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 /*
  70  * Calculate and return the CIFS signature based on the mac key and SMB PDU.
  71  * The 16 byte signature must be allocated by the caller. Note we only use the
  72  * 1st eight bytes and that the smb header signature field on input contains
  73  * the sequence number before this function is called. Also, this function
  74  * should be called with the server->srv_mutex held.
  75  */
  76 static int cifs_calc_signature(struct smb_rqst *rqst,
  77                         struct TCP_Server_Info *server, char *signature)
  78 {
  79         int i;
  80         int rc;
  81         struct kvec *iov = rqst->rq_iov;
  82         int n_vec = rqst->rq_nvec;
  83
  84         if (iov == NULL || signature == NULL || server == NULL)
  85                 return -EINVAL;
  86
  87         if (!server->secmech.sdescmd5) {
  88                 rc = cifs_crypto_shash_md5_allocate(server);
  89                 if (rc) {
  90                         cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
  91                         return -1;
  92                 }
  93         }
  94
  95         rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
  96         if (rc) {
  97                 cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
  98                 return rc;
  99         }
 100
 101         rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
 102                 server->session_key.response, server->session_key.len);
 103         if (rc) {
 104                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 105                 return rc;
 106         }
 107
 108         for (i = 0; i < n_vec; i++) {
 109                 if (iov[i].iov_len == 0)
 110                         continue;
 111                 if (iov[i].iov_base == NULL) {
 112                         cifs_dbg(VFS, "null iovec entry\n");
 113                         return -EIO;
 114                 }
 115                 /* The first entry includes a length field (which does not get
 116                    signed that occupies the first 4 bytes before the header */
 117                 if (i == 0) {
 118                         if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
 119                                 break; /* nothing to sign or corrupt header */
 120                         rc =
 121                         crypto_shash_update(&server->secmech.sdescmd5->shash,
 122                                 iov[i].iov_base + 4, iov[i].iov_len - 4);
 123                 } else {
 124                         rc =
 125                         crypto_shash_update(&server->secmech.sdescmd5->shash,
 126                                 iov[i].iov_base, iov[i].iov_len);
 127                 }
 128                 if (rc) {
 129                         cifs_dbg(VFS, "%s: Could not update with payload\n",
 130                                  __func__);
 131                         return rc;
 132                 }
 133         }
 134
 135         /* now hash over the rq_pages array */
 136         for (i = 0; i < rqst->rq_npages; i++) {
 137                 struct kvec p_iov;
 138
 139                 cifs_rqst_page_to_kvec(rqst, i, &p_iov);
 140                 crypto_shash_update(&server->secmech.sdescmd5->shash,
 141                                         p_iov.iov_base, p_iov.iov_len);
 142                 kunmap(rqst->rq_pages[i]);
 143         }
 144
 145         rc = crypto_shash_final(&server->secmech.sdescmd5->shash, signature);
 146         if (rc)
 147                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 148
 149         return rc;
 150 }
 151
 152 /* must be called with server->srv_mutex held */
 153 int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 154                    __u32 *pexpected_response_sequence_number)
 155 {
 156         int rc = 0;
 157         char smb_signature[20];
 158         struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 159
 160         if ((cifs_pdu == NULL) || (server == NULL))
 161                 return -EINVAL;
 162
 163         if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) ||
 164             server->tcpStatus == CifsNeedNegotiate)
 165                 return rc;
 166
 167         if (!server->session_estab) {
 168                 memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8);
 169                 return rc;
 170         }
 171
 172         cifs_pdu->Signature.Sequence.SequenceNumber =
 173                                 cpu_to_le32(server->sequence_number);
 174         cifs_pdu->Signature.Sequence.Reserved = 0;
 175
 176         *pexpected_response_sequence_number = ++server->sequence_number;
 177         ++server->sequence_number;
 178
 179         rc = cifs_calc_signature(rqst, server, smb_signature);
 180         if (rc)
 181                 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
 182         else
 183                 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
 184
 185         return rc;
 186 }
 187
 188 int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
 189                    __u32 *pexpected_response_sequence)
 190 {
 191         struct smb_rqst rqst = { .rq_iov = iov,
 192                                  .rq_nvec = n_vec };
 193
 194         return cifs_sign_rqst(&rqst, server, pexpected_response_sequence);
 195 }
 196
 197 /* must be called with server->srv_mutex held */
 198 int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
 199                   __u32 *pexpected_response_sequence_number)
 200 {
 201         struct kvec iov;
 202
 203         iov.iov_base = cifs_pdu;
 204         iov.iov_len = be32_to_cpu(cifs_pdu->smb_buf_length) + 4;
 205
 206         return cifs_sign_smbv(&iov, 1, server,
 207                               pexpected_response_sequence_number);
 208 }
 209
 210 int cifs_verify_signature(struct smb_rqst *rqst,
 211                           struct TCP_Server_Info *server,
 212                           __u32 expected_sequence_number)
 213 {
 214         unsigned int rc;
 215         char server_response_sig[8];
 216         char what_we_think_sig_should_be[20];
 217         struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 218
 219         if (cifs_pdu == NULL || server == NULL)
 220                 return -EINVAL;
 221
 222         if (!server->session_estab)
 223                 return 0;
 224
 225         if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
 226                 struct smb_com_lock_req *pSMB =
 227                         (struct smb_com_lock_req *)cifs_pdu;
 228             if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
 229                         return 0;
 230         }
 231
 232         /* BB what if signatures are supposed to be on for session but
 233            server does not send one? BB */
 234
 235         /* Do not need to verify session setups with signature "BSRSPYL "  */
 236         if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0)
 237                 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
 238                          cifs_pdu->Command);
 239
 240         /* save off the origiginal signature so we can modify the smb and check
 241                 its signature against what the server sent */
 242         memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8);
 243
 244         cifs_pdu->Signature.Sequence.SequenceNumber =
 245                                         cpu_to_le32(expected_sequence_number);
 246         cifs_pdu->Signature.Sequence.Reserved = 0;
 247
 248         mutex_lock(&server->srv_mutex);
 249         rc = cifs_calc_signature(rqst, server, what_we_think_sig_should_be);
 250         mutex_unlock(&server->srv_mutex);
 251
 252         if (rc)
 253                 return rc;
 254
 255 /*      cifs_dump_mem("what we think it should be: ",
 256                       what_we_think_sig_should_be, 16); */
 257
 258         if (memcmp(server_response_sig, what_we_think_sig_should_be, 8))
 259                 return -EACCES;
 260         else
 261                 return 0;
 262
 263 }
 264
 265 /* first calculate 24 bytes ntlm response and then 16 byte session key */
 266 int setup_ntlm_response(struct cifs_ses *ses, const struct nls_table *nls_cp)
 267 {
 268         int rc = 0;
 269         unsigned int temp_len = CIFS_SESS_KEY_SIZE + CIFS_AUTH_RESP_SIZE;
 270         char temp_key[CIFS_SESS_KEY_SIZE];
 271
 272         if (!ses)
 273                 return -EINVAL;
 274
 275         ses->auth_key.response = kmalloc(temp_len, GFP_KERNEL);
 276         if (!ses->auth_key.response)
 277                 return -ENOMEM;
 278
 279         ses->auth_key.len = temp_len;
 280
 281         rc = SMBNTencrypt(ses->password, ses->server->cryptkey,
 282                         ses->auth_key.response + CIFS_SESS_KEY_SIZE, nls_cp);
 283         if (rc) {
 284                 cifs_dbg(FYI, "%s Can't generate NTLM response, error: %d\n",
 285                          __func__, rc);
 286                 return rc;
 287         }
 288
 289         rc = E_md4hash(ses->password, temp_key, nls_cp);
 290         if (rc) {
 291                 cifs_dbg(FYI, "%s Can't generate NT hash, error: %d\n",
 292                          __func__, rc);
 293                 return rc;
 294         }
 295
 296         rc = mdfour(ses->auth_key.response, temp_key, CIFS_SESS_KEY_SIZE);
 297         if (rc)
 298                 cifs_dbg(FYI, "%s Can't generate NTLM session key, error: %d\n",
 299                          __func__, rc);
 300
 301         return rc;
 302 }
 303
 304 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 305 int calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
 306                         char *lnm_session_key)
 307 {
 308         int i;
 309         int rc;
 310         char password_with_pad[CIFS_ENCPWD_SIZE];
 311
 312         memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
 313         if (password)
 314                 strncpy(password_with_pad, password, CIFS_ENCPWD_SIZE);
 315
 316         if (!encrypt && global_secflags & CIFSSEC_MAY_PLNTXT) {
 317                 memcpy(lnm_session_key, password_with_pad,
 318                         CIFS_ENCPWD_SIZE);
 319                 return 0;
 320         }
 321
 322         /* calculate old style session key */
 323         /* calling toupper is less broken than repeatedly
 324         calling nls_toupper would be since that will never
 325         work for UTF8, but neither handles multibyte code pages
 326         but the only alternative would be converting to UCS-16 (Unicode)
 327         (using a routine something like UniStrupr) then
 328         uppercasing and then converting back from Unicode - which
 329         would only worth doing it if we knew it were utf8. Basically
 330         utf8 and other multibyte codepages each need their own strupper
 331         function since a byte at a time will ont work. */
 332
 333         for (i = 0; i < CIFS_ENCPWD_SIZE; i++)
 334                 password_with_pad[i] = toupper(password_with_pad[i]);
 335
 336         rc = SMBencrypt(password_with_pad, cryptkey, lnm_session_key);
 337
 338         return rc;
 339 }
 340 #endif /* CIFS_WEAK_PW_HASH */
 341
 342 /* Build a proper attribute value/target info pairs blob.
 343  * Fill in netbios and dns domain name and workstation name
 344  * and client time (total five av pairs and + one end of fields indicator.
 345  * Allocate domain name which gets freed when session struct is deallocated.
 346  */
 347 static int
 348 build_avpair_blob(struct cifs_ses *ses, const struct nls_table *nls_cp)
 349 {
 350         unsigned int dlen;
 351         unsigned int size = 2 * sizeof(struct ntlmssp2_name);
 352         char *defdmname = "WORKGROUP";
 353         unsigned char *blobptr;
 354         struct ntlmssp2_name *attrptr;
 355
 356         if (!ses->domainName) {
 357                 ses->domainName = kstrdup(defdmname, GFP_KERNEL);
 358                 if (!ses->domainName)
 359                         return -ENOMEM;
 360         }
 361
 362         dlen = strlen(ses->domainName);
 363
 364         /*
 365          * The length of this blob is two times the size of a
 366          * structure (av pair) which holds name/size
 367          * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) +
 368          * unicode length of a netbios domain name
 369          */
 370         ses->auth_key.len = size + 2 * dlen;
 371         ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL);
 372         if (!ses->auth_key.response) {
 373                 ses->auth_key.len = 0;
 374                 return -ENOMEM;
 375         }
 376
 377         blobptr = ses->auth_key.response;
 378         attrptr = (struct ntlmssp2_name *) blobptr;
 379
 380         /*
 381          * As defined in MS-NTLM 3.3.2, just this av pair field
 382          * is sufficient as part of the temp
 383          */
 384         attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME);
 385         attrptr->length = cpu_to_le16(2 * dlen);
 386         blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
 387         cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, nls_cp);
 388
 389         return 0;
 390 }
 391
 392 /* Server has provided av pairs/target info in the type 2 challenge
 393  * packet and we have plucked it and stored within smb session.
 394  * We parse that blob here to find netbios domain name to be used
 395  * as part of ntlmv2 authentication (in Target String), if not already
 396  * specified on the command line.
 397  * If this function returns without any error but without fetching
 398  * domain name, authentication may fail against some server but
 399  * may not fail against other (those who are not very particular
 400  * about target string i.e. for some, just user name might suffice.
 401  */
 402 static int
 403 find_domain_name(struct cifs_ses *ses, const struct nls_table *nls_cp)
 404 {
 405         unsigned int attrsize;
 406         unsigned int type;
 407         unsigned int onesize = sizeof(struct ntlmssp2_name);
 408         unsigned char *blobptr;
 409         unsigned char *blobend;
 410         struct ntlmssp2_name *attrptr;
 411
 412         if (!ses->auth_key.len || !ses->auth_key.response)
 413                 return 0;
 414
 415         blobptr = ses->auth_key.response;
 416         blobend = blobptr + ses->auth_key.len;
 417
 418         while (blobptr + onesize < blobend) {
 419                 attrptr = (struct ntlmssp2_name *) blobptr;
 420                 type = le16_to_cpu(attrptr->type);
 421                 if (type == NTLMSSP_AV_EOL)
 422                         break;
 423                 blobptr += 2; /* advance attr type */
 424                 attrsize = le16_to_cpu(attrptr->length);
 425                 blobptr += 2; /* advance attr size */
 426                 if (blobptr + attrsize > blobend)
 427                         break;
 428                 if (type == NTLMSSP_AV_NB_DOMAIN_NAME) {
 429                         if (!attrsize || attrsize >= CIFS_MAX_DOMAINNAME_LEN)
 430                                 break;
 431                         if (!ses->domainName) {
 432                                 ses->domainName =
 433                                         kmalloc(attrsize + 1, GFP_KERNEL);
 434                                 if (!ses->domainName)
 435                                                 return -ENOMEM;
 436                                 cifs_from_utf16(ses->domainName,
 437                                         (__le16 *)blobptr, attrsize, attrsize,
 438                                         nls_cp, NO_MAP_UNI_RSVD);
 439                                 break;
 440                         }
 441                 }
 442                 blobptr += attrsize; /* advance attr  value */
 443         }
 444
 445         return 0;
 446 }
 447
 448 /* Server has provided av pairs/target info in the type 2 challenge
 449  * packet and we have plucked it and stored within smb session.
 450  * We parse that blob here to find the server given timestamp
 451  * as part of ntlmv2 authentication (or local current time as
 452  * default in case of failure)
 453  */
 454 static __le64
 455 find_timestamp(struct cifs_ses *ses)
 456 {
 457         unsigned int attrsize;
 458         unsigned int type;
 459         unsigned int onesize = sizeof(struct ntlmssp2_name);
 460         unsigned char *blobptr;
 461         unsigned char *blobend;
 462         struct ntlmssp2_name *attrptr;
 463
 464         if (!ses->auth_key.len || !ses->auth_key.response)
 465                 return 0;
 466
 467         blobptr = ses->auth_key.response;
 468         blobend = blobptr + ses->auth_key.len;
 469
 470         while (blobptr + onesize < blobend) {
 471                 attrptr = (struct ntlmssp2_name *) blobptr;
 472                 type = le16_to_cpu(attrptr->type);
 473                 if (type == NTLMSSP_AV_EOL)
 474                         break;
 475                 blobptr += 2; /* advance attr type */
 476                 attrsize = le16_to_cpu(attrptr->length);
 477                 blobptr += 2; /* advance attr size */
 478                 if (blobptr + attrsize > blobend)
 479                         break;
 480                 if (type == NTLMSSP_AV_TIMESTAMP) {
 481                         if (attrsize == sizeof(u64))
 482                                 return *((__le64 *)blobptr);
 483                 }
 484                 blobptr += attrsize; /* advance attr value */
 485         }
 486
 487         return cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
 488 }
 489
 490 static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
 491                             const struct nls_table *nls_cp)
 492 {
 493         int rc = 0;
 494         int len;
 495         char nt_hash[CIFS_NTHASH_SIZE];
 496         __le16 *user;
 497         wchar_t *domain;
 498         wchar_t *server;
 499
 500         if (!ses->server->secmech.sdeschmacmd5) {
 501                 cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
 502                 return -1;
 503         }
 504
 505         /* calculate md4 hash of password */
 506         E_md4hash(ses->password, nt_hash, nls_cp);
 507
 508         rc = crypto_shash_setkey(ses->server->secmech.hmacmd5, nt_hash,
 509                                 CIFS_NTHASH_SIZE);
 510         if (rc) {
 511                 cifs_dbg(VFS, "%s: Could not set NT Hash as a key\n", __func__);
 512                 return rc;
 513         }
 514
 515         rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
 516         if (rc) {
 517                 cifs_dbg(VFS, "%s: could not init hmacmd5\n", __func__);
 518                 return rc;
 519         }
 520
 521         /* convert ses->user_name to unicode */
 522         len = ses->user_name ? strlen(ses->user_name) : 0;
 523         user = kmalloc(2 + (len * 2), GFP_KERNEL);
 524         if (user == NULL) {
 525                 rc = -ENOMEM;
 526                 return rc;
 527         }
 528
 529         if (len) {
 530                 len = cifs_strtoUTF16(user, ses->user_name, len, nls_cp);
 531                 UniStrupr(user);
 532         } else {
 533                 memset(user, '\0', 2);
 534         }
 535
 536         rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 537                                 (char *)user, 2 * len);
 538         kfree(user);
 539         if (rc) {
 540                 cifs_dbg(VFS, "%s: Could not update with user\n", __func__);
 541                 return rc;
 542         }
 543
 544         /* convert ses->domainName to unicode and uppercase */
 545         if (ses->domainName) {
 546                 len = strlen(ses->domainName);
 547
 548                 domain = kmalloc(2 + (len * 2), GFP_KERNEL);
 549                 if (domain == NULL) {
 550                         rc = -ENOMEM;
 551                         return rc;
 552                 }
 553                 len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len,
 554                                       nls_cp);
 555                 rc =
 556                 crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 557                                         (char *)domain, 2 * len);
 558                 kfree(domain);
 559                 if (rc) {
 560                         cifs_dbg(VFS, "%s: Could not update with domain\n",
 561                                  __func__);
 562                         return rc;
 563                 }
 564         } else {
 565                 /* We use ses->serverName if no domain name available */
 566                 len = strlen(ses->serverName);
 567
 568                 server = kmalloc(2 + (len * 2), GFP_KERNEL);
 569                 if (server == NULL) {
 570                         rc = -ENOMEM;
 571                         return rc;
 572                 }
 573                 len = cifs_strtoUTF16((__le16 *)server, ses->serverName, len,
 574                                         nls_cp);
 575                 rc =
 576                 crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 577                                         (char *)server, 2 * len);
 578                 kfree(server);
 579                 if (rc) {
 580                         cifs_dbg(VFS, "%s: Could not update with server\n",
 581                                  __func__);
 582                         return rc;
 583                 }
 584         }
 585
 586         rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
 587                                         ntlmv2_hash);
 588         if (rc)
 589                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 590
 591         return rc;
 592 }
 593
 594 static int
 595 CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash)
 596 {
 597         int rc;
 598         struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *)
 599             (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
 600         unsigned int hash_len;
 601
 602         /* The MD5 hash starts at challenge_key.key */
 603         hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE +
 604                 offsetof(struct ntlmv2_resp, challenge.key[0]));
 605
 606         if (!ses->server->secmech.sdeschmacmd5) {
 607                 cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
 608                 return -1;
 609         }
 610
 611         rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
 612                                  ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
 613         if (rc) {
 614                 cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
 615                          __func__);
 616                 return rc;
 617         }
 618
 619         rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
 620         if (rc) {
 621                 cifs_dbg(VFS, "%s: could not init hmacmd5\n", __func__);
 622                 return rc;
 623         }
 624
 625         if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED)
 626                 memcpy(ntlmv2->challenge.key,
 627                        ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
 628         else
 629                 memcpy(ntlmv2->challenge.key,
 630                        ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
 631         rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 632                                  ntlmv2->challenge.key, hash_len);
 633         if (rc) {
 634                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 635                 return rc;
 636         }
 637
 638         /* Note that the MD5 digest over writes anon.challenge_key.key */
 639         rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
 640                                 ntlmv2->ntlmv2_hash);
 641         if (rc)
 642                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 643
 644         return rc;
 645 }
 646
 647 static int crypto_hmacmd5_alloc(struct TCP_Server_Info *server)
 648 {
 649         int rc;
 650         unsigned int size;
 651
 652         /* check if already allocated */
 653         if (server->secmech.sdeschmacmd5)
 654                 return 0;
 655
 656         server->secmech.hmacmd5 = crypto_alloc_shash("hmac(md5)", 0, 0);
 657         if (IS_ERR(server->secmech.hmacmd5)) {
 658                 cifs_dbg(VFS, "could not allocate crypto hmacmd5\n");
 659                 rc = PTR_ERR(server->secmech.hmacmd5);
 660                 server->secmech.hmacmd5 = NULL;
 661                 return rc;
 662         }
 663
 664         size = sizeof(struct shash_desc) +
 665                         crypto_shash_descsize(server->secmech.hmacmd5);
 666         server->secmech.sdeschmacmd5 = kmalloc(size, GFP_KERNEL);
 667         if (!server->secmech.sdeschmacmd5) {
 668                 crypto_free_shash(server->secmech.hmacmd5);
 669                 server->secmech.hmacmd5 = NULL;
 670                 return -ENOMEM;
 671         }
 672         server->secmech.sdeschmacmd5->shash.tfm = server->secmech.hmacmd5;
 673         server->secmech.sdeschmacmd5->shash.flags = 0x0;
 674
 675         return 0;
 676 }
 677
 678 int
 679 setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
 680 {
 681         int rc;
 682         int baselen;
 683         unsigned int tilen;
 684         struct ntlmv2_resp *ntlmv2;
 685         char ntlmv2_hash[16];
 686         unsigned char *tiblob = NULL; /* target info blob */
 687         __le64 rsp_timestamp;
 688
 689         if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) {
 690                 if (!ses->domainName) {
 691                         rc = find_domain_name(ses, nls_cp);
 692                         if (rc) {
 693                                 cifs_dbg(VFS, "error %d finding domain name\n",
 694                                          rc);
 695                                 goto setup_ntlmv2_rsp_ret;
 696                         }
 697                 }
 698         } else {
 699                 rc = build_avpair_blob(ses, nls_cp);
 700                 if (rc) {
 701                         cifs_dbg(VFS, "error %d building av pair blob\n", rc);
 702                         goto setup_ntlmv2_rsp_ret;
 703                 }
 704         }
 705
 706         /* Must be within 5 minutes of the server (or in range +/-2h
 707          * in case of Mac OS X), so simply carry over server timestamp
 708          * (as Windows 7 does)
 709          */
 710         rsp_timestamp = find_timestamp(ses);
 711
 712         baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp);
 713         tilen = ses->auth_key.len;
 714         tiblob = ses->auth_key.response;
 715
 716         ses->auth_key.response = kmalloc(baselen + tilen, GFP_KERNEL);
 717         if (!ses->auth_key.response) {
 718                 rc = -ENOMEM;
 719                 ses->auth_key.len = 0;
 720                 goto setup_ntlmv2_rsp_ret;
 721         }
 722         ses->auth_key.len += baselen;
 723
 724         ntlmv2 = (struct ntlmv2_resp *)
 725                         (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
 726         ntlmv2->blob_signature = cpu_to_le32(0x00000101);
 727         ntlmv2->reserved = 0;
 728         ntlmv2->time = rsp_timestamp;
 729
 730         get_random_bytes(&ntlmv2->client_chal, sizeof(ntlmv2->client_chal));
 731         ntlmv2->reserved2 = 0;
 732
 733         memcpy(ses->auth_key.response + baselen, tiblob, tilen);
 734
 735         rc = crypto_hmacmd5_alloc(ses->server);
 736         if (rc) {
 737                 cifs_dbg(VFS, "could not crypto alloc hmacmd5 rc %d\n", rc);
 738                 goto setup_ntlmv2_rsp_ret;
 739         }
 740
 741         /* calculate ntlmv2_hash */
 742         rc = calc_ntlmv2_hash(ses, ntlmv2_hash, nls_cp);
 743         if (rc) {
 744                 cifs_dbg(VFS, "could not get v2 hash rc %d\n", rc);
 745                 goto setup_ntlmv2_rsp_ret;
 746         }
 747
 748         /* calculate first part of the client response (CR1) */
 749         rc = CalcNTLMv2_response(ses, ntlmv2_hash);
 750         if (rc) {
 751                 cifs_dbg(VFS, "Could not calculate CR1 rc: %d\n", rc);
 752                 goto setup_ntlmv2_rsp_ret;
 753         }
 754
 755         /* now calculate the session key for NTLMv2 */
 756         rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
 757                 ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
 758         if (rc) {
 759                 cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
 760                          __func__);
 761                 goto setup_ntlmv2_rsp_ret;
 762         }
 763
 764         rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
 765         if (rc) {
 766                 cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
 767                 goto setup_ntlmv2_rsp_ret;
 768         }
 769
 770         rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
 771                 ntlmv2->ntlmv2_hash,
 772                 CIFS_HMAC_MD5_HASH_SIZE);
 773         if (rc) {
 774                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 775                 goto setup_ntlmv2_rsp_ret;
 776         }
 777
 778         rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
 779                 ses->auth_key.response);
 780         if (rc)
 781                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 782
 783 setup_ntlmv2_rsp_ret:
 784         kfree(tiblob);
 785
 786         return rc;
 787 }
 788
 789 int
 790 calc_seckey(struct cifs_ses *ses)
 791 {
 792         int rc;
 793         struct crypto_skcipher *tfm_arc4;
 794         struct scatterlist sgin, sgout;
 795         struct skcipher_request *req;
 796         unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */
 797
 798         get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE);
 799
 800         tfm_arc4 = crypto_alloc_skcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
 801         if (IS_ERR(tfm_arc4)) {
 802                 rc = PTR_ERR(tfm_arc4);
 803                 cifs_dbg(VFS, "could not allocate crypto API arc4\n");
 804                 return rc;
 805         }
 806
 807         rc = crypto_skcipher_setkey(tfm_arc4, ses->auth_key.response,
 808                                         CIFS_SESS_KEY_SIZE);
 809         if (rc) {
 810                 cifs_dbg(VFS, "%s: Could not set response as a key\n",
 811                          __func__);
 812                 goto out_free_cipher;
 813         }
 814
 815         req = skcipher_request_alloc(tfm_arc4, GFP_KERNEL);
 816         if (!req) {
 817                 rc = -ENOMEM;
 818                 cifs_dbg(VFS, "could not allocate crypto API arc4 request\n");
 819                 goto out_free_cipher;
 820         }
 821
 822         sg_init_one(&sgin, sec_key, CIFS_SESS_KEY_SIZE);
 823         sg_init_one(&sgout, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
 824
 825         skcipher_request_set_callback(req, 0, NULL, NULL);
 826         skcipher_request_set_crypt(req, &sgin, &sgout, CIFS_CPHTXT_SIZE, NULL);
 827
 828         rc = crypto_skcipher_encrypt(req);
 829         skcipher_request_free(req);
 830         if (rc) {
 831                 cifs_dbg(VFS, "could not encrypt session key rc: %d\n", rc);
 832                 goto out_free_cipher;
 833         }
 834
 835         /* make secondary_key/nonce as session key */
 836         memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE);
 837         /* and make len as that of session key only */
 838         ses->auth_key.len = CIFS_SESS_KEY_SIZE;
 839
 840 out_free_cipher:
 841         crypto_free_skcipher(tfm_arc4);
 842
 843         return rc;
 844 }
 845
 846 void
 847 cifs_crypto_shash_release(struct TCP_Server_Info *server)
 848 {
 849         if (server->secmech.cmacaes) {
 850                 crypto_free_shash(server->secmech.cmacaes);
 851                 server->secmech.cmacaes = NULL;
 852         }
 853
 854         if (server->secmech.hmacsha256) {
 855                 crypto_free_shash(server->secmech.hmacsha256);
 856                 server->secmech.hmacsha256 = NULL;
 857         }
 858
 859         if (server->secmech.md5) {
 860                 crypto_free_shash(server->secmech.md5);
 861                 server->secmech.md5 = NULL;
 862         }
 863
 864         if (server->secmech.hmacmd5) {
 865                 crypto_free_shash(server->secmech.hmacmd5);
 866                 server->secmech.hmacmd5 = NULL;
 867         }
 868
 869         kfree(server->secmech.sdesccmacaes);
 870         server->secmech.sdesccmacaes = NULL;
 871         kfree(server->secmech.sdeschmacsha256);
 872         server->secmech.sdeschmacsha256 = NULL;
 873         kfree(server->secmech.sdeschmacmd5);
 874         server->secmech.sdeschmacmd5 = NULL;
 875         kfree(server->secmech.sdescmd5);
 876         server->secmech.sdescmd5 = NULL;
 877 }