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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 #include <linux/fips.h>
37 #include <crypto/arc4.h>
38 #include <crypto/aead.h>
39 
__cifs_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,char * signature,struct shash_desc * shash)40 int __cifs_calc_signature(struct smb_rqst *rqst,
41 			struct TCP_Server_Info *server, char *signature,
42 			struct shash_desc *shash)
43 {
44 	int i;
45 	int rc;
46 	struct kvec *iov = rqst->rq_iov;
47 	int n_vec = rqst->rq_nvec;
48 	int is_smb2 = server->vals->header_preamble_size == 0;
49 
50 	/* iov[0] is actual data and not the rfc1002 length for SMB2+ */
51 	if (is_smb2) {
52 		if (iov[0].iov_len <= 4)
53 			return -EIO;
54 		i = 0;
55 	} else {
56 		if (n_vec < 2 || iov[0].iov_len != 4)
57 			return -EIO;
58 		i = 1; /* skip rfc1002 length */
59 	}
60 
61 	for (; i < n_vec; i++) {
62 		if (iov[i].iov_len == 0)
63 			continue;
64 		if (iov[i].iov_base == NULL) {
65 			cifs_dbg(VFS, "null iovec entry\n");
66 			return -EIO;
67 		}
68 
69 		rc = crypto_shash_update(shash,
70 					 iov[i].iov_base, iov[i].iov_len);
71 		if (rc) {
72 			cifs_dbg(VFS, "%s: Could not update with payload\n",
73 				 __func__);
74 			return rc;
75 		}
76 	}
77 
78 	/* now hash over the rq_pages array */
79 	for (i = 0; i < rqst->rq_npages; i++) {
80 		void *kaddr;
81 		unsigned int len, offset;
82 
83 		rqst_page_get_length(rqst, i, &len, &offset);
84 
85 		kaddr = (char *) kmap(rqst->rq_pages[i]) + offset;
86 
87 		rc = crypto_shash_update(shash, kaddr, len);
88 		if (rc) {
89 			cifs_dbg(VFS, "%s: Could not update with payload\n",
90 				 __func__);
91 			kunmap(rqst->rq_pages[i]);
92 			return rc;
93 		}
94 
95 		kunmap(rqst->rq_pages[i]);
96 	}
97 
98 	rc = crypto_shash_final(shash, signature);
99 	if (rc)
100 		cifs_dbg(VFS, "%s: Could not generate hash\n", __func__);
101 
102 	return rc;
103 }
104 
105 /*
106  * Calculate and return the CIFS signature based on the mac key and SMB PDU.
107  * The 16 byte signature must be allocated by the caller. Note we only use the
108  * 1st eight bytes and that the smb header signature field on input contains
109  * the sequence number before this function is called. Also, this function
110  * should be called with the server->srv_mutex held.
111  */
cifs_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,char * signature)112 static int cifs_calc_signature(struct smb_rqst *rqst,
113 			struct TCP_Server_Info *server, char *signature)
114 {
115 	int rc;
116 
117 	if (!rqst->rq_iov || !signature || !server)
118 		return -EINVAL;
119 
120 	rc = cifs_alloc_hash("md5", &server->secmech.md5,
121 			     &server->secmech.sdescmd5);
122 	if (rc)
123 		return -1;
124 
125 	rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
126 	if (rc) {
127 		cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
128 		return rc;
129 	}
130 
131 	rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
132 		server->session_key.response, server->session_key.len);
133 	if (rc) {
134 		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
135 		return rc;
136 	}
137 
138 	return __cifs_calc_signature(rqst, server, signature,
139 				     &server->secmech.sdescmd5->shash);
140 }
141 
142 /* 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)143 int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
144 		   __u32 *pexpected_response_sequence_number)
145 {
146 	int rc = 0;
147 	char smb_signature[20];
148 	struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
149 
150 	if (rqst->rq_iov[0].iov_len != 4 ||
151 	    rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
152 		return -EIO;
153 
154 	if ((cifs_pdu == NULL) || (server == NULL))
155 		return -EINVAL;
156 
157 	if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) ||
158 	    server->tcpStatus == CifsNeedNegotiate)
159 		return rc;
160 
161 	if (!server->session_estab) {
162 		memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8);
163 		return rc;
164 	}
165 
166 	cifs_pdu->Signature.Sequence.SequenceNumber =
167 				cpu_to_le32(server->sequence_number);
168 	cifs_pdu->Signature.Sequence.Reserved = 0;
169 
170 	*pexpected_response_sequence_number = ++server->sequence_number;
171 	++server->sequence_number;
172 
173 	rc = cifs_calc_signature(rqst, server, smb_signature);
174 	if (rc)
175 		memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
176 	else
177 		memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
178 
179 	return rc;
180 }
181 
cifs_sign_smbv(struct kvec * iov,int n_vec,struct TCP_Server_Info * server,__u32 * pexpected_response_sequence)182 int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
183 		   __u32 *pexpected_response_sequence)
184 {
185 	struct smb_rqst rqst = { .rq_iov = iov,
186 				 .rq_nvec = n_vec };
187 
188 	return cifs_sign_rqst(&rqst, server, pexpected_response_sequence);
189 }
190 
191 /* 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)192 int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
193 		  __u32 *pexpected_response_sequence_number)
194 {
195 	struct kvec iov[2];
196 
197 	iov[0].iov_base = cifs_pdu;
198 	iov[0].iov_len = 4;
199 	iov[1].iov_base = (char *)cifs_pdu + 4;
200 	iov[1].iov_len = be32_to_cpu(cifs_pdu->smb_buf_length);
201 
202 	return cifs_sign_smbv(iov, 2, server,
203 			      pexpected_response_sequence_number);
204 }
205 
cifs_verify_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,__u32 expected_sequence_number)206 int cifs_verify_signature(struct smb_rqst *rqst,
207 			  struct TCP_Server_Info *server,
208 			  __u32 expected_sequence_number)
209 {
210 	unsigned int rc;
211 	char server_response_sig[8];
212 	char what_we_think_sig_should_be[20];
213 	struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
214 
215 	if (rqst->rq_iov[0].iov_len != 4 ||
216 	    rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
217 		return -EIO;
218 
219 	if (cifs_pdu == NULL || server == NULL)
220 		return -EINVAL;
221 
222 	if (!server->session_estab)
223 		return 0;
224 
225 	if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
226 		struct smb_com_lock_req *pSMB =
227 			(struct smb_com_lock_req *)cifs_pdu;
228 		if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
229 			return 0;
230 	}
231 
232 	/* BB what if signatures are supposed to be on for session but
233 	   server does not send one? BB */
234 
235 	/* Do not need to verify session setups with signature "BSRSPYL "  */
236 	if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0)
237 		cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
238 			 cifs_pdu->Command);
239 
240 	/* save off the origiginal signature so we can modify the smb and check
241 		its signature against what the server sent */
242 	memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8);
243 
244 	cifs_pdu->Signature.Sequence.SequenceNumber =
245 					cpu_to_le32(expected_sequence_number);
246 	cifs_pdu->Signature.Sequence.Reserved = 0;
247 
248 	mutex_lock(&server->srv_mutex);
249 	rc = cifs_calc_signature(rqst, server, what_we_think_sig_should_be);
250 	mutex_unlock(&server->srv_mutex);
251 
252 	if (rc)
253 		return rc;
254 
255 /*	cifs_dump_mem("what we think it should be: ",
256 		      what_we_think_sig_should_be, 16); */
257 
258 	if (memcmp(server_response_sig, what_we_think_sig_should_be, 8))
259 		return -EACCES;
260 	else
261 		return 0;
262 
263 }
264 
265 /* 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)266 int setup_ntlm_response(struct cifs_ses *ses, const struct nls_table *nls_cp)
267 {
268 	int rc = 0;
269 	unsigned int temp_len = CIFS_SESS_KEY_SIZE + CIFS_AUTH_RESP_SIZE;
270 	char temp_key[CIFS_SESS_KEY_SIZE];
271 
272 	if (!ses)
273 		return -EINVAL;
274 
275 	ses->auth_key.response = kmalloc(temp_len, GFP_KERNEL);
276 	if (!ses->auth_key.response)
277 		return -ENOMEM;
278 
279 	ses->auth_key.len = temp_len;
280 
281 	rc = SMBNTencrypt(ses->password, ses->server->cryptkey,
282 			ses->auth_key.response + CIFS_SESS_KEY_SIZE, nls_cp);
283 	if (rc) {
284 		cifs_dbg(FYI, "%s Can't generate NTLM response, error: %d\n",
285 			 __func__, rc);
286 		return rc;
287 	}
288 
289 	rc = E_md4hash(ses->password, temp_key, nls_cp);
290 	if (rc) {
291 		cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
292 			 __func__, rc);
293 		return rc;
294 	}
295 
296 	rc = mdfour(ses->auth_key.response, temp_key, CIFS_SESS_KEY_SIZE);
297 	if (rc)
298 		cifs_dbg(FYI, "%s Can't generate NTLM session key, error: %d\n",
299 			 __func__, rc);
300 
301 	return rc;
302 }
303 
304 #ifdef CONFIG_CIFS_WEAK_PW_HASH
calc_lanman_hash(const char * password,const char * cryptkey,bool encrypt,char * lnm_session_key)305 int calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
306 			char *lnm_session_key)
307 {
308 	int i, len;
309 	int rc;
310 	char password_with_pad[CIFS_ENCPWD_SIZE] = {0};
311 
312 	if (password) {
313 		for (len = 0; len < CIFS_ENCPWD_SIZE; len++)
314 			if (!password[len])
315 				break;
316 
317 		memcpy(password_with_pad, password, len);
318 	}
319 
320 	if (!encrypt && global_secflags & CIFSSEC_MAY_PLNTXT) {
321 		memcpy(lnm_session_key, password_with_pad,
322 			CIFS_ENCPWD_SIZE);
323 		return 0;
324 	}
325 
326 	/* calculate old style session key */
327 	/* calling toupper is less broken than repeatedly
328 	calling nls_toupper would be since that will never
329 	work for UTF8, but neither handles multibyte code pages
330 	but the only alternative would be converting to UCS-16 (Unicode)
331 	(using a routine something like UniStrupr) then
332 	uppercasing and then converting back from Unicode - which
333 	would only worth doing it if we knew it were utf8. Basically
334 	utf8 and other multibyte codepages each need their own strupper
335 	function since a byte at a time will ont work. */
336 
337 	for (i = 0; i < CIFS_ENCPWD_SIZE; i++)
338 		password_with_pad[i] = toupper(password_with_pad[i]);
339 
340 	rc = SMBencrypt(password_with_pad, cryptkey, lnm_session_key);
341 
342 	return rc;
343 }
344 #endif /* CIFS_WEAK_PW_HASH */
345 
346 /* Build a proper attribute value/target info pairs blob.
347  * Fill in netbios and dns domain name and workstation name
348  * and client time (total five av pairs and + one end of fields indicator.
349  * Allocate domain name which gets freed when session struct is deallocated.
350  */
351 static int
build_avpair_blob(struct cifs_ses * ses,const struct nls_table * nls_cp)352 build_avpair_blob(struct cifs_ses *ses, const struct nls_table *nls_cp)
353 {
354 	unsigned int dlen;
355 	unsigned int size = 2 * sizeof(struct ntlmssp2_name);
356 	char *defdmname = "WORKGROUP";
357 	unsigned char *blobptr;
358 	struct ntlmssp2_name *attrptr;
359 
360 	if (!ses->domainName) {
361 		ses->domainName = kstrdup(defdmname, GFP_KERNEL);
362 		if (!ses->domainName)
363 			return -ENOMEM;
364 	}
365 
366 	dlen = strlen(ses->domainName);
367 
368 	/*
369 	 * The length of this blob is two times the size of a
370 	 * structure (av pair) which holds name/size
371 	 * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) +
372 	 * unicode length of a netbios domain name
373 	 */
374 	ses->auth_key.len = size + 2 * dlen;
375 	ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL);
376 	if (!ses->auth_key.response) {
377 		ses->auth_key.len = 0;
378 		return -ENOMEM;
379 	}
380 
381 	blobptr = ses->auth_key.response;
382 	attrptr = (struct ntlmssp2_name *) blobptr;
383 
384 	/*
385 	 * As defined in MS-NTLM 3.3.2, just this av pair field
386 	 * is sufficient as part of the temp
387 	 */
388 	attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME);
389 	attrptr->length = cpu_to_le16(2 * dlen);
390 	blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
391 	cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, nls_cp);
392 
393 	return 0;
394 }
395 
396 /* Server has provided av pairs/target info in the type 2 challenge
397  * packet and we have plucked it and stored within smb session.
398  * We parse that blob here to find netbios domain name to be used
399  * as part of ntlmv2 authentication (in Target String), if not already
400  * specified on the command line.
401  * If this function returns without any error but without fetching
402  * domain name, authentication may fail against some server but
403  * may not fail against other (those who are not very particular
404  * about target string i.e. for some, just user name might suffice.
405  */
406 static int
find_domain_name(struct cifs_ses * ses,const struct nls_table * nls_cp)407 find_domain_name(struct cifs_ses *ses, const struct nls_table *nls_cp)
408 {
409 	unsigned int attrsize;
410 	unsigned int type;
411 	unsigned int onesize = sizeof(struct ntlmssp2_name);
412 	unsigned char *blobptr;
413 	unsigned char *blobend;
414 	struct ntlmssp2_name *attrptr;
415 
416 	if (!ses->auth_key.len || !ses->auth_key.response)
417 		return 0;
418 
419 	blobptr = ses->auth_key.response;
420 	blobend = blobptr + ses->auth_key.len;
421 
422 	while (blobptr + onesize < blobend) {
423 		attrptr = (struct ntlmssp2_name *) blobptr;
424 		type = le16_to_cpu(attrptr->type);
425 		if (type == NTLMSSP_AV_EOL)
426 			break;
427 		blobptr += 2; /* advance attr type */
428 		attrsize = le16_to_cpu(attrptr->length);
429 		blobptr += 2; /* advance attr size */
430 		if (blobptr + attrsize > blobend)
431 			break;
432 		if (type == NTLMSSP_AV_NB_DOMAIN_NAME) {
433 			if (!attrsize || attrsize >= CIFS_MAX_DOMAINNAME_LEN)
434 				break;
435 			if (!ses->domainName) {
436 				ses->domainName =
437 					kmalloc(attrsize + 1, GFP_KERNEL);
438 				if (!ses->domainName)
439 						return -ENOMEM;
440 				cifs_from_utf16(ses->domainName,
441 					(__le16 *)blobptr, attrsize, attrsize,
442 					nls_cp, NO_MAP_UNI_RSVD);
443 				break;
444 			}
445 		}
446 		blobptr += attrsize; /* advance attr  value */
447 	}
448 
449 	return 0;
450 }
451 
452 /* Server has provided av pairs/target info in the type 2 challenge
453  * packet and we have plucked it and stored within smb session.
454  * We parse that blob here to find the server given timestamp
455  * as part of ntlmv2 authentication (or local current time as
456  * default in case of failure)
457  */
458 static __le64
find_timestamp(struct cifs_ses * ses)459 find_timestamp(struct cifs_ses *ses)
460 {
461 	unsigned int attrsize;
462 	unsigned int type;
463 	unsigned int onesize = sizeof(struct ntlmssp2_name);
464 	unsigned char *blobptr;
465 	unsigned char *blobend;
466 	struct ntlmssp2_name *attrptr;
467 	struct timespec64 ts;
468 
469 	if (!ses->auth_key.len || !ses->auth_key.response)
470 		return 0;
471 
472 	blobptr = ses->auth_key.response;
473 	blobend = blobptr + ses->auth_key.len;
474 
475 	while (blobptr + onesize < blobend) {
476 		attrptr = (struct ntlmssp2_name *) blobptr;
477 		type = le16_to_cpu(attrptr->type);
478 		if (type == NTLMSSP_AV_EOL)
479 			break;
480 		blobptr += 2; /* advance attr type */
481 		attrsize = le16_to_cpu(attrptr->length);
482 		blobptr += 2; /* advance attr size */
483 		if (blobptr + attrsize > blobend)
484 			break;
485 		if (type == NTLMSSP_AV_TIMESTAMP) {
486 			if (attrsize == sizeof(u64))
487 				return *((__le64 *)blobptr);
488 		}
489 		blobptr += attrsize; /* advance attr value */
490 	}
491 
492 	ktime_get_real_ts64(&ts);
493 	return cpu_to_le64(cifs_UnixTimeToNT(ts));
494 }
495 
calc_ntlmv2_hash(struct cifs_ses * ses,char * ntlmv2_hash,const struct nls_table * nls_cp)496 static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
497 			    const struct nls_table *nls_cp)
498 {
499 	int rc = 0;
500 	int len;
501 	char nt_hash[CIFS_NTHASH_SIZE];
502 	__le16 *user;
503 	wchar_t *domain;
504 	wchar_t *server;
505 
506 	if (!ses->server->secmech.sdeschmacmd5) {
507 		cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
508 		return -1;
509 	}
510 
511 	/* calculate md4 hash of password */
512 	E_md4hash(ses->password, nt_hash, nls_cp);
513 
514 	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5, nt_hash,
515 				CIFS_NTHASH_SIZE);
516 	if (rc) {
517 		cifs_dbg(VFS, "%s: Could not set NT Hash as a key\n", __func__);
518 		return rc;
519 	}
520 
521 	rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
522 	if (rc) {
523 		cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
524 		return rc;
525 	}
526 
527 	/* convert ses->user_name to unicode */
528 	len = ses->user_name ? strlen(ses->user_name) : 0;
529 	user = kmalloc(2 + (len * 2), GFP_KERNEL);
530 	if (user == NULL) {
531 		rc = -ENOMEM;
532 		return rc;
533 	}
534 
535 	if (len) {
536 		len = cifs_strtoUTF16(user, ses->user_name, len, nls_cp);
537 		UniStrupr(user);
538 	} else {
539 		memset(user, '\0', 2);
540 	}
541 
542 	rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
543 				(char *)user, 2 * len);
544 	kfree(user);
545 	if (rc) {
546 		cifs_dbg(VFS, "%s: Could not update with user\n", __func__);
547 		return rc;
548 	}
549 
550 	/* convert ses->domainName to unicode and uppercase */
551 	if (ses->domainName) {
552 		len = strlen(ses->domainName);
553 
554 		domain = kmalloc(2 + (len * 2), GFP_KERNEL);
555 		if (domain == NULL) {
556 			rc = -ENOMEM;
557 			return rc;
558 		}
559 		len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len,
560 				      nls_cp);
561 		rc =
562 		crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
563 					(char *)domain, 2 * len);
564 		kfree(domain);
565 		if (rc) {
566 			cifs_dbg(VFS, "%s: Could not update with domain\n",
567 				 __func__);
568 			return rc;
569 		}
570 	} else {
571 		/* We use ses->serverName if no domain name available */
572 		len = strlen(ses->serverName);
573 
574 		server = kmalloc(2 + (len * 2), GFP_KERNEL);
575 		if (server == NULL) {
576 			rc = -ENOMEM;
577 			return rc;
578 		}
579 		len = cifs_strtoUTF16((__le16 *)server, ses->serverName, len,
580 					nls_cp);
581 		rc =
582 		crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
583 					(char *)server, 2 * len);
584 		kfree(server);
585 		if (rc) {
586 			cifs_dbg(VFS, "%s: Could not update with server\n",
587 				 __func__);
588 			return rc;
589 		}
590 	}
591 
592 	rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
593 					ntlmv2_hash);
594 	if (rc)
595 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
596 
597 	return rc;
598 }
599 
600 static int
CalcNTLMv2_response(const struct cifs_ses * ses,char * ntlmv2_hash)601 CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash)
602 {
603 	int rc;
604 	struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *)
605 	    (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
606 	unsigned int hash_len;
607 
608 	/* The MD5 hash starts at challenge_key.key */
609 	hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE +
610 		offsetof(struct ntlmv2_resp, challenge.key[0]));
611 
612 	if (!ses->server->secmech.sdeschmacmd5) {
613 		cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
614 		return -1;
615 	}
616 
617 	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
618 				 ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
619 	if (rc) {
620 		cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
621 			 __func__);
622 		return rc;
623 	}
624 
625 	rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
626 	if (rc) {
627 		cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
628 		return rc;
629 	}
630 
631 	if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED)
632 		memcpy(ntlmv2->challenge.key,
633 		       ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
634 	else
635 		memcpy(ntlmv2->challenge.key,
636 		       ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
637 	rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
638 				 ntlmv2->challenge.key, hash_len);
639 	if (rc) {
640 		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
641 		return rc;
642 	}
643 
644 	/* Note that the MD5 digest over writes anon.challenge_key.key */
645 	rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
646 				ntlmv2->ntlmv2_hash);
647 	if (rc)
648 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
649 
650 	return rc;
651 }
652 
653 int
setup_ntlmv2_rsp(struct cifs_ses * ses,const struct nls_table * nls_cp)654 setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
655 {
656 	int rc;
657 	int baselen;
658 	unsigned int tilen;
659 	struct ntlmv2_resp *ntlmv2;
660 	char ntlmv2_hash[16];
661 	unsigned char *tiblob = NULL; /* target info blob */
662 	__le64 rsp_timestamp;
663 
664 	if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) {
665 		if (!ses->domainName) {
666 			if (ses->domainAuto) {
667 				rc = find_domain_name(ses, nls_cp);
668 				if (rc) {
669 					cifs_dbg(VFS, "error %d finding domain name\n",
670 						 rc);
671 					goto setup_ntlmv2_rsp_ret;
672 				}
673 			} else {
674 				ses->domainName = kstrdup("", GFP_KERNEL);
675 			}
676 		}
677 	} else {
678 		rc = build_avpair_blob(ses, nls_cp);
679 		if (rc) {
680 			cifs_dbg(VFS, "error %d building av pair blob\n", rc);
681 			goto setup_ntlmv2_rsp_ret;
682 		}
683 	}
684 
685 	/* Must be within 5 minutes of the server (or in range +/-2h
686 	 * in case of Mac OS X), so simply carry over server timestamp
687 	 * (as Windows 7 does)
688 	 */
689 	rsp_timestamp = find_timestamp(ses);
690 
691 	baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp);
692 	tilen = ses->auth_key.len;
693 	tiblob = ses->auth_key.response;
694 
695 	ses->auth_key.response = kmalloc(baselen + tilen, GFP_KERNEL);
696 	if (!ses->auth_key.response) {
697 		rc = -ENOMEM;
698 		ses->auth_key.len = 0;
699 		goto setup_ntlmv2_rsp_ret;
700 	}
701 	ses->auth_key.len += baselen;
702 
703 	ntlmv2 = (struct ntlmv2_resp *)
704 			(ses->auth_key.response + CIFS_SESS_KEY_SIZE);
705 	ntlmv2->blob_signature = cpu_to_le32(0x00000101);
706 	ntlmv2->reserved = 0;
707 	ntlmv2->time = rsp_timestamp;
708 
709 	get_random_bytes(&ntlmv2->client_chal, sizeof(ntlmv2->client_chal));
710 	ntlmv2->reserved2 = 0;
711 
712 	memcpy(ses->auth_key.response + baselen, tiblob, tilen);
713 
714 	mutex_lock(&ses->server->srv_mutex);
715 
716 	rc = cifs_alloc_hash("hmac(md5)",
717 			     &ses->server->secmech.hmacmd5,
718 			     &ses->server->secmech.sdeschmacmd5);
719 	if (rc) {
720 		goto unlock;
721 	}
722 
723 	/* calculate ntlmv2_hash */
724 	rc = calc_ntlmv2_hash(ses, ntlmv2_hash, nls_cp);
725 	if (rc) {
726 		cifs_dbg(VFS, "Could not get v2 hash rc %d\n", rc);
727 		goto unlock;
728 	}
729 
730 	/* calculate first part of the client response (CR1) */
731 	rc = CalcNTLMv2_response(ses, ntlmv2_hash);
732 	if (rc) {
733 		cifs_dbg(VFS, "Could not calculate CR1 rc: %d\n", rc);
734 		goto unlock;
735 	}
736 
737 	/* now calculate the session key for NTLMv2 */
738 	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
739 		ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
740 	if (rc) {
741 		cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
742 			 __func__);
743 		goto unlock;
744 	}
745 
746 	rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
747 	if (rc) {
748 		cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
749 		goto unlock;
750 	}
751 
752 	rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
753 		ntlmv2->ntlmv2_hash,
754 		CIFS_HMAC_MD5_HASH_SIZE);
755 	if (rc) {
756 		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
757 		goto unlock;
758 	}
759 
760 	rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
761 		ses->auth_key.response);
762 	if (rc)
763 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
764 
765 unlock:
766 	mutex_unlock(&ses->server->srv_mutex);
767 setup_ntlmv2_rsp_ret:
768 	kfree(tiblob);
769 
770 	return rc;
771 }
772 
773 int
calc_seckey(struct cifs_ses * ses)774 calc_seckey(struct cifs_ses *ses)
775 {
776 	unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */
777 	struct arc4_ctx *ctx_arc4;
778 
779 	if (fips_enabled)
780 		return -ENODEV;
781 
782 	get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE);
783 
784 	ctx_arc4 = kmalloc(sizeof(*ctx_arc4), GFP_KERNEL);
785 	if (!ctx_arc4) {
786 		cifs_dbg(VFS, "Could not allocate arc4 context\n");
787 		return -ENOMEM;
788 	}
789 
790 	arc4_setkey(ctx_arc4, ses->auth_key.response, CIFS_SESS_KEY_SIZE);
791 	arc4_crypt(ctx_arc4, ses->ntlmssp->ciphertext, sec_key,
792 		   CIFS_CPHTXT_SIZE);
793 
794 	/* make secondary_key/nonce as session key */
795 	memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE);
796 	/* and make len as that of session key only */
797 	ses->auth_key.len = CIFS_SESS_KEY_SIZE;
798 
799 	memzero_explicit(sec_key, CIFS_SESS_KEY_SIZE);
800 	kfree_sensitive(ctx_arc4);
801 	return 0;
802 }
803 
804 void
cifs_crypto_secmech_release(struct TCP_Server_Info * server)805 cifs_crypto_secmech_release(struct TCP_Server_Info *server)
806 {
807 	if (server->secmech.cmacaes) {
808 		crypto_free_shash(server->secmech.cmacaes);
809 		server->secmech.cmacaes = NULL;
810 	}
811 
812 	if (server->secmech.hmacsha256) {
813 		crypto_free_shash(server->secmech.hmacsha256);
814 		server->secmech.hmacsha256 = NULL;
815 	}
816 
817 	if (server->secmech.md5) {
818 		crypto_free_shash(server->secmech.md5);
819 		server->secmech.md5 = NULL;
820 	}
821 
822 	if (server->secmech.sha512) {
823 		crypto_free_shash(server->secmech.sha512);
824 		server->secmech.sha512 = NULL;
825 	}
826 
827 	if (server->secmech.hmacmd5) {
828 		crypto_free_shash(server->secmech.hmacmd5);
829 		server->secmech.hmacmd5 = NULL;
830 	}
831 
832 	if (server->secmech.ccmaesencrypt) {
833 		crypto_free_aead(server->secmech.ccmaesencrypt);
834 		server->secmech.ccmaesencrypt = NULL;
835 	}
836 
837 	if (server->secmech.ccmaesdecrypt) {
838 		crypto_free_aead(server->secmech.ccmaesdecrypt);
839 		server->secmech.ccmaesdecrypt = NULL;
840 	}
841 
842 	kfree(server->secmech.sdesccmacaes);
843 	server->secmech.sdesccmacaes = NULL;
844 	kfree(server->secmech.sdeschmacsha256);
845 	server->secmech.sdeschmacsha256 = NULL;
846 	kfree(server->secmech.sdeschmacmd5);
847 	server->secmech.sdeschmacmd5 = NULL;
848 	kfree(server->secmech.sdescmd5);
849 	server->secmech.sdescmd5 = NULL;
850 	kfree(server->secmech.sdescsha512);
851 	server->secmech.sdescsha512 = NULL;
852 }
853