linux/fs/cifs/sess.c
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   1/*
   2 *   fs/cifs/sess.c
   3 *
   4 *   SMB/CIFS session setup handling routines
   5 *
   6 *   Copyright (c) International Business Machines  Corp., 2006, 2009
   7 *   Author(s): Steve French (sfrench@us.ibm.com)
   8 *
   9 *   This library is free software; you can redistribute it and/or modify
  10 *   it under the terms of the GNU Lesser General Public License as published
  11 *   by the Free Software Foundation; either version 2.1 of the License, or
  12 *   (at your option) any later version.
  13 *
  14 *   This library is distributed in the hope that it will be useful,
  15 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17 *   the GNU Lesser General Public License for more details.
  18 *
  19 *   You should have received a copy of the GNU Lesser General Public License
  20 *   along with this library; if not, write to the Free Software
  21 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22 */
  23
  24#include "cifspdu.h"
  25#include "cifsglob.h"
  26#include "cifsproto.h"
  27#include "cifs_unicode.h"
  28#include "cifs_debug.h"
  29#include "ntlmssp.h"
  30#include "nterr.h"
  31#include <linux/utsname.h>
  32#include <linux/slab.h>
  33#include "cifs_spnego.h"
  34
  35/*
  36 * Checks if this is the first smb session to be reconnected after
  37 * the socket has been reestablished (so we know whether to use vc 0).
  38 * Called while holding the cifs_tcp_ses_lock, so do not block
  39 */
  40static bool is_first_ses_reconnect(struct cifs_ses *ses)
  41{
  42        struct list_head *tmp;
  43        struct cifs_ses *tmp_ses;
  44
  45        list_for_each(tmp, &ses->server->smb_ses_list) {
  46                tmp_ses = list_entry(tmp, struct cifs_ses,
  47                                     smb_ses_list);
  48                if (tmp_ses->need_reconnect == false)
  49                        return false;
  50        }
  51        /* could not find a session that was already connected,
  52           this must be the first one we are reconnecting */
  53        return true;
  54}
  55
  56/*
  57 *      vc number 0 is treated specially by some servers, and should be the
  58 *      first one we request.  After that we can use vcnumbers up to maxvcs,
  59 *      one for each smb session (some Windows versions set maxvcs incorrectly
  60 *      so maxvc=1 can be ignored).  If we have too many vcs, we can reuse
  61 *      any vc but zero (some servers reset the connection on vcnum zero)
  62 *
  63 */
  64static __le16 get_next_vcnum(struct cifs_ses *ses)
  65{
  66        __u16 vcnum = 0;
  67        struct list_head *tmp;
  68        struct cifs_ses *tmp_ses;
  69        __u16 max_vcs = ses->server->max_vcs;
  70        __u16 i;
  71        int free_vc_found = 0;
  72
  73        /* Quoting the MS-SMB specification: "Windows-based SMB servers set this
  74        field to one but do not enforce this limit, which allows an SMB client
  75        to establish more virtual circuits than allowed by this value ... but
  76        other server implementations can enforce this limit." */
  77        if (max_vcs < 2)
  78                max_vcs = 0xFFFF;
  79
  80        spin_lock(&cifs_tcp_ses_lock);
  81        if ((ses->need_reconnect) && is_first_ses_reconnect(ses))
  82                        goto get_vc_num_exit;  /* vcnum will be zero */
  83        for (i = ses->server->srv_count - 1; i < max_vcs; i++) {
  84                if (i == 0) /* this is the only connection, use vc 0 */
  85                        break;
  86
  87                free_vc_found = 1;
  88
  89                list_for_each(tmp, &ses->server->smb_ses_list) {
  90                        tmp_ses = list_entry(tmp, struct cifs_ses,
  91                                             smb_ses_list);
  92                        if (tmp_ses->vcnum == i) {
  93                                free_vc_found = 0;
  94                                break; /* found duplicate, try next vcnum */
  95                        }
  96                }
  97                if (free_vc_found)
  98                        break; /* we found a vcnumber that will work - use it */
  99        }
 100
 101        if (i == 0)
 102                vcnum = 0; /* for most common case, ie if one smb session, use
 103                              vc zero.  Also for case when no free vcnum, zero
 104                              is safest to send (some clients only send zero) */
 105        else if (free_vc_found == 0)
 106                vcnum = 1;  /* we can not reuse vc=0 safely, since some servers
 107                                reset all uids on that, but 1 is ok. */
 108        else
 109                vcnum = i;
 110        ses->vcnum = vcnum;
 111get_vc_num_exit:
 112        spin_unlock(&cifs_tcp_ses_lock);
 113
 114        return cpu_to_le16(vcnum);
 115}
 116
 117static __u32 cifs_ssetup_hdr(struct cifs_ses *ses, SESSION_SETUP_ANDX *pSMB)
 118{
 119        __u32 capabilities = 0;
 120
 121        /* init fields common to all four types of SessSetup */
 122        /* Note that offsets for first seven fields in req struct are same  */
 123        /*      in CIFS Specs so does not matter which of 3 forms of struct */
 124        /*      that we use in next few lines                               */
 125        /* Note that header is initialized to zero in header_assemble */
 126        pSMB->req.AndXCommand = 0xFF;
 127        pSMB->req.MaxBufferSize = cpu_to_le16(min_t(u32,
 128                                        CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4,
 129                                        USHRT_MAX));
 130        pSMB->req.MaxMpxCount = cpu_to_le16(ses->server->maxReq);
 131        pSMB->req.VcNumber = get_next_vcnum(ses);
 132
 133        /* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */
 134
 135        /* BB verify whether signing required on neg or just on auth frame
 136           (and NTLM case) */
 137
 138        capabilities = CAP_LARGE_FILES | CAP_NT_SMBS | CAP_LEVEL_II_OPLOCKS |
 139                        CAP_LARGE_WRITE_X | CAP_LARGE_READ_X;
 140
 141        if (ses->server->sign)
 142                pSMB->req.hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
 143
 144        if (ses->capabilities & CAP_UNICODE) {
 145                pSMB->req.hdr.Flags2 |= SMBFLG2_UNICODE;
 146                capabilities |= CAP_UNICODE;
 147        }
 148        if (ses->capabilities & CAP_STATUS32) {
 149                pSMB->req.hdr.Flags2 |= SMBFLG2_ERR_STATUS;
 150                capabilities |= CAP_STATUS32;
 151        }
 152        if (ses->capabilities & CAP_DFS) {
 153                pSMB->req.hdr.Flags2 |= SMBFLG2_DFS;
 154                capabilities |= CAP_DFS;
 155        }
 156        if (ses->capabilities & CAP_UNIX)
 157                capabilities |= CAP_UNIX;
 158
 159        return capabilities;
 160}
 161
 162static void
 163unicode_oslm_strings(char **pbcc_area, const struct nls_table *nls_cp)
 164{
 165        char *bcc_ptr = *pbcc_area;
 166        int bytes_ret = 0;
 167
 168        /* Copy OS version */
 169        bytes_ret = cifs_strtoUTF16((__le16 *)bcc_ptr, "Linux version ", 32,
 170                                    nls_cp);
 171        bcc_ptr += 2 * bytes_ret;
 172        bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, init_utsname()->release,
 173                                    32, nls_cp);
 174        bcc_ptr += 2 * bytes_ret;
 175        bcc_ptr += 2; /* trailing null */
 176
 177        bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, CIFS_NETWORK_OPSYS,
 178                                    32, nls_cp);
 179        bcc_ptr += 2 * bytes_ret;
 180        bcc_ptr += 2; /* trailing null */
 181
 182        *pbcc_area = bcc_ptr;
 183}
 184
 185static void unicode_domain_string(char **pbcc_area, struct cifs_ses *ses,
 186                                   const struct nls_table *nls_cp)
 187{
 188        char *bcc_ptr = *pbcc_area;
 189        int bytes_ret = 0;
 190
 191        /* copy domain */
 192        if (ses->domainName == NULL) {
 193                /* Sending null domain better than using a bogus domain name (as
 194                we did briefly in 2.6.18) since server will use its default */
 195                *bcc_ptr = 0;
 196                *(bcc_ptr+1) = 0;
 197                bytes_ret = 0;
 198        } else
 199                bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->domainName,
 200                                            CIFS_MAX_DOMAINNAME_LEN, nls_cp);
 201        bcc_ptr += 2 * bytes_ret;
 202        bcc_ptr += 2;  /* account for null terminator */
 203
 204        *pbcc_area = bcc_ptr;
 205}
 206
 207
 208static void unicode_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
 209                                   const struct nls_table *nls_cp)
 210{
 211        char *bcc_ptr = *pbcc_area;
 212        int bytes_ret = 0;
 213
 214        /* BB FIXME add check that strings total less
 215        than 335 or will need to send them as arrays */
 216
 217        /* unicode strings, must be word aligned before the call */
 218/*      if ((long) bcc_ptr % 2) {
 219                *bcc_ptr = 0;
 220                bcc_ptr++;
 221        } */
 222        /* copy user */
 223        if (ses->user_name == NULL) {
 224                /* null user mount */
 225                *bcc_ptr = 0;
 226                *(bcc_ptr+1) = 0;
 227        } else {
 228                bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->user_name,
 229                                            MAX_USERNAME_SIZE, nls_cp);
 230        }
 231        bcc_ptr += 2 * bytes_ret;
 232        bcc_ptr += 2; /* account for null termination */
 233
 234        unicode_domain_string(&bcc_ptr, ses, nls_cp);
 235        unicode_oslm_strings(&bcc_ptr, nls_cp);
 236
 237        *pbcc_area = bcc_ptr;
 238}
 239
 240static void ascii_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
 241                                 const struct nls_table *nls_cp)
 242{
 243        char *bcc_ptr = *pbcc_area;
 244
 245        /* copy user */
 246        /* BB what about null user mounts - check that we do this BB */
 247        /* copy user */
 248        if (ses->user_name != NULL) {
 249                strncpy(bcc_ptr, ses->user_name, MAX_USERNAME_SIZE);
 250                bcc_ptr += strnlen(ses->user_name, MAX_USERNAME_SIZE);
 251        }
 252        /* else null user mount */
 253        *bcc_ptr = 0;
 254        bcc_ptr++; /* account for null termination */
 255
 256        /* copy domain */
 257        if (ses->domainName != NULL) {
 258                strncpy(bcc_ptr, ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
 259                bcc_ptr += strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
 260        } /* else we will send a null domain name
 261             so the server will default to its own domain */
 262        *bcc_ptr = 0;
 263        bcc_ptr++;
 264
 265        /* BB check for overflow here */
 266
 267        strcpy(bcc_ptr, "Linux version ");
 268        bcc_ptr += strlen("Linux version ");
 269        strcpy(bcc_ptr, init_utsname()->release);
 270        bcc_ptr += strlen(init_utsname()->release) + 1;
 271
 272        strcpy(bcc_ptr, CIFS_NETWORK_OPSYS);
 273        bcc_ptr += strlen(CIFS_NETWORK_OPSYS) + 1;
 274
 275        *pbcc_area = bcc_ptr;
 276}
 277
 278static void
 279decode_unicode_ssetup(char **pbcc_area, int bleft, struct cifs_ses *ses,
 280                      const struct nls_table *nls_cp)
 281{
 282        int len;
 283        char *data = *pbcc_area;
 284
 285        cifs_dbg(FYI, "bleft %d\n", bleft);
 286
 287        kfree(ses->serverOS);
 288        ses->serverOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
 289        cifs_dbg(FYI, "serverOS=%s\n", ses->serverOS);
 290        len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
 291        data += len;
 292        bleft -= len;
 293        if (bleft <= 0)
 294                return;
 295
 296        kfree(ses->serverNOS);
 297        ses->serverNOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
 298        cifs_dbg(FYI, "serverNOS=%s\n", ses->serverNOS);
 299        len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
 300        data += len;
 301        bleft -= len;
 302        if (bleft <= 0)
 303                return;
 304
 305        kfree(ses->serverDomain);
 306        ses->serverDomain = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
 307        cifs_dbg(FYI, "serverDomain=%s\n", ses->serverDomain);
 308
 309        return;
 310}
 311
 312static void decode_ascii_ssetup(char **pbcc_area, __u16 bleft,
 313                                struct cifs_ses *ses,
 314                                const struct nls_table *nls_cp)
 315{
 316        int len;
 317        char *bcc_ptr = *pbcc_area;
 318
 319        cifs_dbg(FYI, "decode sessetup ascii. bleft %d\n", bleft);
 320
 321        len = strnlen(bcc_ptr, bleft);
 322        if (len >= bleft)
 323                return;
 324
 325        kfree(ses->serverOS);
 326
 327        ses->serverOS = kzalloc(len + 1, GFP_KERNEL);
 328        if (ses->serverOS)
 329                strncpy(ses->serverOS, bcc_ptr, len);
 330        if (strncmp(ses->serverOS, "OS/2", 4) == 0)
 331                cifs_dbg(FYI, "OS/2 server\n");
 332
 333        bcc_ptr += len + 1;
 334        bleft -= len + 1;
 335
 336        len = strnlen(bcc_ptr, bleft);
 337        if (len >= bleft)
 338                return;
 339
 340        kfree(ses->serverNOS);
 341
 342        ses->serverNOS = kzalloc(len + 1, GFP_KERNEL);
 343        if (ses->serverNOS)
 344                strncpy(ses->serverNOS, bcc_ptr, len);
 345
 346        bcc_ptr += len + 1;
 347        bleft -= len + 1;
 348
 349        len = strnlen(bcc_ptr, bleft);
 350        if (len > bleft)
 351                return;
 352
 353        /* No domain field in LANMAN case. Domain is
 354           returned by old servers in the SMB negprot response */
 355        /* BB For newer servers which do not support Unicode,
 356           but thus do return domain here we could add parsing
 357           for it later, but it is not very important */
 358        cifs_dbg(FYI, "ascii: bytes left %d\n", bleft);
 359}
 360
 361int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
 362                                    struct cifs_ses *ses)
 363{
 364        unsigned int tioffset; /* challenge message target info area */
 365        unsigned int tilen; /* challenge message target info area length  */
 366
 367        CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr;
 368
 369        if (blob_len < sizeof(CHALLENGE_MESSAGE)) {
 370                cifs_dbg(VFS, "challenge blob len %d too small\n", blob_len);
 371                return -EINVAL;
 372        }
 373
 374        if (memcmp(pblob->Signature, "NTLMSSP", 8)) {
 375                cifs_dbg(VFS, "blob signature incorrect %s\n",
 376                         pblob->Signature);
 377                return -EINVAL;
 378        }
 379        if (pblob->MessageType != NtLmChallenge) {
 380                cifs_dbg(VFS, "Incorrect message type %d\n",
 381                         pblob->MessageType);
 382                return -EINVAL;
 383        }
 384
 385        memcpy(ses->ntlmssp->cryptkey, pblob->Challenge, CIFS_CRYPTO_KEY_SIZE);
 386        /* BB we could decode pblob->NegotiateFlags; some may be useful */
 387        /* In particular we can examine sign flags */
 388        /* BB spec says that if AvId field of MsvAvTimestamp is populated then
 389                we must set the MIC field of the AUTHENTICATE_MESSAGE */
 390        ses->ntlmssp->server_flags = le32_to_cpu(pblob->NegotiateFlags);
 391        tioffset = le32_to_cpu(pblob->TargetInfoArray.BufferOffset);
 392        tilen = le16_to_cpu(pblob->TargetInfoArray.Length);
 393        if (tioffset > blob_len || tioffset + tilen > blob_len) {
 394                cifs_dbg(VFS, "tioffset + tilen too high %u + %u",
 395                        tioffset, tilen);
 396                return -EINVAL;
 397        }
 398        if (tilen) {
 399                ses->auth_key.response = kmemdup(bcc_ptr + tioffset, tilen,
 400                                                 GFP_KERNEL);
 401                if (!ses->auth_key.response) {
 402                        cifs_dbg(VFS, "Challenge target info alloc failure");
 403                        return -ENOMEM;
 404                }
 405                ses->auth_key.len = tilen;
 406        }
 407
 408        return 0;
 409}
 410
 411/* BB Move to ntlmssp.c eventually */
 412
 413/* We do not malloc the blob, it is passed in pbuffer, because
 414   it is fixed size, and small, making this approach cleaner */
 415void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
 416                                         struct cifs_ses *ses)
 417{
 418        NEGOTIATE_MESSAGE *sec_blob = (NEGOTIATE_MESSAGE *)pbuffer;
 419        __u32 flags;
 420
 421        memset(pbuffer, 0, sizeof(NEGOTIATE_MESSAGE));
 422        memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
 423        sec_blob->MessageType = NtLmNegotiate;
 424
 425        /* BB is NTLMV2 session security format easier to use here? */
 426        flags = NTLMSSP_NEGOTIATE_56 |  NTLMSSP_REQUEST_TARGET |
 427                NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
 428                NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
 429        if (ses->server->sign) {
 430                flags |= NTLMSSP_NEGOTIATE_SIGN;
 431                if (!ses->server->session_estab)
 432                        flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
 433        }
 434
 435        sec_blob->NegotiateFlags = cpu_to_le32(flags);
 436
 437        sec_blob->WorkstationName.BufferOffset = 0;
 438        sec_blob->WorkstationName.Length = 0;
 439        sec_blob->WorkstationName.MaximumLength = 0;
 440
 441        /* Domain name is sent on the Challenge not Negotiate NTLMSSP request */
 442        sec_blob->DomainName.BufferOffset = 0;
 443        sec_blob->DomainName.Length = 0;
 444        sec_blob->DomainName.MaximumLength = 0;
 445}
 446
 447/* We do not malloc the blob, it is passed in pbuffer, because its
 448   maximum possible size is fixed and small, making this approach cleaner.
 449   This function returns the length of the data in the blob */
 450int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 451                                        u16 *buflen,
 452                                   struct cifs_ses *ses,
 453                                   const struct nls_table *nls_cp)
 454{
 455        int rc;
 456        AUTHENTICATE_MESSAGE *sec_blob = (AUTHENTICATE_MESSAGE *)pbuffer;
 457        __u32 flags;
 458        unsigned char *tmp;
 459
 460        memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
 461        sec_blob->MessageType = NtLmAuthenticate;
 462
 463        flags = NTLMSSP_NEGOTIATE_56 |
 464                NTLMSSP_REQUEST_TARGET | NTLMSSP_NEGOTIATE_TARGET_INFO |
 465                NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
 466                NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
 467        if (ses->server->sign) {
 468                flags |= NTLMSSP_NEGOTIATE_SIGN;
 469                if (!ses->server->session_estab)
 470                        flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
 471        }
 472
 473        tmp = pbuffer + sizeof(AUTHENTICATE_MESSAGE);
 474        sec_blob->NegotiateFlags = cpu_to_le32(flags);
 475
 476        sec_blob->LmChallengeResponse.BufferOffset =
 477                                cpu_to_le32(sizeof(AUTHENTICATE_MESSAGE));
 478        sec_blob->LmChallengeResponse.Length = 0;
 479        sec_blob->LmChallengeResponse.MaximumLength = 0;
 480
 481        sec_blob->NtChallengeResponse.BufferOffset = cpu_to_le32(tmp - pbuffer);
 482        rc = setup_ntlmv2_rsp(ses, nls_cp);
 483        if (rc) {
 484                cifs_dbg(VFS, "Error %d during NTLMSSP authentication\n", rc);
 485                goto setup_ntlmv2_ret;
 486        }
 487        memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
 488                        ses->auth_key.len - CIFS_SESS_KEY_SIZE);
 489        tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
 490
 491        sec_blob->NtChallengeResponse.Length =
 492                        cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
 493        sec_blob->NtChallengeResponse.MaximumLength =
 494                        cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
 495
 496        if (ses->domainName == NULL) {
 497                sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
 498                sec_blob->DomainName.Length = 0;
 499                sec_blob->DomainName.MaximumLength = 0;
 500                tmp += 2;
 501        } else {
 502                int len;
 503                len = cifs_strtoUTF16((__le16 *)tmp, ses->domainName,
 504                                      MAX_USERNAME_SIZE, nls_cp);
 505                len *= 2; /* unicode is 2 bytes each */
 506                sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
 507                sec_blob->DomainName.Length = cpu_to_le16(len);
 508                sec_blob->DomainName.MaximumLength = cpu_to_le16(len);
 509                tmp += len;
 510        }
 511
 512        if (ses->user_name == NULL) {
 513                sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - pbuffer);
 514                sec_blob->UserName.Length = 0;
 515                sec_blob->UserName.MaximumLength = 0;
 516                tmp += 2;
 517        } else {
 518                int len;
 519                len = cifs_strtoUTF16((__le16 *)tmp, ses->user_name,
 520                                      MAX_USERNAME_SIZE, nls_cp);
 521                len *= 2; /* unicode is 2 bytes each */
 522                sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - pbuffer);
 523                sec_blob->UserName.Length = cpu_to_le16(len);
 524                sec_blob->UserName.MaximumLength = cpu_to_le16(len);
 525                tmp += len;
 526        }
 527
 528        sec_blob->WorkstationName.BufferOffset = cpu_to_le32(tmp - pbuffer);
 529        sec_blob->WorkstationName.Length = 0;
 530        sec_blob->WorkstationName.MaximumLength = 0;
 531        tmp += 2;
 532
 533        if (((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) ||
 534                (ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC))
 535                        && !calc_seckey(ses)) {
 536                memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
 537                sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
 538                sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
 539                sec_blob->SessionKey.MaximumLength =
 540                                cpu_to_le16(CIFS_CPHTXT_SIZE);
 541                tmp += CIFS_CPHTXT_SIZE;
 542        } else {
 543                sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
 544                sec_blob->SessionKey.Length = 0;
 545                sec_blob->SessionKey.MaximumLength = 0;
 546        }
 547
 548setup_ntlmv2_ret:
 549        *buflen = tmp - pbuffer;
 550        return rc;
 551}
 552
 553enum securityEnum
 554select_sectype(struct TCP_Server_Info *server, enum securityEnum requested)
 555{
 556        switch (server->negflavor) {
 557        case CIFS_NEGFLAVOR_EXTENDED:
 558                switch (requested) {
 559                case Kerberos:
 560                case RawNTLMSSP:
 561                        return requested;
 562                case Unspecified:
 563                        if (server->sec_ntlmssp &&
 564                            (global_secflags & CIFSSEC_MAY_NTLMSSP))
 565                                return RawNTLMSSP;
 566                        if ((server->sec_kerberos || server->sec_mskerberos) &&
 567                            (global_secflags & CIFSSEC_MAY_KRB5))
 568                                return Kerberos;
 569                        /* Fallthrough */
 570                default:
 571                        return Unspecified;
 572                }
 573        case CIFS_NEGFLAVOR_UNENCAP:
 574                switch (requested) {
 575                case NTLM:
 576                case NTLMv2:
 577                        return requested;
 578                case Unspecified:
 579                        if (global_secflags & CIFSSEC_MAY_NTLMV2)
 580                                return NTLMv2;
 581                        if (global_secflags & CIFSSEC_MAY_NTLM)
 582                                return NTLM;
 583                        /* Fallthrough */
 584                default:
 585                        return Unspecified;
 586                }
 587        case CIFS_NEGFLAVOR_LANMAN:
 588                switch (requested) {
 589                case LANMAN:
 590                        return requested;
 591                case Unspecified:
 592                        if (global_secflags & CIFSSEC_MAY_LANMAN)
 593                                return LANMAN;
 594                        /* Fallthrough */
 595                default:
 596                        return Unspecified;
 597                }
 598        default:
 599                return Unspecified;
 600        }
 601}
 602
 603int
 604CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
 605               const struct nls_table *nls_cp)
 606{
 607        int rc = 0;
 608        int wct;
 609        struct smb_hdr *smb_buf;
 610        char *bcc_ptr;
 611        char *str_area;
 612        SESSION_SETUP_ANDX *pSMB;
 613        __u32 capabilities;
 614        __u16 count;
 615        int resp_buf_type;
 616        struct kvec iov[3];
 617        enum securityEnum type;
 618        __u16 action, bytes_remaining;
 619        struct key *spnego_key = NULL;
 620        __le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */
 621        u16 blob_len;
 622        char *ntlmsspblob = NULL;
 623
 624        if (ses == NULL) {
 625                WARN(1, "%s: ses == NULL!", __func__);
 626                return -EINVAL;
 627        }
 628
 629        type = select_sectype(ses->server, ses->sectype);
 630        cifs_dbg(FYI, "sess setup type %d\n", type);
 631        if (type == Unspecified) {
 632                cifs_dbg(VFS, "Unable to select appropriate authentication method!");
 633                return -EINVAL;
 634        }
 635
 636        if (type == RawNTLMSSP) {
 637                /* if memory allocation is successful, caller of this function
 638                 * frees it.
 639                 */
 640                ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
 641                if (!ses->ntlmssp)
 642                        return -ENOMEM;
 643        }
 644
 645ssetup_ntlmssp_authenticate:
 646        if (phase == NtLmChallenge)
 647                phase = NtLmAuthenticate; /* if ntlmssp, now final phase */
 648
 649        if (type == LANMAN) {
 650#ifndef CONFIG_CIFS_WEAK_PW_HASH
 651                /* LANMAN and plaintext are less secure and off by default.
 652                So we make this explicitly be turned on in kconfig (in the
 653                build) and turned on at runtime (changed from the default)
 654                in proc/fs/cifs or via mount parm.  Unfortunately this is
 655                needed for old Win (e.g. Win95), some obscure NAS and OS/2 */
 656                return -EOPNOTSUPP;
 657#endif
 658                wct = 10; /* lanman 2 style sessionsetup */
 659        } else if ((type == NTLM) || (type == NTLMv2)) {
 660                /* For NTLMv2 failures eventually may need to retry NTLM */
 661                wct = 13; /* old style NTLM sessionsetup */
 662        } else /* same size: negotiate or auth, NTLMSSP or extended security */
 663                wct = 12;
 664
 665        rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
 666                            (void **)&smb_buf);
 667        if (rc)
 668                return rc;
 669
 670        pSMB = (SESSION_SETUP_ANDX *)smb_buf;
 671
 672        capabilities = cifs_ssetup_hdr(ses, pSMB);
 673
 674        /* we will send the SMB in three pieces:
 675        a fixed length beginning part, an optional
 676        SPNEGO blob (which can be zero length), and a
 677        last part which will include the strings
 678        and rest of bcc area. This allows us to avoid
 679        a large buffer 17K allocation */
 680        iov[0].iov_base = (char *)pSMB;
 681        iov[0].iov_len = be32_to_cpu(smb_buf->smb_buf_length) + 4;
 682
 683        /* setting this here allows the code at the end of the function
 684           to free the request buffer if there's an error */
 685        resp_buf_type = CIFS_SMALL_BUFFER;
 686
 687        /* 2000 big enough to fit max user, domain, NOS name etc. */
 688        str_area = kmalloc(2000, GFP_KERNEL);
 689        if (str_area == NULL) {
 690                rc = -ENOMEM;
 691                goto ssetup_exit;
 692        }
 693        bcc_ptr = str_area;
 694
 695        iov[1].iov_base = NULL;
 696        iov[1].iov_len = 0;
 697
 698        if (type == LANMAN) {
 699#ifdef CONFIG_CIFS_WEAK_PW_HASH
 700                char lnm_session_key[CIFS_AUTH_RESP_SIZE];
 701
 702                pSMB->req.hdr.Flags2 &= ~SMBFLG2_UNICODE;
 703
 704                /* no capabilities flags in old lanman negotiation */
 705
 706                pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_AUTH_RESP_SIZE);
 707
 708                /* Calculate hash with password and copy into bcc_ptr.
 709                 * Encryption Key (stored as in cryptkey) gets used if the
 710                 * security mode bit in Negottiate Protocol response states
 711                 * to use challenge/response method (i.e. Password bit is 1).
 712                 */
 713
 714                rc = calc_lanman_hash(ses->password, ses->server->cryptkey,
 715                                 ses->server->sec_mode & SECMODE_PW_ENCRYPT ?
 716                                        true : false, lnm_session_key);
 717
 718                memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_AUTH_RESP_SIZE);
 719                bcc_ptr += CIFS_AUTH_RESP_SIZE;
 720
 721                /* can not sign if LANMAN negotiated so no need
 722                to calculate signing key? but what if server
 723                changed to do higher than lanman dialect and
 724                we reconnected would we ever calc signing_key? */
 725
 726                cifs_dbg(FYI, "Negotiating LANMAN setting up strings\n");
 727                /* Unicode not allowed for LANMAN dialects */
 728                ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 729#endif
 730        } else if (type == NTLM) {
 731                pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
 732                pSMB->req_no_secext.CaseInsensitivePasswordLength =
 733                        cpu_to_le16(CIFS_AUTH_RESP_SIZE);
 734                pSMB->req_no_secext.CaseSensitivePasswordLength =
 735                        cpu_to_le16(CIFS_AUTH_RESP_SIZE);
 736
 737                /* calculate ntlm response and session key */
 738                rc = setup_ntlm_response(ses, nls_cp);
 739                if (rc) {
 740                        cifs_dbg(VFS, "Error %d during NTLM authentication\n",
 741                                 rc);
 742                        goto ssetup_exit;
 743                }
 744
 745                /* copy ntlm response */
 746                memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
 747                                CIFS_AUTH_RESP_SIZE);
 748                bcc_ptr += CIFS_AUTH_RESP_SIZE;
 749                memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
 750                                CIFS_AUTH_RESP_SIZE);
 751                bcc_ptr += CIFS_AUTH_RESP_SIZE;
 752
 753                if (ses->capabilities & CAP_UNICODE) {
 754                        /* unicode strings must be word aligned */
 755                        if (iov[0].iov_len % 2) {
 756                                *bcc_ptr = 0;
 757                                bcc_ptr++;
 758                        }
 759                        unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
 760                } else
 761                        ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 762        } else if (type == NTLMv2) {
 763                pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
 764
 765                /* LM2 password would be here if we supported it */
 766                pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
 767
 768                /* calculate nlmv2 response and session key */
 769                rc = setup_ntlmv2_rsp(ses, nls_cp);
 770                if (rc) {
 771                        cifs_dbg(VFS, "Error %d during NTLMv2 authentication\n",
 772                                 rc);
 773                        goto ssetup_exit;
 774                }
 775                memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
 776                                ses->auth_key.len - CIFS_SESS_KEY_SIZE);
 777                bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
 778
 779                /* set case sensitive password length after tilen may get
 780                 * assigned, tilen is 0 otherwise.
 781                 */
 782                pSMB->req_no_secext.CaseSensitivePasswordLength =
 783                        cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
 784
 785                if (ses->capabilities & CAP_UNICODE) {
 786                        if (iov[0].iov_len % 2) {
 787                                *bcc_ptr = 0;
 788                                bcc_ptr++;
 789                        }
 790                        unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
 791                } else
 792                        ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 793        } else if (type == Kerberos) {
 794#ifdef CONFIG_CIFS_UPCALL
 795                struct cifs_spnego_msg *msg;
 796
 797                spnego_key = cifs_get_spnego_key(ses);
 798                if (IS_ERR(spnego_key)) {
 799                        rc = PTR_ERR(spnego_key);
 800                        spnego_key = NULL;
 801                        goto ssetup_exit;
 802                }
 803
 804                msg = spnego_key->payload.data;
 805                /* check version field to make sure that cifs.upcall is
 806                   sending us a response in an expected form */
 807                if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) {
 808                        cifs_dbg(VFS, "incorrect version of cifs.upcall "
 809                                   "expected %d but got %d)",
 810                                   CIFS_SPNEGO_UPCALL_VERSION, msg->version);
 811                        rc = -EKEYREJECTED;
 812                        goto ssetup_exit;
 813                }
 814
 815                ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len,
 816                                                 GFP_KERNEL);
 817                if (!ses->auth_key.response) {
 818                        cifs_dbg(VFS, "Kerberos can't allocate (%u bytes) memory",
 819                                        msg->sesskey_len);
 820                        rc = -ENOMEM;
 821                        goto ssetup_exit;
 822                }
 823                ses->auth_key.len = msg->sesskey_len;
 824
 825                pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
 826                capabilities |= CAP_EXTENDED_SECURITY;
 827                pSMB->req.Capabilities = cpu_to_le32(capabilities);
 828                iov[1].iov_base = msg->data + msg->sesskey_len;
 829                iov[1].iov_len = msg->secblob_len;
 830                pSMB->req.SecurityBlobLength = cpu_to_le16(iov[1].iov_len);
 831
 832                if (ses->capabilities & CAP_UNICODE) {
 833                        /* unicode strings must be word aligned */
 834                        if ((iov[0].iov_len + iov[1].iov_len) % 2) {
 835                                *bcc_ptr = 0;
 836                                bcc_ptr++;
 837                        }
 838                        unicode_oslm_strings(&bcc_ptr, nls_cp);
 839                        unicode_domain_string(&bcc_ptr, ses, nls_cp);
 840                } else
 841                /* BB: is this right? */
 842                        ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 843#else /* ! CONFIG_CIFS_UPCALL */
 844                cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n");
 845                rc = -ENOSYS;
 846                goto ssetup_exit;
 847#endif /* CONFIG_CIFS_UPCALL */
 848        } else if (type == RawNTLMSSP) {
 849                if ((pSMB->req.hdr.Flags2 & SMBFLG2_UNICODE) == 0) {
 850                        cifs_dbg(VFS, "NTLMSSP requires Unicode support\n");
 851                        rc = -ENOSYS;
 852                        goto ssetup_exit;
 853                }
 854
 855                cifs_dbg(FYI, "ntlmssp session setup phase %d\n", phase);
 856                pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
 857                capabilities |= CAP_EXTENDED_SECURITY;
 858                pSMB->req.Capabilities |= cpu_to_le32(capabilities);
 859                switch(phase) {
 860                case NtLmNegotiate:
 861                        build_ntlmssp_negotiate_blob(
 862                                pSMB->req.SecurityBlob, ses);
 863                        iov[1].iov_len = sizeof(NEGOTIATE_MESSAGE);
 864                        iov[1].iov_base = pSMB->req.SecurityBlob;
 865                        pSMB->req.SecurityBlobLength =
 866                                cpu_to_le16(sizeof(NEGOTIATE_MESSAGE));
 867                        break;
 868                case NtLmAuthenticate:
 869                        /*
 870                         * 5 is an empirical value, large enough to hold
 871                         * authenticate message plus max 10 of av paris,
 872                         * domain, user, workstation names, flags, etc.
 873                         */
 874                        ntlmsspblob = kzalloc(
 875                                5*sizeof(struct _AUTHENTICATE_MESSAGE),
 876                                GFP_KERNEL);
 877                        if (!ntlmsspblob) {
 878                                rc = -ENOMEM;
 879                                goto ssetup_exit;
 880                        }
 881
 882                        rc = build_ntlmssp_auth_blob(ntlmsspblob,
 883                                                &blob_len, ses, nls_cp);
 884                        if (rc)
 885                                goto ssetup_exit;
 886                        iov[1].iov_len = blob_len;
 887                        iov[1].iov_base = ntlmsspblob;
 888                        pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
 889                        /*
 890                         * Make sure that we tell the server that we are using
 891                         * the uid that it just gave us back on the response
 892                         * (challenge)
 893                         */
 894                        smb_buf->Uid = ses->Suid;
 895                        break;
 896                default:
 897                        cifs_dbg(VFS, "invalid phase %d\n", phase);
 898                        rc = -ENOSYS;
 899                        goto ssetup_exit;
 900                }
 901                /* unicode strings must be word aligned */
 902                if ((iov[0].iov_len + iov[1].iov_len) % 2) {
 903                        *bcc_ptr = 0;
 904                        bcc_ptr++;
 905                }
 906                unicode_oslm_strings(&bcc_ptr, nls_cp);
 907        } else {
 908                cifs_dbg(VFS, "secType %d not supported!\n", type);
 909                rc = -ENOSYS;
 910                goto ssetup_exit;
 911        }
 912
 913        iov[2].iov_base = str_area;
 914        iov[2].iov_len = (long) bcc_ptr - (long) str_area;
 915
 916        count = iov[1].iov_len + iov[2].iov_len;
 917        smb_buf->smb_buf_length =
 918                cpu_to_be32(be32_to_cpu(smb_buf->smb_buf_length) + count);
 919
 920        put_bcc(count, smb_buf);
 921
 922        rc = SendReceive2(xid, ses, iov, 3 /* num_iovecs */, &resp_buf_type,
 923                          CIFS_LOG_ERROR);
 924        /* SMB request buf freed in SendReceive2 */
 925
 926        pSMB = (SESSION_SETUP_ANDX *)iov[0].iov_base;
 927        smb_buf = (struct smb_hdr *)iov[0].iov_base;
 928
 929        if ((type == RawNTLMSSP) && (resp_buf_type != CIFS_NO_BUFFER) &&
 930            (smb_buf->Status.CifsError ==
 931                        cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))) {
 932                if (phase != NtLmNegotiate) {
 933                        cifs_dbg(VFS, "Unexpected more processing error\n");
 934                        goto ssetup_exit;
 935                }
 936                /* NTLMSSP Negotiate sent now processing challenge (response) */
 937                phase = NtLmChallenge; /* process ntlmssp challenge */
 938                rc = 0; /* MORE_PROC rc is not an error here, but expected */
 939        }
 940        if (rc)
 941                goto ssetup_exit;
 942
 943        if ((smb_buf->WordCount != 3) && (smb_buf->WordCount != 4)) {
 944                rc = -EIO;
 945                cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
 946                goto ssetup_exit;
 947        }
 948        action = le16_to_cpu(pSMB->resp.Action);
 949        if (action & GUEST_LOGIN)
 950                cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
 951        ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
 952        cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
 953        /* response can have either 3 or 4 word count - Samba sends 3 */
 954        /* and lanman response is 3 */
 955        bytes_remaining = get_bcc(smb_buf);
 956        bcc_ptr = pByteArea(smb_buf);
 957
 958        if (smb_buf->WordCount == 4) {
 959                blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
 960                if (blob_len > bytes_remaining) {
 961                        cifs_dbg(VFS, "bad security blob length %d\n",
 962                                 blob_len);
 963                        rc = -EINVAL;
 964                        goto ssetup_exit;
 965                }
 966                if (phase == NtLmChallenge) {
 967                        rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
 968                        /* now goto beginning for ntlmssp authenticate phase */
 969                        if (rc)
 970                                goto ssetup_exit;
 971                }
 972                bcc_ptr += blob_len;
 973                bytes_remaining -= blob_len;
 974        }
 975
 976        /* BB check if Unicode and decode strings */
 977        if (bytes_remaining == 0) {
 978                /* no string area to decode, do nothing */
 979        } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
 980                /* unicode string area must be word-aligned */
 981                if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
 982                        ++bcc_ptr;
 983                        --bytes_remaining;
 984                }
 985                decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses, nls_cp);
 986        } else {
 987                decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses, nls_cp);
 988        }
 989
 990ssetup_exit:
 991        if (spnego_key) {
 992                key_invalidate(spnego_key);
 993                key_put(spnego_key);
 994        }
 995        kfree(str_area);
 996        kfree(ntlmsspblob);
 997        ntlmsspblob = NULL;
 998        if (resp_buf_type == CIFS_SMALL_BUFFER) {
 999                cifs_dbg(FYI, "ssetup freeing small buf %p\n", iov[0].iov_base);
1000                cifs_small_buf_release(iov[0].iov_base);
1001        } else if (resp_buf_type == CIFS_LARGE_BUFFER)
1002                cifs_buf_release(iov[0].iov_base);
1003
1004        /* if ntlmssp, and negotiate succeeded, proceed to authenticate phase */
1005        if ((phase == NtLmChallenge) && (rc == 0))
1006                goto ssetup_ntlmssp_authenticate;
1007
1008        return rc;
1009}
1010
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