source4/smb_server/smb2/negprot.c

   1 /*
   2    Unix SMB2 implementation.
   3
   4    Copyright (C) Andrew Bartlett        2001-2005
   5    Copyright (C) Stefan Metzmacher      2005
   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 "auth/credentials/credentials.h"
  23 #include "auth/auth.h"
  24 #include "auth/gensec/gensec.h"
  25 #include "libcli/raw/libcliraw.h"
  26 #include "libcli/raw/raw_proto.h"
  27 #include "libcli/smb2/smb2.h"
  28 #include "libcli/smb2/smb2_calls.h"
  29 #include "smb_server/smb_server.h"
  30 #include "smb_server/service_smb_proto.h"
  31 #include "smb_server/smb2/smb2_server.h"
  32 #include "smbd/service_stream.h"
  33 #include "param/param.h"
  34 #include "librpc/ndr/libndr.h"
  35
  36 static NTSTATUS smb2srv_negprot_secblob(struct smb2srv_request *req, DATA_BLOB *_blob)
  37 {
  38         struct gensec_security *gensec_security;
  39         DATA_BLOB null_data_blob = data_blob(NULL, 0);
  40         DATA_BLOB blob;
  41         NTSTATUS nt_status;
  42         struct cli_credentials *server_credentials;
  43
  44         server_credentials = cli_credentials_init(req);
  45         if (!server_credentials) {
  46                 smbsrv_terminate_connection(req->smb_conn, "Failed to init server credentials\n");
  47                 return NT_STATUS_NO_MEMORY;
  48         }
  49
  50         cli_credentials_set_conf(server_credentials, req->smb_conn->lp_ctx);
  51         nt_status = cli_credentials_set_machine_account(server_credentials, req->smb_conn->lp_ctx);
  52         if (!NT_STATUS_IS_OK(nt_status)) {
  53                 DEBUG(10, ("Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(nt_status)));
  54                 talloc_free(server_credentials);
  55                 server_credentials = NULL;
  56         }
  57
  58         req->smb_conn->negotiate.server_credentials = talloc_steal(req->smb_conn, server_credentials);
  59
  60         nt_status = samba_server_gensec_start(req,
  61                                               req->smb_conn->connection->event.ctx,
  62                                               req->smb_conn->connection->msg_ctx,
  63                                               req->smb_conn->lp_ctx,
  64                                               server_credentials,
  65                                               "cifs",
  66                                               &gensec_security);
  67         if (!NT_STATUS_IS_OK(nt_status)) {
  68                 DEBUG(0, ("Failed to start GENSEC: %s\n", nt_errstr(nt_status)));
  69                 smbsrv_terminate_connection(req->smb_conn, "Failed to start GENSEC\n");
  70                 return nt_status;
  71         }
  72
  73         gensec_set_target_service(gensec_security, "cifs");
  74
  75         gensec_set_credentials(gensec_security, server_credentials);
  76
  77         nt_status = gensec_start_mech_by_oid(gensec_security, GENSEC_OID_SPNEGO);
  78         if (!NT_STATUS_IS_OK(nt_status)) {
  79                 DEBUG(0, ("Failed to start SPNEGO: %s\n", nt_errstr(nt_status)));
  80                 smbsrv_terminate_connection(req->smb_conn, "Failed to start SPNEGO\n");
  81                 return nt_status;
  82         }
  83
  84         nt_status = gensec_update(gensec_security, req, null_data_blob, &blob);
  85         if (!NT_STATUS_IS_OK(nt_status) && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
  86                 DEBUG(0, ("Failed to get SPNEGO to give us the first token: %s\n", nt_errstr(nt_status)));
  87                 smbsrv_terminate_connection(req->smb_conn, "Failed to start SPNEGO - no first token\n");
  88                 return nt_status;
  89         }
  90
  91         *_blob = blob;
  92         return NT_STATUS_OK;
  93 }
  94
  95 static NTSTATUS smb2srv_negprot_backend(struct smb2srv_request *req, struct smb2_negprot *io)
  96 {
  97         NTSTATUS status;
  98         struct timeval current_time;
  99         struct timeval boot_time;
 100         uint16_t i;
 101         uint16_t dialect = 0;
 102
 103         /* we only do one dialect for now */
 104         if (io->in.dialect_count < 1) {
 105                 return NT_STATUS_NOT_SUPPORTED;
 106         }
 107         for (i=0; i < io->in.dialect_count; i++) {
 108                 dialect = io->in.dialects[i];
 109                 if (dialect == SMB2_DIALECT_REVISION_202) {
 110                         break;
 111                 }
 112         }
 113         if (dialect != SMB2_DIALECT_REVISION_202) {
 114                 DEBUG(0,("Got unexpected SMB2 dialect %u\n", dialect));
 115                 return NT_STATUS_NOT_SUPPORTED;
 116         }
 117
 118         req->smb_conn->negotiate.protocol = PROTOCOL_SMB2;
 119
 120         current_time = timeval_current(); /* TODO: handle timezone?! */
 121         boot_time = timeval_current(); /* TODO: fix me */
 122
 123         ZERO_STRUCT(io->out);
 124         switch (lp_server_signing(req->smb_conn->lp_ctx)) {
 125         case SMB_SIGNING_OFF:
 126                 io->out.security_mode = 0;
 127                 break;
 128         case SMB_SIGNING_SUPPORTED:
 129         case SMB_SIGNING_AUTO:
 130                 io->out.security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED;
 131                 break;
 132         case SMB_SIGNING_REQUIRED:
 133                 io->out.security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED | SMB2_NEGOTIATE_SIGNING_REQUIRED;
 134                 /* force signing on immediately */
 135                 req->smb_conn->smb2_signing_required = true;
 136                 break;
 137         }
 138         io->out.dialect_revision   = dialect;
 139         io->out.capabilities       = 0;
 140         io->out.max_transact_size  = lp_parm_ulong(req->smb_conn->lp_ctx, NULL,
 141                                                    "smb2", "max transaction size", 0x10000);
 142         io->out.max_read_size      = lp_parm_ulong(req->smb_conn->lp_ctx, NULL,
 143                                                    "smb2", "max read size", 0x10000);
 144         io->out.max_write_size     = lp_parm_ulong(req->smb_conn->lp_ctx, NULL,
 145                                                    "smb2", "max write size", 0x10000);
 146         io->out.system_time        = timeval_to_nttime(&current_time);
 147         io->out.server_start_time  = timeval_to_nttime(&boot_time);
 148         io->out.reserved2          = 0;
 149         status = smb2srv_negprot_secblob(req, &io->out.secblob);
 150         NT_STATUS_NOT_OK_RETURN(status);
 151
 152         return NT_STATUS_OK;
 153 }
 154
 155 static void smb2srv_negprot_send(struct smb2srv_request *req, struct smb2_negprot *io)
 156 {
 157         NTSTATUS status;
 158         enum ndr_err_code ndr_err;
 159
 160         if (NT_STATUS_IS_ERR(req->status)) {
 161                 smb2srv_send_error(req, req->status); /* TODO: is this correct? */
 162                 return;
 163         }
 164
 165         status = smb2srv_setup_reply(req, 0x40, true, io->out.secblob.length);
 166         if (!NT_STATUS_IS_OK(status)) {
 167                 smbsrv_terminate_connection(req->smb_conn, nt_errstr(status));
 168                 talloc_free(req);
 169                 return;
 170         }
 171
 172         SSVAL(req->out.body, 0x02, io->out.security_mode);
 173         SIVAL(req->out.body, 0x04, io->out.dialect_revision);
 174         SIVAL(req->out.body, 0x06, io->out.reserved);
 175         ndr_err = smbcli_push_guid(req->out.body, 0x08, &io->out.server_guid);
 176         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 177                 smbsrv_terminate_connection(req->smb_conn, nt_errstr(status));
 178                 talloc_free(req);
 179                 return;
 180         }
 181         SIVAL(req->out.body, 0x18, io->out.capabilities);
 182         SIVAL(req->out.body, 0x1C, io->out.max_transact_size);
 183         SIVAL(req->out.body, 0x20, io->out.max_read_size);
 184         SIVAL(req->out.body, 0x24, io->out.max_write_size);
 185         push_nttime(req->out.body, 0x28, io->out.system_time);
 186         push_nttime(req->out.body, 0x30, io->out.server_start_time);
 187         SIVAL(req->out.body, 0x3C, io->out.reserved2);
 188         status = smb2_push_o16s16_blob(&req->out, 0x38, io->out.secblob);
 189         if (!NT_STATUS_IS_OK(status)) {
 190                 smbsrv_terminate_connection(req->smb_conn, nt_errstr(status));
 191                 talloc_free(req);
 192                 return;
 193         }
 194
 195         smb2srv_send_reply(req);
 196 }
 197
 198 void smb2srv_negprot_recv(struct smb2srv_request *req)
 199 {
 200         struct smb2_negprot *io;
 201         int i;
 202         enum ndr_err_code ndr_err;
 203
 204         if (req->in.body_size < 0x26) {
 205                 smbsrv_terminate_connection(req->smb_conn, "Bad body size in SMB2 negprot");
 206                 return;
 207         }
 208
 209         io = talloc(req, struct smb2_negprot);
 210         if (!io) {
 211                 smbsrv_terminate_connection(req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY));
 212                 talloc_free(req);
 213                 return;
 214         }
 215
 216         io->in.dialect_count = SVAL(req->in.body, 0x02);
 217         io->in.security_mode = SVAL(req->in.body, 0x04);
 218         io->in.reserved      = SVAL(req->in.body, 0x06);
 219         io->in.capabilities  = IVAL(req->in.body, 0x08);
 220         ndr_err = smbcli_pull_guid(req->in.body, 0xC, &io->in.client_guid);
 221         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 222                 smbsrv_terminate_connection(req->smb_conn, "Bad GUID in SMB2 negprot");
 223                 talloc_free(req);
 224                 return;
 225         }
 226         io->in.start_time = smbcli_pull_nttime(req->in.body, 0x1C);
 227
 228         io->in.dialects = talloc_array(req, uint16_t, io->in.dialect_count);
 229         if (io->in.dialects == NULL) {
 230                 smbsrv_terminate_connection(req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY));
 231                 talloc_free(req);
 232                 return;
 233         }
 234         for (i=0;i<io->in.dialect_count;i++) {
 235                 io->in.dialects[i] = SVAL(req->in.body, 0x24+i*2);
 236         }
 237
 238         req->status = smb2srv_negprot_backend(req, io);
 239
 240         if (req->control_flags & SMB2SRV_REQ_CTRL_FLAG_NOT_REPLY) {
 241                 talloc_free(req);
 242                 return;
 243         }
 244         smb2srv_negprot_send(req, io);
 245 }
 246
 247 /*
 248  * reply to a SMB negprot request with dialect "SMB 2.002"
 249  */
 250 void smb2srv_reply_smb_negprot(struct smbsrv_request *smb_req)
 251 {
 252         struct smb2srv_request *req;
 253         uint32_t body_fixed_size = 0x26;
 254
 255         req = talloc_zero(smb_req->smb_conn, struct smb2srv_request);
 256         if (!req) goto nomem;
 257         req->smb_conn           = smb_req->smb_conn;
 258         req->request_time       = smb_req->request_time;
 259         talloc_steal(req, smb_req);
 260
 261         req->in.size      = NBT_HDR_SIZE+SMB2_HDR_BODY+body_fixed_size;
 262         req->in.allocated = req->in.size;
 263         req->in.buffer    = talloc_array(req, uint8_t, req->in.allocated);
 264         if (!req->in.buffer) goto nomem;
 265         req->in.hdr       = req->in.buffer + NBT_HDR_SIZE;
 266         req->in.body      = req->in.hdr + SMB2_HDR_BODY;
 267         req->in.body_size = body_fixed_size;
 268         req->in.dynamic   = NULL;
 269
 270         smb2srv_setup_bufinfo(req);
 271
 272         SIVAL(req->in.hdr, 0,                           SMB2_MAGIC);
 273         SSVAL(req->in.hdr, SMB2_HDR_LENGTH,             SMB2_HDR_BODY);
 274         SSVAL(req->in.hdr, SMB2_HDR_EPOCH,              0);
 275         SIVAL(req->in.hdr, SMB2_HDR_STATUS,             0);
 276         SSVAL(req->in.hdr, SMB2_HDR_OPCODE,             SMB2_OP_NEGPROT);
 277         SSVAL(req->in.hdr, SMB2_HDR_CREDIT,             0);
 278         SIVAL(req->in.hdr, SMB2_HDR_FLAGS,              0);
 279         SIVAL(req->in.hdr, SMB2_HDR_NEXT_COMMAND,       0);
 280         SBVAL(req->in.hdr, SMB2_HDR_MESSAGE_ID,         0);
 281         SIVAL(req->in.hdr, SMB2_HDR_PID,                0);
 282         SIVAL(req->in.hdr, SMB2_HDR_TID,                0);
 283         SBVAL(req->in.hdr, SMB2_HDR_SESSION_ID,         0);
 284         memset(req->in.hdr+SMB2_HDR_SIGNATURE, 0, 16);
 285
 286         /* this seems to be a bug, they use 0x24 but the length is 0x26 */
 287         SSVAL(req->in.body, 0x00, 0x24);
 288
 289         SSVAL(req->in.body, 0x02, 1);
 290         memset(req->in.body+0x04, 0, 32);
 291         SSVAL(req->in.body, 0x24, SMB2_DIALECT_REVISION_202);
 292
 293         smb2srv_negprot_recv(req);
 294         return;
 295 nomem:
 296         smbsrv_terminate_connection(smb_req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY));
 297         talloc_free(req);
 298         return;
 299 }