source3/smbd/smb2_negprot.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Core SMB2 server
   4
   5    Copyright (C) Stefan Metzmacher 2009
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "smbd/smbd.h"
  23 #include "smbd/globals.h"
  24 #include "../libcli/smb/smb_common.h"
  25 #include "../lib/tsocket/tsocket.h"
  26 #include "../librpc/ndr/libndr.h"
  27
  28 extern fstring remote_proto;
  29
  30 /*
  31  * this is the entry point if SMB2 is selected via
  32  * the SMB negprot and the given dialect.
  33  */
  34 static void reply_smb20xx(struct smb_request *req, uint16_t dialect)
  35 {
  36         uint8_t *smb2_inbuf;
  37         uint8_t *smb2_hdr;
  38         uint8_t *smb2_body;
  39         uint8_t *smb2_dyn;
  40         size_t len = 4 + SMB2_HDR_BODY + 0x24 + 2;
  41
  42         smb2_inbuf = talloc_zero_array(talloc_tos(), uint8_t, len);
  43         if (smb2_inbuf == NULL) {
  44                 DEBUG(0, ("Could not push spnego blob\n"));
  45                 reply_nterror(req, NT_STATUS_NO_MEMORY);
  46                 return;
  47         }
  48         smb2_hdr = smb2_inbuf + 4;
  49         smb2_body = smb2_hdr + SMB2_HDR_BODY;
  50         smb2_dyn = smb2_body + 0x24;
  51
  52         SIVAL(smb2_hdr, SMB2_HDR_PROTOCOL_ID,   SMB2_MAGIC);
  53         SIVAL(smb2_hdr, SMB2_HDR_LENGTH,        SMB2_HDR_BODY);
  54
  55         SSVAL(smb2_body, 0x00, 0x0024); /* struct size */
  56         SSVAL(smb2_body, 0x02, 0x0001); /* dialect count */
  57
  58         SSVAL(smb2_dyn,  0x00, dialect);
  59
  60         req->outbuf = NULL;
  61
  62         smbd_smb2_first_negprot(req->xconn, smb2_inbuf, len);
  63         return;
  64 }
  65
  66 /*
  67  * this is the entry point if SMB2 is selected via
  68  * the SMB negprot and the "SMB 2.002" dialect.
  69  */
  70 void reply_smb2002(struct smb_request *req, uint16_t choice)
  71 {
  72         reply_smb20xx(req, SMB2_DIALECT_REVISION_202);
  73 }
  74
  75 /*
  76  * this is the entry point if SMB2 is selected via
  77  * the SMB negprot and the "SMB 2.???" dialect.
  78  */
  79 void reply_smb20ff(struct smb_request *req, uint16_t choice)
  80 {
  81         struct smbXsrv_connection *xconn = req->sconn->conn;
  82         xconn->smb2.allow_2ff = true;
  83         reply_smb20xx(req, SMB2_DIALECT_REVISION_2FF);
  84 }
  85
  86 enum protocol_types smbd_smb2_protocol_dialect_match(const uint8_t *indyn,
  87                                 const int dialect_count,
  88                                 uint16_t *dialect)
  89 {
  90         size_t c = 0;
  91         enum protocol_types protocol = PROTOCOL_NONE;
  92
  93         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
  94                 if (lp_server_max_protocol() < PROTOCOL_SMB3_00) {
  95                         break;
  96                 }
  97                 if (lp_server_min_protocol() > PROTOCOL_SMB3_00) {
  98                         break;
  99                 }
 100
 101                 *dialect = SVAL(indyn, c*2);
 102                 if (*dialect == SMB3_DIALECT_REVISION_300) {
 103                         protocol = PROTOCOL_SMB3_00;
 104                         break;
 105                 }
 106         }
 107
 108         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 109                 if (lp_server_max_protocol() < PROTOCOL_SMB2_24) {
 110                         break;
 111                 }
 112                 if (lp_server_min_protocol() > PROTOCOL_SMB2_24) {
 113                         break;
 114                 }
 115
 116                 *dialect = SVAL(indyn, c*2);
 117                 if (*dialect == SMB2_DIALECT_REVISION_224) {
 118                         protocol = PROTOCOL_SMB2_24;
 119                         break;
 120                 }
 121         }
 122
 123         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 124                 if (lp_server_max_protocol() < PROTOCOL_SMB2_22) {
 125                         break;
 126                 }
 127                 if (lp_server_min_protocol() > PROTOCOL_SMB2_22) {
 128                         break;
 129                 }
 130
 131                 *dialect = SVAL(indyn, c*2);
 132                 if (*dialect == SMB2_DIALECT_REVISION_222) {
 133                         protocol = PROTOCOL_SMB2_22;
 134                         break;
 135                 }
 136         }
 137
 138         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 139                 if (lp_server_max_protocol() < PROTOCOL_SMB2_10) {
 140                         break;
 141                 }
 142                 if (lp_server_min_protocol() > PROTOCOL_SMB2_10) {
 143                         break;
 144                 }
 145
 146                 *dialect = SVAL(indyn, c*2);
 147                 if (*dialect == SMB2_DIALECT_REVISION_210) {
 148                         protocol = PROTOCOL_SMB2_10;
 149                         break;
 150                 }
 151         }
 152
 153         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 154                 if (lp_server_max_protocol() < PROTOCOL_SMB2_02) {
 155                         break;
 156                 }
 157                 if (lp_server_min_protocol() > PROTOCOL_SMB2_02) {
 158                         break;
 159                 }
 160
 161                 *dialect = SVAL(indyn, c*2);
 162                 if (*dialect == SMB2_DIALECT_REVISION_202) {
 163                         protocol = PROTOCOL_SMB2_02;
 164                         break;
 165                 }
 166         }
 167
 168         return protocol;
 169 }
 170
 171 NTSTATUS smbd_smb2_request_process_negprot(struct smbd_smb2_request *req)
 172 {
 173         struct smbXsrv_connection *xconn = req->sconn->conn;
 174         NTSTATUS status;
 175         const uint8_t *inbody;
 176         const uint8_t *indyn = NULL;
 177         DATA_BLOB outbody;
 178         DATA_BLOB outdyn;
 179         DATA_BLOB negprot_spnego_blob;
 180         uint16_t security_offset;
 181         DATA_BLOB security_buffer;
 182         size_t expected_dyn_size = 0;
 183         size_t c;
 184         uint16_t security_mode;
 185         uint16_t dialect_count;
 186         uint16_t in_security_mode;
 187         uint32_t in_capabilities;
 188         DATA_BLOB in_guid_blob;
 189         struct GUID in_guid;
 190         uint16_t dialect = 0;
 191         uint32_t capabilities;
 192         DATA_BLOB out_guid_blob;
 193         struct GUID out_guid;
 194         enum protocol_types protocol = PROTOCOL_NONE;
 195         uint32_t max_limit;
 196         uint32_t max_trans = lp_smb2_max_trans();
 197         uint32_t max_read = lp_smb2_max_read();
 198         uint32_t max_write = lp_smb2_max_write();
 199         NTTIME now = timeval_to_nttime(&req->request_time);
 200
 201         status = smbd_smb2_request_verify_sizes(req, 0x24);
 202         if (!NT_STATUS_IS_OK(status)) {
 203                 return smbd_smb2_request_error(req, status);
 204         }
 205         inbody = SMBD_SMB2_IN_BODY_PTR(req);
 206
 207         dialect_count = SVAL(inbody, 0x02);
 208
 209         in_security_mode = SVAL(inbody, 0x04);
 210         in_capabilities = IVAL(inbody, 0x08);
 211         in_guid_blob = data_blob_const(inbody + 0x0C, 16);
 212
 213         if (dialect_count == 0) {
 214                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
 215         }
 216
 217         status = GUID_from_ndr_blob(&in_guid_blob, &in_guid);
 218         if (!NT_STATUS_IS_OK(status)) {
 219                 return smbd_smb2_request_error(req, status);
 220         }
 221
 222         expected_dyn_size = dialect_count * 2;
 223         if (SMBD_SMB2_IN_DYN_LEN(req) < expected_dyn_size) {
 224                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
 225         }
 226         indyn = SMBD_SMB2_IN_DYN_PTR(req);
 227
 228         protocol = smbd_smb2_protocol_dialect_match(indyn,
 229                                         dialect_count,
 230                                         &dialect);
 231
 232         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 233                 if (lp_server_max_protocol() < PROTOCOL_SMB2_10) {
 234                         break;
 235                 }
 236
 237                 dialect = SVAL(indyn, c*2);
 238                 if (dialect == SMB2_DIALECT_REVISION_2FF) {
 239                         if (xconn->smb2.allow_2ff) {
 240                                 xconn->smb2.allow_2ff = false;
 241                                 protocol = PROTOCOL_SMB2_10;
 242                                 break;
 243                         }
 244                 }
 245         }
 246
 247         if (protocol == PROTOCOL_NONE) {
 248                 return smbd_smb2_request_error(req, NT_STATUS_NOT_SUPPORTED);
 249         }
 250
 251         if (get_remote_arch() != RA_SAMBA) {
 252                 set_remote_arch(RA_VISTA);
 253         }
 254
 255         fstr_sprintf(remote_proto, "SMB%X_%02X",
 256                      (dialect >> 8) & 0xFF, dialect & 0xFF);
 257
 258         reload_services(req->sconn, conn_snum_used, true);
 259         DEBUG(3,("Selected protocol %s\n", remote_proto));
 260
 261         /* negprot_spnego() returns a the server guid in the first 16 bytes */
 262         negprot_spnego_blob = negprot_spnego(req, req->sconn);
 263         if (negprot_spnego_blob.data == NULL) {
 264                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 265         }
 266
 267         if (negprot_spnego_blob.length < 16) {
 268                 return smbd_smb2_request_error(req, NT_STATUS_INTERNAL_ERROR);
 269         }
 270
 271         security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED;
 272         if (lp_server_signing() == SMB_SIGNING_REQUIRED) {
 273                 security_mode |= SMB2_NEGOTIATE_SIGNING_REQUIRED;
 274         }
 275
 276         capabilities = 0;
 277         if (lp_host_msdfs()) {
 278                 capabilities |= SMB2_CAP_DFS;
 279         }
 280
 281         if ((protocol >= PROTOCOL_SMB2_24) &&
 282             (lp_smb_encrypt(-1) != SMB_SIGNING_OFF) &&
 283             (in_capabilities & SMB2_CAP_ENCRYPTION)) {
 284                 capabilities |= SMB2_CAP_ENCRYPTION;
 285         }
 286
 287         /*
 288          * 0x10000 (65536) is the maximum allowed message size
 289          * for SMB 2.0
 290          */
 291         max_limit = 0x10000;
 292
 293         if (protocol >= PROTOCOL_SMB2_10) {
 294                 int p = 0;
 295
 296                 if (tsocket_address_is_inet(req->sconn->local_address, "ip")) {
 297                         p = tsocket_address_inet_port(req->sconn->local_address);
 298                 }
 299
 300                 /* largeMTU is not supported over NBT (tcp port 139) */
 301                 if (p != NBT_SMB_PORT) {
 302                         capabilities |= SMB2_CAP_LARGE_MTU;
 303                         xconn->smb2.credits.multicredit = true;
 304
 305                         /* Windows 2012R2 allows up to 8 MB */
 306                         max_limit = 0x800000; /* 8MB */
 307                 }
 308         }
 309
 310         /*
 311          * the defaults are 8MB, but we'll limit this to max_limit based on
 312          * the dialect (64kb for SMB 2.0, 8MB for SMB >= 2.1 with LargeMTU)
 313          *
 314          * user configured values exceeding the limits will be overwritten,
 315          * only smaller values will be accepted
 316          */
 317
 318         max_trans = MIN(max_limit, lp_smb2_max_trans());
 319         max_read = MIN(max_limit, lp_smb2_max_read());
 320         max_write = MIN(max_limit, lp_smb2_max_write());
 321
 322         security_offset = SMB2_HDR_BODY + 0x40;
 323
 324 #if 1
 325         /* Try SPNEGO auth... */
 326         security_buffer = data_blob_const(negprot_spnego_blob.data + 16,
 327                                           negprot_spnego_blob.length - 16);
 328 #else
 329         /* for now we want raw NTLMSSP */
 330         security_buffer = data_blob_const(NULL, 0);
 331 #endif
 332
 333         out_guid_blob = data_blob_const(negprot_spnego_blob.data, 16);
 334         status = GUID_from_ndr_blob(&out_guid_blob, &out_guid);
 335         if (!NT_STATUS_IS_OK(status)) {
 336                 return smbd_smb2_request_error(req, status);
 337         }
 338
 339         outbody = smbd_smb2_generate_outbody(req, 0x40);
 340         if (outbody.data == NULL) {
 341                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 342         }
 343
 344         SSVAL(outbody.data, 0x00, 0x40 + 1);    /* struct size */
 345         SSVAL(outbody.data, 0x02,
 346               security_mode);                   /* security mode */
 347         SSVAL(outbody.data, 0x04, dialect);     /* dialect revision */
 348         SSVAL(outbody.data, 0x06, 0);           /* reserved */
 349         memcpy(outbody.data + 0x08,
 350                out_guid_blob.data, 16); /* server guid */
 351         SIVAL(outbody.data, 0x18,
 352               capabilities);                    /* capabilities */
 353         SIVAL(outbody.data, 0x1C, max_trans);   /* max transact size */
 354         SIVAL(outbody.data, 0x20, max_read);    /* max read size */
 355         SIVAL(outbody.data, 0x24, max_write);   /* max write size */
 356         SBVAL(outbody.data, 0x28, now);         /* system time */
 357         SBVAL(outbody.data, 0x30, 0);           /* server start time */
 358         SSVAL(outbody.data, 0x38,
 359               security_offset);                 /* security buffer offset */
 360         SSVAL(outbody.data, 0x3A,
 361               security_buffer.length);          /* security buffer length */
 362         SIVAL(outbody.data, 0x3C, 0);           /* reserved */
 363
 364         outdyn = security_buffer;
 365
 366         req->sconn->using_smb2 = true;
 367
 368         if (dialect != SMB2_DIALECT_REVISION_2FF) {
 369                 status = smbXsrv_connection_init_tables(xconn, protocol);
 370                 if (!NT_STATUS_IS_OK(status)) {
 371                         return smbd_smb2_request_error(req, status);
 372                 }
 373
 374                 xconn->smb2.client.capabilities = in_capabilities;
 375                 xconn->smb2.client.security_mode = in_security_mode;
 376                 xconn->smb2.client.guid = in_guid;
 377                 xconn->smb2.client.num_dialects = dialect_count;
 378                 xconn->smb2.client.dialects = talloc_array(xconn,
 379                                                            uint16_t,
 380                                                            dialect_count);
 381                 if (xconn->smb2.client.dialects == NULL) {
 382                         return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 383                 }
 384                 for (c=0; c < dialect_count; c++) {
 385                         xconn->smb2.client.dialects[c] = SVAL(indyn, c*2);
 386                 }
 387
 388                 xconn->smb2.server.capabilities = capabilities;
 389                 xconn->smb2.server.security_mode = security_mode;
 390                 xconn->smb2.server.guid = out_guid;
 391                 xconn->smb2.server.dialect = dialect;
 392                 xconn->smb2.server.max_trans = max_trans;
 393                 xconn->smb2.server.max_read  = max_read;
 394                 xconn->smb2.server.max_write = max_write;
 395         }
 396
 397         return smbd_smb2_request_done(req, outbody, &outdyn);
 398 }