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