r25000: Fix some more C++ compatibility warnings.
[ira/wip.git] / source4 / auth / ntlmssp / ntlmssp_sign.c
1 /* 
2  *  Unix SMB/CIFS implementation.
3  *  Version 3.0
4  *  NTLMSSP Signing routines
5  *  Copyright (C) Luke Kenneth Casson Leighton 1996-2001
6  *  Copyright (C) Andrew Bartlett <abartlet@samba.org> 2003-2005
7  *  
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 3 of the License, or
11  *  (at your option) any later version.
12  *  
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *  
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
20  */
21
22 #include "includes.h"
23 #include "auth/auth.h"
24 #include "auth/ntlmssp/ntlmssp.h"
25 #include "auth/ntlmssp/msrpc_parse.h"
26 #include "lib/crypto/crypto.h"
27 #include "auth/credentials/credentials.h"
28 #include "auth/gensec/gensec.h"
29
30 #define CLI_SIGN "session key to client-to-server signing key magic constant"
31 #define CLI_SEAL "session key to client-to-server sealing key magic constant"
32 #define SRV_SIGN "session key to server-to-client signing key magic constant"
33 #define SRV_SEAL "session key to server-to-client sealing key magic constant"
34
35 /**
36  * Some notes on the NTLM2 code:
37  *
38  * NTLM2 is a AEAD system.  This means that the data encrypted is not
39  * all the data that is signed.  In DCE-RPC case, the headers of the
40  * DCE-RPC packets are also signed.  This prevents some of the
41  * fun-and-games one might have by changing them.
42  *
43  */
44
45 static void calc_ntlmv2_key(TALLOC_CTX *mem_ctx, 
46                             DATA_BLOB *subkey,
47                             DATA_BLOB session_key, 
48                             const char *constant)
49 {
50         struct MD5Context ctx3;
51         *subkey = data_blob_talloc(mem_ctx, NULL, 16);
52         MD5Init(&ctx3);
53         MD5Update(&ctx3, session_key.data, session_key.length);
54         MD5Update(&ctx3, (const uint8_t *)constant, strlen(constant)+1);
55         MD5Final(subkey->data, &ctx3);
56 }
57
58 enum ntlmssp_direction {
59         NTLMSSP_SEND,
60         NTLMSSP_RECEIVE
61 };
62
63 static NTSTATUS ntlmssp_make_packet_signature(struct gensec_ntlmssp_state *gensec_ntlmssp_state,
64                                               TALLOC_CTX *sig_mem_ctx, 
65                                               const uint8_t *data, size_t length, 
66                                               const uint8_t *whole_pdu, size_t pdu_length, 
67                                               enum ntlmssp_direction direction,
68                                               DATA_BLOB *sig, BOOL encrypt_sig)
69 {
70         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
71
72                 HMACMD5Context ctx;
73                 uint8_t digest[16];
74                 uint8_t seq_num[4];
75
76                 *sig = data_blob_talloc(sig_mem_ctx, NULL, NTLMSSP_SIG_SIZE);
77                 if (!sig->data) {
78                         return NT_STATUS_NO_MEMORY;
79                 }
80                         
81                 switch (direction) {
82                 case NTLMSSP_SEND:
83                         SIVAL(seq_num, 0, gensec_ntlmssp_state->crypt.ntlm2.send_seq_num);
84                         gensec_ntlmssp_state->crypt.ntlm2.send_seq_num++;
85                         hmac_md5_init_limK_to_64(gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data, 
86                                                  gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length, &ctx);
87                         break;
88                 case NTLMSSP_RECEIVE:
89                         SIVAL(seq_num, 0, gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num);
90                         gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num++;
91                         hmac_md5_init_limK_to_64(gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data, 
92                                                  gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.length, &ctx);
93                         break;
94                 }
95                 hmac_md5_update(seq_num, sizeof(seq_num), &ctx);
96                 hmac_md5_update(whole_pdu, pdu_length, &ctx);
97                 hmac_md5_final(digest, &ctx);
98
99                 if (encrypt_sig && gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
100                         switch (direction) {
101                         case NTLMSSP_SEND:
102                                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, digest, 8);
103                                 break;
104                         case NTLMSSP_RECEIVE:
105                                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, digest, 8);
106                                 break;
107                         }
108                 }
109
110                 SIVAL(sig->data, 0, NTLMSSP_SIGN_VERSION);
111                 memcpy(sig->data + 4, digest, 8);
112                 memcpy(sig->data + 12, seq_num, 4);
113
114                 DEBUG(10, ("NTLM2: created signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
115                 dump_data(11, sig->data, sig->length);
116                         
117         } else {
118                 uint32_t crc;
119                 crc = crc32_calc_buffer(data, length);
120                 if (!msrpc_gen(sig_mem_ctx, sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
121                         return NT_STATUS_NO_MEMORY;
122                 }
123                 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
124
125                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4);
126
127                 DEBUG(10, ("NTLM1: created signature over %llu bytes of input:\n", (unsigned long long)length));
128                 dump_data(11, sig->data, sig->length);
129         }
130         return NT_STATUS_OK;
131 }
132
133 /* TODO: make this non-public */
134 _PUBLIC_ NTSTATUS gensec_ntlmssp_sign_packet(struct gensec_security *gensec_security, 
135                                     TALLOC_CTX *sig_mem_ctx, 
136                                     const uint8_t *data, size_t length, 
137                                     const uint8_t *whole_pdu, size_t pdu_length, 
138                                     DATA_BLOB *sig)
139 {
140         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
141
142         return ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx, 
143                                              data, length, 
144                                              whole_pdu, pdu_length, 
145                                              NTLMSSP_SEND, sig, True);
146 }
147
148 /**
149  * Check the signature of an incoming packet 
150  *
151  */
152
153 NTSTATUS gensec_ntlmssp_check_packet(struct gensec_security *gensec_security, 
154                                      TALLOC_CTX *sig_mem_ctx, 
155                                      const uint8_t *data, size_t length, 
156                                      const uint8_t *whole_pdu, size_t pdu_length, 
157                                      const DATA_BLOB *sig)
158 {
159         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
160
161         DATA_BLOB local_sig;
162         NTSTATUS nt_status;
163
164         if (!gensec_ntlmssp_state->session_key.length) {
165                 DEBUG(3, ("NO session key, cannot check packet signature\n"));
166                 return NT_STATUS_NO_USER_SESSION_KEY;
167         }
168
169         nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx, 
170                                                   data, length, 
171                                                   whole_pdu, pdu_length, 
172                                                   NTLMSSP_RECEIVE, &local_sig, True);
173         
174         if (!NT_STATUS_IS_OK(nt_status)) {
175                 DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status)));
176                 return nt_status;
177         }
178
179         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
180                 if (local_sig.length != sig->length ||
181                     memcmp(local_sig.data, 
182                            sig->data, sig->length) != 0) {
183                         DEBUG(5, ("BAD SIG NTLM2: wanted signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
184                         dump_data(5, local_sig.data, local_sig.length);
185                         
186                         DEBUG(5, ("BAD SIG: got signature over %llu bytes of input:\n", (unsigned long long)pdu_length));
187                         dump_data(5, sig->data, sig->length);
188                         
189                         DEBUG(1, ("NTLMSSP NTLM2 packet check failed due to invalid signature on %llu bytes of input!\n", (unsigned long long)pdu_length));
190                         return NT_STATUS_ACCESS_DENIED;
191                 }
192         } else {
193                 if (local_sig.length != sig->length ||
194                     memcmp(local_sig.data + 8, 
195                            sig->data + 8, sig->length - 8) != 0) {
196                         DEBUG(5, ("BAD SIG NTLM1: wanted signature of %llu bytes of input:\n", (unsigned long long)length));
197                         dump_data(5, local_sig.data, local_sig.length);
198                         
199                         DEBUG(5, ("BAD SIG: got signature of %llu bytes of input:\n", (unsigned long long)length));
200                         dump_data(5, sig->data, sig->length);
201                         
202                         DEBUG(1, ("NTLMSSP NTLM1 packet check failed due to invalid signature on %llu bytes of input:\n", (unsigned long long)length));
203                         return NT_STATUS_ACCESS_DENIED;
204                 }
205         }
206         dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
207
208         return NT_STATUS_OK;
209 }
210
211
212 /**
213  * Seal data with the NTLMSSP algorithm
214  *
215  */
216
217 NTSTATUS gensec_ntlmssp_seal_packet(struct gensec_security *gensec_security, 
218                                     TALLOC_CTX *sig_mem_ctx, 
219                                     uint8_t *data, size_t length, 
220                                     const uint8_t *whole_pdu, size_t pdu_length, 
221                                     DATA_BLOB *sig)
222 {
223         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
224         NTSTATUS nt_status;
225         if (!gensec_ntlmssp_state->session_key.length) {
226                 DEBUG(3, ("NO session key, cannot seal packet\n"));
227                 return NT_STATUS_NO_USER_SESSION_KEY;
228         }
229
230         DEBUG(10,("ntlmssp_seal_data: seal\n"));
231         dump_data_pw("ntlmssp clear data\n", data, length);
232         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
233                 /* The order of these two operations matters - we must first seal the packet,
234                    then seal the sequence number - this is becouse the send_seal_hash is not
235                    constant, but is is rather updated with each iteration */
236                 nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx, 
237                                                           data, length, 
238                                                           whole_pdu, pdu_length, 
239                                                           NTLMSSP_SEND, sig, False);
240                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, data, length);
241                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
242                         arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, sig->data+4, 8);
243                 }
244         } else {
245                 uint32_t crc;
246                 crc = crc32_calc_buffer(data, length);
247                 if (!msrpc_gen(sig_mem_ctx, sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) {
248                         return NT_STATUS_NO_MEMORY;
249                 }
250
251                 /* The order of these two operations matters - we must
252                    first seal the packet, then seal the sequence
253                    number - this is becouse the ntlmssp_hash is not
254                    constant, but is is rather updated with each
255                    iteration */
256
257                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
258                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4);
259                 /* increment counter on send */
260                 gensec_ntlmssp_state->crypt.ntlm.seq_num++;
261                 nt_status = NT_STATUS_OK;
262         }
263         dump_data_pw("ntlmssp signature\n", sig->data, sig->length);
264         dump_data_pw("ntlmssp sealed data\n", data, length);
265
266
267         return nt_status;
268 }
269
270 /**
271  * Unseal data with the NTLMSSP algorithm
272  *
273  */
274
275 /*
276   wrappers for the ntlmssp_*() functions
277 */
278 NTSTATUS gensec_ntlmssp_unseal_packet(struct gensec_security *gensec_security, 
279                                       TALLOC_CTX *sig_mem_ctx, 
280                                       uint8_t *data, size_t length, 
281                                       const uint8_t *whole_pdu, size_t pdu_length, 
282                                       const DATA_BLOB *sig)
283 {
284         struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data;
285         if (!gensec_ntlmssp_state->session_key.length) {
286                 DEBUG(3, ("NO session key, cannot unseal packet\n"));
287                 return NT_STATUS_NO_USER_SESSION_KEY;
288         }
289
290         dump_data_pw("ntlmssp sealed data\n", data, length);
291         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
292                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, data, length);
293         } else {
294                 arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length);
295         }
296         dump_data_pw("ntlmssp clear data\n", data, length);
297         return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx, data, length, whole_pdu, pdu_length, sig);
298 }
299
300 /**
301    Initialise the state for NTLMSSP signing.
302 */
303 /* TODO: make this non-public */
304 _PUBLIC_ NTSTATUS ntlmssp_sign_init(struct gensec_ntlmssp_state *gensec_ntlmssp_state)
305 {
306         TALLOC_CTX *mem_ctx = talloc_new(gensec_ntlmssp_state);
307
308         if (!mem_ctx) {
309                 return NT_STATUS_NO_MEMORY;
310         }
311
312         DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
313         debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags);
314
315         if (gensec_ntlmssp_state->session_key.length < 8) {
316                 talloc_free(mem_ctx);
317                 DEBUG(3, ("NO session key, cannot intialise signing\n"));
318                 return NT_STATUS_NO_USER_SESSION_KEY;
319         }
320
321         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2)
322         {
323                 DATA_BLOB weak_session_key = gensec_ntlmssp_state->session_key;
324                 const char *send_sign_const;
325                 const char *send_seal_const;
326                 const char *recv_sign_const;
327                 const char *recv_seal_const;
328
329                 DATA_BLOB send_seal_key;
330                 DATA_BLOB recv_seal_key;
331
332                 switch (gensec_ntlmssp_state->role) {
333                 case NTLMSSP_CLIENT:
334                         send_sign_const = CLI_SIGN;
335                         send_seal_const = CLI_SEAL;
336                         recv_sign_const = SRV_SIGN;
337                         recv_seal_const = SRV_SEAL;
338                         break;
339                 case NTLMSSP_SERVER:
340                         send_sign_const = SRV_SIGN;
341                         send_seal_const = SRV_SEAL;
342                         recv_sign_const = CLI_SIGN;
343                         recv_seal_const = CLI_SEAL;
344                         break;
345                 default:
346                         talloc_free(mem_ctx);
347                         return NT_STATUS_INTERNAL_ERROR;
348                 }
349                 
350                 gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
351                 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state);
352                 gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
353                 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state);
354
355                 /**
356                    Weaken NTLMSSP keys to cope with down-level
357                    clients, servers and export restrictions.
358                    
359                    We probably should have some parameters to control
360                    this, once we get NTLM2 working.
361                 */
362
363                 /* Key weakening was not performed on the master key
364                  * for NTLM2 (in ntlmssp_weaken_keys()), but must be
365                  * done on the encryption subkeys only.  That is why
366                  * we don't have this code for the ntlmv1 case.
367                  */
368
369                 if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
370                         
371                 } else if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
372                         weak_session_key.length = 7;
373                 } else { /* forty bits */
374                         weak_session_key.length = 5;
375                 }
376                 dump_data_pw("NTLMSSP weakend master key:\n",
377                              weak_session_key.data, 
378                              weak_session_key.length);
379
380                 /* SEND: sign key */
381                 calc_ntlmv2_key(gensec_ntlmssp_state, 
382                                 &gensec_ntlmssp_state->crypt.ntlm2.send_sign_key, 
383                                 gensec_ntlmssp_state->session_key, send_sign_const);
384                 dump_data_pw("NTLMSSP send sign key:\n",
385                              gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data, 
386                              gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length);
387                 
388                 /* SEND: seal ARCFOUR pad */
389                 calc_ntlmv2_key(mem_ctx, 
390                                 &send_seal_key, 
391                                 weak_session_key, send_seal_const);
392                 dump_data_pw("NTLMSSP send seal key:\n",
393                              send_seal_key.data, 
394                              send_seal_key.length);
395                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, 
396                              &send_seal_key);
397                 dump_data_pw("NTLMSSP send sesl hash:\n", 
398                              gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox, 
399                              sizeof(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox));
400
401                 /* RECV: sign key */
402                 calc_ntlmv2_key(gensec_ntlmssp_state, 
403                                 &gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key, 
404                                 gensec_ntlmssp_state->session_key, recv_sign_const);
405                 dump_data_pw("NTLMSSP recv sign key:\n",
406                              gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data, 
407                              gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.length);
408
409                 /* RECV: seal ARCFOUR pad */
410                 calc_ntlmv2_key(mem_ctx, 
411                                 &recv_seal_key, 
412                                 weak_session_key, recv_seal_const);
413                 dump_data_pw("NTLMSSP recv seal key:\n",
414                              recv_seal_key.data, 
415                              recv_seal_key.length);
416                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, 
417                              &recv_seal_key);
418                 dump_data_pw("NTLMSSP receive seal hash:\n", 
419                              gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox, 
420                              sizeof(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox));
421
422                 gensec_ntlmssp_state->crypt.ntlm2.send_seq_num = 0;
423                 gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num = 0;
424
425         } else {
426                 DATA_BLOB weak_session_key = ntlmssp_weakend_key(gensec_ntlmssp_state, mem_ctx);
427                 DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
428
429                 gensec_ntlmssp_state->crypt.ntlm.arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state);
430                 NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm.arcfour_state);
431
432                 arcfour_init(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, 
433                              &weak_session_key);
434                 dump_data_pw("NTLMSSP hash:\n", gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox,
435                              sizeof(gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox));
436
437                 gensec_ntlmssp_state->crypt.ntlm.seq_num = 0;
438         }
439
440         talloc_free(mem_ctx);
441         return NT_STATUS_OK;
442 }
443
444 size_t gensec_ntlmssp_sig_size(struct gensec_security *gensec_security, size_t data_size) 
445 {
446         return NTLMSSP_SIG_SIZE;
447 }
448
449 NTSTATUS gensec_ntlmssp_wrap(struct gensec_security *gensec_security, 
450                              TALLOC_CTX *sig_mem_ctx, 
451                              const DATA_BLOB *in, 
452                              DATA_BLOB *out)
453 {
454         DATA_BLOB sig;
455         NTSTATUS nt_status;
456
457         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
458
459                 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
460                 if (!out->data) {
461                         return NT_STATUS_NO_MEMORY;
462                 }
463                 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
464                 
465                 nt_status = gensec_ntlmssp_seal_packet(gensec_security, sig_mem_ctx, 
466                                                        out->data + NTLMSSP_SIG_SIZE, 
467                                                        out->length - NTLMSSP_SIG_SIZE, 
468                                                        out->data + NTLMSSP_SIG_SIZE, 
469                                                        out->length - NTLMSSP_SIG_SIZE, 
470                                                        &sig);
471                 
472                 if (NT_STATUS_IS_OK(nt_status)) {
473                         memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
474                 }
475                 return nt_status;
476
477         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
478
479                 *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE);
480                 if (!out->data) {
481                         return NT_STATUS_NO_MEMORY;
482                 }
483                 memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length);
484
485                 nt_status = gensec_ntlmssp_sign_packet(gensec_security, sig_mem_ctx, 
486                                                        out->data + NTLMSSP_SIG_SIZE, 
487                                                        out->length - NTLMSSP_SIG_SIZE, 
488                                                        out->data + NTLMSSP_SIG_SIZE, 
489                                                        out->length - NTLMSSP_SIG_SIZE, 
490                                                        &sig);
491
492                 if (NT_STATUS_IS_OK(nt_status)) {
493                         memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE);
494                 }
495                 return nt_status;
496
497         } else {
498                 *out = *in;
499                 return NT_STATUS_OK;
500         }
501 }
502
503
504 NTSTATUS gensec_ntlmssp_unwrap(struct gensec_security *gensec_security, 
505                                TALLOC_CTX *sig_mem_ctx, 
506                                const DATA_BLOB *in, 
507                                DATA_BLOB *out)
508 {
509         DATA_BLOB sig;
510
511         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
512                 if (in->length < NTLMSSP_SIG_SIZE) {
513                         return NT_STATUS_INVALID_PARAMETER;
514                 }
515                 sig.data = in->data;
516                 sig.length = NTLMSSP_SIG_SIZE;
517
518                 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
519                 
520                 return gensec_ntlmssp_unseal_packet(gensec_security, sig_mem_ctx, 
521                                                     out->data, out->length, 
522                                                     out->data, out->length, 
523                                                     &sig);
524                                                   
525         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
526                 if (in->length < NTLMSSP_SIG_SIZE) {
527                         return NT_STATUS_INVALID_PARAMETER;
528                 }
529                 sig.data = in->data;
530                 sig.length = NTLMSSP_SIG_SIZE;
531
532                 *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE);
533                 
534                 return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx, 
535                                                    out->data, out->length, 
536                                                    out->data, out->length, 
537                                                    &sig);
538         } else {
539                 *out = *in;
540                 return NT_STATUS_OK;
541         }
542 }
543