9b28c45183c3e4ac489d49854fdd5369afe07f80
[samba.git] / auth / gensec / schannel.c
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 "librpc/gen_ndr/ndr_schannel.h"
25 #include "auth/auth.h"
26 #include "auth/credentials/credentials.h"
27 #include "auth/gensec/gensec.h"
28 #include "auth/gensec/gensec_internal.h"
29 #include "auth/gensec/gensec_proto.h"
30 #include "../libcli/auth/schannel.h"
31 #include "librpc/gen_ndr/dcerpc.h"
32 #include "param/param.h"
33 #include "auth/gensec/gensec_toplevel_proto.h"
34 #include "lib/crypto/crypto.h"
35
36 struct schannel_state {
37         struct gensec_security *gensec;
38         uint64_t seq_num;
39         bool initiator;
40         struct netlogon_creds_CredentialState *creds;
41         struct auth_user_info_dc *user_info_dc;
42 };
43
44 #define SETUP_SEQNUM(state, buf, initiator) do { \
45         uint8_t *_buf = buf; \
46         uint32_t _seq_num_low = (state)->seq_num & UINT32_MAX; \
47         uint32_t _seq_num_high = (state)->seq_num >> 32; \
48         if (initiator) { \
49                 _seq_num_high |= 0x80000000; \
50         } \
51         RSIVAL(_buf, 0, _seq_num_low); \
52         RSIVAL(_buf, 4, _seq_num_high); \
53 } while(0)
54
55 static struct schannel_state *netsec_create_state(
56                                 struct gensec_security *gensec,
57                                 struct netlogon_creds_CredentialState *creds,
58                                 bool initiator)
59 {
60         struct schannel_state *state;
61
62         state = talloc_zero(gensec, struct schannel_state);
63         if (state == NULL) {
64                 return NULL;
65         }
66
67         state->gensec = gensec;
68         state->initiator = initiator;
69         state->creds = netlogon_creds_copy(state, creds);
70         if (state->creds == NULL) {
71                 talloc_free(state);
72                 return NULL;
73         }
74
75         gensec->private_data = state;
76
77         return state;
78 }
79
80 static void netsec_offset_and_sizes(struct schannel_state *state,
81                                     bool do_seal,
82                                     uint32_t *_min_sig_size,
83                                     uint32_t *_used_sig_size,
84                                     uint32_t *_checksum_length,
85                                     uint32_t *_confounder_ofs)
86 {
87         uint32_t min_sig_size;
88         uint32_t used_sig_size;
89         uint32_t checksum_length;
90         uint32_t confounder_ofs;
91
92         if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
93                 min_sig_size = 48;
94                 used_sig_size = 56;
95                 /*
96                  * Note: windows has a bug here and uses the old values...
97                  *
98                  * checksum_length = 32;
99                  * confounder_ofs = 48;
100                  */
101                 checksum_length = 8;
102                 confounder_ofs = 24;
103         } else {
104                 min_sig_size = 24;
105                 used_sig_size = 32;
106                 checksum_length = 8;
107                 confounder_ofs = 24;
108         }
109
110         if (do_seal) {
111                 min_sig_size += 8;
112         }
113
114         if (_min_sig_size) {
115                 *_min_sig_size = min_sig_size;
116         }
117
118         if (_used_sig_size) {
119                 *_used_sig_size = used_sig_size;
120         }
121
122         if (_checksum_length) {
123                 *_checksum_length = checksum_length;
124         }
125
126         if (_confounder_ofs) {
127                 *_confounder_ofs = confounder_ofs;
128         }
129 }
130
131 /*******************************************************************
132  Encode or Decode the sequence number (which is symmetric)
133  ********************************************************************/
134 static void netsec_do_seq_num(struct schannel_state *state,
135                               const uint8_t *checksum,
136                               uint32_t checksum_length,
137                               uint8_t seq_num[8])
138 {
139         if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
140                 AES_KEY key;
141                 uint8_t iv[AES_BLOCK_SIZE];
142
143                 AES_set_encrypt_key(state->creds->session_key, 128, &key);
144                 ZERO_STRUCT(iv);
145                 memcpy(iv+0, checksum, 8);
146                 memcpy(iv+8, checksum, 8);
147
148                 aes_cfb8_encrypt(seq_num, seq_num, 8, &key, iv, AES_ENCRYPT);
149         } else {
150                 static const uint8_t zeros[4];
151                 uint8_t sequence_key[16];
152                 uint8_t digest1[16];
153
154                 hmac_md5(state->creds->session_key, zeros, sizeof(zeros), digest1);
155                 hmac_md5(digest1, checksum, checksum_length, sequence_key);
156                 arcfour_crypt(seq_num, sequence_key, 8);
157         }
158
159         state->seq_num++;
160 }
161
162 static void netsec_do_seal(struct schannel_state *state,
163                            const uint8_t seq_num[8],
164                            uint8_t confounder[8],
165                            uint8_t *data, uint32_t length,
166                            bool forward)
167 {
168         if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
169                 AES_KEY key;
170                 uint8_t iv[AES_BLOCK_SIZE];
171                 uint8_t sess_kf0[16];
172                 int i;
173
174                 for (i = 0; i < 16; i++) {
175                         sess_kf0[i] = state->creds->session_key[i] ^ 0xf0;
176                 }
177
178                 AES_set_encrypt_key(sess_kf0, 128, &key);
179                 ZERO_STRUCT(iv);
180                 memcpy(iv+0, seq_num, 8);
181                 memcpy(iv+8, seq_num, 8);
182
183                 if (forward) {
184                         aes_cfb8_encrypt(confounder, confounder, 8, &key, iv, AES_ENCRYPT);
185                         aes_cfb8_encrypt(data, data, length, &key, iv, AES_ENCRYPT);
186                 } else {
187                         aes_cfb8_encrypt(confounder, confounder, 8, &key, iv, AES_DECRYPT);
188                         aes_cfb8_encrypt(data, data, length, &key, iv, AES_DECRYPT);
189                 }
190         } else {
191                 uint8_t sealing_key[16];
192                 static const uint8_t zeros[4];
193                 uint8_t digest2[16];
194                 uint8_t sess_kf0[16];
195                 int i;
196
197                 for (i = 0; i < 16; i++) {
198                         sess_kf0[i] = state->creds->session_key[i] ^ 0xf0;
199                 }
200
201                 hmac_md5(sess_kf0, zeros, 4, digest2);
202                 hmac_md5(digest2, seq_num, 8, sealing_key);
203
204                 arcfour_crypt(confounder, sealing_key, 8);
205                 arcfour_crypt(data, sealing_key, length);
206         }
207 }
208
209 /*******************************************************************
210  Create a digest over the entire packet (including the data), and
211  MD5 it with the session key.
212  ********************************************************************/
213 static void netsec_do_sign(struct schannel_state *state,
214                            const uint8_t *confounder,
215                            const uint8_t *data, size_t length,
216                            uint8_t header[8],
217                            uint8_t *checksum)
218 {
219         if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
220                 struct HMACSHA256Context ctx;
221
222                 hmac_sha256_init(state->creds->session_key,
223                                  sizeof(state->creds->session_key),
224                                  &ctx);
225
226                 if (confounder) {
227                         SSVAL(header, 0, NL_SIGN_HMAC_SHA256);
228                         SSVAL(header, 2, NL_SEAL_AES128);
229                         SSVAL(header, 4, 0xFFFF);
230                         SSVAL(header, 6, 0x0000);
231
232                         hmac_sha256_update(header, 8, &ctx);
233                         hmac_sha256_update(confounder, 8, &ctx);
234                 } else {
235                         SSVAL(header, 0, NL_SIGN_HMAC_SHA256);
236                         SSVAL(header, 2, NL_SEAL_NONE);
237                         SSVAL(header, 4, 0xFFFF);
238                         SSVAL(header, 6, 0x0000);
239
240                         hmac_sha256_update(header, 8, &ctx);
241                 }
242
243                 hmac_sha256_update(data, length, &ctx);
244
245                 hmac_sha256_final(checksum, &ctx);
246         } else {
247                 uint8_t packet_digest[16];
248                 static const uint8_t zeros[4];
249                 MD5_CTX ctx;
250
251                 MD5Init(&ctx);
252                 MD5Update(&ctx, zeros, 4);
253                 if (confounder) {
254                         SSVAL(header, 0, NL_SIGN_HMAC_MD5);
255                         SSVAL(header, 2, NL_SEAL_RC4);
256                         SSVAL(header, 4, 0xFFFF);
257                         SSVAL(header, 6, 0x0000);
258
259                         MD5Update(&ctx, header, 8);
260                         MD5Update(&ctx, confounder, 8);
261                 } else {
262                         SSVAL(header, 0, NL_SIGN_HMAC_MD5);
263                         SSVAL(header, 2, NL_SEAL_NONE);
264                         SSVAL(header, 4, 0xFFFF);
265                         SSVAL(header, 6, 0x0000);
266
267                         MD5Update(&ctx, header, 8);
268                 }
269                 MD5Update(&ctx, data, length);
270                 MD5Final(packet_digest, &ctx);
271
272                 hmac_md5(state->creds->session_key,
273                          packet_digest, sizeof(packet_digest),
274                          checksum);
275         }
276 }
277
278 static NTSTATUS netsec_incoming_packet(struct schannel_state *state,
279                                 bool do_unseal,
280                                 uint8_t *data, size_t length,
281                                 const uint8_t *whole_pdu, size_t pdu_length,
282                                 const DATA_BLOB *sig)
283 {
284         uint32_t min_sig_size = 0;
285         uint8_t header[8];
286         uint8_t checksum[32];
287         uint32_t checksum_length = sizeof(checksum_length);
288         uint8_t _confounder[8];
289         uint8_t *confounder = NULL;
290         uint32_t confounder_ofs = 0;
291         uint8_t seq_num[8];
292         int ret;
293         const uint8_t *sign_data = NULL;
294         size_t sign_length = 0;
295
296         netsec_offset_and_sizes(state,
297                                 do_unseal,
298                                 &min_sig_size,
299                                 NULL,
300                                 &checksum_length,
301                                 &confounder_ofs);
302
303         if (sig->length < min_sig_size) {
304                 return NT_STATUS_ACCESS_DENIED;
305         }
306
307         if (do_unseal) {
308                 confounder = _confounder;
309                 memcpy(confounder, sig->data+confounder_ofs, 8);
310         } else {
311                 confounder = NULL;
312         }
313
314         SETUP_SEQNUM(state, seq_num, !state->initiator);
315
316         if (do_unseal) {
317                 netsec_do_seal(state, seq_num,
318                                confounder,
319                                data, length,
320                                false);
321         }
322
323         if (state->gensec->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
324                 sign_data = whole_pdu;
325                 sign_length = pdu_length;
326         } else {
327                 sign_data = data;
328                 sign_length = length;
329         }
330
331         netsec_do_sign(state, confounder,
332                        sign_data, sign_length,
333                        header, checksum);
334
335         ret = memcmp(checksum, sig->data+16, checksum_length);
336         if (ret != 0) {
337                 dump_data_pw("calc digest:", checksum, checksum_length);
338                 dump_data_pw("wire digest:", sig->data+16, checksum_length);
339                 return NT_STATUS_ACCESS_DENIED;
340         }
341
342         netsec_do_seq_num(state, checksum, checksum_length, seq_num);
343
344         ret = memcmp(seq_num, sig->data+8, 8);
345         if (ret != 0) {
346                 dump_data_pw("calc seq num:", seq_num, 8);
347                 dump_data_pw("wire seq num:", sig->data+8, 8);
348                 return NT_STATUS_ACCESS_DENIED;
349         }
350
351         return NT_STATUS_OK;
352 }
353
354 static uint32_t netsec_outgoing_sig_size(struct schannel_state *state)
355 {
356         uint32_t sig_size = 0;
357
358         netsec_offset_and_sizes(state,
359                                 true,
360                                 NULL,
361                                 &sig_size,
362                                 NULL,
363                                 NULL);
364
365         return sig_size;
366 }
367
368 static NTSTATUS netsec_outgoing_packet(struct schannel_state *state,
369                                 TALLOC_CTX *mem_ctx,
370                                 bool do_seal,
371                                 uint8_t *data, size_t length,
372                                 const uint8_t *whole_pdu, size_t pdu_length,
373                                 DATA_BLOB *sig)
374 {
375         uint32_t min_sig_size = 0;
376         uint32_t used_sig_size = 0;
377         uint8_t header[8];
378         uint8_t checksum[32];
379         uint32_t checksum_length = sizeof(checksum_length);
380         uint8_t _confounder[8];
381         uint8_t *confounder = NULL;
382         uint32_t confounder_ofs = 0;
383         uint8_t seq_num[8];
384         const uint8_t *sign_data = NULL;
385         size_t sign_length = 0;
386
387         netsec_offset_and_sizes(state,
388                                 do_seal,
389                                 &min_sig_size,
390                                 &used_sig_size,
391                                 &checksum_length,
392                                 &confounder_ofs);
393
394         SETUP_SEQNUM(state, seq_num, state->initiator);
395
396         if (do_seal) {
397                 confounder = _confounder;
398                 generate_random_buffer(confounder, 8);
399         } else {
400                 confounder = NULL;
401         }
402
403         if (state->gensec->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
404                 sign_data = whole_pdu;
405                 sign_length = pdu_length;
406         } else {
407                 sign_data = data;
408                 sign_length = length;
409         }
410
411         netsec_do_sign(state, confounder,
412                        sign_data, sign_length,
413                        header, checksum);
414
415         if (do_seal) {
416                 netsec_do_seal(state, seq_num,
417                                confounder,
418                                data, length,
419                                true);
420         }
421
422         netsec_do_seq_num(state, checksum, checksum_length, seq_num);
423
424         (*sig) = data_blob_talloc_zero(mem_ctx, used_sig_size);
425
426         memcpy(sig->data, header, 8);
427         memcpy(sig->data+8, seq_num, 8);
428         memcpy(sig->data+16, checksum, checksum_length);
429
430         if (confounder) {
431                 memcpy(sig->data+confounder_ofs, confounder, 8);
432         }
433
434         dump_data_pw("signature:", sig->data+ 0, 8);
435         dump_data_pw("seq_num  :", sig->data+ 8, 8);
436         dump_data_pw("digest   :", sig->data+16, checksum_length);
437         dump_data_pw("confound :", sig->data+confounder_ofs, 8);
438
439         return NT_STATUS_OK;
440 }
441
442 _PUBLIC_ NTSTATUS gensec_schannel_init(void);
443
444 static size_t schannel_sig_size(struct gensec_security *gensec_security, size_t data_size)
445 {
446         struct schannel_state *state =
447                 talloc_get_type_abort(gensec_security->private_data,
448                 struct schannel_state);
449
450         return netsec_outgoing_sig_size(state);
451 }
452
453 static NTSTATUS schannel_update(struct gensec_security *gensec_security, TALLOC_CTX *out_mem_ctx,
454                                 struct tevent_context *ev,
455                                 const DATA_BLOB in, DATA_BLOB *out)
456 {
457         struct schannel_state *state =
458                 talloc_get_type(gensec_security->private_data,
459                 struct schannel_state);
460         NTSTATUS status;
461         enum ndr_err_code ndr_err;
462         struct NL_AUTH_MESSAGE bind_schannel = {};
463         struct NL_AUTH_MESSAGE bind_schannel_ack;
464         struct netlogon_creds_CredentialState *creds;
465         const char *workstation;
466         const char *domain;
467
468         *out = data_blob(NULL, 0);
469
470         switch (gensec_security->gensec_role) {
471         case GENSEC_CLIENT:
472                 if (state != NULL) {
473                         /* we could parse the bind ack, but we don't know what it is yet */
474                         return NT_STATUS_OK;
475                 }
476
477                 creds = cli_credentials_get_netlogon_creds(gensec_security->credentials);
478                 if (creds == NULL) {
479                         return NT_STATUS_INVALID_PARAMETER_MIX;
480                 }
481
482                 state = netsec_create_state(gensec_security,
483                                             creds, true /* initiator */);
484                 if (state == NULL) {
485                         return NT_STATUS_NO_MEMORY;
486                 }
487
488                 bind_schannel.MessageType = NL_NEGOTIATE_REQUEST;
489
490                 bind_schannel.Flags = NL_FLAG_OEM_NETBIOS_DOMAIN_NAME |
491                                       NL_FLAG_OEM_NETBIOS_COMPUTER_NAME;
492                 bind_schannel.oem_netbios_domain.a = cli_credentials_get_domain(gensec_security->credentials);
493                 bind_schannel.oem_netbios_computer.a = creds->computer_name;
494
495                 if (creds->secure_channel_type == SEC_CHAN_DNS_DOMAIN) {
496                         bind_schannel.Flags |= NL_FLAG_UTF8_DNS_DOMAIN_NAME;
497                         bind_schannel.utf8_dns_domain.u = cli_credentials_get_realm(gensec_security->credentials);
498
499                         bind_schannel.Flags |= NL_FLAG_UTF8_NETBIOS_COMPUTER_NAME;
500                         bind_schannel.utf8_netbios_computer.u = creds->computer_name;
501                 }
502
503                 ndr_err = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel,
504                                                (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
505                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
506                         status = ndr_map_error2ntstatus(ndr_err);
507                         DEBUG(3, ("Could not create schannel bind: %s\n",
508                                   nt_errstr(status)));
509                         return status;
510                 }
511
512                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
513         case GENSEC_SERVER:
514
515                 if (state != NULL) {
516                         /* no third leg on this protocol */
517                         return NT_STATUS_INVALID_PARAMETER;
518                 }
519
520                 /* parse the schannel startup blob */
521                 ndr_err = ndr_pull_struct_blob(&in, out_mem_ctx, &bind_schannel,
522                         (ndr_pull_flags_fn_t)ndr_pull_NL_AUTH_MESSAGE);
523                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
524                         status = ndr_map_error2ntstatus(ndr_err);
525                         DEBUG(3, ("Could not parse incoming schannel bind: %s\n",
526                                   nt_errstr(status)));
527                         return status;
528                 }
529
530                 if (bind_schannel.Flags & NL_FLAG_OEM_NETBIOS_DOMAIN_NAME) {
531                         domain = bind_schannel.oem_netbios_domain.a;
532                         if (strcasecmp_m(domain, lpcfg_workgroup(gensec_security->settings->lp_ctx)) != 0) {
533                                 DEBUG(3, ("Request for schannel to incorrect domain: %s != our domain %s\n",
534                                           domain, lpcfg_workgroup(gensec_security->settings->lp_ctx)));
535                                 return NT_STATUS_LOGON_FAILURE;
536                         }
537                 } else if (bind_schannel.Flags & NL_FLAG_UTF8_DNS_DOMAIN_NAME) {
538                         domain = bind_schannel.utf8_dns_domain.u;
539                         if (strcasecmp_m(domain, lpcfg_dnsdomain(gensec_security->settings->lp_ctx)) != 0) {
540                                 DEBUG(3, ("Request for schannel to incorrect domain: %s != our domain %s\n",
541                                           domain, lpcfg_dnsdomain(gensec_security->settings->lp_ctx)));
542                                 return NT_STATUS_LOGON_FAILURE;
543                         }
544                 } else {
545                         DEBUG(3, ("Request for schannel to without domain\n"));
546                         return NT_STATUS_LOGON_FAILURE;
547                 }
548
549                 if (bind_schannel.Flags & NL_FLAG_OEM_NETBIOS_COMPUTER_NAME) {
550                         workstation = bind_schannel.oem_netbios_computer.a;
551                 } else if (bind_schannel.Flags & NL_FLAG_UTF8_NETBIOS_COMPUTER_NAME) {
552                         workstation = bind_schannel.utf8_netbios_computer.u;
553                 } else {
554                         DEBUG(3, ("Request for schannel to without netbios workstation\n"));
555                         return NT_STATUS_LOGON_FAILURE;
556                 }
557
558                 status = schannel_get_creds_state(out_mem_ctx,
559                                                   gensec_security->settings->lp_ctx,
560                                                   workstation, &creds);
561                 if (!NT_STATUS_IS_OK(status)) {
562                         DEBUG(3, ("Could not find session key for attempted schannel connection from %s: %s\n",
563                                   workstation, nt_errstr(status)));
564                         if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_HANDLE)) {
565                                 return NT_STATUS_LOGON_FAILURE;
566                         }
567                         return status;
568                 }
569
570                 state = netsec_create_state(gensec_security,
571                                             creds, false /* not initiator */);
572                 if (state == NULL) {
573                         return NT_STATUS_NO_MEMORY;
574                 }
575
576                 status = auth_anonymous_user_info_dc(state,
577                                 lpcfg_netbios_name(gensec_security->settings->lp_ctx),
578                                 &state->user_info_dc);
579                 if (!NT_STATUS_IS_OK(status)) {
580                         return status;
581                 }
582
583                 bind_schannel_ack.MessageType = NL_NEGOTIATE_RESPONSE;
584                 bind_schannel_ack.Flags = 0;
585                 bind_schannel_ack.Buffer.dummy = 0x6c0000; /* actually I think
586                                                             * this does not have
587                                                             * any meaning here
588                                                             * - gd */
589
590                 ndr_err = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel_ack,
591                                                (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
592                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
593                         status = ndr_map_error2ntstatus(ndr_err);
594                         DEBUG(3, ("Could not return schannel bind ack for client %s: %s\n",
595                                   workstation, nt_errstr(status)));
596                         return status;
597                 }
598
599                 return NT_STATUS_OK;
600         }
601         return NT_STATUS_INVALID_PARAMETER;
602 }
603
604 /**
605  * Returns anonymous credentials for schannel, matching Win2k3.
606  *
607  */
608
609 static NTSTATUS schannel_session_info(struct gensec_security *gensec_security,
610                                       TALLOC_CTX *mem_ctx,
611                                       struct auth_session_info **_session_info)
612 {
613         struct schannel_state *state =
614                 talloc_get_type(gensec_security->private_data,
615                 struct schannel_state);
616         struct auth4_context *auth_ctx = gensec_security->auth_context;
617         struct auth_session_info *session_info = NULL;
618         uint32_t session_info_flags = 0;
619         NTSTATUS status;
620
621         if (auth_ctx == NULL) {
622                 DEBUG(0, ("Cannot generate a session_info without the auth_context\n"));
623                 return NT_STATUS_INTERNAL_ERROR;
624         }
625
626         if (auth_ctx->generate_session_info == NULL) {
627                 DEBUG(0, ("Cannot generate a session_info without the generate_session_info hook\n"));
628                 return NT_STATUS_INTERNAL_ERROR;
629         }
630
631         if (gensec_security->want_features & GENSEC_FEATURE_UNIX_TOKEN) {
632                 session_info_flags |= AUTH_SESSION_INFO_UNIX_TOKEN;
633         }
634
635         session_info_flags |= AUTH_SESSION_INFO_SIMPLE_PRIVILEGES;
636
637         status = auth_ctx->generate_session_info(
638                                 auth_ctx,
639                                 mem_ctx,
640                                 state->user_info_dc,
641                                 state->user_info_dc->info->account_name,
642                                 session_info_flags,
643                                 &session_info);
644         if (!NT_STATUS_IS_OK(status)) {
645                 return status;
646         }
647
648         *_session_info = session_info;
649         return NT_STATUS_OK;
650 }
651
652 static NTSTATUS schannel_server_start(struct gensec_security *gensec_security)
653 {
654         return NT_STATUS_OK;
655 }
656
657 static NTSTATUS schannel_client_start(struct gensec_security *gensec_security)
658 {
659         return NT_STATUS_OK;
660 }
661
662 static bool schannel_have_feature(struct gensec_security *gensec_security,
663                                          uint32_t feature)
664 {
665         if (feature & (GENSEC_FEATURE_SIGN |
666                        GENSEC_FEATURE_SEAL)) {
667                 return true;
668         }
669         if (feature & GENSEC_FEATURE_DCE_STYLE) {
670                 return true;
671         }
672         if (feature & GENSEC_FEATURE_SIGN_PKT_HEADER) {
673                 return true;
674         }
675         return false;
676 }
677
678 /*
679   unseal a packet
680 */
681 static NTSTATUS schannel_unseal_packet(struct gensec_security *gensec_security,
682                                        uint8_t *data, size_t length,
683                                        const uint8_t *whole_pdu, size_t pdu_length,
684                                        const DATA_BLOB *sig)
685 {
686         struct schannel_state *state =
687                 talloc_get_type_abort(gensec_security->private_data,
688                 struct schannel_state);
689
690         return netsec_incoming_packet(state, true,
691                                       discard_const_p(uint8_t, data),
692                                       length,
693                                       whole_pdu, pdu_length,
694                                       sig);
695 }
696
697 /*
698   check the signature on a packet
699 */
700 static NTSTATUS schannel_check_packet(struct gensec_security *gensec_security,
701                                       const uint8_t *data, size_t length,
702                                       const uint8_t *whole_pdu, size_t pdu_length,
703                                       const DATA_BLOB *sig)
704 {
705         struct schannel_state *state =
706                 talloc_get_type_abort(gensec_security->private_data,
707                 struct schannel_state);
708
709         return netsec_incoming_packet(state, false,
710                                       discard_const_p(uint8_t, data),
711                                       length,
712                                       whole_pdu, pdu_length,
713                                       sig);
714 }
715 /*
716   seal a packet
717 */
718 static NTSTATUS schannel_seal_packet(struct gensec_security *gensec_security,
719                                      TALLOC_CTX *mem_ctx,
720                                      uint8_t *data, size_t length,
721                                      const uint8_t *whole_pdu, size_t pdu_length,
722                                      DATA_BLOB *sig)
723 {
724         struct schannel_state *state =
725                 talloc_get_type_abort(gensec_security->private_data,
726                 struct schannel_state);
727
728         return netsec_outgoing_packet(state, mem_ctx, true,
729                                       data, length,
730                                       whole_pdu, pdu_length,
731                                       sig);
732 }
733
734 /*
735   sign a packet
736 */
737 static NTSTATUS schannel_sign_packet(struct gensec_security *gensec_security,
738                                      TALLOC_CTX *mem_ctx,
739                                      const uint8_t *data, size_t length,
740                                      const uint8_t *whole_pdu, size_t pdu_length,
741                                      DATA_BLOB *sig)
742 {
743         struct schannel_state *state =
744                 talloc_get_type_abort(gensec_security->private_data,
745                 struct schannel_state);
746
747         return netsec_outgoing_packet(state, mem_ctx, false,
748                                       discard_const_p(uint8_t, data),
749                                       length,
750                                       whole_pdu, pdu_length,
751                                       sig);
752 }
753
754 static const struct gensec_security_ops gensec_schannel_security_ops = {
755         .name           = "schannel",
756         .auth_type      = DCERPC_AUTH_TYPE_SCHANNEL,
757         .client_start   = schannel_client_start,
758         .server_start   = schannel_server_start,
759         .update         = schannel_update,
760         .seal_packet    = schannel_seal_packet,
761         .sign_packet    = schannel_sign_packet,
762         .check_packet   = schannel_check_packet,
763         .unseal_packet  = schannel_unseal_packet,
764         .session_info   = schannel_session_info,
765         .sig_size       = schannel_sig_size,
766         .have_feature   = schannel_have_feature,
767         .enabled        = true,
768         .priority       = GENSEC_SCHANNEL
769 };
770
771 _PUBLIC_ NTSTATUS gensec_schannel_init(void)
772 {
773         NTSTATUS ret;
774         ret = gensec_register(&gensec_schannel_security_ops);
775         if (!NT_STATUS_IS_OK(ret)) {
776                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
777                         gensec_schannel_security_ops.name));
778                 return ret;
779         }
780
781         return ret;
782 }