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 "libcli/raw/libcliraw.h"
  24 #include "libcli/smb2/smb2.h"
  25 #include "libcli/smb2/smb2_calls.h"
  26 #include "libcli/composite/composite.h"
  27 #include "auth/gensec/gensec.h"
  28 #include "param/param.h"
  29
  30 /**
  31   initialise a smb2_session structure
  32  */
  33 struct smb2_session *smb2_session_init(struct smb2_transport *transport,
  34                                        struct loadparm_context *lp_ctx,
  35                                        TALLOC_CTX *parent_ctx, bool primary)
  36 {
  37         struct smb2_session *session;
  38         NTSTATUS status;
  39
  40         session = talloc_zero(parent_ctx, struct smb2_session);
  41         if (!session) {
  42                 return NULL;
  43         }
  44         if (primary) {
  45                 session->transport = talloc_steal(session, transport);
  46         } else {
  47                 session->transport = talloc_reference(session, transport);
  48         }
  49
  50         /* prepare a gensec context for later use */
  51         status = gensec_client_start(session, &session->gensec,
  52                                      session->transport->socket->event.ctx,
  53                                      lp_ctx);
  54         if (!NT_STATUS_IS_OK(status)) {
  55                 talloc_free(session);
  56                 return NULL;
  57         }
  58
  59         gensec_want_feature(session->gensec, GENSEC_FEATURE_SESSION_KEY);
  60
  61         return session;
  62 }
  63
  64 /**
  65   send a session setup request
  66 */
  67 struct smb2_request *smb2_session_setup_send(struct smb2_session *session,
  68                                              struct smb2_session_setup *io)
  69 {
  70         struct smb2_request *req;
  71         NTSTATUS status;
  72
  73         req = smb2_request_init(session->transport, SMB2_OP_SESSSETUP,
  74                                 0x18, true, io->in.secblob.length);
  75         if (req == NULL) return NULL;
  76
  77         SBVAL(req->out.hdr,  SMB2_HDR_SESSION_ID, session->uid);
  78         SCVAL(req->out.body, 0x02, io->in.vc_number);
  79         SCVAL(req->out.body, 0x03, io->in.security_mode);
  80         SIVAL(req->out.body, 0x04, io->in.capabilities);
  81         SIVAL(req->out.body, 0x08, io->in.channel);
  82         SBVAL(req->out.body, 0x10, io->in.previous_sessionid);
  83
  84         req->session = session;
  85
  86         status = smb2_push_o16s16_blob(&req->out, 0x0C, io->in.secblob);
  87         if (!NT_STATUS_IS_OK(status)) {
  88                 talloc_free(req);
  89                 return NULL;
  90         }
  91
  92         smb2_transport_send(req);
  93
  94         return req;
  95 }
  96
  97
  98 /**
  99   recv a session setup reply
 100 */
 101 NTSTATUS smb2_session_setup_recv(struct smb2_request *req, TALLOC_CTX *mem_ctx,
 102                                  struct smb2_session_setup *io)
 103 {
 104         NTSTATUS status;
 105
 106         if (!smb2_request_receive(req) ||
 107             (smb2_request_is_error(req) &&
 108              !NT_STATUS_EQUAL(req->status, NT_STATUS_MORE_PROCESSING_REQUIRED))) {
 109                 return smb2_request_destroy(req);
 110         }
 111
 112         SMB2_CHECK_PACKET_RECV(req, 0x08, true);
 113
 114         io->out.session_flags = SVAL(req->in.body, 0x02);
 115         io->out.uid           = BVAL(req->in.hdr,  SMB2_HDR_SESSION_ID);
 116
 117         status = smb2_pull_o16s16_blob(&req->in, mem_ctx, req->in.body+0x04, &io->out.secblob);
 118         if (!NT_STATUS_IS_OK(status)) {
 119                 smb2_request_destroy(req);
 120                 return status;
 121         }
 122
 123         return smb2_request_destroy(req);
 124 }
 125
 126 /*
 127   sync session setup request
 128 */
 129 NTSTATUS smb2_session_setup(struct smb2_session *session,
 130                             TALLOC_CTX *mem_ctx, struct smb2_session_setup *io)
 131 {
 132         struct smb2_request *req = smb2_session_setup_send(session, io);
 133         return smb2_session_setup_recv(req, mem_ctx, io);
 134 }
 135
 136
 137 struct smb2_session_state {
 138         struct smb2_session_setup io;
 139         struct smb2_request *req;
 140         NTSTATUS gensec_status;
 141 };
 142
 143 /*
 144   handle continuations of the spnego session setup
 145 */
 146 static void session_request_handler(struct smb2_request *req)
 147 {
 148         struct composite_context *c = talloc_get_type(req->async.private_data,
 149                                                       struct composite_context);
 150         struct smb2_session_state *state = talloc_get_type(c->private_data,
 151                                                            struct smb2_session_state);
 152         struct smb2_session *session = req->session;
 153
 154         c->status = smb2_session_setup_recv(req, c, &state->io);
 155         if (NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED) ||
 156             (NT_STATUS_IS_OK(c->status) &&
 157              NT_STATUS_EQUAL(state->gensec_status, NT_STATUS_MORE_PROCESSING_REQUIRED))) {
 158                 NTSTATUS session_key_err;
 159                 DATA_BLOB session_key;
 160                 c->status = gensec_update(session->gensec, c,
 161                                           state->io.out.secblob,
 162                                           &state->io.in.secblob);
 163                 state->gensec_status = c->status;
 164
 165                 session_key_err = gensec_session_key(session->gensec, &session_key);
 166                 if (NT_STATUS_IS_OK(session_key_err)) {
 167                         session->session_key = session_key;
 168                 }
 169         }
 170
 171         session->uid = state->io.out.uid;
 172
 173         if (NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 174                 state->req = smb2_session_setup_send(session, &state->io);
 175                 if (state->req == NULL) {
 176                         composite_error(c, NT_STATUS_NO_MEMORY);
 177                         return;
 178                 }
 179
 180                 state->req->async.fn = session_request_handler;
 181                 state->req->async.private_data = c;
 182                 return;
 183         }
 184
 185         if (!NT_STATUS_IS_OK(c->status)) {
 186                 composite_error(c, c->status);
 187                 return;
 188         }
 189
 190         if (session->transport->signing_required) {
 191                 if (session->session_key.length == 0) {
 192                         DEBUG(0,("Wrong session key length %u for SMB2 signing\n",
 193                                  (unsigned)session->session_key.length));
 194                         composite_error(c, NT_STATUS_ACCESS_DENIED);
 195                         return;
 196                 }
 197                 session->signing_active = true;
 198         }
 199
 200         composite_done(c);
 201 }
 202
 203 /*
 204   a composite function that does a full SPNEGO session setup
 205  */
 206 struct composite_context *smb2_session_setup_spnego_send(struct smb2_session *session,
 207                                                          struct cli_credentials *credentials)
 208 {
 209         struct composite_context *c;
 210         struct smb2_session_state *state;
 211
 212         c = composite_create(session, session->transport->socket->event.ctx);
 213         if (c == NULL) return NULL;
 214
 215         state = talloc(c, struct smb2_session_state);
 216         if (composite_nomem(state, c)) return c;
 217         c->private_data = state;
 218
 219         ZERO_STRUCT(state->io);
 220         state->io.in.vc_number          = 0;
 221         if (session->transport->signing_required) {
 222                 state->io.in.security_mode =
 223                         SMB2_NEGOTIATE_SIGNING_ENABLED | SMB2_NEGOTIATE_SIGNING_REQUIRED;
 224         }
 225         state->io.in.capabilities       = 0;
 226         state->io.in.channel            = 0;
 227         state->io.in.previous_sessionid = 0;
 228
 229         c->status = gensec_set_credentials(session->gensec, credentials);
 230         if (!composite_is_ok(c)) return c;
 231
 232         c->status = gensec_set_target_hostname(session->gensec,
 233                                                session->transport->socket->hostname);
 234         if (!composite_is_ok(c)) return c;
 235
 236         c->status = gensec_set_target_service(session->gensec, "cifs");
 237         if (!composite_is_ok(c)) return c;
 238
 239         c->status = gensec_start_mech_by_oid(session->gensec, GENSEC_OID_SPNEGO);
 240         if (!composite_is_ok(c)) return c;
 241
 242         c->status = gensec_update(session->gensec, c,
 243                                   session->transport->negotiate.secblob,
 244                                   &state->io.in.secblob);
 245         if (!NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 246                 composite_error(c, c->status);
 247                 return c;
 248         }
 249         state->gensec_status = c->status;
 250
 251         state->req = smb2_session_setup_send(session, &state->io);
 252         composite_continue_smb2(c, state->req, session_request_handler, c);
 253         return c;
 254 }
 255
 256 /*
 257   receive a composite session setup reply
 258 */
 259 NTSTATUS smb2_session_setup_spnego_recv(struct composite_context *c)
 260 {
 261         NTSTATUS status;
 262         status = composite_wait(c);
 263         talloc_free(c);
 264         return status;
 265 }
 266
 267 /*
 268   sync version of smb2_session_setup_spnego
 269 */
 270 NTSTATUS smb2_session_setup_spnego(struct smb2_session *session,
 271                                    struct cli_credentials *credentials)
 272 {
 273         struct composite_context *c = smb2_session_setup_spnego_send(session, credentials);
 274         return smb2_session_setup_spnego_recv(c);
 275 }