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 rc = generate_key(ses, ptriplet->decryption.label,
437 ptriplet->decryption.context,
438 ses->smb3decryptionkey,
439 SMB3_ENC_DEC_KEY_SIZE);
440 if (rc)
441 return rc;
442 }
443
444 if (rc)
445 return rc;
446
447 #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
448 cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__);
449 /*
450 * The session id is opaque in terms of endianness, so we can't
451 * print it as a long long. we dump it as we got it on the wire
452 */
453 cifs_dbg(VFS, "Session Id %*ph\n", (int)sizeof(ses->Suid),
454 &ses->Suid);
455 cifs_dbg(VFS, "Cipher type %d\n", server->cipher_type);
456 cifs_dbg(VFS, "Session Key %*ph\n",
457 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response);
458 cifs_dbg(VFS, "Signing Key %*ph\n",
459 SMB3_SIGN_KEY_SIZE, ses->smb3signingkey);
460 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
461 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
462 cifs_dbg(VFS, "ServerIn Key %*ph\n",
463 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3encryptionkey);
464 cifs_dbg(VFS, "ServerOut Key %*ph\n",
465 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3decryptionkey);
466 } else {
467 cifs_dbg(VFS, "ServerIn Key %*ph\n",
468 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3encryptionkey);
469 cifs_dbg(VFS, "ServerOut Key %*ph\n",
470 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3decryptionkey);
471 }
472 #endif
473 return rc;
474 }
475
476 int
generate_smb30signingkey(struct cifs_ses * ses)477 generate_smb30signingkey(struct cifs_ses *ses)
478
479 {
480 struct derivation_triplet triplet;
481 struct derivation *d;
482
483 d = &triplet.signing;
484 d->label.iov_base = "SMB2AESCMAC";
485 d->label.iov_len = 12;
486 d->context.iov_base = "SmbSign";
487 d->context.iov_len = 8;
488
489 d = &triplet.encryption;
490 d->label.iov_base = "SMB2AESCCM";
491 d->label.iov_len = 11;
492 d->context.iov_base = "ServerIn ";
493 d->context.iov_len = 10;
494
495 d = &triplet.decryption;
496 d->label.iov_base = "SMB2AESCCM";
497 d->label.iov_len = 11;
498 d->context.iov_base = "ServerOut";
499 d->context.iov_len = 10;
500
501 return generate_smb3signingkey(ses, &triplet);
502 }
503
504 int
generate_smb311signingkey(struct cifs_ses * ses)505 generate_smb311signingkey(struct cifs_ses *ses)
506
507 {
508 struct derivation_triplet triplet;
509 struct derivation *d;
510
511 d = &triplet.signing;
512 d->label.iov_base = "SMBSigningKey";
513 d->label.iov_len = 14;
514 d->context.iov_base = ses->preauth_sha_hash;
515 d->context.iov_len = 64;
516
517 d = &triplet.encryption;
518 d->label.iov_base = "SMBC2SCipherKey";
519 d->label.iov_len = 16;
520 d->context.iov_base = ses->preauth_sha_hash;
521 d->context.iov_len = 64;
522
523 d = &triplet.decryption;
524 d->label.iov_base = "SMBS2CCipherKey";
525 d->label.iov_len = 16;
526 d->context.iov_base = ses->preauth_sha_hash;
527 d->context.iov_len = 64;
528
529 return generate_smb3signingkey(ses, &triplet);
530 }
531
532 int
smb3_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,bool allocate_crypto)533 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
534 bool allocate_crypto)
535 {
536 int rc;
537 unsigned char smb3_signature[SMB2_CMACAES_SIZE];
538 unsigned char *sigptr = smb3_signature;
539 struct kvec *iov = rqst->rq_iov;
540 struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[0].iov_base;
541 struct shash_desc *shash;
542 struct crypto_shash *hash;
543 struct sdesc *sdesc = NULL;
544 struct smb_rqst drqst;
545 u8 key[SMB3_SIGN_KEY_SIZE];
546
547 rc = smb2_get_sign_key(shdr->SessionId, server, key);
548 if (rc)
549 return 0;
550
551 if (allocate_crypto) {
552 rc = cifs_alloc_hash("cmac(aes)", &hash, &sdesc);
553 if (rc)
554 return rc;
555
556 shash = &sdesc->shash;
557 } else {
558 hash = server->secmech.cmacaes;
559 shash = &server->secmech.sdesccmacaes->shash;
560 }
561
562 memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
563 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
564
565 rc = crypto_shash_setkey(hash, key, SMB2_CMACAES_SIZE);
566 if (rc) {
567 cifs_server_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
568 goto out;
569 }
570
571 /*
572 * we already allocate sdesccmacaes when we init smb3 signing key,
573 * so unlike smb2 case we do not have to check here if secmech are
574 * initialized
575 */
576 rc = crypto_shash_init(shash);
577 if (rc) {
578 cifs_server_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
579 goto out;
580 }
581
582 /*
583 * For SMB2+, __cifs_calc_signature() expects to sign only the actual
584 * data, that is, iov[0] should not contain a rfc1002 length.
585 *
586 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
587 * __cifs_calc_signature().
588 */
589 drqst = *rqst;
590 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
591 rc = crypto_shash_update(shash, iov[0].iov_base,
592 iov[0].iov_len);
593 if (rc) {
594 cifs_server_dbg(VFS, "%s: Could not update with payload\n",
595 __func__);
596 goto out;
597 }
598 drqst.rq_iov++;
599 drqst.rq_nvec--;
600 }
601
602 rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
603 if (!rc)
604 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
605
606 out:
607 if (allocate_crypto)
608 cifs_free_hash(&hash, &sdesc);
609 return rc;
610 }
611
612 /* must be called with server->srv_mutex held */
613 static int
smb2_sign_rqst(struct smb_rqst * rqst,struct TCP_Server_Info * server)614 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
615 {
616 int rc = 0;
617 struct smb2_sync_hdr *shdr;
618 struct smb2_sess_setup_req *ssr;
619 bool is_binding;
620 bool is_signed;
621
622 shdr = (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
623 ssr = (struct smb2_sess_setup_req *)shdr;
624
625 is_binding = shdr->Command == SMB2_SESSION_SETUP &&
626 (ssr->Flags & SMB2_SESSION_REQ_FLAG_BINDING);
627 is_signed = shdr->Flags & SMB2_FLAGS_SIGNED;
628
629 if (!is_signed)
630 return 0;
631 if (server->tcpStatus == CifsNeedNegotiate)
632 return 0;
633 if (!is_binding && !server->session_estab) {
634 strncpy(shdr->Signature, "BSRSPYL", 8);
635 return 0;
636 }
637
638 rc = server->ops->calc_signature(rqst, server, false);
639
640 return rc;
641 }
642
643 int
smb2_verify_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server)644 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
645 {
646 unsigned int rc;
647 char server_response_sig[SMB2_SIGNATURE_SIZE];
648 struct smb2_sync_hdr *shdr =
649 (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
650
651 if ((shdr->Command == SMB2_NEGOTIATE) ||
652 (shdr->Command == SMB2_SESSION_SETUP) ||
653 (shdr->Command == SMB2_OPLOCK_BREAK) ||
654 server->ignore_signature ||
655 (!server->session_estab))
656 return 0;
657
658 /*
659 * BB what if signatures are supposed to be on for session but
660 * server does not send one? BB
661 */
662
663 /* Do not need to verify session setups with signature "BSRSPYL " */
664 if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0)
665 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
666 shdr->Command);
667
668 /*
669 * Save off the origiginal signature so we can modify the smb and check
670 * our calculated signature against what the server sent.
671 */
672 memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE);
673
674 memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE);
675
676 rc = server->ops->calc_signature(rqst, server, true);
677
678 if (rc)
679 return rc;
680
681 if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE)) {
682 cifs_dbg(VFS, "sign fail cmd 0x%x message id 0x%llx\n",
683 shdr->Command, shdr->MessageId);
684 return -EACCES;
685 } else
686 return 0;
687 }
688
689 /*
690 * Set message id for the request. Should be called after wait_for_free_request
691 * and when srv_mutex is held.
692 */
693 static inline void
smb2_seq_num_into_buf(struct TCP_Server_Info * server,struct smb2_sync_hdr * shdr)694 smb2_seq_num_into_buf(struct TCP_Server_Info *server,
695 struct smb2_sync_hdr *shdr)
696 {
697 unsigned int i, num = le16_to_cpu(shdr->CreditCharge);
698
699 shdr->MessageId = get_next_mid64(server);
700 /* skip message numbers according to CreditCharge field */
701 for (i = 1; i < num; i++)
702 get_next_mid(server);
703 }
704
705 static struct mid_q_entry *
smb2_mid_entry_alloc(const struct smb2_sync_hdr * shdr,struct TCP_Server_Info * server)706 smb2_mid_entry_alloc(const struct smb2_sync_hdr *shdr,
707 struct TCP_Server_Info *server)
708 {
709 struct mid_q_entry *temp;
710 unsigned int credits = le16_to_cpu(shdr->CreditCharge);
711
712 if (server == NULL) {
713 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
714 return NULL;
715 }
716
717 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
718 memset(temp, 0, sizeof(struct mid_q_entry));
719 kref_init(&temp->refcount);
720 temp->mid = le64_to_cpu(shdr->MessageId);
721 temp->credits = credits > 0 ? credits : 1;
722 temp->pid = current->pid;
723 temp->command = shdr->Command; /* Always LE */
724 temp->when_alloc = jiffies;
725 temp->server = server;
726
727 /*
728 * The default is for the mid to be synchronous, so the
729 * default callback just wakes up the current task.
730 */
731 get_task_struct(current);
732 temp->creator = current;
733 temp->callback = cifs_wake_up_task;
734 temp->callback_data = current;
735
736 atomic_inc(&midCount);
737 temp->mid_state = MID_REQUEST_ALLOCATED;
738 trace_smb3_cmd_enter(shdr->TreeId, shdr->SessionId,
739 le16_to_cpu(shdr->Command), temp->mid);
740 return temp;
741 }
742
743 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)744 smb2_get_mid_entry(struct cifs_ses *ses, struct TCP_Server_Info *server,
745 struct smb2_sync_hdr *shdr, struct mid_q_entry **mid)
746 {
747 if (server->tcpStatus == CifsExiting)
748 return -ENOENT;
749
750 if (server->tcpStatus == CifsNeedReconnect) {
751 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
752 return -EAGAIN;
753 }
754
755 if (server->tcpStatus == CifsNeedNegotiate &&
756 shdr->Command != SMB2_NEGOTIATE)
757 return -EAGAIN;
758
759 if (ses->status == CifsNew) {
760 if ((shdr->Command != SMB2_SESSION_SETUP) &&
761 (shdr->Command != SMB2_NEGOTIATE))
762 return -EAGAIN;
763 /* else ok - we are setting up session */
764 }
765
766 if (ses->status == CifsExiting) {
767 if (shdr->Command != SMB2_LOGOFF)
768 return -EAGAIN;
769 /* else ok - we are shutting down the session */
770 }
771
772 *mid = smb2_mid_entry_alloc(shdr, server);
773 if (*mid == NULL)
774 return -ENOMEM;
775 spin_lock(&GlobalMid_Lock);
776 list_add_tail(&(*mid)->qhead, &server->pending_mid_q);
777 spin_unlock(&GlobalMid_Lock);
778
779 return 0;
780 }
781
782 int
smb2_check_receive(struct mid_q_entry * mid,struct TCP_Server_Info * server,bool log_error)783 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
784 bool log_error)
785 {
786 unsigned int len = mid->resp_buf_size;
787 struct kvec iov[1];
788 struct smb_rqst rqst = { .rq_iov = iov,
789 .rq_nvec = 1 };
790
791 iov[0].iov_base = (char *)mid->resp_buf;
792 iov[0].iov_len = len;
793
794 dump_smb(mid->resp_buf, min_t(u32, 80, len));
795 /* convert the length into a more usable form */
796 if (len > 24 && server->sign && !mid->decrypted) {
797 int rc;
798
799 rc = smb2_verify_signature(&rqst, server);
800 if (rc)
801 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
802 rc);
803 }
804
805 return map_smb2_to_linux_error(mid->resp_buf, log_error);
806 }
807
808 struct mid_q_entry *
smb2_setup_request(struct cifs_ses * ses,struct TCP_Server_Info * server,struct smb_rqst * rqst)809 smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server,
810 struct smb_rqst *rqst)
811 {
812 int rc;
813 struct smb2_sync_hdr *shdr =
814 (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
815 struct mid_q_entry *mid;
816
817 smb2_seq_num_into_buf(server, shdr);
818
819 rc = smb2_get_mid_entry(ses, server, shdr, &mid);
820 if (rc) {
821 revert_current_mid_from_hdr(server, shdr);
822 return ERR_PTR(rc);
823 }
824
825 rc = smb2_sign_rqst(rqst, server);
826 if (rc) {
827 revert_current_mid_from_hdr(server, shdr);
828 cifs_delete_mid(mid);
829 return ERR_PTR(rc);
830 }
831
832 return mid;
833 }
834
835 struct mid_q_entry *
smb2_setup_async_request(struct TCP_Server_Info * server,struct smb_rqst * rqst)836 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
837 {
838 int rc;
839 struct smb2_sync_hdr *shdr =
840 (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
841 struct mid_q_entry *mid;
842
843 if (server->tcpStatus == CifsNeedNegotiate &&
844 shdr->Command != SMB2_NEGOTIATE)
845 return ERR_PTR(-EAGAIN);
846
847 smb2_seq_num_into_buf(server, shdr);
848
849 mid = smb2_mid_entry_alloc(shdr, server);
850 if (mid == NULL) {
851 revert_current_mid_from_hdr(server, shdr);
852 return ERR_PTR(-ENOMEM);
853 }
854
855 rc = smb2_sign_rqst(rqst, server);
856 if (rc) {
857 revert_current_mid_from_hdr(server, shdr);
858 DeleteMidQEntry(mid);
859 return ERR_PTR(rc);
860 }
861
862 return mid;
863 }
864
865 int
smb3_crypto_aead_allocate(struct TCP_Server_Info * server)866 smb3_crypto_aead_allocate(struct TCP_Server_Info *server)
867 {
868 struct crypto_aead *tfm;
869
870 if (!server->secmech.ccmaesencrypt) {
871 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
872 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
873 tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
874 else
875 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
876 if (IS_ERR(tfm)) {
877 cifs_server_dbg(VFS, "%s: Failed alloc encrypt aead\n",
878 __func__);
879 return PTR_ERR(tfm);
880 }
881 server->secmech.ccmaesencrypt = tfm;
882 }
883
884 if (!server->secmech.ccmaesdecrypt) {
885 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
886 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
887 tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
888 else
889 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
890 if (IS_ERR(tfm)) {
891 crypto_free_aead(server->secmech.ccmaesencrypt);
892 server->secmech.ccmaesencrypt = NULL;
893 cifs_server_dbg(VFS, "%s: Failed to alloc decrypt aead\n",
894 __func__);
895 return PTR_ERR(tfm);
896 }
897 server->secmech.ccmaesdecrypt = tfm;
898 }
899
900 return 0;
901 }
902