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_ACCESSDENIED 5
30 #define KRB5_KPASSWD_BAD_VERSION 6
32 /* This implements the Kerb password change protocol as specifed in
33 * kerb-chg-password-02.txt
35 static DATA_BLOB encode_krb5_setpw(const char *principal, const char *password)
37 char* princ_part1 = NULL;
38 char* princ_part2 = NULL;
47 princ = strdup(principal);
49 if ((c = strchr(princ, '/')) == NULL) {
59 if ((c = strchr(c, '@')) != NULL) {
65 memset(&req, 0, sizeof(req));
67 asn1_push_tag(&req, ASN1_SEQUENCE(0));
68 asn1_push_tag(&req, ASN1_CONTEXT(0));
69 asn1_write_OctetString(&req, password, strlen(password));
72 asn1_push_tag(&req, ASN1_CONTEXT(1));
73 asn1_push_tag(&req, ASN1_SEQUENCE(0));
75 asn1_push_tag(&req, ASN1_CONTEXT(0));
76 asn1_write_Integer(&req, 1);
79 asn1_push_tag(&req, ASN1_CONTEXT(1));
80 asn1_push_tag(&req, ASN1_SEQUENCE(0));
83 asn1_write_GeneralString(&req, princ_part1);
85 asn1_write_GeneralString(&req, princ_part2);
91 asn1_push_tag(&req, ASN1_CONTEXT(2));
92 asn1_write_GeneralString(&req, realm);
96 ret = data_blob(req.data, req.length);
104 static krb5_error_code build_setpw_request(krb5_context context,
105 krb5_auth_context auth_context,
113 krb5_data encoded_setpw;
114 krb5_replay_data replay;
118 ret = krb5_auth_con_setflags(context,
119 auth_context,KRB5_AUTH_CONTEXT_DO_SEQUENCE);
121 DEBUG(1,("krb5_auth_con_setflags failed (%s)\n",
122 error_message(ret)));
126 setpw = encode_krb5_setpw(princ, passwd);
128 encoded_setpw.data = setpw.data;
129 encoded_setpw.length = setpw.length;
131 ret = krb5_mk_priv(context, auth_context,
132 &encoded_setpw, &cipherpw, &replay);
134 data_blob_free(&setpw); /*from 'encode_krb5_setpw(...)' */
137 DEBUG(1,("krb5_mk_priv failed (%s)\n", error_message(ret)));
141 packet->data = (char *)malloc(ap_req->length + cipherpw.length + 6);
143 /* see the RFC for details */
144 p = packet->data + 2;
145 RSSVAL(p, 0, 0xff80); p += 2;
146 RSSVAL(p, 0, ap_req->length); p += 2;
147 memcpy(p, ap_req->data, ap_req->length); p += ap_req->length;
148 memcpy(p, cipherpw.data, cipherpw.length); p += cipherpw.length;
149 packet->length = PTR_DIFF(p,packet->data);
150 RSSVAL(packet->data, 0, packet->length);
152 free(cipherpw.data); /* from 'krb5_mk_priv(...)' */
157 static krb5_error_code parse_setpw_reply(krb5_context context,
158 krb5_auth_context auth_context,
163 int vnum, ret, res_code;
164 krb5_data cipherresult;
165 krb5_data clearresult;
166 krb5_ap_rep_enc_part *ap_rep_enc;
167 krb5_replay_data replay;
169 if (packet->length < 4) {
170 return KRB5KRB_AP_ERR_MODIFIED;
175 if (packet->data[0] == 0x7e || packet->data[0] == 0x5e) {
176 /* it's an error packet. We should parse it ... */
177 DEBUG(1,("Got error packet 0x%x from kpasswd server\n",
179 return KRB5KRB_AP_ERR_MODIFIED;
182 if (RSVAL(p, 0) != packet->length) {
183 DEBUG(1,("Bad packet length (%d/%d) from kpasswd server\n",
184 RSVAL(p, 0), packet->length));
185 return KRB5KRB_AP_ERR_MODIFIED;
190 vnum = RSVAL(p, 0); p += 2;
192 if (vnum != KRB5_KPASSWD_VERS_SETPW && vnum != KRB5_KPASSWD_VERS_CHANGEPW) {
193 DEBUG(1,("Bad vnum (%d) from kpasswd server\n", vnum));
194 return KRB5KDC_ERR_BAD_PVNO;
197 ap_rep.length = RSVAL(p, 0); p += 2;
199 if (p + ap_rep.length >= packet->data + packet->length) {
200 DEBUG(1,("ptr beyond end of packet from kpasswd server\n"));
201 return KRB5KRB_AP_ERR_MODIFIED;
204 if (ap_rep.length == 0) {
205 DEBUG(1,("got unencrypted setpw result?!\n"));
206 return KRB5KRB_AP_ERR_MODIFIED;
213 ret = krb5_rd_rep(context, auth_context, &ap_rep, &ap_rep_enc);
215 DEBUG(1,("failed to rd setpw reply (%s)\n", error_message(ret)));
216 return KRB5KRB_AP_ERR_MODIFIED;
219 krb5_free_ap_rep_enc_part(context, ap_rep_enc);
221 cipherresult.data = p;
222 cipherresult.length = (packet->data + packet->length) - p;
224 ret = krb5_rd_priv(context, auth_context, &cipherresult, &clearresult,
227 DEBUG(1,("failed to decrypt setpw reply (%s)\n", error_message(ret)));
228 return KRB5KRB_AP_ERR_MODIFIED;
231 if (clearresult.length < 2) {
232 free(clearresult.data);
233 ret = KRB5KRB_AP_ERR_MODIFIED;
234 return KRB5KRB_AP_ERR_MODIFIED;
237 p = clearresult.data;
239 res_code = RSVAL(p, 0);
241 free(clearresult.data);
243 if ((res_code < KRB5_KPASSWD_SUCCESS) ||
244 (res_code >= KRB5_KPASSWD_ACCESSDENIED)) {
245 return KRB5KRB_AP_ERR_MODIFIED;
251 ADS_STATUS krb5_set_password(const char *kdc_host, const char *princ, const char *newpw)
253 krb5_context context;
254 krb5_auth_context auth_context = NULL;
255 krb5_principal principal;
258 krb5_creds creds, *credsp;
260 krb5_data ap_req, chpw_req, chpw_rep;
261 int ret, sock, addr_len;
262 struct sockaddr remote_addr, local_addr;
263 krb5_address local_kaddr, remote_kaddr;
265 ret = krb5_init_context(&context);
267 DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
268 return ADS_ERROR_KRB5(ret);
271 ret = krb5_cc_default(context, &ccache);
273 krb5_free_context(context);
274 DEBUG(1,("Failed to get default creds (%s)\n", error_message(ret)));
275 return ADS_ERROR_KRB5(ret);
280 realm = strchr(princ, '@');
283 asprintf(&princ_name, "kadmin/changepw@%s", realm);
284 ret = krb5_parse_name(context, princ_name, &creds.server);
286 krb5_free_context(context);
287 DEBUG(1,("Failed to parse kadmin/changepw (%s)\n", error_message(ret)));
288 return ADS_ERROR_KRB5(ret);
292 /* parse the principal we got as a function argument */
293 ret = krb5_parse_name(context, princ, &principal);
295 krb5_free_context(context);
296 DEBUG(1,("Failed to parse %s (%s)\n", princ_name, error_message(ret)));
297 return ADS_ERROR_KRB5(ret);
300 krb5_princ_set_realm(context, creds.server,
301 krb5_princ_realm(context, principal));
303 ret = krb5_cc_get_principal(context, ccache, &creds.client);
305 krb5_free_principal(context, principal);
306 krb5_free_context(context);
307 DEBUG(1,("Failed to get principal from ccache (%s)\n",
308 error_message(ret)));
309 return ADS_ERROR_KRB5(ret);
312 ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
314 krb5_free_principal(context, creds.client);
315 krb5_free_principal(context, principal);
316 krb5_free_context(context);
317 DEBUG(1,("krb5_get_credentials failed (%s)\n", error_message(ret)));
318 return ADS_ERROR_KRB5(ret);
321 /* we might have to call krb5_free_creds(...) from now on ... */
322 ret = krb5_mk_req_extended(context, &auth_context, AP_OPTS_USE_SUBKEY,
323 NULL, credsp, &ap_req);
325 krb5_free_creds(context, credsp);
326 krb5_free_principal(context, creds.client);
327 krb5_free_principal(context, principal);
328 krb5_free_context(context);
329 DEBUG(1,("krb5_mk_req_extended failed (%s)\n", error_message(ret)));
330 return ADS_ERROR_KRB5(ret);
333 sock = open_udp_socket(kdc_host, DEFAULT_KPASSWD_PORT);
337 krb5_free_creds(context, credsp);
338 krb5_free_principal(context, creds.client);
339 krb5_free_principal(context, principal);
340 krb5_free_context(context);
341 DEBUG(1,("failed to open kpasswd socket to %s (%s)\n",
342 kdc_host, strerror(errno)));
343 return ADS_ERROR_SYSTEM(rc);
346 addr_len = sizeof(remote_addr);
347 getpeername(sock, &remote_addr, &addr_len);
348 addr_len = sizeof(local_addr);
349 getsockname(sock, &local_addr, &addr_len);
351 remote_kaddr.addrtype = ADDRTYPE_INET;
352 remote_kaddr.length = sizeof(((struct sockaddr_in *)&remote_addr)->sin_addr);
353 remote_kaddr.contents = (char *)&(((struct sockaddr_in *)&remote_addr)->sin_addr);
354 local_kaddr.addrtype = ADDRTYPE_INET;
355 local_kaddr.length = sizeof(((struct sockaddr_in *)&local_addr)->sin_addr);
356 local_kaddr.contents = (char *)&(((struct sockaddr_in *)&local_addr)->sin_addr);
358 ret = krb5_auth_con_setaddrs(context, auth_context, &local_kaddr, NULL);
362 krb5_free_creds(context, credsp);
363 krb5_free_principal(context, creds.client);
364 krb5_free_principal(context, principal);
365 krb5_free_context(context);
366 DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n", error_message(ret)));
367 return ADS_ERROR_KRB5(ret);
370 ret = build_setpw_request(context, auth_context, &ap_req,
371 princ, newpw, &chpw_req);
375 krb5_free_creds(context, credsp);
376 krb5_free_principal(context, creds.client);
377 krb5_free_principal(context, principal);
378 krb5_free_context(context);
379 DEBUG(1,("build_setpw_request failed (%s)\n", error_message(ret)));
380 return ADS_ERROR_KRB5(ret);
383 if (write(sock, chpw_req.data, chpw_req.length) != chpw_req.length) {
387 krb5_free_creds(context, credsp);
388 krb5_free_principal(context, creds.client);
389 krb5_free_principal(context, principal);
390 krb5_free_context(context);
391 DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
392 return ADS_ERROR_SYSTEM(errno);
397 chpw_rep.length = 1500;
398 chpw_rep.data = (char *) malloc(chpw_rep.length);
400 ret = read(sock, chpw_rep.data, chpw_rep.length);
405 krb5_free_creds(context, credsp);
406 krb5_free_principal(context, creds.client);
407 krb5_free_principal(context, principal);
408 krb5_free_context(context);
409 DEBUG(1,("recv of chpw reply failed (%s)\n", strerror(errno)));
410 return ADS_ERROR_SYSTEM(errno);
414 chpw_rep.length = ret;
416 ret = krb5_auth_con_setaddrs(context, auth_context, NULL,&remote_kaddr);
420 krb5_free_creds(context, credsp);
421 krb5_free_principal(context, creds.client);
422 krb5_free_principal(context, principal);
423 krb5_free_context(context);
424 DEBUG(1,("krb5_auth_con_setaddrs on reply failed (%s)\n",
425 error_message(ret)));
426 return ADS_ERROR_KRB5(ret);
429 ret = parse_setpw_reply(context, auth_context, &chpw_rep);
434 krb5_free_creds(context, credsp);
435 krb5_free_principal(context, creds.client);
436 krb5_free_principal(context, principal);
437 krb5_free_context(context);
438 DEBUG(1,("parse_setpw_reply failed (%s)\n",
439 error_message(ret)));
440 return ADS_ERROR_KRB5(ret);
444 krb5_free_creds(context, credsp);
445 krb5_free_principal(context, creds.client);
446 krb5_free_principal(context, principal);
447 krb5_free_context(context);
453 ADS_STATUS kerberos_set_password(const char *kpasswd_server,
454 const char *auth_principal, const char *auth_password,
455 const char *target_principal, const char *new_password)
459 if ((ret = kerberos_kinit_password(auth_principal, auth_password))) {
460 DEBUG(1,("Failed kinit for principal %s (%s)\n", auth_principal, error_message(ret)));
461 return ADS_ERROR_KRB5(ret);
464 return krb5_set_password(kpasswd_server, target_principal, new_password);