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");
826 if (vp->length > room) return 0; /* can't chop TLVs to fit */
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 return rad_vp2rfc(packet, original, secret, vp,
1329 if (vp->vendor > FR_MAX_VENDOR) {
1330 return rad_vp2extended(packet, original, secret, vp,
1334 if (vp->vendor == VENDORPEC_WIMAX) {
1335 return rad_vp2wimax(packet, original, secret, vp,
1339 return rad_vp2vsa(packet, original, secret, vp,
1347 int rad_encode(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1350 radius_packet_t *hdr;
1352 uint16_t total_length;
1356 char ip_buffer[128];
1359 * A 4K packet, aligned on 64-bits.
1361 uint64_t data[MAX_PACKET_LEN / sizeof(uint64_t)];
1363 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1364 what = fr_packet_codes[packet->code];
1369 DEBUG("Sending %s of id %d to %s port %d\n",
1371 inet_ntop(packet->dst_ipaddr.af,
1372 &packet->dst_ipaddr.ipaddr,
1373 ip_buffer, sizeof(ip_buffer)),
1377 * Double-check some things based on packet code.
1379 switch (packet->code) {
1380 case PW_AUTHENTICATION_ACK:
1381 case PW_AUTHENTICATION_REJECT:
1382 case PW_ACCESS_CHALLENGE:
1384 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1390 * These packet vectors start off as all zero.
1392 case PW_ACCOUNTING_REQUEST:
1393 case PW_DISCONNECT_REQUEST:
1394 case PW_COA_REQUEST:
1395 memset(packet->vector, 0, sizeof(packet->vector));
1403 * Use memory on the stack, until we know how
1404 * large the packet will be.
1406 hdr = (radius_packet_t *) data;
1409 * Build standard header
1411 hdr->code = packet->code;
1412 hdr->id = packet->id;
1414 memcpy(hdr->vector, packet->vector, sizeof(hdr->vector));
1416 total_length = AUTH_HDR_LEN;
1419 * Load up the configuration values for the user
1425 * FIXME: Loop twice over the reply list. The first time,
1426 * calculate the total length of data. The second time,
1427 * allocate the memory, and fill in the VP's.
1429 * Hmm... this may be slower than just doing a small
1434 * Loop over the reply attributes for the packet.
1436 for (reply = packet->vps; reply; reply = reply->next) {
1438 * Ignore non-wire attributes, but allow extended
1441 if ((reply->vendor == 0) &&
1442 ((reply->attribute & 0xFFFF) >= 256) &&
1443 !reply->flags.extended && !reply->flags.extended_flags) {
1446 * Permit the admin to send BADLY formatted
1447 * attributes with a debug build.
1449 if (reply->attribute == PW_RAW_ATTRIBUTE) {
1450 memcpy(ptr, reply->vp_octets, reply->length);
1451 len = reply->length;
1459 * Set the Message-Authenticator to the correct
1460 * length and initial value.
1462 if (reply->attribute == PW_MESSAGE_AUTHENTICATOR) {
1463 reply->length = AUTH_VECTOR_LEN;
1464 memset(reply->vp_strvalue, 0, AUTH_VECTOR_LEN);
1467 * Cache the offset to the
1468 * Message-Authenticator
1470 packet->offset = total_length;
1474 * Print out ONLY the attributes which
1475 * we're sending over the wire, and print
1476 * them out BEFORE they're encrypted.
1481 * Skip attributes that have already been
1482 * encoded. This can be done when the "vp2attr"
1483 * function sees multiple contiguous TLVs.
1485 if (reply->flags.encoded) continue;
1487 len = rad_vp2attr(packet, original, secret, reply, ptr,
1488 ((uint8_t *) data) + sizeof(data) - ptr);
1489 if (len < 0) return -1;
1492 * Failed to encode the attribute, likely because
1493 * the packet is full.
1496 (total_length > (sizeof(data) - 2 - reply->length))) {
1497 DEBUG("WARNING: Attributes are too long for packet. Discarding data past %d bytes", total_length);
1503 total_length += len;
1504 } /* done looping over all attributes */
1507 * Fill in the rest of the fields, and copy the data over
1508 * from the local stack to the newly allocated memory.
1510 * Yes, all this 'memcpy' is slow, but it means
1511 * that we only allocate the minimum amount of
1512 * memory for a request.
1514 packet->data_len = total_length;
1515 packet->data = (uint8_t *) malloc(packet->data_len);
1516 if (!packet->data) {
1517 fr_strerror_printf("Out of memory");
1521 memcpy(packet->data, hdr, packet->data_len);
1522 hdr = (radius_packet_t *) packet->data;
1524 total_length = htons(total_length);
1525 memcpy(hdr->length, &total_length, sizeof(total_length));
1532 * Sign a previously encoded packet.
1534 int rad_sign(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1537 radius_packet_t *hdr = (radius_packet_t *)packet->data;
1540 * It wasn't assigned an Id, this is bad!
1542 if (packet->id < 0) {
1543 fr_strerror_printf("ERROR: RADIUS packets must be assigned an Id.");
1547 if (!packet->data || (packet->data_len < AUTH_HDR_LEN) ||
1548 (packet->offset < 0)) {
1549 fr_strerror_printf("ERROR: You must call rad_encode() before rad_sign()");
1554 * If there's a Message-Authenticator, update it
1555 * now, BEFORE updating the authentication vector.
1557 if (packet->offset > 0) {
1558 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
1560 switch (packet->code) {
1561 case PW_ACCOUNTING_REQUEST:
1562 case PW_ACCOUNTING_RESPONSE:
1563 case PW_DISCONNECT_REQUEST:
1564 case PW_DISCONNECT_ACK:
1565 case PW_DISCONNECT_NAK:
1566 case PW_COA_REQUEST:
1569 memset(hdr->vector, 0, AUTH_VECTOR_LEN);
1572 case PW_AUTHENTICATION_ACK:
1573 case PW_AUTHENTICATION_REJECT:
1574 case PW_ACCESS_CHALLENGE:
1576 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1579 memcpy(hdr->vector, original->vector,
1583 default: /* others have vector already set to zero */
1589 * Set the authentication vector to zero,
1590 * calculate the signature, and put it
1591 * into the Message-Authenticator
1594 fr_hmac_md5(packet->data, packet->data_len,
1595 (const uint8_t *) secret, strlen(secret),
1597 memcpy(packet->data + packet->offset + 2,
1598 calc_auth_vector, AUTH_VECTOR_LEN);
1601 * Copy the original request vector back
1602 * to the raw packet.
1604 memcpy(hdr->vector, packet->vector, AUTH_VECTOR_LEN);
1608 * Switch over the packet code, deciding how to
1611 switch (packet->code) {
1613 * Request packets are not signed, bur
1614 * have a random authentication vector.
1616 case PW_AUTHENTICATION_REQUEST:
1617 case PW_STATUS_SERVER:
1621 * Reply packets are signed with the
1622 * authentication vector of the request.
1629 fr_MD5Init(&context);
1630 fr_MD5Update(&context, packet->data, packet->data_len);
1631 fr_MD5Update(&context, (const uint8_t *) secret,
1633 fr_MD5Final(digest, &context);
1635 memcpy(hdr->vector, digest, AUTH_VECTOR_LEN);
1636 memcpy(packet->vector, digest, AUTH_VECTOR_LEN);
1639 }/* switch over packet codes */
1645 * Reply to the request. Also attach
1646 * reply attribute value pairs and any user message provided.
1648 int rad_send(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1653 char ip_buffer[128];
1656 * Maybe it's a fake packet. Don't send it.
1658 if (!packet || (packet->sockfd < 0)) {
1662 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1663 what = fr_packet_codes[packet->code];
1669 * First time through, allocate room for the packet
1671 if (!packet->data) {
1673 * Encode the packet.
1675 if (rad_encode(packet, original, secret) < 0) {
1680 * Re-sign it, including updating the
1681 * Message-Authenticator.
1683 if (rad_sign(packet, original, secret) < 0) {
1688 * If packet->data points to data, then we print out
1689 * the VP list again only for debugging.
1691 } else if (fr_debug_flag) {
1692 DEBUG("Sending %s of id %d to %s port %d\n", what, packet->id,
1693 inet_ntop(packet->dst_ipaddr.af,
1694 &packet->dst_ipaddr.ipaddr,
1695 ip_buffer, sizeof(ip_buffer)),
1698 for (reply = packet->vps; reply; reply = reply->next) {
1699 if ((reply->vendor == 0) &&
1700 ((reply->attribute & 0xFFFF) > 0xff)) continue;
1706 * And send it on it's way.
1708 return rad_sendto(packet->sockfd, packet->data, packet->data_len, 0,
1709 &packet->src_ipaddr, packet->src_port,
1710 &packet->dst_ipaddr, packet->dst_port);
1714 * Do a comparison of two authentication digests by comparing
1715 * the FULL digest. Otehrwise, the server can be subject to
1716 * timing attacks that allow attackers find a valid message
1719 * http://www.cs.rice.edu/~dwallach/pub/crosby-timing2009.pdf
1721 static int digest_cmp(const uint8_t *a, const uint8_t *b, size_t length)
1726 for (i = 0; i < length; i++) {
1727 result |= a[i] ^ b[i];
1730 return result; /* 0 is OK, !0 is !OK, just like memcmp */
1735 * Validates the requesting client NAS. Calculates the
1736 * signature based on the clients private key.
1738 static int calc_acctdigest(RADIUS_PACKET *packet, const char *secret)
1740 uint8_t digest[AUTH_VECTOR_LEN];
1744 * Zero out the auth_vector in the received packet.
1745 * Then append the shared secret to the received packet,
1746 * and calculate the MD5 sum. This must be the same
1747 * as the original MD5 sum (packet->vector).
1749 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
1752 * MD5(packet + secret);
1754 fr_MD5Init(&context);
1755 fr_MD5Update(&context, packet->data, packet->data_len);
1756 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1757 fr_MD5Final(digest, &context);
1760 * Return 0 if OK, 2 if not OK.
1762 if (digest_cmp(digest, packet->vector, AUTH_VECTOR_LEN) != 0) return 2;
1768 * Validates the requesting client NAS. Calculates the
1769 * signature based on the clients private key.
1771 static int calc_replydigest(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1774 uint8_t calc_digest[AUTH_VECTOR_LEN];
1780 if (original == NULL) {
1785 * Copy the original vector in place.
1787 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
1790 * MD5(packet + secret);
1792 fr_MD5Init(&context);
1793 fr_MD5Update(&context, packet->data, packet->data_len);
1794 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1795 fr_MD5Final(calc_digest, &context);
1798 * Copy the packet's vector back to the packet.
1800 memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
1803 * Return 0 if OK, 2 if not OK.
1805 if (digest_cmp(packet->vector, calc_digest, AUTH_VECTOR_LEN) != 0) return 2;
1811 * Check if a set of RADIUS formatted TLVs are OK.
1813 int rad_tlv_ok(const uint8_t *data, size_t length,
1814 size_t dv_type, size_t dv_length)
1816 const uint8_t *end = data + length;
1818 if ((dv_length > 2) || (dv_type == 0) || (dv_type > 4)) {
1819 fr_strerror_printf("rad_tlv_ok: Invalid arguments");
1823 while (data < end) {
1826 if ((data + dv_type + dv_length) > end) {
1827 fr_strerror_printf("Attribute header overflow");
1833 if ((data[0] == 0) && (data[1] == 0) &&
1834 (data[2] == 0) && (data[3] == 0)) {
1836 fr_strerror_printf("Invalid attribute 0");
1841 fr_strerror_printf("Invalid attribute > 2^24");
1847 if ((data[1] == 0) && (data[1] == 0)) goto zero;
1851 if (data[0] == 0) goto zero;
1855 fr_strerror_printf("Internal sanity check failed");
1859 switch (dv_length) {
1864 if (data[dv_type + 1] != 0) {
1865 fr_strerror_printf("Attribute is longer than 256 octets");
1870 attrlen = data[dv_type + dv_length - 1];
1875 fr_strerror_printf("Internal sanity check failed");
1879 if (attrlen < (dv_type + dv_length)) {
1880 fr_strerror_printf("Attribute header has invalid length");
1884 if (attrlen > length) {
1885 fr_strerror_printf("Attribute overflows container");
1898 * See if the data pointed to by PTR is a valid RADIUS packet.
1900 * packet is not 'const * const' because we may update data_len,
1901 * if there's more data in the UDP packet than in the RADIUS packet.
1903 int rad_packet_ok(RADIUS_PACKET *packet, int flags)
1908 radius_packet_t *hdr;
1909 char host_ipaddr[128];
1915 * Check for packets smaller than the packet header.
1917 * RFC 2865, Section 3., subsection 'length' says:
1919 * "The minimum length is 20 ..."
1921 if (packet->data_len < AUTH_HDR_LEN) {
1922 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (received %d < minimum %d)",
1923 inet_ntop(packet->src_ipaddr.af,
1924 &packet->src_ipaddr.ipaddr,
1925 host_ipaddr, sizeof(host_ipaddr)),
1926 (int) packet->data_len, AUTH_HDR_LEN);
1931 * RFC 2865, Section 3., subsection 'length' says:
1933 * " ... and maximum length is 4096."
1935 if (packet->data_len > MAX_PACKET_LEN) {
1936 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (received %d > maximum %d)",
1937 inet_ntop(packet->src_ipaddr.af,
1938 &packet->src_ipaddr.ipaddr,
1939 host_ipaddr, sizeof(host_ipaddr)),
1940 (int) packet->data_len, MAX_PACKET_LEN);
1945 * Check for packets with mismatched size.
1946 * i.e. We've received 128 bytes, and the packet header
1947 * says it's 256 bytes long.
1949 totallen = (packet->data[2] << 8) | packet->data[3];
1950 hdr = (radius_packet_t *)packet->data;
1953 * Code of 0 is not understood.
1954 * Code of 16 or greate is not understood.
1956 if ((hdr->code == 0) ||
1957 (hdr->code >= FR_MAX_PACKET_CODE)) {
1958 fr_strerror_printf("WARNING: Bad RADIUS packet from host %s: unknown packet code%d ",
1959 inet_ntop(packet->src_ipaddr.af,
1960 &packet->src_ipaddr.ipaddr,
1961 host_ipaddr, sizeof(host_ipaddr)),
1967 * Message-Authenticator is required in Status-Server
1968 * packets, otherwise they can be trivially forged.
1970 if (hdr->code == PW_STATUS_SERVER) require_ma = 1;
1973 * It's also required if the caller asks for it.
1975 if (flags) require_ma = 1;
1978 * Repeat the length checks. This time, instead of
1979 * looking at the data we received, look at the value
1980 * of the 'length' field inside of the packet.
1982 * Check for packets smaller than the packet header.
1984 * RFC 2865, Section 3., subsection 'length' says:
1986 * "The minimum length is 20 ..."
1988 if (totallen < AUTH_HDR_LEN) {
1989 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (length %d < minimum %d)",
1990 inet_ntop(packet->src_ipaddr.af,
1991 &packet->src_ipaddr.ipaddr,
1992 host_ipaddr, sizeof(host_ipaddr)),
1993 totallen, AUTH_HDR_LEN);
1998 * And again, for the value of the 'length' field.
2000 * RFC 2865, Section 3., subsection 'length' says:
2002 * " ... and maximum length is 4096."
2004 if (totallen > MAX_PACKET_LEN) {
2005 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (length %d > maximum %d)",
2006 inet_ntop(packet->src_ipaddr.af,
2007 &packet->src_ipaddr.ipaddr,
2008 host_ipaddr, sizeof(host_ipaddr)),
2009 totallen, MAX_PACKET_LEN);
2014 * RFC 2865, Section 3., subsection 'length' says:
2016 * "If the packet is shorter than the Length field
2017 * indicates, it MUST be silently discarded."
2019 * i.e. No response to the NAS.
2021 if (packet->data_len < totallen) {
2022 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: received %d octets, packet length says %d",
2023 inet_ntop(packet->src_ipaddr.af,
2024 &packet->src_ipaddr.ipaddr,
2025 host_ipaddr, sizeof(host_ipaddr)),
2026 (int) packet->data_len, totallen);
2031 * RFC 2865, Section 3., subsection 'length' says:
2033 * "Octets outside the range of the Length field MUST be
2034 * treated as padding and ignored on reception."
2036 if (packet->data_len > totallen) {
2038 * We're shortening the packet below, but just
2039 * to be paranoid, zero out the extra data.
2041 memset(packet->data + totallen, 0, packet->data_len - totallen);
2042 packet->data_len = totallen;
2046 * Walk through the packet's attributes, ensuring that
2047 * they add up EXACTLY to the size of the packet.
2049 * If they don't, then the attributes either under-fill
2050 * or over-fill the packet. Any parsing of the packet
2051 * is impossible, and will result in unknown side effects.
2053 * This would ONLY happen with buggy RADIUS implementations,
2054 * or with an intentional attack. Either way, we do NOT want
2055 * to be vulnerable to this problem.
2058 count = totallen - AUTH_HDR_LEN;
2063 * We need at least 2 bytes to check the
2067 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute header overflows the packet",
2068 inet_ntop(packet->src_ipaddr.af,
2069 &packet->src_ipaddr.ipaddr,
2070 host_ipaddr, sizeof(host_ipaddr)));
2075 * Attribute number zero is NOT defined.
2078 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Invalid attribute 0",
2079 inet_ntop(packet->src_ipaddr.af,
2080 &packet->src_ipaddr.ipaddr,
2081 host_ipaddr, sizeof(host_ipaddr)));
2086 * Attributes are at LEAST as long as the ID & length
2087 * fields. Anything shorter is an invalid attribute.
2090 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %u too short",
2091 inet_ntop(packet->src_ipaddr.af,
2092 &packet->src_ipaddr.ipaddr,
2093 host_ipaddr, sizeof(host_ipaddr)),
2099 * If there are fewer bytes in the packet than in the
2100 * attribute, it's a bad packet.
2102 if (count < attr[1]) {
2103 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %u data overflows the packet",
2104 inet_ntop(packet->src_ipaddr.af,
2105 &packet->src_ipaddr.ipaddr,
2106 host_ipaddr, sizeof(host_ipaddr)),
2112 * Sanity check the attributes for length.
2115 default: /* don't do anything by default */
2119 * If there's an EAP-Message, we require
2120 * a Message-Authenticator.
2122 case PW_EAP_MESSAGE:
2126 case PW_MESSAGE_AUTHENTICATOR:
2127 if (attr[1] != 2 + AUTH_VECTOR_LEN) {
2128 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Message-Authenticator has invalid length %d",
2129 inet_ntop(packet->src_ipaddr.af,
2130 &packet->src_ipaddr.ipaddr,
2131 host_ipaddr, sizeof(host_ipaddr)),
2140 * FIXME: Look up the base 255 attributes in the
2141 * dictionary, and switch over their type. For
2142 * integer/date/ip, the attribute length SHOULD
2145 count -= attr[1]; /* grab the attribute length */
2147 num_attributes++; /* seen one more attribute */
2151 * If the attributes add up to a packet, it's allowed.
2153 * If not, we complain, and throw the packet away.
2156 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: packet attributes do NOT exactly fill the packet",
2157 inet_ntop(packet->src_ipaddr.af,
2158 &packet->src_ipaddr.ipaddr,
2159 host_ipaddr, sizeof(host_ipaddr)));
2164 * If we're configured to look for a maximum number of
2165 * attributes, and we've seen more than that maximum,
2166 * then throw the packet away, as a possible DoS.
2168 if ((fr_max_attributes > 0) &&
2169 (num_attributes > fr_max_attributes)) {
2170 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
2171 inet_ntop(packet->src_ipaddr.af,
2172 &packet->src_ipaddr.ipaddr,
2173 host_ipaddr, sizeof(host_ipaddr)),
2174 num_attributes, fr_max_attributes);
2179 * http://www.freeradius.org/rfc/rfc2869.html#EAP-Message
2181 * A packet with an EAP-Message attribute MUST also have
2182 * a Message-Authenticator attribute.
2184 * A Message-Authenticator all by itself is OK, though.
2186 * Similarly, Status-Server packets MUST contain
2187 * Message-Authenticator attributes.
2189 if (require_ma && ! seen_ma) {
2190 fr_strerror_printf("WARNING: Insecure packet from host %s: Packet does not contain required Message-Authenticator attribute",
2191 inet_ntop(packet->src_ipaddr.af,
2192 &packet->src_ipaddr.ipaddr,
2193 host_ipaddr, sizeof(host_ipaddr)));
2198 * Fill RADIUS header fields
2200 packet->code = hdr->code;
2201 packet->id = hdr->id;
2202 memcpy(packet->vector, hdr->vector, AUTH_VECTOR_LEN);
2209 * Receive UDP client requests, and fill in
2210 * the basics of a RADIUS_PACKET structure.
2212 RADIUS_PACKET *rad_recv(int fd, int flags)
2215 RADIUS_PACKET *packet;
2218 * Allocate the new request data structure
2220 if ((packet = malloc(sizeof(*packet))) == NULL) {
2221 fr_strerror_printf("out of memory");
2224 memset(packet, 0, sizeof(*packet));
2227 sock_flags = MSG_PEEK;
2231 packet->data_len = rad_recvfrom(fd, &packet->data, sock_flags,
2232 &packet->src_ipaddr, &packet->src_port,
2233 &packet->dst_ipaddr, &packet->dst_port);
2236 * Check for socket errors.
2238 if (packet->data_len < 0) {
2239 fr_strerror_printf("Error receiving packet: %s", strerror(errno));
2240 /* packet->data is NULL */
2246 * If the packet is too big, then rad_recvfrom did NOT
2247 * allocate memory. Instead, it just discarded the
2250 if (packet->data_len > MAX_PACKET_LEN) {
2251 fr_strerror_printf("Discarding packet: Larger than RFC limitation of 4096 bytes.");
2252 /* packet->data is NULL */
2258 * Read no data. Continue.
2259 * This check is AFTER the MAX_PACKET_LEN check above, because
2260 * if the packet is larger than MAX_PACKET_LEN, we also have
2261 * packet->data == NULL
2263 if ((packet->data_len == 0) || !packet->data) {
2264 fr_strerror_printf("Empty packet: Socket is not ready.");
2270 * See if it's a well-formed RADIUS packet.
2272 if (!rad_packet_ok(packet, flags)) {
2278 * Remember which socket we read the packet from.
2280 packet->sockfd = fd;
2283 * FIXME: Do even more filtering by only permitting
2284 * certain IP's. The problem is that we don't know
2285 * how to do this properly for all possible clients...
2289 * Explicitely set the VP list to empty.
2293 if (fr_debug_flag) {
2294 char host_ipaddr[128];
2296 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
2297 DEBUG("rad_recv: %s packet from host %s port %d",
2298 fr_packet_codes[packet->code],
2299 inet_ntop(packet->src_ipaddr.af,
2300 &packet->src_ipaddr.ipaddr,
2301 host_ipaddr, sizeof(host_ipaddr)),
2304 DEBUG("rad_recv: Packet from host %s port %d code=%d",
2305 inet_ntop(packet->src_ipaddr.af,
2306 &packet->src_ipaddr.ipaddr,
2307 host_ipaddr, sizeof(host_ipaddr)),
2311 DEBUG(", id=%d, length=%d\n",
2312 packet->id, (int) packet->data_len);
2320 * Verify the signature of a packet.
2322 int rad_verify(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2329 if (!packet || !packet->data) return -1;
2332 * Before we allocate memory for the attributes, do more
2335 ptr = packet->data + AUTH_HDR_LEN;
2336 length = packet->data_len - AUTH_HDR_LEN;
2337 while (length > 0) {
2338 uint8_t msg_auth_vector[AUTH_VECTOR_LEN];
2339 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
2344 default: /* don't do anything. */
2348 * Note that more than one Message-Authenticator
2349 * attribute is invalid.
2351 case PW_MESSAGE_AUTHENTICATOR:
2352 memcpy(msg_auth_vector, &ptr[2], sizeof(msg_auth_vector));
2353 memset(&ptr[2], 0, AUTH_VECTOR_LEN);
2355 switch (packet->code) {
2359 case PW_ACCOUNTING_REQUEST:
2360 case PW_ACCOUNTING_RESPONSE:
2361 case PW_DISCONNECT_REQUEST:
2362 case PW_DISCONNECT_ACK:
2363 case PW_DISCONNECT_NAK:
2364 case PW_COA_REQUEST:
2367 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
2370 case PW_AUTHENTICATION_ACK:
2371 case PW_AUTHENTICATION_REJECT:
2372 case PW_ACCESS_CHALLENGE:
2374 fr_strerror_printf("ERROR: Cannot validate Message-Authenticator in response packet without a request packet.");
2377 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
2381 fr_hmac_md5(packet->data, packet->data_len,
2382 (const uint8_t *) secret, strlen(secret),
2384 if (digest_cmp(calc_auth_vector, msg_auth_vector,
2385 sizeof(calc_auth_vector)) != 0) {
2387 fr_strerror_printf("Received packet from %s with invalid Message-Authenticator! (Shared secret is incorrect.)",
2388 inet_ntop(packet->src_ipaddr.af,
2389 &packet->src_ipaddr.ipaddr,
2390 buffer, sizeof(buffer)));
2391 /* Silently drop packet, according to RFC 3579 */
2393 } /* else the message authenticator was good */
2396 * Reinitialize Authenticators.
2398 memcpy(&ptr[2], msg_auth_vector, AUTH_VECTOR_LEN);
2399 memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
2401 } /* switch over the attributes */
2405 } /* loop over the packet, sanity checking the attributes */
2408 * It looks like a RADIUS packet, but we can't validate
2411 if ((packet->code == 0) || (packet->code >= FR_MAX_PACKET_CODE)) {
2413 fr_strerror_printf("Received Unknown packet code %d "
2414 "from client %s port %d: Cannot validate signature.",
2416 inet_ntop(packet->src_ipaddr.af,
2417 &packet->src_ipaddr.ipaddr,
2418 buffer, sizeof(buffer)),
2424 * Calculate and/or verify digest.
2426 switch(packet->code) {
2430 case PW_AUTHENTICATION_REQUEST:
2431 case PW_STATUS_SERVER:
2433 * The authentication vector is random
2434 * nonsense, invented by the client.
2438 case PW_COA_REQUEST:
2439 case PW_DISCONNECT_REQUEST:
2440 case PW_ACCOUNTING_REQUEST:
2441 if (calc_acctdigest(packet, secret) > 1) {
2442 fr_strerror_printf("Received %s packet "
2443 "from client %s with invalid signature! (Shared secret is incorrect.)",
2444 fr_packet_codes[packet->code],
2445 inet_ntop(packet->src_ipaddr.af,
2446 &packet->src_ipaddr.ipaddr,
2447 buffer, sizeof(buffer)));
2452 /* Verify the reply digest */
2453 case PW_AUTHENTICATION_ACK:
2454 case PW_AUTHENTICATION_REJECT:
2455 case PW_ACCESS_CHALLENGE:
2456 case PW_ACCOUNTING_RESPONSE:
2457 case PW_DISCONNECT_ACK:
2458 case PW_DISCONNECT_NAK:
2461 rcode = calc_replydigest(packet, original, secret);
2463 fr_strerror_printf("Received %s packet "
2464 "from home server %s port %d with invalid signature! (Shared secret is incorrect.)",
2465 fr_packet_codes[packet->code],
2466 inet_ntop(packet->src_ipaddr.af,
2467 &packet->src_ipaddr.ipaddr,
2468 buffer, sizeof(buffer)),
2475 fr_strerror_printf("Received Unknown packet code %d "
2476 "from client %s port %d: Cannot validate signature",
2478 inet_ntop(packet->src_ipaddr.af,
2479 &packet->src_ipaddr.ipaddr,
2480 buffer, sizeof(buffer)),
2490 * Create a "raw" attribute from the attribute contents.
2492 static ssize_t data2vp_raw(UNUSED const RADIUS_PACKET *packet,
2493 UNUSED const RADIUS_PACKET *original,
2494 UNUSED const char *secret,
2495 unsigned int attribute, unsigned int vendor,
2496 const uint8_t *data, size_t length,
2502 if (length > sizeof(vp->vp_octets)) {
2503 fr_strerror_printf("data2vp_raw: Too much data");
2509 * Keep the next function happy.
2511 vp = pairalloc(NULL);
2512 vp = paircreate_raw(attribute, vendor, PW_TYPE_OCTETS, vp);
2514 fr_strerror_printf("data2vp_raw: Failed creating attribute");
2518 vp->length = length;
2519 memcpy(vp->vp_octets, data, length);
2527 static ssize_t data2vp_tlvs(const RADIUS_PACKET *packet,
2528 const RADIUS_PACKET *original,
2530 unsigned int attribute, unsigned int vendor,
2532 const uint8_t *start, size_t length,
2536 * Create any kind of VP from the attribute contents.
2538 * Will return -1 on error, or "length".
2540 static ssize_t data2vp_any(const RADIUS_PACKET *packet,
2541 const RADIUS_PACKET *original,
2542 const char *secret, int nest,
2543 unsigned int attribute, unsigned int vendor,
2544 const uint8_t *data, size_t length,
2547 int data_offset = 0;
2549 VALUE_PAIR *vp = NULL;
2553 * Hacks for CUI. The WiMAX spec says that it
2554 * can be zero length, even though this is
2555 * forbidden by the RADIUS specs. So... we make
2556 * a special case for it.
2558 if ((vendor == 0) &&
2559 (attribute == PW_CHARGEABLE_USER_IDENTITY)) {
2560 data = (const uint8_t *) "";
2568 da = dict_attrbyvalue(attribute, vendor);
2571 * Unknown attribute. Create it as a "raw" attribute.
2575 if (vp) pairfree(&vp);
2576 return data2vp_raw(packet, original, secret,
2577 attribute, vendor, data, length, pvp);
2581 * TLVs are handled first. They can't be tagged, and
2582 * they can't be encrypted.
2584 if (da->type == PW_TYPE_TLV) {
2585 return data2vp_tlvs(packet, original, secret,
2586 attribute, vendor, nest,
2591 * The attribute is known, and well formed. We can now
2592 * create it. The main failure from here on in is being
2601 if (vp->flags.has_tag) {
2602 if (TAG_VALID(data[0]) ||
2603 (vp->flags.encrypt == FLAG_ENCRYPT_TUNNEL_PASSWORD)) {
2605 * Tunnel passwords REQUIRE a tag, even
2606 * if don't have a valid tag.
2608 vp->flags.tag = data[0];
2610 if ((vp->type == PW_TYPE_STRING) ||
2611 (vp->type == PW_TYPE_OCTETS)) {
2612 if (length == 0) goto raw;
2619 * Copy the data to be decrypted
2621 vp->length = length - data_offset;
2622 memcpy(&vp->vp_octets[0], data + data_offset, vp->length);
2625 * Decrypt the attribute.
2627 switch (vp->flags.encrypt) {
2631 case FLAG_ENCRYPT_USER_PASSWORD:
2633 rad_pwdecode(vp->vp_strvalue,
2637 rad_pwdecode(vp->vp_strvalue,
2641 if (vp->attribute == PW_USER_PASSWORD) {
2642 vp->length = strlen(vp->vp_strvalue);
2647 * Tunnel-Password's may go ONLY
2648 * in response packets.
2650 case FLAG_ENCRYPT_TUNNEL_PASSWORD:
2651 if (!original) goto raw;
2653 if (rad_tunnel_pwdecode(vp->vp_octets, &vp->length,
2654 secret, original->vector) < 0) {
2660 * Ascend-Send-Secret
2661 * Ascend-Receive-Secret
2663 case FLAG_ENCRYPT_ASCEND_SECRET:
2667 uint8_t my_digest[AUTH_VECTOR_LEN];
2668 make_secret(my_digest,
2671 memcpy(vp->vp_strvalue, my_digest,
2673 vp->vp_strvalue[AUTH_VECTOR_LEN] = '\0';
2674 vp->length = strlen(vp->vp_strvalue);
2680 } /* switch over encryption flags */
2684 case PW_TYPE_STRING:
2685 case PW_TYPE_OCTETS:
2686 case PW_TYPE_ABINARY:
2687 /* nothing more to do */
2691 if (vp->length != 1) goto raw;
2693 vp->vp_integer = vp->vp_octets[0];
2698 if (vp->length != 2) goto raw;
2700 vp->vp_integer = (vp->vp_octets[0] << 8) | vp->vp_octets[1];
2703 case PW_TYPE_INTEGER:
2704 if (vp->length != 4) goto raw;
2706 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2707 vp->vp_integer = ntohl(vp->vp_integer);
2709 if (vp->flags.has_tag) vp->vp_integer &= 0x00ffffff;
2712 * Try to get named VALUEs
2716 dval = dict_valbyattr(vp->attribute, vp->vendor,
2719 strlcpy(vp->vp_strvalue,
2721 sizeof(vp->vp_strvalue));
2727 if (vp->length != 4) goto raw;
2729 memcpy(&vp->vp_date, vp->vp_octets, 4);
2730 vp->vp_date = ntohl(vp->vp_date);
2734 case PW_TYPE_IPADDR:
2735 if (vp->length != 4) goto raw;
2737 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2741 * IPv6 interface ID is 8 octets long.
2744 if (vp->length != 8) goto raw;
2745 /* vp->vp_ifid == vp->vp_octets */
2749 * IPv6 addresses are 16 octets long
2751 case PW_TYPE_IPV6ADDR:
2752 if (vp->length != 16) goto raw;
2753 /* vp->vp_ipv6addr == vp->vp_octets */
2757 * IPv6 prefixes are 2 to 18 octets long.
2759 * RFC 3162: The first octet is unused.
2760 * The second is the length of the prefix
2761 * the rest are the prefix data.
2763 * The prefix length can have value 0 to 128.
2765 case PW_TYPE_IPV6PREFIX:
2766 if (vp->length < 2 || vp->length > 18) goto raw;
2767 if (vp->vp_octets[1] > 128) goto raw;
2770 * FIXME: double-check that
2771 * (vp->vp_octets[1] >> 3) matches vp->length + 2
2773 if (vp->length < 18) {
2774 memset(vp->vp_octets + vp->length, 0,
2779 case PW_TYPE_SIGNED:
2780 if (vp->length != 4) goto raw;
2783 * Overload vp_integer for ntohl, which takes
2784 * uint32_t, not int32_t
2786 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2787 vp->vp_integer = ntohl(vp->vp_integer);
2788 memcpy(&vp->vp_signed, &vp->vp_integer, 4);
2793 fr_strerror_printf("data2vp_any: Internal sanity check failed");
2796 case PW_TYPE_COMBO_IP:
2797 if (vp->length == 4) {
2798 vp->type = PW_TYPE_IPADDR;
2799 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2802 } else if (vp->length == 16) {
2803 vp->type = PW_TYPE_IPV6ADDR;
2804 /* vp->vp_ipv6addr == vp->vp_octets */
2821 * Convert a top-level VSA to a VP.
2823 static ssize_t attr2vp_vsa(const RADIUS_PACKET *packet,
2824 const RADIUS_PACKET *original,
2825 const char *secret, DICT_VENDOR *dv,
2826 const uint8_t *data, size_t length,
2829 unsigned int attribute;
2830 ssize_t attrlen, my_len;
2833 if (length <= (dv->type + dv->length)) {
2834 fr_strerror_printf("attr2vp_vsa: Failure to call rad_tlv_ok");
2841 /* data[0] must be zero */
2842 attribute = data[1] << 16;
2843 attribute |= data[2] << 8;
2844 attribute |= data[3];
2848 attribute = data[0];
2849 attribute |= data[1];
2853 attribute = data[0];
2857 fr_strerror_printf("attr2vp_vsa: Internal sanity check failed");
2861 switch (dv->length) {
2863 /* data[dv->type] must be zero */
2864 attrlen = data[dv->type + 1];
2868 attrlen = data[dv->type];
2876 fr_strerror_printf("attr2vp_vsa: Internal sanity check failed");
2881 if (attrlen <= (ssize_t) (dv->type + dv->length)) {
2882 fr_strerror_printf("attr2vp_vsa: Failure to call rad_tlv_ok");
2887 attrlen -= (dv->type + dv->length);
2889 my_len = data2vp_any(packet, original, secret, 0,
2890 attribute, dv->vendorpec,
2891 data + dv->type + dv->length, attrlen, pvp);
2892 if (my_len < 0) return my_len;
2895 if (my_len != attrlen) {
2897 fr_strerror_printf("attr2vp_vsa: Incomplete decode %d != %d",
2898 (int) my_len, (int) attrlen);
2903 return dv->type + dv->length + attrlen;
2907 * Convert one or more TLVs to VALUE_PAIRs. This function can
2908 * be called recursively...
2910 static ssize_t data2vp_tlvs(const RADIUS_PACKET *packet,
2911 const RADIUS_PACKET *original,
2913 unsigned int attribute, unsigned int vendor,
2915 const uint8_t *start, size_t length,
2918 size_t dv_type, dv_length;
2919 const uint8_t *data, *end;
2920 VALUE_PAIR *head, **last, *vp;
2925 * The default format for a VSA is the RFC recommended
2932 * Top-level TLVs can be of a weird format. TLVs
2933 * encapsulated in a TLV can only be in the RFC format.
2937 dv = dict_vendorbyvalue(vendor);
2940 dv_length = dv->length;
2941 /* dict.c enforces sane values on the above fields */
2945 if (nest >= fr_attr_max_tlv) {
2946 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed in recursion");
2951 * The VSAs do not exactly fill the data, it's malformed.
2953 if (rad_tlv_ok(data, length, dv_type, dv_length) < 0) {
2954 return data2vp_raw(packet, original, secret,
2955 attribute, vendor, data, length, pvp);
2958 end = data + length;
2962 while (data < end) {
2963 unsigned int my_attr;
2964 unsigned int my_len;
2967 if ((data + dv_type + dv_length) > end) {
2968 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed in tlvs: Insufficient data");
2976 my_attr = attribute;
2977 my_attr |= ((data[0] & fr_attr_mask[nest + 1])
2978 << fr_attr_shift[nest + 1]);
2981 my_attr = (data[0] << 8) | data[1];
2985 my_attr = (data[1] << 16) | (data[1] << 8) | data[3];
2989 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed");
2993 switch (dv_length) {
3000 my_len = data[dv_type + dv_length - 1];
3004 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed");
3009 if (my_len < (dv_type + dv_length)) {
3010 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed in tlvs: underflow");
3015 if ((data + my_len) > end) {
3016 fr_strerror_printf("data2vp_tlvs: Internal sanity check failed in tlvs: overflow");
3022 my_len -= dv_type + dv_length;
3025 * If this returns > 0, it returns "my_len"
3027 if (data2vp_any(packet, original, secret, nest + 1,
3029 data + dv_type + dv_length, my_len, &vp) < 0) {
3034 data += my_len + dv_type + dv_length;
3044 return data - start;
3049 * Group "continued" attributes together, and create VPs from them.
3050 * The caller ensures that the RADIUS packet is OK, and that the
3051 * continuations have all been checked.
3053 static ssize_t data2vp_continued(const RADIUS_PACKET *packet,
3054 const RADIUS_PACKET *original,
3056 const uint8_t *start, size_t length,
3057 VALUE_PAIR **pvp, int nest,
3058 unsigned int attribute, unsigned int vendor,
3059 int first_offset, int later_offset,
3063 uint8_t *attr, *ptr;
3064 const uint8_t *data;
3066 attr = malloc(attrlen);
3068 fr_strerror_printf("Out of memory");
3079 memcpy(ptr, data + first_offset, data[1] - first_offset);
3080 ptr += data[1] - first_offset;
3081 left -= data[1] - first_offset;
3086 if (data >= (start + length)) {
3087 fr_strerror_printf("data2vp_continued: Internal sanity check failed");
3091 memcpy(ptr, data + later_offset, data[1] - later_offset);
3092 ptr += data[1] - later_offset;
3093 left -= data[1] - later_offset;
3097 left = data2vp_any(packet, original, secret, nest,
3099 attr, attrlen, pvp);
3101 if (left < 0) return left;
3103 return data - start;
3108 * Create a "raw" VALUE_PAIR from a RADIUS attribute.
3110 ssize_t rad_attr2vp_raw(const RADIUS_PACKET *packet,
3111 const RADIUS_PACKET *original,
3113 const uint8_t *data, size_t length,
3118 if ((data[1] < 2) || (data[1] > length)) {
3119 fr_strerror_printf("rad_attr2vp_raw: Invalid length");
3123 my_len = data2vp_raw(packet, original, secret, data[0], 0,
3124 data + 2, data[1] - 2, pvp);
3125 if (my_len < 0) return my_len;
3132 * Get the length of the data portion of all of the contiguous
3133 * continued attributes.
3135 * 0 for "no continuation"
3136 * -1 on malformed packets (continuation followed by non-wimax, etc.)
3138 static ssize_t wimax_attrlen(const uint8_t *start, const uint8_t *end)
3140 uint32_t lvalue = htonl(VENDORPEC_WIMAX);
3142 const uint8_t *data = start;
3144 if ((data[8] & 0x80) == 0) return 0;
3145 total = data[7] - 3;
3148 while (data < end) {
3150 if ((data + 9) > end) return -1;
3152 if ((data[0] != PW_VENDOR_SPECIFIC) ||
3154 (memcmp(data + 2, &lvalue, 4) != 0) ||
3155 (data[6] != start[6]) ||
3156 ((data[7] + 6) != data[1])) return -1;
3158 total += data[7] - 3;
3159 if ((data[8] & 0x80) == 0) break;
3168 * Get the length of the data portion of all of the contiguous
3169 * continued attributes.
3171 * 0 for "no continuation"
3172 * -1 on malformed packets (continuation followed by non-wimax, etc.)
3174 static ssize_t extended_attrlen(const uint8_t *start, const uint8_t *end)
3177 const uint8_t *data = start;
3179 if ((data[3] & 0x80) == 0) return 0;
3180 total = data[1] - 4;
3183 while (data < end) {
3184 if ((data + 4) > end) return -1;
3186 if ((data[0] != start[0]) ||
3188 (data[2] != start[2])) return -1;
3190 total += data[1] - 4;
3191 if ((data[3] & 0x80) == 0) break;
3200 * Create WiMAX VALUE_PAIRs from a RADIUS attribute.
3202 ssize_t rad_attr2vp_wimax(const RADIUS_PACKET *packet,
3203 const RADIUS_PACKET *original,
3205 const uint8_t *data, size_t length,
3209 unsigned int attribute;
3212 if ((length < 2) || (data[1] < 2) || (data[1] > length)) {
3213 fr_strerror_printf("rad_attr2vp_wimax: Invalid length");
3217 if (data[0] != PW_VENDOR_SPECIFIC) {
3218 fr_strerror_printf("rad_attr2vp_wimax: Invalid attribute");
3223 * Not enough room for a Vendor-Id. + WiMAX header
3226 return rad_attr2vp_raw(packet, original, secret,
3230 memcpy(&lvalue, data + 2, 4);
3231 lvalue = ntohl(lvalue);
3236 if (lvalue != VENDORPEC_WIMAX) {
3237 fr_strerror_printf("rad_attr2vp_wimax: Not a WiMAX attribute");
3242 * The WiMAX attribute is encapsulated in a VSA. If the
3243 * WiMAX length disagrees with the VSA length, it's malformed.
3245 if ((data[7] + 6) != data[1]) {
3246 return rad_attr2vp_raw(packet, original, secret,
3250 attribute = data[6];
3253 * Attribute is continued. Do some more work.
3256 my_len = wimax_attrlen(data, data + length);
3258 return rad_attr2vp_raw(packet, original, secret,
3262 return data2vp_continued(packet, original, secret,
3263 data, length, pvp, 0,
3264 data[6], VENDORPEC_WIMAX,
3268 my_len = data2vp_any(packet, original, secret, 0, attribute, lvalue,
3269 data + 9, data[1] - 9, pvp);
3270 if (my_len < 0) return my_len;
3276 * Create Vendor-Specifc VALUE_PAIRs from a RADIUS attribute.
3278 ssize_t rad_attr2vp_vsa(const RADIUS_PACKET *packet,
3279 const RADIUS_PACKET *original,
3281 const uint8_t *data, size_t length,
3284 size_t dv_type, dv_length;
3289 if ((length < 2) || (data[1] < 2) || (data[1] > length)) {
3290 fr_strerror_printf("rad_attr2vp_vsa: Invalid length");
3294 if (data[0] != PW_VENDOR_SPECIFIC) {
3295 fr_strerror_printf("rad_attr2vp_vsa: Invalid attribute");
3300 * Not enough room for a Vendor-Id.
3301 * Or the high octet of the Vendor-Id is set.
3303 if ((data[1] < 6) || (data[2] != 0)) {
3304 return rad_attr2vp_raw(packet, original, secret,
3308 memcpy(&lvalue, data + 2, 4);
3309 lvalue = ntohl(lvalue);
3312 * WiMAX gets its own set of magic.
3314 if (lvalue == VENDORPEC_WIMAX) {
3315 return rad_attr2vp_wimax(packet, original, secret,
3319 dv_type = dv_length = 1;
3320 dv = dict_vendorbyvalue(lvalue);
3323 dv_length = dv->length;
3327 * Attribute is not in the correct form.
3329 if (rad_tlv_ok(data + 6, data[1] - 6, dv_type, dv_length) < 0) {
3330 return rad_attr2vp_raw(packet, original, secret,
3334 my_len = attr2vp_vsa(packet, original, secret, dv,
3335 data + 6, data[1] - 6, pvp);
3336 if (my_len < 0) return my_len;
3339 if (my_len != (data[1] - 6)) {
3341 fr_strerror_printf("rad_attr2vp_vsa: Incomplete decode");
3350 * Create an "extended" VALUE_PAIR from a RADIUS attribute.
3352 ssize_t rad_attr2vp_extended(const RADIUS_PACKET *packet,
3353 const RADIUS_PACKET *original,
3355 const uint8_t *start, size_t length,
3358 unsigned int attribute;
3361 unsigned int vendor = VENDORPEC_EXTENDED;
3362 size_t data_len = length;
3363 const uint8_t *data;
3368 if ((length < 2) || (data[1] < 2) || (data[1] > length)) {
3369 fr_strerror_printf("rad_attr2vp_extended: Invalid length");
3373 da = dict_attrbyvalue(data[0], vendor);
3375 fr_strerror_printf("rad_attr2vp_extended: Attribute is not extended format");
3382 * No Extended-Type. It's a raw attribute.
3383 * Also, if there's no data following the Extended-Type,
3384 * it's a raw attribute.
3388 return rad_attr2vp_raw(packet, original, secret, start,
3393 * The attribute is "241.1", for example. Go look that
3394 * up to see what type it is.
3396 attribute = data[0];
3397 attribute |= (data[2] << fr_attr_shift[1]);
3399 da = dict_attrbyvalue(attribute, vendor);
3402 vendor = VENDORPEC_EXTENDED;
3405 if (data[1] < length) data_len = data[1];
3411 * If there's supposed to be a flag octet. If not, it's
3412 * a raw attribute. If the flag is set, it's supposed to
3415 if (da->flags.extended_flags) {
3416 if (data_len == 0) goto raw;
3418 continued = ((data[0] & 0x80) != 0);
3424 * Extended VSAs have 4 octets of
3425 * Vendor-Id followed by one octet of
3428 if (da->flags.evs) {
3429 if (data_len < 5) goto raw;
3432 * Vendor Ids can only be 24-bit.
3434 if (data[0] != 0) goto raw;
3436 vendor = ((data[1] << 16) |
3441 * Pack the *encapsulating* attribute number into
3444 vendor |= start[0] * FR_MAX_VENDOR;
3448 * Over-write the attribute with the
3451 attribute = data[4];
3457 int first_offset = 4;
3460 if (vendor != VENDORPEC_EXTENDED) first_offset += 5;
3462 my_len = extended_attrlen(start, start + length);
3463 if (my_len < 0) goto raw;
3465 if (vendor != VENDORPEC_EXTENDED) my_len -= 5;
3467 return data2vp_continued(packet, original, secret,
3468 start, length, pvp, shift,
3470 first_offset, 4, my_len);
3473 if (data2vp_any(packet, original, secret, shift,
3474 attribute, vendor, data, data_len, pvp) < 0) {
3478 return (data + data_len) - start;
3483 * Create a "standard" RFC VALUE_PAIR from the given data.
3485 ssize_t rad_attr2vp_rfc(const RADIUS_PACKET *packet,
3486 const RADIUS_PACKET *original,
3488 const uint8_t *data, size_t length,
3491 if ((length < 2) || (data[1] < 2) || (data[1] > length)) {
3492 fr_strerror_printf("rad_attr2vp_rfc: Insufficient data");
3496 if (data2vp_any(packet, original, secret, 0,
3497 data[0], 0, data + 2, data[1] - 2, pvp) < 0) {
3505 * Create a "normal" VALUE_PAIR from the given data.
3507 ssize_t rad_attr2vp(const RADIUS_PACKET *packet,
3508 const RADIUS_PACKET *original,
3510 const uint8_t *data, size_t length,
3513 if ((length < 2) || (data[1] < 2) || (data[1] > length)) {
3514 fr_strerror_printf("rad_attr2vp: Insufficient data");
3519 * VSAs get their own handler.
3521 if (data[0] == PW_VENDOR_SPECIFIC) {
3522 return rad_attr2vp_vsa(packet, original, secret,
3527 * Extended attribute format gets their own handler.
3529 if (dict_attrbyvalue(data[0], VENDORPEC_EXTENDED) != NULL) {
3530 return rad_attr2vp_extended(packet, original, secret,
3534 return rad_attr2vp_rfc(packet, original, secret, data, length, pvp);
3539 * Calculate/check digest, and decode radius attributes.
3541 * -1 on decoding error
3544 int rad_decode(RADIUS_PACKET *packet, RADIUS_PACKET *original,
3550 radius_packet_t *hdr;
3551 VALUE_PAIR *head, **tail, *vp;
3554 * Extract attribute-value pairs
3556 hdr = (radius_packet_t *)packet->data;
3558 packet_length = packet->data_len - AUTH_HDR_LEN;
3565 * Loop over the attributes, decoding them into VPs.
3567 while (packet_length > 0) {
3571 * This may return many VPs
3573 my_len = rad_attr2vp(packet, original, secret,
3574 ptr, packet_length, &vp);
3589 * VSA's may not have been counted properly in
3590 * rad_packet_ok() above, as it is hard to count
3591 * then without using the dictionary. We
3592 * therefore enforce the limits here, too.
3594 if ((fr_max_attributes > 0) &&
3595 (num_attributes > fr_max_attributes)) {
3596 char host_ipaddr[128];
3599 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
3600 inet_ntop(packet->src_ipaddr.af,
3601 &packet->src_ipaddr.ipaddr,
3602 host_ipaddr, sizeof(host_ipaddr)),
3603 num_attributes, fr_max_attributes);
3608 packet_length -= my_len;
3612 * Merge information from the outside world into our
3615 fr_rand_seed(packet->data, AUTH_HDR_LEN);
3618 * There may be VP's already in the packet. Don't
3619 * destroy them. Instead, add the decoded attributes to
3620 * the tail of the list.
3622 for (tail = &packet->vps; *tail != NULL; tail = &((*tail)->next)) {
3634 * We assume that the passwd buffer passed is big enough.
3635 * RFC2138 says the password is max 128 chars, so the size
3636 * of the passwd buffer must be at least 129 characters.
3637 * Preferably it's just MAX_STRING_LEN.
3639 * int *pwlen is updated to the new length of the encrypted
3640 * password - a multiple of 16 bytes.
3642 int rad_pwencode(char *passwd, size_t *pwlen, const char *secret,
3643 const uint8_t *vector)
3645 FR_MD5_CTX context, old;
3646 uint8_t digest[AUTH_VECTOR_LEN];
3647 int i, n, secretlen;
3651 * RFC maximum is 128 bytes.
3653 * If length is zero, pad it out with zeros.
3655 * If the length isn't aligned to 16 bytes,
3656 * zero out the extra data.
3660 if (len > 128) len = 128;
3663 memset(passwd, 0, AUTH_PASS_LEN);
3664 len = AUTH_PASS_LEN;
3665 } else if ((len % AUTH_PASS_LEN) != 0) {
3666 memset(&passwd[len], 0, AUTH_PASS_LEN - (len % AUTH_PASS_LEN));
3667 len += AUTH_PASS_LEN - (len % AUTH_PASS_LEN);
3672 * Use the secret to setup the decryption digest
3674 secretlen = strlen(secret);
3676 fr_MD5Init(&context);
3677 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3678 old = context; /* save intermediate work */
3681 * Encrypt it in place. Don't bother checking
3682 * len, as we've ensured above that it's OK.
3684 for (n = 0; n < len; n += AUTH_PASS_LEN) {
3686 fr_MD5Update(&context, vector, AUTH_PASS_LEN);
3687 fr_MD5Final(digest, &context);
3690 fr_MD5Update(&context,
3691 (uint8_t *) passwd + n - AUTH_PASS_LEN,
3693 fr_MD5Final(digest, &context);
3696 for (i = 0; i < AUTH_PASS_LEN; i++) {
3697 passwd[i + n] ^= digest[i];
3707 int rad_pwdecode(char *passwd, size_t pwlen, const char *secret,
3708 const uint8_t *vector)
3710 FR_MD5_CTX context, old;
3711 uint8_t digest[AUTH_VECTOR_LEN];
3713 size_t n, secretlen;
3716 * The RFC's say that the maximum is 128.
3717 * The buffer we're putting it into above is 254, so
3718 * we don't need to do any length checking.
3720 if (pwlen > 128) pwlen = 128;
3725 if (pwlen == 0) goto done;
3728 * Use the secret to setup the decryption digest
3730 secretlen = strlen(secret);
3732 fr_MD5Init(&context);
3733 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3734 old = context; /* save intermediate work */
3737 * The inverse of the code above.
3739 for (n = 0; n < pwlen; n += AUTH_PASS_LEN) {
3741 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3742 fr_MD5Final(digest, &context);
3745 if (pwlen > AUTH_PASS_LEN) {
3746 fr_MD5Update(&context, (uint8_t *) passwd,
3750 fr_MD5Final(digest, &context);
3753 if (pwlen > (n + AUTH_PASS_LEN)) {
3754 fr_MD5Update(&context, (uint8_t *) passwd + n,
3759 for (i = 0; i < AUTH_PASS_LEN; i++) {
3760 passwd[i + n] ^= digest[i];
3765 passwd[pwlen] = '\0';
3766 return strlen(passwd);
3771 * Encode Tunnel-Password attributes when sending them out on the wire.
3773 * int *pwlen is updated to the new length of the encrypted
3774 * password - a multiple of 16 bytes.
3776 * This is per RFC-2868 which adds a two char SALT to the initial intermediate
3779 int rad_tunnel_pwencode(char *passwd, size_t *pwlen, const char *secret,
3780 const uint8_t *vector)
3782 uint8_t buffer[AUTH_VECTOR_LEN + MAX_STRING_LEN + 3];
3783 unsigned char digest[AUTH_VECTOR_LEN];
3785 int i, n, secretlen;
3790 if (len > 127) len = 127;
3793 * Shift the password 3 positions right to place a salt and original
3794 * length, tag will be added automatically on packet send
3796 for (n=len ; n>=0 ; n--) passwd[n+3] = passwd[n];
3800 * save original password length as first password character;
3807 * Generate salt. The RFC's say:
3809 * The high bit of salt[0] must be set, each salt in a
3810 * packet should be unique, and they should be random
3812 * So, we set the high bit, add in a counter, and then
3813 * add in some CSPRNG data. should be OK..
3815 salt[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
3816 (fr_rand() & 0x07));
3817 salt[1] = fr_rand();
3820 * Padd password to multiple of AUTH_PASS_LEN bytes.
3822 n = len % AUTH_PASS_LEN;
3824 n = AUTH_PASS_LEN - n;
3825 for (; n > 0; n--, len++)
3828 /* set new password length */
3832 * Use the secret to setup the decryption digest
3834 secretlen = strlen(secret);
3835 memcpy(buffer, secret, secretlen);
3837 for (n2 = 0; n2 < len; n2+=AUTH_PASS_LEN) {
3839 memcpy(buffer + secretlen, vector, AUTH_VECTOR_LEN);
3840 memcpy(buffer + secretlen + AUTH_VECTOR_LEN, salt, 2);
3841 fr_md5_calc(digest, buffer, secretlen + AUTH_VECTOR_LEN + 2);
3843 memcpy(buffer + secretlen, passwd + n2 - AUTH_PASS_LEN, AUTH_PASS_LEN);
3844 fr_md5_calc(digest, buffer, secretlen + AUTH_PASS_LEN);
3847 for (i = 0; i < AUTH_PASS_LEN; i++) {
3848 passwd[i + n2] ^= digest[i];
3856 * Decode Tunnel-Password encrypted attributes.
3858 * Defined in RFC-2868, this uses a two char SALT along with the
3859 * initial intermediate value, to differentiate it from the
3862 int rad_tunnel_pwdecode(uint8_t *passwd, size_t *pwlen, const char *secret,
3863 const uint8_t *vector)
3865 FR_MD5_CTX context, old;
3866 uint8_t digest[AUTH_VECTOR_LEN];
3868 unsigned i, n, len, reallen;
3873 * We need at least a salt.
3876 fr_strerror_printf("tunnel password is too short");
3881 * There's a salt, but no password. Or, there's a salt
3882 * and a 'data_len' octet. It's wrong, but at least we
3883 * can figure out what it means: the password is empty.
3885 * Note that this means we ignore the 'data_len' field,
3886 * if the attribute length tells us that there's no
3887 * more data. So the 'data_len' field may be wrong,
3896 len -= 2; /* discount the salt */
3899 * Use the secret to setup the decryption digest
3901 secretlen = strlen(secret);
3903 fr_MD5Init(&context);
3904 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3905 old = context; /* save intermediate work */
3908 * Set up the initial key:
3910 * b(1) = MD5(secret + vector + salt)
3912 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3913 fr_MD5Update(&context, passwd, 2);
3916 for (n = 0; n < len; n += AUTH_PASS_LEN) {
3920 fr_MD5Final(digest, &context);
3925 * A quick check: decrypt the first octet
3926 * of the password, which is the
3927 * 'data_len' field. Ensure it's sane.
3929 reallen = passwd[2] ^ digest[0];
3930 if (reallen >= len) {
3931 fr_strerror_printf("tunnel password is too long for the attribute");
3935 fr_MD5Update(&context, passwd + 2, AUTH_PASS_LEN);
3939 fr_MD5Final(digest, &context);
3942 fr_MD5Update(&context, passwd + n + 2, AUTH_PASS_LEN);
3945 for (i = base; i < AUTH_PASS_LEN; i++) {
3946 passwd[n + i - 1] = passwd[n + i + 2] ^ digest[i];
3951 * See make_tunnel_password, above.
3953 if (reallen > 239) reallen = 239;
3956 passwd[reallen] = 0;
3962 * Encode a CHAP password
3964 * FIXME: might not work with Ascend because
3965 * we use vp->length, and Ascend gear likes
3966 * to send an extra '\0' in the string!
3968 int rad_chap_encode(RADIUS_PACKET *packet, uint8_t *output, int id,
3969 VALUE_PAIR *password)
3973 uint8_t string[MAX_STRING_LEN * 2 + 1];
3974 VALUE_PAIR *challenge;
3977 * Sanity check the input parameters
3979 if ((packet == NULL) || (password == NULL)) {
3984 * Note that the password VP can be EITHER
3985 * a User-Password attribute (from a check-item list),
3986 * or a CHAP-Password attribute (the client asking
3987 * the library to encode it).
3995 memcpy(ptr, password->vp_strvalue, password->length);
3996 ptr += password->length;
3997 i += password->length;
4000 * Use Chap-Challenge pair if present,
4001 * Request-Authenticator otherwise.
4003 challenge = pairfind(packet->vps, PW_CHAP_CHALLENGE, 0);
4005 memcpy(ptr, challenge->vp_strvalue, challenge->length);
4006 i += challenge->length;
4008 memcpy(ptr, packet->vector, AUTH_VECTOR_LEN);
4009 i += AUTH_VECTOR_LEN;
4013 fr_md5_calc((uint8_t *)output + 1, (uint8_t *)string, i);
4020 * Seed the random number generator.
4022 * May be called any number of times.
4024 void fr_rand_seed(const void *data, size_t size)
4029 * Ensure that the pool is initialized.
4031 if (!fr_rand_initialized) {
4034 memset(&fr_rand_pool, 0, sizeof(fr_rand_pool));
4036 fd = open("/dev/urandom", O_RDONLY);
4042 while (total < sizeof(fr_rand_pool.randrsl)) {
4043 this = read(fd, fr_rand_pool.randrsl,
4044 sizeof(fr_rand_pool.randrsl) - total);
4045 if ((this < 0) && (errno != EINTR)) break;
4046 if (this > 0) total += this;
4050 fr_rand_pool.randrsl[0] = fd;
4051 fr_rand_pool.randrsl[1] = time(NULL);
4052 fr_rand_pool.randrsl[2] = errno;
4055 fr_randinit(&fr_rand_pool, 1);
4056 fr_rand_pool.randcnt = 0;
4057 fr_rand_initialized = 1;
4063 * Hash the user data
4066 if (!hash) hash = fr_rand();
4067 hash = fr_hash_update(data, size, hash);
4069 fr_rand_pool.randmem[fr_rand_pool.randcnt] ^= hash;
4074 * Return a 32-bit random number.
4076 uint32_t fr_rand(void)
4081 * Ensure that the pool is initialized.
4083 if (!fr_rand_initialized) {
4084 fr_rand_seed(NULL, 0);
4087 num = fr_rand_pool.randrsl[fr_rand_pool.randcnt++];
4088 if (fr_rand_pool.randcnt >= 256) {
4089 fr_rand_pool.randcnt = 0;
4090 fr_isaac(&fr_rand_pool);
4098 * Allocate a new RADIUS_PACKET
4100 RADIUS_PACKET *rad_alloc(int newvector)
4104 if ((rp = malloc(sizeof(RADIUS_PACKET))) == NULL) {
4105 fr_strerror_printf("out of memory");
4108 memset(rp, 0, sizeof(*rp));
4114 uint32_t hash, base;
4117 * Don't expose the actual contents of the random
4121 for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(uint32_t)) {
4122 hash = fr_rand() ^ base;
4123 memcpy(rp->vector + i, &hash, sizeof(hash));
4126 fr_rand(); /* stir the pool again */
4131 RADIUS_PACKET *rad_alloc_reply(RADIUS_PACKET *packet)
4133 RADIUS_PACKET *reply;
4135 if (!packet) return NULL;
4137 reply = rad_alloc(0);
4138 if (!reply) return NULL;
4141 * Initialize the fields from the request.
4143 reply->sockfd = packet->sockfd;
4144 reply->dst_ipaddr = packet->src_ipaddr;
4145 reply->src_ipaddr = packet->dst_ipaddr;
4146 reply->dst_port = packet->src_port;
4147 reply->src_port = packet->dst_port;
4148 reply->id = packet->id;
4149 reply->code = 0; /* UNKNOWN code */
4150 memcpy(reply->vector, packet->vector,
4151 sizeof(reply->vector));
4154 reply->data_len = 0;
4161 * Free a RADIUS_PACKET
4163 void rad_free(RADIUS_PACKET **radius_packet_ptr)
4165 RADIUS_PACKET *radius_packet;
4167 if (!radius_packet_ptr || !*radius_packet_ptr) return;
4168 radius_packet = *radius_packet_ptr;
4170 free(radius_packet->data);
4172 pairfree(&radius_packet->vps);
4174 free(radius_packet);
4176 *radius_packet_ptr = NULL;