2 Unix SMB/CIFS implementation.
3 kerberos utility library
4 Copyright (C) Andrew Tridgell 2001
5 Copyright (C) Remus Koos 2001
6 Copyright (C) Luke Howard 2003
7 Copyright (C) Guenther Deschner 2003
8 Copyright (C) Jim McDonough (jmcd@us.ibm.com) 2003
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 #if !defined(HAVE_KRB5_PRINC_COMPONENT)
30 const krb5_data *krb5_princ_component(krb5_context, krb5_principal, int );
33 /**********************************************************************************
34 Try to verify a ticket using the system keytab... the system keytab has kvno -1 entries, so
35 it's more like what microsoft does... see comment in utils/net_ads.c in the
36 ads_keytab_add_entry function for details.
37 ***********************************************************************************/
39 static BOOL ads_keytab_verify_ticket(krb5_context context, krb5_auth_context auth_context,
40 const DATA_BLOB *ticket, krb5_data *p_packet, krb5_ticket **pp_tkt)
42 krb5_error_code ret = 0;
44 krb5_keytab keytab = NULL;
45 krb5_kt_cursor kt_cursor;
46 krb5_keytab_entry kt_entry;
47 char *valid_princ_formats[7] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL };
48 char *entry_princ_s = NULL;
49 fstring my_name, my_fqdn;
51 int number_matched_principals = 0;
53 /* Generate the list of principal names which we expect
54 * clients might want to use for authenticating to the file
55 * service. We allow name$,{host,cifs}/{name,fqdn,name.REALM}. */
57 fstrcpy(my_name, global_myname());
60 name_to_fqdn(my_fqdn, global_myname());
62 asprintf(&valid_princ_formats[0], "%s$@%s", my_name, lp_realm());
63 asprintf(&valid_princ_formats[1], "host/%s@%s", my_name, lp_realm());
64 asprintf(&valid_princ_formats[2], "host/%s@%s", my_fqdn, lp_realm());
65 asprintf(&valid_princ_formats[3], "host/%s.%s@%s", my_name, lp_realm(), lp_realm());
66 asprintf(&valid_princ_formats[4], "cifs/%s@%s", my_name, lp_realm());
67 asprintf(&valid_princ_formats[5], "cifs/%s@%s", my_fqdn, lp_realm());
68 asprintf(&valid_princ_formats[6], "cifs/%s.%s@%s", my_name, lp_realm(), lp_realm());
70 ZERO_STRUCT(kt_entry);
71 ZERO_STRUCT(kt_cursor);
73 ret = krb5_kt_default(context, &keytab);
75 DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_default failed (%s)\n", error_message(ret)));
79 /* Iterate through the keytab. For each key, if the principal
80 * name case-insensitively matches one of the allowed formats,
81 * try verifying the ticket using that principal. */
83 ret = krb5_kt_start_seq_get(context, keytab, &kt_cursor);
85 DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_start_seq_get failed (%s)\n", error_message(ret)));
89 if (ret != KRB5_KT_END && ret != ENOENT ) {
90 while (!auth_ok && (krb5_kt_next_entry(context, keytab, &kt_entry, &kt_cursor) == 0)) {
91 ret = krb5_unparse_name(context, kt_entry.principal, &entry_princ_s);
93 DEBUG(1, ("ads_keytab_verify_ticket: krb5_unparse_name failed (%s)\n", error_message(ret)));
97 for (i = 0; i < sizeof(valid_princ_formats) / sizeof(valid_princ_formats[0]); i++) {
98 if (strequal(entry_princ_s, valid_princ_formats[i])) {
99 number_matched_principals++;
100 p_packet->length = ticket->length;
101 p_packet->data = (krb5_pointer)ticket->data;
103 ret = krb5_rd_req(context, &auth_context, p_packet, kt_entry.principal, keytab, NULL, pp_tkt);
105 DEBUG(10, ("ads_keytab_verify_ticket: krb5_rd_req(%s) failed: %s\n",
106 entry_princ_s, error_message(ret)));
108 DEBUG(3,("ads_keytab_verify_ticket: krb5_rd_req succeeded for principal %s\n",
116 /* Free the name we parsed. */
117 krb5_free_unparsed_name(context, entry_princ_s);
118 entry_princ_s = NULL;
120 /* Free the entry we just read. */
121 smb_krb5_kt_free_entry(context, &kt_entry);
122 ZERO_STRUCT(kt_entry);
124 krb5_kt_end_seq_get(context, keytab, &kt_cursor);
127 ZERO_STRUCT(kt_cursor);
131 for (i = 0; i < sizeof(valid_princ_formats) / sizeof(valid_princ_formats[0]); i++) {
132 SAFE_FREE(valid_princ_formats[i]);
136 if (!number_matched_principals) {
137 DEBUG(3, ("ads_keytab_verify_ticket: no keytab principals matched expected file service name.\n"));
139 DEBUG(3, ("ads_keytab_verify_ticket: krb5_rd_req failed for all %d matched keytab principals\n",
140 number_matched_principals));
145 krb5_free_unparsed_name(context, entry_princ_s);
149 krb5_keytab_entry zero_kt_entry;
150 ZERO_STRUCT(zero_kt_entry);
151 if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
152 smb_krb5_kt_free_entry(context, &kt_entry);
157 krb5_kt_cursor zero_csr;
158 ZERO_STRUCT(zero_csr);
159 if ((memcmp(&kt_cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
160 krb5_kt_end_seq_get(context, keytab, &kt_cursor);
165 krb5_kt_close(context, keytab);
170 /**********************************************************************************
171 Try to verify a ticket using the secrets.tdb.
172 ***********************************************************************************/
174 static BOOL ads_secrets_verify_ticket(krb5_context context, krb5_auth_context auth_context,
175 krb5_principal host_princ,
176 const DATA_BLOB *ticket, krb5_data *p_packet, krb5_ticket **pp_tkt)
178 krb5_error_code ret = 0;
179 BOOL auth_ok = False;
180 char *password_s = NULL;
182 krb5_enctype *enctypes = NULL;
185 if (!secrets_init()) {
186 DEBUG(1,("ads_secrets_verify_ticket: secrets_init failed\n"));
190 password_s = secrets_fetch_machine_password(lp_workgroup(), NULL, NULL);
192 DEBUG(1,("ads_secrets_verify_ticket: failed to fetch machine password\n"));
196 password.data = password_s;
197 password.length = strlen(password_s);
199 /* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
201 if ((ret = get_kerberos_allowed_etypes(context, &enctypes))) {
202 DEBUG(1,("ads_secrets_verify_ticket: krb5_get_permitted_enctypes failed (%s)\n",
203 error_message(ret)));
207 p_packet->length = ticket->length;
208 p_packet->data = (krb5_pointer)ticket->data;
210 /* We need to setup a auth context with each possible encoding type in turn. */
211 for (i=0;enctypes[i];i++) {
212 krb5_keyblock *key = NULL;
214 if (!(key = SMB_MALLOC_P(krb5_keyblock))) {
218 if (create_kerberos_key_from_string(context, host_princ, &password, key, enctypes[i])) {
223 krb5_auth_con_setuseruserkey(context, auth_context, key);
225 krb5_free_keyblock(context, key);
227 if (!(ret = krb5_rd_req(context, &auth_context, p_packet,
229 NULL, NULL, pp_tkt))) {
230 DEBUG(10,("ads_secrets_verify_ticket: enc type [%u] decrypted message !\n",
231 (unsigned int)enctypes[i] ));
236 DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
237 ("ads_secrets_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
238 (unsigned int)enctypes[i], error_message(ret)));
243 free_kerberos_etypes(context, enctypes);
244 SAFE_FREE(password_s);
249 /**********************************************************************************
250 Verify an incoming ticket and parse out the principal name and
251 authorization_data if available.
252 ***********************************************************************************/
254 NTSTATUS ads_verify_ticket(const char *realm, const DATA_BLOB *ticket,
255 char **principal, DATA_BLOB *auth_data,
257 DATA_BLOB *session_key)
259 NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
260 krb5_context context = NULL;
261 krb5_auth_context auth_context = NULL;
263 krb5_ticket *tkt = NULL;
264 krb5_rcache rcache = NULL;
267 krb5_principal host_princ = NULL;
268 char *host_princ_s = NULL;
269 BOOL got_replay_mutex = False;
271 BOOL auth_ok = False;
274 ZERO_STRUCTP(auth_data);
275 ZERO_STRUCTP(ap_rep);
276 ZERO_STRUCTP(session_key);
278 initialize_krb5_error_table();
279 ret = krb5_init_context(&context);
281 DEBUG(1,("ads_verify_ticket: krb5_init_context failed (%s)\n", error_message(ret)));
282 return NT_STATUS_LOGON_FAILURE;
285 ret = krb5_set_default_realm(context, realm);
287 DEBUG(1,("ads_verify_ticket: krb5_set_default_realm failed (%s)\n", error_message(ret)));
291 /* This whole process is far more complex than I would
292 like. We have to go through all this to allow us to store
293 the secret internally, instead of using /etc/krb5.keytab */
295 ret = krb5_auth_con_init(context, &auth_context);
297 DEBUG(1,("ads_verify_ticket: krb5_auth_con_init failed (%s)\n", error_message(ret)));
301 asprintf(&host_princ_s, "%s$", global_myname());
302 strlower_m(host_princ_s);
303 ret = krb5_parse_name(context, host_princ_s, &host_princ);
305 DEBUG(1,("ads_verify_ticket: krb5_parse_name(%s) failed (%s)\n",
306 host_princ_s, error_message(ret)));
311 /* Lock a mutex surrounding the replay as there is no locking in the MIT krb5
312 * code surrounding the replay cache... */
314 if (!grab_server_mutex("replay cache mutex")) {
315 DEBUG(1,("ads_verify_ticket: unable to protect replay cache with mutex.\n"));
319 got_replay_mutex = True;
322 * JRA. We must set the rcache here. This will prevent replay attacks.
325 ret = krb5_get_server_rcache(context, krb5_princ_component(context, host_princ, 0), &rcache);
327 DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache failed (%s)\n", error_message(ret)));
331 ret = krb5_auth_con_setrcache(context, auth_context, rcache);
333 DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache failed (%s)\n", error_message(ret)));
337 if (lp_use_kerberos_keytab()) {
338 auth_ok = ads_keytab_verify_ticket(context, auth_context, ticket, &packet, &tkt);
341 auth_ok = ads_secrets_verify_ticket(context, auth_context, host_princ,
342 ticket, &packet, &tkt);
345 release_server_mutex();
346 got_replay_mutex = False;
349 DEBUG(3,("ads_verify_ticket: krb5_rd_req with auth failed (%s)\n",
350 error_message(ret)));
354 ret = krb5_mk_rep(context, auth_context, &packet);
356 DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
357 error_message(ret)));
361 *ap_rep = data_blob(packet.data, packet.length);
362 SAFE_FREE(packet.data);
365 get_krb5_smb_session_key(context, auth_context, session_key, True);
366 dump_data_pw("SMB session key (from ticket)\n", session_key->data, session_key->length);
369 file_save("/tmp/ticket.dat", ticket->data, ticket->length);
372 get_auth_data_from_tkt(auth_data, tkt);
375 TALLOC_CTX *ctx = talloc_init("pac data");
376 decode_pac_data(auth_data, ctx);
381 if (tkt->enc_part2) {
382 file_save("/tmp/authdata.dat",
383 tkt->enc_part2->authorization_data[0]->contents,
384 tkt->enc_part2->authorization_data[0]->length);
388 if ((ret = krb5_unparse_name(context, get_principal_from_tkt(tkt),
390 DEBUG(3,("ads_verify_ticket: krb5_unparse_name failed (%s)\n",
391 error_message(ret)));
392 sret = NT_STATUS_LOGON_FAILURE;
400 if (got_replay_mutex) {
401 release_server_mutex();
404 if (!NT_STATUS_IS_OK(sret)) {
405 data_blob_free(auth_data);
408 if (!NT_STATUS_IS_OK(sret)) {
409 data_blob_free(ap_rep);
413 krb5_free_principal(context, host_princ);
417 krb5_free_ticket(context, tkt);
420 SAFE_FREE(host_princ_s);
423 krb5_auth_con_free(context, auth_context);
427 krb5_free_context(context);
433 #endif /* HAVE_KRB5 */