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 2 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, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 #define DEFAULT_KPASSWD_PORT 464
27 #define KRB5_KPASSWD_VERS_CHANGEPW 1
28 #define KRB5_KPASSWD_VERS_SETPW 0xff80
29 #define KRB5_KPASSWD_VERS_SETPW_ALT 2
30 #define KRB5_KPASSWD_ACCESSDENIED 5
31 #define KRB5_KPASSWD_BAD_VERSION 6
32 #define KRB5_KPASSWD_INITIAL_FLAG_NEEDED 7
34 /* Those are defined by kerberos-set-passwd-02.txt and are probably
35 * not supported by M$ implementation */
36 #define KRB5_KPASSWD_POLICY_REJECT 8
37 #define KRB5_KPASSWD_BAD_PRINCIPAL 9
38 #define KRB5_KPASSWD_ETYPE_NOSUPP 10
40 /* This implements kerberos password change protocol as specified in
41 * kerb-chg-password-02.txt and kerberos-set-passwd-02.txt
42 * as well as microsoft version of the protocol
43 * as specified in kerberos-set-passwd-00.txt
45 static DATA_BLOB
encode_krb5_setpw(const char *principal
, const char *password
)
47 char* princ_part1
= NULL
;
48 char* princ_part2
= NULL
;
57 princ
= SMB_STRDUP(principal
);
59 if ((c
= strchr_m(princ
, '/')) == NULL
) {
69 if ((c
= strchr_m(c
, '@')) != NULL
) {
75 memset(&req
, 0, sizeof(req
));
77 asn1_push_tag(&req
, ASN1_SEQUENCE(0));
78 asn1_push_tag(&req
, ASN1_CONTEXT(0));
79 asn1_write_OctetString(&req
, password
, strlen(password
));
82 asn1_push_tag(&req
, ASN1_CONTEXT(1));
83 asn1_push_tag(&req
, ASN1_SEQUENCE(0));
85 asn1_push_tag(&req
, ASN1_CONTEXT(0));
86 asn1_write_Integer(&req
, 1);
89 asn1_push_tag(&req
, ASN1_CONTEXT(1));
90 asn1_push_tag(&req
, ASN1_SEQUENCE(0));
93 asn1_write_GeneralString(&req
, princ_part1
);
95 asn1_write_GeneralString(&req
, princ_part2
);
101 asn1_push_tag(&req
, ASN1_CONTEXT(2));
102 asn1_write_GeneralString(&req
, realm
);
106 ret
= data_blob(req
.data
, req
.length
);
114 static krb5_error_code
build_kpasswd_request(uint16 pversion
,
115 krb5_context context
,
116 krb5_auth_context auth_context
,
124 krb5_data encoded_setpw
;
125 krb5_replay_data replay
;
129 ret
= krb5_auth_con_setflags(context
,
130 auth_context
,KRB5_AUTH_CONTEXT_DO_SEQUENCE
);
132 DEBUG(1,("krb5_auth_con_setflags failed (%s)\n",
133 error_message(ret
)));
137 /* handle protocol differences in chpw and setpw */
138 if (pversion
== KRB5_KPASSWD_VERS_CHANGEPW
)
139 setpw
= data_blob(passwd
, strlen(passwd
));
140 else if (pversion
== KRB5_KPASSWD_VERS_SETPW
||
141 pversion
== KRB5_KPASSWD_VERS_SETPW_ALT
)
142 setpw
= encode_krb5_setpw(princ
, passwd
);
146 encoded_setpw
.data
= (char *)setpw
.data
;
147 encoded_setpw
.length
= setpw
.length
;
149 ret
= krb5_mk_priv(context
, auth_context
,
150 &encoded_setpw
, &cipherpw
, &replay
);
152 data_blob_free(&setpw
); /*from 'encode_krb5_setpw(...)' */
155 DEBUG(1,("krb5_mk_priv failed (%s)\n", error_message(ret
)));
159 packet
->data
= (char *)SMB_MALLOC(ap_req
->length
+ cipherpw
.length
+ 6);
163 /* see the RFC for details */
164 p
= ((char *)packet
->data
) + 2;
165 RSSVAL(p
, 0, pversion
);
167 RSSVAL(p
, 0, ap_req
->length
);
169 memcpy(p
, ap_req
->data
, ap_req
->length
);
171 memcpy(p
, cipherpw
.data
, cipherpw
.length
);
172 p
+= cipherpw
.length
;
173 packet
->length
= PTR_DIFF(p
,packet
->data
);
174 RSSVAL(packet
->data
, 0, packet
->length
);
176 free(cipherpw
.data
); /* from 'krb5_mk_priv(...)' */
181 static const struct kpasswd_errors
{
183 const char *error_string
;
184 } kpasswd_errors
[] = {
185 {KRB5_KPASSWD_MALFORMED
, "Malformed request error"},
186 {KRB5_KPASSWD_HARDERROR
, "Server error"},
187 {KRB5_KPASSWD_AUTHERROR
, "Authentication error"},
188 {KRB5_KPASSWD_SOFTERROR
, "Password change rejected"},
189 {KRB5_KPASSWD_ACCESSDENIED
, "Client does not have proper authorization"},
190 {KRB5_KPASSWD_BAD_VERSION
, "Protocol version not supported"},
191 {KRB5_KPASSWD_INITIAL_FLAG_NEEDED
, "Authorization ticket must have initial flag set"},
192 {KRB5_KPASSWD_POLICY_REJECT
, "Password rejected due to policy requirements"},
193 {KRB5_KPASSWD_BAD_PRINCIPAL
, "Target principal does not exist"},
194 {KRB5_KPASSWD_ETYPE_NOSUPP
, "Unsupported encryption type"},
198 static krb5_error_code
setpw_result_code_string(krb5_context context
,
200 const char **code_string
)
202 unsigned int idx
= 0;
204 while (kpasswd_errors
[idx
].error_string
!= NULL
) {
205 if (kpasswd_errors
[idx
].result_code
==
207 *code_string
= kpasswd_errors
[idx
].error_string
;
212 *code_string
= "Password change failed";
216 static krb5_error_code
parse_setpw_reply(krb5_context context
,
217 krb5_auth_context auth_context
,
222 int vnum
, ret
, res_code
;
223 krb5_data cipherresult
;
224 krb5_data clearresult
;
225 krb5_ap_rep_enc_part
*ap_rep_enc
;
226 krb5_replay_data replay
;
228 if (packet
->length
< 4) {
229 return KRB5KRB_AP_ERR_MODIFIED
;
234 if (((char *)packet
->data
)[0] == 0x7e || ((char *)packet
->data
)[0] == 0x5e) {
235 /* it's an error packet. We should parse it ... */
236 DEBUG(1,("Got error packet 0x%x from kpasswd server\n",
237 ((char *)packet
->data
)[0]));
238 return KRB5KRB_AP_ERR_MODIFIED
;
241 if (RSVAL(p
, 0) != packet
->length
) {
242 DEBUG(1,("Bad packet length (%d/%d) from kpasswd server\n",
243 RSVAL(p
, 0), packet
->length
));
244 return KRB5KRB_AP_ERR_MODIFIED
;
249 vnum
= RSVAL(p
, 0); p
+= 2;
251 /* FIXME: According to standard there is only one type of reply */
252 if (vnum
!= KRB5_KPASSWD_VERS_SETPW
&&
253 vnum
!= KRB5_KPASSWD_VERS_SETPW_ALT
&&
254 vnum
!= KRB5_KPASSWD_VERS_CHANGEPW
) {
255 DEBUG(1,("Bad vnum (%d) from kpasswd server\n", vnum
));
256 return KRB5KDC_ERR_BAD_PVNO
;
259 ap_rep
.length
= RSVAL(p
, 0); p
+= 2;
261 if (p
+ ap_rep
.length
>= (char *)packet
->data
+ packet
->length
) {
262 DEBUG(1,("ptr beyond end of packet from kpasswd server\n"));
263 return KRB5KRB_AP_ERR_MODIFIED
;
266 if (ap_rep
.length
== 0) {
267 DEBUG(1,("got unencrypted setpw result?!\n"));
268 return KRB5KRB_AP_ERR_MODIFIED
;
275 ret
= krb5_rd_rep(context
, auth_context
, &ap_rep
, &ap_rep_enc
);
277 DEBUG(1,("failed to rd setpw reply (%s)\n", error_message(ret
)));
278 return KRB5KRB_AP_ERR_MODIFIED
;
281 krb5_free_ap_rep_enc_part(context
, ap_rep_enc
);
283 cipherresult
.data
= p
;
284 cipherresult
.length
= ((char *)packet
->data
+ packet
->length
) - p
;
286 ret
= krb5_rd_priv(context
, auth_context
, &cipherresult
, &clearresult
,
289 DEBUG(1,("failed to decrypt setpw reply (%s)\n", error_message(ret
)));
290 return KRB5KRB_AP_ERR_MODIFIED
;
293 if (clearresult
.length
< 2) {
294 free(clearresult
.data
);
295 ret
= KRB5KRB_AP_ERR_MODIFIED
;
296 return KRB5KRB_AP_ERR_MODIFIED
;
299 p
= clearresult
.data
;
301 res_code
= RSVAL(p
, 0);
303 free(clearresult
.data
);
305 if ((res_code
< KRB5_KPASSWD_SUCCESS
) ||
306 (res_code
> KRB5_KPASSWD_ETYPE_NOSUPP
)) {
307 return KRB5KRB_AP_ERR_MODIFIED
;
310 if(res_code
== KRB5_KPASSWD_SUCCESS
)
314 setpw_result_code_string(context
, res_code
, &errstr
);
315 DEBUG(1, ("Error changing password: %s\n", errstr
));
318 case KRB5_KPASSWD_ACCESSDENIED
:
319 return KRB5KDC_ERR_BADOPTION
;
320 case KRB5_KPASSWD_INITIAL_FLAG_NEEDED
:
321 return KRB5KDC_ERR_BADOPTION
;
322 /* return KV5M_ALT_METHOD; MIT-only define */
323 case KRB5_KPASSWD_ETYPE_NOSUPP
:
324 return KRB5KDC_ERR_ETYPE_NOSUPP
;
325 case KRB5_KPASSWD_BAD_PRINCIPAL
:
326 return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN
;
327 case KRB5_KPASSWD_POLICY_REJECT
:
328 return KRB5KDC_ERR_POLICY
;
330 return KRB5KRB_ERR_GENERIC
;
335 static ADS_STATUS
do_krb5_kpasswd_request(krb5_context context
,
336 const char *kdc_host
,
342 krb5_auth_context auth_context
= NULL
;
343 krb5_data ap_req
, chpw_req
, chpw_rep
;
346 struct sockaddr remote_addr
, local_addr
;
347 krb5_address local_kaddr
, remote_kaddr
;
349 ret
= krb5_mk_req_extended(context
, &auth_context
, AP_OPTS_USE_SUBKEY
,
350 NULL
, credsp
, &ap_req
);
352 DEBUG(1,("krb5_mk_req_extended failed (%s)\n", error_message(ret
)));
353 return ADS_ERROR_KRB5(ret
);
356 sock
= open_udp_socket(kdc_host
, DEFAULT_KPASSWD_PORT
);
360 krb5_auth_con_free(context
, auth_context
);
361 DEBUG(1,("failed to open kpasswd socket to %s (%s)\n",
362 kdc_host
, strerror(errno
)));
363 return ADS_ERROR_SYSTEM(rc
);
366 addr_len
= sizeof(remote_addr
);
367 getpeername(sock
, &remote_addr
, &addr_len
);
368 addr_len
= sizeof(local_addr
);
369 getsockname(sock
, &local_addr
, &addr_len
);
371 setup_kaddr(&remote_kaddr
, &remote_addr
);
372 setup_kaddr(&local_kaddr
, &local_addr
);
374 ret
= krb5_auth_con_setaddrs(context
, auth_context
, &local_kaddr
, NULL
);
378 krb5_auth_con_free(context
, auth_context
);
379 DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n", error_message(ret
)));
380 return ADS_ERROR_KRB5(ret
);
383 ret
= build_kpasswd_request(pversion
, context
, auth_context
, &ap_req
,
384 princ
, newpw
, &chpw_req
);
388 krb5_auth_con_free(context
, auth_context
);
389 DEBUG(1,("build_setpw_request failed (%s)\n", error_message(ret
)));
390 return ADS_ERROR_KRB5(ret
);
393 if (write(sock
, chpw_req
.data
, chpw_req
.length
) != chpw_req
.length
) {
397 krb5_auth_con_free(context
, auth_context
);
398 DEBUG(1,("send of chpw failed (%s)\n", strerror(errno
)));
399 return ADS_ERROR_SYSTEM(errno
);
404 chpw_rep
.length
= 1500;
405 chpw_rep
.data
= (char *) SMB_MALLOC(chpw_rep
.length
);
406 if (!chpw_rep
.data
) {
409 krb5_auth_con_free(context
, auth_context
);
410 DEBUG(1,("send of chpw failed (%s)\n", strerror(errno
)));
412 return ADS_ERROR_SYSTEM(errno
);
415 ret
= read(sock
, chpw_rep
.data
, chpw_rep
.length
);
420 krb5_auth_con_free(context
, auth_context
);
421 DEBUG(1,("recv of chpw reply failed (%s)\n", strerror(errno
)));
422 return ADS_ERROR_SYSTEM(errno
);
426 chpw_rep
.length
= ret
;
428 ret
= krb5_auth_con_setaddrs(context
, auth_context
, NULL
,&remote_kaddr
);
432 krb5_auth_con_free(context
, auth_context
);
433 DEBUG(1,("krb5_auth_con_setaddrs on reply failed (%s)\n",
434 error_message(ret
)));
435 return ADS_ERROR_KRB5(ret
);
438 ret
= parse_setpw_reply(context
, auth_context
, &chpw_rep
);
443 krb5_auth_con_free(context
, auth_context
);
444 DEBUG(1,("parse_setpw_reply failed (%s)\n",
445 error_message(ret
)));
446 return ADS_ERROR_KRB5(ret
);
450 krb5_auth_con_free(context
, auth_context
);
455 ADS_STATUS
ads_krb5_set_password(const char *kdc_host
, const char *princ
,
456 const char *newpw
, int time_offset
)
460 krb5_error_code ret
= 0;
461 krb5_context context
= NULL
;
462 krb5_principal principal
= NULL
;
463 char *princ_name
= NULL
;
465 krb5_creds creds
, *credsp
= NULL
;
466 #if KRB5_PRINC_REALM_RETURNS_REALM
467 krb5_realm orig_realm
;
469 krb5_data orig_realm
;
471 krb5_ccache ccache
= NULL
;
475 initialize_krb5_error_table();
476 ret
= krb5_init_context(&context
);
478 DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret
)));
479 return ADS_ERROR_KRB5(ret
);
482 if (time_offset
!= 0) {
483 krb5_set_real_time(context
, time(NULL
) + time_offset
, 0);
486 ret
= krb5_cc_default(context
, &ccache
);
488 krb5_free_context(context
);
489 DEBUG(1,("Failed to get default creds (%s)\n", error_message(ret
)));
490 return ADS_ERROR_KRB5(ret
);
493 realm
= strchr_m(princ
, '@');
495 krb5_cc_close(context
, ccache
);
496 krb5_free_context(context
);
497 DEBUG(1,("Failed to get realm\n"));
498 return ADS_ERROR_KRB5(-1);
502 asprintf(&princ_name
, "kadmin/changepw@%s", realm
);
503 ret
= krb5_parse_name(context
, princ_name
, &creds
.server
);
505 krb5_cc_close(context
, ccache
);
506 krb5_free_context(context
);
507 DEBUG(1,("Failed to parse kadmin/changepw (%s)\n", error_message(ret
)));
508 return ADS_ERROR_KRB5(ret
);
512 /* parse the principal we got as a function argument */
513 ret
= krb5_parse_name(context
, princ
, &principal
);
515 krb5_cc_close(context
, ccache
);
516 krb5_free_principal(context
, creds
.server
);
517 krb5_free_context(context
);
518 DEBUG(1,("Failed to parse %s (%s)\n", princ_name
, error_message(ret
)));
519 return ADS_ERROR_KRB5(ret
);
522 /* The creds.server principal takes ownership of this memory.
523 Remember to set back to original value before freeing. */
524 orig_realm
= *krb5_princ_realm(context
, creds
.server
);
525 krb5_princ_set_realm(context
, creds
.server
, krb5_princ_realm(context
, principal
));
527 ret
= krb5_cc_get_principal(context
, ccache
, &creds
.client
);
529 krb5_cc_close(context
, ccache
);
530 krb5_princ_set_realm(context
, creds
.server
, &orig_realm
);
531 krb5_free_principal(context
, creds
.server
);
532 krb5_free_principal(context
, principal
);
533 krb5_free_context(context
);
534 DEBUG(1,("Failed to get principal from ccache (%s)\n",
535 error_message(ret
)));
536 return ADS_ERROR_KRB5(ret
);
539 ret
= krb5_get_credentials(context
, 0, ccache
, &creds
, &credsp
);
541 krb5_cc_close(context
, ccache
);
542 krb5_free_principal(context
, creds
.client
);
543 krb5_princ_set_realm(context
, creds
.server
, &orig_realm
);
544 krb5_free_principal(context
, creds
.server
);
545 krb5_free_principal(context
, principal
);
546 krb5_free_context(context
);
547 DEBUG(1,("krb5_get_credentials failed (%s)\n", error_message(ret
)));
548 return ADS_ERROR_KRB5(ret
);
551 /* we might have to call krb5_free_creds(...) from now on ... */
553 aret
= do_krb5_kpasswd_request(context
, kdc_host
,
554 KRB5_KPASSWD_VERS_SETPW
,
555 credsp
, princ
, newpw
);
557 krb5_free_creds(context
, credsp
);
558 krb5_free_principal(context
, creds
.client
);
559 krb5_princ_set_realm(context
, creds
.server
, &orig_realm
);
560 krb5_free_principal(context
, creds
.server
);
561 krb5_free_principal(context
, principal
);
562 krb5_cc_close(context
, ccache
);
563 krb5_free_context(context
);
569 we use a prompter to avoid a crash bug in the kerberos libs when
570 dealing with empty passwords
571 this prompter is just a string copy ...
573 static krb5_error_code
574 kerb_prompter(krb5_context ctx
, void *data
,
578 krb5_prompt prompts
[])
580 if (num_prompts
== 0) return 0;
582 memset(prompts
[0].reply
->data
, 0, prompts
[0].reply
->length
);
583 if (prompts
[0].reply
->length
> 0) {
585 strncpy(prompts
[0].reply
->data
, data
, prompts
[0].reply
->length
-1);
586 prompts
[0].reply
->length
= strlen(prompts
[0].reply
->data
);
588 prompts
[0].reply
->length
= 0;
594 static ADS_STATUS
ads_krb5_chg_password(const char *kdc_host
,
595 const char *principal
,
602 krb5_context context
= NULL
;
603 krb5_principal princ
;
604 krb5_get_init_creds_opt opts
;
606 char *chpw_princ
= NULL
, *password
;
608 initialize_krb5_error_table();
609 ret
= krb5_init_context(&context
);
611 DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret
)));
612 return ADS_ERROR_KRB5(ret
);
615 if ((ret
= krb5_parse_name(context
, principal
,
617 krb5_free_context(context
);
618 DEBUG(1,("Failed to parse %s (%s)\n", principal
, error_message(ret
)));
619 return ADS_ERROR_KRB5(ret
);
622 krb5_get_init_creds_opt_init(&opts
);
623 krb5_get_init_creds_opt_set_tkt_life(&opts
, 5*60);
624 krb5_get_init_creds_opt_set_renew_life(&opts
, 0);
625 krb5_get_init_creds_opt_set_forwardable(&opts
, 0);
626 krb5_get_init_creds_opt_set_proxiable(&opts
, 0);
628 /* We have to obtain an INITIAL changepw ticket for changing password */
629 asprintf(&chpw_princ
, "kadmin/changepw@%s",
630 (char *) krb5_princ_realm(context
, princ
));
631 password
= SMB_STRDUP(oldpw
);
632 ret
= krb5_get_init_creds_password(context
, &creds
, princ
, password
,
634 0, chpw_princ
, &opts
);
635 SAFE_FREE(chpw_princ
);
639 if (ret
== KRB5KRB_AP_ERR_BAD_INTEGRITY
)
640 DEBUG(1,("Password incorrect while getting initial ticket"));
642 DEBUG(1,("krb5_get_init_creds_password failed (%s)\n", error_message(ret
)));
644 krb5_free_principal(context
, princ
);
645 krb5_free_context(context
);
646 return ADS_ERROR_KRB5(ret
);
649 aret
= do_krb5_kpasswd_request(context
, kdc_host
,
650 KRB5_KPASSWD_VERS_CHANGEPW
,
651 &creds
, principal
, newpw
);
653 krb5_free_principal(context
, princ
);
654 krb5_free_context(context
);
660 ADS_STATUS
kerberos_set_password(const char *kpasswd_server
,
661 const char *auth_principal
, const char *auth_password
,
662 const char *target_principal
, const char *new_password
,
667 if ((ret
= kerberos_kinit_password(auth_principal
, auth_password
, time_offset
, NULL
, NULL
))) {
668 DEBUG(1,("Failed kinit for principal %s (%s)\n", auth_principal
, error_message(ret
)));
669 return ADS_ERROR_KRB5(ret
);
672 if (!strcmp(auth_principal
, target_principal
))
673 return ads_krb5_chg_password(kpasswd_server
, target_principal
,
674 auth_password
, new_password
, time_offset
);
676 return ads_krb5_set_password(kpasswd_server
, target_principal
,
677 new_password
, time_offset
);
682 * Set the machine account password
683 * @param ads connection to ads server
684 * @param hostname machine whose password is being set
685 * @param password new password
686 * @return status of password change
688 ADS_STATUS
ads_set_machine_password(ADS_STRUCT
*ads
,
689 const char *machine_account
,
690 const char *password
)
693 char *principal
= NULL
;
696 we need to use the '$' form of the name here (the machine account name),
697 as otherwise the server might end up setting the password for a user
700 asprintf(&principal
, "%s@%s", machine_account
, ads
->config
.realm
);
702 status
= ads_krb5_set_password(ads
->auth
.kdc_server
, principal
,
703 password
, ads
->auth
.time_offset
);