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_inpdu;
  37         uint8_t *smb2_hdr;
  38         uint8_t *smb2_body;
  39         uint8_t *smb2_dyn;
  40         size_t len = SMB2_HDR_BODY + 0x24 + 2;
  41
  42         smb2_inpdu = talloc_zero_array(talloc_tos(), uint8_t, len);
  43         if (smb2_inpdu == 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_inpdu;
  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_inpdu, 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->xconn;
  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         struct {
  91                 enum protocol_types proto;
  92                 uint16_t dialect;
  93         } pd[] = {
  94                 { PROTOCOL_SMB3_00, SMB3_DIALECT_REVISION_300 },
  95                 { PROTOCOL_SMB2_24, SMB2_DIALECT_REVISION_224 },
  96                 { PROTOCOL_SMB2_22, SMB2_DIALECT_REVISION_222 },
  97                 { PROTOCOL_SMB2_10, SMB2_DIALECT_REVISION_210 },
  98                 { PROTOCOL_SMB2_02, SMB2_DIALECT_REVISION_202 },
  99         };
 100         size_t i;
 101
 102         for (i = 0; i < ARRAY_SIZE(pd); i ++) {
 103                 size_t c = 0;
 104
 105                 if (lp_server_max_protocol() < pd[i].proto) {
 106                         continue;
 107                 }
 108                 if (lp_server_min_protocol() > pd[i].proto) {
 109                         continue;
 110                 }
 111
 112                 for (c = 0; c < dialect_count; c++) {
 113                         *dialect = SVAL(indyn, c*2);
 114                         if (*dialect == pd[i].dialect) {
 115                                 return pd[i].proto;
 116                         }
 117                 }
 118         }
 119
 120         return PROTOCOL_NONE;
 121 }
 122
 123 NTSTATUS smbd_smb2_request_process_negprot(struct smbd_smb2_request *req)
 124 {
 125         struct smbXsrv_connection *xconn = req->xconn;
 126         NTSTATUS status;
 127         const uint8_t *inbody;
 128         const uint8_t *indyn = NULL;
 129         DATA_BLOB outbody;
 130         DATA_BLOB outdyn;
 131         DATA_BLOB negprot_spnego_blob;
 132         uint16_t security_offset;
 133         DATA_BLOB security_buffer;
 134         size_t expected_dyn_size = 0;
 135         size_t c;
 136         uint16_t security_mode;
 137         uint16_t dialect_count;
 138         uint16_t in_security_mode;
 139         uint32_t in_capabilities;
 140         DATA_BLOB in_guid_blob;
 141         struct GUID in_guid;
 142         uint16_t dialect = 0;
 143         uint32_t capabilities;
 144         DATA_BLOB out_guid_blob;
 145         struct GUID out_guid;
 146         enum protocol_types protocol = PROTOCOL_NONE;
 147         uint32_t max_limit;
 148         uint32_t max_trans = lp_smb2_max_trans();
 149         uint32_t max_read = lp_smb2_max_read();
 150         uint32_t max_write = lp_smb2_max_write();
 151         NTTIME now = timeval_to_nttime(&req->request_time);
 152
 153         status = smbd_smb2_request_verify_sizes(req, 0x24);
 154         if (!NT_STATUS_IS_OK(status)) {
 155                 return smbd_smb2_request_error(req, status);
 156         }
 157         inbody = SMBD_SMB2_IN_BODY_PTR(req);
 158
 159         dialect_count = SVAL(inbody, 0x02);
 160
 161         in_security_mode = SVAL(inbody, 0x04);
 162         in_capabilities = IVAL(inbody, 0x08);
 163         in_guid_blob = data_blob_const(inbody + 0x0C, 16);
 164
 165         if (dialect_count == 0) {
 166                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
 167         }
 168
 169         status = GUID_from_ndr_blob(&in_guid_blob, &in_guid);
 170         if (!NT_STATUS_IS_OK(status)) {
 171                 return smbd_smb2_request_error(req, status);
 172         }
 173
 174         expected_dyn_size = dialect_count * 2;
 175         if (SMBD_SMB2_IN_DYN_LEN(req) < expected_dyn_size) {
 176                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
 177         }
 178         indyn = SMBD_SMB2_IN_DYN_PTR(req);
 179
 180         protocol = smbd_smb2_protocol_dialect_match(indyn,
 181                                         dialect_count,
 182                                         &dialect);
 183
 184         for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
 185                 if (lp_server_max_protocol() < PROTOCOL_SMB2_10) {
 186                         break;
 187                 }
 188
 189                 dialect = SVAL(indyn, c*2);
 190                 if (dialect == SMB2_DIALECT_REVISION_2FF) {
 191                         if (xconn->smb2.allow_2ff) {
 192                                 xconn->smb2.allow_2ff = false;
 193                                 protocol = PROTOCOL_SMB2_10;
 194                                 break;
 195                         }
 196                 }
 197         }
 198
 199         if (protocol == PROTOCOL_NONE) {
 200                 return smbd_smb2_request_error(req, NT_STATUS_NOT_SUPPORTED);
 201         }
 202
 203         if (get_remote_arch() != RA_SAMBA) {
 204                 set_remote_arch(RA_VISTA);
 205         }
 206
 207         fstr_sprintf(remote_proto, "SMB%X_%02X",
 208                      (dialect >> 8) & 0xFF, dialect & 0xFF);
 209
 210         reload_services(req->sconn, conn_snum_used, true);
 211         DEBUG(3,("Selected protocol %s\n", remote_proto));
 212
 213         /* negprot_spnego() returns a the server guid in the first 16 bytes */
 214         negprot_spnego_blob = negprot_spnego(req, xconn);
 215         if (negprot_spnego_blob.data == NULL) {
 216                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 217         }
 218
 219         if (negprot_spnego_blob.length < 16) {
 220                 return smbd_smb2_request_error(req, NT_STATUS_INTERNAL_ERROR);
 221         }
 222
 223         security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED;
 224         if (lp_server_signing() == SMB_SIGNING_REQUIRED) {
 225                 security_mode |= SMB2_NEGOTIATE_SIGNING_REQUIRED;
 226         }
 227
 228         capabilities = 0;
 229         if (lp_host_msdfs()) {
 230                 capabilities |= SMB2_CAP_DFS;
 231         }
 232
 233         if (protocol >= PROTOCOL_SMB2_10 &&
 234             lp_smb2_leases() &&
 235             lp_oplocks(GLOBAL_SECTION_SNUM) &&
 236             !lp_kernel_oplocks(GLOBAL_SECTION_SNUM))
 237         {
 238                 capabilities |= SMB2_CAP_LEASING;
 239         }
 240
 241         if ((protocol >= PROTOCOL_SMB2_24) &&
 242             (lp_smb_encrypt(-1) != SMB_SIGNING_OFF) &&
 243             (in_capabilities & SMB2_CAP_ENCRYPTION)) {
 244                 capabilities |= SMB2_CAP_ENCRYPTION;
 245         }
 246
 247         /*
 248          * 0x10000 (65536) is the maximum allowed message size
 249          * for SMB 2.0
 250          */
 251         max_limit = 0x10000;
 252
 253         if (protocol >= PROTOCOL_SMB2_10) {
 254                 int p = 0;
 255
 256                 if (tsocket_address_is_inet(req->sconn->local_address, "ip")) {
 257                         p = tsocket_address_inet_port(req->sconn->local_address);
 258                 }
 259
 260                 /* largeMTU is not supported over NBT (tcp port 139) */
 261                 if (p != NBT_SMB_PORT) {
 262                         capabilities |= SMB2_CAP_LARGE_MTU;
 263                         xconn->smb2.credits.multicredit = true;
 264
 265                         /*
 266                          * We allow up to allmost 16MB.
 267                          *
 268                          * The maximum PDU size is 0xFFFFFF (16776960)
 269                          * and we need some space for the header.
 270                          */
 271                         max_limit = 0xFFFF00;
 272                 }
 273         }
 274
 275         /*
 276          * the defaults are 8MB, but we'll limit this to max_limit based on
 277          * the dialect (64kb for SMB 2.0, 8MB for SMB >= 2.1 with LargeMTU)
 278          *
 279          * user configured values exceeding the limits will be overwritten,
 280          * only smaller values will be accepted
 281          */
 282
 283         max_trans = MIN(max_limit, lp_smb2_max_trans());
 284         max_read = MIN(max_limit, lp_smb2_max_read());
 285         max_write = MIN(max_limit, lp_smb2_max_write());
 286
 287         if (capabilities & SMB2_CAP_ENCRYPTION) {
 288                 xconn->smb2.server.cipher = SMB2_ENCRYPTION_AES128_CCM;
 289         }
 290
 291         security_offset = SMB2_HDR_BODY + 0x40;
 292
 293 #if 1
 294         /* Try SPNEGO auth... */
 295         security_buffer = data_blob_const(negprot_spnego_blob.data + 16,
 296                                           negprot_spnego_blob.length - 16);
 297 #else
 298         /* for now we want raw NTLMSSP */
 299         security_buffer = data_blob_const(NULL, 0);
 300 #endif
 301
 302         out_guid_blob = data_blob_const(negprot_spnego_blob.data, 16);
 303         status = GUID_from_ndr_blob(&out_guid_blob, &out_guid);
 304         if (!NT_STATUS_IS_OK(status)) {
 305                 return smbd_smb2_request_error(req, status);
 306         }
 307
 308         outbody = smbd_smb2_generate_outbody(req, 0x40);
 309         if (outbody.data == NULL) {
 310                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 311         }
 312
 313         SSVAL(outbody.data, 0x00, 0x40 + 1);    /* struct size */
 314         SSVAL(outbody.data, 0x02,
 315               security_mode);                   /* security mode */
 316         SSVAL(outbody.data, 0x04, dialect);     /* dialect revision */
 317         SSVAL(outbody.data, 0x06, 0);           /* reserved */
 318         memcpy(outbody.data + 0x08,
 319                out_guid_blob.data, 16); /* server guid */
 320         SIVAL(outbody.data, 0x18,
 321               capabilities);                    /* capabilities */
 322         SIVAL(outbody.data, 0x1C, max_trans);   /* max transact size */
 323         SIVAL(outbody.data, 0x20, max_read);    /* max read size */
 324         SIVAL(outbody.data, 0x24, max_write);   /* max write size */
 325         SBVAL(outbody.data, 0x28, now);         /* system time */
 326         SBVAL(outbody.data, 0x30, 0);           /* server start time */
 327         SSVAL(outbody.data, 0x38,
 328               security_offset);                 /* security buffer offset */
 329         SSVAL(outbody.data, 0x3A,
 330               security_buffer.length);          /* security buffer length */
 331         SIVAL(outbody.data, 0x3C, 0);           /* reserved */
 332
 333         outdyn = security_buffer;
 334
 335         req->sconn->using_smb2 = true;
 336
 337         if (dialect != SMB2_DIALECT_REVISION_2FF) {
 338                 status = smbXsrv_connection_init_tables(xconn, protocol);
 339                 if (!NT_STATUS_IS_OK(status)) {
 340                         return smbd_smb2_request_error(req, status);
 341                 }
 342
 343                 xconn->smb2.client.capabilities = in_capabilities;
 344                 xconn->smb2.client.security_mode = in_security_mode;
 345                 xconn->smb2.client.guid = in_guid;
 346                 xconn->smb2.client.num_dialects = dialect_count;
 347                 xconn->smb2.client.dialects = talloc_array(xconn,
 348                                                            uint16_t,
 349                                                            dialect_count);
 350                 if (xconn->smb2.client.dialects == NULL) {
 351                         return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 352                 }
 353                 for (c=0; c < dialect_count; c++) {
 354                         xconn->smb2.client.dialects[c] = SVAL(indyn, c*2);
 355                 }
 356
 357                 xconn->smb2.server.capabilities = capabilities;
 358                 xconn->smb2.server.security_mode = security_mode;
 359                 xconn->smb2.server.guid = out_guid;
 360                 xconn->smb2.server.dialect = dialect;
 361                 xconn->smb2.server.max_trans = max_trans;
 362                 xconn->smb2.server.max_read  = max_read;
 363                 xconn->smb2.server.max_write = max_write;
 364         }
 365
 366         return smbd_smb2_request_done(req, outbody, &outdyn);
 367 }