2 Unix SMB/Netbios implementation.
4 krb5 set password implementation
5 Copyright (C) Andrew Tridgell 2001
6 Copyright (C) Remus Koos 2001 (remuskoos@yahoo.com)
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 #define DEFAULT_KPASSWD_PORT 464
28 #define KRB5_KPASSWD_VERS_CHANGEPW 1
29 #define KRB5_KPASSWD_VERS_SETPW 0xff80
30 #define KRB5_KPASSWD_ACCESSDENIED 5
31 #define KRB5_KPASSWD_BAD_VERSION 6
33 /* This implements the Kerb password change protocol as specifed in
34 * kerb-chg-password-02.txt
36 static DATA_BLOB encode_krb5_setpw(const char *principal, const char *password)
38 char* princ_part1 = NULL;
39 char* princ_part2 = NULL;
48 princ = strdup(principal);
50 if ((c = strchr(princ, '/')) == NULL) {
60 if ((c = strchr(c, '@')) != NULL) {
66 memset(&req, 0, sizeof(req));
68 asn1_push_tag(&req, ASN1_SEQUENCE(0));
69 asn1_push_tag(&req, ASN1_CONTEXT(0));
70 asn1_write_OctetString(&req, password, strlen(password));
73 asn1_push_tag(&req, ASN1_CONTEXT(1));
74 asn1_push_tag(&req, ASN1_SEQUENCE(0));
76 asn1_push_tag(&req, ASN1_CONTEXT(0));
77 asn1_write_Integer(&req, 1);
80 asn1_push_tag(&req, ASN1_CONTEXT(1));
81 asn1_push_tag(&req, ASN1_SEQUENCE(0));
84 asn1_write_GeneralString(&req, princ_part1);
86 asn1_write_GeneralString(&req, princ_part2);
92 asn1_push_tag(&req, ASN1_CONTEXT(2));
93 asn1_write_GeneralString(&req, realm);
97 ret = data_blob(req.data, req.length);
105 static krb5_error_code build_setpw_request(krb5_context context,
106 krb5_auth_context auth_context,
114 krb5_data encoded_setpw;
115 krb5_replay_data replay;
119 ret = krb5_auth_con_setflags(context,
120 auth_context,KRB5_AUTH_CONTEXT_DO_SEQUENCE);
122 DEBUG(1,("krb5_auth_con_setflags failed (%s)\n",
123 error_message(ret)));
127 setpw = encode_krb5_setpw(princ, passwd);
129 encoded_setpw.data = setpw.data;
130 encoded_setpw.length = setpw.length;
132 ret = krb5_mk_priv(context, auth_context,
133 &encoded_setpw, &cipherpw, &replay);
135 data_blob_free(&setpw); /*from 'encode_krb5_setpw(...)' */
138 DEBUG(1,("krb5_mk_priv failed (%s)\n", error_message(ret)));
142 packet->data = (char *)malloc(ap_req->length + cipherpw.length + 6);
144 /* see the RFC for details */
145 p = packet->data + 2;
146 RSSVAL(p, 0, 0xff80); p += 2;
147 RSSVAL(p, 0, ap_req->length); p += 2;
148 memcpy(p, ap_req->data, ap_req->length); p += ap_req->length;
149 memcpy(p, cipherpw.data, cipherpw.length); p += cipherpw.length;
150 packet->length = PTR_DIFF(p,packet->data);
151 RSSVAL(packet->data, 0, packet->length);
153 free(cipherpw.data); /* from 'krb5_mk_priv(...)' */
158 static krb5_error_code parse_setpw_reply(krb5_context context,
159 krb5_auth_context auth_context,
164 int vnum, ret, res_code;
165 krb5_data cipherresult;
166 krb5_data clearresult;
167 krb5_ap_rep_enc_part *ap_rep_enc;
168 krb5_replay_data replay;
170 if (packet->length < 4) {
171 return KRB5KRB_AP_ERR_MODIFIED;
176 if (packet->data[0] == 0x7e || packet->data[0] == 0x5e) {
177 /* it's an error packet. We should parse it ... */
178 DEBUG(1,("Got error packet 0x%x from kpasswd server\n",
180 return KRB5KRB_AP_ERR_MODIFIED;
183 if (RSVAL(p, 0) != packet->length) {
184 DEBUG(1,("Bad packet length (%d/%d) from kpasswd server\n",
185 RSVAL(p, 0), packet->length));
186 return KRB5KRB_AP_ERR_MODIFIED;
191 vnum = RSVAL(p, 0); p += 2;
193 if (vnum != KRB5_KPASSWD_VERS_SETPW && vnum != KRB5_KPASSWD_VERS_CHANGEPW) {
194 DEBUG(1,("Bad vnum (%d) from kpasswd server\n", vnum));
195 return KRB5KDC_ERR_BAD_PVNO;
198 ap_rep.length = RSVAL(p, 0); p += 2;
200 if (p + ap_rep.length >= packet->data + packet->length) {
201 DEBUG(1,("ptr beyond end of packet from kpasswd server\n"));
202 return KRB5KRB_AP_ERR_MODIFIED;
205 if (ap_rep.length == 0) {
206 DEBUG(1,("got unencrypted setpw result?!\n"));
207 return KRB5KRB_AP_ERR_MODIFIED;
214 ret = krb5_rd_rep(context, auth_context, &ap_rep, &ap_rep_enc);
216 DEBUG(1,("failed to rd setpw reply (%s)\n", error_message(ret)));
217 return KRB5KRB_AP_ERR_MODIFIED;
220 krb5_free_ap_rep_enc_part(context, ap_rep_enc);
222 cipherresult.data = p;
223 cipherresult.length = (packet->data + packet->length) - p;
225 ret = krb5_rd_priv(context, auth_context, &cipherresult, &clearresult,
228 DEBUG(1,("failed to decrypt setpw reply (%s)\n", error_message(ret)));
229 return KRB5KRB_AP_ERR_MODIFIED;
232 if (clearresult.length < 2) {
233 free(clearresult.data);
234 ret = KRB5KRB_AP_ERR_MODIFIED;
235 return KRB5KRB_AP_ERR_MODIFIED;
238 p = clearresult.data;
240 res_code = RSVAL(p, 0);
242 free(clearresult.data);
244 if ((res_code < KRB5_KPASSWD_SUCCESS) ||
245 (res_code >= KRB5_KPASSWD_ACCESSDENIED)) {
246 return KRB5KRB_AP_ERR_MODIFIED;
252 ADS_STATUS krb5_set_password(const char *kdc_host, const char *princ, const char *newpw)
254 krb5_context context;
255 krb5_auth_context auth_context = NULL;
256 krb5_principal principal;
259 krb5_creds creds, *credsp;
261 krb5_data ap_req, chpw_req, chpw_rep;
262 int ret, sock, addr_len;
263 struct sockaddr remote_addr, local_addr;
264 krb5_address local_kaddr, remote_kaddr;
266 ret = krb5_init_context(&context);
268 DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
269 return ADS_ERROR_KRB5(ret);
272 ret = krb5_cc_default(context, &ccache);
274 krb5_free_context(context);
275 DEBUG(1,("Failed to get default creds (%s)\n", error_message(ret)));
276 return ADS_ERROR_KRB5(ret);
281 realm = strchr(princ, '@');
284 asprintf(&princ_name, "kadmin/changepw@%s", realm);
285 ret = krb5_parse_name(context, princ_name, &creds.server);
287 krb5_free_context(context);
288 DEBUG(1,("Failed to parse kadmin/changepw (%s)\n", error_message(ret)));
289 return ADS_ERROR_KRB5(ret);
293 /* parse the principal we got as a function argument */
294 ret = krb5_parse_name(context, princ, &principal);
296 krb5_free_context(context);
297 DEBUG(1,("Failed to parse %s (%s)\n", princ_name, error_message(ret)));
298 return ADS_ERROR_KRB5(ret);
301 krb5_princ_set_realm(context, creds.server,
302 krb5_princ_realm(context, principal));
304 ret = krb5_cc_get_principal(context, ccache, &creds.client);
306 krb5_free_principal(context, principal);
307 krb5_free_context(context);
308 DEBUG(1,("Failed to get principal from ccache (%s)\n",
309 error_message(ret)));
310 return ADS_ERROR_KRB5(ret);
313 ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
315 krb5_free_principal(context, creds.client);
316 krb5_free_principal(context, principal);
317 krb5_free_context(context);
318 DEBUG(1,("krb5_get_credentials failed (%s)\n", error_message(ret)));
319 return ADS_ERROR_KRB5(ret);
322 /* we might have to call krb5_free_creds(...) from now on ... */
323 ret = krb5_mk_req_extended(context, &auth_context, AP_OPTS_USE_SUBKEY,
324 NULL, credsp, &ap_req);
326 krb5_free_creds(context, credsp);
327 krb5_free_principal(context, creds.client);
328 krb5_free_principal(context, principal);
329 krb5_free_context(context);
330 DEBUG(1,("krb5_mk_req_extended failed (%s)\n", error_message(ret)));
331 return ADS_ERROR_KRB5(ret);
334 sock = open_udp_socket(kdc_host, DEFAULT_KPASSWD_PORT);
338 krb5_free_creds(context, credsp);
339 krb5_free_principal(context, creds.client);
340 krb5_free_principal(context, principal);
341 krb5_free_context(context);
342 DEBUG(1,("failed to open kpasswd socket to %s (%s)\n",
343 kdc_host, strerror(errno)));
344 return ADS_ERROR_SYSTEM(rc);
347 addr_len = sizeof(remote_addr);
348 getpeername(sock, &remote_addr, &addr_len);
349 addr_len = sizeof(local_addr);
350 getsockname(sock, &local_addr, &addr_len);
352 remote_kaddr.addrtype = ADDRTYPE_INET;
353 remote_kaddr.length = sizeof(((struct sockaddr_in *)&remote_addr)->sin_addr);
354 remote_kaddr.contents = (char *)&(((struct sockaddr_in *)&remote_addr)->sin_addr);
355 local_kaddr.addrtype = ADDRTYPE_INET;
356 local_kaddr.length = sizeof(((struct sockaddr_in *)&local_addr)->sin_addr);
357 local_kaddr.contents = (char *)&(((struct sockaddr_in *)&local_addr)->sin_addr);
359 ret = krb5_auth_con_setaddrs(context, auth_context, &local_kaddr, NULL);
363 krb5_free_creds(context, credsp);
364 krb5_free_principal(context, creds.client);
365 krb5_free_principal(context, principal);
366 krb5_free_context(context);
367 DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n", error_message(ret)));
368 return ADS_ERROR_KRB5(ret);
371 ret = build_setpw_request(context, auth_context, &ap_req,
372 princ, newpw, &chpw_req);
376 krb5_free_creds(context, credsp);
377 krb5_free_principal(context, creds.client);
378 krb5_free_principal(context, principal);
379 krb5_free_context(context);
380 DEBUG(1,("build_setpw_request failed (%s)\n", error_message(ret)));
381 return ADS_ERROR_KRB5(ret);
384 if (write(sock, chpw_req.data, chpw_req.length) != chpw_req.length) {
388 krb5_free_creds(context, credsp);
389 krb5_free_principal(context, creds.client);
390 krb5_free_principal(context, principal);
391 krb5_free_context(context);
392 DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
393 return ADS_ERROR_SYSTEM(errno);
398 chpw_rep.length = 1500;
399 chpw_rep.data = (char *) malloc(chpw_rep.length);
401 ret = read(sock, chpw_rep.data, chpw_rep.length);
406 krb5_free_creds(context, credsp);
407 krb5_free_principal(context, creds.client);
408 krb5_free_principal(context, principal);
409 krb5_free_context(context);
410 DEBUG(1,("recv of chpw reply failed (%s)\n", strerror(errno)));
411 return ADS_ERROR_SYSTEM(errno);
415 chpw_rep.length = ret;
417 ret = krb5_auth_con_setaddrs(context, auth_context, NULL,&remote_kaddr);
421 krb5_free_creds(context, credsp);
422 krb5_free_principal(context, creds.client);
423 krb5_free_principal(context, principal);
424 krb5_free_context(context);
425 DEBUG(1,("krb5_auth_con_setaddrs on reply failed (%s)\n",
426 error_message(ret)));
427 return ADS_ERROR_KRB5(ret);
430 ret = parse_setpw_reply(context, auth_context, &chpw_rep);
435 krb5_free_creds(context, credsp);
436 krb5_free_principal(context, creds.client);
437 krb5_free_principal(context, principal);
438 krb5_free_context(context);
439 DEBUG(1,("parse_setpw_reply failed (%s)\n",
440 error_message(ret)));
441 return ADS_ERROR_KRB5(ret);
445 krb5_free_creds(context, credsp);
446 krb5_free_principal(context, creds.client);
447 krb5_free_principal(context, principal);
448 krb5_free_context(context);
454 ADS_STATUS kerberos_set_password(const char *kpasswd_server,
455 const char *auth_principal, const char *auth_password,
456 const char *target_principal, const char *new_password)
460 if ((ret = kerberos_kinit_password(auth_principal, auth_password))) {
461 DEBUG(1,("Failed kinit for principal %s (%s)\n", auth_principal, error_message(ret)));
462 return ADS_ERROR_KRB5(ret);
465 return krb5_set_password(kpasswd_server, target_principal, new_password);