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);
629 for (i = 0; i < AUTH_PASS_LEN; i++) {
630 passwd[i + 2 + n] ^= digest[i];
633 memcpy(output, passwd, len + 2);
637 * Returns the end of the data.
639 static int vp2data(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
640 const char *secret, const VALUE_PAIR *vp, uint8_t *start,
646 uint8_t *ptr = start;
650 * Set up the default sources for the data.
652 data = vp->vp_octets;
659 case PW_TYPE_IPV6ADDR:
660 case PW_TYPE_IPV6PREFIX:
661 case PW_TYPE_ABINARY:
662 /* nothing more to do */
666 len = 1; /* just in case */
667 array[0] = vp->vp_integer & 0xff;
672 len = 2; /* just in case */
673 array[0] = (vp->vp_integer >> 8) & 0xff;
674 array[1] = vp->vp_integer & 0xff;
678 case PW_TYPE_INTEGER:
679 len = 4; /* just in case */
680 lvalue = htonl(vp->vp_integer);
681 memcpy(array, &lvalue, sizeof(lvalue));
686 data = (const uint8_t *) &vp->vp_ipaddr;
687 len = 4; /* just in case */
691 * There are no tagged date attributes.
694 lvalue = htonl(vp->vp_date);
695 data = (const uint8_t *) &lvalue;
696 len = 4; /* just in case */
703 len = 4; /* just in case */
704 slvalue = htonl(vp->vp_signed);
705 memcpy(array, &slvalue, sizeof(slvalue));
712 fr_strerror_printf("ERROR: Cannot encode NULL TLV");
715 if (vp->length > room) return 0; /* can't chop TLVs to fit */
718 default: /* unknown type: ignore it */
719 fr_strerror_printf("ERROR: Unknown attribute type %d", vp->type);
724 * Bound the data to the calling size
726 if (len > room) len = room;
729 * Encrypt the various password styles
731 * Attributes with encrypted values MUST be less than
734 switch (vp->flags.encrypt) {
735 case FLAG_ENCRYPT_USER_PASSWORD:
736 make_passwd(ptr, &len, data, len,
737 secret, packet->vector);
740 case FLAG_ENCRYPT_TUNNEL_PASSWORD:
742 * Check if there's enough room. If there isn't,
743 * we discard the attribute.
745 * This is ONLY a problem if we have multiple VSA's
746 * in one Vendor-Specific, though.
748 if (room < 19) return 0;
750 switch (packet->code) {
751 case PW_AUTHENTICATION_ACK:
752 case PW_AUTHENTICATION_REJECT:
753 case PW_ACCESS_CHALLENGE:
756 fr_strerror_printf("ERROR: No request packet, cannot encrypt %s attribute in the vp.", vp->name);
759 ptr[0] = vp->flags.tag;
760 make_tunnel_passwd(ptr + 1, &len, data, len, room - 1,
761 secret, original->vector);
763 case PW_ACCOUNTING_REQUEST:
764 case PW_DISCONNECT_REQUEST:
766 ptr[0] = vp->flags.tag;
767 make_tunnel_passwd(ptr + 1, &len, data, len - 1, room,
768 secret, packet->vector);
774 * The code above ensures that this attribute
777 case FLAG_ENCRYPT_ASCEND_SECRET:
778 make_secret(ptr, packet->vector, secret, data);
779 len = AUTH_VECTOR_LEN;
784 if (vp->flags.has_tag && TAG_VALID(vp->flags.tag)) {
785 if (vp->type == PW_TYPE_STRING) {
786 if (len > (room - 1)) len = room - 1;
787 ptr[0] = vp->flags.tag;
789 } else if (vp->type == PW_TYPE_INTEGER) {
790 array[0] = vp->flags.tag;
791 } /* else it can't be any other type */
793 memcpy(ptr, data, len);
795 } /* switch over encryption flags */
797 return len + (ptr - start);;
801 static int rad_vp2rfc(const RADIUS_PACKET *packet,
802 const RADIUS_PACKET *original,
803 const char *secret, const VALUE_PAIR *vp,
804 unsigned int attribute, uint8_t *ptr, size_t room)
808 if (room < 2) return 0;
810 ptr[0] = attribute & 0xff; /* NOT vp->attribute */
813 len = vp2data(packet, original, secret, vp, ptr + 2, room - 2);
814 if (len < 0) return len;
821 static int tlv2data(const RADIUS_PACKET *packet,
822 const RADIUS_PACKET *original,
823 const char *secret, const VALUE_PAIR *vp, int attribute,
824 uint8_t *ptr, size_t room)
828 if (room < 2) return 0;
831 ptr[0] = attribute & 0xff;
835 * No more nested TLVs: pack the data.
837 if ((attribute & ~0xff) == 0) {
838 len = vp2data(packet, original, secret, vp, ptr + 2, room);
840 len = tlv2data(packet, original, secret, vp, attribute >> 8,
843 if (len <= 0) return len;
850 static int wimax2data(const RADIUS_PACKET *packet,
851 const RADIUS_PACKET *original,
852 const char *secret, const VALUE_PAIR *vp,
853 uint8_t *start, size_t room, uint8_t *ptr)
858 * Offsets to Vendor-Specific length, and to length of
864 if (room < 1) return 0;
868 * Account for continuation bytes. The caller has
869 * already accounting for the continuation byte in the
870 * Vendor-Specific "length" field.
876 * Chop everything to fit in one attribute.
878 if (room > (255 - 9)) room = (255 - 9);
881 * The attribute contains TLVs that we have NOT decoded
882 * properly, OR it contains TLV that the user has encoded
883 * manually. If it has no data, OR it's too long,
884 * discard it. We're not going to walk through its
885 * contents trying to figure out how to chop it across
886 * multiple continuations.
888 if (vp->flags.has_tlv && (!vp->vp_tlv || (vp->length > room))) {
893 * The attribute is a top-level integer, ipaddr, etc.
896 if (!vp->flags.is_tlv) {
897 len = vp2data(packet, original, secret, vp, ptr, room);
899 len = tlv2data(packet, original, secret, vp, vp->attribute >> 8,
903 if (len <= 0) return len;
905 start[VS_OFF] += len;
906 start[WM_OFF] += len;
908 return start[VS_OFF];
913 * Parse a data structure into a RADIUS attribute.
915 int rad_vp2attr(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
916 const char *secret, const VALUE_PAIR *vp, uint8_t *start,
925 * RFC format attributes take the fast path.
927 if (vp->vendor == 0) {
928 len = rad_vp2rfc(packet, original, secret, vp,
929 vp->attribute, start, room);
930 if (len < 0) return -1;
933 * RFC 2865 section 5 says that zero-length
934 * attributes MUST NOT be sent.
936 * ... and the WiMAX forum ignores
937 * this... because of one vendor. Don't they
938 * have anything better to do with their time?
941 (vp->attribute != PW_CHARGEABLE_USER_IDENTITY)) return 0;
948 * Not enough room for:
949 * attr, len, vendor-id, vsa, vsalen
951 if (room < 8) return 0;
954 * Build the Vendor-Specific header
957 *ptr++ = PW_VENDOR_SPECIFIC;
960 lvalue = htonl(vp->vendor);
961 memcpy(ptr, &lvalue, 4);
965 * Unknown vendors, and type=1,length=1,no-continuation
966 * are RFC format attributes.
968 dv = dict_vendorbyvalue(vp->vendor);
970 ((dv->type == 1) && (dv->length = 1) && !dv->flags)) {
971 len = rad_vp2rfc(packet, original, secret, vp,
972 vp->attribute, ptr, room);
973 if (len <= 0) return len;
979 if (room < (dv->type + dv->length + dv->flags)) return 0;
980 room -= (dv->type + dv->length + dv->flags);
981 start[1] += (dv->type + dv->length + dv->flags);
985 ptr[0] = (vp->attribute & 0xFF);
989 ptr[0] = ((vp->attribute >> 8) & 0xFF);
990 ptr[1] = (vp->attribute & 0xFF);
995 ptr[1] = ((vp->attribute >> 16) & 0xFF);
996 ptr[2] = ((vp->attribute >> 8) & 0xFF);
997 ptr[3] = (vp->attribute & 0xFF);
1001 return 0; /* silently discard it */
1005 switch (dv->length) {
1009 ptr[0] = dv->type + 1;
1013 ptr[1] = dv->type + 2;
1017 return 0; /* silently discard it */
1022 * WiMAX attributes take their own path through the
1025 if (dv->flags) return wimax2data(packet, original, secret, vp,
1028 len = vp2data(packet, original, secret, vp, ptr, room);
1029 if (len <= 0) return len;
1031 if (dv->length != 0) ptr[-1] += len;
1041 #define REORDER(x) ((x & 0xff00) << 8) | ((x & 0xff0000) >> 8) | ((x & 0xff000000 >> 24))
1045 * Encode a WiMAX sub-TLV. It must NOT be called for WiMAX
1046 * attributes that are of type integer, string, etc.
1048 static int rad_encode_wimax(const RADIUS_PACKET *packet,
1049 const RADIUS_PACKET *original,
1050 const char *secret, VALUE_PAIR *reply,
1051 uint8_t *start, size_t room)
1055 uint8_t *ptr = start, *vsa = start;
1057 VALUE_PAIR *vp = reply;
1060 * Swap the order of the WiMAX hacks, to make later
1061 * comparisons easier.
1063 maxattr = REORDER(vp->attribute);
1066 * Build the Vendor-Specific header
1074 if (room < 9) return 0;
1075 *ptr++ = PW_VENDOR_SPECIFIC;
1078 lvalue = htonl(vp->vendor);
1079 memcpy(ptr, &lvalue, 4);
1081 *(ptr++) = vp->attribute & 0xff;
1083 *(ptr++) = 0; /* continuation */
1087 len = tlv2data(packet, original, secret, vp, vp->attribute >> 8,
1089 if (len < 0) return len;
1092 * Not enough room. Do a continuation.
1094 if ((len == 0) || ((vsa[VS_OFF] + len) > 255)) {
1095 if (redo) return (start - vsa);
1107 vp->flags.encoded = 1;
1111 * Look at the NEXT tlv. Ensure that we encode
1112 * attributes into a common VSA *only* if they are for
1113 * the same WiMAX VSA, AND if the TLVs are in numerically
1116 if (vp && vp->flags.is_tlv && (reply->vendor == vp->vendor) &&
1117 ((reply->attribute & 0xff) == (vp->attribute & 0xff))) {
1120 attr = REORDER(vp->attribute);
1121 if (attr >= maxattr) {
1134 int rad_encode(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1137 radius_packet_t *hdr;
1139 uint16_t total_length;
1143 char ip_buffer[128];
1146 * A 4K packet, aligned on 64-bits.
1148 uint64_t data[MAX_PACKET_LEN / sizeof(uint64_t)];
1150 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1151 what = fr_packet_codes[packet->code];
1156 DEBUG("Sending %s of id %d to %s port %d\n",
1158 inet_ntop(packet->dst_ipaddr.af,
1159 &packet->dst_ipaddr.ipaddr,
1160 ip_buffer, sizeof(ip_buffer)),
1164 * Double-check some things based on packet code.
1166 switch (packet->code) {
1167 case PW_AUTHENTICATION_ACK:
1168 case PW_AUTHENTICATION_REJECT:
1169 case PW_ACCESS_CHALLENGE:
1171 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1177 * These packet vectors start off as all zero.
1179 case PW_ACCOUNTING_REQUEST:
1180 case PW_DISCONNECT_REQUEST:
1181 case PW_COA_REQUEST:
1182 memset(packet->vector, 0, sizeof(packet->vector));
1190 * Use memory on the stack, until we know how
1191 * large the packet will be.
1193 hdr = (radius_packet_t *) data;
1196 * Build standard header
1198 hdr->code = packet->code;
1199 hdr->id = packet->id;
1201 memcpy(hdr->vector, packet->vector, sizeof(hdr->vector));
1203 total_length = AUTH_HDR_LEN;
1206 * Load up the configuration values for the user
1212 * FIXME: Loop twice over the reply list. The first time,
1213 * calculate the total length of data. The second time,
1214 * allocate the memory, and fill in the VP's.
1216 * Hmm... this may be slower than just doing a small
1221 * Loop over the reply attributes for the packet.
1223 for (reply = packet->vps; reply; reply = reply->next) {
1225 * Ignore non-wire attributes
1227 if ((reply->vendor == 0) &&
1228 ((reply->attribute & 0xFFFF) > 0xff)) {
1231 * Permit the admin to send BADLY formatted
1232 * attributes with a debug build.
1234 if (reply->attribute == PW_RAW_ATTRIBUTE) {
1235 memcpy(ptr, reply->vp_octets, reply->length);
1236 len = reply->length;
1244 * Set the Message-Authenticator to the correct
1245 * length and initial value.
1247 if (reply->attribute == PW_MESSAGE_AUTHENTICATOR) {
1248 reply->length = AUTH_VECTOR_LEN;
1249 memset(reply->vp_strvalue, 0, AUTH_VECTOR_LEN);
1252 * Cache the offset to the
1253 * Message-Authenticator
1255 packet->offset = total_length;
1259 * Print out ONLY the attributes which
1260 * we're sending over the wire, and print
1261 * them out BEFORE they're encrypted.
1266 * Skip attributes that are encoded.
1268 if (reply->flags.encoded) continue;
1270 if (reply->flags.is_tlv) {
1271 len = rad_encode_wimax(packet, original, secret,
1273 ((uint8_t *) data) + sizeof(data) - ptr);
1276 len = rad_vp2attr(packet, original, secret, reply, ptr,
1277 ((uint8_t *) data) + sizeof(data) - ptr);
1280 if (len < 0) return -1;
1284 total_length += len;
1285 } /* done looping over all attributes */
1288 * Fill in the rest of the fields, and copy the data over
1289 * from the local stack to the newly allocated memory.
1291 * Yes, all this 'memcpy' is slow, but it means
1292 * that we only allocate the minimum amount of
1293 * memory for a request.
1295 packet->data_len = total_length;
1296 packet->data = (uint8_t *) malloc(packet->data_len);
1297 if (!packet->data) {
1298 fr_strerror_printf("Out of memory");
1302 memcpy(packet->data, hdr, packet->data_len);
1303 hdr = (radius_packet_t *) packet->data;
1305 total_length = htons(total_length);
1306 memcpy(hdr->length, &total_length, sizeof(total_length));
1313 * Sign a previously encoded packet.
1315 int rad_sign(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1318 radius_packet_t *hdr = (radius_packet_t *)packet->data;
1321 * It wasn't assigned an Id, this is bad!
1323 if (packet->id < 0) {
1324 fr_strerror_printf("ERROR: RADIUS packets must be assigned an Id.");
1328 if (!packet->data || (packet->data_len < AUTH_HDR_LEN) ||
1329 (packet->offset < 0)) {
1330 fr_strerror_printf("ERROR: You must call rad_encode() before rad_sign()");
1335 * If there's a Message-Authenticator, update it
1336 * now, BEFORE updating the authentication vector.
1338 if (packet->offset > 0) {
1339 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
1341 switch (packet->code) {
1342 case PW_ACCOUNTING_REQUEST:
1343 case PW_ACCOUNTING_RESPONSE:
1344 case PW_DISCONNECT_REQUEST:
1345 case PW_DISCONNECT_ACK:
1346 case PW_DISCONNECT_NAK:
1347 case PW_COA_REQUEST:
1350 memset(hdr->vector, 0, AUTH_VECTOR_LEN);
1353 case PW_AUTHENTICATION_ACK:
1354 case PW_AUTHENTICATION_REJECT:
1355 case PW_ACCESS_CHALLENGE:
1357 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1360 memcpy(hdr->vector, original->vector,
1364 default: /* others have vector already set to zero */
1370 * Set the authentication vector to zero,
1371 * calculate the signature, and put it
1372 * into the Message-Authenticator
1375 fr_hmac_md5(packet->data, packet->data_len,
1376 (const uint8_t *) secret, strlen(secret),
1378 memcpy(packet->data + packet->offset + 2,
1379 calc_auth_vector, AUTH_VECTOR_LEN);
1382 * Copy the original request vector back
1383 * to the raw packet.
1385 memcpy(hdr->vector, packet->vector, AUTH_VECTOR_LEN);
1389 * Switch over the packet code, deciding how to
1392 switch (packet->code) {
1394 * Request packets are not signed, bur
1395 * have a random authentication vector.
1397 case PW_AUTHENTICATION_REQUEST:
1398 case PW_STATUS_SERVER:
1402 * Reply packets are signed with the
1403 * authentication vector of the request.
1410 fr_MD5Init(&context);
1411 fr_MD5Update(&context, packet->data, packet->data_len);
1412 fr_MD5Update(&context, (const uint8_t *) secret,
1414 fr_MD5Final(digest, &context);
1416 memcpy(hdr->vector, digest, AUTH_VECTOR_LEN);
1417 memcpy(packet->vector, digest, AUTH_VECTOR_LEN);
1420 }/* switch over packet codes */
1426 * Reply to the request. Also attach
1427 * reply attribute value pairs and any user message provided.
1429 int rad_send(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1434 char ip_buffer[128];
1437 * Maybe it's a fake packet. Don't send it.
1439 if (!packet || (packet->sockfd < 0)) {
1443 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1444 what = fr_packet_codes[packet->code];
1450 * First time through, allocate room for the packet
1452 if (!packet->data) {
1454 * Encode the packet.
1456 if (rad_encode(packet, original, secret) < 0) {
1461 * Re-sign it, including updating the
1462 * Message-Authenticator.
1464 if (rad_sign(packet, original, secret) < 0) {
1469 * If packet->data points to data, then we print out
1470 * the VP list again only for debugging.
1472 } else if (fr_debug_flag) {
1473 DEBUG("Sending %s of id %d to %s port %d\n", what, packet->id,
1474 inet_ntop(packet->dst_ipaddr.af,
1475 &packet->dst_ipaddr.ipaddr,
1476 ip_buffer, sizeof(ip_buffer)),
1479 for (reply = packet->vps; reply; reply = reply->next) {
1480 if ((reply->vendor == 0) &&
1481 ((reply->attribute & 0xFFFF) > 0xff)) continue;
1487 * And send it on it's way.
1489 return rad_sendto(packet->sockfd, packet->data, packet->data_len, 0,
1490 &packet->src_ipaddr, packet->src_port,
1491 &packet->dst_ipaddr, packet->dst_port);
1495 * Do a comparison of two authentication digests by comparing
1496 * the FULL digest. Otehrwise, the server can be subject to
1497 * timing attacks that allow attackers find a valid message
1500 * http://www.cs.rice.edu/~dwallach/pub/crosby-timing2009.pdf
1502 static int digest_cmp(const uint8_t *a, const uint8_t *b, size_t length)
1507 for (i = 0; i < length; i++) {
1508 result |= a[i] ^ b[i];
1511 return result; /* 0 is OK, !0 is !OK, just like memcmp */
1516 * Validates the requesting client NAS. Calculates the
1517 * signature based on the clients private key.
1519 static int calc_acctdigest(RADIUS_PACKET *packet, const char *secret)
1521 uint8_t digest[AUTH_VECTOR_LEN];
1525 * Zero out the auth_vector in the received packet.
1526 * Then append the shared secret to the received packet,
1527 * and calculate the MD5 sum. This must be the same
1528 * as the original MD5 sum (packet->vector).
1530 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
1533 * MD5(packet + secret);
1535 fr_MD5Init(&context);
1536 fr_MD5Update(&context, packet->data, packet->data_len);
1537 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1538 fr_MD5Final(digest, &context);
1541 * Return 0 if OK, 2 if not OK.
1543 if (digest_cmp(digest, packet->vector, AUTH_VECTOR_LEN) != 0) return 2;
1549 * Validates the requesting client NAS. Calculates the
1550 * signature based on the clients private key.
1552 static int calc_replydigest(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1555 uint8_t calc_digest[AUTH_VECTOR_LEN];
1561 if (original == NULL) {
1566 * Copy the original vector in place.
1568 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
1571 * MD5(packet + secret);
1573 fr_MD5Init(&context);
1574 fr_MD5Update(&context, packet->data, packet->data_len);
1575 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1576 fr_MD5Final(calc_digest, &context);
1579 * Copy the packet's vector back to the packet.
1581 memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
1584 * Return 0 if OK, 2 if not OK.
1586 if (digest_cmp(packet->vector, calc_digest, AUTH_VECTOR_LEN) != 0) return 2;
1592 * See if the data pointed to by PTR is a valid RADIUS packet.
1594 * packet is not 'const * const' because we may update data_len,
1595 * if there's more data in the UDP packet than in the RADIUS packet.
1597 int rad_packet_ok(RADIUS_PACKET *packet, int flags)
1602 radius_packet_t *hdr;
1603 char host_ipaddr[128];
1609 * Check for packets smaller than the packet header.
1611 * RFC 2865, Section 3., subsection 'length' says:
1613 * "The minimum length is 20 ..."
1615 if (packet->data_len < AUTH_HDR_LEN) {
1616 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (received %d < minimum %d)",
1617 inet_ntop(packet->src_ipaddr.af,
1618 &packet->src_ipaddr.ipaddr,
1619 host_ipaddr, sizeof(host_ipaddr)),
1620 (int) packet->data_len, AUTH_HDR_LEN);
1625 * RFC 2865, Section 3., subsection 'length' says:
1627 * " ... and maximum length is 4096."
1629 if (packet->data_len > MAX_PACKET_LEN) {
1630 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (received %d > maximum %d)",
1631 inet_ntop(packet->src_ipaddr.af,
1632 &packet->src_ipaddr.ipaddr,
1633 host_ipaddr, sizeof(host_ipaddr)),
1634 (int) packet->data_len, MAX_PACKET_LEN);
1639 * Check for packets with mismatched size.
1640 * i.e. We've received 128 bytes, and the packet header
1641 * says it's 256 bytes long.
1643 totallen = (packet->data[2] << 8) | packet->data[3];
1644 hdr = (radius_packet_t *)packet->data;
1647 * Code of 0 is not understood.
1648 * Code of 16 or greate is not understood.
1650 if ((hdr->code == 0) ||
1651 (hdr->code >= FR_MAX_PACKET_CODE)) {
1652 fr_strerror_printf("WARNING: Bad RADIUS packet from host %s: unknown packet code%d ",
1653 inet_ntop(packet->src_ipaddr.af,
1654 &packet->src_ipaddr.ipaddr,
1655 host_ipaddr, sizeof(host_ipaddr)),
1661 * Message-Authenticator is required in Status-Server
1662 * packets, otherwise they can be trivially forged.
1664 if (hdr->code == PW_STATUS_SERVER) require_ma = 1;
1667 * It's also required if the caller asks for it.
1669 if (flags) require_ma = 1;
1672 * Repeat the length checks. This time, instead of
1673 * looking at the data we received, look at the value
1674 * of the 'length' field inside of the packet.
1676 * Check for packets smaller than the packet header.
1678 * RFC 2865, Section 3., subsection 'length' says:
1680 * "The minimum length is 20 ..."
1682 if (totallen < AUTH_HDR_LEN) {
1683 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (length %d < minimum %d)",
1684 inet_ntop(packet->src_ipaddr.af,
1685 &packet->src_ipaddr.ipaddr,
1686 host_ipaddr, sizeof(host_ipaddr)),
1687 totallen, AUTH_HDR_LEN);
1692 * And again, for the value of the 'length' field.
1694 * RFC 2865, Section 3., subsection 'length' says:
1696 * " ... and maximum length is 4096."
1698 if (totallen > MAX_PACKET_LEN) {
1699 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (length %d > maximum %d)",
1700 inet_ntop(packet->src_ipaddr.af,
1701 &packet->src_ipaddr.ipaddr,
1702 host_ipaddr, sizeof(host_ipaddr)),
1703 totallen, MAX_PACKET_LEN);
1708 * RFC 2865, Section 3., subsection 'length' says:
1710 * "If the packet is shorter than the Length field
1711 * indicates, it MUST be silently discarded."
1713 * i.e. No response to the NAS.
1715 if (packet->data_len < totallen) {
1716 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: received %d octets, packet length says %d",
1717 inet_ntop(packet->src_ipaddr.af,
1718 &packet->src_ipaddr.ipaddr,
1719 host_ipaddr, sizeof(host_ipaddr)),
1720 (int) packet->data_len, totallen);
1725 * RFC 2865, Section 3., subsection 'length' says:
1727 * "Octets outside the range of the Length field MUST be
1728 * treated as padding and ignored on reception."
1730 if (packet->data_len > totallen) {
1732 * We're shortening the packet below, but just
1733 * to be paranoid, zero out the extra data.
1735 memset(packet->data + totallen, 0, packet->data_len - totallen);
1736 packet->data_len = totallen;
1740 * Walk through the packet's attributes, ensuring that
1741 * they add up EXACTLY to the size of the packet.
1743 * If they don't, then the attributes either under-fill
1744 * or over-fill the packet. Any parsing of the packet
1745 * is impossible, and will result in unknown side effects.
1747 * This would ONLY happen with buggy RADIUS implementations,
1748 * or with an intentional attack. Either way, we do NOT want
1749 * to be vulnerable to this problem.
1752 count = totallen - AUTH_HDR_LEN;
1757 * Attribute number zero is NOT defined.
1760 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Invalid attribute 0",
1761 inet_ntop(packet->src_ipaddr.af,
1762 &packet->src_ipaddr.ipaddr,
1763 host_ipaddr, sizeof(host_ipaddr)));
1768 * Attributes are at LEAST as long as the ID & length
1769 * fields. Anything shorter is an invalid attribute.
1772 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %d too short",
1773 inet_ntop(packet->src_ipaddr.af,
1774 &packet->src_ipaddr.ipaddr,
1775 host_ipaddr, sizeof(host_ipaddr)),
1781 * Sanity check the attributes for length.
1784 default: /* don't do anything by default */
1788 * If there's an EAP-Message, we require
1789 * a Message-Authenticator.
1791 case PW_EAP_MESSAGE:
1795 case PW_MESSAGE_AUTHENTICATOR:
1796 if (attr[1] != 2 + AUTH_VECTOR_LEN) {
1797 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Message-Authenticator has invalid length %d",
1798 inet_ntop(packet->src_ipaddr.af,
1799 &packet->src_ipaddr.ipaddr,
1800 host_ipaddr, sizeof(host_ipaddr)),
1809 * FIXME: Look up the base 255 attributes in the
1810 * dictionary, and switch over their type. For
1811 * integer/date/ip, the attribute length SHOULD
1814 count -= attr[1]; /* grab the attribute length */
1816 num_attributes++; /* seen one more attribute */
1820 * If the attributes add up to a packet, it's allowed.
1822 * If not, we complain, and throw the packet away.
1825 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: packet attributes do NOT exactly fill the packet",
1826 inet_ntop(packet->src_ipaddr.af,
1827 &packet->src_ipaddr.ipaddr,
1828 host_ipaddr, sizeof(host_ipaddr)));
1833 * If we're configured to look for a maximum number of
1834 * attributes, and we've seen more than that maximum,
1835 * then throw the packet away, as a possible DoS.
1837 if ((fr_max_attributes > 0) &&
1838 (num_attributes > fr_max_attributes)) {
1839 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
1840 inet_ntop(packet->src_ipaddr.af,
1841 &packet->src_ipaddr.ipaddr,
1842 host_ipaddr, sizeof(host_ipaddr)),
1843 num_attributes, fr_max_attributes);
1848 * http://www.freeradius.org/rfc/rfc2869.html#EAP-Message
1850 * A packet with an EAP-Message attribute MUST also have
1851 * a Message-Authenticator attribute.
1853 * A Message-Authenticator all by itself is OK, though.
1855 * Similarly, Status-Server packets MUST contain
1856 * Message-Authenticator attributes.
1858 if (require_ma && ! seen_ma) {
1859 fr_strerror_printf("WARNING: Insecure packet from host %s: Packet does not contain required Message-Authenticator attribute",
1860 inet_ntop(packet->src_ipaddr.af,
1861 &packet->src_ipaddr.ipaddr,
1862 host_ipaddr, sizeof(host_ipaddr)));
1867 * Fill RADIUS header fields
1869 packet->code = hdr->code;
1870 packet->id = hdr->id;
1871 memcpy(packet->vector, hdr->vector, AUTH_VECTOR_LEN);
1878 * Receive UDP client requests, and fill in
1879 * the basics of a RADIUS_PACKET structure.
1881 RADIUS_PACKET *rad_recv(int fd, int flags)
1884 RADIUS_PACKET *packet;
1887 * Allocate the new request data structure
1889 if ((packet = malloc(sizeof(*packet))) == NULL) {
1890 fr_strerror_printf("out of memory");
1893 memset(packet, 0, sizeof(*packet));
1896 sock_flags = MSG_PEEK;
1900 packet->data_len = rad_recvfrom(fd, &packet->data, sock_flags,
1901 &packet->src_ipaddr, &packet->src_port,
1902 &packet->dst_ipaddr, &packet->dst_port);
1905 * Check for socket errors.
1907 if (packet->data_len < 0) {
1908 fr_strerror_printf("Error receiving packet: %s", strerror(errno));
1909 /* packet->data is NULL */
1915 * If the packet is too big, then rad_recvfrom did NOT
1916 * allocate memory. Instead, it just discarded the
1919 if (packet->data_len > MAX_PACKET_LEN) {
1920 fr_strerror_printf("Discarding packet: Larger than RFC limitation of 4096 bytes.");
1921 /* packet->data is NULL */
1927 * Read no data. Continue.
1928 * This check is AFTER the MAX_PACKET_LEN check above, because
1929 * if the packet is larger than MAX_PACKET_LEN, we also have
1930 * packet->data == NULL
1932 if ((packet->data_len == 0) || !packet->data) {
1933 fr_strerror_printf("Empty packet: Socket is not ready.");
1939 * See if it's a well-formed RADIUS packet.
1941 if (!rad_packet_ok(packet, flags)) {
1947 * Remember which socket we read the packet from.
1949 packet->sockfd = fd;
1952 * FIXME: Do even more filtering by only permitting
1953 * certain IP's. The problem is that we don't know
1954 * how to do this properly for all possible clients...
1958 * Explicitely set the VP list to empty.
1962 if (fr_debug_flag) {
1963 char host_ipaddr[128];
1965 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1966 DEBUG("rad_recv: %s packet from host %s port %d",
1967 fr_packet_codes[packet->code],
1968 inet_ntop(packet->src_ipaddr.af,
1969 &packet->src_ipaddr.ipaddr,
1970 host_ipaddr, sizeof(host_ipaddr)),
1973 DEBUG("rad_recv: Packet from host %s port %d code=%d",
1974 inet_ntop(packet->src_ipaddr.af,
1975 &packet->src_ipaddr.ipaddr,
1976 host_ipaddr, sizeof(host_ipaddr)),
1980 DEBUG(", id=%d, length=%d\n",
1981 packet->id, (int) packet->data_len);
1989 * Verify the signature of a packet.
1991 int rad_verify(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1998 if (!packet || !packet->data) return -1;
2001 * Before we allocate memory for the attributes, do more
2004 ptr = packet->data + AUTH_HDR_LEN;
2005 length = packet->data_len - AUTH_HDR_LEN;
2006 while (length > 0) {
2007 uint8_t msg_auth_vector[AUTH_VECTOR_LEN];
2008 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
2013 default: /* don't do anything. */
2017 * Note that more than one Message-Authenticator
2018 * attribute is invalid.
2020 case PW_MESSAGE_AUTHENTICATOR:
2021 memcpy(msg_auth_vector, &ptr[2], sizeof(msg_auth_vector));
2022 memset(&ptr[2], 0, AUTH_VECTOR_LEN);
2024 switch (packet->code) {
2028 case PW_ACCOUNTING_REQUEST:
2029 case PW_ACCOUNTING_RESPONSE:
2030 case PW_DISCONNECT_REQUEST:
2031 case PW_DISCONNECT_ACK:
2032 case PW_DISCONNECT_NAK:
2033 case PW_COA_REQUEST:
2036 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
2039 case PW_AUTHENTICATION_ACK:
2040 case PW_AUTHENTICATION_REJECT:
2041 case PW_ACCESS_CHALLENGE:
2043 fr_strerror_printf("ERROR: Cannot validate Message-Authenticator in response packet without a request packet.");
2046 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
2050 fr_hmac_md5(packet->data, packet->data_len,
2051 (const uint8_t *) secret, strlen(secret),
2053 if (digest_cmp(calc_auth_vector, msg_auth_vector,
2054 sizeof(calc_auth_vector)) != 0) {
2056 fr_strerror_printf("Received packet from %s with invalid Message-Authenticator! (Shared secret is incorrect.)",
2057 inet_ntop(packet->src_ipaddr.af,
2058 &packet->src_ipaddr.ipaddr,
2059 buffer, sizeof(buffer)));
2060 /* Silently drop packet, according to RFC 3579 */
2062 } /* else the message authenticator was good */
2065 * Reinitialize Authenticators.
2067 memcpy(&ptr[2], msg_auth_vector, AUTH_VECTOR_LEN);
2068 memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
2070 } /* switch over the attributes */
2074 } /* loop over the packet, sanity checking the attributes */
2077 * It looks like a RADIUS packet, but we can't validate
2080 if ((packet->code == 0) || (packet->code >= FR_MAX_PACKET_CODE)) {
2082 fr_strerror_printf("Received Unknown packet code %d "
2083 "from client %s port %d: Cannot validate signature.",
2085 inet_ntop(packet->src_ipaddr.af,
2086 &packet->src_ipaddr.ipaddr,
2087 buffer, sizeof(buffer)),
2093 * Calculate and/or verify digest.
2095 switch(packet->code) {
2099 case PW_AUTHENTICATION_REQUEST:
2100 case PW_STATUS_SERVER:
2102 * The authentication vector is random
2103 * nonsense, invented by the client.
2107 case PW_COA_REQUEST:
2108 case PW_DISCONNECT_REQUEST:
2109 case PW_ACCOUNTING_REQUEST:
2110 if (calc_acctdigest(packet, secret) > 1) {
2111 fr_strerror_printf("Received %s packet "
2112 "from %s with invalid signature! (Shared secret is incorrect.)",
2113 fr_packet_codes[packet->code],
2114 inet_ntop(packet->src_ipaddr.af,
2115 &packet->src_ipaddr.ipaddr,
2116 buffer, sizeof(buffer)));
2121 /* Verify the reply digest */
2122 case PW_AUTHENTICATION_ACK:
2123 case PW_AUTHENTICATION_REJECT:
2124 case PW_ACCESS_CHALLENGE:
2125 case PW_ACCOUNTING_RESPONSE:
2126 case PW_DISCONNECT_ACK:
2127 case PW_DISCONNECT_NAK:
2130 rcode = calc_replydigest(packet, original, secret);
2132 fr_strerror_printf("Received %s packet "
2133 "from client %s port %d with invalid signature (err=%d)! (Shared secret is incorrect.)",
2134 fr_packet_codes[packet->code],
2135 inet_ntop(packet->src_ipaddr.af,
2136 &packet->src_ipaddr.ipaddr,
2137 buffer, sizeof(buffer)),
2145 fr_strerror_printf("Received Unknown packet code %d "
2146 "from client %s port %d: Cannot validate signature",
2148 inet_ntop(packet->src_ipaddr.af,
2149 &packet->src_ipaddr.ipaddr,
2150 buffer, sizeof(buffer)),
2159 static VALUE_PAIR *data2vp(const RADIUS_PACKET *packet,
2160 const RADIUS_PACKET *original,
2161 const char *secret, size_t length,
2162 const uint8_t *data, VALUE_PAIR *vp)
2167 * If length is greater than 253, something is SERIOUSLY
2170 if (length > 253) length = 253; /* paranoia (pair-anoia?) */
2172 vp->length = length;
2173 vp->operator = T_OP_EQ;
2179 if (vp->flags.has_tag) {
2180 if (TAG_VALID(data[0]) ||
2181 (vp->flags.encrypt == FLAG_ENCRYPT_TUNNEL_PASSWORD)) {
2183 * Tunnel passwords REQUIRE a tag, even
2184 * if don't have a valid tag.
2186 vp->flags.tag = data[0];
2188 if ((vp->type == PW_TYPE_STRING) ||
2189 (vp->type == PW_TYPE_OCTETS)) offset = 1;
2194 * Copy the data to be decrypted
2196 memcpy(&vp->vp_octets[0], data + offset, length - offset);
2197 vp->length -= offset;
2200 * Decrypt the attribute.
2202 switch (vp->flags.encrypt) {
2206 case FLAG_ENCRYPT_USER_PASSWORD:
2208 rad_pwdecode((char *)vp->vp_strvalue,
2212 rad_pwdecode((char *)vp->vp_strvalue,
2216 if (vp->attribute == PW_USER_PASSWORD) {
2217 vp->length = strlen(vp->vp_strvalue);
2222 * Tunnel-Password's may go ONLY
2223 * in response packets.
2225 case FLAG_ENCRYPT_TUNNEL_PASSWORD:
2226 if (!original) goto raw;
2228 if (rad_tunnel_pwdecode(vp->vp_octets, &vp->length,
2229 secret, original->vector) < 0) {
2235 * Ascend-Send-Secret
2236 * Ascend-Receive-Secret
2238 case FLAG_ENCRYPT_ASCEND_SECRET:
2242 uint8_t my_digest[AUTH_VECTOR_LEN];
2243 make_secret(my_digest,
2246 memcpy(vp->vp_strvalue, my_digest,
2248 vp->vp_strvalue[AUTH_VECTOR_LEN] = '\0';
2249 vp->length = strlen(vp->vp_strvalue);
2255 } /* switch over encryption flags */
2259 case PW_TYPE_STRING:
2260 case PW_TYPE_OCTETS:
2261 case PW_TYPE_ABINARY:
2262 /* nothing more to do */
2266 if (vp->length != 1) goto raw;
2268 vp->vp_integer = vp->vp_octets[0];
2273 if (vp->length != 2) goto raw;
2275 vp->vp_integer = (vp->vp_octets[0] << 8) | vp->vp_octets[1];
2278 case PW_TYPE_INTEGER:
2279 if (vp->length != 4) goto raw;
2281 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2282 vp->vp_integer = ntohl(vp->vp_integer);
2284 if (vp->flags.has_tag) vp->vp_integer &= 0x00ffffff;
2287 * Try to get named VALUEs
2291 dval = dict_valbyattr(vp->attribute, vp->vendor,
2294 strlcpy(vp->vp_strvalue,
2296 sizeof(vp->vp_strvalue));
2302 if (vp->length != 4) goto raw;
2304 memcpy(&vp->vp_date, vp->vp_octets, 4);
2305 vp->vp_date = ntohl(vp->vp_date);
2309 case PW_TYPE_IPADDR:
2310 if (vp->length != 4) goto raw;
2312 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2316 * IPv6 interface ID is 8 octets long.
2319 if (vp->length != 8) goto raw;
2320 /* vp->vp_ifid == vp->vp_octets */
2324 * IPv6 addresses are 16 octets long
2326 case PW_TYPE_IPV6ADDR:
2327 if (vp->length != 16) goto raw;
2328 /* vp->vp_ipv6addr == vp->vp_octets */
2332 * IPv6 prefixes are 2 to 18 octets long.
2334 * RFC 3162: The first octet is unused.
2335 * The second is the length of the prefix
2336 * the rest are the prefix data.
2338 * The prefix length can have value 0 to 128.
2340 case PW_TYPE_IPV6PREFIX:
2341 if (vp->length < 2 || vp->length > 18) goto raw;
2342 if (vp->vp_octets[1] > 128) goto raw;
2345 * FIXME: double-check that
2346 * (vp->vp_octets[1] >> 3) matches vp->length + 2
2348 if (vp->length < 18) {
2349 memset(vp->vp_octets + vp->length, 0,
2354 case PW_TYPE_SIGNED:
2355 if (vp->length != 4) goto raw;
2358 * Overload vp_integer for ntohl, which takes
2359 * uint32_t, not int32_t
2361 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2362 vp->vp_integer = ntohl(vp->vp_integer);
2363 memcpy(&vp->vp_signed, &vp->vp_integer, 4);
2367 vp->length = length;
2368 vp->vp_tlv = malloc(length);
2371 fr_strerror_printf("No memory");
2374 memcpy(vp->vp_tlv, data, length);
2377 case PW_TYPE_COMBO_IP:
2378 if (vp->length == 4) {
2379 vp->type = PW_TYPE_IPADDR;
2380 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2383 } else if (vp->length == 16) {
2384 vp->type = PW_TYPE_IPV6ADDR;
2385 /* vp->vp_ipv6addr == vp->vp_octets */
2393 vp->type = PW_TYPE_OCTETS;
2394 vp->length = length;
2395 memcpy(vp->vp_octets, data, length);
2399 * Ensure there's no encryption or tag stuff,
2400 * we just pass the attribute as-is.
2402 memset(&vp->flags, 0, sizeof(vp->flags));
2408 static void rad_sortvp(VALUE_PAIR **head)
2411 VALUE_PAIR *vp, **tail;
2414 * Walk over the VP's, sorting them in order. Did I
2415 * mention that I hate WiMAX continuations?
2417 * And bubble sort! WTF is up with that?
2424 if (!vp->next) break;
2426 if (vp->attribute > vp->next->attribute) {
2428 vp->next = (*tail)->next;
2439 * Walk the packet, looking for continuations of this attribute.
2441 * This is (worst-case) O(N^2) in the number of RADIUS
2442 * attributes. That happens only when perverse clients create
2443 * continued attributes, AND separate the fragmented portions
2444 * with a lot of other attributes.
2446 * Sane clients should put the fragments next to each other, in
2447 * which case this is O(N), in the number of fragments.
2449 static uint8_t *rad_coalesce(unsigned int attribute, int vendor,
2450 size_t length, uint8_t *data,
2451 size_t packet_length, size_t *ptlv_length)
2455 size_t tlv_length = length;
2456 uint8_t *ptr, *tlv, *tlv_data;
2458 for (ptr = data + length;
2459 ptr != (data + packet_length);
2461 /* FIXME: Check that there are 6 bytes of data here... */
2462 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2463 (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2464 (ptr[2] != 0) || (ptr[3] != 0) || /* our requirement */
2465 (ptr[4] != ((vendor >> 8) & 0xff)) ||
2466 (ptr[5] != (vendor & 0xff))) {
2470 memcpy(&lvalue, ptr + 2, 4); /* Vendor Id */
2471 lvalue = ntohl(lvalue);
2473 lvalue |= ptr[2 + 4]; /* add in VSA number */
2474 if (lvalue != attribute) continue;
2477 * If the vendor-length is too small, it's badly
2478 * formed, so we stop.
2480 if ((ptr[2 + 4 + 1]) < 3) break;
2482 tlv_length += ptr[2 + 4 + 1] - 3;
2483 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2486 tlv = tlv_data = malloc(tlv_length);
2487 if (!tlv_data) return NULL;
2489 memcpy(tlv, data, length);
2493 * Now we walk the list again, copying the data over to
2494 * our newly created memory.
2496 for (ptr = data + length;
2497 ptr != (data + packet_length);
2501 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2502 (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2503 (ptr[2] != 0) || (ptr[3] != 0)) { /* our requirement */
2507 memcpy(&lvalue, ptr + 2, 4);
2508 lvalue = ntohl(lvalue);
2510 lvalue |= ptr[2 + 4];
2511 if (lvalue != attribute) continue;
2514 * If the vendor-length is too small, it's badly
2515 * formed, so we stop.
2517 if ((ptr[2 + 4 + 1]) < 3) break;
2519 this_length = ptr[2 + 4 + 1] - 3;
2520 memcpy(tlv, ptr + 2 + 4 + 3, this_length);
2523 ptr[2 + 4] = 0; /* What a hack! */
2524 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2527 *ptlv_length = tlv_length;
2532 * Walk over Evil WIMAX Hell, creating attributes.
2534 * Won't someone think of the children? What if they read this code?
2536 static VALUE_PAIR *recurse_evil(const RADIUS_PACKET *packet,
2537 const RADIUS_PACKET *original,
2539 int attribute, int vendor,
2540 uint8_t *ptr, size_t len, int shift)
2542 VALUE_PAIR *head = NULL;
2543 VALUE_PAIR **tail = &head;
2545 uint8_t *y; /* why do I need to do this? */
2547 if (shift > 24) return NULL;
2550 * Sanity check the attribute.
2552 for (y = ptr; y < (ptr + len); y += y[1]) {
2553 if ((y[0] == 0) || ((y + 2) > (ptr + len)) ||
2554 (y[1] < 2) || ((y + y[1]) > (ptr + len))) {
2559 for (y = ptr; y < (ptr + len); y += y[1]) {
2562 da = dict_attrbyvalue(attribute | (ptr[0] << shift), vendor);
2563 if (da && (da->type == PW_TYPE_TLV)) {
2564 vp = recurse_evil(packet, original, secret,
2565 attribute | (ptr[0] << shift),
2566 vendor, ptr + 2, ptr[1] - 2,
2568 if (!vp) goto error;
2570 vp = paircreate(attribute | (ptr[0] << shift), vendor,
2578 if (!data2vp(packet, original, secret,
2579 y[1] - 2, y + 2, vp)) {
2585 while (*tail) tail = &((*tail)->next);
2592 * Start at the *data* portion of a continued attribute. search
2593 * through the rest of the attributes to find a matching one, and
2594 * add it's contents to our contents.
2596 static VALUE_PAIR *rad_continuation2vp(const RADIUS_PACKET *packet,
2597 const RADIUS_PACKET *original,
2598 const char *secret, int attribute,
2600 int length, /* CANNOT be zero */
2601 uint8_t *data, size_t packet_length,
2602 int flag, DICT_ATTR *da)
2604 size_t tlv_length, left;
2607 VALUE_PAIR *vp, *head, **tail;
2611 * Ensure we have data that hasn't been split across
2612 * multiple attributes.
2615 tlv_data = rad_coalesce(attribute, vendor, length,
2616 data, packet_length, &tlv_length);
2617 if (!tlv_data) return NULL;
2620 tlv_length = length;
2624 * Non-TLV types cannot be continued across multiple
2625 * attributes. This is true even of keys that are
2626 * encrypted with the tunnel-password method. The spec
2627 * says that they can be continued... but also that the
2628 * keys are 160 bits, which means that they CANNOT be
2631 * Note that we don't check "flag" here. The calling
2634 if (!da || (da->type != PW_TYPE_TLV)) {
2636 if (tlv_data == data) { /* true if we had 'goto' */
2637 tlv_data = malloc(tlv_length);
2638 if (!tlv_data) return NULL;
2639 memcpy(tlv_data, data, tlv_length);
2642 vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2643 if (!vp) return NULL;
2645 vp->type = PW_TYPE_TLV;
2646 vp->flags.encrypt = FLAG_ENCRYPT_NONE;
2647 vp->flags.has_tag = 0;
2648 vp->flags.is_tlv = 0;
2649 vp->vp_tlv = tlv_data;
2650 vp->length = tlv_length;
2652 } /* else it WAS a TLV, go decode the sub-tlv's */
2655 * Now (sigh) we walk over the TLV, seeing if it is
2659 for (ptr = tlv_data;
2660 ptr != (tlv_data + tlv_length);
2665 goto not_well_formed;
2672 * Now we walk over the TLV *again*, creating sub-tlv's.
2677 for (ptr = tlv_data;
2678 ptr != (tlv_data + tlv_length);
2681 tlv_da = dict_attrbyvalue(attribute | (ptr[0] << 8), vendor);
2682 if (tlv_da && (tlv_da->type == PW_TYPE_TLV)) {
2683 vp = recurse_evil(packet, original, secret,
2684 attribute | (ptr[0] << 8),
2685 vendor, ptr + 2, ptr[1] - 2, 16);
2689 goto not_well_formed;
2692 vp = paircreate(attribute | (ptr[0] << 8), vendor,
2696 goto not_well_formed;
2699 if (!data2vp(packet, original, secret,
2700 ptr[1] - 2, ptr + 2, vp)) {
2702 goto not_well_formed;
2708 while (*tail) tail = &((*tail)->next);
2712 * TLV's MAY be continued, but sometimes they're not.
2714 if (tlv_data != data) free(tlv_data);
2716 if (head->next) rad_sortvp(&head);
2723 * Parse a RADIUS attribute into a data structure.
2725 VALUE_PAIR *rad_attr2vp(const RADIUS_PACKET *packet,
2726 const RADIUS_PACKET *original,
2727 const char *secret, int attribute, int vendor,
2728 int length, const uint8_t *data)
2732 vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2733 if (!vp) return NULL;
2735 return data2vp(packet, original, secret, length, data, vp);
2740 * Calculate/check digest, and decode radius attributes.
2742 * -1 on decoding error
2745 int rad_decode(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2749 uint32_t vendorcode;
2752 uint8_t *ptr, *vsa_ptr;
2757 radius_packet_t *hdr;
2758 int vsa_tlen, vsa_llen, vsa_offset;
2759 DICT_VENDOR *dv = NULL;
2760 int num_attributes = 0;
2763 * Extract attribute-value pairs
2765 hdr = (radius_packet_t *)packet->data;
2767 packet_length = packet->data_len - AUTH_HDR_LEN;
2770 * There may be VP's already in the packet. Don't
2773 for (tail = &packet->vps; *tail != NULL; tail = &((*tail)->next)) {
2779 vsa_tlen = vsa_llen = 1;
2783 * We have to read at least two bytes.
2785 * rad_recv() above ensures that this is OK.
2787 while (packet_length > 0) {
2792 * Normal attribute, handle it like normal.
2794 if (vendorcode == 0) {
2796 * No room to read attr/length,
2797 * or bad attribute, or attribute is
2798 * too short, or attribute is too long,
2799 * stop processing the packet.
2801 if ((packet_length < 2) ||
2802 (ptr[0] == 0) || (ptr[1] < 2) ||
2803 (ptr[1] > packet_length)) break;
2811 if (attribute != PW_VENDOR_SPECIFIC) goto create_pair;
2814 * No vendor code, or ONLY vendor code.
2816 if (attrlen <= 4) goto create_pair;
2822 * Handle Vendor-Specific
2824 if (vendorlen == 0) {
2830 * attrlen was checked above.
2832 memcpy(&lvalue, ptr, 4);
2833 myvendor = ntohl(lvalue);
2836 * Zero isn't allowed.
2838 if (myvendor == 0) goto create_pair;
2841 * This is an implementation issue.
2842 * We currently pack vendor into the upper
2843 * 16 bits of a 32-bit attribute number,
2844 * so we can't handle vendor numbers larger
2847 if (myvendor > 65535) goto create_pair;
2849 vsa_tlen = vsa_llen = 1;
2851 dv = dict_vendorbyvalue(myvendor);
2853 vsa_tlen = dv->type;
2854 vsa_llen = dv->length;
2855 if (dv->flags) vsa_offset = 1;
2859 * Sweep through the list of VSA's,
2860 * seeing if they exactly fill the
2861 * outer Vendor-Specific attribute.
2863 * If not, create a raw Vendor-Specific.
2866 sublen = attrlen - 4;
2869 * See if we can parse it.
2875 * Not enough room for one more
2878 if (sublen < (vsa_tlen + vsa_llen + vsa_offset)) goto create_pair;
2881 * Ensure that the attribute number
2890 myattr = (subptr[0] << 8) | subptr[1];
2894 if ((subptr[0] != 0) ||
2895 (subptr[1] != 0)) goto create_pair;
2897 myattr = (subptr[2] << 8) | subptr[3];
2901 * Our dictionary is broken.
2910 ptr += 4 + vsa_tlen;
2911 attrlen -= (4 + vsa_tlen);
2912 packet_length -= 4 + vsa_tlen;
2916 if (subptr[vsa_tlen] < (vsa_tlen + vsa_llen + vsa_offset))
2919 if (subptr[vsa_tlen] > sublen)
2924 * Reserved bits MUST be
2928 ((subptr[vsa_tlen + vsa_llen] & 0x7f) != 0))
2931 sublen -= subptr[vsa_tlen];
2932 subptr += subptr[vsa_tlen];
2936 if (subptr[vsa_tlen] != 0) goto create_pair;
2937 if (subptr[vsa_tlen + 1] < (vsa_tlen + vsa_llen))
2939 if (subptr[vsa_tlen + 1] > sublen)
2941 sublen -= subptr[vsa_tlen + 1];
2942 subptr += subptr[vsa_tlen + 1];
2946 * Our dictionaries are
2952 } while (sublen > 0);
2954 vendorcode = myvendor;
2955 vendorlen = attrlen - 4;
2962 * attrlen is the length of this attribute.
2963 * total_len is the length of the encompassing
2972 attribute = (ptr[0] << 8) | ptr[1];
2975 default: /* can't hit this. */
2983 attrlen = ptr[0] - (vsa_tlen + vsa_llen + vsa_offset);
2987 attrlen = ptr[1] - (vsa_tlen + vsa_llen);
2990 default: /* can't hit this. */
2994 ptr += vsa_llen + vsa_offset;
2995 vendorlen -= vsa_tlen + vsa_llen + vsa_offset + attrlen;
2996 packet_length -= (vsa_tlen + vsa_llen + vsa_offset);
2999 * Ignore VSAs that have no data.
3001 if (attrlen == 0) goto next;
3004 * WiMAX attributes of type 0 are ignored. They
3005 * are a secret flag to us that the attribute has
3006 * already been dealt with.
3008 if ((vendorcode == VENDORPEC_WIMAX) && (attribute == 0)) {
3015 da = dict_attrbyvalue(attribute, vendorcode);
3018 * If it's NOT continued, AND we know
3019 * about it, AND it's not a TLV, we can
3020 * create a normal pair.
3022 if (((vsa_ptr[2] & 0x80) == 0) &&
3023 da && (da->type != PW_TYPE_TLV)) goto create_pair;
3026 * Else it IS continued, or it's a TLV.
3027 * Go do a lot of work to find the stuff.
3029 pair = rad_continuation2vp(packet, original, secret,
3030 attribute, vendorcode,
3033 ((vsa_ptr[2] & 0x80) != 0),
3039 * Create the attribute, setting the default type
3040 * to 'octets'. If the type in the dictionary
3041 * is different, then the dictionary type will
3042 * over-ride this one.
3044 * If the attribute has no data, then discard it.
3046 * Unless it's CUI. Damn you, CUI!
3050 (attribute != PW_CHARGEABLE_USER_IDENTITY)) goto next;
3052 pair = rad_attr2vp(packet, original, secret,
3053 attribute, vendorcode, attrlen, ptr);
3055 pairfree(&packet->vps);
3056 fr_strerror_printf("out of memory");
3070 * VSA's may not have been counted properly in
3071 * rad_packet_ok() above, as it is hard to count
3072 * then without using the dictionary. We
3073 * therefore enforce the limits here, too.
3075 if ((fr_max_attributes > 0) &&
3076 (num_attributes > fr_max_attributes)) {
3077 char host_ipaddr[128];
3079 pairfree(&packet->vps);
3080 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
3081 inet_ntop(packet->src_ipaddr.af,
3082 &packet->src_ipaddr.ipaddr,
3083 host_ipaddr, sizeof(host_ipaddr)),
3084 num_attributes, fr_max_attributes);
3089 if (vendorlen == 0) vendorcode = 0;
3091 packet_length -= attrlen;
3095 * Merge information from the outside world into our
3098 fr_rand_seed(packet->data, AUTH_HDR_LEN);
3107 * We assume that the passwd buffer passed is big enough.
3108 * RFC2138 says the password is max 128 chars, so the size
3109 * of the passwd buffer must be at least 129 characters.
3110 * Preferably it's just MAX_STRING_LEN.
3112 * int *pwlen is updated to the new length of the encrypted
3113 * password - a multiple of 16 bytes.
3115 int rad_pwencode(char *passwd, size_t *pwlen, const char *secret,
3116 const uint8_t *vector)
3118 FR_MD5_CTX context, old;
3119 uint8_t digest[AUTH_VECTOR_LEN];
3120 int i, n, secretlen;
3124 * RFC maximum is 128 bytes.
3126 * If length is zero, pad it out with zeros.
3128 * If the length isn't aligned to 16 bytes,
3129 * zero out the extra data.
3133 if (len > 128) len = 128;
3136 memset(passwd, 0, AUTH_PASS_LEN);
3137 len = AUTH_PASS_LEN;
3138 } else if ((len % AUTH_PASS_LEN) != 0) {
3139 memset(&passwd[len], 0, AUTH_PASS_LEN - (len % AUTH_PASS_LEN));
3140 len += AUTH_PASS_LEN - (len % AUTH_PASS_LEN);
3145 * Use the secret to setup the decryption digest
3147 secretlen = strlen(secret);
3149 fr_MD5Init(&context);
3150 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3151 old = context; /* save intermediate work */
3154 * Encrypt it in place. Don't bother checking
3155 * len, as we've ensured above that it's OK.
3157 for (n = 0; n < len; n += AUTH_PASS_LEN) {
3159 fr_MD5Update(&context, vector, AUTH_PASS_LEN);
3160 fr_MD5Final(digest, &context);
3163 fr_MD5Update(&context,
3164 (uint8_t *) passwd + n - AUTH_PASS_LEN,
3166 fr_MD5Final(digest, &context);
3169 for (i = 0; i < AUTH_PASS_LEN; i++) {
3170 passwd[i + n] ^= digest[i];
3180 int rad_pwdecode(char *passwd, size_t pwlen, const char *secret,
3181 const uint8_t *vector)
3183 FR_MD5_CTX context, old;
3184 uint8_t digest[AUTH_VECTOR_LEN];
3186 size_t n, secretlen;
3189 * The RFC's say that the maximum is 128.
3190 * The buffer we're putting it into above is 254, so
3191 * we don't need to do any length checking.
3193 if (pwlen > 128) pwlen = 128;
3198 if (pwlen == 0) goto done;
3201 * Use the secret to setup the decryption digest
3203 secretlen = strlen(secret);
3205 fr_MD5Init(&context);
3206 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3207 old = context; /* save intermediate work */
3210 * The inverse of the code above.
3212 for (n = 0; n < pwlen; n += AUTH_PASS_LEN) {
3214 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3215 fr_MD5Final(digest, &context);
3218 if (pwlen > AUTH_PASS_LEN) {
3219 fr_MD5Update(&context, (uint8_t *) passwd,
3223 fr_MD5Final(digest, &context);
3226 if (pwlen > (n + AUTH_PASS_LEN)) {
3227 fr_MD5Update(&context, (uint8_t *) passwd + n,
3232 for (i = 0; i < AUTH_PASS_LEN; i++) {
3233 passwd[i + n] ^= digest[i];
3238 passwd[pwlen] = '\0';
3239 return strlen(passwd);
3244 * Encode Tunnel-Password attributes when sending them out on the wire.
3246 * int *pwlen is updated to the new length of the encrypted
3247 * password - a multiple of 16 bytes.
3249 * This is per RFC-2868 which adds a two char SALT to the initial intermediate
3252 int rad_tunnel_pwencode(char *passwd, size_t *pwlen, const char *secret,
3253 const uint8_t *vector)
3255 uint8_t buffer[AUTH_VECTOR_LEN + MAX_STRING_LEN + 3];
3256 unsigned char digest[AUTH_VECTOR_LEN];
3258 int i, n, secretlen;
3263 if (len > 127) len = 127;
3266 * Shift the password 3 positions right to place a salt and original
3267 * length, tag will be added automatically on packet send
3269 for (n=len ; n>=0 ; n--) passwd[n+3] = passwd[n];
3273 * save original password length as first password character;
3280 * Generate salt. The RFC's say:
3282 * The high bit of salt[0] must be set, each salt in a
3283 * packet should be unique, and they should be random
3285 * So, we set the high bit, add in a counter, and then
3286 * add in some CSPRNG data. should be OK..
3288 salt[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
3289 (fr_rand() & 0x07));
3290 salt[1] = fr_rand();
3293 * Padd password to multiple of AUTH_PASS_LEN bytes.
3295 n = len % AUTH_PASS_LEN;
3297 n = AUTH_PASS_LEN - n;
3298 for (; n > 0; n--, len++)
3301 /* set new password length */
3305 * Use the secret to setup the decryption digest
3307 secretlen = strlen(secret);
3308 memcpy(buffer, secret, secretlen);
3310 for (n2 = 0; n2 < len; n2+=AUTH_PASS_LEN) {
3312 memcpy(buffer + secretlen, vector, AUTH_VECTOR_LEN);
3313 memcpy(buffer + secretlen + AUTH_VECTOR_LEN, salt, 2);
3314 fr_md5_calc(digest, buffer, secretlen + AUTH_VECTOR_LEN + 2);
3316 memcpy(buffer + secretlen, passwd + n2 - AUTH_PASS_LEN, AUTH_PASS_LEN);
3317 fr_md5_calc(digest, buffer, secretlen + AUTH_PASS_LEN);
3320 for (i = 0; i < AUTH_PASS_LEN; i++) {
3321 passwd[i + n2] ^= digest[i];
3329 * Decode Tunnel-Password encrypted attributes.
3331 * Defined in RFC-2868, this uses a two char SALT along with the
3332 * initial intermediate value, to differentiate it from the
3335 int rad_tunnel_pwdecode(uint8_t *passwd, size_t *pwlen, const char *secret,
3336 const uint8_t *vector)
3338 FR_MD5_CTX context, old;
3339 uint8_t digest[AUTH_VECTOR_LEN];
3341 unsigned i, n, len, reallen;
3346 * We need at least a salt.
3349 fr_strerror_printf("tunnel password is too short");
3354 * There's a salt, but no password. Or, there's a salt
3355 * and a 'data_len' octet. It's wrong, but at least we
3356 * can figure out what it means: the password is empty.
3358 * Note that this means we ignore the 'data_len' field,
3359 * if the attribute length tells us that there's no
3360 * more data. So the 'data_len' field may be wrong,
3369 len -= 2; /* discount the salt */
3372 * Use the secret to setup the decryption digest
3374 secretlen = strlen(secret);
3376 fr_MD5Init(&context);
3377 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3378 old = context; /* save intermediate work */
3381 * Set up the initial key:
3383 * b(1) = MD5(secret + vector + salt)
3385 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3386 fr_MD5Update(&context, passwd, 2);
3389 for (n = 0; n < len; n += AUTH_PASS_LEN) {
3393 fr_MD5Final(digest, &context);
3398 * A quick check: decrypt the first octet
3399 * of the password, which is the
3400 * 'data_len' field. Ensure it's sane.
3402 reallen = passwd[2] ^ digest[0];
3403 if (reallen >= len) {
3404 fr_strerror_printf("tunnel password is too long for the attribute");
3408 fr_MD5Update(&context, passwd + 2, AUTH_PASS_LEN);
3412 fr_MD5Final(digest, &context);
3415 fr_MD5Update(&context, passwd + n + 2, AUTH_PASS_LEN);
3418 for (i = base; i < AUTH_PASS_LEN; i++) {
3419 passwd[n + i - 1] = passwd[n + i + 2] ^ digest[i];
3424 * See make_tunnel_password, above.
3426 if (reallen > 239) reallen = 239;
3429 passwd[reallen] = 0;
3435 * Encode a CHAP password
3437 * FIXME: might not work with Ascend because
3438 * we use vp->length, and Ascend gear likes
3439 * to send an extra '\0' in the string!
3441 int rad_chap_encode(RADIUS_PACKET *packet, uint8_t *output, int id,
3442 VALUE_PAIR *password)
3446 uint8_t string[MAX_STRING_LEN * 2 + 1];
3447 VALUE_PAIR *challenge;
3450 * Sanity check the input parameters
3452 if ((packet == NULL) || (password == NULL)) {
3457 * Note that the password VP can be EITHER
3458 * a User-Password attribute (from a check-item list),
3459 * or a CHAP-Password attribute (the client asking
3460 * the library to encode it).
3468 memcpy(ptr, password->vp_strvalue, password->length);
3469 ptr += password->length;
3470 i += password->length;
3473 * Use Chap-Challenge pair if present,
3474 * Request-Authenticator otherwise.
3476 challenge = pairfind(packet->vps, PW_CHAP_CHALLENGE, 0);
3478 memcpy(ptr, challenge->vp_strvalue, challenge->length);
3479 i += challenge->length;
3481 memcpy(ptr, packet->vector, AUTH_VECTOR_LEN);
3482 i += AUTH_VECTOR_LEN;
3486 fr_md5_calc((uint8_t *)output + 1, (uint8_t *)string, i);
3493 * Seed the random number generator.
3495 * May be called any number of times.
3497 void fr_rand_seed(const void *data, size_t size)
3502 * Ensure that the pool is initialized.
3504 if (!fr_rand_initialized) {
3507 memset(&fr_rand_pool, 0, sizeof(fr_rand_pool));
3509 fd = open("/dev/urandom", O_RDONLY);
3515 while (total < sizeof(fr_rand_pool.randrsl)) {
3516 this = read(fd, fr_rand_pool.randrsl,
3517 sizeof(fr_rand_pool.randrsl) - total);
3518 if ((this < 0) && (errno != EINTR)) break;
3519 if (this > 0) total += this;
3523 fr_rand_pool.randrsl[0] = fd;
3524 fr_rand_pool.randrsl[1] = time(NULL);
3525 fr_rand_pool.randrsl[2] = errno;
3528 fr_randinit(&fr_rand_pool, 1);
3529 fr_rand_pool.randcnt = 0;
3530 fr_rand_initialized = 1;
3536 * Hash the user data
3539 if (!hash) hash = fr_rand();
3540 hash = fr_hash_update(data, size, hash);
3542 fr_rand_pool.randmem[fr_rand_pool.randcnt] ^= hash;
3547 * Return a 32-bit random number.
3549 uint32_t fr_rand(void)
3554 * Ensure that the pool is initialized.
3556 if (!fr_rand_initialized) {
3557 fr_rand_seed(NULL, 0);
3560 num = fr_rand_pool.randrsl[fr_rand_pool.randcnt++];
3561 if (fr_rand_pool.randcnt >= 256) {
3562 fr_rand_pool.randcnt = 0;
3563 fr_isaac(&fr_rand_pool);
3571 * Allocate a new RADIUS_PACKET
3573 RADIUS_PACKET *rad_alloc(int newvector)
3577 if ((rp = malloc(sizeof(RADIUS_PACKET))) == NULL) {
3578 fr_strerror_printf("out of memory");
3581 memset(rp, 0, sizeof(*rp));
3587 uint32_t hash, base;
3590 * Don't expose the actual contents of the random
3594 for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(uint32_t)) {
3595 hash = fr_rand() ^ base;
3596 memcpy(rp->vector + i, &hash, sizeof(hash));
3599 fr_rand(); /* stir the pool again */
3604 RADIUS_PACKET *rad_alloc_reply(RADIUS_PACKET *packet)
3606 RADIUS_PACKET *reply;
3608 if (!packet) return NULL;
3610 reply = rad_alloc(0);
3611 if (!reply) return NULL;
3614 * Initialize the fields from the request.
3616 reply->sockfd = packet->sockfd;
3617 reply->dst_ipaddr = packet->src_ipaddr;
3618 reply->src_ipaddr = packet->dst_ipaddr;
3619 reply->dst_port = packet->src_port;
3620 reply->src_port = packet->dst_port;
3621 reply->id = packet->id;
3622 reply->code = 0; /* UNKNOWN code */
3623 memcpy(reply->vector, packet->vector,
3624 sizeof(reply->vector));
3627 reply->data_len = 0;
3634 * Free a RADIUS_PACKET
3636 void rad_free(RADIUS_PACKET **radius_packet_ptr)
3638 RADIUS_PACKET *radius_packet;
3640 if (!radius_packet_ptr || !*radius_packet_ptr) return;
3641 radius_packet = *radius_packet_ptr;
3643 free(radius_packet->data);
3645 pairfree(&radius_packet->vps);
3647 free(radius_packet);
3649 *radius_packet_ptr = NULL;