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 /**********************************************************************************
30 Try to verify a ticket using the system keytab... the system keytab has kvno -1 entries, so
31 it's more like what microsoft does... see comment in utils/net_ads.c in the
32 ads_keytab_add_entry function for details.
33 ***********************************************************************************/
35 static BOOL ads_keytab_verify_ticket(krb5_context context, krb5_auth_context auth_context,
36 const DATA_BLOB *ticket, krb5_data *p_packet, krb5_ticket **pp_tkt)
38 krb5_error_code ret = 0;
41 krb5_keytab keytab = NULL;
42 krb5_kt_cursor cursor;
43 krb5_keytab_entry kt_entry;
44 char *princ_name = NULL;
46 ZERO_STRUCT(kt_entry);
49 ret = krb5_kt_default(context, &keytab);
51 DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_default failed (%s)\n", error_message(ret)));
55 ret = krb5_kt_start_seq_get(context, keytab, &cursor);
57 DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_start_seq_get failed (%s)\n", error_message(ret)));
61 while (!krb5_kt_next_entry(context, keytab, &kt_entry, &cursor)) {
62 ret = krb5_unparse_name(context, kt_entry.principal, &princ_name);
64 DEBUG(1, ("ads_keytab_verify_ticket: krb5_unparse_name failed (%s)\n", error_message(ret)));
67 /* Look for a CIFS ticket */
68 if (!StrnCaseCmp(princ_name, "cifs/", 5)) {
69 #ifdef HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK
70 krb5_auth_con_setuseruserkey(context, auth_context, &kt_entry.keyblock);
72 krb5_auth_con_setuseruserkey(context, auth_context, &kt_entry.key);
75 p_packet->length = ticket->length;
76 p_packet->data = (krb5_pointer)ticket->data;
78 if (!(ret = krb5_rd_req(context, &auth_context, p_packet, NULL, NULL, NULL, pp_tkt))) {
79 krb5_free_unparsed_name(context, princ_name);
81 DEBUG(10,("ads_keytab_verify_ticket: enc type [%u] decrypted message !\n",
82 #ifdef HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK
83 (unsigned int) kt_entry.keyblock.keytype));
85 (unsigned int) kt_entry.key.enctype));
91 krb5_free_unparsed_name(context, princ_name);
94 if (ret && ret != KRB5_KT_END) {
95 /* This failed because something went wrong, not because the keytab file was empty. */
96 DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_next_entry failed (%s)\n", error_message(ret)));
103 krb5_free_unparsed_name(context, princ_name);
106 krb5_kt_cursor zero_csr;
107 ZERO_STRUCT(zero_csr);
108 if ((memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
109 krb5_kt_end_seq_get(context, keytab, &cursor);
113 krb5_kt_close(context, keytab);
119 /**********************************************************************************
120 Try to verify a ticket using the secrets.tdb.
121 ***********************************************************************************/
123 static BOOL ads_secrets_verify_ticket(krb5_context context, krb5_auth_context auth_context,
124 krb5_principal host_princ,
125 const DATA_BLOB *ticket, krb5_data *p_packet, krb5_ticket **pp_tkt)
127 krb5_error_code ret = 0;
128 BOOL auth_ok = False;
129 char *password_s = NULL;
131 krb5_enctype *enctypes = NULL;
134 if (!secrets_init()) {
135 DEBUG(1,("ads_secrets_verify_ticket: secrets_init failed\n"));
139 password_s = secrets_fetch_machine_password(lp_workgroup(), NULL, NULL);
141 DEBUG(1,("ads_secrets_verify_ticket: failed to fetch machine password\n"));
145 password.data = password_s;
146 password.length = strlen(password_s);
148 /* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
150 if ((ret = get_kerberos_allowed_etypes(context, &enctypes))) {
151 DEBUG(1,("ads_secrets_verify_ticket: krb5_get_permitted_enctypes failed (%s)\n",
152 error_message(ret)));
156 p_packet->length = ticket->length;
157 p_packet->data = (krb5_pointer)ticket->data;
159 /* We need to setup a auth context with each possible encoding type in turn. */
160 for (i=0;enctypes[i];i++) {
161 krb5_keyblock *key = NULL;
163 if (!(key = (krb5_keyblock *)malloc(sizeof(*key)))) {
167 if (create_kerberos_key_from_string(context, host_princ, &password, key, enctypes[i])) {
172 krb5_auth_con_setuseruserkey(context, auth_context, key);
174 krb5_free_keyblock(context, key);
176 if (!(ret = krb5_rd_req(context, &auth_context, p_packet,
178 NULL, NULL, pp_tkt))) {
179 DEBUG(10,("ads_secrets_verify_ticket: enc type [%u] decrypted message !\n",
180 (unsigned int)enctypes[i] ));
185 DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
186 ("ads_secrets_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
187 (unsigned int)enctypes[i], error_message(ret)));
192 free_kerberos_etypes(context, enctypes);
193 SAFE_FREE(password_s);
198 /**********************************************************************************
199 Verify an incoming ticket and parse out the principal name and
200 authorization_data if available.
201 ***********************************************************************************/
203 NTSTATUS ads_verify_ticket(const char *realm, const DATA_BLOB *ticket,
204 char **principal, DATA_BLOB *auth_data,
206 DATA_BLOB *session_key)
208 NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
209 krb5_context context = NULL;
210 krb5_auth_context auth_context = NULL;
212 krb5_ticket *tkt = NULL;
213 krb5_rcache rcache = NULL;
216 krb5_principal host_princ = NULL;
217 char *host_princ_s = NULL;
218 BOOL got_replay_mutex = False;
221 BOOL auth_ok = False;
224 ZERO_STRUCTP(auth_data);
225 ZERO_STRUCTP(ap_rep);
226 ZERO_STRUCTP(session_key);
228 initialize_krb5_error_table();
229 ret = krb5_init_context(&context);
231 DEBUG(1,("ads_verify_ticket: krb5_init_context failed (%s)\n", error_message(ret)));
232 return NT_STATUS_LOGON_FAILURE;
235 ret = krb5_set_default_realm(context, realm);
237 DEBUG(1,("ads_verify_ticket: krb5_set_default_realm failed (%s)\n", error_message(ret)));
241 /* This whole process is far more complex than I would
242 like. We have to go through all this to allow us to store
243 the secret internally, instead of using /etc/krb5.keytab */
245 ret = krb5_auth_con_init(context, &auth_context);
247 DEBUG(1,("ads_verify_ticket: krb5_auth_con_init failed (%s)\n", error_message(ret)));
251 name_to_fqdn(myname, global_myname());
253 asprintf(&host_princ_s, "host/%s@%s", myname, lp_realm());
254 ret = krb5_parse_name(context, host_princ_s, &host_princ);
256 DEBUG(1,("ads_verify_ticket: krb5_parse_name(%s) failed (%s)\n",
257 host_princ_s, error_message(ret)));
262 /* Lock a mutex surrounding the replay as there is no locking in the MIT krb5
263 * code surrounding the replay cache... */
265 if (!grab_server_mutex("replay cache mutex")) {
266 DEBUG(1,("ads_verify_ticket: unable to protect replay cache with mutex.\n"));
270 got_replay_mutex = True;
273 * JRA. We must set the rcache here. This will prevent replay attacks.
276 ret = krb5_get_server_rcache(context, krb5_princ_component(context, host_princ, 0), &rcache);
278 DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache failed (%s)\n", error_message(ret)));
282 ret = krb5_auth_con_setrcache(context, auth_context, rcache);
284 DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache failed (%s)\n", error_message(ret)));
288 if (lp_use_kerberos_keytab()) {
289 auth_ok = ads_keytab_verify_ticket(context, auth_context, ticket, &packet, &tkt);
292 auth_ok = ads_secrets_verify_ticket(context, auth_context, host_princ,
293 ticket, &packet, &tkt);
296 release_server_mutex();
297 got_replay_mutex = False;
300 DEBUG(3,("ads_verify_ticket: krb5_rd_req with auth failed (%s)\n",
301 error_message(ret)));
305 ret = krb5_mk_rep(context, auth_context, &packet);
307 DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
308 error_message(ret)));
312 *ap_rep = data_blob(packet.data, packet.length);
313 SAFE_FREE(packet.data);
316 get_krb5_smb_session_key(context, auth_context, session_key, True);
317 dump_data_pw("SMB session key (from ticket)\n", session_key->data, session_key->length);
320 file_save("/tmp/ticket.dat", ticket->data, ticket->length);
323 get_auth_data_from_tkt(auth_data, tkt);
326 TALLOC_CTX *ctx = talloc_init("pac data");
327 decode_pac_data(auth_data, ctx);
332 if (tkt->enc_part2) {
333 file_save("/tmp/authdata.dat",
334 tkt->enc_part2->authorization_data[0]->contents,
335 tkt->enc_part2->authorization_data[0]->length);
339 if ((ret = krb5_unparse_name(context, get_principal_from_tkt(tkt),
341 DEBUG(3,("ads_verify_ticket: krb5_unparse_name failed (%s)\n",
342 error_message(ret)));
343 sret = NT_STATUS_LOGON_FAILURE;
351 if (got_replay_mutex) {
352 release_server_mutex();
355 if (!NT_STATUS_IS_OK(sret)) {
356 data_blob_free(auth_data);
359 if (!NT_STATUS_IS_OK(sret)) {
360 data_blob_free(ap_rep);
364 krb5_free_principal(context, host_princ);
368 krb5_free_ticket(context, tkt);
371 SAFE_FREE(host_princ_s);
374 krb5_auth_con_free(context, auth_context);
378 krb5_free_context(context);
384 #endif /* HAVE_KRB5 */