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
  29 /**
  30   initialise a smb2_session structure
  31  */
  32 struct smb2_session *smb2_session_init(struct smb2_transport *transport,
  33                                        struct gensec_settings *settings,
  34                                        TALLOC_CTX *parent_ctx, bool primary)
  35 {
  36         struct smb2_session *session;
  37         NTSTATUS status;
  38
  39         session = talloc_zero(parent_ctx, struct smb2_session);
  40         if (!session) {
  41                 return NULL;
  42         }
  43         if (primary) {
  44                 session->transport = talloc_steal(session, transport);
  45         } else {
  46                 session->transport = talloc_reference(session, transport);
  47         }
  48
  49         /* prepare a gensec context for later use */
  50         status = gensec_client_start(session, &session->gensec,
  51                                      session->transport->socket->event.ctx,
  52                                      settings);
  53         if (!NT_STATUS_IS_OK(status)) {
  54                 talloc_free(session);
  55                 return NULL;
  56         }
  57
  58         gensec_want_feature(session->gensec, GENSEC_FEATURE_SESSION_KEY);
  59
  60         return session;
  61 }
  62
  63 /**
  64   send a session setup request
  65 */
  66 struct smb2_request *smb2_session_setup_send(struct smb2_session *session,
  67                                              struct smb2_session_setup *io)
  68 {
  69         struct smb2_request *req;
  70         NTSTATUS status;
  71
  72         req = smb2_request_init(session->transport, SMB2_OP_SESSSETUP,
  73                                 0x18, true, io->in.secblob.length);
  74         if (req == NULL) return NULL;
  75
  76         SBVAL(req->out.hdr,  SMB2_HDR_SESSION_ID, session->uid);
  77         SCVAL(req->out.body, 0x02, io->in.vc_number);
  78         SCVAL(req->out.body, 0x03, io->in.security_mode);
  79         SIVAL(req->out.body, 0x04, io->in.capabilities);
  80         SIVAL(req->out.body, 0x08, io->in.channel);
  81         SBVAL(req->out.body, 0x10, io->in.previous_sessionid);
  82
  83         req->session = session;
  84
  85         status = smb2_push_o16s16_blob(&req->out, 0x0C, io->in.secblob);
  86         if (!NT_STATUS_IS_OK(status)) {
  87                 talloc_free(req);
  88                 return NULL;
  89         }
  90
  91         smb2_transport_send(req);
  92
  93         return req;
  94 }
  95
  96
  97 /**
  98   recv a session setup reply
  99 */
 100 NTSTATUS smb2_session_setup_recv(struct smb2_request *req, TALLOC_CTX *mem_ctx,
 101                                  struct smb2_session_setup *io)
 102 {
 103         NTSTATUS status;
 104
 105         if (!smb2_request_receive(req) ||
 106             (smb2_request_is_error(req) &&
 107              !NT_STATUS_EQUAL(req->status, NT_STATUS_MORE_PROCESSING_REQUIRED))) {
 108                 return smb2_request_destroy(req);
 109         }
 110
 111         SMB2_CHECK_PACKET_RECV(req, 0x08, true);
 112
 113         io->out.session_flags = SVAL(req->in.body, 0x02);
 114         io->out.uid           = BVAL(req->in.hdr,  SMB2_HDR_SESSION_ID);
 115
 116         status = smb2_pull_o16s16_blob(&req->in, mem_ctx, req->in.body+0x04, &io->out.secblob);
 117         if (!NT_STATUS_IS_OK(status)) {
 118                 smb2_request_destroy(req);
 119                 return status;
 120         }
 121
 122         return smb2_request_destroy(req);
 123 }
 124
 125 /*
 126   sync session setup request
 127 */
 128 NTSTATUS smb2_session_setup(struct smb2_session *session,
 129                             TALLOC_CTX *mem_ctx, struct smb2_session_setup *io)
 130 {
 131         struct smb2_request *req = smb2_session_setup_send(session, io);
 132         return smb2_session_setup_recv(req, mem_ctx, io);
 133 }
 134
 135
 136 struct smb2_session_state {
 137         struct smb2_session_setup io;
 138         struct smb2_request *req;
 139         NTSTATUS gensec_status;
 140 };
 141
 142 /*
 143   handle continuations of the spnego session setup
 144 */
 145 static void session_request_handler(struct smb2_request *req)
 146 {
 147         struct composite_context *c = talloc_get_type(req->async.private_data,
 148                                                       struct composite_context);
 149         struct smb2_session_state *state = talloc_get_type(c->private_data,
 150                                                            struct smb2_session_state);
 151         struct smb2_session *session = req->session;
 152         NTSTATUS session_key_err;
 153         DATA_BLOB session_key;
 154         NTSTATUS peer_status;
 155
 156         c->status = smb2_session_setup_recv(req, c, &state->io);
 157         peer_status = c->status;
 158
 159         if (NT_STATUS_EQUAL(peer_status, NT_STATUS_MORE_PROCESSING_REQUIRED) ||
 160             (NT_STATUS_IS_OK(peer_status) &&
 161              NT_STATUS_EQUAL(state->gensec_status, NT_STATUS_MORE_PROCESSING_REQUIRED))) {
 162                 c->status = gensec_update(session->gensec, c,
 163                                           state->io.out.secblob,
 164                                           &state->io.in.secblob);
 165                 state->gensec_status = c->status;
 166
 167                 session->uid = state->io.out.uid;
 168         }
 169
 170         if (!NT_STATUS_IS_OK(c->status) &&
 171             !NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 172                 composite_error(c, c->status);
 173                 return;
 174         }
 175
 176         if (NT_STATUS_EQUAL(peer_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 177                 state->req = smb2_session_setup_send(session, &state->io);
 178                 if (state->req == NULL) {
 179                         composite_error(c, NT_STATUS_NO_MEMORY);
 180                         return;
 181                 }
 182
 183                 state->req->async.fn = session_request_handler;
 184                 state->req->async.private_data = c;
 185                 return;
 186         }
 187
 188         session_key_err = gensec_session_key(session->gensec, &session_key);
 189         if (NT_STATUS_IS_OK(session_key_err)) {
 190                 session->session_key = session_key;
 191         }
 192
 193         if (session->transport->signing_required) {
 194                 if (session->session_key.length == 0) {
 195                         DEBUG(0,("Wrong session key length %u for SMB2 signing\n",
 196                                  (unsigned)session->session_key.length));
 197                         composite_error(c, NT_STATUS_ACCESS_DENIED);
 198                         return;
 199                 }
 200                 session->signing_active = true;
 201         }
 202
 203         composite_done(c);
 204 }
 205
 206 /*
 207   a composite function that does a full SPNEGO session setup
 208  */
 209 struct composite_context *smb2_session_setup_spnego_send(struct smb2_session *session,
 210                                                          struct cli_credentials *credentials)
 211 {
 212         struct composite_context *c;
 213         struct smb2_session_state *state;
 214         const char *chosen_oid;
 215
 216         c = composite_create(session, session->transport->socket->event.ctx);
 217         if (c == NULL) return NULL;
 218
 219         state = talloc(c, struct smb2_session_state);
 220         if (composite_nomem(state, c)) return c;
 221         c->private_data = state;
 222
 223         ZERO_STRUCT(state->io);
 224         state->io.in.vc_number          = 0;
 225         if (session->transport->signing_required) {
 226                 state->io.in.security_mode =
 227                         SMB2_NEGOTIATE_SIGNING_ENABLED | SMB2_NEGOTIATE_SIGNING_REQUIRED;
 228         }
 229         state->io.in.capabilities       = 0;
 230         state->io.in.channel            = 0;
 231         state->io.in.previous_sessionid = 0;
 232
 233         c->status = gensec_set_credentials(session->gensec, credentials);
 234         if (!composite_is_ok(c)) return c;
 235
 236         c->status = gensec_set_target_hostname(session->gensec,
 237                                                session->transport->socket->hostname);
 238         if (!composite_is_ok(c)) return c;
 239
 240         c->status = gensec_set_target_service(session->gensec, "cifs");
 241         if (!composite_is_ok(c)) return c;
 242
 243         if (session->transport->negotiate.secblob.length > 0) {
 244                 chosen_oid = GENSEC_OID_SPNEGO;
 245         } else {
 246                 chosen_oid = GENSEC_OID_NTLMSSP;
 247         }
 248
 249         c->status = gensec_start_mech_by_oid(session->gensec, chosen_oid);
 250         if (!composite_is_ok(c)) return c;
 251
 252         c->status = gensec_update(session->gensec, c,
 253                                   session->transport->negotiate.secblob,
 254                                   &state->io.in.secblob);
 255         if (!NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 256                 composite_error(c, c->status);
 257                 return c;
 258         }
 259         state->gensec_status = c->status;
 260
 261         state->req = smb2_session_setup_send(session, &state->io);
 262         composite_continue_smb2(c, state->req, session_request_handler, c);
 263         return c;
 264 }
 265
 266 /*
 267   receive a composite session setup reply
 268 */
 269 NTSTATUS smb2_session_setup_spnego_recv(struct composite_context *c)
 270 {
 271         NTSTATUS status;
 272         status = composite_wait(c);
 273         talloc_free(c);
 274         return status;
 275 }
 276
 277 /*
 278   sync version of smb2_session_setup_spnego
 279 */
 280 NTSTATUS smb2_session_setup_spnego(struct smb2_session *session,
 281                                    struct cli_credentials *credentials)
 282 {
 283         struct composite_context *c = smb2_session_setup_spnego_send(session, credentials);
 284         return smb2_session_setup_spnego_recv(c);
 285 }