source: trunk/server/source4/auth/gensec/gensec_krb5.c

Last change on this file was 745, checked in by Silvan Scherrer, 13 years ago

Samba Server: updated trunk to 3.6.0
File size: 29.5 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3
4 Kerberos backend for GENSEC
5
6 Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004
7 Copyright (C) Andrew Tridgell 2001
8 Copyright (C) Luke Howard 2002-2003
9 Copyright (C) Stefan Metzmacher 2004-2005
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
22 You should have received a copy of the GNU General Public License
23 along with this program. If not, see <http://www.gnu.org/licenses/>.
24*/
25
26#include "includes.h"
27#include "system/kerberos.h"
28#include "auth/kerberos/kerberos.h"
29#include "auth/auth.h"
30#include "lib/socket/socket.h"
31#include "lib/tsocket/tsocket.h"
32#include "librpc/rpc/dcerpc.h"
33#include "auth/credentials/credentials.h"
34#include "auth/credentials/credentials_krb5.h"
35#include "auth/kerberos/kerberos_credentials.h"
36#include "auth/gensec/gensec.h"
37#include "auth/gensec/gensec_proto.h"
38#include "param/param.h"
39#include "auth/auth_sam_reply.h"
40#include "lib/util/util_net.h"
41
42enum GENSEC_KRB5_STATE {
43 GENSEC_KRB5_SERVER_START,
44 GENSEC_KRB5_CLIENT_START,
45 GENSEC_KRB5_CLIENT_MUTUAL_AUTH,
46 GENSEC_KRB5_DONE
47};
48
49struct gensec_krb5_state {
50 DATA_BLOB session_key;
51 DATA_BLOB pac;
52 enum GENSEC_KRB5_STATE state_position;
53 struct smb_krb5_context *smb_krb5_context;
54 krb5_auth_context auth_context;
55 krb5_data enc_ticket;
56 krb5_keyblock *keyblock;
57 krb5_ticket *ticket;
58 bool gssapi;
59 krb5_flags ap_req_options;
60};
61
62static int gensec_krb5_destroy(struct gensec_krb5_state *gensec_krb5_state)
63{
64 if (!gensec_krb5_state->smb_krb5_context) {
65 /* We can't clean anything else up unless we started up this far */
66 return 0;
67 }
68 if (gensec_krb5_state->enc_ticket.length) {
69 kerberos_free_data_contents(gensec_krb5_state->smb_krb5_context->krb5_context,
70 &gensec_krb5_state->enc_ticket);
71 }
72
73 if (gensec_krb5_state->ticket) {
74 krb5_free_ticket(gensec_krb5_state->smb_krb5_context->krb5_context,
75 gensec_krb5_state->ticket);
76 }
77
78 /* ccache freed in a child destructor */
79
80 krb5_free_keyblock(gensec_krb5_state->smb_krb5_context->krb5_context,
81 gensec_krb5_state->keyblock);
82
83 if (gensec_krb5_state->auth_context) {
84 krb5_auth_con_free(gensec_krb5_state->smb_krb5_context->krb5_context,
85 gensec_krb5_state->auth_context);
86 }
87
88 return 0;
89}
90
91static NTSTATUS gensec_krb5_start(struct gensec_security *gensec_security, bool gssapi)
92{
93 krb5_error_code ret;
94 struct gensec_krb5_state *gensec_krb5_state;
95 struct cli_credentials *creds;
96 const struct tsocket_address *tlocal_addr, *tremote_addr;
97 krb5_address my_krb5_addr, peer_krb5_addr;
98
99 creds = gensec_get_credentials(gensec_security);
100 if (!creds) {
101 return NT_STATUS_INVALID_PARAMETER;
102 }
103
104 gensec_krb5_state = talloc(gensec_security, struct gensec_krb5_state);
105 if (!gensec_krb5_state) {
106 return NT_STATUS_NO_MEMORY;
107 }
108
109 gensec_security->private_data = gensec_krb5_state;
110 gensec_krb5_state->smb_krb5_context = NULL;
111 gensec_krb5_state->auth_context = NULL;
112 gensec_krb5_state->ticket = NULL;
113 ZERO_STRUCT(gensec_krb5_state->enc_ticket);
114 gensec_krb5_state->keyblock = NULL;
115 gensec_krb5_state->session_key = data_blob(NULL, 0);
116 gensec_krb5_state->pac = data_blob(NULL, 0);
117 gensec_krb5_state->gssapi = gssapi;
118
119 talloc_set_destructor(gensec_krb5_state, gensec_krb5_destroy);
120
121 if (cli_credentials_get_krb5_context(creds,
122 gensec_security->settings->lp_ctx, &gensec_krb5_state->smb_krb5_context)) {
123 talloc_free(gensec_krb5_state);
124 return NT_STATUS_INTERNAL_ERROR;
125 }
126
127 ret = krb5_auth_con_init(gensec_krb5_state->smb_krb5_context->krb5_context, &gensec_krb5_state->auth_context);
128 if (ret) {
129 DEBUG(1,("gensec_krb5_start: krb5_auth_con_init failed (%s)\n",
130 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
131 ret, gensec_krb5_state)));
132 talloc_free(gensec_krb5_state);
133 return NT_STATUS_INTERNAL_ERROR;
134 }
135
136 ret = krb5_auth_con_setflags(gensec_krb5_state->smb_krb5_context->krb5_context,
137 gensec_krb5_state->auth_context,
138 KRB5_AUTH_CONTEXT_DO_SEQUENCE);
139 if (ret) {
140 DEBUG(1,("gensec_krb5_start: krb5_auth_con_setflags failed (%s)\n",
141 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
142 ret, gensec_krb5_state)));
143 talloc_free(gensec_krb5_state);
144 return NT_STATUS_INTERNAL_ERROR;
145 }
146
147 tlocal_addr = gensec_get_local_address(gensec_security);
148 if (tlocal_addr) {
149 ssize_t socklen;
150 struct sockaddr_storage ss;
151
152 socklen = tsocket_address_bsd_sockaddr(tlocal_addr,
153 (struct sockaddr *) &ss,
154 sizeof(struct sockaddr_storage));
155 if (socklen < 0) {
156 talloc_free(gensec_krb5_state);
157 return NT_STATUS_INTERNAL_ERROR;
158 }
159 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
160 (const struct sockaddr *) &ss, &my_krb5_addr);
161 if (ret) {
162 DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
163 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
164 ret, gensec_krb5_state)));
165 talloc_free(gensec_krb5_state);
166 return NT_STATUS_INTERNAL_ERROR;
167 }
168 }
169
170 tremote_addr = gensec_get_remote_address(gensec_security);
171 if (tremote_addr) {
172 ssize_t socklen;
173 struct sockaddr_storage ss;
174
175 socklen = tsocket_address_bsd_sockaddr(tremote_addr,
176 (struct sockaddr *) &ss,
177 sizeof(struct sockaddr_storage));
178 if (socklen < 0) {
179 talloc_free(gensec_krb5_state);
180 return NT_STATUS_INTERNAL_ERROR;
181 }
182 ret = krb5_sockaddr2address(gensec_krb5_state->smb_krb5_context->krb5_context,
183 (const struct sockaddr *) &ss, &peer_krb5_addr);
184 if (ret) {
185 DEBUG(1,("gensec_krb5_start: krb5_sockaddr2address (local) failed (%s)\n",
186 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
187 ret, gensec_krb5_state)));
188 talloc_free(gensec_krb5_state);
189 return NT_STATUS_INTERNAL_ERROR;
190 }
191 }
192
193 ret = krb5_auth_con_setaddrs(gensec_krb5_state->smb_krb5_context->krb5_context,
194 gensec_krb5_state->auth_context,
195 tlocal_addr ? &my_krb5_addr : NULL,
196 tremote_addr ? &peer_krb5_addr : NULL);
197 if (ret) {
198 DEBUG(1,("gensec_krb5_start: krb5_auth_con_setaddrs failed (%s)\n",
199 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
200 ret, gensec_krb5_state)));
201 talloc_free(gensec_krb5_state);
202 return NT_STATUS_INTERNAL_ERROR;
203 }
204
205 return NT_STATUS_OK;
206}
207
208static NTSTATUS gensec_krb5_common_server_start(struct gensec_security *gensec_security, bool gssapi)
209{
210 NTSTATUS nt_status;
211 struct gensec_krb5_state *gensec_krb5_state;
212
213 nt_status = gensec_krb5_start(gensec_security, gssapi);
214 if (!NT_STATUS_IS_OK(nt_status)) {
215 return nt_status;
216 }
217
218 gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
219 gensec_krb5_state->state_position = GENSEC_KRB5_SERVER_START;
220
221 return NT_STATUS_OK;
222}
223
224static NTSTATUS gensec_krb5_server_start(struct gensec_security *gensec_security)
225{
226 return gensec_krb5_common_server_start(gensec_security, false);
227}
228
229static NTSTATUS gensec_fake_gssapi_krb5_server_start(struct gensec_security *gensec_security)
230{
231 return gensec_krb5_common_server_start(gensec_security, true);
232}
233
234static NTSTATUS gensec_krb5_common_client_start(struct gensec_security *gensec_security, bool gssapi)
235{
236 struct gensec_krb5_state *gensec_krb5_state;
237 krb5_error_code ret;
238 NTSTATUS nt_status;
239 struct ccache_container *ccache_container;
240 const char *hostname;
241 const char *error_string;
242 const char *principal;
243 krb5_data in_data;
244 struct tevent_context *previous_ev;
245
246 hostname = gensec_get_target_hostname(gensec_security);
247 if (!hostname) {
248 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
249 return NT_STATUS_INVALID_PARAMETER;
250 }
251 if (is_ipaddress(hostname)) {
252 DEBUG(2, ("Cannot do krb5 to an IP address"));
253 return NT_STATUS_INVALID_PARAMETER;
254 }
255 if (strcmp(hostname, "localhost") == 0) {
256 DEBUG(2, ("krb5 to 'localhost' does not make sense"));
257 return NT_STATUS_INVALID_PARAMETER;
258 }
259
260 nt_status = gensec_krb5_start(gensec_security, gssapi);
261 if (!NT_STATUS_IS_OK(nt_status)) {
262 return nt_status;
263 }
264
265 gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
266 gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
267 gensec_krb5_state->ap_req_options = AP_OPTS_USE_SUBKEY;
268
269 if (gensec_krb5_state->gssapi) {
270 /* The Fake GSSAPI modal emulates Samba3, which does not do mutual authentication */
271 if (gensec_setting_bool(gensec_security->settings, "gensec_fake_gssapi_krb5", "mutual", false)) {
272 gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
273 }
274 } else {
275 /* The wrapping for KPASSWD (a user of the raw KRB5 API) should be mutually authenticated */
276 if (gensec_setting_bool(gensec_security->settings, "gensec_krb5", "mutual", true)) {
277 gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
278 }
279 }
280
281 principal = gensec_get_target_principal(gensec_security);
282
283 ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security),
284 gensec_security->event_ctx,
285 gensec_security->settings->lp_ctx, &ccache_container, &error_string);
286 switch (ret) {
287 case 0:
288 break;
289 case KRB5KDC_ERR_PREAUTH_FAILED:
290 case KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN:
291 return NT_STATUS_LOGON_FAILURE;
292 case KRB5_KDC_UNREACH:
293 DEBUG(3, ("Cannot reach a KDC we require to contact %s: %s\n", principal, error_string));
294 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
295 case KRB5_CC_NOTFOUND:
296 case KRB5_CC_END:
297 DEBUG(3, ("Error preparing credentials we require to contact %s : %s\n", principal, error_string));
298 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
299 default:
300 DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_string));
301 return NT_STATUS_UNSUCCESSFUL;
302 }
303 in_data.length = 0;
304
305 /* Do this every time, in case we have weird recursive issues here */
306 ret = smb_krb5_context_set_event_ctx(gensec_krb5_state->smb_krb5_context, gensec_security->event_ctx, &previous_ev);
307 if (ret != 0) {
308 DEBUG(1, ("gensec_krb5_start: Setting event context failed\n"));
309 return NT_STATUS_NO_MEMORY;
310 }
311 if (principal) {
312 krb5_principal target_principal;
313 ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
314 &target_principal);
315 if (ret == 0) {
316 ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context,
317 &gensec_krb5_state->auth_context,
318 gensec_krb5_state->ap_req_options,
319 target_principal,
320 &in_data, ccache_container->ccache,
321 &gensec_krb5_state->enc_ticket);
322 krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
323 target_principal);
324 }
325 } else {
326 ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context,
327 &gensec_krb5_state->auth_context,
328 gensec_krb5_state->ap_req_options,
329 gensec_get_target_service(gensec_security),
330 hostname,
331 &in_data, ccache_container->ccache,
332 &gensec_krb5_state->enc_ticket);
333 }
334
335 smb_krb5_context_remove_event_ctx(gensec_krb5_state->smb_krb5_context, previous_ev, gensec_security->event_ctx);
336
337 switch (ret) {
338 case 0:
339 return NT_STATUS_OK;
340 case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
341 DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
342 hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
343 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
344 case KRB5_KDC_UNREACH:
345 DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
346 hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
347 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
348 case KRB5KDC_ERR_PREAUTH_FAILED:
349 case KRB5KRB_AP_ERR_TKT_EXPIRED:
350 case KRB5_CC_END:
351 /* Too much clock skew - we will need to kinit to re-skew the clock */
352 case KRB5KRB_AP_ERR_SKEW:
353 case KRB5_KDCREP_SKEW:
354 {
355 DEBUG(3, ("kerberos (mk_req) failed: %s\n",
356 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
357 /*fall through*/
358 }
359
360 /* just don't print a message for these really ordinary messages */
361 case KRB5_FCC_NOFILE:
362 case KRB5_CC_NOTFOUND:
363 case ENOENT:
364
365 return NT_STATUS_UNSUCCESSFUL;
366 break;
367
368 default:
369 DEBUG(0, ("kerberos: %s\n",
370 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
371 return NT_STATUS_UNSUCCESSFUL;
372 }
373}
374
375static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
376{
377 return gensec_krb5_common_client_start(gensec_security, false);
378}
379
380static NTSTATUS gensec_fake_gssapi_krb5_client_start(struct gensec_security *gensec_security)
381{
382 return gensec_krb5_common_client_start(gensec_security, true);
383}
384
385/**
386 * Check if the packet is one for this mechansim
387 *
388 * @param gensec_security GENSEC state
389 * @param in The request, as a DATA_BLOB
390 * @return Error, INVALID_PARAMETER if it's not a packet for us
391 * or NT_STATUS_OK if the packet is ok.
392 */
393
394static NTSTATUS gensec_fake_gssapi_krb5_magic(struct gensec_security *gensec_security,
395 const DATA_BLOB *in)
396{
397 if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
398 return NT_STATUS_OK;
399 } else {
400 return NT_STATUS_INVALID_PARAMETER;
401 }
402}
403
404
405/**
406 * Next state function for the Krb5 GENSEC mechanism
407 *
408 * @param gensec_krb5_state KRB5 State
409 * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
410 * @param in The request, as a DATA_BLOB
411 * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
412 * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
413 * or NT_STATUS_OK if the user is authenticated.
414 */
415
416static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security,
417 TALLOC_CTX *out_mem_ctx,
418 const DATA_BLOB in, DATA_BLOB *out)
419{
420 struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
421 krb5_error_code ret = 0;
422 NTSTATUS nt_status;
423
424 switch (gensec_krb5_state->state_position) {
425 case GENSEC_KRB5_CLIENT_START:
426 {
427 DATA_BLOB unwrapped_out;
428
429 if (gensec_krb5_state->gssapi) {
430 unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
431
432 /* wrap that up in a nice GSS-API wrapping */
433 *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
434 } else {
435 *out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
436 }
437 if (gensec_krb5_state->ap_req_options & AP_OPTS_MUTUAL_REQUIRED) {
438 gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
439 nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
440 } else {
441 gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
442 nt_status = NT_STATUS_OK;
443 }
444 return nt_status;
445 }
446
447 case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
448 {
449 DATA_BLOB unwrapped_in;
450 krb5_data inbuf;
451 krb5_ap_rep_enc_part *repl = NULL;
452 uint8_t tok_id[2];
453
454 if (gensec_krb5_state->gssapi) {
455 if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
456 DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
457 dump_data_pw("Mutual authentication message:\n", in.data, in.length);
458 return NT_STATUS_INVALID_PARAMETER;
459 }
460 } else {
461 unwrapped_in = in;
462 }
463 /* TODO: check the tok_id */
464
465 inbuf.data = unwrapped_in.data;
466 inbuf.length = unwrapped_in.length;
467 ret = krb5_rd_rep(gensec_krb5_state->smb_krb5_context->krb5_context,
468 gensec_krb5_state->auth_context,
469 &inbuf, &repl);
470 if (ret) {
471 DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
472 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, out_mem_ctx)));
473 dump_data_pw("Mutual authentication message:\n", (uint8_t *)inbuf.data, inbuf.length);
474 nt_status = NT_STATUS_ACCESS_DENIED;
475 } else {
476 *out = data_blob(NULL, 0);
477 nt_status = NT_STATUS_OK;
478 gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
479 }
480 if (repl) {
481 krb5_free_ap_rep_enc_part(gensec_krb5_state->smb_krb5_context->krb5_context, repl);
482 }
483 return nt_status;
484 }
485
486 case GENSEC_KRB5_SERVER_START:
487 {
488 DATA_BLOB unwrapped_in;
489 DATA_BLOB unwrapped_out = data_blob(NULL, 0);
490 krb5_data inbuf, outbuf;
491 uint8_t tok_id[2];
492 struct keytab_container *keytab;
493 krb5_principal server_in_keytab;
494 const char *error_string;
495 enum credentials_obtained obtained;
496
497 if (!in.data) {
498 return NT_STATUS_INVALID_PARAMETER;
499 }
500
501 /* Grab the keytab, however generated */
502 ret = cli_credentials_get_keytab(gensec_get_credentials(gensec_security),
503 gensec_security->settings->lp_ctx, &keytab);
504 if (ret) {
505 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
506 }
507
508 /* This ensures we lookup the correct entry in that keytab */
509 ret = principal_from_credentials(out_mem_ctx, gensec_get_credentials(gensec_security),
510 gensec_krb5_state->smb_krb5_context,
511 &server_in_keytab, &obtained, &error_string);
512
513 if (ret) {
514 DEBUG(2,("Failed to make credentials from principal: %s\n", error_string));
515 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
516 }
517
518 /* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
519 if (gensec_krb5_state->gssapi
520 && gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
521 inbuf.data = unwrapped_in.data;
522 inbuf.length = unwrapped_in.length;
523 } else {
524 inbuf.data = in.data;
525 inbuf.length = in.length;
526 }
527
528 ret = smb_rd_req_return_stuff(gensec_krb5_state->smb_krb5_context->krb5_context,
529 &gensec_krb5_state->auth_context,
530 &inbuf, keytab->keytab, server_in_keytab,
531 &outbuf,
532 &gensec_krb5_state->ticket,
533 &gensec_krb5_state->keyblock);
534
535 if (ret) {
536 return NT_STATUS_LOGON_FAILURE;
537 }
538 unwrapped_out.data = (uint8_t *)outbuf.data;
539 unwrapped_out.length = outbuf.length;
540 gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
541 /* wrap that up in a nice GSS-API wrapping */
542 if (gensec_krb5_state->gssapi) {
543 *out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
544 } else {
545 *out = data_blob_talloc(out_mem_ctx, outbuf.data, outbuf.length);
546 }
547 krb5_data_free(&outbuf);
548 return NT_STATUS_OK;
549 }
550
551 case GENSEC_KRB5_DONE:
552 default:
553 /* Asking too many times... */
554 return NT_STATUS_INVALID_PARAMETER;
555 }
556}
557
558static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security,
559 DATA_BLOB *session_key)
560{
561 struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
562 krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
563 krb5_auth_context auth_context = gensec_krb5_state->auth_context;
564 krb5_keyblock *skey;
565 krb5_error_code err = -1;
566
567 if (gensec_krb5_state->state_position != GENSEC_KRB5_DONE) {
568 return NT_STATUS_NO_USER_SESSION_KEY;
569 }
570
571 if (gensec_krb5_state->session_key.data) {
572 *session_key = gensec_krb5_state->session_key;
573 return NT_STATUS_OK;
574 }
575
576 switch (gensec_security->gensec_role) {
577 case GENSEC_CLIENT:
578 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
579 break;
580 case GENSEC_SERVER:
581 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
582 break;
583 }
584 if (err == 0 && skey != NULL) {
585 DEBUG(10, ("Got KRB5 session key of length %d\n",
586 (int)KRB5_KEY_LENGTH(skey)));
587 gensec_krb5_state->session_key = data_blob_talloc(gensec_krb5_state,
588 KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
589 *session_key = gensec_krb5_state->session_key;
590 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
591
592 krb5_free_keyblock(context, skey);
593 return NT_STATUS_OK;
594 } else {
595 DEBUG(10, ("KRB5 error getting session key %d\n", err));
596 return NT_STATUS_NO_USER_SESSION_KEY;
597 }
598}
599
600static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
601 struct auth_session_info **_session_info)
602{
603 NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
604 struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
605 krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
606 struct auth_user_info_dc *user_info_dc = NULL;
607 struct auth_session_info *session_info = NULL;
608 struct PAC_LOGON_INFO *logon_info;
609
610 krb5_principal client_principal;
611 char *principal_string;
612
613 DATA_BLOB pac;
614 krb5_data pac_data;
615
616 krb5_error_code ret;
617
618 TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
619 if (!mem_ctx) {
620 return NT_STATUS_NO_MEMORY;
621 }
622
623 ret = krb5_ticket_get_client(context, gensec_krb5_state->ticket, &client_principal);
624 if (ret) {
625 DEBUG(5, ("krb5_ticket_get_client failed to get cleint principal: %s\n",
626 smb_get_krb5_error_message(context,
627 ret, mem_ctx)));
628 talloc_free(mem_ctx);
629 return NT_STATUS_NO_MEMORY;
630 }
631
632 ret = krb5_unparse_name(gensec_krb5_state->smb_krb5_context->krb5_context,
633 client_principal, &principal_string);
634 if (ret) {
635 DEBUG(1, ("Unable to parse client principal: %s\n",
636 smb_get_krb5_error_message(context,
637 ret, mem_ctx)));
638 krb5_free_principal(context, client_principal);
639 talloc_free(mem_ctx);
640 return NT_STATUS_NO_MEMORY;
641 }
642
643 ret = krb5_ticket_get_authorization_data_type(context, gensec_krb5_state->ticket,
644 KRB5_AUTHDATA_WIN2K_PAC,
645 &pac_data);
646
647 if (ret && gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
648 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s \n",
649 principal_string,
650 smb_get_krb5_error_message(context,
651 ret, mem_ctx)));
652 free(principal_string);
653 krb5_free_principal(context, client_principal);
654 talloc_free(mem_ctx);
655 return NT_STATUS_ACCESS_DENIED;
656 } else if (ret) {
657 /* NO pac */
658 DEBUG(5, ("krb5_ticket_get_authorization_data_type failed to find PAC: %s\n",
659 smb_get_krb5_error_message(context,
660 ret, mem_ctx)));
661 if (gensec_security->auth_context &&
662 !gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
663 DEBUG(1, ("Unable to find PAC for %s, resorting to local user lookup: %s",
664 principal_string, smb_get_krb5_error_message(context,
665 ret, mem_ctx)));
666 nt_status = gensec_security->auth_context->get_user_info_dc_principal(mem_ctx,
667 gensec_security->auth_context,
668 principal_string,
669 NULL, &user_info_dc);
670 if (!NT_STATUS_IS_OK(nt_status)) {
671 free(principal_string);
672 krb5_free_principal(context, client_principal);
673 talloc_free(mem_ctx);
674 return nt_status;
675 }
676 } else {
677 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access\n",
678 principal_string));
679 free(principal_string);
680 krb5_free_principal(context, client_principal);
681 talloc_free(mem_ctx);
682 return NT_STATUS_ACCESS_DENIED;
683 }
684 } else {
685 /* Found pac */
686 union netr_Validation validation;
687
688 pac = data_blob_talloc(mem_ctx, pac_data.data, pac_data.length);
689 if (!pac.data) {
690 free(principal_string);
691 krb5_free_principal(context, client_principal);
692 talloc_free(mem_ctx);
693 return NT_STATUS_NO_MEMORY;
694 }
695
696 /* decode and verify the pac */
697 nt_status = kerberos_pac_logon_info(gensec_krb5_state,
698 &logon_info, pac,
699 gensec_krb5_state->smb_krb5_context->krb5_context,
700 NULL, gensec_krb5_state->keyblock,
701 client_principal,
702 gensec_krb5_state->ticket->ticket.authtime, NULL);
703
704 if (!NT_STATUS_IS_OK(nt_status)) {
705 free(principal_string);
706 krb5_free_principal(context, client_principal);
707 talloc_free(mem_ctx);
708 return nt_status;
709 }
710
711 validation.sam3 = &logon_info->info3;
712 nt_status = make_user_info_dc_netlogon_validation(mem_ctx,
713 NULL,
714 3, &validation,
715 &user_info_dc);
716 if (!NT_STATUS_IS_OK(nt_status)) {
717 free(principal_string);
718 krb5_free_principal(context, client_principal);
719 talloc_free(mem_ctx);
720 return nt_status;
721 }
722 }
723
724 free(principal_string);
725 krb5_free_principal(context, client_principal);
726
727 /* references the user_info_dc into the session_info */
728 nt_status = gensec_generate_session_info(mem_ctx, gensec_security, user_info_dc, &session_info);
729
730 if (!NT_STATUS_IS_OK(nt_status)) {
731 talloc_free(mem_ctx);
732 return nt_status;
733 }
734
735 nt_status = gensec_krb5_session_key(gensec_security, &session_info->session_key);
736
737 if (!NT_STATUS_IS_OK(nt_status)) {
738 talloc_free(mem_ctx);
739 return nt_status;
740 }
741
742 *_session_info = session_info;
743
744 talloc_steal(gensec_krb5_state, session_info);
745 talloc_free(mem_ctx);
746 return NT_STATUS_OK;
747}
748
749static NTSTATUS gensec_krb5_wrap(struct gensec_security *gensec_security,
750 TALLOC_CTX *mem_ctx,
751 const DATA_BLOB *in,
752 DATA_BLOB *out)
753{
754 struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
755 krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
756 krb5_auth_context auth_context = gensec_krb5_state->auth_context;
757 krb5_error_code ret;
758 krb5_data input, output;
759 input.length = in->length;
760 input.data = in->data;
761
762 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
763 ret = krb5_mk_priv(context, auth_context, &input, &output, NULL);
764 if (ret) {
765 DEBUG(1, ("krb5_mk_priv failed: %s\n",
766 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
767 ret, mem_ctx)));
768 return NT_STATUS_ACCESS_DENIED;
769 }
770 *out = data_blob_talloc(mem_ctx, output.data, output.length);
771
772 krb5_data_free(&output);
773 } else {
774 return NT_STATUS_ACCESS_DENIED;
775 }
776 return NT_STATUS_OK;
777}
778
779static NTSTATUS gensec_krb5_unwrap(struct gensec_security *gensec_security,
780 TALLOC_CTX *mem_ctx,
781 const DATA_BLOB *in,
782 DATA_BLOB *out)
783{
784 struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
785 krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
786 krb5_auth_context auth_context = gensec_krb5_state->auth_context;
787 krb5_error_code ret;
788 krb5_data input, output;
789 krb5_replay_data replay;
790 input.length = in->length;
791 input.data = in->data;
792
793 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
794 ret = krb5_rd_priv(context, auth_context, &input, &output, &replay);
795 if (ret) {
796 DEBUG(1, ("krb5_rd_priv failed: %s\n",
797 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context,
798 ret, mem_ctx)));
799 return NT_STATUS_ACCESS_DENIED;
800 }
801 *out = data_blob_talloc(mem_ctx, output.data, output.length);
802
803 krb5_data_free(&output);
804 } else {
805 return NT_STATUS_ACCESS_DENIED;
806 }
807 return NT_STATUS_OK;
808}
809
810static bool gensec_krb5_have_feature(struct gensec_security *gensec_security,
811 uint32_t feature)
812{
813 struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
814 if (feature & GENSEC_FEATURE_SESSION_KEY) {
815 return true;
816 }
817 if (!gensec_krb5_state->gssapi &&
818 (feature & GENSEC_FEATURE_SEAL)) {
819 return true;
820 }
821
822 return false;
823}
824
825static const char *gensec_krb5_oids[] = {
826 GENSEC_OID_KERBEROS5,
827 GENSEC_OID_KERBEROS5_OLD,
828 NULL
829};
830
831static const struct gensec_security_ops gensec_fake_gssapi_krb5_security_ops = {
832 .name = "fake_gssapi_krb5",
833 .auth_type = DCERPC_AUTH_TYPE_KRB5,
834 .oid = gensec_krb5_oids,
835 .client_start = gensec_fake_gssapi_krb5_client_start,
836 .server_start = gensec_fake_gssapi_krb5_server_start,
837 .update = gensec_krb5_update,
838 .magic = gensec_fake_gssapi_krb5_magic,
839 .session_key = gensec_krb5_session_key,
840 .session_info = gensec_krb5_session_info,
841 .have_feature = gensec_krb5_have_feature,
842 .enabled = false,
843 .kerberos = true,
844 .priority = GENSEC_KRB5
845};
846
847static const struct gensec_security_ops gensec_krb5_security_ops = {
848 .name = "krb5",
849 .client_start = gensec_krb5_client_start,
850 .server_start = gensec_krb5_server_start,
851 .update = gensec_krb5_update,
852 .session_key = gensec_krb5_session_key,
853 .session_info = gensec_krb5_session_info,
854 .have_feature = gensec_krb5_have_feature,
855 .wrap = gensec_krb5_wrap,
856 .unwrap = gensec_krb5_unwrap,
857 .enabled = true,
858 .kerberos = true,
859 .priority = GENSEC_KRB5
860};
861
862_PUBLIC_ NTSTATUS gensec_krb5_init(void)
863{
864 NTSTATUS ret;
865
866 ret = gensec_register(&gensec_krb5_security_ops);
867 if (!NT_STATUS_IS_OK(ret)) {
868 DEBUG(0,("Failed to register '%s' gensec backend!\n",
869 gensec_krb5_security_ops.name));
870 return ret;
871 }
872
873 ret = gensec_register(&gensec_fake_gssapi_krb5_security_ops);
874 if (!NT_STATUS_IS_OK(ret)) {
875 DEBUG(0,("Failed to register '%s' gensec backend!\n",
876 gensec_krb5_security_ops.name));
877 return ret;
878 }
879
880 return ret;
881}
Note: See TracBrowser for help on using the repository browser.