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 NTSTATUS smbd_smb2_request_process_negprot(struct smbd_smb2_request *req)
  86 {
  87         NTSTATUS status;
  88         const uint8_t *inbody;
  89         const uint8_t *indyn = NULL;
  90         DATA_BLOB outbody;
  91         DATA_BLOB outdyn;
  92         DATA_BLOB negprot_spnego_blob;
  93         uint16_t security_offset;
  94         DATA_BLOB security_buffer;
  95         size_t expected_dyn_size = 0;
  96         size_t c;
  97         uint16_t security_mode;
  98         uint16_t dialect_count;
  99         uint16_t in_security_mode;
 100         uint32_t in_capabilities;
 101         DATA_BLOB in_guid_blob;
 102         struct GUID in_guid;
 103         uint16_t dialect = 0;
 104         uint32_t capabilities;
 105         DATA_BLOB out_guid_blob;
 106         struct GUID out_guid;
 107         enum protocol_types protocol = PROTOCOL_NONE;
 108         uint32_t max_limit;
 109         uint32_t max_trans = lp_smb2_max_trans();
 110         uint32_t max_read = lp_smb2_max_read();
 111         uint32_t max_write = lp_smb2_max_write();
 112         NTTIME now = timeval_to_nttime(&req->request_time);
 113
 114         status = smbd_smb2_request_verify_sizes(req, 0x24);
 115         if (!NT_STATUS_IS_OK(status)) {
 116                 return smbd_smb2_request_error(req, status);
 117         }
 118         inbody = SMBD_SMB2_IN_BODY_PTR(req);
 119
 120         dialect_count = SVAL(inbody, 0x02);
 121
 122         in_security_mode = SVAL(inbody, 0x04);
 123         in_capabilities = IVAL(inbody, 0x08);
 124         in_guid_blob = data_blob_const(inbody + 0x0C, 16);
 125
 126         if (dialect_count == 0) {
 127                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
 128         }
 129
 130         status = GUID_from_ndr_blob(&in_guid_blob, &in_guid);
 131         if (!NT_STATUS_IS_OK(status)) {
 132                 return smbd_smb2_request_error(req, status);
 133         }
 134
 135         expected_dyn_size = dialect_count * 2;
 136         if (SMBD_SMB2_IN_DYN_LEN(req) < expected_dyn_size) {
 137                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
 138         }
 139         indyn = SMBD_SMB2_IN_DYN_PTR(req);
 140
 141         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 142                 if (lp_server_max_protocol() < PROTOCOL_SMB3_00) {
 143                         break;
 144                 }
 145                 if (lp_server_min_protocol() > PROTOCOL_SMB3_00) {
 146                         break;
 147                 }
 148
 149                 dialect = SVAL(indyn, c*2);
 150                 if (dialect == SMB3_DIALECT_REVISION_300) {
 151                         protocol = PROTOCOL_SMB3_00;
 152                         break;
 153                 }
 154         }
 155
 156         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 157                 if (lp_server_max_protocol() < PROTOCOL_SMB2_24) {
 158                         break;
 159                 }
 160                 if (lp_server_min_protocol() > PROTOCOL_SMB2_24) {
 161                         break;
 162                 }
 163
 164                 dialect = SVAL(indyn, c*2);
 165                 if (dialect == SMB2_DIALECT_REVISION_224) {
 166                         protocol = PROTOCOL_SMB2_24;
 167                         break;
 168                 }
 169         }
 170
 171         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 172                 if (lp_server_max_protocol() < PROTOCOL_SMB2_22) {
 173                         break;
 174                 }
 175                 if (lp_server_min_protocol() > PROTOCOL_SMB2_22) {
 176                         break;
 177                 }
 178
 179                 dialect = SVAL(indyn, c*2);
 180                 if (dialect == SMB2_DIALECT_REVISION_222) {
 181                         protocol = PROTOCOL_SMB2_22;
 182                         break;
 183                 }
 184         }
 185
 186         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 187                 if (lp_server_max_protocol() < PROTOCOL_SMB2_10) {
 188                         break;
 189                 }
 190                 if (lp_server_min_protocol() > PROTOCOL_SMB2_10) {
 191                         break;
 192                 }
 193
 194                 dialect = SVAL(indyn, c*2);
 195                 if (dialect == SMB2_DIALECT_REVISION_210) {
 196                         protocol = PROTOCOL_SMB2_10;
 197                         break;
 198                 }
 199         }
 200
 201         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 202                 if (lp_server_max_protocol() < PROTOCOL_SMB2_02) {
 203                         break;
 204                 }
 205                 if (lp_server_min_protocol() > PROTOCOL_SMB2_02) {
 206                         break;
 207                 }
 208
 209                 dialect = SVAL(indyn, c*2);
 210                 if (dialect == SMB2_DIALECT_REVISION_202) {
 211                         protocol = PROTOCOL_SMB2_02;
 212                         break;
 213                 }
 214         }
 215
 216         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 217                 if (lp_server_max_protocol() < PROTOCOL_SMB2_10) {
 218                         break;
 219                 }
 220
 221                 dialect = SVAL(indyn, c*2);
 222                 if (dialect == SMB2_DIALECT_REVISION_2FF) {
 223                         if (req->sconn->smb2.negprot_2ff) {
 224                                 req->sconn->smb2.negprot_2ff = false;
 225                                 protocol = PROTOCOL_SMB2_10;
 226                                 break;
 227                         }
 228                 }
 229         }
 230
 231         if (protocol == PROTOCOL_NONE) {
 232                 return smbd_smb2_request_error(req, NT_STATUS_NOT_SUPPORTED);
 233         }
 234
 235         if (get_remote_arch() != RA_SAMBA) {
 236                 set_remote_arch(RA_VISTA);
 237         }
 238
 239         fstr_sprintf(remote_proto, "SMB%X_%02X",
 240                      (dialect >> 8) & 0xFF, dialect & 0xFF);
 241
 242         reload_services(req->sconn, conn_snum_used, true);
 243         DEBUG(3,("Selected protocol %s\n", remote_proto));
 244
 245         /* negprot_spnego() returns a the server guid in the first 16 bytes */
 246         negprot_spnego_blob = negprot_spnego(req, req->sconn);
 247         if (negprot_spnego_blob.data == NULL) {
 248                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 249         }
 250
 251         if (negprot_spnego_blob.length < 16) {
 252                 return smbd_smb2_request_error(req, NT_STATUS_INTERNAL_ERROR);
 253         }
 254
 255         security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED;
 256         if (lp_server_signing() == SMB_SIGNING_REQUIRED) {
 257                 security_mode |= SMB2_NEGOTIATE_SIGNING_REQUIRED;
 258         }
 259
 260         capabilities = 0;
 261         if (lp_host_msdfs()) {
 262                 capabilities |= SMB2_CAP_DFS;
 263         }
 264
 265         if ((protocol >= PROTOCOL_SMB2_24) &&
 266             (lp_smb_encrypt(-1) != SMB_SIGNING_OFF) &&
 267             (in_capabilities & SMB2_CAP_ENCRYPTION)) {
 268                 capabilities |= SMB2_CAP_ENCRYPTION;
 269         }
 270
 271         /*
 272          * 0x10000 (65536) is the maximum allowed message size
 273          * for SMB 2.0
 274          */
 275         max_limit = 0x10000;
 276
 277         if (protocol >= PROTOCOL_SMB2_10) {
 278                 int p = 0;
 279
 280                 if (tsocket_address_is_inet(req->sconn->local_address, "ip")) {
 281                         p = tsocket_address_inet_port(req->sconn->local_address);
 282                 }
 283
 284                 /* largeMTU is not supported over NBT (tcp port 139) */
 285                 if (p != NBT_SMB_PORT) {
 286                         capabilities |= SMB2_CAP_LARGE_MTU;
 287                         req->sconn->smb2.supports_multicredit = true;
 288
 289                         /* SMB >= 2.1 has 1 MB of allowed size */
 290                         max_limit = 0x100000; /* 1MB */
 291                 }
 292         }
 293
 294         /*
 295          * the defaults are 1MB, but we'll limit this to max_limit based on
 296          * the dialect (64kb for SMB2.0, 1MB for SMB2.1 with LargeMTU)
 297          *
 298          * user configured values exceeding the limits will be overwritten,
 299          * only smaller values will be accepted
 300          */
 301
 302         max_trans = MIN(max_limit, lp_smb2_max_trans());
 303         max_read = MIN(max_limit, lp_smb2_max_read());
 304         max_write = MIN(max_limit, lp_smb2_max_write());
 305
 306         security_offset = SMB2_HDR_BODY + 0x40;
 307
 308 #if 1
 309         /* Try SPNEGO auth... */
 310         security_buffer = data_blob_const(negprot_spnego_blob.data + 16,
 311                                           negprot_spnego_blob.length - 16);
 312 #else
 313         /* for now we want raw NTLMSSP */
 314         security_buffer = data_blob_const(NULL, 0);
 315 #endif
 316
 317         out_guid_blob = data_blob_const(negprot_spnego_blob.data, 16);
 318         status = GUID_from_ndr_blob(&out_guid_blob, &out_guid);
 319         if (!NT_STATUS_IS_OK(status)) {
 320                 return smbd_smb2_request_error(req, status);
 321         }
 322
 323         outbody = smbd_smb2_generate_outbody(req, 0x40);
 324         if (outbody.data == NULL) {
 325                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 326         }
 327
 328         SSVAL(outbody.data, 0x00, 0x40 + 1);    /* struct size */
 329         SSVAL(outbody.data, 0x02,
 330               security_mode);                   /* security mode */
 331         SSVAL(outbody.data, 0x04, dialect);     /* dialect revision */
 332         SSVAL(outbody.data, 0x06, 0);           /* reserved */
 333         memcpy(outbody.data + 0x08,
 334                out_guid_blob.data, 16); /* server guid */
 335         SIVAL(outbody.data, 0x18,
 336               capabilities);                    /* capabilities */
 337         SIVAL(outbody.data, 0x1C, max_trans);   /* max transact size */
 338         SIVAL(outbody.data, 0x20, max_read);    /* max read size */
 339         SIVAL(outbody.data, 0x24, max_write);   /* max write size */
 340         SBVAL(outbody.data, 0x28, now);         /* system time */
 341         SBVAL(outbody.data, 0x30, 0);           /* server start time */
 342         SSVAL(outbody.data, 0x38,
 343               security_offset);                 /* security buffer offset */
 344         SSVAL(outbody.data, 0x3A,
 345               security_buffer.length);          /* security buffer length */
 346         SIVAL(outbody.data, 0x3C, 0);           /* reserved */
 347
 348         outdyn = security_buffer;
 349
 350         req->sconn->using_smb2 = true;
 351
 352         if (dialect != SMB2_DIALECT_REVISION_2FF) {
 353                 struct smbXsrv_connection *conn = req->sconn->conn;
 354
 355                 status = smbXsrv_connection_init_tables(conn, protocol);
 356                 if (!NT_STATUS_IS_OK(status)) {
 357                         return smbd_smb2_request_error(req, status);
 358                 }
 359
 360                 conn->smb2.client.capabilities = in_capabilities;
 361                 conn->smb2.client.security_mode = in_security_mode;
 362                 conn->smb2.client.guid = in_guid;
 363                 conn->smb2.client.num_dialects = dialect_count;
 364                 conn->smb2.client.dialects = talloc_array(conn,
 365                                                           uint16_t,
 366                                                           dialect_count);
 367                 if (conn->smb2.client.dialects == NULL) {
 368                         return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 369                 }
 370                 for (c=0; c < dialect_count; c++) {
 371                         conn->smb2.client.dialects[c] = SVAL(indyn, c*2);
 372                 }
 373
 374                 conn->smb2.server.capabilities = capabilities;
 375                 conn->smb2.server.security_mode = security_mode;
 376                 conn->smb2.server.guid = out_guid;
 377                 conn->smb2.server.dialect = dialect;
 378                 conn->smb2.server.max_trans = max_trans;
 379                 conn->smb2.server.max_read  = max_read;
 380                 conn->smb2.server.max_write = max_write;
 381
 382                 req->sconn->smb2.max_trans = max_trans;
 383                 req->sconn->smb2.max_read  = max_read;
 384                 req->sconn->smb2.max_write = max_write;
 385         }
 386
 387         return smbd_smb2_request_done(req, outbody, &outdyn);
 388 }