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
  38 static int
  39 cifs_crypto_shash_md5_allocate(struct TCP_Server_Info *server)
  40 {
  41         int rc;
  42         unsigned int size;
  43
  44         if (server->secmech.sdescmd5 != NULL)
  45                 return 0; /* already allocated */
  46
  47         server->secmech.md5 = crypto_alloc_shash("md5", 0, 0);
  48         if (IS_ERR(server->secmech.md5)) {
  49                 cifs_dbg(VFS, "could not allocate crypto md5\n");
  50                 rc = PTR_ERR(server->secmech.md5);
  51                 server->secmech.md5 = NULL;
  52                 return rc;
  53         }
  54
  55         size = sizeof(struct shash_desc) +
  56                         crypto_shash_descsize(server->secmech.md5);
  57         server->secmech.sdescmd5 = kmalloc(size, GFP_KERNEL);
  58         if (!server->secmech.sdescmd5) {
  59                 crypto_free_shash(server->secmech.md5);
  60                 server->secmech.md5 = NULL;
  61                 return -ENOMEM;
  62         }
  63         server->secmech.sdescmd5->shash.tfm = server->secmech.md5;
  64         server->secmech.sdescmd5->shash.flags = 0x0;
  65
  66         return 0;
  67 }
  68
  69 int __cifs_calc_signature(struct smb_rqst *rqst,
  70                         struct TCP_Server_Info *server, char *signature,
  71                         struct shash_desc *shash)
  72 {
  73         int i;
  74         int rc;
  75         struct kvec *iov = rqst->rq_iov;
  76         int n_vec = rqst->rq_nvec;
  77
  78         for (i = 0; i < n_vec; i++) {
  79                 if (iov[i].iov_len == 0)
  80                         continue;
  81                 if (iov[i].iov_base == NULL) {
  82                         cifs_dbg(VFS, "null iovec entry\n");
  83                         return -EIO;
  84                 }
  85                 /* The first entry includes a length field (which does not get
  86                    signed that occupies the first 4 bytes before the header */
  87                 if (i == 0) {
  88                         if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
  89                                 break; /* nothing to sign or corrupt header */
  90                         rc = crypto_shash_update(shash,
  91                                 iov[i].iov_base + 4, iov[i].iov_len - 4);
  92                 } else {
  93                         rc = crypto_shash_update(shash,
  94                                 iov[i].iov_base, iov[i].iov_len);
  95                 }
  96                 if (rc) {
  97                         cifs_dbg(VFS, "%s: Could not update with payload\n",
  98                                  __func__);
  99                         return rc;
 100                 }
 101         }
 102
 103         /* now hash over the rq_pages array */
 104         for (i = 0; i < rqst->rq_npages; i++) {
 105                 void *kaddr = kmap(rqst->rq_pages[i]);
 106                 size_t len = rqst->rq_pagesz;
 107
 108                 if (i == rqst->rq_npages - 1)
 109                         len = rqst->rq_tailsz;
 110
 111                 crypto_shash_update(shash, kaddr, len);
 112
 113                 kunmap(rqst->rq_pages[i]);
 114         }
 115
 116         rc = crypto_shash_final(shash, signature);
 117         if (rc)
 118                 cifs_dbg(VFS, "%s: Could not generate hash\n", __func__);
 119
 120         return rc;
 121 }
 122
 123 /*
 124  * Calculate and return the CIFS signature based on the mac key and SMB PDU.
 125  * The 16 byte signature must be allocated by the caller. Note we only use the
 126  * 1st eight bytes and that the smb header signature field on input contains
 127  * the sequence number before this function is called. Also, this function
 128  * should be called with the server->srv_mutex held.
 129  */
 130 static int cifs_calc_signature(struct smb_rqst *rqst,
 131                         struct TCP_Server_Info *server, char *signature)
 132 {
 133         int rc;
 134
 135         if (!rqst->rq_iov || !signature || !server)
 136                 return -EINVAL;
 137
 138         if (!server->secmech.sdescmd5) {
 139                 rc = cifs_crypto_shash_md5_allocate(server);
 140                 if (rc) {
 141                         cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
 142                         return -1;
 143                 }
 144         }
 145
 146         rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
 147         if (rc) {
 148                 cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
 149                 return rc;
 150         }
 151
 152         rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
 153                 server->session_key.response, server->session_key.len);
 154         if (rc) {
 155                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 156                 return rc;
 157         }
 158
 159         return __cifs_calc_signature(rqst, server, signature,
 160                                      &server->secmech.sdescmd5->shash);
 161 }
 162
 163 /* must be called with server->srv_mutex held */
 164 int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 165                    __u32 *pexpected_response_sequence_number)
 166 {
 167         int rc = 0;
 168         char smb_signature[20];
 169         struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 170
 171         if ((cifs_pdu == NULL) || (server == NULL))
 172                 return -EINVAL;
 173
 174         if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) ||
 175             server->tcpStatus == CifsNeedNegotiate)
 176                 return rc;
 177
 178         if (!server->session_estab) {
 179                 memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8);
 180                 return rc;
 181         }
 182
 183         cifs_pdu->Signature.Sequence.SequenceNumber =
 184                                 cpu_to_le32(server->sequence_number);
 185         cifs_pdu->Signature.Sequence.Reserved = 0;
 186
 187         *pexpected_response_sequence_number = ++server->sequence_number;
 188         ++server->sequence_number;
 189
 190         rc = cifs_calc_signature(rqst, server, smb_signature);
 191         if (rc)
 192                 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
 193         else
 194                 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
 195
 196         return rc;
 197 }
 198
 199 int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
 200                    __u32 *pexpected_response_sequence)
 201 {
 202         struct smb_rqst rqst = { .rq_iov = iov,
 203                                  .rq_nvec = n_vec };
 204
 205         return cifs_sign_rqst(&rqst, server, pexpected_response_sequence);
 206 }
 207
 208 /* must be called with server->srv_mutex held */
 209 int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
 210                   __u32 *pexpected_response_sequence_number)
 211 {
 212         struct kvec iov;
 213
 214         iov.iov_base = cifs_pdu;
 215         iov.iov_len = be32_to_cpu(cifs_pdu->smb_buf_length) + 4;
 216
 217         return cifs_sign_smbv(&iov, 1, server,
 218                               pexpected_response_sequence_number);
 219 }
 220
 221 int cifs_verify_signature(struct smb_rqst *rqst,
 222                           struct TCP_Server_Info *server,
 223                           __u32 expected_sequence_number)
 224 {
 225         unsigned int rc;
 226         char server_response_sig[8];
 227         char what_we_think_sig_should_be[20];
 228         struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 229
 230         if (cifs_pdu == NULL || server == NULL)
 231                 return -EINVAL;
 232
 233         if (!server->session_estab)
 234                 return 0;
 235
 236         if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
 237                 struct smb_com_lock_req *pSMB =
 238                         (struct smb_com_lock_req *)cifs_pdu;
 239             if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
 240                         return 0;
 241         }
 242
 243         /* BB what if signatures are supposed to be on for session but
 244            server does not send one? BB */
 245
 246         /* Do not need to verify session setups with signature "BSRSPYL "  */
 247         if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0)
 248                 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
 249                          cifs_pdu->Command);
 250
 251         /* save off the origiginal signature so we can modify the smb and check
 252                 its signature against what the server sent */
 253         memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8);
 254
 255         cifs_pdu->Signature.Sequence.SequenceNumber =
 256                                         cpu_to_le32(expected_sequence_number);
 257         cifs_pdu->Signature.Sequence.Reserved = 0;
 258
 259         mutex_lock(&server->srv_mutex);
 260         rc = cifs_calc_signature(rqst, server, what_we_think_sig_should_be);
 261         mutex_unlock(&server->srv_mutex);
 262
 263         if (rc)
 264                 return rc;
 265
 266 /*      cifs_dump_mem("what we think it should be: ",
 267                       what_we_think_sig_should_be, 16); */
 268
 269         if (memcmp(server_response_sig, what_we_think_sig_should_be, 8))
 270                 return -EACCES;
 271         else
 272                 return 0;
 273
 274 }
 275
 276 /* first calculate 24 bytes ntlm response and then 16 byte session key */
 277 int setup_ntlm_response(struct cifs_ses *ses, const struct nls_table *nls_cp)
 278 {
 279         int rc = 0;
 280         unsigned int temp_len = CIFS_SESS_KEY_SIZE + CIFS_AUTH_RESP_SIZE;
 281         char temp_key[CIFS_SESS_KEY_SIZE];
 282
 283         if (!ses)
 284                 return -EINVAL;
 285
 286         ses->auth_key.response = kmalloc(temp_len, GFP_KERNEL);
 287         if (!ses->auth_key.response)
 288                 return -ENOMEM;
 289
 290         ses->auth_key.len = temp_len;
 291
 292         rc = SMBNTencrypt(ses->password, ses->server->cryptkey,
 293                         ses->auth_key.response + CIFS_SESS_KEY_SIZE, nls_cp);
 294         if (rc) {
 295                 cifs_dbg(FYI, "%s Can't generate NTLM response, error: %d\n",
 296                          __func__, rc);
 297                 return rc;
 298         }
 299
 300         rc = E_md4hash(ses->password, temp_key, nls_cp);
 301         if (rc) {
 302                 cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
 303                          __func__, rc);
 304                 return rc;
 305         }
 306
 307         rc = mdfour(ses->auth_key.response, temp_key, CIFS_SESS_KEY_SIZE);
 308         if (rc)
 309                 cifs_dbg(FYI, "%s Can't generate NTLM session key, error: %d\n",
 310                          __func__, rc);
 311
 312         return rc;
 313 }
 314
 315 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 316 int calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
 317                         char *lnm_session_key)
 318 {
 319         int i;
 320         int rc;
 321         char password_with_pad[CIFS_ENCPWD_SIZE];
 322
 323         memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
 324         if (password)
 325                 strncpy(password_with_pad, password, CIFS_ENCPWD_SIZE);
 326
 327         if (!encrypt && global_secflags & CIFSSEC_MAY_PLNTXT) {
 328                 memcpy(lnm_session_key, password_with_pad,
 329                         CIFS_ENCPWD_SIZE);
 330                 return 0;
 331         }
 332
 333         /* calculate old style session key */
 334         /* calling toupper is less broken than repeatedly
 335         calling nls_toupper would be since that will never
 336         work for UTF8, but neither handles multibyte code pages
 337         but the only alternative would be converting to UCS-16 (Unicode)
 338         (using a routine something like UniStrupr) then
 339         uppercasing and then converting back from Unicode - which
 340         would only worth doing it if we knew it were utf8. Basically
 341         utf8 and other multibyte codepages each need their own strupper
 342         function since a byte at a time will ont work. */
 343
 344         for (i = 0; i < CIFS_ENCPWD_SIZE; i++)
 345                 password_with_pad[i] = toupper(password_with_pad[i]);
 346
 347         rc = SMBencrypt(password_with_pad, cryptkey, lnm_session_key);
 348
 349         return rc;
 350 }
 351 #endif /* CIFS_WEAK_PW_HASH */
 352
 353 /* Build a proper attribute value/target info pairs blob.
 354  * Fill in netbios and dns domain name and workstation name
 355  * and client time (total five av pairs and + one end of fields indicator.
 356  * Allocate domain name which gets freed when session struct is deallocated.
 357  */
 358 static int
 359 build_avpair_blob(struct cifs_ses *ses, const struct nls_table *nls_cp)
 360 {
 361         unsigned int dlen;
 362         unsigned int size = 2 * sizeof(struct ntlmssp2_name);
 363         char *defdmname = "WORKGROUP";
 364         unsigned char *blobptr;
 365         struct ntlmssp2_name *attrptr;
 366
 367         if (!ses->domainName) {
 368                 ses->domainName = kstrdup(defdmname, GFP_KERNEL);
 369                 if (!ses->domainName)
 370                         return -ENOMEM;
 371         }
 372
 373         dlen = strlen(ses->domainName);
 374
 375         /*
 376          * The length of this blob is two times the size of a
 377          * structure (av pair) which holds name/size
 378          * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) +
 379          * unicode length of a netbios domain name
 380          */
 381         ses->auth_key.len = size + 2 * dlen;
 382         ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL);
 383         if (!ses->auth_key.response) {
 384                 ses->auth_key.len = 0;
 385                 return -ENOMEM;
 386         }
 387
 388         blobptr = ses->auth_key.response;
 389         attrptr = (struct ntlmssp2_name *) blobptr;
 390
 391         /*
 392          * As defined in MS-NTLM 3.3.2, just this av pair field
 393          * is sufficient as part of the temp
 394          */
 395         attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME);
 396         attrptr->length = cpu_to_le16(2 * dlen);
 397         blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
 398         cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, nls_cp);
 399
 400         return 0;
 401 }
 402
 403 /* Server has provided av pairs/target info in the type 2 challenge
 404  * packet and we have plucked it and stored within smb session.
 405  * We parse that blob here to find netbios domain name to be used
 406  * as part of ntlmv2 authentication (in Target String), if not already
 407  * specified on the command line.
 408  * If this function returns without any error but without fetching
 409  * domain name, authentication may fail against some server but
 410  * may not fail against other (those who are not very particular
 411  * about target string i.e. for some, just user name might suffice.
 412  */
 413 static int
 414 find_domain_name(struct cifs_ses *ses, const struct nls_table *nls_cp)
 415 {
 416         unsigned int attrsize;
 417         unsigned int type;
 418         unsigned int onesize = sizeof(struct ntlmssp2_name);
 419         unsigned char *blobptr;
 420         unsigned char *blobend;
 421         struct ntlmssp2_name *attrptr;
 422
 423         if (!ses->auth_key.len || !ses->auth_key.response)
 424                 return 0;
 425
 426         blobptr = ses->auth_key.response;
 427         blobend = blobptr + ses->auth_key.len;
 428
 429         while (blobptr + onesize < blobend) {
 430                 attrptr = (struct ntlmssp2_name *) blobptr;
 431                 type = le16_to_cpu(attrptr->type);
 432                 if (type == NTLMSSP_AV_EOL)
 433                         break;
 434                 blobptr += 2; /* advance attr type */
 435                 attrsize = le16_to_cpu(attrptr->length);
 436                 blobptr += 2; /* advance attr size */
 437                 if (blobptr + attrsize > blobend)
 438                         break;
 439                 if (type == NTLMSSP_AV_NB_DOMAIN_NAME) {
 440                         if (!attrsize || attrsize >= CIFS_MAX_DOMAINNAME_LEN)
 441                                 break;
 442                         if (!ses->domainName) {
 443                                 ses->domainName =
 444                                         kmalloc(attrsize + 1, GFP_KERNEL);
 445                                 if (!ses->domainName)
 446                                                 return -ENOMEM;
 447                                 cifs_from_utf16(ses->domainName,
 448                                         (__le16 *)blobptr, attrsize, attrsize,
 449                                         nls_cp, NO_MAP_UNI_RSVD);
 450                                 break;
 451                         }
 452                 }
 453                 blobptr += attrsize; /* advance attr  value */
 454         }
 455
 456         return 0;
 457 }
 458
 459 /* Server has provided av pairs/target info in the type 2 challenge
 460  * packet and we have plucked it and stored within smb session.
 461  * We parse that blob here to find the server given timestamp
 462  * as part of ntlmv2 authentication (or local current time as
 463  * default in case of failure)
 464  */
 465 static __le64
 466 find_timestamp(struct cifs_ses *ses)
 467 {
 468         unsigned int attrsize;
 469         unsigned int type;
 470         unsigned int onesize = sizeof(struct ntlmssp2_name);
 471         unsigned char *blobptr;
 472         unsigned char *blobend;
 473         struct ntlmssp2_name *attrptr;
 474
 475         if (!ses->auth_key.len || !ses->auth_key.response)
 476                 return 0;
 477
 478         blobptr = ses->auth_key.response;
 479         blobend = blobptr + ses->auth_key.len;
 480
 481         while (blobptr + onesize < blobend) {
 482                 attrptr = (struct ntlmssp2_name *) blobptr;
 483                 type = le16_to_cpu(attrptr->type);
 484                 if (type == NTLMSSP_AV_EOL)
 485                         break;
 486                 blobptr += 2; /* advance attr type */
 487                 attrsize = le16_to_cpu(attrptr->length);
 488                 blobptr += 2; /* advance attr size */
 489                 if (blobptr + attrsize > blobend)
 490                         break;
 491                 if (type == NTLMSSP_AV_TIMESTAMP) {
 492                         if (attrsize == sizeof(u64))
 493                                 return *((__le64 *)blobptr);
 494                 }
 495                 blobptr += attrsize; /* advance attr value */
 496         }
 497
 498         return cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
 499 }
 500
 501 static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
 502                             const struct nls_table *nls_cp)
 503 {
 504         int rc = 0;
 505         int len;
 506         char nt_hash[CIFS_NTHASH_SIZE];
 507         __le16 *user;
 508         wchar_t *domain;
 509         wchar_t *server;
 510
 511         if (!ses->server->secmech.sdeschmacmd5) {
 512                 cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
 513                 return -1;
 514         }
 515
 516         /* calculate md4 hash of password */
 517         E_md4hash(ses->password, nt_hash, nls_cp);
 518
 519         rc = crypto_shash_setkey(ses->server->secmech.hmacmd5, nt_hash,
 520                                 CIFS_NTHASH_SIZE);
 521         if (rc) {
 522                 cifs_dbg(VFS, "%s: Could not set NT Hash as a key\n", __func__);
 523                 return rc;
 524         }
 525
 526         rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
 527         if (rc) {
 528                 cifs_dbg(VFS, "%s: could not init hmacmd5\n", __func__);
 529                 return rc;
 530         }
 531
 532         /* convert ses->user_name to unicode */
 533         len = ses->user_name ? strlen(ses->user_name) : 0;
 534         user = kmalloc(2 + (len * 2), GFP_KERNEL);
 535         if (user == NULL) {
 536                 rc = -ENOMEM;
 537                 return rc;
 538         }
 539
 540         if (len) {
 541                 len = cifs_strtoUTF16(user, ses->user_name, len, nls_cp);
 542                 UniStrupr(user);
 543         } else {
 544                 memset(user, '\0', 2);
 545         }
 546
 547         rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 548                                 (char *)user, 2 * len);
 549         kfree(user);
 550         if (rc) {
 551                 cifs_dbg(VFS, "%s: Could not update with user\n", __func__);
 552                 return rc;
 553         }
 554
 555         /* convert ses->domainName to unicode and uppercase */
 556         if (ses->domainName) {
 557                 len = strlen(ses->domainName);
 558
 559                 domain = kmalloc(2 + (len * 2), GFP_KERNEL);
 560                 if (domain == NULL) {
 561                         rc = -ENOMEM;
 562                         return rc;
 563                 }
 564                 len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len,
 565                                       nls_cp);
 566                 rc =
 567                 crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 568                                         (char *)domain, 2 * len);
 569                 kfree(domain);
 570                 if (rc) {
 571                         cifs_dbg(VFS, "%s: Could not update with domain\n",
 572                                  __func__);
 573                         return rc;
 574                 }
 575         } else {
 576                 /* We use ses->serverName if no domain name available */
 577                 len = strlen(ses->serverName);
 578
 579                 server = kmalloc(2 + (len * 2), GFP_KERNEL);
 580                 if (server == NULL) {
 581                         rc = -ENOMEM;
 582                         return rc;
 583                 }
 584                 len = cifs_strtoUTF16((__le16 *)server, ses->serverName, len,
 585                                         nls_cp);
 586                 rc =
 587                 crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 588                                         (char *)server, 2 * len);
 589                 kfree(server);
 590                 if (rc) {
 591                         cifs_dbg(VFS, "%s: Could not update with server\n",
 592                                  __func__);
 593                         return rc;
 594                 }
 595         }
 596
 597         rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
 598                                         ntlmv2_hash);
 599         if (rc)
 600                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 601
 602         return rc;
 603 }
 604
 605 static int
 606 CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash)
 607 {
 608         int rc;
 609         struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *)
 610             (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
 611         unsigned int hash_len;
 612
 613         /* The MD5 hash starts at challenge_key.key */
 614         hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE +
 615                 offsetof(struct ntlmv2_resp, challenge.key[0]));
 616
 617         if (!ses->server->secmech.sdeschmacmd5) {
 618                 cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
 619                 return -1;
 620         }
 621
 622         rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
 623                                  ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
 624         if (rc) {
 625                 cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
 626                          __func__);
 627                 return rc;
 628         }
 629
 630         rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
 631         if (rc) {
 632                 cifs_dbg(VFS, "%s: could not init hmacmd5\n", __func__);
 633                 return rc;
 634         }
 635
 636         if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED)
 637                 memcpy(ntlmv2->challenge.key,
 638                        ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
 639         else
 640                 memcpy(ntlmv2->challenge.key,
 641                        ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
 642         rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 643                                  ntlmv2->challenge.key, hash_len);
 644         if (rc) {
 645                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 646                 return rc;
 647         }
 648
 649         /* Note that the MD5 digest over writes anon.challenge_key.key */
 650         rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
 651                                 ntlmv2->ntlmv2_hash);
 652         if (rc)
 653                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 654
 655         return rc;
 656 }
 657
 658 static int crypto_hmacmd5_alloc(struct TCP_Server_Info *server)
 659 {
 660         int rc;
 661         unsigned int size;
 662
 663         /* check if already allocated */
 664         if (server->secmech.sdeschmacmd5)
 665                 return 0;
 666
 667         server->secmech.hmacmd5 = crypto_alloc_shash("hmac(md5)", 0, 0);
 668         if (IS_ERR(server->secmech.hmacmd5)) {
 669                 cifs_dbg(VFS, "could not allocate crypto hmacmd5\n");
 670                 rc = PTR_ERR(server->secmech.hmacmd5);
 671                 server->secmech.hmacmd5 = NULL;
 672                 return rc;
 673         }
 674
 675         size = sizeof(struct shash_desc) +
 676                         crypto_shash_descsize(server->secmech.hmacmd5);
 677         server->secmech.sdeschmacmd5 = kmalloc(size, GFP_KERNEL);
 678         if (!server->secmech.sdeschmacmd5) {
 679                 crypto_free_shash(server->secmech.hmacmd5);
 680                 server->secmech.hmacmd5 = NULL;
 681                 return -ENOMEM;
 682         }
 683         server->secmech.sdeschmacmd5->shash.tfm = server->secmech.hmacmd5;
 684         server->secmech.sdeschmacmd5->shash.flags = 0x0;
 685
 686         return 0;
 687 }
 688
 689 int
 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 (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) {
 701                 if (!ses->domainName) {
 702                         rc = find_domain_name(ses, nls_cp);
 703                         if (rc) {
 704                                 cifs_dbg(VFS, "error %d finding domain name\n",
 705                                          rc);
 706                                 goto setup_ntlmv2_rsp_ret;
 707                         }
 708                 }
 709         } else {
 710                 rc = build_avpair_blob(ses, nls_cp);
 711                 if (rc) {
 712                         cifs_dbg(VFS, "error %d building av pair blob\n", rc);
 713                         goto setup_ntlmv2_rsp_ret;
 714                 }
 715         }
 716
 717         /* Must be within 5 minutes of the server (or in range +/-2h
 718          * in case of Mac OS X), so simply carry over server timestamp
 719          * (as Windows 7 does)
 720          */
 721         rsp_timestamp = find_timestamp(ses);
 722
 723         baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp);
 724         tilen = ses->auth_key.len;
 725         tiblob = ses->auth_key.response;
 726
 727         ses->auth_key.response = kmalloc(baselen + tilen, GFP_KERNEL);
 728         if (!ses->auth_key.response) {
 729                 rc = -ENOMEM;
 730                 ses->auth_key.len = 0;
 731                 goto setup_ntlmv2_rsp_ret;
 732         }
 733         ses->auth_key.len += baselen;
 734
 735         ntlmv2 = (struct ntlmv2_resp *)
 736                         (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
 737         ntlmv2->blob_signature = cpu_to_le32(0x00000101);
 738         ntlmv2->reserved = 0;
 739         ntlmv2->time = rsp_timestamp;
 740
 741         get_random_bytes(&ntlmv2->client_chal, sizeof(ntlmv2->client_chal));
 742         ntlmv2->reserved2 = 0;
 743
 744         memcpy(ses->auth_key.response + baselen, tiblob, tilen);
 745
 746         mutex_lock(&ses->server->srv_mutex);
 747
 748         rc = crypto_hmacmd5_alloc(ses->server);
 749         if (rc) {
 750                 cifs_dbg(VFS, "could not crypto alloc hmacmd5 rc %d\n", rc);
 751                 goto unlock;
 752         }
 753
 754         /* calculate ntlmv2_hash */
 755         rc = calc_ntlmv2_hash(ses, ntlmv2_hash, nls_cp);
 756         if (rc) {
 757                 cifs_dbg(VFS, "could not get v2 hash rc %d\n", rc);
 758                 goto unlock;
 759         }
 760
 761         /* calculate first part of the client response (CR1) */
 762         rc = CalcNTLMv2_response(ses, ntlmv2_hash);
 763         if (rc) {
 764                 cifs_dbg(VFS, "Could not calculate CR1 rc: %d\n", rc);
 765                 goto unlock;
 766         }
 767
 768         /* now calculate the session key for NTLMv2 */
 769         rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
 770                 ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
 771         if (rc) {
 772                 cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
 773                          __func__);
 774                 goto unlock;
 775         }
 776
 777         rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
 778         if (rc) {
 779                 cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
 780                 goto unlock;
 781         }
 782
 783         rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 784                 ntlmv2->ntlmv2_hash,
 785                 CIFS_HMAC_MD5_HASH_SIZE);
 786         if (rc) {
 787                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 788                 goto unlock;
 789         }
 790
 791         rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
 792                 ses->auth_key.response);
 793         if (rc)
 794                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 795
 796 unlock:
 797         mutex_unlock(&ses->server->srv_mutex);
 798 setup_ntlmv2_rsp_ret:
 799         kfree(tiblob);
 800
 801         return rc;
 802 }
 803
 804 int
 805 calc_seckey(struct cifs_ses *ses)
 806 {
 807         int rc;
 808         struct crypto_skcipher *tfm_arc4;
 809         struct scatterlist sgin, sgout;
 810         struct skcipher_request *req;
 811         unsigned char *sec_key;
 812
 813         sec_key = kmalloc(CIFS_SESS_KEY_SIZE, GFP_KERNEL);
 814         if (sec_key == NULL)
 815                 return -ENOMEM;
 816
 817         get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE);
 818
 819         tfm_arc4 = crypto_alloc_skcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
 820         if (IS_ERR(tfm_arc4)) {
 821                 rc = PTR_ERR(tfm_arc4);
 822                 cifs_dbg(VFS, "could not allocate crypto API arc4\n");
 823                 goto out;
 824         }
 825
 826         rc = crypto_skcipher_setkey(tfm_arc4, ses->auth_key.response,
 827                                         CIFS_SESS_KEY_SIZE);
 828         if (rc) {
 829                 cifs_dbg(VFS, "%s: Could not set response as a key\n",
 830                          __func__);
 831                 goto out_free_cipher;
 832         }
 833
 834         req = skcipher_request_alloc(tfm_arc4, GFP_KERNEL);
 835         if (!req) {
 836                 rc = -ENOMEM;
 837                 cifs_dbg(VFS, "could not allocate crypto API arc4 request\n");
 838                 goto out_free_cipher;
 839         }
 840
 841         sg_init_one(&sgin, sec_key, CIFS_SESS_KEY_SIZE);
 842         sg_init_one(&sgout, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
 843
 844         skcipher_request_set_callback(req, 0, NULL, NULL);
 845         skcipher_request_set_crypt(req, &sgin, &sgout, CIFS_CPHTXT_SIZE, NULL);
 846
 847         rc = crypto_skcipher_encrypt(req);
 848         skcipher_request_free(req);
 849         if (rc) {
 850                 cifs_dbg(VFS, "could not encrypt session key rc: %d\n", rc);
 851                 goto out_free_cipher;
 852         }
 853
 854         /* make secondary_key/nonce as session key */
 855         memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE);
 856         /* and make len as that of session key only */
 857         ses->auth_key.len = CIFS_SESS_KEY_SIZE;
 858
 859 out_free_cipher:
 860         crypto_free_skcipher(tfm_arc4);
 861 out:
 862         kfree(sec_key);
 863         return rc;
 864 }
 865
 866 void
 867 cifs_crypto_shash_release(struct TCP_Server_Info *server)
 868 {
 869         if (server->secmech.cmacaes) {
 870                 crypto_free_shash(server->secmech.cmacaes);
 871                 server->secmech.cmacaes = NULL;
 872         }
 873
 874         if (server->secmech.hmacsha256) {
 875                 crypto_free_shash(server->secmech.hmacsha256);
 876                 server->secmech.hmacsha256 = NULL;
 877         }
 878
 879         if (server->secmech.md5) {
 880                 crypto_free_shash(server->secmech.md5);
 881                 server->secmech.md5 = NULL;
 882         }
 883
 884         if (server->secmech.hmacmd5) {
 885                 crypto_free_shash(server->secmech.hmacmd5);
 886                 server->secmech.hmacmd5 = NULL;
 887         }
 888
 889         kfree(server->secmech.sdesccmacaes);
 890         server->secmech.sdesccmacaes = NULL;
 891         kfree(server->secmech.sdeschmacsha256);
 892         server->secmech.sdeschmacsha256 = NULL;
 893         kfree(server->secmech.sdeschmacmd5);
 894         server->secmech.sdeschmacmd5 = NULL;
 895         kfree(server->secmech.sdescmd5);
 896         server->secmech.sdescmd5 = NULL;
 897 }