1 /*
2 * fs/cifs/cifsencrypt.c
3 *
4 * Encryption and hashing operations relating to NTLM, NTLMv2. See MS-NLMP
5 * for more detailed information
6 *
7 * Copyright (C) International Business Machines Corp., 2005,2013
8 * Author(s): Steve French (sfrench@us.ibm.com)
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/slab.h>
27 #include "cifspdu.h"
28 #include "cifsglob.h"
29 #include "cifs_debug.h"
30 #include "cifs_unicode.h"
31 #include "cifsproto.h"
32 #include "ntlmssp.h"
33 #include <linux/ctype.h>
34 #include <linux/random.h>
35 #include <linux/highmem.h>
36
37 static int
cifs_crypto_shash_md5_allocate(struct TCP_Server_Info * server)38 cifs_crypto_shash_md5_allocate(struct TCP_Server_Info *server)
39 {
40 int rc;
41 unsigned int size;
42
43 if (server->secmech.sdescmd5 != NULL)
44 return 0; /* already allocated */
45
46 server->secmech.md5 = crypto_alloc_shash("md5", 0, 0);
47 if (IS_ERR(server->secmech.md5)) {
48 cifs_dbg(VFS, "could not allocate crypto md5\n");
49 rc = PTR_ERR(server->secmech.md5);
50 server->secmech.md5 = NULL;
51 return rc;
52 }
53
54 size = sizeof(struct shash_desc) +
55 crypto_shash_descsize(server->secmech.md5);
56 server->secmech.sdescmd5 = kmalloc(size, GFP_KERNEL);
57 if (!server->secmech.sdescmd5) {
58 crypto_free_shash(server->secmech.md5);
59 server->secmech.md5 = NULL;
60 return -ENOMEM;
61 }
62 server->secmech.sdescmd5->shash.tfm = server->secmech.md5;
63 server->secmech.sdescmd5->shash.flags = 0x0;
64
65 return 0;
66 }
67
68 /*
69 * Calculate and return the CIFS signature based on the mac key and SMB PDU.
70 * The 16 byte signature must be allocated by the caller. Note we only use the
71 * 1st eight bytes and that the smb header signature field on input contains
72 * the sequence number before this function is called. Also, this function
73 * should be called with the server->srv_mutex held.
74 */
cifs_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,char * signature)75 static int cifs_calc_signature(struct smb_rqst *rqst,
76 struct TCP_Server_Info *server, char *signature)
77 {
78 int i;
79 int rc;
80 struct kvec *iov = rqst->rq_iov;
81 int n_vec = rqst->rq_nvec;
82
83 if (iov == NULL || signature == NULL || server == NULL)
84 return -EINVAL;
85
86 if (!server->secmech.sdescmd5) {
87 rc = cifs_crypto_shash_md5_allocate(server);
88 if (rc) {
89 cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
90 return -1;
91 }
92 }
93
94 rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
95 if (rc) {
96 cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
97 return rc;
98 }
99
100 rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
101 server->session_key.response, server->session_key.len);
102 if (rc) {
103 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
104 return rc;
105 }
106
107 for (i = 0; i < n_vec; i++) {
108 if (iov[i].iov_len == 0)
109 continue;
110 if (iov[i].iov_base == NULL) {
111 cifs_dbg(VFS, "null iovec entry\n");
112 return -EIO;
113 }
114 /* The first entry includes a length field (which does not get
115 signed that occupies the first 4 bytes before the header */
116 if (i == 0) {
117 if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
118 break; /* nothing to sign or corrupt header */
119 rc =
120 crypto_shash_update(&server->secmech.sdescmd5->shash,
121 iov[i].iov_base + 4, iov[i].iov_len - 4);
122 } else {
123 rc =
124 crypto_shash_update(&server->secmech.sdescmd5->shash,
125 iov[i].iov_base, iov[i].iov_len);
126 }
127 if (rc) {
128 cifs_dbg(VFS, "%s: Could not update with payload\n",
129 __func__);
130 return rc;
131 }
132 }
133
134 /* now hash over the rq_pages array */
135 for (i = 0; i < rqst->rq_npages; i++) {
136 struct kvec p_iov;
137
138 cifs_rqst_page_to_kvec(rqst, i, &p_iov);
139 crypto_shash_update(&server->secmech.sdescmd5->shash,
140 p_iov.iov_base, p_iov.iov_len);
141 kunmap(rqst->rq_pages[i]);
142 }
143
144 rc = crypto_shash_final(&server->secmech.sdescmd5->shash, signature);
145 if (rc)
146 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
147
148 return rc;
149 }
150
151 /* must be called with server->srv_mutex held */
cifs_sign_rqst(struct smb_rqst * rqst,struct TCP_Server_Info * server,__u32 * pexpected_response_sequence_number)152 int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
153 __u32 *pexpected_response_sequence_number)
154 {
155 int rc = 0;
156 char smb_signature[20];
157 struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
158
159 if ((cifs_pdu == NULL) || (server == NULL))
160 return -EINVAL;
161
162 if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) ||
163 server->tcpStatus == CifsNeedNegotiate)
164 return rc;
165
166 if (!server->session_estab) {
167 memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8);
168 return rc;
169 }
170
171 cifs_pdu->Signature.Sequence.SequenceNumber =
172 cpu_to_le32(server->sequence_number);
173 cifs_pdu->Signature.Sequence.Reserved = 0;
174
175 *pexpected_response_sequence_number = ++server->sequence_number;
176 ++server->sequence_number;
177
178 rc = cifs_calc_signature(rqst, server, smb_signature);
179 if (rc)
180 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
181 else
182 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
183
184 return rc;
185 }
186
cifs_sign_smbv(struct kvec * iov,int n_vec,struct TCP_Server_Info * server,__u32 * pexpected_response_sequence)187 int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
188 __u32 *pexpected_response_sequence)
189 {
190 struct smb_rqst rqst = { .rq_iov = iov,
191 .rq_nvec = n_vec };
192
193 return cifs_sign_rqst(&rqst, server, pexpected_response_sequence);
194 }
195
196 /* must be called with server->srv_mutex held */
cifs_sign_smb(struct smb_hdr * cifs_pdu,struct TCP_Server_Info * server,__u32 * pexpected_response_sequence_number)197 int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
198 __u32 *pexpected_response_sequence_number)
199 {
200 struct kvec iov;
201
202 iov.iov_base = cifs_pdu;
203 iov.iov_len = be32_to_cpu(cifs_pdu->smb_buf_length) + 4;
204
205 return cifs_sign_smbv(&iov, 1, server,
206 pexpected_response_sequence_number);
207 }
208
cifs_verify_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,__u32 expected_sequence_number)209 int cifs_verify_signature(struct smb_rqst *rqst,
210 struct TCP_Server_Info *server,
211 __u32 expected_sequence_number)
212 {
213 unsigned int rc;
214 char server_response_sig[8];
215 char what_we_think_sig_should_be[20];
216 struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
217
218 if (cifs_pdu == NULL || server == NULL)
219 return -EINVAL;
220
221 if (!server->session_estab)
222 return 0;
223
224 if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
225 struct smb_com_lock_req *pSMB =
226 (struct smb_com_lock_req *)cifs_pdu;
227 if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
228 return 0;
229 }
230
231 /* BB what if signatures are supposed to be on for session but
232 server does not send one? BB */
233
234 /* Do not need to verify session setups with signature "BSRSPYL " */
235 if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0)
236 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
237 cifs_pdu->Command);
238
239 /* save off the origiginal signature so we can modify the smb and check
240 its signature against what the server sent */
241 memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8);
242
243 cifs_pdu->Signature.Sequence.SequenceNumber =
244 cpu_to_le32(expected_sequence_number);
245 cifs_pdu->Signature.Sequence.Reserved = 0;
246
247 mutex_lock(&server->srv_mutex);
248 rc = cifs_calc_signature(rqst, server, what_we_think_sig_should_be);
249 mutex_unlock(&server->srv_mutex);
250
251 if (rc)
252 return rc;
253
254 /* cifs_dump_mem("what we think it should be: ",
255 what_we_think_sig_should_be, 16); */
256
257 if (memcmp(server_response_sig, what_we_think_sig_should_be, 8))
258 return -EACCES;
259 else
260 return 0;
261
262 }
263
264 /* first calculate 24 bytes ntlm response and then 16 byte session key */
setup_ntlm_response(struct cifs_ses * ses,const struct nls_table * nls_cp)265 int setup_ntlm_response(struct cifs_ses *ses, const struct nls_table *nls_cp)
266 {
267 int rc = 0;
268 unsigned int temp_len = CIFS_SESS_KEY_SIZE + CIFS_AUTH_RESP_SIZE;
269 char temp_key[CIFS_SESS_KEY_SIZE];
270
271 if (!ses)
272 return -EINVAL;
273
274 ses->auth_key.response = kmalloc(temp_len, GFP_KERNEL);
275 if (!ses->auth_key.response)
276 return -ENOMEM;
277
278 ses->auth_key.len = temp_len;
279
280 rc = SMBNTencrypt(ses->password, ses->server->cryptkey,
281 ses->auth_key.response + CIFS_SESS_KEY_SIZE, nls_cp);
282 if (rc) {
283 cifs_dbg(FYI, "%s Can't generate NTLM response, error: %d\n",
284 __func__, rc);
285 return rc;
286 }
287
288 rc = E_md4hash(ses->password, temp_key, nls_cp);
289 if (rc) {
290 cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
291 __func__, rc);
292 return rc;
293 }
294
295 rc = mdfour(ses->auth_key.response, temp_key, CIFS_SESS_KEY_SIZE);
296 if (rc)
297 cifs_dbg(FYI, "%s Can't generate NTLM session key, error: %d\n",
298 __func__, rc);
299
300 return rc;
301 }
302
303 #ifdef CONFIG_CIFS_WEAK_PW_HASH
calc_lanman_hash(const char * password,const char * cryptkey,bool encrypt,char * lnm_session_key)304 int calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
305 char *lnm_session_key)
306 {
307 int i;
308 int rc;
309 char password_with_pad[CIFS_ENCPWD_SIZE];
310
311 memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
312 if (password)
313 strncpy(password_with_pad, password, CIFS_ENCPWD_SIZE);
314
315 if (!encrypt && global_secflags & CIFSSEC_MAY_PLNTXT) {
316 memcpy(lnm_session_key, password_with_pad,
317 CIFS_ENCPWD_SIZE);
318 return 0;
319 }
320
321 /* calculate old style session key */
322 /* calling toupper is less broken than repeatedly
323 calling nls_toupper would be since that will never
324 work for UTF8, but neither handles multibyte code pages
325 but the only alternative would be converting to UCS-16 (Unicode)
326 (using a routine something like UniStrupr) then
327 uppercasing and then converting back from Unicode - which
328 would only worth doing it if we knew it were utf8. Basically
329 utf8 and other multibyte codepages each need their own strupper
330 function since a byte at a time will ont work. */
331
332 for (i = 0; i < CIFS_ENCPWD_SIZE; i++)
333 password_with_pad[i] = toupper(password_with_pad[i]);
334
335 rc = SMBencrypt(password_with_pad, cryptkey, lnm_session_key);
336
337 return rc;
338 }
339 #endif /* CIFS_WEAK_PW_HASH */
340
341 /* Build a proper attribute value/target info pairs blob.
342 * Fill in netbios and dns domain name and workstation name
343 * and client time (total five av pairs and + one end of fields indicator.
344 * Allocate domain name which gets freed when session struct is deallocated.
345 */
346 static int
build_avpair_blob(struct cifs_ses * ses,const struct nls_table * nls_cp)347 build_avpair_blob(struct cifs_ses *ses, const struct nls_table *nls_cp)
348 {
349 unsigned int dlen;
350 unsigned int size = 2 * sizeof(struct ntlmssp2_name);
351 char *defdmname = "WORKGROUP";
352 unsigned char *blobptr;
353 struct ntlmssp2_name *attrptr;
354
355 if (!ses->domainName) {
356 ses->domainName = kstrdup(defdmname, GFP_KERNEL);
357 if (!ses->domainName)
358 return -ENOMEM;
359 }
360
361 dlen = strlen(ses->domainName);
362
363 /*
364 * The length of this blob is two times the size of a
365 * structure (av pair) which holds name/size
366 * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) +
367 * unicode length of a netbios domain name
368 */
369 ses->auth_key.len = size + 2 * dlen;
370 ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL);
371 if (!ses->auth_key.response) {
372 ses->auth_key.len = 0;
373 return -ENOMEM;
374 }
375
376 blobptr = ses->auth_key.response;
377 attrptr = (struct ntlmssp2_name *) blobptr;
378
379 /*
380 * As defined in MS-NTLM 3.3.2, just this av pair field
381 * is sufficient as part of the temp
382 */
383 attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME);
384 attrptr->length = cpu_to_le16(2 * dlen);
385 blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
386 cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, nls_cp);
387
388 return 0;
389 }
390
391 /* Server has provided av pairs/target info in the type 2 challenge
392 * packet and we have plucked it and stored within smb session.
393 * We parse that blob here to find netbios domain name to be used
394 * as part of ntlmv2 authentication (in Target String), if not already
395 * specified on the command line.
396 * If this function returns without any error but without fetching
397 * domain name, authentication may fail against some server but
398 * may not fail against other (those who are not very particular
399 * about target string i.e. for some, just user name might suffice.
400 */
401 static int
find_domain_name(struct cifs_ses * ses,const struct nls_table * nls_cp)402 find_domain_name(struct cifs_ses *ses, const struct nls_table *nls_cp)
403 {
404 unsigned int attrsize;
405 unsigned int type;
406 unsigned int onesize = sizeof(struct ntlmssp2_name);
407 unsigned char *blobptr;
408 unsigned char *blobend;
409 struct ntlmssp2_name *attrptr;
410
411 if (!ses->auth_key.len || !ses->auth_key.response)
412 return 0;
413
414 blobptr = ses->auth_key.response;
415 blobend = blobptr + ses->auth_key.len;
416
417 while (blobptr + onesize < blobend) {
418 attrptr = (struct ntlmssp2_name *) blobptr;
419 type = le16_to_cpu(attrptr->type);
420 if (type == NTLMSSP_AV_EOL)
421 break;
422 blobptr += 2; /* advance attr type */
423 attrsize = le16_to_cpu(attrptr->length);
424 blobptr += 2; /* advance attr size */
425 if (blobptr + attrsize > blobend)
426 break;
427 if (type == NTLMSSP_AV_NB_DOMAIN_NAME) {
428 if (!attrsize || attrsize >= CIFS_MAX_DOMAINNAME_LEN)
429 break;
430 if (!ses->domainName) {
431 ses->domainName =
432 kmalloc(attrsize + 1, GFP_KERNEL);
433 if (!ses->domainName)
434 return -ENOMEM;
435 cifs_from_utf16(ses->domainName,
436 (__le16 *)blobptr, attrsize, attrsize,
437 nls_cp, NO_MAP_UNI_RSVD);
438 break;
439 }
440 }
441 blobptr += attrsize; /* advance attr value */
442 }
443
444 return 0;
445 }
446
447 /* Server has provided av pairs/target info in the type 2 challenge
448 * packet and we have plucked it and stored within smb session.
449 * We parse that blob here to find the server given timestamp
450 * as part of ntlmv2 authentication (or local current time as
451 * default in case of failure)
452 */
453 static __le64
find_timestamp(struct cifs_ses * ses)454 find_timestamp(struct cifs_ses *ses)
455 {
456 unsigned int attrsize;
457 unsigned int type;
458 unsigned int onesize = sizeof(struct ntlmssp2_name);
459 unsigned char *blobptr;
460 unsigned char *blobend;
461 struct ntlmssp2_name *attrptr;
462
463 if (!ses->auth_key.len || !ses->auth_key.response)
464 return 0;
465
466 blobptr = ses->auth_key.response;
467 blobend = blobptr + ses->auth_key.len;
468
469 while (blobptr + onesize < blobend) {
470 attrptr = (struct ntlmssp2_name *) blobptr;
471 type = le16_to_cpu(attrptr->type);
472 if (type == NTLMSSP_AV_EOL)
473 break;
474 blobptr += 2; /* advance attr type */
475 attrsize = le16_to_cpu(attrptr->length);
476 blobptr += 2; /* advance attr size */
477 if (blobptr + attrsize > blobend)
478 break;
479 if (type == NTLMSSP_AV_TIMESTAMP) {
480 if (attrsize == sizeof(u64))
481 return *((__le64 *)blobptr);
482 }
483 blobptr += attrsize; /* advance attr value */
484 }
485
486 return cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
487 }
488
calc_ntlmv2_hash(struct cifs_ses * ses,char * ntlmv2_hash,const struct nls_table * nls_cp)489 static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
490 const struct nls_table *nls_cp)
491 {
492 int rc = 0;
493 int len;
494 char nt_hash[CIFS_NTHASH_SIZE];
495 __le16 *user;
496 wchar_t *domain;
497 wchar_t *server;
498
499 if (!ses->server->secmech.sdeschmacmd5) {
500 cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
501 return -1;
502 }
503
504 /* calculate md4 hash of password */
505 E_md4hash(ses->password, nt_hash, nls_cp);
506
507 rc = crypto_shash_setkey(ses->server->secmech.hmacmd5, nt_hash,
508 CIFS_NTHASH_SIZE);
509 if (rc) {
510 cifs_dbg(VFS, "%s: Could not set NT Hash as a key\n", __func__);
511 return rc;
512 }
513
514 rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
515 if (rc) {
516 cifs_dbg(VFS, "%s: could not init hmacmd5\n", __func__);
517 return rc;
518 }
519
520 /* convert ses->user_name to unicode */
521 len = ses->user_name ? strlen(ses->user_name) : 0;
522 user = kmalloc(2 + (len * 2), GFP_KERNEL);
523 if (user == NULL) {
524 rc = -ENOMEM;
525 return rc;
526 }
527
528 if (len) {
529 len = cifs_strtoUTF16(user, ses->user_name, len, nls_cp);
530 UniStrupr(user);
531 } else {
532 memset(user, '\0', 2);
533 }
534
535 rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
536 (char *)user, 2 * len);
537 kfree(user);
538 if (rc) {
539 cifs_dbg(VFS, "%s: Could not update with user\n", __func__);
540 return rc;
541 }
542
543 /* convert ses->domainName to unicode and uppercase */
544 if (ses->domainName) {
545 len = strlen(ses->domainName);
546
547 domain = kmalloc(2 + (len * 2), GFP_KERNEL);
548 if (domain == NULL) {
549 rc = -ENOMEM;
550 return rc;
551 }
552 len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len,
553 nls_cp);
554 rc =
555 crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
556 (char *)domain, 2 * len);
557 kfree(domain);
558 if (rc) {
559 cifs_dbg(VFS, "%s: Could not update with domain\n",
560 __func__);
561 return rc;
562 }
563 } else {
564 /* We use ses->serverName if no domain name available */
565 len = strlen(ses->serverName);
566
567 server = kmalloc(2 + (len * 2), GFP_KERNEL);
568 if (server == NULL) {
569 rc = -ENOMEM;
570 return rc;
571 }
572 len = cifs_strtoUTF16((__le16 *)server, ses->serverName, len,
573 nls_cp);
574 rc =
575 crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
576 (char *)server, 2 * len);
577 kfree(server);
578 if (rc) {
579 cifs_dbg(VFS, "%s: Could not update with server\n",
580 __func__);
581 return rc;
582 }
583 }
584
585 rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
586 ntlmv2_hash);
587 if (rc)
588 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
589
590 return rc;
591 }
592
593 static int
CalcNTLMv2_response(const struct cifs_ses * ses,char * ntlmv2_hash)594 CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash)
595 {
596 int rc;
597 struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *)
598 (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
599 unsigned int hash_len;
600
601 /* The MD5 hash starts at challenge_key.key */
602 hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE +
603 offsetof(struct ntlmv2_resp, challenge.key[0]));
604
605 if (!ses->server->secmech.sdeschmacmd5) {
606 cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
607 return -1;
608 }
609
610 rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
611 ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
612 if (rc) {
613 cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
614 __func__);
615 return rc;
616 }
617
618 rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
619 if (rc) {
620 cifs_dbg(VFS, "%s: could not init hmacmd5\n", __func__);
621 return rc;
622 }
623
624 if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED)
625 memcpy(ntlmv2->challenge.key,
626 ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
627 else
628 memcpy(ntlmv2->challenge.key,
629 ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
630 rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
631 ntlmv2->challenge.key, hash_len);
632 if (rc) {
633 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
634 return rc;
635 }
636
637 /* Note that the MD5 digest over writes anon.challenge_key.key */
638 rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
639 ntlmv2->ntlmv2_hash);
640 if (rc)
641 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
642
643 return rc;
644 }
645
crypto_hmacmd5_alloc(struct TCP_Server_Info * server)646 static int crypto_hmacmd5_alloc(struct TCP_Server_Info *server)
647 {
648 int rc;
649 unsigned int size;
650
651 /* check if already allocated */
652 if (server->secmech.sdeschmacmd5)
653 return 0;
654
655 server->secmech.hmacmd5 = crypto_alloc_shash("hmac(md5)", 0, 0);
656 if (IS_ERR(server->secmech.hmacmd5)) {
657 cifs_dbg(VFS, "could not allocate crypto hmacmd5\n");
658 rc = PTR_ERR(server->secmech.hmacmd5);
659 server->secmech.hmacmd5 = NULL;
660 return rc;
661 }
662
663 size = sizeof(struct shash_desc) +
664 crypto_shash_descsize(server->secmech.hmacmd5);
665 server->secmech.sdeschmacmd5 = kmalloc(size, GFP_KERNEL);
666 if (!server->secmech.sdeschmacmd5) {
667 crypto_free_shash(server->secmech.hmacmd5);
668 server->secmech.hmacmd5 = NULL;
669 return -ENOMEM;
670 }
671 server->secmech.sdeschmacmd5->shash.tfm = server->secmech.hmacmd5;
672 server->secmech.sdeschmacmd5->shash.flags = 0x0;
673
674 return 0;
675 }
676
677 int
setup_ntlmv2_rsp(struct cifs_ses * ses,const struct nls_table * nls_cp)678 setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
679 {
680 int rc;
681 int baselen;
682 unsigned int tilen;
683 struct ntlmv2_resp *ntlmv2;
684 char ntlmv2_hash[16];
685 unsigned char *tiblob = NULL; /* target info blob */
686 __le64 rsp_timestamp;
687
688 if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) {
689 if (!ses->domainName) {
690 rc = find_domain_name(ses, nls_cp);
691 if (rc) {
692 cifs_dbg(VFS, "error %d finding domain name\n",
693 rc);
694 goto setup_ntlmv2_rsp_ret;
695 }
696 }
697 } else {
698 rc = build_avpair_blob(ses, nls_cp);
699 if (rc) {
700 cifs_dbg(VFS, "error %d building av pair blob\n", rc);
701 goto setup_ntlmv2_rsp_ret;
702 }
703 }
704
705 /* Must be within 5 minutes of the server (or in range +/-2h
706 * in case of Mac OS X), so simply carry over server timestamp
707 * (as Windows 7 does)
708 */
709 rsp_timestamp = find_timestamp(ses);
710
711 baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp);
712 tilen = ses->auth_key.len;
713 tiblob = ses->auth_key.response;
714
715 ses->auth_key.response = kmalloc(baselen + tilen, GFP_KERNEL);
716 if (!ses->auth_key.response) {
717 rc = -ENOMEM;
718 ses->auth_key.len = 0;
719 goto setup_ntlmv2_rsp_ret;
720 }
721 ses->auth_key.len += baselen;
722
723 ntlmv2 = (struct ntlmv2_resp *)
724 (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
725 ntlmv2->blob_signature = cpu_to_le32(0x00000101);
726 ntlmv2->reserved = 0;
727 ntlmv2->time = rsp_timestamp;
728
729 get_random_bytes(&ntlmv2->client_chal, sizeof(ntlmv2->client_chal));
730 ntlmv2->reserved2 = 0;
731
732 memcpy(ses->auth_key.response + baselen, tiblob, tilen);
733
734 rc = crypto_hmacmd5_alloc(ses->server);
735 if (rc) {
736 cifs_dbg(VFS, "could not crypto alloc hmacmd5 rc %d\n", rc);
737 goto setup_ntlmv2_rsp_ret;
738 }
739
740 /* calculate ntlmv2_hash */
741 rc = calc_ntlmv2_hash(ses, ntlmv2_hash, nls_cp);
742 if (rc) {
743 cifs_dbg(VFS, "could not get v2 hash rc %d\n", rc);
744 goto setup_ntlmv2_rsp_ret;
745 }
746
747 /* calculate first part of the client response (CR1) */
748 rc = CalcNTLMv2_response(ses, ntlmv2_hash);
749 if (rc) {
750 cifs_dbg(VFS, "Could not calculate CR1 rc: %d\n", rc);
751 goto setup_ntlmv2_rsp_ret;
752 }
753
754 /* now calculate the session key for NTLMv2 */
755 rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
756 ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
757 if (rc) {
758 cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
759 __func__);
760 goto setup_ntlmv2_rsp_ret;
761 }
762
763 rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
764 if (rc) {
765 cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
766 goto setup_ntlmv2_rsp_ret;
767 }
768
769 rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
770 ntlmv2->ntlmv2_hash,
771 CIFS_HMAC_MD5_HASH_SIZE);
772 if (rc) {
773 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
774 goto setup_ntlmv2_rsp_ret;
775 }
776
777 rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
778 ses->auth_key.response);
779 if (rc)
780 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
781
782 setup_ntlmv2_rsp_ret:
783 kfree(tiblob);
784
785 return rc;
786 }
787
788 int
calc_seckey(struct cifs_ses * ses)789 calc_seckey(struct cifs_ses *ses)
790 {
791 int rc;
792 struct crypto_blkcipher *tfm_arc4;
793 struct scatterlist sgin, sgout;
794 struct blkcipher_desc desc;
795 unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */
796
797 get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE);
798
799 tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
800 if (IS_ERR(tfm_arc4)) {
801 rc = PTR_ERR(tfm_arc4);
802 cifs_dbg(VFS, "could not allocate crypto API arc4\n");
803 return rc;
804 }
805
806 desc.tfm = tfm_arc4;
807
808 rc = crypto_blkcipher_setkey(tfm_arc4, ses->auth_key.response,
809 CIFS_SESS_KEY_SIZE);
810 if (rc) {
811 cifs_dbg(VFS, "%s: Could not set response as a key\n",
812 __func__);
813 return rc;
814 }
815
816 sg_init_one(&sgin, sec_key, CIFS_SESS_KEY_SIZE);
817 sg_init_one(&sgout, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
818
819 rc = crypto_blkcipher_encrypt(&desc, &sgout, &sgin, CIFS_CPHTXT_SIZE);
820 if (rc) {
821 cifs_dbg(VFS, "could not encrypt session key rc: %d\n", rc);
822 crypto_free_blkcipher(tfm_arc4);
823 return rc;
824 }
825
826 /* make secondary_key/nonce as session key */
827 memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE);
828 /* and make len as that of session key only */
829 ses->auth_key.len = CIFS_SESS_KEY_SIZE;
830
831 crypto_free_blkcipher(tfm_arc4);
832
833 return rc;
834 }
835
836 void
cifs_crypto_shash_release(struct TCP_Server_Info * server)837 cifs_crypto_shash_release(struct TCP_Server_Info *server)
838 {
839 if (server->secmech.cmacaes) {
840 crypto_free_shash(server->secmech.cmacaes);
841 server->secmech.cmacaes = NULL;
842 }
843
844 if (server->secmech.hmacsha256) {
845 crypto_free_shash(server->secmech.hmacsha256);
846 server->secmech.hmacsha256 = NULL;
847 }
848
849 if (server->secmech.md5) {
850 crypto_free_shash(server->secmech.md5);
851 server->secmech.md5 = NULL;
852 }
853
854 if (server->secmech.hmacmd5) {
855 crypto_free_shash(server->secmech.hmacmd5);
856 server->secmech.hmacmd5 = NULL;
857 }
858
859 kfree(server->secmech.sdesccmacaes);
860 server->secmech.sdesccmacaes = NULL;
861 kfree(server->secmech.sdeschmacsha256);
862 server->secmech.sdeschmacsha256 = NULL;
863 kfree(server->secmech.sdeschmacmd5);
864 server->secmech.sdeschmacmd5 = NULL;
865 kfree(server->secmech.sdescmd5);
866 server->secmech.sdescmd5 = NULL;
867 }
868