2 Unix SMB/CIFS implementation.
3 krb5 set password implementation
4 Copyright (C) Andrew Tridgell 2001
5 Copyright (C) Remus Koos 2001 (remuskoos@yahoo.com)
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
25 #define DEFAULT_KPASSWD_PORT 464
27 #define KRB5_KPASSWD_VERS_CHANGEPW 1
29 #define KRB5_KPASSWD_VERS_SETPW 0xff80
30 #define KRB5_KPASSWD_VERS_SETPW_ALT 2
32 #define KRB5_KPASSWD_SUCCESS 0
33 #define KRB5_KPASSWD_MALFORMED 1
34 #define KRB5_KPASSWD_HARDERROR 2
35 #define KRB5_KPASSWD_AUTHERROR 3
36 #define KRB5_KPASSWD_SOFTERROR 4
37 #define KRB5_KPASSWD_ACCESSDENIED 5
38 #define KRB5_KPASSWD_BAD_VERSION 6
39 #define KRB5_KPASSWD_INITIAL_FLAG_NEEDED 7
41 /* Those are defined by kerberos-set-passwd-02.txt and are probably
42 * not supported by M$ implementation */
43 #define KRB5_KPASSWD_POLICY_REJECT 8
44 #define KRB5_KPASSWD_BAD_PRINCIPAL 9
45 #define KRB5_KPASSWD_ETYPE_NOSUPP 10
48 * we've got to be able to distinguish KRB_ERRORs from other
49 * requests - valid response for CHPW v2 replies.
52 #define krb5_is_krb_error(packet) \
53 ( packet && packet->length && (((char *)packet->data)[0] == 0x7e || ((char *)packet->data)[0] == 0x5e))
55 /* This implements kerberos password change protocol as specified in
56 * kerb-chg-password-02.txt and kerberos-set-passwd-02.txt
57 * as well as microsoft version of the protocol
58 * as specified in kerberos-set-passwd-00.txt
60 static DATA_BLOB encode_krb5_setpw(const char *principal, const char *password)
62 char* princ_part1 = NULL;
63 char* princ_part2 = NULL;
72 princ = SMB_STRDUP(principal);
74 if ((c = strchr_m(princ, '/')) == NULL) {
84 if ((c = strchr_m(c, '@')) != NULL) {
89 /* We must have a realm component. */
90 return data_blob_null;
93 memset(&req, 0, sizeof(req));
95 asn1_push_tag(&req, ASN1_SEQUENCE(0));
96 asn1_push_tag(&req, ASN1_CONTEXT(0));
97 asn1_write_OctetString(&req, password, strlen(password));
100 asn1_push_tag(&req, ASN1_CONTEXT(1));
101 asn1_push_tag(&req, ASN1_SEQUENCE(0));
103 asn1_push_tag(&req, ASN1_CONTEXT(0));
104 asn1_write_Integer(&req, 1);
107 asn1_push_tag(&req, ASN1_CONTEXT(1));
108 asn1_push_tag(&req, ASN1_SEQUENCE(0));
111 asn1_write_GeneralString(&req, princ_part1);
114 asn1_write_GeneralString(&req, princ_part2);
120 asn1_push_tag(&req, ASN1_CONTEXT(2));
121 asn1_write_GeneralString(&req, realm);
125 ret = data_blob(req.data, req.length);
133 static krb5_error_code build_kpasswd_request(uint16 pversion,
134 krb5_context context,
135 krb5_auth_context auth_context,
144 krb5_data encoded_setpw;
145 krb5_replay_data replay;
148 unsigned int msg_length;
150 ret = krb5_auth_con_setflags(context,
151 auth_context,KRB5_AUTH_CONTEXT_DO_SEQUENCE);
153 DEBUG(1,("krb5_auth_con_setflags failed (%s)\n",
154 error_message(ret)));
158 /* handle protocol differences in chpw and setpw */
159 if (pversion == KRB5_KPASSWD_VERS_CHANGEPW)
160 setpw = data_blob(passwd, strlen(passwd));
161 else if (pversion == KRB5_KPASSWD_VERS_SETPW ||
162 pversion == KRB5_KPASSWD_VERS_SETPW_ALT)
163 setpw = encode_krb5_setpw(princ, passwd);
167 if (setpw.data == NULL || setpw.length == 0) {
171 encoded_setpw.data = (char *)setpw.data;
172 encoded_setpw.length = setpw.length;
174 ret = krb5_mk_priv(context, auth_context,
175 &encoded_setpw, &cipherpw, &replay);
177 data_blob_free(&setpw); /*from 'encode_krb5_setpw(...)' */
180 DEBUG(1,("krb5_mk_priv failed (%s)\n", error_message(ret)));
184 packet->data = (char *)SMB_MALLOC(ap_req->length + cipherpw.length + (use_tcp ? 10 : 6 ));
190 /* see the RFC for details */
192 msg_start = p = ((char *)packet->data) + (use_tcp ? 4 : 0);
194 RSSVAL(p, 0, pversion);
196 RSSVAL(p, 0, ap_req->length);
198 memcpy(p, ap_req->data, ap_req->length);
200 memcpy(p, cipherpw.data, cipherpw.length);
201 p += cipherpw.length;
202 packet->length = PTR_DIFF(p,packet->data);
203 msg_length = PTR_DIFF(p,msg_start);
206 RSIVAL(packet->data, 0, msg_length);
208 RSSVAL(msg_start, 0, msg_length);
210 free(cipherpw.data); /* from 'krb5_mk_priv(...)' */
215 static const struct kpasswd_errors {
217 const char *error_string;
218 } kpasswd_errors[] = {
219 {KRB5_KPASSWD_MALFORMED, "Malformed request error"},
220 {KRB5_KPASSWD_HARDERROR, "Server error"},
221 {KRB5_KPASSWD_AUTHERROR, "Authentication error"},
222 {KRB5_KPASSWD_SOFTERROR, "Password change rejected"},
223 {KRB5_KPASSWD_ACCESSDENIED, "Client does not have proper authorization"},
224 {KRB5_KPASSWD_BAD_VERSION, "Protocol version not supported"},
225 {KRB5_KPASSWD_INITIAL_FLAG_NEEDED, "Authorization ticket must have initial flag set"},
226 {KRB5_KPASSWD_POLICY_REJECT, "Password rejected due to policy requirements"},
227 {KRB5_KPASSWD_BAD_PRINCIPAL, "Target principal does not exist"},
228 {KRB5_KPASSWD_ETYPE_NOSUPP, "Unsupported encryption type"},
232 static krb5_error_code setpw_result_code_string(krb5_context context,
234 const char **code_string)
236 unsigned int idx = 0;
238 while (kpasswd_errors[idx].error_string != NULL) {
239 if (kpasswd_errors[idx].result_code ==
241 *code_string = kpasswd_errors[idx].error_string;
246 *code_string = "Password change failed";
250 krb5_error_code kpasswd_err_to_krb5_err(krb5_error_code res_code)
253 case KRB5_KPASSWD_ACCESSDENIED:
254 return KRB5KDC_ERR_BADOPTION;
255 case KRB5_KPASSWD_INITIAL_FLAG_NEEDED:
256 return KRB5KDC_ERR_BADOPTION;
257 /* return KV5M_ALT_METHOD; MIT-only define */
258 case KRB5_KPASSWD_ETYPE_NOSUPP:
259 return KRB5KDC_ERR_ETYPE_NOSUPP;
260 case KRB5_KPASSWD_BAD_PRINCIPAL:
261 return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
262 case KRB5_KPASSWD_POLICY_REJECT:
263 case KRB5_KPASSWD_SOFTERROR:
264 return KRB5KDC_ERR_POLICY;
266 return KRB5KRB_ERR_GENERIC;
269 static krb5_error_code parse_setpw_reply(krb5_context context,
271 krb5_auth_context auth_context,
276 int vnum, ret, res_code;
277 krb5_data cipherresult;
278 krb5_data clearresult;
279 krb5_ap_rep_enc_part *ap_rep_enc;
280 krb5_replay_data replay;
281 unsigned int msg_length = packet->length;
284 if (packet->length < (use_tcp ? 8 : 4)) {
285 return KRB5KRB_AP_ERR_MODIFIED;
290 ** see if it is an error
292 if (krb5_is_krb_error(packet)) {
294 ret = handle_krberror_packet(context, packet);
304 if (RIVAL(p, 0) != msg_length) {
305 DEBUG(1,("Bad TCP packet length (%d/%d) from kpasswd server\n",
306 RIVAL(p, 0), msg_length));
307 return KRB5KRB_AP_ERR_MODIFIED;
313 if (RSVAL(p, 0) != msg_length) {
314 DEBUG(1,("Bad packet length (%d/%d) from kpasswd server\n",
315 RSVAL(p, 0), msg_length));
316 return KRB5KRB_AP_ERR_MODIFIED;
321 vnum = RSVAL(p, 0); p += 2;
323 /* FIXME: According to standard there is only one type of reply */
324 if (vnum != KRB5_KPASSWD_VERS_SETPW &&
325 vnum != KRB5_KPASSWD_VERS_SETPW_ALT &&
326 vnum != KRB5_KPASSWD_VERS_CHANGEPW) {
327 DEBUG(1,("Bad vnum (%d) from kpasswd server\n", vnum));
328 return KRB5KDC_ERR_BAD_PVNO;
331 ap_rep.length = RSVAL(p, 0); p += 2;
333 if (p + ap_rep.length >= (char *)packet->data + packet->length) {
334 DEBUG(1,("ptr beyond end of packet from kpasswd server\n"));
335 return KRB5KRB_AP_ERR_MODIFIED;
338 if (ap_rep.length == 0) {
339 DEBUG(1,("got unencrypted setpw result?!\n"));
340 return KRB5KRB_AP_ERR_MODIFIED;
347 ret = krb5_rd_rep(context, auth_context, &ap_rep, &ap_rep_enc);
349 DEBUG(1,("failed to rd setpw reply (%s)\n", error_message(ret)));
350 return KRB5KRB_AP_ERR_MODIFIED;
353 krb5_free_ap_rep_enc_part(context, ap_rep_enc);
355 cipherresult.data = p;
356 cipherresult.length = ((char *)packet->data + packet->length) - p;
358 ret = krb5_rd_priv(context, auth_context, &cipherresult, &clearresult,
361 DEBUG(1,("failed to decrypt setpw reply (%s)\n", error_message(ret)));
362 return KRB5KRB_AP_ERR_MODIFIED;
365 if (clearresult.length < 2) {
366 free(clearresult.data);
367 ret = KRB5KRB_AP_ERR_MODIFIED;
368 return KRB5KRB_AP_ERR_MODIFIED;
371 p = clearresult.data;
373 res_code = RSVAL(p, 0);
375 free(clearresult.data);
377 if ((res_code < KRB5_KPASSWD_SUCCESS) ||
378 (res_code > KRB5_KPASSWD_ETYPE_NOSUPP)) {
379 return KRB5KRB_AP_ERR_MODIFIED;
382 if (res_code == KRB5_KPASSWD_SUCCESS) {
386 setpw_result_code_string(context, res_code, &errstr);
387 DEBUG(1, ("Error changing password: %s (%d)\n", errstr, res_code));
389 return kpasswd_err_to_krb5_err(res_code);
393 static ADS_STATUS do_krb5_kpasswd_request(krb5_context context,
394 const char *kdc_host,
400 krb5_auth_context auth_context = NULL;
401 krb5_data ap_req, chpw_req, chpw_rep;
404 struct sockaddr remote_addr, local_addr;
405 struct in_addr *addr = interpret_addr2(kdc_host);
406 krb5_address local_kaddr, remote_kaddr;
407 BOOL use_tcp = False;
410 ret = krb5_mk_req_extended(context, &auth_context, AP_OPTS_USE_SUBKEY,
411 NULL, credsp, &ap_req);
413 DEBUG(1,("krb5_mk_req_extended failed (%s)\n", error_message(ret)));
414 return ADS_ERROR_KRB5(ret);
421 sock = open_udp_socket(kdc_host, DEFAULT_KPASSWD_PORT);
425 sock = open_socket_out(SOCK_STREAM, addr, DEFAULT_KPASSWD_PORT,
426 LONG_CONNECT_TIMEOUT);
431 SAFE_FREE(ap_req.data);
432 krb5_auth_con_free(context, auth_context);
433 DEBUG(1,("failed to open kpasswd socket to %s (%s)\n",
434 kdc_host, strerror(errno)));
435 return ADS_ERROR_SYSTEM(rc);
438 addr_len = sizeof(remote_addr);
439 getpeername(sock, &remote_addr, &addr_len);
440 addr_len = sizeof(local_addr);
441 getsockname(sock, &local_addr, &addr_len);
443 setup_kaddr(&remote_kaddr, &remote_addr);
444 setup_kaddr(&local_kaddr, &local_addr);
446 ret = krb5_auth_con_setaddrs(context, auth_context, &local_kaddr, NULL);
449 SAFE_FREE(ap_req.data);
450 krb5_auth_con_free(context, auth_context);
451 DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n", error_message(ret)));
452 return ADS_ERROR_KRB5(ret);
455 ret = build_kpasswd_request(pversion, context, auth_context, &ap_req,
456 princ, newpw, use_tcp, &chpw_req);
459 SAFE_FREE(ap_req.data);
460 krb5_auth_con_free(context, auth_context);
461 DEBUG(1,("build_setpw_request failed (%s)\n", error_message(ret)));
462 return ADS_ERROR_KRB5(ret);
465 ret = write(sock, chpw_req.data, chpw_req.length);
467 if (ret != chpw_req.length) {
469 SAFE_FREE(chpw_req.data);
470 SAFE_FREE(ap_req.data);
471 krb5_auth_con_free(context, auth_context);
472 DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
473 return ADS_ERROR_SYSTEM(errno);
476 SAFE_FREE(chpw_req.data);
478 chpw_rep.length = 1500;
479 chpw_rep.data = (char *) SMB_MALLOC(chpw_rep.length);
480 if (!chpw_rep.data) {
482 SAFE_FREE(ap_req.data);
483 krb5_auth_con_free(context, auth_context);
484 DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
486 return ADS_ERROR_SYSTEM(errno);
489 ret = read(sock, chpw_rep.data, chpw_rep.length);
492 SAFE_FREE(chpw_rep.data);
493 SAFE_FREE(ap_req.data);
494 krb5_auth_con_free(context, auth_context);
495 DEBUG(1,("recv of chpw reply failed (%s)\n", strerror(errno)));
496 return ADS_ERROR_SYSTEM(errno);
500 chpw_rep.length = ret;
502 ret = krb5_auth_con_setaddrs(context, auth_context, NULL,&remote_kaddr);
504 SAFE_FREE(chpw_rep.data);
505 SAFE_FREE(ap_req.data);
506 krb5_auth_con_free(context, auth_context);
507 DEBUG(1,("krb5_auth_con_setaddrs on reply failed (%s)\n",
508 error_message(ret)));
509 return ADS_ERROR_KRB5(ret);
512 ret = parse_setpw_reply(context, use_tcp, auth_context, &chpw_rep);
513 SAFE_FREE(chpw_rep.data);
517 if (ret == KRB5KRB_ERR_RESPONSE_TOO_BIG && !use_tcp) {
518 DEBUG(5, ("Trying setpw with TCP!!!\n"));
523 SAFE_FREE(ap_req.data);
524 krb5_auth_con_free(context, auth_context);
525 DEBUG(1,("parse_setpw_reply failed (%s)\n",
526 error_message(ret)));
527 return ADS_ERROR_KRB5(ret);
530 SAFE_FREE(ap_req.data);
531 krb5_auth_con_free(context, auth_context);
537 ADS_STATUS ads_krb5_set_password(const char *kdc_host, const char *princ,
538 const char *newpw, int time_offset)
542 krb5_error_code ret = 0;
543 krb5_context context = NULL;
544 krb5_principal principal = NULL;
545 char *princ_name = NULL;
547 krb5_creds creds, *credsp = NULL;
548 #if KRB5_PRINC_REALM_RETURNS_REALM
549 krb5_realm orig_realm;
551 krb5_data orig_realm;
553 krb5_ccache ccache = NULL;
557 initialize_krb5_error_table();
558 ret = krb5_init_context(&context);
560 DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
561 return ADS_ERROR_KRB5(ret);
564 if (time_offset != 0) {
565 krb5_set_real_time(context, time(NULL) + time_offset, 0);
568 ret = krb5_cc_default(context, &ccache);
570 krb5_free_context(context);
571 DEBUG(1,("Failed to get default creds (%s)\n", error_message(ret)));
572 return ADS_ERROR_KRB5(ret);
575 realm = strchr_m(princ, '@');
577 krb5_cc_close(context, ccache);
578 krb5_free_context(context);
579 DEBUG(1,("Failed to get realm\n"));
580 return ADS_ERROR_KRB5(-1);
584 asprintf(&princ_name, "kadmin/changepw@%s", realm);
585 ret = smb_krb5_parse_name(context, princ_name, &creds.server);
587 krb5_cc_close(context, ccache);
588 krb5_free_context(context);
589 DEBUG(1,("Failed to parse kadmin/changepw (%s)\n", error_message(ret)));
590 return ADS_ERROR_KRB5(ret);
593 /* parse the principal we got as a function argument */
594 ret = smb_krb5_parse_name(context, princ, &principal);
596 krb5_cc_close(context, ccache);
597 krb5_free_principal(context, creds.server);
598 krb5_free_context(context);
599 DEBUG(1,("Failed to parse %s (%s)\n", princ_name, error_message(ret)));
601 return ADS_ERROR_KRB5(ret);
606 /* The creds.server principal takes ownership of this memory.
607 Remember to set back to original value before freeing. */
608 orig_realm = *krb5_princ_realm(context, creds.server);
609 krb5_princ_set_realm(context, creds.server, krb5_princ_realm(context, principal));
611 ret = krb5_cc_get_principal(context, ccache, &creds.client);
613 krb5_cc_close(context, ccache);
614 krb5_princ_set_realm(context, creds.server, &orig_realm);
615 krb5_free_principal(context, creds.server);
616 krb5_free_principal(context, principal);
617 krb5_free_context(context);
618 DEBUG(1,("Failed to get principal from ccache (%s)\n",
619 error_message(ret)));
620 return ADS_ERROR_KRB5(ret);
623 ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
625 krb5_cc_close(context, ccache);
626 krb5_free_principal(context, creds.client);
627 krb5_princ_set_realm(context, creds.server, &orig_realm);
628 krb5_free_principal(context, creds.server);
629 krb5_free_principal(context, principal);
630 krb5_free_context(context);
631 DEBUG(1,("krb5_get_credentials failed (%s)\n", error_message(ret)));
632 return ADS_ERROR_KRB5(ret);
635 /* we might have to call krb5_free_creds(...) from now on ... */
637 aret = do_krb5_kpasswd_request(context, kdc_host,
638 KRB5_KPASSWD_VERS_SETPW,
639 credsp, princ, newpw);
641 krb5_free_creds(context, credsp);
642 krb5_free_principal(context, creds.client);
643 krb5_princ_set_realm(context, creds.server, &orig_realm);
644 krb5_free_principal(context, creds.server);
645 krb5_free_principal(context, principal);
646 krb5_cc_close(context, ccache);
647 krb5_free_context(context);
653 we use a prompter to avoid a crash bug in the kerberos libs when
654 dealing with empty passwords
655 this prompter is just a string copy ...
657 static krb5_error_code
658 kerb_prompter(krb5_context ctx, void *data,
662 krb5_prompt prompts[])
664 if (num_prompts == 0) return 0;
666 memset(prompts[0].reply->data, 0, prompts[0].reply->length);
667 if (prompts[0].reply->length > 0) {
669 strncpy(prompts[0].reply->data,
671 prompts[0].reply->length-1);
672 prompts[0].reply->length = strlen(prompts[0].reply->data);
674 prompts[0].reply->length = 0;
680 static ADS_STATUS ads_krb5_chg_password(const char *kdc_host,
681 const char *principal,
688 krb5_context context = NULL;
689 krb5_principal princ;
690 krb5_get_init_creds_opt opts;
692 char *chpw_princ = NULL, *password;
694 initialize_krb5_error_table();
695 ret = krb5_init_context(&context);
697 DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
698 return ADS_ERROR_KRB5(ret);
701 if ((ret = smb_krb5_parse_name(context, principal,
703 krb5_free_context(context);
704 DEBUG(1,("Failed to parse %s (%s)\n", principal, error_message(ret)));
705 return ADS_ERROR_KRB5(ret);
708 krb5_get_init_creds_opt_init(&opts);
709 krb5_get_init_creds_opt_set_tkt_life(&opts, 5*60);
710 krb5_get_init_creds_opt_set_renew_life(&opts, 0);
711 krb5_get_init_creds_opt_set_forwardable(&opts, 0);
712 krb5_get_init_creds_opt_set_proxiable(&opts, 0);
714 /* We have to obtain an INITIAL changepw ticket for changing password */
715 asprintf(&chpw_princ, "kadmin/changepw@%s",
716 (char *) krb5_princ_realm(context, princ));
717 password = SMB_STRDUP(oldpw);
718 ret = krb5_get_init_creds_password(context, &creds, princ, password,
720 0, chpw_princ, &opts);
721 SAFE_FREE(chpw_princ);
725 if (ret == KRB5KRB_AP_ERR_BAD_INTEGRITY)
726 DEBUG(1,("Password incorrect while getting initial ticket"));
728 DEBUG(1,("krb5_get_init_creds_password failed (%s)\n", error_message(ret)));
730 krb5_free_principal(context, princ);
731 krb5_free_context(context);
732 return ADS_ERROR_KRB5(ret);
735 aret = do_krb5_kpasswd_request(context, kdc_host,
736 KRB5_KPASSWD_VERS_CHANGEPW,
737 &creds, principal, newpw);
739 krb5_free_principal(context, princ);
740 krb5_free_context(context);
746 ADS_STATUS kerberos_set_password(const char *kpasswd_server,
747 const char *auth_principal, const char *auth_password,
748 const char *target_principal, const char *new_password,
753 if ((ret = kerberos_kinit_password(auth_principal, auth_password, time_offset, NULL))) {
754 DEBUG(1,("Failed kinit for principal %s (%s)\n", auth_principal, error_message(ret)));
755 return ADS_ERROR_KRB5(ret);
758 if (!strcmp(auth_principal, target_principal))
759 return ads_krb5_chg_password(kpasswd_server, target_principal,
760 auth_password, new_password, time_offset);
762 return ads_krb5_set_password(kpasswd_server, target_principal,
763 new_password, time_offset);
768 * Set the machine account password
769 * @param ads connection to ads server
770 * @param hostname machine whose password is being set
771 * @param password new password
772 * @return status of password change
774 ADS_STATUS ads_set_machine_password(ADS_STRUCT *ads,
775 const char *machine_account,
776 const char *password)
779 char *principal = NULL;
782 we need to use the '$' form of the name here (the machine account name),
783 as otherwise the server might end up setting the password for a user
786 asprintf(&principal, "%s@%s", machine_account, ads->config.realm);
788 status = ads_krb5_set_password(ads->auth.kdc_server, principal,
789 password, ads->auth.time_offset);