1 /*
2 Unix SMB/CIFS implementation.
3 Authenticate against Samba4's auth subsystem
4 Copyright (C) Volker Lendecke 2008
5 Copyright (C) Andrew Bartlett 2010
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
19 */
20
21 #include "includes.h"
22 #include "source3/include/auth.h"
23 #include "source3/include/messages.h"
24 #include "source4/auth/auth.h"
25 #include "auth/auth_sam_reply.h"
26 #include "param/param.h"
27 #include "source4/lib/events/events.h"
28 #include "source4/lib/messaging/messaging.h"
29 #include "auth/gensec/gensec.h"
30 #include "auth/credentials/credentials.h"
31
32 #undef DBGC_CLASS
33 #define DBGC_CLASS DBGC_AUTH
34
35 static NTSTATUS make_auth4_context_s4(const struct auth_context *auth_context,
36 TALLOC_CTX *mem_ctx,
37 struct auth4_context **auth4_context);
38
39 static struct idr_context *task_id_tree;
40
free_task_id(struct server_id * server_id)41 static int free_task_id(struct server_id *server_id)
42 {
43 idr_remove(task_id_tree, server_id->task_id);
44 return 0;
45 }
46
47 /* Return a server_id with a unique task_id element. Free the
48 * returned pointer to de-allocate the task_id via a talloc destructor
49 * (ie, use talloc_free()) */
new_server_id_task(TALLOC_CTX * mem_ctx)50 static struct server_id *new_server_id_task(TALLOC_CTX *mem_ctx)
51 {
52 struct messaging_context *msg_ctx;
53 struct server_id *server_id;
54 int task_id;
55 if (!task_id_tree) {
56 task_id_tree = idr_init(NULL);
57 if (!task_id_tree) {
58 return NULL;
59 }
60 }
61
62 msg_ctx = global_messaging_context();
63 if (msg_ctx == NULL) {
64 return NULL;
65 }
66
67 server_id = talloc(mem_ctx, struct server_id);
68
69 if (!server_id) {
70 return NULL;
71 }
72 *server_id = messaging_server_id(msg_ctx);
73
74 /* 0 is the default server_id, so we need to start with 1 */
75 task_id = idr_get_new_above(task_id_tree, server_id, 1, INT32_MAX);
76
77 if (task_id == -1) {
78 talloc_free(server_id);
79 return NULL;
80 }
81
82 talloc_set_destructor(server_id, free_task_id);
83 server_id->task_id = task_id;
84 return server_id;
85 }
86
87 /*
88 * This module is not an ordinary authentication module. It is really
89 * a way to redirect the whole authentication and authorization stack
90 * to use the source4 auth code, not a way to just handle NTLM
91 * authentication.
92 *
93 * See the comments above each function for how that hook changes the
94 * behaviour.
95 */
96
97 /*
98 * This hook is currently used by winbindd only, as all other NTLM
99 * logins go via the hooks provided by make_auth4_context_s4() below.
100 *
101 * This is only left in case we find a way that it might become useful
102 * in future. Importantly, this routine returns the information
103 * needed for a NETLOGON SamLogon, not what is needed to establish a
104 * session.
105 *
106 * We expect we may use this hook in the source3/ winbind when this
107 * services the AD DC. It is tested via pdbtest.
108 */
109
check_samba4_security(const struct auth_context * auth_context,void * my_private_data,TALLOC_CTX * mem_ctx,const struct auth_usersupplied_info * user_info,struct auth_serversupplied_info ** server_info)110 static NTSTATUS check_samba4_security(const struct auth_context *auth_context,
111 void *my_private_data,
112 TALLOC_CTX *mem_ctx,
113 const struct auth_usersupplied_info *user_info,
114 struct auth_serversupplied_info **server_info)
115 {
116 TALLOC_CTX *frame = talloc_stackframe();
117 struct netr_SamInfo3 *info3 = NULL;
118 NTSTATUS nt_status;
119 struct auth_user_info_dc *user_info_dc;
120 struct auth4_context *auth4_context;
121 uint8_t authoritative = 0;
122
123 nt_status = make_auth4_context_s4(auth_context, mem_ctx, &auth4_context);
124 if (!NT_STATUS_IS_OK(nt_status)) {
125 TALLOC_FREE(frame);
126 goto done;
127 }
128
129 nt_status = auth_context_set_challenge(auth4_context, auth_context->challenge.data, "auth_samba4");
130 if (!NT_STATUS_IS_OK(nt_status)) {
131 TALLOC_FREE(auth4_context);
132 TALLOC_FREE(frame);
133 return nt_status;
134 }
135
136 nt_status = auth_check_password(auth4_context, auth4_context, user_info,
137 &user_info_dc, &authoritative);
138 if (!NT_STATUS_IS_OK(nt_status)) {
139 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_SUCH_USER) &&
140 authoritative == 0)
141 {
142 nt_status = NT_STATUS_NOT_IMPLEMENTED;
143 }
144 TALLOC_FREE(auth4_context);
145 TALLOC_FREE(frame);
146 return nt_status;
147 }
148
149 nt_status = auth_convert_user_info_dc_saminfo3(mem_ctx,
150 user_info_dc,
151 &info3);
152 if (NT_STATUS_IS_OK(nt_status)) {
153 /* We need the strings from the server_info to be valid as long as the info3 is around */
154 talloc_steal(info3, user_info_dc);
155 }
156 talloc_free(auth4_context);
157
158 if (!NT_STATUS_IS_OK(nt_status)) {
159 goto done;
160 }
161
162 if (user_info->flags & USER_INFO_INFO3_AND_NO_AUTHZ) {
163 *server_info = make_server_info(mem_ctx);
164 if (*server_info == NULL) {
165 nt_status = NT_STATUS_NO_MEMORY;
166 goto done;
167 }
168 (*server_info)->info3 = talloc_steal(*server_info, info3);
169
170 } else {
171 nt_status = make_server_info_info3(mem_ctx, user_info->client.account_name,
172 user_info->mapped.domain_name, server_info,
173 info3);
174 if (!NT_STATUS_IS_OK(nt_status)) {
175 DEBUG(10, ("make_server_info_info3 failed: %s\n",
176 nt_errstr(nt_status)));
177 goto done;
178 }
179 }
180
181 nt_status = NT_STATUS_OK;
182
183 done:
184 TALLOC_FREE(frame);
185 return nt_status;
186 }
187
188 /*
189 * Hook to allow the source4 set of GENSEC modules to handle
190 * blob-based authentication mechanisms, without directly linking the
191 * mechanism code.
192 *
193 * This may eventually go away, when the GSSAPI acceptors are merged,
194 * when we will just rely on the make_auth4_context_s4 hook instead.
195 *
196 * Even for NTLMSSP, which has a common module, significant parts of
197 * the behaviour are overridden here, because it uses the source4 NTLM
198 * stack and the source4 mapping between the PAC/SamLogon response and
199 * the local token.
200 *
201 * It is important to override all this to ensure that the exact same
202 * token is generated and used in the SMB and LDAP servers, for NTLM
203 * and for Kerberos.
204 */
prepare_gensec(const struct auth_context * auth_context,TALLOC_CTX * mem_ctx,struct gensec_security ** gensec_context)205 static NTSTATUS prepare_gensec(const struct auth_context *auth_context,
206 TALLOC_CTX *mem_ctx,
207 struct gensec_security **gensec_context)
208 {
209 NTSTATUS status;
210 struct loadparm_context *lp_ctx;
211 struct tevent_context *event_ctx;
212 TALLOC_CTX *frame = talloc_stackframe();
213 struct gensec_security *gensec_ctx;
214 struct imessaging_context *msg_ctx;
215 struct cli_credentials *server_credentials;
216 struct server_id *server_id;
217
218 lp_ctx = loadparm_init_s3(frame, loadparm_s3_helpers());
219 if (lp_ctx == NULL) {
220 DEBUG(1, ("loadparm_init_s3 failed\n"));
221 TALLOC_FREE(frame);
222 return NT_STATUS_INVALID_SERVER_STATE;
223 }
224 event_ctx = s4_event_context_init(frame);
225 if (event_ctx == NULL) {
226 DEBUG(1, ("s4_event_context_init failed\n"));
227 TALLOC_FREE(frame);
228 return NT_STATUS_INVALID_SERVER_STATE;
229 }
230
231 server_id = new_server_id_task(frame);
232 if (server_id == NULL) {
233 DEBUG(1, ("new_server_id_task failed\n"));
234 TALLOC_FREE(frame);
235 return NT_STATUS_INVALID_SERVER_STATE;
236 }
237
238 msg_ctx = imessaging_init(frame,
239 lp_ctx,
240 *server_id,
241 event_ctx);
242 if (msg_ctx == NULL) {
243 DEBUG(1, ("imessaging_init failed\n"));
244 TALLOC_FREE(frame);
245 return NT_STATUS_INVALID_SERVER_STATE;
246 }
247
248 talloc_reparent(frame, msg_ctx, server_id);
249
250 server_credentials
251 = cli_credentials_init(frame);
252 if (!server_credentials) {
253 DEBUG(1, ("Failed to init server credentials"));
254 TALLOC_FREE(frame);
255 return NT_STATUS_INVALID_SERVER_STATE;
256 }
257
258 cli_credentials_set_conf(server_credentials, lp_ctx);
259 status = cli_credentials_set_machine_account(server_credentials, lp_ctx);
260 if (!NT_STATUS_IS_OK(status)) {
261 DEBUG(10, ("Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(status)));
262 TALLOC_FREE(frame);
263 return status;
264 }
265
266 status = samba_server_gensec_start(mem_ctx,
267 event_ctx, msg_ctx,
268 lp_ctx, server_credentials, "cifs",
269 &gensec_ctx);
270 if (!NT_STATUS_IS_OK(status)) {
271 DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
272 TALLOC_FREE(frame);
273 return status;
274 }
275
276 talloc_reparent(frame, gensec_ctx, msg_ctx);
277 talloc_reparent(frame, gensec_ctx, event_ctx);
278 talloc_reparent(frame, gensec_ctx, lp_ctx);
279 talloc_reparent(frame, gensec_ctx, server_credentials);
280
281 gensec_want_feature(gensec_ctx, GENSEC_FEATURE_SESSION_KEY);
282 gensec_want_feature(gensec_ctx, GENSEC_FEATURE_UNIX_TOKEN);
283
284 *gensec_context = gensec_ctx;
285 TALLOC_FREE(frame);
286 return status;
287 }
288
289 /*
290 * Hook to allow handling of NTLM authentication for AD operation
291 * without directly linking the s4 auth stack
292 *
293 * This ensures we use the source4 authentication stack, as well as
294 * the authorization stack to create the user's token. This ensures
295 * consistency between NTLM logins and NTLMSSP logins, as NTLMSSP is
296 * handled by the hook above.
297 */
make_auth4_context_s4(const struct auth_context * auth_context,TALLOC_CTX * mem_ctx,struct auth4_context ** auth4_context)298 static NTSTATUS make_auth4_context_s4(const struct auth_context *auth_context,
299 TALLOC_CTX *mem_ctx,
300 struct auth4_context **auth4_context)
301 {
302 NTSTATUS status;
303 struct loadparm_context *lp_ctx;
304 struct tevent_context *event_ctx;
305 TALLOC_CTX *frame = talloc_stackframe();
306 struct imessaging_context *msg_ctx;
307 struct server_id *server_id;
308
309 lp_ctx = loadparm_init_s3(frame, loadparm_s3_helpers());
310 if (lp_ctx == NULL) {
311 DEBUG(1, ("loadparm_init_s3 failed\n"));
312 TALLOC_FREE(frame);
313 return NT_STATUS_INVALID_SERVER_STATE;
314 }
315 event_ctx = s4_event_context_init(frame);
316 if (event_ctx == NULL) {
317 DEBUG(1, ("s4_event_context_init failed\n"));
318 TALLOC_FREE(frame);
319 return NT_STATUS_INVALID_SERVER_STATE;
320 }
321
322 server_id = new_server_id_task(frame);
323 if (server_id == NULL) {
324 DEBUG(1, ("new_server_id_task failed\n"));
325 TALLOC_FREE(frame);
326 return NT_STATUS_INVALID_SERVER_STATE;
327 }
328
329 msg_ctx = imessaging_init(frame,
330 lp_ctx,
331 *server_id,
332 event_ctx);
333 if (msg_ctx == NULL) {
334 DEBUG(1, ("imessaging_init failed\n"));
335 TALLOC_FREE(frame);
336 return NT_STATUS_INVALID_SERVER_STATE;
337 }
338 talloc_reparent(frame, msg_ctx, server_id);
339
340 /* Allow forcing a specific auth4 module */
341 if (!auth_context->forced_samba4_methods) {
342 status = auth_context_create(mem_ctx,
343 event_ctx,
344 msg_ctx,
345 lp_ctx,
346 auth4_context);
347 } else {
348 const char * const *forced_auth_methods = (const char * const *)str_list_make(mem_ctx, auth_context->forced_samba4_methods, NULL);
349 status = auth_context_create_methods(mem_ctx, forced_auth_methods, event_ctx, msg_ctx, lp_ctx, NULL, auth4_context);
350 }
351 if (!NT_STATUS_IS_OK(status)) {
352 DEBUG(1, ("Failed to start auth server code: %s\n", nt_errstr(status)));
353 TALLOC_FREE(frame);
354 return status;
355 }
356
357 talloc_reparent(frame, *auth4_context, msg_ctx);
358 talloc_reparent(frame, *auth4_context, event_ctx);
359 talloc_reparent(frame, *auth4_context, lp_ctx);
360
361 TALLOC_FREE(frame);
362 return status;
363 }
364
365 /* module initialisation */
auth_init_samba4(struct auth_context * auth_context,const char * param,struct auth_methods ** auth_method)366 static NTSTATUS auth_init_samba4(struct auth_context *auth_context,
367 const char *param,
368 struct auth_methods **auth_method)
369 {
370 struct auth_methods *result;
371
372 gensec_init();
373
374 result = talloc_zero(auth_context, struct auth_methods);
375 if (result == NULL) {
376 return NT_STATUS_NO_MEMORY;
377 }
378 result->name = "samba4";
379 result->auth = check_samba4_security;
380 result->prepare_gensec = prepare_gensec;
381 result->make_auth4_context = make_auth4_context_s4;
382
383 if (param && *param) {
384 auth_context->forced_samba4_methods = talloc_strdup(result, param);
385 if (!auth_context->forced_samba4_methods) {
386 return NT_STATUS_NO_MEMORY;
387 }
388 }
389
390 *auth_method = result;
391 return NT_STATUS_OK;
392 }
393
394 NTSTATUS auth_samba4_init(TALLOC_CTX *mem_ctx);
auth_samba4_init(TALLOC_CTX * mem_ctx)395 NTSTATUS auth_samba4_init(TALLOC_CTX *mem_ctx)
396 {
397 smb_register_auth(AUTH_INTERFACE_VERSION, "samba4",
398 auth_init_samba4);
399 return NT_STATUS_OK;
400 }
401