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