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 "cifsglob.h"
15 #include "cifs_debug.h"
16 #include "cifs_unicode.h"
17 #include "cifsproto.h"
18 #include "ntlmssp.h"
19 #include <linux/ctype.h>
20 #include <linux/random.h>
21 #include <linux/highmem.h>
22 #include <linux/fips.h>
23 #include <linux/iov_iter.h>
24 #include <crypto/aead.h>
25 #include <crypto/arc4.h>
26 #include <crypto/md5.h>
27 #include <crypto/sha2.h>
28
cifs_sig_update(struct cifs_calc_sig_ctx * ctx,const u8 * data,size_t len)29 static int cifs_sig_update(struct cifs_calc_sig_ctx *ctx,
30 const u8 *data, size_t len)
31 {
32 if (ctx->md5) {
33 md5_update(ctx->md5, data, len);
34 return 0;
35 }
36 if (ctx->hmac) {
37 hmac_sha256_update(ctx->hmac, data, len);
38 return 0;
39 }
40 return crypto_shash_update(ctx->shash, data, len);
41 }
42
cifs_sig_final(struct cifs_calc_sig_ctx * ctx,u8 * out)43 static int cifs_sig_final(struct cifs_calc_sig_ctx *ctx, u8 *out)
44 {
45 if (ctx->md5) {
46 md5_final(ctx->md5, out);
47 return 0;
48 }
49 if (ctx->hmac) {
50 hmac_sha256_final(ctx->hmac, out);
51 return 0;
52 }
53 return crypto_shash_final(ctx->shash, out);
54 }
55
cifs_sig_step(void * iter_base,size_t progress,size_t len,void * priv,void * priv2)56 static size_t cifs_sig_step(void *iter_base, size_t progress, size_t len,
57 void *priv, void *priv2)
58 {
59 struct cifs_calc_sig_ctx *ctx = priv;
60 int ret, *pret = priv2;
61
62 ret = cifs_sig_update(ctx, iter_base, len);
63 if (ret < 0) {
64 *pret = ret;
65 return len;
66 }
67 return 0;
68 }
69
70 /*
71 * Pass the data from an iterator into a hash.
72 */
cifs_sig_iter(const struct iov_iter * iter,size_t maxsize,struct cifs_calc_sig_ctx * ctx)73 static int cifs_sig_iter(const struct iov_iter *iter, size_t maxsize,
74 struct cifs_calc_sig_ctx *ctx)
75 {
76 struct iov_iter tmp_iter = *iter;
77 size_t did;
78 int err;
79
80 did = iterate_and_advance_kernel(&tmp_iter, maxsize, ctx, &err,
81 cifs_sig_step);
82 if (did != maxsize)
83 return smb_EIO2(smb_eio_trace_sig_iter, did, maxsize);
84 return 0;
85 }
86
__cifs_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,char * signature,struct cifs_calc_sig_ctx * ctx)87 int __cifs_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
88 char *signature, struct cifs_calc_sig_ctx *ctx)
89 {
90 struct iov_iter iter;
91 ssize_t rc;
92 size_t size = 0;
93
94 for (int i = 0; i < rqst->rq_nvec; i++)
95 size += rqst->rq_iov[i].iov_len;
96
97 iov_iter_kvec(&iter, ITER_SOURCE, rqst->rq_iov, rqst->rq_nvec, size);
98
99 if (iov_iter_count(&iter) <= 4)
100 return smb_EIO2(smb_eio_trace_sig_data_too_small,
101 iov_iter_count(&iter), 4);
102
103 rc = cifs_sig_iter(&iter, iov_iter_count(&iter), ctx);
104 if (rc < 0)
105 return rc;
106
107 rc = cifs_sig_iter(&rqst->rq_iter, iov_iter_count(&rqst->rq_iter), ctx);
108 if (rc < 0)
109 return rc;
110
111 rc = cifs_sig_final(ctx, signature);
112 if (rc)
113 cifs_dbg(VFS, "%s: Could not generate hash\n", __func__);
114
115 return rc;
116 }
117
118 /* Build a proper attribute value/target info pairs blob.
119 * Fill in netbios and dns domain name and workstation name
120 * and client time (total five av pairs and + one end of fields indicator.
121 * Allocate domain name which gets freed when session struct is deallocated.
122 */
123 static int
build_avpair_blob(struct cifs_ses * ses,const struct nls_table * nls_cp)124 build_avpair_blob(struct cifs_ses *ses, const struct nls_table *nls_cp)
125 {
126 unsigned int dlen;
127 unsigned int size = 2 * sizeof(struct ntlmssp2_name);
128 char *defdmname = "WORKGROUP";
129 unsigned char *blobptr;
130 struct ntlmssp2_name *attrptr;
131
132 if (!ses->domainName) {
133 ses->domainName = kstrdup(defdmname, GFP_KERNEL);
134 if (!ses->domainName)
135 return -ENOMEM;
136 }
137
138 dlen = strlen(ses->domainName);
139
140 /*
141 * The length of this blob is two times the size of a
142 * structure (av pair) which holds name/size
143 * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) +
144 * unicode length of a netbios domain name
145 */
146 kfree_sensitive(ses->auth_key.response);
147 ses->auth_key.len = size + 2 * dlen;
148 ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL);
149 if (!ses->auth_key.response) {
150 ses->auth_key.len = 0;
151 return -ENOMEM;
152 }
153
154 blobptr = ses->auth_key.response;
155 attrptr = (struct ntlmssp2_name *) blobptr;
156
157 /*
158 * As defined in MS-NTLM 3.3.2, just this av pair field
159 * is sufficient as part of the temp
160 */
161 attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME);
162 attrptr->length = cpu_to_le16(2 * dlen);
163 blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
164 cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, nls_cp);
165
166 return 0;
167 }
168
169 #define AV_TYPE(av) (le16_to_cpu(av->type))
170 #define AV_LEN(av) (le16_to_cpu(av->length))
171 #define AV_DATA_PTR(av) ((void *)av->data)
172
173 #define av_for_each_entry(ses, av) \
174 for (av = NULL; (av = find_next_av(ses, av));)
175
find_next_av(struct cifs_ses * ses,struct ntlmssp2_name * av)176 static struct ntlmssp2_name *find_next_av(struct cifs_ses *ses,
177 struct ntlmssp2_name *av)
178 {
179 u16 len;
180 u8 *end;
181
182 end = (u8 *)ses->auth_key.response + ses->auth_key.len;
183 if (!av) {
184 if (unlikely(!ses->auth_key.response || !ses->auth_key.len))
185 return NULL;
186 av = (void *)ses->auth_key.response;
187 } else {
188 av = (void *)((u8 *)av + sizeof(*av) + AV_LEN(av));
189 }
190
191 if ((u8 *)av + sizeof(*av) > end)
192 return NULL;
193
194 len = AV_LEN(av);
195 if (AV_TYPE(av) == NTLMSSP_AV_EOL)
196 return NULL;
197 if ((u8 *)av + sizeof(*av) + len > end)
198 return NULL;
199 return av;
200 }
201
202 /*
203 * Check if server has provided av pair of @type in the NTLMSSP
204 * CHALLENGE_MESSAGE blob.
205 */
find_av_name(struct cifs_ses * ses,u16 type,char ** name,u16 maxlen)206 static int find_av_name(struct cifs_ses *ses, u16 type, char **name, u16 maxlen)
207 {
208 const struct nls_table *nlsc = ses->local_nls;
209 struct ntlmssp2_name *av;
210 u16 len, nlen;
211
212 if (*name)
213 return 0;
214
215 av_for_each_entry(ses, av) {
216 len = AV_LEN(av);
217 if (AV_TYPE(av) != type || !len)
218 continue;
219 if (!IS_ALIGNED(len, sizeof(__le16))) {
220 cifs_dbg(VFS | ONCE, "%s: bad length(%u) for type %u\n",
221 __func__, len, type);
222 continue;
223 }
224 nlen = len / sizeof(__le16);
225 if (nlen <= maxlen) {
226 ++nlen;
227 *name = kmalloc(nlen, GFP_KERNEL);
228 if (!*name)
229 return -ENOMEM;
230 cifs_from_utf16(*name, AV_DATA_PTR(av), nlen,
231 len, nlsc, NO_MAP_UNI_RSVD);
232 break;
233 }
234 }
235 return 0;
236 }
237
238 /* Server has provided av pairs/target info in the type 2 challenge
239 * packet and we have plucked it and stored within smb session.
240 * We parse that blob here to find the server given timestamp
241 * as part of ntlmv2 authentication (or local current time as
242 * default in case of failure)
243 */
find_timestamp(struct cifs_ses * ses)244 static __le64 find_timestamp(struct cifs_ses *ses)
245 {
246 struct ntlmssp2_name *av;
247 struct timespec64 ts;
248
249 av_for_each_entry(ses, av) {
250 if (AV_TYPE(av) == NTLMSSP_AV_TIMESTAMP &&
251 AV_LEN(av) == sizeof(u64))
252 return *((__le64 *)AV_DATA_PTR(av));
253 }
254 ktime_get_real_ts64(&ts);
255 return cpu_to_le64(cifs_UnixTimeToNT(ts));
256 }
257
calc_ntlmv2_hash(struct cifs_ses * ses,char * ntlmv2_hash,const struct nls_table * nls_cp)258 static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
259 const struct nls_table *nls_cp)
260 {
261 int len;
262 char nt_hash[CIFS_NTHASH_SIZE];
263 struct hmac_md5_ctx hmac_ctx;
264 __le16 *user;
265 wchar_t *domain;
266 wchar_t *server;
267
268 /* calculate md4 hash of password */
269 E_md4hash(ses->password, nt_hash, nls_cp);
270
271 hmac_md5_init_usingrawkey(&hmac_ctx, nt_hash, CIFS_NTHASH_SIZE);
272
273 /* convert ses->user_name to unicode */
274 len = ses->user_name ? strlen(ses->user_name) : 0;
275 user = kmalloc(2 + (len * 2), GFP_KERNEL);
276 if (user == NULL)
277 return -ENOMEM;
278
279 if (len) {
280 len = cifs_strtoUTF16(user, ses->user_name, len, nls_cp);
281 UniStrupr(user);
282 } else {
283 *(u16 *)user = 0;
284 }
285
286 hmac_md5_update(&hmac_ctx, (const u8 *)user, 2 * len);
287 kfree(user);
288
289 /* convert ses->domainName to unicode and uppercase */
290 if (ses->domainName) {
291 len = strlen(ses->domainName);
292
293 domain = kmalloc(2 + (len * 2), GFP_KERNEL);
294 if (domain == NULL)
295 return -ENOMEM;
296
297 len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len,
298 nls_cp);
299 hmac_md5_update(&hmac_ctx, (const u8 *)domain, 2 * len);
300 kfree(domain);
301 } else {
302 /* We use ses->ip_addr if no domain name available */
303 len = strlen(ses->ip_addr);
304
305 server = kmalloc(2 + (len * 2), GFP_KERNEL);
306 if (server == NULL)
307 return -ENOMEM;
308
309 len = cifs_strtoUTF16((__le16 *)server, ses->ip_addr, len, nls_cp);
310 hmac_md5_update(&hmac_ctx, (const u8 *)server, 2 * len);
311 kfree(server);
312 }
313
314 hmac_md5_final(&hmac_ctx, ntlmv2_hash);
315 return 0;
316 }
317
CalcNTLMv2_response(const struct cifs_ses * ses,char * ntlmv2_hash)318 static void CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash)
319 {
320 struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *)
321 (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
322 unsigned int hash_len;
323
324 /* The MD5 hash starts at challenge_key.key */
325 hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE +
326 offsetof(struct ntlmv2_resp, challenge.key[0]));
327
328 if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED)
329 memcpy(ntlmv2->challenge.key, ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
330 else
331 memcpy(ntlmv2->challenge.key, ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
332
333 /* Note that the HMAC-MD5 value overwrites ntlmv2->challenge.key */
334 hmac_md5_usingrawkey(ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE,
335 ntlmv2->challenge.key, hash_len,
336 ntlmv2->ntlmv2_hash);
337 }
338
339 /*
340 * Set up NTLMv2 response blob with SPN (cifs/<hostname>) appended to the
341 * existing list of AV pairs.
342 */
set_auth_key_response(struct cifs_ses * ses)343 static int set_auth_key_response(struct cifs_ses *ses)
344 {
345 size_t baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp);
346 size_t len, spnlen, tilen = 0, num_avs = 2 /* SPN + EOL */;
347 struct TCP_Server_Info *server = ses->server;
348 char *spn __free(kfree) = NULL;
349 struct ntlmssp2_name *av;
350 char *rsp = NULL;
351 int rc;
352
353 spnlen = strlen(server->hostname);
354 len = sizeof("cifs/") + spnlen;
355 spn = kmalloc(len, GFP_KERNEL);
356 if (!spn) {
357 rc = -ENOMEM;
358 goto out;
359 }
360
361 spnlen = scnprintf(spn, len, "cifs/%.*s",
362 (int)spnlen, server->hostname);
363
364 av_for_each_entry(ses, av)
365 tilen += sizeof(*av) + AV_LEN(av);
366
367 len = baselen + tilen + spnlen * sizeof(__le16) + num_avs * sizeof(*av);
368 rsp = kmalloc(len, GFP_KERNEL);
369 if (!rsp) {
370 rc = -ENOMEM;
371 goto out;
372 }
373
374 memcpy(rsp + baselen, ses->auth_key.response, tilen);
375 av = (void *)(rsp + baselen + tilen);
376 av->type = cpu_to_le16(NTLMSSP_AV_TARGET_NAME);
377 av->length = cpu_to_le16(spnlen * sizeof(__le16));
378 cifs_strtoUTF16((__le16 *)av->data, spn, spnlen, ses->local_nls);
379 av = (void *)((__u8 *)av + sizeof(*av) + AV_LEN(av));
380 av->type = cpu_to_le16(NTLMSSP_AV_EOL);
381 av->length = 0;
382
383 rc = 0;
384 ses->auth_key.len = len;
385 out:
386 ses->auth_key.response = rsp;
387 return rc;
388 }
389
390 int
setup_ntlmv2_rsp(struct cifs_ses * ses,const struct nls_table * nls_cp)391 setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
392 {
393 unsigned char *tiblob = NULL; /* target info blob */
394 struct ntlmv2_resp *ntlmv2;
395 char ntlmv2_hash[16];
396 __le64 rsp_timestamp;
397 __u64 cc;
398 int rc;
399
400 if (nls_cp == NULL) {
401 cifs_dbg(VFS, "%s called with nls_cp==NULL\n", __func__);
402 return -EINVAL;
403 }
404
405 if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) {
406 if (!ses->domainName) {
407 if (ses->domainAuto) {
408 /*
409 * Domain (workgroup) hasn't been specified in
410 * mount options, so try to find it in
411 * CHALLENGE_MESSAGE message and then use it as
412 * part of NTLMv2 authentication.
413 */
414 rc = find_av_name(ses, NTLMSSP_AV_NB_DOMAIN_NAME,
415 &ses->domainName,
416 CIFS_MAX_DOMAINNAME_LEN);
417 if (rc)
418 goto setup_ntlmv2_rsp_ret;
419 } else {
420 ses->domainName = kstrdup("", GFP_KERNEL);
421 if (!ses->domainName) {
422 rc = -ENOMEM;
423 goto setup_ntlmv2_rsp_ret;
424 }
425 }
426 }
427 rc = find_av_name(ses, NTLMSSP_AV_DNS_DOMAIN_NAME,
428 &ses->dns_dom, CIFS_MAX_DOMAINNAME_LEN);
429 if (rc)
430 goto setup_ntlmv2_rsp_ret;
431 } else {
432 rc = build_avpair_blob(ses, nls_cp);
433 if (rc) {
434 cifs_dbg(VFS, "error %d building av pair blob\n", rc);
435 goto setup_ntlmv2_rsp_ret;
436 }
437 }
438
439 /* Must be within 5 minutes of the server (or in range +/-2h
440 * in case of Mac OS X), so simply carry over server timestamp
441 * (as Windows 7 does)
442 */
443 rsp_timestamp = find_timestamp(ses);
444 get_random_bytes(&cc, sizeof(cc));
445
446 cifs_server_lock(ses->server);
447
448 tiblob = ses->auth_key.response;
449 rc = set_auth_key_response(ses);
450 if (rc) {
451 ses->auth_key.len = 0;
452 goto unlock;
453 }
454
455 ntlmv2 = (struct ntlmv2_resp *)
456 (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
457 ntlmv2->blob_signature = cpu_to_le32(0x00000101);
458 ntlmv2->reserved = 0;
459 ntlmv2->time = rsp_timestamp;
460 ntlmv2->client_chal = cc;
461 ntlmv2->reserved2 = 0;
462
463 if (fips_enabled) {
464 cifs_dbg(VFS, "NTLMv2 support is disabled due to FIPS\n");
465 rc = -EOPNOTSUPP;
466 goto unlock;
467 }
468
469 /* calculate ntlmv2_hash */
470 rc = calc_ntlmv2_hash(ses, ntlmv2_hash, nls_cp);
471 if (rc) {
472 cifs_dbg(VFS, "Could not get NTLMv2 hash, rc=%d\n", rc);
473 goto unlock;
474 }
475
476 /* calculate first part of the client response (CR1) */
477 CalcNTLMv2_response(ses, ntlmv2_hash);
478
479 /* now calculate the session key for NTLMv2 */
480 hmac_md5_usingrawkey(ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE,
481 ntlmv2->ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE,
482 ses->auth_key.response);
483 rc = 0;
484 unlock:
485 cifs_server_unlock(ses->server);
486 setup_ntlmv2_rsp_ret:
487 kfree_sensitive(tiblob);
488
489 return rc;
490 }
491
492 int
calc_seckey(struct cifs_ses * ses)493 calc_seckey(struct cifs_ses *ses)
494 {
495 unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */
496 struct arc4_ctx *ctx_arc4;
497
498 if (fips_enabled)
499 return -ENODEV;
500
501 get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE);
502
503 ctx_arc4 = kmalloc_obj(*ctx_arc4);
504 if (!ctx_arc4) {
505 cifs_dbg(VFS, "Could not allocate arc4 context\n");
506 return -ENOMEM;
507 }
508
509 arc4_setkey(ctx_arc4, ses->auth_key.response, CIFS_SESS_KEY_SIZE);
510 arc4_crypt(ctx_arc4, ses->ntlmssp->ciphertext, sec_key,
511 CIFS_CPHTXT_SIZE);
512
513 /* make secondary_key/nonce as session key */
514 memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE);
515 /* and make len as that of session key only */
516 ses->auth_key.len = CIFS_SESS_KEY_SIZE;
517
518 memzero_explicit(sec_key, CIFS_SESS_KEY_SIZE);
519 kfree_sensitive(ctx_arc4);
520 return 0;
521 }
522
523 void
cifs_crypto_secmech_release(struct TCP_Server_Info * server)524 cifs_crypto_secmech_release(struct TCP_Server_Info *server)
525 {
526 cifs_free_hash(&server->secmech.aes_cmac);
527
528 if (server->secmech.enc) {
529 crypto_free_aead(server->secmech.enc);
530 server->secmech.enc = NULL;
531 }
532 if (server->secmech.dec) {
533 crypto_free_aead(server->secmech.dec);
534 server->secmech.dec = NULL;
535 }
536 }
537