source4/libcli/smb2/session.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    SMB2 client session handling
   5
   6    Copyright (C) Andrew Tridgell 2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include <tevent.h>
  24 #include "lib/util/tevent_ntstatus.h"
  25 #include "libcli/raw/libcliraw.h"
  26 #include "libcli/smb2/smb2.h"
  27 #include "libcli/smb2/smb2_calls.h"
  28 #include "auth/gensec/gensec.h"
  29
  30 #include <unistd.h>
  31
  32 /**
  33   initialise a smb2_session structure
  34  */
  35 struct smb2_session *smb2_session_init(struct smb2_transport *transport,
  36                                        struct gensec_settings *settings,
  37                                        TALLOC_CTX *parent_ctx, bool primary)
  38 {
  39         struct smb2_session *session;
  40         NTSTATUS status;
  41
  42         session = talloc_zero(parent_ctx, struct smb2_session);
  43         if (!session) {
  44                 return NULL;
  45         }
  46         if (primary) {
  47                 session->transport = talloc_steal(session, transport);
  48         } else {
  49                 session->transport = talloc_reference(session, transport);
  50         }
  51
  52         session->pid = getpid();
  53
  54         /* prepare a gensec context for later use */
  55         status = gensec_client_start(session, &session->gensec,
  56                                      session->transport->socket->event.ctx,
  57                                      settings);
  58         if (!NT_STATUS_IS_OK(status)) {
  59                 talloc_free(session);
  60                 return NULL;
  61         }
  62
  63         gensec_want_feature(session->gensec, GENSEC_FEATURE_SESSION_KEY);
  64
  65         return session;
  66 }
  67
  68 /**
  69   send a session setup request
  70 */
  71 struct smb2_request *smb2_session_setup_send(struct smb2_session *session,
  72                                              struct smb2_session_setup *io)
  73 {
  74         struct smb2_request *req;
  75         NTSTATUS status;
  76
  77         req = smb2_request_init(session->transport, SMB2_OP_SESSSETUP,
  78                                 0x18, true, io->in.secblob.length);
  79         if (req == NULL) return NULL;
  80
  81         SBVAL(req->out.hdr,  SMB2_HDR_SESSION_ID, session->uid);
  82         SCVAL(req->out.body, 0x02, io->in.vc_number);
  83         SCVAL(req->out.body, 0x03, io->in.security_mode);
  84         SIVAL(req->out.body, 0x04, io->in.capabilities);
  85         SIVAL(req->out.body, 0x08, io->in.channel);
  86         SBVAL(req->out.body, 0x10, io->in.previous_sessionid);
  87
  88         req->session = session;
  89
  90         status = smb2_push_o16s16_blob(&req->out, 0x0C, io->in.secblob);
  91         if (!NT_STATUS_IS_OK(status)) {
  92                 talloc_free(req);
  93                 return NULL;
  94         }
  95
  96         smb2_transport_send(req);
  97
  98         return req;
  99 }
 100
 101
 102 /**
 103   recv a session setup reply
 104 */
 105 NTSTATUS smb2_session_setup_recv(struct smb2_request *req, TALLOC_CTX *mem_ctx,
 106                                  struct smb2_session_setup *io)
 107 {
 108         NTSTATUS status;
 109
 110         if (!smb2_request_receive(req) ||
 111             (smb2_request_is_error(req) &&
 112              !NT_STATUS_EQUAL(req->status, NT_STATUS_MORE_PROCESSING_REQUIRED))) {
 113                 return smb2_request_destroy(req);
 114         }
 115
 116         SMB2_CHECK_PACKET_RECV(req, 0x08, true);
 117
 118         io->out.session_flags = SVAL(req->in.body, 0x02);
 119         io->out.uid           = BVAL(req->in.hdr,  SMB2_HDR_SESSION_ID);
 120
 121         status = smb2_pull_o16s16_blob(&req->in, mem_ctx, req->in.body+0x04, &io->out.secblob);
 122         if (!NT_STATUS_IS_OK(status)) {
 123                 smb2_request_destroy(req);
 124                 return status;
 125         }
 126
 127         return smb2_request_destroy(req);
 128 }
 129
 130 /*
 131   sync session setup request
 132 */
 133 NTSTATUS smb2_session_setup(struct smb2_session *session,
 134                             TALLOC_CTX *mem_ctx, struct smb2_session_setup *io)
 135 {
 136         struct smb2_request *req = smb2_session_setup_send(session, io);
 137         return smb2_session_setup_recv(req, mem_ctx, io);
 138 }
 139
 140 struct smb2_session_setup_spnego_state {
 141         struct smb2_session_setup io;
 142         struct smb2_request *req;
 143         NTSTATUS gensec_status;
 144 };
 145
 146 static void smb2_session_setup_spnego_handler(struct smb2_request *req);
 147
 148 /*
 149   a composite function that does a full SPNEGO session setup
 150  */
 151 struct tevent_req *smb2_session_setup_spnego_send(TALLOC_CTX *mem_ctx,
 152                                                   struct tevent_context *ev,
 153                                                   struct smb2_session *session,
 154                                                   struct cli_credentials *credentials)
 155 {
 156         struct tevent_req *req;
 157         struct smb2_session_setup_spnego_state *state;
 158         const char *chosen_oid;
 159         struct smb2_request *subreq;
 160         NTSTATUS status;
 161
 162         req = tevent_req_create(mem_ctx, &state,
 163                                 struct smb2_session_setup_spnego_state);
 164         if (req == NULL) {
 165                 return NULL;
 166         }
 167
 168         ZERO_STRUCT(state->io);
 169         state->io.in.vc_number          = 0;
 170         if (session->transport->signing_required) {
 171                 state->io.in.security_mode =
 172                         SMB2_NEGOTIATE_SIGNING_ENABLED | SMB2_NEGOTIATE_SIGNING_REQUIRED;
 173         }
 174         state->io.in.capabilities       = 0;
 175         state->io.in.channel            = 0;
 176         state->io.in.previous_sessionid = 0;
 177
 178         status = gensec_set_credentials(session->gensec, credentials);
 179         if (tevent_req_nterror(req, status)) {
 180                 return tevent_req_post(req, ev);
 181         }
 182
 183         status = gensec_set_target_hostname(session->gensec,
 184                                             session->transport->socket->hostname);
 185         if (tevent_req_nterror(req, status)) {
 186                 return tevent_req_post(req, ev);
 187         }
 188
 189         status = gensec_set_target_service(session->gensec, "cifs");
 190         if (tevent_req_nterror(req, status)) {
 191                 return tevent_req_post(req, ev);
 192         }
 193
 194         if (session->transport->negotiate.secblob.length > 0) {
 195                 chosen_oid = GENSEC_OID_SPNEGO;
 196         } else {
 197                 chosen_oid = GENSEC_OID_NTLMSSP;
 198         }
 199
 200         status = gensec_start_mech_by_oid(session->gensec, chosen_oid);
 201         if (tevent_req_nterror(req, status)) {
 202                 return tevent_req_post(req, ev);
 203         }
 204
 205         status = gensec_update(session->gensec, state,
 206                                session->transport->negotiate.secblob,
 207                                &state->io.in.secblob);
 208         if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 209                 tevent_req_nterror(req, status);
 210                 return tevent_req_post(req, ev);
 211         }
 212         state->gensec_status = status;
 213
 214         subreq = smb2_session_setup_send(session, &state->io);
 215         if (tevent_req_nomem(subreq, req)) {
 216                 return tevent_req_post(req, ev);
 217         }
 218         subreq->async.fn = smb2_session_setup_spnego_handler;
 219         subreq->async.private_data = req;
 220
 221         return req;
 222 }
 223
 224 /*
 225   handle continuations of the spnego session setup
 226 */
 227 static void smb2_session_setup_spnego_handler(struct smb2_request *subreq)
 228 {
 229         struct tevent_req *req =
 230                 talloc_get_type_abort(subreq->async.private_data,
 231                 struct tevent_req);
 232         struct smb2_session_setup_spnego_state *state =
 233                 tevent_req_data(req,
 234                 struct smb2_session_setup_spnego_state);
 235         struct smb2_session *session = subreq->session;
 236         NTSTATUS session_key_err;
 237         DATA_BLOB session_key;
 238         NTSTATUS peer_status;
 239         NTSTATUS status;
 240
 241         status = smb2_session_setup_recv(subreq, state, &state->io);
 242         peer_status = status;
 243         if (NT_STATUS_EQUAL(peer_status, NT_STATUS_MORE_PROCESSING_REQUIRED) ||
 244             (NT_STATUS_IS_OK(peer_status) &&
 245              NT_STATUS_EQUAL(state->gensec_status, NT_STATUS_MORE_PROCESSING_REQUIRED))) {
 246                 status = gensec_update(session->gensec, state,
 247                                        state->io.out.secblob,
 248                                        &state->io.in.secblob);
 249                 state->gensec_status = status;
 250                 session->uid = state->io.out.uid;
 251         }
 252
 253         if (!NT_STATUS_IS_OK(status) &&
 254             !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 255                 tevent_req_nterror(req, status);
 256                 return;
 257         }
 258
 259         if (NT_STATUS_EQUAL(peer_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 260                 subreq = smb2_session_setup_send(session, &state->io);
 261                 if (tevent_req_nomem(subreq, req)) {
 262                         return;
 263                 }
 264
 265                 subreq->async.fn = smb2_session_setup_spnego_handler;
 266                 subreq->async.private_data = req;
 267                 return;
 268         }
 269
 270         session_key_err = gensec_session_key(session->gensec, &session_key);
 271         if (NT_STATUS_IS_OK(session_key_err)) {
 272                 session->session_key = session_key;
 273         }
 274
 275         if (session->transport->signing_required) {
 276                 if (session->session_key.length == 0) {
 277                         DEBUG(0,("Wrong session key length %u for SMB2 signing\n",
 278                                  (unsigned)session->session_key.length));
 279                         tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
 280                         return;
 281                 }
 282                 session->signing_active = true;
 283         }
 284
 285         tevent_req_done(req);
 286 }
 287
 288 /*
 289   receive a composite session setup reply
 290 */
 291 NTSTATUS smb2_session_setup_spnego_recv(struct tevent_req *req)
 292 {
 293         return tevent_req_simple_recv_ntstatus(req);
 294 }
 295
 296 /*
 297   sync version of smb2_session_setup_spnego
 298 */
 299 NTSTATUS smb2_session_setup_spnego(struct smb2_session *session,
 300                                    struct cli_credentials *credentials)
 301 {
 302         struct tevent_req *subreq;
 303         NTSTATUS status;
 304         bool ok;
 305         TALLOC_CTX *frame = talloc_stackframe();
 306         struct tevent_context *ev = session->transport->socket->event.ctx;
 307
 308         if (frame == NULL) {
 309                 return NT_STATUS_NO_MEMORY;
 310         }
 311
 312         subreq = smb2_session_setup_spnego_send(frame, ev,
 313                                                 session, credentials);
 314         if (subreq == NULL) {
 315                 TALLOC_FREE(frame);
 316                 return NT_STATUS_NO_MEMORY;
 317         }
 318
 319         ok = tevent_req_poll(subreq, ev);
 320         if (!ok) {
 321                 status = map_nt_error_from_unix_common(errno);
 322                 TALLOC_FREE(frame);
 323                 return status;
 324         }
 325
 326         status = smb2_session_setup_spnego_recv(subreq);
 327         TALLOC_FREE(subreq);
 328         if (!NT_STATUS_IS_OK(status)) {
 329                 TALLOC_FREE(frame);
 330                 return status;
 331         }
 332
 333         TALLOC_FREE(frame);
 334         return NT_STATUS_OK;
 335 }