source4/libcli/smb_composite/sesssetup.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Copyright (C) Andrew Tridgell 2005
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20 /*
  21   a composite API for making handling a generic async session setup
  22 */
  23
  24 #include "includes.h"
  25 #include "libcli/raw/libcliraw.h"
  26 #include "libcli/composite/composite.h"
  27 #include "libcli/smb_composite/smb_composite.h"
  28 #include "auth/auth.h"
  29 #include "version.h"
  30
  31 struct sesssetup_state {
  32         union smb_sesssetup setup;
  33         NTSTATUS gensec_status;
  34         struct smb_composite_sesssetup *io;
  35         struct smbcli_request *req;
  36 };
  37
  38
  39 /*
  40   form an encrypted lanman password from a plaintext password
  41   and the server supplied challenge
  42 */
  43 static DATA_BLOB lanman_blob(TALLOC_CTX *mem_ctx, const char *pass, DATA_BLOB challenge)
  44 {
  45         DATA_BLOB blob = data_blob_talloc(mem_ctx, NULL, 24);
  46         SMBencrypt(pass, challenge.data, blob.data);
  47         return blob;
  48 }
  49
  50 /*
  51   form an encrypted NT password from a plaintext password
  52   and the server supplied challenge
  53 */
  54 static DATA_BLOB nt_blob(TALLOC_CTX *mem_ctx, const struct samr_Password *nt_hash, DATA_BLOB challenge)
  55 {
  56         DATA_BLOB blob = data_blob_talloc(mem_ctx, NULL, 24);
  57         SMBOWFencrypt(nt_hash->hash, challenge.data, blob.data);
  58         return blob;
  59 }
  60
  61 /*
  62   store the user session key for a transport
  63 */
  64 static void set_user_session_key(struct smbcli_session *session,
  65                                  const DATA_BLOB *session_key)
  66 {
  67         session->user_session_key = data_blob_talloc(session,
  68                                                      session_key->data,
  69                                                      session_key->length);
  70 }
  71
  72 /*
  73   handler for completion of a smbcli_request sub-request
  74 */
  75 static void request_handler(struct smbcli_request *req)
  76 {
  77         struct composite_context *c = req->async.private;
  78         struct sesssetup_state *state = talloc_get_type(c->private_data, struct sesssetup_state);
  79         struct smbcli_session *session = req->session;
  80         DATA_BLOB session_key = data_blob(NULL, 0);
  81         DATA_BLOB null_data_blob = data_blob(NULL, 0);
  82         NTSTATUS session_key_err;
  83
  84         c->status = smb_raw_sesssetup_recv(req, state, &state->setup);
  85
  86         switch (state->setup.old.level) {
  87         case RAW_SESSSETUP_OLD:
  88                 state->io->out.vuid = state->setup.old.out.vuid;
  89                 break;
  90
  91         case RAW_SESSSETUP_NT1:
  92                 state->io->out.vuid = state->setup.nt1.out.vuid;
  93                 break;
  94
  95         case RAW_SESSSETUP_SPNEGO:
  96                 session->vuid = state->io->out.vuid = state->setup.spnego.out.vuid;
  97                 if (!NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
  98                     !NT_STATUS_IS_OK(c->status)) {
  99                         break;
 100                 }
 101                 if (NT_STATUS_EQUAL(state->gensec_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 102
 103                         /* The status value here, from the earlier pass at GENSEC is
 104                          * vital to the security of the system.  Even if the other end
 105                          * accepts, if GENSEC claims 'MORE_PROCESSING_REQUIRED' then
 106                          * you must keep feeding it blobs, or else the remote
 107                          * host/attacker might avoid mutal authentication
 108                          * requirements */
 109
 110                         state->gensec_status = gensec_update(session->gensec, state,
 111                                                          state->setup.spnego.out.secblob,
 112                                                          &state->setup.spnego.in.secblob);
 113                         c->status = state->gensec_status;
 114                         if (!NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
 115                             !NT_STATUS_IS_OK(c->status)) {
 116                                 break;
 117                         }
 118                 } else {
 119                         state->setup.spnego.in.secblob = data_blob(NULL, 0);
 120                 }
 121
 122                 /* we need to do another round of session setup. We keep going until both sides
 123                    are happy */
 124                 session_key_err = gensec_session_key(session->gensec, &session_key);
 125                 if (NT_STATUS_IS_OK(session_key_err)) {
 126                         set_user_session_key(session, &session_key);
 127                         smbcli_transport_simple_set_signing(session->transport, session_key, null_data_blob);
 128                 }
 129
 130                 if (state->setup.spnego.in.secblob.length) {
 131                         state->req = smb_raw_sesssetup_send(session, &state->setup);
 132                         state->req->async.fn = request_handler;
 133                         state->req->async.private = c;
 134                         return;
 135                 }
 136         }
 137
 138         /* enforce the local signing required flag */
 139         if (NT_STATUS_IS_OK(c->status) && !cli_credentials_is_anonymous(state->io->in.credentials)) {
 140                 if (!session->transport->negotiate.sign_info.doing_signing
 141                     && session->transport->negotiate.sign_info.mandatory_signing) {
 142                         DEBUG(0, ("SMB signing required, but server does not support it\n"));
 143                         c->status = NT_STATUS_ACCESS_DENIED;
 144                 }
 145         }
 146
 147         if (NT_STATUS_IS_OK(c->status)) {
 148                 c->state = COMPOSITE_STATE_DONE;
 149         } else {
 150                 c->state = COMPOSITE_STATE_ERROR;
 151         }
 152         if (c->async.fn) {
 153                 c->async.fn(c);
 154         }
 155 }
 156
 157
 158 /*
 159   send a nt1 style session setup
 160 */
 161 static NTSTATUS session_setup_nt1(struct composite_context *c,
 162                                   struct smbcli_session *session,
 163                                   struct smb_composite_sesssetup *io,
 164                                   struct smbcli_request **req)
 165 {
 166         struct sesssetup_state *state = talloc_get_type(c->private_data, struct sesssetup_state);
 167         const struct samr_Password *nt_hash = cli_credentials_get_nt_hash(io->in.credentials, state);
 168         const char *password = cli_credentials_get_password(io->in.credentials);
 169
 170         state->setup.nt1.level           = RAW_SESSSETUP_NT1;
 171         state->setup.nt1.in.bufsize      = session->transport->options.max_xmit;
 172         state->setup.nt1.in.mpx_max      = session->transport->options.max_mux;
 173         state->setup.nt1.in.vc_num       = 1;
 174         state->setup.nt1.in.sesskey      = io->in.sesskey;
 175         state->setup.nt1.in.capabilities = io->in.capabilities;
 176         state->setup.nt1.in.os           = "Unix";
 177         state->setup.nt1.in.lanman       = talloc_asprintf(state, "Samba %s", SAMBA_VERSION_STRING);
 178         cli_credentials_get_ntlm_username_domain(io->in.credentials, state,
 179                                                  &state->setup.nt1.in.user,
 180                                                  &state->setup.nt1.in.domain);
 181
 182         if (!password) {
 183                 state->setup.nt1.in.password1 = data_blob(NULL, 0);
 184                 state->setup.nt1.in.password2 = data_blob(NULL, 0);
 185         } else if (session->transport->negotiate.sec_mode &
 186                    NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) {
 187                 DATA_BLOB session_key;
 188                 if (lp_client_ntlmv2_auth()) {
 189                         DATA_BLOB names_blob = NTLMv2_generate_names_blob(state, lp_netbios_name(), lp_workgroup());
 190                         DATA_BLOB lmv2_response, ntlmv2_response, lmv2_session_key;
 191
 192                         if (!SMBNTLMv2encrypt_hash(state,
 193                                                    state->setup.nt1.in.user, state->setup.nt1.in.domain,
 194                                                    nt_hash->hash, &session->transport->negotiate.secblob,
 195                                                    &names_blob,
 196                                                    &lmv2_response, &ntlmv2_response,
 197                                                    &lmv2_session_key, &session_key)) {
 198                                 data_blob_free(&names_blob);
 199                                 return NT_STATUS_NO_MEMORY;
 200                         }
 201                         data_blob_free(&names_blob);
 202                         state->setup.nt1.in.password1 = lmv2_response;
 203                         state->setup.nt1.in.password2 = ntlmv2_response;
 204
 205                         smbcli_transport_simple_set_signing(session->transport, session_key,
 206                                                             state->setup.nt1.in.password2);
 207                         set_user_session_key(session, &session_key);
 208
 209                         data_blob_free(&lmv2_session_key);
 210                         data_blob_free(&session_key);
 211                 } else {
 212
 213                         state->setup.nt1.in.password2 = nt_blob(state, nt_hash,
 214                                                                 session->transport->negotiate.secblob);
 215                         if (lp_client_lanman_auth()) {
 216                                 state->setup.nt1.in.password1 = lanman_blob(state, password,
 217                                                                             session->transport->negotiate.secblob);
 218                         } else {
 219                                 /* if not sending the LM password, send the NT password twice */
 220                                 state->setup.nt1.in.password1 = state->setup.nt1.in.password2;
 221                         }
 222
 223                         session_key = data_blob_talloc(session, NULL, 16);
 224                         SMBsesskeygen_ntv1(nt_hash->hash, session_key.data);
 225                         smbcli_transport_simple_set_signing(session->transport, session_key,
 226                                                             state->setup.nt1.in.password2);
 227                         set_user_session_key(session, &session_key);
 228
 229                         data_blob_free(&session_key);
 230                 }
 231
 232         } else if (lp_client_plaintext_auth()) {
 233                 state->setup.nt1.in.password1 = data_blob_talloc(state, password, strlen(password));
 234                 state->setup.nt1.in.password2 = data_blob(NULL, 0);
 235         } else {
 236                 /* could match windows client and return 'cannot logon from this workstation', but it just confuses everybody */
 237                 return NT_STATUS_INVALID_PARAMETER;
 238         }
 239
 240         *req = smb_raw_sesssetup_send(session, &state->setup);
 241         if (!*req) {
 242                 return NT_STATUS_NO_MEMORY;
 243         }
 244         return (*req)->status;
 245 }
 246
 247
 248 /*
 249   old style session setup (pre NT1 protocol level)
 250 */
 251 static NTSTATUS session_setup_old(struct composite_context *c,
 252                                   struct smbcli_session *session,
 253                                   struct smb_composite_sesssetup *io,
 254                                   struct smbcli_request **req)
 255 {
 256         struct sesssetup_state *state = talloc_get_type(c->private_data, struct sesssetup_state);
 257         const char *password = cli_credentials_get_password(io->in.credentials);
 258
 259         state->setup.old.level      = RAW_SESSSETUP_OLD;
 260         state->setup.old.in.bufsize = session->transport->options.max_xmit;
 261         state->setup.old.in.mpx_max = session->transport->options.max_mux;
 262         state->setup.old.in.vc_num  = 1;
 263         state->setup.old.in.sesskey = io->in.sesskey;
 264         state->setup.old.in.os      = "Unix";
 265         state->setup.old.in.lanman  = talloc_asprintf(state, "Samba %s", SAMBA_VERSION_STRING);
 266         cli_credentials_get_ntlm_username_domain(io->in.credentials, state,
 267                                                  &state->setup.old.in.user,
 268                                                  &state->setup.old.in.domain);
 269
 270         if (!password) {
 271                 state->setup.old.in.password = data_blob(NULL, 0);
 272         } else if (session->transport->negotiate.sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) {
 273                 state->setup.old.in.password = lanman_blob(state, password,
 274                                                            session->transport->negotiate.secblob);
 275         } else {
 276                 state->setup.old.in.password = data_blob_talloc(state,
 277                                                                 password,
 278                                                                 strlen(password));
 279         }
 280
 281         *req = smb_raw_sesssetup_send(session, &state->setup);
 282         if (!*req) {
 283                 return NT_STATUS_NO_MEMORY;
 284         }
 285         return (*req)->status;
 286 }
 287
 288
 289 /*
 290   Modern, all singing, all dancing extended security (and possibly SPNEGO) request
 291 */
 292 static NTSTATUS session_setup_spnego(struct composite_context *c,
 293                                      struct smbcli_session *session,
 294                                      struct smb_composite_sesssetup *io,
 295                                      struct smbcli_request **req)
 296 {
 297         struct sesssetup_state *state = talloc_get_type(c->private_data, struct sesssetup_state);
 298         NTSTATUS status, session_key_err;
 299         DATA_BLOB session_key = data_blob(NULL, 0);
 300         DATA_BLOB null_data_blob = data_blob(NULL, 0);
 301         const char *chosen_oid = NULL;
 302
 303         state->setup.spnego.level           = RAW_SESSSETUP_SPNEGO;
 304         state->setup.spnego.in.bufsize      = session->transport->options.max_xmit;
 305         state->setup.spnego.in.mpx_max      = session->transport->options.max_mux;
 306         state->setup.spnego.in.vc_num       = 1;
 307         state->setup.spnego.in.sesskey      = io->in.sesskey;
 308         state->setup.spnego.in.capabilities = io->in.capabilities;
 309         state->setup.spnego.in.os           = "Unix";
 310         state->setup.spnego.in.lanman       = talloc_asprintf(state, "Samba %s", SAMBA_VERSION_STRING);
 311         state->setup.spnego.in.workgroup    = io->in.workgroup;
 312
 313         state->setup.spnego.out.vuid        = session->vuid;
 314
 315         smbcli_temp_set_signing(session->transport);
 316
 317         status = gensec_client_start(session, &session->gensec, c->event_ctx);
 318         if (!NT_STATUS_IS_OK(status)) {
 319                 DEBUG(1, ("Failed to start GENSEC client mode: %s\n", nt_errstr(status)));
 320                 return status;
 321         }
 322
 323         gensec_want_feature(session->gensec, GENSEC_FEATURE_SESSION_KEY);
 324
 325         status = gensec_set_credentials(session->gensec, io->in.credentials);
 326         if (!NT_STATUS_IS_OK(status)) {
 327                 DEBUG(1, ("Failed to start set GENSEC client credentails: %s\n",
 328                           nt_errstr(status)));
 329                 return status;
 330         }
 331
 332         status = gensec_set_target_hostname(session->gensec, session->transport->socket->hostname);
 333         if (!NT_STATUS_IS_OK(status)) {
 334                 DEBUG(1, ("Failed to start set GENSEC target hostname: %s\n",
 335                           nt_errstr(status)));
 336                 return status;
 337         }
 338
 339         status = gensec_set_target_service(session->gensec, "cifs");
 340         if (!NT_STATUS_IS_OK(status)) {
 341                 DEBUG(1, ("Failed to start set GENSEC target service: %s\n",
 342                           nt_errstr(status)));
 343                 return status;
 344         }
 345
 346         if (session->transport->negotiate.secblob.length) {
 347                 chosen_oid = GENSEC_OID_SPNEGO;
 348         } else {
 349                 /* without a sec blob, means raw NTLMSSP */
 350                 chosen_oid = GENSEC_OID_NTLMSSP;
 351         }
 352
 353         status = gensec_start_mech_by_oid(session->gensec, chosen_oid);
 354         if (!NT_STATUS_IS_OK(status)) {
 355                 DEBUG(1, ("Failed to start set GENSEC client SPNEGO mechanism %s: %s\n",
 356                           gensec_get_name_by_oid(chosen_oid), nt_errstr(status)));
 357                 return status;
 358         }
 359
 360         status = gensec_update(session->gensec, state,
 361                                session->transport->negotiate.secblob,
 362                                &state->setup.spnego.in.secblob);
 363         if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
 364             !NT_STATUS_IS_OK(status)) {
 365                 DEBUG(1, ("Failed initial gensec_update with mechanism %s: %s\n",
 366                           gensec_get_name_by_oid(chosen_oid), nt_errstr(status)));
 367                 return status;
 368         }
 369         state->gensec_status = status;
 370
 371         session_key_err = gensec_session_key(session->gensec, &session_key);
 372         if (NT_STATUS_IS_OK(session_key_err)) {
 373                 smbcli_transport_simple_set_signing(session->transport, session_key, null_data_blob);
 374         }
 375
 376         *req = smb_raw_sesssetup_send(session, &state->setup);
 377         if (!*req) {
 378                 return NT_STATUS_NO_MEMORY;
 379         }
 380         return (*req)->status;
 381 }
 382
 383
 384 /*
 385   composite session setup function that hides the details of all the
 386   different session setup varients, including the multi-pass nature of
 387   the spnego varient
 388 */
 389 struct composite_context *smb_composite_sesssetup_send(struct smbcli_session *session,
 390                                                        struct smb_composite_sesssetup *io)
 391 {
 392         struct composite_context *c;
 393         struct sesssetup_state *state;
 394         NTSTATUS status;
 395
 396         c = talloc_zero(session, struct composite_context);
 397         if (c == NULL) return NULL;
 398
 399         state = talloc(c, struct sesssetup_state);
 400         if (state == NULL) {
 401                 c->state = COMPOSITE_STATE_ERROR;
 402                 c->status = NT_STATUS_NO_MEMORY;
 403         }
 404
 405         state->io = io;
 406
 407         c->state = COMPOSITE_STATE_IN_PROGRESS;
 408         c->private_data = state;
 409         c->event_ctx = session->transport->socket->event.ctx;
 410
 411         /* no session setup at all in earliest protocol varients */
 412         if (session->transport->negotiate.protocol < PROTOCOL_LANMAN1) {
 413                 ZERO_STRUCT(io->out);
 414                 c->state = COMPOSITE_STATE_DONE;
 415                 return c;
 416         }
 417
 418         /* see what session setup interface we will use */
 419         if (session->transport->negotiate.protocol < PROTOCOL_NT1) {
 420                 status = session_setup_old(c, session, io, &state->req);
 421         } else if (!session->transport->options.use_spnego ||
 422                    !(io->in.capabilities & CAP_EXTENDED_SECURITY)) {
 423                 status = session_setup_nt1(c, session, io, &state->req);
 424         } else {
 425                 status = session_setup_spnego(c, session, io, &state->req);
 426         }
 427
 428         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) ||
 429             NT_STATUS_IS_OK(status)) {
 430                 state->req->async.fn = request_handler;
 431                 state->req->async.private = c;
 432                 return c;
 433         }
 434
 435         c->state = COMPOSITE_STATE_ERROR;
 436         c->status = status;
 437         return c;
 438 }
 439
 440
 441 /*
 442   receive a composite session setup reply
 443 */
 444 NTSTATUS smb_composite_sesssetup_recv(struct composite_context *c)
 445 {
 446         NTSTATUS status;
 447         status = composite_wait(c);
 448         talloc_free(c);
 449         return status;
 450 }
 451
 452 /*
 453   sync version of smb_composite_sesssetup
 454 */
 455 NTSTATUS smb_composite_sesssetup(struct smbcli_session *session, struct smb_composite_sesssetup *io)
 456 {
 457         struct composite_context *c = smb_composite_sesssetup_send(session, io);
 458         return smb_composite_sesssetup_recv(c);
 459 }