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 /*
  29  * this is the entry point if SMB2 is selected via
  30  * the SMB negprot and the given dialect.
  31  */
  32 static void reply_smb20xx(struct smb_request *req, uint16_t dialect)
  33 {
  34         uint8_t *smb2_inbuf;
  35         uint8_t *smb2_hdr;
  36         uint8_t *smb2_body;
  37         uint8_t *smb2_dyn;
  38         size_t len = 4 + SMB2_HDR_BODY + 0x24 + 2;
  39
  40         smb2_inbuf = talloc_zero_array(talloc_tos(), uint8_t, len);
  41         if (smb2_inbuf == NULL) {
  42                 DEBUG(0, ("Could not push spnego blob\n"));
  43                 reply_nterror(req, NT_STATUS_NO_MEMORY);
  44                 return;
  45         }
  46         smb2_hdr = smb2_inbuf + 4;
  47         smb2_body = smb2_hdr + SMB2_HDR_BODY;
  48         smb2_dyn = smb2_body + 0x24;
  49
  50         SIVAL(smb2_hdr, SMB2_HDR_PROTOCOL_ID,   SMB2_MAGIC);
  51         SIVAL(smb2_hdr, SMB2_HDR_LENGTH,        SMB2_HDR_BODY);
  52
  53         SSVAL(smb2_body, 0x00, 0x0024); /* struct size */
  54         SSVAL(smb2_body, 0x02, 0x0001); /* dialect count */
  55
  56         SSVAL(smb2_dyn,  0x00, dialect);
  57
  58         req->outbuf = NULL;
  59
  60         smbd_smb2_first_negprot(req->sconn, smb2_inbuf, len);
  61         return;
  62 }
  63
  64 /*
  65  * this is the entry point if SMB2 is selected via
  66  * the SMB negprot and the "SMB 2.002" dialect.
  67  */
  68 void reply_smb2002(struct smb_request *req, uint16_t choice)
  69 {
  70         reply_smb20xx(req, SMB2_DIALECT_REVISION_202);
  71 }
  72
  73 /*
  74  * this is the entry point if SMB2 is selected via
  75  * the SMB negprot and the "SMB 2.???" dialect.
  76  */
  77 void reply_smb20ff(struct smb_request *req, uint16_t choice)
  78 {
  79         req->sconn->smb2.negprot_2ff = true;
  80         reply_smb20xx(req, SMB2_DIALECT_REVISION_2FF);
  81 }
  82
  83 NTSTATUS smbd_smb2_request_process_negprot(struct smbd_smb2_request *req)
  84 {
  85         NTSTATUS status;
  86         const uint8_t *inbody;
  87         const uint8_t *indyn = NULL;
  88         DATA_BLOB outbody;
  89         DATA_BLOB outdyn;
  90         DATA_BLOB negprot_spnego_blob;
  91         uint16_t security_offset;
  92         DATA_BLOB security_buffer;
  93         size_t expected_dyn_size = 0;
  94         size_t c;
  95         uint16_t security_mode;
  96         uint16_t dialect_count;
  97         uint16_t in_security_mode;
  98         uint32_t in_capabilities;
  99         DATA_BLOB in_guid_blob;
 100         struct GUID in_guid;
 101         uint16_t dialect = 0;
 102         uint32_t capabilities;
 103         DATA_BLOB out_guid_blob;
 104         struct GUID out_guid;
 105         enum protocol_types protocol = PROTOCOL_NONE;
 106         uint32_t max_limit;
 107         uint32_t max_trans = lp_smb2_max_trans();
 108         uint32_t max_read = lp_smb2_max_read();
 109         uint32_t max_write = lp_smb2_max_write();
 110         NTTIME now = timeval_to_nttime(&req->request_time);
 111
 112         status = smbd_smb2_request_verify_sizes(req, 0x24);
 113         if (!NT_STATUS_IS_OK(status)) {
 114                 return smbd_smb2_request_error(req, status);
 115         }
 116         inbody = SMBD_SMB2_IN_BODY_PTR(req);
 117
 118         dialect_count = SVAL(inbody, 0x02);
 119
 120         in_security_mode = SVAL(inbody, 0x04);
 121         in_capabilities = IVAL(inbody, 0x08);
 122         in_guid_blob = data_blob_const(inbody + 0x0C, 16);
 123
 124         if (dialect_count == 0) {
 125                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
 126         }
 127
 128         status = GUID_from_ndr_blob(&in_guid_blob, &in_guid);
 129         if (!NT_STATUS_IS_OK(status)) {
 130                 return smbd_smb2_request_error(req, status);
 131         }
 132
 133         expected_dyn_size = dialect_count * 2;
 134         if (SMBD_SMB2_IN_DYN_LEN(req) < expected_dyn_size) {
 135                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
 136         }
 137         indyn = SMBD_SMB2_IN_DYN_PTR(req);
 138
 139         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 140                 if (lp_srv_maxprotocol() < PROTOCOL_SMB3_00) {
 141                         break;
 142                 }
 143                 if (lp_srv_minprotocol() > PROTOCOL_SMB3_00) {
 144                         break;
 145                 }
 146
 147                 dialect = SVAL(indyn, c*2);
 148                 if (dialect == SMB3_DIALECT_REVISION_300) {
 149                         protocol = PROTOCOL_SMB3_00;
 150                         break;
 151                 }
 152         }
 153
 154         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 155                 if (lp_srv_maxprotocol() < PROTOCOL_SMB2_24) {
 156                         break;
 157                 }
 158                 if (lp_srv_minprotocol() > PROTOCOL_SMB2_24) {
 159                         break;
 160                 }
 161
 162                 dialect = SVAL(indyn, c*2);
 163                 if (dialect == SMB2_DIALECT_REVISION_224) {
 164                         protocol = PROTOCOL_SMB2_24;
 165                         break;
 166                 }
 167         }
 168
 169         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 170                 if (lp_srv_maxprotocol() < PROTOCOL_SMB2_22) {
 171                         break;
 172                 }
 173                 if (lp_srv_minprotocol() > PROTOCOL_SMB2_22) {
 174                         break;
 175                 }
 176
 177                 dialect = SVAL(indyn, c*2);
 178                 if (dialect == SMB2_DIALECT_REVISION_222) {
 179                         protocol = PROTOCOL_SMB2_22;
 180                         break;
 181                 }
 182         }
 183
 184         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 185                 if (lp_srv_maxprotocol() < PROTOCOL_SMB2_10) {
 186                         break;
 187                 }
 188                 if (lp_srv_minprotocol() > PROTOCOL_SMB2_10) {
 189                         break;
 190                 }
 191
 192                 dialect = SVAL(indyn, c*2);
 193                 if (dialect == SMB2_DIALECT_REVISION_210) {
 194                         protocol = PROTOCOL_SMB2_10;
 195                         break;
 196                 }
 197         }
 198
 199         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 200                 if (lp_srv_maxprotocol() < PROTOCOL_SMB2_02) {
 201                         break;
 202                 }
 203                 if (lp_srv_minprotocol() > PROTOCOL_SMB2_02) {
 204                         break;
 205                 }
 206
 207                 dialect = SVAL(indyn, c*2);
 208                 if (dialect == SMB2_DIALECT_REVISION_202) {
 209                         protocol = PROTOCOL_SMB2_02;
 210                         break;
 211                 }
 212         }
 213
 214         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 215                 if (lp_srv_maxprotocol() < PROTOCOL_SMB2_10) {
 216                         break;
 217                 }
 218
 219                 dialect = SVAL(indyn, c*2);
 220                 if (dialect == SMB2_DIALECT_REVISION_2FF) {
 221                         if (req->sconn->smb2.negprot_2ff) {
 222                                 req->sconn->smb2.negprot_2ff = false;
 223                                 protocol = PROTOCOL_SMB2_10;
 224                                 break;
 225                         }
 226                 }
 227         }
 228
 229         if (protocol == PROTOCOL_NONE) {
 230                 return smbd_smb2_request_error(req, NT_STATUS_NOT_SUPPORTED);
 231         }
 232
 233         if (get_remote_arch() != RA_SAMBA) {
 234                 set_remote_arch(RA_VISTA);
 235         }
 236
 237         /* negprot_spnego() returns a the server guid in the first 16 bytes */
 238         negprot_spnego_blob = negprot_spnego(req, req->sconn);
 239         if (negprot_spnego_blob.data == NULL) {
 240                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 241         }
 242
 243         if (negprot_spnego_blob.length < 16) {
 244                 return smbd_smb2_request_error(req, NT_STATUS_INTERNAL_ERROR);
 245         }
 246
 247         security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED;
 248         if (lp_server_signing() == SMB_SIGNING_REQUIRED) {
 249                 security_mode |= SMB2_NEGOTIATE_SIGNING_REQUIRED;
 250         }
 251
 252         capabilities = 0;
 253         if (lp_host_msdfs()) {
 254                 capabilities |= SMB2_CAP_DFS;
 255         }
 256
 257         if ((protocol >= PROTOCOL_SMB2_24) &&
 258             (lp_smb_encrypt(-1) != SMB_SIGNING_OFF) &&
 259             (in_capabilities & SMB2_CAP_ENCRYPTION)) {
 260                 capabilities |= SMB2_CAP_ENCRYPTION;
 261         }
 262
 263         /*
 264          * 0x10000 (65536) is the maximum allowed message size
 265          * for SMB 2.0
 266          */
 267         max_limit = 0x10000;
 268
 269         if (protocol >= PROTOCOL_SMB2_10) {
 270                 int p = 0;
 271
 272                 if (tsocket_address_is_inet(req->sconn->local_address, "ip")) {
 273                         p = tsocket_address_inet_port(req->sconn->local_address);
 274                 }
 275
 276                 /* largeMTU is not supported over NBT (tcp port 139) */
 277                 if (p != NBT_SMB_PORT) {
 278                         capabilities |= SMB2_CAP_LARGE_MTU;
 279                         req->sconn->smb2.supports_multicredit = true;
 280
 281                         /* SMB >= 2.1 has 1 MB of allowed size */
 282                         max_limit = 0x100000; /* 1MB */
 283                 }
 284         }
 285
 286         /*
 287          * the defaults are 1MB, but we'll limit this to max_limit based on
 288          * the dialect (64kb for SMB2.0, 1MB for SMB2.1 with LargeMTU)
 289          *
 290          * user configured values exceeding the limits will be overwritten,
 291          * only smaller values will be accepted
 292          */
 293
 294         max_trans = MIN(max_limit, lp_smb2_max_trans());
 295         max_read = MIN(max_limit, lp_smb2_max_read());
 296         max_write = MIN(max_limit, lp_smb2_max_write());
 297
 298         security_offset = SMB2_HDR_BODY + 0x40;
 299
 300 #if 1
 301         /* Try SPNEGO auth... */
 302         security_buffer = data_blob_const(negprot_spnego_blob.data + 16,
 303                                           negprot_spnego_blob.length - 16);
 304 #else
 305         /* for now we want raw NTLMSSP */
 306         security_buffer = data_blob_const(NULL, 0);
 307 #endif
 308
 309         out_guid_blob = data_blob_const(negprot_spnego_blob.data, 16);
 310         status = GUID_from_ndr_blob(&out_guid_blob, &out_guid);
 311         if (!NT_STATUS_IS_OK(status)) {
 312                 return smbd_smb2_request_error(req, status);
 313         }
 314
 315         outbody = data_blob_talloc(req->out.vector, NULL, 0x40);
 316         if (outbody.data == NULL) {
 317                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 318         }
 319
 320         SSVAL(outbody.data, 0x00, 0x40 + 1);    /* struct size */
 321         SSVAL(outbody.data, 0x02,
 322               security_mode);                   /* security mode */
 323         SSVAL(outbody.data, 0x04, dialect);     /* dialect revision */
 324         SSVAL(outbody.data, 0x06, 0);           /* reserved */
 325         memcpy(outbody.data + 0x08,
 326                out_guid_blob.data, 16); /* server guid */
 327         SIVAL(outbody.data, 0x18,
 328               capabilities);                    /* capabilities */
 329         SIVAL(outbody.data, 0x1C, max_trans);   /* max transact size */
 330         SIVAL(outbody.data, 0x20, max_read);    /* max read size */
 331         SIVAL(outbody.data, 0x24, max_write);   /* max write size */
 332         SBVAL(outbody.data, 0x28, now);         /* system time */
 333         SBVAL(outbody.data, 0x30, 0);           /* server start time */
 334         SSVAL(outbody.data, 0x38,
 335               security_offset);                 /* security buffer offset */
 336         SSVAL(outbody.data, 0x3A,
 337               security_buffer.length);          /* security buffer length */
 338         SIVAL(outbody.data, 0x3C, 0);           /* reserved */
 339
 340         outdyn = security_buffer;
 341
 342         req->sconn->using_smb2 = true;
 343
 344         if (dialect != SMB2_DIALECT_REVISION_2FF) {
 345                 struct smbXsrv_connection *conn = req->sconn->conn;
 346
 347                 status = smbXsrv_connection_init_tables(conn, protocol);
 348                 if (!NT_STATUS_IS_OK(status)) {
 349                         return smbd_smb2_request_error(req, status);
 350                 }
 351
 352                 conn->smb2.client.capabilities = in_capabilities;
 353                 conn->smb2.client.security_mode = in_security_mode;
 354                 conn->smb2.client.guid = in_guid;
 355                 conn->smb2.client.num_dialects = dialect_count;
 356                 conn->smb2.client.dialects = talloc_array(conn,
 357                                                           uint16_t,
 358                                                           dialect_count);
 359                 if (conn->smb2.client.dialects == NULL) {
 360                         return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 361                 }
 362                 for (c=0; c < dialect_count; c++) {
 363                         conn->smb2.client.dialects[c] = SVAL(indyn, c*2);
 364                 }
 365
 366                 conn->smb2.server.capabilities = capabilities;
 367                 conn->smb2.server.security_mode = security_mode;
 368                 conn->smb2.server.guid = out_guid;
 369                 conn->smb2.server.dialect = dialect;
 370                 conn->smb2.server.max_trans = max_trans;
 371                 conn->smb2.server.max_read  = max_read;
 372                 conn->smb2.server.max_write = max_write;
 373
 374                 req->sconn->smb2.max_trans = max_trans;
 375                 req->sconn->smb2.max_read  = max_read;
 376                 req->sconn->smb2.max_write = max_write;
 377         }
 378
 379         return smbd_smb2_request_done(req, outbody, &outdyn);
 380 }