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 "../libcli/auth/spnego.h"
34 : #include "lib/util/asn1.h"
35 :
36 : #ifdef HAVE_KRB5
37 :
38 : #include "auth/kerberos/pac_utils.h"
39 :
40 : struct smb_krb5_context;
41 :
42 : /*
43 : generate a krb5 GSS-API wrapper packet given a ticket
44 : */
45 0 : static DATA_BLOB spnego_gen_krb5_wrap(
46 : TALLOC_CTX *ctx, const DATA_BLOB ticket, const uint8_t tok_id[2])
47 : {
48 0 : ASN1_DATA *data;
49 0 : DATA_BLOB ret = data_blob_null;
50 :
51 0 : data = asn1_init(talloc_tos(), ASN1_MAX_TREE_DEPTH);
52 0 : if (data == NULL) {
53 0 : return data_blob_null;
54 : }
55 :
56 0 : if (!asn1_push_tag(data, ASN1_APPLICATION(0))) goto err;
57 0 : if (!asn1_write_OID(data, OID_KERBEROS5)) goto err;
58 :
59 0 : if (!asn1_write(data, tok_id, 2)) goto err;
60 0 : if (!asn1_write(data, ticket.data, ticket.length)) goto err;
61 0 : if (!asn1_pop_tag(data)) goto err;
62 :
63 0 : if (!asn1_extract_blob(data, ctx, &ret)) {
64 0 : goto err;
65 : }
66 :
67 0 : asn1_free(data);
68 0 : data = NULL;
69 :
70 0 : err:
71 :
72 0 : if (data != NULL) {
73 0 : if (asn1_has_error(data)) {
74 0 : DEBUG(1, ("Failed to build krb5 wrapper at offset %d\n",
75 : (int)asn1_current_ofs(data)));
76 : }
77 :
78 0 : asn1_free(data);
79 : }
80 :
81 0 : return ret;
82 : }
83 :
84 : /*
85 : * Given the username/password, do a kinit, store the ticket in
86 : * cache_name if specified, and return the PAC_LOGON_INFO (the
87 : * structure containing the important user information such as
88 : * groups).
89 : */
90 0 : NTSTATUS kerberos_return_pac(TALLOC_CTX *mem_ctx,
91 : const char *name,
92 : const char *pass,
93 : time_t time_offset,
94 : time_t *expire_time,
95 : time_t *renew_till_time,
96 : const char *cache_name,
97 : bool request_pac,
98 : bool add_netbios_addr,
99 : time_t renewable_time,
100 : const char *impersonate_princ_s,
101 : const char *local_service,
102 : char **_canon_principal,
103 : char **_canon_realm,
104 : struct PAC_DATA_CTR **_pac_data_ctr)
105 : {
106 0 : krb5_error_code ret;
107 0 : NTSTATUS status = NT_STATUS_INVALID_PARAMETER;
108 0 : DATA_BLOB tkt = data_blob_null;
109 0 : DATA_BLOB tkt_wrapped = data_blob_null;
110 0 : DATA_BLOB ap_rep = data_blob_null;
111 0 : DATA_BLOB sesskey1 = data_blob_null;
112 0 : const char *auth_princ = NULL;
113 0 : const char *cc = NULL;
114 0 : struct auth_session_info *session_info;
115 0 : struct gensec_security *gensec_server_context;
116 0 : const struct gensec_security_ops **backends;
117 0 : struct gensec_settings *gensec_settings;
118 0 : size_t idx = 0;
119 0 : struct auth4_context *auth_context;
120 0 : struct loadparm_context *lp_ctx;
121 0 : struct PAC_DATA_CTR *pac_data_ctr = NULL;
122 0 : char *canon_principal = NULL;
123 0 : char *canon_realm = NULL;
124 0 : krb5_context ctx = NULL;
125 0 : krb5_ccache ccid = NULL;
126 :
127 0 : TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
128 0 : NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
129 :
130 0 : ZERO_STRUCT(tkt);
131 0 : ZERO_STRUCT(ap_rep);
132 0 : ZERO_STRUCT(sesskey1);
133 :
134 0 : if (!name || !pass) {
135 0 : status = NT_STATUS_INVALID_PARAMETER;
136 0 : goto out;
137 : }
138 :
139 0 : if (_canon_principal != NULL) {
140 0 : *_canon_principal = NULL;
141 : }
142 :
143 0 : if (_canon_realm != NULL) {
144 0 : *_canon_realm = NULL;
145 : }
146 :
147 0 : if (cache_name) {
148 0 : cc = cache_name;
149 : } else {
150 0 : char *ccname = NULL;
151 :
152 0 : ret = smb_krb5_init_context_common(&ctx);
153 0 : if (ret != 0) {
154 0 : status = krb5_to_nt_status(ret);
155 0 : goto out;
156 : }
157 :
158 0 : ret = smb_krb5_cc_new_unique_memory(ctx,
159 : tmp_ctx,
160 : &ccname,
161 : &ccid);
162 0 : if (ret != 0) {
163 0 : status = krb5_to_nt_status(ret);
164 0 : goto out;
165 : }
166 0 : cc = ccname;
167 : }
168 :
169 0 : if (!strchr_m(name, '@')) {
170 0 : auth_princ = talloc_asprintf(mem_ctx, "%s@%s", name,
171 : lp_realm());
172 : } else {
173 0 : auth_princ = name;
174 : }
175 0 : NT_STATUS_HAVE_NO_MEMORY(auth_princ);
176 :
177 0 : ret = kerberos_kinit_password_ext(auth_princ,
178 : pass,
179 : time_offset,
180 : expire_time,
181 : renew_till_time,
182 : cc,
183 : request_pac,
184 : add_netbios_addr,
185 : renewable_time,
186 : tmp_ctx,
187 : &canon_principal,
188 : &canon_realm,
189 : &status);
190 0 : if (ret) {
191 0 : DEBUG(1,("kinit failed for '%s' with: %s (%d)\n",
192 : auth_princ, error_message(ret), ret));
193 : /* status already set */
194 0 : goto out;
195 : }
196 :
197 0 : DEBUG(10,("got TGT for %s in %s\n", auth_princ, cc));
198 0 : if (expire_time) {
199 0 : DEBUGADD(10,("\tvalid until: %s (%d)\n",
200 : http_timestring(talloc_tos(), *expire_time),
201 : (int)*expire_time));
202 : }
203 0 : if (renew_till_time) {
204 0 : DEBUGADD(10,("\trenewable till: %s (%d)\n",
205 : http_timestring(talloc_tos(), *renew_till_time),
206 : (int)*renew_till_time));
207 : }
208 :
209 : /* we cannot continue with krb5 when UF_DONT_REQUIRE_PREAUTH is set,
210 : * in that case fallback to NTLM - gd */
211 :
212 0 : if (expire_time && renew_till_time &&
213 0 : (*expire_time == 0) && (*renew_till_time == 0)) {
214 0 : status = NT_STATUS_INVALID_LOGON_TYPE;
215 0 : goto out;
216 : }
217 :
218 0 : ret = ads_krb5_cli_get_ticket(mem_ctx,
219 : local_service,
220 : time_offset,
221 : &tkt,
222 : &sesskey1,
223 : 0,
224 : cc,
225 : NULL,
226 : impersonate_princ_s);
227 0 : if (ret) {
228 0 : DEBUG(1,("failed to get ticket for %s: %s\n",
229 : local_service, error_message(ret)));
230 0 : if (impersonate_princ_s) {
231 0 : DEBUGADD(1,("tried S4U2SELF impersonation as: %s\n",
232 : impersonate_princ_s));
233 : }
234 0 : status = krb5_to_nt_status(ret);
235 0 : goto out;
236 : }
237 :
238 : /* wrap that up in a nice GSS-API wrapping */
239 0 : tkt_wrapped = spnego_gen_krb5_wrap(tmp_ctx, tkt, TOK_ID_KRB_AP_REQ);
240 0 : if (tkt_wrapped.data == NULL) {
241 0 : status = NT_STATUS_NO_MEMORY;
242 0 : goto out;
243 : }
244 :
245 0 : auth_context = auth4_context_for_PAC_DATA_CTR(tmp_ctx);
246 0 : if (auth_context == NULL) {
247 0 : status = NT_STATUS_NO_MEMORY;
248 0 : goto out;
249 : }
250 :
251 0 : lp_ctx = loadparm_init_s3(tmp_ctx, loadparm_s3_helpers());
252 0 : if (lp_ctx == NULL) {
253 0 : status = NT_STATUS_INVALID_SERVER_STATE;
254 0 : DEBUG(10, ("loadparm_init_s3 failed\n"));
255 0 : goto out;
256 : }
257 :
258 0 : gensec_settings = lpcfg_gensec_settings(tmp_ctx, lp_ctx);
259 0 : if (gensec_settings == NULL) {
260 0 : status = NT_STATUS_NO_MEMORY;
261 0 : DEBUG(10, ("lpcfg_gensec_settings failed\n"));
262 0 : goto out;
263 : }
264 :
265 0 : backends = talloc_zero_array(gensec_settings,
266 : const struct gensec_security_ops *, 2);
267 0 : if (backends == NULL) {
268 0 : status = NT_STATUS_NO_MEMORY;
269 0 : goto out;
270 : }
271 0 : gensec_settings->backends = backends;
272 :
273 0 : gensec_init();
274 :
275 0 : backends[idx++] = gensec_gse_security_by_oid(GENSEC_OID_KERBEROS5);
276 :
277 0 : status = gensec_server_start(tmp_ctx, gensec_settings,
278 : auth_context, &gensec_server_context);
279 :
280 0 : if (!NT_STATUS_IS_OK(status)) {
281 0 : DEBUG(1, (__location__ "Failed to start server-side GENSEC to validate a Kerberos ticket: %s\n", nt_errstr(status)));
282 0 : goto out;
283 : }
284 :
285 0 : talloc_unlink(tmp_ctx, lp_ctx);
286 0 : talloc_unlink(tmp_ctx, gensec_settings);
287 0 : talloc_unlink(tmp_ctx, auth_context);
288 :
289 : /* Session info is not complete, do not pass to auth log */
290 0 : gensec_want_feature(gensec_server_context, GENSEC_FEATURE_NO_AUTHZ_LOG);
291 :
292 0 : status = gensec_start_mech_by_oid(gensec_server_context, GENSEC_OID_KERBEROS5);
293 0 : if (!NT_STATUS_IS_OK(status)) {
294 0 : DEBUG(1, (__location__ "Failed to start server-side GENSEC krb5 to validate a Kerberos ticket: %s\n", nt_errstr(status)));
295 0 : goto out;
296 : }
297 :
298 : /* Do a client-server update dance */
299 0 : status = gensec_update(gensec_server_context, tmp_ctx, tkt_wrapped, &ap_rep);
300 0 : if (!NT_STATUS_IS_OK(status)) {
301 0 : DEBUG(1, ("gensec_update() failed: %s\n", nt_errstr(status)));
302 0 : goto out;
303 : }
304 :
305 : /* Now return the PAC information to the callers. We ignore
306 : * the session_info and instead pick out the PAC via the
307 : * private_data on the auth_context */
308 0 : status = gensec_session_info(gensec_server_context, tmp_ctx, &session_info);
309 0 : if (!NT_STATUS_IS_OK(status)) {
310 0 : DEBUG(1, ("Unable to obtain PAC via gensec_session_info\n"));
311 0 : goto out;
312 : }
313 :
314 0 : pac_data_ctr = auth4_context_get_PAC_DATA_CTR(auth_context, mem_ctx);
315 0 : if (pac_data_ctr == NULL) {
316 0 : DEBUG(1,("no PAC\n"));
317 0 : status = NT_STATUS_INVALID_PARAMETER;
318 0 : goto out;
319 : }
320 :
321 0 : *_pac_data_ctr = talloc_move(mem_ctx, &pac_data_ctr);
322 0 : if (_canon_principal != NULL) {
323 0 : *_canon_principal = talloc_move(mem_ctx, &canon_principal);
324 : }
325 0 : if (_canon_realm != NULL) {
326 0 : *_canon_realm = talloc_move(mem_ctx, &canon_realm);
327 : }
328 :
329 0 : out:
330 0 : if (ccid != NULL) {
331 0 : krb5_cc_destroy(ctx, ccid);
332 0 : ccid = NULL;
333 : }
334 0 : if (ctx != NULL) {
335 0 : krb5_free_context(ctx);
336 0 : ctx = NULL;
337 : }
338 0 : talloc_free(tmp_ctx);
339 :
340 0 : data_blob_free(&tkt);
341 0 : data_blob_free(&ap_rep);
342 0 : data_blob_free(&sesskey1);
343 :
344 0 : return status;
345 : }
346 :
347 : #endif
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