xref: /openbmc/linux/fs/smb/client/cifsencrypt.c (revision 8fbefa7a)
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 "../common/arc4.h"
25 #include <crypto/aead.h>
26 
27 /*
28  * Hash data from a BVEC-type iterator.
29  */
cifs_shash_bvec(const struct iov_iter * iter,ssize_t maxsize,struct shash_desc * shash)30 static int cifs_shash_bvec(const struct iov_iter *iter, ssize_t maxsize,
31 			   struct shash_desc *shash)
32 {
33 	const struct bio_vec *bv = iter->bvec;
34 	unsigned long start = iter->iov_offset;
35 	unsigned int i;
36 	void *p;
37 	int ret;
38 
39 	for (i = 0; i < iter->nr_segs; i++) {
40 		size_t off, len;
41 
42 		len = bv[i].bv_len;
43 		if (start >= len) {
44 			start -= len;
45 			continue;
46 		}
47 
48 		len = min_t(size_t, maxsize, len - start);
49 		off = bv[i].bv_offset + start;
50 
51 		p = kmap_local_page(bv[i].bv_page);
52 		ret = crypto_shash_update(shash, p + off, len);
53 		kunmap_local(p);
54 		if (ret < 0)
55 			return ret;
56 
57 		maxsize -= len;
58 		if (maxsize <= 0)
59 			break;
60 		start = 0;
61 	}
62 
63 	return 0;
64 }
65 
66 /*
67  * Hash data from a KVEC-type iterator.
68  */
cifs_shash_kvec(const struct iov_iter * iter,ssize_t maxsize,struct shash_desc * shash)69 static int cifs_shash_kvec(const struct iov_iter *iter, ssize_t maxsize,
70 			   struct shash_desc *shash)
71 {
72 	const struct kvec *kv = iter->kvec;
73 	unsigned long start = iter->iov_offset;
74 	unsigned int i;
75 	int ret;
76 
77 	for (i = 0; i < iter->nr_segs; i++) {
78 		size_t len;
79 
80 		len = kv[i].iov_len;
81 		if (start >= len) {
82 			start -= len;
83 			continue;
84 		}
85 
86 		len = min_t(size_t, maxsize, len - start);
87 		ret = crypto_shash_update(shash, kv[i].iov_base + start, len);
88 		if (ret < 0)
89 			return ret;
90 		maxsize -= len;
91 
92 		if (maxsize <= 0)
93 			break;
94 		start = 0;
95 	}
96 
97 	return 0;
98 }
99 
100 /*
101  * Hash data from an XARRAY-type iterator.
102  */
cifs_shash_xarray(const struct iov_iter * iter,ssize_t maxsize,struct shash_desc * shash)103 static ssize_t cifs_shash_xarray(const struct iov_iter *iter, ssize_t maxsize,
104 				 struct shash_desc *shash)
105 {
106 	struct folio *folios[16], *folio;
107 	unsigned int nr, i, j, npages;
108 	loff_t start = iter->xarray_start + iter->iov_offset;
109 	pgoff_t last, index = start / PAGE_SIZE;
110 	ssize_t ret = 0;
111 	size_t len, offset, foffset;
112 	void *p;
113 
114 	if (maxsize == 0)
115 		return 0;
116 
117 	last = (start + maxsize - 1) / PAGE_SIZE;
118 	do {
119 		nr = xa_extract(iter->xarray, (void **)folios, index, last,
120 				ARRAY_SIZE(folios), XA_PRESENT);
121 		if (nr == 0)
122 			return -EIO;
123 
124 		for (i = 0; i < nr; i++) {
125 			folio = folios[i];
126 			npages = folio_nr_pages(folio);
127 			foffset = start - folio_pos(folio);
128 			offset = foffset % PAGE_SIZE;
129 			for (j = foffset / PAGE_SIZE; j < npages; j++) {
130 				len = min_t(size_t, maxsize, PAGE_SIZE - offset);
131 				p = kmap_local_page(folio_page(folio, j));
132 				ret = crypto_shash_update(shash, p, len);
133 				kunmap_local(p);
134 				if (ret < 0)
135 					return ret;
136 				maxsize -= len;
137 				if (maxsize <= 0)
138 					return 0;
139 				start += len;
140 				offset = 0;
141 				index++;
142 			}
143 		}
144 	} while (nr == ARRAY_SIZE(folios));
145 	return 0;
146 }
147 
148 /*
149  * Pass the data from an iterator into a hash.
150  */
cifs_shash_iter(const struct iov_iter * iter,size_t maxsize,struct shash_desc * shash)151 static int cifs_shash_iter(const struct iov_iter *iter, size_t maxsize,
152 			   struct shash_desc *shash)
153 {
154 	if (maxsize == 0)
155 		return 0;
156 
157 	switch (iov_iter_type(iter)) {
158 	case ITER_BVEC:
159 		return cifs_shash_bvec(iter, maxsize, shash);
160 	case ITER_KVEC:
161 		return cifs_shash_kvec(iter, maxsize, shash);
162 	case ITER_XARRAY:
163 		return cifs_shash_xarray(iter, maxsize, shash);
164 	default:
165 		pr_err("cifs_shash_iter(%u) unsupported\n", iov_iter_type(iter));
166 		WARN_ON_ONCE(1);
167 		return -EIO;
168 	}
169 }
170 
__cifs_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,char * signature,struct shash_desc * shash)171 int __cifs_calc_signature(struct smb_rqst *rqst,
172 			  struct TCP_Server_Info *server, char *signature,
173 			  struct shash_desc *shash)
174 {
175 	int i;
176 	ssize_t rc;
177 	struct kvec *iov = rqst->rq_iov;
178 	int n_vec = rqst->rq_nvec;
179 
180 	/* iov[0] is actual data and not the rfc1002 length for SMB2+ */
181 	if (!is_smb1(server)) {
182 		if (iov[0].iov_len <= 4)
183 			return -EIO;
184 		i = 0;
185 	} else {
186 		if (n_vec < 2 || iov[0].iov_len != 4)
187 			return -EIO;
188 		i = 1; /* skip rfc1002 length */
189 	}
190 
191 	for (; i < n_vec; i++) {
192 		if (iov[i].iov_len == 0)
193 			continue;
194 		if (iov[i].iov_base == NULL) {
195 			cifs_dbg(VFS, "null iovec entry\n");
196 			return -EIO;
197 		}
198 
199 		rc = crypto_shash_update(shash,
200 					 iov[i].iov_base, iov[i].iov_len);
201 		if (rc) {
202 			cifs_dbg(VFS, "%s: Could not update with payload\n",
203 				 __func__);
204 			return rc;
205 		}
206 	}
207 
208 	rc = cifs_shash_iter(&rqst->rq_iter, iov_iter_count(&rqst->rq_iter), shash);
209 	if (rc < 0)
210 		return rc;
211 
212 	rc = crypto_shash_final(shash, signature);
213 	if (rc)
214 		cifs_dbg(VFS, "%s: Could not generate hash\n", __func__);
215 
216 	return rc;
217 }
218 
219 /*
220  * Calculate and return the CIFS signature based on the mac key and SMB PDU.
221  * The 16 byte signature must be allocated by the caller. Note we only use the
222  * 1st eight bytes and that the smb header signature field on input contains
223  * the sequence number before this function is called. Also, this function
224  * should be called with the server->srv_mutex held.
225  */
cifs_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,char * signature)226 static int cifs_calc_signature(struct smb_rqst *rqst,
227 			struct TCP_Server_Info *server, char *signature)
228 {
229 	int rc;
230 
231 	if (!rqst->rq_iov || !signature || !server)
232 		return -EINVAL;
233 
234 	rc = cifs_alloc_hash("md5", &server->secmech.md5);
235 	if (rc)
236 		return -1;
237 
238 	rc = crypto_shash_init(server->secmech.md5);
239 	if (rc) {
240 		cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
241 		return rc;
242 	}
243 
244 	rc = crypto_shash_update(server->secmech.md5,
245 		server->session_key.response, server->session_key.len);
246 	if (rc) {
247 		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
248 		return rc;
249 	}
250 
251 	return __cifs_calc_signature(rqst, server, signature, server->secmech.md5);
252 }
253 
254 /* 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)255 int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
256 		   __u32 *pexpected_response_sequence_number)
257 {
258 	int rc = 0;
259 	char smb_signature[20];
260 	struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
261 
262 	if (rqst->rq_iov[0].iov_len != 4 ||
263 	    rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
264 		return -EIO;
265 
266 	if ((cifs_pdu == NULL) || (server == NULL))
267 		return -EINVAL;
268 
269 	spin_lock(&server->srv_lock);
270 	if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) ||
271 	    server->tcpStatus == CifsNeedNegotiate) {
272 		spin_unlock(&server->srv_lock);
273 		return rc;
274 	}
275 	spin_unlock(&server->srv_lock);
276 
277 	if (!server->session_estab) {
278 		memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8);
279 		return rc;
280 	}
281 
282 	cifs_pdu->Signature.Sequence.SequenceNumber =
283 				cpu_to_le32(server->sequence_number);
284 	cifs_pdu->Signature.Sequence.Reserved = 0;
285 
286 	*pexpected_response_sequence_number = ++server->sequence_number;
287 	++server->sequence_number;
288 
289 	rc = cifs_calc_signature(rqst, server, smb_signature);
290 	if (rc)
291 		memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
292 	else
293 		memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
294 
295 	return rc;
296 }
297 
cifs_sign_smbv(struct kvec * iov,int n_vec,struct TCP_Server_Info * server,__u32 * pexpected_response_sequence)298 int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
299 		   __u32 *pexpected_response_sequence)
300 {
301 	struct smb_rqst rqst = { .rq_iov = iov,
302 				 .rq_nvec = n_vec };
303 
304 	return cifs_sign_rqst(&rqst, server, pexpected_response_sequence);
305 }
306 
307 /* 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)308 int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
309 		  __u32 *pexpected_response_sequence_number)
310 {
311 	struct kvec iov[2];
312 
313 	iov[0].iov_base = cifs_pdu;
314 	iov[0].iov_len = 4;
315 	iov[1].iov_base = (char *)cifs_pdu + 4;
316 	iov[1].iov_len = be32_to_cpu(cifs_pdu->smb_buf_length);
317 
318 	return cifs_sign_smbv(iov, 2, server,
319 			      pexpected_response_sequence_number);
320 }
321 
cifs_verify_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,__u32 expected_sequence_number)322 int cifs_verify_signature(struct smb_rqst *rqst,
323 			  struct TCP_Server_Info *server,
324 			  __u32 expected_sequence_number)
325 {
326 	unsigned int rc;
327 	char server_response_sig[8];
328 	char what_we_think_sig_should_be[20];
329 	struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
330 
331 	if (rqst->rq_iov[0].iov_len != 4 ||
332 	    rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
333 		return -EIO;
334 
335 	if (cifs_pdu == NULL || server == NULL)
336 		return -EINVAL;
337 
338 	if (!server->session_estab)
339 		return 0;
340 
341 	if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
342 		struct smb_com_lock_req *pSMB =
343 			(struct smb_com_lock_req *)cifs_pdu;
344 		if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
345 			return 0;
346 	}
347 
348 	/* BB what if signatures are supposed to be on for session but
349 	   server does not send one? BB */
350 
351 	/* Do not need to verify session setups with signature "BSRSPYL "  */
352 	if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0)
353 		cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
354 			 cifs_pdu->Command);
355 
356 	/* save off the origiginal signature so we can modify the smb and check
357 		its signature against what the server sent */
358 	memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8);
359 
360 	cifs_pdu->Signature.Sequence.SequenceNumber =
361 					cpu_to_le32(expected_sequence_number);
362 	cifs_pdu->Signature.Sequence.Reserved = 0;
363 
364 	cifs_server_lock(server);
365 	rc = cifs_calc_signature(rqst, server, what_we_think_sig_should_be);
366 	cifs_server_unlock(server);
367 
368 	if (rc)
369 		return rc;
370 
371 /*	cifs_dump_mem("what we think it should be: ",
372 		      what_we_think_sig_should_be, 16); */
373 
374 	if (memcmp(server_response_sig, what_we_think_sig_should_be, 8))
375 		return -EACCES;
376 	else
377 		return 0;
378 
379 }
380 
381 /* Build a proper attribute value/target info pairs blob.
382  * Fill in netbios and dns domain name and workstation name
383  * and client time (total five av pairs and + one end of fields indicator.
384  * Allocate domain name which gets freed when session struct is deallocated.
385  */
386 static int
build_avpair_blob(struct cifs_ses * ses,const struct nls_table * nls_cp)387 build_avpair_blob(struct cifs_ses *ses, const struct nls_table *nls_cp)
388 {
389 	unsigned int dlen;
390 	unsigned int size = 2 * sizeof(struct ntlmssp2_name);
391 	char *defdmname = "WORKGROUP";
392 	unsigned char *blobptr;
393 	struct ntlmssp2_name *attrptr;
394 
395 	if (!ses->domainName) {
396 		ses->domainName = kstrdup(defdmname, GFP_KERNEL);
397 		if (!ses->domainName)
398 			return -ENOMEM;
399 	}
400 
401 	dlen = strlen(ses->domainName);
402 
403 	/*
404 	 * The length of this blob is two times the size of a
405 	 * structure (av pair) which holds name/size
406 	 * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) +
407 	 * unicode length of a netbios domain name
408 	 */
409 	kfree_sensitive(ses->auth_key.response);
410 	ses->auth_key.len = size + 2 * dlen;
411 	ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL);
412 	if (!ses->auth_key.response) {
413 		ses->auth_key.len = 0;
414 		return -ENOMEM;
415 	}
416 
417 	blobptr = ses->auth_key.response;
418 	attrptr = (struct ntlmssp2_name *) blobptr;
419 
420 	/*
421 	 * As defined in MS-NTLM 3.3.2, just this av pair field
422 	 * is sufficient as part of the temp
423 	 */
424 	attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME);
425 	attrptr->length = cpu_to_le16(2 * dlen);
426 	blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
427 	cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, nls_cp);
428 
429 	return 0;
430 }
431 
432 /* Server has provided av pairs/target info in the type 2 challenge
433  * packet and we have plucked it and stored within smb session.
434  * We parse that blob here to find netbios domain name to be used
435  * as part of ntlmv2 authentication (in Target String), if not already
436  * specified on the command line.
437  * If this function returns without any error but without fetching
438  * domain name, authentication may fail against some server but
439  * may not fail against other (those who are not very particular
440  * about target string i.e. for some, just user name might suffice.
441  */
442 static int
find_domain_name(struct cifs_ses * ses,const struct nls_table * nls_cp)443 find_domain_name(struct cifs_ses *ses, const struct nls_table *nls_cp)
444 {
445 	unsigned int attrsize;
446 	unsigned int type;
447 	unsigned int onesize = sizeof(struct ntlmssp2_name);
448 	unsigned char *blobptr;
449 	unsigned char *blobend;
450 	struct ntlmssp2_name *attrptr;
451 
452 	if (!ses->auth_key.len || !ses->auth_key.response)
453 		return 0;
454 
455 	blobptr = ses->auth_key.response;
456 	blobend = blobptr + ses->auth_key.len;
457 
458 	while (blobptr + onesize < blobend) {
459 		attrptr = (struct ntlmssp2_name *) blobptr;
460 		type = le16_to_cpu(attrptr->type);
461 		if (type == NTLMSSP_AV_EOL)
462 			break;
463 		blobptr += 2; /* advance attr type */
464 		attrsize = le16_to_cpu(attrptr->length);
465 		blobptr += 2; /* advance attr size */
466 		if (blobptr + attrsize > blobend)
467 			break;
468 		if (type == NTLMSSP_AV_NB_DOMAIN_NAME) {
469 			if (!attrsize || attrsize >= CIFS_MAX_DOMAINNAME_LEN)
470 				break;
471 			if (!ses->domainName) {
472 				ses->domainName =
473 					kmalloc(attrsize + 1, GFP_KERNEL);
474 				if (!ses->domainName)
475 						return -ENOMEM;
476 				cifs_from_utf16(ses->domainName,
477 					(__le16 *)blobptr, attrsize, attrsize,
478 					nls_cp, NO_MAP_UNI_RSVD);
479 				break;
480 			}
481 		}
482 		blobptr += attrsize; /* advance attr  value */
483 	}
484 
485 	return 0;
486 }
487 
488 /* Server has provided av pairs/target info in the type 2 challenge
489  * packet and we have plucked it and stored within smb session.
490  * We parse that blob here to find the server given timestamp
491  * as part of ntlmv2 authentication (or local current time as
492  * default in case of failure)
493  */
494 static __le64
find_timestamp(struct cifs_ses * ses)495 find_timestamp(struct cifs_ses *ses)
496 {
497 	unsigned int attrsize;
498 	unsigned int type;
499 	unsigned int onesize = sizeof(struct ntlmssp2_name);
500 	unsigned char *blobptr;
501 	unsigned char *blobend;
502 	struct ntlmssp2_name *attrptr;
503 	struct timespec64 ts;
504 
505 	if (!ses->auth_key.len || !ses->auth_key.response)
506 		return 0;
507 
508 	blobptr = ses->auth_key.response;
509 	blobend = blobptr + ses->auth_key.len;
510 
511 	while (blobptr + onesize < blobend) {
512 		attrptr = (struct ntlmssp2_name *) blobptr;
513 		type = le16_to_cpu(attrptr->type);
514 		if (type == NTLMSSP_AV_EOL)
515 			break;
516 		blobptr += 2; /* advance attr type */
517 		attrsize = le16_to_cpu(attrptr->length);
518 		blobptr += 2; /* advance attr size */
519 		if (blobptr + attrsize > blobend)
520 			break;
521 		if (type == NTLMSSP_AV_TIMESTAMP) {
522 			if (attrsize == sizeof(u64))
523 				return *((__le64 *)blobptr);
524 		}
525 		blobptr += attrsize; /* advance attr value */
526 	}
527 
528 	ktime_get_real_ts64(&ts);
529 	return cpu_to_le64(cifs_UnixTimeToNT(ts));
530 }
531 
calc_ntlmv2_hash(struct cifs_ses * ses,char * ntlmv2_hash,const struct nls_table * nls_cp)532 static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
533 			    const struct nls_table *nls_cp)
534 {
535 	int rc = 0;
536 	int len;
537 	char nt_hash[CIFS_NTHASH_SIZE];
538 	__le16 *user;
539 	wchar_t *domain;
540 	wchar_t *server;
541 
542 	if (!ses->server->secmech.hmacmd5) {
543 		cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
544 		return -1;
545 	}
546 
547 	/* calculate md4 hash of password */
548 	E_md4hash(ses->password, nt_hash, nls_cp);
549 
550 	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5->tfm, nt_hash,
551 				CIFS_NTHASH_SIZE);
552 	if (rc) {
553 		cifs_dbg(VFS, "%s: Could not set NT Hash as a key\n", __func__);
554 		return rc;
555 	}
556 
557 	rc = crypto_shash_init(ses->server->secmech.hmacmd5);
558 	if (rc) {
559 		cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
560 		return rc;
561 	}
562 
563 	/* convert ses->user_name to unicode */
564 	len = ses->user_name ? strlen(ses->user_name) : 0;
565 	user = kmalloc(2 + (len * 2), GFP_KERNEL);
566 	if (user == NULL) {
567 		rc = -ENOMEM;
568 		return rc;
569 	}
570 
571 	if (len) {
572 		len = cifs_strtoUTF16(user, ses->user_name, len, nls_cp);
573 		UniStrupr(user);
574 	} else {
575 		*(u16 *)user = 0;
576 	}
577 
578 	rc = crypto_shash_update(ses->server->secmech.hmacmd5,
579 				(char *)user, 2 * len);
580 	kfree(user);
581 	if (rc) {
582 		cifs_dbg(VFS, "%s: Could not update with user\n", __func__);
583 		return rc;
584 	}
585 
586 	/* convert ses->domainName to unicode and uppercase */
587 	if (ses->domainName) {
588 		len = strlen(ses->domainName);
589 
590 		domain = kmalloc(2 + (len * 2), GFP_KERNEL);
591 		if (domain == NULL) {
592 			rc = -ENOMEM;
593 			return rc;
594 		}
595 		len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len,
596 				      nls_cp);
597 		rc =
598 		crypto_shash_update(ses->server->secmech.hmacmd5,
599 					(char *)domain, 2 * len);
600 		kfree(domain);
601 		if (rc) {
602 			cifs_dbg(VFS, "%s: Could not update with domain\n",
603 				 __func__);
604 			return rc;
605 		}
606 	} else {
607 		/* We use ses->ip_addr if no domain name available */
608 		len = strlen(ses->ip_addr);
609 
610 		server = kmalloc(2 + (len * 2), GFP_KERNEL);
611 		if (server == NULL) {
612 			rc = -ENOMEM;
613 			return rc;
614 		}
615 		len = cifs_strtoUTF16((__le16 *)server, ses->ip_addr, len,
616 					nls_cp);
617 		rc =
618 		crypto_shash_update(ses->server->secmech.hmacmd5,
619 					(char *)server, 2 * len);
620 		kfree(server);
621 		if (rc) {
622 			cifs_dbg(VFS, "%s: Could not update with server\n",
623 				 __func__);
624 			return rc;
625 		}
626 	}
627 
628 	rc = crypto_shash_final(ses->server->secmech.hmacmd5,
629 					ntlmv2_hash);
630 	if (rc)
631 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
632 
633 	return rc;
634 }
635 
636 static int
CalcNTLMv2_response(const struct cifs_ses * ses,char * ntlmv2_hash)637 CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash)
638 {
639 	int rc;
640 	struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *)
641 	    (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
642 	unsigned int hash_len;
643 
644 	/* The MD5 hash starts at challenge_key.key */
645 	hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE +
646 		offsetof(struct ntlmv2_resp, challenge.key[0]));
647 
648 	if (!ses->server->secmech.hmacmd5) {
649 		cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
650 		return -1;
651 	}
652 
653 	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5->tfm,
654 				 ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
655 	if (rc) {
656 		cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
657 			 __func__);
658 		return rc;
659 	}
660 
661 	rc = crypto_shash_init(ses->server->secmech.hmacmd5);
662 	if (rc) {
663 		cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
664 		return rc;
665 	}
666 
667 	if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED)
668 		memcpy(ntlmv2->challenge.key,
669 		       ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
670 	else
671 		memcpy(ntlmv2->challenge.key,
672 		       ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
673 	rc = crypto_shash_update(ses->server->secmech.hmacmd5,
674 				 ntlmv2->challenge.key, hash_len);
675 	if (rc) {
676 		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
677 		return rc;
678 	}
679 
680 	/* Note that the MD5 digest over writes anon.challenge_key.key */
681 	rc = crypto_shash_final(ses->server->secmech.hmacmd5,
682 				ntlmv2->ntlmv2_hash);
683 	if (rc)
684 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
685 
686 	return rc;
687 }
688 
689 int
setup_ntlmv2_rsp(struct cifs_ses * ses,const struct nls_table * nls_cp)690 setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
691 {
692 	int rc;
693 	int baselen;
694 	unsigned int tilen;
695 	struct ntlmv2_resp *ntlmv2;
696 	char ntlmv2_hash[16];
697 	unsigned char *tiblob = NULL; /* target info blob */
698 	__le64 rsp_timestamp;
699 
700 	if (nls_cp == NULL) {
701 		cifs_dbg(VFS, "%s called with nls_cp==NULL\n", __func__);
702 		return -EINVAL;
703 	}
704 
705 	if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) {
706 		if (!ses->domainName) {
707 			if (ses->domainAuto) {
708 				rc = find_domain_name(ses, nls_cp);
709 				if (rc) {
710 					cifs_dbg(VFS, "error %d finding domain name\n",
711 						 rc);
712 					goto setup_ntlmv2_rsp_ret;
713 				}
714 			} else {
715 				ses->domainName = kstrdup("", GFP_KERNEL);
716 			}
717 		}
718 	} else {
719 		rc = build_avpair_blob(ses, nls_cp);
720 		if (rc) {
721 			cifs_dbg(VFS, "error %d building av pair blob\n", rc);
722 			goto setup_ntlmv2_rsp_ret;
723 		}
724 	}
725 
726 	/* Must be within 5 minutes of the server (or in range +/-2h
727 	 * in case of Mac OS X), so simply carry over server timestamp
728 	 * (as Windows 7 does)
729 	 */
730 	rsp_timestamp = find_timestamp(ses);
731 
732 	baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp);
733 	tilen = ses->auth_key.len;
734 	tiblob = ses->auth_key.response;
735 
736 	ses->auth_key.response = kmalloc(baselen + tilen, GFP_KERNEL);
737 	if (!ses->auth_key.response) {
738 		rc = -ENOMEM;
739 		ses->auth_key.len = 0;
740 		goto setup_ntlmv2_rsp_ret;
741 	}
742 	ses->auth_key.len += baselen;
743 
744 	ntlmv2 = (struct ntlmv2_resp *)
745 			(ses->auth_key.response + CIFS_SESS_KEY_SIZE);
746 	ntlmv2->blob_signature = cpu_to_le32(0x00000101);
747 	ntlmv2->reserved = 0;
748 	ntlmv2->time = rsp_timestamp;
749 
750 	get_random_bytes(&ntlmv2->client_chal, sizeof(ntlmv2->client_chal));
751 	ntlmv2->reserved2 = 0;
752 
753 	memcpy(ses->auth_key.response + baselen, tiblob, tilen);
754 
755 	cifs_server_lock(ses->server);
756 
757 	rc = cifs_alloc_hash("hmac(md5)", &ses->server->secmech.hmacmd5);
758 	if (rc) {
759 		goto unlock;
760 	}
761 
762 	/* calculate ntlmv2_hash */
763 	rc = calc_ntlmv2_hash(ses, ntlmv2_hash, nls_cp);
764 	if (rc) {
765 		cifs_dbg(VFS, "Could not get v2 hash rc %d\n", rc);
766 		goto unlock;
767 	}
768 
769 	/* calculate first part of the client response (CR1) */
770 	rc = CalcNTLMv2_response(ses, ntlmv2_hash);
771 	if (rc) {
772 		cifs_dbg(VFS, "Could not calculate CR1 rc: %d\n", rc);
773 		goto unlock;
774 	}
775 
776 	/* now calculate the session key for NTLMv2 */
777 	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5->tfm,
778 		ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
779 	if (rc) {
780 		cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
781 			 __func__);
782 		goto unlock;
783 	}
784 
785 	rc = crypto_shash_init(ses->server->secmech.hmacmd5);
786 	if (rc) {
787 		cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
788 		goto unlock;
789 	}
790 
791 	rc = crypto_shash_update(ses->server->secmech.hmacmd5,
792 		ntlmv2->ntlmv2_hash,
793 		CIFS_HMAC_MD5_HASH_SIZE);
794 	if (rc) {
795 		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
796 		goto unlock;
797 	}
798 
799 	rc = crypto_shash_final(ses->server->secmech.hmacmd5,
800 		ses->auth_key.response);
801 	if (rc)
802 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
803 
804 unlock:
805 	cifs_server_unlock(ses->server);
806 setup_ntlmv2_rsp_ret:
807 	kfree_sensitive(tiblob);
808 
809 	return rc;
810 }
811 
812 int
calc_seckey(struct cifs_ses * ses)813 calc_seckey(struct cifs_ses *ses)
814 {
815 	unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */
816 	struct arc4_ctx *ctx_arc4;
817 
818 	if (fips_enabled)
819 		return -ENODEV;
820 
821 	get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE);
822 
823 	ctx_arc4 = kmalloc(sizeof(*ctx_arc4), GFP_KERNEL);
824 	if (!ctx_arc4) {
825 		cifs_dbg(VFS, "Could not allocate arc4 context\n");
826 		return -ENOMEM;
827 	}
828 
829 	cifs_arc4_setkey(ctx_arc4, ses->auth_key.response, CIFS_SESS_KEY_SIZE);
830 	cifs_arc4_crypt(ctx_arc4, ses->ntlmssp->ciphertext, sec_key,
831 			CIFS_CPHTXT_SIZE);
832 
833 	/* make secondary_key/nonce as session key */
834 	memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE);
835 	/* and make len as that of session key only */
836 	ses->auth_key.len = CIFS_SESS_KEY_SIZE;
837 
838 	memzero_explicit(sec_key, CIFS_SESS_KEY_SIZE);
839 	kfree_sensitive(ctx_arc4);
840 	return 0;
841 }
842 
843 void
cifs_crypto_secmech_release(struct TCP_Server_Info * server)844 cifs_crypto_secmech_release(struct TCP_Server_Info *server)
845 {
846 	cifs_free_hash(&server->secmech.aes_cmac);
847 	cifs_free_hash(&server->secmech.hmacsha256);
848 	cifs_free_hash(&server->secmech.md5);
849 	cifs_free_hash(&server->secmech.sha512);
850 	cifs_free_hash(&server->secmech.hmacmd5);
851 
852 	if (server->secmech.enc) {
853 		crypto_free_aead(server->secmech.enc);
854 		server->secmech.enc = NULL;
855 	}
856 
857 	if (server->secmech.dec) {
858 		crypto_free_aead(server->secmech.dec);
859 		server->secmech.dec = NULL;
860 	}
861 }
862