Line data Source code
1 : /*
2 : Unix SMB/CIFS implementation.
3 : kerberos authorization data (PAC) utility library
4 : Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003
5 : Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
6 : Copyright (C) Andrew Tridgell 2001
7 : Copyright (C) Luke Howard 2002-2003
8 : Copyright (C) Stefan Metzmacher 2004-2005
9 : Copyright (C) Guenther Deschner 2005,2007,2008
10 :
11 : This program is free software; you can redistribute it and/or modify
12 : it under the terms of the GNU General Public License as published by
13 : the Free Software Foundation; either version 3 of the License, or
14 : (at your option) any later version.
15 :
16 : This program is distributed in the hope that it will be useful,
17 : but WITHOUT ANY WARRANTY; without even the implied warranty of
18 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 : GNU General Public License for more details.
20 :
21 : You should have received a copy of the GNU General Public License
22 : along with this program. If not, see <http://www.gnu.org/licenses/>.
23 : */
24 :
25 : #include "includes.h"
26 : #include "librpc/gen_ndr/ndr_krb5pac.h"
27 : #include "smb_krb5.h"
28 : #include "libads/kerberos_proto.h"
29 : #include "auth/common_auth.h"
30 : #include "lib/param/param.h"
31 : #include "librpc/crypto/gse.h"
32 : #include "auth/gensec/gensec.h"
33 : #include "auth/gensec/gensec_internal.h" /* TODO: remove this */
34 : #include "../libcli/auth/spnego.h"
35 : #include "lib/util/asn1.h"
36 :
37 : #ifdef HAVE_KRB5
38 :
39 : #include "auth/kerberos/pac_utils.h"
40 :
41 : struct smb_krb5_context;
42 :
43 : /*
44 : generate a krb5 GSS-API wrapper packet given a ticket
45 : */
46 0 : static DATA_BLOB spnego_gen_krb5_wrap(
47 : TALLOC_CTX *ctx, const DATA_BLOB ticket, const uint8_t tok_id[2])
48 : {
49 0 : ASN1_DATA *data;
50 0 : DATA_BLOB ret = data_blob_null;
51 :
52 0 : data = asn1_init(talloc_tos(), ASN1_MAX_TREE_DEPTH);
53 0 : if (data == NULL) {
54 0 : return data_blob_null;
55 : }
56 :
57 0 : if (!asn1_push_tag(data, ASN1_APPLICATION(0))) goto err;
58 0 : if (!asn1_write_OID(data, OID_KERBEROS5)) goto err;
59 :
60 0 : if (!asn1_write(data, tok_id, 2)) goto err;
61 0 : if (!asn1_write(data, ticket.data, ticket.length)) goto err;
62 0 : if (!asn1_pop_tag(data)) goto err;
63 :
64 0 : if (!asn1_extract_blob(data, ctx, &ret)) {
65 0 : goto err;
66 : }
67 :
68 0 : asn1_free(data);
69 0 : data = NULL;
70 :
71 0 : err:
72 :
73 0 : if (data != NULL) {
74 0 : if (asn1_has_error(data)) {
75 0 : DEBUG(1, ("Failed to build krb5 wrapper at offset %d\n",
76 : (int)asn1_current_ofs(data)));
77 : }
78 :
79 0 : asn1_free(data);
80 : }
81 :
82 0 : return ret;
83 : }
84 :
85 : /*
86 : * Given the username/password, do a kinit, store the ticket in
87 : * cache_name if specified, and return the PAC_LOGON_INFO (the
88 : * structure containing the important user information such as
89 : * groups).
90 : */
91 0 : NTSTATUS kerberos_return_pac(TALLOC_CTX *mem_ctx,
92 : const char *name,
93 : const char *pass,
94 : time_t time_offset,
95 : time_t *expire_time,
96 : time_t *renew_till_time,
97 : const char *cache_name,
98 : bool request_pac,
99 : bool add_netbios_addr,
100 : time_t renewable_time,
101 : const char *impersonate_princ_s,
102 : const char *local_service,
103 : char **_canon_principal,
104 : char **_canon_realm,
105 : struct PAC_DATA_CTR **_pac_data_ctr)
106 : {
107 0 : krb5_error_code ret;
108 0 : NTSTATUS status = NT_STATUS_INVALID_PARAMETER;
109 0 : DATA_BLOB tkt = data_blob_null;
110 0 : DATA_BLOB tkt_wrapped = data_blob_null;
111 0 : DATA_BLOB ap_rep = data_blob_null;
112 0 : DATA_BLOB sesskey1 = data_blob_null;
113 0 : const char *auth_princ = NULL;
114 0 : const char *cc = "MEMORY:kerberos_return_pac";
115 0 : struct auth_session_info *session_info;
116 0 : struct gensec_security *gensec_server_context;
117 0 : const struct gensec_security_ops **backends;
118 0 : struct gensec_settings *gensec_settings;
119 0 : size_t idx = 0;
120 0 : struct auth4_context *auth_context;
121 0 : struct loadparm_context *lp_ctx;
122 0 : struct PAC_DATA_CTR *pac_data_ctr = NULL;
123 0 : char *canon_principal = NULL;
124 0 : char *canon_realm = NULL;
125 :
126 0 : TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
127 0 : NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
128 :
129 0 : ZERO_STRUCT(tkt);
130 0 : ZERO_STRUCT(ap_rep);
131 0 : ZERO_STRUCT(sesskey1);
132 :
133 0 : if (!name || !pass) {
134 0 : status = NT_STATUS_INVALID_PARAMETER;
135 0 : goto out;
136 : }
137 :
138 0 : if (_canon_principal != NULL) {
139 0 : *_canon_principal = NULL;
140 : }
141 :
142 0 : if (_canon_realm != NULL) {
143 0 : *_canon_realm = NULL;
144 : }
145 :
146 0 : if (cache_name) {
147 0 : cc = cache_name;
148 : }
149 :
150 0 : if (!strchr_m(name, '@')) {
151 0 : auth_princ = talloc_asprintf(mem_ctx, "%s@%s", name,
152 : lp_realm());
153 : } else {
154 0 : auth_princ = name;
155 : }
156 0 : NT_STATUS_HAVE_NO_MEMORY(auth_princ);
157 :
158 0 : ret = kerberos_kinit_password_ext(auth_princ,
159 : pass,
160 : time_offset,
161 : expire_time,
162 : renew_till_time,
163 : cc,
164 : request_pac,
165 : add_netbios_addr,
166 : renewable_time,
167 : tmp_ctx,
168 : &canon_principal,
169 : &canon_realm,
170 : &status);
171 0 : if (ret) {
172 0 : DEBUG(1,("kinit failed for '%s' with: %s (%d)\n",
173 : auth_princ, error_message(ret), ret));
174 : /* status already set */
175 0 : goto out;
176 : }
177 :
178 0 : DEBUG(10,("got TGT for %s in %s\n", auth_princ, cc));
179 0 : if (expire_time) {
180 0 : DEBUGADD(10,("\tvalid until: %s (%d)\n",
181 : http_timestring(talloc_tos(), *expire_time),
182 : (int)*expire_time));
183 : }
184 0 : if (renew_till_time) {
185 0 : DEBUGADD(10,("\trenewable till: %s (%d)\n",
186 : http_timestring(talloc_tos(), *renew_till_time),
187 : (int)*renew_till_time));
188 : }
189 :
190 : /* we cannot continue with krb5 when UF_DONT_REQUIRE_PREAUTH is set,
191 : * in that case fallback to NTLM - gd */
192 :
193 0 : if (expire_time && renew_till_time &&
194 0 : (*expire_time == 0) && (*renew_till_time == 0)) {
195 0 : status = NT_STATUS_INVALID_LOGON_TYPE;
196 0 : goto out;
197 : }
198 :
199 0 : ret = ads_krb5_cli_get_ticket(mem_ctx,
200 : local_service,
201 : time_offset,
202 : &tkt,
203 : &sesskey1,
204 : 0,
205 : cc,
206 : NULL,
207 : impersonate_princ_s);
208 0 : if (ret) {
209 0 : DEBUG(1,("failed to get ticket for %s: %s\n",
210 : local_service, error_message(ret)));
211 0 : if (impersonate_princ_s) {
212 0 : DEBUGADD(1,("tried S4U2SELF impersonation as: %s\n",
213 : impersonate_princ_s));
214 : }
215 0 : status = krb5_to_nt_status(ret);
216 0 : goto out;
217 : }
218 :
219 : /* wrap that up in a nice GSS-API wrapping */
220 0 : tkt_wrapped = spnego_gen_krb5_wrap(tmp_ctx, tkt, TOK_ID_KRB_AP_REQ);
221 0 : if (tkt_wrapped.data == NULL) {
222 0 : status = NT_STATUS_NO_MEMORY;
223 0 : goto out;
224 : }
225 :
226 0 : auth_context = auth4_context_for_PAC_DATA_CTR(tmp_ctx);
227 0 : if (auth_context == NULL) {
228 0 : status = NT_STATUS_NO_MEMORY;
229 0 : goto out;
230 : }
231 :
232 0 : lp_ctx = loadparm_init_s3(tmp_ctx, loadparm_s3_helpers());
233 0 : if (lp_ctx == NULL) {
234 0 : status = NT_STATUS_INVALID_SERVER_STATE;
235 0 : DEBUG(10, ("loadparm_init_s3 failed\n"));
236 0 : goto out;
237 : }
238 :
239 0 : gensec_settings = lpcfg_gensec_settings(tmp_ctx, lp_ctx);
240 0 : if (gensec_settings == NULL) {
241 0 : status = NT_STATUS_NO_MEMORY;
242 0 : DEBUG(10, ("lpcfg_gensec_settings failed\n"));
243 0 : goto out;
244 : }
245 :
246 0 : backends = talloc_zero_array(gensec_settings,
247 : const struct gensec_security_ops *, 2);
248 0 : if (backends == NULL) {
249 0 : status = NT_STATUS_NO_MEMORY;
250 0 : goto out;
251 : }
252 0 : gensec_settings->backends = backends;
253 :
254 0 : gensec_init();
255 :
256 0 : backends[idx++] = &gensec_gse_krb5_security_ops;
257 :
258 0 : status = gensec_server_start(tmp_ctx, gensec_settings,
259 : auth_context, &gensec_server_context);
260 :
261 0 : if (!NT_STATUS_IS_OK(status)) {
262 0 : DEBUG(1, (__location__ "Failed to start server-side GENSEC to validate a Kerberos ticket: %s\n", nt_errstr(status)));
263 0 : goto out;
264 : }
265 :
266 0 : talloc_unlink(tmp_ctx, lp_ctx);
267 0 : talloc_unlink(tmp_ctx, gensec_settings);
268 0 : talloc_unlink(tmp_ctx, auth_context);
269 :
270 : /* Session info is not complete, do not pass to auth log */
271 0 : gensec_want_feature(gensec_server_context, GENSEC_FEATURE_NO_AUTHZ_LOG);
272 :
273 0 : status = gensec_start_mech_by_oid(gensec_server_context, GENSEC_OID_KERBEROS5);
274 0 : if (!NT_STATUS_IS_OK(status)) {
275 0 : DEBUG(1, (__location__ "Failed to start server-side GENSEC krb5 to validate a Kerberos ticket: %s\n", nt_errstr(status)));
276 0 : goto out;
277 : }
278 :
279 : /* Do a client-server update dance */
280 0 : status = gensec_update(gensec_server_context, tmp_ctx, tkt_wrapped, &ap_rep);
281 0 : if (!NT_STATUS_IS_OK(status)) {
282 0 : DEBUG(1, ("gensec_update() failed: %s\n", nt_errstr(status)));
283 0 : goto out;
284 : }
285 :
286 : /* Now return the PAC information to the callers. We ignore
287 : * the session_info and instead pick out the PAC via the
288 : * private_data on the auth_context */
289 0 : status = gensec_session_info(gensec_server_context, tmp_ctx, &session_info);
290 0 : if (!NT_STATUS_IS_OK(status)) {
291 0 : DEBUG(1, ("Unable to obtain PAC via gensec_session_info\n"));
292 0 : goto out;
293 : }
294 :
295 0 : pac_data_ctr = auth4_context_get_PAC_DATA_CTR(auth_context, mem_ctx);
296 0 : if (pac_data_ctr == NULL) {
297 0 : DEBUG(1,("no PAC\n"));
298 0 : status = NT_STATUS_INVALID_PARAMETER;
299 0 : goto out;
300 : }
301 :
302 0 : *_pac_data_ctr = talloc_move(mem_ctx, &pac_data_ctr);
303 0 : if (_canon_principal != NULL) {
304 0 : *_canon_principal = talloc_move(mem_ctx, &canon_principal);
305 : }
306 0 : if (_canon_realm != NULL) {
307 0 : *_canon_realm = talloc_move(mem_ctx, &canon_realm);
308 : }
309 :
310 0 : out:
311 0 : talloc_free(tmp_ctx);
312 0 : if (cc != cache_name) {
313 0 : ads_kdestroy(cc);
314 : }
315 :
316 0 : data_blob_free(&tkt);
317 0 : data_blob_free(&ap_rep);
318 0 : data_blob_free(&sesskey1);
319 :
320 0 : return status;
321 : }
322 :
323 : #endif
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