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smbd: replace CHECK_WRITE() macro with calls to check_any_access_fsp()
[Samba.git] / auth / gensec / schannel.c
blob4f5db9fc32ec246da88e1ad62d49106643aff573
1 /*
2 Unix SMB/CIFS implementation.
3
4 dcerpc schannel operations
5
6 Copyright (C) Andrew Tridgell 2004
7 Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 */
22
23 #include "includes.h"
24 #include <tevent.h>
25 #include "lib/util/tevent_ntstatus.h"
26 #include "librpc/gen_ndr/ndr_schannel.h"
27 #include "auth/auth.h"
28 #include "auth/credentials/credentials.h"
29 #include "auth/gensec/gensec.h"
30 #include "auth/gensec/gensec_internal.h"
31 #include "auth/gensec/gensec_proto.h"
32 #include "../libcli/auth/schannel.h"
33 #include "librpc/gen_ndr/dcerpc.h"
34 #include "param/param.h"
35 #include "auth/gensec/gensec_toplevel_proto.h"
36 #include "libds/common/roles.h"
37
38 #include "lib/crypto/gnutls_helpers.h"
39 #include <gnutls/gnutls.h>
40 #include <gnutls/crypto.h>
41
42 #undef DBGC_CLASS
43 #define DBGC_CLASS DBGC_AUTH
44
45 struct schannel_state {
46 struct gensec_security *gensec;
47 uint64_t seq_num;
48 bool initiator;
49 struct netlogon_creds_CredentialState *creds;
50 struct auth_user_info_dc *user_info_dc;
51 };
52
53 #define SETUP_SEQNUM(state, buf, initiator) do { \
54 uint8_t *_buf = buf; \
55 uint32_t _seq_num_low = (state)->seq_num & UINT32_MAX; \
56 uint32_t _seq_num_high = (state)->seq_num >> 32; \
57 if (initiator) { \
58 _seq_num_high |= 0x80000000; \
59 } \
60 RSIVAL(_buf, 0, _seq_num_low); \
61 RSIVAL(_buf, 4, _seq_num_high); \
62 } while(0)
63
64 static struct schannel_state *netsec_create_state(
65 struct gensec_security *gensec,
66 struct netlogon_creds_CredentialState *creds,
67 bool initiator)
68 {
69 struct schannel_state *state;
70
71 state = talloc_zero(gensec, struct schannel_state);
72 if (state == NULL) {
73 return NULL;
74 }
75
76 state->gensec = gensec;
77 state->initiator = initiator;
78 state->creds = netlogon_creds_copy(state, creds);
79 if (state->creds == NULL) {
80 talloc_free(state);
81 return NULL;
82 }
83
84 gensec->private_data = state;
85
86 return state;
87 }
88
89 static void netsec_offset_and_sizes(struct schannel_state *state,
90 bool do_seal,
91 uint32_t *_min_sig_size,
92 uint32_t *_used_sig_size,
93 uint32_t *_checksum_length,
94 uint32_t *_confounder_ofs)
95 {
96 uint32_t min_sig_size;
97 uint32_t used_sig_size;
98 uint32_t checksum_length;
99 uint32_t confounder_ofs;
100
101 if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
102 min_sig_size = 48;
103 used_sig_size = 56;
104 /*
105 * Note: windows has a bug here and uses the old values...
106 *
107 * checksum_length = 32;
108 * confounder_ofs = 48;
109 */
110 checksum_length = 8;
111 confounder_ofs = 24;
112 } else {
113 min_sig_size = 24;
114 used_sig_size = 32;
115 checksum_length = 8;
116 confounder_ofs = 24;
117 }
118
119 if (do_seal) {
120 min_sig_size += 8;
121 }
122
123 if (_min_sig_size) {
124 *_min_sig_size = min_sig_size;
125 }
126
127 if (_used_sig_size) {
128 *_used_sig_size = used_sig_size;
129 }
130
131 if (_checksum_length) {
132 *_checksum_length = checksum_length;
133 }
134
135 if (_confounder_ofs) {
136 *_confounder_ofs = confounder_ofs;
137 }
138 }
139
140 /*******************************************************************
141 Encode or Decode the sequence number (which is symmetric)
142 ********************************************************************/
143 static NTSTATUS netsec_do_seq_num(struct schannel_state *state,
144 const uint8_t *checksum,
145 uint32_t checksum_length,
146 uint8_t seq_num[8])
147 {
148 if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
149 gnutls_cipher_hd_t cipher_hnd = NULL;
150 gnutls_datum_t key = {
151 .data = state->creds->session_key,
152 .size = sizeof(state->creds->session_key),
153 };
154 uint32_t iv_size =
155 gnutls_cipher_get_iv_size(GNUTLS_CIPHER_AES_128_CFB8);
156 uint8_t _iv[iv_size];
157 gnutls_datum_t iv = {
158 .data = _iv,
159 .size = iv_size,
160 };
161 int rc;
162
163 ZERO_ARRAY(_iv);
164
165 memcpy(iv.data + 0, checksum, 8);
166 memcpy(iv.data + 8, checksum, 8);
167
168 rc = gnutls_cipher_init(&cipher_hnd,
169 GNUTLS_CIPHER_AES_128_CFB8,
170 &key,
171 &iv);
172 if (rc < 0) {
173 return gnutls_error_to_ntstatus(rc,
174 NT_STATUS_CRYPTO_SYSTEM_INVALID);
175 }
176
177 rc = gnutls_cipher_encrypt(cipher_hnd, seq_num, 8);
178 gnutls_cipher_deinit(cipher_hnd);
179 if (rc < 0) {
180 return gnutls_error_to_ntstatus(rc,
181 NT_STATUS_CRYPTO_SYSTEM_INVALID);
182 }
183
184 } else {
185 static const uint8_t zeros[4];
186 uint8_t _sequence_key[16];
187 gnutls_cipher_hd_t cipher_hnd;
188 gnutls_datum_t sequence_key = {
189 .data = _sequence_key,
190 .size = sizeof(_sequence_key),
191 };
192 uint8_t digest1[16];
193 int rc;
194
195 rc = gnutls_hmac_fast(GNUTLS_MAC_MD5,
196 state->creds->session_key,
197 sizeof(state->creds->session_key),
198 zeros,
199 sizeof(zeros),
200 digest1);
201 if (rc < 0) {
202 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
203 }
204
205 rc = gnutls_hmac_fast(GNUTLS_MAC_MD5,
206 digest1,
207 sizeof(digest1),
208 checksum,
209 checksum_length,
210 _sequence_key);
211 if (rc < 0) {
212 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
213 }
214
215 ZERO_ARRAY(digest1);
216
217 rc = gnutls_cipher_init(&cipher_hnd,
218 GNUTLS_CIPHER_ARCFOUR_128,
219 &sequence_key,
220 NULL);
221 if (rc < 0) {
222 ZERO_ARRAY(_sequence_key);
223 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
224 }
225
226 rc = gnutls_cipher_encrypt(cipher_hnd,
227 seq_num,
228 8);
229 gnutls_cipher_deinit(cipher_hnd);
230 ZERO_ARRAY(_sequence_key);
231 if (rc < 0) {
232 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
233 }
234 }
235
236 state->seq_num++;
237
238 return NT_STATUS_OK;
239 }
240
241 static NTSTATUS netsec_do_seal(struct schannel_state *state,
242 const uint8_t seq_num[8],
243 uint8_t confounder[8],
244 uint8_t *data, uint32_t length,
245 bool forward)
246 {
247 if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
248 gnutls_cipher_hd_t cipher_hnd = NULL;
249 uint8_t sess_kf0[16] = {0};
250 gnutls_datum_t key = {
251 .data = sess_kf0,
252 .size = sizeof(sess_kf0),
253 };
254 uint32_t iv_size =
255 gnutls_cipher_get_iv_size(GNUTLS_CIPHER_AES_128_CFB8);
256 uint8_t _iv[iv_size];
257 gnutls_datum_t iv = {
258 .data = _iv,
259 .size = iv_size,
260 };
261 uint32_t i;
262 int rc;
263
264 for (i = 0; i < key.size; i++) {
265 key.data[i] = state->creds->session_key[i] ^ 0xf0;
266 }
267
268 ZERO_ARRAY(_iv);
269
270 memcpy(iv.data + 0, seq_num, 8);
271 memcpy(iv.data + 8, seq_num, 8);
272
273 rc = gnutls_cipher_init(&cipher_hnd,
274 GNUTLS_CIPHER_AES_128_CFB8,
275 &key,
276 &iv);
277 if (rc < 0) {
278 DBG_ERR("ERROR: gnutls_cipher_init: %s\n",
279 gnutls_strerror(rc));
280 return NT_STATUS_NO_MEMORY;
281 }
282
283 if (forward) {
284 rc = gnutls_cipher_encrypt(cipher_hnd,
285 confounder,
286 8);
287 if (rc < 0) {
288 gnutls_cipher_deinit(cipher_hnd);
289 return gnutls_error_to_ntstatus(rc, NT_STATUS_CRYPTO_SYSTEM_INVALID);
290 }
291
292 rc = gnutls_cipher_encrypt(cipher_hnd,
293 data,
294 length);
295 if (rc < 0) {
296 gnutls_cipher_deinit(cipher_hnd);
297 return gnutls_error_to_ntstatus(rc, NT_STATUS_CRYPTO_SYSTEM_INVALID);
298 }
299 } else {
300
301 /*
302 * Workaround bug present in gnutls 3.6.8:
303 *
304 * gnutls_cipher_decrypt() uses an optimization
305 * internally that breaks decryption when processing
306 * buffers with their length not being a multiple
307 * of the blocksize.
308 */
309
310 uint8_t tmp[16] = { 0, };
311 uint32_t tmp_dlength = MIN(length, sizeof(tmp) - 8);
312
313 memcpy(tmp, confounder, 8);
314 memcpy(tmp + 8, data, tmp_dlength);
315
316 rc = gnutls_cipher_decrypt(cipher_hnd,
317 tmp,
318 8 + tmp_dlength);
319 if (rc < 0) {
320 ZERO_STRUCT(tmp);
321 gnutls_cipher_deinit(cipher_hnd);
322 return gnutls_error_to_ntstatus(rc, NT_STATUS_CRYPTO_SYSTEM_INVALID);
323 }
324
325 memcpy(confounder, tmp, 8);
326 memcpy(data, tmp + 8, tmp_dlength);
327 ZERO_STRUCT(tmp);
328
329 if (length > tmp_dlength) {
330 rc = gnutls_cipher_decrypt(cipher_hnd,
331 data + tmp_dlength,
332 length - tmp_dlength);
333 if (rc < 0) {
334 gnutls_cipher_deinit(cipher_hnd);
335 return gnutls_error_to_ntstatus(rc, NT_STATUS_CRYPTO_SYSTEM_INVALID);
336 }
337 }
338 }
339 gnutls_cipher_deinit(cipher_hnd);
340 } else {
341 gnutls_cipher_hd_t cipher_hnd;
342 uint8_t _sealing_key[16];
343 gnutls_datum_t sealing_key = {
344 .data = _sealing_key,
345 .size = sizeof(_sealing_key),
346 };
347 static const uint8_t zeros[4];
348 uint8_t digest2[16];
349 uint8_t sess_kf0[16];
350 int rc;
351 int i;
352
353 for (i = 0; i < 16; i++) {
354 sess_kf0[i] = state->creds->session_key[i] ^ 0xf0;
355 }
356
357 rc = gnutls_hmac_fast(GNUTLS_MAC_MD5,
358 sess_kf0,
359 sizeof(sess_kf0),
360 zeros,
361 4,
362 digest2);
363 if (rc < 0) {
364 ZERO_ARRAY(digest2);
365 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
366 }
367
368 rc = gnutls_hmac_fast(GNUTLS_MAC_MD5,
369 digest2,
370 sizeof(digest2),
371 seq_num,
372 8,
373 _sealing_key);
374
375 ZERO_ARRAY(digest2);
376 if (rc < 0) {
377 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
378 }
379
380 rc = gnutls_cipher_init(&cipher_hnd,
381 GNUTLS_CIPHER_ARCFOUR_128,
382 &sealing_key,
383 NULL);
384 if (rc < 0) {
385 ZERO_ARRAY(_sealing_key);
386 return gnutls_error_to_ntstatus(rc, NT_STATUS_CRYPTO_SYSTEM_INVALID);
387 }
388 rc = gnutls_cipher_encrypt(cipher_hnd,
389 confounder,
390 8);
391 if (rc < 0) {
392 ZERO_ARRAY(_sealing_key);
393 return gnutls_error_to_ntstatus(rc, NT_STATUS_CRYPTO_SYSTEM_INVALID);
394 }
395 gnutls_cipher_deinit(cipher_hnd);
396 rc = gnutls_cipher_init(&cipher_hnd,
397 GNUTLS_CIPHER_ARCFOUR_128,
398 &sealing_key,
399 NULL);
400 if (rc < 0) {
401 ZERO_ARRAY(_sealing_key);
402 return gnutls_error_to_ntstatus(rc, NT_STATUS_CRYPTO_SYSTEM_INVALID);
403 }
404 rc = gnutls_cipher_encrypt(cipher_hnd,
405 data,
406 length);
407 gnutls_cipher_deinit(cipher_hnd);
408 ZERO_ARRAY(_sealing_key);
409 if (rc < 0) {
410 return gnutls_error_to_ntstatus(rc, NT_STATUS_CRYPTO_SYSTEM_INVALID);
411 }
412 }
413
414 return NT_STATUS_OK;
415 }
416
417 /*******************************************************************
418 Create a digest over the entire packet (including the data), and
419 MD5 it with the session key.
420 ********************************************************************/
421 static NTSTATUS netsec_do_sign(struct schannel_state *state,
422 const uint8_t *confounder,
423 const uint8_t *data, size_t length,
424 uint8_t header[8],
425 uint8_t *checksum)
426 {
427 if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
428 gnutls_hmac_hd_t hmac_hnd = NULL;
429 int rc;
430
431 rc = gnutls_hmac_init(&hmac_hnd,
432 GNUTLS_MAC_SHA256,
433 state->creds->session_key,
434 sizeof(state->creds->session_key));
435 if (rc < 0) {
436 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
437 }
438
439 if (confounder) {
440 SSVAL(header, 0, NL_SIGN_HMAC_SHA256);
441 SSVAL(header, 2, NL_SEAL_AES128);
442 SSVAL(header, 4, 0xFFFF);
443 SSVAL(header, 6, 0x0000);
444
445 rc = gnutls_hmac(hmac_hnd, header, 8);
446 if (rc < 0) {
447 gnutls_hmac_deinit(hmac_hnd, NULL);
448 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
449 }
450 rc = gnutls_hmac(hmac_hnd, confounder, 8);
451 if (rc < 0) {
452 gnutls_hmac_deinit(hmac_hnd, NULL);
453 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
454 }
455 } else {
456 SSVAL(header, 0, NL_SIGN_HMAC_SHA256);
457 SSVAL(header, 2, NL_SEAL_NONE);
458 SSVAL(header, 4, 0xFFFF);
459 SSVAL(header, 6, 0x0000);
460
461 rc = gnutls_hmac(hmac_hnd, header, 8);
462 if (rc < 0) {
463 gnutls_hmac_deinit(hmac_hnd, NULL);
464 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
465 }
466 }
467
468 rc = gnutls_hmac(hmac_hnd, data, length);
469 if (rc < 0) {
470 gnutls_hmac_deinit(hmac_hnd, NULL);
471 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
472 }
473
474 gnutls_hmac_deinit(hmac_hnd, checksum);
475 } else {
476 uint8_t packet_digest[16];
477 static const uint8_t zeros[4];
478 gnutls_hash_hd_t hash_hnd = NULL;
479 int rc;
480
481 rc = gnutls_hash_init(&hash_hnd, GNUTLS_DIG_MD5);
482 if (rc < 0) {
483 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
484 }
485
486 rc = gnutls_hash(hash_hnd, zeros, sizeof(zeros));
487 if (rc < 0) {
488 gnutls_hash_deinit(hash_hnd, NULL);
489 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
490 }
491 if (confounder) {
492 SSVAL(header, 0, NL_SIGN_HMAC_MD5);
493 SSVAL(header, 2, NL_SEAL_RC4);
494 SSVAL(header, 4, 0xFFFF);
495 SSVAL(header, 6, 0x0000);
496
497 rc = gnutls_hash(hash_hnd, header, 8);
498 if (rc < 0) {
499 gnutls_hash_deinit(hash_hnd, NULL);
500 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
501 }
502 rc = gnutls_hash(hash_hnd, confounder, 8);
503 if (rc < 0) {
504 gnutls_hash_deinit(hash_hnd, NULL);
505 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
506 }
507 } else {
508 SSVAL(header, 0, NL_SIGN_HMAC_MD5);
509 SSVAL(header, 2, NL_SEAL_NONE);
510 SSVAL(header, 4, 0xFFFF);
511 SSVAL(header, 6, 0x0000);
512
513 rc = gnutls_hash(hash_hnd, header, 8);
514 if (rc < 0) {
515 gnutls_hash_deinit(hash_hnd, NULL);
516 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
517 }
518 }
519 rc = gnutls_hash(hash_hnd, data, length);
520 if (rc < 0) {
521 gnutls_hash_deinit(hash_hnd, NULL);
522 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
523 }
524 gnutls_hash_deinit(hash_hnd, packet_digest);
525
526 rc = gnutls_hmac_fast(GNUTLS_MAC_MD5,
527 state->creds->session_key,
528 sizeof(state->creds->session_key),
529 packet_digest,
530 sizeof(packet_digest),
531 checksum);
532 ZERO_ARRAY(packet_digest);
533 if (rc < 0) {
534 return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED);
535 }
536 }
537
538 return NT_STATUS_OK;
539 }
540
541 static NTSTATUS netsec_incoming_packet(struct schannel_state *state,
542 bool do_unseal,
543 uint8_t *data, size_t length,
544 const uint8_t *whole_pdu, size_t pdu_length,
545 const DATA_BLOB *sig)
546 {
547 uint32_t min_sig_size = 0;
548 uint8_t header[8];
549 uint8_t checksum[32];
550 uint32_t checksum_length = sizeof(checksum_length);
551 uint8_t _confounder[8];
552 uint8_t *confounder = NULL;
553 uint32_t confounder_ofs = 0;
554 uint8_t seq_num[8];
555 bool ret;
556 const uint8_t *sign_data = NULL;
557 size_t sign_length = 0;
558 NTSTATUS status;
559
560 netsec_offset_and_sizes(state,
561 do_unseal,
562 &min_sig_size,
563 NULL,
564 &checksum_length,
565 &confounder_ofs);
566
567 if (sig->length < min_sig_size) {
568 return NT_STATUS_ACCESS_DENIED;
569 }
570
571 if (do_unseal) {
572 confounder = _confounder;
573 memcpy(confounder, sig->data+confounder_ofs, 8);
574 } else {
575 confounder = NULL;
576 }
577
578 SETUP_SEQNUM(state, seq_num, !state->initiator);
579
580 if (do_unseal) {
581 status = netsec_do_seal(state,
582 seq_num,
583 confounder,
584 data,
585 length,
586 false);
587 if (!NT_STATUS_IS_OK(status)) {
588 DBG_WARNING("netsec_do_seal failed: %s\n", nt_errstr(status));
589 return NT_STATUS_ACCESS_DENIED;
590 }
591 }
592
593 if (state->gensec->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
594 sign_data = whole_pdu;
595 sign_length = pdu_length;
596 } else {
597 sign_data = data;
598 sign_length = length;
599 }
600
601 status = netsec_do_sign(state,
602 confounder,
603 sign_data,
604 sign_length,
605 header,
606 checksum);
607 if (!NT_STATUS_IS_OK(status)) {
608 DBG_WARNING("netsec_do_sign failed: %s\n", nt_errstr(status));
609 return NT_STATUS_ACCESS_DENIED;
610 }
611
612 ret = mem_equal_const_time(checksum, sig->data+16, checksum_length);
613 if (!ret) {
614 dump_data_pw("calc digest:", checksum, checksum_length);
615 dump_data_pw("wire digest:", sig->data+16, checksum_length);
616 return NT_STATUS_ACCESS_DENIED;
617 }
618
619 status = netsec_do_seq_num(state, checksum, checksum_length, seq_num);
620 if (!NT_STATUS_IS_OK(status)) {
621 DBG_WARNING("netsec_do_seq_num failed: %s\n",
622 nt_errstr(status));
623 return status;
624 }
625
626 ZERO_ARRAY(checksum);
627
628 ret = mem_equal_const_time(seq_num, sig->data+8, 8);
629 if (!ret) {
630 dump_data_pw("calc seq num:", seq_num, 8);
631 dump_data_pw("wire seq num:", sig->data+8, 8);
632 return NT_STATUS_ACCESS_DENIED;
633 }
634
635 return NT_STATUS_OK;
636 }
637
638 static uint32_t netsec_outgoing_sig_size(struct schannel_state *state)
639 {
640 uint32_t sig_size = 0;
641
642 netsec_offset_and_sizes(state,
643 true,
644 NULL,
645 &sig_size,
646 NULL,
647 NULL);
648
649 return sig_size;
650 }
651
652 static NTSTATUS netsec_outgoing_packet(struct schannel_state *state,
653 TALLOC_CTX *mem_ctx,
654 bool do_seal,
655 uint8_t *data, size_t length,
656 const uint8_t *whole_pdu, size_t pdu_length,
657 DATA_BLOB *sig)
658 {
659 uint32_t min_sig_size = 0;
660 uint32_t used_sig_size = 0;
661 uint8_t header[8];
662 uint8_t checksum[32];
663 uint32_t checksum_length = sizeof(checksum_length);
664 uint8_t _confounder[8];
665 uint8_t *confounder = NULL;
666 uint32_t confounder_ofs = 0;
667 uint8_t seq_num[8];
668 const uint8_t *sign_data = NULL;
669 size_t sign_length = 0;
670 NTSTATUS status;
671
672 netsec_offset_and_sizes(state,
673 do_seal,
674 &min_sig_size,
675 &used_sig_size,
676 &checksum_length,
677 &confounder_ofs);
678
679 SETUP_SEQNUM(state, seq_num, state->initiator);
680
681 if (do_seal) {
682 confounder = _confounder;
683 generate_random_buffer(confounder, 8);
684 } else {
685 confounder = NULL;
686 }
687
688 if (state->gensec->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
689 sign_data = whole_pdu;
690 sign_length = pdu_length;
691 } else {
692 sign_data = data;
693 sign_length = length;
694 }
695
696 status = netsec_do_sign(state,
697 confounder,
698 sign_data,
699 sign_length,
700 header,
701 checksum);
702 if (!NT_STATUS_IS_OK(status)) {
703 DBG_WARNING("netsec_do_sign failed: %s\n", nt_errstr(status));
704 return NT_STATUS_ACCESS_DENIED;
705 }
706
707 if (do_seal) {
708 status = netsec_do_seal(state,
709 seq_num,
710 confounder,
711 data,
712 length,
713 true);
714 if (!NT_STATUS_IS_OK(status)) {
715 DBG_WARNING("netsec_do_seal failed: %s\n",
716 nt_errstr(status));
717 return status;
718 }
719 }
720
721 status = netsec_do_seq_num(state, checksum, checksum_length, seq_num);
722 if (!NT_STATUS_IS_OK(status)) {
723 DBG_WARNING("netsec_do_seq_num failed: %s\n",
724 nt_errstr(status));
725 return status;
726 }
727
728 (*sig) = data_blob_talloc_zero(mem_ctx, used_sig_size);
729
730 memcpy(sig->data, header, 8);
731 memcpy(sig->data+8, seq_num, 8);
732 memcpy(sig->data+16, checksum, checksum_length);
733
734 if (confounder) {
735 memcpy(sig->data+confounder_ofs, confounder, 8);
736 }
737
738 dump_data_pw("signature:", sig->data+ 0, 8);
739 dump_data_pw("seq_num :", sig->data+ 8, 8);
740 dump_data_pw("digest :", sig->data+16, checksum_length);
741 dump_data_pw("confound :", sig->data+confounder_ofs, 8);
742
743 return NT_STATUS_OK;
744 }
745
746 _PUBLIC_ NTSTATUS gensec_schannel_init(TALLOC_CTX *ctx);
747
748 static size_t schannel_sig_size(struct gensec_security *gensec_security, size_t data_size)
749 {
750 struct schannel_state *state =
751 talloc_get_type_abort(gensec_security->private_data,
752 struct schannel_state);
753
754 return netsec_outgoing_sig_size(state);
755 }
756
757 struct schannel_update_state {
758 NTSTATUS status;
759 DATA_BLOB out;
760 };
761
762 static NTSTATUS schannel_update_internal(struct gensec_security *gensec_security,
763 TALLOC_CTX *out_mem_ctx,
764 const DATA_BLOB in, DATA_BLOB *out);
765
766 static struct tevent_req *schannel_update_send(TALLOC_CTX *mem_ctx,
767 struct tevent_context *ev,
768 struct gensec_security *gensec_security,
769 const DATA_BLOB in)
770 {
771 struct tevent_req *req;
772 struct schannel_update_state *state = NULL;
773 NTSTATUS status;
774
775 req = tevent_req_create(mem_ctx, &state,
776 struct schannel_update_state);
777 if (req == NULL) {
778 return NULL;
779 }
780
781 status = schannel_update_internal(gensec_security,
782 state, in,
783 &state->out);
784 state->status = status;
785 if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
786 status = NT_STATUS_OK;
787 }
788 if (tevent_req_nterror(req, status)) {
789 return tevent_req_post(req, ev);
790 }
791
792 tevent_req_done(req);
793 return tevent_req_post(req, ev);
794 }
795
796 static NTSTATUS schannel_update_internal(struct gensec_security *gensec_security,
797 TALLOC_CTX *out_mem_ctx,
798 const DATA_BLOB in, DATA_BLOB *out)
799 {
800 struct schannel_state *state =
801 talloc_get_type(gensec_security->private_data,
802 struct schannel_state);
803 NTSTATUS status;
804 enum ndr_err_code ndr_err;
805 struct NL_AUTH_MESSAGE bind_schannel = {
806 .Flags = 0,
807 };
808 struct NL_AUTH_MESSAGE bind_schannel_ack;
809 struct netlogon_creds_CredentialState *creds;
810 const char *workstation;
811 const char *domain;
812
813 *out = data_blob(NULL, 0);
814
815 if (gensec_security->dcerpc_auth_level < DCERPC_AUTH_LEVEL_INTEGRITY) {
816 switch (gensec_security->gensec_role) {
817 case GENSEC_CLIENT:
818 return NT_STATUS_INVALID_PARAMETER_MIX;
819 case GENSEC_SERVER:
820 return NT_STATUS_INVALID_PARAMETER;
821 }
822 return NT_STATUS_INTERNAL_ERROR;
823 }
824
825 switch (gensec_security->gensec_role) {
826 case GENSEC_CLIENT:
827 if (state != NULL) {
828 /* we could parse the bind ack, but we don't know what it is yet */
829 return NT_STATUS_OK;
830 }
831
832 creds = cli_credentials_get_netlogon_creds(gensec_security->credentials);
833 if (creds == NULL) {
834 return NT_STATUS_INVALID_PARAMETER_MIX;
835 }
836
837 state = netsec_create_state(gensec_security,
838 creds, true /* initiator */);
839 if (state == NULL) {
840 return NT_STATUS_NO_MEMORY;
841 }
842
843 bind_schannel.MessageType = NL_NEGOTIATE_REQUEST;
844
845 bind_schannel.Flags = NL_FLAG_OEM_NETBIOS_DOMAIN_NAME |
846 NL_FLAG_OEM_NETBIOS_COMPUTER_NAME;
847 bind_schannel.oem_netbios_domain.a = cli_credentials_get_domain(gensec_security->credentials);
848 bind_schannel.oem_netbios_computer.a = creds->computer_name;
849
850 if (creds->secure_channel_type == SEC_CHAN_DNS_DOMAIN) {
851 bind_schannel.Flags |= NL_FLAG_UTF8_DNS_DOMAIN_NAME;
852 bind_schannel.utf8_dns_domain.u = cli_credentials_get_realm(gensec_security->credentials);
853
854 bind_schannel.Flags |= NL_FLAG_UTF8_NETBIOS_COMPUTER_NAME;
855 bind_schannel.utf8_netbios_computer.u = creds->computer_name;
856 }
857
858 ndr_err = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel,
859 (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
860 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
861 status = ndr_map_error2ntstatus(ndr_err);
862 DEBUG(3, ("Could not create schannel bind: %s\n",
863 nt_errstr(status)));
864 return status;
865 }
866
867 return NT_STATUS_MORE_PROCESSING_REQUIRED;
868 case GENSEC_SERVER:
869
870 if (state != NULL) {
871 /* no third leg on this protocol */
872 return NT_STATUS_INVALID_PARAMETER;
873 }
874
875 /* parse the schannel startup blob */
876 ndr_err = ndr_pull_struct_blob(&in, out_mem_ctx, &bind_schannel,
877 (ndr_pull_flags_fn_t)ndr_pull_NL_AUTH_MESSAGE);
878 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
879 status = ndr_map_error2ntstatus(ndr_err);
880 DEBUG(3, ("Could not parse incoming schannel bind: %s\n",
881 nt_errstr(status)));
882 return status;
883 }
884
885 if (bind_schannel.Flags & NL_FLAG_OEM_NETBIOS_DOMAIN_NAME) {
886 domain = bind_schannel.oem_netbios_domain.a;
887 if (strcasecmp_m(domain, lpcfg_workgroup(gensec_security->settings->lp_ctx)) != 0) {
888 DEBUG(3, ("Request for schannel to incorrect domain: %s != our domain %s\n",
889 domain, lpcfg_workgroup(gensec_security->settings->lp_ctx)));
890 return NT_STATUS_LOGON_FAILURE;
891 }
892 } else if (bind_schannel.Flags & NL_FLAG_UTF8_DNS_DOMAIN_NAME) {
893 domain = bind_schannel.utf8_dns_domain.u;
894 if (strcasecmp_m(domain, lpcfg_dnsdomain(gensec_security->settings->lp_ctx)) != 0) {
895 DEBUG(3, ("Request for schannel to incorrect domain: %s != our domain %s\n",
896 domain, lpcfg_dnsdomain(gensec_security->settings->lp_ctx)));
897 return NT_STATUS_LOGON_FAILURE;
898 }
899 } else {
900 DEBUG(3, ("Request for schannel to without domain\n"));
901 return NT_STATUS_LOGON_FAILURE;
902 }
903
904 if (bind_schannel.Flags & NL_FLAG_OEM_NETBIOS_COMPUTER_NAME) {
905 workstation = bind_schannel.oem_netbios_computer.a;
906 } else if (bind_schannel.Flags & NL_FLAG_UTF8_NETBIOS_COMPUTER_NAME) {
907 workstation = bind_schannel.utf8_netbios_computer.u;
908 } else {
909 DEBUG(3, ("Request for schannel to without netbios workstation\n"));
910 return NT_STATUS_LOGON_FAILURE;
911 }
912
913 status = schannel_get_creds_state(out_mem_ctx,
914 gensec_security->settings->lp_ctx,
915 workstation, &creds);
916 if (!NT_STATUS_IS_OK(status)) {
917 DEBUG(3, ("Could not find session key for attempted schannel connection from %s: %s\n",
918 workstation, nt_errstr(status)));
919 if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_HANDLE)) {
920 return NT_STATUS_LOGON_FAILURE;
921 }
922 return status;
923 }
924
925 state = netsec_create_state(gensec_security,
926 creds, false /* not initiator */);
927 if (state == NULL) {
928 return NT_STATUS_NO_MEMORY;
929 }
930
931 status = auth_anonymous_user_info_dc(state,
932 lpcfg_netbios_name(gensec_security->settings->lp_ctx),
933 &state->user_info_dc);
934 if (!NT_STATUS_IS_OK(status)) {
935 return status;
936 }
937
938 bind_schannel_ack.MessageType = NL_NEGOTIATE_RESPONSE;
939 bind_schannel_ack.Flags = 0;
940 bind_schannel_ack.Buffer.dummy = 0x6c0000; /* actually I think
941 * this does not have
942 * any meaning here
943 * - gd */
944
945 ndr_err = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel_ack,
946 (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
947 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
948 status = ndr_map_error2ntstatus(ndr_err);
949 DEBUG(3, ("Could not return schannel bind ack for client %s: %s\n",
950 workstation, nt_errstr(status)));
951 return status;
952 }
953
954 return NT_STATUS_OK;
955 }
956 return NT_STATUS_INVALID_PARAMETER;
957 }
958
959 static NTSTATUS schannel_update_recv(struct tevent_req *req,
960 TALLOC_CTX *out_mem_ctx,
961 DATA_BLOB *out)
962 {
963 struct schannel_update_state *state =
964 tevent_req_data(req,
965 struct schannel_update_state);
966 NTSTATUS status;
967
968 *out = data_blob_null;
969
970 if (tevent_req_is_nterror(req, &status)) {
971 tevent_req_received(req);
972 return status;
973 }
974
975 status = state->status;
976 talloc_steal(out_mem_ctx, state->out.data);
977 *out = state->out;
978 tevent_req_received(req);
979 return status;
980 }
981
982 /**
983 * Returns anonymous credentials for schannel, matching Win2k3.
984 *
985 */
986
987 static NTSTATUS schannel_session_info(struct gensec_security *gensec_security,
988 TALLOC_CTX *mem_ctx,
989 struct auth_session_info **_session_info)
990 {
991 struct schannel_state *state =
992 talloc_get_type(gensec_security->private_data,
993 struct schannel_state);
994 struct auth4_context *auth_ctx = gensec_security->auth_context;
995 struct auth_session_info *session_info = NULL;
996 uint32_t session_info_flags = 0;
997 NTSTATUS status;
998
999 if (auth_ctx == NULL) {
1000 DEBUG(0, ("Cannot generate a session_info without the auth_context\n"));
1001 return NT_STATUS_INTERNAL_ERROR;
1002 }
1003
1004 if (auth_ctx->generate_session_info == NULL) {
1005 DEBUG(0, ("Cannot generate a session_info without the generate_session_info hook\n"));
1006 return NT_STATUS_INTERNAL_ERROR;
1007 }
1008
1009 if (gensec_security->want_features & GENSEC_FEATURE_UNIX_TOKEN) {
1010 session_info_flags |= AUTH_SESSION_INFO_UNIX_TOKEN;
1011 }
1012
1013 session_info_flags |= AUTH_SESSION_INFO_SIMPLE_PRIVILEGES;
1014
1015 status = auth_ctx->generate_session_info(
1016 auth_ctx,
1017 mem_ctx,
1018 state->user_info_dc,
1019 state->user_info_dc->info->account_name,
1020 session_info_flags,
1021 &session_info);
1022 if (!NT_STATUS_IS_OK(status)) {
1023 return status;
1024 }
1025
1026 *_session_info = session_info;
1027 return NT_STATUS_OK;
1028 }
1029
1030 /*
1031 * Reduce the attack surface by ensuring schannel is not available when
1032 * we are not a DC
1033 */
1034 static NTSTATUS schannel_server_start(struct gensec_security *gensec_security)
1035 {
1036 enum server_role server_role
1037 = lpcfg_server_role(gensec_security->settings->lp_ctx);
1038
1039 switch (server_role) {
1040 case ROLE_DOMAIN_BDC:
1041 case ROLE_DOMAIN_PDC:
1042 case ROLE_ACTIVE_DIRECTORY_DC:
1043 case ROLE_IPA_DC:
1044 return NT_STATUS_OK;
1045 default:
1046 return NT_STATUS_NOT_IMPLEMENTED;
1047 }
1048 }
1049
1050 static NTSTATUS schannel_client_start(struct gensec_security *gensec_security)
1051 {
1052 return NT_STATUS_OK;
1053 }
1054
1055 static bool schannel_have_feature(struct gensec_security *gensec_security,
1056 uint32_t feature)
1057 {
1058 if (gensec_security->dcerpc_auth_level >= DCERPC_AUTH_LEVEL_INTEGRITY) {
1059 if (feature & GENSEC_FEATURE_SIGN) {
1060 return true;
1061 }
1062 }
1063 if (gensec_security->dcerpc_auth_level == DCERPC_AUTH_LEVEL_PRIVACY) {
1064 if (feature & GENSEC_FEATURE_SEAL) {
1065 return true;
1066 }
1067 }
1068 if (feature & GENSEC_FEATURE_DCE_STYLE) {
1069 return true;
1070 }
1071 if (feature & GENSEC_FEATURE_SIGN_PKT_HEADER) {
1072 return true;
1073 }
1074 return false;
1075 }
1076
1077 /*
1078 unseal a packet
1079 */
1080 static NTSTATUS schannel_unseal_packet(struct gensec_security *gensec_security,
1081 uint8_t *data, size_t length,
1082 const uint8_t *whole_pdu, size_t pdu_length,
1083 const DATA_BLOB *sig)
1084 {
1085 struct schannel_state *state =
1086 talloc_get_type_abort(gensec_security->private_data,
1087 struct schannel_state);
1088
1089 return netsec_incoming_packet(state, true,
1090 discard_const_p(uint8_t, data),
1091 length,
1092 whole_pdu, pdu_length,
1093 sig);
1094 }
1095
1096 /*
1097 check the signature on a packet
1098 */
1099 static NTSTATUS schannel_check_packet(struct gensec_security *gensec_security,
1100 const uint8_t *data, size_t length,
1101 const uint8_t *whole_pdu, size_t pdu_length,
1102 const DATA_BLOB *sig)
1103 {
1104 struct schannel_state *state =
1105 talloc_get_type_abort(gensec_security->private_data,
1106 struct schannel_state);
1107
1108 return netsec_incoming_packet(state, false,
1109 discard_const_p(uint8_t, data),
1110 length,
1111 whole_pdu, pdu_length,
1112 sig);
1113 }
1114 /*
1115 seal a packet
1116 */
1117 static NTSTATUS schannel_seal_packet(struct gensec_security *gensec_security,
1118 TALLOC_CTX *mem_ctx,
1119 uint8_t *data, size_t length,
1120 const uint8_t *whole_pdu, size_t pdu_length,
1121 DATA_BLOB *sig)
1122 {
1123 struct schannel_state *state =
1124 talloc_get_type_abort(gensec_security->private_data,
1125 struct schannel_state);
1126
1127 return netsec_outgoing_packet(state, mem_ctx, true,
1128 data, length,
1129 whole_pdu, pdu_length,
1130 sig);
1131 }
1132
1133 /*
1134 sign a packet
1135 */
1136 static NTSTATUS schannel_sign_packet(struct gensec_security *gensec_security,
1137 TALLOC_CTX *mem_ctx,
1138 const uint8_t *data, size_t length,
1139 const uint8_t *whole_pdu, size_t pdu_length,
1140 DATA_BLOB *sig)
1141 {
1142 struct schannel_state *state =
1143 talloc_get_type_abort(gensec_security->private_data,
1144 struct schannel_state);
1145
1146 return netsec_outgoing_packet(state, mem_ctx, false,
1147 discard_const_p(uint8_t, data),
1148 length,
1149 whole_pdu, pdu_length,
1150 sig);
1151 }
1152
1153 static const struct gensec_security_ops gensec_schannel_security_ops = {
1154 .name = "schannel",
1155 .auth_type = DCERPC_AUTH_TYPE_SCHANNEL,
1156 .client_start = schannel_client_start,
1157 .server_start = schannel_server_start,
1158 .update_send = schannel_update_send,
1159 .update_recv = schannel_update_recv,
1160 .seal_packet = schannel_seal_packet,
1161 .sign_packet = schannel_sign_packet,
1162 .check_packet = schannel_check_packet,
1163 .unseal_packet = schannel_unseal_packet,
1164 .session_info = schannel_session_info,
1165 .sig_size = schannel_sig_size,
1166 .have_feature = schannel_have_feature,
1167 .enabled = true,
1168 .priority = GENSEC_SCHANNEL
1169 };
1170
1171 _PUBLIC_ NTSTATUS gensec_schannel_init(TALLOC_CTX *ctx)
1172 {
1173 NTSTATUS ret;
1174 ret = gensec_register(ctx, &gensec_schannel_security_ops);
1175 if (!NT_STATUS_IS_OK(ret)) {
1176 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1177 gensec_schannel_security_ops.name));
1178 return ret;
1179 }
1180
1181 return ret;
1182 }
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