1 /*
2 * fs/cifs/smb2transport.c
3 *
4 * Copyright (C) International Business Machines Corp., 2002, 2011
5 * Etersoft, 2012
6 * Author(s): Steve French (sfrench@us.ibm.com)
7 * Jeremy Allison (jra@samba.org) 2006
8 * Pavel Shilovsky (pshilovsky@samba.org) 2012
9 *
10 * This library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published
12 * by the Free Software Foundation; either version 2.1 of the License, or
13 * (at your option) any later version.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
18 * the GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25 #include <linux/fs.h>
26 #include <linux/list.h>
27 #include <linux/wait.h>
28 #include <linux/net.h>
29 #include <linux/delay.h>
30 #include <linux/uaccess.h>
31 #include <asm/processor.h>
32 #include <linux/mempool.h>
33 #include <linux/highmem.h>
34 #include <crypto/aead.h>
35 #include "smb2pdu.h"
36 #include "cifsglob.h"
37 #include "cifsproto.h"
38 #include "smb2proto.h"
39 #include "cifs_debug.h"
40 #include "smb2status.h"
41 #include "smb2glob.h"
42
43 static int
smb3_crypto_shash_allocate(struct TCP_Server_Info * server)44 smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
45 {
46 struct cifs_secmech *p = &server->secmech;
47 int rc;
48
49 rc = cifs_alloc_hash("hmac(sha256)",
50 &p->hmacsha256,
51 &p->sdeschmacsha256);
52 if (rc)
53 goto err;
54
55 rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
56 if (rc)
57 goto err;
58
59 return 0;
60 err:
61 cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
62 return rc;
63 }
64
65 int
smb311_crypto_shash_allocate(struct TCP_Server_Info * server)66 smb311_crypto_shash_allocate(struct TCP_Server_Info *server)
67 {
68 struct cifs_secmech *p = &server->secmech;
69 int rc = 0;
70
71 rc = cifs_alloc_hash("hmac(sha256)",
72 &p->hmacsha256,
73 &p->sdeschmacsha256);
74 if (rc)
75 return rc;
76
77 rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
78 if (rc)
79 goto err;
80
81 rc = cifs_alloc_hash("sha512", &p->sha512, &p->sdescsha512);
82 if (rc)
83 goto err;
84
85 return 0;
86
87 err:
88 cifs_free_hash(&p->cmacaes, &p->sdesccmacaes);
89 cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
90 return rc;
91 }
92
93
94 static
smb2_get_sign_key(__u64 ses_id,struct TCP_Server_Info * server,u8 * key)95 int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
96 {
97 struct cifs_chan *chan;
98 struct cifs_ses *ses = NULL;
99 struct TCP_Server_Info *it = NULL;
100 int i;
101 int rc = 0;
102
103 spin_lock(&cifs_tcp_ses_lock);
104
105 list_for_each_entry(it, &cifs_tcp_ses_list, tcp_ses_list) {
106 list_for_each_entry(ses, &it->smb_ses_list, smb_ses_list) {
107 if (ses->Suid == ses_id)
108 goto found;
109 }
110 }
111 cifs_server_dbg(VFS, "%s: Could not find session 0x%llx\n",
112 __func__, ses_id);
113 rc = -ENOENT;
114 goto out;
115
116 found:
117 if (ses->binding) {
118 /*
119 * If we are in the process of binding a new channel
120 * to an existing session, use the master connection
121 * session key
122 */
123 memcpy(key, ses->smb3signingkey, SMB3_SIGN_KEY_SIZE);
124 goto out;
125 }
126
127 /*
128 * Otherwise, use the channel key.
129 */
130
131 for (i = 0; i < ses->chan_count; i++) {
132 chan = ses->chans + i;
133 if (chan->server == server) {
134 memcpy(key, chan->signkey, SMB3_SIGN_KEY_SIZE);
135 goto out;
136 }
137 }
138
139 cifs_dbg(VFS,
140 "%s: Could not find channel signing key for session 0x%llx\n",
141 __func__, ses_id);
142 rc = -ENOENT;
143
144 out:
145 spin_unlock(&cifs_tcp_ses_lock);
146 return rc;
147 }
148
149 static struct cifs_ses *
smb2_find_smb_ses_unlocked(struct TCP_Server_Info * server,__u64 ses_id)150 smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id)
151 {
152 struct cifs_ses *ses;
153
154 list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
155 if (ses->Suid != ses_id)
156 continue;
157 return ses;
158 }
159
160 return NULL;
161 }
162
163 struct cifs_ses *
smb2_find_smb_ses(struct TCP_Server_Info * server,__u64 ses_id)164 smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id)
165 {
166 struct cifs_ses *ses;
167
168 spin_lock(&cifs_tcp_ses_lock);
169 ses = smb2_find_smb_ses_unlocked(server, ses_id);
170 spin_unlock(&cifs_tcp_ses_lock);
171
172 return ses;
173 }
174
175 static struct cifs_tcon *
smb2_find_smb_sess_tcon_unlocked(struct cifs_ses * ses,__u32 tid)176 smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32 tid)
177 {
178 struct cifs_tcon *tcon;
179
180 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
181 if (tcon->tid != tid)
182 continue;
183 ++tcon->tc_count;
184 return tcon;
185 }
186
187 return NULL;
188 }
189
190 /*
191 * Obtain tcon corresponding to the tid in the given
192 * cifs_ses
193 */
194
195 struct cifs_tcon *
smb2_find_smb_tcon(struct TCP_Server_Info * server,__u64 ses_id,__u32 tid)196 smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32 tid)
197 {
198 struct cifs_ses *ses;
199 struct cifs_tcon *tcon;
200
201 spin_lock(&cifs_tcp_ses_lock);
202 ses = smb2_find_smb_ses_unlocked(server, ses_id);
203 if (!ses) {
204 spin_unlock(&cifs_tcp_ses_lock);
205 return NULL;
206 }
207 tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid);
208 spin_unlock(&cifs_tcp_ses_lock);
209
210 return tcon;
211 }
212
213 int
smb2_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,bool allocate_crypto)214 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
215 bool allocate_crypto)
216 {
217 int rc;
218 unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
219 unsigned char *sigptr = smb2_signature;
220 struct kvec *iov = rqst->rq_iov;
221 struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[0].iov_base;
222 struct cifs_ses *ses;
223 struct shash_desc *shash;
224 struct crypto_shash *hash;
225 struct sdesc *sdesc = NULL;
226 struct smb_rqst drqst;
227
228 ses = smb2_find_smb_ses(server, shdr->SessionId);
229 if (!ses) {
230 cifs_server_dbg(VFS, "%s: Could not find session\n", __func__);
231 return 0;
232 }
233
234 memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
235 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
236
237 if (allocate_crypto) {
238 rc = cifs_alloc_hash("hmac(sha256)", &hash, &sdesc);
239 if (rc) {
240 cifs_server_dbg(VFS,
241 "%s: sha256 alloc failed\n", __func__);
242 return rc;
243 }
244 shash = &sdesc->shash;
245 } else {
246 hash = server->secmech.hmacsha256;
247 shash = &server->secmech.sdeschmacsha256->shash;
248 }
249
250 rc = crypto_shash_setkey(hash, ses->auth_key.response,
251 SMB2_NTLMV2_SESSKEY_SIZE);
252 if (rc) {
253 cifs_server_dbg(VFS,
254 "%s: Could not update with response\n",
255 __func__);
256 goto out;
257 }
258
259 rc = crypto_shash_init(shash);
260 if (rc) {
261 cifs_server_dbg(VFS, "%s: Could not init sha256", __func__);
262 goto out;
263 }
264
265 /*
266 * For SMB2+, __cifs_calc_signature() expects to sign only the actual
267 * data, that is, iov[0] should not contain a rfc1002 length.
268 *
269 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
270 * __cifs_calc_signature().
271 */
272 drqst = *rqst;
273 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
274 rc = crypto_shash_update(shash, iov[0].iov_base,
275 iov[0].iov_len);
276 if (rc) {
277 cifs_server_dbg(VFS,
278 "%s: Could not update with payload\n",
279 __func__);
280 goto out;
281 }
282 drqst.rq_iov++;
283 drqst.rq_nvec--;
284 }
285
286 rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
287 if (!rc)
288 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
289
290 out:
291 if (allocate_crypto)
292 cifs_free_hash(&hash, &sdesc);
293 return rc;
294 }
295
generate_key(struct cifs_ses * ses,struct kvec label,struct kvec context,__u8 * key,unsigned int key_size)296 static int generate_key(struct cifs_ses *ses, struct kvec label,
297 struct kvec context, __u8 *key, unsigned int key_size)
298 {
299 unsigned char zero = 0x0;
300 __u8 i[4] = {0, 0, 0, 1};
301 __u8 L128[4] = {0, 0, 0, 128};
302 __u8 L256[4] = {0, 0, 1, 0};
303 int rc = 0;
304 unsigned char prfhash[SMB2_HMACSHA256_SIZE];
305 unsigned char *hashptr = prfhash;
306 struct TCP_Server_Info *server = ses->server;
307
308 memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
309 memset(key, 0x0, key_size);
310
311 rc = smb3_crypto_shash_allocate(server);
312 if (rc) {
313 cifs_server_dbg(VFS, "%s: crypto alloc failed\n", __func__);
314 goto smb3signkey_ret;
315 }
316
317 rc = crypto_shash_setkey(server->secmech.hmacsha256,
318 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
319 if (rc) {
320 cifs_server_dbg(VFS, "%s: Could not set with session key\n", __func__);
321 goto smb3signkey_ret;
322 }
323
324 rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
325 if (rc) {
326 cifs_server_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
327 goto smb3signkey_ret;
328 }
329
330 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
331 i, 4);
332 if (rc) {
333 cifs_server_dbg(VFS, "%s: Could not update with n\n", __func__);
334 goto smb3signkey_ret;
335 }
336
337 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
338 label.iov_base, label.iov_len);
339 if (rc) {
340 cifs_server_dbg(VFS, "%s: Could not update with label\n", __func__);
341 goto smb3signkey_ret;
342 }
343
344 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
345 &zero, 1);
346 if (rc) {
347 cifs_server_dbg(VFS, "%s: Could not update with zero\n", __func__);
348 goto smb3signkey_ret;
349 }
350
351 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
352 context.iov_base, context.iov_len);
353 if (rc) {
354 cifs_server_dbg(VFS, "%s: Could not update with context\n", __func__);
355 goto smb3signkey_ret;
356 }
357
358 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
359 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
360 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
361 L256, 4);
362 } else {
363 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
364 L128, 4);
365 }
366 if (rc) {
367 cifs_server_dbg(VFS, "%s: Could not update with L\n", __func__);
368 goto smb3signkey_ret;
369 }
370
371 rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
372 hashptr);
373 if (rc) {
374 cifs_server_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
375 goto smb3signkey_ret;
376 }
377
378 memcpy(key, hashptr, key_size);
379
380 smb3signkey_ret:
381 return rc;
382 }
383
384 struct derivation {
385 struct kvec label;
386 struct kvec context;
387 };
388
389 struct derivation_triplet {
390 struct derivation signing;
391 struct derivation encryption;
392 struct derivation decryption;
393 };
394
395 static int
generate_smb3signingkey(struct cifs_ses * ses,const struct derivation_triplet * ptriplet)396 generate_smb3signingkey(struct cifs_ses *ses,
397 const struct derivation_triplet *ptriplet)
398 {
399 int rc;
400 #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
401 struct TCP_Server_Info *server = ses->server;
402 #endif
403
404 /*
405 * All channels use the same encryption/decryption keys but
406 * they have their own signing key.
407 *
408 * When we generate the keys, check if it is for a new channel
409 * (binding) in which case we only need to generate a signing
410 * key and store it in the channel as to not overwrite the
411 * master connection signing key stored in the session
412 */
413
414 if (ses->binding) {
415 rc = generate_key(ses, ptriplet->signing.label,
416 ptriplet->signing.context,
417 cifs_ses_binding_channel(ses)->signkey,
418 SMB3_SIGN_KEY_SIZE);
419 if (rc)
420 return rc;
421 } else {
422 rc = generate_key(ses, ptriplet->signing.label,
423 ptriplet->signing.context,
424 ses->smb3signingkey,
425 SMB3_SIGN_KEY_SIZE);
426 if (rc)
427 return rc;
428
429 memcpy(ses->chans[0].signkey, ses->smb3signingkey,
430 SMB3_SIGN_KEY_SIZE);
431
432 rc = generate_key(ses, ptriplet->encryption.label,
433 ptriplet->encryption.context,
434 ses->smb3encryptionkey,
435 SMB3_ENC_DEC_KEY_SIZE);
436 if (rc)
437 return rc;
438 rc = generate_key(ses, ptriplet->decryption.label,
439 ptriplet->decryption.context,
440 ses->smb3decryptionkey,
441 SMB3_ENC_DEC_KEY_SIZE);
442 if (rc)
443 return rc;
444 }
445
446 #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
447 cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__);
448 /*
449 * The session id is opaque in terms of endianness, so we can't
450 * print it as a long long. we dump it as we got it on the wire
451 */
452 cifs_dbg(VFS, "Session Id %*ph\n", (int)sizeof(ses->Suid),
453 &ses->Suid);
454 cifs_dbg(VFS, "Cipher type %d\n", server->cipher_type);
455 cifs_dbg(VFS, "Session Key %*ph\n",
456 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response);
457 cifs_dbg(VFS, "Signing Key %*ph\n",
458 SMB3_SIGN_KEY_SIZE, ses->smb3signingkey);
459 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
460 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
461 cifs_dbg(VFS, "ServerIn Key %*ph\n",
462 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3encryptionkey);
463 cifs_dbg(VFS, "ServerOut Key %*ph\n",
464 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3decryptionkey);
465 } else {
466 cifs_dbg(VFS, "ServerIn Key %*ph\n",
467 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3encryptionkey);
468 cifs_dbg(VFS, "ServerOut Key %*ph\n",
469 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3decryptionkey);
470 }
471 #endif
472 return rc;
473 }
474
475 int
generate_smb30signingkey(struct cifs_ses * ses)476 generate_smb30signingkey(struct cifs_ses *ses)
477
478 {
479 struct derivation_triplet triplet;
480 struct derivation *d;
481
482 d = &triplet.signing;
483 d->label.iov_base = "SMB2AESCMAC";
484 d->label.iov_len = 12;
485 d->context.iov_base = "SmbSign";
486 d->context.iov_len = 8;
487
488 d = &triplet.encryption;
489 d->label.iov_base = "SMB2AESCCM";
490 d->label.iov_len = 11;
491 d->context.iov_base = "ServerIn ";
492 d->context.iov_len = 10;
493
494 d = &triplet.decryption;
495 d->label.iov_base = "SMB2AESCCM";
496 d->label.iov_len = 11;
497 d->context.iov_base = "ServerOut";
498 d->context.iov_len = 10;
499
500 return generate_smb3signingkey(ses, &triplet);
501 }
502
503 int
generate_smb311signingkey(struct cifs_ses * ses)504 generate_smb311signingkey(struct cifs_ses *ses)
505
506 {
507 struct derivation_triplet triplet;
508 struct derivation *d;
509
510 d = &triplet.signing;
511 d->label.iov_base = "SMBSigningKey";
512 d->label.iov_len = 14;
513 d->context.iov_base = ses->preauth_sha_hash;
514 d->context.iov_len = 64;
515
516 d = &triplet.encryption;
517 d->label.iov_base = "SMBC2SCipherKey";
518 d->label.iov_len = 16;
519 d->context.iov_base = ses->preauth_sha_hash;
520 d->context.iov_len = 64;
521
522 d = &triplet.decryption;
523 d->label.iov_base = "SMBS2CCipherKey";
524 d->label.iov_len = 16;
525 d->context.iov_base = ses->preauth_sha_hash;
526 d->context.iov_len = 64;
527
528 return generate_smb3signingkey(ses, &triplet);
529 }
530
531 int
smb3_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,bool allocate_crypto)532 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
533 bool allocate_crypto)
534 {
535 int rc;
536 unsigned char smb3_signature[SMB2_CMACAES_SIZE];
537 unsigned char *sigptr = smb3_signature;
538 struct kvec *iov = rqst->rq_iov;
539 struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[0].iov_base;
540 struct shash_desc *shash;
541 struct crypto_shash *hash;
542 struct sdesc *sdesc = NULL;
543 struct smb_rqst drqst;
544 u8 key[SMB3_SIGN_KEY_SIZE];
545
546 rc = smb2_get_sign_key(shdr->SessionId, server, key);
547 if (rc)
548 return 0;
549
550 if (allocate_crypto) {
551 rc = cifs_alloc_hash("cmac(aes)", &hash, &sdesc);
552 if (rc)
553 return rc;
554
555 shash = &sdesc->shash;
556 } else {
557 hash = server->secmech.cmacaes;
558 shash = &server->secmech.sdesccmacaes->shash;
559 }
560
561 memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
562 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
563
564 rc = crypto_shash_setkey(hash, key, SMB2_CMACAES_SIZE);
565 if (rc) {
566 cifs_server_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
567 goto out;
568 }
569
570 /*
571 * we already allocate sdesccmacaes when we init smb3 signing key,
572 * so unlike smb2 case we do not have to check here if secmech are
573 * initialized
574 */
575 rc = crypto_shash_init(shash);
576 if (rc) {
577 cifs_server_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
578 goto out;
579 }
580
581 /*
582 * For SMB2+, __cifs_calc_signature() expects to sign only the actual
583 * data, that is, iov[0] should not contain a rfc1002 length.
584 *
585 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
586 * __cifs_calc_signature().
587 */
588 drqst = *rqst;
589 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
590 rc = crypto_shash_update(shash, iov[0].iov_base,
591 iov[0].iov_len);
592 if (rc) {
593 cifs_server_dbg(VFS, "%s: Could not update with payload\n",
594 __func__);
595 goto out;
596 }
597 drqst.rq_iov++;
598 drqst.rq_nvec--;
599 }
600
601 rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
602 if (!rc)
603 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
604
605 out:
606 if (allocate_crypto)
607 cifs_free_hash(&hash, &sdesc);
608 return rc;
609 }
610
611 /* must be called with server->srv_mutex held */
612 static int
smb2_sign_rqst(struct smb_rqst * rqst,struct TCP_Server_Info * server)613 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
614 {
615 int rc = 0;
616 struct smb2_sync_hdr *shdr;
617 struct smb2_sess_setup_req *ssr;
618 bool is_binding;
619 bool is_signed;
620
621 shdr = (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
622 ssr = (struct smb2_sess_setup_req *)shdr;
623
624 is_binding = shdr->Command == SMB2_SESSION_SETUP &&
625 (ssr->Flags & SMB2_SESSION_REQ_FLAG_BINDING);
626 is_signed = shdr->Flags & SMB2_FLAGS_SIGNED;
627
628 if (!is_signed)
629 return 0;
630 if (server->tcpStatus == CifsNeedNegotiate)
631 return 0;
632 if (!is_binding && !server->session_estab) {
633 strncpy(shdr->Signature, "BSRSPYL", 8);
634 return 0;
635 }
636
637 rc = server->ops->calc_signature(rqst, server, false);
638
639 return rc;
640 }
641
642 int
smb2_verify_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server)643 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
644 {
645 unsigned int rc;
646 char server_response_sig[SMB2_SIGNATURE_SIZE];
647 struct smb2_sync_hdr *shdr =
648 (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
649
650 if ((shdr->Command == SMB2_NEGOTIATE) ||
651 (shdr->Command == SMB2_SESSION_SETUP) ||
652 (shdr->Command == SMB2_OPLOCK_BREAK) ||
653 server->ignore_signature ||
654 (!server->session_estab))
655 return 0;
656
657 /*
658 * BB what if signatures are supposed to be on for session but
659 * server does not send one? BB
660 */
661
662 /* Do not need to verify session setups with signature "BSRSPYL " */
663 if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0)
664 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
665 shdr->Command);
666
667 /*
668 * Save off the origiginal signature so we can modify the smb and check
669 * our calculated signature against what the server sent.
670 */
671 memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE);
672
673 memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE);
674
675 rc = server->ops->calc_signature(rqst, server, true);
676
677 if (rc)
678 return rc;
679
680 if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE)) {
681 cifs_dbg(VFS, "sign fail cmd 0x%x message id 0x%llx\n",
682 shdr->Command, shdr->MessageId);
683 return -EACCES;
684 } else
685 return 0;
686 }
687
688 /*
689 * Set message id for the request. Should be called after wait_for_free_request
690 * and when srv_mutex is held.
691 */
692 static inline void
smb2_seq_num_into_buf(struct TCP_Server_Info * server,struct smb2_sync_hdr * shdr)693 smb2_seq_num_into_buf(struct TCP_Server_Info *server,
694 struct smb2_sync_hdr *shdr)
695 {
696 unsigned int i, num = le16_to_cpu(shdr->CreditCharge);
697
698 shdr->MessageId = get_next_mid64(server);
699 /* skip message numbers according to CreditCharge field */
700 for (i = 1; i < num; i++)
701 get_next_mid(server);
702 }
703
704 static struct mid_q_entry *
smb2_mid_entry_alloc(const struct smb2_sync_hdr * shdr,struct TCP_Server_Info * server)705 smb2_mid_entry_alloc(const struct smb2_sync_hdr *shdr,
706 struct TCP_Server_Info *server)
707 {
708 struct mid_q_entry *temp;
709 unsigned int credits = le16_to_cpu(shdr->CreditCharge);
710
711 if (server == NULL) {
712 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
713 return NULL;
714 }
715
716 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
717 memset(temp, 0, sizeof(struct mid_q_entry));
718 kref_init(&temp->refcount);
719 temp->mid = le64_to_cpu(shdr->MessageId);
720 temp->credits = credits > 0 ? credits : 1;
721 temp->pid = current->pid;
722 temp->command = shdr->Command; /* Always LE */
723 temp->when_alloc = jiffies;
724 temp->server = server;
725
726 /*
727 * The default is for the mid to be synchronous, so the
728 * default callback just wakes up the current task.
729 */
730 get_task_struct(current);
731 temp->creator = current;
732 temp->callback = cifs_wake_up_task;
733 temp->callback_data = current;
734
735 atomic_inc(&midCount);
736 temp->mid_state = MID_REQUEST_ALLOCATED;
737 trace_smb3_cmd_enter(shdr->TreeId, shdr->SessionId,
738 le16_to_cpu(shdr->Command), temp->mid);
739 return temp;
740 }
741
742 static int
smb2_get_mid_entry(struct cifs_ses * ses,struct TCP_Server_Info * server,struct smb2_sync_hdr * shdr,struct mid_q_entry ** mid)743 smb2_get_mid_entry(struct cifs_ses *ses, struct TCP_Server_Info *server,
744 struct smb2_sync_hdr *shdr, struct mid_q_entry **mid)
745 {
746 if (server->tcpStatus == CifsExiting)
747 return -ENOENT;
748
749 if (server->tcpStatus == CifsNeedReconnect) {
750 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
751 return -EAGAIN;
752 }
753
754 if (server->tcpStatus == CifsNeedNegotiate &&
755 shdr->Command != SMB2_NEGOTIATE)
756 return -EAGAIN;
757
758 if (ses->status == CifsNew) {
759 if ((shdr->Command != SMB2_SESSION_SETUP) &&
760 (shdr->Command != SMB2_NEGOTIATE))
761 return -EAGAIN;
762 /* else ok - we are setting up session */
763 }
764
765 if (ses->status == CifsExiting) {
766 if (shdr->Command != SMB2_LOGOFF)
767 return -EAGAIN;
768 /* else ok - we are shutting down the session */
769 }
770
771 *mid = smb2_mid_entry_alloc(shdr, server);
772 if (*mid == NULL)
773 return -ENOMEM;
774 spin_lock(&GlobalMid_Lock);
775 list_add_tail(&(*mid)->qhead, &server->pending_mid_q);
776 spin_unlock(&GlobalMid_Lock);
777
778 return 0;
779 }
780
781 int
smb2_check_receive(struct mid_q_entry * mid,struct TCP_Server_Info * server,bool log_error)782 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
783 bool log_error)
784 {
785 unsigned int len = mid->resp_buf_size;
786 struct kvec iov[1];
787 struct smb_rqst rqst = { .rq_iov = iov,
788 .rq_nvec = 1 };
789
790 iov[0].iov_base = (char *)mid->resp_buf;
791 iov[0].iov_len = len;
792
793 dump_smb(mid->resp_buf, min_t(u32, 80, len));
794 /* convert the length into a more usable form */
795 if (len > 24 && server->sign && !mid->decrypted) {
796 int rc;
797
798 rc = smb2_verify_signature(&rqst, server);
799 if (rc)
800 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
801 rc);
802 }
803
804 return map_smb2_to_linux_error(mid->resp_buf, log_error);
805 }
806
807 struct mid_q_entry *
smb2_setup_request(struct cifs_ses * ses,struct TCP_Server_Info * server,struct smb_rqst * rqst)808 smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server,
809 struct smb_rqst *rqst)
810 {
811 int rc;
812 struct smb2_sync_hdr *shdr =
813 (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
814 struct mid_q_entry *mid;
815
816 smb2_seq_num_into_buf(server, shdr);
817
818 rc = smb2_get_mid_entry(ses, server, shdr, &mid);
819 if (rc) {
820 revert_current_mid_from_hdr(server, shdr);
821 return ERR_PTR(rc);
822 }
823
824 rc = smb2_sign_rqst(rqst, server);
825 if (rc) {
826 revert_current_mid_from_hdr(server, shdr);
827 cifs_delete_mid(mid);
828 return ERR_PTR(rc);
829 }
830
831 return mid;
832 }
833
834 struct mid_q_entry *
smb2_setup_async_request(struct TCP_Server_Info * server,struct smb_rqst * rqst)835 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
836 {
837 int rc;
838 struct smb2_sync_hdr *shdr =
839 (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
840 struct mid_q_entry *mid;
841
842 if (server->tcpStatus == CifsNeedNegotiate &&
843 shdr->Command != SMB2_NEGOTIATE)
844 return ERR_PTR(-EAGAIN);
845
846 smb2_seq_num_into_buf(server, shdr);
847
848 mid = smb2_mid_entry_alloc(shdr, server);
849 if (mid == NULL) {
850 revert_current_mid_from_hdr(server, shdr);
851 return ERR_PTR(-ENOMEM);
852 }
853
854 rc = smb2_sign_rqst(rqst, server);
855 if (rc) {
856 revert_current_mid_from_hdr(server, shdr);
857 DeleteMidQEntry(mid);
858 return ERR_PTR(rc);
859 }
860
861 return mid;
862 }
863
864 int
smb3_crypto_aead_allocate(struct TCP_Server_Info * server)865 smb3_crypto_aead_allocate(struct TCP_Server_Info *server)
866 {
867 struct crypto_aead *tfm;
868
869 if (!server->secmech.ccmaesencrypt) {
870 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
871 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
872 tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
873 else
874 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
875 if (IS_ERR(tfm)) {
876 cifs_server_dbg(VFS, "%s: Failed alloc encrypt aead\n",
877 __func__);
878 return PTR_ERR(tfm);
879 }
880 server->secmech.ccmaesencrypt = tfm;
881 }
882
883 if (!server->secmech.ccmaesdecrypt) {
884 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
885 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
886 tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
887 else
888 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
889 if (IS_ERR(tfm)) {
890 crypto_free_aead(server->secmech.ccmaesencrypt);
891 server->secmech.ccmaesencrypt = NULL;
892 cifs_server_dbg(VFS, "%s: Failed to alloc decrypt aead\n",
893 __func__);
894 return PTR_ERR(tfm);
895 }
896 server->secmech.ccmaesdecrypt = tfm;
897 }
898
899 return 0;
900 }
901