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);
143 static void print_hex(RADIUS_PACKET *packet)
147 if (!packet->data) return;
149 printf(" Code:\t\t%u\n", packet->data[0]);
150 printf(" Id:\t\t%u\n", packet->data[1]);
151 printf(" Length:\t%u\n", ((packet->data[2] << 8) |
153 printf(" Vector:\t");
154 for (i = 4; i < 20; i++) {
155 printf("%02x", packet->data[i]);
159 if (packet->data_len > 20) {
164 total = packet->data_len - 20;
165 ptr = packet->data + 20;
171 if (total < 2) { /* too short */
172 printf("%02x\n", *ptr);
176 if (ptr[1] > total) { /* too long */
177 for (i = 0; i < total; i++) {
178 printf("%02x ", ptr[i]);
183 printf("%02x %02x ", ptr[0], ptr[1]);
184 attrlen = ptr[1] - 2;
188 for (i = 0; i < attrlen; i++) {
189 if ((i > 0) && ((i & 0x0f) == 0x00))
191 printf("%02x ", ptr[i]);
192 if ((i & 0x0f) == 0x0f) printf("\n");
195 if ((attrlen & 0x0f) != 0x00) printf("\n");
206 * Wrapper for sendto which handles sendfromto, IPv6, and all
207 * possible combinations.
209 static int rad_sendto(int sockfd, void *data, size_t data_len, int flags,
210 fr_ipaddr_t *src_ipaddr, int src_port,
211 fr_ipaddr_t *dst_ipaddr, int dst_port)
213 struct sockaddr_storage dst;
214 socklen_t sizeof_dst;
216 #ifdef WITH_UDPFROMTO
217 struct sockaddr_storage src;
218 socklen_t sizeof_src;
220 fr_ipaddr2sockaddr(src_ipaddr, src_port, &src, &sizeof_src);
222 src_port = src_port; /* -Wunused */
225 if (!fr_ipaddr2sockaddr(dst_ipaddr, dst_port, &dst, &sizeof_dst)) {
229 #ifdef WITH_UDPFROMTO
231 * Only IPv4 is supported for udpfromto.
233 * And if they don't specify a source IP address, don't
236 if ((dst_ipaddr->af == AF_INET) ||
237 (src_ipaddr->af != AF_UNSPEC)) {
238 return sendfromto(sockfd, data, data_len, flags,
239 (struct sockaddr *)&src, sizeof_src,
240 (struct sockaddr *)&dst, sizeof_dst);
243 src_ipaddr = src_ipaddr; /* -Wunused */
247 * No udpfromto, OR an IPv6 socket, fail gracefully.
249 return sendto(sockfd, data, data_len, flags,
250 (struct sockaddr *) &dst, sizeof_dst);
254 void rad_recv_discard(int sockfd)
257 struct sockaddr_storage src;
258 socklen_t sizeof_src = sizeof(src);
260 recvfrom(sockfd, header, sizeof(header), 0,
261 (struct sockaddr *)&src, &sizeof_src);
265 ssize_t rad_recv_header(int sockfd, fr_ipaddr_t *src_ipaddr, int *src_port,
268 ssize_t data_len, packet_len;
270 struct sockaddr_storage src;
271 socklen_t sizeof_src = sizeof(src);
273 data_len = recvfrom(sockfd, header, sizeof(header), MSG_PEEK,
274 (struct sockaddr *)&src, &sizeof_src);
276 if ((errno == EAGAIN) || (errno == EINTR)) return 0;
281 * Too little data is available, discard the packet.
284 recvfrom(sockfd, header, sizeof(header), 0,
285 (struct sockaddr *)&src, &sizeof_src);
288 } else { /* we got 4 bytes of data. */
290 * See how long the packet says it is.
292 packet_len = (header[2] * 256) + header[3];
295 * The length in the packet says it's less than
296 * a RADIUS header length: discard it.
298 if (packet_len < AUTH_HDR_LEN) {
299 recvfrom(sockfd, header, sizeof(header), 0,
300 (struct sockaddr *)&src, &sizeof_src);
304 * Enforce RFC requirements, for sanity.
305 * Anything after 4k will be discarded.
307 } else if (packet_len > MAX_PACKET_LEN) {
308 recvfrom(sockfd, header, sizeof(header), 0,
309 (struct sockaddr *)&src, &sizeof_src);
315 * Convert AF. If unknown, discard packet.
317 if (!fr_sockaddr2ipaddr(&src, sizeof_src, src_ipaddr, src_port)) {
318 recvfrom(sockfd, header, sizeof(header), 0,
319 (struct sockaddr *)&src, &sizeof_src);
326 * The packet says it's this long, but the actual UDP
327 * size could still be smaller.
334 * wrapper for recvfrom, which handles recvfromto, IPv6, and all
335 * possible combinations.
337 static ssize_t rad_recvfrom(int sockfd, uint8_t **pbuf, int flags,
338 fr_ipaddr_t *src_ipaddr, uint16_t *src_port,
339 fr_ipaddr_t *dst_ipaddr, uint16_t *dst_port)
341 struct sockaddr_storage src;
342 struct sockaddr_storage dst;
343 socklen_t sizeof_src = sizeof(src);
344 socklen_t sizeof_dst = sizeof(dst);
351 memset(&src, 0, sizeof_src);
352 memset(&dst, 0, sizeof_dst);
355 * Get address family, etc. first, so we know if we
356 * need to do udpfromto.
358 * FIXME: udpfromto also does this, but it's not
359 * a critical problem.
361 if (getsockname(sockfd, (struct sockaddr *)&dst,
362 &sizeof_dst) < 0) return -1;
365 * Read the length of the packet, from the packet.
366 * This lets us allocate the buffer to use for
367 * reading the rest of the packet.
369 data_len = recvfrom(sockfd, header, sizeof(header), MSG_PEEK,
370 (struct sockaddr *)&src, &sizeof_src);
372 if ((errno == EAGAIN) || (errno == EINTR)) return 0;
377 * Too little data is available, discard the packet.
380 recvfrom(sockfd, header, sizeof(header), flags,
381 (struct sockaddr *)&src, &sizeof_src);
384 } else { /* we got 4 bytes of data. */
386 * See how long the packet says it is.
388 len = (header[2] * 256) + header[3];
391 * The length in the packet says it's less than
392 * a RADIUS header length: discard it.
394 if (len < AUTH_HDR_LEN) {
395 recvfrom(sockfd, header, sizeof(header), flags,
396 (struct sockaddr *)&src, &sizeof_src);
400 * Enforce RFC requirements, for sanity.
401 * Anything after 4k will be discarded.
403 } else if (len > MAX_PACKET_LEN) {
404 recvfrom(sockfd, header, sizeof(header), flags,
405 (struct sockaddr *)&src, &sizeof_src);
414 * Receive the packet. The OS will discard any data in the
415 * packet after "len" bytes.
417 #ifdef WITH_UDPFROMTO
418 if (dst.ss_family == AF_INET) {
419 data_len = recvfromto(sockfd, buf, len, flags,
420 (struct sockaddr *)&src, &sizeof_src,
421 (struct sockaddr *)&dst, &sizeof_dst);
425 * No udpfromto, OR an IPv6 socket. Fail gracefully.
427 data_len = recvfrom(sockfd, buf, len, flags,
428 (struct sockaddr *)&src, &sizeof_src);
434 if (!fr_sockaddr2ipaddr(&src, sizeof_src, src_ipaddr, &port)) {
436 return -1; /* Unknown address family, Die Die Die! */
440 fr_sockaddr2ipaddr(&dst, sizeof_dst, dst_ipaddr, &port);
444 * Different address families should never happen.
446 if (src.ss_family != dst.ss_family) {
452 * Tell the caller about the data
460 #define AUTH_PASS_LEN (AUTH_VECTOR_LEN)
461 /*************************************************************************
463 * Function: make_secret
465 * Purpose: Build an encrypted secret value to return in a reply
466 * packet. The secret is hidden by xoring with a MD5 digest
467 * created from the shared secret and the authentication
468 * vector. We put them into MD5 in the reverse order from
469 * that used when encrypting passwords to RADIUS.
471 *************************************************************************/
472 static void make_secret(uint8_t *digest, const uint8_t *vector,
473 const char *secret, const uint8_t *value)
478 fr_MD5Init(&context);
479 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
480 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
481 fr_MD5Final(digest, &context);
483 for ( i = 0; i < AUTH_VECTOR_LEN; i++ ) {
484 digest[i] ^= value[i];
488 #define MAX_PASS_LEN (128)
489 static void make_passwd(uint8_t *output, size_t *outlen,
490 const uint8_t *input, size_t inlen,
491 const char *secret, const uint8_t *vector)
493 FR_MD5_CTX context, old;
494 uint8_t digest[AUTH_VECTOR_LEN];
495 uint8_t passwd[MAX_PASS_LEN];
500 * If the length is zero, round it up.
504 if (len > MAX_PASS_LEN) len = MAX_PASS_LEN;
506 memcpy(passwd, input, len);
507 memset(passwd + len, 0, sizeof(passwd) - len);
513 else if ((len & 0x0f) != 0) {
519 fr_MD5Init(&context);
520 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
526 fr_MD5Update(&context, vector, AUTH_PASS_LEN);
528 for (n = 0; n < len; n += AUTH_PASS_LEN) {
531 fr_MD5Update(&context,
532 passwd + n - AUTH_PASS_LEN,
536 fr_MD5Final(digest, &context);
537 for (i = 0; i < AUTH_PASS_LEN; i++) {
538 passwd[i + n] ^= digest[i];
542 memcpy(output, passwd, len);
545 static void make_tunnel_passwd(uint8_t *output, size_t *outlen,
546 const uint8_t *input, size_t inlen, size_t room,
547 const char *secret, const uint8_t *vector)
549 FR_MD5_CTX context, old;
550 uint8_t digest[AUTH_VECTOR_LEN];
551 uint8_t passwd[MAX_STRING_LEN + AUTH_VECTOR_LEN];
558 if (room > 253) room = 253;
561 * Account for 2 bytes of the salt, and round the room
562 * available down to the nearest multiple of 16. Then,
563 * subtract one from that to account for the length byte,
564 * and the resulting number is the upper bound on the data
567 * We could short-cut this calculation just be forcing
568 * inlen to be no more than 239. It would work for all
569 * VSA's, as we don't pack multiple VSA's into one
572 * However, this calculation is more general, if a little
573 * complex. And it will work in the future for all possible
574 * kinds of weird attribute packing.
577 room -= (room & 0x0f);
580 if (inlen > room) inlen = room;
583 * Length of the encrypted data is password length plus
584 * one byte for the length of the password.
587 if ((len & 0x0f) != 0) {
591 *outlen = len + 2; /* account for the salt */
594 * Copy the password over.
596 memcpy(passwd + 3, input, inlen);
597 memset(passwd + 3 + inlen, 0, sizeof(passwd) - 3 - inlen);
600 * Generate salt. The RFC's say:
602 * The high bit of salt[0] must be set, each salt in a
603 * packet should be unique, and they should be random
605 * So, we set the high bit, add in a counter, and then
606 * add in some CSPRNG data. should be OK..
608 passwd[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
610 passwd[1] = fr_rand();
611 passwd[2] = inlen; /* length of the password string */
613 fr_MD5Init(&context);
614 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
617 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
618 fr_MD5Update(&context, &passwd[0], 2);
620 for (n = 0; n < len; n += AUTH_PASS_LEN) {
623 fr_MD5Update(&context,
624 passwd + 2 + n - AUTH_PASS_LEN,
628 fr_MD5Final(digest, &context);
630 for (i = 0; i < AUTH_PASS_LEN; i++) {
631 passwd[i + 2 + n] ^= digest[i];
634 memcpy(output, passwd, len + 2);
638 * Returns the end of the data.
640 static int vp2data(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
641 const char *secret, const VALUE_PAIR *vp, uint8_t *start,
647 uint8_t *ptr = start;
651 * Set up the default sources for the data.
653 data = vp->vp_octets;
660 case PW_TYPE_IPV6ADDR:
661 case PW_TYPE_IPV6PREFIX:
662 case PW_TYPE_ABINARY:
663 /* nothing more to do */
667 len = 1; /* just in case */
668 array[0] = vp->vp_integer & 0xff;
673 len = 2; /* just in case */
674 array[0] = (vp->vp_integer >> 8) & 0xff;
675 array[1] = vp->vp_integer & 0xff;
679 case PW_TYPE_INTEGER:
680 len = 4; /* just in case */
681 lvalue = htonl(vp->vp_integer);
682 memcpy(array, &lvalue, sizeof(lvalue));
687 data = (const uint8_t *) &vp->vp_ipaddr;
688 len = 4; /* just in case */
692 * There are no tagged date attributes.
695 lvalue = htonl(vp->vp_date);
696 data = (const uint8_t *) &lvalue;
697 len = 4; /* just in case */
704 len = 4; /* just in case */
705 slvalue = htonl(vp->vp_signed);
706 memcpy(array, &slvalue, sizeof(slvalue));
713 fr_strerror_printf("ERROR: Cannot encode NULL TLV");
716 if (vp->length > room) return 0; /* can't chop TLVs to fit */
719 default: /* unknown type: ignore it */
720 fr_strerror_printf("ERROR: Unknown attribute type %d", vp->type);
725 * Bound the data to the calling size
727 if (len > room) len = room;
730 * Encrypt the various password styles
732 * Attributes with encrypted values MUST be less than
735 switch (vp->flags.encrypt) {
736 case FLAG_ENCRYPT_USER_PASSWORD:
737 make_passwd(ptr, &len, data, len,
738 secret, packet->vector);
741 case FLAG_ENCRYPT_TUNNEL_PASSWORD:
743 if (vp->flags.has_tag) lvalue = 1;
746 * Check if there's enough room. If there isn't,
747 * we discard the attribute.
749 * This is ONLY a problem if we have multiple VSA's
750 * in one Vendor-Specific, though.
752 if (room < (18 + lvalue)) return 0;
754 switch (packet->code) {
755 case PW_AUTHENTICATION_ACK:
756 case PW_AUTHENTICATION_REJECT:
757 case PW_ACCESS_CHALLENGE:
760 fr_strerror_printf("ERROR: No request packet, cannot encrypt %s attribute in the vp.", vp->name);
764 if (lvalue) ptr[0] = vp->flags.tag;
765 make_tunnel_passwd(ptr + lvalue, &len, data, len,
767 secret, original->vector);
769 case PW_ACCOUNTING_REQUEST:
770 case PW_DISCONNECT_REQUEST:
772 ptr[0] = vp->flags.tag;
773 make_tunnel_passwd(ptr + 1, &len, data, len - 1, room,
774 secret, packet->vector);
780 * The code above ensures that this attribute
783 case FLAG_ENCRYPT_ASCEND_SECRET:
784 make_secret(ptr, packet->vector, secret, data);
785 len = AUTH_VECTOR_LEN;
790 if (vp->flags.has_tag && TAG_VALID(vp->flags.tag)) {
791 if (vp->type == PW_TYPE_STRING) {
792 if (len > (room - 1)) len = room - 1;
793 ptr[0] = vp->flags.tag;
795 } else if (vp->type == PW_TYPE_INTEGER) {
796 array[0] = vp->flags.tag;
797 } /* else it can't be any other type */
799 memcpy(ptr, data, len);
801 } /* switch over encryption flags */
803 return len + (ptr - start);;
807 static int rad_vp2rfc(const RADIUS_PACKET *packet,
808 const RADIUS_PACKET *original,
809 const char *secret, const VALUE_PAIR *vp,
810 unsigned int attribute, uint8_t *ptr, size_t room)
814 if (room < 2) return 0;
816 ptr[0] = attribute & 0xff; /* NOT vp->attribute */
819 if (room > (255 - ptr[1])) room = 255 - ptr[1];
820 len = vp2data(packet, original, secret, vp, ptr + 2, room);
821 if (len < 0) return len;
828 extern int fr_wimax_max_tlv;
829 extern int fr_wimax_shift[];
830 extern int fr_wimax_mask[];
832 static int tlv2data(const RADIUS_PACKET *packet,
833 const RADIUS_PACKET *original,
834 const char *secret, const VALUE_PAIR *vp,
835 uint8_t *ptr, size_t room, int nest)
839 if (nest > fr_wimax_max_tlv) return -1;
841 if (room < 2) return 0;
844 ptr[0] = (vp->attribute >> fr_wimax_shift[nest]) & fr_wimax_mask[nest];
848 * No more nested TLVs: pack the data.
850 if ((nest == fr_wimax_max_tlv) ||
851 ((vp->attribute >> fr_wimax_shift[nest + 1]) == 0)) {
852 len = vp2data(packet, original, secret, vp, ptr + 2, room);
854 len = tlv2data(packet, original, secret, vp, ptr + 2, room,
857 if (len <= 0) return len;
864 static int wimax2data(const RADIUS_PACKET *packet,
865 const RADIUS_PACKET *original,
866 const char *secret, const VALUE_PAIR *vp,
867 uint8_t *start, size_t room, uint8_t *ptr)
872 * Offsets to Vendor-Specific length, and to length of
878 if (room < 1) return 0;
882 * Account for continuation bytes. The caller has
883 * already accounting for the continuation byte in the
884 * Vendor-Specific "length" field.
890 * Chop everything to fit in one attribute.
892 if (room > (255 - 9)) room = (255 - 9);
895 * The attribute contains TLVs that we have NOT decoded
896 * properly, OR it contains TLV that the user has encoded
897 * manually. If it has no data, OR it's too long,
898 * discard it. We're not going to walk through its
899 * contents trying to figure out how to chop it across
900 * multiple continuations.
902 if (vp->flags.has_tlv && (!vp->vp_tlv || (vp->length > room))) {
907 * The attribute is a top-level integer, ipaddr, etc.
910 if (!vp->flags.is_tlv) {
911 len = vp2data(packet, original, secret, vp, ptr, room);
913 len = tlv2data(packet, original, secret, vp, ptr, room, 1);
916 if (len <= 0) return len;
918 start[VS_OFF] += len;
919 start[WM_OFF] += len;
921 return start[VS_OFF];
925 static int rad_vp2extended(const RADIUS_PACKET *packet,
926 const RADIUS_PACKET *original,
927 const char *secret, const VALUE_PAIR *vp,
928 unsigned int attribute, uint8_t *ptr, size_t room)
932 if (room < 3) return 0;
934 ptr[0] = attribute & 0xff; /* NOT vp->attribute */
937 if (vp->flags.extended) {
938 ptr[2] = (attribute & 0xff00) >> 8;
941 } else if (vp->flags.extended_flags) {
942 if (room < 4) return 0;
945 ptr[2] = (attribute & 0xff00) >> 8;
952 * For now, no extended attribute can be longer than the
953 * encapsulating attribute. Once we add support for the
954 * "M" bit, this restriction will be relaxed.
956 if (room > (255 - ptr[1])) room = 255 - ptr[1];
958 if (!vp->flags.is_tlv) {
959 len = vp2data(packet, original, secret, vp, ptr + ptr[1], room);
961 len = tlv2data(packet, original, secret, vp, ptr + ptr[1], room, 2);
964 if (len < 0) return len;
972 * Parse a data structure into a RADIUS attribute.
974 int rad_vp2attr(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
975 const char *secret, const VALUE_PAIR *vp, uint8_t *start,
984 * RFC format attributes take the fast path.
986 if (vp->vendor == 0) {
987 return rad_vp2rfc(packet, original, secret, vp,
988 vp->attribute, start, room);
991 if (vp->vendor == VENDORPEC_EXTENDED) {
992 return rad_vp2extended(packet, original, secret, vp,
993 vp->attribute, start, room);
997 * Not enough room for:
998 * attr, len, vendor-id, vsa, vsalen
1000 if (room < 8) return 0;
1003 * Build the Vendor-Specific header
1006 *ptr++ = PW_VENDOR_SPECIFIC;
1009 lvalue = htonl(vp->vendor);
1010 memcpy(ptr, &lvalue, 4);
1014 * Unknown vendors, and type=1,length=1,no-continuation
1015 * are RFC format attributes.
1017 dv = dict_vendorbyvalue(vp->vendor);
1019 ((dv->type == 1) && (dv->length = 1) && !dv->flags)) {
1020 len = rad_vp2rfc(packet, original, secret, vp,
1021 vp->attribute, ptr, room);
1022 if (len <= 0) return len;
1028 if (room < (dv->type + dv->length + dv->flags)) return 0;
1029 room -= (dv->type + dv->length + dv->flags);
1030 start[1] += (dv->type + dv->length + dv->flags);
1034 ptr[0] = (vp->attribute & 0xFF);
1038 ptr[0] = ((vp->attribute >> 8) & 0xFF);
1039 ptr[1] = (vp->attribute & 0xFF);
1044 ptr[1] = ((vp->attribute >> 16) & 0xFF);
1045 ptr[2] = ((vp->attribute >> 8) & 0xFF);
1046 ptr[3] = (vp->attribute & 0xFF);
1050 return 0; /* silently discard it */
1054 switch (dv->length) {
1058 ptr[0] = dv->type + 1;
1062 ptr[1] = dv->type + 2;
1066 return 0; /* silently discard it */
1071 * WiMAX attributes take their own path through the
1074 if (dv->flags) return wimax2data(packet, original, secret, vp,
1077 len = vp2data(packet, original, secret, vp, ptr, room);
1078 if (len <= 0) return len;
1080 if (dv->length != 0) ptr[-1] += len;
1090 #define REORDER(x) ((x & 0xff00) << 8) | ((x & 0xff0000) >> 8) | ((x & 0xff000000 >> 24))
1094 * Encode a WiMAX sub-TLV. It must NOT be called for WiMAX
1095 * attributes that are of type integer, string, etc.
1097 static int rad_encode_wimax(const RADIUS_PACKET *packet,
1098 const RADIUS_PACKET *original,
1099 const char *secret, VALUE_PAIR *reply,
1100 uint8_t *start, size_t room)
1104 uint8_t *ptr = start, *vsa = start;
1106 VALUE_PAIR *vp = reply;
1109 * Swap the order of the WiMAX hacks, to make later
1110 * comparisons easier.
1112 maxattr = REORDER(vp->attribute);
1115 * Build the Vendor-Specific header
1123 if (room < 9) return 0;
1124 *ptr++ = PW_VENDOR_SPECIFIC;
1127 lvalue = htonl(vp->vendor);
1128 memcpy(ptr, &lvalue, 4);
1130 *(ptr++) = vp->attribute & 0xff;
1132 *(ptr++) = 0; /* continuation */
1136 len = tlv2data(packet, original, secret, vp, ptr, room, 1);
1137 if (len < 0) return len;
1140 * Not enough room. Do a continuation.
1142 if ((len == 0) || ((vsa[VS_OFF] + len) > 255)) {
1143 if (redo) return (start - vsa);
1155 vp->flags.encoded = 1;
1159 * Look at the NEXT tlv. Ensure that we encode
1160 * attributes into a common VSA *only* if they are for
1161 * the same WiMAX VSA, AND if the TLVs are in numerically
1164 if (vp && vp->flags.is_tlv && (reply->vendor == vp->vendor) &&
1165 ((reply->attribute & 0xff) == (vp->attribute & 0xff))) {
1168 attr = REORDER(vp->attribute);
1169 if (attr >= maxattr) {
1182 int rad_encode(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1185 radius_packet_t *hdr;
1187 uint16_t total_length;
1191 char ip_buffer[128];
1194 * A 4K packet, aligned on 64-bits.
1196 uint64_t data[MAX_PACKET_LEN / sizeof(uint64_t)];
1198 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1199 what = fr_packet_codes[packet->code];
1204 DEBUG("Sending %s of id %d to %s port %d\n",
1206 inet_ntop(packet->dst_ipaddr.af,
1207 &packet->dst_ipaddr.ipaddr,
1208 ip_buffer, sizeof(ip_buffer)),
1212 * Double-check some things based on packet code.
1214 switch (packet->code) {
1215 case PW_AUTHENTICATION_ACK:
1216 case PW_AUTHENTICATION_REJECT:
1217 case PW_ACCESS_CHALLENGE:
1219 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1225 * These packet vectors start off as all zero.
1227 case PW_ACCOUNTING_REQUEST:
1228 case PW_DISCONNECT_REQUEST:
1229 case PW_COA_REQUEST:
1230 memset(packet->vector, 0, sizeof(packet->vector));
1238 * Use memory on the stack, until we know how
1239 * large the packet will be.
1241 hdr = (radius_packet_t *) data;
1244 * Build standard header
1246 hdr->code = packet->code;
1247 hdr->id = packet->id;
1249 memcpy(hdr->vector, packet->vector, sizeof(hdr->vector));
1251 total_length = AUTH_HDR_LEN;
1254 * Load up the configuration values for the user
1260 * FIXME: Loop twice over the reply list. The first time,
1261 * calculate the total length of data. The second time,
1262 * allocate the memory, and fill in the VP's.
1264 * Hmm... this may be slower than just doing a small
1269 * Loop over the reply attributes for the packet.
1271 for (reply = packet->vps; reply; reply = reply->next) {
1273 * Ignore non-wire attributes, but allow extended
1276 if ((reply->vendor == 0) &&
1277 ((reply->attribute & 0xFFFF) >= 256) &&
1278 !reply->flags.extended && !reply->flags.extended_flags) {
1281 * Permit the admin to send BADLY formatted
1282 * attributes with a debug build.
1284 if (reply->attribute == PW_RAW_ATTRIBUTE) {
1285 memcpy(ptr, reply->vp_octets, reply->length);
1286 len = reply->length;
1294 * Set the Message-Authenticator to the correct
1295 * length and initial value.
1297 if (reply->attribute == PW_MESSAGE_AUTHENTICATOR) {
1298 reply->length = AUTH_VECTOR_LEN;
1299 memset(reply->vp_strvalue, 0, AUTH_VECTOR_LEN);
1302 * Cache the offset to the
1303 * Message-Authenticator
1305 packet->offset = total_length;
1309 * Print out ONLY the attributes which
1310 * we're sending over the wire, and print
1311 * them out BEFORE they're encrypted.
1316 * Skip attributes that are encoded.
1318 if (reply->flags.encoded) continue;
1320 if ((reply->vendor == VENDORPEC_WIMAX) && reply->flags.is_tlv) {
1321 len = rad_encode_wimax(packet, original, secret,
1323 ((uint8_t *) data) + sizeof(data) - ptr);
1326 len = rad_vp2attr(packet, original, secret, reply, ptr,
1327 ((uint8_t *) data) + sizeof(data) - ptr);
1330 if (len < 0) return -1;
1333 * Failed to encode the attribute, likely because
1334 * the packet is full.
1337 (total_length > (sizeof(data) - 2 - reply->length))) {
1338 DEBUG("WARNING: Attributes are too long for packet. Discarding data past %d bytes", total_length);
1344 total_length += len;
1345 } /* done looping over all attributes */
1348 * Fill in the rest of the fields, and copy the data over
1349 * from the local stack to the newly allocated memory.
1351 * Yes, all this 'memcpy' is slow, but it means
1352 * that we only allocate the minimum amount of
1353 * memory for a request.
1355 packet->data_len = total_length;
1356 packet->data = (uint8_t *) malloc(packet->data_len);
1357 if (!packet->data) {
1358 fr_strerror_printf("Out of memory");
1362 memcpy(packet->data, hdr, packet->data_len);
1363 hdr = (radius_packet_t *) packet->data;
1365 total_length = htons(total_length);
1366 memcpy(hdr->length, &total_length, sizeof(total_length));
1373 * Sign a previously encoded packet.
1375 int rad_sign(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1378 radius_packet_t *hdr = (radius_packet_t *)packet->data;
1381 * It wasn't assigned an Id, this is bad!
1383 if (packet->id < 0) {
1384 fr_strerror_printf("ERROR: RADIUS packets must be assigned an Id.");
1388 if (!packet->data || (packet->data_len < AUTH_HDR_LEN) ||
1389 (packet->offset < 0)) {
1390 fr_strerror_printf("ERROR: You must call rad_encode() before rad_sign()");
1395 * If there's a Message-Authenticator, update it
1396 * now, BEFORE updating the authentication vector.
1398 if (packet->offset > 0) {
1399 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
1401 switch (packet->code) {
1402 case PW_ACCOUNTING_REQUEST:
1403 case PW_ACCOUNTING_RESPONSE:
1404 case PW_DISCONNECT_REQUEST:
1405 case PW_DISCONNECT_ACK:
1406 case PW_DISCONNECT_NAK:
1407 case PW_COA_REQUEST:
1410 memset(hdr->vector, 0, AUTH_VECTOR_LEN);
1413 case PW_AUTHENTICATION_ACK:
1414 case PW_AUTHENTICATION_REJECT:
1415 case PW_ACCESS_CHALLENGE:
1417 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1420 memcpy(hdr->vector, original->vector,
1424 default: /* others have vector already set to zero */
1430 * Set the authentication vector to zero,
1431 * calculate the signature, and put it
1432 * into the Message-Authenticator
1435 fr_hmac_md5(packet->data, packet->data_len,
1436 (const uint8_t *) secret, strlen(secret),
1438 memcpy(packet->data + packet->offset + 2,
1439 calc_auth_vector, AUTH_VECTOR_LEN);
1442 * Copy the original request vector back
1443 * to the raw packet.
1445 memcpy(hdr->vector, packet->vector, AUTH_VECTOR_LEN);
1449 * Switch over the packet code, deciding how to
1452 switch (packet->code) {
1454 * Request packets are not signed, bur
1455 * have a random authentication vector.
1457 case PW_AUTHENTICATION_REQUEST:
1458 case PW_STATUS_SERVER:
1462 * Reply packets are signed with the
1463 * authentication vector of the request.
1470 fr_MD5Init(&context);
1471 fr_MD5Update(&context, packet->data, packet->data_len);
1472 fr_MD5Update(&context, (const uint8_t *) secret,
1474 fr_MD5Final(digest, &context);
1476 memcpy(hdr->vector, digest, AUTH_VECTOR_LEN);
1477 memcpy(packet->vector, digest, AUTH_VECTOR_LEN);
1480 }/* switch over packet codes */
1486 * Reply to the request. Also attach
1487 * reply attribute value pairs and any user message provided.
1489 int rad_send(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1494 char ip_buffer[128];
1497 * Maybe it's a fake packet. Don't send it.
1499 if (!packet || (packet->sockfd < 0)) {
1503 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1504 what = fr_packet_codes[packet->code];
1510 * First time through, allocate room for the packet
1512 if (!packet->data) {
1514 * Encode the packet.
1516 if (rad_encode(packet, original, secret) < 0) {
1521 * Re-sign it, including updating the
1522 * Message-Authenticator.
1524 if (rad_sign(packet, original, secret) < 0) {
1529 * If packet->data points to data, then we print out
1530 * the VP list again only for debugging.
1532 } else if (fr_debug_flag) {
1533 DEBUG("Sending %s of id %d to %s port %d\n", what, packet->id,
1534 inet_ntop(packet->dst_ipaddr.af,
1535 &packet->dst_ipaddr.ipaddr,
1536 ip_buffer, sizeof(ip_buffer)),
1539 for (reply = packet->vps; reply; reply = reply->next) {
1540 if ((reply->vendor == 0) &&
1541 ((reply->attribute & 0xFFFF) > 0xff)) continue;
1547 * And send it on it's way.
1549 return rad_sendto(packet->sockfd, packet->data, packet->data_len, 0,
1550 &packet->src_ipaddr, packet->src_port,
1551 &packet->dst_ipaddr, packet->dst_port);
1555 * Do a comparison of two authentication digests by comparing
1556 * the FULL digest. Otehrwise, the server can be subject to
1557 * timing attacks that allow attackers find a valid message
1560 * http://www.cs.rice.edu/~dwallach/pub/crosby-timing2009.pdf
1562 static int digest_cmp(const uint8_t *a, const uint8_t *b, size_t length)
1567 for (i = 0; i < length; i++) {
1568 result |= a[i] ^ b[i];
1571 return result; /* 0 is OK, !0 is !OK, just like memcmp */
1576 * Validates the requesting client NAS. Calculates the
1577 * signature based on the clients private key.
1579 static int calc_acctdigest(RADIUS_PACKET *packet, const char *secret)
1581 uint8_t digest[AUTH_VECTOR_LEN];
1585 * Zero out the auth_vector in the received packet.
1586 * Then append the shared secret to the received packet,
1587 * and calculate the MD5 sum. This must be the same
1588 * as the original MD5 sum (packet->vector).
1590 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
1593 * MD5(packet + secret);
1595 fr_MD5Init(&context);
1596 fr_MD5Update(&context, packet->data, packet->data_len);
1597 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1598 fr_MD5Final(digest, &context);
1601 * Return 0 if OK, 2 if not OK.
1603 if (digest_cmp(digest, packet->vector, AUTH_VECTOR_LEN) != 0) return 2;
1609 * Validates the requesting client NAS. Calculates the
1610 * signature based on the clients private key.
1612 static int calc_replydigest(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1615 uint8_t calc_digest[AUTH_VECTOR_LEN];
1621 if (original == NULL) {
1626 * Copy the original vector in place.
1628 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
1631 * MD5(packet + secret);
1633 fr_MD5Init(&context);
1634 fr_MD5Update(&context, packet->data, packet->data_len);
1635 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1636 fr_MD5Final(calc_digest, &context);
1639 * Copy the packet's vector back to the packet.
1641 memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
1644 * Return 0 if OK, 2 if not OK.
1646 if (digest_cmp(packet->vector, calc_digest, AUTH_VECTOR_LEN) != 0) return 2;
1652 * See if the data pointed to by PTR is a valid RADIUS packet.
1654 * packet is not 'const * const' because we may update data_len,
1655 * if there's more data in the UDP packet than in the RADIUS packet.
1657 int rad_packet_ok(RADIUS_PACKET *packet, int flags)
1662 radius_packet_t *hdr;
1663 char host_ipaddr[128];
1669 * Check for packets smaller than the packet header.
1671 * RFC 2865, Section 3., subsection 'length' says:
1673 * "The minimum length is 20 ..."
1675 if (packet->data_len < AUTH_HDR_LEN) {
1676 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (received %d < minimum %d)",
1677 inet_ntop(packet->src_ipaddr.af,
1678 &packet->src_ipaddr.ipaddr,
1679 host_ipaddr, sizeof(host_ipaddr)),
1680 (int) packet->data_len, AUTH_HDR_LEN);
1685 * RFC 2865, Section 3., subsection 'length' says:
1687 * " ... and maximum length is 4096."
1689 if (packet->data_len > MAX_PACKET_LEN) {
1690 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (received %d > maximum %d)",
1691 inet_ntop(packet->src_ipaddr.af,
1692 &packet->src_ipaddr.ipaddr,
1693 host_ipaddr, sizeof(host_ipaddr)),
1694 (int) packet->data_len, MAX_PACKET_LEN);
1699 * Check for packets with mismatched size.
1700 * i.e. We've received 128 bytes, and the packet header
1701 * says it's 256 bytes long.
1703 totallen = (packet->data[2] << 8) | packet->data[3];
1704 hdr = (radius_packet_t *)packet->data;
1707 * Code of 0 is not understood.
1708 * Code of 16 or greate is not understood.
1710 if ((hdr->code == 0) ||
1711 (hdr->code >= FR_MAX_PACKET_CODE)) {
1712 fr_strerror_printf("WARNING: Bad RADIUS packet from host %s: unknown packet code%d ",
1713 inet_ntop(packet->src_ipaddr.af,
1714 &packet->src_ipaddr.ipaddr,
1715 host_ipaddr, sizeof(host_ipaddr)),
1721 * Message-Authenticator is required in Status-Server
1722 * packets, otherwise they can be trivially forged.
1724 if (hdr->code == PW_STATUS_SERVER) require_ma = 1;
1727 * It's also required if the caller asks for it.
1729 if (flags) require_ma = 1;
1732 * Repeat the length checks. This time, instead of
1733 * looking at the data we received, look at the value
1734 * of the 'length' field inside of the packet.
1736 * Check for packets smaller than the packet header.
1738 * RFC 2865, Section 3., subsection 'length' says:
1740 * "The minimum length is 20 ..."
1742 if (totallen < AUTH_HDR_LEN) {
1743 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (length %d < minimum %d)",
1744 inet_ntop(packet->src_ipaddr.af,
1745 &packet->src_ipaddr.ipaddr,
1746 host_ipaddr, sizeof(host_ipaddr)),
1747 totallen, AUTH_HDR_LEN);
1752 * And again, for the value of the 'length' field.
1754 * RFC 2865, Section 3., subsection 'length' says:
1756 * " ... and maximum length is 4096."
1758 if (totallen > MAX_PACKET_LEN) {
1759 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (length %d > maximum %d)",
1760 inet_ntop(packet->src_ipaddr.af,
1761 &packet->src_ipaddr.ipaddr,
1762 host_ipaddr, sizeof(host_ipaddr)),
1763 totallen, MAX_PACKET_LEN);
1768 * RFC 2865, Section 3., subsection 'length' says:
1770 * "If the packet is shorter than the Length field
1771 * indicates, it MUST be silently discarded."
1773 * i.e. No response to the NAS.
1775 if (packet->data_len < totallen) {
1776 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: received %d octets, packet length says %d",
1777 inet_ntop(packet->src_ipaddr.af,
1778 &packet->src_ipaddr.ipaddr,
1779 host_ipaddr, sizeof(host_ipaddr)),
1780 (int) packet->data_len, totallen);
1785 * RFC 2865, Section 3., subsection 'length' says:
1787 * "Octets outside the range of the Length field MUST be
1788 * treated as padding and ignored on reception."
1790 if (packet->data_len > totallen) {
1792 * We're shortening the packet below, but just
1793 * to be paranoid, zero out the extra data.
1795 memset(packet->data + totallen, 0, packet->data_len - totallen);
1796 packet->data_len = totallen;
1800 * Walk through the packet's attributes, ensuring that
1801 * they add up EXACTLY to the size of the packet.
1803 * If they don't, then the attributes either under-fill
1804 * or over-fill the packet. Any parsing of the packet
1805 * is impossible, and will result in unknown side effects.
1807 * This would ONLY happen with buggy RADIUS implementations,
1808 * or with an intentional attack. Either way, we do NOT want
1809 * to be vulnerable to this problem.
1812 count = totallen - AUTH_HDR_LEN;
1817 * We need at least 2 bytes to check the
1821 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute header overflows the packet",
1822 inet_ntop(packet->src_ipaddr.af,
1823 &packet->src_ipaddr.ipaddr,
1824 host_ipaddr, sizeof(host_ipaddr)));
1829 * Attribute number zero is NOT defined.
1832 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Invalid attribute 0",
1833 inet_ntop(packet->src_ipaddr.af,
1834 &packet->src_ipaddr.ipaddr,
1835 host_ipaddr, sizeof(host_ipaddr)));
1840 * Attributes are at LEAST as long as the ID & length
1841 * fields. Anything shorter is an invalid attribute.
1844 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %u too short",
1845 inet_ntop(packet->src_ipaddr.af,
1846 &packet->src_ipaddr.ipaddr,
1847 host_ipaddr, sizeof(host_ipaddr)),
1853 * If there are fewer bytes in the packet than in the
1854 * attribute, it's a bad packet.
1856 if (count < attr[1]) {
1857 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %u data overflows the packet",
1858 inet_ntop(packet->src_ipaddr.af,
1859 &packet->src_ipaddr.ipaddr,
1860 host_ipaddr, sizeof(host_ipaddr)),
1866 * Sanity check the attributes for length.
1869 default: /* don't do anything by default */
1873 * If there's an EAP-Message, we require
1874 * a Message-Authenticator.
1876 case PW_EAP_MESSAGE:
1880 case PW_MESSAGE_AUTHENTICATOR:
1881 if (attr[1] != 2 + AUTH_VECTOR_LEN) {
1882 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Message-Authenticator has invalid length %d",
1883 inet_ntop(packet->src_ipaddr.af,
1884 &packet->src_ipaddr.ipaddr,
1885 host_ipaddr, sizeof(host_ipaddr)),
1894 * FIXME: Look up the base 255 attributes in the
1895 * dictionary, and switch over their type. For
1896 * integer/date/ip, the attribute length SHOULD
1899 count -= attr[1]; /* grab the attribute length */
1901 num_attributes++; /* seen one more attribute */
1905 * If the attributes add up to a packet, it's allowed.
1907 * If not, we complain, and throw the packet away.
1910 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: packet attributes do NOT exactly fill the packet",
1911 inet_ntop(packet->src_ipaddr.af,
1912 &packet->src_ipaddr.ipaddr,
1913 host_ipaddr, sizeof(host_ipaddr)));
1918 * If we're configured to look for a maximum number of
1919 * attributes, and we've seen more than that maximum,
1920 * then throw the packet away, as a possible DoS.
1922 if ((fr_max_attributes > 0) &&
1923 (num_attributes > fr_max_attributes)) {
1924 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
1925 inet_ntop(packet->src_ipaddr.af,
1926 &packet->src_ipaddr.ipaddr,
1927 host_ipaddr, sizeof(host_ipaddr)),
1928 num_attributes, fr_max_attributes);
1933 * http://www.freeradius.org/rfc/rfc2869.html#EAP-Message
1935 * A packet with an EAP-Message attribute MUST also have
1936 * a Message-Authenticator attribute.
1938 * A Message-Authenticator all by itself is OK, though.
1940 * Similarly, Status-Server packets MUST contain
1941 * Message-Authenticator attributes.
1943 if (require_ma && ! seen_ma) {
1944 fr_strerror_printf("WARNING: Insecure packet from host %s: Packet does not contain required Message-Authenticator attribute",
1945 inet_ntop(packet->src_ipaddr.af,
1946 &packet->src_ipaddr.ipaddr,
1947 host_ipaddr, sizeof(host_ipaddr)));
1952 * Fill RADIUS header fields
1954 packet->code = hdr->code;
1955 packet->id = hdr->id;
1956 memcpy(packet->vector, hdr->vector, AUTH_VECTOR_LEN);
1963 * Receive UDP client requests, and fill in
1964 * the basics of a RADIUS_PACKET structure.
1966 RADIUS_PACKET *rad_recv(int fd, int flags)
1969 RADIUS_PACKET *packet;
1972 * Allocate the new request data structure
1974 if ((packet = malloc(sizeof(*packet))) == NULL) {
1975 fr_strerror_printf("out of memory");
1978 memset(packet, 0, sizeof(*packet));
1981 sock_flags = MSG_PEEK;
1985 packet->data_len = rad_recvfrom(fd, &packet->data, sock_flags,
1986 &packet->src_ipaddr, &packet->src_port,
1987 &packet->dst_ipaddr, &packet->dst_port);
1990 * Check for socket errors.
1992 if (packet->data_len < 0) {
1993 fr_strerror_printf("Error receiving packet: %s", strerror(errno));
1994 /* packet->data is NULL */
2000 * If the packet is too big, then rad_recvfrom did NOT
2001 * allocate memory. Instead, it just discarded the
2004 if (packet->data_len > MAX_PACKET_LEN) {
2005 fr_strerror_printf("Discarding packet: Larger than RFC limitation of 4096 bytes.");
2006 /* packet->data is NULL */
2012 * Read no data. Continue.
2013 * This check is AFTER the MAX_PACKET_LEN check above, because
2014 * if the packet is larger than MAX_PACKET_LEN, we also have
2015 * packet->data == NULL
2017 if ((packet->data_len == 0) || !packet->data) {
2018 fr_strerror_printf("Empty packet: Socket is not ready.");
2024 * See if it's a well-formed RADIUS packet.
2026 if (!rad_packet_ok(packet, flags)) {
2032 * Remember which socket we read the packet from.
2034 packet->sockfd = fd;
2037 * FIXME: Do even more filtering by only permitting
2038 * certain IP's. The problem is that we don't know
2039 * how to do this properly for all possible clients...
2043 * Explicitely set the VP list to empty.
2047 if (fr_debug_flag) {
2048 char host_ipaddr[128];
2050 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
2051 DEBUG("rad_recv: %s packet from host %s port %d",
2052 fr_packet_codes[packet->code],
2053 inet_ntop(packet->src_ipaddr.af,
2054 &packet->src_ipaddr.ipaddr,
2055 host_ipaddr, sizeof(host_ipaddr)),
2058 DEBUG("rad_recv: Packet from host %s port %d code=%d",
2059 inet_ntop(packet->src_ipaddr.af,
2060 &packet->src_ipaddr.ipaddr,
2061 host_ipaddr, sizeof(host_ipaddr)),
2065 DEBUG(", id=%d, length=%d\n",
2066 packet->id, (int) packet->data_len);
2074 * Verify the signature of a packet.
2076 int rad_verify(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2083 if (!packet || !packet->data) return -1;
2086 * Before we allocate memory for the attributes, do more
2089 ptr = packet->data + AUTH_HDR_LEN;
2090 length = packet->data_len - AUTH_HDR_LEN;
2091 while (length > 0) {
2092 uint8_t msg_auth_vector[AUTH_VECTOR_LEN];
2093 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
2098 default: /* don't do anything. */
2102 * Note that more than one Message-Authenticator
2103 * attribute is invalid.
2105 case PW_MESSAGE_AUTHENTICATOR:
2106 memcpy(msg_auth_vector, &ptr[2], sizeof(msg_auth_vector));
2107 memset(&ptr[2], 0, AUTH_VECTOR_LEN);
2109 switch (packet->code) {
2113 case PW_ACCOUNTING_REQUEST:
2114 case PW_ACCOUNTING_RESPONSE:
2115 case PW_DISCONNECT_REQUEST:
2116 case PW_DISCONNECT_ACK:
2117 case PW_DISCONNECT_NAK:
2118 case PW_COA_REQUEST:
2121 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
2124 case PW_AUTHENTICATION_ACK:
2125 case PW_AUTHENTICATION_REJECT:
2126 case PW_ACCESS_CHALLENGE:
2128 fr_strerror_printf("ERROR: Cannot validate Message-Authenticator in response packet without a request packet.");
2131 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
2135 fr_hmac_md5(packet->data, packet->data_len,
2136 (const uint8_t *) secret, strlen(secret),
2138 if (digest_cmp(calc_auth_vector, msg_auth_vector,
2139 sizeof(calc_auth_vector)) != 0) {
2141 fr_strerror_printf("Received packet from %s with invalid Message-Authenticator! (Shared secret is incorrect.)",
2142 inet_ntop(packet->src_ipaddr.af,
2143 &packet->src_ipaddr.ipaddr,
2144 buffer, sizeof(buffer)));
2145 /* Silently drop packet, according to RFC 3579 */
2147 } /* else the message authenticator was good */
2150 * Reinitialize Authenticators.
2152 memcpy(&ptr[2], msg_auth_vector, AUTH_VECTOR_LEN);
2153 memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
2155 } /* switch over the attributes */
2159 } /* loop over the packet, sanity checking the attributes */
2162 * It looks like a RADIUS packet, but we can't validate
2165 if ((packet->code == 0) || (packet->code >= FR_MAX_PACKET_CODE)) {
2167 fr_strerror_printf("Received Unknown packet code %d "
2168 "from client %s port %d: Cannot validate signature.",
2170 inet_ntop(packet->src_ipaddr.af,
2171 &packet->src_ipaddr.ipaddr,
2172 buffer, sizeof(buffer)),
2178 * Calculate and/or verify digest.
2180 switch(packet->code) {
2184 case PW_AUTHENTICATION_REQUEST:
2185 case PW_STATUS_SERVER:
2187 * The authentication vector is random
2188 * nonsense, invented by the client.
2192 case PW_COA_REQUEST:
2193 case PW_DISCONNECT_REQUEST:
2194 case PW_ACCOUNTING_REQUEST:
2195 if (calc_acctdigest(packet, secret) > 1) {
2196 fr_strerror_printf("Received %s packet "
2197 "from client %s with invalid signature! (Shared secret is incorrect.)",
2198 fr_packet_codes[packet->code],
2199 inet_ntop(packet->src_ipaddr.af,
2200 &packet->src_ipaddr.ipaddr,
2201 buffer, sizeof(buffer)));
2206 /* Verify the reply digest */
2207 case PW_AUTHENTICATION_ACK:
2208 case PW_AUTHENTICATION_REJECT:
2209 case PW_ACCESS_CHALLENGE:
2210 case PW_ACCOUNTING_RESPONSE:
2211 case PW_DISCONNECT_ACK:
2212 case PW_DISCONNECT_NAK:
2215 rcode = calc_replydigest(packet, original, secret);
2217 fr_strerror_printf("Received %s packet "
2218 "from home server %s port %d with invalid signature! (Shared secret is incorrect.)",
2219 fr_packet_codes[packet->code],
2220 inet_ntop(packet->src_ipaddr.af,
2221 &packet->src_ipaddr.ipaddr,
2222 buffer, sizeof(buffer)),
2229 fr_strerror_printf("Received Unknown packet code %d "
2230 "from client %s port %d: Cannot validate signature",
2232 inet_ntop(packet->src_ipaddr.af,
2233 &packet->src_ipaddr.ipaddr,
2234 buffer, sizeof(buffer)),
2243 static VALUE_PAIR *data2vp(const RADIUS_PACKET *packet,
2244 const RADIUS_PACKET *original,
2245 const char *secret, size_t length,
2246 const uint8_t *data, VALUE_PAIR *vp)
2251 * If length is greater than 253, something is SERIOUSLY
2254 if (length > 253) length = 253; /* paranoia (pair-anoia?) */
2256 vp->length = length;
2257 vp->operator = T_OP_EQ;
2261 * It's supposed to be a fixed length, but we found
2262 * a different length instead. Make it type "octets",
2263 * and do no more processing on it.
2265 if ((vp->flags.length > 0) && (vp->flags.length != length)) {
2272 if (vp->flags.has_tag) {
2273 if (TAG_VALID(data[0]) ||
2274 (vp->flags.encrypt == FLAG_ENCRYPT_TUNNEL_PASSWORD)) {
2276 * Tunnel passwords REQUIRE a tag, even
2277 * if don't have a valid tag.
2279 vp->flags.tag = data[0];
2281 if ((vp->type == PW_TYPE_STRING) ||
2282 (vp->type == PW_TYPE_OCTETS)) {
2283 if (length == 0) goto raw;
2290 * Copy the data to be decrypted
2292 memcpy(&vp->vp_octets[0], data + offset, length - offset);
2293 vp->length -= offset;
2296 * Decrypt the attribute.
2298 switch (vp->flags.encrypt) {
2302 case FLAG_ENCRYPT_USER_PASSWORD:
2304 rad_pwdecode((char *)vp->vp_strvalue,
2308 rad_pwdecode((char *)vp->vp_strvalue,
2312 if (vp->attribute == PW_USER_PASSWORD) {
2313 vp->length = strlen(vp->vp_strvalue);
2318 * Tunnel-Password's may go ONLY
2319 * in response packets.
2321 case FLAG_ENCRYPT_TUNNEL_PASSWORD:
2322 if (!original) goto raw;
2324 if (rad_tunnel_pwdecode(vp->vp_octets, &vp->length,
2325 secret, original->vector) < 0) {
2331 * Ascend-Send-Secret
2332 * Ascend-Receive-Secret
2334 case FLAG_ENCRYPT_ASCEND_SECRET:
2338 uint8_t my_digest[AUTH_VECTOR_LEN];
2339 make_secret(my_digest,
2342 memcpy(vp->vp_strvalue, my_digest,
2344 vp->vp_strvalue[AUTH_VECTOR_LEN] = '\0';
2345 vp->length = strlen(vp->vp_strvalue);
2351 } /* switch over encryption flags */
2355 case PW_TYPE_STRING:
2356 case PW_TYPE_OCTETS:
2357 case PW_TYPE_ABINARY:
2358 /* nothing more to do */
2362 if (vp->length != 1) goto raw;
2364 vp->vp_integer = vp->vp_octets[0];
2369 if (vp->length != 2) goto raw;
2371 vp->vp_integer = (vp->vp_octets[0] << 8) | vp->vp_octets[1];
2374 case PW_TYPE_INTEGER:
2375 if (vp->length != 4) goto raw;
2377 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2378 vp->vp_integer = ntohl(vp->vp_integer);
2380 if (vp->flags.has_tag) vp->vp_integer &= 0x00ffffff;
2383 * Try to get named VALUEs
2387 dval = dict_valbyattr(vp->attribute, vp->vendor,
2390 strlcpy(vp->vp_strvalue,
2392 sizeof(vp->vp_strvalue));
2398 if (vp->length != 4) goto raw;
2400 memcpy(&vp->vp_date, vp->vp_octets, 4);
2401 vp->vp_date = ntohl(vp->vp_date);
2405 case PW_TYPE_IPADDR:
2406 if (vp->length != 4) goto raw;
2408 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2412 * IPv6 interface ID is 8 octets long.
2415 if (vp->length != 8) goto raw;
2416 /* vp->vp_ifid == vp->vp_octets */
2420 * IPv6 addresses are 16 octets long
2422 case PW_TYPE_IPV6ADDR:
2423 if (vp->length != 16) goto raw;
2424 /* vp->vp_ipv6addr == vp->vp_octets */
2428 * IPv6 prefixes are 2 to 18 octets long.
2430 * RFC 3162: The first octet is unused.
2431 * The second is the length of the prefix
2432 * the rest are the prefix data.
2434 * The prefix length can have value 0 to 128.
2436 case PW_TYPE_IPV6PREFIX:
2437 if (vp->length < 2 || vp->length > 18) goto raw;
2438 if (vp->vp_octets[1] > 128) goto raw;
2441 * FIXME: double-check that
2442 * (vp->vp_octets[1] >> 3) matches vp->length + 2
2444 if (vp->length < 18) {
2445 memset(vp->vp_octets + vp->length, 0,
2450 case PW_TYPE_SIGNED:
2451 if (vp->length != 4) goto raw;
2454 * Overload vp_integer for ntohl, which takes
2455 * uint32_t, not int32_t
2457 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2458 vp->vp_integer = ntohl(vp->vp_integer);
2459 memcpy(&vp->vp_signed, &vp->vp_integer, 4);
2463 vp->length = length;
2464 vp->vp_tlv = malloc(length);
2467 fr_strerror_printf("No memory");
2470 memcpy(vp->vp_tlv, data, length);
2473 case PW_TYPE_COMBO_IP:
2474 if (vp->length == 4) {
2475 vp->type = PW_TYPE_IPADDR;
2476 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2479 } else if (vp->length == 16) {
2480 vp->type = PW_TYPE_IPV6ADDR;
2481 /* vp->vp_ipv6addr == vp->vp_octets */
2490 * Change the name to show the user that the
2491 * attribute is not of the correct format.
2494 int attr = vp->attribute;
2495 int vendor = vp->vendor;
2498 vp2 = pairalloc(NULL);
2507 * This sets "vp->flags" appropriately,
2510 if (!paircreate_raw(attr, vendor, PW_TYPE_OCTETS, vp)) {
2514 vp->length = length;
2515 memcpy(vp->vp_octets, data, length);
2523 static void rad_sortvp(VALUE_PAIR **head)
2526 VALUE_PAIR *vp, **tail;
2529 * Walk over the VP's, sorting them in order. Did I
2530 * mention that I hate WiMAX continuations?
2532 * And bubble sort! WTF is up with that?
2539 if (!vp->next) break;
2541 if (vp->attribute > vp->next->attribute) {
2543 vp->next = (*tail)->next;
2554 * Walk the packet, looking for continuations of this attribute.
2556 * This is (worst-case) O(N^2) in the number of RADIUS
2557 * attributes. That happens only when perverse clients create
2558 * continued attributes, AND separate the fragmented portions
2559 * with a lot of other attributes.
2561 * Sane clients should put the fragments next to each other, in
2562 * which case this is O(N), in the number of fragments.
2564 static uint8_t *rad_coalesce(unsigned int attribute, int vendor,
2565 size_t length, uint8_t *data,
2566 size_t packet_length, size_t *ptlv_length)
2570 size_t tlv_length = length;
2571 uint8_t *ptr, *tlv, *tlv_data;
2573 for (ptr = data + length;
2574 ptr != (data + packet_length);
2576 /* FIXME: Check that there are 6 bytes of data here... */
2577 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2578 (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2579 (ptr[2] != 0) || (ptr[3] != 0) || /* our requirement */
2580 (ptr[4] != ((vendor >> 8) & 0xff)) ||
2581 (ptr[5] != (vendor & 0xff))) {
2585 memcpy(&lvalue, ptr + 2, 4); /* Vendor Id */
2586 lvalue = ntohl(lvalue);
2588 lvalue |= ptr[2 + 4]; /* add in VSA number */
2589 if (lvalue != attribute) continue;
2592 * If the vendor-length is too small, it's badly
2593 * formed, so we stop.
2595 if ((ptr[2 + 4 + 1]) < 3) break;
2597 tlv_length += ptr[2 + 4 + 1] - 3;
2598 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2601 tlv = tlv_data = malloc(tlv_length);
2602 if (!tlv_data) return NULL;
2604 memcpy(tlv, data, length);
2608 * Now we walk the list again, copying the data over to
2609 * our newly created memory.
2611 for (ptr = data + length;
2612 ptr != (data + packet_length);
2616 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2617 (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2618 (ptr[2] != 0) || (ptr[3] != 0)) { /* our requirement */
2622 memcpy(&lvalue, ptr + 2, 4);
2623 lvalue = ntohl(lvalue);
2625 lvalue |= ptr[2 + 4];
2626 if (lvalue != attribute) continue;
2629 * If the vendor-length is too small, it's badly
2630 * formed, so we stop.
2632 if ((ptr[2 + 4 + 1]) < 3) break;
2634 this_length = ptr[2 + 4 + 1] - 3;
2635 memcpy(tlv, ptr + 2 + 4 + 3, this_length);
2638 ptr[2 + 4] = 0; /* What a hack! */
2639 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2642 *ptlv_length = tlv_length;
2648 * Walk over Evil WIMAX TLVs, creating attributes.
2650 static VALUE_PAIR *tlv2wimax(const RADIUS_PACKET *packet,
2651 const RADIUS_PACKET *original,
2653 int attribute, int vendor,
2654 uint8_t *ptr, size_t len, int nest)
2656 VALUE_PAIR *head = NULL;
2657 VALUE_PAIR **tail = &head;
2659 uint8_t *y; /* why do I need to do this? */
2661 if (nest > fr_wimax_max_tlv) return NULL;
2664 * Sanity check the attribute.
2666 for (y = ptr; y < (ptr + len); y += y[1]) {
2667 if ((y[0] == 0) || ((y + 2) > (ptr + len)) ||
2668 (y[1] < 2) || ((y + y[1]) > (ptr + len))) {
2673 * Attribute number is too large for us to
2674 * represent it in our horrible internal
2677 if ((ptr[0] & ~fr_wimax_mask[nest]) != 0) {
2682 for (y = ptr; y < (ptr + len); y += y[1]) {
2685 da = dict_attrbyvalue(attribute | (ptr[0] << fr_wimax_shift[nest]), vendor);
2686 if (da && (da->type == PW_TYPE_TLV)) {
2687 vp = tlv2wimax(packet, original, secret,
2688 attribute | (ptr[0] << fr_wimax_shift[nest]),
2689 vendor, ptr + 2, ptr[1] - 2,
2691 if (!vp) goto error;
2693 vp = paircreate(attribute | (ptr[0] << fr_wimax_shift[nest]), vendor,
2701 if (!data2vp(packet, original, secret,
2702 y[1] - 2, y + 2, vp)) {
2708 while (*tail) tail = &((*tail)->next);
2715 * Start at the *data* portion of a continued attribute. search
2716 * through the rest of the attributes to find a matching one, and
2717 * add it's contents to our contents.
2719 static VALUE_PAIR *rad_continuation2vp(const RADIUS_PACKET *packet,
2720 const RADIUS_PACKET *original,
2721 const char *secret, int attribute,
2723 int length, /* CANNOT be zero */
2724 uint8_t *data, size_t packet_length,
2725 int flag, DICT_ATTR *da)
2727 size_t tlv_length, left;
2730 VALUE_PAIR *vp, *head, **tail;
2734 * Ensure we have data that hasn't been split across
2735 * multiple attributes.
2738 tlv_data = rad_coalesce(attribute, vendor, length,
2739 data, packet_length, &tlv_length);
2740 if (!tlv_data) return NULL;
2743 tlv_length = length;
2747 * Non-TLV types cannot be continued across multiple
2748 * attributes. This is true even of keys that are
2749 * encrypted with the tunnel-password method. The spec
2750 * says that they can be continued... but also that the
2751 * keys are 160 bits, which means that they CANNOT be
2754 * Note that we don't check "flag" here. The calling
2757 if (!da || (da->type != PW_TYPE_TLV)) {
2759 if (tlv_data == data) { /* true if we had 'goto' */
2760 tlv_data = malloc(tlv_length);
2761 if (!tlv_data) return NULL;
2762 memcpy(tlv_data, data, tlv_length);
2765 vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2766 if (!vp) return NULL;
2768 vp->type = PW_TYPE_TLV;
2769 vp->flags.encrypt = FLAG_ENCRYPT_NONE;
2770 vp->flags.has_tag = 0;
2771 vp->flags.is_tlv = 0;
2772 vp->vp_tlv = tlv_data;
2773 vp->length = tlv_length;
2775 } /* else it WAS a TLV, go decode the sub-tlv's */
2778 * Now (sigh) we walk over the TLV, seeing if it is
2782 for (ptr = tlv_data;
2783 ptr != (tlv_data + tlv_length);
2788 goto not_well_formed;
2795 * Now we walk over the TLV *again*, creating sub-tlv's.
2800 for (ptr = tlv_data;
2801 ptr != (tlv_data + tlv_length);
2804 tlv_da = dict_attrbyvalue(attribute | (ptr[0] << fr_wimax_shift[1]), vendor);
2805 if (tlv_da && (tlv_da->type == PW_TYPE_TLV)) {
2806 vp = tlv2wimax(packet, original, secret,
2807 attribute | (ptr[0] << 8),
2808 vendor, ptr + 2, ptr[1] - 2, 2);
2810 if (!vp) goto error;
2812 vp = paircreate(attribute | (ptr[0] << fr_wimax_shift[1]), vendor,
2817 goto not_well_formed;
2820 if (!data2vp(packet, original, secret,
2821 ptr[1] - 2, ptr + 2, vp)) {
2828 while (*tail) tail = &((*tail)->next);
2832 * TLV's MAY be continued, but sometimes they're not.
2834 if (tlv_data != data) free(tlv_data);
2836 if (head->next) rad_sortvp(&head);
2843 * Extended attribute TLV to VP.
2845 static VALUE_PAIR *tlv2vp(const RADIUS_PACKET *packet,
2846 const RADIUS_PACKET *original,
2847 const char *secret, int attribute,
2848 int length, const uint8_t *data)
2852 if ((length < 2) || (data[1] < 2)) return NULL;
2855 * For now, only one TLV is allowed.
2857 if (data[1] != length) return NULL;
2859 attribute |= (data[0] << fr_wimax_shift[2]);
2861 vp = paircreate(attribute, VENDORPEC_EXTENDED, PW_TYPE_OCTETS);
2862 if (!vp) return NULL;
2864 return data2vp(packet, original, secret, length - 2, data + 2, vp);
2868 * Parse a RADIUS attribute into a data structure.
2870 VALUE_PAIR *rad_attr2vp(const RADIUS_PACKET *packet,
2871 const RADIUS_PACKET *original,
2872 const char *secret, int attribute, int vendor,
2873 int length, const uint8_t *data)
2878 * Hard-coded values are bad...
2880 if ((vendor == 0) && (attribute >= 241) && (attribute <= 246)) {
2883 da = dict_attrbyvalue(attribute, VENDORPEC_EXTENDED);
2884 if (da && (da->flags.extended || da->flags.extended_flags)) {
2886 if (length == 0) return NULL;
2888 attribute |= (data[0] << fr_wimax_shift[1]);
2889 vendor = VENDORPEC_EXTENDED;
2895 * There may be a flag octet.
2897 if (da->flags.extended_flags) {
2898 if (length == 0) return NULL;
2901 * If there's a flag, we can't
2904 if (data[0] != 0) return NULL;
2910 * Now look up the extended attribute, to
2911 * see if it's a TLV carrying more data.
2914 da = dict_attrbyvalue(attribute, VENDORPEC_EXTENDED);
2915 if (da && da->flags.has_tlv) {
2916 return tlv2vp(packet, original, secret,
2917 attribute, length, data);
2921 vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2922 if (!vp) return NULL;
2924 return data2vp(packet, original, secret, length, data, vp);
2929 * Calculate/check digest, and decode radius attributes.
2931 * -1 on decoding error
2934 int rad_decode(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2938 uint32_t vendorcode;
2941 uint8_t *ptr, *vsa_ptr;
2946 radius_packet_t *hdr;
2947 int vsa_tlen, vsa_llen, vsa_offset;
2948 DICT_VENDOR *dv = NULL;
2949 int num_attributes = 0;
2952 * Extract attribute-value pairs
2954 hdr = (radius_packet_t *)packet->data;
2956 packet_length = packet->data_len - AUTH_HDR_LEN;
2959 * There may be VP's already in the packet. Don't
2962 for (tail = &packet->vps; *tail != NULL; tail = &((*tail)->next)) {
2968 vsa_tlen = vsa_llen = 1;
2972 * We have to read at least two bytes.
2974 * rad_recv() above ensures that this is OK.
2976 while (packet_length > 0) {
2981 * Normal attribute, handle it like normal.
2983 if (vendorcode == 0) {
2985 * No room to read attr/length,
2986 * or bad attribute, or attribute is
2987 * too short, or attribute is too long,
2988 * stop processing the packet.
2990 if ((packet_length < 2) ||
2991 (ptr[0] == 0) || (ptr[1] < 2) ||
2992 (ptr[1] > packet_length)) break;
3000 if (attribute != PW_VENDOR_SPECIFIC) goto create_pair;
3003 * No vendor code, or ONLY vendor code.
3005 if (attrlen <= 4) goto create_pair;
3011 * Handle Vendor-Specific
3013 if (vendorlen == 0) {
3019 * attrlen was checked above.
3021 memcpy(&lvalue, ptr, 4);
3022 myvendor = ntohl(lvalue);
3025 * Zero isn't allowed.
3027 if (myvendor == 0) goto create_pair;
3030 * Allow vendors up to 2^24. Past that,
3033 if (myvendor > FR_MAX_VENDOR) goto create_pair;
3035 vsa_tlen = vsa_llen = 1;
3037 dv = dict_vendorbyvalue(myvendor);
3039 vsa_tlen = dv->type;
3040 vsa_llen = dv->length;
3041 if (dv->flags) vsa_offset = 1;
3045 * Sweep through the list of VSA's,
3046 * seeing if they exactly fill the
3047 * outer Vendor-Specific attribute.
3049 * If not, create a raw Vendor-Specific.
3052 sublen = attrlen - 4;
3055 * See if we can parse it.
3061 * Not enough room for one more
3064 if (sublen < (vsa_tlen + vsa_llen + vsa_offset)) goto create_pair;
3067 * Ensure that the attribute number
3076 myattr = (subptr[0] << 8) | subptr[1];
3080 if ((subptr[0] != 0) ||
3081 (subptr[1] != 0)) goto create_pair;
3083 myattr = (subptr[2] << 8) | subptr[3];
3087 * Our dictionary is broken.
3096 ptr += 4 + vsa_tlen;
3097 attrlen -= (4 + vsa_tlen);
3098 packet_length -= 4 + vsa_tlen;
3102 if (subptr[vsa_tlen] < (vsa_tlen + vsa_llen + vsa_offset))
3105 if (subptr[vsa_tlen] > sublen)
3110 * Reserved bits MUST be
3114 ((subptr[vsa_tlen + vsa_llen] & 0x7f) != 0))
3117 sublen -= subptr[vsa_tlen];
3118 subptr += subptr[vsa_tlen];
3122 if (subptr[vsa_tlen] != 0) goto create_pair;
3123 if (subptr[vsa_tlen + 1] < (vsa_tlen + vsa_llen))
3125 if (subptr[vsa_tlen + 1] > sublen)
3127 sublen -= subptr[vsa_tlen + 1];
3128 subptr += subptr[vsa_tlen + 1];
3132 * Our dictionaries are
3138 } while (sublen > 0);
3140 vendorcode = myvendor;
3141 vendorlen = attrlen - 4;
3148 * attrlen is the length of this attribute.
3149 * total_len is the length of the encompassing
3158 attribute = (ptr[0] << 8) | ptr[1];
3161 default: /* can't hit this. */
3169 attrlen = ptr[0] - (vsa_tlen + vsa_llen + vsa_offset);
3173 attrlen = ptr[1] - (vsa_tlen + vsa_llen);
3176 default: /* can't hit this. */
3180 ptr += vsa_llen + vsa_offset;
3181 vendorlen -= vsa_tlen + vsa_llen + vsa_offset + attrlen;
3182 packet_length -= (vsa_tlen + vsa_llen + vsa_offset);
3185 * Ignore VSAs that have no data.
3187 if (attrlen == 0) goto next;
3190 * WiMAX attributes of type 0 are ignored. They
3191 * are a secret flag to us that the attribute has
3192 * already been dealt with.
3194 if ((vendorcode == VENDORPEC_WIMAX) && (attribute == 0)) {
3201 da = dict_attrbyvalue(attribute, vendorcode);
3204 * If it's NOT continued, AND we know
3205 * about it, AND it's not a TLV, we can
3206 * create a normal pair.
3208 if (((vsa_ptr[2] & 0x80) == 0) &&
3209 da && (da->type != PW_TYPE_TLV)) goto create_pair;
3212 * Else it IS continued, or it's a TLV.
3213 * Go do a lot of work to find the stuff.
3215 pair = rad_continuation2vp(packet, original, secret,
3216 attribute, vendorcode,
3219 ((vsa_ptr[2] & 0x80) != 0),
3225 * Create the attribute, setting the default type
3226 * to 'octets'. If the type in the dictionary
3227 * is different, then the dictionary type will
3228 * over-ride this one.
3230 * If the attribute has no data, then discard it.
3232 * Unless it's CUI. Damn you, CUI!
3236 (attribute != PW_CHARGEABLE_USER_IDENTITY)) goto next;
3238 pair = rad_attr2vp(packet, original, secret,
3239 attribute, vendorcode, attrlen, ptr);
3241 pairfree(&packet->vps);
3242 fr_strerror_printf("out of memory");
3256 * VSA's may not have been counted properly in
3257 * rad_packet_ok() above, as it is hard to count
3258 * then without using the dictionary. We
3259 * therefore enforce the limits here, too.
3261 if ((fr_max_attributes > 0) &&
3262 (num_attributes > fr_max_attributes)) {
3263 char host_ipaddr[128];
3265 pairfree(&packet->vps);
3266 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
3267 inet_ntop(packet->src_ipaddr.af,
3268 &packet->src_ipaddr.ipaddr,
3269 host_ipaddr, sizeof(host_ipaddr)),
3270 num_attributes, fr_max_attributes);
3275 if (vendorlen == 0) vendorcode = 0;
3277 packet_length -= attrlen;
3281 * Merge information from the outside world into our
3284 fr_rand_seed(packet->data, AUTH_HDR_LEN);
3293 * We assume that the passwd buffer passed is big enough.
3294 * RFC2138 says the password is max 128 chars, so the size
3295 * of the passwd buffer must be at least 129 characters.
3296 * Preferably it's just MAX_STRING_LEN.
3298 * int *pwlen is updated to the new length of the encrypted
3299 * password - a multiple of 16 bytes.
3301 int rad_pwencode(char *passwd, size_t *pwlen, const char *secret,
3302 const uint8_t *vector)
3304 FR_MD5_CTX context, old;
3305 uint8_t digest[AUTH_VECTOR_LEN];
3306 int i, n, secretlen;
3310 * RFC maximum is 128 bytes.
3312 * If length is zero, pad it out with zeros.
3314 * If the length isn't aligned to 16 bytes,
3315 * zero out the extra data.
3319 if (len > 128) len = 128;
3322 memset(passwd, 0, AUTH_PASS_LEN);
3323 len = AUTH_PASS_LEN;
3324 } else if ((len % AUTH_PASS_LEN) != 0) {
3325 memset(&passwd[len], 0, AUTH_PASS_LEN - (len % AUTH_PASS_LEN));
3326 len += AUTH_PASS_LEN - (len % AUTH_PASS_LEN);
3331 * Use the secret to setup the decryption digest
3333 secretlen = strlen(secret);
3335 fr_MD5Init(&context);
3336 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3337 old = context; /* save intermediate work */
3340 * Encrypt it in place. Don't bother checking
3341 * len, as we've ensured above that it's OK.
3343 for (n = 0; n < len; n += AUTH_PASS_LEN) {
3345 fr_MD5Update(&context, vector, AUTH_PASS_LEN);
3346 fr_MD5Final(digest, &context);
3349 fr_MD5Update(&context,
3350 (uint8_t *) passwd + n - AUTH_PASS_LEN,
3352 fr_MD5Final(digest, &context);
3355 for (i = 0; i < AUTH_PASS_LEN; i++) {
3356 passwd[i + n] ^= digest[i];
3366 int rad_pwdecode(char *passwd, size_t pwlen, const char *secret,
3367 const uint8_t *vector)
3369 FR_MD5_CTX context, old;
3370 uint8_t digest[AUTH_VECTOR_LEN];
3372 size_t n, secretlen;
3375 * The RFC's say that the maximum is 128.
3376 * The buffer we're putting it into above is 254, so
3377 * we don't need to do any length checking.
3379 if (pwlen > 128) pwlen = 128;
3384 if (pwlen == 0) goto done;
3387 * Use the secret to setup the decryption digest
3389 secretlen = strlen(secret);
3391 fr_MD5Init(&context);
3392 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3393 old = context; /* save intermediate work */
3396 * The inverse of the code above.
3398 for (n = 0; n < pwlen; n += AUTH_PASS_LEN) {
3400 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3401 fr_MD5Final(digest, &context);
3404 if (pwlen > AUTH_PASS_LEN) {
3405 fr_MD5Update(&context, (uint8_t *) passwd,
3409 fr_MD5Final(digest, &context);
3412 if (pwlen > (n + AUTH_PASS_LEN)) {
3413 fr_MD5Update(&context, (uint8_t *) passwd + n,
3418 for (i = 0; i < AUTH_PASS_LEN; i++) {
3419 passwd[i + n] ^= digest[i];
3424 passwd[pwlen] = '\0';
3425 return strlen(passwd);
3430 * Encode Tunnel-Password attributes when sending them out on the wire.
3432 * int *pwlen is updated to the new length of the encrypted
3433 * password - a multiple of 16 bytes.
3435 * This is per RFC-2868 which adds a two char SALT to the initial intermediate
3438 int rad_tunnel_pwencode(char *passwd, size_t *pwlen, const char *secret,
3439 const uint8_t *vector)
3441 uint8_t buffer[AUTH_VECTOR_LEN + MAX_STRING_LEN + 3];
3442 unsigned char digest[AUTH_VECTOR_LEN];
3444 int i, n, secretlen;
3449 if (len > 127) len = 127;
3452 * Shift the password 3 positions right to place a salt and original
3453 * length, tag will be added automatically on packet send
3455 for (n=len ; n>=0 ; n--) passwd[n+3] = passwd[n];
3459 * save original password length as first password character;
3466 * Generate salt. The RFC's say:
3468 * The high bit of salt[0] must be set, each salt in a
3469 * packet should be unique, and they should be random
3471 * So, we set the high bit, add in a counter, and then
3472 * add in some CSPRNG data. should be OK..
3474 salt[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
3475 (fr_rand() & 0x07));
3476 salt[1] = fr_rand();
3479 * Padd password to multiple of AUTH_PASS_LEN bytes.
3481 n = len % AUTH_PASS_LEN;
3483 n = AUTH_PASS_LEN - n;
3484 for (; n > 0; n--, len++)
3487 /* set new password length */
3491 * Use the secret to setup the decryption digest
3493 secretlen = strlen(secret);
3494 memcpy(buffer, secret, secretlen);
3496 for (n2 = 0; n2 < len; n2+=AUTH_PASS_LEN) {
3498 memcpy(buffer + secretlen, vector, AUTH_VECTOR_LEN);
3499 memcpy(buffer + secretlen + AUTH_VECTOR_LEN, salt, 2);
3500 fr_md5_calc(digest, buffer, secretlen + AUTH_VECTOR_LEN + 2);
3502 memcpy(buffer + secretlen, passwd + n2 - AUTH_PASS_LEN, AUTH_PASS_LEN);
3503 fr_md5_calc(digest, buffer, secretlen + AUTH_PASS_LEN);
3506 for (i = 0; i < AUTH_PASS_LEN; i++) {
3507 passwd[i + n2] ^= digest[i];
3515 * Decode Tunnel-Password encrypted attributes.
3517 * Defined in RFC-2868, this uses a two char SALT along with the
3518 * initial intermediate value, to differentiate it from the
3521 int rad_tunnel_pwdecode(uint8_t *passwd, size_t *pwlen, const char *secret,
3522 const uint8_t *vector)
3524 FR_MD5_CTX context, old;
3525 uint8_t digest[AUTH_VECTOR_LEN];
3527 unsigned i, n, len, reallen;
3532 * We need at least a salt.
3535 fr_strerror_printf("tunnel password is too short");
3540 * There's a salt, but no password. Or, there's a salt
3541 * and a 'data_len' octet. It's wrong, but at least we
3542 * can figure out what it means: the password is empty.
3544 * Note that this means we ignore the 'data_len' field,
3545 * if the attribute length tells us that there's no
3546 * more data. So the 'data_len' field may be wrong,
3555 len -= 2; /* discount the salt */
3558 * Use the secret to setup the decryption digest
3560 secretlen = strlen(secret);
3562 fr_MD5Init(&context);
3563 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3564 old = context; /* save intermediate work */
3567 * Set up the initial key:
3569 * b(1) = MD5(secret + vector + salt)
3571 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3572 fr_MD5Update(&context, passwd, 2);
3575 for (n = 0; n < len; n += AUTH_PASS_LEN) {
3579 fr_MD5Final(digest, &context);
3584 * A quick check: decrypt the first octet
3585 * of the password, which is the
3586 * 'data_len' field. Ensure it's sane.
3588 reallen = passwd[2] ^ digest[0];
3589 if (reallen >= len) {
3590 fr_strerror_printf("tunnel password is too long for the attribute");
3594 fr_MD5Update(&context, passwd + 2, AUTH_PASS_LEN);
3598 fr_MD5Final(digest, &context);
3601 fr_MD5Update(&context, passwd + n + 2, AUTH_PASS_LEN);
3604 for (i = base; i < AUTH_PASS_LEN; i++) {
3605 passwd[n + i - 1] = passwd[n + i + 2] ^ digest[i];
3610 * See make_tunnel_password, above.
3612 if (reallen > 239) reallen = 239;
3615 passwd[reallen] = 0;
3621 * Encode a CHAP password
3623 * FIXME: might not work with Ascend because
3624 * we use vp->length, and Ascend gear likes
3625 * to send an extra '\0' in the string!
3627 int rad_chap_encode(RADIUS_PACKET *packet, uint8_t *output, int id,
3628 VALUE_PAIR *password)
3632 uint8_t string[MAX_STRING_LEN * 2 + 1];
3633 VALUE_PAIR *challenge;
3636 * Sanity check the input parameters
3638 if ((packet == NULL) || (password == NULL)) {
3643 * Note that the password VP can be EITHER
3644 * a User-Password attribute (from a check-item list),
3645 * or a CHAP-Password attribute (the client asking
3646 * the library to encode it).
3654 memcpy(ptr, password->vp_strvalue, password->length);
3655 ptr += password->length;
3656 i += password->length;
3659 * Use Chap-Challenge pair if present,
3660 * Request-Authenticator otherwise.
3662 challenge = pairfind(packet->vps, PW_CHAP_CHALLENGE, 0);
3664 memcpy(ptr, challenge->vp_strvalue, challenge->length);
3665 i += challenge->length;
3667 memcpy(ptr, packet->vector, AUTH_VECTOR_LEN);
3668 i += AUTH_VECTOR_LEN;
3672 fr_md5_calc((uint8_t *)output + 1, (uint8_t *)string, i);
3679 * Seed the random number generator.
3681 * May be called any number of times.
3683 void fr_rand_seed(const void *data, size_t size)
3688 * Ensure that the pool is initialized.
3690 if (!fr_rand_initialized) {
3693 memset(&fr_rand_pool, 0, sizeof(fr_rand_pool));
3695 fd = open("/dev/urandom", O_RDONLY);
3701 while (total < sizeof(fr_rand_pool.randrsl)) {
3702 this = read(fd, fr_rand_pool.randrsl,
3703 sizeof(fr_rand_pool.randrsl) - total);
3704 if ((this < 0) && (errno != EINTR)) break;
3705 if (this > 0) total += this;
3709 fr_rand_pool.randrsl[0] = fd;
3710 fr_rand_pool.randrsl[1] = time(NULL);
3711 fr_rand_pool.randrsl[2] = errno;
3714 fr_randinit(&fr_rand_pool, 1);
3715 fr_rand_pool.randcnt = 0;
3716 fr_rand_initialized = 1;
3722 * Hash the user data
3725 if (!hash) hash = fr_rand();
3726 hash = fr_hash_update(data, size, hash);
3728 fr_rand_pool.randmem[fr_rand_pool.randcnt] ^= hash;
3733 * Return a 32-bit random number.
3735 uint32_t fr_rand(void)
3740 * Ensure that the pool is initialized.
3742 if (!fr_rand_initialized) {
3743 fr_rand_seed(NULL, 0);
3746 num = fr_rand_pool.randrsl[fr_rand_pool.randcnt++];
3747 if (fr_rand_pool.randcnt >= 256) {
3748 fr_rand_pool.randcnt = 0;
3749 fr_isaac(&fr_rand_pool);
3757 * Allocate a new RADIUS_PACKET
3759 RADIUS_PACKET *rad_alloc(int newvector)
3763 if ((rp = malloc(sizeof(RADIUS_PACKET))) == NULL) {
3764 fr_strerror_printf("out of memory");
3767 memset(rp, 0, sizeof(*rp));
3773 uint32_t hash, base;
3776 * Don't expose the actual contents of the random
3780 for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(uint32_t)) {
3781 hash = fr_rand() ^ base;
3782 memcpy(rp->vector + i, &hash, sizeof(hash));
3785 fr_rand(); /* stir the pool again */
3790 RADIUS_PACKET *rad_alloc_reply(RADIUS_PACKET *packet)
3792 RADIUS_PACKET *reply;
3794 if (!packet) return NULL;
3796 reply = rad_alloc(0);
3797 if (!reply) return NULL;
3800 * Initialize the fields from the request.
3802 reply->sockfd = packet->sockfd;
3803 reply->dst_ipaddr = packet->src_ipaddr;
3804 reply->src_ipaddr = packet->dst_ipaddr;
3805 reply->dst_port = packet->src_port;
3806 reply->src_port = packet->dst_port;
3807 reply->id = packet->id;
3808 reply->code = 0; /* UNKNOWN code */
3809 memcpy(reply->vector, packet->vector,
3810 sizeof(reply->vector));
3813 reply->data_len = 0;
3820 * Free a RADIUS_PACKET
3822 void rad_free(RADIUS_PACKET **radius_packet_ptr)
3824 RADIUS_PACKET *radius_packet;
3826 if (!radius_packet_ptr || !*radius_packet_ptr) return;
3827 radius_packet = *radius_packet_ptr;
3829 free(radius_packet->data);
3831 pairfree(&radius_packet->vps);
3833 free(radius_packet);
3835 *radius_packet_ptr = NULL;