2 * radius.c Functions to send/receive radius packets.
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.
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.
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
20 * Copyright 2000-2003,2006 The FreeRADIUS server project
23 #include <freeradius-devel/ident.h>
26 #include <freeradius-devel/libradius.h>
27 #include <freeradius-devel/md5.h>
33 #include <freeradius-devel/udpfromto.h>
41 * The RFC says 4096 octets max, and most packets are less than 256.
43 #define MAX_PACKET_LEN 4096
46 * The maximum number of attributes which we allow in an incoming
47 * request. If there are more attributes than this, the request
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.
56 int fr_max_attributes = 0;
57 FILE *fr_log_fp = NULL;
59 typedef struct radius_packet_t {
63 uint8_t vector[AUTH_VECTOR_LEN];
67 static fr_randctx fr_rand_pool; /* across multiple calls */
68 static int fr_rand_initialized = 0;
69 static unsigned int salt_offset = 0;
71 const char *fr_packet_codes[FR_MAX_PACKET_CODE] = {
77 "Accounting-Response",
93 "Resource-Free-Request",
94 "Resource-Free-Response",
95 "Resource-Query-Request",
96 "Resource-Query-Response",
97 "Alternate-Resource-Reclaim-Request",
99 "NAS-Reboot-Response",
112 "Disconnect-Request",
122 "IP-Address-Allocate",
127 void fr_printf_log(const char *fmt, ...)
132 if ((fr_debug_flag == 0) || !fr_log_fp) {
137 vfprintf(fr_log_fp, fmt, ap);
144 static void print_hex(RADIUS_PACKET *packet)
148 if (!packet->data) return;
150 printf(" Code:\t\t%u\n", packet->data[0]);
151 printf(" Id:\t\t%u\n", packet->data[1]);
152 printf(" Length:\t%u\n", ((packet->data[2] << 8) |
154 printf(" Vector:\t");
155 for (i = 4; i < 20; i++) {
156 printf("%02x", packet->data[i]);
160 if (packet->data_len > 20) {
165 total = packet->data_len - 20;
166 ptr = packet->data + 20;
172 if (total < 2) { /* too short */
173 printf("%02x\n", *ptr);
177 if (ptr[1] > total) { /* too long */
178 for (i = 0; i < total; i++) {
179 printf("%02x ", ptr[i]);
184 printf("%02x %02x ", ptr[0], ptr[1]);
185 attrlen = ptr[1] - 2;
189 for (i = 0; i < attrlen; i++) {
190 if ((i > 0) && ((i & 0x0f) == 0x00))
192 printf("%02x ", ptr[i]);
193 if ((i & 0x0f) == 0x0f) printf("\n");
196 if ((attrlen & 0x0f) != 0x00) printf("\n");
207 * Wrapper for sendto which handles sendfromto, IPv6, and all
208 * possible combinations.
210 static int rad_sendto(int sockfd, void *data, size_t data_len, int flags,
211 fr_ipaddr_t *src_ipaddr, int src_port,
212 fr_ipaddr_t *dst_ipaddr, int dst_port)
214 struct sockaddr_storage dst;
215 socklen_t sizeof_dst;
217 #ifdef WITH_UDPFROMTO
218 struct sockaddr_storage src;
219 socklen_t sizeof_src;
221 fr_ipaddr2sockaddr(src_ipaddr, src_port, &src, &sizeof_src);
223 src_port = src_port; /* -Wunused */
226 if (!fr_ipaddr2sockaddr(dst_ipaddr, dst_port, &dst, &sizeof_dst)) {
230 #ifdef WITH_UDPFROMTO
232 * Only IPv4 is supported for udpfromto.
234 * And if they don't specify a source IP address, don't
237 if ((dst_ipaddr->af == AF_INET) &&
238 (src_ipaddr->af != AF_UNSPEC)) {
239 return sendfromto(sockfd, data, data_len, flags,
240 (struct sockaddr *)&src, sizeof_src,
241 (struct sockaddr *)&dst, sizeof_dst);
244 src_ipaddr = src_ipaddr; /* -Wunused */
248 * No udpfromto, OR an IPv6 socket, fail gracefully.
250 return sendto(sockfd, data, data_len, flags,
251 (struct sockaddr *) &dst, sizeof_dst);
255 void rad_recv_discard(int sockfd)
258 struct sockaddr_storage src;
259 socklen_t sizeof_src = sizeof(src);
261 recvfrom(sockfd, header, sizeof(header), 0,
262 (struct sockaddr *)&src, &sizeof_src);
266 ssize_t rad_recv_header(int sockfd, fr_ipaddr_t *src_ipaddr, int *src_port,
269 ssize_t data_len, packet_len;
271 struct sockaddr_storage src;
272 socklen_t sizeof_src = sizeof(src);
274 data_len = recvfrom(sockfd, header, sizeof(header), MSG_PEEK,
275 (struct sockaddr *)&src, &sizeof_src);
277 if ((errno == EAGAIN) || (errno == EINTR)) return 0;
282 * Too little data is available, discard the packet.
285 recvfrom(sockfd, header, sizeof(header), 0,
286 (struct sockaddr *)&src, &sizeof_src);
289 } else { /* we got 4 bytes of data. */
291 * See how long the packet says it is.
293 packet_len = (header[2] * 256) + header[3];
296 * The length in the packet says it's less than
297 * a RADIUS header length: discard it.
299 if (packet_len < AUTH_HDR_LEN) {
300 recvfrom(sockfd, header, sizeof(header), 0,
301 (struct sockaddr *)&src, &sizeof_src);
305 * Enforce RFC requirements, for sanity.
306 * Anything after 4k will be discarded.
308 } else if (packet_len > MAX_PACKET_LEN) {
309 recvfrom(sockfd, header, sizeof(header), 0,
310 (struct sockaddr *)&src, &sizeof_src);
316 * Convert AF. If unknown, discard packet.
318 if (!fr_sockaddr2ipaddr(&src, sizeof_src, src_ipaddr, src_port)) {
319 recvfrom(sockfd, header, sizeof(header), 0,
320 (struct sockaddr *)&src, &sizeof_src);
327 * The packet says it's this long, but the actual UDP
328 * size could still be smaller.
335 * wrapper for recvfrom, which handles recvfromto, IPv6, and all
336 * possible combinations.
338 static ssize_t rad_recvfrom(int sockfd, uint8_t **pbuf, int flags,
339 fr_ipaddr_t *src_ipaddr, uint16_t *src_port,
340 fr_ipaddr_t *dst_ipaddr, uint16_t *dst_port)
342 struct sockaddr_storage src;
343 struct sockaddr_storage dst;
344 socklen_t sizeof_src = sizeof(src);
345 socklen_t sizeof_dst = sizeof(dst);
352 memset(&src, 0, sizeof_src);
353 memset(&dst, 0, sizeof_dst);
356 * Get address family, etc. first, so we know if we
357 * need to do udpfromto.
359 * FIXME: udpfromto also does this, but it's not
360 * a critical problem.
362 if (getsockname(sockfd, (struct sockaddr *)&dst,
363 &sizeof_dst) < 0) return -1;
366 * Read the length of the packet, from the packet.
367 * This lets us allocate the buffer to use for
368 * reading the rest of the packet.
370 data_len = recvfrom(sockfd, header, sizeof(header), MSG_PEEK,
371 (struct sockaddr *)&src, &sizeof_src);
373 if ((errno == EAGAIN) || (errno == EINTR)) return 0;
378 * Too little data is available, discard the packet.
381 recvfrom(sockfd, header, sizeof(header), flags,
382 (struct sockaddr *)&src, &sizeof_src);
385 } else { /* we got 4 bytes of data. */
387 * See how long the packet says it is.
389 len = (header[2] * 256) + header[3];
392 * The length in the packet says it's less than
393 * a RADIUS header length: discard it.
395 if (len < AUTH_HDR_LEN) {
396 recvfrom(sockfd, header, sizeof(header), flags,
397 (struct sockaddr *)&src, &sizeof_src);
401 * Enforce RFC requirements, for sanity.
402 * Anything after 4k will be discarded.
404 } else if (len > MAX_PACKET_LEN) {
405 recvfrom(sockfd, header, sizeof(header), flags,
406 (struct sockaddr *)&src, &sizeof_src);
415 * Receive the packet. The OS will discard any data in the
416 * packet after "len" bytes.
418 #ifdef WITH_UDPFROMTO
419 if (dst.ss_family == AF_INET) {
420 data_len = recvfromto(sockfd, buf, len, flags,
421 (struct sockaddr *)&src, &sizeof_src,
422 (struct sockaddr *)&dst, &sizeof_dst);
426 * No udpfromto, OR an IPv6 socket. Fail gracefully.
428 data_len = recvfrom(sockfd, buf, len, flags,
429 (struct sockaddr *)&src, &sizeof_src);
435 if (!fr_sockaddr2ipaddr(&src, sizeof_src, src_ipaddr, &port)) {
437 return -1; /* Unknown address family, Die Die Die! */
441 fr_sockaddr2ipaddr(&dst, sizeof_dst, dst_ipaddr, &port);
445 * Different address families should never happen.
447 if (src.ss_family != dst.ss_family) {
453 * Tell the caller about the data
461 #define AUTH_PASS_LEN (AUTH_VECTOR_LEN)
462 /*************************************************************************
464 * Function: make_secret
466 * Purpose: Build an encrypted secret value to return in a reply
467 * packet. The secret is hidden by xoring with a MD5 digest
468 * created from the shared secret and the authentication
469 * vector. We put them into MD5 in the reverse order from
470 * that used when encrypting passwords to RADIUS.
472 *************************************************************************/
473 static void make_secret(uint8_t *digest, const uint8_t *vector,
474 const char *secret, const uint8_t *value)
479 fr_MD5Init(&context);
480 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
481 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
482 fr_MD5Final(digest, &context);
484 for ( i = 0; i < AUTH_VECTOR_LEN; i++ ) {
485 digest[i] ^= value[i];
489 #define MAX_PASS_LEN (128)
490 static void make_passwd(uint8_t *output, ssize_t *outlen,
491 const uint8_t *input, size_t inlen,
492 const char *secret, const uint8_t *vector)
494 FR_MD5_CTX context, old;
495 uint8_t digest[AUTH_VECTOR_LEN];
496 uint8_t passwd[MAX_PASS_LEN];
501 * If the length is zero, round it up.
505 if (len > MAX_PASS_LEN) len = MAX_PASS_LEN;
507 memcpy(passwd, input, len);
508 memset(passwd + len, 0, sizeof(passwd) - len);
514 else if ((len & 0x0f) != 0) {
520 fr_MD5Init(&context);
521 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
527 fr_MD5Update(&context, vector, AUTH_PASS_LEN);
529 for (n = 0; n < len; n += AUTH_PASS_LEN) {
532 fr_MD5Update(&context,
533 passwd + n - AUTH_PASS_LEN,
537 fr_MD5Final(digest, &context);
538 for (i = 0; i < AUTH_PASS_LEN; i++) {
539 passwd[i + n] ^= digest[i];
543 memcpy(output, passwd, len);
546 static void make_tunnel_passwd(uint8_t *output, ssize_t *outlen,
547 const uint8_t *input, size_t inlen, size_t room,
548 const char *secret, const uint8_t *vector)
550 FR_MD5_CTX context, old;
551 uint8_t digest[AUTH_VECTOR_LEN];
552 uint8_t passwd[MAX_STRING_LEN + AUTH_VECTOR_LEN];
559 if (room > 253) room = 253;
562 * Account for 2 bytes of the salt, and round the room
563 * available down to the nearest multiple of 16. Then,
564 * subtract one from that to account for the length byte,
565 * and the resulting number is the upper bound on the data
568 * We could short-cut this calculation just be forcing
569 * inlen to be no more than 239. It would work for all
570 * VSA's, as we don't pack multiple VSA's into one
573 * However, this calculation is more general, if a little
574 * complex. And it will work in the future for all possible
575 * kinds of weird attribute packing.
578 room -= (room & 0x0f);
581 if (inlen > room) inlen = room;
584 * Length of the encrypted data is password length plus
585 * one byte for the length of the password.
588 if ((len & 0x0f) != 0) {
592 *outlen = len + 2; /* account for the salt */
595 * Copy the password over.
597 memcpy(passwd + 3, input, inlen);
598 memset(passwd + 3 + inlen, 0, sizeof(passwd) - 3 - inlen);
601 * Generate salt. The RFC's say:
603 * The high bit of salt[0] must be set, each salt in a
604 * packet should be unique, and they should be random
606 * So, we set the high bit, add in a counter, and then
607 * add in some CSPRNG data. should be OK..
609 passwd[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
611 passwd[1] = fr_rand();
612 passwd[2] = inlen; /* length of the password string */
614 fr_MD5Init(&context);
615 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
618 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
619 fr_MD5Update(&context, &passwd[0], 2);
621 for (n = 0; n < len; n += AUTH_PASS_LEN) {
624 fr_MD5Update(&context,
625 passwd + 2 + n - AUTH_PASS_LEN,
629 fr_MD5Final(digest, &context);
631 for (i = 0; i < AUTH_PASS_LEN; i++) {
632 passwd[i + 2 + n] ^= digest[i];
635 memcpy(output, passwd, len + 2);
638 extern int fr_attr_max_tlv;
639 extern int fr_attr_shift[];
640 extern int fr_attr_mask[];
642 static int do_next_tlv(const VALUE_PAIR *vp, int nest)
644 unsigned int tlv1, tlv2;
646 if (nest > fr_attr_max_tlv) return 0;
649 * Keep encoding TLVs which have the same scope.
650 * e.g. two attributes of:
651 * ATTR.TLV1.TLV2.TLV3 = data1
652 * ATTR.TLV1.TLV2.TLV4 = data2
653 * both get put into a container of "ATTR.TLV1.TLV2"
657 * Nothing to follow, we're done.
659 if (!vp->next) return 0;
662 * Not from the same vendor, skip it.
664 if (vp->vendor != vp->next->vendor) return 0;
667 * The next one has already been done. Maybe by
668 * another level of recursion. Skip it.
670 if (vp->next->flags.encoded) return 0;
673 * In a different TLV space, skip it.
675 tlv1 = vp->attribute;
676 tlv2 = vp->next->attribute;
678 tlv1 &= ((1 << fr_attr_shift[nest]) - 1);
679 tlv2 &= ((1 << fr_attr_shift[nest]) - 1);
681 if (tlv1 != tlv2) return 0;
687 static ssize_t vp2data_any(const RADIUS_PACKET *packet,
688 const RADIUS_PACKET *original,
689 const char *secret, int nest, VALUE_PAIR *vps,
690 uint8_t *start, size_t room);
692 static ssize_t vp2data_tlvs(const RADIUS_PACKET *packet,
693 const RADIUS_PACKET *original,
694 const char *secret, int nest, VALUE_PAIR *vps,
695 uint8_t *start, size_t room)
698 uint8_t *ptr = start;
699 uint8_t *end = start + room;
700 VALUE_PAIR *vp = vps;
703 if (nest > fr_attr_max_tlv) {
704 fr_strerror_printf("vp2data_tlvs: attribute nesting overflow");
710 ptr[0] = (vp->attribute >> fr_attr_shift[nest]) & fr_attr_mask[nest];
713 len = vp2data_any(packet, original, secret, nest + 1, vp,
714 ptr + ptr[1], end - ptr);
716 if (vp != vps) break;
722 vp->flags.encoded = 1;
724 if (!do_next_tlv(vp, nest)) break;
732 * Encodes the data portion of an attribute.
733 * Returns -1 on error, or the length of the data portion.
735 static ssize_t vp2data_any(const RADIUS_PACKET *packet,
736 const RADIUS_PACKET *original,
737 const char *secret, int nest, VALUE_PAIR *vp,
738 uint8_t *start, size_t room)
743 uint8_t *ptr = start;
747 * See if we need to encode a TLV. The low portion of
748 * the attribute has already been placed into the packer.
749 * If there are still attribute bytes left, then go
750 * encode them as TLVs.
752 * If we cared about the stack, we could unroll the loop.
754 if ((nest > 0) && (nest <= fr_attr_max_tlv) &&
755 ((vp->attribute >> fr_attr_shift[nest]) != 0)) {
756 return vp2data_tlvs(packet, original, secret, nest, vp,
761 * Set up the default sources for the data.
763 data = vp->vp_octets;
770 case PW_TYPE_IPV6ADDR:
771 case PW_TYPE_IPV6PREFIX:
772 case PW_TYPE_ABINARY:
773 /* nothing more to do */
777 len = 1; /* just in case */
778 array[0] = vp->vp_integer & 0xff;
783 len = 2; /* just in case */
784 array[0] = (vp->vp_integer >> 8) & 0xff;
785 array[1] = vp->vp_integer & 0xff;
789 case PW_TYPE_INTEGER:
790 len = 4; /* just in case */
791 lvalue = htonl(vp->vp_integer);
792 memcpy(array, &lvalue, sizeof(lvalue));
797 data = (const uint8_t *) &vp->vp_ipaddr;
798 len = 4; /* just in case */
802 * There are no tagged date attributes.
805 lvalue = htonl(vp->vp_date);
806 data = (const uint8_t *) &lvalue;
807 len = 4; /* just in case */
814 len = 4; /* just in case */
815 slvalue = htonl(vp->vp_signed);
816 memcpy(array, &slvalue, sizeof(slvalue));
823 fr_strerror_printf("ERROR: Cannot encode NULL TLV");
829 default: /* unknown type: ignore it */
830 fr_strerror_printf("ERROR: Unknown attribute type %d", vp->type);
835 * Bound the data to the calling size
837 if (len > (ssize_t) room) len = room;
840 * Encrypt the various password styles
842 * Attributes with encrypted values MUST be less than
845 switch (vp->flags.encrypt) {
846 case FLAG_ENCRYPT_USER_PASSWORD:
847 make_passwd(ptr, &len, data, len,
848 secret, packet->vector);
851 case FLAG_ENCRYPT_TUNNEL_PASSWORD:
853 if (vp->flags.has_tag) lvalue = 1;
856 * Check if there's enough room. If there isn't,
857 * we discard the attribute.
859 * This is ONLY a problem if we have multiple VSA's
860 * in one Vendor-Specific, though.
862 if (room < (18 + lvalue)) return 0;
864 switch (packet->code) {
865 case PW_AUTHENTICATION_ACK:
866 case PW_AUTHENTICATION_REJECT:
867 case PW_ACCESS_CHALLENGE:
870 fr_strerror_printf("ERROR: No request packet, cannot encrypt %s attribute in the vp.", vp->name);
874 if (lvalue) ptr[0] = vp->flags.tag;
875 make_tunnel_passwd(ptr + lvalue, &len, data, len,
877 secret, original->vector);
879 case PW_ACCOUNTING_REQUEST:
880 case PW_DISCONNECT_REQUEST:
882 ptr[0] = vp->flags.tag;
883 make_tunnel_passwd(ptr + 1, &len, data, len - 1, room,
884 secret, packet->vector);
890 * The code above ensures that this attribute
893 case FLAG_ENCRYPT_ASCEND_SECRET:
894 make_secret(ptr, packet->vector, secret, data);
895 len = AUTH_VECTOR_LEN;
900 if (vp->flags.has_tag && TAG_VALID(vp->flags.tag)) {
901 if (vp->type == PW_TYPE_STRING) {
902 if (len > ((ssize_t) (room - 1))) len = room - 1;
903 ptr[0] = vp->flags.tag;
905 } else if (vp->type == PW_TYPE_INTEGER) {
906 array[0] = vp->flags.tag;
907 } /* else it can't be any other type */
909 memcpy(ptr, data, len);
911 } /* switch over encryption flags */
913 vp->flags.encoded = 1;
914 return len + (ptr - start);;
917 static ssize_t attr_shift(const uint8_t *start, const uint8_t *end,
918 uint8_t *ptr, int hdr_len, ssize_t len,
919 int flag_offset, int vsa_offset)
921 int check_len = len - ptr[1];
922 int total = len + hdr_len;
925 * Pass 1: Check if the addition of the headers
926 * overflows the available room. If so, return
927 * what we were capable of encoding.
930 while (check_len > (255 - hdr_len)) {
932 check_len -= (255 - hdr_len);
936 * Note that this results in a number of attributes maybe
937 * being marked as "encoded", but which aren't in the
938 * packet. Oh well. The solution is to fix the
939 * "vp2data_any" function to take into account the header
942 if ((ptr + ptr[1] + total) > end) {
943 return (ptr + ptr[1]) - start;
947 * Pass 2: Now that we know there's enough room,
948 * re-arrange the data to form a set of valid
952 int sublen = 255 - ptr[1];
959 memmove(ptr + 255 + hdr_len, ptr + 255, sublen);
960 memcpy(ptr + 255, ptr, hdr_len);
962 if (vsa_offset) ptr[vsa_offset] += sublen;
963 ptr[flag_offset] |= 0x80;
967 if (vsa_offset) ptr[vsa_offset] = 3;
971 if (vsa_offset) ptr[vsa_offset] += len;
973 return (ptr + ptr[1]) - start;
978 * Encode an "extended" attribute.
980 int rad_vp2extended(const RADIUS_PACKET *packet,
981 const RADIUS_PACKET *original,
982 const char *secret, VALUE_PAIR *vp,
983 uint8_t *ptr, size_t room)
988 uint8_t *start = ptr;
990 if (vp->vendor < VENDORPEC_EXTENDED) {
991 fr_strerror_printf("rad_vp2extended called for non-extended attribute");
995 if (room < 3) return 0;
997 ptr[0] = vp->attribute & 0xff;
1000 if (vp->flags.extended) {
1001 ptr[2] = (vp->attribute & 0xff00) >> 8;
1003 } else if (vp->flags.extended_flags) {
1004 if (room < 4) return 0;
1007 ptr[2] = (vp->attribute & 0xff00) >> 8;
1012 * Only "flagged" attributes can be longer than one
1015 if (!vp->flags.extended_flags && (room > 255)) {
1022 if (vp->flags.evs) {
1023 uint8_t *evs = ptr + ptr[1];
1025 if (room < (size_t) (ptr[1] + 5)) return 0;
1028 * RADIUS Attribute Type is packed into the high byte
1029 * of the Vendor Id. So over-write it in the packet.
1031 * And hard-code Extended-Type to Vendor-Specific.
1033 ptr[0] = (vp->vendor >> 24) & 0xff;
1036 evs[0] = 0; /* always zero */
1037 evs[1] = (vp->vendor >> 16) & 0xff;
1038 evs[2] = (vp->vendor >> 8) & 0xff;
1039 evs[3] = vp->vendor & 0xff;
1040 evs[4] = vp->attribute & 0xff;
1047 len = vp2data_any(packet, original, secret, nest,
1048 vp, ptr + ptr[1], room - hdr_len);
1049 if (len < 0) return len;
1052 * There may be more than 252 octets of data encoded in
1053 * the attribute. If so, move the data up in the packet,
1054 * and copy the existing header over. Set the "M" flag ONLY
1055 * after copying the rest of the data.
1057 if (vp->flags.extended_flags && (len > (255 - ptr[1]))) {
1058 return attr_shift(start, start + room, ptr, 4, len, 3, 0);
1063 return (ptr + ptr[1]) - start;
1068 * Encode a WiMAX attribute.
1070 int rad_vp2wimax(const RADIUS_PACKET *packet,
1071 const RADIUS_PACKET *original,
1072 const char *secret, VALUE_PAIR *vp,
1073 uint8_t *ptr, size_t room)
1078 uint8_t *start = ptr;
1081 * Double-check for WiMAX
1083 if (vp->vendor != VENDORPEC_WIMAX) {
1084 fr_strerror_printf("rad_vp2wimax called for non-WIMAX VSA");
1089 * Not enough room for:
1090 * attr, len, vendor-id, vsa, vsalen, continuation
1092 if (room < 9) return 0;
1095 * Build the Vendor-Specific header
1098 ptr[0] = PW_VENDOR_SPECIFIC;
1100 lvalue = htonl(vp->vendor);
1101 memcpy(ptr + 2, &lvalue, 4);
1102 ptr[6] = (vp->attribute & fr_attr_mask[1]);
1104 ptr[8] = 0; /* continuation byte */
1108 len = vp2data_any(packet, original, secret, 1, vp, ptr + ptr[1],
1110 if (len <= 0) return len;
1113 * There may be more than 252 octets of data encoded in
1114 * the attribute. If so, move the data up in the packet,
1115 * and copy the existing header over. Set the "C" flag
1116 * ONLY after copying the rest of the data.
1118 if (len > (255 - ptr[1])) {
1119 return attr_shift(start, start + room, ptr, hdr_len, len, 8, 7);
1125 return (ptr + ptr[1]) - start;
1129 * Encode an RFC format TLV. This could be a standard attribute,
1130 * or a TLV data type. If it's a standard attribute, then
1131 * vp->attribute == attribute. Otherwise, attribute may be
1134 static ssize_t vp2attr_rfc(const RADIUS_PACKET *packet,
1135 const RADIUS_PACKET *original,
1136 const char *secret, VALUE_PAIR *vp,
1137 unsigned int attribute, uint8_t *ptr, size_t room)
1141 if (room < 2) return 0;
1143 ptr[0] = attribute & 0xff;
1146 if (room > ((unsigned) 255 - ptr[1])) room = 255 - ptr[1];
1148 len = vp2data_any(packet, original, secret, 0, vp, ptr + ptr[1], room);
1149 if (len < 0) return len;
1158 * Encode a VSA which is a TLV. If it's in the RFC format, call
1159 * vp2attr_rfc. Otherwise, encode it here.
1161 static ssize_t vp2attr_vsa(const RADIUS_PACKET *packet,
1162 const RADIUS_PACKET *original,
1163 const char *secret, VALUE_PAIR *vp,
1164 unsigned int attribute, unsigned int vendor,
1165 uint8_t *ptr, size_t room)
1171 * Unknown vendor: RFC format.
1172 * Known vendor and RFC format: go do that.
1174 dv = dict_vendorbyvalue(vendor);
1175 if (!dv || ((dv->type == 1) && (dv->length == 1))) {
1176 return vp2attr_rfc(packet, original, secret, vp,
1177 attribute, ptr, room);
1182 fr_strerror_printf("vp2attr_vsa: Internal sanity check failed,"
1183 " type %u", (unsigned) dv->type);
1187 ptr[0] = 0; /* attr must be 24-bit */
1188 ptr[1] = (attribute >> 16) & 0xff;
1189 ptr[2] = (attribute >> 8) & 0xff;
1190 ptr[3] = attribute & 0xff;
1194 ptr[0] = (attribute >> 8) & 0xff;
1195 ptr[1] = attribute & 0xff;
1199 ptr[0] = attribute & 0xff;
1203 switch (dv->length) {
1205 fr_strerror_printf("vp2attr_vsa: Internal sanity check failed,"
1206 " length %u", (unsigned) dv->length);
1217 ptr[dv->type + dv->length - 1] = dv->type + dv->length;
1222 if (room > ((unsigned) 255 - (dv->type + dv->length))) {
1223 room = 255 - (dv->type + dv->length);
1226 len = vp2data_any(packet, original, secret, 0, vp,
1227 ptr + dv->type + dv->length, room);
1228 if (len < 0) return len;
1230 if (dv->length) ptr[dv->type + dv->length - 1] += len;
1232 return dv->type + dv->length + len;
1237 * Encode a Vendor-Specific attribute.
1239 int rad_vp2vsa(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1240 const char *secret, VALUE_PAIR *vp, uint8_t *ptr,
1247 * Double-check for WiMAX
1249 if (vp->vendor == VENDORPEC_WIMAX) {
1250 return rad_vp2wimax(packet, original, secret, vp,
1254 if (vp->vendor > FR_MAX_VENDOR) {
1255 fr_strerror_printf("rad_vp2vsa: Invalid arguments");
1260 * Not enough room for:
1261 * attr, len, vendor-id
1263 if (room < 6) return 0;
1266 * Build the Vendor-Specific header
1268 ptr[0] = PW_VENDOR_SPECIFIC;
1270 lvalue = htonl(vp->vendor);
1271 memcpy(ptr + 2, &lvalue, 4);
1273 if (room > ((unsigned) 255 - ptr[1])) room = 255 - ptr[1];
1275 len = vp2attr_vsa(packet, original, secret, vp,
1276 vp->attribute, vp->vendor,
1277 ptr + ptr[1], room);
1278 if (len < 0) return len;
1287 * Encode an RFC standard attribute 1..255
1289 int rad_vp2rfc(const RADIUS_PACKET *packet,
1290 const RADIUS_PACKET *original,
1291 const char *secret, VALUE_PAIR *vp,
1292 uint8_t *ptr, size_t room)
1294 if (vp->vendor != 0) {
1295 fr_strerror_printf("rad_vp2rfc called with VSA");
1299 if ((vp->attribute == 0) || (vp->attribute > 255)) {
1300 fr_strerror_printf("rad_vp2rfc called with non-standard attribute %u", vp->attribute);
1304 if ((vp->length == 0) &&
1305 (vp->attribute != PW_CHARGEABLE_USER_IDENTITY)) {
1309 return vp2attr_rfc(packet, original, secret, vp, vp->attribute,
1315 * Parse a data structure into a RADIUS attribute.
1317 int rad_vp2attr(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1318 const char *secret, VALUE_PAIR *vp, uint8_t *start,
1322 * RFC format attributes take the fast path.
1324 if (vp->vendor == 0) {
1325 if (vp->attribute > 255) return 0;
1327 return rad_vp2rfc(packet, original, secret, vp,
1331 if (vp->vendor > FR_MAX_VENDOR) {
1332 return rad_vp2extended(packet, original, secret, vp,
1336 if (vp->vendor == VENDORPEC_WIMAX) {
1337 return rad_vp2wimax(packet, original, secret, vp,
1341 return rad_vp2vsa(packet, original, secret, vp,
1349 int rad_encode(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1352 radius_packet_t *hdr;
1354 uint16_t total_length;
1358 char ip_buffer[128];
1361 * A 4K packet, aligned on 64-bits.
1363 uint64_t data[MAX_PACKET_LEN / sizeof(uint64_t)];
1365 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1366 what = fr_packet_codes[packet->code];
1371 DEBUG("Sending %s of id %d to %s port %d\n",
1373 inet_ntop(packet->dst_ipaddr.af,
1374 &packet->dst_ipaddr.ipaddr,
1375 ip_buffer, sizeof(ip_buffer)),
1379 * Double-check some things based on packet code.
1381 switch (packet->code) {
1382 case PW_AUTHENTICATION_ACK:
1383 case PW_AUTHENTICATION_REJECT:
1384 case PW_ACCESS_CHALLENGE:
1386 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1392 * These packet vectors start off as all zero.
1394 case PW_ACCOUNTING_REQUEST:
1395 case PW_DISCONNECT_REQUEST:
1396 case PW_COA_REQUEST:
1397 memset(packet->vector, 0, sizeof(packet->vector));
1405 * Use memory on the stack, until we know how
1406 * large the packet will be.
1408 hdr = (radius_packet_t *) data;
1411 * Build standard header
1413 hdr->code = packet->code;
1414 hdr->id = packet->id;
1416 memcpy(hdr->vector, packet->vector, sizeof(hdr->vector));
1418 total_length = AUTH_HDR_LEN;
1421 * Load up the configuration values for the user
1427 * FIXME: Loop twice over the reply list. The first time,
1428 * calculate the total length of data. The second time,
1429 * allocate the memory, and fill in the VP's.
1431 * Hmm... this may be slower than just doing a small
1436 * Loop over the reply attributes for the packet.
1438 for (reply = packet->vps; reply; reply = reply->next) {
1440 * Ignore non-wire attributes, but allow extended
1443 if ((reply->vendor == 0) &&
1444 ((reply->attribute & 0xFFFF) >= 256) &&
1445 !reply->flags.extended && !reply->flags.extended_flags) {
1448 * Permit the admin to send BADLY formatted
1449 * attributes with a debug build.
1451 if (reply->attribute == PW_RAW_ATTRIBUTE) {
1452 memcpy(ptr, reply->vp_octets, reply->length);
1453 len = reply->length;
1461 * Set the Message-Authenticator to the correct
1462 * length and initial value.
1464 if (reply->attribute == PW_MESSAGE_AUTHENTICATOR) {
1465 reply->length = AUTH_VECTOR_LEN;
1466 memset(reply->vp_strvalue, 0, AUTH_VECTOR_LEN);
1469 * Cache the offset to the
1470 * Message-Authenticator
1472 packet->offset = total_length;
1476 * Print out ONLY the attributes which
1477 * we're sending over the wire, and print
1478 * them out BEFORE they're encrypted.
1483 * Skip attributes that have already been
1484 * encoded. This can be done when the "vp2attr"
1485 * function sees multiple contiguous TLVs.
1487 if (reply->flags.encoded) continue;
1489 len = rad_vp2attr(packet, original, secret, reply, ptr,
1490 ((uint8_t *) data) + sizeof(data) - ptr);
1491 if (len < 0) return -1;
1494 * Failed to encode the attribute, likely because
1495 * the packet is full.
1498 (total_length > (sizeof(data) - 2 - reply->length))) {
1499 DEBUG("WARNING: Attributes are too long for packet. Discarding data past %d bytes", total_length);
1505 total_length += len;
1506 } /* done looping over all attributes */
1509 * Fill in the rest of the fields, and copy the data over
1510 * from the local stack to the newly allocated memory.
1512 * Yes, all this 'memcpy' is slow, but it means
1513 * that we only allocate the minimum amount of
1514 * memory for a request.
1516 packet->data_len = total_length;
1517 packet->data = (uint8_t *) malloc(packet->data_len);
1518 if (!packet->data) {
1519 fr_strerror_printf("Out of memory");
1523 memcpy(packet->data, hdr, packet->data_len);
1524 hdr = (radius_packet_t *) packet->data;
1526 total_length = htons(total_length);
1527 memcpy(hdr->length, &total_length, sizeof(total_length));
1534 * Sign a previously encoded packet.
1536 int rad_sign(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1539 radius_packet_t *hdr = (radius_packet_t *)packet->data;
1542 * It wasn't assigned an Id, this is bad!
1544 if (packet->id < 0) {
1545 fr_strerror_printf("ERROR: RADIUS packets must be assigned an Id.");
1549 if (!packet->data || (packet->data_len < AUTH_HDR_LEN) ||
1550 (packet->offset < 0)) {
1551 fr_strerror_printf("ERROR: You must call rad_encode() before rad_sign()");
1556 * If there's a Message-Authenticator, update it
1557 * now, BEFORE updating the authentication vector.
1559 if (packet->offset > 0) {
1560 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
1562 switch (packet->code) {
1563 case PW_ACCOUNTING_REQUEST:
1564 case PW_ACCOUNTING_RESPONSE:
1565 case PW_DISCONNECT_REQUEST:
1566 case PW_DISCONNECT_ACK:
1567 case PW_DISCONNECT_NAK:
1568 case PW_COA_REQUEST:
1571 memset(hdr->vector, 0, AUTH_VECTOR_LEN);
1574 case PW_AUTHENTICATION_ACK:
1575 case PW_AUTHENTICATION_REJECT:
1576 case PW_ACCESS_CHALLENGE:
1578 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1581 memcpy(hdr->vector, original->vector,
1585 default: /* others have vector already set to zero */
1591 * Set the authentication vector to zero,
1592 * calculate the signature, and put it
1593 * into the Message-Authenticator
1596 fr_hmac_md5(packet->data, packet->data_len,
1597 (const uint8_t *) secret, strlen(secret),
1599 memcpy(packet->data + packet->offset + 2,
1600 calc_auth_vector, AUTH_VECTOR_LEN);
1603 * Copy the original request vector back
1604 * to the raw packet.
1606 memcpy(hdr->vector, packet->vector, AUTH_VECTOR_LEN);
1610 * Switch over the packet code, deciding how to
1613 switch (packet->code) {
1615 * Request packets are not signed, bur
1616 * have a random authentication vector.
1618 case PW_AUTHENTICATION_REQUEST:
1619 case PW_STATUS_SERVER:
1623 * Reply packets are signed with the
1624 * authentication vector of the request.
1631 fr_MD5Init(&context);
1632 fr_MD5Update(&context, packet->data, packet->data_len);
1633 fr_MD5Update(&context, (const uint8_t *) secret,
1635 fr_MD5Final(digest, &context);
1637 memcpy(hdr->vector, digest, AUTH_VECTOR_LEN);
1638 memcpy(packet->vector, digest, AUTH_VECTOR_LEN);
1641 }/* switch over packet codes */
1647 * Reply to the request. Also attach
1648 * reply attribute value pairs and any user message provided.
1650 int rad_send(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1655 char ip_buffer[128];
1658 * Maybe it's a fake packet. Don't send it.
1660 if (!packet || (packet->sockfd < 0)) {
1664 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1665 what = fr_packet_codes[packet->code];
1671 * First time through, allocate room for the packet
1673 if (!packet->data) {
1675 * Encode the packet.
1677 if (rad_encode(packet, original, secret) < 0) {
1682 * Re-sign it, including updating the
1683 * Message-Authenticator.
1685 if (rad_sign(packet, original, secret) < 0) {
1690 * If packet->data points to data, then we print out
1691 * the VP list again only for debugging.
1693 } else if (fr_debug_flag) {
1694 DEBUG("Sending %s of id %d to %s port %d\n", what, packet->id,
1695 inet_ntop(packet->dst_ipaddr.af,
1696 &packet->dst_ipaddr.ipaddr,
1697 ip_buffer, sizeof(ip_buffer)),
1700 for (reply = packet->vps; reply; reply = reply->next) {
1701 if ((reply->vendor == 0) &&
1702 ((reply->attribute & 0xFFFF) > 0xff)) continue;
1708 * And send it on it's way.
1710 return rad_sendto(packet->sockfd, packet->data, packet->data_len, 0,
1711 &packet->src_ipaddr, packet->src_port,
1712 &packet->dst_ipaddr, packet->dst_port);
1716 * Do a comparison of two authentication digests by comparing
1717 * the FULL digest. Otehrwise, the server can be subject to
1718 * timing attacks that allow attackers find a valid message
1721 * http://www.cs.rice.edu/~dwallach/pub/crosby-timing2009.pdf
1723 static int digest_cmp(const uint8_t *a, const uint8_t *b, size_t length)
1728 for (i = 0; i < length; i++) {
1729 result |= a[i] ^ b[i];
1732 return result; /* 0 is OK, !0 is !OK, just like memcmp */
1737 * Validates the requesting client NAS. Calculates the
1738 * signature based on the clients private key.
1740 static int calc_acctdigest(RADIUS_PACKET *packet, const char *secret)
1742 uint8_t digest[AUTH_VECTOR_LEN];
1746 * Zero out the auth_vector in the received packet.
1747 * Then append the shared secret to the received packet,
1748 * and calculate the MD5 sum. This must be the same
1749 * as the original MD5 sum (packet->vector).
1751 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
1754 * MD5(packet + secret);
1756 fr_MD5Init(&context);
1757 fr_MD5Update(&context, packet->data, packet->data_len);
1758 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1759 fr_MD5Final(digest, &context);
1762 * Return 0 if OK, 2 if not OK.
1764 if (digest_cmp(digest, packet->vector, AUTH_VECTOR_LEN) != 0) return 2;
1770 * Validates the requesting client NAS. Calculates the
1771 * signature based on the clients private key.
1773 static int calc_replydigest(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1776 uint8_t calc_digest[AUTH_VECTOR_LEN];
1782 if (original == NULL) {
1787 * Copy the original vector in place.
1789 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
1792 * MD5(packet + secret);
1794 fr_MD5Init(&context);
1795 fr_MD5Update(&context, packet->data, packet->data_len);
1796 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1797 fr_MD5Final(calc_digest, &context);
1800 * Copy the packet's vector back to the packet.
1802 memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
1805 * Return 0 if OK, 2 if not OK.
1807 if (digest_cmp(packet->vector, calc_digest, AUTH_VECTOR_LEN) != 0) return 2;
1813 * Check if a set of RADIUS formatted TLVs are OK.
1815 int rad_tlv_ok(const uint8_t *data, size_t length,
1816 size_t dv_type, size_t dv_length)
1818 const uint8_t *end = data + length;
1820 if ((dv_length > 2) || (dv_type == 0) || (dv_type > 4)) {
1821 fr_strerror_printf("rad_tlv_ok: Invalid arguments");
1825 while (data < end) {
1828 if ((data + dv_type + dv_length) > end) {
1829 fr_strerror_printf("Attribute header overflow");
1835 if ((data[0] == 0) && (data[1] == 0) &&
1836 (data[2] == 0) && (data[3] == 0)) {
1838 fr_strerror_printf("Invalid attribute 0");
1843 fr_strerror_printf("Invalid attribute > 2^24");
1849 if ((data[1] == 0) && (data[1] == 0)) goto zero;
1853 if (data[0] == 0) goto zero;
1857 fr_strerror_printf("Internal sanity check failed");
1861 switch (dv_length) {
1866 if (data[dv_type + 1] != 0) {
1867 fr_strerror_printf("Attribute is longer than 256 octets");
1872 attrlen = data[dv_type + dv_length - 1];
1877 fr_strerror_printf("Internal sanity check failed");
1881 if (attrlen < (dv_type + dv_length)) {
1882 fr_strerror_printf("Attribute header has invalid length");
1886 if (attrlen > length) {
1887 fr_strerror_printf("Attribute overflows container");
1900 * See if the data pointed to by PTR is a valid RADIUS packet.
1902 * packet is not 'const * const' because we may update data_len,
1903 * if there's more data in the UDP packet than in the RADIUS packet.
1905 int rad_packet_ok(RADIUS_PACKET *packet, int flags)
1910 radius_packet_t *hdr;
1911 char host_ipaddr[128];
1917 * Check for packets smaller than the packet header.
1919 * RFC 2865, Section 3., subsection 'length' says:
1921 * "The minimum length is 20 ..."
1923 if (packet->data_len < AUTH_HDR_LEN) {
1924 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (received %d < minimum %d)",
1925 inet_ntop(packet->src_ipaddr.af,
1926 &packet->src_ipaddr.ipaddr,
1927 host_ipaddr, sizeof(host_ipaddr)),
1928 (int) packet->data_len, AUTH_HDR_LEN);
1933 * RFC 2865, Section 3., subsection 'length' says:
1935 * " ... and maximum length is 4096."
1937 if (packet->data_len > MAX_PACKET_LEN) {
1938 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (received %d > maximum %d)",
1939 inet_ntop(packet->src_ipaddr.af,
1940 &packet->src_ipaddr.ipaddr,
1941 host_ipaddr, sizeof(host_ipaddr)),
1942 (int) packet->data_len, MAX_PACKET_LEN);
1947 * Check for packets with mismatched size.
1948 * i.e. We've received 128 bytes, and the packet header
1949 * says it's 256 bytes long.
1951 totallen = (packet->data[2] << 8) | packet->data[3];
1952 hdr = (radius_packet_t *)packet->data;
1955 * Code of 0 is not understood.
1956 * Code of 16 or greate is not understood.
1958 if ((hdr->code == 0) ||
1959 (hdr->code >= FR_MAX_PACKET_CODE)) {
1960 fr_strerror_printf("WARNING: Bad RADIUS packet from host %s: unknown packet code%d ",
1961 inet_ntop(packet->src_ipaddr.af,
1962 &packet->src_ipaddr.ipaddr,
1963 host_ipaddr, sizeof(host_ipaddr)),
1969 * Message-Authenticator is required in Status-Server
1970 * packets, otherwise they can be trivially forged.
1972 if (hdr->code == PW_STATUS_SERVER) require_ma = 1;
1975 * It's also required if the caller asks for it.
1977 if (flags) require_ma = 1;
1980 * Repeat the length checks. This time, instead of
1981 * looking at the data we received, look at the value
1982 * of the 'length' field inside of the packet.
1984 * Check for packets smaller than the packet header.
1986 * RFC 2865, Section 3., subsection 'length' says:
1988 * "The minimum length is 20 ..."
1990 if (totallen < AUTH_HDR_LEN) {
1991 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (length %d < minimum %d)",
1992 inet_ntop(packet->src_ipaddr.af,
1993 &packet->src_ipaddr.ipaddr,
1994 host_ipaddr, sizeof(host_ipaddr)),
1995 totallen, AUTH_HDR_LEN);
2000 * And again, for the value of the 'length' field.
2002 * RFC 2865, Section 3., subsection 'length' says:
2004 * " ... and maximum length is 4096."
2006 if (totallen > MAX_PACKET_LEN) {
2007 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (length %d > maximum %d)",
2008 inet_ntop(packet->src_ipaddr.af,
2009 &packet->src_ipaddr.ipaddr,
2010 host_ipaddr, sizeof(host_ipaddr)),
2011 totallen, MAX_PACKET_LEN);
2016 * RFC 2865, Section 3., subsection 'length' says:
2018 * "If the packet is shorter than the Length field
2019 * indicates, it MUST be silently discarded."
2021 * i.e. No response to the NAS.
2023 if (packet->data_len < totallen) {
2024 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: received %d octets, packet length says %d",
2025 inet_ntop(packet->src_ipaddr.af,
2026 &packet->src_ipaddr.ipaddr,
2027 host_ipaddr, sizeof(host_ipaddr)),
2028 (int) packet->data_len, totallen);
2033 * RFC 2865, Section 3., subsection 'length' says:
2035 * "Octets outside the range of the Length field MUST be
2036 * treated as padding and ignored on reception."
2038 if (packet->data_len > totallen) {
2040 * We're shortening the packet below, but just
2041 * to be paranoid, zero out the extra data.
2043 memset(packet->data + totallen, 0, packet->data_len - totallen);
2044 packet->data_len = totallen;
2048 * Walk through the packet's attributes, ensuring that
2049 * they add up EXACTLY to the size of the packet.
2051 * If they don't, then the attributes either under-fill
2052 * or over-fill the packet. Any parsing of the packet
2053 * is impossible, and will result in unknown side effects.
2055 * This would ONLY happen with buggy RADIUS implementations,
2056 * or with an intentional attack. Either way, we do NOT want
2057 * to be vulnerable to this problem.
2060 count = totallen - AUTH_HDR_LEN;
2065 * We need at least 2 bytes to check the
2069 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute header overflows the packet",
2070 inet_ntop(packet->src_ipaddr.af,
2071 &packet->src_ipaddr.ipaddr,
2072 host_ipaddr, sizeof(host_ipaddr)));
2077 * Attribute number zero is NOT defined.
2080 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Invalid attribute 0",
2081 inet_ntop(packet->src_ipaddr.af,
2082 &packet->src_ipaddr.ipaddr,
2083 host_ipaddr, sizeof(host_ipaddr)));
2088 * Attributes are at LEAST as long as the ID & length
2089 * fields. Anything shorter is an invalid attribute.
2092 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %u too short",
2093 inet_ntop(packet->src_ipaddr.af,
2094 &packet->src_ipaddr.ipaddr,
2095 host_ipaddr, sizeof(host_ipaddr)),
2101 * If there are fewer bytes in the packet than in the
2102 * attribute, it's a bad packet.
2104 if (count < attr[1]) {
2105 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %u data overflows the packet",
2106 inet_ntop(packet->src_ipaddr.af,
2107 &packet->src_ipaddr.ipaddr,
2108 host_ipaddr, sizeof(host_ipaddr)),
2114 * Sanity check the attributes for length.
2117 default: /* don't do anything by default */
2121 * If there's an EAP-Message, we require
2122 * a Message-Authenticator.
2124 case PW_EAP_MESSAGE:
2128 case PW_MESSAGE_AUTHENTICATOR:
2129 if (attr[1] != 2 + AUTH_VECTOR_LEN) {
2130 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Message-Authenticator has invalid length %d",
2131 inet_ntop(packet->src_ipaddr.af,
2132 &packet->src_ipaddr.ipaddr,
2133 host_ipaddr, sizeof(host_ipaddr)),
2142 * FIXME: Look up the base 255 attributes in the
2143 * dictionary, and switch over their type. For
2144 * integer/date/ip, the attribute length SHOULD
2147 count -= attr[1]; /* grab the attribute length */
2149 num_attributes++; /* seen one more attribute */
2153 * If the attributes add up to a packet, it's allowed.
2155 * If not, we complain, and throw the packet away.
2158 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: packet attributes do NOT exactly fill the packet",
2159 inet_ntop(packet->src_ipaddr.af,
2160 &packet->src_ipaddr.ipaddr,
2161 host_ipaddr, sizeof(host_ipaddr)));
2166 * If we're configured to look for a maximum number of
2167 * attributes, and we've seen more than that maximum,
2168 * then throw the packet away, as a possible DoS.
2170 if ((fr_max_attributes > 0) &&
2171 (num_attributes > fr_max_attributes)) {
2172 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
2173 inet_ntop(packet->src_ipaddr.af,
2174 &packet->src_ipaddr.ipaddr,
2175 host_ipaddr, sizeof(host_ipaddr)),
2176 num_attributes, fr_max_attributes);
2181 * http://www.freeradius.org/rfc/rfc2869.html#EAP-Message
2183 * A packet with an EAP-Message attribute MUST also have
2184 * a Message-Authenticator attribute.
2186 * A Message-Authenticator all by itself is OK, though.
2188 * Similarly, Status-Server packets MUST contain
2189 * Message-Authenticator attributes.
2191 if (require_ma && ! seen_ma) {
2192 fr_strerror_printf("WARNING: Insecure packet from host %s: Packet does not contain required Message-Authenticator attribute",
2193 inet_ntop(packet->src_ipaddr.af,
2194 &packet->src_ipaddr.ipaddr,
2195 host_ipaddr, sizeof(host_ipaddr)));
2200 * Fill RADIUS header fields
2202 packet->code = hdr->code;
2203 packet->id = hdr->id;
2204 memcpy(packet->vector, hdr->vector, AUTH_VECTOR_LEN);
2211 * Receive UDP client requests, and fill in
2212 * the basics of a RADIUS_PACKET structure.
2214 RADIUS_PACKET *rad_recv(int fd, int flags)
2217 RADIUS_PACKET *packet;
2220 * Allocate the new request data structure
2222 if ((packet = malloc(sizeof(*packet))) == NULL) {
2223 fr_strerror_printf("out of memory");
2226 memset(packet, 0, sizeof(*packet));
2229 sock_flags = MSG_PEEK;
2233 packet->data_len = rad_recvfrom(fd, &packet->data, sock_flags,
2234 &packet->src_ipaddr, &packet->src_port,
2235 &packet->dst_ipaddr, &packet->dst_port);
2238 * Check for socket errors.
2240 if (packet->data_len < 0) {
2241 fr_strerror_printf("Error receiving packet: %s", strerror(errno));
2242 /* packet->data is NULL */
2248 * If the packet is too big, then rad_recvfrom did NOT
2249 * allocate memory. Instead, it just discarded the
2252 if (packet->data_len > MAX_PACKET_LEN) {
2253 fr_strerror_printf("Discarding packet: Larger than RFC limitation of 4096 bytes.");
2254 /* packet->data is NULL */
2260 * Read no data. Continue.
2261 * This check is AFTER the MAX_PACKET_LEN check above, because
2262 * if the packet is larger than MAX_PACKET_LEN, we also have
2263 * packet->data == NULL
2265 if ((packet->data_len == 0) || !packet->data) {
2266 fr_strerror_printf("Empty packet: Socket is not ready.");
2272 * See if it's a well-formed RADIUS packet.
2274 if (!rad_packet_ok(packet, flags)) {
2280 * Remember which socket we read the packet from.
2282 packet->sockfd = fd;
2285 * FIXME: Do even more filtering by only permitting
2286 * certain IP's. The problem is that we don't know
2287 * how to do this properly for all possible clients...
2291 * Explicitely set the VP list to empty.
2295 if (fr_debug_flag) {
2296 char host_ipaddr[128];
2298 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
2299 DEBUG("rad_recv: %s packet from host %s port %d",
2300 fr_packet_codes[packet->code],
2301 inet_ntop(packet->src_ipaddr.af,
2302 &packet->src_ipaddr.ipaddr,
2303 host_ipaddr, sizeof(host_ipaddr)),
2306 DEBUG("rad_recv: Packet from host %s port %d code=%d",
2307 inet_ntop(packet->src_ipaddr.af,
2308 &packet->src_ipaddr.ipaddr,
2309 host_ipaddr, sizeof(host_ipaddr)),
2313 DEBUG(", id=%d, length=%d\n",
2314 packet->id, (int) packet->data_len);
2322 * Verify the signature of a packet.
2324 int rad_verify(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2331 if (!packet || !packet->data) return -1;
2334 * Before we allocate memory for the attributes, do more
2337 ptr = packet->data + AUTH_HDR_LEN;
2338 length = packet->data_len - AUTH_HDR_LEN;
2339 while (length > 0) {
2340 uint8_t msg_auth_vector[AUTH_VECTOR_LEN];
2341 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
2346 default: /* don't do anything. */
2350 * Note that more than one Message-Authenticator
2351 * attribute is invalid.
2353 case PW_MESSAGE_AUTHENTICATOR:
2354 memcpy(msg_auth_vector, &ptr[2], sizeof(msg_auth_vector));
2355 memset(&ptr[2], 0, AUTH_VECTOR_LEN);
2357 switch (packet->code) {
2361 case PW_ACCOUNTING_REQUEST:
2362 case PW_ACCOUNTING_RESPONSE:
2363 case PW_DISCONNECT_REQUEST:
2364 case PW_DISCONNECT_ACK:
2365 case PW_DISCONNECT_NAK:
2366 case PW_COA_REQUEST:
2369 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
2372 case PW_AUTHENTICATION_ACK:
2373 case PW_AUTHENTICATION_REJECT:
2374 case PW_ACCESS_CHALLENGE:
2376 fr_strerror_printf("ERROR: Cannot validate Message-Authenticator in response packet without a request packet.");
2379 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
2383 fr_hmac_md5(packet->data, packet->data_len,
2384 (const uint8_t *) secret, strlen(secret),
2386 if (digest_cmp(calc_auth_vector, msg_auth_vector,
2387 sizeof(calc_auth_vector)) != 0) {
2389 fr_strerror_printf("Received packet from %s with invalid Message-Authenticator! (Shared secret is incorrect.)",
2390 inet_ntop(packet->src_ipaddr.af,
2391 &packet->src_ipaddr.ipaddr,
2392 buffer, sizeof(buffer)));
2393 /* Silently drop packet, according to RFC 3579 */
2395 } /* else the message authenticator was good */
2398 * Reinitialize Authenticators.
2400 memcpy(&ptr[2], msg_auth_vector, AUTH_VECTOR_LEN);
2401 memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
2403 } /* switch over the attributes */
2407 } /* loop over the packet, sanity checking the attributes */
2410 * It looks like a RADIUS packet, but we can't validate
2413 if ((packet->code == 0) || (packet->code >= FR_MAX_PACKET_CODE)) {
2415 fr_strerror_printf("Received Unknown packet code %d "
2416 "from client %s port %d: Cannot validate signature.",
2418 inet_ntop(packet->src_ipaddr.af,
2419 &packet->src_ipaddr.ipaddr,
2420 buffer, sizeof(buffer)),
2426 * Calculate and/or verify digest.
2428 switch(packet->code) {
2432 case PW_AUTHENTICATION_REQUEST:
2433 case PW_STATUS_SERVER:
2435 * The authentication vector is random
2436 * nonsense, invented by the client.
2440 case PW_COA_REQUEST:
2441 case PW_DISCONNECT_REQUEST:
2442 case PW_ACCOUNTING_REQUEST:
2443 if (calc_acctdigest(packet, secret) > 1) {
2444 fr_strerror_printf("Received %s packet "
2445 "from client %s with invalid signature! (Shared secret is incorrect.)",
2446 fr_packet_codes[packet->code],
2447 inet_ntop(packet->src_ipaddr.af,
2448 &packet->src_ipaddr.ipaddr,
2449 buffer, sizeof(buffer)));
2454 /* Verify the reply digest */
2455 case PW_AUTHENTICATION_ACK:
2456 case PW_AUTHENTICATION_REJECT:
2457 case PW_ACCESS_CHALLENGE:
2458 case PW_ACCOUNTING_RESPONSE:
2459 case PW_DISCONNECT_ACK:
2460 case PW_DISCONNECT_NAK:
2463 rcode = calc_replydigest(packet, original, secret);
2465 fr_strerror_printf("Received %s packet "
2466 "from home server %s port %d with invalid signature! (Shared secret is incorrect.)",
2467 fr_packet_codes[packet->code],
2468 inet_ntop(packet->src_ipaddr.af,
2469 &packet->src_ipaddr.ipaddr,
2470 buffer, sizeof(buffer)),
2477 fr_strerror_printf("Received Unknown packet code %d "
2478 "from client %s port %d: Cannot validate signature",
2480 inet_ntop(packet->src_ipaddr.af,
2481 &packet->src_ipaddr.ipaddr,
2482 buffer, sizeof(buffer)),
2492 * Create a "raw" attribute from the attribute contents.
2494 static ssize_t data2vp_raw(UNUSED const RADIUS_PACKET *packet,
2495 UNUSED const RADIUS_PACKET *original,
2496 UNUSED const char *secret,
2497 unsigned int attribute, unsigned int vendor,
2498 const uint8_t *data, size_t length,
2504 * Keep the next function happy.
2506 vp = pairalloc(NULL);
2507 vp = paircreate_raw(attribute, vendor, PW_TYPE_OCTETS, vp);
2509 fr_strerror_printf("data2vp_raw: Failed creating attribute");
2513 vp->length = length;
2516 * If the data is too large, mark it as a "TLV".
2518 if (length <= sizeof(vp->vp_octets)) {
2519 memcpy(vp->vp_octets, data, length);
2521 vp->type = PW_TYPE_TLV;
2522 vp->vp_tlv = malloc(length);
2527 memcpy(vp->vp_tlv, data, length);
2536 static ssize_t data2vp_tlvs(const RADIUS_PACKET *packet,
2537 const RADIUS_PACKET *original,
2539 unsigned int attribute, unsigned int vendor,
2541 const uint8_t *start, size_t length,
2545 * Create any kind of VP from the attribute contents.
2547 * Will return -1 on error, or "length".
2549 static ssize_t data2vp_any(const RADIUS_PACKET *packet,
2550 const RADIUS_PACKET *original,
2551 const char *secret, int nest,
2552 unsigned int attribute, unsigned int vendor,
2553 const uint8_t *data, size_t length,
2556 int data_offset = 0;
2558 VALUE_PAIR *vp = NULL;
2562 * Hacks for CUI. The WiMAX spec says that it
2563 * can be zero length, even though this is
2564 * forbidden by the RADIUS specs. So... we make
2565 * a special case for it.
2567 if ((vendor == 0) &&
2568 (attribute == PW_CHARGEABLE_USER_IDENTITY)) {
2569 data = (const uint8_t *) "";
2577 da = dict_attrbyvalue(attribute, vendor);
2580 * Unknown attribute. Create it as a "raw" attribute.
2584 if (vp) pairfree(&vp);
2585 return data2vp_raw(packet, original, secret,
2586 attribute, vendor, data, length, pvp);
2590 * TLVs are handled first. They can't be tagged, and
2591 * they can't be encrypted.
2593 if (da->type == PW_TYPE_TLV) {
2594 return data2vp_tlvs(packet, original, secret,
2595 attribute, vendor, nest,
2600 * The attribute is known, and well formed. We can now
2601 * create it. The main failure from here on in is being
2610 if (vp->flags.has_tag) {
2611 if (TAG_VALID(data[0]) ||
2612 (vp->flags.encrypt == FLAG_ENCRYPT_TUNNEL_PASSWORD)) {
2614 * Tunnel passwords REQUIRE a tag, even
2615 * if don't have a valid tag.
2617 vp->flags.tag = data[0];
2619 if ((vp->type == PW_TYPE_STRING) ||
2620 (vp->type == PW_TYPE_OCTETS)) {
2621 if (length == 0) goto raw;
2628 * Copy the data to be decrypted
2630 vp->length = length - data_offset;
2631 memcpy(&vp->vp_octets[0], data + data_offset, vp->length);
2634 * Decrypt the attribute.
2636 switch (vp->flags.encrypt) {
2640 case FLAG_ENCRYPT_USER_PASSWORD:
2642 rad_pwdecode(vp->vp_strvalue,
2646 rad_pwdecode(vp->vp_strvalue,
2650 if (vp->attribute == PW_USER_PASSWORD) {
2651 vp->length = strlen(vp->vp_strvalue);
2656 * Tunnel-Password's may go ONLY
2657 * in response packets.
2659 case FLAG_ENCRYPT_TUNNEL_PASSWORD:
2660 if (!original) goto raw;
2662 if (rad_tunnel_pwdecode(vp->vp_octets, &vp->length,
2663 secret, original->vector) < 0) {
2669 * Ascend-Send-Secret
2670 * Ascend-Receive-Secret
2672 case FLAG_ENCRYPT_ASCEND_SECRET:
2676 uint8_t my_digest[AUTH_VECTOR_LEN];
2677 make_secret(my_digest,
2680 memcpy(vp->vp_strvalue, my_digest,
2682 vp->vp_strvalue[AUTH_VECTOR_LEN] = '\0';
2683 vp->length = strlen(vp->vp_strvalue);
2689 } /* switch over encryption flags */
2693 case PW_TYPE_STRING:
2694 case PW_TYPE_OCTETS:
2695 case PW_TYPE_ABINARY:
2696 /* nothing more to do */
2700 if (vp->length != 1) goto raw;
2702 vp->vp_integer = vp->vp_octets[0];
2707 if (vp->length != 2) goto raw;
2709 vp->vp_integer = (vp->vp_octets[0] << 8) | vp->vp_octets[1];
2712 case PW_TYPE_INTEGER:
2713 if (vp->length != 4) goto raw;
2715 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2716 vp->vp_integer = ntohl(vp->vp_integer);
2718 if (vp->flags.has_tag) vp->vp_integer &= 0x00ffffff;
2721 * Try to get named VALUEs
2725 dval = dict_valbyattr(vp->attribute, vp->vendor,
2728 strlcpy(vp->vp_strvalue,
2730 sizeof(vp->vp_strvalue));
2736 if (vp->length != 4) goto raw;
2738 memcpy(&vp->vp_date, vp->vp_octets, 4);
2739 vp->vp_date = ntohl(vp->vp_date);
2743 case PW_TYPE_IPADDR:
2744 if (vp->length != 4) goto raw;
2746 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2750 * IPv6 interface ID is 8 octets long.
2753 if (vp->length != 8) goto raw;
2754 /* vp->vp_ifid == vp->vp_octets */
2758 * IPv6 addresses are 16 octets long
2760 case PW_TYPE_IPV6ADDR:
2761 if (vp->length != 16) goto raw;
2762 /* vp->vp_ipv6addr == vp->vp_octets */
2766 * IPv6 prefixes are 2 to 18 octets long.
2768 * RFC 3162: The first octet is unused.
2769 * The second is the length of the prefix
2770 * the rest are the prefix data.
2772 * The prefix length can have value 0 to 128.
2774 case PW_TYPE_IPV6PREFIX:
2775 if (vp->length < 2 || vp->length > 18) goto raw;
2776 if (vp->vp_octets[1] > 128) goto raw;
2779 * FIXME: double-check that
2780 * (vp->vp_octets[1] >> 3) matches vp->length + 2
2782 if (vp->length < 18) {
2783 memset(vp->vp_octets + vp->length, 0,
2788 case PW_TYPE_SIGNED:
2789 if (vp->length != 4) goto raw;
2792 * Overload vp_integer for ntohl, which takes
2793 * uint32_t, not int32_t
2795 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2796 vp->vp_integer = ntohl(vp->vp_integer);
2797 memcpy(&vp->vp_signed, &vp->vp_integer, 4);
2802 fr_strerror_printf("data2vp_any: Internal sanity check failed");
2805 case PW_TYPE_COMBO_IP:
2806 if (vp->length == 4) {
2807 vp->type = PW_TYPE_IPADDR;
2808 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2811 } else if (vp->length == 16) {
2812 vp->type = PW_TYPE_IPV6ADDR;
2813 /* vp->vp_ipv6addr == vp->vp_octets */
2830 * Convert a top-level VSA to a VP.
2832 static ssize_t attr2vp_vsa(const RADIUS_PACKET *packet,
2833 const RADIUS_PACKET *original,
2834 const char *secret, unsigned int vendor,
2835 size_t dv_type, size_t dv_length,
2836 const uint8_t *data, size_t length,
2839 unsigned int attribute;
2840 ssize_t attrlen, my_len;
2843 if (length <= (dv_type + dv_length)) {
2844 fr_strerror_printf("attr2vp_vsa: Failure to call rad_tlv_ok");
2851 /* data[0] must be zero */
2852 attribute = data[1] << 16;
2853 attribute |= data[2] << 8;
2854 attribute |= data[3];
2858 attribute = data[0] << 8;
2859 attribute |= data[1];
2863 attribute = data[0];
2867 fr_strerror_printf("attr2vp_vsa: Internal sanity check failed");
2871 switch (dv_length) {
2873 /* data[dv_type] must be zero */
2874 attrlen = data[dv_type + 1];
2878 attrlen = data[dv_type];
2886 fr_strerror_printf("attr2vp_vsa: Internal sanity check failed");
2891 if (attrlen <= (ssize_t) (dv_type + dv_length)) {
2892 fr_strerror_printf("attr2vp_vsa: Failure to call rad_tlv_ok");
2897 attrlen -= (dv_type + dv_length);
2899 my_len = data2vp_any(packet, original, secret, 0,
2901 data + dv_type + dv_length, attrlen, pvp);
2902 if (my_len < 0) return my_len;
2905 if (my_len != attrlen) {
2907 fr_strerror_printf("attr2vp_vsa: Incomplete decode %d != %d",
2908 (int) my_len, (int) attrlen);
2913 return dv_type + dv_length + attrlen;
2917 * Convert one or more TLVs to VALUE_PAIRs. This function can
2918 * be called recursively...
2920 static ssize_t data2vp_tlvs(const RADIUS_PACKET *packet,
2921 const RADIUS_PACKET *original,
2923 unsigned int attribute, unsigned int vendor,
2925 const uint8_t *start, size_t length,
2928 size_t dv_type, dv_length;
2929 const uint8_t *data, *end;
2930 VALUE_PAIR *head, **last, *vp;
2935 * The default format for a VSA is the RFC recommended
2942 * Top-level TLVs can be of a weird format. TLVs
2943 * encapsulated in a TLV can only be in the RFC format.
2947 dv = dict_vendorbyvalue(vendor);
2950 dv_length = dv->length;
2951 /* dict.c enforces sane values on the above fields */
2955 if (nest >= fr_attr_max_tlv) {
2956 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed in recursion");
2961 * The VSAs do not exactly fill the data,
2962 * The *entire* TLV is malformed.
2964 if (rad_tlv_ok(data, length, dv_type, dv_length) < 0) {
2965 return data2vp_raw(packet, original, secret,
2966 attribute, vendor, data, length, pvp);
2969 end = data + length;
2973 while (data < end) {
2974 unsigned int my_attr;
2975 unsigned int my_len;
2978 if ((data + dv_type + dv_length) > end) {
2979 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed in tlvs: Insufficient data");
2987 my_attr = attribute;
2988 my_attr |= ((data[0] & fr_attr_mask[nest + 1])
2989 << fr_attr_shift[nest + 1]);
2992 my_attr = (data[0] << 8) | data[1];
2996 my_attr = (data[1] << 16) | (data[1] << 8) | data[3];
3000 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed");
3004 switch (dv_length) {
3011 my_len = data[dv_type + dv_length - 1];
3015 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed");
3020 if (my_len < (dv_type + dv_length)) {
3021 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed in tlvs: underflow");
3026 if ((data + my_len) > end) {
3027 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed in tlvs: overflow");
3033 my_len -= dv_type + dv_length;
3036 * If this returns > 0, it returns "my_len"
3038 if (data2vp_any(packet, original, secret, nest + 1,
3040 data + dv_type + dv_length, my_len, &vp) < 0) {
3045 data += my_len + dv_type + dv_length;
3055 return data - start;
3060 * Group "continued" attributes together, and create VPs from them.
3061 * The caller ensures that the RADIUS packet is OK, and that the
3062 * continuations have all been checked.
3064 static ssize_t data2vp_continued(const RADIUS_PACKET *packet,
3065 const RADIUS_PACKET *original,
3067 const uint8_t *start, size_t length,
3068 VALUE_PAIR **pvp, int nest,
3069 unsigned int attribute, unsigned int vendor,
3070 int first_offset, int later_offset,
3074 uint8_t *attr, *ptr;
3075 const uint8_t *data;
3077 attr = malloc(attrlen);
3079 fr_strerror_printf("Out of memory");
3090 memcpy(ptr, data + first_offset, data[1] - first_offset);
3091 ptr += data[1] - first_offset;
3092 left -= data[1] - first_offset;
3097 if (data >= (start + length)) {
3098 fr_strerror_printf("data2vp_continued: Internal sanity check failed");
3102 memcpy(ptr, data + later_offset, data[1] - later_offset);
3103 ptr += data[1] - later_offset;
3104 left -= data[1] - later_offset;
3108 left = data2vp_any(packet, original, secret, nest,
3110 attr, attrlen, pvp);
3112 if (left < 0) return left;
3114 return data - start;
3119 * Create a "raw" VALUE_PAIR from a RADIUS attribute.
3121 ssize_t rad_attr2vp_raw(const RADIUS_PACKET *packet,
3122 const RADIUS_PACKET *original,
3124 const uint8_t *data, size_t length,
3129 if ((length < 2) || (data[1] < 2) || (data[1] > length)) {
3130 fr_strerror_printf("rad_attr2vp_raw: Invalid length");
3134 my_len = data2vp_raw(packet, original, secret, data[0], 0,
3135 data + 2, data[1] - 2, pvp);
3136 if (my_len < 0) return my_len;
3143 * Get the length of the data portion of all of the contiguous
3144 * continued attributes.
3146 * 0 for "no continuation"
3147 * -1 on malformed packets (continuation followed by non-wimax, etc.)
3149 static ssize_t wimax_attrlen(const uint8_t *start, const uint8_t *end)
3151 uint32_t lvalue = htonl(VENDORPEC_WIMAX);
3153 const uint8_t *data = start;
3155 if ((data[8] & 0x80) == 0) return 0;
3156 total = data[7] - 3;
3159 while (data < end) {
3161 if ((data + 9) > end) return -1;
3163 if ((data[0] != PW_VENDOR_SPECIFIC) ||
3165 (memcmp(data + 2, &lvalue, 4) != 0) ||
3166 (data[6] != start[6]) ||
3167 ((data[7] + 6) != data[1])) return -1;
3169 total += data[7] - 3;
3170 if ((data[8] & 0x80) == 0) break;
3179 * Get the length of the data portion of all of the contiguous
3180 * continued attributes.
3182 * 0 for "no continuation"
3183 * -1 on malformed packets (continuation followed by non-wimax, etc.)
3185 static ssize_t extended_attrlen(const uint8_t *start, const uint8_t *end)
3188 const uint8_t *data = start;
3190 if ((data[3] & 0x80) == 0) return 0;
3191 total = data[1] - 4;
3194 while (data < end) {
3195 if ((data + 4) > end) return -1;
3197 if ((data[0] != start[0]) ||
3199 (data[2] != start[2])) return -1;
3201 total += data[1] - 4;
3202 if ((data[3] & 0x80) == 0) break;
3211 * Create WiMAX VALUE_PAIRs from a RADIUS attribute.
3213 ssize_t rad_attr2vp_wimax(const RADIUS_PACKET *packet,
3214 const RADIUS_PACKET *original,
3216 const uint8_t *data, size_t length,
3220 unsigned int attribute;
3223 if ((length < 2) || (data[1] < 2) || (data[1] > length)) {
3224 fr_strerror_printf("rad_attr2vp_wimax: Invalid length");
3228 if (data[0] != PW_VENDOR_SPECIFIC) {
3229 fr_strerror_printf("rad_attr2vp_wimax: Invalid attribute");
3234 * Not enough room for a Vendor-Id. + WiMAX header
3237 return rad_attr2vp_raw(packet, original, secret,
3241 memcpy(&lvalue, data + 2, 4);
3242 lvalue = ntohl(lvalue);
3247 if (lvalue != VENDORPEC_WIMAX) {
3248 fr_strerror_printf("rad_attr2vp_wimax: Not a WiMAX attribute");
3253 * The WiMAX attribute is encapsulated in a VSA. If the
3254 * WiMAX length disagrees with the VSA length, it's malformed.
3256 if ((data[7] + 6) != data[1]) {
3257 return rad_attr2vp_raw(packet, original, secret,
3261 attribute = data[6];
3264 * Attribute is continued. Do some more work.
3267 my_len = wimax_attrlen(data, data + length);
3269 return rad_attr2vp_raw(packet, original, secret,
3273 return data2vp_continued(packet, original, secret,
3274 data, length, pvp, 0,
3275 data[6], VENDORPEC_WIMAX,
3279 my_len = data2vp_any(packet, original, secret, 0, attribute, lvalue,
3280 data + 9, data[1] - 9, pvp);
3281 if (my_len < 0) return my_len;
3287 * Create Vendor-Specifc VALUE_PAIRs from a RADIUS attribute.
3289 ssize_t rad_attr2vp_vsa(const RADIUS_PACKET *packet,
3290 const RADIUS_PACKET *original,
3292 const uint8_t *data, size_t length,
3295 size_t dv_type, dv_length;
3300 if ((length < 2) || (data[1] < 2) || (data[1] > length)) {
3301 fr_strerror_printf("rad_attr2vp_vsa: Invalid length");
3305 if (data[0] != PW_VENDOR_SPECIFIC) {
3306 fr_strerror_printf("rad_attr2vp_vsa: Invalid attribute");
3311 * Not enough room for a Vendor-Id.
3312 * Or the high octet of the Vendor-Id is set.
3314 if ((data[1] < 6) || (data[2] != 0)) {
3315 return rad_attr2vp_raw(packet, original, secret,
3319 memcpy(&lvalue, data + 2, 4);
3320 lvalue = ntohl(lvalue);
3323 * WiMAX gets its own set of magic.
3325 if (lvalue == VENDORPEC_WIMAX) {
3326 return rad_attr2vp_wimax(packet, original, secret,
3330 dv_type = dv_length = 1;
3331 dv = dict_vendorbyvalue(lvalue);
3334 dv_length = dv->length;
3338 * Attribute is not in the correct form.
3340 if (rad_tlv_ok(data + 6, data[1] - 6, dv_type, dv_length) < 0) {
3341 return rad_attr2vp_raw(packet, original, secret,
3345 my_len = attr2vp_vsa(packet, original, secret,
3346 lvalue, dv_type, dv_length,
3347 data + 6, data[1] - 6, pvp);
3348 if (my_len < 0) return my_len;
3351 if (my_len != (data[1] - 6)) {
3353 fr_strerror_printf("rad_attr2vp_vsa: Incomplete decode");
3362 * Create an "extended" VALUE_PAIR from a RADIUS attribute.
3364 ssize_t rad_attr2vp_extended(const RADIUS_PACKET *packet,
3365 const RADIUS_PACKET *original,
3367 const uint8_t *start, size_t length,
3370 unsigned int attribute;
3373 unsigned int vendor = VENDORPEC_EXTENDED;
3374 size_t data_len = length;
3375 const uint8_t *data;
3380 if ((length < 2) || (data[1] < 2) || (data[1] > length)) {
3381 fr_strerror_printf("rad_attr2vp_extended: Invalid length");
3385 da = dict_attrbyvalue(data[0], vendor);
3387 fr_strerror_printf("rad_attr2vp_extended: Attribute is not extended format");
3394 * No Extended-Type. It's a raw attribute.
3395 * Also, if there's no data following the Extended-Type,
3396 * it's a raw attribute.
3400 return rad_attr2vp_raw(packet, original, secret, start,
3405 * The attribute is "241.1", for example. Go look that
3406 * up to see what type it is.
3408 attribute = data[0];
3409 attribute |= (data[2] << fr_attr_shift[1]);
3411 da = dict_attrbyvalue(attribute, vendor);
3414 vendor = VENDORPEC_EXTENDED;
3417 if (data[1] < length) data_len = data[1];
3423 * If there's supposed to be a flag octet. If not, it's
3424 * a raw attribute. If the flag is set, it's supposed to
3427 if (da->flags.extended_flags) {
3428 if (data_len == 0) goto raw;
3430 continued = ((data[0] & 0x80) != 0);
3436 * Extended VSAs have 4 octets of
3437 * Vendor-Id followed by one octet of
3440 if (da->flags.evs) {
3441 if (data_len < 5) goto raw;
3444 * Vendor Ids can only be 24-bit.
3446 if (data[0] != 0) goto raw;
3448 vendor = ((data[1] << 16) |
3453 * Pack the *encapsulating* attribute number into
3456 vendor |= start[0] * FR_MAX_VENDOR;
3460 * Over-write the attribute with the
3463 attribute = data[4];
3469 int first_offset = 4;
3472 if (vendor != VENDORPEC_EXTENDED) first_offset += 5;
3474 my_len = extended_attrlen(start, start + length);
3475 if (my_len < 0) goto raw;
3477 if (vendor != VENDORPEC_EXTENDED) my_len -= 5;
3479 return data2vp_continued(packet, original, secret,
3480 start, length, pvp, shift,
3482 first_offset, 4, my_len);
3485 if (data2vp_any(packet, original, secret, shift,
3486 attribute, vendor, data, data_len, pvp) < 0) {
3490 return (data + data_len) - start;
3495 * Create a "standard" RFC VALUE_PAIR from the given data.
3497 ssize_t rad_attr2vp_rfc(const RADIUS_PACKET *packet,
3498 const RADIUS_PACKET *original,
3500 const uint8_t *data, size_t length,
3503 if ((length < 2) || (data[1] < 2) || (data[1] > length)) {
3504 fr_strerror_printf("rad_attr2vp_rfc: Insufficient data");
3508 if (data2vp_any(packet, original, secret, 0,
3509 data[0], 0, data + 2, data[1] - 2, pvp) < 0) {
3517 * Create a "normal" VALUE_PAIR from the given data.
3519 ssize_t rad_attr2vp(const RADIUS_PACKET *packet,
3520 const RADIUS_PACKET *original,
3522 const uint8_t *data, size_t length,
3525 if ((length < 2) || (data[1] < 2) || (data[1] > length)) {
3526 fr_strerror_printf("rad_attr2vp: Insufficient data");
3531 * VSAs get their own handler.
3533 if (data[0] == PW_VENDOR_SPECIFIC) {
3534 return rad_attr2vp_vsa(packet, original, secret,
3539 * Extended attribute format gets their own handler.
3541 if (dict_attrbyvalue(data[0], VENDORPEC_EXTENDED) != NULL) {
3542 return rad_attr2vp_extended(packet, original, secret,
3546 return rad_attr2vp_rfc(packet, original, secret, data, length, pvp);
3551 * Calculate/check digest, and decode radius attributes.
3553 * -1 on decoding error
3556 int rad_decode(RADIUS_PACKET *packet, RADIUS_PACKET *original,
3562 radius_packet_t *hdr;
3563 VALUE_PAIR *head, **tail, *vp;
3566 * Extract attribute-value pairs
3568 hdr = (radius_packet_t *)packet->data;
3570 packet_length = packet->data_len - AUTH_HDR_LEN;
3577 * Loop over the attributes, decoding them into VPs.
3579 while (packet_length > 0) {
3583 * This may return many VPs
3585 my_len = rad_attr2vp(packet, original, secret,
3586 ptr, packet_length, &vp);
3601 * VSA's may not have been counted properly in
3602 * rad_packet_ok() above, as it is hard to count
3603 * then without using the dictionary. We
3604 * therefore enforce the limits here, too.
3606 if ((fr_max_attributes > 0) &&
3607 (num_attributes > fr_max_attributes)) {
3608 char host_ipaddr[128];
3611 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
3612 inet_ntop(packet->src_ipaddr.af,
3613 &packet->src_ipaddr.ipaddr,
3614 host_ipaddr, sizeof(host_ipaddr)),
3615 num_attributes, fr_max_attributes);
3620 packet_length -= my_len;
3624 * Merge information from the outside world into our
3627 fr_rand_seed(packet->data, AUTH_HDR_LEN);
3630 * There may be VP's already in the packet. Don't
3631 * destroy them. Instead, add the decoded attributes to
3632 * the tail of the list.
3634 for (tail = &packet->vps; *tail != NULL; tail = &((*tail)->next)) {
3646 * We assume that the passwd buffer passed is big enough.
3647 * RFC2138 says the password is max 128 chars, so the size
3648 * of the passwd buffer must be at least 129 characters.
3649 * Preferably it's just MAX_STRING_LEN.
3651 * int *pwlen is updated to the new length of the encrypted
3652 * password - a multiple of 16 bytes.
3654 int rad_pwencode(char *passwd, size_t *pwlen, const char *secret,
3655 const uint8_t *vector)
3657 FR_MD5_CTX context, old;
3658 uint8_t digest[AUTH_VECTOR_LEN];
3659 int i, n, secretlen;
3663 * RFC maximum is 128 bytes.
3665 * If length is zero, pad it out with zeros.
3667 * If the length isn't aligned to 16 bytes,
3668 * zero out the extra data.
3672 if (len > 128) len = 128;
3675 memset(passwd, 0, AUTH_PASS_LEN);
3676 len = AUTH_PASS_LEN;
3677 } else if ((len % AUTH_PASS_LEN) != 0) {
3678 memset(&passwd[len], 0, AUTH_PASS_LEN - (len % AUTH_PASS_LEN));
3679 len += AUTH_PASS_LEN - (len % AUTH_PASS_LEN);
3684 * Use the secret to setup the decryption digest
3686 secretlen = strlen(secret);
3688 fr_MD5Init(&context);
3689 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3690 old = context; /* save intermediate work */
3693 * Encrypt it in place. Don't bother checking
3694 * len, as we've ensured above that it's OK.
3696 for (n = 0; n < len; n += AUTH_PASS_LEN) {
3698 fr_MD5Update(&context, vector, AUTH_PASS_LEN);
3699 fr_MD5Final(digest, &context);
3702 fr_MD5Update(&context,
3703 (uint8_t *) passwd + n - AUTH_PASS_LEN,
3705 fr_MD5Final(digest, &context);
3708 for (i = 0; i < AUTH_PASS_LEN; i++) {
3709 passwd[i + n] ^= digest[i];
3719 int rad_pwdecode(char *passwd, size_t pwlen, const char *secret,
3720 const uint8_t *vector)
3722 FR_MD5_CTX context, old;
3723 uint8_t digest[AUTH_VECTOR_LEN];
3725 size_t n, secretlen;
3728 * The RFC's say that the maximum is 128.
3729 * The buffer we're putting it into above is 254, so
3730 * we don't need to do any length checking.
3732 if (pwlen > 128) pwlen = 128;
3737 if (pwlen == 0) goto done;
3740 * Use the secret to setup the decryption digest
3742 secretlen = strlen(secret);
3744 fr_MD5Init(&context);
3745 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3746 old = context; /* save intermediate work */
3749 * The inverse of the code above.
3751 for (n = 0; n < pwlen; n += AUTH_PASS_LEN) {
3753 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3754 fr_MD5Final(digest, &context);
3757 if (pwlen > AUTH_PASS_LEN) {
3758 fr_MD5Update(&context, (uint8_t *) passwd,
3762 fr_MD5Final(digest, &context);
3765 if (pwlen > (n + AUTH_PASS_LEN)) {
3766 fr_MD5Update(&context, (uint8_t *) passwd + n,
3771 for (i = 0; i < AUTH_PASS_LEN; i++) {
3772 passwd[i + n] ^= digest[i];
3777 passwd[pwlen] = '\0';
3778 return strlen(passwd);
3783 * Encode Tunnel-Password attributes when sending them out on the wire.
3785 * int *pwlen is updated to the new length of the encrypted
3786 * password - a multiple of 16 bytes.
3788 * This is per RFC-2868 which adds a two char SALT to the initial intermediate
3791 int rad_tunnel_pwencode(char *passwd, size_t *pwlen, const char *secret,
3792 const uint8_t *vector)
3794 uint8_t buffer[AUTH_VECTOR_LEN + MAX_STRING_LEN + 3];
3795 unsigned char digest[AUTH_VECTOR_LEN];
3797 int i, n, secretlen;
3802 if (len > 127) len = 127;
3805 * Shift the password 3 positions right to place a salt and original
3806 * length, tag will be added automatically on packet send
3808 for (n=len ; n>=0 ; n--) passwd[n+3] = passwd[n];
3812 * save original password length as first password character;
3819 * Generate salt. The RFC's say:
3821 * The high bit of salt[0] must be set, each salt in a
3822 * packet should be unique, and they should be random
3824 * So, we set the high bit, add in a counter, and then
3825 * add in some CSPRNG data. should be OK..
3827 salt[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
3828 (fr_rand() & 0x07));
3829 salt[1] = fr_rand();
3832 * Padd password to multiple of AUTH_PASS_LEN bytes.
3834 n = len % AUTH_PASS_LEN;
3836 n = AUTH_PASS_LEN - n;
3837 for (; n > 0; n--, len++)
3840 /* set new password length */
3844 * Use the secret to setup the decryption digest
3846 secretlen = strlen(secret);
3847 memcpy(buffer, secret, secretlen);
3849 for (n2 = 0; n2 < len; n2+=AUTH_PASS_LEN) {
3851 memcpy(buffer + secretlen, vector, AUTH_VECTOR_LEN);
3852 memcpy(buffer + secretlen + AUTH_VECTOR_LEN, salt, 2);
3853 fr_md5_calc(digest, buffer, secretlen + AUTH_VECTOR_LEN + 2);
3855 memcpy(buffer + secretlen, passwd + n2 - AUTH_PASS_LEN, AUTH_PASS_LEN);
3856 fr_md5_calc(digest, buffer, secretlen + AUTH_PASS_LEN);
3859 for (i = 0; i < AUTH_PASS_LEN; i++) {
3860 passwd[i + n2] ^= digest[i];
3868 * Decode Tunnel-Password encrypted attributes.
3870 * Defined in RFC-2868, this uses a two char SALT along with the
3871 * initial intermediate value, to differentiate it from the
3874 int rad_tunnel_pwdecode(uint8_t *passwd, size_t *pwlen, const char *secret,
3875 const uint8_t *vector)
3877 FR_MD5_CTX context, old;
3878 uint8_t digest[AUTH_VECTOR_LEN];
3880 unsigned i, n, len, reallen;
3885 * We need at least a salt.
3888 fr_strerror_printf("tunnel password is too short");
3893 * There's a salt, but no password. Or, there's a salt
3894 * and a 'data_len' octet. It's wrong, but at least we
3895 * can figure out what it means: the password is empty.
3897 * Note that this means we ignore the 'data_len' field,
3898 * if the attribute length tells us that there's no
3899 * more data. So the 'data_len' field may be wrong,
3908 len -= 2; /* discount the salt */
3911 * Use the secret to setup the decryption digest
3913 secretlen = strlen(secret);
3915 fr_MD5Init(&context);
3916 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3917 old = context; /* save intermediate work */
3920 * Set up the initial key:
3922 * b(1) = MD5(secret + vector + salt)
3924 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3925 fr_MD5Update(&context, passwd, 2);
3928 for (n = 0; n < len; n += AUTH_PASS_LEN) {
3932 fr_MD5Final(digest, &context);
3937 * A quick check: decrypt the first octet
3938 * of the password, which is the
3939 * 'data_len' field. Ensure it's sane.
3941 reallen = passwd[2] ^ digest[0];
3942 if (reallen >= len) {
3943 fr_strerror_printf("tunnel password is too long for the attribute");
3947 fr_MD5Update(&context, passwd + 2, AUTH_PASS_LEN);
3951 fr_MD5Final(digest, &context);
3954 fr_MD5Update(&context, passwd + n + 2, AUTH_PASS_LEN);
3957 for (i = base; i < AUTH_PASS_LEN; i++) {
3958 passwd[n + i - 1] = passwd[n + i + 2] ^ digest[i];
3963 * See make_tunnel_password, above.
3965 if (reallen > 239) reallen = 239;
3968 passwd[reallen] = 0;
3974 * Encode a CHAP password
3976 * FIXME: might not work with Ascend because
3977 * we use vp->length, and Ascend gear likes
3978 * to send an extra '\0' in the string!
3980 int rad_chap_encode(RADIUS_PACKET *packet, uint8_t *output, int id,
3981 VALUE_PAIR *password)
3985 uint8_t string[MAX_STRING_LEN * 2 + 1];
3986 VALUE_PAIR *challenge;
3989 * Sanity check the input parameters
3991 if ((packet == NULL) || (password == NULL)) {
3996 * Note that the password VP can be EITHER
3997 * a User-Password attribute (from a check-item list),
3998 * or a CHAP-Password attribute (the client asking
3999 * the library to encode it).
4007 memcpy(ptr, password->vp_strvalue, password->length);
4008 ptr += password->length;
4009 i += password->length;
4012 * Use Chap-Challenge pair if present,
4013 * Request-Authenticator otherwise.
4015 challenge = pairfind(packet->vps, PW_CHAP_CHALLENGE, 0);
4017 memcpy(ptr, challenge->vp_strvalue, challenge->length);
4018 i += challenge->length;
4020 memcpy(ptr, packet->vector, AUTH_VECTOR_LEN);
4021 i += AUTH_VECTOR_LEN;
4025 fr_md5_calc((uint8_t *)output + 1, (uint8_t *)string, i);
4032 * Seed the random number generator.
4034 * May be called any number of times.
4036 void fr_rand_seed(const void *data, size_t size)
4041 * Ensure that the pool is initialized.
4043 if (!fr_rand_initialized) {
4046 memset(&fr_rand_pool, 0, sizeof(fr_rand_pool));
4048 fd = open("/dev/urandom", O_RDONLY);
4054 while (total < sizeof(fr_rand_pool.randrsl)) {
4055 this = read(fd, fr_rand_pool.randrsl,
4056 sizeof(fr_rand_pool.randrsl) - total);
4057 if ((this < 0) && (errno != EINTR)) break;
4058 if (this > 0) total += this;
4062 fr_rand_pool.randrsl[0] = fd;
4063 fr_rand_pool.randrsl[1] = time(NULL);
4064 fr_rand_pool.randrsl[2] = errno;
4067 fr_randinit(&fr_rand_pool, 1);
4068 fr_rand_pool.randcnt = 0;
4069 fr_rand_initialized = 1;
4075 * Hash the user data
4078 if (!hash) hash = fr_rand();
4079 hash = fr_hash_update(data, size, hash);
4081 fr_rand_pool.randmem[fr_rand_pool.randcnt] ^= hash;
4086 * Return a 32-bit random number.
4088 uint32_t fr_rand(void)
4093 * Ensure that the pool is initialized.
4095 if (!fr_rand_initialized) {
4096 fr_rand_seed(NULL, 0);
4099 num = fr_rand_pool.randrsl[fr_rand_pool.randcnt++];
4100 if (fr_rand_pool.randcnt >= 256) {
4101 fr_rand_pool.randcnt = 0;
4102 fr_isaac(&fr_rand_pool);
4110 * Allocate a new RADIUS_PACKET
4112 RADIUS_PACKET *rad_alloc(int newvector)
4116 if ((rp = malloc(sizeof(RADIUS_PACKET))) == NULL) {
4117 fr_strerror_printf("out of memory");
4120 memset(rp, 0, sizeof(*rp));
4126 uint32_t hash, base;
4129 * Don't expose the actual contents of the random
4133 for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(uint32_t)) {
4134 hash = fr_rand() ^ base;
4135 memcpy(rp->vector + i, &hash, sizeof(hash));
4138 fr_rand(); /* stir the pool again */
4143 RADIUS_PACKET *rad_alloc_reply(RADIUS_PACKET *packet)
4145 RADIUS_PACKET *reply;
4147 if (!packet) return NULL;
4149 reply = rad_alloc(0);
4150 if (!reply) return NULL;
4153 * Initialize the fields from the request.
4155 reply->sockfd = packet->sockfd;
4156 reply->dst_ipaddr = packet->src_ipaddr;
4157 reply->src_ipaddr = packet->dst_ipaddr;
4158 reply->dst_port = packet->src_port;
4159 reply->src_port = packet->dst_port;
4160 reply->id = packet->id;
4161 reply->code = 0; /* UNKNOWN code */
4162 memcpy(reply->vector, packet->vector,
4163 sizeof(reply->vector));
4166 reply->data_len = 0;
4173 * Free a RADIUS_PACKET
4175 void rad_free(RADIUS_PACKET **radius_packet_ptr)
4177 RADIUS_PACKET *radius_packet;
4179 if (!radius_packet_ptr || !*radius_packet_ptr) return;
4180 radius_packet = *radius_packet_ptr;
4182 free(radius_packet->data);
4184 pairfree(&radius_packet->vps);
4186 free(radius_packet);
4188 *radius_packet_ptr = NULL;