src/lib/radius.c

   1 /*
   2  * radius.c     Functions to send/receive radius packets.
   3  *
   4  * Version:     $Id$
   5  *
   6  *   This library is free software; you can redistribute it and/or
   7  *   modify it under the terms of the GNU Lesser General Public
   8  *   License as published by the Free Software Foundation; either
   9  *   version 2.1 of the License, or (at your option) any later version.
  10  *
  11  *   This library is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14  *   Lesser General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU Lesser General Public
  17  *   License along with this library; if not, write to the Free Software
  18  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * Copyright 2000-2003,2006  The FreeRADIUS server project
  21  */
  22
  23 #include        <freeradius-devel/ident.h>
  24 RCSID("$Id$")
  25
  26 #include        <freeradius-devel/libradius.h>
  27 #include        <freeradius-devel/md5.h>
  28
  29 #include        <fcntl.h>
  30 #include        <ctype.h>
  31
  32 #ifdef WITH_UDPFROMTO
  33 #include        <freeradius-devel/udpfromto.h>
  34 #endif
  35
  36 #ifdef HAVE_MALLOC_H
  37 #include        <malloc.h>
  38 #endif
  39
  40 /*
  41  *  The RFC says 4096 octets max, and most packets are less than 256.
  42  */
  43 #define MAX_PACKET_LEN 4096
  44
  45 /*
  46  *      The maximum number of attributes which we allow in an incoming
  47  *      request.  If there are more attributes than this, the request
  48  *      is rejected.
  49  *
  50  *      This helps to minimize the potential for a DoS, when an
  51  *      attacker spoofs Access-Request packets, which don't have a
  52  *      Message-Authenticator attribute.  This means that the packet
  53  *      is unsigned, and the attacker can use resources on the server,
  54  *      even if the end request is rejected.
  55  */
  56 int fr_max_attributes = 0;
  57 FILE *fr_log_fp = NULL;
  58
  59 typedef struct radius_packet_t {
  60   uint8_t       code;
  61   uint8_t       id;
  62   uint8_t       length[2];
  63   uint8_t       vector[AUTH_VECTOR_LEN];
  64   uint8_t       data[1];
  65 } radius_packet_t;
  66
  67 static fr_randctx fr_rand_pool; /* across multiple calls */
  68 static int fr_rand_initialized = 0;
  69 static unsigned int salt_offset = 0;
  70
  71 const char *fr_packet_codes[FR_MAX_PACKET_CODE] = {
  72   "",
  73   "Access-Request",
  74   "Access-Accept",
  75   "Access-Reject",
  76   "Accounting-Request",
  77   "Accounting-Response",
  78   "Accounting-Status",
  79   "Password-Request",
  80   "Password-Accept",
  81   "Password-Reject",
  82   "Accounting-Message",
  83   "Access-Challenge",
  84   "Status-Server",
  85   "Status-Client",
  86   "14",
  87   "15",
  88   "16",
  89   "17",
  90   "18",
  91   "19",
  92   "20",
  93   "Resource-Free-Request",
  94   "Resource-Free-Response",
  95   "Resource-Query-Request",
  96   "Resource-Query-Response",
  97   "Alternate-Resource-Reclaim-Request",
  98   "NAS-Reboot-Request",
  99   "NAS-Reboot-Response",
 100   "28",
 101   "Next-Passcode",
 102   "New-Pin",
 103   "Terminate-Session",
 104   "Password-Expired",
 105   "Event-Request",
 106   "Event-Response",
 107   "35",
 108   "36",
 109   "37",
 110   "38",
 111   "39",
 112   "Disconnect-Request",
 113   "Disconnect-ACK",
 114   "Disconnect-NAK",
 115   "CoA-Request",
 116   "CoA-ACK",
 117   "CoA-NAK",
 118   "46",
 119   "47",
 120   "48",
 121   "49",
 122   "IP-Address-Allocate",
 123   "IP-Address-Release"
 124 };
 125
 126
 127 void fr_printf_log(const char *fmt, ...)
 128 {
 129         va_list ap;
 130
 131         va_start(ap, fmt);
 132         if ((fr_debug_flag == 0) || !fr_log_fp) {
 133                 va_end(ap);
 134                 return;
 135         }
 136
 137         vfprintf(fr_log_fp, fmt, ap);
 138         va_end(ap);
 139
 140         return;
 141 }
 142
 143 static void print_hex(RADIUS_PACKET *packet)
 144 {
 145         int i;
 146
 147         if (!packet->data) return;
 148
 149         printf("  Code:\t\t%u\n", packet->data[0]);
 150         printf("  Id:\t\t%u\n", packet->data[1]);
 151         printf("  Length:\t%u\n", ((packet->data[2] << 8) |
 152                                    (packet->data[3])));
 153         printf("  Vector:\t");
 154         for (i = 4; i < 20; i++) {
 155                 printf("%02x", packet->data[i]);
 156         }
 157         printf("\n");
 158
 159         if (packet->data_len > 20) {
 160                 int total;
 161                 const uint8_t *ptr;
 162                 printf("  Data:");
 163
 164                 total = packet->data_len - 20;
 165                 ptr = packet->data + 20;
 166
 167                 while (total > 0) {
 168                         int attrlen;
 169
 170                         printf("\t\t");
 171                         if (total < 2) { /* too short */
 172                                 printf("%02x\n", *ptr);
 173                                 break;
 174                         }
 175
 176                         if (ptr[1] > total) { /* too long */
 177                                 for (i = 0; i < total; i++) {
 178                                         printf("%02x ", ptr[i]);
 179                                 }
 180                                 break;
 181                         }
 182
 183                         printf("%02x  %02x  ", ptr[0], ptr[1]);
 184                         attrlen = ptr[1] - 2;
 185                         ptr += 2;
 186                         total -= 2;
 187
 188                         for (i = 0; i < attrlen; i++) {
 189                                 if ((i > 0) && ((i & 0x0f) == 0x00))
 190                                         printf("\t\t\t");
 191                                 printf("%02x ", ptr[i]);
 192                                 if ((i & 0x0f) == 0x0f) printf("\n");
 193                         }
 194
 195                         if ((attrlen & 0x0f) != 0x00) printf("\n");
 196
 197                         ptr += attrlen;
 198                         total -= attrlen;
 199                 }
 200         }
 201         fflush(stdout);
 202 }
 203
 204
 205 /*
 206  *      Wrapper for sendto which handles sendfromto, IPv6, and all
 207  *      possible combinations.
 208  */
 209 static int rad_sendto(int sockfd, void *data, size_t data_len, int flags,
 210                       fr_ipaddr_t *src_ipaddr, int src_port,
 211                       fr_ipaddr_t *dst_ipaddr, int dst_port)
 212 {
 213         struct sockaddr_storage dst;
 214         socklen_t               sizeof_dst;
 215
 216 #ifdef WITH_UDPFROMTO
 217         struct sockaddr_storage src;
 218         socklen_t               sizeof_src;
 219
 220         fr_ipaddr2sockaddr(src_ipaddr, src_port, &src, &sizeof_src);
 221 #else
 222         src_port = src_port;    /* -Wunused */
 223 #endif
 224
 225         if (!fr_ipaddr2sockaddr(dst_ipaddr, dst_port, &dst, &sizeof_dst)) {
 226                 return -1;
 227         }
 228
 229 #ifdef WITH_UDPFROMTO
 230         /*
 231          *      Only IPv4 is supported for udpfromto.
 232          *
 233          *      And if they don't specify a source IP address, don't
 234          *      use udpfromto.
 235          */
 236         if ((dst_ipaddr->af == AF_INET) ||
 237             (src_ipaddr->af != AF_UNSPEC)) {
 238                 return sendfromto(sockfd, data, data_len, flags,
 239                                   (struct sockaddr *)&src, sizeof_src,
 240                                   (struct sockaddr *)&dst, sizeof_dst);
 241         }
 242 #else
 243         src_ipaddr = src_ipaddr; /* -Wunused */
 244 #endif
 245
 246         /*
 247          *      No udpfromto, OR an IPv6 socket, fail gracefully.
 248          */
 249         return sendto(sockfd, data, data_len, flags,
 250                       (struct sockaddr *) &dst, sizeof_dst);
 251 }
 252
 253
 254 void rad_recv_discard(int sockfd)
 255 {
 256         uint8_t                 header[4];
 257         struct sockaddr_storage src;
 258         socklen_t               sizeof_src = sizeof(src);
 259
 260         recvfrom(sockfd, header, sizeof(header), 0,
 261                  (struct sockaddr *)&src, &sizeof_src);
 262 }
 263
 264
 265 ssize_t rad_recv_header(int sockfd, fr_ipaddr_t *src_ipaddr, int *src_port,
 266                         int *code)
 267 {
 268         ssize_t                 data_len, packet_len;
 269         uint8_t                 header[4];
 270         struct sockaddr_storage src;
 271         socklen_t               sizeof_src = sizeof(src);
 272
 273         data_len = recvfrom(sockfd, header, sizeof(header), MSG_PEEK,
 274                             (struct sockaddr *)&src, &sizeof_src);
 275         if (data_len < 0) {
 276                 if ((errno == EAGAIN) || (errno == EINTR)) return 0;
 277                 return -1;
 278         }
 279
 280         /*
 281          *      Too little data is available, discard the packet.
 282          */
 283         if (data_len < 4) {
 284                 recvfrom(sockfd, header, sizeof(header), 0,
 285                          (struct sockaddr *)&src, &sizeof_src);
 286                 return 1;
 287
 288         } else {                /* we got 4 bytes of data. */
 289                 /*
 290                  *      See how long the packet says it is.
 291                  */
 292                 packet_len = (header[2] * 256) + header[3];
 293
 294                 /*
 295                  *      The length in the packet says it's less than
 296                  *      a RADIUS header length: discard it.
 297                  */
 298                 if (packet_len < AUTH_HDR_LEN) {
 299                         recvfrom(sockfd, header, sizeof(header), 0,
 300                                  (struct sockaddr *)&src, &sizeof_src);
 301                         return 1;
 302
 303                         /*
 304                          *      Enforce RFC requirements, for sanity.
 305                          *      Anything after 4k will be discarded.
 306                          */
 307                 } else if (packet_len > MAX_PACKET_LEN) {
 308                         recvfrom(sockfd, header, sizeof(header), 0,
 309                                  (struct sockaddr *)&src, &sizeof_src);
 310                         return 1;
 311                 }
 312         }
 313
 314         /*
 315          *      Convert AF.  If unknown, discard packet.
 316          */
 317         if (!fr_sockaddr2ipaddr(&src, sizeof_src, src_ipaddr, src_port)) {
 318                 recvfrom(sockfd, header, sizeof(header), 0,
 319                          (struct sockaddr *)&src, &sizeof_src);
 320                 return 1;
 321         }
 322
 323         *code = header[0];
 324
 325         /*
 326          *      The packet says it's this long, but the actual UDP
 327          *      size could still be smaller.
 328          */
 329         return packet_len;
 330 }
 331
 332
 333 /*
 334  *      wrapper for recvfrom, which handles recvfromto, IPv6, and all
 335  *      possible combinations.
 336  */
 337 static ssize_t rad_recvfrom(int sockfd, uint8_t **pbuf, int flags,
 338                             fr_ipaddr_t *src_ipaddr, uint16_t *src_port,
 339                             fr_ipaddr_t *dst_ipaddr, uint16_t *dst_port)
 340 {
 341         struct sockaddr_storage src;
 342         struct sockaddr_storage dst;
 343         socklen_t               sizeof_src = sizeof(src);
 344         socklen_t               sizeof_dst = sizeof(dst);
 345         ssize_t                 data_len;
 346         uint8_t                 header[4];
 347         void                    *buf;
 348         size_t                  len;
 349         int                     port;
 350
 351         memset(&src, 0, sizeof_src);
 352         memset(&dst, 0, sizeof_dst);
 353
 354         /*
 355          *      Get address family, etc. first, so we know if we
 356          *      need to do udpfromto.
 357          *
 358          *      FIXME: udpfromto also does this, but it's not
 359          *      a critical problem.
 360          */
 361         if (getsockname(sockfd, (struct sockaddr *)&dst,
 362                         &sizeof_dst) < 0) return -1;
 363
 364         /*
 365          *      Read the length of the packet, from the packet.
 366          *      This lets us allocate the buffer to use for
 367          *      reading the rest of the packet.
 368          */
 369         data_len = recvfrom(sockfd, header, sizeof(header), MSG_PEEK,
 370                             (struct sockaddr *)&src, &sizeof_src);
 371         if (data_len < 0) {
 372                 if ((errno == EAGAIN) || (errno == EINTR)) return 0;
 373                 return -1;
 374         }
 375
 376         /*
 377          *      Too little data is available, discard the packet.
 378          */
 379         if (data_len < 4) {
 380                 recvfrom(sockfd, header, sizeof(header), flags,
 381                          (struct sockaddr *)&src, &sizeof_src);
 382                 return 0;
 383
 384         } else {                /* we got 4 bytes of data. */
 385                 /*
 386                  *      See how long the packet says it is.
 387                  */
 388                 len = (header[2] * 256) + header[3];
 389
 390                 /*
 391                  *      The length in the packet says it's less than
 392                  *      a RADIUS header length: discard it.
 393                  */
 394                 if (len < AUTH_HDR_LEN) {
 395                         recvfrom(sockfd, header, sizeof(header), flags,
 396                                  (struct sockaddr *)&src, &sizeof_src);
 397                         return 0;
 398
 399                         /*
 400                          *      Enforce RFC requirements, for sanity.
 401                          *      Anything after 4k will be discarded.
 402                          */
 403                 } else if (len > MAX_PACKET_LEN) {
 404                         recvfrom(sockfd, header, sizeof(header), flags,
 405                                  (struct sockaddr *)&src, &sizeof_src);
 406                         return len;
 407                 }
 408         }
 409
 410         buf = malloc(len);
 411         if (!buf) return -1;
 412
 413         /*
 414          *      Receive the packet.  The OS will discard any data in the
 415          *      packet after "len" bytes.
 416          */
 417 #ifdef WITH_UDPFROMTO
 418         if (dst.ss_family == AF_INET) {
 419                 data_len = recvfromto(sockfd, buf, len, flags,
 420                                       (struct sockaddr *)&src, &sizeof_src,
 421                                       (struct sockaddr *)&dst, &sizeof_dst);
 422         } else
 423 #endif
 424                 /*
 425                  *      No udpfromto, OR an IPv6 socket.  Fail gracefully.
 426                  */
 427                 data_len = recvfrom(sockfd, buf, len, flags,
 428                                     (struct sockaddr *)&src, &sizeof_src);
 429         if (data_len < 0) {
 430                 free(buf);
 431                 return data_len;
 432         }
 433
 434         if (!fr_sockaddr2ipaddr(&src, sizeof_src, src_ipaddr, &port)) {
 435                 free(buf);
 436                 return -1;      /* Unknown address family, Die Die Die! */
 437         }
 438         *src_port = port;
 439
 440         fr_sockaddr2ipaddr(&dst, sizeof_dst, dst_ipaddr, &port);
 441         *dst_port = port;
 442
 443         /*
 444          *      Different address families should never happen.
 445          */
 446         if (src.ss_family != dst.ss_family) {
 447                 free(buf);
 448                 return -1;
 449         }
 450
 451         /*
 452          *      Tell the caller about the data
 453          */
 454         *pbuf = buf;
 455
 456         return data_len;
 457 }
 458
 459
 460 #define AUTH_PASS_LEN (AUTH_VECTOR_LEN)
 461 /*************************************************************************
 462  *
 463  *      Function: make_secret
 464  *
 465  *      Purpose: Build an encrypted secret value to return in a reply
 466  *               packet.  The secret is hidden by xoring with a MD5 digest
 467  *               created from the shared secret and the authentication
 468  *               vector.  We put them into MD5 in the reverse order from
 469  *               that used when encrypting passwords to RADIUS.
 470  *
 471  *************************************************************************/
 472 static void make_secret(uint8_t *digest, const uint8_t *vector,
 473                         const char *secret, const uint8_t *value)
 474 {
 475         FR_MD5_CTX context;
 476         int             i;
 477
 478         fr_MD5Init(&context);
 479         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
 480         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
 481         fr_MD5Final(digest, &context);
 482
 483         for ( i = 0; i < AUTH_VECTOR_LEN; i++ ) {
 484                 digest[i] ^= value[i];
 485         }
 486 }
 487
 488 #define MAX_PASS_LEN (128)
 489 static void make_passwd(uint8_t *output, size_t *outlen,
 490                         const uint8_t *input, size_t inlen,
 491                         const char *secret, const uint8_t *vector)
 492 {
 493         FR_MD5_CTX context, old;
 494         uint8_t digest[AUTH_VECTOR_LEN];
 495         uint8_t passwd[MAX_PASS_LEN];
 496         int     i, n;
 497         int     len;
 498
 499         /*
 500          *      If the length is zero, round it up.
 501          */
 502         len = inlen;
 503
 504         if (len > MAX_PASS_LEN) len = MAX_PASS_LEN;
 505
 506         memcpy(passwd, input, len);
 507         memset(passwd + len, 0, sizeof(passwd) - len);
 508
 509         if (len == 0) {
 510                 len = AUTH_PASS_LEN;
 511         }
 512
 513         else if ((len & 0x0f) != 0) {
 514                 len += 0x0f;
 515                 len &= ~0x0f;
 516         }
 517         *outlen = len;
 518
 519         fr_MD5Init(&context);
 520         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
 521         old = context;
 522
 523         /*
 524          *      Do first pass.
 525          */
 526         fr_MD5Update(&context, vector, AUTH_PASS_LEN);
 527
 528         for (n = 0; n < len; n += AUTH_PASS_LEN) {
 529                 if (n > 0) {
 530                         context = old;
 531                         fr_MD5Update(&context,
 532                                        passwd + n - AUTH_PASS_LEN,
 533                                        AUTH_PASS_LEN);
 534                 }
 535
 536                 fr_MD5Final(digest, &context);
 537                 for (i = 0; i < AUTH_PASS_LEN; i++) {
 538                         passwd[i + n] ^= digest[i];
 539                 }
 540         }
 541
 542         memcpy(output, passwd, len);
 543 }
 544
 545 static void make_tunnel_passwd(uint8_t *output, size_t *outlen,
 546                                const uint8_t *input, size_t inlen, size_t room,
 547                                const char *secret, const uint8_t *vector)
 548 {
 549         FR_MD5_CTX context, old;
 550         uint8_t digest[AUTH_VECTOR_LEN];
 551         uint8_t passwd[MAX_STRING_LEN + AUTH_VECTOR_LEN];
 552         int     i, n;
 553         int     len;
 554
 555         /*
 556          *      Be paranoid.
 557          */
 558         if (room > 253) room = 253;
 559
 560         /*
 561          *      Account for 2 bytes of the salt, and round the room
 562          *      available down to the nearest multiple of 16.  Then,
 563          *      subtract one from that to account for the length byte,
 564          *      and the resulting number is the upper bound on the data
 565          *      to copy.
 566          *
 567          *      We could short-cut this calculation just be forcing
 568          *      inlen to be no more than 239.  It would work for all
 569          *      VSA's, as we don't pack multiple VSA's into one
 570          *      attribute.
 571          *
 572          *      However, this calculation is more general, if a little
 573          *      complex.  And it will work in the future for all possible
 574          *      kinds of weird attribute packing.
 575          */
 576         room -= 2;
 577         room -= (room & 0x0f);
 578         room--;
 579
 580         if (inlen > room) inlen = room;
 581
 582         /*
 583          *      Length of the encrypted data is password length plus
 584          *      one byte for the length of the password.
 585          */
 586         len = inlen + 1;
 587         if ((len & 0x0f) != 0) {
 588                 len += 0x0f;
 589                 len &= ~0x0f;
 590         }
 591         *outlen = len + 2;      /* account for the salt */
 592
 593         /*
 594          *      Copy the password over.
 595          */
 596         memcpy(passwd + 3, input, inlen);
 597         memset(passwd + 3 + inlen, 0, sizeof(passwd) - 3 - inlen);
 598
 599         /*
 600          *      Generate salt.  The RFC's say:
 601          *
 602          *      The high bit of salt[0] must be set, each salt in a
 603          *      packet should be unique, and they should be random
 604          *
 605          *      So, we set the high bit, add in a counter, and then
 606          *      add in some CSPRNG data.  should be OK..
 607          */
 608         passwd[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
 609                      (fr_rand() & 0x07));
 610         passwd[1] = fr_rand();
 611         passwd[2] = inlen;      /* length of the password string */
 612
 613         fr_MD5Init(&context);
 614         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
 615         old = context;
 616
 617         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
 618         fr_MD5Update(&context, &passwd[0], 2);
 619
 620         for (n = 0; n < len; n += AUTH_PASS_LEN) {
 621                 if (n > 0) {
 622                         context = old;
 623                         fr_MD5Update(&context,
 624                                        passwd + 2 + n - AUTH_PASS_LEN,
 625                                        AUTH_PASS_LEN);
 626                 }
 627
 628                 fr_MD5Final(digest, &context);
 629
 630                 for (i = 0; i < AUTH_PASS_LEN; i++) {
 631                         passwd[i + 2 + n] ^= digest[i];
 632                 }
 633         }
 634         memcpy(output, passwd, len + 2);
 635 }
 636
 637 /*
 638  *      Returns the end of the data.
 639  */
 640 static int vp2data(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
 641                    const char *secret, const VALUE_PAIR *vp, uint8_t *start,
 642                    size_t room)
 643 {
 644         uint32_t lvalue;
 645         size_t len;
 646         const uint8_t *data;
 647         uint8_t *ptr = start;
 648         uint8_t array[4];
 649
 650         /*
 651          *      Set up the default sources for the data.
 652          */
 653         data = vp->vp_octets;
 654         len = vp->length;
 655
 656         switch(vp->type) {
 657         case PW_TYPE_STRING:
 658         case PW_TYPE_OCTETS:
 659         case PW_TYPE_IFID:
 660         case PW_TYPE_IPV6ADDR:
 661         case PW_TYPE_IPV6PREFIX:
 662         case PW_TYPE_ABINARY:
 663                 /* nothing more to do */
 664                 break;
 665
 666         case PW_TYPE_BYTE:
 667                 len = 1;        /* just in case */
 668                 array[0] = vp->vp_integer & 0xff;
 669                 data = array;
 670                 break;
 671
 672         case PW_TYPE_SHORT:
 673                 len = 2;        /* just in case */
 674                 array[0] = (vp->vp_integer >> 8) & 0xff;
 675                 array[1] = vp->vp_integer & 0xff;
 676                 data = array;
 677                 break;
 678
 679         case PW_TYPE_INTEGER:
 680                 len = 4;        /* just in case */
 681                 lvalue = htonl(vp->vp_integer);
 682                 memcpy(array, &lvalue, sizeof(lvalue));
 683                 data = array;
 684                 break;
 685
 686         case PW_TYPE_IPADDR:
 687                 data = (const uint8_t *) &vp->vp_ipaddr;
 688                 len = 4;        /* just in case */
 689                 break;
 690
 691                 /*
 692                  *  There are no tagged date attributes.
 693                  */
 694         case PW_TYPE_DATE:
 695                 lvalue = htonl(vp->vp_date);
 696                 data = (const uint8_t *) &lvalue;
 697                 len = 4;        /* just in case */
 698                 break;
 699
 700         case PW_TYPE_SIGNED:
 701         {
 702                 int32_t slvalue;
 703
 704                 len = 4;        /* just in case */
 705                 slvalue = htonl(vp->vp_signed);
 706                 memcpy(array, &slvalue, sizeof(slvalue));
 707                 break;
 708         }
 709
 710         case PW_TYPE_TLV:
 711                 data = vp->vp_tlv;
 712                 if (!data) {
 713                         fr_strerror_printf("ERROR: Cannot encode NULL TLV");
 714                         return -1;
 715                 }
 716                 if (vp->length > room) return 0; /* can't chop TLVs to fit */
 717                 break;
 718
 719         default:                /* unknown type: ignore it */
 720                 fr_strerror_printf("ERROR: Unknown attribute type %d", vp->type);
 721                 return -1;
 722         }
 723
 724         /*
 725          *      Bound the data to the calling size
 726          */
 727         if (len > room) len = room;
 728
 729         /*
 730          *      Encrypt the various password styles
 731          *
 732          *      Attributes with encrypted values MUST be less than
 733          *      128 bytes long.
 734          */
 735         switch (vp->flags.encrypt) {
 736         case FLAG_ENCRYPT_USER_PASSWORD:
 737                 make_passwd(ptr, &len, data, len,
 738                             secret, packet->vector);
 739                 break;
 740
 741         case FLAG_ENCRYPT_TUNNEL_PASSWORD:
 742                 lvalue = 0;
 743                 if (vp->flags.has_tag) lvalue = 1;
 744
 745                 /*
 746                  *      Check if there's enough room.  If there isn't,
 747                  *      we discard the attribute.
 748                  *
 749                  *      This is ONLY a problem if we have multiple VSA's
 750                  *      in one Vendor-Specific, though.
 751                  */
 752                 if (room < (18 + lvalue)) return 0;
 753
 754                 switch (packet->code) {
 755                 case PW_AUTHENTICATION_ACK:
 756                 case PW_AUTHENTICATION_REJECT:
 757                 case PW_ACCESS_CHALLENGE:
 758                 default:
 759                         if (!original) {
 760                                 fr_strerror_printf("ERROR: No request packet, cannot encrypt %s attribute in the vp.", vp->name);
 761                                 return -1;
 762                         }
 763
 764                         if (lvalue) ptr[0] = vp->flags.tag;
 765                         make_tunnel_passwd(ptr + lvalue, &len, data, len,
 766                                            room - lvalue,
 767                                            secret, original->vector);
 768                         break;
 769                 case PW_ACCOUNTING_REQUEST:
 770                 case PW_DISCONNECT_REQUEST:
 771                 case PW_COA_REQUEST:
 772                         ptr[0] = vp->flags.tag;
 773                         make_tunnel_passwd(ptr + 1, &len, data, len - 1, room,
 774                                            secret, packet->vector);
 775                         break;
 776                 }
 777                 break;
 778
 779                 /*
 780                  *      The code above ensures that this attribute
 781                  *      always fits.
 782                  */
 783         case FLAG_ENCRYPT_ASCEND_SECRET:
 784                 make_secret(ptr, packet->vector, secret, data);
 785                 len = AUTH_VECTOR_LEN;
 786                 break;
 787
 788
 789         default:
 790                 if (vp->flags.has_tag && TAG_VALID(vp->flags.tag)) {
 791                         if (vp->type == PW_TYPE_STRING) {
 792                                 if (len > (room - 1)) len = room - 1;
 793                                 ptr[0] = vp->flags.tag;
 794                                 ptr++;
 795                         } else if (vp->type == PW_TYPE_INTEGER) {
 796                                 array[0] = vp->flags.tag;
 797                         } /* else it can't be any other type */
 798                 }
 799                 memcpy(ptr, data, len);
 800                 break;
 801         } /* switch over encryption flags */
 802
 803         return len + (ptr - start);;
 804 }
 805
 806
 807 static int rad_vp2rfc(const RADIUS_PACKET *packet,
 808                       const RADIUS_PACKET *original,
 809                       const char *secret, const VALUE_PAIR *vp,
 810                       unsigned int attribute, uint8_t *ptr, size_t room)
 811 {
 812         int len;
 813
 814         if (room < 2) return 0;
 815
 816         ptr[0] = attribute & 0xff; /* NOT vp->attribute */
 817         ptr[1] = 2;
 818
 819         len = vp2data(packet, original, secret, vp, ptr + 2, room - 2);
 820         if (len < 0) return len;
 821
 822         ptr[1] += len;
 823
 824         return ptr[1];
 825 }
 826
 827 extern int fr_wimax_max_tlv;
 828 extern int fr_wimax_shift[];
 829 extern int fr_wimax_mask[];
 830
 831 static int tlv2data(const RADIUS_PACKET *packet,
 832                     const RADIUS_PACKET *original,
 833                     const char *secret, const VALUE_PAIR *vp,
 834                     uint8_t *ptr, size_t room, int nest)
 835 {
 836         int len;
 837
 838         if (nest > fr_wimax_max_tlv) return -1;
 839
 840         if (room < 2) return 0;
 841         room -= 2;
 842
 843         ptr[0] = (vp->attribute >> fr_wimax_shift[nest]) & fr_wimax_mask[nest];
 844         ptr[1] = 2;
 845
 846         /*
 847          *      No more nested TLVs: pack the data.
 848          */
 849         if ((nest == fr_wimax_max_tlv) ||
 850             ((vp->attribute >> fr_wimax_shift[nest + 1]) == 0)) {
 851                 len = vp2data(packet, original, secret, vp, ptr + 2, room);
 852         } else {
 853                 len = tlv2data(packet, original, secret, vp, ptr + 2, room,
 854                                nest + 1);
 855         }
 856         if (len <= 0) return len;
 857
 858         ptr[1] += len;
 859
 860         return ptr[1];
 861 }
 862
 863 static int wimax2data(const RADIUS_PACKET *packet,
 864                       const RADIUS_PACKET *original,
 865                       const char *secret, const VALUE_PAIR *vp,
 866                       uint8_t *start, size_t room, uint8_t *ptr)
 867 {
 868         int len;
 869
 870         /*
 871          *      Offsets to Vendor-Specific length, and to length of
 872          *      WiMAX attribute.
 873          */
 874 #define VS_OFF (1)
 875 #define WM_OFF (7)
 876
 877         if (room < 1) return 0;
 878         room--;
 879
 880         /*
 881          *      Account for continuation bytes.  The caller has
 882          *      already accounting for the continuation byte in the
 883          *      Vendor-Specific "length" field.
 884          */
 885         start[WM_OFF]++;
 886         *(ptr++) = 0;
 887
 888         /*
 889          *      Chop everything to fit in one attribute.
 890          */
 891         if (room > (255 - 9)) room = (255 - 9);
 892
 893         /*
 894          *      The attribute contains TLVs that we have NOT decoded
 895          *      properly, OR it contains TLV that the user has encoded
 896          *      manually.  If it has no data, OR it's too long,
 897          *      discard it.  We're not going to walk through its
 898          *      contents trying to figure out how to chop it across
 899          *      multiple continuations.
 900          */
 901         if (vp->flags.has_tlv && (!vp->vp_tlv || (vp->length > room))) {
 902                 return 0;
 903         }
 904
 905         /*
 906          *      The attribute is a top-level integer, ipaddr, etc.
 907          *      Encode it.
 908          */
 909         if (!vp->flags.is_tlv) {
 910                 len = vp2data(packet, original, secret, vp, ptr, room);
 911         } else {
 912                 len = tlv2data(packet, original, secret, vp, ptr, room, 1);
 913         }
 914
 915         if (len <= 0) return len;
 916
 917         start[VS_OFF] += len;
 918         start[WM_OFF] += len;
 919
 920         return start[VS_OFF];
 921 }
 922
 923
 924 /*
 925  *      Parse a data structure into a RADIUS attribute.
 926  */
 927 int rad_vp2attr(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
 928                 const char *secret, const VALUE_PAIR *vp, uint8_t *start,
 929                 size_t room)
 930 {
 931         int len;
 932         uint32_t lvalue;
 933         uint8_t *ptr;
 934         DICT_VENDOR *dv;
 935
 936         /*
 937          *      RFC format attributes take the fast path.
 938          */
 939         if (vp->vendor == 0) {
 940                 return rad_vp2rfc(packet, original, secret, vp,
 941                                   vp->attribute, start, room);
 942         }
 943
 944         /*
 945          *      Not enough room for:
 946          *              attr, len, vendor-id, vsa, vsalen
 947          */
 948         if (room < 8) return 0;
 949
 950         /*
 951          *      Build the Vendor-Specific header
 952          */
 953         ptr = start;
 954         *ptr++ = PW_VENDOR_SPECIFIC;
 955         *ptr++ = 6;
 956         room -= 6;
 957         lvalue = htonl(vp->vendor);
 958         memcpy(ptr, &lvalue, 4);
 959         ptr += 4;
 960
 961         /*
 962          *      Unknown vendors, and type=1,length=1,no-continuation
 963          *      are RFC format attributes.
 964          */
 965         dv = dict_vendorbyvalue(vp->vendor);
 966         if (!dv ||
 967             ((dv->type == 1) && (dv->length = 1) && !dv->flags)) {
 968                 len = rad_vp2rfc(packet, original, secret, vp,
 969                                  vp->attribute, ptr, room);
 970                 if (len <= 0) return len;
 971
 972                 start[1] += len;
 973                 return start[1];
 974         }
 975
 976         if (room < (dv->type + dv->length + dv->flags)) return 0;
 977         room -= (dv->type + dv->length + dv->flags);
 978         start[1] += (dv->type + dv->length + dv->flags);
 979
 980         switch (dv->type) {
 981                 case 1:
 982                         ptr[0] = (vp->attribute & 0xFF);
 983                         break;
 984
 985                 case 2:
 986                         ptr[0] = ((vp->attribute >> 8) & 0xFF);
 987                         ptr[1] = (vp->attribute & 0xFF);
 988                         break;
 989
 990                 case 4:
 991                         ptr[0] = 0;
 992                         ptr[1] = ((vp->attribute >> 16) & 0xFF);
 993                         ptr[2] = ((vp->attribute >> 8) & 0xFF);
 994                         ptr[3] = (vp->attribute & 0xFF);
 995                         break;
 996
 997                 default:
 998                         return 0; /* silently discard it */
 999         }
1000         ptr += dv->type;
1001
1002         switch (dv->length) {
1003         case 0:
1004                 break;
1005         case 1:
1006                 ptr[0] = dv->type + 1;
1007                 break;
1008         case 2:
1009                 ptr[0] = 0;
1010                 ptr[1] = dv->type + 2;
1011                 break;
1012
1013         default:
1014                 return 0; /* silently discard it */
1015         }
1016         ptr += dv->length;
1017
1018         /*
1019          *      WiMAX attributes take their own path through the
1020          *      system.
1021          */
1022         if (dv->flags) return wimax2data(packet, original, secret, vp,
1023                                          start, room, ptr);
1024
1025         len = vp2data(packet, original, secret, vp, ptr, room);
1026         if (len <= 0) return len;
1027
1028         if (dv->length != 0) ptr[-1] += len;
1029
1030         start[1] += len;
1031
1032         return start[1];
1033 }
1034
1035 /*
1036  *  Swap 123a -> 0321
1037  */
1038 #define REORDER(x) ((x & 0xff00) << 8) | ((x & 0xff0000) >> 8) | ((x & 0xff000000 >> 24))
1039
1040
1041 /*
1042  *      Encode a WiMAX sub-TLV.  It must NOT be called for WiMAX
1043  *      attributes that are of type integer, string, etc.
1044  */
1045 static int rad_encode_wimax(const RADIUS_PACKET *packet,
1046                             const RADIUS_PACKET *original,
1047                             const char *secret, VALUE_PAIR *reply,
1048                             uint8_t *start, size_t room)
1049 {
1050         int len, redo;
1051         uint32_t lvalue;
1052         uint8_t *ptr = start, *vsa = start;
1053         uint32_t maxattr;
1054         VALUE_PAIR *vp = reply;
1055
1056         /*
1057          *      Swap the order of the WiMAX hacks, to make later
1058          *      comparisons easier.
1059          */
1060         maxattr = REORDER(vp->attribute);
1061
1062         /*
1063          *      Build the Vendor-Specific header
1064          */
1065         ptr = start;
1066         redo = 0;
1067
1068 redo_vsa:
1069         vsa = ptr;
1070
1071         if (room < 9) return 0;
1072         *ptr++ = PW_VENDOR_SPECIFIC;
1073         *ptr++ = 9;
1074         room -= 9;
1075         lvalue = htonl(vp->vendor);
1076         memcpy(ptr, &lvalue, 4);
1077         ptr += 4;
1078         *(ptr++) = vp->attribute & 0xff;
1079         *(ptr++) = 3;
1080         *(ptr++) = 0;           /* continuation */
1081         room -= 9;
1082
1083 redo_tlv:
1084         len = tlv2data(packet, original, secret, vp, ptr, room, 1);
1085         if (len < 0) return len;
1086
1087         /*
1088          *      Not enough room.  Do a continuation.
1089          */
1090         if ((len == 0) || ((vsa[VS_OFF] + len) > 255)) {
1091                 if (redo) return (start - vsa);
1092
1093                 vsa[8] = 0x80;
1094                 redo = 1;
1095                 goto redo_vsa;
1096         }
1097         redo = 0;
1098
1099         ptr += len;
1100         vsa[VS_OFF] += len;
1101         vsa[WM_OFF] += len;
1102
1103         vp->flags.encoded = 1;
1104         vp = vp->next;
1105
1106         /*
1107          *      Look at the NEXT tlv.  Ensure that we encode
1108          *      attributes into a common VSA *only* if they are for
1109          *      the same WiMAX VSA, AND if the TLVs are in numerically
1110          *      increasing order.
1111          */
1112         if (vp && vp->flags.is_tlv && (reply->vendor == vp->vendor) &&
1113             ((reply->attribute & 0xff) == (vp->attribute & 0xff))) {
1114                 uint32_t attr;
1115
1116                 attr = REORDER(vp->attribute);
1117                 if (attr >= maxattr) {
1118                         maxattr = attr;
1119                         goto redo_tlv;
1120                 }
1121         }
1122
1123         return ptr - start;
1124 }
1125
1126
1127 /*
1128  *      Encode a packet.
1129  */
1130 int rad_encode(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1131                const char *secret)
1132 {
1133         radius_packet_t *hdr;
1134         uint8_t         *ptr;
1135         uint16_t        total_length;
1136         int             len;
1137         VALUE_PAIR      *reply;
1138         const char      *what;
1139         char            ip_buffer[128];
1140
1141         /*
1142          *      A 4K packet, aligned on 64-bits.
1143          */
1144         uint64_t        data[MAX_PACKET_LEN / sizeof(uint64_t)];
1145
1146         if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1147                 what = fr_packet_codes[packet->code];
1148         } else {
1149                 what = "Reply";
1150         }
1151
1152         DEBUG("Sending %s of id %d to %s port %d\n",
1153               what, packet->id,
1154               inet_ntop(packet->dst_ipaddr.af,
1155                         &packet->dst_ipaddr.ipaddr,
1156                         ip_buffer, sizeof(ip_buffer)),
1157               packet->dst_port);
1158
1159         /*
1160          *      Double-check some things based on packet code.
1161          */
1162         switch (packet->code) {
1163         case PW_AUTHENTICATION_ACK:
1164         case PW_AUTHENTICATION_REJECT:
1165         case PW_ACCESS_CHALLENGE:
1166                 if (!original) {
1167                         fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1168                         return -1;
1169                 }
1170                 break;
1171
1172                 /*
1173                  *      These packet vectors start off as all zero.
1174                  */
1175         case PW_ACCOUNTING_REQUEST:
1176         case PW_DISCONNECT_REQUEST:
1177         case PW_COA_REQUEST:
1178                 memset(packet->vector, 0, sizeof(packet->vector));
1179                 break;
1180
1181         default:
1182                 break;
1183         }
1184
1185         /*
1186          *      Use memory on the stack, until we know how
1187          *      large the packet will be.
1188          */
1189         hdr = (radius_packet_t *) data;
1190
1191         /*
1192          *      Build standard header
1193          */
1194         hdr->code = packet->code;
1195         hdr->id = packet->id;
1196
1197         memcpy(hdr->vector, packet->vector, sizeof(hdr->vector));
1198
1199         total_length = AUTH_HDR_LEN;
1200
1201         /*
1202          *      Load up the configuration values for the user
1203          */
1204         ptr = hdr->data;
1205         packet->offset = 0;
1206
1207         /*
1208          *      FIXME: Loop twice over the reply list.  The first time,
1209          *      calculate the total length of data.  The second time,
1210          *      allocate the memory, and fill in the VP's.
1211          *
1212          *      Hmm... this may be slower than just doing a small
1213          *      memcpy.
1214          */
1215
1216         /*
1217          *      Loop over the reply attributes for the packet.
1218          */
1219         for (reply = packet->vps; reply; reply = reply->next) {
1220                 /*
1221                  *      Ignore non-wire attributes
1222                  */
1223                 if ((reply->vendor == 0) &&
1224                     ((reply->attribute & 0xFFFF) > 0xff)) {
1225 #ifndef NDEBUG
1226                         /*
1227                          *      Permit the admin to send BADLY formatted
1228                          *      attributes with a debug build.
1229                          */
1230                         if (reply->attribute == PW_RAW_ATTRIBUTE) {
1231                                 memcpy(ptr, reply->vp_octets, reply->length);
1232                                 len = reply->length;
1233                                 goto next;
1234                         }
1235 #endif
1236                         continue;
1237                 }
1238
1239                 /*
1240                  *      Set the Message-Authenticator to the correct
1241                  *      length and initial value.
1242                  */
1243                 if (reply->attribute == PW_MESSAGE_AUTHENTICATOR) {
1244                         reply->length = AUTH_VECTOR_LEN;
1245                         memset(reply->vp_strvalue, 0, AUTH_VECTOR_LEN);
1246
1247                         /*
1248                          *      Cache the offset to the
1249                          *      Message-Authenticator
1250                          */
1251                         packet->offset = total_length;
1252                 }
1253
1254                 /*
1255                  *      Print out ONLY the attributes which
1256                  *      we're sending over the wire, and print
1257                  *      them out BEFORE they're encrypted.
1258                  */
1259                 debug_pair(reply);
1260
1261                 /*
1262                  *      Skip attributes that are encoded.
1263                  */
1264                 if (reply->flags.encoded) continue;
1265
1266                 if (reply->flags.is_tlv) {
1267                         len = rad_encode_wimax(packet, original, secret,
1268                                                reply, ptr,
1269                                                ((uint8_t *) data) + sizeof(data) - ptr);
1270                 } else {
1271
1272                         len = rad_vp2attr(packet, original, secret, reply, ptr,
1273                                           ((uint8_t *) data) + sizeof(data) - ptr);
1274                 }
1275
1276                 if (len < 0) return -1;
1277
1278                 /*
1279                  *      Failed to encode the attribute, likely because
1280                  *      the packet is full.
1281                  */
1282                 if ((len == 0) &&
1283                     (total_length > (sizeof(data) - 2 - reply->length))) {
1284                         DEBUG("WARNING: Attributes are too long for packet.  Discarding data past %d bytes", total_length);
1285                         break;
1286                 }
1287
1288         next:
1289                 ptr += len;
1290                 total_length += len;
1291         } /* done looping over all attributes */
1292
1293         /*
1294          *      Fill in the rest of the fields, and copy the data over
1295          *      from the local stack to the newly allocated memory.
1296          *
1297          *      Yes, all this 'memcpy' is slow, but it means
1298          *      that we only allocate the minimum amount of
1299          *      memory for a request.
1300          */
1301         packet->data_len = total_length;
1302         packet->data = (uint8_t *) malloc(packet->data_len);
1303         if (!packet->data) {
1304                 fr_strerror_printf("Out of memory");
1305                 return -1;
1306         }
1307
1308         memcpy(packet->data, hdr, packet->data_len);
1309         hdr = (radius_packet_t *) packet->data;
1310
1311         total_length = htons(total_length);
1312         memcpy(hdr->length, &total_length, sizeof(total_length));
1313
1314         return 0;
1315 }
1316
1317
1318 /*
1319  *      Sign a previously encoded packet.
1320  */
1321 int rad_sign(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1322              const char *secret)
1323 {
1324         radius_packet_t *hdr = (radius_packet_t *)packet->data;
1325
1326         /*
1327          *      It wasn't assigned an Id, this is bad!
1328          */
1329         if (packet->id < 0) {
1330                 fr_strerror_printf("ERROR: RADIUS packets must be assigned an Id.");
1331                 return -1;
1332         }
1333
1334         if (!packet->data || (packet->data_len < AUTH_HDR_LEN) ||
1335             (packet->offset < 0)) {
1336                 fr_strerror_printf("ERROR: You must call rad_encode() before rad_sign()");
1337                 return -1;
1338         }
1339
1340         /*
1341          *      If there's a Message-Authenticator, update it
1342          *      now, BEFORE updating the authentication vector.
1343          */
1344         if (packet->offset > 0) {
1345                 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
1346
1347                 switch (packet->code) {
1348                 case PW_ACCOUNTING_REQUEST:
1349                 case PW_ACCOUNTING_RESPONSE:
1350                 case PW_DISCONNECT_REQUEST:
1351                 case PW_DISCONNECT_ACK:
1352                 case PW_DISCONNECT_NAK:
1353                 case PW_COA_REQUEST:
1354                 case PW_COA_ACK:
1355                 case PW_COA_NAK:
1356                         memset(hdr->vector, 0, AUTH_VECTOR_LEN);
1357                         break;
1358
1359                 case PW_AUTHENTICATION_ACK:
1360                 case PW_AUTHENTICATION_REJECT:
1361                 case PW_ACCESS_CHALLENGE:
1362                         if (!original) {
1363                                 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1364                                 return -1;
1365                         }
1366                         memcpy(hdr->vector, original->vector,
1367                                AUTH_VECTOR_LEN);
1368                         break;
1369
1370                 default:        /* others have vector already set to zero */
1371                         break;
1372
1373                 }
1374
1375                 /*
1376                  *      Set the authentication vector to zero,
1377                  *      calculate the signature, and put it
1378                  *      into the Message-Authenticator
1379                  *      attribute.
1380                  */
1381                 fr_hmac_md5(packet->data, packet->data_len,
1382                             (const uint8_t *) secret, strlen(secret),
1383                             calc_auth_vector);
1384                 memcpy(packet->data + packet->offset + 2,
1385                        calc_auth_vector, AUTH_VECTOR_LEN);
1386
1387                 /*
1388                  *      Copy the original request vector back
1389                  *      to the raw packet.
1390                  */
1391                 memcpy(hdr->vector, packet->vector, AUTH_VECTOR_LEN);
1392         }
1393
1394         /*
1395          *      Switch over the packet code, deciding how to
1396          *      sign the packet.
1397          */
1398         switch (packet->code) {
1399                 /*
1400                  *      Request packets are not signed, bur
1401                  *      have a random authentication vector.
1402                  */
1403         case PW_AUTHENTICATION_REQUEST:
1404         case PW_STATUS_SERVER:
1405                 break;
1406
1407                 /*
1408                  *      Reply packets are signed with the
1409                  *      authentication vector of the request.
1410                  */
1411         default:
1412                 {
1413                         uint8_t digest[16];
1414
1415                         FR_MD5_CTX      context;
1416                         fr_MD5Init(&context);
1417                         fr_MD5Update(&context, packet->data, packet->data_len);
1418                         fr_MD5Update(&context, (const uint8_t *) secret,
1419                                      strlen(secret));
1420                         fr_MD5Final(digest, &context);
1421
1422                         memcpy(hdr->vector, digest, AUTH_VECTOR_LEN);
1423                         memcpy(packet->vector, digest, AUTH_VECTOR_LEN);
1424                         break;
1425                 }
1426         }/* switch over packet codes */
1427
1428         return 0;
1429 }
1430
1431 /*
1432  *      Reply to the request.  Also attach
1433  *      reply attribute value pairs and any user message provided.
1434  */
1435 int rad_send(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1436              const char *secret)
1437 {
1438         VALUE_PAIR              *reply;
1439         const char              *what;
1440         char                    ip_buffer[128];
1441
1442         /*
1443          *      Maybe it's a fake packet.  Don't send it.
1444          */
1445         if (!packet || (packet->sockfd < 0)) {
1446                 return 0;
1447         }
1448
1449         if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1450                 what = fr_packet_codes[packet->code];
1451         } else {
1452                 what = "Reply";
1453         }
1454
1455         /*
1456          *  First time through, allocate room for the packet
1457          */
1458         if (!packet->data) {
1459                 /*
1460                  *      Encode the packet.
1461                  */
1462                 if (rad_encode(packet, original, secret) < 0) {
1463                         return -1;
1464                 }
1465
1466                 /*
1467                  *      Re-sign it, including updating the
1468                  *      Message-Authenticator.
1469                  */
1470                 if (rad_sign(packet, original, secret) < 0) {
1471                         return -1;
1472                 }
1473
1474                 /*
1475                  *      If packet->data points to data, then we print out
1476                  *      the VP list again only for debugging.
1477                  */
1478         } else if (fr_debug_flag) {
1479                 DEBUG("Sending %s of id %d to %s port %d\n", what, packet->id,
1480                       inet_ntop(packet->dst_ipaddr.af,
1481                                 &packet->dst_ipaddr.ipaddr,
1482                                 ip_buffer, sizeof(ip_buffer)),
1483                       packet->dst_port);
1484
1485                 for (reply = packet->vps; reply; reply = reply->next) {
1486                         if ((reply->vendor == 0) &&
1487                             ((reply->attribute & 0xFFFF) > 0xff)) continue;
1488                         debug_pair(reply);
1489                 }
1490         }
1491
1492         /*
1493          *      And send it on it's way.
1494          */
1495         return rad_sendto(packet->sockfd, packet->data, packet->data_len, 0,
1496                           &packet->src_ipaddr, packet->src_port,
1497                           &packet->dst_ipaddr, packet->dst_port);
1498 }
1499
1500 /*
1501  *      Do a comparison of two authentication digests by comparing
1502  *      the FULL digest.  Otehrwise, the server can be subject to
1503  *      timing attacks that allow attackers find a valid message
1504  *      authenticator.
1505  *
1506  *      http://www.cs.rice.edu/~dwallach/pub/crosby-timing2009.pdf
1507  */
1508 static int digest_cmp(const uint8_t *a, const uint8_t *b, size_t length)
1509 {
1510         int result = 0;
1511         size_t i;
1512
1513         for (i = 0; i < length; i++) {
1514                 result |= a[i] ^ b[i];
1515         }
1516
1517         return result;          /* 0 is OK, !0 is !OK, just like memcmp */
1518 }
1519
1520
1521 /*
1522  *      Validates the requesting client NAS.  Calculates the
1523  *      signature based on the clients private key.
1524  */
1525 static int calc_acctdigest(RADIUS_PACKET *packet, const char *secret)
1526 {
1527         uint8_t         digest[AUTH_VECTOR_LEN];
1528         FR_MD5_CTX              context;
1529
1530         /*
1531          *      Zero out the auth_vector in the received packet.
1532          *      Then append the shared secret to the received packet,
1533          *      and calculate the MD5 sum. This must be the same
1534          *      as the original MD5 sum (packet->vector).
1535          */
1536         memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
1537
1538         /*
1539          *  MD5(packet + secret);
1540          */
1541         fr_MD5Init(&context);
1542         fr_MD5Update(&context, packet->data, packet->data_len);
1543         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1544         fr_MD5Final(digest, &context);
1545
1546         /*
1547          *      Return 0 if OK, 2 if not OK.
1548          */
1549         if (digest_cmp(digest, packet->vector, AUTH_VECTOR_LEN) != 0) return 2;
1550         return 0;
1551 }
1552
1553
1554 /*
1555  *      Validates the requesting client NAS.  Calculates the
1556  *      signature based on the clients private key.
1557  */
1558 static int calc_replydigest(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1559                             const char *secret)
1560 {
1561         uint8_t         calc_digest[AUTH_VECTOR_LEN];
1562         FR_MD5_CTX              context;
1563
1564         /*
1565          *      Very bad!
1566          */
1567         if (original == NULL) {
1568                 return 3;
1569         }
1570
1571         /*
1572          *  Copy the original vector in place.
1573          */
1574         memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
1575
1576         /*
1577          *  MD5(packet + secret);
1578          */
1579         fr_MD5Init(&context);
1580         fr_MD5Update(&context, packet->data, packet->data_len);
1581         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1582         fr_MD5Final(calc_digest, &context);
1583
1584         /*
1585          *  Copy the packet's vector back to the packet.
1586          */
1587         memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
1588
1589         /*
1590          *      Return 0 if OK, 2 if not OK.
1591          */
1592         if (digest_cmp(packet->vector, calc_digest, AUTH_VECTOR_LEN) != 0) return 2;
1593         return 0;
1594 }
1595
1596
1597 /*
1598  *      See if the data pointed to by PTR is a valid RADIUS packet.
1599  *
1600  *      packet is not 'const * const' because we may update data_len,
1601  *      if there's more data in the UDP packet than in the RADIUS packet.
1602  */
1603 int rad_packet_ok(RADIUS_PACKET *packet, int flags)
1604 {
1605         uint8_t                 *attr;
1606         int                     totallen;
1607         int                     count;
1608         radius_packet_t         *hdr;
1609         char                    host_ipaddr[128];
1610         int                     require_ma = 0;
1611         int                     seen_ma = 0;
1612         int                     num_attributes;
1613
1614         /*
1615          *      Check for packets smaller than the packet header.
1616          *
1617          *      RFC 2865, Section 3., subsection 'length' says:
1618          *
1619          *      "The minimum length is 20 ..."
1620          */
1621         if (packet->data_len < AUTH_HDR_LEN) {
1622                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (received %d < minimum %d)",
1623                            inet_ntop(packet->src_ipaddr.af,
1624                                      &packet->src_ipaddr.ipaddr,
1625                                      host_ipaddr, sizeof(host_ipaddr)),
1626                                    (int) packet->data_len, AUTH_HDR_LEN);
1627                 return 0;
1628         }
1629
1630         /*
1631          *      RFC 2865, Section 3., subsection 'length' says:
1632          *
1633          *      " ... and maximum length is 4096."
1634          */
1635         if (packet->data_len > MAX_PACKET_LEN) {
1636                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (received %d > maximum %d)",
1637                            inet_ntop(packet->src_ipaddr.af,
1638                                      &packet->src_ipaddr.ipaddr,
1639                                      host_ipaddr, sizeof(host_ipaddr)),
1640                                    (int) packet->data_len, MAX_PACKET_LEN);
1641                 return 0;
1642         }
1643
1644         /*
1645          *      Check for packets with mismatched size.
1646          *      i.e. We've received 128 bytes, and the packet header
1647          *      says it's 256 bytes long.
1648          */
1649         totallen = (packet->data[2] << 8) | packet->data[3];
1650         hdr = (radius_packet_t *)packet->data;
1651
1652         /*
1653          *      Code of 0 is not understood.
1654          *      Code of 16 or greate is not understood.
1655          */
1656         if ((hdr->code == 0) ||
1657             (hdr->code >= FR_MAX_PACKET_CODE)) {
1658                 fr_strerror_printf("WARNING: Bad RADIUS packet from host %s: unknown packet code%d ",
1659                            inet_ntop(packet->src_ipaddr.af,
1660                                      &packet->src_ipaddr.ipaddr,
1661                                      host_ipaddr, sizeof(host_ipaddr)),
1662                            hdr->code);
1663                 return 0;
1664         }
1665
1666         /*
1667          *      Message-Authenticator is required in Status-Server
1668          *      packets, otherwise they can be trivially forged.
1669          */
1670         if (hdr->code == PW_STATUS_SERVER) require_ma = 1;
1671
1672         /*
1673          *      It's also required if the caller asks for it.
1674          */
1675         if (flags) require_ma = 1;
1676
1677         /*
1678          *      Repeat the length checks.  This time, instead of
1679          *      looking at the data we received, look at the value
1680          *      of the 'length' field inside of the packet.
1681          *
1682          *      Check for packets smaller than the packet header.
1683          *
1684          *      RFC 2865, Section 3., subsection 'length' says:
1685          *
1686          *      "The minimum length is 20 ..."
1687          */
1688         if (totallen < AUTH_HDR_LEN) {
1689                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (length %d < minimum %d)",
1690                            inet_ntop(packet->src_ipaddr.af,
1691                                      &packet->src_ipaddr.ipaddr,
1692                                      host_ipaddr, sizeof(host_ipaddr)),
1693                            totallen, AUTH_HDR_LEN);
1694                 return 0;
1695         }
1696
1697         /*
1698          *      And again, for the value of the 'length' field.
1699          *
1700          *      RFC 2865, Section 3., subsection 'length' says:
1701          *
1702          *      " ... and maximum length is 4096."
1703          */
1704         if (totallen > MAX_PACKET_LEN) {
1705                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (length %d > maximum %d)",
1706                            inet_ntop(packet->src_ipaddr.af,
1707                                      &packet->src_ipaddr.ipaddr,
1708                                      host_ipaddr, sizeof(host_ipaddr)),
1709                            totallen, MAX_PACKET_LEN);
1710                 return 0;
1711         }
1712
1713         /*
1714          *      RFC 2865, Section 3., subsection 'length' says:
1715          *
1716          *      "If the packet is shorter than the Length field
1717          *      indicates, it MUST be silently discarded."
1718          *
1719          *      i.e. No response to the NAS.
1720          */
1721         if (packet->data_len < totallen) {
1722                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: received %d octets, packet length says %d",
1723                            inet_ntop(packet->src_ipaddr.af,
1724                                      &packet->src_ipaddr.ipaddr,
1725                                      host_ipaddr, sizeof(host_ipaddr)),
1726                                    (int) packet->data_len, totallen);
1727                 return 0;
1728         }
1729
1730         /*
1731          *      RFC 2865, Section 3., subsection 'length' says:
1732          *
1733          *      "Octets outside the range of the Length field MUST be
1734          *      treated as padding and ignored on reception."
1735          */
1736         if (packet->data_len > totallen) {
1737                 /*
1738                  *      We're shortening the packet below, but just
1739                  *      to be paranoid, zero out the extra data.
1740                  */
1741                 memset(packet->data + totallen, 0, packet->data_len - totallen);
1742                 packet->data_len = totallen;
1743         }
1744
1745         /*
1746          *      Walk through the packet's attributes, ensuring that
1747          *      they add up EXACTLY to the size of the packet.
1748          *
1749          *      If they don't, then the attributes either under-fill
1750          *      or over-fill the packet.  Any parsing of the packet
1751          *      is impossible, and will result in unknown side effects.
1752          *
1753          *      This would ONLY happen with buggy RADIUS implementations,
1754          *      or with an intentional attack.  Either way, we do NOT want
1755          *      to be vulnerable to this problem.
1756          */
1757         attr = hdr->data;
1758         count = totallen - AUTH_HDR_LEN;
1759         num_attributes = 0;
1760
1761         while (count > 0) {
1762                 /*
1763                  *      We need at least 2 bytes to check the
1764                  *      attribute header.
1765                  */
1766                 if (count < 2) {
1767                         fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute header overflows the packet",
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                  *      Attribute number zero is NOT defined.
1776                  */
1777                 if (attr[0] == 0) {
1778                         fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Invalid attribute 0",
1779                                    inet_ntop(packet->src_ipaddr.af,
1780                                              &packet->src_ipaddr.ipaddr,
1781                                              host_ipaddr, sizeof(host_ipaddr)));
1782                         return 0;
1783                 }
1784
1785                 /*
1786                  *      Attributes are at LEAST as long as the ID & length
1787                  *      fields.  Anything shorter is an invalid attribute.
1788                  */
1789                 if (attr[1] < 2) {
1790                         fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %u too short",
1791                                    inet_ntop(packet->src_ipaddr.af,
1792                                              &packet->src_ipaddr.ipaddr,
1793                                              host_ipaddr, sizeof(host_ipaddr)),
1794                                    attr[0]);
1795                         return 0;
1796                 }
1797
1798                 /*
1799                  *      If there are fewer bytes in the packet than in the
1800                  *      attribute, it's a bad packet.
1801                  */
1802                 if (count < attr[1]) {
1803                         fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %u data overflows the packet",
1804                                    inet_ntop(packet->src_ipaddr.af,
1805                                              &packet->src_ipaddr.ipaddr,
1806                                              host_ipaddr, sizeof(host_ipaddr)),
1807                                            attr[0]);
1808                         return 0;
1809                 }
1810
1811                 /*
1812                  *      Sanity check the attributes for length.
1813                  */
1814                 switch (attr[0]) {
1815                 default:        /* don't do anything by default */
1816                         break;
1817
1818                         /*
1819                          *      If there's an EAP-Message, we require
1820                          *      a Message-Authenticator.
1821                          */
1822                 case PW_EAP_MESSAGE:
1823                         require_ma = 1;
1824                         break;
1825
1826                 case PW_MESSAGE_AUTHENTICATOR:
1827                         if (attr[1] != 2 + AUTH_VECTOR_LEN) {
1828                                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Message-Authenticator has invalid length %d",
1829                                            inet_ntop(packet->src_ipaddr.af,
1830                                                      &packet->src_ipaddr.ipaddr,
1831                                                      host_ipaddr, sizeof(host_ipaddr)),
1832                                            attr[1] - 2);
1833                                 return 0;
1834                         }
1835                         seen_ma = 1;
1836                         break;
1837                 }
1838
1839                 /*
1840                  *      FIXME: Look up the base 255 attributes in the
1841                  *      dictionary, and switch over their type.  For
1842                  *      integer/date/ip, the attribute length SHOULD
1843                  *      be 6.
1844                  */
1845                 count -= attr[1];       /* grab the attribute length */
1846                 attr += attr[1];
1847                 num_attributes++;       /* seen one more attribute */
1848         }
1849
1850         /*
1851          *      If the attributes add up to a packet, it's allowed.
1852          *
1853          *      If not, we complain, and throw the packet away.
1854          */
1855         if (count != 0) {
1856                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: packet attributes do NOT exactly fill the packet",
1857                            inet_ntop(packet->src_ipaddr.af,
1858                                      &packet->src_ipaddr.ipaddr,
1859                                      host_ipaddr, sizeof(host_ipaddr)));
1860                 return 0;
1861         }
1862
1863         /*
1864          *      If we're configured to look for a maximum number of
1865          *      attributes, and we've seen more than that maximum,
1866          *      then throw the packet away, as a possible DoS.
1867          */
1868         if ((fr_max_attributes > 0) &&
1869             (num_attributes > fr_max_attributes)) {
1870                 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
1871                            inet_ntop(packet->src_ipaddr.af,
1872                                      &packet->src_ipaddr.ipaddr,
1873                                      host_ipaddr, sizeof(host_ipaddr)),
1874                            num_attributes, fr_max_attributes);
1875                 return 0;
1876         }
1877
1878         /*
1879          *      http://www.freeradius.org/rfc/rfc2869.html#EAP-Message
1880          *
1881          *      A packet with an EAP-Message attribute MUST also have
1882          *      a Message-Authenticator attribute.
1883          *
1884          *      A Message-Authenticator all by itself is OK, though.
1885          *
1886          *      Similarly, Status-Server packets MUST contain
1887          *      Message-Authenticator attributes.
1888          */
1889         if (require_ma && ! seen_ma) {
1890                 fr_strerror_printf("WARNING: Insecure packet from host %s:  Packet does not contain required Message-Authenticator attribute",
1891                            inet_ntop(packet->src_ipaddr.af,
1892                                      &packet->src_ipaddr.ipaddr,
1893                                      host_ipaddr, sizeof(host_ipaddr)));
1894                 return 0;
1895         }
1896
1897         /*
1898          *      Fill RADIUS header fields
1899          */
1900         packet->code = hdr->code;
1901         packet->id = hdr->id;
1902         memcpy(packet->vector, hdr->vector, AUTH_VECTOR_LEN);
1903
1904         return 1;
1905 }
1906
1907
1908 /*
1909  *      Receive UDP client requests, and fill in
1910  *      the basics of a RADIUS_PACKET structure.
1911  */
1912 RADIUS_PACKET *rad_recv(int fd, int flags)
1913 {
1914         int sock_flags = 0;
1915         RADIUS_PACKET           *packet;
1916
1917         /*
1918          *      Allocate the new request data structure
1919          */
1920         if ((packet = malloc(sizeof(*packet))) == NULL) {
1921                 fr_strerror_printf("out of memory");
1922                 return NULL;
1923         }
1924         memset(packet, 0, sizeof(*packet));
1925
1926         if (flags & 0x02) {
1927                 sock_flags = MSG_PEEK;
1928                 flags &= ~0x02;
1929         }
1930
1931         packet->data_len = rad_recvfrom(fd, &packet->data, sock_flags,
1932                                         &packet->src_ipaddr, &packet->src_port,
1933                                         &packet->dst_ipaddr, &packet->dst_port);
1934
1935         /*
1936          *      Check for socket errors.
1937          */
1938         if (packet->data_len < 0) {
1939                 fr_strerror_printf("Error receiving packet: %s", strerror(errno));
1940                 /* packet->data is NULL */
1941                 free(packet);
1942                 return NULL;
1943         }
1944
1945         /*
1946          *      If the packet is too big, then rad_recvfrom did NOT
1947          *      allocate memory.  Instead, it just discarded the
1948          *      packet.
1949          */
1950         if (packet->data_len > MAX_PACKET_LEN) {
1951                 fr_strerror_printf("Discarding packet: Larger than RFC limitation of 4096 bytes.");
1952                 /* packet->data is NULL */
1953                 free(packet);
1954                 return NULL;
1955         }
1956
1957         /*
1958          *      Read no data.  Continue.
1959          *      This check is AFTER the MAX_PACKET_LEN check above, because
1960          *      if the packet is larger than MAX_PACKET_LEN, we also have
1961          *      packet->data == NULL
1962          */
1963         if ((packet->data_len == 0) || !packet->data) {
1964                 fr_strerror_printf("Empty packet: Socket is not ready.");
1965                 free(packet);
1966                 return NULL;
1967         }
1968
1969         /*
1970          *      See if it's a well-formed RADIUS packet.
1971          */
1972         if (!rad_packet_ok(packet, flags)) {
1973                 rad_free(&packet);
1974                 return NULL;
1975         }
1976
1977         /*
1978          *      Remember which socket we read the packet from.
1979          */
1980         packet->sockfd = fd;
1981
1982         /*
1983          *      FIXME: Do even more filtering by only permitting
1984          *      certain IP's.  The problem is that we don't know
1985          *      how to do this properly for all possible clients...
1986          */
1987
1988         /*
1989          *      Explicitely set the VP list to empty.
1990          */
1991         packet->vps = NULL;
1992
1993         if (fr_debug_flag) {
1994                 char host_ipaddr[128];
1995
1996                 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1997                         DEBUG("rad_recv: %s packet from host %s port %d",
1998                               fr_packet_codes[packet->code],
1999                               inet_ntop(packet->src_ipaddr.af,
2000                                         &packet->src_ipaddr.ipaddr,
2001                                         host_ipaddr, sizeof(host_ipaddr)),
2002                               packet->src_port);
2003                 } else {
2004                         DEBUG("rad_recv: Packet from host %s port %d code=%d",
2005                               inet_ntop(packet->src_ipaddr.af,
2006                                         &packet->src_ipaddr.ipaddr,
2007                                         host_ipaddr, sizeof(host_ipaddr)),
2008                               packet->src_port,
2009                               packet->code);
2010                 }
2011                 DEBUG(", id=%d, length=%d\n",
2012                       packet->id, (int) packet->data_len);
2013         }
2014
2015         return packet;
2016 }
2017
2018
2019 /*
2020  *      Verify the signature of a packet.
2021  */
2022 int rad_verify(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2023                const char *secret)
2024 {
2025         uint8_t                 *ptr;
2026         int                     length;
2027         int                     attrlen;
2028
2029         if (!packet || !packet->data) return -1;
2030
2031         /*
2032          *      Before we allocate memory for the attributes, do more
2033          *      sanity checking.
2034          */
2035         ptr = packet->data + AUTH_HDR_LEN;
2036         length = packet->data_len - AUTH_HDR_LEN;
2037         while (length > 0) {
2038                 uint8_t msg_auth_vector[AUTH_VECTOR_LEN];
2039                 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
2040
2041                 attrlen = ptr[1];
2042
2043                 switch (ptr[0]) {
2044                 default:        /* don't do anything. */
2045                         break;
2046
2047                         /*
2048                          *      Note that more than one Message-Authenticator
2049                          *      attribute is invalid.
2050                          */
2051                 case PW_MESSAGE_AUTHENTICATOR:
2052                         memcpy(msg_auth_vector, &ptr[2], sizeof(msg_auth_vector));
2053                         memset(&ptr[2], 0, AUTH_VECTOR_LEN);
2054
2055                         switch (packet->code) {
2056                         default:
2057                                 break;
2058
2059                         case PW_ACCOUNTING_REQUEST:
2060                         case PW_ACCOUNTING_RESPONSE:
2061                         case PW_DISCONNECT_REQUEST:
2062                         case PW_DISCONNECT_ACK:
2063                         case PW_DISCONNECT_NAK:
2064                         case PW_COA_REQUEST:
2065                         case PW_COA_ACK:
2066                         case PW_COA_NAK:
2067                                 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
2068                                 break;
2069
2070                         case PW_AUTHENTICATION_ACK:
2071                         case PW_AUTHENTICATION_REJECT:
2072                         case PW_ACCESS_CHALLENGE:
2073                                 if (!original) {
2074                                         fr_strerror_printf("ERROR: Cannot validate Message-Authenticator in response packet without a request packet.");
2075                                         return -1;
2076                                 }
2077                                 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
2078                                 break;
2079                         }
2080
2081                         fr_hmac_md5(packet->data, packet->data_len,
2082                                     (const uint8_t *) secret, strlen(secret),
2083                                     calc_auth_vector);
2084                         if (digest_cmp(calc_auth_vector, msg_auth_vector,
2085                                    sizeof(calc_auth_vector)) != 0) {
2086                                 char buffer[32];
2087                                 fr_strerror_printf("Received packet from %s with invalid Message-Authenticator!  (Shared secret is incorrect.)",
2088                                            inet_ntop(packet->src_ipaddr.af,
2089                                                      &packet->src_ipaddr.ipaddr,
2090                                                      buffer, sizeof(buffer)));
2091                                 /* Silently drop packet, according to RFC 3579 */
2092                                 return -1;
2093                         } /* else the message authenticator was good */
2094
2095                         /*
2096                          *      Reinitialize Authenticators.
2097                          */
2098                         memcpy(&ptr[2], msg_auth_vector, AUTH_VECTOR_LEN);
2099                         memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
2100                         break;
2101                 } /* switch over the attributes */
2102
2103                 ptr += attrlen;
2104                 length -= attrlen;
2105         } /* loop over the packet, sanity checking the attributes */
2106
2107         /*
2108          *      It looks like a RADIUS packet, but we can't validate
2109          *      the signature.
2110          */
2111         if ((packet->code == 0) || (packet->code >= FR_MAX_PACKET_CODE)) {
2112                 char buffer[32];
2113                 fr_strerror_printf("Received Unknown packet code %d "
2114                            "from client %s port %d: Cannot validate signature.",
2115                            packet->code,
2116                            inet_ntop(packet->src_ipaddr.af,
2117                                      &packet->src_ipaddr.ipaddr,
2118                                      buffer, sizeof(buffer)),
2119                            packet->src_port);
2120                 return -1;
2121         }
2122
2123         /*
2124          *      Calculate and/or verify digest.
2125          */
2126         switch(packet->code) {
2127                 int rcode;
2128                 char buffer[32];
2129
2130                 case PW_AUTHENTICATION_REQUEST:
2131                 case PW_STATUS_SERVER:
2132                         /*
2133                          *      The authentication vector is random
2134                          *      nonsense, invented by the client.
2135                          */
2136                         break;
2137
2138                 case PW_COA_REQUEST:
2139                 case PW_DISCONNECT_REQUEST:
2140                 case PW_ACCOUNTING_REQUEST:
2141                         if (calc_acctdigest(packet, secret) > 1) {
2142                                 fr_strerror_printf("Received %s packet "
2143                                            "from client %s with invalid signature!  (Shared secret is incorrect.)",
2144                                            fr_packet_codes[packet->code],
2145                                            inet_ntop(packet->src_ipaddr.af,
2146                                                      &packet->src_ipaddr.ipaddr,
2147                                                      buffer, sizeof(buffer)));
2148                                 return -1;
2149                         }
2150                         break;
2151
2152                         /* Verify the reply digest */
2153                 case PW_AUTHENTICATION_ACK:
2154                 case PW_AUTHENTICATION_REJECT:
2155                 case PW_ACCESS_CHALLENGE:
2156                 case PW_ACCOUNTING_RESPONSE:
2157                 case PW_DISCONNECT_ACK:
2158                 case PW_DISCONNECT_NAK:
2159                 case PW_COA_ACK:
2160                 case PW_COA_NAK:
2161                         rcode = calc_replydigest(packet, original, secret);
2162                         if (rcode > 1) {
2163                                 fr_strerror_printf("Received %s packet "
2164                                            "from home server %s port %d with invalid signature!  (Shared secret is incorrect.)",
2165                                            fr_packet_codes[packet->code],
2166                                            inet_ntop(packet->src_ipaddr.af,
2167                                                      &packet->src_ipaddr.ipaddr,
2168                                                      buffer, sizeof(buffer)),
2169                                            packet->src_port);
2170                                 return -1;
2171                         }
2172                         break;
2173
2174                 default:
2175                         fr_strerror_printf("Received Unknown packet code %d "
2176                                    "from client %s port %d: Cannot validate signature",
2177                                    packet->code,
2178                                    inet_ntop(packet->src_ipaddr.af,
2179                                              &packet->src_ipaddr.ipaddr,
2180                                                      buffer, sizeof(buffer)),
2181                                    packet->src_port);
2182                         return -1;
2183         }
2184
2185         return 0;
2186 }
2187
2188
2189 static VALUE_PAIR *data2vp(const RADIUS_PACKET *packet,
2190                            const RADIUS_PACKET *original,
2191                            const char *secret, size_t length,
2192                            const uint8_t *data, VALUE_PAIR *vp)
2193 {
2194         int offset = 0;
2195
2196         /*
2197          *      If length is greater than 253, something is SERIOUSLY
2198          *      wrong.
2199          */
2200         if (length > 253) length = 253; /* paranoia (pair-anoia?) */
2201
2202         vp->length = length;
2203         vp->operator = T_OP_EQ;
2204         vp->next = NULL;
2205
2206         /*
2207          *      It's supposed to be a fixed length, but we found
2208          *      a different length instead.  Make it type "octets",
2209          *      and do no more processing on it.
2210          */
2211         if ((vp->flags.length > 0) && (vp->flags.length != length)) {
2212                 goto raw;
2213         }
2214
2215         /*
2216          *      Handle tags.
2217          */
2218         if (vp->flags.has_tag) {
2219                 if (TAG_VALID(data[0]) ||
2220                     (vp->flags.encrypt == FLAG_ENCRYPT_TUNNEL_PASSWORD)) {
2221                         /*
2222                          *      Tunnel passwords REQUIRE a tag, even
2223                          *      if don't have a valid tag.
2224                          */
2225                         vp->flags.tag = data[0];
2226
2227                         if ((vp->type == PW_TYPE_STRING) ||
2228                             (vp->type == PW_TYPE_OCTETS)) {
2229                                 if (length == 0) goto raw;
2230                                 offset = 1;
2231                         }
2232                 }
2233         }
2234
2235         /*
2236          *      Copy the data to be decrypted
2237          */
2238         memcpy(&vp->vp_octets[0], data + offset, length - offset);
2239         vp->length -= offset;
2240
2241         /*
2242          *      Decrypt the attribute.
2243          */
2244         switch (vp->flags.encrypt) {
2245                 /*
2246                  *  User-Password
2247                  */
2248         case FLAG_ENCRYPT_USER_PASSWORD:
2249                 if (original) {
2250                         rad_pwdecode((char *)vp->vp_strvalue,
2251                                      vp->length, secret,
2252                                      original->vector);
2253                 } else {
2254                         rad_pwdecode((char *)vp->vp_strvalue,
2255                                      vp->length, secret,
2256                                      packet->vector);
2257                 }
2258                 if (vp->attribute == PW_USER_PASSWORD) {
2259                         vp->length = strlen(vp->vp_strvalue);
2260                 }
2261                 break;
2262
2263                 /*
2264                  *      Tunnel-Password's may go ONLY
2265                  *      in response packets.
2266                  */
2267         case FLAG_ENCRYPT_TUNNEL_PASSWORD:
2268                 if (!original) goto raw;
2269
2270                 if (rad_tunnel_pwdecode(vp->vp_octets, &vp->length,
2271                                         secret, original->vector) < 0) {
2272                         goto raw;
2273                 }
2274                 break;
2275
2276                 /*
2277                  *  Ascend-Send-Secret
2278                  *  Ascend-Receive-Secret
2279                  */
2280         case FLAG_ENCRYPT_ASCEND_SECRET:
2281                 if (!original) {
2282                         goto raw;
2283                 } else {
2284                         uint8_t my_digest[AUTH_VECTOR_LEN];
2285                         make_secret(my_digest,
2286                                     original->vector,
2287                                     secret, data);
2288                         memcpy(vp->vp_strvalue, my_digest,
2289                                AUTH_VECTOR_LEN );
2290                         vp->vp_strvalue[AUTH_VECTOR_LEN] = '\0';
2291                         vp->length = strlen(vp->vp_strvalue);
2292                 }
2293                 break;
2294
2295         default:
2296                 break;
2297         } /* switch over encryption flags */
2298
2299
2300         switch (vp->type) {
2301         case PW_TYPE_STRING:
2302         case PW_TYPE_OCTETS:
2303         case PW_TYPE_ABINARY:
2304                 /* nothing more to do */
2305                 break;
2306
2307         case PW_TYPE_BYTE:
2308                 if (vp->length != 1) goto raw;
2309
2310                 vp->vp_integer = vp->vp_octets[0];
2311                 break;
2312
2313
2314         case PW_TYPE_SHORT:
2315                 if (vp->length != 2) goto raw;
2316
2317                 vp->vp_integer = (vp->vp_octets[0] << 8) | vp->vp_octets[1];
2318                 break;
2319
2320         case PW_TYPE_INTEGER:
2321                 if (vp->length != 4) goto raw;
2322
2323                 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2324                 vp->vp_integer = ntohl(vp->vp_integer);
2325
2326                 if (vp->flags.has_tag) vp->vp_integer &= 0x00ffffff;
2327
2328                 /*
2329                  *      Try to get named VALUEs
2330                  */
2331                 {
2332                         DICT_VALUE *dval;
2333                         dval = dict_valbyattr(vp->attribute, vp->vendor,
2334                                               vp->vp_integer);
2335                         if (dval) {
2336                                 strlcpy(vp->vp_strvalue,
2337                                         dval->name,
2338                                         sizeof(vp->vp_strvalue));
2339                         }
2340                 }
2341                 break;
2342
2343         case PW_TYPE_DATE:
2344                 if (vp->length != 4) goto raw;
2345
2346                 memcpy(&vp->vp_date, vp->vp_octets, 4);
2347                 vp->vp_date = ntohl(vp->vp_date);
2348                 break;
2349
2350
2351         case PW_TYPE_IPADDR:
2352                 if (vp->length != 4) goto raw;
2353
2354                 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2355                 break;
2356
2357                 /*
2358                  *      IPv6 interface ID is 8 octets long.
2359                  */
2360         case PW_TYPE_IFID:
2361                 if (vp->length != 8) goto raw;
2362                 /* vp->vp_ifid == vp->vp_octets */
2363                 break;
2364
2365                 /*
2366                  *      IPv6 addresses are 16 octets long
2367                  */
2368         case PW_TYPE_IPV6ADDR:
2369                 if (vp->length != 16) goto raw;
2370                 /* vp->vp_ipv6addr == vp->vp_octets */
2371                 break;
2372
2373                 /*
2374                  *      IPv6 prefixes are 2 to 18 octets long.
2375                  *
2376                  *      RFC 3162: The first octet is unused.
2377                  *      The second is the length of the prefix
2378                  *      the rest are the prefix data.
2379                  *
2380                  *      The prefix length can have value 0 to 128.
2381                  */
2382         case PW_TYPE_IPV6PREFIX:
2383                 if (vp->length < 2 || vp->length > 18) goto raw;
2384                 if (vp->vp_octets[1] > 128) goto raw;
2385
2386                 /*
2387                  *      FIXME: double-check that
2388                  *      (vp->vp_octets[1] >> 3) matches vp->length + 2
2389                  */
2390                 if (vp->length < 18) {
2391                         memset(vp->vp_octets + vp->length, 0,
2392                                18 - vp->length);
2393                 }
2394                 break;
2395
2396         case PW_TYPE_SIGNED:
2397                 if (vp->length != 4) goto raw;
2398
2399                 /*
2400                  *      Overload vp_integer for ntohl, which takes
2401                  *      uint32_t, not int32_t
2402                  */
2403                 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2404                 vp->vp_integer = ntohl(vp->vp_integer);
2405                 memcpy(&vp->vp_signed, &vp->vp_integer, 4);
2406                 break;
2407
2408         case PW_TYPE_TLV:
2409                 vp->length = length;
2410                 vp->vp_tlv = malloc(length);
2411                 if (!vp->vp_tlv) {
2412                         pairfree(&vp);
2413                         fr_strerror_printf("No memory");
2414                         return NULL;
2415                 }
2416                 memcpy(vp->vp_tlv, data, length);
2417                 break;
2418
2419         case PW_TYPE_COMBO_IP:
2420                 if (vp->length == 4) {
2421                         vp->type = PW_TYPE_IPADDR;
2422                         memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2423                         break;
2424
2425                 } else if (vp->length == 16) {
2426                         vp->type = PW_TYPE_IPV6ADDR;
2427                         /* vp->vp_ipv6addr == vp->vp_octets */
2428                         break;
2429
2430                 }
2431                 /* FALL-THROUGH */
2432
2433         default:
2434         raw:
2435                 /*
2436                  *      Change the name to show the user that the
2437                  *      attribute is not of the correct format.
2438                  */
2439                 {
2440                         int attr = vp->attribute;
2441                         int vendor = vp->vendor;
2442                         VALUE_PAIR *vp2;
2443
2444                         vp2 = pairalloc(NULL);
2445                         if (!vp2) {
2446                                 pairfree(&vp);
2447                                 return NULL;
2448                         }
2449                         pairfree(&vp);
2450                         vp = vp2;
2451
2452                         /*
2453                          *      This sets "vp->flags" appropriately,
2454                          *      and vp->type.
2455                          */
2456                         if (!paircreate_raw(attr, vendor, PW_TYPE_OCTETS, vp)) {
2457                                 return NULL;
2458                         }
2459
2460                         vp->length = length;
2461                         memcpy(vp->vp_octets, data, length);
2462                 }
2463                 break;
2464         }
2465
2466         return vp;
2467 }
2468
2469 static void rad_sortvp(VALUE_PAIR **head)
2470 {
2471         int swapped;
2472         VALUE_PAIR *vp, **tail;
2473
2474         /*
2475          *      Walk over the VP's, sorting them in order.  Did I
2476          *      mention that I hate WiMAX continuations?
2477          *
2478          *      And bubble sort!  WTF is up with that?
2479          */
2480         do {
2481                 swapped = 0;
2482                 tail = head;
2483                 while (*tail) {
2484                         vp = *tail;
2485                         if (!vp->next) break;
2486
2487                         if (vp->attribute > vp->next->attribute) {
2488                                 *tail = vp->next;
2489                                 vp->next = (*tail)->next;
2490                                 (*tail)->next = vp;
2491                                 swapped = 1;
2492                         }
2493                         tail = &(vp->next);
2494                 }
2495         } while (swapped);
2496 }
2497
2498
2499 /*
2500  *      Walk the packet, looking for continuations of this attribute.
2501  *
2502  *      This is (worst-case) O(N^2) in the number of RADIUS
2503  *      attributes.  That happens only when perverse clients create
2504  *      continued attributes, AND separate the fragmented portions
2505  *      with a lot of other attributes.
2506  *
2507  *      Sane clients should put the fragments next to each other, in
2508  *      which case this is O(N), in the number of fragments.
2509  */
2510 static uint8_t *rad_coalesce(unsigned int attribute, int vendor,
2511                              size_t length, uint8_t *data,
2512                              size_t packet_length, size_t *ptlv_length)
2513
2514 {
2515         uint32_t lvalue;
2516         size_t tlv_length = length;
2517         uint8_t *ptr, *tlv, *tlv_data;
2518
2519         for (ptr = data + length;
2520              ptr != (data + packet_length);
2521              ptr += ptr[1]) {
2522                 /* FIXME: Check that there are 6 bytes of data here... */
2523                 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2524                     (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2525                     (ptr[2] != 0) || (ptr[3] != 0) ||  /* our requirement */
2526                     (ptr[4] != ((vendor >> 8) & 0xff)) ||
2527                     (ptr[5] != (vendor & 0xff))) {
2528                         continue;
2529                 }
2530
2531                 memcpy(&lvalue, ptr + 2, 4); /* Vendor Id */
2532                 lvalue = ntohl(lvalue);
2533                 lvalue <<= 16;
2534                 lvalue |= ptr[2 + 4]; /* add in VSA number */
2535                 if (lvalue != attribute) continue;
2536
2537                 /*
2538                  *      If the vendor-length is too small, it's badly
2539                  *      formed, so we stop.
2540                  */
2541                 if ((ptr[2 + 4 + 1]) < 3) break;
2542
2543                 tlv_length += ptr[2 + 4 + 1] - 3;
2544                 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2545         }
2546
2547         tlv = tlv_data = malloc(tlv_length);
2548         if (!tlv_data) return NULL;
2549
2550         memcpy(tlv, data, length);
2551         tlv += length;
2552
2553         /*
2554          *      Now we walk the list again, copying the data over to
2555          *      our newly created memory.
2556          */
2557         for (ptr = data + length;
2558              ptr != (data + packet_length);
2559              ptr += ptr[1]) {
2560                 int this_length;
2561
2562                 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2563                     (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2564                     (ptr[2] != 0) || (ptr[3] != 0)) { /* our requirement */
2565                         continue;
2566                 }
2567
2568                 memcpy(&lvalue, ptr + 2, 4);
2569                 lvalue = ntohl(lvalue);
2570                 lvalue <<= 16;
2571                 lvalue |= ptr[2 + 4];
2572                 if (lvalue != attribute) continue;
2573
2574                 /*
2575                  *      If the vendor-length is too small, it's badly
2576                  *      formed, so we stop.
2577                  */
2578                 if ((ptr[2 + 4 + 1]) < 3) break;
2579
2580                 this_length = ptr[2 + 4 + 1] - 3;
2581                 memcpy(tlv, ptr + 2 + 4 + 3, this_length);
2582                 tlv += this_length;
2583
2584                 ptr[2 + 4] = 0; /* What a hack! */
2585                 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2586         }
2587
2588         *ptlv_length = tlv_length;
2589         return tlv_data;
2590 }
2591
2592
2593 /*
2594  *      Walk over Evil WIMAX TLVs, creating attributes.
2595  */
2596 static VALUE_PAIR *tlv2wimax(const RADIUS_PACKET *packet,
2597                              const RADIUS_PACKET *original,
2598                              const char *secret,
2599                              int attribute, int vendor,
2600                              uint8_t *ptr, size_t len, int nest)
2601 {
2602         VALUE_PAIR *head = NULL;
2603         VALUE_PAIR **tail = &head;
2604         VALUE_PAIR *vp;
2605         uint8_t *y;             /* why do I need to do this? */
2606
2607         if (nest > fr_wimax_max_tlv) return NULL;
2608
2609         /*
2610          *      Sanity check the attribute.
2611          */
2612         for (y = ptr; y < (ptr + len); y += y[1]) {
2613                 if ((y[0] == 0) || ((y + 2) > (ptr + len)) ||
2614                     (y[1] < 2) || ((y + y[1]) > (ptr + len))) {
2615                         return NULL;
2616                 }
2617
2618                 /*
2619                  *      Attribute number is too large for us to
2620                  *      represent it in our horrible internal
2621                  *      representation.
2622                  */
2623                 if ((ptr[0] & ~fr_wimax_mask[nest]) != 0) {
2624                         return NULL;
2625                 }
2626         }
2627
2628         for (y = ptr; y < (ptr + len); y += y[1]) {
2629                 DICT_ATTR *da;
2630
2631                 da = dict_attrbyvalue(attribute | (ptr[0] << fr_wimax_shift[nest]), vendor);
2632                 if (da && (da->type == PW_TYPE_TLV)) {
2633                         vp = tlv2wimax(packet, original, secret,
2634                                        attribute | (ptr[0] << fr_wimax_shift[nest]),
2635                                        vendor, ptr + 2, ptr[1] - 2,
2636                                        nest + 1);
2637                         if (!vp) goto error;
2638                 } else {
2639                         vp = paircreate(attribute | (ptr[0] << fr_wimax_shift[nest]), vendor,
2640                                         PW_TYPE_OCTETS);
2641                         if (!vp) {
2642                         error:
2643                                 pairfree(&head);
2644                                 return NULL;
2645                         }
2646
2647                         if (!data2vp(packet, original, secret,
2648                                      y[1] - 2, y + 2, vp)) {
2649                                 goto error;
2650                         }
2651                 }
2652
2653                 *tail = vp;
2654                 while (*tail) tail = &((*tail)->next);
2655         }
2656
2657         return head;
2658 }
2659
2660 /*
2661  *      Start at the *data* portion of a continued attribute.  search
2662  *      through the rest of the attributes to find a matching one, and
2663  *      add it's contents to our contents.
2664  */
2665 static VALUE_PAIR *rad_continuation2vp(const RADIUS_PACKET *packet,
2666                                        const RADIUS_PACKET *original,
2667                                        const char *secret, int attribute,
2668                                        int vendor,
2669                                        int length, /* CANNOT be zero */
2670                                        uint8_t *data, size_t packet_length,
2671                                        int flag, DICT_ATTR *da)
2672 {
2673         size_t tlv_length, left;
2674         uint8_t *ptr;
2675         uint8_t *tlv_data;
2676         VALUE_PAIR *vp, *head, **tail;
2677         DICT_ATTR *tlv_da;
2678
2679         /*
2680          *      Ensure we have data that hasn't been split across
2681          *      multiple attributes.
2682          */
2683         if (flag) {
2684                 tlv_data = rad_coalesce(attribute, vendor, length,
2685                                         data, packet_length, &tlv_length);
2686                 if (!tlv_data) return NULL;
2687         } else {
2688                 tlv_data = data;
2689                 tlv_length = length;
2690         }
2691
2692         /*
2693          *      Non-TLV types cannot be continued across multiple
2694          *      attributes.  This is true even of keys that are
2695          *      encrypted with the tunnel-password method.  The spec
2696          *      says that they can be continued... but also that the
2697          *      keys are 160 bits, which means that they CANNOT be
2698          *      continued.  <sigh>
2699          *
2700          *      Note that we don't check "flag" here.  The calling
2701          *      code ensures that
2702          */
2703         if (!da || (da->type != PW_TYPE_TLV)) {
2704         not_well_formed:
2705                 if (tlv_data == data) { /* true if we had 'goto' */
2706                         tlv_data = malloc(tlv_length);
2707                         if (!tlv_data) return NULL;
2708                         memcpy(tlv_data, data, tlv_length);
2709                 }
2710
2711                 vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2712                 if (!vp) return NULL;
2713
2714                 vp->type = PW_TYPE_TLV;
2715                 vp->flags.encrypt = FLAG_ENCRYPT_NONE;
2716                 vp->flags.has_tag = 0;
2717                 vp->flags.is_tlv = 0;
2718                 vp->vp_tlv = tlv_data;
2719                 vp->length = tlv_length;
2720                 return vp;
2721         } /* else it WAS a TLV, go decode the sub-tlv's */
2722
2723         /*
2724          *      Now (sigh) we walk over the TLV, seeing if it is
2725          *      well-formed.
2726          */
2727         left = tlv_length;
2728         for (ptr = tlv_data;
2729              ptr != (tlv_data + tlv_length);
2730              ptr += ptr[1]) {
2731                 if ((left < 2) ||
2732                     (ptr[1] < 2) ||
2733                     (ptr[1] > left)) {
2734                         goto not_well_formed;
2735                 }
2736
2737                 left -= ptr[1];
2738         }
2739
2740         /*
2741          *      Now we walk over the TLV *again*, creating sub-tlv's.
2742          */
2743         head = NULL;
2744         tail = &head;
2745
2746         for (ptr = tlv_data;
2747              ptr != (tlv_data + tlv_length);
2748              ptr += ptr[1]) {
2749
2750                 tlv_da = dict_attrbyvalue(attribute | (ptr[0] << fr_wimax_shift[1]), vendor);
2751                 if (tlv_da && (tlv_da->type == PW_TYPE_TLV)) {
2752                         vp = tlv2wimax(packet, original, secret,
2753                                        attribute | (ptr[0] << 8),
2754                                        vendor, ptr + 2, ptr[1] - 2, 2);
2755
2756                         if (!vp) goto error;
2757                 } else {
2758                         vp = paircreate(attribute | (ptr[0] << fr_wimax_shift[1]), vendor,
2759                                         PW_TYPE_OCTETS);
2760                         if (!vp) {
2761                         error:
2762                                 pairfree(&head);
2763                                 goto not_well_formed;
2764                         }
2765
2766                         if (!data2vp(packet, original, secret,
2767                                      ptr[1] - 2, ptr + 2, vp)) {
2768                                 goto error;
2769                         }
2770                 }
2771
2772                 *tail = vp;
2773
2774                 while (*tail) tail = &((*tail)->next);
2775         }
2776
2777         /*
2778          *      TLV's MAY be continued, but sometimes they're not.
2779          */
2780         if (tlv_data != data) free(tlv_data);
2781
2782         if (head->next) rad_sortvp(&head);
2783
2784         return head;
2785 }
2786
2787
2788 /*
2789  *      Parse a RADIUS attribute into a data structure.
2790  */
2791 VALUE_PAIR *rad_attr2vp(const RADIUS_PACKET *packet,
2792                         const RADIUS_PACKET *original,
2793                         const char *secret, int attribute, int vendor,
2794                         int length, const uint8_t *data)
2795 {
2796         VALUE_PAIR *vp;
2797
2798         vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2799         if (!vp) return NULL;
2800
2801         return data2vp(packet, original, secret, length, data, vp);
2802 }
2803
2804
2805 /*
2806  *      Calculate/check digest, and decode radius attributes.
2807  *      Returns:
2808  *      -1 on decoding error
2809  *      0 on success
2810  */
2811 int rad_decode(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2812                const char *secret)
2813 {
2814         uint32_t                lvalue;
2815         uint32_t                vendorcode;
2816         VALUE_PAIR              **tail;
2817         VALUE_PAIR              *pair;
2818         uint8_t                 *ptr, *vsa_ptr;
2819         int                     packet_length;
2820         int                     attribute;
2821         int                     attrlen;
2822         int                     vendorlen;
2823         radius_packet_t         *hdr;
2824         int                     vsa_tlen, vsa_llen, vsa_offset;
2825         DICT_VENDOR             *dv = NULL;
2826         int                     num_attributes = 0;
2827
2828         /*
2829          *      Extract attribute-value pairs
2830          */
2831         hdr = (radius_packet_t *)packet->data;
2832         ptr = hdr->data;
2833         packet_length = packet->data_len - AUTH_HDR_LEN;
2834
2835         /*
2836          *      There may be VP's already in the packet.  Don't
2837          *      destroy them.
2838          */
2839         for (tail = &packet->vps; *tail != NULL; tail = &((*tail)->next)) {
2840                 /* nothing */
2841         }
2842
2843         vendorcode = 0;
2844         vendorlen  = 0;
2845         vsa_tlen = vsa_llen = 1;
2846         vsa_offset = 0;
2847
2848         /*
2849          *      We have to read at least two bytes.
2850          *
2851          *      rad_recv() above ensures that this is OK.
2852          */
2853         while (packet_length > 0) {
2854                 attribute = -1;
2855                 attrlen = -1;
2856
2857                 /*
2858                  *      Normal attribute, handle it like normal.
2859                  */
2860                 if (vendorcode == 0) {
2861                         /*
2862                          *      No room to read attr/length,
2863                          *      or bad attribute, or attribute is
2864                          *      too short, or attribute is too long,
2865                          *      stop processing the packet.
2866                          */
2867                         if ((packet_length < 2) ||
2868                             (ptr[0] == 0) ||  (ptr[1] < 2) ||
2869                             (ptr[1] > packet_length)) break;
2870
2871                         attribute = *ptr++;
2872                         attrlen   = *ptr++;
2873
2874                         attrlen -= 2;
2875                         packet_length  -= 2;
2876
2877                         if (attribute != PW_VENDOR_SPECIFIC) goto create_pair;
2878
2879                         /*
2880                          *      No vendor code, or ONLY vendor code.
2881                          */
2882                         if (attrlen <= 4) goto create_pair;
2883
2884                         vendorlen = 0;
2885                 }
2886
2887                 /*
2888                  *      Handle Vendor-Specific
2889                  */
2890                 if (vendorlen == 0) {
2891                         uint8_t *subptr;
2892                         int sublen;
2893                         int myvendor;
2894
2895                         /*
2896                          *      attrlen was checked above.
2897                          */
2898                         memcpy(&lvalue, ptr, 4);
2899                         myvendor = ntohl(lvalue);
2900
2901                         /*
2902                          *      Zero isn't allowed.
2903                          */
2904                         if (myvendor == 0) goto create_pair;
2905
2906                         /*
2907                          *      Allow vendors up to 2^24.  Past that,
2908                          *      get confused.
2909                          */
2910                         if (myvendor > FR_MAX_VENDOR) goto create_pair;
2911
2912                         vsa_tlen = vsa_llen = 1;
2913                         vsa_offset = 0;
2914                         dv = dict_vendorbyvalue(myvendor);
2915                         if (dv) {
2916                                 vsa_tlen = dv->type;
2917                                 vsa_llen = dv->length;
2918                                 if (dv->flags) vsa_offset = 1;
2919                         }
2920
2921                         /*
2922                          *      Sweep through the list of VSA's,
2923                          *      seeing if they exactly fill the
2924                          *      outer Vendor-Specific attribute.
2925                          *
2926                          *      If not, create a raw Vendor-Specific.
2927                          */
2928                         subptr = ptr + 4;
2929                         sublen = attrlen - 4;
2930
2931                         /*
2932                          *      See if we can parse it.
2933                          */
2934                         do {
2935                                 int myattr = 0;
2936
2937                                 /*
2938                                  *      Not enough room for one more
2939                                  *      attribute.  Die!
2940                                  */
2941                                 if (sublen < (vsa_tlen + vsa_llen + vsa_offset)) goto create_pair;
2942
2943                                 /*
2944                                  *      Ensure that the attribute number
2945                                  *      is OK.
2946                                  */
2947                                 switch (vsa_tlen) {
2948                                 case 1:
2949                                         myattr = subptr[0];
2950                                         break;
2951
2952                                 case 2:
2953                                         myattr = (subptr[0] << 8) | subptr[1];
2954                                         break;
2955
2956                                 case 4:
2957                                         if ((subptr[0] != 0) ||
2958                                             (subptr[1] != 0)) goto create_pair;
2959
2960                                         myattr = (subptr[2] << 8) | subptr[3];
2961                                         break;
2962
2963                                         /*
2964                                          *      Our dictionary is broken.
2965                                          */
2966                                 default:
2967                                         goto create_pair;
2968                                 }
2969
2970                                 switch (vsa_llen) {
2971                                 case 0:
2972                                         attribute = myattr;
2973                                         ptr += 4 + vsa_tlen;
2974                                         attrlen -= (4 + vsa_tlen);
2975                                         packet_length -= 4 + vsa_tlen;
2976                                         goto create_pair;
2977
2978                                 case 1:
2979                                         if (subptr[vsa_tlen] < (vsa_tlen + vsa_llen + vsa_offset))
2980                                                 goto create_pair;
2981
2982                                         if (subptr[vsa_tlen] > sublen)
2983                                                 goto create_pair;
2984
2985                                         /*
2986                                          *      WiMAX: 0bCrrrrrrr
2987                                          *      Reserved bits MUST be
2988                                          *      zero.
2989                                          */
2990                                         if (vsa_offset &&
2991                                             ((subptr[vsa_tlen + vsa_llen] & 0x7f) != 0))
2992                                                 goto create_pair;
2993
2994                                         sublen -= subptr[vsa_tlen];
2995                                         subptr += subptr[vsa_tlen];
2996                                         break;
2997
2998                                 case 2:
2999                                         if (subptr[vsa_tlen] != 0) goto create_pair;
3000                                         if (subptr[vsa_tlen + 1] < (vsa_tlen + vsa_llen))
3001                                                 goto create_pair;
3002                                         if (subptr[vsa_tlen + 1] > sublen)
3003                                                 goto create_pair;
3004                                         sublen -= subptr[vsa_tlen + 1];
3005                                         subptr += subptr[vsa_tlen + 1];
3006                                         break;
3007
3008                                         /*
3009                                          *      Our dictionaries are
3010                                          *      broken.
3011                                          */
3012                                 default:
3013                                         goto create_pair;
3014                                 }
3015                         } while (sublen > 0);
3016
3017                         vendorcode = myvendor;
3018                         vendorlen = attrlen - 4;
3019                         packet_length -= 4;
3020
3021                         ptr += 4;
3022                 }
3023
3024                 /*
3025                  *      attrlen is the length of this attribute.
3026                  *      total_len is the length of the encompassing
3027                  *      attribute.
3028                  */
3029                 switch (vsa_tlen) {
3030                 case 1:
3031                         attribute = ptr[0];
3032                         break;
3033
3034                 case 2:
3035                         attribute = (ptr[0] << 8) | ptr[1];
3036                         break;
3037
3038                 default:        /* can't hit this. */
3039                         return -1;
3040                 }
3041                 vsa_ptr = ptr;
3042                 ptr += vsa_tlen;
3043
3044                 switch (vsa_llen) {
3045                 case 1:
3046                         attrlen = ptr[0] - (vsa_tlen + vsa_llen + vsa_offset);
3047                         break;
3048
3049                 case 2:
3050                         attrlen = ptr[1] - (vsa_tlen + vsa_llen);
3051                         break;
3052
3053                 default:        /* can't hit this. */
3054                         return -1;
3055                 }
3056
3057                 ptr += vsa_llen + vsa_offset;
3058                 vendorlen -= vsa_tlen + vsa_llen + vsa_offset + attrlen;
3059                 packet_length -= (vsa_tlen + vsa_llen + vsa_offset);
3060
3061                 /*
3062                  *      Ignore VSAs that have no data.
3063                  */
3064                 if (attrlen == 0) goto next;
3065
3066                 /*
3067                  *      WiMAX attributes of type 0 are ignored.  They
3068                  *      are a secret flag to us that the attribute has
3069                  *      already been dealt with.
3070                  */
3071                 if ((vendorcode == VENDORPEC_WIMAX) && (attribute == 0)) {
3072                         goto next;
3073                 }
3074
3075                 if (vsa_offset) {
3076                         DICT_ATTR *da;
3077
3078                         da = dict_attrbyvalue(attribute, vendorcode);
3079
3080                         /*
3081                          *      If it's NOT continued, AND we know
3082                          *      about it, AND it's not a TLV, we can
3083                          *      create a normal pair.
3084                          */
3085                         if (((vsa_ptr[2] & 0x80) == 0) &&
3086                             da && (da->type != PW_TYPE_TLV)) goto create_pair;
3087
3088                         /*
3089                          *      Else it IS continued, or it's a TLV.
3090                          *      Go do a lot of work to find the stuff.
3091                          */
3092                         pair = rad_continuation2vp(packet, original, secret,
3093                                                    attribute, vendorcode,
3094                                                    attrlen, ptr,
3095                                                    packet_length,
3096                                                    ((vsa_ptr[2] & 0x80) != 0),
3097                                                    da);
3098                         goto created_pair;
3099                 }
3100
3101                 /*
3102                  *      Create the attribute, setting the default type
3103                  *      to 'octets'.  If the type in the dictionary
3104                  *      is different, then the dictionary type will
3105                  *      over-ride this one.
3106                  *
3107                  *      If the attribute has no data, then discard it.
3108                  *
3109                  *      Unless it's CUI.  Damn you, CUI!
3110                  */
3111         create_pair:
3112                 if (!attrlen &&
3113                     (attribute != PW_CHARGEABLE_USER_IDENTITY)) goto next;
3114
3115                 pair = rad_attr2vp(packet, original, secret,
3116                                    attribute, vendorcode, attrlen, ptr);
3117                 if (!pair) {
3118                         pairfree(&packet->vps);
3119                         fr_strerror_printf("out of memory");
3120                         return -1;
3121                 }
3122
3123         created_pair:
3124                 *tail = pair;
3125                 while (pair) {
3126                         num_attributes++;
3127                         debug_pair(pair);
3128                         tail = &pair->next;
3129                         pair = pair->next;
3130                 }
3131
3132                 /*
3133                  *      VSA's may not have been counted properly in
3134                  *      rad_packet_ok() above, as it is hard to count
3135                  *      then without using the dictionary.  We
3136                  *      therefore enforce the limits here, too.
3137                  */
3138                 if ((fr_max_attributes > 0) &&
3139                     (num_attributes > fr_max_attributes)) {
3140                         char host_ipaddr[128];
3141
3142                         pairfree(&packet->vps);
3143                         fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
3144                                    inet_ntop(packet->src_ipaddr.af,
3145                                              &packet->src_ipaddr.ipaddr,
3146                                              host_ipaddr, sizeof(host_ipaddr)),
3147                                    num_attributes, fr_max_attributes);
3148                         return -1;
3149                 }
3150
3151         next:
3152                 if (vendorlen == 0) vendorcode = 0;
3153                 ptr += attrlen;
3154                 packet_length -= attrlen;
3155         }
3156
3157         /*
3158          *      Merge information from the outside world into our
3159          *      random pool.
3160          */
3161         fr_rand_seed(packet->data, AUTH_HDR_LEN);
3162
3163         return 0;
3164 }
3165
3166
3167 /*
3168  *      Encode password.
3169  *
3170  *      We assume that the passwd buffer passed is big enough.
3171  *      RFC2138 says the password is max 128 chars, so the size
3172  *      of the passwd buffer must be at least 129 characters.
3173  *      Preferably it's just MAX_STRING_LEN.
3174  *
3175  *      int *pwlen is updated to the new length of the encrypted
3176  *      password - a multiple of 16 bytes.
3177  */
3178 int rad_pwencode(char *passwd, size_t *pwlen, const char *secret,
3179                  const uint8_t *vector)
3180 {
3181         FR_MD5_CTX context, old;
3182         uint8_t digest[AUTH_VECTOR_LEN];
3183         int     i, n, secretlen;
3184         int     len;
3185
3186         /*
3187          *      RFC maximum is 128 bytes.
3188          *
3189          *      If length is zero, pad it out with zeros.
3190          *
3191          *      If the length isn't aligned to 16 bytes,
3192          *      zero out the extra data.
3193          */
3194         len = *pwlen;
3195
3196         if (len > 128) len = 128;
3197
3198         if (len == 0) {
3199                 memset(passwd, 0, AUTH_PASS_LEN);
3200                 len = AUTH_PASS_LEN;
3201         } else if ((len % AUTH_PASS_LEN) != 0) {
3202                 memset(&passwd[len], 0, AUTH_PASS_LEN - (len % AUTH_PASS_LEN));
3203                 len += AUTH_PASS_LEN - (len % AUTH_PASS_LEN);
3204         }
3205         *pwlen = len;
3206
3207         /*
3208          *      Use the secret to setup the decryption digest
3209          */
3210         secretlen = strlen(secret);
3211
3212         fr_MD5Init(&context);
3213         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3214         old = context;          /* save intermediate work */
3215
3216         /*
3217          *      Encrypt it in place.  Don't bother checking
3218          *      len, as we've ensured above that it's OK.
3219          */
3220         for (n = 0; n < len; n += AUTH_PASS_LEN) {
3221                 if (n == 0) {
3222                         fr_MD5Update(&context, vector, AUTH_PASS_LEN);
3223                         fr_MD5Final(digest, &context);
3224                 } else {
3225                         context = old;
3226                         fr_MD5Update(&context,
3227                                      (uint8_t *) passwd + n - AUTH_PASS_LEN,
3228                                      AUTH_PASS_LEN);
3229                         fr_MD5Final(digest, &context);
3230                 }
3231
3232                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3233                         passwd[i + n] ^= digest[i];
3234                 }
3235         }
3236
3237         return 0;
3238 }
3239
3240 /*
3241  *      Decode password.
3242  */
3243 int rad_pwdecode(char *passwd, size_t pwlen, const char *secret,
3244                  const uint8_t *vector)
3245 {
3246         FR_MD5_CTX context, old;
3247         uint8_t digest[AUTH_VECTOR_LEN];
3248         int     i;
3249         size_t  n, secretlen;
3250
3251         /*
3252          *      The RFC's say that the maximum is 128.
3253          *      The buffer we're putting it into above is 254, so
3254          *      we don't need to do any length checking.
3255          */
3256         if (pwlen > 128) pwlen = 128;
3257
3258         /*
3259          *      Catch idiots.
3260          */
3261         if (pwlen == 0) goto done;
3262
3263         /*
3264          *      Use the secret to setup the decryption digest
3265          */
3266         secretlen = strlen(secret);
3267
3268         fr_MD5Init(&context);
3269         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3270         old = context;          /* save intermediate work */
3271
3272         /*
3273          *      The inverse of the code above.
3274          */
3275         for (n = 0; n < pwlen; n += AUTH_PASS_LEN) {
3276                 if (n == 0) {
3277                         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3278                         fr_MD5Final(digest, &context);
3279
3280                         context = old;
3281                         if (pwlen > AUTH_PASS_LEN) {
3282                                 fr_MD5Update(&context, (uint8_t *) passwd,
3283                                              AUTH_PASS_LEN);
3284                         }
3285                 } else {
3286                         fr_MD5Final(digest, &context);
3287
3288                         context = old;
3289                         if (pwlen > (n + AUTH_PASS_LEN)) {
3290                                 fr_MD5Update(&context, (uint8_t *) passwd + n,
3291                                              AUTH_PASS_LEN);
3292                         }
3293                 }
3294
3295                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3296                         passwd[i + n] ^= digest[i];
3297                 }
3298         }
3299
3300  done:
3301         passwd[pwlen] = '\0';
3302         return strlen(passwd);
3303 }
3304
3305
3306 /*
3307  *      Encode Tunnel-Password attributes when sending them out on the wire.
3308  *
3309  *      int *pwlen is updated to the new length of the encrypted
3310  *      password - a multiple of 16 bytes.
3311  *
3312  *      This is per RFC-2868 which adds a two char SALT to the initial intermediate
3313  *      value MD5 hash.
3314  */
3315 int rad_tunnel_pwencode(char *passwd, size_t *pwlen, const char *secret,
3316                         const uint8_t *vector)
3317 {
3318         uint8_t buffer[AUTH_VECTOR_LEN + MAX_STRING_LEN + 3];
3319         unsigned char   digest[AUTH_VECTOR_LEN];
3320         char*   salt;
3321         int     i, n, secretlen;
3322         unsigned len, n2;
3323
3324         len = *pwlen;
3325
3326         if (len > 127) len = 127;
3327
3328         /*
3329          * Shift the password 3 positions right to place a salt and original
3330          * length, tag will be added automatically on packet send
3331          */
3332         for (n=len ; n>=0 ; n--) passwd[n+3] = passwd[n];
3333         salt = passwd;
3334         passwd += 2;
3335         /*
3336          * save original password length as first password character;
3337          */
3338         *passwd = len;
3339         len += 1;
3340
3341
3342         /*
3343          *      Generate salt.  The RFC's say:
3344          *
3345          *      The high bit of salt[0] must be set, each salt in a
3346          *      packet should be unique, and they should be random
3347          *
3348          *      So, we set the high bit, add in a counter, and then
3349          *      add in some CSPRNG data.  should be OK..
3350          */
3351         salt[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
3352                    (fr_rand() & 0x07));
3353         salt[1] = fr_rand();
3354
3355         /*
3356          *      Padd password to multiple of AUTH_PASS_LEN bytes.
3357          */
3358         n = len % AUTH_PASS_LEN;
3359         if (n) {
3360                 n = AUTH_PASS_LEN - n;
3361                 for (; n > 0; n--, len++)
3362                         passwd[len] = 0;
3363         }
3364         /* set new password length */
3365         *pwlen = len + 2;
3366
3367         /*
3368          *      Use the secret to setup the decryption digest
3369          */
3370         secretlen = strlen(secret);
3371         memcpy(buffer, secret, secretlen);
3372
3373         for (n2 = 0; n2 < len; n2+=AUTH_PASS_LEN) {
3374                 if (!n2) {
3375                         memcpy(buffer + secretlen, vector, AUTH_VECTOR_LEN);
3376                         memcpy(buffer + secretlen + AUTH_VECTOR_LEN, salt, 2);
3377                         fr_md5_calc(digest, buffer, secretlen + AUTH_VECTOR_LEN + 2);
3378                 } else {
3379                         memcpy(buffer + secretlen, passwd + n2 - AUTH_PASS_LEN, AUTH_PASS_LEN);
3380                         fr_md5_calc(digest, buffer, secretlen + AUTH_PASS_LEN);
3381                 }
3382
3383                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3384                         passwd[i + n2] ^= digest[i];
3385                 }
3386         }
3387         passwd[n2] = 0;
3388         return 0;
3389 }
3390
3391 /*
3392  *      Decode Tunnel-Password encrypted attributes.
3393  *
3394  *      Defined in RFC-2868, this uses a two char SALT along with the
3395  *      initial intermediate value, to differentiate it from the
3396  *      above.
3397  */
3398 int rad_tunnel_pwdecode(uint8_t *passwd, size_t *pwlen, const char *secret,
3399                         const uint8_t *vector)
3400 {
3401         FR_MD5_CTX  context, old;
3402         uint8_t         digest[AUTH_VECTOR_LEN];
3403         int             secretlen;
3404         unsigned        i, n, len, reallen;
3405
3406         len = *pwlen;
3407
3408         /*
3409          *      We need at least a salt.
3410          */
3411         if (len < 2) {
3412                 fr_strerror_printf("tunnel password is too short");
3413                 return -1;
3414         }
3415
3416         /*
3417          *      There's a salt, but no password.  Or, there's a salt
3418          *      and a 'data_len' octet.  It's wrong, but at least we
3419          *      can figure out what it means: the password is empty.
3420          *
3421          *      Note that this means we ignore the 'data_len' field,
3422          *      if the attribute length tells us that there's no
3423          *      more data.  So the 'data_len' field may be wrong,
3424          *      but that's ok...
3425          */
3426         if (len <= 3) {
3427                 passwd[0] = 0;
3428                 *pwlen = 0;
3429                 return 0;
3430         }
3431
3432         len -= 2;               /* discount the salt */
3433
3434         /*
3435          *      Use the secret to setup the decryption digest
3436          */
3437         secretlen = strlen(secret);
3438
3439         fr_MD5Init(&context);
3440         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3441         old = context;          /* save intermediate work */
3442
3443         /*
3444          *      Set up the initial key:
3445          *
3446          *       b(1) = MD5(secret + vector + salt)
3447          */
3448         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3449         fr_MD5Update(&context, passwd, 2);
3450
3451         reallen = 0;
3452         for (n = 0; n < len; n += AUTH_PASS_LEN) {
3453                 int base = 0;
3454
3455                 if (n == 0) {
3456                         fr_MD5Final(digest, &context);
3457
3458                         context = old;
3459
3460                         /*
3461                          *      A quick check: decrypt the first octet
3462                          *      of the password, which is the
3463                          *      'data_len' field.  Ensure it's sane.
3464                          */
3465                         reallen = passwd[2] ^ digest[0];
3466                         if (reallen >= len) {
3467                                 fr_strerror_printf("tunnel password is too long for the attribute");
3468                                 return -1;
3469                         }
3470
3471                         fr_MD5Update(&context, passwd + 2, AUTH_PASS_LEN);
3472
3473                         base = 1;
3474                 } else {
3475                         fr_MD5Final(digest, &context);
3476
3477                         context = old;
3478                         fr_MD5Update(&context, passwd + n + 2, AUTH_PASS_LEN);
3479                 }
3480
3481                 for (i = base; i < AUTH_PASS_LEN; i++) {
3482                         passwd[n + i - 1] = passwd[n + i + 2] ^ digest[i];
3483                 }
3484         }
3485
3486         /*
3487          *      See make_tunnel_password, above.
3488          */
3489         if (reallen > 239) reallen = 239;
3490
3491         *pwlen = reallen;
3492         passwd[reallen] = 0;
3493
3494         return reallen;
3495 }
3496
3497 /*
3498  *      Encode a CHAP password
3499  *
3500  *      FIXME: might not work with Ascend because
3501  *      we use vp->length, and Ascend gear likes
3502  *      to send an extra '\0' in the string!
3503  */
3504 int rad_chap_encode(RADIUS_PACKET *packet, uint8_t *output, int id,
3505                     VALUE_PAIR *password)
3506 {
3507         int             i;
3508         uint8_t         *ptr;
3509         uint8_t         string[MAX_STRING_LEN * 2 + 1];
3510         VALUE_PAIR      *challenge;
3511
3512         /*
3513          *      Sanity check the input parameters
3514          */
3515         if ((packet == NULL) || (password == NULL)) {
3516                 return -1;
3517         }
3518
3519         /*
3520          *      Note that the password VP can be EITHER
3521          *      a User-Password attribute (from a check-item list),
3522          *      or a CHAP-Password attribute (the client asking
3523          *      the library to encode it).
3524          */
3525
3526         i = 0;
3527         ptr = string;
3528         *ptr++ = id;
3529
3530         i++;
3531         memcpy(ptr, password->vp_strvalue, password->length);
3532         ptr += password->length;
3533         i += password->length;
3534
3535         /*
3536          *      Use Chap-Challenge pair if present,
3537          *      Request-Authenticator otherwise.
3538          */
3539         challenge = pairfind(packet->vps, PW_CHAP_CHALLENGE, 0);
3540         if (challenge) {
3541                 memcpy(ptr, challenge->vp_strvalue, challenge->length);
3542                 i += challenge->length;
3543         } else {
3544                 memcpy(ptr, packet->vector, AUTH_VECTOR_LEN);
3545                 i += AUTH_VECTOR_LEN;
3546         }
3547
3548         *output = id;
3549         fr_md5_calc((uint8_t *)output + 1, (uint8_t *)string, i);
3550
3551         return 0;
3552 }
3553
3554
3555 /*
3556  *      Seed the random number generator.
3557  *
3558  *      May be called any number of times.
3559  */
3560 void fr_rand_seed(const void *data, size_t size)
3561 {
3562         uint32_t hash;
3563
3564         /*
3565          *      Ensure that the pool is initialized.
3566          */
3567         if (!fr_rand_initialized) {
3568                 int fd;
3569
3570                 memset(&fr_rand_pool, 0, sizeof(fr_rand_pool));
3571
3572                 fd = open("/dev/urandom", O_RDONLY);
3573                 if (fd >= 0) {
3574                         size_t total;
3575                         ssize_t this;
3576
3577                         total = this = 0;
3578                         while (total < sizeof(fr_rand_pool.randrsl)) {
3579                                 this = read(fd, fr_rand_pool.randrsl,
3580                                             sizeof(fr_rand_pool.randrsl) - total);
3581                                 if ((this < 0) && (errno != EINTR)) break;
3582                                 if (this > 0) total += this;
3583                         }
3584                         close(fd);
3585                 } else {
3586                         fr_rand_pool.randrsl[0] = fd;
3587                         fr_rand_pool.randrsl[1] = time(NULL);
3588                         fr_rand_pool.randrsl[2] = errno;
3589                 }
3590
3591                 fr_randinit(&fr_rand_pool, 1);
3592                 fr_rand_pool.randcnt = 0;
3593                 fr_rand_initialized = 1;
3594         }
3595
3596         if (!data) return;
3597
3598         /*
3599          *      Hash the user data
3600          */
3601         hash = fr_rand();
3602         if (!hash) hash = fr_rand();
3603         hash = fr_hash_update(data, size, hash);
3604
3605         fr_rand_pool.randmem[fr_rand_pool.randcnt] ^= hash;
3606 }
3607
3608
3609 /*
3610  *      Return a 32-bit random number.
3611  */
3612 uint32_t fr_rand(void)
3613 {
3614         uint32_t num;
3615
3616         /*
3617          *      Ensure that the pool is initialized.
3618          */
3619         if (!fr_rand_initialized) {
3620                 fr_rand_seed(NULL, 0);
3621         }
3622
3623         num = fr_rand_pool.randrsl[fr_rand_pool.randcnt++];
3624         if (fr_rand_pool.randcnt >= 256) {
3625                 fr_rand_pool.randcnt = 0;
3626                 fr_isaac(&fr_rand_pool);
3627         }
3628
3629         return num;
3630 }
3631
3632
3633 /*
3634  *      Allocate a new RADIUS_PACKET
3635  */
3636 RADIUS_PACKET *rad_alloc(int newvector)
3637 {
3638         RADIUS_PACKET   *rp;
3639
3640         if ((rp = malloc(sizeof(RADIUS_PACKET))) == NULL) {
3641                 fr_strerror_printf("out of memory");
3642                 return NULL;
3643         }
3644         memset(rp, 0, sizeof(*rp));
3645         rp->id = -1;
3646         rp->offset = -1;
3647
3648         if (newvector) {
3649                 int i;
3650                 uint32_t hash, base;
3651
3652                 /*
3653                  *      Don't expose the actual contents of the random
3654                  *      pool.
3655                  */
3656                 base = fr_rand();
3657                 for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(uint32_t)) {
3658                         hash = fr_rand() ^ base;
3659                         memcpy(rp->vector + i, &hash, sizeof(hash));
3660                 }
3661         }
3662         fr_rand();              /* stir the pool again */
3663
3664         return rp;
3665 }
3666
3667 RADIUS_PACKET *rad_alloc_reply(RADIUS_PACKET *packet)
3668 {
3669         RADIUS_PACKET *reply;
3670
3671         if (!packet) return NULL;
3672
3673         reply = rad_alloc(0);
3674         if (!reply) return NULL;
3675
3676         /*
3677          *      Initialize the fields from the request.
3678          */
3679         reply->sockfd = packet->sockfd;
3680         reply->dst_ipaddr = packet->src_ipaddr;
3681         reply->src_ipaddr = packet->dst_ipaddr;
3682         reply->dst_port = packet->src_port;
3683         reply->src_port = packet->dst_port;
3684         reply->id = packet->id;
3685         reply->code = 0; /* UNKNOWN code */
3686         memcpy(reply->vector, packet->vector,
3687                sizeof(reply->vector));
3688         reply->vps = NULL;
3689         reply->data = NULL;
3690         reply->data_len = 0;
3691
3692         return reply;
3693 }
3694
3695
3696 /*
3697  *      Free a RADIUS_PACKET
3698  */
3699 void rad_free(RADIUS_PACKET **radius_packet_ptr)
3700 {
3701         RADIUS_PACKET *radius_packet;
3702
3703         if (!radius_packet_ptr || !*radius_packet_ptr) return;
3704         radius_packet = *radius_packet_ptr;
3705
3706         free(radius_packet->data);
3707
3708         pairfree(&radius_packet->vps);
3709
3710         free(radius_packet);
3711
3712         *radius_packet_ptr = NULL;
3713 }