1 // SPDX-License-Identifier: LGPL-2.1
2 /*
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 */
11
12 #include <linux/fs.h>
13 #include <linux/slab.h>
14 #include "cifspdu.h"
15 #include "cifsglob.h"
16 #include "cifs_debug.h"
17 #include "cifs_unicode.h"
18 #include "cifsproto.h"
19 #include "ntlmssp.h"
20 #include <linux/ctype.h>
21 #include <linux/random.h>
22 #include <linux/highmem.h>
23 #include <linux/fips.h>
24 #include <linux/iov_iter.h>
25 #include <crypto/aead.h>
26 #include <crypto/arc4.h>
27 #include <crypto/md5.h>
28 #include <crypto/sha2.h>
29
cifs_sig_update(struct cifs_calc_sig_ctx * ctx,const u8 * data,size_t len)30 static int cifs_sig_update(struct cifs_calc_sig_ctx *ctx,
31 const u8 *data, size_t len)
32 {
33 if (ctx->md5) {
34 md5_update(ctx->md5, data, len);
35 return 0;
36 }
37 if (ctx->hmac) {
38 hmac_sha256_update(ctx->hmac, data, len);
39 return 0;
40 }
41 return crypto_shash_update(ctx->shash, data, len);
42 }
43
cifs_sig_final(struct cifs_calc_sig_ctx * ctx,u8 * out)44 static int cifs_sig_final(struct cifs_calc_sig_ctx *ctx, u8 *out)
45 {
46 if (ctx->md5) {
47 md5_final(ctx->md5, out);
48 return 0;
49 }
50 if (ctx->hmac) {
51 hmac_sha256_final(ctx->hmac, out);
52 return 0;
53 }
54 return crypto_shash_final(ctx->shash, out);
55 }
56
cifs_sig_step(void * iter_base,size_t progress,size_t len,void * priv,void * priv2)57 static size_t cifs_sig_step(void *iter_base, size_t progress, size_t len,
58 void *priv, void *priv2)
59 {
60 struct cifs_calc_sig_ctx *ctx = priv;
61 int ret, *pret = priv2;
62
63 ret = cifs_sig_update(ctx, iter_base, len);
64 if (ret < 0) {
65 *pret = ret;
66 return len;
67 }
68 return 0;
69 }
70
71 /*
72 * Pass the data from an iterator into a hash.
73 */
cifs_sig_iter(const struct iov_iter * iter,size_t maxsize,struct cifs_calc_sig_ctx * ctx)74 static int cifs_sig_iter(const struct iov_iter *iter, size_t maxsize,
75 struct cifs_calc_sig_ctx *ctx)
76 {
77 struct iov_iter tmp_iter = *iter;
78 int err = -EIO;
79
80 if (iterate_and_advance_kernel(&tmp_iter, maxsize, ctx, &err,
81 cifs_sig_step) != maxsize)
82 return err;
83 return 0;
84 }
85
__cifs_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,char * signature,struct cifs_calc_sig_ctx * ctx)86 int __cifs_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
87 char *signature, struct cifs_calc_sig_ctx *ctx)
88 {
89 int i;
90 ssize_t rc;
91 struct kvec *iov = rqst->rq_iov;
92 int n_vec = rqst->rq_nvec;
93
94 /* iov[0] is actual data and not the rfc1002 length for SMB2+ */
95 if (!is_smb1(server)) {
96 if (iov[0].iov_len <= 4)
97 return -EIO;
98 i = 0;
99 } else {
100 if (n_vec < 2 || iov[0].iov_len != 4)
101 return -EIO;
102 i = 1; /* skip rfc1002 length */
103 }
104
105 for (; i < n_vec; i++) {
106 if (iov[i].iov_len == 0)
107 continue;
108 if (iov[i].iov_base == NULL) {
109 cifs_dbg(VFS, "null iovec entry\n");
110 return -EIO;
111 }
112
113 rc = cifs_sig_update(ctx, iov[i].iov_base, iov[i].iov_len);
114 if (rc) {
115 cifs_dbg(VFS, "%s: Could not update with payload\n",
116 __func__);
117 return rc;
118 }
119 }
120
121 rc = cifs_sig_iter(&rqst->rq_iter, iov_iter_count(&rqst->rq_iter), ctx);
122 if (rc < 0)
123 return rc;
124
125 rc = cifs_sig_final(ctx, signature);
126 if (rc)
127 cifs_dbg(VFS, "%s: Could not generate hash\n", __func__);
128
129 return rc;
130 }
131
132 /*
133 * Calculate and return the CIFS signature based on the mac key and SMB PDU.
134 * The 16 byte signature must be allocated by the caller. Note we only use the
135 * 1st eight bytes and that the smb header signature field on input contains
136 * the sequence number before this function is called. Also, this function
137 * should be called with the server->srv_mutex held.
138 */
cifs_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,char * signature)139 static int cifs_calc_signature(struct smb_rqst *rqst,
140 struct TCP_Server_Info *server, char *signature)
141 {
142 struct md5_ctx ctx;
143
144 if (!rqst->rq_iov || !signature || !server)
145 return -EINVAL;
146 if (fips_enabled) {
147 cifs_dbg(VFS,
148 "MD5 signature support is disabled due to FIPS\n");
149 return -EOPNOTSUPP;
150 }
151
152 md5_init(&ctx);
153 md5_update(&ctx, server->session_key.response, server->session_key.len);
154
155 return __cifs_calc_signature(
156 rqst, server, signature,
157 &(struct cifs_calc_sig_ctx){ .md5 = &ctx });
158 }
159
160 /* 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)161 int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
162 __u32 *pexpected_response_sequence_number)
163 {
164 int rc = 0;
165 char smb_signature[20];
166 struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
167
168 if (rqst->rq_iov[0].iov_len != 4 ||
169 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
170 return -EIO;
171
172 if ((cifs_pdu == NULL) || (server == NULL))
173 return -EINVAL;
174
175 spin_lock(&server->srv_lock);
176 if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) ||
177 server->tcpStatus == CifsNeedNegotiate) {
178 spin_unlock(&server->srv_lock);
179 return rc;
180 }
181 spin_unlock(&server->srv_lock);
182
183 if (!server->session_estab) {
184 memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8);
185 return rc;
186 }
187
188 cifs_pdu->Signature.Sequence.SequenceNumber =
189 cpu_to_le32(server->sequence_number);
190 cifs_pdu->Signature.Sequence.Reserved = 0;
191
192 *pexpected_response_sequence_number = ++server->sequence_number;
193 ++server->sequence_number;
194
195 rc = cifs_calc_signature(rqst, server, smb_signature);
196 if (rc)
197 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
198 else
199 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
200
201 return rc;
202 }
203
cifs_sign_smbv(struct kvec * iov,int n_vec,struct TCP_Server_Info * server,__u32 * pexpected_response_sequence)204 int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
205 __u32 *pexpected_response_sequence)
206 {
207 struct smb_rqst rqst = { .rq_iov = iov,
208 .rq_nvec = n_vec };
209
210 return cifs_sign_rqst(&rqst, server, pexpected_response_sequence);
211 }
212
213 /* 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)214 int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
215 __u32 *pexpected_response_sequence_number)
216 {
217 struct kvec iov[2];
218
219 iov[0].iov_base = cifs_pdu;
220 iov[0].iov_len = 4;
221 iov[1].iov_base = (char *)cifs_pdu + 4;
222 iov[1].iov_len = be32_to_cpu(cifs_pdu->smb_buf_length);
223
224 return cifs_sign_smbv(iov, 2, server,
225 pexpected_response_sequence_number);
226 }
227
cifs_verify_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,__u32 expected_sequence_number)228 int cifs_verify_signature(struct smb_rqst *rqst,
229 struct TCP_Server_Info *server,
230 __u32 expected_sequence_number)
231 {
232 unsigned int rc;
233 char server_response_sig[8];
234 char what_we_think_sig_should_be[20];
235 struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
236
237 if (rqst->rq_iov[0].iov_len != 4 ||
238 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
239 return -EIO;
240
241 if (cifs_pdu == NULL || server == NULL)
242 return -EINVAL;
243
244 if (!server->session_estab)
245 return 0;
246
247 if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
248 struct smb_com_lock_req *pSMB =
249 (struct smb_com_lock_req *)cifs_pdu;
250 if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
251 return 0;
252 }
253
254 /* BB what if signatures are supposed to be on for session but
255 server does not send one? BB */
256
257 /* Do not need to verify session setups with signature "BSRSPYL " */
258 if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0)
259 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
260 cifs_pdu->Command);
261
262 /* save off the original signature so we can modify the smb and check
263 its signature against what the server sent */
264 memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8);
265
266 cifs_pdu->Signature.Sequence.SequenceNumber =
267 cpu_to_le32(expected_sequence_number);
268 cifs_pdu->Signature.Sequence.Reserved = 0;
269
270 cifs_server_lock(server);
271 rc = cifs_calc_signature(rqst, server, what_we_think_sig_should_be);
272 cifs_server_unlock(server);
273
274 if (rc)
275 return rc;
276
277 /* cifs_dump_mem("what we think it should be: ",
278 what_we_think_sig_should_be, 16); */
279
280 if (memcmp(server_response_sig, what_we_think_sig_should_be, 8))
281 return -EACCES;
282 else
283 return 0;
284
285 }
286
287 /* Build a proper attribute value/target info pairs blob.
288 * Fill in netbios and dns domain name and workstation name
289 * and client time (total five av pairs and + one end of fields indicator.
290 * Allocate domain name which gets freed when session struct is deallocated.
291 */
292 static int
build_avpair_blob(struct cifs_ses * ses,const struct nls_table * nls_cp)293 build_avpair_blob(struct cifs_ses *ses, const struct nls_table *nls_cp)
294 {
295 unsigned int dlen;
296 unsigned int size = 2 * sizeof(struct ntlmssp2_name);
297 char *defdmname = "WORKGROUP";
298 unsigned char *blobptr;
299 struct ntlmssp2_name *attrptr;
300
301 if (!ses->domainName) {
302 ses->domainName = kstrdup(defdmname, GFP_KERNEL);
303 if (!ses->domainName)
304 return -ENOMEM;
305 }
306
307 dlen = strlen(ses->domainName);
308
309 /*
310 * The length of this blob is two times the size of a
311 * structure (av pair) which holds name/size
312 * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) +
313 * unicode length of a netbios domain name
314 */
315 kfree_sensitive(ses->auth_key.response);
316 ses->auth_key.len = size + 2 * dlen;
317 ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL);
318 if (!ses->auth_key.response) {
319 ses->auth_key.len = 0;
320 return -ENOMEM;
321 }
322
323 blobptr = ses->auth_key.response;
324 attrptr = (struct ntlmssp2_name *) blobptr;
325
326 /*
327 * As defined in MS-NTLM 3.3.2, just this av pair field
328 * is sufficient as part of the temp
329 */
330 attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME);
331 attrptr->length = cpu_to_le16(2 * dlen);
332 blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
333 cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, nls_cp);
334
335 return 0;
336 }
337
338 #define AV_TYPE(av) (le16_to_cpu(av->type))
339 #define AV_LEN(av) (le16_to_cpu(av->length))
340 #define AV_DATA_PTR(av) ((void *)av->data)
341
342 #define av_for_each_entry(ses, av) \
343 for (av = NULL; (av = find_next_av(ses, av));)
344
find_next_av(struct cifs_ses * ses,struct ntlmssp2_name * av)345 static struct ntlmssp2_name *find_next_av(struct cifs_ses *ses,
346 struct ntlmssp2_name *av)
347 {
348 u16 len;
349 u8 *end;
350
351 end = (u8 *)ses->auth_key.response + ses->auth_key.len;
352 if (!av) {
353 if (unlikely(!ses->auth_key.response || !ses->auth_key.len))
354 return NULL;
355 av = (void *)ses->auth_key.response;
356 } else {
357 av = (void *)((u8 *)av + sizeof(*av) + AV_LEN(av));
358 }
359
360 if ((u8 *)av + sizeof(*av) > end)
361 return NULL;
362
363 len = AV_LEN(av);
364 if (AV_TYPE(av) == NTLMSSP_AV_EOL)
365 return NULL;
366 if ((u8 *)av + sizeof(*av) + len > end)
367 return NULL;
368 return av;
369 }
370
371 /*
372 * Check if server has provided av pair of @type in the NTLMSSP
373 * CHALLENGE_MESSAGE blob.
374 */
find_av_name(struct cifs_ses * ses,u16 type,char ** name,u16 maxlen)375 static int find_av_name(struct cifs_ses *ses, u16 type, char **name, u16 maxlen)
376 {
377 const struct nls_table *nlsc = ses->local_nls;
378 struct ntlmssp2_name *av;
379 u16 len, nlen;
380
381 if (*name)
382 return 0;
383
384 av_for_each_entry(ses, av) {
385 len = AV_LEN(av);
386 if (AV_TYPE(av) != type || !len)
387 continue;
388 if (!IS_ALIGNED(len, sizeof(__le16))) {
389 cifs_dbg(VFS | ONCE, "%s: bad length(%u) for type %u\n",
390 __func__, len, type);
391 continue;
392 }
393 nlen = len / sizeof(__le16);
394 if (nlen <= maxlen) {
395 ++nlen;
396 *name = kmalloc(nlen, GFP_KERNEL);
397 if (!*name)
398 return -ENOMEM;
399 cifs_from_utf16(*name, AV_DATA_PTR(av), nlen,
400 len, nlsc, NO_MAP_UNI_RSVD);
401 break;
402 }
403 }
404 return 0;
405 }
406
407 /* Server has provided av pairs/target info in the type 2 challenge
408 * packet and we have plucked it and stored within smb session.
409 * We parse that blob here to find the server given timestamp
410 * as part of ntlmv2 authentication (or local current time as
411 * default in case of failure)
412 */
find_timestamp(struct cifs_ses * ses)413 static __le64 find_timestamp(struct cifs_ses *ses)
414 {
415 struct ntlmssp2_name *av;
416 struct timespec64 ts;
417
418 av_for_each_entry(ses, av) {
419 if (AV_TYPE(av) == NTLMSSP_AV_TIMESTAMP &&
420 AV_LEN(av) == sizeof(u64))
421 return *((__le64 *)AV_DATA_PTR(av));
422 }
423 ktime_get_real_ts64(&ts);
424 return cpu_to_le64(cifs_UnixTimeToNT(ts));
425 }
426
calc_ntlmv2_hash(struct cifs_ses * ses,char * ntlmv2_hash,const struct nls_table * nls_cp)427 static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
428 const struct nls_table *nls_cp)
429 {
430 int len;
431 char nt_hash[CIFS_NTHASH_SIZE];
432 struct hmac_md5_ctx hmac_ctx;
433 __le16 *user;
434 wchar_t *domain;
435 wchar_t *server;
436
437 /* calculate md4 hash of password */
438 E_md4hash(ses->password, nt_hash, nls_cp);
439
440 hmac_md5_init_usingrawkey(&hmac_ctx, nt_hash, CIFS_NTHASH_SIZE);
441
442 /* convert ses->user_name to unicode */
443 len = ses->user_name ? strlen(ses->user_name) : 0;
444 user = kmalloc(2 + (len * 2), GFP_KERNEL);
445 if (user == NULL)
446 return -ENOMEM;
447
448 if (len) {
449 len = cifs_strtoUTF16(user, ses->user_name, len, nls_cp);
450 UniStrupr(user);
451 } else {
452 *(u16 *)user = 0;
453 }
454
455 hmac_md5_update(&hmac_ctx, (const u8 *)user, 2 * len);
456 kfree(user);
457
458 /* convert ses->domainName to unicode and uppercase */
459 if (ses->domainName) {
460 len = strlen(ses->domainName);
461
462 domain = kmalloc(2 + (len * 2), GFP_KERNEL);
463 if (domain == NULL)
464 return -ENOMEM;
465
466 len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len,
467 nls_cp);
468 hmac_md5_update(&hmac_ctx, (const u8 *)domain, 2 * len);
469 kfree(domain);
470 } else {
471 /* We use ses->ip_addr if no domain name available */
472 len = strlen(ses->ip_addr);
473
474 server = kmalloc(2 + (len * 2), GFP_KERNEL);
475 if (server == NULL)
476 return -ENOMEM;
477
478 len = cifs_strtoUTF16((__le16 *)server, ses->ip_addr, len, nls_cp);
479 hmac_md5_update(&hmac_ctx, (const u8 *)server, 2 * len);
480 kfree(server);
481 }
482
483 hmac_md5_final(&hmac_ctx, ntlmv2_hash);
484 return 0;
485 }
486
CalcNTLMv2_response(const struct cifs_ses * ses,char * ntlmv2_hash)487 static void CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash)
488 {
489 struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *)
490 (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
491 unsigned int hash_len;
492
493 /* The MD5 hash starts at challenge_key.key */
494 hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE +
495 offsetof(struct ntlmv2_resp, challenge.key[0]));
496
497 if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED)
498 memcpy(ntlmv2->challenge.key, ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
499 else
500 memcpy(ntlmv2->challenge.key, ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
501
502 /* Note that the HMAC-MD5 value overwrites ntlmv2->challenge.key */
503 hmac_md5_usingrawkey(ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE,
504 ntlmv2->challenge.key, hash_len,
505 ntlmv2->ntlmv2_hash);
506 }
507
508 /*
509 * Set up NTLMv2 response blob with SPN (cifs/<hostname>) appended to the
510 * existing list of AV pairs.
511 */
set_auth_key_response(struct cifs_ses * ses)512 static int set_auth_key_response(struct cifs_ses *ses)
513 {
514 size_t baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp);
515 size_t len, spnlen, tilen = 0, num_avs = 2 /* SPN + EOL */;
516 struct TCP_Server_Info *server = ses->server;
517 char *spn __free(kfree) = NULL;
518 struct ntlmssp2_name *av;
519 char *rsp = NULL;
520 int rc;
521
522 spnlen = strlen(server->hostname);
523 len = sizeof("cifs/") + spnlen;
524 spn = kmalloc(len, GFP_KERNEL);
525 if (!spn) {
526 rc = -ENOMEM;
527 goto out;
528 }
529
530 spnlen = scnprintf(spn, len, "cifs/%.*s",
531 (int)spnlen, server->hostname);
532
533 av_for_each_entry(ses, av)
534 tilen += sizeof(*av) + AV_LEN(av);
535
536 len = baselen + tilen + spnlen * sizeof(__le16) + num_avs * sizeof(*av);
537 rsp = kmalloc(len, GFP_KERNEL);
538 if (!rsp) {
539 rc = -ENOMEM;
540 goto out;
541 }
542
543 memcpy(rsp + baselen, ses->auth_key.response, tilen);
544 av = (void *)(rsp + baselen + tilen);
545 av->type = cpu_to_le16(NTLMSSP_AV_TARGET_NAME);
546 av->length = cpu_to_le16(spnlen * sizeof(__le16));
547 cifs_strtoUTF16((__le16 *)av->data, spn, spnlen, ses->local_nls);
548 av = (void *)((__u8 *)av + sizeof(*av) + AV_LEN(av));
549 av->type = cpu_to_le16(NTLMSSP_AV_EOL);
550 av->length = 0;
551
552 rc = 0;
553 ses->auth_key.len = len;
554 out:
555 ses->auth_key.response = rsp;
556 return rc;
557 }
558
559 int
setup_ntlmv2_rsp(struct cifs_ses * ses,const struct nls_table * nls_cp)560 setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
561 {
562 unsigned char *tiblob = NULL; /* target info blob */
563 struct ntlmv2_resp *ntlmv2;
564 char ntlmv2_hash[16];
565 __le64 rsp_timestamp;
566 __u64 cc;
567 int rc;
568
569 if (nls_cp == NULL) {
570 cifs_dbg(VFS, "%s called with nls_cp==NULL\n", __func__);
571 return -EINVAL;
572 }
573
574 if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) {
575 if (!ses->domainName) {
576 if (ses->domainAuto) {
577 /*
578 * Domain (workgroup) hasn't been specified in
579 * mount options, so try to find it in
580 * CHALLENGE_MESSAGE message and then use it as
581 * part of NTLMv2 authentication.
582 */
583 rc = find_av_name(ses, NTLMSSP_AV_NB_DOMAIN_NAME,
584 &ses->domainName,
585 CIFS_MAX_DOMAINNAME_LEN);
586 if (rc)
587 goto setup_ntlmv2_rsp_ret;
588 } else {
589 ses->domainName = kstrdup("", GFP_KERNEL);
590 if (!ses->domainName) {
591 rc = -ENOMEM;
592 goto setup_ntlmv2_rsp_ret;
593 }
594 }
595 }
596 rc = find_av_name(ses, NTLMSSP_AV_DNS_DOMAIN_NAME,
597 &ses->dns_dom, CIFS_MAX_DOMAINNAME_LEN);
598 if (rc)
599 goto setup_ntlmv2_rsp_ret;
600 } else {
601 rc = build_avpair_blob(ses, nls_cp);
602 if (rc) {
603 cifs_dbg(VFS, "error %d building av pair blob\n", rc);
604 goto setup_ntlmv2_rsp_ret;
605 }
606 }
607
608 /* Must be within 5 minutes of the server (or in range +/-2h
609 * in case of Mac OS X), so simply carry over server timestamp
610 * (as Windows 7 does)
611 */
612 rsp_timestamp = find_timestamp(ses);
613 get_random_bytes(&cc, sizeof(cc));
614
615 cifs_server_lock(ses->server);
616
617 tiblob = ses->auth_key.response;
618 rc = set_auth_key_response(ses);
619 if (rc) {
620 ses->auth_key.len = 0;
621 goto unlock;
622 }
623
624 ntlmv2 = (struct ntlmv2_resp *)
625 (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
626 ntlmv2->blob_signature = cpu_to_le32(0x00000101);
627 ntlmv2->reserved = 0;
628 ntlmv2->time = rsp_timestamp;
629 ntlmv2->client_chal = cc;
630 ntlmv2->reserved2 = 0;
631
632 if (fips_enabled) {
633 cifs_dbg(VFS, "NTLMv2 support is disabled due to FIPS\n");
634 rc = -EOPNOTSUPP;
635 goto unlock;
636 }
637
638 /* calculate ntlmv2_hash */
639 rc = calc_ntlmv2_hash(ses, ntlmv2_hash, nls_cp);
640 if (rc) {
641 cifs_dbg(VFS, "Could not get NTLMv2 hash, rc=%d\n", rc);
642 goto unlock;
643 }
644
645 /* calculate first part of the client response (CR1) */
646 CalcNTLMv2_response(ses, ntlmv2_hash);
647
648 /* now calculate the session key for NTLMv2 */
649 hmac_md5_usingrawkey(ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE,
650 ntlmv2->ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE,
651 ses->auth_key.response);
652 rc = 0;
653 unlock:
654 cifs_server_unlock(ses->server);
655 setup_ntlmv2_rsp_ret:
656 kfree_sensitive(tiblob);
657
658 return rc;
659 }
660
661 int
calc_seckey(struct cifs_ses * ses)662 calc_seckey(struct cifs_ses *ses)
663 {
664 unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */
665 struct arc4_ctx *ctx_arc4;
666
667 if (fips_enabled)
668 return -ENODEV;
669
670 get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE);
671
672 ctx_arc4 = kmalloc(sizeof(*ctx_arc4), GFP_KERNEL);
673 if (!ctx_arc4) {
674 cifs_dbg(VFS, "Could not allocate arc4 context\n");
675 return -ENOMEM;
676 }
677
678 arc4_setkey(ctx_arc4, ses->auth_key.response, CIFS_SESS_KEY_SIZE);
679 arc4_crypt(ctx_arc4, ses->ntlmssp->ciphertext, sec_key,
680 CIFS_CPHTXT_SIZE);
681
682 /* make secondary_key/nonce as session key */
683 memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE);
684 /* and make len as that of session key only */
685 ses->auth_key.len = CIFS_SESS_KEY_SIZE;
686
687 memzero_explicit(sec_key, CIFS_SESS_KEY_SIZE);
688 kfree_sensitive(ctx_arc4);
689 return 0;
690 }
691
692 void
cifs_crypto_secmech_release(struct TCP_Server_Info * server)693 cifs_crypto_secmech_release(struct TCP_Server_Info *server)
694 {
695 cifs_free_hash(&server->secmech.aes_cmac);
696
697 if (server->secmech.enc) {
698 crypto_free_aead(server->secmech.enc);
699 server->secmech.enc = NULL;
700 }
701 if (server->secmech.dec) {
702 crypto_free_aead(server->secmech.dec);
703 server->secmech.dec = NULL;
704 }
705 }
706