length */
1826                 attr += attr[1];
1827                 num_attributes++;       /* seen one more attribute */
1828         }
1829
1830         /*
1831          *      If the attributes add up to a packet, it's allowed.
1832          *
1833          *      If not, we complain, and throw the packet away.
1834          */
1835         if (count != 0) {
1836                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: packet attributes do NOT exactly fill the packet",
1837                            inet_ntop(packet->src_ipaddr.af,
1838                                      &packet->src_ipaddr.ipaddr,
1839                                      host_ipaddr, sizeof(host_ipaddr)));
1840                 return 0;
1841         }
1842
1843         /*
1844          *      If we're configured to look for a maximum number of
1845          *      attributes, and we've seen more than that maximum,
1846          *      then throw the packet away, as a possible DoS.
1847          */
1848         if ((fr_max_attributes > 0) &&
1849             (num_attributes > fr_max_attributes)) {
1850                 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
1851                            inet_ntop(packet->src_ipaddr.af,
1852                                      &packet->src_ipaddr.ipaddr,
1853                                      host_ipaddr, sizeof(host_ipaddr)),
1854                            num_attributes, fr_max_attributes);
1855                 return 0;
1856         }
1857
1858         /*
1859          *      http://www.freeradius.org/rfc/rfc2869.html#EAP-Message
1860          *
1861          *      A packet with an EAP-Message attribute MUST also have
1862          *      a Message-Authenticator attribute.
1863          *
1864          *      A Message-Authenticator all by itself is OK, though.
1865          *
1866          *      Similarly, Status-Server packets MUST contain
1867          *      Message-Authenticator attributes.
1868          */
1869         if (require_ma && ! seen_ma) {
1870                 fr_strerror_printf("WARNING: Insecure packet from host %s:  Packet does not contain required Message-Authenticator attribute",
1871                            inet_ntop(packet->src_ipaddr.af,
1872                                      &packet->src_ipaddr.ipaddr,
1873                                      host_ipaddr, sizeof(host_ipaddr)));
1874                 return 0;
1875         }
1876
1877         /*
1878          *      Fill RADIUS header fields
1879          */
1880         packet->code = hdr->code;
1881         packet->id = hdr->id;
1882         memcpy(packet->vector, hdr->vector, AUTH_VECTOR_LEN);
1883
1884         return 1;
1885 }
1886
1887
1888 /*
1889  *      Receive UDP client requests, and fill in
1890  *      the basics of a RADIUS_PACKET structure.
1891  */
1892 RADIUS_PACKET *rad_recv(int fd, int flags)
1893 {
1894         int sock_flags = 0;
1895         RADIUS_PACKET           *packet;
1896
1897         /*
1898          *      Allocate the new request data structure
1899          */
1900         if ((packet = malloc(sizeof(*packet))) == NULL) {
1901                 fr_strerror_printf("out of memory");
1902                 return NULL;
1903         }
1904         memset(packet, 0, sizeof(*packet));
1905
1906         if (flags & 0x02) {
1907                 sock_flags = MSG_PEEK;
1908                 flags &= ~0x02;
1909         }
1910
1911         packet->data_len = rad_recvfrom(fd, &packet->data, sock_flags,
1912                                         &packet->src_ipaddr, &packet->src_port,
1913                                         &packet->dst_ipaddr, &packet->dst_port);
1914
1915         /*
1916          *      Check for socket errors.
1917          */
1918         if (packet->data_len < 0) {
1919                 fr_strerror_printf("Error receiving packet: %s", strerror(errno));
1920                 /* packet->data is NULL */
1921                 free(packet);
1922                 return NULL;
1923         }
1924
1925         /*
1926          *      If the packet is too big, then rad_recvfrom did NOT
1927          *      allocate memory.  Instead, it just discarded the
1928          *      packet.
1929          */
1930         if (packet->data_len > MAX_PACKET_LEN) {
1931                 fr_strerror_printf("Discarding packet: Larger than RFC limitation of 4096 bytes.");
1932                 /* packet->data is NULL */
1933                 free(packet);
1934                 return NULL;
1935         }
1936
1937         /*
1938          *      Read no data.  Continue.
1939          *      This check is AFTER the MAX_PACKET_LEN check above, because
1940          *      if the packet is larger than MAX_PACKET_LEN, we also have
1941          *      packet->data == NULL
1942          */
1943         if ((packet->data_len == 0) || !packet->data) {
1944                 fr_strerror_printf("Empty packet: Socket is not ready.");
1945                 free(packet);
1946                 return NULL;
1947         }
1948
1949         /*
1950          *      See if it's a well-formed RADIUS packet.
1951          */
1952         if (!rad_packet_ok(packet, flags)) {
1953                 rad_free(&packet);
1954                 return NULL;
1955         }
1956
1957         /*
1958          *      Remember which socket we read the packet from.
1959          */
1960         packet->sockfd = fd;
1961
1962         /*
1963          *      FIXME: Do even more filtering by only permitting
1964          *      certain IP's.  The problem is that we don't know
1965          *      how to do this properly for all possible clients...
1966          */
1967
1968         /*
1969          *      Explicitely set the VP list to empty.
1970          */
1971         packet->vps = NULL;
1972
1973         if (fr_debug_flag) {
1974                 char host_ipaddr[128];
1975
1976                 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1977                         DEBUG("rad_recv: %s packet from host %s port %d",
1978                               fr_packet_codes[packet->code],
1979                               inet_ntop(packet->src_ipaddr.af,
1980                                         &packet->src_ipaddr.ipaddr,
1981                                         host_ipaddr, sizeof(host_ipaddr)),
1982                               packet->src_port);
1983                 } else {
1984                         DEBUG("rad_recv: Packet from host %s port %d code=%d",
1985                               inet_ntop(packet->src_ipaddr.af,
1986                                         &packet->src_ipaddr.ipaddr,
1987                                         host_ipaddr, sizeof(host_ipaddr)),
1988                               packet->src_port,
1989                               packet->code);
1990                 }
1991                 DEBUG(", id=%d, length=%d\n",
1992                       packet->id, (int) packet->data_len);
1993         }
1994
1995         return packet;
1996 }
1997
1998
1999 /*
2000  *      Verify the signature of a packet.
2001  */
2002 int rad_verify(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2003                const char *secret)
2004 {
2005         uint8_t                 *ptr;
2006         int                     length;
2007         int                     attrlen;
2008
2009         if (!packet || !packet->data) return -1;
2010
2011         /*
2012          *      Before we allocate memory for the attributes, do more
2013          *      sanity checking.
2014          */
2015         ptr = packet->data + AUTH_HDR_LEN;
2016         length = packet->data_len - AUTH_HDR_LEN;
2017         while (length > 0) {
2018                 uint8_t msg_auth_vector[AUTH_VECTOR_LEN];
2019                 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
2020
2021                 attrlen = ptr[1];
2022
2023                 switch (ptr[0]) {
2024                 default:        /* don't do anything. */
2025                         break;
2026
2027                         /*
2028                          *      Note that more than one Message-Authenticator
2029                          *      attribute is invalid.
2030                          */
2031                 case PW_MESSAGE_AUTHENTICATOR:
2032                         memcpy(msg_auth_vector, &ptr[2], sizeof(msg_auth_vector));
2033                         memset(&ptr[2], 0, AUTH_VECTOR_LEN);
2034
2035                         switch (packet->code) {
2036                         default:
2037                                 break;
2038
2039                         case PW_ACCOUNTING_REQUEST:
2040                         case PW_ACCOUNTING_RESPONSE:
2041                         case PW_DISCONNECT_REQUEST:
2042                         case PW_DISCONNECT_ACK:
2043                         case PW_DISCONNECT_NAK:
2044                         case PW_COA_REQUEST:
2045                         case PW_COA_ACK:
2046                         case PW_COA_NAK:
2047                                 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
2048                                 break;
2049
2050                         case PW_AUTHENTICATION_ACK:
2051                         case PW_AUTHENTICATION_REJECT:
2052                         case PW_ACCESS_CHALLENGE:
2053                                 if (!original) {
2054                                         fr_strerror_printf("ERROR: Cannot validate Message-Authenticator in response packet without a request packet.");
2055                                         return -1;
2056                                 }
2057                                 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
2058                                 break;
2059                         }
2060
2061                         fr_hmac_md5(packet->data, packet->data_len,
2062                                     (const uint8_t *) secret, strlen(secret),
2063                                     calc_auth_vector);
2064                         if (digest_cmp(calc_auth_vector, msg_auth_vector,
2065                                    sizeof(calc_auth_vector)) != 0) {
2066                                 char buffer[32];
2067                                 fr_strerror_printf("Received packet from %s with invalid Message-Authenticator!  (Shared secret is incorrect.)",
2068                                            inet_ntop(packet->src_ipaddr.af,
2069                                                      &packet->src_ipaddr.ipaddr,
2070                                                      buffer, sizeof(buffer)));
2071                                 /* Silently drop packet, according to RFC 3579 */
2072                                 return -1;
2073                         } /* else the message authenticator was good */
2074
2075                         /*
2076                          *      Reinitialize Authenticators.
2077                          */
2078                         memcpy(&ptr[2], msg_auth_vector, AUTH_VECTOR_LEN);
2079                         memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
2080                         break;
2081                 } /* switch over the attributes */
2082
2083                 ptr += attrlen;
2084                 length -= attrlen;
2085         } /* loop over the packet, sanity checking the attributes */
2086
2087         /*
2088          *      It looks like a RADIUS packet, but we can't validate
2089          *      the signature.
2090          */
2091         if ((packet->code == 0) || (packet->code >= FR_MAX_PACKET_CODE)) {
2092                 char buffer[32];
2093                 fr_strerror_printf("Received Unknown packet code %d "
2094                            "from client %s port %d: Cannot validate signature.",
2095                            packet->code,
2096                            inet_ntop(packet->src_ipaddr.af,
2097                                      &packet->src_ipaddr.ipaddr,
2098                                      buffer, sizeof(buffer)),
2099                            packet->src_port);
2100                 return -1;
2101         }
2102
2103         /*
2104          *      Calculate and/or verify digest.
2105          */
2106         switch(packet->code) {
2107                 int rcode;
2108                 char buffer[32];
2109
2110                 case PW_AUTHENTICATION_REQUEST:
2111                 case PW_STATUS_SERVER:
2112                         /*
2113                          *      The authentication vector is random
2114                          *      nonsense, invented by the client.
2115                          */
2116                         break;
2117
2118                 case PW_COA_REQUEST:
2119                 case PW_DISCONNECT_REQUEST:
2120                 case PW_ACCOUNTING_REQUEST:
2121                         if (calc_acctdigest(packet, secret) > 1) {
2122                                 fr_strerror_printf("Received %s packet "
2123                                            "from %s with invalid signature!  (Shared secret is incorrect.)",
2124                                            fr_packet_codes[packet->code],
2125                                            inet_ntop(packet->src_ipaddr.af,
2126                                                      &packet->src_ipaddr.ipaddr,
2127                                                      buffer, sizeof(buffer)));
2128                                 return -1;
2129                         }
2130                         break;
2131
2132                         /* Verify the reply digest */
2133                 case PW_AUTHENTICATION_ACK:
2134                 case PW_AUTHENTICATION_REJECT:
2135                 case PW_ACCESS_CHALLENGE:
2136                 case PW_ACCOUNTING_RESPONSE:
2137                 case PW_DISCONNECT_ACK:
2138                 case PW_DISCONNECT_NAK:
2139                 case PW_COA_ACK:
2140                 case PW_COA_NAK:
2141                         rcode = calc_replydigest(packet, original, secret);
2142                         if (rcode > 1) {
2143                                 fr_strerror_printf("Received %s packet "
2144                                            "from client %s port %d with invalid signature (err=%d)!  (Shared secret is incorrect.)",
2145                                            fr_packet_codes[packet->code],
2146                                            inet_ntop(packet->src_ipaddr.af,
2147                                                      &packet->src_ipaddr.ipaddr,
2148                                                      buffer, sizeof(buffer)),
2149                                            packet->src_port,
2150                                            rcode);
2151                                 return -1;
2152                         }
2153                         break;
2154
2155                 default:
2156                         fr_strerror_printf("Received Unknown packet code %d "
2157                                    "from client %s port %d: Cannot validate signature",
2158                                    packet->code,
2159                                    inet_ntop(packet->src_ipaddr.af,
2160                                              &packet->src_ipaddr.ipaddr,
2161                                                      buffer, sizeof(buffer)),
2162                                    packet->src_port);
2163                         return -1;
2164         }
2165
2166         return 0;
2167 }
2168
2169
2170 static VALUE_PAIR *data2vp(const RADIUS_PACKET *packet,
2171                            const RADIUS_PACKET *original,
2172                            const char *secret, size_t length,
2173                            const uint8_t *data, VALUE_PAIR *vp)
2174 {
2175         int offset = 0;
2176
2177         /*
2178          *      If length is greater than 253, something is SERIOUSLY
2179          *      wrong.
2180          */
2181         if (length > 253) length = 253; /* paranoia (pair-anoia?) */
2182
2183         vp->length = length;
2184         vp->operator = T_OP_EQ;
2185         vp->next = NULL;
2186
2187         /*
2188          *      Handle tags.
2189          */
2190         if (vp->flags.has_tag) {
2191                 if (TAG_VALID(data[0]) ||
2192                     (vp->flags.encrypt == FLAG_ENCRYPT_TUNNEL_PASSWORD)) {
2193                         /*
2194                          *      Tunnel passwords REQUIRE a tag, even
2195                          *      if don't have a valid tag.
2196                          */
2197                         vp->flags.tag = data[0];
2198
2199                         if ((vp->type == PW_TYPE_STRING) ||
2200                             (vp->type == PW_TYPE_OCTETS)) {
2201                                 if (length == 0) goto raw;
2202                                 offset = 1;
2203                         }
2204                 }
2205         }
2206
2207         /*
2208          *      Copy the data to be decrypted
2209          */
2210         memcpy(&vp->vp_octets[0], data + offset, length - offset);
2211         vp->length -= offset;
2212
2213         /*
2214          *      Decrypt the attribute.
2215          */
2216         switch (vp->flags.encrypt) {
2217                 /*
2218                  *  User-Password
2219                  */
2220         case FLAG_ENCRYPT_USER_PASSWORD:
2221                 if (original) {
2222                         rad_pwdecode((char *)vp->vp_strvalue,
2223                                      vp->length, secret,
2224                                      original->vector);
2225                 } else {
2226                         rad_pwdecode((char *)vp->vp_strvalue,
2227                                      vp->length, secret,
2228                                      packet->vector);
2229                 }
2230                 if (vp->attribute == PW_USER_PASSWORD) {
2231                         vp->length = strlen(vp->vp_strvalue);
2232                 }
2233                 break;
2234
2235                 /*
2236                  *      Tunnel-Password's may go ONLY
2237                  *      in response packets.
2238                  */
2239         case FLAG_ENCRYPT_TUNNEL_PASSWORD:
2240                 if (!original) goto raw;
2241
2242                 if (rad_tunnel_pwdecode(vp->vp_octets, &vp->length,
2243                                         secret, original->vector) < 0) {
2244                         goto raw;
2245                 }
2246                 break;
2247
2248                 /*
2249                  *  Ascend-Send-Secret
2250                  *  Ascend-Receive-Secret
2251                  */
2252         case FLAG_ENCRYPT_ASCEND_SECRET:
2253                 if (!original) {
2254                         goto raw;
2255                 } else {
2256                         uint8_t my_digest[AUTH_VECTOR_LEN];
2257                         make_secret(my_digest,
2258                                     original->vector,
2259                                     secret, data);
2260                         memcpy(vp->vp_strvalue, my_digest,
2261                                AUTH_VECTOR_LEN );
2262                         vp->vp_strvalue[AUTH_VECTOR_LEN] = '\0';
2263                         vp->length = strlen(vp->vp_strvalue);
2264                 }
2265                 break;
2266
2267         default:
2268                 break;
2269         } /* switch over encryption flags */
2270
2271
2272         switch (vp->type) {
2273         case PW_TYPE_STRING:
2274         case PW_TYPE_OCTETS:
2275         case PW_TYPE_ABINARY:
2276                 /* nothing more to do */
2277                 break;
2278
2279         case PW_TYPE_BYTE:
2280                 if (vp->length != 1) goto raw;
2281
2282                 vp->vp_integer = vp->vp_octets[0];
2283                 break;
2284
2285
2286         case PW_TYPE_SHORT:
2287                 if (vp->length != 2) goto raw;
2288
2289                 vp->vp_integer = (vp->vp_octets[0] << 8) | vp->vp_octets[1];
2290                 break;
2291
2292         case PW_TYPE_INTEGER:
2293                 if (vp->length != 4) goto raw;
2294
2295                 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2296                 vp->vp_integer = ntohl(vp->vp_integer);
2297
2298                 if (vp->flags.has_tag) vp->vp_integer &= 0x00ffffff;
2299
2300                 /*
2301                  *      Try to get named VALUEs
2302                  */
2303                 {
2304                         DICT_VALUE *dval;
2305                         dval = dict_valbyattr(vp->attribute, vp->vendor,
2306                                               vp->vp_integer);
2307                         if (dval) {
2308                                 strlcpy(vp->vp_strvalue,
2309                                         dval->name,
2310                                         sizeof(vp->vp_strvalue));
2311                         }
2312                 }
2313                 break;
2314
2315         case PW_TYPE_DATE:
2316                 if (vp->length != 4) goto raw;
2317
2318                 memcpy(&vp->vp_date, vp->vp_octets, 4);
2319                 vp->vp_date = ntohl(vp->vp_date);
2320                 break;
2321
2322
2323         case PW_TYPE_IPADDR:
2324                 if (vp->length != 4) goto raw;
2325
2326                 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2327                 break;
2328
2329                 /*
2330                  *      IPv6 interface ID is 8 octets long.
2331                  */
2332         case PW_TYPE_IFID:
2333                 if (vp->length != 8) goto raw;
2334                 /* vp->vp_ifid == vp->vp_octets */
2335                 break;
2336
2337                 /*
2338                  *      IPv6 addresses are 16 octets long
2339                  */
2340         case PW_TYPE_IPV6ADDR:
2341                 if (vp->length != 16) goto raw;
2342                 /* vp->vp_ipv6addr == vp->vp_octets */
2343                 break;
2344
2345                 /*
2346                  *      IPv6 prefixes are 2 to 18 octets long.
2347                  *
2348                  *      RFC 3162: The first octet is unused.
2349                  *      The second is the length of the prefix
2350                  *      the rest are the prefix data.
2351                  *
2352                  *      The prefix length can have value 0 to 128.
2353                  */
2354         case PW_TYPE_IPV6PREFIX:
2355                 if (vp->length < 2 || vp->length > 18) goto raw;
2356                 if (vp->vp_octets[1] > 128) goto raw;
2357
2358                 /*
2359                  *      FIXME: double-check that
2360                  *      (vp->vp_octets[1] >> 3) matches vp->length + 2
2361                  */
2362                 if (vp->length < 18) {
2363                         memset(vp->vp_octets + vp->length, 0,
2364                                18 - vp->length);
2365                 }
2366                 break;
2367
2368         case PW_TYPE_SIGNED:
2369                 if (vp->length != 4) goto raw;
2370
2371                 /*
2372                  *      Overload vp_integer for ntohl, which takes
2373                  *      uint32_t, not int32_t
2374                  */
2375                 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2376                 vp->vp_integer = ntohl(vp->vp_integer);
2377                 memcpy(&vp->vp_signed, &vp->vp_integer, 4);
2378                 break;
2379
2380         case PW_TYPE_TLV:
2381                 vp->length = length;
2382                 vp->vp_tlv = malloc(length);
2383                 if (!vp->vp_tlv) {
2384                         pairfree(&vp);
2385                         fr_strerror_printf("No memory");
2386                         return NULL;
2387                 }
2388                 memcpy(vp->vp_tlv, data, length);
2389                 break;
2390
2391         case PW_TYPE_COMBO_IP:
2392                 if (vp->length == 4) {
2393                         vp->type = PW_TYPE_IPADDR;
2394                         memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2395                         break;
2396
2397                 } else if (vp->length == 16) {
2398                         vp->type = PW_TYPE_IPV6ADDR;
2399                         /* vp->vp_ipv6addr == vp->vp_octets */
2400                         break;
2401
2402                 }
2403                 /* FALL-THROUGH */
2404
2405         default:
2406         raw:
2407                 vp->type = PW_TYPE_OCTETS;
2408                 vp->length = length;
2409                 memcpy(vp->vp_octets, data, length);
2410
2411
2412                 /*
2413                  *      Ensure there's no encryption or tag stuff,
2414                  *      we just pass the attribute as-is.
2415                  */
2416                 memset(&vp->flags, 0, sizeof(vp->flags));
2417         }
2418
2419         return vp;
2420 }
2421
2422 static void rad_sortvp(VALUE_PAIR **head)
2423 {
2424         int swapped;
2425         VALUE_PAIR *vp, **tail;
2426
2427         /*
2428          *      Walk over the VP's, sorting them in order.  Did I
2429          *      mention that I hate WiMAX continuations?
2430          *
2431          *      And bubble sort!  WTF is up with that?
2432          */
2433         do {
2434                 swapped = 0;
2435                 tail = head;
2436                 while (*tail) {
2437                         vp = *tail;
2438                         if (!vp->next) break;
2439
2440                         if (vp->attribute > vp->next->attribute) {
2441                                 *tail = vp->next;
2442                                 vp->next = (*tail)->next;
2443                                 (*tail)->next = vp;
2444                                 swapped = 1;
2445                         }
2446                         tail = &(vp->next);
2447                 }
2448         } while (swapped);
2449 }
2450
2451
2452 /*
2453  *      Walk the packet, looking for continuations of this attribute.
2454  *
2455  *      This is (worst-case) O(N^2) in the number of RADIUS
2456  *      attributes.  That happens only when perverse clients create
2457  *      continued attributes, AND separate the fragmented portions
2458  *      with a lot of other attributes.
2459  *
2460  *      Sane clients should put the fragments next to each other, in
2461  *      which case this is O(N), in the number of fragments.
2462  */
2463 static uint8_t *rad_coalesce(unsigned int attribute, int vendor,
2464                              size_t length, uint8_t *data,
2465                              size_t packet_length, size_t *ptlv_length)
2466
2467 {
2468         uint32_t lvalue;
2469         size_t tlv_length = length;
2470         uint8_t *ptr, *tlv, *tlv_data;
2471
2472         for (ptr = data + length;
2473              ptr != (data + packet_length);
2474              ptr += ptr[1]) {
2475                 /* FIXME: Check that there are 6 bytes of data here... */
2476                 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2477                     (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2478                     (ptr[2] != 0) || (ptr[3] != 0) ||  /* our requirement */
2479                     (ptr[4] != ((vendor >> 8) & 0xff)) ||
2480                     (ptr[5] != (vendor & 0xff))) {
2481                         continue;
2482                 }
2483
2484                 memcpy(&lvalue, ptr + 2, 4); /* Vendor Id */
2485                 lvalue = ntohl(lvalue);
2486                 lvalue <<= 16;
2487                 lvalue |= ptr[2 + 4]; /* add in VSA number */
2488                 if (lvalue != attribute) continue;
2489
2490                 /*
2491                  *      If the vendor-length is too small, it's badly
2492                  *      formed, so we stop.
2493                  */
2494                 if ((ptr[2 + 4 + 1]) < 3) break;
2495
2496                 tlv_length += ptr[2 + 4 + 1] - 3;
2497                 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2498         }
2499
2500         tlv = tlv_data = malloc(tlv_length);
2501         if (!tlv_data) return NULL;
2502
2503         memcpy(tlv, data, length);
2504         tlv += length;
2505
2506         /*
2507          *      Now we walk the list again, copying the data over to
2508          *      our newly created memory.
2509          */
2510         for (ptr = data + length;
2511              ptr != (data + packet_length);
2512              ptr += ptr[1]) {
2513                 int this_length;
2514
2515                 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2516                     (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2517                     (ptr[2] != 0) || (ptr[3] != 0)) { /* our requirement */
2518                         continue;
2519                 }
2520
2521                 memcpy(&lvalue, ptr + 2, 4);
2522                 lvalue = ntohl(lvalue);
2523                 lvalue <<= 16;
2524                 lvalue |= ptr[2 + 4];
2525                 if (lvalue != attribute) continue;
2526
2527                 /*
2528                  *      If the vendor-length is too small, it's badly
2529                  *      formed, so we stop.
2530                  */
2531                 if ((ptr[2 + 4 + 1]) < 3) break;
2532
2533                 this_length = ptr[2 + 4 + 1] - 3;
2534                 memcpy(tlv, ptr + 2 + 4 + 3, this_length);
2535                 tlv += this_length;
2536
2537                 ptr[2 + 4] = 0; /* What a hack! */
2538                 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2539         }
2540
2541         *ptlv_length = tlv_length;
2542         return tlv_data;
2543 }
2544
2545
2546 /*
2547  *      Walk over Evil WIMAX TLVs, creating attributes.
2548  */
2549 static VALUE_PAIR *tlv2wimax(const RADIUS_PACKET *packet,
2550                              const RADIUS_PACKET *original,
2551                              const char *secret,
2552                              int attribute, int vendor,
2553                              uint8_t *ptr, size_t len, int nest)
2554 {
2555         VALUE_PAIR *head = NULL;
2556         VALUE_PAIR **tail = &head;
2557         VALUE_PAIR *vp;
2558         uint8_t *y;             /* why do I need to do this? */
2559
2560         if (nest > fr_wimax_max_tlv) return NULL;
2561
2562         /*
2563          *      Sanity check the attribute.
2564          */
2565         for (y = ptr; y < (ptr + len); y += y[1]) {
2566                 if ((y[0] == 0) || ((y + 2) > (ptr + len)) ||
2567                     (y[1] < 2) || ((y + y[1]) > (ptr + len))) {
2568                         return NULL;
2569                 }
2570
2571                 /*
2572                  *      Attribute number is too large for us to
2573                  *      represent it in our horrible internal
2574                  *      representation.
2575                  */
2576                 if ((ptr[0] & ~fr_wimax_mask[nest]) != 0) {
2577                         return NULL;
2578                 }
2579         }
2580
2581         for (y = ptr; y < (ptr + len); y += y[1]) {
2582                 DICT_ATTR *da;
2583
2584                 da = dict_attrbyvalue(attribute | (ptr[0] << fr_wimax_shift[nest]), vendor);
2585                 if (da && (da->type == PW_TYPE_TLV)) {
2586                         vp = tlv2wimax(packet, original, secret,
2587                                        attribute | (ptr[0] << fr_wimax_shift[nest]),
2588                                        vendor, ptr + 2, ptr[1] - 2,
2589                                        nest + 1);
2590                         if (!vp) goto error;
2591                 } else {
2592                         vp = paircreate(attribute | (ptr[0] << fr_wimax_shift[nest]), vendor,
2593                                         PW_TYPE_OCTETS);
2594                         if (!vp) {
2595                         error:
2596                                 pairfree(&head);
2597                                 return NULL;
2598                         }
2599
2600                         if (!data2vp(packet, original, secret,
2601                                      y[1] - 2, y + 2, vp)) {
2602                                 goto error;
2603                         }
2604                 }
2605
2606                 *tail = vp;
2607                 while (*tail) tail = &((*tail)->next);
2608         }
2609
2610         return head;
2611 }
2612
2613 /*
2614  *      Start at the *data* portion of a continued attribute.  search
2615  *      through the rest of the attributes to find a matching one, and
2616  *      add it's contents to our contents.
2617  */
2618 static VALUE_PAIR *rad_continuation2vp(const RADIUS_PACKET *packet,
2619                                        const RADIUS_PACKET *original,
2620                                        const char *secret, int attribute,
2621                                        int vendor,
2622                                        int length, /* CANNOT be zero */
2623                                        uint8_t *data, size_t packet_length,
2624                                        int flag, DICT_ATTR *da)
2625 {
2626         size_t tlv_length, left;
2627         uint8_t *ptr;
2628         uint8_t *tlv_data;
2629         VALUE_PAIR *vp, *head, **tail;
2630         DICT_ATTR *tlv_da;
2631
2632         /*
2633          *      Ensure we have data that hasn't been split across
2634          *      multiple attributes.
2635          */
2636         if (flag) {
2637                 tlv_data = rad_coalesce(attribute, vendor, length,
2638                                         data, packet_length, &tlv_length);
2639                 if (!tlv_data) return NULL;
2640         } else {
2641                 tlv_data = data;
2642                 tlv_length = length;
2643         }
2644
2645         /*
2646          *      Non-TLV types cannot be continued across multiple
2647          *      attributes.  This is true even of keys that are
2648          *      encrypted with the tunnel-password method.  The spec
2649          *      says that they can be continued... but also that the
2650          *      keys are 160 bits, which means that they CANNOT be
2651          *      continued.  <sigh>
2652          *
2653          *      Note that we don't check "flag" here.  The calling
2654          *      code ensures that
2655          */
2656         if (!da || (da->type != PW_TYPE_TLV)) {
2657         not_well_formed:
2658                 if (tlv_data == data) { /* true if we had 'goto' */
2659                         tlv_data = malloc(tlv_length);
2660                         if (!tlv_data) return NULL;
2661                         memcpy(tlv_data, data, tlv_length);
2662                 }
2663
2664                 vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2665                 if (!vp) return NULL;
2666
2667                 vp->type = PW_TYPE_TLV;
2668                 vp->flags.encrypt = FLAG_ENCRYPT_NONE;
2669                 vp->flags.has_tag = 0;
2670                 vp->flags.is_tlv = 0;
2671                 vp->vp_tlv = tlv_data;
2672                 vp->length = tlv_length;
2673                 return vp;
2674         } /* else it WAS a TLV, go decode the sub-tlv's */
2675
2676         /*
2677          *      Now (sigh) we walk over the TLV, seeing if it is
2678          *      well-formed.
2679          */
2680         left = tlv_length;
2681         for (ptr = tlv_data;
2682              ptr != (tlv_data + tlv_length);
2683              ptr += ptr[1]) {
2684                 if ((left < 2) ||
2685                     (ptr[1] < 2) ||
2686                     (ptr[1] > left)) {
2687                         goto not_well_formed;
2688                 }
2689
2690                 left -= ptr[1];
2691         }
2692
2693         /*
2694          *      Now we walk over the TLV *again*, creating sub-tlv's.
2695          */
2696         head = NULL;
2697         tail = &head;
2698
2699         for (ptr = tlv_data;
2700              ptr != (tlv_data + tlv_length);
2701              ptr += ptr[1]) {
2702
2703                 tlv_da = dict_attrbyvalue(attribute | (ptr[0] << fr_wimax_shift[1]), vendor);
2704                 if (tlv_da && (tlv_da->type == PW_TYPE_TLV)) {
2705                         vp = tlv2wimax(packet, original, secret,
2706                                        attribute | (ptr[0] << 8),
2707                                        vendor, ptr + 2, ptr[1] - 2, 2);
2708
2709                         if (!vp) goto error;
2710                 } else {
2711                         vp = paircreate(attribute | (ptr[0] << fr_wimax_shift[1]), vendor,
2712                                         PW_TYPE_OCTETS);
2713                         if (!vp) {
2714                         error:
2715                                 pairfree(&head);
2716                                 goto not_well_formed;
2717                         }
2718
2719                         if (!data2vp(packet, original, secret,
2720                                      ptr[1] - 2, ptr + 2, vp)) {
2721                                 goto error;
2722                         }
2723                 }
2724
2725                 *tail = vp;
2726
2727                 while (*tail) tail = &((*tail)->next);
2728         }
2729
2730         /*
2731          *      TLV's MAY be continued, but sometimes they're not.
2732          */
2733         if (tlv_data != data) free(tlv_data);
2734
2735         if (head->next) rad_sortvp(&head);
2736
2737         return head;
2738 }
2739
2740
2741 /*
2742  *      Parse a RADIUS attribute into a data structure.
2743  */
2744 VALUE_PAIR *rad_attr2vp(const RADIUS_PACKET *packet,
2745                         const RADIUS_PACKET *original,
2746                         const char *secret, int attribute, int vendor,
2747                         int length, const uint8_t *data)
2748 {
2749         VALUE_PAIR *vp;
2750
2751         vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2752         if (!vp) return NULL;
2753
2754         return data2vp(packet, original, secret, length, data, vp);
2755 }
2756
2757
2758 /*
2759  *      Calculate/check digest, and decode radius attributes.
2760  *      Returns:
2761  *      -1 on decoding error
2762  *      0 on success
2763  */
2764 int rad_decode(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2765                const char *secret)
2766 {
2767         uint32_t                lvalue;
2768         uint32_t                vendorcode;
2769         VALUE_PAIR              **tail;
2770         VALUE_PAIR              *pair;
2771         uint8_t                 *ptr, *vsa_ptr;
2772         int                     packet_length;
2773         int                     attribute;
2774         int                     attrlen;
2775         int                     vendorlen;
2776         radius_packet_t         *hdr;
2777         int                     vsa_tlen, vsa_llen, vsa_offset;
2778         DICT_VENDOR             *dv = NULL;
2779         int                     num_attributes = 0;
2780
2781         /*
2782          *      Extract attribute-value pairs
2783          */
2784         hdr = (radius_packet_t *)packet->data;
2785         ptr = hdr->data;
2786         packet_length = packet->data_len - AUTH_HDR_LEN;
2787
2788         /*
2789          *      There may be VP's already in the packet.  Don't
2790          *      destroy them.
2791          */
2792         for (tail = &packet->vps; *tail != NULL; tail = &((*tail)->next)) {
2793                 /* nothing */
2794         }
2795
2796         vendorcode = 0;
2797         vendorlen  = 0;
2798         vsa_tlen = vsa_llen = 1;
2799         vsa_offset = 0;
2800
2801         /*
2802          *      We have to read at least two bytes.
2803          *
2804          *      rad_recv() above ensures that this is OK.
2805          */
2806         while (packet_length > 0) {
2807                 attribute = -1;
2808                 attrlen = -1;
2809
2810                 /*
2811                  *      Normal attribute, handle it like normal.
2812                  */
2813                 if (vendorcode == 0) {
2814                         /*
2815                          *      No room to read attr/length,
2816                          *      or bad attribute, or attribute is
2817                          *      too short, or attribute is too long,
2818                          *      stop processing the packet.
2819                          */
2820                         if ((packet_length < 2) ||
2821                             (ptr[0] == 0) ||  (ptr[1] < 2) ||
2822                             (ptr[1] > packet_length)) break;
2823
2824                         attribute = *ptr++;
2825                         attrlen   = *ptr++;
2826
2827                         attrlen -= 2;
2828                         packet_length  -= 2;
2829
2830                         if (attribute != PW_VENDOR_SPECIFIC) goto create_pair;
2831
2832                         /*
2833                          *      No vendor code, or ONLY vendor code.
2834                          */
2835                         if (attrlen <= 4) goto create_pair;
2836
2837                         vendorlen = 0;
2838                 }
2839
2840                 /*
2841                  *      Handle Vendor-Specific
2842                  */
2843                 if (vendorlen == 0) {
2844                         uint8_t *subptr;
2845                         int sublen;
2846                         int myvendor;
2847
2848                         /*
2849                          *      attrlen was checked above.
2850                          */
2851                         memcpy(&lvalue, ptr, 4);
2852                         myvendor = ntohl(lvalue);
2853
2854                         /*
2855                          *      Zero isn't allowed.
2856                          */
2857                         if (myvendor == 0) goto create_pair;
2858
2859                         /*
2860                          *      This is an implementation issue.
2861                          *      We currently pack vendor into the upper
2862                          *      16 bits of a 32-bit attribute number,
2863                          *      so we can't handle vendor numbers larger
2864                          *      than 16 bits.
2865                          */
2866                         if (myvendor > 65535) goto create_pair;
2867
2868                         vsa_tlen = vsa_llen = 1;
2869                         vsa_offset = 0;
2870                         dv = dict_vendorbyvalue(myvendor);
2871                         if (dv) {
2872                                 vsa_tlen = dv->type;
2873                                 vsa_llen = dv->length;
2874                                 if (dv->flags) vsa_offset = 1;
2875                         }
2876
2877                         /*
2878                          *      Sweep through the list of VSA's,
2879                          *      seeing if they exactly fill the
2880                          *      outer Vendor-Specific attribute.
2881                          *
2882                          *      If not, create a raw Vendor-Specific.
2883                          */
2884                         subptr = ptr + 4;
2885                         sublen = attrlen - 4;
2886
2887                         /*
2888                          *      See if we can parse it.
2889                          */
2890                         do {
2891                                 int myattr = 0;
2892
2893                                 /*
2894                                  *      Not enough room for one more
2895                                  *      attribute.  Die!
2896                                  */
2897                                 if (sublen < (vsa_tlen + vsa_llen + vsa_offset)) goto create_pair;
2898
2899                                 /*
2900                                  *      Ensure that the attribute number
2901                                  *      is OK.
2902                                  */
2903                                 switch (vsa_tlen) {
2904                                 case 1:
2905                                         myattr = subptr[0];
2906                                         break;
2907
2908                                 case 2:
2909                                         myattr = (subptr[0] << 8) | subptr[1];
2910                                         break;
2911
2912                                 case 4:
2913                                         if ((subptr[0] != 0) ||
2914                                             (subptr[1] != 0)) goto create_pair;
2915
2916                                         myattr = (subptr[2] << 8) | subptr[3];
2917                                         break;
2918
2919                                         /*
2920                                          *      Our dictionary is broken.
2921                                          */
2922                                 default:
2923                                         goto create_pair;
2924                                 }
2925
2926                                 switch (vsa_llen) {
2927                                 case 0:
2928                                         attribute = myattr;
2929                                         ptr += 4 + vsa_tlen;
2930                                         attrlen -= (4 + vsa_tlen);
2931                                         packet_length -= 4 + vsa_tlen;
2932                                         goto create_pair;
2933
2934                                 case 1:
2935                                         if (subptr[vsa_tlen] < (vsa_tlen + vsa_llen + vsa_offset))
2936                                                 goto create_pair;
2937
2938                                         if (subptr[vsa_tlen] > sublen)
2939                                                 goto create_pair;
2940
2941                                         /*
2942                                          *      WiMAX: 0bCrrrrrrr
2943                                          *      Reserved bits MUST be
2944                                          *      zero.
2945                                          */
2946                                         if (vsa_offset &&
2947                                             ((subptr[vsa_tlen + vsa_llen] & 0x7f) != 0))
2948                                                 goto create_pair;
2949
2950                                         sublen -= subptr[vsa_tlen];
2951                                         subptr += subptr[vsa_tlen];
2952                                         break;
2953
2954                                 case 2:
2955                                         if (subptr[vsa_tlen] != 0) goto create_pair;
2956                                         if (subptr[vsa_tlen + 1] < (vsa_tlen + vsa_llen))
2957                                                 goto create_pair;
2958                                         if (subptr[vsa_tlen + 1] > sublen)
2959                                                 goto create_pair;
2960                                         sublen -= subptr[vsa_tlen + 1];
2961                                         subptr += subptr[vsa_tlen + 1];
2962                                         break;
2963
2964                                         /*
2965                                          *      Our dictionaries are
2966                                          *      broken.
2967                                          */
2968                                 default:
2969                                         goto create_pair;
2970                                 }
2971                         } while (sublen > 0);
2972
2973                         vendorcode = myvendor;
2974                         vendorlen = attrlen - 4;
2975                         packet_length -= 4;
2976
2977                         ptr += 4;
2978                 }
2979
2980                 /*
2981                  *      attrlen is the length of this attribute.
2982                  *      total_len is the length of the encompassing
2983                  *      attribute.
2984                  */
2985                 switch (vsa_tlen) {
2986                 case 1:
2987                         attribute = ptr[0];
2988                         break;
2989
2990                 case 2:
2991                         attribute = (ptr[0] << 8) | ptr[1];
2992                         break;
2993
2994                 default:        /* can't hit this. */
2995                         return -1;
2996                 }
2997                 vsa_ptr = ptr;
2998                 ptr += vsa_tlen;
2999
3000                 switch (vsa_llen) {
3001                 case 1:
3002                         attrlen = ptr[0] - (vsa_tlen + vsa_llen + vsa_offset);
3003                         break;
3004
3005                 case 2:
3006                         attrlen = ptr[1] - (vsa_tlen + vsa_llen);
3007                         break;
3008
3009                 default:        /* can't hit this. */
3010                         return -1;
3011                 }
3012
3013                 ptr += vsa_llen + vsa_offset;
3014                 vendorlen -= vsa_tlen + vsa_llen + vsa_offset + attrlen;
3015                 packet_length -= (vsa_tlen + vsa_llen + vsa_offset);
3016
3017                 /*
3018                  *      Ignore VSAs that have no data.
3019                  */
3020                 if (attrlen == 0) goto next;
3021
3022                 /*
3023                  *      WiMAX attributes of type 0 are ignored.  They
3024                  *      are a secret flag to us that the attribute has
3025                  *      already been dealt with.
3026                  */
3027                 if ((vendorcode == VENDORPEC_WIMAX) && (attribute == 0)) {
3028                         goto next;
3029                 }
3030
3031                 if (vsa_offset) {
3032                         DICT_ATTR *da;
3033
3034                         da = dict_attrbyvalue(attribute, vendorcode);
3035
3036                         /*
3037                          *      If it's NOT continued, AND we know
3038                          *      about it, AND it's not a TLV, we can
3039                          *      create a normal pair.
3040                          */
3041                         if (((vsa_ptr[2] & 0x80) == 0) &&
3042                             da && (da->type != PW_TYPE_TLV)) goto create_pair;
3043
3044                         /*
3045                          *      Else it IS continued, or it's a TLV.
3046                          *      Go do a lot of work to find the stuff.
3047                          */
3048                         pair = rad_continuation2vp(packet, original, secret,
3049                                                    attribute, vendorcode,
3050                                                    attrlen, ptr,
3051                                                    packet_length,
3052                                                    ((vsa_ptr[2] & 0x80) != 0),
3053                                                    da);
3054                         goto created_pair;
3055                 }
3056
3057                 /*
3058                  *      Create the attribute, setting the default type
3059                  *      to 'octets'.  If the type in the dictionary
3060                  *      is different, then the dictionary type will
3061                  *      over-ride this one.
3062                  *
3063                  *      If the attribute has no data, then discard it.
3064                  *
3065                  *      Unless it's CUI.  Damn you, CUI!
3066                  */
3067         create_pair:
3068                 if (!attrlen &&
3069                     (attribute != PW_CHARGEABLE_USER_IDENTITY)) goto next;
3070
3071                 pair = rad_attr2vp(packet, original, secret,
3072                                    attribute, vendorcode, attrlen, ptr);
3073                 if (!pair) {
3074                         pairfree(&packet->vps);
3075                         fr_strerror_printf("out of memory");
3076                         return -1;
3077                 }
3078
3079         created_pair:
3080                 *tail = pair;
3081                 while (pair) {
3082                         num_attributes++;
3083                         debug_pair(pair);
3084                         tail = &pair->next;
3085                         pair = pair->next;
3086                 }
3087
3088                 /*
3089                  *      VSA's may not have been counted properly in
3090                  *      rad_packet_ok() above, as it is hard to count
3091                  *      then without using the dictionary.  We
3092                  *      therefore enforce the limits here, too.
3093                  */
3094                 if ((fr_max_attributes > 0) &&
3095                     (num_attributes > fr_max_attributes)) {
3096                         char host_ipaddr[128];
3097
3098                         pairfree(&packet->vps);
3099                         fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
3100                                    inet_ntop(packet->src_ipaddr.af,
3101                                              &packet->src_ipaddr.ipaddr,
3102                                              host_ipaddr, sizeof(host_ipaddr)),
3103                                    num_attributes, fr_max_attributes);
3104                         return -1;
3105                 }
3106
3107         next:
3108                 if (vendorlen == 0) vendorcode = 0;
3109                 ptr += attrlen;
3110                 packet_length -= attrlen;
3111         }
3112
3113         /*
3114          *      Merge information from the outside world into our
3115          *      random pool.
3116          */
3117         fr_rand_seed(packet->data, AUTH_HDR_LEN);
3118
3119         return 0;
3120 }
3121
3122
3123 /*
3124  *      Encode password.
3125  *
3126  *      We assume that the passwd buffer passed is big enough.
3127  *      RFC2138 says the password is max 128 chars, so the size
3128  *      of the passwd buffer must be at least 129 characters.
3129  *      Preferably it's just MAX_STRING_LEN.
3130  *
3131  *      int *pwlen is updated to the new length of the encrypted
3132  *      password - a multiple of 16 bytes.
3133  */
3134 int rad_pwencode(char *passwd, size_t *pwlen, const char *secret,
3135                  const uint8_t *vector)
3136 {
3137         FR_MD5_CTX context, old;
3138         uint8_t digest[AUTH_VECTOR_LEN];
3139         int     i, n, secretlen;
3140         int     len;
3141
3142         /*
3143          *      RFC maximum is 128 bytes.
3144          *
3145          *      If length is zero, pad it out with zeros.
3146          *
3147          *      If the length isn't aligned to 16 bytes,
3148          *      zero out the extra data.
3149          */
3150         len = *pwlen;
3151
3152         if (len > 128) len = 128;
3153
3154         if (len == 0) {
3155                 memset(passwd, 0, AUTH_PASS_LEN);
3156                 len = AUTH_PASS_LEN;
3157         } else if ((len % AUTH_PASS_LEN) != 0) {
3158                 memset(&passwd[len], 0, AUTH_PASS_LEN - (len % AUTH_PASS_LEN));
3159                 len += AUTH_PASS_LEN - (len % AUTH_PASS_LEN);
3160         }
3161         *pwlen = len;
3162
3163         /*
3164          *      Use the secret to setup the decryption digest
3165          */
3166         secretlen = strlen(secret);
3167
3168         fr_MD5Init(&context);
3169         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3170         old = context;          /* save intermediate work */
3171
3172         /*
3173          *      Encrypt it in place.  Don't bother checking
3174          *      len, as we've ensured above that it's OK.
3175          */
3176         for (n = 0; n < len; n += AUTH_PASS_LEN) {
3177                 if (n == 0) {
3178                         fr_MD5Update(&context, vector, AUTH_PASS_LEN);
3179                         fr_MD5Final(digest, &context);
3180                 } else {
3181                         context = old;
3182                         fr_MD5Update(&context,
3183                                      (uint8_t *) passwd + n - AUTH_PASS_LEN,
3184                                      AUTH_PASS_LEN);
3185                         fr_MD5Final(digest, &context);
3186                 }
3187
3188                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3189                         passwd[i + n] ^= digest[i];
3190                 }
3191         }
3192
3193         return 0;
3194 }
3195
3196 /*
3197  *      Decode password.
3198  */
3199 int rad_pwdecode(char *passwd, size_t pwlen, const char *secret,
3200                  const uint8_t *vector)
3201 {
3202         FR_MD5_CTX context, old;
3203         uint8_t digest[AUTH_VECTOR_LEN];
3204         int     i;
3205         size_t  n, secretlen;
3206
3207         /*
3208          *      The RFC's say that the maximum is 128.
3209          *      The buffer we're putting it into above is 254, so
3210          *      we don't need to do any length checking.
3211          */
3212         if (pwlen > 128) pwlen = 128;
3213
3214         /*
3215          *      Catch idiots.
3216          */
3217         if (pwlen == 0) goto done;
3218
3219         /*
3220          *      Use the secret to setup the decryption digest
3221          */
3222         secretlen = strlen(secret);
3223
3224         fr_MD5Init(&context);
3225         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3226         old = context;          /* save intermediate work */
3227
3228         /*
3229          *      The inverse of the code above.
3230          */
3231         for (n = 0; n < pwlen; n += AUTH_PASS_LEN) {
3232                 if (n == 0) {
3233                         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3234                         fr_MD5Final(digest, &context);
3235
3236                         context = old;
3237                         if (pwlen > AUTH_PASS_LEN) {
3238                                 fr_MD5Update(&context, (uint8_t *) passwd,
3239                                              AUTH_PASS_LEN);
3240                         }
3241                 } else {
3242                         fr_MD5Final(digest, &context);
3243
3244                         context = old;
3245                         if (pwlen > (n + AUTH_PASS_LEN)) {
3246                                 fr_MD5Update(&context, (uint8_t *) passwd + n,
3247                                              AUTH_PASS_LEN);
3248                         }
3249                 }
3250
3251                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3252                         passwd[i + n] ^= digest[i];
3253                 }
3254         }
3255
3256  done:
3257         passwd[pwlen] = '\0';
3258         return strlen(passwd);
3259 }
3260
3261
3262 /*
3263  *      Encode Tunnel-Password attributes when sending them out on the wire.
3264  *
3265  *      int *pwlen is updated to the new length of the encrypted
3266  *      password - a multiple of 16 bytes.
3267  *
3268  *      This is per RFC-2868 which adds a two char SALT to the initial intermediate
3269  *      value MD5 hash.
3270  */
3271 int rad_tunnel_pwencode(char *passwd, size_t *pwlen, const char *secret,
3272                         const uint8_t *vector)
3273 {
3274         uint8_t buffer[AUTH_VECTOR_LEN + MAX_STRING_LEN + 3];
3275         unsigned char   digest[AUTH_VECTOR_LEN];
3276         char*   salt;
3277         int     i, n, secretlen;
3278         unsigned len, n2;
3279
3280         len = *pwlen;
3281
3282         if (len > 127) len = 127;
3283
3284         /*
3285          * Shift the password 3 positions right to place a salt and original
3286          * length, tag will be added automatically on packet send
3287          */
3288         for (n=len ; n>=0 ; n--) passwd[n+3] = passwd[n];
3289         salt = passwd;
3290         passwd += 2;
3291         /*
3292          * save original password length as first password character;
3293          */
3294         *passwd = len;
3295         len += 1;
3296
3297
3298         /*
3299          *      Generate salt.  The RFC's say:
3300          *
3301          *      The high bit of salt[0] must be set, each salt in a
3302          *      packet should be unique, and they should be random
3303          *
3304          *      So, we set the high bit, add in a counter, and then
3305          *      add in some CSPRNG data.  should be OK..
3306          */
3307         salt[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
3308                    (fr_rand() & 0x07));
3309         salt[1] = fr_rand();
3310
3311         /*
3312          *      Padd password to multiple of AUTH_PASS_LEN bytes.
3313          */
3314         n = len % AUTH_PASS_LEN;
3315         if (n) {
3316                 n = AUTH_PASS_LEN - n;
3317                 for (; n > 0; n--, len++)
3318                         passwd[len] = 0;
3319         }
3320         /* set new password length */
3321         *pwlen = len + 2;
3322
3323         /*
3324          *      Use the secret to setup the decryption digest
3325          */
3326         secretlen = strlen(secret);
3327         memcpy(buffer, secret, secretlen);
3328
3329         for (n2 = 0; n2 < len; n2+=AUTH_PASS_LEN) {
3330                 if (!n2) {
3331                         memcpy(buffer + secretlen, vector, AUTH_VECTOR_LEN);
3332                         memcpy(buffer + secretlen + AUTH_VECTOR_LEN, salt, 2);
3333                         fr_md5_calc(digest, buffer, secretlen + AUTH_VECTOR_LEN + 2);
3334                 } else {
3335                         memcpy(buffer + secretlen, passwd + n2 - AUTH_PASS_LEN, AUTH_PASS_LEN);
3336                         fr_md5_calc(digest, buffer, secretlen + AUTH_PASS_LEN);
3337                 }
3338
3339                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3340                         passwd[i + n2] ^= digest[i];
3341                 }
3342         }
3343         passwd[n2] = 0;
3344         return 0;
3345 }
3346
3347 /*
3348  *      Decode Tunnel-Password encrypted attributes.
3349  *
3350  *      Defined in RFC-2868, this uses a two char SALT along with the
3351  *      initial intermediate value, to differentiate it from the
3352  *      above.
3353  */
3354 int rad_tunnel_pwdecode(uint8_t *passwd, size_t *pwlen, const char *secret,
3355                         const uint8_t *vector)
3356 {
3357         FR_MD5_CTX  context, old;
3358         uint8_t         digest[AUTH_VECTOR_LEN];
3359         int             secretlen;
3360         unsigned        i, n, len, reallen;
3361
3362         len = *pwlen;
3363
3364         /*
3365          *      We need at least a salt.
3366          */
3367         if (len < 2) {
3368                 fr_strerror_printf("tunnel password is too short");
3369                 return -1;
3370         }
3371
3372         /*
3373          *      There's a salt, but no password.  Or, there's a salt
3374          *      and a 'data_len' octet.  It's wrong, but at least we
3375          *      can figure out what it means: the password is empty.
3376          *
3377          *      Note that this means we ignore the 'data_len' field,
3378          *      if the attribute length tells us that there's no
3379          *      more data.  So the 'data_len' field may be wrong,
3380          *      but that's ok...
3381          */
3382         if (len <= 3) {
3383                 passwd[0] = 0;
3384                 *pwlen = 0;
3385                 return 0;
3386         }
3387
3388         len -= 2;               /* discount the salt */
3389
3390         /*
3391          *      Use the secret to setup the decryption digest
3392          */
3393         secretlen = strlen(secret);
3394
3395         fr_MD5Init(&context);
3396         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3397         old = context;          /* save intermediate work */
3398
3399         /*
3400          *      Set up the initial key:
3401          *
3402          *       b(1) = MD5(secret + vector + salt)
3403          */
3404         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3405         fr_MD5Update(&context, passwd, 2);
3406
3407         reallen = 0;
3408         for (n = 0; n < len; n += AUTH_PASS_LEN) {
3409                 int base = 0;
3410
3411                 if (n == 0) {
3412                         fr_MD5Final(digest, &context);
3413
3414                         context = old;
3415
3416                         /*
3417                          *      A quick check: decrypt the first octet
3418                          *      of the password, which is the
3419                          *      'data_len' field.  Ensure it's sane.
3420                          */
3421                         reallen = passwd[2] ^ digest[0];
3422                         if (reallen >= len) {
3423                                 fr_strerror_printf("tunnel password is too long for the attribute");
3424                                 return -1;
3425                         }
3426
3427                         fr_MD5Update(&context, passwd + 2, AUTH_PASS_LEN);
3428
3429                         base = 1;
3430                 } else {
3431                         fr_MD5Final(digest, &context);
3432
3433                         context = old;
3434                         fr_MD5Update(&context, passwd + n + 2, AUTH_PASS_LEN);
3435                 }
3436
3437                 for (i = base; i < AUTH_PASS_LEN; i++) {
3438                         passwd[n + i - 1] = passwd[n + i + 2] ^ digest[i];
3439                 }
3440         }
3441
3442         /*
3443          *      See make_tunnel_password, above.
3444          */
3445         if (reallen > 239) reallen = 239;
3446
3447         *pwlen = reallen;
3448         passwd[reallen] = 0;
3449
3450         return reallen;
3451 }
3452
3453 /*
3454  *      Encode a CHAP password
3455  *
3456  *      FIXME: might not work with Ascend because
3457  *      we use vp->length, and Ascend gear likes
3458  *      to send an extra '\0' in the string!
3459  */
3460 int rad_chap_encode(RADIUS_PACKET *packet, uint8_t *output, int id,
3461                     VALUE_PAIR *password)
3462 {
3463         int             i;
3464         uint8_t         *ptr;
3465         uint8_t         string[MAX_STRING_LEN * 2 + 1];
3466         VALUE_PAIR      *challenge;
3467
3468         /*
3469          *      Sanity check the input parameters
3470          */
3471         if ((packet == NULL) || (password == NULL)) {
3472                 return -1;
3473         }
3474
3475         /*
3476          *      Note that the password VP can be EITHER
3477          *      a User-Password attribute (from a check-item list),
3478          *      or a CHAP-Password attribute (the client asking
3479          *      the library to encode it).
3480          */
3481
3482         i = 0;
3483         ptr = string;
3484         *ptr++ = id;
3485
3486         i++;
3487         memcpy(ptr, password->vp_strvalue, password->length);
3488         ptr += password->length;
3489         i += password->length;
3490
3491         /*
3492          *      Use Chap-Challenge pair if present,
3493          *      Request-Authenticator otherwise.
3494          */
3495         challenge = pairfind(packet->vps, PW_CHAP_CHALLENGE, 0);
3496         if (challenge) {
3497                 memcpy(ptr, challenge->vp_strvalue, challenge->length);
3498                 i += challenge->length;
3499         } else {
3500                 memcpy(ptr, packet->vector, AUTH_VECTOR_LEN);
3501                 i += AUTH_VECTOR_LEN;
3502         }
3503
3504         *output = id;
3505         fr_md5_calc((uint8_t *)output + 1, (uint8_t *)string, i);
3506
3507         return 0;
3508 }
3509
3510
3511 /*
3512  *      Seed the random number generator.
3513  *
3514  *      May be called any number of times.
3515  */
3516 void fr_rand_seed(const void *data, size_t size)
3517 {
3518         uint32_t hash;
3519
3520         /*
3521          *      Ensure that the pool is initialized.
3522          */
3523         if (!fr_rand_initialized) {
3524                 int fd;
3525
3526                 memset(&fr_rand_pool, 0, sizeof(fr_rand_pool));
3527
3528                 fd = open("/dev/urandom", O_RDONLY);
3529                 if (fd >= 0) {
3530                         size_t total;
3531                         ssize_t this;
3532
3533                         total = this = 0;
3534                         while (total < sizeof(fr_rand_pool.randrsl)) {
3535                                 this = read(fd, fr_rand_pool.randrsl,
3536                                             sizeof(fr_rand_pool.randrsl) - total);
3537                                 if ((this < 0) && (errno != EINTR)) break;
3538                                 if (this > 0) total += this;
3539                         }
3540                         close(fd);
3541                 } else {
3542                         fr_rand_pool.randrsl[0] = fd;
3543                         fr_rand_pool.randrsl[1] = time(NULL);
3544                         fr_rand_pool.randrsl[2] = errno;
3545                 }
3546
3547                 fr_randinit(&fr_rand_pool, 1);
3548                 fr_rand_pool.randcnt = 0;
3549                 fr_rand_initialized = 1;
3550         }
3551
3552         if (!data) return;
3553
3554         /*
3555          *      Hash the user data
3556          */
3557         hash = fr_rand();
3558         if (!hash) hash = fr_rand();
3559         hash = fr_hash_update(data, size, hash);
3560
3561         fr_rand_pool.randmem[fr_rand_pool.randcnt] ^= hash;
3562 }
3563
3564
3565 /*
3566  *      Return a 32-bit random number.
3567  */
3568 uint32_t fr_rand(void)
3569 {
3570         uint32_t num;
3571
3572         /*
3573          *      Ensure that the pool is initialized.
3574          */
3575         if (!fr_rand_initialized) {
3576                 fr_rand_seed(NULL, 0);
3577         }
3578
3579         num = fr_rand_pool.randrsl[fr_rand_pool.randcnt++];
3580         if (fr_rand_pool.randcnt >= 256) {
3581                 fr_rand_pool.randcnt = 0;
3582                 fr_isaac(&fr_rand_pool);
3583         }
3584
3585         return num;
3586 }
3587
3588
3589 /*
3590  *      Allocate a new RADIUS_PACKET
3591  */
3592 RADIUS_PACKET *rad_alloc(int newvector)
3593 {
3594         RADIUS_PACKET   *rp;
3595
3596         if ((rp = malloc(sizeof(RADIUS_PACKET))) == NULL) {
3597                 fr_strerror_printf("out of memory");
3598                 return NULL;
3599         }
3600         memset(rp, 0, sizeof(*rp));
3601         rp->id = -1;
3602         rp->offset = -1;
3603
3604         if (newvector) {
3605                 int i;
3606                 uint32_t hash, base;
3607
3608                 /*
3609                  *      Don't expose the actual contents of the random
3610                  *      pool.
3611                  */
3612                 base = fr_rand();
3613                 for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(uint32_t)) {
3614                         hash = fr_rand() ^ base;
3615                         memcpy(rp->vector + i, &hash, sizeof(hash));
3616                 }
3617         }
3618         fr_rand();              /* stir the pool again */
3619
3620         return rp;
3621 }
3622
3623 RADIUS_PACKET *rad_alloc_reply(RADIUS_PACKET *packet)
3624 {
3625         RADIUS_PACKET *reply;
3626
3627         if (!packet) return NULL;
3628
3629         reply = rad_alloc(0);
3630         if (!reply) return NULL;
3631
3632         /*
3633          *      Initialize the fields from the request.
3634          */
3635         reply->sockfd = packet->sockfd;
3636         reply->dst_ipaddr = packet->src_ipaddr;
3637         reply->src_ipaddr = packet->dst_ipaddr;
3638         reply->dst_port = packet->src_port;
3639         reply->src_port = packet->dst_port;
3640         reply->id = packet->id;
3641         reply->code = 0; /* UNKNOWN code */
3642         memcpy(reply->vector, packet->vector,
3643                sizeof(reply->vector));
3644         reply->vps = NULL;
3645         reply->data = NULL;
3646         reply->data_len = 0;
3647
3648         return reply;
3649 }
3650
3651
3652 /*
3653  *      Free a RADIUS_PACKET
3654  */
3655 void rad_free(RADIUS_PACKET **radius_packet_ptr)
3656 {
3657         RADIUS_PACKET *radius_packet;
3658
3659         if (!radius_packet_ptr || !*radius_packet_ptr) return;
3660         radius_packet = *radius_packet_ptr;
3661
3662         free(radius_packet->data);
3663
3664         pairfree(&radius_packet->vps);
3665
3666         free(radius_packet);
3667
3668         *radius_packet_ptr = NULL;
3669 }