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
smb3_get_sign_key(__u64 ses_id,struct TCP_Server_Info * server,u8 * key)77 int smb3_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
smb2_get_sign_key(struct TCP_Server_Info * server,__u64 ses_id,u8 * key)171 static int smb2_get_sign_key(struct TCP_Server_Info *server,
172 __u64 ses_id, u8 *key)
173 {
174 struct cifs_ses *ses;
175 int rc = -ENOENT;
176
177 if (SERVER_IS_CHAN(server))
178 server = server->primary_server;
179
180 spin_lock(&cifs_tcp_ses_lock);
181 list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
182 if (ses->Suid != ses_id)
183 continue;
184
185 rc = 0;
186 spin_lock(&ses->ses_lock);
187 switch (ses->ses_status) {
188 case SES_EXITING: /* SMB2_LOGOFF */
189 case SES_GOOD:
190 if (likely(ses->auth_key.response)) {
191 memcpy(key, ses->auth_key.response,
192 SMB2_NTLMV2_SESSKEY_SIZE);
193 } else {
194 rc = -EIO;
195 }
196 break;
197 default:
198 rc = -EAGAIN;
199 break;
200 }
201 spin_unlock(&ses->ses_lock);
202 break;
203 }
204 spin_unlock(&cifs_tcp_ses_lock);
205 return rc;
206 }
207
208 static struct cifs_tcon *
smb2_find_smb_sess_tcon_unlocked(struct cifs_ses * ses,__u32 tid)209 smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32 tid)
210 {
211 struct cifs_tcon *tcon;
212
213 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
214 if (tcon->tid != tid)
215 continue;
216 ++tcon->tc_count;
217 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
218 netfs_trace_tcon_ref_get_find_sess_tcon);
219 return tcon;
220 }
221
222 return NULL;
223 }
224
225 /*
226 * Obtain tcon corresponding to the tid in the given
227 * cifs_ses
228 */
229
230 struct cifs_tcon *
smb2_find_smb_tcon(struct TCP_Server_Info * server,__u64 ses_id,__u32 tid)231 smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32 tid)
232 {
233 struct cifs_ses *ses;
234 struct cifs_tcon *tcon;
235
236 spin_lock(&cifs_tcp_ses_lock);
237 ses = smb2_find_smb_ses_unlocked(server, ses_id);
238 if (!ses) {
239 spin_unlock(&cifs_tcp_ses_lock);
240 return NULL;
241 }
242 tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid);
243 if (!tcon) {
244 spin_unlock(&cifs_tcp_ses_lock);
245 cifs_put_smb_ses(ses);
246 return NULL;
247 }
248 spin_unlock(&cifs_tcp_ses_lock);
249 /* tcon already has a ref to ses, so we don't need ses anymore */
250 cifs_put_smb_ses(ses);
251
252 return tcon;
253 }
254
255 int
smb2_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,bool allocate_crypto)256 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
257 bool allocate_crypto)
258 {
259 int rc;
260 unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
261 unsigned char *sigptr = smb2_signature;
262 struct kvec *iov = rqst->rq_iov;
263 struct smb2_hdr *shdr = (struct smb2_hdr *)iov[0].iov_base;
264 struct shash_desc *shash = NULL;
265 struct smb_rqst drqst;
266 __u64 sid = le64_to_cpu(shdr->SessionId);
267 u8 key[SMB2_NTLMV2_SESSKEY_SIZE];
268
269 rc = smb2_get_sign_key(server, sid, key);
270 if (unlikely(rc)) {
271 cifs_server_dbg(FYI, "%s: [sesid=0x%llx] couldn't find signing key: %d\n",
272 __func__, sid, rc);
273 return rc;
274 }
275
276 memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
277 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
278
279 if (allocate_crypto) {
280 rc = cifs_alloc_hash("hmac(sha256)", &shash);
281 if (rc) {
282 cifs_server_dbg(VFS,
283 "%s: sha256 alloc failed\n", __func__);
284 goto out;
285 }
286 } else {
287 shash = server->secmech.hmacsha256;
288 }
289
290 rc = crypto_shash_setkey(shash->tfm, key, sizeof(key));
291 if (rc) {
292 cifs_server_dbg(VFS,
293 "%s: Could not update with response\n",
294 __func__);
295 goto out;
296 }
297
298 rc = crypto_shash_init(shash);
299 if (rc) {
300 cifs_server_dbg(VFS, "%s: Could not init sha256", __func__);
301 goto out;
302 }
303
304 /*
305 * For SMB2+, __cifs_calc_signature() expects to sign only the actual
306 * data, that is, iov[0] should not contain a rfc1002 length.
307 *
308 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
309 * __cifs_calc_signature().
310 */
311 drqst = *rqst;
312 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
313 rc = crypto_shash_update(shash, iov[0].iov_base,
314 iov[0].iov_len);
315 if (rc) {
316 cifs_server_dbg(VFS,
317 "%s: Could not update with payload\n",
318 __func__);
319 goto out;
320 }
321 drqst.rq_iov++;
322 drqst.rq_nvec--;
323 }
324
325 rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
326 if (!rc)
327 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
328
329 out:
330 if (allocate_crypto)
331 cifs_free_hash(&shash);
332 return rc;
333 }
334
generate_key(struct cifs_ses * ses,struct kvec label,struct kvec context,__u8 * key,unsigned int key_size)335 static int generate_key(struct cifs_ses *ses, struct kvec label,
336 struct kvec context, __u8 *key, unsigned int key_size)
337 {
338 unsigned char zero = 0x0;
339 __u8 i[4] = {0, 0, 0, 1};
340 __u8 L128[4] = {0, 0, 0, 128};
341 __u8 L256[4] = {0, 0, 1, 0};
342 int rc = 0;
343 unsigned char prfhash[SMB2_HMACSHA256_SIZE];
344 unsigned char *hashptr = prfhash;
345 struct TCP_Server_Info *server = ses->server;
346
347 memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
348 memset(key, 0x0, key_size);
349
350 rc = smb3_crypto_shash_allocate(server);
351 if (rc) {
352 cifs_server_dbg(VFS, "%s: crypto alloc failed\n", __func__);
353 goto smb3signkey_ret;
354 }
355
356 rc = crypto_shash_setkey(server->secmech.hmacsha256->tfm,
357 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
358 if (rc) {
359 cifs_server_dbg(VFS, "%s: Could not set with session key\n", __func__);
360 goto smb3signkey_ret;
361 }
362
363 rc = crypto_shash_init(server->secmech.hmacsha256);
364 if (rc) {
365 cifs_server_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
366 goto smb3signkey_ret;
367 }
368
369 rc = crypto_shash_update(server->secmech.hmacsha256, i, 4);
370 if (rc) {
371 cifs_server_dbg(VFS, "%s: Could not update with n\n", __func__);
372 goto smb3signkey_ret;
373 }
374
375 rc = crypto_shash_update(server->secmech.hmacsha256, label.iov_base, label.iov_len);
376 if (rc) {
377 cifs_server_dbg(VFS, "%s: Could not update with label\n", __func__);
378 goto smb3signkey_ret;
379 }
380
381 rc = crypto_shash_update(server->secmech.hmacsha256, &zero, 1);
382 if (rc) {
383 cifs_server_dbg(VFS, "%s: Could not update with zero\n", __func__);
384 goto smb3signkey_ret;
385 }
386
387 rc = crypto_shash_update(server->secmech.hmacsha256, context.iov_base, context.iov_len);
388 if (rc) {
389 cifs_server_dbg(VFS, "%s: Could not update with context\n", __func__);
390 goto smb3signkey_ret;
391 }
392
393 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
394 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
395 rc = crypto_shash_update(server->secmech.hmacsha256, L256, 4);
396 } else {
397 rc = crypto_shash_update(server->secmech.hmacsha256, L128, 4);
398 }
399 if (rc) {
400 cifs_server_dbg(VFS, "%s: Could not update with L\n", __func__);
401 goto smb3signkey_ret;
402 }
403
404 rc = crypto_shash_final(server->secmech.hmacsha256, hashptr);
405 if (rc) {
406 cifs_server_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
407 goto smb3signkey_ret;
408 }
409
410 memcpy(key, hashptr, key_size);
411
412 smb3signkey_ret:
413 return rc;
414 }
415
416 struct derivation {
417 struct kvec label;
418 struct kvec context;
419 };
420
421 struct derivation_triplet {
422 struct derivation signing;
423 struct derivation encryption;
424 struct derivation decryption;
425 };
426
427 static int
generate_smb3signingkey(struct cifs_ses * ses,struct TCP_Server_Info * server,const struct derivation_triplet * ptriplet)428 generate_smb3signingkey(struct cifs_ses *ses,
429 struct TCP_Server_Info *server,
430 const struct derivation_triplet *ptriplet)
431 {
432 int rc;
433 bool is_binding = false;
434 int chan_index = 0;
435
436 spin_lock(&ses->ses_lock);
437 spin_lock(&ses->chan_lock);
438 is_binding = (cifs_chan_needs_reconnect(ses, server) &&
439 ses->ses_status == SES_GOOD);
440
441 chan_index = cifs_ses_get_chan_index(ses, server);
442 if (chan_index == CIFS_INVAL_CHAN_INDEX) {
443 spin_unlock(&ses->chan_lock);
444 spin_unlock(&ses->ses_lock);
445
446 return -EINVAL;
447 }
448
449 spin_unlock(&ses->chan_lock);
450 spin_unlock(&ses->ses_lock);
451
452 /*
453 * All channels use the same encryption/decryption keys but
454 * they have their own signing key.
455 *
456 * When we generate the keys, check if it is for a new channel
457 * (binding) in which case we only need to generate a signing
458 * key and store it in the channel as to not overwrite the
459 * master connection signing key stored in the session
460 */
461
462 if (is_binding) {
463 rc = generate_key(ses, ptriplet->signing.label,
464 ptriplet->signing.context,
465 ses->chans[chan_index].signkey,
466 SMB3_SIGN_KEY_SIZE);
467 if (rc)
468 return rc;
469 } else {
470 rc = generate_key(ses, ptriplet->signing.label,
471 ptriplet->signing.context,
472 ses->smb3signingkey,
473 SMB3_SIGN_KEY_SIZE);
474 if (rc)
475 return rc;
476
477 /* safe to access primary channel, since it will never go away */
478 spin_lock(&ses->chan_lock);
479 memcpy(ses->chans[chan_index].signkey, ses->smb3signingkey,
480 SMB3_SIGN_KEY_SIZE);
481 spin_unlock(&ses->chan_lock);
482
483 rc = generate_key(ses, ptriplet->encryption.label,
484 ptriplet->encryption.context,
485 ses->smb3encryptionkey,
486 SMB3_ENC_DEC_KEY_SIZE);
487 if (rc)
488 return rc;
489 rc = generate_key(ses, ptriplet->decryption.label,
490 ptriplet->decryption.context,
491 ses->smb3decryptionkey,
492 SMB3_ENC_DEC_KEY_SIZE);
493 if (rc)
494 return rc;
495 }
496
497 #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
498 cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__);
499 /*
500 * The session id is opaque in terms of endianness, so we can't
501 * print it as a long long. we dump it as we got it on the wire
502 */
503 cifs_dbg(VFS, "Session Id %*ph\n", (int)sizeof(ses->Suid),
504 &ses->Suid);
505 cifs_dbg(VFS, "Cipher type %d\n", server->cipher_type);
506 cifs_dbg(VFS, "Session Key %*ph\n",
507 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response);
508 cifs_dbg(VFS, "Signing Key %*ph\n",
509 SMB3_SIGN_KEY_SIZE, ses->smb3signingkey);
510 if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
511 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
512 cifs_dbg(VFS, "ServerIn Key %*ph\n",
513 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3encryptionkey);
514 cifs_dbg(VFS, "ServerOut Key %*ph\n",
515 SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3decryptionkey);
516 } else {
517 cifs_dbg(VFS, "ServerIn Key %*ph\n",
518 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3encryptionkey);
519 cifs_dbg(VFS, "ServerOut Key %*ph\n",
520 SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3decryptionkey);
521 }
522 #endif
523 return rc;
524 }
525
526 int
generate_smb30signingkey(struct cifs_ses * ses,struct TCP_Server_Info * server)527 generate_smb30signingkey(struct cifs_ses *ses,
528 struct TCP_Server_Info *server)
529
530 {
531 struct derivation_triplet triplet;
532 struct derivation *d;
533
534 d = &triplet.signing;
535 d->label.iov_base = "SMB2AESCMAC";
536 d->label.iov_len = 12;
537 d->context.iov_base = "SmbSign";
538 d->context.iov_len = 8;
539
540 d = &triplet.encryption;
541 d->label.iov_base = "SMB2AESCCM";
542 d->label.iov_len = 11;
543 d->context.iov_base = "ServerIn ";
544 d->context.iov_len = 10;
545
546 d = &triplet.decryption;
547 d->label.iov_base = "SMB2AESCCM";
548 d->label.iov_len = 11;
549 d->context.iov_base = "ServerOut";
550 d->context.iov_len = 10;
551
552 return generate_smb3signingkey(ses, server, &triplet);
553 }
554
555 int
generate_smb311signingkey(struct cifs_ses * ses,struct TCP_Server_Info * server)556 generate_smb311signingkey(struct cifs_ses *ses,
557 struct TCP_Server_Info *server)
558
559 {
560 struct derivation_triplet triplet;
561 struct derivation *d;
562
563 d = &triplet.signing;
564 d->label.iov_base = "SMBSigningKey";
565 d->label.iov_len = 14;
566 d->context.iov_base = ses->preauth_sha_hash;
567 d->context.iov_len = 64;
568
569 d = &triplet.encryption;
570 d->label.iov_base = "SMBC2SCipherKey";
571 d->label.iov_len = 16;
572 d->context.iov_base = ses->preauth_sha_hash;
573 d->context.iov_len = 64;
574
575 d = &triplet.decryption;
576 d->label.iov_base = "SMBS2CCipherKey";
577 d->label.iov_len = 16;
578 d->context.iov_base = ses->preauth_sha_hash;
579 d->context.iov_len = 64;
580
581 return generate_smb3signingkey(ses, server, &triplet);
582 }
583
584 int
smb3_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,bool allocate_crypto)585 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
586 bool allocate_crypto)
587 {
588 int rc;
589 unsigned char smb3_signature[SMB2_CMACAES_SIZE];
590 unsigned char *sigptr = smb3_signature;
591 struct kvec *iov = rqst->rq_iov;
592 struct smb2_hdr *shdr = (struct smb2_hdr *)iov[0].iov_base;
593 struct shash_desc *shash = NULL;
594 struct smb_rqst drqst;
595 u8 key[SMB3_SIGN_KEY_SIZE];
596
597 rc = smb3_get_sign_key(le64_to_cpu(shdr->SessionId), server, key);
598 if (unlikely(rc)) {
599 cifs_server_dbg(FYI, "%s: Could not get signing key\n", __func__);
600 return rc;
601 }
602
603 if (allocate_crypto) {
604 rc = cifs_alloc_hash("cmac(aes)", &shash);
605 if (rc)
606 return rc;
607 } else {
608 shash = server->secmech.aes_cmac;
609 }
610
611 memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
612 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
613
614 rc = crypto_shash_setkey(shash->tfm, key, SMB2_CMACAES_SIZE);
615 if (rc) {
616 cifs_server_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
617 goto out;
618 }
619
620 /*
621 * we already allocate aes_cmac when we init smb3 signing key,
622 * so unlike smb2 case we do not have to check here if secmech are
623 * initialized
624 */
625 rc = crypto_shash_init(shash);
626 if (rc) {
627 cifs_server_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
628 goto out;
629 }
630
631 /*
632 * For SMB2+, __cifs_calc_signature() expects to sign only the actual
633 * data, that is, iov[0] should not contain a rfc1002 length.
634 *
635 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
636 * __cifs_calc_signature().
637 */
638 drqst = *rqst;
639 if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
640 rc = crypto_shash_update(shash, iov[0].iov_base,
641 iov[0].iov_len);
642 if (rc) {
643 cifs_server_dbg(VFS, "%s: Could not update with payload\n",
644 __func__);
645 goto out;
646 }
647 drqst.rq_iov++;
648 drqst.rq_nvec--;
649 }
650
651 rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
652 if (!rc)
653 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
654
655 out:
656 if (allocate_crypto)
657 cifs_free_hash(&shash);
658 return rc;
659 }
660
661 /* must be called with server->srv_mutex held */
662 static int
smb2_sign_rqst(struct smb_rqst * rqst,struct TCP_Server_Info * server)663 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
664 {
665 int rc = 0;
666 struct smb2_hdr *shdr;
667 struct smb2_sess_setup_req *ssr;
668 bool is_binding;
669 bool is_signed;
670
671 shdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
672 ssr = (struct smb2_sess_setup_req *)shdr;
673
674 is_binding = shdr->Command == SMB2_SESSION_SETUP &&
675 (ssr->Flags & SMB2_SESSION_REQ_FLAG_BINDING);
676 is_signed = shdr->Flags & SMB2_FLAGS_SIGNED;
677
678 if (!is_signed)
679 return 0;
680 spin_lock(&server->srv_lock);
681 if (server->ops->need_neg &&
682 server->ops->need_neg(server)) {
683 spin_unlock(&server->srv_lock);
684 return 0;
685 }
686 spin_unlock(&server->srv_lock);
687 if (!is_binding && !server->session_estab) {
688 strncpy(shdr->Signature, "BSRSPYL", 8);
689 return 0;
690 }
691
692 rc = server->ops->calc_signature(rqst, server, false);
693
694 return rc;
695 }
696
697 int
smb2_verify_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server)698 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
699 {
700 unsigned int rc;
701 char server_response_sig[SMB2_SIGNATURE_SIZE];
702 struct smb2_hdr *shdr =
703 (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
704
705 if ((shdr->Command == SMB2_NEGOTIATE) ||
706 (shdr->Command == SMB2_SESSION_SETUP) ||
707 (shdr->Command == SMB2_OPLOCK_BREAK) ||
708 server->ignore_signature ||
709 (!server->session_estab))
710 return 0;
711
712 /*
713 * BB what if signatures are supposed to be on for session but
714 * server does not send one? BB
715 */
716
717 /* Do not need to verify session setups with signature "BSRSPYL " */
718 if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0)
719 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
720 shdr->Command);
721
722 /*
723 * Save off the origiginal signature so we can modify the smb and check
724 * our calculated signature against what the server sent.
725 */
726 memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE);
727
728 memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE);
729
730 rc = server->ops->calc_signature(rqst, server, true);
731
732 if (rc)
733 return rc;
734
735 if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE)) {
736 cifs_dbg(VFS, "sign fail cmd 0x%x message id 0x%llx\n",
737 shdr->Command, shdr->MessageId);
738 return -EACCES;
739 } else
740 return 0;
741 }
742
743 /*
744 * Set message id for the request. Should be called after wait_for_free_request
745 * and when srv_mutex is held.
746 */
747 static inline void
smb2_seq_num_into_buf(struct TCP_Server_Info * server,struct smb2_hdr * shdr)748 smb2_seq_num_into_buf(struct TCP_Server_Info *server,
749 struct smb2_hdr *shdr)
750 {
751 unsigned int i, num = le16_to_cpu(shdr->CreditCharge);
752
753 shdr->MessageId = get_next_mid64(server);
754 /* skip message numbers according to CreditCharge field */
755 for (i = 1; i < num; i++)
756 get_next_mid(server);
757 }
758
759 static struct mid_q_entry *
smb2_mid_entry_alloc(const struct smb2_hdr * shdr,struct TCP_Server_Info * server)760 smb2_mid_entry_alloc(const struct smb2_hdr *shdr,
761 struct TCP_Server_Info *server)
762 {
763 struct mid_q_entry *temp;
764 unsigned int credits = le16_to_cpu(shdr->CreditCharge);
765
766 if (server == NULL) {
767 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
768 return NULL;
769 }
770
771 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
772 memset(temp, 0, sizeof(struct mid_q_entry));
773 kref_init(&temp->refcount);
774 temp->mid = le64_to_cpu(shdr->MessageId);
775 temp->credits = credits > 0 ? credits : 1;
776 temp->pid = current->pid;
777 temp->command = shdr->Command; /* Always LE */
778 temp->when_alloc = jiffies;
779 temp->server = server;
780
781 /*
782 * The default is for the mid to be synchronous, so the
783 * default callback just wakes up the current task.
784 */
785 get_task_struct(current);
786 temp->creator = current;
787 temp->callback = cifs_wake_up_task;
788 temp->callback_data = current;
789
790 atomic_inc(&mid_count);
791 temp->mid_state = MID_REQUEST_ALLOCATED;
792 trace_smb3_cmd_enter(le32_to_cpu(shdr->Id.SyncId.TreeId),
793 le64_to_cpu(shdr->SessionId),
794 le16_to_cpu(shdr->Command), temp->mid);
795 return temp;
796 }
797
798 static int
smb2_get_mid_entry(struct cifs_ses * ses,struct TCP_Server_Info * server,struct smb2_hdr * shdr,struct mid_q_entry ** mid)799 smb2_get_mid_entry(struct cifs_ses *ses, struct TCP_Server_Info *server,
800 struct smb2_hdr *shdr, struct mid_q_entry **mid)
801 {
802 spin_lock(&server->srv_lock);
803 if (server->tcpStatus == CifsExiting) {
804 spin_unlock(&server->srv_lock);
805 return -ENOENT;
806 }
807
808 if (server->tcpStatus == CifsNeedReconnect) {
809 spin_unlock(&server->srv_lock);
810 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
811 return -EAGAIN;
812 }
813
814 if (server->tcpStatus == CifsNeedNegotiate &&
815 shdr->Command != SMB2_NEGOTIATE) {
816 spin_unlock(&server->srv_lock);
817 return -EAGAIN;
818 }
819 spin_unlock(&server->srv_lock);
820
821 spin_lock(&ses->ses_lock);
822 if (ses->ses_status == SES_NEW) {
823 if ((shdr->Command != SMB2_SESSION_SETUP) &&
824 (shdr->Command != SMB2_NEGOTIATE)) {
825 spin_unlock(&ses->ses_lock);
826 return -EAGAIN;
827 }
828 /* else ok - we are setting up session */
829 }
830
831 if (ses->ses_status == SES_EXITING) {
832 if (shdr->Command != SMB2_LOGOFF) {
833 spin_unlock(&ses->ses_lock);
834 return -EAGAIN;
835 }
836 /* else ok - we are shutting down the session */
837 }
838 spin_unlock(&ses->ses_lock);
839
840 *mid = smb2_mid_entry_alloc(shdr, server);
841 if (*mid == NULL)
842 return -ENOMEM;
843 spin_lock(&server->mid_lock);
844 list_add_tail(&(*mid)->qhead, &server->pending_mid_q);
845 spin_unlock(&server->mid_lock);
846
847 return 0;
848 }
849
850 int
smb2_check_receive(struct mid_q_entry * mid,struct TCP_Server_Info * server,bool log_error)851 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
852 bool log_error)
853 {
854 unsigned int len = mid->resp_buf_size;
855 struct kvec iov[1];
856 struct smb_rqst rqst = { .rq_iov = iov,
857 .rq_nvec = 1 };
858
859 iov[0].iov_base = (char *)mid->resp_buf;
860 iov[0].iov_len = len;
861
862 dump_smb(mid->resp_buf, min_t(u32, 80, len));
863 /* convert the length into a more usable form */
864 if (len > 24 && server->sign && !mid->decrypted) {
865 int rc;
866
867 rc = smb2_verify_signature(&rqst, server);
868 if (rc)
869 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
870 rc);
871 }
872
873 return map_smb2_to_linux_error(mid->resp_buf, log_error);
874 }
875
876 struct mid_q_entry *
smb2_setup_request(struct cifs_ses * ses,struct TCP_Server_Info * server,struct smb_rqst * rqst)877 smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server,
878 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 smb2_seq_num_into_buf(server, shdr);
886
887 rc = smb2_get_mid_entry(ses, server, shdr, &mid);
888 if (rc) {
889 revert_current_mid_from_hdr(server, shdr);
890 return ERR_PTR(rc);
891 }
892
893 rc = smb2_sign_rqst(rqst, server);
894 if (rc) {
895 revert_current_mid_from_hdr(server, shdr);
896 delete_mid(mid);
897 return ERR_PTR(rc);
898 }
899
900 return mid;
901 }
902
903 struct mid_q_entry *
smb2_setup_async_request(struct TCP_Server_Info * server,struct smb_rqst * rqst)904 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
905 {
906 int rc;
907 struct smb2_hdr *shdr =
908 (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
909 struct mid_q_entry *mid;
910
911 spin_lock(&server->srv_lock);
912 if (server->tcpStatus == CifsNeedNegotiate &&
913 shdr->Command != SMB2_NEGOTIATE) {
914 spin_unlock(&server->srv_lock);
915 return ERR_PTR(-EAGAIN);
916 }
917 spin_unlock(&server->srv_lock);
918
919 smb2_seq_num_into_buf(server, shdr);
920
921 mid = smb2_mid_entry_alloc(shdr, server);
922 if (mid == NULL) {
923 revert_current_mid_from_hdr(server, shdr);
924 return ERR_PTR(-ENOMEM);
925 }
926
927 rc = smb2_sign_rqst(rqst, server);
928 if (rc) {
929 revert_current_mid_from_hdr(server, shdr);
930 release_mid(mid);
931 return ERR_PTR(rc);
932 }
933
934 return mid;
935 }
936
937 int
smb3_crypto_aead_allocate(struct TCP_Server_Info * server)938 smb3_crypto_aead_allocate(struct TCP_Server_Info *server)
939 {
940 struct crypto_aead *tfm;
941
942 if (!server->secmech.enc) {
943 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
944 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
945 tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
946 else
947 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
948 if (IS_ERR(tfm)) {
949 cifs_server_dbg(VFS, "%s: Failed alloc encrypt aead\n",
950 __func__);
951 return PTR_ERR(tfm);
952 }
953 server->secmech.enc = tfm;
954 }
955
956 if (!server->secmech.dec) {
957 if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
958 (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
959 tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
960 else
961 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
962 if (IS_ERR(tfm)) {
963 crypto_free_aead(server->secmech.enc);
964 server->secmech.enc = NULL;
965 cifs_server_dbg(VFS, "%s: Failed to alloc decrypt aead\n",
966 __func__);
967 return PTR_ERR(tfm);
968 }
969 server->secmech.dec = tfm;
970 }
971
972 return 0;
973 }
974