Write bug number like in the rest of the file
[Samba/nascimento.git] / source3 / libads / krb5_setpw.c
blob9cf15221a8dd2417ca96415c300d4bdccdd5075f
1 /*
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.
22 #include "includes.h"
24 #ifdef HAVE_KRB5
26 #define DEFAULT_KPASSWD_PORT 464
27 #define KRB5_KPASSWD_VERS_CHANGEPW 1
28 #define KRB5_KPASSWD_VERS_SETPW 2
29 #define KRB5_KPASSWD_VERS_SETPW_MS 0xff80
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;
49 char* realm = NULL;
50 char* c;
51 char* princ;
53 ASN1_DATA req;
54 DATA_BLOB ret;
57 princ = strdup(principal);
59 if ((c = strchr(princ, '/')) == NULL) {
60 c = princ;
61 } else {
62 *c = '\0';
63 c++;
64 princ_part1 = princ;
67 princ_part2 = c;
69 if ((c = strchr(c, '@')) != NULL) {
70 *c = '\0';
71 c++;
72 realm = c;
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));
80 asn1_pop_tag(&req);
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);
87 asn1_pop_tag(&req);
89 asn1_push_tag(&req, ASN1_CONTEXT(1));
90 asn1_push_tag(&req, ASN1_SEQUENCE(0));
92 if (princ_part1)
93 asn1_write_GeneralString(&req, princ_part1);
95 asn1_write_GeneralString(&req, princ_part2);
96 asn1_pop_tag(&req);
97 asn1_pop_tag(&req);
98 asn1_pop_tag(&req);
99 asn1_pop_tag(&req);
101 asn1_push_tag(&req, ASN1_CONTEXT(2));
102 asn1_write_GeneralString(&req, realm);
103 asn1_pop_tag(&req);
104 asn1_pop_tag(&req);
106 ret = data_blob(req.data, req.length);
107 asn1_free(&req);
109 free(princ);
111 return ret;
114 static krb5_error_code build_kpasswd_request(uint16 pversion,
115 krb5_context context,
116 krb5_auth_context auth_context,
117 krb5_data *ap_req,
118 const char *princ,
119 const char *passwd,
120 krb5_data *packet)
122 krb5_error_code ret;
123 krb5_data cipherpw;
124 krb5_data encoded_setpw;
125 krb5_replay_data replay;
126 char *p;
127 DATA_BLOB setpw;
129 ret = krb5_auth_con_setflags(context,
130 auth_context,KRB5_AUTH_CONTEXT_DO_SEQUENCE);
131 if (ret) {
132 DEBUG(1,("krb5_auth_con_setflags failed (%s)\n",
133 error_message(ret)));
134 return 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_MS)
142 setpw = encode_krb5_setpw(princ, passwd);
143 else
144 return EINVAL;
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(...)' */
154 if (ret) {
155 DEBUG(1,("krb5_mk_priv failed (%s)\n", error_message(ret)));
156 return ret;
159 packet->data = (char *)malloc(ap_req->length + cipherpw.length + 6);
160 if (!packet->data)
161 return -1;
163 /* see the RFC for details */
164 p = ((char *)packet->data) + 2;
165 RSSVAL(p, 0, pversion);
166 p += 2;
167 RSSVAL(p, 0, ap_req->length);
168 p += 2;
169 memcpy(p, ap_req->data, ap_req->length);
170 p += 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(...)' */
178 return 0;
181 static const struct kpasswd_errors {
182 int result_code;
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"},
195 {0, NULL}
198 static krb5_error_code setpw_result_code_string(krb5_context context,
199 int result_code,
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 ==
206 result_code) {
207 *code_string = kpasswd_errors[idx].error_string;
208 return 0;
210 idx++;
212 *code_string = "Password change failed";
213 return (0);
216 static krb5_error_code parse_setpw_reply(krb5_context context,
217 krb5_auth_context auth_context,
218 krb5_data *packet)
220 krb5_data ap_rep;
221 char *p;
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;
232 p = packet->data;
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;
247 p += 2;
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_MS &&
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;
271 /* verify ap_rep */
272 ap_rep.data = p;
273 p += ap_rep.length;
275 ret = krb5_rd_rep(context, auth_context, &ap_rep, &ap_rep_enc);
276 if (ret) {
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,
287 &replay);
288 if (ret) {
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)
311 return 0;
312 else {
313 const char *errstr;
314 setpw_result_code_string(context, res_code, &errstr);
315 DEBUG(1, ("Error changing password: %s\n", errstr));
317 switch(res_code) {
318 case KRB5_KPASSWD_ACCESSDENIED:
319 return KRB5KDC_ERR_BADOPTION;
320 break;
321 case KRB5_KPASSWD_INITIAL_FLAG_NEEDED:
322 return KRB5KDC_ERR_BADOPTION;
323 /* return KV5M_ALT_METHOD; MIT-only define */
324 break;
325 case KRB5_KPASSWD_ETYPE_NOSUPP:
326 return KRB5KDC_ERR_ETYPE_NOSUPP;
327 break;
328 case KRB5_KPASSWD_BAD_PRINCIPAL:
329 return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
330 break;
331 case KRB5_KPASSWD_POLICY_REJECT:
332 return KRB5KDC_ERR_POLICY;
333 break;
334 default:
335 return KRB5KRB_ERR_GENERIC;
336 break;
341 static ADS_STATUS do_krb5_kpasswd_request(krb5_context context,
342 const char *kdc_host,
343 uint16 pversion,
344 krb5_creds *credsp,
345 const char *princ,
346 const char *newpw)
348 krb5_auth_context auth_context = NULL;
349 krb5_data ap_req, chpw_req, chpw_rep;
350 int ret, sock, addr_len;
351 struct sockaddr remote_addr, local_addr;
352 krb5_address local_kaddr, remote_kaddr;
354 ret = krb5_mk_req_extended(context, &auth_context, AP_OPTS_USE_SUBKEY,
355 NULL, credsp, &ap_req);
356 if (ret) {
357 DEBUG(1,("krb5_mk_req_extended failed (%s)\n", error_message(ret)));
358 return ADS_ERROR_KRB5(ret);
361 sock = open_udp_socket(kdc_host, DEFAULT_KPASSWD_PORT);
362 if (sock == -1) {
363 int rc = errno;
364 free(ap_req.data);
365 krb5_auth_con_free(context, auth_context);
366 DEBUG(1,("failed to open kpasswd socket to %s (%s)\n",
367 kdc_host, strerror(errno)));
368 return ADS_ERROR_SYSTEM(rc);
371 addr_len = sizeof(remote_addr);
372 getpeername(sock, &remote_addr, &addr_len);
373 addr_len = sizeof(local_addr);
374 getsockname(sock, &local_addr, &addr_len);
376 setup_kaddr(&remote_kaddr, &remote_addr);
377 setup_kaddr(&local_kaddr, &local_addr);
379 ret = krb5_auth_con_setaddrs(context, auth_context, &local_kaddr, NULL);
380 if (ret) {
381 close(sock);
382 free(ap_req.data);
383 krb5_auth_con_free(context, auth_context);
384 DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n", error_message(ret)));
385 return ADS_ERROR_KRB5(ret);
388 ret = build_kpasswd_request(pversion, context, auth_context, &ap_req,
389 princ, newpw, &chpw_req);
390 if (ret) {
391 close(sock);
392 free(ap_req.data);
393 krb5_auth_con_free(context, auth_context);
394 DEBUG(1,("build_setpw_request failed (%s)\n", error_message(ret)));
395 return ADS_ERROR_KRB5(ret);
398 if (write(sock, chpw_req.data, chpw_req.length) != chpw_req.length) {
399 close(sock);
400 free(chpw_req.data);
401 free(ap_req.data);
402 krb5_auth_con_free(context, auth_context);
403 DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
404 return ADS_ERROR_SYSTEM(errno);
407 free(chpw_req.data);
409 chpw_rep.length = 1500;
410 chpw_rep.data = (char *) malloc(chpw_rep.length);
411 if (!chpw_rep.data) {
412 close(sock);
413 free(ap_req.data);
414 krb5_auth_con_free(context, auth_context);
415 DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
416 errno = ENOMEM;
417 return ADS_ERROR_SYSTEM(errno);
420 ret = read(sock, chpw_rep.data, chpw_rep.length);
421 if (ret < 0) {
422 close(sock);
423 free(chpw_rep.data);
424 free(ap_req.data);
425 krb5_auth_con_free(context, auth_context);
426 DEBUG(1,("recv of chpw reply failed (%s)\n", strerror(errno)));
427 return ADS_ERROR_SYSTEM(errno);
430 close(sock);
431 chpw_rep.length = ret;
433 ret = krb5_auth_con_setaddrs(context, auth_context, NULL,&remote_kaddr);
434 if (ret) {
435 free(chpw_rep.data);
436 free(ap_req.data);
437 krb5_auth_con_free(context, auth_context);
438 DEBUG(1,("krb5_auth_con_setaddrs on reply failed (%s)\n",
439 error_message(ret)));
440 return ADS_ERROR_KRB5(ret);
443 ret = parse_setpw_reply(context, auth_context, &chpw_rep);
444 free(chpw_rep.data);
446 if (ret) {
447 free(ap_req.data);
448 krb5_auth_con_free(context, auth_context);
449 DEBUG(1,("parse_setpw_reply failed (%s)\n",
450 error_message(ret)));
451 return ADS_ERROR_KRB5(ret);
454 free(ap_req.data);
455 krb5_auth_con_free(context, auth_context);
457 return ADS_SUCCESS;
460 ADS_STATUS ads_krb5_set_password(const char *kdc_host, const char *princ,
461 const char *newpw, int time_offset)
464 ADS_STATUS aret;
465 krb5_error_code ret;
466 krb5_context context;
467 krb5_principal principal;
468 char *princ_name;
469 char *realm;
470 krb5_creds creds, *credsp;
471 krb5_ccache ccache;
473 ret = krb5_init_context(&context);
474 if (ret) {
475 DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
476 return ADS_ERROR_KRB5(ret);
479 if (time_offset != 0) {
480 krb5_set_real_time(context, time(NULL) + time_offset, 0);
483 ret = krb5_cc_default(context, &ccache);
484 if (ret) {
485 krb5_free_context(context);
486 DEBUG(1,("Failed to get default creds (%s)\n", error_message(ret)));
487 return ADS_ERROR_KRB5(ret);
490 ZERO_STRUCT(creds);
492 realm = strchr(princ, '@');
493 realm++;
495 asprintf(&princ_name, "kadmin/changepw@%s", realm);
496 ret = krb5_parse_name(context, princ_name, &creds.server);
497 if (ret) {
498 krb5_free_context(context);
499 DEBUG(1,("Failed to parse kadmin/changepw (%s)\n", error_message(ret)));
500 return ADS_ERROR_KRB5(ret);
502 free(princ_name);
504 /* parse the principal we got as a function argument */
505 ret = krb5_parse_name(context, princ, &principal);
506 if (ret) {
507 krb5_free_context(context);
508 DEBUG(1,("Failed to parse %s (%s)\n", princ_name, error_message(ret)));
509 return ADS_ERROR_KRB5(ret);
512 krb5_princ_set_realm(context, creds.server,
513 krb5_princ_realm(context, principal));
515 ret = krb5_cc_get_principal(context, ccache, &creds.client);
516 if (ret) {
517 krb5_free_principal(context, principal);
518 krb5_free_context(context);
519 DEBUG(1,("Failed to get principal from ccache (%s)\n",
520 error_message(ret)));
521 return ADS_ERROR_KRB5(ret);
524 ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
525 if (ret) {
526 krb5_free_principal(context, creds.client);
527 krb5_free_principal(context, principal);
528 krb5_free_context(context);
529 DEBUG(1,("krb5_get_credentials failed (%s)\n", error_message(ret)));
530 return ADS_ERROR_KRB5(ret);
533 /* we might have to call krb5_free_creds(...) from now on ... */
535 aret = do_krb5_kpasswd_request(context, kdc_host,
536 KRB5_KPASSWD_VERS_SETPW_MS,
537 credsp, princ, newpw);
539 krb5_free_creds(context, credsp);
540 krb5_free_principal(context, creds.client);
541 krb5_free_principal(context, principal);
542 krb5_free_context(context);
544 return aret;
548 we use a prompter to avoid a crash bug in the kerberos libs when
549 dealing with empty passwords
550 this prompter is just a string copy ...
552 static krb5_error_code
553 kerb_prompter(krb5_context ctx, void *data,
554 const char *name,
555 const char *banner,
556 int num_prompts,
557 krb5_prompt prompts[])
559 if (num_prompts == 0) return 0;
561 memset(prompts[0].reply->data, 0, prompts[0].reply->length);
562 if (prompts[0].reply->length > 0) {
563 if (data) {
564 strncpy(prompts[0].reply->data, data, prompts[0].reply->length-1);
565 prompts[0].reply->length = strlen(prompts[0].reply->data);
566 } else {
567 prompts[0].reply->length = 0;
570 return 0;
573 static ADS_STATUS ads_krb5_chg_password(const char *kdc_host,
574 const char *principal,
575 const char *oldpw,
576 const char *newpw,
577 int time_offset)
579 ADS_STATUS aret;
580 krb5_error_code ret;
581 krb5_context context;
582 krb5_principal princ;
583 krb5_get_init_creds_opt opts;
584 krb5_creds creds;
585 char *chpw_princ = NULL, *password;
587 ret = krb5_init_context(&context);
588 if (ret) {
589 DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
590 return ADS_ERROR_KRB5(ret);
593 if ((ret = krb5_parse_name(context, principal,
594 &princ))) {
595 krb5_free_context(context);
596 DEBUG(1,("Failed to parse %s (%s)\n", principal, error_message(ret)));
597 return ADS_ERROR_KRB5(ret);
600 krb5_get_init_creds_opt_init(&opts);
601 krb5_get_init_creds_opt_set_tkt_life(&opts, 5*60);
602 krb5_get_init_creds_opt_set_renew_life(&opts, 0);
603 krb5_get_init_creds_opt_set_forwardable(&opts, 0);
604 krb5_get_init_creds_opt_set_proxiable(&opts, 0);
606 /* We have to obtain an INITIAL changepw ticket for changing password */
607 asprintf(&chpw_princ, "kadmin/changepw@%s",
608 (char *) krb5_princ_realm(context, princ));
609 password = strdup(oldpw);
610 ret = krb5_get_init_creds_password(context, &creds, princ, password,
611 kerb_prompter, NULL,
612 0, chpw_princ, &opts);
613 SAFE_FREE(chpw_princ);
614 SAFE_FREE(password);
616 if (ret) {
617 if (ret == KRB5KRB_AP_ERR_BAD_INTEGRITY)
618 DEBUG(1,("Password incorrect while getting initial ticket"));
619 else
620 DEBUG(1,("krb5_get_init_creds_password failed (%s)\n", error_message(ret)));
622 krb5_free_principal(context, princ);
623 krb5_free_context(context);
624 return ADS_ERROR_KRB5(ret);
627 aret = do_krb5_kpasswd_request(context, kdc_host,
628 KRB5_KPASSWD_VERS_CHANGEPW,
629 &creds, principal, newpw);
631 krb5_free_principal(context, princ);
632 krb5_free_context(context);
634 return aret;
638 ADS_STATUS kerberos_set_password(const char *kpasswd_server,
639 const char *auth_principal, const char *auth_password,
640 const char *target_principal, const char *new_password,
641 int time_offset)
643 int ret;
645 if ((ret = kerberos_kinit_password(auth_principal, auth_password, time_offset))) {
646 DEBUG(1,("Failed kinit for principal %s (%s)\n", auth_principal, error_message(ret)));
647 return ADS_ERROR_KRB5(ret);
650 if (!strcmp(auth_principal, target_principal))
651 return ads_krb5_chg_password(kpasswd_server, target_principal,
652 auth_password, new_password, time_offset);
653 else
654 return ads_krb5_set_password(kpasswd_server, target_principal,
655 new_password, time_offset);
660 * Set the machine account password
661 * @param ads connection to ads server
662 * @param hostname machine whose password is being set
663 * @param password new password
664 * @return status of password change
666 ADS_STATUS ads_set_machine_password(ADS_STRUCT *ads,
667 const char *machine_account,
668 const char *password)
670 ADS_STATUS status;
671 char *principal = NULL;
674 we need to use the '$' form of the name here (the machine account name),
675 as otherwise the server might end up setting the password for a user
676 instead
678 asprintf(&principal, "%s@%s", machine_account, ads->config.realm);
680 status = ads_krb5_set_password(ads->auth.kdc_server, principal,
681 password, ads->auth.time_offset);
683 free(principal);
685 return status;
690 #endif