xref: /linux/fs/smb/client/cifsencrypt.c (revision e9f49fee)
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 "../common/arc4.h"
26 #include <crypto/aead.h>
27 
cifs_shash_step(void * iter_base,size_t progress,size_t len,void * priv,void * priv2)28 static size_t cifs_shash_step(void *iter_base, size_t progress, size_t len,
29 			      void *priv, void *priv2)
30 {
31 	struct shash_desc *shash = priv;
32 	int ret, *pret = priv2;
33 
34 	ret = crypto_shash_update(shash, iter_base, len);
35 	if (ret < 0) {
36 		*pret = ret;
37 		return len;
38 	}
39 	return 0;
40 }
41 
42 /*
43  * Pass the data from an iterator into a hash.
44  */
cifs_shash_iter(const struct iov_iter * iter,size_t maxsize,struct shash_desc * shash)45 static int cifs_shash_iter(const struct iov_iter *iter, size_t maxsize,
46 			   struct shash_desc *shash)
47 {
48 	struct iov_iter tmp_iter = *iter;
49 	int err = -EIO;
50 
51 	if (iterate_and_advance_kernel(&tmp_iter, maxsize, shash, &err,
52 				       cifs_shash_step) != maxsize)
53 		return err;
54 	return 0;
55 }
56 
__cifs_calc_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,char * signature,struct shash_desc * shash)57 int __cifs_calc_signature(struct smb_rqst *rqst,
58 			  struct TCP_Server_Info *server, char *signature,
59 			  struct shash_desc *shash)
60 {
61 	int i;
62 	ssize_t rc;
63 	struct kvec *iov = rqst->rq_iov;
64 	int n_vec = rqst->rq_nvec;
65 
66 	/* iov[0] is actual data and not the rfc1002 length for SMB2+ */
67 	if (!is_smb1(server)) {
68 		if (iov[0].iov_len <= 4)
69 			return -EIO;
70 		i = 0;
71 	} else {
72 		if (n_vec < 2 || iov[0].iov_len != 4)
73 			return -EIO;
74 		i = 1; /* skip rfc1002 length */
75 	}
76 
77 	for (; i < n_vec; i++) {
78 		if (iov[i].iov_len == 0)
79 			continue;
80 		if (iov[i].iov_base == NULL) {
81 			cifs_dbg(VFS, "null iovec entry\n");
82 			return -EIO;
83 		}
84 
85 		rc = crypto_shash_update(shash,
86 					 iov[i].iov_base, iov[i].iov_len);
87 		if (rc) {
88 			cifs_dbg(VFS, "%s: Could not update with payload\n",
89 				 __func__);
90 			return rc;
91 		}
92 	}
93 
94 	rc = cifs_shash_iter(&rqst->rq_iter, iov_iter_count(&rqst->rq_iter), shash);
95 	if (rc < 0)
96 		return rc;
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 	if (rc)
122 		return -1;
123 
124 	rc = crypto_shash_init(server->secmech.md5);
125 	if (rc) {
126 		cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
127 		return rc;
128 	}
129 
130 	rc = crypto_shash_update(server->secmech.md5,
131 		server->session_key.response, server->session_key.len);
132 	if (rc) {
133 		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
134 		return rc;
135 	}
136 
137 	return __cifs_calc_signature(rqst, server, signature, server->secmech.md5);
138 }
139 
140 /* 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)141 int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
142 		   __u32 *pexpected_response_sequence_number)
143 {
144 	int rc = 0;
145 	char smb_signature[20];
146 	struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
147 
148 	if (rqst->rq_iov[0].iov_len != 4 ||
149 	    rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
150 		return -EIO;
151 
152 	if ((cifs_pdu == NULL) || (server == NULL))
153 		return -EINVAL;
154 
155 	spin_lock(&server->srv_lock);
156 	if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) ||
157 	    server->tcpStatus == CifsNeedNegotiate) {
158 		spin_unlock(&server->srv_lock);
159 		return rc;
160 	}
161 	spin_unlock(&server->srv_lock);
162 
163 	if (!server->session_estab) {
164 		memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8);
165 		return rc;
166 	}
167 
168 	cifs_pdu->Signature.Sequence.SequenceNumber =
169 				cpu_to_le32(server->sequence_number);
170 	cifs_pdu->Signature.Sequence.Reserved = 0;
171 
172 	*pexpected_response_sequence_number = ++server->sequence_number;
173 	++server->sequence_number;
174 
175 	rc = cifs_calc_signature(rqst, server, smb_signature);
176 	if (rc)
177 		memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
178 	else
179 		memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
180 
181 	return rc;
182 }
183 
cifs_sign_smbv(struct kvec * iov,int n_vec,struct TCP_Server_Info * server,__u32 * pexpected_response_sequence)184 int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
185 		   __u32 *pexpected_response_sequence)
186 {
187 	struct smb_rqst rqst = { .rq_iov = iov,
188 				 .rq_nvec = n_vec };
189 
190 	return cifs_sign_rqst(&rqst, server, pexpected_response_sequence);
191 }
192 
193 /* 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)194 int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
195 		  __u32 *pexpected_response_sequence_number)
196 {
197 	struct kvec iov[2];
198 
199 	iov[0].iov_base = cifs_pdu;
200 	iov[0].iov_len = 4;
201 	iov[1].iov_base = (char *)cifs_pdu + 4;
202 	iov[1].iov_len = be32_to_cpu(cifs_pdu->smb_buf_length);
203 
204 	return cifs_sign_smbv(iov, 2, server,
205 			      pexpected_response_sequence_number);
206 }
207 
cifs_verify_signature(struct smb_rqst * rqst,struct TCP_Server_Info * server,__u32 expected_sequence_number)208 int cifs_verify_signature(struct smb_rqst *rqst,
209 			  struct TCP_Server_Info *server,
210 			  __u32 expected_sequence_number)
211 {
212 	unsigned int rc;
213 	char server_response_sig[8];
214 	char what_we_think_sig_should_be[20];
215 	struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
216 
217 	if (rqst->rq_iov[0].iov_len != 4 ||
218 	    rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
219 		return -EIO;
220 
221 	if (cifs_pdu == NULL || server == NULL)
222 		return -EINVAL;
223 
224 	if (!server->session_estab)
225 		return 0;
226 
227 	if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
228 		struct smb_com_lock_req *pSMB =
229 			(struct smb_com_lock_req *)cifs_pdu;
230 		if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
231 			return 0;
232 	}
233 
234 	/* BB what if signatures are supposed to be on for session but
235 	   server does not send one? BB */
236 
237 	/* Do not need to verify session setups with signature "BSRSPYL "  */
238 	if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0)
239 		cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
240 			 cifs_pdu->Command);
241 
242 	/* save off the original signature so we can modify the smb and check
243 		its signature against what the server sent */
244 	memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8);
245 
246 	cifs_pdu->Signature.Sequence.SequenceNumber =
247 					cpu_to_le32(expected_sequence_number);
248 	cifs_pdu->Signature.Sequence.Reserved = 0;
249 
250 	cifs_server_lock(server);
251 	rc = cifs_calc_signature(rqst, server, what_we_think_sig_should_be);
252 	cifs_server_unlock(server);
253 
254 	if (rc)
255 		return rc;
256 
257 /*	cifs_dump_mem("what we think it should be: ",
258 		      what_we_think_sig_should_be, 16); */
259 
260 	if (memcmp(server_response_sig, what_we_think_sig_should_be, 8))
261 		return -EACCES;
262 	else
263 		return 0;
264 
265 }
266 
267 /* Build a proper attribute value/target info pairs blob.
268  * Fill in netbios and dns domain name and workstation name
269  * and client time (total five av pairs and + one end of fields indicator.
270  * Allocate domain name which gets freed when session struct is deallocated.
271  */
272 static int
build_avpair_blob(struct cifs_ses * ses,const struct nls_table * nls_cp)273 build_avpair_blob(struct cifs_ses *ses, const struct nls_table *nls_cp)
274 {
275 	unsigned int dlen;
276 	unsigned int size = 2 * sizeof(struct ntlmssp2_name);
277 	char *defdmname = "WORKGROUP";
278 	unsigned char *blobptr;
279 	struct ntlmssp2_name *attrptr;
280 
281 	if (!ses->domainName) {
282 		ses->domainName = kstrdup(defdmname, GFP_KERNEL);
283 		if (!ses->domainName)
284 			return -ENOMEM;
285 	}
286 
287 	dlen = strlen(ses->domainName);
288 
289 	/*
290 	 * The length of this blob is two times the size of a
291 	 * structure (av pair) which holds name/size
292 	 * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) +
293 	 * unicode length of a netbios domain name
294 	 */
295 	kfree_sensitive(ses->auth_key.response);
296 	ses->auth_key.len = size + 2 * dlen;
297 	ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL);
298 	if (!ses->auth_key.response) {
299 		ses->auth_key.len = 0;
300 		return -ENOMEM;
301 	}
302 
303 	blobptr = ses->auth_key.response;
304 	attrptr = (struct ntlmssp2_name *) blobptr;
305 
306 	/*
307 	 * As defined in MS-NTLM 3.3.2, just this av pair field
308 	 * is sufficient as part of the temp
309 	 */
310 	attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME);
311 	attrptr->length = cpu_to_le16(2 * dlen);
312 	blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
313 	cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, nls_cp);
314 
315 	return 0;
316 }
317 
318 /* Server has provided av pairs/target info in the type 2 challenge
319  * packet and we have plucked it and stored within smb session.
320  * We parse that blob here to find netbios domain name to be used
321  * as part of ntlmv2 authentication (in Target String), if not already
322  * specified on the command line.
323  * If this function returns without any error but without fetching
324  * domain name, authentication may fail against some server but
325  * may not fail against other (those who are not very particular
326  * about target string i.e. for some, just user name might suffice.
327  */
328 static int
find_domain_name(struct cifs_ses * ses,const struct nls_table * nls_cp)329 find_domain_name(struct cifs_ses *ses, const struct nls_table *nls_cp)
330 {
331 	unsigned int attrsize;
332 	unsigned int type;
333 	unsigned int onesize = sizeof(struct ntlmssp2_name);
334 	unsigned char *blobptr;
335 	unsigned char *blobend;
336 	struct ntlmssp2_name *attrptr;
337 
338 	if (!ses->auth_key.len || !ses->auth_key.response)
339 		return 0;
340 
341 	blobptr = ses->auth_key.response;
342 	blobend = blobptr + ses->auth_key.len;
343 
344 	while (blobptr + onesize < blobend) {
345 		attrptr = (struct ntlmssp2_name *) blobptr;
346 		type = le16_to_cpu(attrptr->type);
347 		if (type == NTLMSSP_AV_EOL)
348 			break;
349 		blobptr += 2; /* advance attr type */
350 		attrsize = le16_to_cpu(attrptr->length);
351 		blobptr += 2; /* advance attr size */
352 		if (blobptr + attrsize > blobend)
353 			break;
354 		if (type == NTLMSSP_AV_NB_DOMAIN_NAME) {
355 			if (!attrsize || attrsize >= CIFS_MAX_DOMAINNAME_LEN)
356 				break;
357 			if (!ses->domainName) {
358 				ses->domainName =
359 					kmalloc(attrsize + 1, GFP_KERNEL);
360 				if (!ses->domainName)
361 						return -ENOMEM;
362 				cifs_from_utf16(ses->domainName,
363 					(__le16 *)blobptr, attrsize, attrsize,
364 					nls_cp, NO_MAP_UNI_RSVD);
365 				break;
366 			}
367 		}
368 		blobptr += attrsize; /* advance attr  value */
369 	}
370 
371 	return 0;
372 }
373 
374 /* Server has provided av pairs/target info in the type 2 challenge
375  * packet and we have plucked it and stored within smb session.
376  * We parse that blob here to find the server given timestamp
377  * as part of ntlmv2 authentication (or local current time as
378  * default in case of failure)
379  */
380 static __le64
find_timestamp(struct cifs_ses * ses)381 find_timestamp(struct cifs_ses *ses)
382 {
383 	unsigned int attrsize;
384 	unsigned int type;
385 	unsigned int onesize = sizeof(struct ntlmssp2_name);
386 	unsigned char *blobptr;
387 	unsigned char *blobend;
388 	struct ntlmssp2_name *attrptr;
389 	struct timespec64 ts;
390 
391 	if (!ses->auth_key.len || !ses->auth_key.response)
392 		return 0;
393 
394 	blobptr = ses->auth_key.response;
395 	blobend = blobptr + ses->auth_key.len;
396 
397 	while (blobptr + onesize < blobend) {
398 		attrptr = (struct ntlmssp2_name *) blobptr;
399 		type = le16_to_cpu(attrptr->type);
400 		if (type == NTLMSSP_AV_EOL)
401 			break;
402 		blobptr += 2; /* advance attr type */
403 		attrsize = le16_to_cpu(attrptr->length);
404 		blobptr += 2; /* advance attr size */
405 		if (blobptr + attrsize > blobend)
406 			break;
407 		if (type == NTLMSSP_AV_TIMESTAMP) {
408 			if (attrsize == sizeof(u64))
409 				return *((__le64 *)blobptr);
410 		}
411 		blobptr += attrsize; /* advance attr value */
412 	}
413 
414 	ktime_get_real_ts64(&ts);
415 	return cpu_to_le64(cifs_UnixTimeToNT(ts));
416 }
417 
calc_ntlmv2_hash(struct cifs_ses * ses,char * ntlmv2_hash,const struct nls_table * nls_cp,struct shash_desc * hmacmd5)418 static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
419 			    const struct nls_table *nls_cp, struct shash_desc *hmacmd5)
420 {
421 	int rc = 0;
422 	int len;
423 	char nt_hash[CIFS_NTHASH_SIZE];
424 	__le16 *user;
425 	wchar_t *domain;
426 	wchar_t *server;
427 
428 	/* calculate md4 hash of password */
429 	E_md4hash(ses->password, nt_hash, nls_cp);
430 
431 	rc = crypto_shash_setkey(hmacmd5->tfm, nt_hash, CIFS_NTHASH_SIZE);
432 	if (rc) {
433 		cifs_dbg(VFS, "%s: Could not set NT hash as a key, rc=%d\n", __func__, rc);
434 		return rc;
435 	}
436 
437 	rc = crypto_shash_init(hmacmd5);
438 	if (rc) {
439 		cifs_dbg(VFS, "%s: Could not init HMAC-MD5, rc=%d\n", __func__, rc);
440 		return rc;
441 	}
442 
443 	/* convert ses->user_name to unicode */
444 	len = ses->user_name ? strlen(ses->user_name) : 0;
445 	user = kmalloc(2 + (len * 2), GFP_KERNEL);
446 	if (user == NULL)
447 		return -ENOMEM;
448 
449 	if (len) {
450 		len = cifs_strtoUTF16(user, ses->user_name, len, nls_cp);
451 		UniStrupr(user);
452 	} else {
453 		*(u16 *)user = 0;
454 	}
455 
456 	rc = crypto_shash_update(hmacmd5, (char *)user, 2 * len);
457 	kfree(user);
458 	if (rc) {
459 		cifs_dbg(VFS, "%s: Could not update with user, rc=%d\n", __func__, rc);
460 		return rc;
461 	}
462 
463 	/* convert ses->domainName to unicode and uppercase */
464 	if (ses->domainName) {
465 		len = strlen(ses->domainName);
466 
467 		domain = kmalloc(2 + (len * 2), GFP_KERNEL);
468 		if (domain == NULL)
469 			return -ENOMEM;
470 
471 		len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len,
472 				      nls_cp);
473 		rc = crypto_shash_update(hmacmd5, (char *)domain, 2 * len);
474 		kfree(domain);
475 		if (rc) {
476 			cifs_dbg(VFS, "%s: Could not update with domain, rc=%d\n", __func__, rc);
477 			return rc;
478 		}
479 	} else {
480 		/* We use ses->ip_addr if no domain name available */
481 		len = strlen(ses->ip_addr);
482 
483 		server = kmalloc(2 + (len * 2), GFP_KERNEL);
484 		if (server == NULL)
485 			return -ENOMEM;
486 
487 		len = cifs_strtoUTF16((__le16 *)server, ses->ip_addr, len, nls_cp);
488 		rc = crypto_shash_update(hmacmd5, (char *)server, 2 * len);
489 		kfree(server);
490 		if (rc) {
491 			cifs_dbg(VFS, "%s: Could not update with server, rc=%d\n", __func__, rc);
492 			return rc;
493 		}
494 	}
495 
496 	rc = crypto_shash_final(hmacmd5, ntlmv2_hash);
497 	if (rc)
498 		cifs_dbg(VFS, "%s: Could not generate MD5 hash, rc=%d\n", __func__, rc);
499 
500 	return rc;
501 }
502 
503 static int
CalcNTLMv2_response(const struct cifs_ses * ses,char * ntlmv2_hash,struct shash_desc * hmacmd5)504 CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash, struct shash_desc *hmacmd5)
505 {
506 	int rc;
507 	struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *)
508 	    (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
509 	unsigned int hash_len;
510 
511 	/* The MD5 hash starts at challenge_key.key */
512 	hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE +
513 		offsetof(struct ntlmv2_resp, challenge.key[0]));
514 
515 	rc = crypto_shash_setkey(hmacmd5->tfm, ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
516 	if (rc) {
517 		cifs_dbg(VFS, "%s: Could not set NTLMv2 hash as a key, rc=%d\n", __func__, rc);
518 		return rc;
519 	}
520 
521 	rc = crypto_shash_init(hmacmd5);
522 	if (rc) {
523 		cifs_dbg(VFS, "%s: Could not init HMAC-MD5, rc=%d\n", __func__, rc);
524 		return rc;
525 	}
526 
527 	if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED)
528 		memcpy(ntlmv2->challenge.key, ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
529 	else
530 		memcpy(ntlmv2->challenge.key, ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
531 
532 	rc = crypto_shash_update(hmacmd5, ntlmv2->challenge.key, hash_len);
533 	if (rc) {
534 		cifs_dbg(VFS, "%s: Could not update with response, rc=%d\n", __func__, rc);
535 		return rc;
536 	}
537 
538 	/* Note that the MD5 digest over writes anon.challenge_key.key */
539 	rc = crypto_shash_final(hmacmd5, ntlmv2->ntlmv2_hash);
540 	if (rc)
541 		cifs_dbg(VFS, "%s: Could not generate MD5 hash, rc=%d\n", __func__, rc);
542 
543 	return rc;
544 }
545 
546 int
setup_ntlmv2_rsp(struct cifs_ses * ses,const struct nls_table * nls_cp)547 setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
548 {
549 	struct shash_desc *hmacmd5 = NULL;
550 	int rc;
551 	int baselen;
552 	unsigned int tilen;
553 	struct ntlmv2_resp *ntlmv2;
554 	char ntlmv2_hash[16];
555 	unsigned char *tiblob = NULL; /* target info blob */
556 	__le64 rsp_timestamp;
557 
558 	if (nls_cp == NULL) {
559 		cifs_dbg(VFS, "%s called with nls_cp==NULL\n", __func__);
560 		return -EINVAL;
561 	}
562 
563 	if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) {
564 		if (!ses->domainName) {
565 			if (ses->domainAuto) {
566 				rc = find_domain_name(ses, nls_cp);
567 				if (rc) {
568 					cifs_dbg(VFS, "error %d finding domain name\n",
569 						 rc);
570 					goto setup_ntlmv2_rsp_ret;
571 				}
572 			} else {
573 				ses->domainName = kstrdup("", GFP_KERNEL);
574 			}
575 		}
576 	} else {
577 		rc = build_avpair_blob(ses, nls_cp);
578 		if (rc) {
579 			cifs_dbg(VFS, "error %d building av pair blob\n", rc);
580 			goto setup_ntlmv2_rsp_ret;
581 		}
582 	}
583 
584 	/* Must be within 5 minutes of the server (or in range +/-2h
585 	 * in case of Mac OS X), so simply carry over server timestamp
586 	 * (as Windows 7 does)
587 	 */
588 	rsp_timestamp = find_timestamp(ses);
589 
590 	baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp);
591 	tilen = ses->auth_key.len;
592 	tiblob = ses->auth_key.response;
593 
594 	ses->auth_key.response = kmalloc(baselen + tilen, GFP_KERNEL);
595 	if (!ses->auth_key.response) {
596 		rc = -ENOMEM;
597 		ses->auth_key.len = 0;
598 		goto setup_ntlmv2_rsp_ret;
599 	}
600 	ses->auth_key.len += baselen;
601 
602 	ntlmv2 = (struct ntlmv2_resp *)
603 			(ses->auth_key.response + CIFS_SESS_KEY_SIZE);
604 	ntlmv2->blob_signature = cpu_to_le32(0x00000101);
605 	ntlmv2->reserved = 0;
606 	ntlmv2->time = rsp_timestamp;
607 
608 	get_random_bytes(&ntlmv2->client_chal, sizeof(ntlmv2->client_chal));
609 	ntlmv2->reserved2 = 0;
610 
611 	memcpy(ses->auth_key.response + baselen, tiblob, tilen);
612 
613 	cifs_server_lock(ses->server);
614 
615 	rc = cifs_alloc_hash("hmac(md5)", &hmacmd5);
616 	if (rc) {
617 		cifs_dbg(VFS, "Could not allocate HMAC-MD5, rc=%d\n", rc);
618 		goto unlock;
619 	}
620 
621 	/* calculate ntlmv2_hash */
622 	rc = calc_ntlmv2_hash(ses, ntlmv2_hash, nls_cp, hmacmd5);
623 	if (rc) {
624 		cifs_dbg(VFS, "Could not get NTLMv2 hash, rc=%d\n", rc);
625 		goto unlock;
626 	}
627 
628 	/* calculate first part of the client response (CR1) */
629 	rc = CalcNTLMv2_response(ses, ntlmv2_hash, hmacmd5);
630 	if (rc) {
631 		cifs_dbg(VFS, "Could not calculate CR1, rc=%d\n", rc);
632 		goto unlock;
633 	}
634 
635 	/* now calculate the session key for NTLMv2 */
636 	rc = crypto_shash_setkey(hmacmd5->tfm, ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
637 	if (rc) {
638 		cifs_dbg(VFS, "%s: Could not set NTLMv2 hash as a key, rc=%d\n", __func__, rc);
639 		goto unlock;
640 	}
641 
642 	rc = crypto_shash_init(hmacmd5);
643 	if (rc) {
644 		cifs_dbg(VFS, "%s: Could not init HMAC-MD5, rc=%d\n", __func__, rc);
645 		goto unlock;
646 	}
647 
648 	rc = crypto_shash_update(hmacmd5, ntlmv2->ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
649 	if (rc) {
650 		cifs_dbg(VFS, "%s: Could not update with response, rc=%d\n", __func__, rc);
651 		goto unlock;
652 	}
653 
654 	rc = crypto_shash_final(hmacmd5, ses->auth_key.response);
655 	if (rc)
656 		cifs_dbg(VFS, "%s: Could not generate MD5 hash, rc=%d\n", __func__, rc);
657 unlock:
658 	cifs_server_unlock(ses->server);
659 	cifs_free_hash(&hmacmd5);
660 setup_ntlmv2_rsp_ret:
661 	kfree_sensitive(tiblob);
662 
663 	return rc;
664 }
665 
666 int
calc_seckey(struct cifs_ses * ses)667 calc_seckey(struct cifs_ses *ses)
668 {
669 	unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */
670 	struct arc4_ctx *ctx_arc4;
671 
672 	if (fips_enabled)
673 		return -ENODEV;
674 
675 	get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE);
676 
677 	ctx_arc4 = kmalloc(sizeof(*ctx_arc4), GFP_KERNEL);
678 	if (!ctx_arc4) {
679 		cifs_dbg(VFS, "Could not allocate arc4 context\n");
680 		return -ENOMEM;
681 	}
682 
683 	cifs_arc4_setkey(ctx_arc4, ses->auth_key.response, CIFS_SESS_KEY_SIZE);
684 	cifs_arc4_crypt(ctx_arc4, ses->ntlmssp->ciphertext, sec_key,
685 			CIFS_CPHTXT_SIZE);
686 
687 	/* make secondary_key/nonce as session key */
688 	memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE);
689 	/* and make len as that of session key only */
690 	ses->auth_key.len = CIFS_SESS_KEY_SIZE;
691 
692 	memzero_explicit(sec_key, CIFS_SESS_KEY_SIZE);
693 	kfree_sensitive(ctx_arc4);
694 	return 0;
695 }
696 
697 void
cifs_crypto_secmech_release(struct TCP_Server_Info * server)698 cifs_crypto_secmech_release(struct TCP_Server_Info *server)
699 {
700 	cifs_free_hash(&server->secmech.aes_cmac);
701 	cifs_free_hash(&server->secmech.hmacsha256);
702 	cifs_free_hash(&server->secmech.md5);
703 	cifs_free_hash(&server->secmech.sha512);
704 
705 	if (!SERVER_IS_CHAN(server)) {
706 		if (server->secmech.enc) {
707 			crypto_free_aead(server->secmech.enc);
708 			server->secmech.enc = NULL;
709 		}
710 
711 		if (server->secmech.dec) {
712 			crypto_free_aead(server->secmech.dec);
713 			server->secmech.dec = NULL;
714 		}
715 	} else {
716 		server->secmech.enc = NULL;
717 		server->secmech.dec = NULL;
718 	}
719 }
720