2 * RADIUS message processing
3 * Copyright (c) 2002-2009, 2011-2015, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
9 #include "utils/includes.h"
11 #include "utils/common.h"
12 #include "utils/wpabuf.h"
13 #include "crypto/md5.h"
14 #include "crypto/crypto.h"
19 * struct radius_msg - RADIUS message structure for new and parsed messages
23 * buf - Allocated buffer for RADIUS message
28 * hdr - Pointer to the RADIUS header in buf
30 struct radius_hdr *hdr;
33 * attr_pos - Array of indexes to attributes
35 * The values are number of bytes from buf to the beginning of
36 * struct radius_attr_hdr.
41 * attr_size - Total size of the attribute pointer array
46 * attr_used - Total number of attributes in the array
52 struct radius_hdr * radius_msg_get_hdr(struct radius_msg *msg)
58 struct wpabuf * radius_msg_get_buf(struct radius_msg *msg)
64 static struct radius_attr_hdr *
65 radius_get_attr_hdr(struct radius_msg *msg, int idx)
67 return (struct radius_attr_hdr *)
68 (wpabuf_mhead_u8(msg->buf) + msg->attr_pos[idx]);
72 static void radius_msg_set_hdr(struct radius_msg *msg, u8 code, u8 identifier)
74 msg->hdr->code = code;
75 msg->hdr->identifier = identifier;
79 static int radius_msg_initialize(struct radius_msg *msg)
81 msg->attr_pos = os_calloc(RADIUS_DEFAULT_ATTR_COUNT,
82 sizeof(*msg->attr_pos));
83 if (msg->attr_pos == NULL)
86 msg->attr_size = RADIUS_DEFAULT_ATTR_COUNT;
94 * radius_msg_new - Create a new RADIUS message
95 * @code: Code for RADIUS header
96 * @identifier: Identifier for RADIUS header
97 * Returns: Context for RADIUS message or %NULL on failure
99 * The caller is responsible for freeing the returned data with
102 struct radius_msg * radius_msg_new(u8 code, u8 identifier)
104 struct radius_msg *msg;
106 msg = os_zalloc(sizeof(*msg));
110 msg->buf = wpabuf_alloc(RADIUS_DEFAULT_MSG_SIZE);
111 if (msg->buf == NULL || radius_msg_initialize(msg)) {
112 radius_msg_free(msg);
115 msg->hdr = wpabuf_put(msg->buf, sizeof(struct radius_hdr));
117 radius_msg_set_hdr(msg, code, identifier);
124 * radius_msg_free - Free a RADIUS message
125 * @msg: RADIUS message from radius_msg_new() or radius_msg_parse()
127 void radius_msg_free(struct radius_msg *msg)
132 wpabuf_free(msg->buf);
133 os_free(msg->attr_pos);
138 static const char *radius_code_string(u8 code)
141 case RADIUS_CODE_ACCESS_REQUEST: return "Access-Request";
142 case RADIUS_CODE_ACCESS_ACCEPT: return "Access-Accept";
143 case RADIUS_CODE_ACCESS_REJECT: return "Access-Reject";
144 case RADIUS_CODE_ACCOUNTING_REQUEST: return "Accounting-Request";
145 case RADIUS_CODE_ACCOUNTING_RESPONSE: return "Accounting-Response";
146 case RADIUS_CODE_ACCESS_CHALLENGE: return "Access-Challenge";
147 case RADIUS_CODE_STATUS_SERVER: return "Status-Server";
148 case RADIUS_CODE_STATUS_CLIENT: return "Status-Client";
149 case RADIUS_CODE_RESERVED: return "Reserved";
150 case RADIUS_CODE_DISCONNECT_REQUEST: return "Disconnect-Request";
151 case RADIUS_CODE_DISCONNECT_ACK: return "Disconnect-ACK";
152 case RADIUS_CODE_DISCONNECT_NAK: return "Disconnect-NAK";
153 case RADIUS_CODE_COA_REQUEST: return "CoA-Request";
154 case RADIUS_CODE_COA_ACK: return "CoA-ACK";
155 case RADIUS_CODE_COA_NAK: return "CoA-NAK";
156 default: return "?Unknown?";
161 struct radius_attr_type {
165 RADIUS_ATTR_UNDIST, RADIUS_ATTR_TEXT, RADIUS_ATTR_IP,
166 RADIUS_ATTR_HEXDUMP, RADIUS_ATTR_INT32, RADIUS_ATTR_IPV6
170 static const struct radius_attr_type radius_attrs[] =
172 { RADIUS_ATTR_USER_NAME, "User-Name", RADIUS_ATTR_TEXT },
173 { RADIUS_ATTR_USER_PASSWORD, "User-Password", RADIUS_ATTR_UNDIST },
174 { RADIUS_ATTR_NAS_IP_ADDRESS, "NAS-IP-Address", RADIUS_ATTR_IP },
175 { RADIUS_ATTR_NAS_PORT, "NAS-Port", RADIUS_ATTR_INT32 },
176 { RADIUS_ATTR_SERVICE_TYPE, "Service-Type", RADIUS_ATTR_INT32 },
177 { RADIUS_ATTR_FRAMED_IP_ADDRESS, "Framed-IP-Address", RADIUS_ATTR_IP },
178 { RADIUS_ATTR_FRAMED_MTU, "Framed-MTU", RADIUS_ATTR_INT32 },
179 { RADIUS_ATTR_REPLY_MESSAGE, "Reply-Message", RADIUS_ATTR_TEXT },
180 { RADIUS_ATTR_STATE, "State", RADIUS_ATTR_UNDIST },
181 { RADIUS_ATTR_CLASS, "Class", RADIUS_ATTR_UNDIST },
182 { RADIUS_ATTR_VENDOR_SPECIFIC, "Vendor-Specific", RADIUS_ATTR_UNDIST },
183 { RADIUS_ATTR_SESSION_TIMEOUT, "Session-Timeout", RADIUS_ATTR_INT32 },
184 { RADIUS_ATTR_IDLE_TIMEOUT, "Idle-Timeout", RADIUS_ATTR_INT32 },
185 { RADIUS_ATTR_TERMINATION_ACTION, "Termination-Action",
187 { RADIUS_ATTR_CALLED_STATION_ID, "Called-Station-Id",
189 { RADIUS_ATTR_CALLING_STATION_ID, "Calling-Station-Id",
191 { RADIUS_ATTR_NAS_IDENTIFIER, "NAS-Identifier", RADIUS_ATTR_TEXT },
192 { RADIUS_ATTR_PROXY_STATE, "Proxy-State", RADIUS_ATTR_UNDIST },
193 { RADIUS_ATTR_ACCT_STATUS_TYPE, "Acct-Status-Type",
195 { RADIUS_ATTR_ACCT_DELAY_TIME, "Acct-Delay-Time", RADIUS_ATTR_INT32 },
196 { RADIUS_ATTR_ACCT_INPUT_OCTETS, "Acct-Input-Octets",
198 { RADIUS_ATTR_ACCT_OUTPUT_OCTETS, "Acct-Output-Octets",
200 { RADIUS_ATTR_ACCT_SESSION_ID, "Acct-Session-Id", RADIUS_ATTR_TEXT },
201 { RADIUS_ATTR_ACCT_AUTHENTIC, "Acct-Authentic", RADIUS_ATTR_INT32 },
202 { RADIUS_ATTR_ACCT_SESSION_TIME, "Acct-Session-Time",
204 { RADIUS_ATTR_ACCT_INPUT_PACKETS, "Acct-Input-Packets",
206 { RADIUS_ATTR_ACCT_OUTPUT_PACKETS, "Acct-Output-Packets",
208 { RADIUS_ATTR_ACCT_TERMINATE_CAUSE, "Acct-Terminate-Cause",
210 { RADIUS_ATTR_ACCT_MULTI_SESSION_ID, "Acct-Multi-Session-Id",
212 { RADIUS_ATTR_ACCT_LINK_COUNT, "Acct-Link-Count", RADIUS_ATTR_INT32 },
213 { RADIUS_ATTR_ACCT_INPUT_GIGAWORDS, "Acct-Input-Gigawords",
215 { RADIUS_ATTR_ACCT_OUTPUT_GIGAWORDS, "Acct-Output-Gigawords",
217 { RADIUS_ATTR_EVENT_TIMESTAMP, "Event-Timestamp",
219 { RADIUS_ATTR_EGRESS_VLANID, "EGRESS-VLANID", RADIUS_ATTR_HEXDUMP },
220 { RADIUS_ATTR_NAS_PORT_TYPE, "NAS-Port-Type", RADIUS_ATTR_INT32 },
221 { RADIUS_ATTR_TUNNEL_TYPE, "Tunnel-Type", RADIUS_ATTR_HEXDUMP },
222 { RADIUS_ATTR_TUNNEL_MEDIUM_TYPE, "Tunnel-Medium-Type",
223 RADIUS_ATTR_HEXDUMP },
224 { RADIUS_ATTR_TUNNEL_PASSWORD, "Tunnel-Password",
225 RADIUS_ATTR_UNDIST },
226 { RADIUS_ATTR_CONNECT_INFO, "Connect-Info", RADIUS_ATTR_TEXT },
227 { RADIUS_ATTR_EAP_MESSAGE, "EAP-Message", RADIUS_ATTR_UNDIST },
228 { RADIUS_ATTR_MESSAGE_AUTHENTICATOR, "Message-Authenticator",
229 RADIUS_ATTR_UNDIST },
230 { RADIUS_ATTR_TUNNEL_PRIVATE_GROUP_ID, "Tunnel-Private-Group-Id",
231 RADIUS_ATTR_HEXDUMP },
232 { RADIUS_ATTR_ACCT_INTERIM_INTERVAL, "Acct-Interim-Interval",
234 { RADIUS_ATTR_CHARGEABLE_USER_IDENTITY, "Chargeable-User-Identity",
236 { RADIUS_ATTR_NAS_IPV6_ADDRESS, "NAS-IPv6-Address", RADIUS_ATTR_IPV6 },
237 { RADIUS_ATTR_ERROR_CAUSE, "Error-Cause", RADIUS_ATTR_INT32 },
238 { RADIUS_ATTR_EAP_KEY_NAME, "EAP-Key-Name", RADIUS_ATTR_HEXDUMP },
239 { RADIUS_ATTR_OPERATOR_NAME, "Operator-Name", RADIUS_ATTR_TEXT },
240 { RADIUS_ATTR_LOCATION_INFO, "Location-Information",
241 RADIUS_ATTR_HEXDUMP },
242 { RADIUS_ATTR_LOCATION_DATA, "Location-Data", RADIUS_ATTR_HEXDUMP },
243 { RADIUS_ATTR_BASIC_LOCATION_POLICY_RULES,
244 "Basic-Location-Policy-Rules", RADIUS_ATTR_HEXDUMP },
245 { RADIUS_ATTR_EXTENDED_LOCATION_POLICY_RULES,
246 "Extended-Location-Policy-Rules", RADIUS_ATTR_HEXDUMP },
247 { RADIUS_ATTR_LOCATION_CAPABLE, "Location-Capable", RADIUS_ATTR_INT32 },
248 { RADIUS_ATTR_REQUESTED_LOCATION_INFO, "Requested-Location-Info",
250 { RADIUS_ATTR_MOBILITY_DOMAIN_ID, "Mobility-Domain-Id",
252 { RADIUS_ATTR_WLAN_HESSID, "WLAN-HESSID", RADIUS_ATTR_TEXT },
253 { RADIUS_ATTR_WLAN_REASON_CODE, "WLAN-Reason-Code",
255 { RADIUS_ATTR_WLAN_PAIRWISE_CIPHER, "WLAN-Pairwise-Cipher",
256 RADIUS_ATTR_HEXDUMP },
257 { RADIUS_ATTR_WLAN_GROUP_CIPHER, "WLAN-Group-Cipher",
258 RADIUS_ATTR_HEXDUMP },
259 { RADIUS_ATTR_WLAN_AKM_SUITE, "WLAN-AKM-Suite",
260 RADIUS_ATTR_HEXDUMP },
261 { RADIUS_ATTR_WLAN_GROUP_MGMT_CIPHER, "WLAN-Group-Mgmt-Pairwise-Cipher",
262 RADIUS_ATTR_HEXDUMP },
264 #define RADIUS_ATTRS ARRAY_SIZE(radius_attrs)
267 static const struct radius_attr_type *radius_get_attr_type(u8 type)
271 for (i = 0; i < RADIUS_ATTRS; i++) {
272 if (type == radius_attrs[i].type)
273 return &radius_attrs[i];
280 static void radius_msg_dump_attr(struct radius_attr_hdr *hdr)
282 const struct radius_attr_type *attr;
287 attr = radius_get_attr_type(hdr->type);
289 wpa_printf(MSG_INFO, " Attribute %d (%s) length=%d",
290 hdr->type, attr ? attr->name : "?Unknown?", hdr->length);
292 if (attr == NULL || hdr->length < sizeof(struct radius_attr_hdr))
295 len = hdr->length - sizeof(struct radius_attr_hdr);
296 pos = (unsigned char *) (hdr + 1);
298 switch (attr->data_type) {
299 case RADIUS_ATTR_TEXT:
300 printf_encode(buf, sizeof(buf), pos, len);
301 wpa_printf(MSG_INFO, " Value: '%s'", buf);
307 os_memcpy(&addr, pos, 4);
308 wpa_printf(MSG_INFO, " Value: %s",
311 wpa_printf(MSG_INFO, " Invalid IP address length %d",
317 case RADIUS_ATTR_IPV6:
320 struct in6_addr *addr = (struct in6_addr *) pos;
321 atxt = inet_ntop(AF_INET6, addr, buf, sizeof(buf));
322 wpa_printf(MSG_INFO, " Value: %s",
325 wpa_printf(MSG_INFO, " Invalid IPv6 address length %d",
329 #endif /* CONFIG_IPV6 */
331 case RADIUS_ATTR_HEXDUMP:
332 case RADIUS_ATTR_UNDIST:
333 wpa_snprintf_hex(buf, sizeof(buf), pos, len);
334 wpa_printf(MSG_INFO, " Value: %s", buf);
337 case RADIUS_ATTR_INT32:
339 wpa_printf(MSG_INFO, " Value: %u",
342 wpa_printf(MSG_INFO, " Invalid INT32 length %d",
352 void radius_msg_dump(struct radius_msg *msg)
356 wpa_printf(MSG_INFO, "RADIUS message: code=%d (%s) identifier=%d length=%d",
357 msg->hdr->code, radius_code_string(msg->hdr->code),
358 msg->hdr->identifier, be_to_host16(msg->hdr->length));
360 for (i = 0; i < msg->attr_used; i++) {
361 struct radius_attr_hdr *attr = radius_get_attr_hdr(msg, i);
362 radius_msg_dump_attr(attr);
367 int radius_msg_finish(struct radius_msg *msg, const u8 *secret,
371 u8 auth[MD5_MAC_LEN];
372 struct radius_attr_hdr *attr;
374 os_memset(auth, 0, MD5_MAC_LEN);
375 attr = radius_msg_add_attr(msg,
376 RADIUS_ATTR_MESSAGE_AUTHENTICATOR,
379 wpa_printf(MSG_WARNING, "RADIUS: Could not add "
380 "Message-Authenticator");
383 msg->hdr->length = host_to_be16(wpabuf_len(msg->buf));
384 hmac_md5(secret, secret_len, wpabuf_head(msg->buf),
385 wpabuf_len(msg->buf), (u8 *) (attr + 1));
387 msg->hdr->length = host_to_be16(wpabuf_len(msg->buf));
389 if (wpabuf_len(msg->buf) > 0xffff) {
390 wpa_printf(MSG_WARNING, "RADIUS: Too long message (%lu)",
391 (unsigned long) wpabuf_len(msg->buf));
398 int radius_msg_finish_srv(struct radius_msg *msg, const u8 *secret,
399 size_t secret_len, const u8 *req_authenticator)
401 u8 auth[MD5_MAC_LEN];
402 struct radius_attr_hdr *attr;
406 os_memset(auth, 0, MD5_MAC_LEN);
407 attr = radius_msg_add_attr(msg, RADIUS_ATTR_MESSAGE_AUTHENTICATOR,
410 wpa_printf(MSG_ERROR, "WARNING: Could not add Message-Authenticator");
413 msg->hdr->length = host_to_be16(wpabuf_len(msg->buf));
414 os_memcpy(msg->hdr->authenticator, req_authenticator,
415 sizeof(msg->hdr->authenticator));
416 hmac_md5(secret, secret_len, wpabuf_head(msg->buf),
417 wpabuf_len(msg->buf), (u8 *) (attr + 1));
419 /* ResponseAuth = MD5(Code+ID+Length+RequestAuth+Attributes+Secret) */
420 addr[0] = (u8 *) msg->hdr;
422 addr[1] = req_authenticator;
423 len[1] = MD5_MAC_LEN;
424 addr[2] = wpabuf_head_u8(msg->buf) + sizeof(struct radius_hdr);
425 len[2] = wpabuf_len(msg->buf) - sizeof(struct radius_hdr);
428 md5_vector(4, addr, len, msg->hdr->authenticator);
430 if (wpabuf_len(msg->buf) > 0xffff) {
431 wpa_printf(MSG_WARNING, "RADIUS: Too long message (%lu)",
432 (unsigned long) wpabuf_len(msg->buf));
439 int radius_msg_finish_das_resp(struct radius_msg *msg, const u8 *secret,
441 const struct radius_hdr *req_hdr)
445 u8 auth[MD5_MAC_LEN];
446 struct radius_attr_hdr *attr;
448 os_memset(auth, 0, MD5_MAC_LEN);
449 attr = radius_msg_add_attr(msg, RADIUS_ATTR_MESSAGE_AUTHENTICATOR,
452 wpa_printf(MSG_WARNING, "Could not add Message-Authenticator");
456 msg->hdr->length = host_to_be16(wpabuf_len(msg->buf));
457 os_memcpy(msg->hdr->authenticator, req_hdr->authenticator, 16);
458 hmac_md5(secret, secret_len, wpabuf_head(msg->buf),
459 wpabuf_len(msg->buf), (u8 *) (attr + 1));
461 /* ResponseAuth = MD5(Code+ID+Length+RequestAuth+Attributes+Secret) */
462 addr[0] = wpabuf_head_u8(msg->buf);
463 len[0] = wpabuf_len(msg->buf);
466 if (md5_vector(2, addr, len, msg->hdr->authenticator) < 0)
469 if (wpabuf_len(msg->buf) > 0xffff) {
470 wpa_printf(MSG_WARNING, "RADIUS: Too long message (%lu)",
471 (unsigned long) wpabuf_len(msg->buf));
478 void radius_msg_finish_acct(struct radius_msg *msg, const u8 *secret,
484 msg->hdr->length = host_to_be16(wpabuf_len(msg->buf));
485 os_memset(msg->hdr->authenticator, 0, MD5_MAC_LEN);
486 addr[0] = wpabuf_head(msg->buf);
487 len[0] = wpabuf_len(msg->buf);
490 md5_vector(2, addr, len, msg->hdr->authenticator);
492 if (wpabuf_len(msg->buf) > 0xffff) {
493 wpa_printf(MSG_WARNING, "RADIUS: Too long messages (%lu)",
494 (unsigned long) wpabuf_len(msg->buf));
499 void radius_msg_finish_acct_resp(struct radius_msg *msg, const u8 *secret,
500 size_t secret_len, const u8 *req_authenticator)
505 msg->hdr->length = host_to_be16(wpabuf_len(msg->buf));
506 os_memcpy(msg->hdr->authenticator, req_authenticator, MD5_MAC_LEN);
507 addr[0] = wpabuf_head(msg->buf);
508 len[0] = wpabuf_len(msg->buf);
511 md5_vector(2, addr, len, msg->hdr->authenticator);
513 if (wpabuf_len(msg->buf) > 0xffff) {
514 wpa_printf(MSG_WARNING, "RADIUS: Too long messages (%lu)",
515 (unsigned long) wpabuf_len(msg->buf));
520 int radius_msg_verify_acct_req(struct radius_msg *msg, const u8 *secret,
525 u8 zero[MD5_MAC_LEN];
526 u8 hash[MD5_MAC_LEN];
528 os_memset(zero, 0, sizeof(zero));
529 addr[0] = (u8 *) msg->hdr;
530 len[0] = sizeof(struct radius_hdr) - MD5_MAC_LEN;
532 len[1] = MD5_MAC_LEN;
533 addr[2] = (u8 *) (msg->hdr + 1);
534 len[2] = wpabuf_len(msg->buf) - sizeof(struct radius_hdr);
537 md5_vector(4, addr, len, hash);
538 return os_memcmp_const(msg->hdr->authenticator, hash, MD5_MAC_LEN) != 0;
542 int radius_msg_verify_das_req(struct radius_msg *msg, const u8 *secret,
544 int require_message_authenticator)
548 u8 zero[MD5_MAC_LEN];
549 u8 hash[MD5_MAC_LEN];
550 u8 auth[MD5_MAC_LEN], orig[MD5_MAC_LEN];
551 u8 orig_authenticator[16];
553 struct radius_attr_hdr *attr = NULL, *tmp;
556 os_memset(zero, 0, sizeof(zero));
557 addr[0] = (u8 *) msg->hdr;
558 len[0] = sizeof(struct radius_hdr) - MD5_MAC_LEN;
560 len[1] = MD5_MAC_LEN;
561 addr[2] = (u8 *) (msg->hdr + 1);
562 len[2] = wpabuf_len(msg->buf) - sizeof(struct radius_hdr);
565 md5_vector(4, addr, len, hash);
566 if (os_memcmp_const(msg->hdr->authenticator, hash, MD5_MAC_LEN) != 0)
569 for (i = 0; i < msg->attr_used; i++) {
570 tmp = radius_get_attr_hdr(msg, i);
571 if (tmp->type == RADIUS_ATTR_MESSAGE_AUTHENTICATOR) {
573 wpa_printf(MSG_WARNING, "Multiple "
574 "Message-Authenticator attributes "
575 "in RADIUS message");
583 if (require_message_authenticator) {
584 wpa_printf(MSG_WARNING,
585 "Missing Message-Authenticator attribute in RADIUS message");
591 os_memcpy(orig, attr + 1, MD5_MAC_LEN);
592 os_memset(attr + 1, 0, MD5_MAC_LEN);
593 os_memcpy(orig_authenticator, msg->hdr->authenticator,
594 sizeof(orig_authenticator));
595 os_memset(msg->hdr->authenticator, 0,
596 sizeof(msg->hdr->authenticator));
597 hmac_md5(secret, secret_len, wpabuf_head(msg->buf),
598 wpabuf_len(msg->buf), auth);
599 os_memcpy(attr + 1, orig, MD5_MAC_LEN);
600 os_memcpy(msg->hdr->authenticator, orig_authenticator,
601 sizeof(orig_authenticator));
603 return os_memcmp_const(orig, auth, MD5_MAC_LEN) != 0;
607 static int radius_msg_add_attr_to_array(struct radius_msg *msg,
608 struct radius_attr_hdr *attr)
610 if (msg->attr_used >= msg->attr_size) {
612 int nlen = msg->attr_size * 2;
614 nattr_pos = os_realloc_array(msg->attr_pos, nlen,
615 sizeof(*msg->attr_pos));
616 if (nattr_pos == NULL)
619 msg->attr_pos = nattr_pos;
620 msg->attr_size = nlen;
623 msg->attr_pos[msg->attr_used++] =
624 (unsigned char *) attr - wpabuf_head_u8(msg->buf);
630 struct radius_attr_hdr *radius_msg_add_attr(struct radius_msg *msg, u8 type,
631 const u8 *data, size_t data_len)
634 struct radius_attr_hdr *attr;
639 if (data_len > RADIUS_MAX_ATTR_LEN) {
640 wpa_printf(MSG_ERROR, "radius_msg_add_attr: too long attribute (%lu bytes)",
641 (unsigned long) data_len);
645 buf_needed = sizeof(*attr) + data_len;
647 if (wpabuf_tailroom(msg->buf) < buf_needed) {
648 /* allocate more space for message buffer */
649 if (wpabuf_resize(&msg->buf, buf_needed) < 0)
651 msg->hdr = wpabuf_mhead(msg->buf);
654 attr = wpabuf_put(msg->buf, sizeof(struct radius_attr_hdr));
656 attr->length = sizeof(*attr) + data_len;
657 wpabuf_put_data(msg->buf, data, data_len);
659 if (radius_msg_add_attr_to_array(msg, attr))
667 * radius_msg_parse - Parse a RADIUS message
668 * @data: RADIUS message to be parsed
669 * @len: Length of data buffer in octets
670 * Returns: Parsed RADIUS message or %NULL on failure
672 * This parses a RADIUS message and makes a copy of its data. The caller is
673 * responsible for freeing the returned data with radius_msg_free().
675 struct radius_msg * radius_msg_parse(const u8 *data, size_t len)
677 struct radius_msg *msg;
678 struct radius_hdr *hdr;
679 struct radius_attr_hdr *attr;
681 unsigned char *pos, *end;
683 if (data == NULL || len < sizeof(*hdr))
686 hdr = (struct radius_hdr *) data;
688 msg_len = be_to_host16(hdr->length);
689 if (msg_len < sizeof(*hdr) || msg_len > len) {
690 wpa_printf(MSG_INFO, "RADIUS: Invalid message length");
695 wpa_printf(MSG_DEBUG, "RADIUS: Ignored %lu extra bytes after "
696 "RADIUS message", (unsigned long) len - msg_len);
699 msg = os_zalloc(sizeof(*msg));
703 msg->buf = wpabuf_alloc_copy(data, msg_len);
704 if (msg->buf == NULL || radius_msg_initialize(msg)) {
705 radius_msg_free(msg);
708 msg->hdr = wpabuf_mhead(msg->buf);
710 /* parse attributes */
711 pos = wpabuf_mhead_u8(msg->buf) + sizeof(struct radius_hdr);
712 end = wpabuf_mhead_u8(msg->buf) + wpabuf_len(msg->buf);
714 if ((size_t) (end - pos) < sizeof(*attr))
717 attr = (struct radius_attr_hdr *) pos;
719 if (attr->length > end - pos || attr->length < sizeof(*attr))
722 /* TODO: check that attr->length is suitable for attr->type */
724 if (radius_msg_add_attr_to_array(msg, attr))
733 radius_msg_free(msg);
738 int radius_msg_add_eap(struct radius_msg *msg, const u8 *data, size_t data_len)
740 const u8 *pos = data;
741 size_t left = data_len;
745 if (left > RADIUS_MAX_ATTR_LEN)
746 len = RADIUS_MAX_ATTR_LEN;
750 if (!radius_msg_add_attr(msg, RADIUS_ATTR_EAP_MESSAGE,
762 struct wpabuf * radius_msg_get_eap(struct radius_msg *msg)
766 struct radius_attr_hdr *attr;
772 for (i = 0; i < msg->attr_used; i++) {
773 attr = radius_get_attr_hdr(msg, i);
774 if (attr->type == RADIUS_ATTR_EAP_MESSAGE &&
775 attr->length > sizeof(struct radius_attr_hdr))
776 len += attr->length - sizeof(struct radius_attr_hdr);
782 eap = wpabuf_alloc(len);
786 for (i = 0; i < msg->attr_used; i++) {
787 attr = radius_get_attr_hdr(msg, i);
788 if (attr->type == RADIUS_ATTR_EAP_MESSAGE &&
789 attr->length > sizeof(struct radius_attr_hdr)) {
790 int flen = attr->length - sizeof(*attr);
791 wpabuf_put_data(eap, attr + 1, flen);
799 int radius_msg_verify_msg_auth(struct radius_msg *msg, const u8 *secret,
800 size_t secret_len, const u8 *req_auth)
802 u8 auth[MD5_MAC_LEN], orig[MD5_MAC_LEN];
803 u8 orig_authenticator[16];
804 struct radius_attr_hdr *attr = NULL, *tmp;
807 for (i = 0; i < msg->attr_used; i++) {
808 tmp = radius_get_attr_hdr(msg, i);
809 if (tmp->type == RADIUS_ATTR_MESSAGE_AUTHENTICATOR) {
811 wpa_printf(MSG_INFO, "Multiple Message-Authenticator attributes in RADIUS message");
819 wpa_printf(MSG_INFO, "No Message-Authenticator attribute found");
823 os_memcpy(orig, attr + 1, MD5_MAC_LEN);
824 os_memset(attr + 1, 0, MD5_MAC_LEN);
826 os_memcpy(orig_authenticator, msg->hdr->authenticator,
827 sizeof(orig_authenticator));
828 os_memcpy(msg->hdr->authenticator, req_auth,
829 sizeof(msg->hdr->authenticator));
831 if (hmac_md5(secret, secret_len, wpabuf_head(msg->buf),
832 wpabuf_len(msg->buf), auth) < 0)
834 os_memcpy(attr + 1, orig, MD5_MAC_LEN);
836 os_memcpy(msg->hdr->authenticator, orig_authenticator,
837 sizeof(orig_authenticator));
840 if (os_memcmp_const(orig, auth, MD5_MAC_LEN) != 0) {
841 wpa_printf(MSG_INFO, "Invalid Message-Authenticator!");
849 int radius_msg_verify(struct radius_msg *msg, const u8 *secret,
850 size_t secret_len, struct radius_msg *sent_msg, int auth)
854 u8 hash[MD5_MAC_LEN];
856 if (sent_msg == NULL) {
857 wpa_printf(MSG_INFO, "No matching Access-Request message found");
862 radius_msg_verify_msg_auth(msg, secret, secret_len,
863 sent_msg->hdr->authenticator)) {
867 /* ResponseAuth = MD5(Code+ID+Length+RequestAuth+Attributes+Secret) */
868 addr[0] = (u8 *) msg->hdr;
870 addr[1] = sent_msg->hdr->authenticator;
871 len[1] = MD5_MAC_LEN;
872 addr[2] = wpabuf_head_u8(msg->buf) + sizeof(struct radius_hdr);
873 len[2] = wpabuf_len(msg->buf) - sizeof(struct radius_hdr);
876 if (md5_vector(4, addr, len, hash) < 0 ||
877 os_memcmp_const(hash, msg->hdr->authenticator, MD5_MAC_LEN) != 0) {
878 wpa_printf(MSG_INFO, "Response Authenticator invalid!");
886 int radius_msg_copy_attr(struct radius_msg *dst, struct radius_msg *src,
889 struct radius_attr_hdr *attr;
893 for (i = 0; i < src->attr_used; i++) {
894 attr = radius_get_attr_hdr(src, i);
895 if (attr->type == type && attr->length >= sizeof(*attr)) {
896 if (!radius_msg_add_attr(dst, type, (u8 *) (attr + 1),
897 attr->length - sizeof(*attr)))
907 /* Create Request Authenticator. The value should be unique over the lifetime
908 * of the shared secret between authenticator and authentication server.
910 int radius_msg_make_authenticator(struct radius_msg *msg)
912 return os_get_random((u8 *) &msg->hdr->authenticator,
913 sizeof(msg->hdr->authenticator));
917 /* Get Vendor-specific RADIUS Attribute from a parsed RADIUS message.
918 * Returns the Attribute payload and sets alen to indicate the length of the
919 * payload if a vendor attribute with subtype is found, otherwise returns NULL.
920 * The returned payload is allocated with os_malloc() and caller must free it
921 * by calling os_free().
923 static u8 *radius_msg_get_vendor_attr(struct radius_msg *msg, u32 vendor,
924 u8 subtype, size_t *alen)
932 for (i = 0; i < msg->attr_used; i++) {
933 struct radius_attr_hdr *attr = radius_get_attr_hdr(msg, i);
936 struct radius_attr_vendor *vhdr;
938 if (attr->type != RADIUS_ATTR_VENDOR_SPECIFIC ||
939 attr->length < sizeof(*attr))
942 left = attr->length - sizeof(*attr);
946 pos = (u8 *) (attr + 1);
948 os_memcpy(&vendor_id, pos, 4);
952 if (ntohl(vendor_id) != vendor)
955 while (left >= sizeof(*vhdr)) {
956 vhdr = (struct radius_attr_vendor *) pos;
957 if (vhdr->vendor_length > left ||
958 vhdr->vendor_length < sizeof(*vhdr)) {
961 if (vhdr->vendor_type != subtype) {
962 pos += vhdr->vendor_length;
963 left -= vhdr->vendor_length;
967 len = vhdr->vendor_length - sizeof(*vhdr);
968 data = os_memdup(pos + sizeof(*vhdr), len);
981 static u8 * decrypt_ms_key(const u8 *key, size_t len,
982 const u8 *req_authenticator,
983 const u8 *secret, size_t secret_len, size_t *reslen)
985 u8 *plain, *ppos, *res;
988 u8 hash[MD5_MAC_LEN];
993 /* key: 16-bit salt followed by encrypted key info */
996 wpa_printf(MSG_DEBUG, "RADIUS: %s: Len is too small: %d",
997 __func__, (int) len);
1004 wpa_printf(MSG_INFO, "RADIUS: Invalid ms key len %lu",
1005 (unsigned long) left);
1010 ppos = plain = os_malloc(plen);
1016 /* b(1) = MD5(Secret + Request-Authenticator + Salt)
1017 * b(i) = MD5(Secret + c(i - 1)) for i > 1 */
1020 elen[0] = secret_len;
1022 addr[1] = req_authenticator;
1023 elen[1] = MD5_MAC_LEN;
1025 elen[2] = 2; /* Salt */
1027 addr[1] = pos - MD5_MAC_LEN;
1028 elen[1] = MD5_MAC_LEN;
1030 if (md5_vector(first ? 3 : 2, addr, elen, hash) < 0) {
1036 for (i = 0; i < MD5_MAC_LEN; i++)
1037 *ppos++ = *pos++ ^ hash[i];
1038 left -= MD5_MAC_LEN;
1041 if (plain[0] == 0 || plain[0] > plen - 1) {
1042 wpa_printf(MSG_INFO, "RADIUS: Failed to decrypt MPPE key");
1047 res = os_memdup(plain + 1, plain[0]);
1059 static void encrypt_ms_key(const u8 *key, size_t key_len, u16 salt,
1060 const u8 *req_authenticator,
1061 const u8 *secret, size_t secret_len,
1062 u8 *ebuf, size_t *elen)
1064 int i, len, first = 1;
1065 u8 hash[MD5_MAC_LEN], saltbuf[2], *pos;
1069 WPA_PUT_BE16(saltbuf, salt);
1073 len = (len & 0xf0) + 16;
1075 os_memset(ebuf, 0, len);
1077 os_memcpy(ebuf + 1, key, key_len);
1083 /* b(1) = MD5(Secret + Request-Authenticator + Salt)
1084 * b(i) = MD5(Secret + c(i - 1)) for i > 1 */
1086 _len[0] = secret_len;
1088 addr[1] = req_authenticator;
1089 _len[1] = MD5_MAC_LEN;
1091 _len[2] = sizeof(saltbuf);
1093 addr[1] = pos - MD5_MAC_LEN;
1094 _len[1] = MD5_MAC_LEN;
1096 md5_vector(first ? 3 : 2, addr, _len, hash);
1099 for (i = 0; i < MD5_MAC_LEN; i++)
1107 struct radius_ms_mppe_keys *
1108 radius_msg_get_ms_keys(struct radius_msg *msg, struct radius_msg *sent_msg,
1109 const u8 *secret, size_t secret_len)
1113 struct radius_ms_mppe_keys *keys;
1115 if (msg == NULL || sent_msg == NULL)
1118 keys = os_zalloc(sizeof(*keys));
1122 key = radius_msg_get_vendor_attr(msg, RADIUS_VENDOR_ID_MICROSOFT,
1123 RADIUS_VENDOR_ATTR_MS_MPPE_SEND_KEY,
1126 keys->send = decrypt_ms_key(key, keylen,
1127 sent_msg->hdr->authenticator,
1131 wpa_printf(MSG_DEBUG,
1132 "RADIUS: Failed to decrypt send key");
1137 key = radius_msg_get_vendor_attr(msg, RADIUS_VENDOR_ID_MICROSOFT,
1138 RADIUS_VENDOR_ATTR_MS_MPPE_RECV_KEY,
1141 keys->recv = decrypt_ms_key(key, keylen,
1142 sent_msg->hdr->authenticator,
1146 wpa_printf(MSG_DEBUG,
1147 "RADIUS: Failed to decrypt recv key");
1156 struct radius_ms_mppe_keys *
1157 radius_msg_get_cisco_keys(struct radius_msg *msg, struct radius_msg *sent_msg,
1158 const u8 *secret, size_t secret_len)
1162 struct radius_ms_mppe_keys *keys;
1164 if (msg == NULL || sent_msg == NULL)
1167 keys = os_zalloc(sizeof(*keys));
1171 key = radius_msg_get_vendor_attr(msg, RADIUS_VENDOR_ID_CISCO,
1172 RADIUS_CISCO_AV_PAIR, &keylen);
1173 if (key && keylen == 51 &&
1174 os_memcmp(key, "leap:session-key=", 17) == 0) {
1175 keys->recv = decrypt_ms_key(key + 17, keylen - 17,
1176 sent_msg->hdr->authenticator,
1186 int radius_msg_add_mppe_keys(struct radius_msg *msg,
1187 const u8 *req_authenticator,
1188 const u8 *secret, size_t secret_len,
1189 const u8 *send_key, size_t send_key_len,
1190 const u8 *recv_key, size_t recv_key_len)
1192 struct radius_attr_hdr *attr;
1193 u32 vendor_id = htonl(RADIUS_VENDOR_ID_MICROSOFT);
1195 struct radius_attr_vendor *vhdr;
1201 hlen = sizeof(vendor_id) + sizeof(*vhdr) + 2;
1203 /* MS-MPPE-Send-Key */
1204 buf = os_malloc(hlen + send_key_len + 16);
1209 os_memcpy(pos, &vendor_id, sizeof(vendor_id));
1210 pos += sizeof(vendor_id);
1211 vhdr = (struct radius_attr_vendor *) pos;
1212 vhdr->vendor_type = RADIUS_VENDOR_ATTR_MS_MPPE_SEND_KEY;
1213 pos = (u8 *) (vhdr + 1);
1214 if (os_get_random((u8 *) &salt, sizeof(salt)) < 0) {
1219 WPA_PUT_BE16(pos, salt);
1221 encrypt_ms_key(send_key, send_key_len, salt, req_authenticator, secret,
1222 secret_len, pos, &elen);
1223 vhdr->vendor_length = hlen + elen - sizeof(vendor_id);
1225 attr = radius_msg_add_attr(msg, RADIUS_ATTR_VENDOR_SPECIFIC,
1232 /* MS-MPPE-Recv-Key */
1233 buf = os_malloc(hlen + recv_key_len + 16);
1238 os_memcpy(pos, &vendor_id, sizeof(vendor_id));
1239 pos += sizeof(vendor_id);
1240 vhdr = (struct radius_attr_vendor *) pos;
1241 vhdr->vendor_type = RADIUS_VENDOR_ATTR_MS_MPPE_RECV_KEY;
1242 pos = (u8 *) (vhdr + 1);
1244 WPA_PUT_BE16(pos, salt);
1246 encrypt_ms_key(recv_key, recv_key_len, salt, req_authenticator, secret,
1247 secret_len, pos, &elen);
1248 vhdr->vendor_length = hlen + elen - sizeof(vendor_id);
1250 attr = radius_msg_add_attr(msg, RADIUS_ATTR_VENDOR_SPECIFIC,
1261 int radius_msg_add_wfa(struct radius_msg *msg, u8 subtype, const u8 *data,
1264 struct radius_attr_hdr *attr;
1269 buf = os_malloc(alen);
1273 WPA_PUT_BE32(pos, RADIUS_VENDOR_ID_WFA);
1277 os_memcpy(pos, data, len);
1278 attr = radius_msg_add_attr(msg, RADIUS_ATTR_VENDOR_SPECIFIC,
1288 int radius_user_password_hide(struct radius_msg *msg,
1289 const u8 *data, size_t data_len,
1290 const u8 *secret, size_t secret_len,
1291 u8 *buf, size_t buf_len)
1293 size_t padlen, i, pos;
1298 if (data_len + 16 > buf_len)
1301 os_memcpy(buf, data, data_len);
1303 padlen = data_len % 16;
1304 if (padlen && data_len < buf_len) {
1305 padlen = 16 - padlen;
1306 os_memset(buf + data_len, 0, padlen);
1307 buf_len = data_len + padlen;
1313 len[0] = secret_len;
1314 addr[1] = msg->hdr->authenticator;
1316 md5_vector(2, addr, len, hash);
1318 for (i = 0; i < 16; i++)
1322 while (pos < buf_len) {
1324 len[0] = secret_len;
1325 addr[1] = &buf[pos - 16];
1327 md5_vector(2, addr, len, hash);
1329 for (i = 0; i < 16; i++)
1330 buf[pos + i] ^= hash[i];
1339 /* Add User-Password attribute to a RADIUS message and encrypt it as specified
1340 * in RFC 2865, Chap. 5.2 */
1341 struct radius_attr_hdr *
1342 radius_msg_add_attr_user_password(struct radius_msg *msg,
1343 const u8 *data, size_t data_len,
1344 const u8 *secret, size_t secret_len)
1349 res = radius_user_password_hide(msg, data, data_len,
1350 secret, secret_len, buf, sizeof(buf));
1354 return radius_msg_add_attr(msg, RADIUS_ATTR_USER_PASSWORD,
1359 int radius_msg_get_attr(struct radius_msg *msg, u8 type, u8 *buf, size_t len)
1361 struct radius_attr_hdr *attr = NULL, *tmp;
1364 for (i = 0; i < msg->attr_used; i++) {
1365 tmp = radius_get_attr_hdr(msg, i);
1366 if (tmp->type == type) {
1372 if (!attr || attr->length < sizeof(*attr))
1375 dlen = attr->length - sizeof(*attr);
1377 os_memcpy(buf, (attr + 1), dlen > len ? len : dlen);
1382 int radius_msg_get_attr_ptr(struct radius_msg *msg, u8 type, u8 **buf,
1383 size_t *len, const u8 *start)
1386 struct radius_attr_hdr *attr = NULL, *tmp;
1388 for (i = 0; i < msg->attr_used; i++) {
1389 tmp = radius_get_attr_hdr(msg, i);
1390 if (tmp->type == type &&
1391 (start == NULL || (u8 *) tmp > start)) {
1397 if (!attr || attr->length < sizeof(*attr))
1400 *buf = (u8 *) (attr + 1);
1401 *len = attr->length - sizeof(*attr);
1406 int radius_msg_count_attr(struct radius_msg *msg, u8 type, int min_len)
1411 for (count = 0, i = 0; i < msg->attr_used; i++) {
1412 struct radius_attr_hdr *attr = radius_get_attr_hdr(msg, i);
1413 if (attr->type == type &&
1414 attr->length >= sizeof(struct radius_attr_hdr) + min_len)
1422 struct radius_tunnel_attrs {
1424 int type; /* Tunnel-Type */
1425 int medium_type; /* Tunnel-Medium-Type */
1430 static int cmp_int(const void *a, const void *b)
1441 * radius_msg_get_vlanid - Parse RADIUS attributes for VLAN tunnel information
1442 * The k tagged vlans found are sorted by vlan_id and stored in the first k
1445 * @msg: RADIUS message
1446 * @untagged: Pointer to store untagged vid
1447 * @numtagged: Size of tagged
1448 * @tagged: Pointer to store tagged list
1450 * Returns: 0 if neither tagged nor untagged configuration is found, 1 otherwise
1452 int radius_msg_get_vlanid(struct radius_msg *msg, int *untagged, int numtagged,
1455 struct radius_tunnel_attrs tunnel[RADIUS_TUNNEL_TAGS], *tun;
1457 struct radius_attr_hdr *attr = NULL;
1461 int j, taggedidx = 0, vlan_id;
1463 os_memset(&tunnel, 0, sizeof(tunnel));
1464 for (j = 0; j < numtagged; j++)
1468 for (i = 0; i < msg->attr_used; i++) {
1469 attr = radius_get_attr_hdr(msg, i);
1470 if (attr->length < sizeof(*attr))
1472 data = (const u8 *) (attr + 1);
1473 dlen = attr->length - sizeof(*attr);
1474 if (attr->length < 3)
1476 if (data[0] >= RADIUS_TUNNEL_TAGS)
1479 tun = &tunnel[data[0]];
1481 switch (attr->type) {
1482 case RADIUS_ATTR_TUNNEL_TYPE:
1483 if (attr->length != 6)
1486 tun->type = WPA_GET_BE24(data + 1);
1488 case RADIUS_ATTR_TUNNEL_MEDIUM_TYPE:
1489 if (attr->length != 6)
1492 tun->medium_type = WPA_GET_BE24(data + 1);
1494 case RADIUS_ATTR_TUNNEL_PRIVATE_GROUP_ID:
1495 if (data[0] < RADIUS_TUNNEL_TAGS) {
1499 if (dlen >= sizeof(buf))
1501 os_memcpy(buf, data, dlen);
1503 vlan_id = atoi(buf);
1507 tun->vlanid = vlan_id;
1509 case RADIUS_ATTR_EGRESS_VLANID: /* RFC 4675 */
1510 if (attr->length != 6)
1512 vlan_id = WPA_GET_BE24(data + 1);
1515 if (data[0] == 0x32)
1516 *untagged = vlan_id;
1517 else if (data[0] == 0x31 && tagged &&
1518 taggedidx < numtagged)
1519 tagged[taggedidx++] = vlan_id;
1524 /* Use tunnel with the lowest tag for untagged VLAN id */
1525 for (i = 0; i < RADIUS_TUNNEL_TAGS; i++) {
1527 if (tun->tag_used &&
1528 tun->type == RADIUS_TUNNEL_TYPE_VLAN &&
1529 tun->medium_type == RADIUS_TUNNEL_MEDIUM_TYPE_802 &&
1531 *untagged = tun->vlanid;
1537 qsort(tagged, taggedidx, sizeof(int), cmp_int);
1539 if (*untagged > 0 || taggedidx)
1546 * radius_msg_get_tunnel_password - Parse RADIUS attribute Tunnel-Password
1547 * @msg: Received RADIUS message
1548 * @keylen: Length of returned password
1549 * @secret: RADIUS shared secret
1550 * @secret_len: Length of secret
1551 * @sent_msg: Sent RADIUS message
1552 * @n: Number of password attribute to return (starting with 0)
1553 * Returns: Pointer to n-th password (free with os_free) or %NULL
1555 char * radius_msg_get_tunnel_password(struct radius_msg *msg, int *keylen,
1556 const u8 *secret, size_t secret_len,
1557 struct radius_msg *sent_msg, size_t n)
1568 struct radius_attr_hdr *attr;
1571 const u8 *fdata = NULL; /* points to found item */
1575 /* find n-th valid Tunnel-Password attribute */
1576 for (i = 0; i < msg->attr_used; i++) {
1577 attr = radius_get_attr_hdr(msg, i);
1579 attr->type != RADIUS_ATTR_TUNNEL_PASSWORD) {
1582 if (attr->length <= 5)
1584 data = (const u8 *) (attr + 1);
1585 dlen = attr->length - sizeof(*attr);
1586 if (dlen <= 3 || dlen % 16 != 3)
1599 /* alloc writable memory for decryption */
1600 buf = os_memdup(fdata, fdlen);
1609 /* decrypt blocks */
1610 pos = buf + buflen - 16; /* last block */
1611 while (pos >= str + 16) { /* all but the first block */
1613 len[0] = secret_len;
1616 md5_vector(2, addr, len, hash);
1618 for (i = 0; i < 16; i++)
1624 /* decrypt first block */
1628 len[0] = secret_len;
1629 addr[1] = sent_msg->hdr->authenticator;
1633 md5_vector(3, addr, len, hash);
1635 for (i = 0; i < 16; i++)
1638 /* derive plaintext length from first subfield */
1639 *keylen = (unsigned char) str[0];
1640 if ((u8 *) (str + *keylen) >= (u8 *) (buf + buflen)) {
1641 /* decryption error - invalid key length */
1645 /* empty password */
1649 /* copy passphrase into new buffer */
1650 ret = os_malloc(*keylen);
1652 os_memcpy(ret, str + 1, *keylen);
1655 /* return new buffer */
1661 void radius_free_class(struct radius_class_data *c)
1666 for (i = 0; i < c->count; i++)
1667 os_free(c->attr[i].data);
1674 int radius_copy_class(struct radius_class_data *dst,
1675 const struct radius_class_data *src)
1679 if (src->attr == NULL)
1682 dst->attr = os_calloc(src->count, sizeof(struct radius_attr_data));
1683 if (dst->attr == NULL)
1688 for (i = 0; i < src->count; i++) {
1689 dst->attr[i].data = os_memdup(src->attr[i].data,
1691 if (dst->attr[i].data == NULL)
1694 dst->attr[i].len = src->attr[i].len;
1701 u8 radius_msg_find_unlisted_attr(struct radius_msg *msg, u8 *attrs)
1704 struct radius_attr_hdr *attr;
1706 for (i = 0; i < msg->attr_used; i++) {
1707 attr = radius_get_attr_hdr(msg, i);
1709 for (j = 0; attrs[j]; j++) {
1710 if (attr->type == attrs[j])
1715 return attr->type; /* unlisted attr */
1722 int radius_gen_session_id(u8 *id, size_t len)
1725 * Acct-Session-Id and Acct-Multi-Session-Id should be globally and
1726 * temporarily unique. A high quality random number is required
1727 * therefore. This could be be improved by switching to a GUID.
1729 return os_get_random(id, len);