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