fs/cifs/cifsencrypt.c

   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 <crypto/skcipher.h>
  37 #include <crypto/aead.h>
  38
  39 static int
  40 cifs_crypto_shash_md5_allocate(struct TCP_Server_Info *server)
  41 {
  42         int rc;
  43         unsigned int size;
  44
  45         if (server->secmech.sdescmd5 != NULL)
  46                 return 0; /* already allocated */
  47
  48         server->secmech.md5 = crypto_alloc_shash("md5", 0, 0);
  49         if (IS_ERR(server->secmech.md5)) {
  50                 cifs_dbg(VFS, "could not allocate crypto md5\n");
  51                 rc = PTR_ERR(server->secmech.md5);
  52                 server->secmech.md5 = NULL;
  53                 return rc;
  54         }
  55
  56         size = sizeof(struct shash_desc) +
  57                         crypto_shash_descsize(server->secmech.md5);
  58         server->secmech.sdescmd5 = kmalloc(size, GFP_KERNEL);
  59         if (!server->secmech.sdescmd5) {
  60                 crypto_free_shash(server->secmech.md5);
  61                 server->secmech.md5 = NULL;
  62                 return -ENOMEM;
  63         }
  64         server->secmech.sdescmd5->shash.tfm = server->secmech.md5;
  65         server->secmech.sdescmd5->shash.flags = 0x0;
  66
  67         return 0;
  68 }
  69
  70 int __cifs_calc_signature(struct smb_rqst *rqst,
  71                         struct TCP_Server_Info *server, char *signature,
  72                         struct shash_desc *shash)
  73 {
  74         int i;
  75         int rc;
  76         struct kvec *iov = rqst->rq_iov;
  77         int n_vec = rqst->rq_nvec;
  78
  79         if (n_vec < 2 || iov[0].iov_len != 4)
  80                 return -EIO;
  81
  82         for (i = 1; i < n_vec; i++) {
  83                 if (iov[i].iov_len == 0)
  84                         continue;
  85                 if (iov[i].iov_base == NULL) {
  86                         cifs_dbg(VFS, "null iovec entry\n");
  87                         return -EIO;
  88                 }
  89                 if (i == 1 && iov[1].iov_len <= 4)
  90                         break; /* nothing to sign or corrupt header */
  91                 rc = crypto_shash_update(shash,
  92                                          iov[i].iov_base, iov[i].iov_len);
  93                 if (rc) {
  94                         cifs_dbg(VFS, "%s: Could not update with payload\n",
  95                                  __func__);
  96                         return rc;
  97                 }
  98         }
  99
 100         /* now hash over the rq_pages array */
 101         for (i = 0; i < rqst->rq_npages; i++) {
 102                 void *kaddr = kmap(rqst->rq_pages[i]);
 103                 size_t len = rqst->rq_pagesz;
 104
 105                 if (i == rqst->rq_npages - 1)
 106                         len = rqst->rq_tailsz;
 107
 108                 crypto_shash_update(shash, kaddr, len);
 109
 110                 kunmap(rqst->rq_pages[i]);
 111         }
 112
 113         rc = crypto_shash_final(shash, signature);
 114         if (rc)
 115                 cifs_dbg(VFS, "%s: Could not generate hash\n", __func__);
 116
 117         return rc;
 118 }
 119
 120 /*
 121  * Calculate and return the CIFS signature based on the mac key and SMB PDU.
 122  * The 16 byte signature must be allocated by the caller. Note we only use the
 123  * 1st eight bytes and that the smb header signature field on input contains
 124  * the sequence number before this function is called. Also, this function
 125  * should be called with the server->srv_mutex held.
 126  */
 127 static int cifs_calc_signature(struct smb_rqst *rqst,
 128                         struct TCP_Server_Info *server, char *signature)
 129 {
 130         int rc;
 131
 132         if (!rqst->rq_iov || !signature || !server)
 133                 return -EINVAL;
 134
 135         if (!server->secmech.sdescmd5) {
 136                 rc = cifs_crypto_shash_md5_allocate(server);
 137                 if (rc) {
 138                         cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
 139                         return -1;
 140                 }
 141         }
 142
 143         rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
 144         if (rc) {
 145                 cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
 146                 return rc;
 147         }
 148
 149         rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
 150                 server->session_key.response, server->session_key.len);
 151         if (rc) {
 152                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 153                 return rc;
 154         }
 155
 156         return __cifs_calc_signature(rqst, server, signature,
 157                                      &server->secmech.sdescmd5->shash);
 158 }
 159
 160 /* must be called with server->srv_mutex held */
 161 int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 162                    __u32 *pexpected_response_sequence_number)
 163 {
 164         int rc = 0;
 165         char smb_signature[20];
 166         struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 167
 168         if (rqst->rq_iov[0].iov_len != 4 ||
 169             rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
 170                 return -EIO;
 171
 172         if ((cifs_pdu == NULL) || (server == NULL))
 173                 return -EINVAL;
 174
 175         if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) ||
 176             server->tcpStatus == CifsNeedNegotiate)
 177                 return rc;
 178
 179         if (!server->session_estab) {
 180                 memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8);
 181                 return rc;
 182         }
 183
 184         cifs_pdu->Signature.Sequence.SequenceNumber =
 185                                 cpu_to_le32(server->sequence_number);
 186         cifs_pdu->Signature.Sequence.Reserved = 0;
 187
 188         *pexpected_response_sequence_number = ++server->sequence_number;
 189         ++server->sequence_number;
 190
 191         rc = cifs_calc_signature(rqst, server, smb_signature);
 192         if (rc)
 193                 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
 194         else
 195                 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
 196
 197         return rc;
 198 }
 199
 200 int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
 201                    __u32 *pexpected_response_sequence)
 202 {
 203         struct smb_rqst rqst = { .rq_iov = iov,
 204                                  .rq_nvec = n_vec };
 205
 206         return cifs_sign_rqst(&rqst, server, pexpected_response_sequence);
 207 }
 208
 209 /* must be called with server->srv_mutex held */
 210 int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
 211                   __u32 *pexpected_response_sequence_number)
 212 {
 213         struct kvec iov[2];
 214
 215         iov[0].iov_base = cifs_pdu;
 216         iov[0].iov_len = 4;
 217         iov[1].iov_base = (char *)cifs_pdu + 4;
 218         iov[1].iov_len = be32_to_cpu(cifs_pdu->smb_buf_length);
 219
 220         return cifs_sign_smbv(iov, 2, server,
 221                               pexpected_response_sequence_number);
 222 }
 223
 224 int cifs_verify_signature(struct smb_rqst *rqst,
 225                           struct TCP_Server_Info *server,
 226                           __u32 expected_sequence_number)
 227 {
 228         unsigned int rc;
 229         char server_response_sig[8];
 230         char what_we_think_sig_should_be[20];
 231         struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 232
 233         if (rqst->rq_iov[0].iov_len != 4 ||
 234             rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
 235                 return -EIO;
 236
 237         if (cifs_pdu == NULL || server == NULL)
 238                 return -EINVAL;
 239
 240         if (!server->session_estab)
 241                 return 0;
 242
 243         if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
 244                 struct smb_com_lock_req *pSMB =
 245                         (struct smb_com_lock_req *)cifs_pdu;
 246             if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
 247                         return 0;
 248         }
 249
 250         /* BB what if signatures are supposed to be on for session but
 251            server does not send one? BB */
 252
 253         /* Do not need to verify session setups with signature "BSRSPYL "  */
 254         if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0)
 255                 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
 256                          cifs_pdu->Command);
 257
 258         /* save off the origiginal signature so we can modify the smb and check
 259                 its signature against what the server sent */
 260         memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8);
 261
 262         cifs_pdu->Signature.Sequence.SequenceNumber =
 263                                         cpu_to_le32(expected_sequence_number);
 264         cifs_pdu->Signature.Sequence.Reserved = 0;
 265
 266         mutex_lock(&server->srv_mutex);
 267         rc = cifs_calc_signature(rqst, server, what_we_think_sig_should_be);
 268         mutex_unlock(&server->srv_mutex);
 269
 270         if (rc)
 271                 return rc;
 272
 273 /*      cifs_dump_mem("what we think it should be: ",
 274                       what_we_think_sig_should_be, 16); */
 275
 276         if (memcmp(server_response_sig, what_we_think_sig_should_be, 8))
 277                 return -EACCES;
 278         else
 279                 return 0;
 280
 281 }
 282
 283 /* first calculate 24 bytes ntlm response and then 16 byte session key */
 284 int setup_ntlm_response(struct cifs_ses *ses, const struct nls_table *nls_cp)
 285 {
 286         int rc = 0;
 287         unsigned int temp_len = CIFS_SESS_KEY_SIZE + CIFS_AUTH_RESP_SIZE;
 288         char temp_key[CIFS_SESS_KEY_SIZE];
 289
 290         if (!ses)
 291                 return -EINVAL;
 292
 293         ses->auth_key.response = kmalloc(temp_len, GFP_KERNEL);
 294         if (!ses->auth_key.response)
 295                 return -ENOMEM;
 296
 297         ses->auth_key.len = temp_len;
 298
 299         rc = SMBNTencrypt(ses->password, ses->server->cryptkey,
 300                         ses->auth_key.response + CIFS_SESS_KEY_SIZE, nls_cp);
 301         if (rc) {
 302                 cifs_dbg(FYI, "%s Can't generate NTLM response, error: %d\n",
 303                          __func__, rc);
 304                 return rc;
 305         }
 306
 307         rc = E_md4hash(ses->password, temp_key, nls_cp);
 308         if (rc) {
 309                 cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
 310                          __func__, rc);
 311                 return rc;
 312         }
 313
 314         rc = mdfour(ses->auth_key.response, temp_key, CIFS_SESS_KEY_SIZE);
 315         if (rc)
 316                 cifs_dbg(FYI, "%s Can't generate NTLM session key, error: %d\n",
 317                          __func__, rc);
 318
 319         return rc;
 320 }
 321
 322 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 323 int calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
 324                         char *lnm_session_key)
 325 {
 326         int i;
 327         int rc;
 328         char password_with_pad[CIFS_ENCPWD_SIZE];
 329
 330         memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
 331         if (password)
 332                 strncpy(password_with_pad, password, CIFS_ENCPWD_SIZE);
 333
 334         if (!encrypt && global_secflags & CIFSSEC_MAY_PLNTXT) {
 335                 memcpy(lnm_session_key, password_with_pad,
 336                         CIFS_ENCPWD_SIZE);
 337                 return 0;
 338         }
 339
 340         /* calculate old style session key */
 341         /* calling toupper is less broken than repeatedly
 342         calling nls_toupper would be since that will never
 343         work for UTF8, but neither handles multibyte code pages
 344         but the only alternative would be converting to UCS-16 (Unicode)
 345         (using a routine something like UniStrupr) then
 346         uppercasing and then converting back from Unicode - which
 347         would only worth doing it if we knew it were utf8. Basically
 348         utf8 and other multibyte codepages each need their own strupper
 349         function since a byte at a time will ont work. */
 350
 351         for (i = 0; i < CIFS_ENCPWD_SIZE; i++)
 352                 password_with_pad[i] = toupper(password_with_pad[i]);
 353
 354         rc = SMBencrypt(password_with_pad, cryptkey, lnm_session_key);
 355
 356         return rc;
 357 }
 358 #endif /* CIFS_WEAK_PW_HASH */
 359
 360 /* Build a proper attribute value/target info pairs blob.
 361  * Fill in netbios and dns domain name and workstation name
 362  * and client time (total five av pairs and + one end of fields indicator.
 363  * Allocate domain name which gets freed when session struct is deallocated.
 364  */
 365 static int
 366 build_avpair_blob(struct cifs_ses *ses, const struct nls_table *nls_cp)
 367 {
 368         unsigned int dlen;
 369         unsigned int size = 2 * sizeof(struct ntlmssp2_name);
 370         char *defdmname = "WORKGROUP";
 371         unsigned char *blobptr;
 372         struct ntlmssp2_name *attrptr;
 373
 374         if (!ses->domainName) {
 375                 ses->domainName = kstrdup(defdmname, GFP_KERNEL);
 376                 if (!ses->domainName)
 377                         return -ENOMEM;
 378         }
 379
 380         dlen = strlen(ses->domainName);
 381
 382         /*
 383          * The length of this blob is two times the size of a
 384          * structure (av pair) which holds name/size
 385          * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) +
 386          * unicode length of a netbios domain name
 387          */
 388         ses->auth_key.len = size + 2 * dlen;
 389         ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL);
 390         if (!ses->auth_key.response) {
 391                 ses->auth_key.len = 0;
 392                 return -ENOMEM;
 393         }
 394
 395         blobptr = ses->auth_key.response;
 396         attrptr = (struct ntlmssp2_name *) blobptr;
 397
 398         /*
 399          * As defined in MS-NTLM 3.3.2, just this av pair field
 400          * is sufficient as part of the temp
 401          */
 402         attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME);
 403         attrptr->length = cpu_to_le16(2 * dlen);
 404         blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
 405         cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, nls_cp);
 406
 407         return 0;
 408 }
 409
 410 /* Server has provided av pairs/target info in the type 2 challenge
 411  * packet and we have plucked it and stored within smb session.
 412  * We parse that blob here to find netbios domain name to be used
 413  * as part of ntlmv2 authentication (in Target String), if not already
 414  * specified on the command line.
 415  * If this function returns without any error but without fetching
 416  * domain name, authentication may fail against some server but
 417  * may not fail against other (those who are not very particular
 418  * about target string i.e. for some, just user name might suffice.
 419  */
 420 static int
 421 find_domain_name(struct cifs_ses *ses, const struct nls_table *nls_cp)
 422 {
 423         unsigned int attrsize;
 424         unsigned int type;
 425         unsigned int onesize = sizeof(struct ntlmssp2_name);
 426         unsigned char *blobptr;
 427         unsigned char *blobend;
 428         struct ntlmssp2_name *attrptr;
 429
 430         if (!ses->auth_key.len || !ses->auth_key.response)
 431                 return 0;
 432
 433         blobptr = ses->auth_key.response;
 434         blobend = blobptr + ses->auth_key.len;
 435
 436         while (blobptr + onesize < blobend) {
 437                 attrptr = (struct ntlmssp2_name *) blobptr;
 438                 type = le16_to_cpu(attrptr->type);
 439                 if (type == NTLMSSP_AV_EOL)
 440                         break;
 441                 blobptr += 2; /* advance attr type */
 442                 attrsize = le16_to_cpu(attrptr->length);
 443                 blobptr += 2; /* advance attr size */
 444                 if (blobptr + attrsize > blobend)
 445                         break;
 446                 if (type == NTLMSSP_AV_NB_DOMAIN_NAME) {
 447                         if (!attrsize || attrsize >= CIFS_MAX_DOMAINNAME_LEN)
 448                                 break;
 449                         if (!ses->domainName) {
 450                                 ses->domainName =
 451                                         kmalloc(attrsize + 1, GFP_KERNEL);
 452                                 if (!ses->domainName)
 453                                                 return -ENOMEM;
 454                                 cifs_from_utf16(ses->domainName,
 455                                         (__le16 *)blobptr, attrsize, attrsize,
 456                                         nls_cp, NO_MAP_UNI_RSVD);
 457                                 break;
 458                         }
 459                 }
 460                 blobptr += attrsize; /* advance attr  value */
 461         }
 462
 463         return 0;
 464 }
 465
 466 /* Server has provided av pairs/target info in the type 2 challenge
 467  * packet and we have plucked it and stored within smb session.
 468  * We parse that blob here to find the server given timestamp
 469  * as part of ntlmv2 authentication (or local current time as
 470  * default in case of failure)
 471  */
 472 static __le64
 473 find_timestamp(struct cifs_ses *ses)
 474 {
 475         unsigned int attrsize;
 476         unsigned int type;
 477         unsigned int onesize = sizeof(struct ntlmssp2_name);
 478         unsigned char *blobptr;
 479         unsigned char *blobend;
 480         struct ntlmssp2_name *attrptr;
 481
 482         if (!ses->auth_key.len || !ses->auth_key.response)
 483                 return 0;
 484
 485         blobptr = ses->auth_key.response;
 486         blobend = blobptr + ses->auth_key.len;
 487
 488         while (blobptr + onesize < blobend) {
 489                 attrptr = (struct ntlmssp2_name *) blobptr;
 490                 type = le16_to_cpu(attrptr->type);
 491                 if (type == NTLMSSP_AV_EOL)
 492                         break;
 493                 blobptr += 2; /* advance attr type */
 494                 attrsize = le16_to_cpu(attrptr->length);
 495                 blobptr += 2; /* advance attr size */
 496                 if (blobptr + attrsize > blobend)
 497                         break;
 498                 if (type == NTLMSSP_AV_TIMESTAMP) {
 499                         if (attrsize == sizeof(u64))
 500                                 return *((__le64 *)blobptr);
 501                 }
 502                 blobptr += attrsize; /* advance attr value */
 503         }
 504
 505         return cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
 506 }
 507
 508 static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
 509                             const struct nls_table *nls_cp)
 510 {
 511         int rc = 0;
 512         int len;
 513         char nt_hash[CIFS_NTHASH_SIZE];
 514         __le16 *user;
 515         wchar_t *domain;
 516         wchar_t *server;
 517
 518         if (!ses->server->secmech.sdeschmacmd5) {
 519                 cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
 520                 return -1;
 521         }
 522
 523         /* calculate md4 hash of password */
 524         E_md4hash(ses->password, nt_hash, nls_cp);
 525
 526         rc = crypto_shash_setkey(ses->server->secmech.hmacmd5, nt_hash,
 527                                 CIFS_NTHASH_SIZE);
 528         if (rc) {
 529                 cifs_dbg(VFS, "%s: Could not set NT Hash as a key\n", __func__);
 530                 return rc;
 531         }
 532
 533         rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
 534         if (rc) {
 535                 cifs_dbg(VFS, "%s: could not init hmacmd5\n", __func__);
 536                 return rc;
 537         }
 538
 539         /* convert ses->user_name to unicode */
 540         len = ses->user_name ? strlen(ses->user_name) : 0;
 541         user = kmalloc(2 + (len * 2), GFP_KERNEL);
 542         if (user == NULL) {
 543                 rc = -ENOMEM;
 544                 return rc;
 545         }
 546
 547         if (len) {
 548                 len = cifs_strtoUTF16(user, ses->user_name, len, nls_cp);
 549                 UniStrupr(user);
 550         } else {
 551                 memset(user, '\0', 2);
 552         }
 553
 554         rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 555                                 (char *)user, 2 * len);
 556         kfree(user);
 557         if (rc) {
 558                 cifs_dbg(VFS, "%s: Could not update with user\n", __func__);
 559                 return rc;
 560         }
 561
 562         /* convert ses->domainName to unicode and uppercase */
 563         if (ses->domainName) {
 564                 len = strlen(ses->domainName);
 565
 566                 domain = kmalloc(2 + (len * 2), GFP_KERNEL);
 567                 if (domain == NULL) {
 568                         rc = -ENOMEM;
 569                         return rc;
 570                 }
 571                 len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len,
 572                                       nls_cp);
 573                 rc =
 574                 crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 575                                         (char *)domain, 2 * len);
 576                 kfree(domain);
 577                 if (rc) {
 578                         cifs_dbg(VFS, "%s: Could not update with domain\n",
 579                                  __func__);
 580                         return rc;
 581                 }
 582         } else {
 583                 /* We use ses->serverName if no domain name available */
 584                 len = strlen(ses->serverName);
 585
 586                 server = kmalloc(2 + (len * 2), GFP_KERNEL);
 587                 if (server == NULL) {
 588                         rc = -ENOMEM;
 589                         return rc;
 590                 }
 591                 len = cifs_strtoUTF16((__le16 *)server, ses->serverName, len,
 592                                         nls_cp);
 593                 rc =
 594                 crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 595                                         (char *)server, 2 * len);
 596                 kfree(server);
 597                 if (rc) {
 598                         cifs_dbg(VFS, "%s: Could not update with server\n",
 599                                  __func__);
 600                         return rc;
 601                 }
 602         }
 603
 604         rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
 605                                         ntlmv2_hash);
 606         if (rc)
 607                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 608
 609         return rc;
 610 }
 611
 612 static int
 613 CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash)
 614 {
 615         int rc;
 616         struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *)
 617             (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
 618         unsigned int hash_len;
 619
 620         /* The MD5 hash starts at challenge_key.key */
 621         hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE +
 622                 offsetof(struct ntlmv2_resp, challenge.key[0]));
 623
 624         if (!ses->server->secmech.sdeschmacmd5) {
 625                 cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
 626                 return -1;
 627         }
 628
 629         rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
 630                                  ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
 631         if (rc) {
 632                 cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
 633                          __func__);
 634                 return rc;
 635         }
 636
 637         rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
 638         if (rc) {
 639                 cifs_dbg(VFS, "%s: could not init hmacmd5\n", __func__);
 640                 return rc;
 641         }
 642
 643         if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED)
 644                 memcpy(ntlmv2->challenge.key,
 645                        ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
 646         else
 647                 memcpy(ntlmv2->challenge.key,
 648                        ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
 649         rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 650                                  ntlmv2->challenge.key, hash_len);
 651         if (rc) {
 652                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 653                 return rc;
 654         }
 655
 656         /* Note that the MD5 digest over writes anon.challenge_key.key */
 657         rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
 658                                 ntlmv2->ntlmv2_hash);
 659         if (rc)
 660                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 661
 662         return rc;
 663 }
 664
 665 static int crypto_hmacmd5_alloc(struct TCP_Server_Info *server)
 666 {
 667         int rc;
 668         unsigned int size;
 669
 670         /* check if already allocated */
 671         if (server->secmech.sdeschmacmd5)
 672                 return 0;
 673
 674         server->secmech.hmacmd5 = crypto_alloc_shash("hmac(md5)", 0, 0);
 675         if (IS_ERR(server->secmech.hmacmd5)) {
 676                 cifs_dbg(VFS, "could not allocate crypto hmacmd5\n");
 677                 rc = PTR_ERR(server->secmech.hmacmd5);
 678                 server->secmech.hmacmd5 = NULL;
 679                 return rc;
 680         }
 681
 682         size = sizeof(struct shash_desc) +
 683                         crypto_shash_descsize(server->secmech.hmacmd5);
 684         server->secmech.sdeschmacmd5 = kmalloc(size, GFP_KERNEL);
 685         if (!server->secmech.sdeschmacmd5) {
 686                 crypto_free_shash(server->secmech.hmacmd5);
 687                 server->secmech.hmacmd5 = NULL;
 688                 return -ENOMEM;
 689         }
 690         server->secmech.sdeschmacmd5->shash.tfm = server->secmech.hmacmd5;
 691         server->secmech.sdeschmacmd5->shash.flags = 0x0;
 692
 693         return 0;
 694 }
 695
 696 int
 697 setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
 698 {
 699         int rc;
 700         int baselen;
 701         unsigned int tilen;
 702         struct ntlmv2_resp *ntlmv2;
 703         char ntlmv2_hash[16];
 704         unsigned char *tiblob = NULL; /* target info blob */
 705         __le64 rsp_timestamp;
 706
 707         if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) {
 708                 if (!ses->domainName) {
 709                         if (ses->domainAuto) {
 710                                 rc = find_domain_name(ses, nls_cp);
 711                                 if (rc) {
 712                                         cifs_dbg(VFS, "error %d finding domain name\n",
 713                                                  rc);
 714                                         goto setup_ntlmv2_rsp_ret;
 715                                 }
 716                         } else {
 717                                 ses->domainName = kstrdup("", GFP_KERNEL);
 718                         }
 719                 }
 720         } else {
 721                 rc = build_avpair_blob(ses, nls_cp);
 722                 if (rc) {
 723                         cifs_dbg(VFS, "error %d building av pair blob\n", rc);
 724                         goto setup_ntlmv2_rsp_ret;
 725                 }
 726         }
 727
 728         /* Must be within 5 minutes of the server (or in range +/-2h
 729          * in case of Mac OS X), so simply carry over server timestamp
 730          * (as Windows 7 does)
 731          */
 732         rsp_timestamp = find_timestamp(ses);
 733
 734         baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp);
 735         tilen = ses->auth_key.len;
 736         tiblob = ses->auth_key.response;
 737
 738         ses->auth_key.response = kmalloc(baselen + tilen, GFP_KERNEL);
 739         if (!ses->auth_key.response) {
 740                 rc = -ENOMEM;
 741                 ses->auth_key.len = 0;
 742                 goto setup_ntlmv2_rsp_ret;
 743         }
 744         ses->auth_key.len += baselen;
 745
 746         ntlmv2 = (struct ntlmv2_resp *)
 747                         (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
 748         ntlmv2->blob_signature = cpu_to_le32(0x00000101);
 749         ntlmv2->reserved = 0;
 750         ntlmv2->time = rsp_timestamp;
 751
 752         get_random_bytes(&ntlmv2->client_chal, sizeof(ntlmv2->client_chal));
 753         ntlmv2->reserved2 = 0;
 754
 755         memcpy(ses->auth_key.response + baselen, tiblob, tilen);
 756
 757         mutex_lock(&ses->server->srv_mutex);
 758
 759         rc = crypto_hmacmd5_alloc(ses->server);
 760         if (rc) {
 761                 cifs_dbg(VFS, "could not crypto alloc hmacmd5 rc %d\n", rc);
 762                 goto unlock;
 763         }
 764
 765         /* calculate ntlmv2_hash */
 766         rc = calc_ntlmv2_hash(ses, ntlmv2_hash, nls_cp);
 767         if (rc) {
 768                 cifs_dbg(VFS, "could not get v2 hash rc %d\n", rc);
 769                 goto unlock;
 770         }
 771
 772         /* calculate first part of the client response (CR1) */
 773         rc = CalcNTLMv2_response(ses, ntlmv2_hash);
 774         if (rc) {
 775                 cifs_dbg(VFS, "Could not calculate CR1 rc: %d\n", rc);
 776                 goto unlock;
 777         }
 778
 779         /* now calculate the session key for NTLMv2 */
 780         rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
 781                 ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
 782         if (rc) {
 783                 cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
 784                          __func__);
 785                 goto unlock;
 786         }
 787
 788         rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
 789         if (rc) {
 790                 cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
 791                 goto unlock;
 792         }
 793
 794         rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 795                 ntlmv2->ntlmv2_hash,
 796                 CIFS_HMAC_MD5_HASH_SIZE);
 797         if (rc) {
 798                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 799                 goto unlock;
 800         }
 801
 802         rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
 803                 ses->auth_key.response);
 804         if (rc)
 805                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 806
 807 unlock:
 808         mutex_unlock(&ses->server->srv_mutex);
 809 setup_ntlmv2_rsp_ret:
 810         kfree(tiblob);
 811
 812         return rc;
 813 }
 814
 815 int
 816 calc_seckey(struct cifs_ses *ses)
 817 {
 818         int rc;
 819         struct crypto_skcipher *tfm_arc4;
 820         struct scatterlist sgin, sgout;
 821         struct skcipher_request *req;
 822         unsigned char *sec_key;
 823
 824         sec_key = kmalloc(CIFS_SESS_KEY_SIZE, GFP_KERNEL);
 825         if (sec_key == NULL)
 826                 return -ENOMEM;
 827
 828         get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE);
 829
 830         tfm_arc4 = crypto_alloc_skcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
 831         if (IS_ERR(tfm_arc4)) {
 832                 rc = PTR_ERR(tfm_arc4);
 833                 cifs_dbg(VFS, "could not allocate crypto API arc4\n");
 834                 goto out;
 835         }
 836
 837         rc = crypto_skcipher_setkey(tfm_arc4, ses->auth_key.response,
 838                                         CIFS_SESS_KEY_SIZE);
 839         if (rc) {
 840                 cifs_dbg(VFS, "%s: Could not set response as a key\n",
 841                          __func__);
 842                 goto out_free_cipher;
 843         }
 844
 845         req = skcipher_request_alloc(tfm_arc4, GFP_KERNEL);
 846         if (!req) {
 847                 rc = -ENOMEM;
 848                 cifs_dbg(VFS, "could not allocate crypto API arc4 request\n");
 849                 goto out_free_cipher;
 850         }
 851
 852         sg_init_one(&sgin, sec_key, CIFS_SESS_KEY_SIZE);
 853         sg_init_one(&sgout, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
 854
 855         skcipher_request_set_callback(req, 0, NULL, NULL);
 856         skcipher_request_set_crypt(req, &sgin, &sgout, CIFS_CPHTXT_SIZE, NULL);
 857
 858         rc = crypto_skcipher_encrypt(req);
 859         skcipher_request_free(req);
 860         if (rc) {
 861                 cifs_dbg(VFS, "could not encrypt session key rc: %d\n", rc);
 862                 goto out_free_cipher;
 863         }
 864
 865         /* make secondary_key/nonce as session key */
 866         memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE);
 867         /* and make len as that of session key only */
 868         ses->auth_key.len = CIFS_SESS_KEY_SIZE;
 869
 870 out_free_cipher:
 871         crypto_free_skcipher(tfm_arc4);
 872 out:
 873         kfree(sec_key);
 874         return rc;
 875 }
 876
 877 void
 878 cifs_crypto_secmech_release(struct TCP_Server_Info *server)
 879 {
 880         if (server->secmech.cmacaes) {
 881                 crypto_free_shash(server->secmech.cmacaes);
 882                 server->secmech.cmacaes = NULL;
 883         }
 884
 885         if (server->secmech.hmacsha256) {
 886                 crypto_free_shash(server->secmech.hmacsha256);
 887                 server->secmech.hmacsha256 = NULL;
 888         }
 889
 890         if (server->secmech.md5) {
 891                 crypto_free_shash(server->secmech.md5);
 892                 server->secmech.md5 = NULL;
 893         }
 894
 895         if (server->secmech.hmacmd5) {
 896                 crypto_free_shash(server->secmech.hmacmd5);
 897                 server->secmech.hmacmd5 = NULL;
 898         }
 899
 900         if (server->secmech.ccmaesencrypt) {
 901                 crypto_free_aead(server->secmech.ccmaesencrypt);
 902                 server->secmech.ccmaesencrypt = NULL;
 903         }
 904
 905         if (server->secmech.ccmaesdecrypt) {
 906                 crypto_free_aead(server->secmech.ccmaesdecrypt);
 907                 server->secmech.ccmaesdecrypt = NULL;
 908         }
 909
 910         kfree(server->secmech.sdesccmacaes);
 911         server->secmech.sdesccmacaes = NULL;
 912         kfree(server->secmech.sdeschmacsha256);
 913         server->secmech.sdeschmacsha256 = NULL;
 914         kfree(server->secmech.sdeschmacmd5);
 915         server->secmech.sdeschmacmd5 = NULL;
 916         kfree(server->secmech.sdescmd5);
 917         server->secmech.sdescmd5 = NULL;
 918 }