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)",
36 &p->hmacsha256,
37 &p->sdeschmacsha256);
38 if (rc)
39 goto err;
40
41 rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
42 if (rc)
43 goto err;
44
45 return 0;
46 err:
47 cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
48 return rc;
49 }
50
51 int
smb311_crypto_shash_allocate(struct TCP_Server_Info * server)52 smb311_crypto_shash_allocate(struct TCP_Server_Info *server)
53 {
54 struct cifs_secmech *p = &server->secmech;
55 int rc = 0;
56
57 rc = cifs_alloc_hash("hmac(sha256)",
58 &p->hmacsha256,
59 &p->sdeschmacsha256);
60 if (rc)
61 return rc;
62
63 rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
64 if (rc)
65 goto err;
66
67 rc = cifs_alloc_hash("sha512", &p->sha512, &p->sdescsha512);
68 if (rc)
69 goto err;
70
71 return 0;
72
73 err:
74 cifs_free_hash(&p->cmacaes, &p->sdesccmacaes);
75 cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
76 return rc;
77 }
78
79
80 static
smb2_get_sign_key(__u64 ses_id,struct TCP_Server_Info * server,u8 * key)81 int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
82 {
83 struct cifs_chan *chan;
84 struct cifs_ses *ses = NULL;
85 struct TCP_Server_Info *it = NULL;
86 int i;
87 int rc = 0;
88
89 spin_lock(&cifs_tcp_ses_lock);
90
91 list_for_each_entry(it, &cifs_tcp_ses_list, tcp_ses_list) {
92 list_for_each_entry(ses, &it->smb_ses_list, smb_ses_list) {
93 if (ses->Suid == ses_id)
94 goto found;
95 }
96 }
97 cifs_server_dbg(VFS, "%s: Could not find session 0x%llx\n",
98 __func__, ses_id);
99 rc = -ENOENT;
100 goto out;
101
102 found:
103 spin_lock(&ses->chan_lock);
104 if (cifs_chan_needs_reconnect(ses, server) &&
105 !CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
106 /*
107 * If we are in the process of binding a new channel
108 * to an existing session, use the master connection
109 * session key
110 */
111 memcpy(key, ses->smb3signingkey, SMB3_SIGN_KEY_SIZE);
112 spin_unlock(&ses->chan_lock);
113 goto out;
114 }
115
116 /*
117 * Otherwise, use the channel key.
118 */
119
120 for (i = 0; i < ses->chan_count; i++) {
121 chan = ses->chans + i;
122 if (chan->server == server) {
123 memcpy(key, chan->signkey, SMB3_SIGN_KEY_SIZE);
124 spin_unlock(&ses->chan_lock);
125 goto out;
126 }
127 }
128 spin_unlock(&ses->chan_lock);
129
130 cifs_dbg(VFS,
131 "%s: Could not find channel signing key for session 0x%llx\n",
132 __func__, ses_id);
133 rc = -ENOENT;
134
135 out:
136 spin_unlock(&cifs_tcp_ses_lock);
137 return rc;
138 }
139
140 static struct cifs_ses *
smb2_find_smb_ses_unlocked(struct TCP_Server_Info * server,__u64 ses_id)141 smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id)
142 {
143 struct cifs_ses *ses;
144
145 list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
146 if (ses->Suid != ses_id)
147 continue;
148 ++ses->ses_count;
149 return ses;
150 }
151
152 return NULL;
153 }
154
155 struct cifs_ses *
smb2_find_smb_ses(struct TCP_Server_Info * server,__u64 ses_id)156 smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id)
157 {
158 struct cifs_ses *ses;
159
160 spin_lock(&cifs_tcp_ses_lock);
161 ses = smb2_find_smb_ses_unlocked(server, ses_id);
162 spin_unlock(&cifs_tcp_ses_lock);
163
164 return ses;
165 }
166
167 static struct cifs_tcon *
smb2_find_smb_sess_tcon_unlocked(struct cifs_ses * ses,__u32 tid)168 smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32 tid)
169 {
170 struct cifs_tcon *tcon;
171
172 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
173 if (tcon->tid != tid)
174 continue;
175 ++tcon->tc_count;
176 return tcon;
177 }
178
179 return NULL;
180 }
181
182 /*
183 * Obtain tcon corresponding to the tid in the given
184 * cifs_ses
185 */
186
187 struct cifs_tcon *
smb2_find_smb_tcon(struct TCP_Server_Info * server,__u64 ses_id,__u32 tid)188 smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32 tid)
189 {
190 struct cifs_ses *ses;
191 struct cifs_tcon *tcon;
192
193 spin_lock(&cifs_tcp_ses_lock);
194 ses = smb2_find_smb_ses_unlocked(server, ses_id);
195 if (!ses) {
196 spin_unlock(&cifs_tcp_ses_lock);
197 return NULL;
198 }
199 tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid);
200 if (!tcon) {
201 cifs_put_smb_ses(ses);
202 spin_unlock(&cifs_tcp_ses_lock);
203 return NULL;
204 }
205 spin_unlock(&cifs_tcp_ses_lock);
206 /* tcon already has a ref to ses, so we don't need ses anymore */
207 cifs_put_smb_ses(ses);
208
209 return tcon;
210 }
211
212 int
smb2_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,bool allocate_crypto)213 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
214 bool allocate_crypto)
215 {
216 int rc;
217 unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
218 unsigned char *sigptr = smb2_signature;
219 struct kvec *iov = rqst->rq_iov;
220 struct smb2_hdr *shdr = (struct smb2_hdr *)iov[0].iov_base;
221 struct cifs_ses *ses;
222 struct shash_desc *shash;
223 struct crypto_shash *hash;
224 struct sdesc *sdesc = NULL;
225 struct smb_rqst drqst;
226
227 ses = smb2_find_smb_ses(server, le64_to_cpu(shdr->SessionId));
228 if (!ses) {
229 cifs_server_dbg(VFS, "%s: Could not find session\n", __func__);
230 return 0;
231 }
232
233 memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
234 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
235
236 if (allocate_crypto) {
237 rc = cifs_alloc_hash("hmac(sha256)", &hash, &sdesc);
238 if (rc) {
239 cifs_server_dbg(VFS,
240 "%s: sha256 alloc failed\n", __func__);
241 goto out;
242 }
243 shash = &sdesc->shash;
244 } else {
245 hash = server->secmech.hmacsha256;
246 shash = &server->secmech.sdeschmacsha256->shash;
247 }
248
249 rc = crypto_shash_setkey(hash, ses->auth_key.response,
250 SMB2_NTLMV2_SESSKEY_SIZE);
251 if (rc) {
252 cifs_server_dbg(VFS,
253 "%s: Could not update with response\n",
254 __func__);
255 goto out;
256 }
257
258 rc = crypto_shash_init(shash);
259 if (rc) {
260 cifs_server_dbg(VFS, "%s: Could not init sha256", __func__);
261 goto out;
262 }
263
264 /*
265 * For SMB2+, __cifs_calc_signature() expects to sign only the actual
266 * data, that is, iov[0] should not contain a rfc1002 length.
267 *
268 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
269 * __cifs_calc_signature().
270 */
271 drqst = *rqst;
272 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
273 rc = crypto_shash_update(shash, iov[0].iov_base,
274 iov[0].iov_len);
275 if (rc) {
276 cifs_server_dbg(VFS,
277 "%s: Could not update with payload\n",
278 __func__);
279 goto out;
280 }
281 drqst.rq_iov++;
282 drqst.rq_nvec--;
283 }
284
285 rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
286 if (!rc)
287 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
288
289 out:
290 if (allocate_crypto)
291 cifs_free_hash(&hash, &sdesc);
292 if (ses)
293 cifs_put_smb_ses(ses);
294 return rc;
295 }
296
generate_key(struct cifs_ses * ses,struct kvec label,struct kvec context,__u8 * key,unsigned int key_size)297 static int generate_key(struct cifs_ses *ses, struct kvec label,
298 struct kvec context, __u8 *key, unsigned int key_size)
299 {
300 unsigned char zero = 0x0;
301 __u8 i[4] = {0, 0, 0, 1};
302 __u8 L128[4] = {0, 0, 0, 128};
303 __u8 L256[4] = {0, 0, 1, 0};
304 int rc = 0;
305 unsigned char prfhash[SMB2_HMACSHA256_SIZE];
306 unsigned char *hashptr = prfhash;
307 struct TCP_Server_Info *server = ses->server;
308
309 memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
310 memset(key, 0x0, key_size);
311
312 rc = smb3_crypto_shash_allocate(server);
313 if (rc) {
314 cifs_server_dbg(VFS, "%s: crypto alloc failed\n", __func__);
315 goto smb3signkey_ret;
316 }
317
318 rc = crypto_shash_setkey(server->secmech.hmacsha256,
319 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
320 if (rc) {
321 cifs_server_dbg(VFS, "%s: Could not set with session key\n", __func__);
322 goto smb3signkey_ret;
323 }
324
325 rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
326 if (rc) {
327 cifs_server_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
328 goto smb3signkey_ret;
329 }
330
331 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
332 i, 4);
333 if (rc) {
334 cifs_server_dbg(VFS, "%s: Could not update with n\n", __func__);
335 goto smb3signkey_ret;
336 }
337
338 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
339 label.iov_base, label.iov_len);
340 if (rc) {
341 cifs_server_dbg(VFS, "%s: Could not update with label\n", __func__);
342 goto smb3signkey_ret;
343 }
344
345 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
346 &zero, 1);
347 if (rc) {
348 cifs_server_dbg(VFS, "%s: Could not update with zero\n", __func__);
349 goto smb3signkey_ret;
350 }
351
352 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
353 context.iov_base, context.iov_len);
354 if (rc) {
355 cifs_server_dbg(VFS, "%s: Could not update with context\n", __func__);
356 goto smb3signkey_ret;
357 }
358
359 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
360 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
361 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
362 L256, 4);
363 } else {
364 rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
365 L128, 4);
366 }
367 if (rc) {
368 cifs_server_dbg(VFS, "%s: Could not update with L\n", __func__);
369 goto smb3signkey_ret;
370 }
371
372 rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
373 hashptr);
374 if (rc) {
375 cifs_server_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
376 goto smb3signkey_ret;
377 }
378
379 memcpy(key, hashptr, key_size);
380
381 smb3signkey_ret:
382 return rc;
383 }
384
385 struct derivation {
386 struct kvec label;
387 struct kvec context;
388 };
389
390 struct derivation_triplet {
391 struct derivation signing;
392 struct derivation encryption;
393 struct derivation decryption;
394 };
395
396 static int
generate_smb3signingkey(struct cifs_ses * ses,struct TCP_Server_Info * server,const struct derivation_triplet * ptriplet)397 generate_smb3signingkey(struct cifs_ses *ses,
398 struct TCP_Server_Info *server,
399 const struct derivation_triplet *ptriplet)
400 {
401 int rc;
402 bool is_binding = false;
403 int chan_index = 0;
404
405 spin_lock(&ses->chan_lock);
406 is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
407 chan_index = cifs_ses_get_chan_index(ses, server);
408 /* TODO: introduce ref counting for channels when the can be freed */
409 spin_unlock(&ses->chan_lock);
410
411 /*
412 * All channels use the same encryption/decryption keys but
413 * they have their own signing key.
414 *
415 * When we generate the keys, check if it is for a new channel
416 * (binding) in which case we only need to generate a signing
417 * key and store it in the channel as to not overwrite the
418 * master connection signing key stored in the session
419 */
420
421 if (is_binding) {
422 rc = generate_key(ses, ptriplet->signing.label,
423 ptriplet->signing.context,
424 ses->chans[chan_index].signkey,
425 SMB3_SIGN_KEY_SIZE);
426 if (rc)
427 return rc;
428 } else {
429 rc = generate_key(ses, ptriplet->signing.label,
430 ptriplet->signing.context,
431 ses->smb3signingkey,
432 SMB3_SIGN_KEY_SIZE);
433 if (rc)
434 return rc;
435
436 /* safe to access primary channel, since it will never go away */
437 spin_lock(&ses->chan_lock);
438 memcpy(ses->chans[0].signkey, ses->smb3signingkey,
439 SMB3_SIGN_KEY_SIZE);
440 spin_unlock(&ses->chan_lock);
441
442 rc = generate_key(ses, ptriplet->encryption.label,
443 ptriplet->encryption.context,
444 ses->smb3encryptionkey,
445 SMB3_ENC_DEC_KEY_SIZE);
446 rc = generate_key(ses, ptriplet->decryption.label,
447 ptriplet->decryption.context,
448 ses->smb3decryptionkey,
449 SMB3_ENC_DEC_KEY_SIZE);
450 if (rc)
451 return rc;
452 }
453
454 if (rc)
455 return rc;
456
457 #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
458 cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__);
459 /*
460 * The session id is opaque in terms of endianness, so we can't
461 * print it as a long long. we dump it as we got it on the wire
462 */
463 cifs_dbg(VFS, "Session Id %*ph\n", (int)sizeof(ses->Suid),
464 &ses->Suid);
465 cifs_dbg(VFS, "Cipher type %d\n", server->cipher_type);
466 cifs_dbg(VFS, "Session Key %*ph\n",
467 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response);
468 cifs_dbg(VFS, "Signing Key %*ph\n",
469 SMB3_SIGN_KEY_SIZE, ses->smb3signingkey);
470 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
471 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
472 cifs_dbg(VFS, "ServerIn Key %*ph\n",
473 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3encryptionkey);
474 cifs_dbg(VFS, "ServerOut Key %*ph\n",
475 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3decryptionkey);
476 } else {
477 cifs_dbg(VFS, "ServerIn Key %*ph\n",
478 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3encryptionkey);
479 cifs_dbg(VFS, "ServerOut Key %*ph\n",
480 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3decryptionkey);
481 }
482 #endif
483 return rc;
484 }
485
486 int
generate_smb30signingkey(struct cifs_ses * ses,struct TCP_Server_Info * server)487 generate_smb30signingkey(struct cifs_ses *ses,
488 struct TCP_Server_Info *server)
489
490 {
491 struct derivation_triplet triplet;
492 struct derivation *d;
493
494 d = &triplet.signing;
495 d->label.iov_base = "SMB2AESCMAC";
496 d->label.iov_len = 12;
497 d->context.iov_base = "SmbSign";
498 d->context.iov_len = 8;
499
500 d = &triplet.encryption;
501 d->label.iov_base = "SMB2AESCCM";
502 d->label.iov_len = 11;
503 d->context.iov_base = "ServerIn ";
504 d->context.iov_len = 10;
505
506 d = &triplet.decryption;
507 d->label.iov_base = "SMB2AESCCM";
508 d->label.iov_len = 11;
509 d->context.iov_base = "ServerOut";
510 d->context.iov_len = 10;
511
512 return generate_smb3signingkey(ses, server, &triplet);
513 }
514
515 int
generate_smb311signingkey(struct cifs_ses * ses,struct TCP_Server_Info * server)516 generate_smb311signingkey(struct cifs_ses *ses,
517 struct TCP_Server_Info *server)
518
519 {
520 struct derivation_triplet triplet;
521 struct derivation *d;
522
523 d = &triplet.signing;
524 d->label.iov_base = "SMBSigningKey";
525 d->label.iov_len = 14;
526 d->context.iov_base = ses->preauth_sha_hash;
527 d->context.iov_len = 64;
528
529 d = &triplet.encryption;
530 d->label.iov_base = "SMBC2SCipherKey";
531 d->label.iov_len = 16;
532 d->context.iov_base = ses->preauth_sha_hash;
533 d->context.iov_len = 64;
534
535 d = &triplet.decryption;
536 d->label.iov_base = "SMBS2CCipherKey";
537 d->label.iov_len = 16;
538 d->context.iov_base = ses->preauth_sha_hash;
539 d->context.iov_len = 64;
540
541 return generate_smb3signingkey(ses, server, &triplet);
542 }
543
544 int
smb3_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,bool allocate_crypto)545 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
546 bool allocate_crypto)
547 {
548 int rc;
549 unsigned char smb3_signature[SMB2_CMACAES_SIZE];
550 unsigned char *sigptr = smb3_signature;
551 struct kvec *iov = rqst->rq_iov;
552 struct smb2_hdr *shdr = (struct smb2_hdr *)iov[0].iov_base;
553 struct shash_desc *shash;
554 struct crypto_shash *hash;
555 struct sdesc *sdesc = NULL;
556 struct smb_rqst drqst;
557 u8 key[SMB3_SIGN_KEY_SIZE];
558
559 rc = smb2_get_sign_key(le64_to_cpu(shdr->SessionId), server, key);
560 if (rc)
561 return 0;
562
563 if (allocate_crypto) {
564 rc = cifs_alloc_hash("cmac(aes)", &hash, &sdesc);
565 if (rc)
566 return rc;
567
568 shash = &sdesc->shash;
569 } else {
570 hash = server->secmech.cmacaes;
571 shash = &server->secmech.sdesccmacaes->shash;
572 }
573
574 memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
575 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
576
577 rc = crypto_shash_setkey(hash, key, SMB2_CMACAES_SIZE);
578 if (rc) {
579 cifs_server_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
580 goto out;
581 }
582
583 /*
584 * we already allocate sdesccmacaes when we init smb3 signing key,
585 * so unlike smb2 case we do not have to check here if secmech are
586 * initialized
587 */
588 rc = crypto_shash_init(shash);
589 if (rc) {
590 cifs_server_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
591 goto out;
592 }
593
594 /*
595 * For SMB2+, __cifs_calc_signature() expects to sign only the actual
596 * data, that is, iov[0] should not contain a rfc1002 length.
597 *
598 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
599 * __cifs_calc_signature().
600 */
601 drqst = *rqst;
602 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
603 rc = crypto_shash_update(shash, iov[0].iov_base,
604 iov[0].iov_len);
605 if (rc) {
606 cifs_server_dbg(VFS, "%s: Could not update with payload\n",
607 __func__);
608 goto out;
609 }
610 drqst.rq_iov++;
611 drqst.rq_nvec--;
612 }
613
614 rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
615 if (!rc)
616 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
617
618 out:
619 if (allocate_crypto)
620 cifs_free_hash(&hash, &sdesc);
621 return rc;
622 }
623
624 /* must be called with server->srv_mutex held */
625 static int
smb2_sign_rqst(struct smb_rqst * rqst,struct TCP_Server_Info * server)626 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
627 {
628 int rc = 0;
629 struct smb2_hdr *shdr;
630 struct smb2_sess_setup_req *ssr;
631 bool is_binding;
632 bool is_signed;
633
634 shdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
635 ssr = (struct smb2_sess_setup_req *)shdr;
636
637 is_binding = shdr->Command == SMB2_SESSION_SETUP &&
638 (ssr->Flags & SMB2_SESSION_REQ_FLAG_BINDING);
639 is_signed = shdr->Flags & SMB2_FLAGS_SIGNED;
640
641 if (!is_signed)
642 return 0;
643 spin_lock(&cifs_tcp_ses_lock);
644 if (server->ops->need_neg &&
645 server->ops->need_neg(server)) {
646 spin_unlock(&cifs_tcp_ses_lock);
647 return 0;
648 }
649 spin_unlock(&cifs_tcp_ses_lock);
650 if (!is_binding && !server->session_estab) {
651 strncpy(shdr->Signature, "BSRSPYL", 8);
652 return 0;
653 }
654
655 rc = server->ops->calc_signature(rqst, server, false);
656
657 return rc;
658 }
659
660 int
smb2_verify_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server)661 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
662 {
663 unsigned int rc;
664 char server_response_sig[SMB2_SIGNATURE_SIZE];
665 struct smb2_hdr *shdr =
666 (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
667
668 if ((shdr->Command == SMB2_NEGOTIATE) ||
669 (shdr->Command == SMB2_SESSION_SETUP) ||
670 (shdr->Command == SMB2_OPLOCK_BREAK) ||
671 server->ignore_signature ||
672 (!server->session_estab))
673 return 0;
674
675 /*
676 * BB what if signatures are supposed to be on for session but
677 * server does not send one? BB
678 */
679
680 /* Do not need to verify session setups with signature "BSRSPYL " */
681 if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0)
682 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
683 shdr->Command);
684
685 /*
686 * Save off the origiginal signature so we can modify the smb and check
687 * our calculated signature against what the server sent.
688 */
689 memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE);
690
691 memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE);
692
693 rc = server->ops->calc_signature(rqst, server, true);
694
695 if (rc)
696 return rc;
697
698 if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE)) {
699 cifs_dbg(VFS, "sign fail cmd 0x%x message id 0x%llx\n",
700 shdr->Command, shdr->MessageId);
701 return -EACCES;
702 } else
703 return 0;
704 }
705
706 /*
707 * Set message id for the request. Should be called after wait_for_free_request
708 * and when srv_mutex is held.
709 */
710 static inline void
smb2_seq_num_into_buf(struct TCP_Server_Info * server,struct smb2_hdr * shdr)711 smb2_seq_num_into_buf(struct TCP_Server_Info *server,
712 struct smb2_hdr *shdr)
713 {
714 unsigned int i, num = le16_to_cpu(shdr->CreditCharge);
715
716 shdr->MessageId = get_next_mid64(server);
717 /* skip message numbers according to CreditCharge field */
718 for (i = 1; i < num; i++)
719 get_next_mid(server);
720 }
721
722 static struct mid_q_entry *
smb2_mid_entry_alloc(const struct smb2_hdr * shdr,struct TCP_Server_Info * server)723 smb2_mid_entry_alloc(const struct smb2_hdr *shdr,
724 struct TCP_Server_Info *server)
725 {
726 struct mid_q_entry *temp;
727 unsigned int credits = le16_to_cpu(shdr->CreditCharge);
728
729 if (server == NULL) {
730 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
731 return NULL;
732 }
733
734 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
735 memset(temp, 0, sizeof(struct mid_q_entry));
736 kref_init(&temp->refcount);
737 temp->mid = le64_to_cpu(shdr->MessageId);
738 temp->credits = credits > 0 ? credits : 1;
739 temp->pid = current->pid;
740 temp->command = shdr->Command; /* Always LE */
741 temp->when_alloc = jiffies;
742 temp->server = server;
743
744 /*
745 * The default is for the mid to be synchronous, so the
746 * default callback just wakes up the current task.
747 */
748 get_task_struct(current);
749 temp->creator = current;
750 temp->callback = cifs_wake_up_task;
751 temp->callback_data = current;
752
753 atomic_inc(&midCount);
754 temp->mid_state = MID_REQUEST_ALLOCATED;
755 trace_smb3_cmd_enter(le32_to_cpu(shdr->Id.SyncId.TreeId),
756 le64_to_cpu(shdr->SessionId),
757 le16_to_cpu(shdr->Command), temp->mid);
758 return temp;
759 }
760
761 static int
smb2_get_mid_entry(struct cifs_ses * ses,struct TCP_Server_Info * server,struct smb2_hdr * shdr,struct mid_q_entry ** mid)762 smb2_get_mid_entry(struct cifs_ses *ses, struct TCP_Server_Info *server,
763 struct smb2_hdr *shdr, struct mid_q_entry **mid)
764 {
765 spin_lock(&cifs_tcp_ses_lock);
766 if (server->tcpStatus == CifsExiting) {
767 spin_unlock(&cifs_tcp_ses_lock);
768 return -ENOENT;
769 }
770
771 if (server->tcpStatus == CifsNeedReconnect) {
772 spin_unlock(&cifs_tcp_ses_lock);
773 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
774 return -EAGAIN;
775 }
776
777 if (server->tcpStatus == CifsNeedNegotiate &&
778 shdr->Command != SMB2_NEGOTIATE) {
779 spin_unlock(&cifs_tcp_ses_lock);
780 return -EAGAIN;
781 }
782
783 if (ses->ses_status == SES_NEW) {
784 if ((shdr->Command != SMB2_SESSION_SETUP) &&
785 (shdr->Command != SMB2_NEGOTIATE)) {
786 spin_unlock(&cifs_tcp_ses_lock);
787 return -EAGAIN;
788 }
789 /* else ok - we are setting up session */
790 }
791
792 if (ses->ses_status == SES_EXITING) {
793 if (shdr->Command != SMB2_LOGOFF) {
794 spin_unlock(&cifs_tcp_ses_lock);
795 return -EAGAIN;
796 }
797 /* else ok - we are shutting down the session */
798 }
799 spin_unlock(&cifs_tcp_ses_lock);
800
801 *mid = smb2_mid_entry_alloc(shdr, server);
802 if (*mid == NULL)
803 return -ENOMEM;
804 spin_lock(&GlobalMid_Lock);
805 list_add_tail(&(*mid)->qhead, &server->pending_mid_q);
806 spin_unlock(&GlobalMid_Lock);
807
808 return 0;
809 }
810
811 int
smb2_check_receive(struct mid_q_entry * mid,struct TCP_Server_Info * server,bool log_error)812 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
813 bool log_error)
814 {
815 unsigned int len = mid->resp_buf_size;
816 struct kvec iov[1];
817 struct smb_rqst rqst = { .rq_iov = iov,
818 .rq_nvec = 1 };
819
820 iov[0].iov_base = (char *)mid->resp_buf;
821 iov[0].iov_len = len;
822
823 dump_smb(mid->resp_buf, min_t(u32, 80, len));
824 /* convert the length into a more usable form */
825 if (len > 24 && server->sign && !mid->decrypted) {
826 int rc;
827
828 rc = smb2_verify_signature(&rqst, server);
829 if (rc)
830 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
831 rc);
832 }
833
834 return map_smb2_to_linux_error(mid->resp_buf, log_error);
835 }
836
837 struct mid_q_entry *
smb2_setup_request(struct cifs_ses * ses,struct TCP_Server_Info * server,struct smb_rqst * rqst)838 smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server,
839 struct smb_rqst *rqst)
840 {
841 int rc;
842 struct smb2_hdr *shdr =
843 (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
844 struct mid_q_entry *mid;
845
846 smb2_seq_num_into_buf(server, shdr);
847
848 rc = smb2_get_mid_entry(ses, server, shdr, &mid);
849 if (rc) {
850 revert_current_mid_from_hdr(server, shdr);
851 return ERR_PTR(rc);
852 }
853
854 rc = smb2_sign_rqst(rqst, server);
855 if (rc) {
856 revert_current_mid_from_hdr(server, shdr);
857 cifs_delete_mid(mid);
858 return ERR_PTR(rc);
859 }
860
861 return mid;
862 }
863
864 struct mid_q_entry *
smb2_setup_async_request(struct TCP_Server_Info * server,struct smb_rqst * rqst)865 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
866 {
867 int rc;
868 struct smb2_hdr *shdr =
869 (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
870 struct mid_q_entry *mid;
871
872 spin_lock(&cifs_tcp_ses_lock);
873 if (server->tcpStatus == CifsNeedNegotiate &&
874 shdr->Command != SMB2_NEGOTIATE) {
875 spin_unlock(&cifs_tcp_ses_lock);
876 return ERR_PTR(-EAGAIN);
877 }
878 spin_unlock(&cifs_tcp_ses_lock);
879
880 smb2_seq_num_into_buf(server, shdr);
881
882 mid = smb2_mid_entry_alloc(shdr, server);
883 if (mid == NULL) {
884 revert_current_mid_from_hdr(server, shdr);
885 return ERR_PTR(-ENOMEM);
886 }
887
888 rc = smb2_sign_rqst(rqst, server);
889 if (rc) {
890 revert_current_mid_from_hdr(server, shdr);
891 DeleteMidQEntry(mid);
892 return ERR_PTR(rc);
893 }
894
895 return mid;
896 }
897
898 int
smb3_crypto_aead_allocate(struct TCP_Server_Info * server)899 smb3_crypto_aead_allocate(struct TCP_Server_Info *server)
900 {
901 struct crypto_aead *tfm;
902
903 if (!server->secmech.ccmaesencrypt) {
904 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
905 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
906 tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
907 else
908 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
909 if (IS_ERR(tfm)) {
910 cifs_server_dbg(VFS, "%s: Failed alloc encrypt aead\n",
911 __func__);
912 return PTR_ERR(tfm);
913 }
914 server->secmech.ccmaesencrypt = tfm;
915 }
916
917 if (!server->secmech.ccmaesdecrypt) {
918 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
919 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
920 tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
921 else
922 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
923 if (IS_ERR(tfm)) {
924 crypto_free_aead(server->secmech.ccmaesencrypt);
925 server->secmech.ccmaesencrypt = NULL;
926 cifs_server_dbg(VFS, "%s: Failed to alloc decrypt aead\n",
927 __func__);
928 return PTR_ERR(tfm);
929 }
930 server->secmech.ccmaesdecrypt = tfm;
931 }
932
933 return 0;
934 }
935