1 // SPDX-License-Identifier: LGPL-2.1
2 /*
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 */
11
12 #include <linux/fs.h>
13 #include <linux/list.h>
14 #include <linux/wait.h>
15 #include <linux/net.h>
16 #include <linux/delay.h>
17 #include <linux/uaccess.h>
18 #include <asm/processor.h>
19 #include <linux/mempool.h>
20 #include <linux/highmem.h>
21 #include <crypto/aead.h>
22 #include "cifsglob.h"
23 #include "cifsproto.h"
24 #include "smb2proto.h"
25 #include "cifs_debug.h"
26 #include "smb2status.h"
27 #include "smb2glob.h"
28
29 static int
smb3_crypto_shash_allocate(struct TCP_Server_Info * server)30 smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
31 {
32 struct cifs_secmech *p = &server->secmech;
33 int rc;
34
35 rc = cifs_alloc_hash("hmac(sha256)", &p->hmacsha256);
36 if (rc)
37 goto err;
38
39 rc = cifs_alloc_hash("cmac(aes)", &p->aes_cmac);
40 if (rc)
41 goto err;
42
43 return 0;
44 err:
45 cifs_free_hash(&p->hmacsha256);
46 return rc;
47 }
48
49 int
smb311_crypto_shash_allocate(struct TCP_Server_Info * server)50 smb311_crypto_shash_allocate(struct TCP_Server_Info *server)
51 {
52 struct cifs_secmech *p = &server->secmech;
53 int rc = 0;
54
55 rc = cifs_alloc_hash("hmac(sha256)", &p->hmacsha256);
56 if (rc)
57 return rc;
58
59 rc = cifs_alloc_hash("cmac(aes)", &p->aes_cmac);
60 if (rc)
61 goto err;
62
63 rc = cifs_alloc_hash("sha512", &p->sha512);
64 if (rc)
65 goto err;
66
67 return 0;
68
69 err:
70 cifs_free_hash(&p->aes_cmac);
71 cifs_free_hash(&p->hmacsha256);
72 return rc;
73 }
74
75
76 static
smb2_get_sign_key(__u64 ses_id,struct TCP_Server_Info * server,u8 * key)77 int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
78 {
79 struct cifs_chan *chan;
80 struct TCP_Server_Info *pserver;
81 struct cifs_ses *ses = NULL;
82 int i;
83 int rc = 0;
84 bool is_binding = false;
85
86 spin_lock(&cifs_tcp_ses_lock);
87
88 /* If server is a channel, select the primary channel */
89 pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
90
91 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
92 if (ses->Suid == ses_id)
93 goto found;
94 }
95 trace_smb3_ses_not_found(ses_id);
96 cifs_server_dbg(FYI, "%s: Could not find session 0x%llx\n",
97 __func__, ses_id);
98 rc = -ENOENT;
99 goto out;
100
101 found:
102 spin_lock(&ses->ses_lock);
103 spin_lock(&ses->chan_lock);
104
105 is_binding = (cifs_chan_needs_reconnect(ses, server) &&
106 ses->ses_status == SES_GOOD);
107 if (is_binding) {
108 /*
109 * If we are in the process of binding a new channel
110 * to an existing session, use the master connection
111 * session key
112 */
113 memcpy(key, ses->smb3signingkey, SMB3_SIGN_KEY_SIZE);
114 spin_unlock(&ses->chan_lock);
115 spin_unlock(&ses->ses_lock);
116 goto out;
117 }
118
119 /*
120 * Otherwise, use the channel key.
121 */
122
123 for (i = 0; i < ses->chan_count; i++) {
124 chan = ses->chans + i;
125 if (chan->server == server) {
126 memcpy(key, chan->signkey, SMB3_SIGN_KEY_SIZE);
127 spin_unlock(&ses->chan_lock);
128 spin_unlock(&ses->ses_lock);
129 goto out;
130 }
131 }
132 spin_unlock(&ses->chan_lock);
133 spin_unlock(&ses->ses_lock);
134
135 cifs_dbg(VFS,
136 "%s: Could not find channel signing key for session 0x%llx\n",
137 __func__, ses_id);
138 rc = -ENOENT;
139
140 out:
141 spin_unlock(&cifs_tcp_ses_lock);
142 return rc;
143 }
144
145 static struct cifs_ses *
smb2_find_smb_ses_unlocked(struct TCP_Server_Info * server,__u64 ses_id)146 smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id)
147 {
148 struct TCP_Server_Info *pserver;
149 struct cifs_ses *ses;
150
151 /* If server is a channel, select the primary channel */
152 pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
153
154 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
155 if (ses->Suid != ses_id)
156 continue;
157
158 spin_lock(&ses->ses_lock);
159 if (ses->ses_status == SES_EXITING) {
160 spin_unlock(&ses->ses_lock);
161 continue;
162 }
163 cifs_smb_ses_inc_refcount(ses);
164 spin_unlock(&ses->ses_lock);
165 return ses;
166 }
167
168 return NULL;
169 }
170
171 struct cifs_ses *
smb2_find_smb_ses(struct TCP_Server_Info * server,__u64 ses_id)172 smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id)
173 {
174 struct cifs_ses *ses;
175
176 spin_lock(&cifs_tcp_ses_lock);
177 ses = smb2_find_smb_ses_unlocked(server, ses_id);
178 spin_unlock(&cifs_tcp_ses_lock);
179
180 return ses;
181 }
182
183 static struct cifs_tcon *
smb2_find_smb_sess_tcon_unlocked(struct cifs_ses * ses,__u32 tid)184 smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32 tid)
185 {
186 struct cifs_tcon *tcon;
187
188 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
189 if (tcon->tid != tid)
190 continue;
191 ++tcon->tc_count;
192 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
193 netfs_trace_tcon_ref_get_find_sess_tcon);
194 return tcon;
195 }
196
197 return NULL;
198 }
199
200 /*
201 * Obtain tcon corresponding to the tid in the given
202 * cifs_ses
203 */
204
205 struct cifs_tcon *
smb2_find_smb_tcon(struct TCP_Server_Info * server,__u64 ses_id,__u32 tid)206 smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32 tid)
207 {
208 struct cifs_ses *ses;
209 struct cifs_tcon *tcon;
210
211 spin_lock(&cifs_tcp_ses_lock);
212 ses = smb2_find_smb_ses_unlocked(server, ses_id);
213 if (!ses) {
214 spin_unlock(&cifs_tcp_ses_lock);
215 return NULL;
216 }
217 tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid);
218 if (!tcon) {
219 spin_unlock(&cifs_tcp_ses_lock);
220 cifs_put_smb_ses(ses);
221 return NULL;
222 }
223 spin_unlock(&cifs_tcp_ses_lock);
224 /* tcon already has a ref to ses, so we don't need ses anymore */
225 cifs_put_smb_ses(ses);
226
227 return tcon;
228 }
229
230 int
smb2_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,bool allocate_crypto)231 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
232 bool allocate_crypto)
233 {
234 int rc;
235 unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
236 unsigned char *sigptr = smb2_signature;
237 struct kvec *iov = rqst->rq_iov;
238 struct smb2_hdr *shdr = (struct smb2_hdr *)iov[0].iov_base;
239 struct cifs_ses *ses;
240 struct shash_desc *shash = NULL;
241 struct smb_rqst drqst;
242
243 ses = smb2_find_smb_ses(server, le64_to_cpu(shdr->SessionId));
244 if (unlikely(!ses)) {
245 cifs_server_dbg(VFS, "%s: Could not find session\n", __func__);
246 return -ENOENT;
247 }
248
249 memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
250 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
251
252 if (allocate_crypto) {
253 rc = cifs_alloc_hash("hmac(sha256)", &shash);
254 if (rc) {
255 cifs_server_dbg(VFS,
256 "%s: sha256 alloc failed\n", __func__);
257 goto out;
258 }
259 } else {
260 shash = server->secmech.hmacsha256;
261 }
262
263 rc = crypto_shash_setkey(shash->tfm, ses->auth_key.response,
264 SMB2_NTLMV2_SESSKEY_SIZE);
265 if (rc) {
266 cifs_server_dbg(VFS,
267 "%s: Could not update with response\n",
268 __func__);
269 goto out;
270 }
271
272 rc = crypto_shash_init(shash);
273 if (rc) {
274 cifs_server_dbg(VFS, "%s: Could not init sha256", __func__);
275 goto out;
276 }
277
278 /*
279 * For SMB2+, __cifs_calc_signature() expects to sign only the actual
280 * data, that is, iov[0] should not contain a rfc1002 length.
281 *
282 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
283 * __cifs_calc_signature().
284 */
285 drqst = *rqst;
286 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
287 rc = crypto_shash_update(shash, iov[0].iov_base,
288 iov[0].iov_len);
289 if (rc) {
290 cifs_server_dbg(VFS,
291 "%s: Could not update with payload\n",
292 __func__);
293 goto out;
294 }
295 drqst.rq_iov++;
296 drqst.rq_nvec--;
297 }
298
299 rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
300 if (!rc)
301 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
302
303 out:
304 if (allocate_crypto)
305 cifs_free_hash(&shash);
306 if (ses)
307 cifs_put_smb_ses(ses);
308 return rc;
309 }
310
generate_key(struct cifs_ses * ses,struct kvec label,struct kvec context,__u8 * key,unsigned int key_size)311 static int generate_key(struct cifs_ses *ses, struct kvec label,
312 struct kvec context, __u8 *key, unsigned int key_size)
313 {
314 unsigned char zero = 0x0;
315 __u8 i[4] = {0, 0, 0, 1};
316 __u8 L128[4] = {0, 0, 0, 128};
317 __u8 L256[4] = {0, 0, 1, 0};
318 int rc = 0;
319 unsigned char prfhash[SMB2_HMACSHA256_SIZE];
320 unsigned char *hashptr = prfhash;
321 struct TCP_Server_Info *server = ses->server;
322
323 memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
324 memset(key, 0x0, key_size);
325
326 rc = smb3_crypto_shash_allocate(server);
327 if (rc) {
328 cifs_server_dbg(VFS, "%s: crypto alloc failed\n", __func__);
329 goto smb3signkey_ret;
330 }
331
332 rc = crypto_shash_setkey(server->secmech.hmacsha256->tfm,
333 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
334 if (rc) {
335 cifs_server_dbg(VFS, "%s: Could not set with session key\n", __func__);
336 goto smb3signkey_ret;
337 }
338
339 rc = crypto_shash_init(server->secmech.hmacsha256);
340 if (rc) {
341 cifs_server_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
342 goto smb3signkey_ret;
343 }
344
345 rc = crypto_shash_update(server->secmech.hmacsha256, i, 4);
346 if (rc) {
347 cifs_server_dbg(VFS, "%s: Could not update with n\n", __func__);
348 goto smb3signkey_ret;
349 }
350
351 rc = crypto_shash_update(server->secmech.hmacsha256, label.iov_base, label.iov_len);
352 if (rc) {
353 cifs_server_dbg(VFS, "%s: Could not update with label\n", __func__);
354 goto smb3signkey_ret;
355 }
356
357 rc = crypto_shash_update(server->secmech.hmacsha256, &zero, 1);
358 if (rc) {
359 cifs_server_dbg(VFS, "%s: Could not update with zero\n", __func__);
360 goto smb3signkey_ret;
361 }
362
363 rc = crypto_shash_update(server->secmech.hmacsha256, context.iov_base, context.iov_len);
364 if (rc) {
365 cifs_server_dbg(VFS, "%s: Could not update with context\n", __func__);
366 goto smb3signkey_ret;
367 }
368
369 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
370 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
371 rc = crypto_shash_update(server->secmech.hmacsha256, L256, 4);
372 } else {
373 rc = crypto_shash_update(server->secmech.hmacsha256, L128, 4);
374 }
375 if (rc) {
376 cifs_server_dbg(VFS, "%s: Could not update with L\n", __func__);
377 goto smb3signkey_ret;
378 }
379
380 rc = crypto_shash_final(server->secmech.hmacsha256, hashptr);
381 if (rc) {
382 cifs_server_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
383 goto smb3signkey_ret;
384 }
385
386 memcpy(key, hashptr, key_size);
387
388 smb3signkey_ret:
389 return rc;
390 }
391
392 struct derivation {
393 struct kvec label;
394 struct kvec context;
395 };
396
397 struct derivation_triplet {
398 struct derivation signing;
399 struct derivation encryption;
400 struct derivation decryption;
401 };
402
403 static int
generate_smb3signingkey(struct cifs_ses * ses,struct TCP_Server_Info * server,const struct derivation_triplet * ptriplet)404 generate_smb3signingkey(struct cifs_ses *ses,
405 struct TCP_Server_Info *server,
406 const struct derivation_triplet *ptriplet)
407 {
408 int rc;
409 bool is_binding = false;
410 int chan_index = 0;
411
412 spin_lock(&ses->ses_lock);
413 spin_lock(&ses->chan_lock);
414 is_binding = (cifs_chan_needs_reconnect(ses, server) &&
415 ses->ses_status == SES_GOOD);
416
417 chan_index = cifs_ses_get_chan_index(ses, server);
418 if (chan_index == CIFS_INVAL_CHAN_INDEX) {
419 spin_unlock(&ses->chan_lock);
420 spin_unlock(&ses->ses_lock);
421
422 return -EINVAL;
423 }
424
425 spin_unlock(&ses->chan_lock);
426 spin_unlock(&ses->ses_lock);
427
428 /*
429 * All channels use the same encryption/decryption keys but
430 * they have their own signing key.
431 *
432 * When we generate the keys, check if it is for a new channel
433 * (binding) in which case we only need to generate a signing
434 * key and store it in the channel as to not overwrite the
435 * master connection signing key stored in the session
436 */
437
438 if (is_binding) {
439 rc = generate_key(ses, ptriplet->signing.label,
440 ptriplet->signing.context,
441 ses->chans[chan_index].signkey,
442 SMB3_SIGN_KEY_SIZE);
443 if (rc)
444 return rc;
445 } else {
446 rc = generate_key(ses, ptriplet->signing.label,
447 ptriplet->signing.context,
448 ses->smb3signingkey,
449 SMB3_SIGN_KEY_SIZE);
450 if (rc)
451 return rc;
452
453 /* safe to access primary channel, since it will never go away */
454 spin_lock(&ses->chan_lock);
455 memcpy(ses->chans[chan_index].signkey, ses->smb3signingkey,
456 SMB3_SIGN_KEY_SIZE);
457 spin_unlock(&ses->chan_lock);
458
459 rc = generate_key(ses, ptriplet->encryption.label,
460 ptriplet->encryption.context,
461 ses->smb3encryptionkey,
462 SMB3_ENC_DEC_KEY_SIZE);
463 if (rc)
464 return rc;
465 rc = generate_key(ses, ptriplet->decryption.label,
466 ptriplet->decryption.context,
467 ses->smb3decryptionkey,
468 SMB3_ENC_DEC_KEY_SIZE);
469 if (rc)
470 return rc;
471 }
472
473 #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
474 cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__);
475 /*
476 * The session id is opaque in terms of endianness, so we can't
477 * print it as a long long. we dump it as we got it on the wire
478 */
479 cifs_dbg(VFS, "Session Id %*ph\n", (int)sizeof(ses->Suid),
480 &ses->Suid);
481 cifs_dbg(VFS, "Cipher type %d\n", server->cipher_type);
482 cifs_dbg(VFS, "Session Key %*ph\n",
483 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response);
484 cifs_dbg(VFS, "Signing Key %*ph\n",
485 SMB3_SIGN_KEY_SIZE, ses->smb3signingkey);
486 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
487 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
488 cifs_dbg(VFS, "ServerIn Key %*ph\n",
489 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3encryptionkey);
490 cifs_dbg(VFS, "ServerOut Key %*ph\n",
491 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3decryptionkey);
492 } else {
493 cifs_dbg(VFS, "ServerIn Key %*ph\n",
494 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3encryptionkey);
495 cifs_dbg(VFS, "ServerOut Key %*ph\n",
496 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3decryptionkey);
497 }
498 #endif
499 return rc;
500 }
501
502 int
generate_smb30signingkey(struct cifs_ses * ses,struct TCP_Server_Info * server)503 generate_smb30signingkey(struct cifs_ses *ses,
504 struct TCP_Server_Info *server)
505
506 {
507 struct derivation_triplet triplet;
508 struct derivation *d;
509
510 d = &triplet.signing;
511 d->label.iov_base = "SMB2AESCMAC";
512 d->label.iov_len = 12;
513 d->context.iov_base = "SmbSign";
514 d->context.iov_len = 8;
515
516 d = &triplet.encryption;
517 d->label.iov_base = "SMB2AESCCM";
518 d->label.iov_len = 11;
519 d->context.iov_base = "ServerIn ";
520 d->context.iov_len = 10;
521
522 d = &triplet.decryption;
523 d->label.iov_base = "SMB2AESCCM";
524 d->label.iov_len = 11;
525 d->context.iov_base = "ServerOut";
526 d->context.iov_len = 10;
527
528 return generate_smb3signingkey(ses, server, &triplet);
529 }
530
531 int
generate_smb311signingkey(struct cifs_ses * ses,struct TCP_Server_Info * server)532 generate_smb311signingkey(struct cifs_ses *ses,
533 struct TCP_Server_Info *server)
534
535 {
536 struct derivation_triplet triplet;
537 struct derivation *d;
538
539 d = &triplet.signing;
540 d->label.iov_base = "SMBSigningKey";
541 d->label.iov_len = 14;
542 d->context.iov_base = ses->preauth_sha_hash;
543 d->context.iov_len = 64;
544
545 d = &triplet.encryption;
546 d->label.iov_base = "SMBC2SCipherKey";
547 d->label.iov_len = 16;
548 d->context.iov_base = ses->preauth_sha_hash;
549 d->context.iov_len = 64;
550
551 d = &triplet.decryption;
552 d->label.iov_base = "SMBS2CCipherKey";
553 d->label.iov_len = 16;
554 d->context.iov_base = ses->preauth_sha_hash;
555 d->context.iov_len = 64;
556
557 return generate_smb3signingkey(ses, server, &triplet);
558 }
559
560 int
smb3_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,bool allocate_crypto)561 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
562 bool allocate_crypto)
563 {
564 int rc;
565 unsigned char smb3_signature[SMB2_CMACAES_SIZE];
566 unsigned char *sigptr = smb3_signature;
567 struct kvec *iov = rqst->rq_iov;
568 struct smb2_hdr *shdr = (struct smb2_hdr *)iov[0].iov_base;
569 struct shash_desc *shash = NULL;
570 struct smb_rqst drqst;
571 u8 key[SMB3_SIGN_KEY_SIZE];
572
573 rc = smb2_get_sign_key(le64_to_cpu(shdr->SessionId), server, key);
574 if (unlikely(rc)) {
575 cifs_server_dbg(FYI, "%s: Could not get signing key\n", __func__);
576 return rc;
577 }
578
579 if (allocate_crypto) {
580 rc = cifs_alloc_hash("cmac(aes)", &shash);
581 if (rc)
582 return rc;
583 } else {
584 shash = server->secmech.aes_cmac;
585 }
586
587 memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
588 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
589
590 rc = crypto_shash_setkey(shash->tfm, key, SMB2_CMACAES_SIZE);
591 if (rc) {
592 cifs_server_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
593 goto out;
594 }
595
596 /*
597 * we already allocate aes_cmac when we init smb3 signing key,
598 * so unlike smb2 case we do not have to check here if secmech are
599 * initialized
600 */
601 rc = crypto_shash_init(shash);
602 if (rc) {
603 cifs_server_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
604 goto out;
605 }
606
607 /*
608 * For SMB2+, __cifs_calc_signature() expects to sign only the actual
609 * data, that is, iov[0] should not contain a rfc1002 length.
610 *
611 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
612 * __cifs_calc_signature().
613 */
614 drqst = *rqst;
615 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
616 rc = crypto_shash_update(shash, iov[0].iov_base,
617 iov[0].iov_len);
618 if (rc) {
619 cifs_server_dbg(VFS, "%s: Could not update with payload\n",
620 __func__);
621 goto out;
622 }
623 drqst.rq_iov++;
624 drqst.rq_nvec--;
625 }
626
627 rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
628 if (!rc)
629 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
630
631 out:
632 if (allocate_crypto)
633 cifs_free_hash(&shash);
634 return rc;
635 }
636
637 /* must be called with server->srv_mutex held */
638 static int
smb2_sign_rqst(struct smb_rqst * rqst,struct TCP_Server_Info * server)639 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
640 {
641 int rc = 0;
642 struct smb2_hdr *shdr;
643 struct smb2_sess_setup_req *ssr;
644 bool is_binding;
645 bool is_signed;
646
647 shdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
648 ssr = (struct smb2_sess_setup_req *)shdr;
649
650 is_binding = shdr->Command == SMB2_SESSION_SETUP &&
651 (ssr->Flags & SMB2_SESSION_REQ_FLAG_BINDING);
652 is_signed = shdr->Flags & SMB2_FLAGS_SIGNED;
653
654 if (!is_signed)
655 return 0;
656 spin_lock(&server->srv_lock);
657 if (server->ops->need_neg &&
658 server->ops->need_neg(server)) {
659 spin_unlock(&server->srv_lock);
660 return 0;
661 }
662 spin_unlock(&server->srv_lock);
663 if (!is_binding && !server->session_estab) {
664 strncpy(shdr->Signature, "BSRSPYL", 8);
665 return 0;
666 }
667
668 rc = server->ops->calc_signature(rqst, server, false);
669
670 return rc;
671 }
672
673 int
smb2_verify_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server)674 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
675 {
676 unsigned int rc;
677 char server_response_sig[SMB2_SIGNATURE_SIZE];
678 struct smb2_hdr *shdr =
679 (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
680
681 if ((shdr->Command == SMB2_NEGOTIATE) ||
682 (shdr->Command == SMB2_SESSION_SETUP) ||
683 (shdr->Command == SMB2_OPLOCK_BREAK) ||
684 server->ignore_signature ||
685 (!server->session_estab))
686 return 0;
687
688 /*
689 * BB what if signatures are supposed to be on for session but
690 * server does not send one? BB
691 */
692
693 /* Do not need to verify session setups with signature "BSRSPYL " */
694 if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0)
695 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
696 shdr->Command);
697
698 /*
699 * Save off the origiginal signature so we can modify the smb and check
700 * our calculated signature against what the server sent.
701 */
702 memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE);
703
704 memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE);
705
706 rc = server->ops->calc_signature(rqst, server, true);
707
708 if (rc)
709 return rc;
710
711 if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE)) {
712 cifs_dbg(VFS, "sign fail cmd 0x%x message id 0x%llx\n",
713 shdr->Command, shdr->MessageId);
714 return -EACCES;
715 } else
716 return 0;
717 }
718
719 /*
720 * Set message id for the request. Should be called after wait_for_free_request
721 * and when srv_mutex is held.
722 */
723 static inline void
smb2_seq_num_into_buf(struct TCP_Server_Info * server,struct smb2_hdr * shdr)724 smb2_seq_num_into_buf(struct TCP_Server_Info *server,
725 struct smb2_hdr *shdr)
726 {
727 unsigned int i, num = le16_to_cpu(shdr->CreditCharge);
728
729 shdr->MessageId = get_next_mid64(server);
730 /* skip message numbers according to CreditCharge field */
731 for (i = 1; i < num; i++)
732 get_next_mid(server);
733 }
734
735 static struct mid_q_entry *
smb2_mid_entry_alloc(const struct smb2_hdr * shdr,struct TCP_Server_Info * server)736 smb2_mid_entry_alloc(const struct smb2_hdr *shdr,
737 struct TCP_Server_Info *server)
738 {
739 struct mid_q_entry *temp;
740 unsigned int credits = le16_to_cpu(shdr->CreditCharge);
741
742 if (server == NULL) {
743 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
744 return NULL;
745 }
746
747 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
748 memset(temp, 0, sizeof(struct mid_q_entry));
749 kref_init(&temp->refcount);
750 temp->mid = le64_to_cpu(shdr->MessageId);
751 temp->credits = credits > 0 ? credits : 1;
752 temp->pid = current->pid;
753 temp->command = shdr->Command; /* Always LE */
754 temp->when_alloc = jiffies;
755 temp->server = server;
756
757 /*
758 * The default is for the mid to be synchronous, so the
759 * default callback just wakes up the current task.
760 */
761 get_task_struct(current);
762 temp->creator = current;
763 temp->callback = cifs_wake_up_task;
764 temp->callback_data = current;
765
766 atomic_inc(&mid_count);
767 temp->mid_state = MID_REQUEST_ALLOCATED;
768 trace_smb3_cmd_enter(le32_to_cpu(shdr->Id.SyncId.TreeId),
769 le64_to_cpu(shdr->SessionId),
770 le16_to_cpu(shdr->Command), temp->mid);
771 return temp;
772 }
773
774 static int
smb2_get_mid_entry(struct cifs_ses * ses,struct TCP_Server_Info * server,struct smb2_hdr * shdr,struct mid_q_entry ** mid)775 smb2_get_mid_entry(struct cifs_ses *ses, struct TCP_Server_Info *server,
776 struct smb2_hdr *shdr, struct mid_q_entry **mid)
777 {
778 spin_lock(&server->srv_lock);
779 if (server->tcpStatus == CifsExiting) {
780 spin_unlock(&server->srv_lock);
781 return -ENOENT;
782 }
783
784 if (server->tcpStatus == CifsNeedReconnect) {
785 spin_unlock(&server->srv_lock);
786 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
787 return -EAGAIN;
788 }
789
790 if (server->tcpStatus == CifsNeedNegotiate &&
791 shdr->Command != SMB2_NEGOTIATE) {
792 spin_unlock(&server->srv_lock);
793 return -EAGAIN;
794 }
795 spin_unlock(&server->srv_lock);
796
797 spin_lock(&ses->ses_lock);
798 if (ses->ses_status == SES_NEW) {
799 if ((shdr->Command != SMB2_SESSION_SETUP) &&
800 (shdr->Command != SMB2_NEGOTIATE)) {
801 spin_unlock(&ses->ses_lock);
802 return -EAGAIN;
803 }
804 /* else ok - we are setting up session */
805 }
806
807 if (ses->ses_status == SES_EXITING) {
808 if (shdr->Command != SMB2_LOGOFF) {
809 spin_unlock(&ses->ses_lock);
810 return -EAGAIN;
811 }
812 /* else ok - we are shutting down the session */
813 }
814 spin_unlock(&ses->ses_lock);
815
816 *mid = smb2_mid_entry_alloc(shdr, server);
817 if (*mid == NULL)
818 return -ENOMEM;
819 spin_lock(&server->mid_lock);
820 list_add_tail(&(*mid)->qhead, &server->pending_mid_q);
821 spin_unlock(&server->mid_lock);
822
823 return 0;
824 }
825
826 int
smb2_check_receive(struct mid_q_entry * mid,struct TCP_Server_Info * server,bool log_error)827 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
828 bool log_error)
829 {
830 unsigned int len = mid->resp_buf_size;
831 struct kvec iov[1];
832 struct smb_rqst rqst = { .rq_iov = iov,
833 .rq_nvec = 1 };
834
835 iov[0].iov_base = (char *)mid->resp_buf;
836 iov[0].iov_len = len;
837
838 dump_smb(mid->resp_buf, min_t(u32, 80, len));
839 /* convert the length into a more usable form */
840 if (len > 24 && server->sign && !mid->decrypted) {
841 int rc;
842
843 rc = smb2_verify_signature(&rqst, server);
844 if (rc)
845 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
846 rc);
847 }
848
849 return map_smb2_to_linux_error(mid->resp_buf, log_error);
850 }
851
852 struct mid_q_entry *
smb2_setup_request(struct cifs_ses * ses,struct TCP_Server_Info * server,struct smb_rqst * rqst)853 smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server,
854 struct smb_rqst *rqst)
855 {
856 int rc;
857 struct smb2_hdr *shdr =
858 (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
859 struct mid_q_entry *mid;
860
861 smb2_seq_num_into_buf(server, shdr);
862
863 rc = smb2_get_mid_entry(ses, server, shdr, &mid);
864 if (rc) {
865 revert_current_mid_from_hdr(server, shdr);
866 return ERR_PTR(rc);
867 }
868
869 rc = smb2_sign_rqst(rqst, server);
870 if (rc) {
871 revert_current_mid_from_hdr(server, shdr);
872 delete_mid(mid);
873 return ERR_PTR(rc);
874 }
875
876 return mid;
877 }
878
879 struct mid_q_entry *
smb2_setup_async_request(struct TCP_Server_Info * server,struct smb_rqst * rqst)880 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
881 {
882 int rc;
883 struct smb2_hdr *shdr =
884 (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
885 struct mid_q_entry *mid;
886
887 spin_lock(&server->srv_lock);
888 if (server->tcpStatus == CifsNeedNegotiate &&
889 shdr->Command != SMB2_NEGOTIATE) {
890 spin_unlock(&server->srv_lock);
891 return ERR_PTR(-EAGAIN);
892 }
893 spin_unlock(&server->srv_lock);
894
895 smb2_seq_num_into_buf(server, shdr);
896
897 mid = smb2_mid_entry_alloc(shdr, server);
898 if (mid == NULL) {
899 revert_current_mid_from_hdr(server, shdr);
900 return ERR_PTR(-ENOMEM);
901 }
902
903 rc = smb2_sign_rqst(rqst, server);
904 if (rc) {
905 revert_current_mid_from_hdr(server, shdr);
906 release_mid(mid);
907 return ERR_PTR(rc);
908 }
909
910 return mid;
911 }
912
913 int
smb3_crypto_aead_allocate(struct TCP_Server_Info * server)914 smb3_crypto_aead_allocate(struct TCP_Server_Info *server)
915 {
916 struct crypto_aead *tfm;
917
918 if (!server->secmech.enc) {
919 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
920 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
921 tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
922 else
923 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
924 if (IS_ERR(tfm)) {
925 cifs_server_dbg(VFS, "%s: Failed alloc encrypt aead\n",
926 __func__);
927 return PTR_ERR(tfm);
928 }
929 server->secmech.enc = tfm;
930 }
931
932 if (!server->secmech.dec) {
933 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
934 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
935 tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
936 else
937 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
938 if (IS_ERR(tfm)) {
939 crypto_free_aead(server->secmech.enc);
940 server->secmech.enc = NULL;
941 cifs_server_dbg(VFS, "%s: Failed to alloc decrypt aead\n",
942 __func__);
943 return PTR_ERR(tfm);
944 }
945 server->secmech.dec = tfm;
946 }
947
948 return 0;
949 }
950