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1/*
2 * fs/cifs/smb2transport.c
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 * This library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published
12 * by the Free Software Foundation; either version 2.1 of the License, or
13 * (at your option) any later version.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
18 * the GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25#include <linux/fs.h>
26#include <linux/list.h>
27#include <linux/wait.h>
28#include <linux/net.h>
29#include <linux/delay.h>
30#include <linux/uaccess.h>
31#include <asm/processor.h>
32#include <linux/mempool.h>
33#include <linux/highmem.h>
34#include <crypto/aead.h>
35#include "smb2pdu.h"
36#include "cifsglob.h"
37#include "cifsproto.h"
38#include "smb2proto.h"
39#include "cifs_debug.h"
40#include "smb2status.h"
41#include "smb2glob.h"
42
43static int
44smb2_crypto_shash_allocate(struct TCP_Server_Info *server)
45{
46 return cifs_alloc_hash("hmac(sha256)",
47 &server->secmech.hmacsha256,
48 &server->secmech.sdeschmacsha256);
49}
50
51static int
52smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
53{
54 struct cifs_secmech *p = &server->secmech;
55 int rc;
56
57 rc = cifs_alloc_hash("hmac(sha256)",
58 &p->hmacsha256,
59 &p->sdeschmacsha256);
60 if (rc)
61 goto err;
62
63 rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
64 if (rc)
65 goto err;
66
67 return 0;
68err:
69 cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
70 return rc;
71}
72
73#ifdef CONFIG_CIFS_SMB311
74int
75smb311_crypto_shash_allocate(struct TCP_Server_Info *server)
76{
77 struct cifs_secmech *p = &server->secmech;
78 int rc = 0;
79
80 rc = cifs_alloc_hash("hmac(sha256)",
81 &p->hmacsha256,
82 &p->sdeschmacsha256);
83 if (rc)
84 return rc;
85
86 rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
87 if (rc)
88 goto err;
89
90 rc = cifs_alloc_hash("sha512", &p->sha512, &p->sdescsha512);
91 if (rc)
92 goto err;
93
94 return 0;
95
96err:
97 cifs_free_hash(&p->cmacaes, &p->sdesccmacaes);
98 cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
99 return rc;
100}
101#endif
102
103static struct cifs_ses *
104smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id)
105{
106 struct cifs_ses *ses;
107
108 list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
109 if (ses->Suid != ses_id)
110 continue;
111 return ses;
112 }
113
114 return NULL;
115}
116
117struct cifs_ses *
118smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id)
119{
120 struct cifs_ses *ses;
121
122 spin_lock(&cifs_tcp_ses_lock);
123 ses = smb2_find_smb_ses_unlocked(server, ses_id);
124 spin_unlock(&cifs_tcp_ses_lock);
125
126 return ses;
127}
128
129static struct cifs_tcon *
130smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32 tid)
131{
132 struct cifs_tcon *tcon;
133
134 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
135 if (tcon->tid != tid)
136 continue;
137 ++tcon->tc_count;
138 return tcon;
139 }
140
141 return NULL;
142}
143
144/*
145 * Obtain tcon corresponding to the tid in the given
146 * cifs_ses
147 */
148
149struct cifs_tcon *
150smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32 tid)
151{
152 struct cifs_ses *ses;
153 struct cifs_tcon *tcon;
154
155 spin_lock(&cifs_tcp_ses_lock);
156 ses = smb2_find_smb_ses_unlocked(server, ses_id);
157 if (!ses) {
158 spin_unlock(&cifs_tcp_ses_lock);
159 return NULL;
160 }
161 tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid);
162 spin_unlock(&cifs_tcp_ses_lock);
163
164 return tcon;
165}
166
167int
168smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
169{
170 int rc;
171 unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
172 unsigned char *sigptr = smb2_signature;
173 struct kvec *iov = rqst->rq_iov;
174 struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[1].iov_base;
175 struct cifs_ses *ses;
176
177 ses = smb2_find_smb_ses(server, shdr->SessionId);
178 if (!ses) {
179 cifs_dbg(VFS, "%s: Could not find session\n", __func__);
180 return 0;
181 }
182
183 memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
184 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
185
186 rc = smb2_crypto_shash_allocate(server);
187 if (rc) {
188 cifs_dbg(VFS, "%s: shah256 alloc failed\n", __func__);
189 return rc;
190 }
191
192 rc = crypto_shash_setkey(server->secmech.hmacsha256,
193 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
194 if (rc) {
195 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
196 return rc;
197 }
198
199 rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
200 if (rc) {
201 cifs_dbg(VFS, "%s: Could not init sha256", __func__);
202 return rc;
203 }
204
205 rc = __cifs_calc_signature(rqst, server, sigptr,
206 &server->secmech.sdeschmacsha256->shash);
207
208 if (!rc)
209 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
210
211 return rc;
212}
213
214static int generate_key(struct cifs_ses *ses, struct kvec label,
215 struct kvec context, __u8 *key, unsigned int key_size)
216{
217 unsigned char zero = 0x0;
218 __u8 i[4] = {0, 0, 0, 1};
219 __u8 L[4] = {0, 0, 0, 128};
220 int rc = 0;
221 unsigned char prfhash[SMB2_HMACSHA256_SIZE];
222 unsigned char *hashptr = prfhash;
223
224 memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
225 memset(key, 0x0, key_size);
226
227 rc = smb3_crypto_shash_allocate(ses->server);
228 if (rc) {
229 cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
230 goto smb3signkey_ret;
231 }
232
233 rc = crypto_shash_setkey(ses->server->secmech.hmacsha256,
234 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
235 if (rc) {
236 cifs_dbg(VFS, "%s: Could not set with session key\n", __func__);
237 goto smb3signkey_ret;
238 }
239
240 rc = crypto_shash_init(&ses->server->secmech.sdeschmacsha256->shash);
241 if (rc) {
242 cifs_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
243 goto smb3signkey_ret;
244 }
245
246 rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
247 i, 4);
248 if (rc) {
249 cifs_dbg(VFS, "%s: Could not update with n\n", __func__);
250 goto smb3signkey_ret;
251 }
252
253 rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
254 label.iov_base, label.iov_len);
255 if (rc) {
256 cifs_dbg(VFS, "%s: Could not update with label\n", __func__);
257 goto smb3signkey_ret;
258 }
259
260 rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
261 &zero, 1);
262 if (rc) {
263 cifs_dbg(VFS, "%s: Could not update with zero\n", __func__);
264 goto smb3signkey_ret;
265 }
266
267 rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
268 context.iov_base, context.iov_len);
269 if (rc) {
270 cifs_dbg(VFS, "%s: Could not update with context\n", __func__);
271 goto smb3signkey_ret;
272 }
273
274 rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
275 L, 4);
276 if (rc) {
277 cifs_dbg(VFS, "%s: Could not update with L\n", __func__);
278 goto smb3signkey_ret;
279 }
280
281 rc = crypto_shash_final(&ses->server->secmech.sdeschmacsha256->shash,
282 hashptr);
283 if (rc) {
284 cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
285 goto smb3signkey_ret;
286 }
287
288 memcpy(key, hashptr, key_size);
289
290smb3signkey_ret:
291 return rc;
292}
293
294struct derivation {
295 struct kvec label;
296 struct kvec context;
297};
298
299struct derivation_triplet {
300 struct derivation signing;
301 struct derivation encryption;
302 struct derivation decryption;
303};
304
305static int
306generate_smb3signingkey(struct cifs_ses *ses,
307 const struct derivation_triplet *ptriplet)
308{
309 int rc;
310
311 rc = generate_key(ses, ptriplet->signing.label,
312 ptriplet->signing.context, ses->smb3signingkey,
313 SMB3_SIGN_KEY_SIZE);
314 if (rc)
315 return rc;
316
317 rc = generate_key(ses, ptriplet->encryption.label,
318 ptriplet->encryption.context, ses->smb3encryptionkey,
319 SMB3_SIGN_KEY_SIZE);
320 if (rc)
321 return rc;
322
323 rc = generate_key(ses, ptriplet->decryption.label,
324 ptriplet->decryption.context,
325 ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE);
326
327 if (rc)
328 return rc;
329
330#ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
331 cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__);
332 /*
333 * The session id is opaque in terms of endianness, so we can't
334 * print it as a long long. we dump it as we got it on the wire
335 */
336 cifs_dbg(VFS, "Session Id %*ph\n", (int)sizeof(ses->Suid),
337 &ses->Suid);
338 cifs_dbg(VFS, "Session Key %*ph\n",
339 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response);
340 cifs_dbg(VFS, "Signing Key %*ph\n",
341 SMB3_SIGN_KEY_SIZE, ses->smb3signingkey);
342 cifs_dbg(VFS, "ServerIn Key %*ph\n",
343 SMB3_SIGN_KEY_SIZE, ses->smb3encryptionkey);
344 cifs_dbg(VFS, "ServerOut Key %*ph\n",
345 SMB3_SIGN_KEY_SIZE, ses->smb3decryptionkey);
346#endif
347 return rc;
348}
349
350int
351generate_smb30signingkey(struct cifs_ses *ses)
352
353{
354 struct derivation_triplet triplet;
355 struct derivation *d;
356
357 d = &triplet.signing;
358 d->label.iov_base = "SMB2AESCMAC";
359 d->label.iov_len = 12;
360 d->context.iov_base = "SmbSign";
361 d->context.iov_len = 8;
362
363 d = &triplet.encryption;
364 d->label.iov_base = "SMB2AESCCM";
365 d->label.iov_len = 11;
366 d->context.iov_base = "ServerIn ";
367 d->context.iov_len = 10;
368
369 d = &triplet.decryption;
370 d->label.iov_base = "SMB2AESCCM";
371 d->label.iov_len = 11;
372 d->context.iov_base = "ServerOut";
373 d->context.iov_len = 10;
374
375 return generate_smb3signingkey(ses, &triplet);
376}
377
378#ifdef CONFIG_CIFS_SMB311
379int
380generate_smb311signingkey(struct cifs_ses *ses)
381
382{
383 struct derivation_triplet triplet;
384 struct derivation *d;
385
386 d = &triplet.signing;
387 d->label.iov_base = "SMBSigningKey";
388 d->label.iov_len = 14;
389 d->context.iov_base = ses->preauth_sha_hash;
390 d->context.iov_len = 64;
391
392 d = &triplet.encryption;
393 d->label.iov_base = "SMBC2SCipherKey";
394 d->label.iov_len = 16;
395 d->context.iov_base = ses->preauth_sha_hash;
396 d->context.iov_len = 64;
397
398 d = &triplet.decryption;
399 d->label.iov_base = "SMBS2CCipherKey";
400 d->label.iov_len = 16;
401 d->context.iov_base = ses->preauth_sha_hash;
402 d->context.iov_len = 64;
403
404 return generate_smb3signingkey(ses, &triplet);
405}
406#endif /* 311 */
407
408int
409smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
410{
411 int rc = 0;
412 unsigned char smb3_signature[SMB2_CMACAES_SIZE];
413 unsigned char *sigptr = smb3_signature;
414 struct kvec *iov = rqst->rq_iov;
415 struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[1].iov_base;
416 struct cifs_ses *ses;
417
418 ses = smb2_find_smb_ses(server, shdr->SessionId);
419 if (!ses) {
420 cifs_dbg(VFS, "%s: Could not find session\n", __func__);
421 return 0;
422 }
423
424 memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
425 memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
426
427 rc = crypto_shash_setkey(server->secmech.cmacaes,
428 ses->smb3signingkey, SMB2_CMACAES_SIZE);
429
430 if (rc) {
431 cifs_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
432 return rc;
433 }
434
435 /*
436 * we already allocate sdesccmacaes when we init smb3 signing key,
437 * so unlike smb2 case we do not have to check here if secmech are
438 * initialized
439 */
440 rc = crypto_shash_init(&server->secmech.sdesccmacaes->shash);
441 if (rc) {
442 cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
443 return rc;
444 }
445
446 rc = __cifs_calc_signature(rqst, server, sigptr,
447 &server->secmech.sdesccmacaes->shash);
448
449 if (!rc)
450 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
451
452 return rc;
453}
454
455/* must be called with server->srv_mutex held */
456static int
457smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
458{
459 int rc = 0;
460 struct smb2_sync_hdr *shdr =
461 (struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;
462
463 if (!(shdr->Flags & SMB2_FLAGS_SIGNED) ||
464 server->tcpStatus == CifsNeedNegotiate)
465 return rc;
466
467 if (!server->session_estab) {
468 strncpy(shdr->Signature, "BSRSPYL", 8);
469 return rc;
470 }
471
472 rc = server->ops->calc_signature(rqst, server);
473
474 return rc;
475}
476
477int
478smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
479{
480 unsigned int rc;
481 char server_response_sig[16];
482 struct smb2_sync_hdr *shdr =
483 (struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;
484
485 if ((shdr->Command == SMB2_NEGOTIATE) ||
486 (shdr->Command == SMB2_SESSION_SETUP) ||
487 (shdr->Command == SMB2_OPLOCK_BREAK) ||
488 (!server->session_estab))
489 return 0;
490
491 /*
492 * BB what if signatures are supposed to be on for session but
493 * server does not send one? BB
494 */
495
496 /* Do not need to verify session setups with signature "BSRSPYL " */
497 if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0)
498 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
499 shdr->Command);
500
501 /*
502 * Save off the origiginal signature so we can modify the smb and check
503 * our calculated signature against what the server sent.
504 */
505 memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE);
506
507 memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE);
508
509 mutex_lock(&server->srv_mutex);
510 rc = server->ops->calc_signature(rqst, server);
511 mutex_unlock(&server->srv_mutex);
512
513 if (rc)
514 return rc;
515
516 if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE))
517 return -EACCES;
518 else
519 return 0;
520}
521
522/*
523 * Set message id for the request. Should be called after wait_for_free_request
524 * and when srv_mutex is held.
525 */
526static inline void
527smb2_seq_num_into_buf(struct TCP_Server_Info *server,
528 struct smb2_sync_hdr *shdr)
529{
530 unsigned int i, num = le16_to_cpu(shdr->CreditCharge);
531
532 shdr->MessageId = get_next_mid64(server);
533 /* skip message numbers according to CreditCharge field */
534 for (i = 1; i < num; i++)
535 get_next_mid(server);
536}
537
538static struct mid_q_entry *
539smb2_mid_entry_alloc(const struct smb2_sync_hdr *shdr,
540 struct TCP_Server_Info *server)
541{
542 struct mid_q_entry *temp;
543
544 if (server == NULL) {
545 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
546 return NULL;
547 }
548
549 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
550 memset(temp, 0, sizeof(struct mid_q_entry));
551 temp->mid = le64_to_cpu(shdr->MessageId);
552 temp->pid = current->pid;
553 temp->command = shdr->Command; /* Always LE */
554 temp->when_alloc = jiffies;
555 temp->server = server;
556
557 /*
558 * The default is for the mid to be synchronous, so the
559 * default callback just wakes up the current task.
560 */
561 temp->callback = cifs_wake_up_task;
562 temp->callback_data = current;
563
564 atomic_inc(&midCount);
565 temp->mid_state = MID_REQUEST_ALLOCATED;
566 return temp;
567}
568
569static int
570smb2_get_mid_entry(struct cifs_ses *ses, struct smb2_sync_hdr *shdr,
571 struct mid_q_entry **mid)
572{
573 if (ses->server->tcpStatus == CifsExiting)
574 return -ENOENT;
575
576 if (ses->server->tcpStatus == CifsNeedReconnect) {
577 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
578 return -EAGAIN;
579 }
580
581 if (ses->status == CifsNew) {
582 if ((shdr->Command != SMB2_SESSION_SETUP) &&
583 (shdr->Command != SMB2_NEGOTIATE))
584 return -EAGAIN;
585 /* else ok - we are setting up session */
586 }
587
588 if (ses->status == CifsExiting) {
589 if (shdr->Command != SMB2_LOGOFF)
590 return -EAGAIN;
591 /* else ok - we are shutting down the session */
592 }
593
594 *mid = smb2_mid_entry_alloc(shdr, ses->server);
595 if (*mid == NULL)
596 return -ENOMEM;
597 spin_lock(&GlobalMid_Lock);
598 list_add_tail(&(*mid)->qhead, &ses->server->pending_mid_q);
599 spin_unlock(&GlobalMid_Lock);
600 return 0;
601}
602
603int
604smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
605 bool log_error)
606{
607 unsigned int len = mid->resp_buf_size;
608 struct kvec iov[2];
609 struct smb_rqst rqst = { .rq_iov = iov,
610 .rq_nvec = 2 };
611
612 iov[0].iov_base = (char *)mid->resp_buf;
613 iov[0].iov_len = 4;
614 iov[1].iov_base = (char *)mid->resp_buf + 4;
615 iov[1].iov_len = len;
616
617 dump_smb(mid->resp_buf, min_t(u32, 80, len));
618 /* convert the length into a more usable form */
619 if (len > 24 && server->sign && !mid->decrypted) {
620 int rc;
621
622 rc = smb2_verify_signature(&rqst, server);
623 if (rc)
624 cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
625 rc);
626 }
627
628 return map_smb2_to_linux_error(mid->resp_buf, log_error);
629}
630
631struct mid_q_entry *
632smb2_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
633{
634 int rc;
635 struct smb2_sync_hdr *shdr =
636 (struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;
637 struct mid_q_entry *mid;
638
639 smb2_seq_num_into_buf(ses->server, shdr);
640
641 rc = smb2_get_mid_entry(ses, shdr, &mid);
642 if (rc)
643 return ERR_PTR(rc);
644 rc = smb2_sign_rqst(rqst, ses->server);
645 if (rc) {
646 cifs_delete_mid(mid);
647 return ERR_PTR(rc);
648 }
649 return mid;
650}
651
652struct mid_q_entry *
653smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
654{
655 int rc;
656 struct smb2_sync_hdr *shdr =
657 (struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;
658 struct mid_q_entry *mid;
659
660 smb2_seq_num_into_buf(server, shdr);
661
662 mid = smb2_mid_entry_alloc(shdr, server);
663 if (mid == NULL)
664 return ERR_PTR(-ENOMEM);
665
666 rc = smb2_sign_rqst(rqst, server);
667 if (rc) {
668 DeleteMidQEntry(mid);
669 return ERR_PTR(rc);
670 }
671
672 return mid;
673}
674
675int
676smb3_crypto_aead_allocate(struct TCP_Server_Info *server)
677{
678 struct crypto_aead *tfm;
679
680 if (!server->secmech.ccmaesencrypt) {
681 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
682 if (IS_ERR(tfm)) {
683 cifs_dbg(VFS, "%s: Failed to alloc encrypt aead\n",
684 __func__);
685 return PTR_ERR(tfm);
686 }
687 server->secmech.ccmaesencrypt = tfm;
688 }
689
690 if (!server->secmech.ccmaesdecrypt) {
691 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
692 if (IS_ERR(tfm)) {
693 crypto_free_aead(server->secmech.ccmaesencrypt);
694 server->secmech.ccmaesencrypt = NULL;
695 cifs_dbg(VFS, "%s: Failed to alloc decrypt aead\n",
696 __func__);
697 return PTR_ERR(tfm);
698 }
699 server->secmech.ccmaesdecrypt = tfm;
700 }
701
702 return 0;
703}