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 len = vp2data(packet, original, secret, vp, ptr + 2, room - 2);
820 if (len < 0) return len;
827 static int tlv2data(const RADIUS_PACKET *packet,
828 const RADIUS_PACKET *original,
829 const char *secret, const VALUE_PAIR *vp, int attribute,
830 uint8_t *ptr, size_t room)
834 if (room < 2) return 0;
837 ptr[0] = attribute & 0xff;
841 * No more nested TLVs: pack the data.
843 if ((attribute & ~0xff) == 0) {
844 len = vp2data(packet, original, secret, vp, ptr + 2, room);
846 len = tlv2data(packet, original, secret, vp, attribute >> 8,
849 if (len <= 0) return len;
856 static int wimax2data(const RADIUS_PACKET *packet,
857 const RADIUS_PACKET *original,
858 const char *secret, const VALUE_PAIR *vp,
859 uint8_t *start, size_t room, uint8_t *ptr)
864 * Offsets to Vendor-Specific length, and to length of
870 if (room < 1) return 0;
874 * Account for continuation bytes. The caller has
875 * already accounting for the continuation byte in the
876 * Vendor-Specific "length" field.
882 * Chop everything to fit in one attribute.
884 if (room > (255 - 9)) room = (255 - 9);
887 * The attribute contains TLVs that we have NOT decoded
888 * properly, OR it contains TLV that the user has encoded
889 * manually. If it has no data, OR it's too long,
890 * discard it. We're not going to walk through its
891 * contents trying to figure out how to chop it across
892 * multiple continuations.
894 if (vp->flags.has_tlv && (!vp->vp_tlv || (vp->length > room))) {
899 * The attribute is a top-level integer, ipaddr, etc.
902 if (!vp->flags.is_tlv) {
903 len = vp2data(packet, original, secret, vp, ptr, room);
905 len = tlv2data(packet, original, secret, vp, vp->attribute >> 8,
909 if (len <= 0) return len;
911 start[VS_OFF] += len;
912 start[WM_OFF] += len;
914 return start[VS_OFF];
919 * Parse a data structure into a RADIUS attribute.
921 int rad_vp2attr(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
922 const char *secret, const VALUE_PAIR *vp, uint8_t *start,
931 * RFC format attributes take the fast path.
933 if (vp->vendor == 0) {
934 len = rad_vp2rfc(packet, original, secret, vp,
935 vp->attribute, start, room);
936 if (len < 0) return -1;
939 * RFC 2865 section 5 says that zero-length
940 * attributes MUST NOT be sent.
942 * ... and the WiMAX forum ignores
943 * this... because of one vendor. Don't they
944 * have anything better to do with their time?
947 (vp->attribute != PW_CHARGEABLE_USER_IDENTITY)) return 0;
954 * Not enough room for:
955 * attr, len, vendor-id, vsa, vsalen
957 if (room < 8) return 0;
960 * Build the Vendor-Specific header
963 *ptr++ = PW_VENDOR_SPECIFIC;
966 lvalue = htonl(vp->vendor);
967 memcpy(ptr, &lvalue, 4);
971 * Unknown vendors, and type=1,length=1,no-continuation
972 * are RFC format attributes.
974 dv = dict_vendorbyvalue(vp->vendor);
976 ((dv->type == 1) && (dv->length = 1) && !dv->flags)) {
977 len = rad_vp2rfc(packet, original, secret, vp,
978 vp->attribute, ptr, room);
979 if (len <= 0) return len;
985 if (room < (dv->type + dv->length + dv->flags)) return 0;
986 room -= (dv->type + dv->length + dv->flags);
987 start[1] += (dv->type + dv->length + dv->flags);
991 ptr[0] = (vp->attribute & 0xFF);
995 ptr[0] = ((vp->attribute >> 8) & 0xFF);
996 ptr[1] = (vp->attribute & 0xFF);
1001 ptr[1] = ((vp->attribute >> 16) & 0xFF);
1002 ptr[2] = ((vp->attribute >> 8) & 0xFF);
1003 ptr[3] = (vp->attribute & 0xFF);
1007 return 0; /* silently discard it */
1011 switch (dv->length) {
1015 ptr[0] = dv->type + 1;
1019 ptr[1] = dv->type + 2;
1023 return 0; /* silently discard it */
1028 * WiMAX attributes take their own path through the
1031 if (dv->flags) return wimax2data(packet, original, secret, vp,
1034 len = vp2data(packet, original, secret, vp, ptr, room);
1035 if (len <= 0) return len;
1037 if (dv->length != 0) ptr[-1] += len;
1047 #define REORDER(x) ((x & 0xff00) << 8) | ((x & 0xff0000) >> 8) | ((x & 0xff000000 >> 24))
1051 * Encode a WiMAX sub-TLV. It must NOT be called for WiMAX
1052 * attributes that are of type integer, string, etc.
1054 static int rad_encode_wimax(const RADIUS_PACKET *packet,
1055 const RADIUS_PACKET *original,
1056 const char *secret, VALUE_PAIR *reply,
1057 uint8_t *start, size_t room)
1061 uint8_t *ptr = start, *vsa = start;
1063 VALUE_PAIR *vp = reply;
1066 * Swap the order of the WiMAX hacks, to make later
1067 * comparisons easier.
1069 maxattr = REORDER(vp->attribute);
1072 * Build the Vendor-Specific header
1080 if (room < 9) return 0;
1081 *ptr++ = PW_VENDOR_SPECIFIC;
1084 lvalue = htonl(vp->vendor);
1085 memcpy(ptr, &lvalue, 4);
1087 *(ptr++) = vp->attribute & 0xff;
1089 *(ptr++) = 0; /* continuation */
1093 len = tlv2data(packet, original, secret, vp, vp->attribute >> 8,
1095 if (len < 0) return len;
1098 * Not enough room. Do a continuation.
1100 if ((len == 0) || ((vsa[VS_OFF] + len) > 255)) {
1101 if (redo) return (start - vsa);
1113 vp->flags.encoded = 1;
1117 * Look at the NEXT tlv. Ensure that we encode
1118 * attributes into a common VSA *only* if they are for
1119 * the same WiMAX VSA, AND if the TLVs are in numerically
1122 if (vp && vp->flags.is_tlv && (reply->vendor == vp->vendor) &&
1123 ((reply->attribute & 0xff) == (vp->attribute & 0xff))) {
1126 attr = REORDER(vp->attribute);
1127 if (attr >= maxattr) {
1140 int rad_encode(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1143 radius_packet_t *hdr;
1145 uint16_t total_length;
1149 char ip_buffer[128];
1152 * A 4K packet, aligned on 64-bits.
1154 uint64_t data[MAX_PACKET_LEN / sizeof(uint64_t)];
1156 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1157 what = fr_packet_codes[packet->code];
1162 DEBUG("Sending %s of id %d to %s port %d\n",
1164 inet_ntop(packet->dst_ipaddr.af,
1165 &packet->dst_ipaddr.ipaddr,
1166 ip_buffer, sizeof(ip_buffer)),
1170 * Double-check some things based on packet code.
1172 switch (packet->code) {
1173 case PW_AUTHENTICATION_ACK:
1174 case PW_AUTHENTICATION_REJECT:
1175 case PW_ACCESS_CHALLENGE:
1177 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1183 * These packet vectors start off as all zero.
1185 case PW_ACCOUNTING_REQUEST:
1186 case PW_DISCONNECT_REQUEST:
1187 case PW_COA_REQUEST:
1188 memset(packet->vector, 0, sizeof(packet->vector));
1196 * Use memory on the stack, until we know how
1197 * large the packet will be.
1199 hdr = (radius_packet_t *) data;
1202 * Build standard header
1204 hdr->code = packet->code;
1205 hdr->id = packet->id;
1207 memcpy(hdr->vector, packet->vector, sizeof(hdr->vector));
1209 total_length = AUTH_HDR_LEN;
1212 * Load up the configuration values for the user
1218 * FIXME: Loop twice over the reply list. The first time,
1219 * calculate the total length of data. The second time,
1220 * allocate the memory, and fill in the VP's.
1222 * Hmm... this may be slower than just doing a small
1227 * Loop over the reply attributes for the packet.
1229 for (reply = packet->vps; reply; reply = reply->next) {
1231 * Ignore non-wire attributes
1233 if ((reply->vendor == 0) &&
1234 ((reply->attribute & 0xFFFF) > 0xff)) {
1237 * Permit the admin to send BADLY formatted
1238 * attributes with a debug build.
1240 if (reply->attribute == PW_RAW_ATTRIBUTE) {
1241 memcpy(ptr, reply->vp_octets, reply->length);
1242 len = reply->length;
1250 * Set the Message-Authenticator to the correct
1251 * length and initial value.
1253 if (reply->attribute == PW_MESSAGE_AUTHENTICATOR) {
1254 reply->length = AUTH_VECTOR_LEN;
1255 memset(reply->vp_strvalue, 0, AUTH_VECTOR_LEN);
1258 * Cache the offset to the
1259 * Message-Authenticator
1261 packet->offset = total_length;
1265 * Print out ONLY the attributes which
1266 * we're sending over the wire, and print
1267 * them out BEFORE they're encrypted.
1272 * Skip attributes that are encoded.
1274 if (reply->flags.encoded) continue;
1276 if (reply->flags.is_tlv) {
1277 len = rad_encode_wimax(packet, original, secret,
1279 ((uint8_t *) data) + sizeof(data) - ptr);
1282 len = rad_vp2attr(packet, original, secret, reply, ptr,
1283 ((uint8_t *) data) + sizeof(data) - ptr);
1286 if (len < 0) return -1;
1290 total_length += len;
1291 } /* done looping over all attributes */
1294 * Fill in the rest of the fields, and copy the data over
1295 * from the local stack to the newly allocated memory.
1297 * Yes, all this 'memcpy' is slow, but it means
1298 * that we only allocate the minimum amount of
1299 * memory for a request.
1301 packet->data_len = total_length;
1302 packet->data = (uint8_t *) malloc(packet->data_len);
1303 if (!packet->data) {
1304 fr_strerror_printf("Out of memory");
1308 memcpy(packet->data, hdr, packet->data_len);
1309 hdr = (radius_packet_t *) packet->data;
1311 total_length = htons(total_length);
1312 memcpy(hdr->length, &total_length, sizeof(total_length));
1319 * Sign a previously encoded packet.
1321 int rad_sign(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1324 radius_packet_t *hdr = (radius_packet_t *)packet->data;
1327 * It wasn't assigned an Id, this is bad!
1329 if (packet->id < 0) {
1330 fr_strerror_printf("ERROR: RADIUS packets must be assigned an Id.");
1334 if (!packet->data || (packet->data_len < AUTH_HDR_LEN) ||
1335 (packet->offset < 0)) {
1336 fr_strerror_printf("ERROR: You must call rad_encode() before rad_sign()");
1341 * If there's a Message-Authenticator, update it
1342 * now, BEFORE updating the authentication vector.
1344 if (packet->offset > 0) {
1345 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
1347 switch (packet->code) {
1348 case PW_ACCOUNTING_REQUEST:
1349 case PW_ACCOUNTING_RESPONSE:
1350 case PW_DISCONNECT_REQUEST:
1351 case PW_DISCONNECT_ACK:
1352 case PW_DISCONNECT_NAK:
1353 case PW_COA_REQUEST:
1356 memset(hdr->vector, 0, AUTH_VECTOR_LEN);
1359 case PW_AUTHENTICATION_ACK:
1360 case PW_AUTHENTICATION_REJECT:
1361 case PW_ACCESS_CHALLENGE:
1363 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1366 memcpy(hdr->vector, original->vector,
1370 default: /* others have vector already set to zero */
1376 * Set the authentication vector to zero,
1377 * calculate the signature, and put it
1378 * into the Message-Authenticator
1381 fr_hmac_md5(packet->data, packet->data_len,
1382 (const uint8_t *) secret, strlen(secret),
1384 memcpy(packet->data + packet->offset + 2,
1385 calc_auth_vector, AUTH_VECTOR_LEN);
1388 * Copy the original request vector back
1389 * to the raw packet.
1391 memcpy(hdr->vector, packet->vector, AUTH_VECTOR_LEN);
1395 * Switch over the packet code, deciding how to
1398 switch (packet->code) {
1400 * Request packets are not signed, bur
1401 * have a random authentication vector.
1403 case PW_AUTHENTICATION_REQUEST:
1404 case PW_STATUS_SERVER:
1408 * Reply packets are signed with the
1409 * authentication vector of the request.
1416 fr_MD5Init(&context);
1417 fr_MD5Update(&context, packet->data, packet->data_len);
1418 fr_MD5Update(&context, (const uint8_t *) secret,
1420 fr_MD5Final(digest, &context);
1422 memcpy(hdr->vector, digest, AUTH_VECTOR_LEN);
1423 memcpy(packet->vector, digest, AUTH_VECTOR_LEN);
1426 }/* switch over packet codes */
1432 * Reply to the request. Also attach
1433 * reply attribute value pairs and any user message provided.
1435 int rad_send(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1440 char ip_buffer[128];
1443 * Maybe it's a fake packet. Don't send it.
1445 if (!packet || (packet->sockfd < 0)) {
1449 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1450 what = fr_packet_codes[packet->code];
1456 * First time through, allocate room for the packet
1458 if (!packet->data) {
1460 * Encode the packet.
1462 if (rad_encode(packet, original, secret) < 0) {
1467 * Re-sign it, including updating the
1468 * Message-Authenticator.
1470 if (rad_sign(packet, original, secret) < 0) {
1475 * If packet->data points to data, then we print out
1476 * the VP list again only for debugging.
1478 } else if (fr_debug_flag) {
1479 DEBUG("Sending %s of id %d to %s port %d\n", what, packet->id,
1480 inet_ntop(packet->dst_ipaddr.af,
1481 &packet->dst_ipaddr.ipaddr,
1482 ip_buffer, sizeof(ip_buffer)),
1485 for (reply = packet->vps; reply; reply = reply->next) {
1486 if ((reply->vendor == 0) &&
1487 ((reply->attribute & 0xFFFF) > 0xff)) continue;
1493 * And send it on it's way.
1495 return rad_sendto(packet->sockfd, packet->data, packet->data_len, 0,
1496 &packet->src_ipaddr, packet->src_port,
1497 &packet->dst_ipaddr, packet->dst_port);
1501 * Do a comparison of two authentication digests by comparing
1502 * the FULL digest. Otehrwise, the server can be subject to
1503 * timing attacks that allow attackers find a valid message
1506 * http://www.cs.rice.edu/~dwallach/pub/crosby-timing2009.pdf
1508 static int digest_cmp(const uint8_t *a, const uint8_t *b, size_t length)
1513 for (i = 0; i < length; i++) {
1514 result |= a[i] ^ b[i];
1517 return result; /* 0 is OK, !0 is !OK, just like memcmp */
1522 * Validates the requesting client NAS. Calculates the
1523 * signature based on the clients private key.
1525 static int calc_acctdigest(RADIUS_PACKET *packet, const char *secret)
1527 uint8_t digest[AUTH_VECTOR_LEN];
1531 * Zero out the auth_vector in the received packet.
1532 * Then append the shared secret to the received packet,
1533 * and calculate the MD5 sum. This must be the same
1534 * as the original MD5 sum (packet->vector).
1536 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
1539 * MD5(packet + secret);
1541 fr_MD5Init(&context);
1542 fr_MD5Update(&context, packet->data, packet->data_len);
1543 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1544 fr_MD5Final(digest, &context);
1547 * Return 0 if OK, 2 if not OK.
1549 if (digest_cmp(digest, packet->vector, AUTH_VECTOR_LEN) != 0) return 2;
1555 * Validates the requesting client NAS. Calculates the
1556 * signature based on the clients private key.
1558 static int calc_replydigest(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1561 uint8_t calc_digest[AUTH_VECTOR_LEN];
1567 if (original == NULL) {
1572 * Copy the original vector in place.
1574 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
1577 * MD5(packet + secret);
1579 fr_MD5Init(&context);
1580 fr_MD5Update(&context, packet->data, packet->data_len);
1581 fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1582 fr_MD5Final(calc_digest, &context);
1585 * Copy the packet's vector back to the packet.
1587 memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
1590 * Return 0 if OK, 2 if not OK.
1592 if (digest_cmp(packet->vector, calc_digest, AUTH_VECTOR_LEN) != 0) return 2;
1598 * See if the data pointed to by PTR is a valid RADIUS packet.
1600 * packet is not 'const * const' because we may update data_len,
1601 * if there's more data in the UDP packet than in the RADIUS packet.
1603 int rad_packet_ok(RADIUS_PACKET *packet, int flags)
1608 radius_packet_t *hdr;
1609 char host_ipaddr[128];
1615 * Check for packets smaller than the packet header.
1617 * RFC 2865, Section 3., subsection 'length' says:
1619 * "The minimum length is 20 ..."
1621 if (packet->data_len < AUTH_HDR_LEN) {
1622 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (received %d < minimum %d)",
1623 inet_ntop(packet->src_ipaddr.af,
1624 &packet->src_ipaddr.ipaddr,
1625 host_ipaddr, sizeof(host_ipaddr)),
1626 (int) packet->data_len, AUTH_HDR_LEN);
1631 * RFC 2865, Section 3., subsection 'length' says:
1633 * " ... and maximum length is 4096."
1635 if (packet->data_len > MAX_PACKET_LEN) {
1636 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (received %d > maximum %d)",
1637 inet_ntop(packet->src_ipaddr.af,
1638 &packet->src_ipaddr.ipaddr,
1639 host_ipaddr, sizeof(host_ipaddr)),
1640 (int) packet->data_len, MAX_PACKET_LEN);
1645 * Check for packets with mismatched size.
1646 * i.e. We've received 128 bytes, and the packet header
1647 * says it's 256 bytes long.
1649 totallen = (packet->data[2] << 8) | packet->data[3];
1650 hdr = (radius_packet_t *)packet->data;
1653 * Code of 0 is not understood.
1654 * Code of 16 or greate is not understood.
1656 if ((hdr->code == 0) ||
1657 (hdr->code >= FR_MAX_PACKET_CODE)) {
1658 fr_strerror_printf("WARNING: Bad RADIUS packet from host %s: unknown packet code%d ",
1659 inet_ntop(packet->src_ipaddr.af,
1660 &packet->src_ipaddr.ipaddr,
1661 host_ipaddr, sizeof(host_ipaddr)),
1667 * Message-Authenticator is required in Status-Server
1668 * packets, otherwise they can be trivially forged.
1670 if (hdr->code == PW_STATUS_SERVER) require_ma = 1;
1673 * It's also required if the caller asks for it.
1675 if (flags) require_ma = 1;
1678 * Repeat the length checks. This time, instead of
1679 * looking at the data we received, look at the value
1680 * of the 'length' field inside of the packet.
1682 * Check for packets smaller than the packet header.
1684 * RFC 2865, Section 3., subsection 'length' says:
1686 * "The minimum length is 20 ..."
1688 if (totallen < AUTH_HDR_LEN) {
1689 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (length %d < minimum %d)",
1690 inet_ntop(packet->src_ipaddr.af,
1691 &packet->src_ipaddr.ipaddr,
1692 host_ipaddr, sizeof(host_ipaddr)),
1693 totallen, AUTH_HDR_LEN);
1698 * And again, for the value of the 'length' field.
1700 * RFC 2865, Section 3., subsection 'length' says:
1702 * " ... and maximum length is 4096."
1704 if (totallen > MAX_PACKET_LEN) {
1705 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (length %d > maximum %d)",
1706 inet_ntop(packet->src_ipaddr.af,
1707 &packet->src_ipaddr.ipaddr,
1708 host_ipaddr, sizeof(host_ipaddr)),
1709 totallen, MAX_PACKET_LEN);
1714 * RFC 2865, Section 3., subsection 'length' says:
1716 * "If the packet is shorter than the Length field
1717 * indicates, it MUST be silently discarded."
1719 * i.e. No response to the NAS.
1721 if (packet->data_len < totallen) {
1722 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: received %d octets, packet length says %d",
1723 inet_ntop(packet->src_ipaddr.af,
1724 &packet->src_ipaddr.ipaddr,
1725 host_ipaddr, sizeof(host_ipaddr)),
1726 (int) packet->data_len, totallen);
1731 * RFC 2865, Section 3., subsection 'length' says:
1733 * "Octets outside the range of the Length field MUST be
1734 * treated as padding and ignored on reception."
1736 if (packet->data_len > totallen) {
1738 * We're shortening the packet below, but just
1739 * to be paranoid, zero out the extra data.
1741 memset(packet->data + totallen, 0, packet->data_len - totallen);
1742 packet->data_len = totallen;
1746 * Walk through the packet's attributes, ensuring that
1747 * they add up EXACTLY to the size of the packet.
1749 * If they don't, then the attributes either under-fill
1750 * or over-fill the packet. Any parsing of the packet
1751 * is impossible, and will result in unknown side effects.
1753 * This would ONLY happen with buggy RADIUS implementations,
1754 * or with an intentional attack. Either way, we do NOT want
1755 * to be vulnerable to this problem.
1758 count = totallen - AUTH_HDR_LEN;
1763 * Attribute number zero is NOT defined.
1766 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Invalid attribute 0",
1767 inet_ntop(packet->src_ipaddr.af,
1768 &packet->src_ipaddr.ipaddr,
1769 host_ipaddr, sizeof(host_ipaddr)));
1774 * Attributes are at LEAST as long as the ID & length
1775 * fields. Anything shorter is an invalid attribute.
1778 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %d too short",
1779 inet_ntop(packet->src_ipaddr.af,
1780 &packet->src_ipaddr.ipaddr,
1781 host_ipaddr, sizeof(host_ipaddr)),
1787 * Sanity check the attributes for length.
1790 default: /* don't do anything by default */
1794 * If there's an EAP-Message, we require
1795 * a Message-Authenticator.
1797 case PW_EAP_MESSAGE:
1801 case PW_MESSAGE_AUTHENTICATOR:
1802 if (attr[1] != 2 + AUTH_VECTOR_LEN) {
1803 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Message-Authenticator has invalid length %d",
1804 inet_ntop(packet->src_ipaddr.af,
1805 &packet->src_ipaddr.ipaddr,
1806 host_ipaddr, sizeof(host_ipaddr)),
1815 * FIXME: Look up the base 255 attributes in the
1816 * dictionary, and switch over their type. For
1817 * integer/date/ip, the attribute length SHOULD
1820 count -= attr[1]; /* grab the attribute length */
1822 num_attributes++; /* seen one more attribute */
1826 * If the attributes add up to a packet, it's allowed.
1828 * If not, we complain, and throw the packet away.
1831 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: packet attributes do NOT exactly fill the packet",
1832 inet_ntop(packet->src_ipaddr.af,
1833 &packet->src_ipaddr.ipaddr,
1834 host_ipaddr, sizeof(host_ipaddr)));
1839 * If we're configured to look for a maximum number of
1840 * attributes, and we've seen more than that maximum,
1841 * then throw the packet away, as a possible DoS.
1843 if ((fr_max_attributes > 0) &&
1844 (num_attributes > fr_max_attributes)) {
1845 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
1846 inet_ntop(packet->src_ipaddr.af,
1847 &packet->src_ipaddr.ipaddr,
1848 host_ipaddr, sizeof(host_ipaddr)),
1849 num_attributes, fr_max_attributes);
1854 * http://www.freeradius.org/rfc/rfc2869.html#EAP-Message
1856 * A packet with an EAP-Message attribute MUST also have
1857 * a Message-Authenticator attribute.
1859 * A Message-Authenticator all by itself is OK, though.
1861 * Similarly, Status-Server packets MUST contain
1862 * Message-Authenticator attributes.
1864 if (require_ma && ! seen_ma) {
1865 fr_strerror_printf("WARNING: Insecure packet from host %s: Packet does not contain required Message-Authenticator attribute",
1866 inet_ntop(packet->src_ipaddr.af,
1867 &packet->src_ipaddr.ipaddr,
1868 host_ipaddr, sizeof(host_ipaddr)));
1873 * Fill RADIUS header fields
1875 packet->code = hdr->code;
1876 packet->id = hdr->id;
1877 memcpy(packet->vector, hdr->vector, AUTH_VECTOR_LEN);
1884 * Receive UDP client requests, and fill in
1885 * the basics of a RADIUS_PACKET structure.
1887 RADIUS_PACKET *rad_recv(int fd, int flags)
1890 RADIUS_PACKET *packet;
1893 * Allocate the new request data structure
1895 if ((packet = malloc(sizeof(*packet))) == NULL) {
1896 fr_strerror_printf("out of memory");
1899 memset(packet, 0, sizeof(*packet));
1902 sock_flags = MSG_PEEK;
1906 packet->data_len = rad_recvfrom(fd, &packet->data, sock_flags,
1907 &packet->src_ipaddr, &packet->src_port,
1908 &packet->dst_ipaddr, &packet->dst_port);
1911 * Check for socket errors.
1913 if (packet->data_len < 0) {
1914 fr_strerror_printf("Error receiving packet: %s", strerror(errno));
1915 /* packet->data is NULL */
1921 * If the packet is too big, then rad_recvfrom did NOT
1922 * allocate memory. Instead, it just discarded the
1925 if (packet->data_len > MAX_PACKET_LEN) {
1926 fr_strerror_printf("Discarding packet: Larger than RFC limitation of 4096 bytes.");
1927 /* packet->data is NULL */
1933 * Read no data. Continue.
1934 * This check is AFTER the MAX_PACKET_LEN check above, because
1935 * if the packet is larger than MAX_PACKET_LEN, we also have
1936 * packet->data == NULL
1938 if ((packet->data_len == 0) || !packet->data) {
1939 fr_strerror_printf("Empty packet: Socket is not ready.");
1945 * See if it's a well-formed RADIUS packet.
1947 if (!rad_packet_ok(packet, flags)) {
1953 * Remember which socket we read the packet from.
1955 packet->sockfd = fd;
1958 * FIXME: Do even more filtering by only permitting
1959 * certain IP's. The problem is that we don't know
1960 * how to do this properly for all possible clients...
1964 * Explicitely set the VP list to empty.
1968 if (fr_debug_flag) {
1969 char host_ipaddr[128];
1971 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1972 DEBUG("rad_recv: %s packet from host %s port %d",
1973 fr_packet_codes[packet->code],
1974 inet_ntop(packet->src_ipaddr.af,
1975 &packet->src_ipaddr.ipaddr,
1976 host_ipaddr, sizeof(host_ipaddr)),
1979 DEBUG("rad_recv: Packet from host %s port %d code=%d",
1980 inet_ntop(packet->src_ipaddr.af,
1981 &packet->src_ipaddr.ipaddr,
1982 host_ipaddr, sizeof(host_ipaddr)),
1986 DEBUG(", id=%d, length=%d\n",
1987 packet->id, (int) packet->data_len);
1995 * Verify the signature of a packet.
1997 int rad_verify(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2004 if (!packet || !packet->data) return -1;
2007 * Before we allocate memory for the attributes, do more
2010 ptr = packet->data + AUTH_HDR_LEN;
2011 length = packet->data_len - AUTH_HDR_LEN;
2012 while (length > 0) {
2013 uint8_t msg_auth_vector[AUTH_VECTOR_LEN];
2014 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
2019 default: /* don't do anything. */
2023 * Note that more than one Message-Authenticator
2024 * attribute is invalid.
2026 case PW_MESSAGE_AUTHENTICATOR:
2027 memcpy(msg_auth_vector, &ptr[2], sizeof(msg_auth_vector));
2028 memset(&ptr[2], 0, AUTH_VECTOR_LEN);
2030 switch (packet->code) {
2034 case PW_ACCOUNTING_REQUEST:
2035 case PW_ACCOUNTING_RESPONSE:
2036 case PW_DISCONNECT_REQUEST:
2037 case PW_DISCONNECT_ACK:
2038 case PW_DISCONNECT_NAK:
2039 case PW_COA_REQUEST:
2042 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
2045 case PW_AUTHENTICATION_ACK:
2046 case PW_AUTHENTICATION_REJECT:
2047 case PW_ACCESS_CHALLENGE:
2049 fr_strerror_printf("ERROR: Cannot validate Message-Authenticator in response packet without a request packet.");
2052 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
2056 fr_hmac_md5(packet->data, packet->data_len,
2057 (const uint8_t *) secret, strlen(secret),
2059 if (digest_cmp(calc_auth_vector, msg_auth_vector,
2060 sizeof(calc_auth_vector)) != 0) {
2062 fr_strerror_printf("Received packet from %s with invalid Message-Authenticator! (Shared secret is incorrect.)",
2063 inet_ntop(packet->src_ipaddr.af,
2064 &packet->src_ipaddr.ipaddr,
2065 buffer, sizeof(buffer)));
2066 /* Silently drop packet, according to RFC 3579 */
2068 } /* else the message authenticator was good */
2071 * Reinitialize Authenticators.
2073 memcpy(&ptr[2], msg_auth_vector, AUTH_VECTOR_LEN);
2074 memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
2076 } /* switch over the attributes */
2080 } /* loop over the packet, sanity checking the attributes */
2083 * It looks like a RADIUS packet, but we can't validate
2086 if ((packet->code == 0) || (packet->code >= FR_MAX_PACKET_CODE)) {
2088 fr_strerror_printf("Received Unknown packet code %d "
2089 "from client %s port %d: Cannot validate signature.",
2091 inet_ntop(packet->src_ipaddr.af,
2092 &packet->src_ipaddr.ipaddr,
2093 buffer, sizeof(buffer)),
2099 * Calculate and/or verify digest.
2101 switch(packet->code) {
2105 case PW_AUTHENTICATION_REQUEST:
2106 case PW_STATUS_SERVER:
2108 * The authentication vector is random
2109 * nonsense, invented by the client.
2113 case PW_COA_REQUEST:
2114 case PW_DISCONNECT_REQUEST:
2115 case PW_ACCOUNTING_REQUEST:
2116 if (calc_acctdigest(packet, secret) > 1) {
2117 fr_strerror_printf("Received %s packet "
2118 "from %s with invalid signature! (Shared secret is incorrect.)",
2119 fr_packet_codes[packet->code],
2120 inet_ntop(packet->src_ipaddr.af,
2121 &packet->src_ipaddr.ipaddr,
2122 buffer, sizeof(buffer)));
2127 /* Verify the reply digest */
2128 case PW_AUTHENTICATION_ACK:
2129 case PW_AUTHENTICATION_REJECT:
2130 case PW_ACCESS_CHALLENGE:
2131 case PW_ACCOUNTING_RESPONSE:
2132 case PW_DISCONNECT_ACK:
2133 case PW_DISCONNECT_NAK:
2136 rcode = calc_replydigest(packet, original, secret);
2138 fr_strerror_printf("Received %s packet "
2139 "from client %s port %d with invalid signature (err=%d)! (Shared secret is incorrect.)",
2140 fr_packet_codes[packet->code],
2141 inet_ntop(packet->src_ipaddr.af,
2142 &packet->src_ipaddr.ipaddr,
2143 buffer, sizeof(buffer)),
2151 fr_strerror_printf("Received Unknown packet code %d "
2152 "from client %s port %d: Cannot validate signature",
2154 inet_ntop(packet->src_ipaddr.af,
2155 &packet->src_ipaddr.ipaddr,
2156 buffer, sizeof(buffer)),
2165 static VALUE_PAIR *data2vp(const RADIUS_PACKET *packet,
2166 const RADIUS_PACKET *original,
2167 const char *secret, size_t length,
2168 const uint8_t *data, VALUE_PAIR *vp)
2173 * If length is greater than 253, something is SERIOUSLY
2176 if (length > 253) length = 253; /* paranoia (pair-anoia?) */
2178 vp->length = length;
2179 vp->operator = T_OP_EQ;
2185 if (vp->flags.has_tag) {
2186 if (TAG_VALID(data[0]) ||
2187 (vp->flags.encrypt == FLAG_ENCRYPT_TUNNEL_PASSWORD)) {
2189 * Tunnel passwords REQUIRE a tag, even
2190 * if don't have a valid tag.
2192 vp->flags.tag = data[0];
2194 if ((vp->type == PW_TYPE_STRING) ||
2195 (vp->type == PW_TYPE_OCTETS)) {
2196 if (length == 0) goto raw;
2203 * Copy the data to be decrypted
2205 memcpy(&vp->vp_octets[0], data + offset, length - offset);
2206 vp->length -= offset;
2209 * Decrypt the attribute.
2211 switch (vp->flags.encrypt) {
2215 case FLAG_ENCRYPT_USER_PASSWORD:
2217 rad_pwdecode((char *)vp->vp_strvalue,
2221 rad_pwdecode((char *)vp->vp_strvalue,
2225 if (vp->attribute == PW_USER_PASSWORD) {
2226 vp->length = strlen(vp->vp_strvalue);
2231 * Tunnel-Password's may go ONLY
2232 * in response packets.
2234 case FLAG_ENCRYPT_TUNNEL_PASSWORD:
2235 if (!original) goto raw;
2237 if (rad_tunnel_pwdecode(vp->vp_octets, &vp->length,
2238 secret, original->vector) < 0) {
2244 * Ascend-Send-Secret
2245 * Ascend-Receive-Secret
2247 case FLAG_ENCRYPT_ASCEND_SECRET:
2251 uint8_t my_digest[AUTH_VECTOR_LEN];
2252 make_secret(my_digest,
2255 memcpy(vp->vp_strvalue, my_digest,
2257 vp->vp_strvalue[AUTH_VECTOR_LEN] = '\0';
2258 vp->length = strlen(vp->vp_strvalue);
2264 } /* switch over encryption flags */
2268 case PW_TYPE_STRING:
2269 case PW_TYPE_OCTETS:
2270 case PW_TYPE_ABINARY:
2271 /* nothing more to do */
2275 if (vp->length != 1) goto raw;
2277 vp->vp_integer = vp->vp_octets[0];
2282 if (vp->length != 2) goto raw;
2284 vp->vp_integer = (vp->vp_octets[0] << 8) | vp->vp_octets[1];
2287 case PW_TYPE_INTEGER:
2288 if (vp->length != 4) goto raw;
2290 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2291 vp->vp_integer = ntohl(vp->vp_integer);
2293 if (vp->flags.has_tag) vp->vp_integer &= 0x00ffffff;
2296 * Try to get named VALUEs
2300 dval = dict_valbyattr(vp->attribute, vp->vendor,
2303 strlcpy(vp->vp_strvalue,
2305 sizeof(vp->vp_strvalue));
2311 if (vp->length != 4) goto raw;
2313 memcpy(&vp->vp_date, vp->vp_octets, 4);
2314 vp->vp_date = ntohl(vp->vp_date);
2318 case PW_TYPE_IPADDR:
2319 if (vp->length != 4) goto raw;
2321 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2325 * IPv6 interface ID is 8 octets long.
2328 if (vp->length != 8) goto raw;
2329 /* vp->vp_ifid == vp->vp_octets */
2333 * IPv6 addresses are 16 octets long
2335 case PW_TYPE_IPV6ADDR:
2336 if (vp->length != 16) goto raw;
2337 /* vp->vp_ipv6addr == vp->vp_octets */
2341 * IPv6 prefixes are 2 to 18 octets long.
2343 * RFC 3162: The first octet is unused.
2344 * The second is the length of the prefix
2345 * the rest are the prefix data.
2347 * The prefix length can have value 0 to 128.
2349 case PW_TYPE_IPV6PREFIX:
2350 if (vp->length < 2 || vp->length > 18) goto raw;
2351 if (vp->vp_octets[1] > 128) goto raw;
2354 * FIXME: double-check that
2355 * (vp->vp_octets[1] >> 3) matches vp->length + 2
2357 if (vp->length < 18) {
2358 memset(vp->vp_octets + vp->length, 0,
2363 case PW_TYPE_SIGNED:
2364 if (vp->length != 4) goto raw;
2367 * Overload vp_integer for ntohl, which takes
2368 * uint32_t, not int32_t
2370 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2371 vp->vp_integer = ntohl(vp->vp_integer);
2372 memcpy(&vp->vp_signed, &vp->vp_integer, 4);
2376 vp->length = length;
2377 vp->vp_tlv = malloc(length);
2380 fr_strerror_printf("No memory");
2383 memcpy(vp->vp_tlv, data, length);
2386 case PW_TYPE_COMBO_IP:
2387 if (vp->length == 4) {
2388 vp->type = PW_TYPE_IPADDR;
2389 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2392 } else if (vp->length == 16) {
2393 vp->type = PW_TYPE_IPV6ADDR;
2394 /* vp->vp_ipv6addr == vp->vp_octets */
2402 vp->type = PW_TYPE_OCTETS;
2403 vp->length = length;
2404 memcpy(vp->vp_octets, data, length);
2408 * Ensure there's no encryption or tag stuff,
2409 * we just pass the attribute as-is.
2411 memset(&vp->flags, 0, sizeof(vp->flags));
2417 static void rad_sortvp(VALUE_PAIR **head)
2420 VALUE_PAIR *vp, **tail;
2423 * Walk over the VP's, sorting them in order. Did I
2424 * mention that I hate WiMAX continuations?
2426 * And bubble sort! WTF is up with that?
2433 if (!vp->next) break;
2435 if (vp->attribute > vp->next->attribute) {
2437 vp->next = (*tail)->next;
2448 * Walk the packet, looking for continuations of this attribute.
2450 * This is (worst-case) O(N^2) in the number of RADIUS
2451 * attributes. That happens only when perverse clients create
2452 * continued attributes, AND separate the fragmented portions
2453 * with a lot of other attributes.
2455 * Sane clients should put the fragments next to each other, in
2456 * which case this is O(N), in the number of fragments.
2458 static uint8_t *rad_coalesce(unsigned int attribute, int vendor,
2459 size_t length, uint8_t *data,
2460 size_t packet_length, size_t *ptlv_length)
2464 size_t tlv_length = length;
2465 uint8_t *ptr, *tlv, *tlv_data;
2467 for (ptr = data + length;
2468 ptr != (data + packet_length);
2470 /* FIXME: Check that there are 6 bytes of data here... */
2471 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2472 (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2473 (ptr[2] != 0) || (ptr[3] != 0) || /* our requirement */
2474 (ptr[4] != ((vendor >> 8) & 0xff)) ||
2475 (ptr[5] != (vendor & 0xff))) {
2479 memcpy(&lvalue, ptr + 2, 4); /* Vendor Id */
2480 lvalue = ntohl(lvalue);
2482 lvalue |= ptr[2 + 4]; /* add in VSA number */
2483 if (lvalue != attribute) continue;
2486 * If the vendor-length is too small, it's badly
2487 * formed, so we stop.
2489 if ((ptr[2 + 4 + 1]) < 3) break;
2491 tlv_length += ptr[2 + 4 + 1] - 3;
2492 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2495 tlv = tlv_data = malloc(tlv_length);
2496 if (!tlv_data) return NULL;
2498 memcpy(tlv, data, length);
2502 * Now we walk the list again, copying the data over to
2503 * our newly created memory.
2505 for (ptr = data + length;
2506 ptr != (data + packet_length);
2510 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2511 (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2512 (ptr[2] != 0) || (ptr[3] != 0)) { /* our requirement */
2516 memcpy(&lvalue, ptr + 2, 4);
2517 lvalue = ntohl(lvalue);
2519 lvalue |= ptr[2 + 4];
2520 if (lvalue != attribute) continue;
2523 * If the vendor-length is too small, it's badly
2524 * formed, so we stop.
2526 if ((ptr[2 + 4 + 1]) < 3) break;
2528 this_length = ptr[2 + 4 + 1] - 3;
2529 memcpy(tlv, ptr + 2 + 4 + 3, this_length);
2532 ptr[2 + 4] = 0; /* What a hack! */
2533 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2536 *ptlv_length = tlv_length;
2541 * Walk over Evil WIMAX TLVs, creating attributes.
2543 static VALUE_PAIR *tlv2wimax(const RADIUS_PACKET *packet,
2544 const RADIUS_PACKET *original,
2546 int attribute, int vendor,
2547 uint8_t *ptr, size_t len, int shift)
2549 VALUE_PAIR *head = NULL;
2550 VALUE_PAIR **tail = &head;
2552 uint8_t *y; /* why do I need to do this? */
2554 if (shift > 24) return NULL;
2557 * Sanity check the attribute.
2559 for (y = ptr; y < (ptr + len); y += y[1]) {
2560 if ((y[0] == 0) || ((y + 2) > (ptr + len)) ||
2561 (y[1] < 2) || ((y + y[1]) > (ptr + len))) {
2566 for (y = ptr; y < (ptr + len); y += y[1]) {
2569 da = dict_attrbyvalue(attribute | (ptr[0] << shift), vendor);
2570 if (da && (da->type == PW_TYPE_TLV)) {
2571 vp = tlv2wimax(packet, original, secret,
2572 attribute | (ptr[0] << shift),
2573 vendor, ptr + 2, ptr[1] - 2,
2575 if (!vp) goto error;
2577 vp = paircreate(attribute | (ptr[0] << shift), vendor,
2585 if (!data2vp(packet, original, secret,
2586 y[1] - 2, y + 2, vp)) {
2592 while (*tail) tail = &((*tail)->next);
2599 * Start at the *data* portion of a continued attribute. search
2600 * through the rest of the attributes to find a matching one, and
2601 * add it's contents to our contents.
2603 static VALUE_PAIR *rad_continuation2vp(const RADIUS_PACKET *packet,
2604 const RADIUS_PACKET *original,
2605 const char *secret, int attribute,
2607 int length, /* CANNOT be zero */
2608 uint8_t *data, size_t packet_length,
2609 int flag, DICT_ATTR *da)
2611 size_t tlv_length, left;
2614 VALUE_PAIR *vp, *head, **tail;
2618 * Ensure we have data that hasn't been split across
2619 * multiple attributes.
2622 tlv_data = rad_coalesce(attribute, vendor, length,
2623 data, packet_length, &tlv_length);
2624 if (!tlv_data) return NULL;
2627 tlv_length = length;
2631 * Non-TLV types cannot be continued across multiple
2632 * attributes. This is true even of keys that are
2633 * encrypted with the tunnel-password method. The spec
2634 * says that they can be continued... but also that the
2635 * keys are 160 bits, which means that they CANNOT be
2638 * Note that we don't check "flag" here. The calling
2641 if (!da || (da->type != PW_TYPE_TLV)) {
2643 if (tlv_data == data) { /* true if we had 'goto' */
2644 tlv_data = malloc(tlv_length);
2645 if (!tlv_data) return NULL;
2646 memcpy(tlv_data, data, tlv_length);
2649 vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2650 if (!vp) return NULL;
2652 vp->type = PW_TYPE_TLV;
2653 vp->flags.encrypt = FLAG_ENCRYPT_NONE;
2654 vp->flags.has_tag = 0;
2655 vp->flags.is_tlv = 0;
2656 vp->vp_tlv = tlv_data;
2657 vp->length = tlv_length;
2659 } /* else it WAS a TLV, go decode the sub-tlv's */
2662 * Now (sigh) we walk over the TLV, seeing if it is
2666 for (ptr = tlv_data;
2667 ptr != (tlv_data + tlv_length);
2672 goto not_well_formed;
2679 * Now we walk over the TLV *again*, creating sub-tlv's.
2684 for (ptr = tlv_data;
2685 ptr != (tlv_data + tlv_length);
2688 tlv_da = dict_attrbyvalue(attribute | (ptr[0] << 8), vendor);
2689 if (tlv_da && (tlv_da->type == PW_TYPE_TLV)) {
2690 vp = tlv2wimax(packet, original, secret,
2691 attribute | (ptr[0] << 8),
2692 vendor, ptr + 2, ptr[1] - 2, 16);
2694 if (!vp) goto error;
2696 vp = paircreate(attribute | (ptr[0] << 8), vendor,
2701 goto not_well_formed;
2704 if (!data2vp(packet, original, secret,
2705 ptr[1] - 2, ptr + 2, vp)) {
2712 while (*tail) tail = &((*tail)->next);
2716 * TLV's MAY be continued, but sometimes they're not.
2718 if (tlv_data != data) free(tlv_data);
2720 if (head->next) rad_sortvp(&head);
2727 * Parse a RADIUS attribute into a data structure.
2729 VALUE_PAIR *rad_attr2vp(const RADIUS_PACKET *packet,
2730 const RADIUS_PACKET *original,
2731 const char *secret, int attribute, int vendor,
2732 int length, const uint8_t *data)
2736 vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2737 if (!vp) return NULL;
2739 return data2vp(packet, original, secret, length, data, vp);
2744 * Calculate/check digest, and decode radius attributes.
2746 * -1 on decoding error
2749 int rad_decode(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2753 uint32_t vendorcode;
2756 uint8_t *ptr, *vsa_ptr;
2761 radius_packet_t *hdr;
2762 int vsa_tlen, vsa_llen, vsa_offset;
2763 DICT_VENDOR *dv = NULL;
2764 int num_attributes = 0;
2767 * Extract attribute-value pairs
2769 hdr = (radius_packet_t *)packet->data;
2771 packet_length = packet->data_len - AUTH_HDR_LEN;
2774 * There may be VP's already in the packet. Don't
2777 for (tail = &packet->vps; *tail != NULL; tail = &((*tail)->next)) {
2783 vsa_tlen = vsa_llen = 1;
2787 * We have to read at least two bytes.
2789 * rad_recv() above ensures that this is OK.
2791 while (packet_length > 0) {
2796 * Normal attribute, handle it like normal.
2798 if (vendorcode == 0) {
2800 * No room to read attr/length,
2801 * or bad attribute, or attribute is
2802 * too short, or attribute is too long,
2803 * stop processing the packet.
2805 if ((packet_length < 2) ||
2806 (ptr[0] == 0) || (ptr[1] < 2) ||
2807 (ptr[1] > packet_length)) break;
2815 if (attribute != PW_VENDOR_SPECIFIC) goto create_pair;
2818 * No vendor code, or ONLY vendor code.
2820 if (attrlen <= 4) goto create_pair;
2826 * Handle Vendor-Specific
2828 if (vendorlen == 0) {
2834 * attrlen was checked above.
2836 memcpy(&lvalue, ptr, 4);
2837 myvendor = ntohl(lvalue);
2840 * Zero isn't allowed.
2842 if (myvendor == 0) goto create_pair;
2845 * This is an implementation issue.
2846 * We currently pack vendor into the upper
2847 * 16 bits of a 32-bit attribute number,
2848 * so we can't handle vendor numbers larger
2851 if (myvendor > 65535) goto create_pair;
2853 vsa_tlen = vsa_llen = 1;
2855 dv = dict_vendorbyvalue(myvendor);
2857 vsa_tlen = dv->type;
2858 vsa_llen = dv->length;
2859 if (dv->flags) vsa_offset = 1;
2863 * Sweep through the list of VSA's,
2864 * seeing if they exactly fill the
2865 * outer Vendor-Specific attribute.
2867 * If not, create a raw Vendor-Specific.
2870 sublen = attrlen - 4;
2873 * See if we can parse it.
2879 * Not enough room for one more
2882 if (sublen < (vsa_tlen + vsa_llen + vsa_offset)) goto create_pair;
2885 * Ensure that the attribute number
2894 myattr = (subptr[0] << 8) | subptr[1];
2898 if ((subptr[0] != 0) ||
2899 (subptr[1] != 0)) goto create_pair;
2901 myattr = (subptr[2] << 8) | subptr[3];
2905 * Our dictionary is broken.
2914 ptr += 4 + vsa_tlen;
2915 attrlen -= (4 + vsa_tlen);
2916 packet_length -= 4 + vsa_tlen;
2920 if (subptr[vsa_tlen] < (vsa_tlen + vsa_llen + vsa_offset))
2923 if (subptr[vsa_tlen] > sublen)
2928 * Reserved bits MUST be
2932 ((subptr[vsa_tlen + vsa_llen] & 0x7f) != 0))
2935 sublen -= subptr[vsa_tlen];
2936 subptr += subptr[vsa_tlen];
2940 if (subptr[vsa_tlen] != 0) goto create_pair;
2941 if (subptr[vsa_tlen + 1] < (vsa_tlen + vsa_llen))
2943 if (subptr[vsa_tlen + 1] > sublen)
2945 sublen -= subptr[vsa_tlen + 1];
2946 subptr += subptr[vsa_tlen + 1];
2950 * Our dictionaries are
2956 } while (sublen > 0);
2958 vendorcode = myvendor;
2959 vendorlen = attrlen - 4;
2966 * attrlen is the length of this attribute.
2967 * total_len is the length of the encompassing
2976 attribute = (ptr[0] << 8) | ptr[1];
2979 default: /* can't hit this. */
2987 attrlen = ptr[0] - (vsa_tlen + vsa_llen + vsa_offset);
2991 attrlen = ptr[1] - (vsa_tlen + vsa_llen);
2994 default: /* can't hit this. */
2998 ptr += vsa_llen + vsa_offset;
2999 vendorlen -= vsa_tlen + vsa_llen + vsa_offset + attrlen;
3000 packet_length -= (vsa_tlen + vsa_llen + vsa_offset);
3003 * Ignore VSAs that have no data.
3005 if (attrlen == 0) goto next;
3008 * WiMAX attributes of type 0 are ignored. They
3009 * are a secret flag to us that the attribute has
3010 * already been dealt with.
3012 if ((vendorcode == VENDORPEC_WIMAX) && (attribute == 0)) {
3019 da = dict_attrbyvalue(attribute, vendorcode);
3022 * If it's NOT continued, AND we know
3023 * about it, AND it's not a TLV, we can
3024 * create a normal pair.
3026 if (((vsa_ptr[2] & 0x80) == 0) &&
3027 da && (da->type != PW_TYPE_TLV)) goto create_pair;
3030 * Else it IS continued, or it's a TLV.
3031 * Go do a lot of work to find the stuff.
3033 pair = rad_continuation2vp(packet, original, secret,
3034 attribute, vendorcode,
3037 ((vsa_ptr[2] & 0x80) != 0),
3043 * Create the attribute, setting the default type
3044 * to 'octets'. If the type in the dictionary
3045 * is different, then the dictionary type will
3046 * over-ride this one.
3048 * If the attribute has no data, then discard it.
3050 * Unless it's CUI. Damn you, CUI!
3054 (attribute != PW_CHARGEABLE_USER_IDENTITY)) goto next;
3056 pair = rad_attr2vp(packet, original, secret,
3057 attribute, vendorcode, attrlen, ptr);
3059 pairfree(&packet->vps);
3060 fr_strerror_printf("out of memory");
3074 * VSA's may not have been counted properly in
3075 * rad_packet_ok() above, as it is hard to count
3076 * then without using the dictionary. We
3077 * therefore enforce the limits here, too.
3079 if ((fr_max_attributes > 0) &&
3080 (num_attributes > fr_max_attributes)) {
3081 char host_ipaddr[128];
3083 pairfree(&packet->vps);
3084 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
3085 inet_ntop(packet->src_ipaddr.af,
3086 &packet->src_ipaddr.ipaddr,
3087 host_ipaddr, sizeof(host_ipaddr)),
3088 num_attributes, fr_max_attributes);
3093 if (vendorlen == 0) vendorcode = 0;
3095 packet_length -= attrlen;
3099 * Merge information from the outside world into our
3102 fr_rand_seed(packet->data, AUTH_HDR_LEN);
3111 * We assume that the passwd buffer passed is big enough.
3112 * RFC2138 says the password is max 128 chars, so the size
3113 * of the passwd buffer must be at least 129 characters.
3114 * Preferably it's just MAX_STRING_LEN.
3116 * int *pwlen is updated to the new length of the encrypted
3117 * password - a multiple of 16 bytes.
3119 int rad_pwencode(char *passwd, size_t *pwlen, const char *secret,
3120 const uint8_t *vector)
3122 FR_MD5_CTX context, old;
3123 uint8_t digest[AUTH_VECTOR_LEN];
3124 int i, n, secretlen;
3128 * RFC maximum is 128 bytes.
3130 * If length is zero, pad it out with zeros.
3132 * If the length isn't aligned to 16 bytes,
3133 * zero out the extra data.
3137 if (len > 128) len = 128;
3140 memset(passwd, 0, AUTH_PASS_LEN);
3141 len = AUTH_PASS_LEN;
3142 } else if ((len % AUTH_PASS_LEN) != 0) {
3143 memset(&passwd[len], 0, AUTH_PASS_LEN - (len % AUTH_PASS_LEN));
3144 len += AUTH_PASS_LEN - (len % AUTH_PASS_LEN);
3149 * Use the secret to setup the decryption digest
3151 secretlen = strlen(secret);
3153 fr_MD5Init(&context);
3154 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3155 old = context; /* save intermediate work */
3158 * Encrypt it in place. Don't bother checking
3159 * len, as we've ensured above that it's OK.
3161 for (n = 0; n < len; n += AUTH_PASS_LEN) {
3163 fr_MD5Update(&context, vector, AUTH_PASS_LEN);
3164 fr_MD5Final(digest, &context);
3167 fr_MD5Update(&context,
3168 (uint8_t *) passwd + n - AUTH_PASS_LEN,
3170 fr_MD5Final(digest, &context);
3173 for (i = 0; i < AUTH_PASS_LEN; i++) {
3174 passwd[i + n] ^= digest[i];
3184 int rad_pwdecode(char *passwd, size_t pwlen, const char *secret,
3185 const uint8_t *vector)
3187 FR_MD5_CTX context, old;
3188 uint8_t digest[AUTH_VECTOR_LEN];
3190 size_t n, secretlen;
3193 * The RFC's say that the maximum is 128.
3194 * The buffer we're putting it into above is 254, so
3195 * we don't need to do any length checking.
3197 if (pwlen > 128) pwlen = 128;
3202 if (pwlen == 0) goto done;
3205 * Use the secret to setup the decryption digest
3207 secretlen = strlen(secret);
3209 fr_MD5Init(&context);
3210 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3211 old = context; /* save intermediate work */
3214 * The inverse of the code above.
3216 for (n = 0; n < pwlen; n += AUTH_PASS_LEN) {
3218 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3219 fr_MD5Final(digest, &context);
3222 if (pwlen > AUTH_PASS_LEN) {
3223 fr_MD5Update(&context, (uint8_t *) passwd,
3227 fr_MD5Final(digest, &context);
3230 if (pwlen > (n + AUTH_PASS_LEN)) {
3231 fr_MD5Update(&context, (uint8_t *) passwd + n,
3236 for (i = 0; i < AUTH_PASS_LEN; i++) {
3237 passwd[i + n] ^= digest[i];
3242 passwd[pwlen] = '\0';
3243 return strlen(passwd);
3248 * Encode Tunnel-Password attributes when sending them out on the wire.
3250 * int *pwlen is updated to the new length of the encrypted
3251 * password - a multiple of 16 bytes.
3253 * This is per RFC-2868 which adds a two char SALT to the initial intermediate
3256 int rad_tunnel_pwencode(char *passwd, size_t *pwlen, const char *secret,
3257 const uint8_t *vector)
3259 uint8_t buffer[AUTH_VECTOR_LEN + MAX_STRING_LEN + 3];
3260 unsigned char digest[AUTH_VECTOR_LEN];
3262 int i, n, secretlen;
3267 if (len > 127) len = 127;
3270 * Shift the password 3 positions right to place a salt and original
3271 * length, tag will be added automatically on packet send
3273 for (n=len ; n>=0 ; n--) passwd[n+3] = passwd[n];
3277 * save original password length as first password character;
3284 * Generate salt. The RFC's say:
3286 * The high bit of salt[0] must be set, each salt in a
3287 * packet should be unique, and they should be random
3289 * So, we set the high bit, add in a counter, and then
3290 * add in some CSPRNG data. should be OK..
3292 salt[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
3293 (fr_rand() & 0x07));
3294 salt[1] = fr_rand();
3297 * Padd password to multiple of AUTH_PASS_LEN bytes.
3299 n = len % AUTH_PASS_LEN;
3301 n = AUTH_PASS_LEN - n;
3302 for (; n > 0; n--, len++)
3305 /* set new password length */
3309 * Use the secret to setup the decryption digest
3311 secretlen = strlen(secret);
3312 memcpy(buffer, secret, secretlen);
3314 for (n2 = 0; n2 < len; n2+=AUTH_PASS_LEN) {
3316 memcpy(buffer + secretlen, vector, AUTH_VECTOR_LEN);
3317 memcpy(buffer + secretlen + AUTH_VECTOR_LEN, salt, 2);
3318 fr_md5_calc(digest, buffer, secretlen + AUTH_VECTOR_LEN + 2);
3320 memcpy(buffer + secretlen, passwd + n2 - AUTH_PASS_LEN, AUTH_PASS_LEN);
3321 fr_md5_calc(digest, buffer, secretlen + AUTH_PASS_LEN);
3324 for (i = 0; i < AUTH_PASS_LEN; i++) {
3325 passwd[i + n2] ^= digest[i];
3333 * Decode Tunnel-Password encrypted attributes.
3335 * Defined in RFC-2868, this uses a two char SALT along with the
3336 * initial intermediate value, to differentiate it from the
3339 int rad_tunnel_pwdecode(uint8_t *passwd, size_t *pwlen, const char *secret,
3340 const uint8_t *vector)
3342 FR_MD5_CTX context, old;
3343 uint8_t digest[AUTH_VECTOR_LEN];
3345 unsigned i, n, len, reallen;
3350 * We need at least a salt.
3353 fr_strerror_printf("tunnel password is too short");
3358 * There's a salt, but no password. Or, there's a salt
3359 * and a 'data_len' octet. It's wrong, but at least we
3360 * can figure out what it means: the password is empty.
3362 * Note that this means we ignore the 'data_len' field,
3363 * if the attribute length tells us that there's no
3364 * more data. So the 'data_len' field may be wrong,
3373 len -= 2; /* discount the salt */
3376 * Use the secret to setup the decryption digest
3378 secretlen = strlen(secret);
3380 fr_MD5Init(&context);
3381 fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3382 old = context; /* save intermediate work */
3385 * Set up the initial key:
3387 * b(1) = MD5(secret + vector + salt)
3389 fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3390 fr_MD5Update(&context, passwd, 2);
3393 for (n = 0; n < len; n += AUTH_PASS_LEN) {
3397 fr_MD5Final(digest, &context);
3402 * A quick check: decrypt the first octet
3403 * of the password, which is the
3404 * 'data_len' field. Ensure it's sane.
3406 reallen = passwd[2] ^ digest[0];
3407 if (reallen >= len) {
3408 fr_strerror_printf("tunnel password is too long for the attribute");
3412 fr_MD5Update(&context, passwd + 2, AUTH_PASS_LEN);
3416 fr_MD5Final(digest, &context);
3419 fr_MD5Update(&context, passwd + n + 2, AUTH_PASS_LEN);
3422 for (i = base; i < AUTH_PASS_LEN; i++) {
3423 passwd[n + i - 1] = passwd[n + i + 2] ^ digest[i];
3428 * See make_tunnel_password, above.
3430 if (reallen > 239) reallen = 239;
3433 passwd[reallen] = 0;
3439 * Encode a CHAP password
3441 * FIXME: might not work with Ascend because
3442 * we use vp->length, and Ascend gear likes
3443 * to send an extra '\0' in the string!
3445 int rad_chap_encode(RADIUS_PACKET *packet, uint8_t *output, int id,
3446 VALUE_PAIR *password)
3450 uint8_t string[MAX_STRING_LEN * 2 + 1];
3451 VALUE_PAIR *challenge;
3454 * Sanity check the input parameters
3456 if ((packet == NULL) || (password == NULL)) {
3461 * Note that the password VP can be EITHER
3462 * a User-Password attribute (from a check-item list),
3463 * or a CHAP-Password attribute (the client asking
3464 * the library to encode it).
3472 memcpy(ptr, password->vp_strvalue, password->length);
3473 ptr += password->length;
3474 i += password->length;
3477 * Use Chap-Challenge pair if present,
3478 * Request-Authenticator otherwise.
3480 challenge = pairfind(packet->vps, PW_CHAP_CHALLENGE, 0);
3482 memcpy(ptr, challenge->vp_strvalue, challenge->length);
3483 i += challenge->length;
3485 memcpy(ptr, packet->vector, AUTH_VECTOR_LEN);
3486 i += AUTH_VECTOR_LEN;
3490 fr_md5_calc((uint8_t *)output + 1, (uint8_t *)string, i);
3497 * Seed the random number generator.
3499 * May be called any number of times.
3501 void fr_rand_seed(const void *data, size_t size)
3506 * Ensure that the pool is initialized.
3508 if (!fr_rand_initialized) {
3511 memset(&fr_rand_pool, 0, sizeof(fr_rand_pool));
3513 fd = open("/dev/urandom", O_RDONLY);
3519 while (total < sizeof(fr_rand_pool.randrsl)) {
3520 this = read(fd, fr_rand_pool.randrsl,
3521 sizeof(fr_rand_pool.randrsl) - total);
3522 if ((this < 0) && (errno != EINTR)) break;
3523 if (this > 0) total += this;
3527 fr_rand_pool.randrsl[0] = fd;
3528 fr_rand_pool.randrsl[1] = time(NULL);
3529 fr_rand_pool.randrsl[2] = errno;
3532 fr_randinit(&fr_rand_pool, 1);
3533 fr_rand_pool.randcnt = 0;
3534 fr_rand_initialized = 1;
3540 * Hash the user data
3543 if (!hash) hash = fr_rand();
3544 hash = fr_hash_update(data, size, hash);
3546 fr_rand_pool.randmem[fr_rand_pool.randcnt] ^= hash;
3551 * Return a 32-bit random number.
3553 uint32_t fr_rand(void)
3558 * Ensure that the pool is initialized.
3560 if (!fr_rand_initialized) {
3561 fr_rand_seed(NULL, 0);
3564 num = fr_rand_pool.randrsl[fr_rand_pool.randcnt++];
3565 if (fr_rand_pool.randcnt >= 256) {
3566 fr_rand_pool.randcnt = 0;
3567 fr_isaac(&fr_rand_pool);
3575 * Allocate a new RADIUS_PACKET
3577 RADIUS_PACKET *rad_alloc(int newvector)
3581 if ((rp = malloc(sizeof(RADIUS_PACKET))) == NULL) {
3582 fr_strerror_printf("out of memory");
3585 memset(rp, 0, sizeof(*rp));
3591 uint32_t hash, base;
3594 * Don't expose the actual contents of the random
3598 for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(uint32_t)) {
3599 hash = fr_rand() ^ base;
3600 memcpy(rp->vector + i, &hash, sizeof(hash));
3603 fr_rand(); /* stir the pool again */
3608 RADIUS_PACKET *rad_alloc_reply(RADIUS_PACKET *packet)
3610 RADIUS_PACKET *reply;
3612 if (!packet) return NULL;
3614 reply = rad_alloc(0);
3615 if (!reply) return NULL;
3618 * Initialize the fields from the request.
3620 reply->sockfd = packet->sockfd;
3621 reply->dst_ipaddr = packet->src_ipaddr;
3622 reply->src_ipaddr = packet->dst_ipaddr;
3623 reply->dst_port = packet->src_port;
3624 reply->src_port = packet->dst_port;
3625 reply->id = packet->id;
3626 reply->code = 0; /* UNKNOWN code */
3627 memcpy(reply->vector, packet->vector,
3628 sizeof(reply->vector));
3631 reply->data_len = 0;
3638 * Free a RADIUS_PACKET
3640 void rad_free(RADIUS_PACKET **radius_packet_ptr)
3642 RADIUS_PACKET *radius_packet;
3644 if (!radius_packet_ptr || !*radius_packet_ptr) return;
3645 radius_packet = *radius_packet_ptr;
3647 free(radius_packet->data);
3649 pairfree(&radius_packet->vps);
3651 free(radius_packet);
3653 *radius_packet_ptr = NULL;