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->sconn, 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         req->sconn->smb2.negprot_2ff = true;
  82         reply_smb20xx(req, SMB2_DIALECT_REVISION_2FF);
  83 }
  84
  85 enum protocol_types smbd_smb2_protocol_dialect_match(const uint8_t *indyn,
  86                                 const int dialect_count,
  87                                 uint16_t *dialect)
  88 {
  89         size_t c = 0;
  90         enum protocol_types protocol = PROTOCOL_NONE;
  91
  92         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
  93                 if (lp_server_max_protocol() < PROTOCOL_SMB3_00) {
  94                         break;
  95                 }
  96                 if (lp_server_min_protocol() > PROTOCOL_SMB3_00) {
  97                         break;
  98                 }
  99
 100                 *dialect = SVAL(indyn, c*2);
 101                 if (*dialect == SMB3_DIALECT_REVISION_300) {
 102                         protocol = PROTOCOL_SMB3_00;
 103                         break;
 104                 }
 105         }
 106
 107         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 108                 if (lp_server_max_protocol() < PROTOCOL_SMB2_24) {
 109                         break;
 110                 }
 111                 if (lp_server_min_protocol() > PROTOCOL_SMB2_24) {
 112                         break;
 113                 }
 114
 115                 *dialect = SVAL(indyn, c*2);
 116                 if (*dialect == SMB2_DIALECT_REVISION_224) {
 117                         protocol = PROTOCOL_SMB2_24;
 118                         break;
 119                 }
 120         }
 121
 122         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 123                 if (lp_server_max_protocol() < PROTOCOL_SMB2_22) {
 124                         break;
 125                 }
 126                 if (lp_server_min_protocol() > PROTOCOL_SMB2_22) {
 127                         break;
 128                 }
 129
 130                 *dialect = SVAL(indyn, c*2);
 131                 if (*dialect == SMB2_DIALECT_REVISION_222) {
 132                         protocol = PROTOCOL_SMB2_22;
 133                         break;
 134                 }
 135         }
 136
 137         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 138                 if (lp_server_max_protocol() < PROTOCOL_SMB2_10) {
 139                         break;
 140                 }
 141                 if (lp_server_min_protocol() > PROTOCOL_SMB2_10) {
 142                         break;
 143                 }
 144
 145                 *dialect = SVAL(indyn, c*2);
 146                 if (*dialect == SMB2_DIALECT_REVISION_210) {
 147                         protocol = PROTOCOL_SMB2_10;
 148                         break;
 149                 }
 150         }
 151
 152         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 153                 if (lp_server_max_protocol() < PROTOCOL_SMB2_02) {
 154                         break;
 155                 }
 156                 if (lp_server_min_protocol() > PROTOCOL_SMB2_02) {
 157                         break;
 158                 }
 159
 160                 *dialect = SVAL(indyn, c*2);
 161                 if (*dialect == SMB2_DIALECT_REVISION_202) {
 162                         protocol = PROTOCOL_SMB2_02;
 163                         break;
 164                 }
 165         }
 166
 167         return protocol;
 168 }
 169
 170 NTSTATUS smbd_smb2_request_process_negprot(struct smbd_smb2_request *req)
 171 {
 172         NTSTATUS status;
 173         const uint8_t *inbody;
 174         const uint8_t *indyn = NULL;
 175         DATA_BLOB outbody;
 176         DATA_BLOB outdyn;
 177         DATA_BLOB negprot_spnego_blob;
 178         uint16_t security_offset;
 179         DATA_BLOB security_buffer;
 180         size_t expected_dyn_size = 0;
 181         size_t c;
 182         uint16_t security_mode;
 183         uint16_t dialect_count;
 184         uint16_t in_security_mode;
 185         uint32_t in_capabilities;
 186         DATA_BLOB in_guid_blob;
 187         struct GUID in_guid;
 188         uint16_t dialect = 0;
 189         uint32_t capabilities;
 190         DATA_BLOB out_guid_blob;
 191         struct GUID out_guid;
 192         enum protocol_types protocol = PROTOCOL_NONE;
 193         uint32_t max_limit;
 194         uint32_t max_trans = lp_smb2_max_trans();
 195         uint32_t max_read = lp_smb2_max_read();
 196         uint32_t max_write = lp_smb2_max_write();
 197         NTTIME now = timeval_to_nttime(&req->request_time);
 198
 199         status = smbd_smb2_request_verify_sizes(req, 0x24);
 200         if (!NT_STATUS_IS_OK(status)) {
 201                 return smbd_smb2_request_error(req, status);
 202         }
 203         inbody = SMBD_SMB2_IN_BODY_PTR(req);
 204
 205         dialect_count = SVAL(inbody, 0x02);
 206
 207         in_security_mode = SVAL(inbody, 0x04);
 208         in_capabilities = IVAL(inbody, 0x08);
 209         in_guid_blob = data_blob_const(inbody + 0x0C, 16);
 210
 211         if (dialect_count == 0) {
 212                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
 213         }
 214
 215         status = GUID_from_ndr_blob(&in_guid_blob, &in_guid);
 216         if (!NT_STATUS_IS_OK(status)) {
 217                 return smbd_smb2_request_error(req, status);
 218         }
 219
 220         expected_dyn_size = dialect_count * 2;
 221         if (SMBD_SMB2_IN_DYN_LEN(req) < expected_dyn_size) {
 222                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
 223         }
 224         indyn = SMBD_SMB2_IN_DYN_PTR(req);
 225
 226         protocol = smbd_smb2_protocol_dialect_match(indyn,
 227                                         dialect_count,
 228                                         &dialect);
 229
 230         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 231                 if (lp_server_max_protocol() < PROTOCOL_SMB2_10) {
 232                         break;
 233                 }
 234
 235                 dialect = SVAL(indyn, c*2);
 236                 if (dialect == SMB2_DIALECT_REVISION_2FF) {
 237                         if (req->sconn->smb2.negprot_2ff) {
 238                                 req->sconn->smb2.negprot_2ff = false;
 239                                 protocol = PROTOCOL_SMB2_10;
 240                                 break;
 241                         }
 242                 }
 243         }
 244
 245         if (protocol == PROTOCOL_NONE) {
 246                 return smbd_smb2_request_error(req, NT_STATUS_NOT_SUPPORTED);
 247         }
 248
 249         if (get_remote_arch() != RA_SAMBA) {
 250                 set_remote_arch(RA_VISTA);
 251         }
 252
 253         fstr_sprintf(remote_proto, "SMB%X_%02X",
 254                      (dialect >> 8) & 0xFF, dialect & 0xFF);
 255
 256         reload_services(req->sconn, conn_snum_used, true);
 257         DEBUG(3,("Selected protocol %s\n", remote_proto));
 258
 259         /* negprot_spnego() returns a the server guid in the first 16 bytes */
 260         negprot_spnego_blob = negprot_spnego(req, req->sconn);
 261         if (negprot_spnego_blob.data == NULL) {
 262                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 263         }
 264
 265         if (negprot_spnego_blob.length < 16) {
 266                 return smbd_smb2_request_error(req, NT_STATUS_INTERNAL_ERROR);
 267         }
 268
 269         security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED;
 270         if (lp_server_signing() == SMB_SIGNING_REQUIRED) {
 271                 security_mode |= SMB2_NEGOTIATE_SIGNING_REQUIRED;
 272         }
 273
 274         capabilities = 0;
 275         if (lp_host_msdfs()) {
 276                 capabilities |= SMB2_CAP_DFS;
 277         }
 278
 279         if ((protocol >= PROTOCOL_SMB2_24) &&
 280             (lp_smb_encrypt(-1) != SMB_SIGNING_OFF) &&
 281             (in_capabilities & SMB2_CAP_ENCRYPTION)) {
 282                 capabilities |= SMB2_CAP_ENCRYPTION;
 283         }
 284
 285         /*
 286          * 0x10000 (65536) is the maximum allowed message size
 287          * for SMB 2.0
 288          */
 289         max_limit = 0x10000;
 290
 291         if (protocol >= PROTOCOL_SMB2_10) {
 292                 int p = 0;
 293
 294                 if (tsocket_address_is_inet(req->sconn->local_address, "ip")) {
 295                         p = tsocket_address_inet_port(req->sconn->local_address);
 296                 }
 297
 298                 /* largeMTU is not supported over NBT (tcp port 139) */
 299                 if (p != NBT_SMB_PORT) {
 300                         capabilities |= SMB2_CAP_LARGE_MTU;
 301                         req->sconn->smb2.supports_multicredit = true;
 302
 303                         /* Windows 2012R2 allows up to 8 MB */
 304                         max_limit = 0x800000; /* 8MB */
 305                 }
 306         }
 307
 308         /*
 309          * the defaults are 8MB, but we'll limit this to max_limit based on
 310          * the dialect (64kb for SMB 2.0, 8MB for SMB >= 2.1 with LargeMTU)
 311          *
 312          * user configured values exceeding the limits will be overwritten,
 313          * only smaller values will be accepted
 314          */
 315
 316         max_trans = MIN(max_limit, lp_smb2_max_trans());
 317         max_read = MIN(max_limit, lp_smb2_max_read());
 318         max_write = MIN(max_limit, lp_smb2_max_write());
 319
 320         security_offset = SMB2_HDR_BODY + 0x40;
 321
 322 #if 1
 323         /* Try SPNEGO auth... */
 324         security_buffer = data_blob_const(negprot_spnego_blob.data + 16,
 325                                           negprot_spnego_blob.length - 16);
 326 #else
 327         /* for now we want raw NTLMSSP */
 328         security_buffer = data_blob_const(NULL, 0);
 329 #endif
 330
 331         out_guid_blob = data_blob_const(negprot_spnego_blob.data, 16);
 332         status = GUID_from_ndr_blob(&out_guid_blob, &out_guid);
 333         if (!NT_STATUS_IS_OK(status)) {
 334                 return smbd_smb2_request_error(req, status);
 335         }
 336
 337         outbody = smbd_smb2_generate_outbody(req, 0x40);
 338         if (outbody.data == NULL) {
 339                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 340         }
 341
 342         SSVAL(outbody.data, 0x00, 0x40 + 1);    /* struct size */
 343         SSVAL(outbody.data, 0x02,
 344               security_mode);                   /* security mode */
 345         SSVAL(outbody.data, 0x04, dialect);     /* dialect revision */
 346         SSVAL(outbody.data, 0x06, 0);           /* reserved */
 347         memcpy(outbody.data + 0x08,
 348                out_guid_blob.data, 16); /* server guid */
 349         SIVAL(outbody.data, 0x18,
 350               capabilities);                    /* capabilities */
 351         SIVAL(outbody.data, 0x1C, max_trans);   /* max transact size */
 352         SIVAL(outbody.data, 0x20, max_read);    /* max read size */
 353         SIVAL(outbody.data, 0x24, max_write);   /* max write size */
 354         SBVAL(outbody.data, 0x28, now);         /* system time */
 355         SBVAL(outbody.data, 0x30, 0);           /* server start time */
 356         SSVAL(outbody.data, 0x38,
 357               security_offset);                 /* security buffer offset */
 358         SSVAL(outbody.data, 0x3A,
 359               security_buffer.length);          /* security buffer length */
 360         SIVAL(outbody.data, 0x3C, 0);           /* reserved */
 361
 362         outdyn = security_buffer;
 363
 364         req->sconn->using_smb2 = true;
 365
 366         if (dialect != SMB2_DIALECT_REVISION_2FF) {
 367                 struct smbXsrv_connection *conn = req->sconn->conn;
 368
 369                 status = smbXsrv_connection_init_tables(conn, protocol);
 370                 if (!NT_STATUS_IS_OK(status)) {
 371                         return smbd_smb2_request_error(req, status);
 372                 }
 373
 374                 conn->smb2.client.capabilities = in_capabilities;
 375                 conn->smb2.client.security_mode = in_security_mode;
 376                 conn->smb2.client.guid = in_guid;
 377                 conn->smb2.client.num_dialects = dialect_count;
 378                 conn->smb2.client.dialects = talloc_array(conn,
 379                                                           uint16_t,
 380                                                           dialect_count);
 381                 if (conn->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                         conn->smb2.client.dialects[c] = SVAL(indyn, c*2);
 386                 }
 387
 388                 conn->smb2.server.capabilities = capabilities;
 389                 conn->smb2.server.security_mode = security_mode;
 390                 conn->smb2.server.guid = out_guid;
 391                 conn->smb2.server.dialect = dialect;
 392                 conn->smb2.server.max_trans = max_trans;
 393                 conn->smb2.server.max_read  = max_read;
 394                 conn->smb2.server.max_write = max_write;
 395
 396                 req->sconn->smb2.max_trans = max_trans;
 397                 req->sconn->smb2.max_read  = max_read;
 398                 req->sconn->smb2.max_write = max_write;
 399         }
 400
 401         return smbd_smb2_request_done(req, outbody, &outdyn);
 402 }