source4/libcli/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 "auth/auth.h"
  28 #include "version.h"
  29
  30 struct sesssetup_state {
  31         union smb_sesssetup setup;
  32         NTSTATUS gensec_status;
  33         struct smb_composite_sesssetup *io;
  34         struct smbcli_request *req;
  35 };
  36
  37
  38 /*
  39   form an encrypted lanman password from a plaintext password
  40   and the server supplied challenge
  41 */
  42 static DATA_BLOB lanman_blob(TALLOC_CTX *mem_ctx, const char *pass, DATA_BLOB challenge)
  43 {
  44         DATA_BLOB blob = data_blob_talloc(mem_ctx, NULL, 24);
  45         SMBencrypt(pass, challenge.data, blob.data);
  46         return blob;
  47 }
  48
  49 /*
  50   form an encrypted NT password from a plaintext password
  51   and the server supplied challenge
  52 */
  53 static DATA_BLOB nt_blob(TALLOC_CTX *mem_ctx, const struct samr_Password *nt_hash, DATA_BLOB challenge)
  54 {
  55         DATA_BLOB blob = data_blob_talloc(mem_ctx, NULL, 24);
  56         SMBOWFencrypt(nt_hash->hash, challenge.data, blob.data);
  57         return blob;
  58 }
  59
  60 /*
  61   store the user session key for a transport
  62 */
  63 static void set_user_session_key(struct smbcli_session *session,
  64                                  const DATA_BLOB *session_key)
  65 {
  66         session->user_session_key = data_blob_talloc(session,
  67                                                      session_key->data,
  68                                                      session_key->length);
  69 }
  70
  71 /*
  72   handler for completion of a smbcli_request sub-request
  73 */
  74 static void request_handler(struct smbcli_request *req)
  75 {
  76         struct composite_context *c = req->async.private;
  77         struct sesssetup_state *state = talloc_get_type(c->private, struct sesssetup_state);
  78         struct smbcli_session *session = req->session;
  79         DATA_BLOB session_key = data_blob(NULL, 0);
  80         DATA_BLOB null_data_blob = data_blob(NULL, 0);
  81         NTSTATUS session_key_err;
  82
  83         c->status = smb_raw_sesssetup_recv(req, state, &state->setup);
  84
  85         switch (state->setup.old.level) {
  86         case RAW_SESSSETUP_OLD:
  87                 state->io->out.vuid = state->setup.old.out.vuid;
  88                 break;
  89
  90         case RAW_SESSSETUP_NT1:
  91                 state->io->out.vuid = state->setup.nt1.out.vuid;
  92                 break;
  93
  94         case RAW_SESSSETUP_SPNEGO:
  95                 session->vuid = state->io->out.vuid = state->setup.spnego.out.vuid;
  96                 if (!NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
  97                     !NT_STATUS_IS_OK(c->status)) {
  98                         break;
  99                 }
 100                 if (NT_STATUS_EQUAL(state->gensec_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 101
 102                         /* The status value here, from the earlier pass at GENSEC is
 103                          * vital to the security of the system.  Even if the other end
 104                          * accepts, if GENSEC claims 'MORE_PROCESSING_REQUIRED' then
 105                          * you must keep feeding it blobs, or else the remote
 106                          * host/attacker might avoid mutal authentication
 107                          * requirements */
 108
 109                         state->gensec_status = gensec_update(session->gensec, state,
 110                                                          state->setup.spnego.out.secblob,
 111                                                          &state->setup.spnego.in.secblob);
 112                         c->status = state->gensec_status;
 113                         if (!NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
 114                             !NT_STATUS_IS_OK(c->status)) {
 115                                 break;
 116                         }
 117                 } else {
 118                         state->setup.spnego.in.secblob = data_blob(NULL, 0);
 119                 }
 120
 121                 /* we need to do another round of session setup. We keep going until both sides
 122                    are happy */
 123                 session_key_err = gensec_session_key(session->gensec, &session_key);
 124                 if (NT_STATUS_IS_OK(session_key_err)) {
 125                         set_user_session_key(session, &session_key);
 126                         smbcli_transport_simple_set_signing(session->transport, session_key, null_data_blob);
 127                 }
 128
 129                 if (state->setup.spnego.in.secblob.length) {
 130                         state->req = smb_raw_sesssetup_send(session, &state->setup);
 131                         state->req->async.fn = request_handler;
 132                         state->req->async.private = c;
 133                         return;
 134                 }
 135         }
 136
 137         /* enforce the local signing required flag */
 138         if (NT_STATUS_IS_OK(c->status) && !cli_credentials_is_anonymous(state->io->in.credentials)) {
 139                 if (!session->transport->negotiate.sign_info.doing_signing
 140                     && session->transport->negotiate.sign_info.mandatory_signing) {
 141                         DEBUG(0, ("SMB signing required, but server does not support it\n"));
 142                         c->status = NT_STATUS_ACCESS_DENIED;
 143                 }
 144         }
 145
 146         if (NT_STATUS_IS_OK(c->status)) {
 147                 c->state = SMBCLI_REQUEST_DONE;
 148         } else {
 149                 c->state = SMBCLI_REQUEST_ERROR;
 150         }
 151         if (c->async.fn) {
 152                 c->async.fn(c);
 153         }
 154 }
 155
 156
 157 /*
 158   send a nt1 style session setup
 159 */
 160 static NTSTATUS session_setup_nt1(struct composite_context *c,
 161                                   struct smbcli_session *session,
 162                                   struct smb_composite_sesssetup *io,
 163                                   struct smbcli_request **req)
 164 {
 165         struct sesssetup_state *state = talloc_get_type(c->private, struct sesssetup_state);
 166         const struct samr_Password *nt_hash = cli_credentials_get_nt_hash(io->in.credentials, state);
 167         const char *password = cli_credentials_get_password(io->in.credentials);
 168
 169         state->setup.nt1.level           = RAW_SESSSETUP_NT1;
 170         state->setup.nt1.in.bufsize      = session->transport->options.max_xmit;
 171         state->setup.nt1.in.mpx_max      = session->transport->options.max_mux;
 172         state->setup.nt1.in.vc_num       = 1;
 173         state->setup.nt1.in.sesskey      = io->in.sesskey;
 174         state->setup.nt1.in.capabilities = io->in.capabilities;
 175         state->setup.nt1.in.os           = "Unix";
 176         state->setup.nt1.in.lanman       = talloc_asprintf(state, "Samba %s", SAMBA_VERSION_STRING);
 177         state->setup.nt1.in.user         = cli_credentials_get_username(io->in.credentials);
 178         state->setup.nt1.in.domain       = cli_credentials_get_domain(io->in.credentials);
 179
 180         if (!password) {
 181                 state->setup.nt1.in.password1 = data_blob(NULL, 0);
 182                 state->setup.nt1.in.password2 = data_blob(NULL, 0);
 183         } else if (session->transport->negotiate.sec_mode &
 184                    NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) {
 185                 DATA_BLOB session_key;
 186                 if (lp_client_ntlmv2_auth()) {
 187                         DATA_BLOB names_blob = NTLMv2_generate_names_blob(state, lp_netbios_name(), lp_workgroup());
 188                         DATA_BLOB lmv2_response, ntlmv2_response, lmv2_session_key;
 189
 190                         if (!SMBNTLMv2encrypt_hash(state,
 191                                                    state->setup.nt1.in.user, state->setup.nt1.in.domain,
 192                                                    nt_hash->hash, &session->transport->negotiate.secblob,
 193                                                    &names_blob,
 194                                                    &lmv2_response, &ntlmv2_response,
 195                                                    &lmv2_session_key, &session_key)) {
 196                                 data_blob_free(&names_blob);
 197                                 return NT_STATUS_NO_MEMORY;
 198                         }
 199                         data_blob_free(&names_blob);
 200                         state->setup.nt1.in.password1 = lmv2_response;
 201                         state->setup.nt1.in.password2 = ntlmv2_response;
 202
 203                         smbcli_transport_simple_set_signing(session->transport, session_key,
 204                                                             state->setup.nt1.in.password2);
 205                         set_user_session_key(session, &session_key);
 206
 207                         data_blob_free(&lmv2_session_key);
 208                         data_blob_free(&session_key);
 209                 } else {
 210
 211                         state->setup.nt1.in.password2 = nt_blob(state, nt_hash,
 212                                                                 session->transport->negotiate.secblob);
 213                         if (lp_client_lanman_auth()) {
 214                                 state->setup.nt1.in.password1 = lanman_blob(state, password,
 215                                                                             session->transport->negotiate.secblob);
 216                         } else {
 217                                 /* if not sending the LM password, send the NT password twice */
 218                                 state->setup.nt1.in.password1 = state->setup.nt1.in.password2;
 219                         }
 220
 221                         session_key = data_blob_talloc(session, NULL, 16);
 222                         SMBsesskeygen_ntv1(nt_hash->hash, session_key.data);
 223                         smbcli_transport_simple_set_signing(session->transport, session_key,
 224                                                             state->setup.nt1.in.password2);
 225                         set_user_session_key(session, &session_key);
 226
 227                         data_blob_free(&session_key);
 228                 }
 229
 230         } else if (lp_client_plaintext_auth()) {
 231                 state->setup.nt1.in.password1 = data_blob_talloc(state, password, strlen(password));
 232                 state->setup.nt1.in.password2 = data_blob(NULL, 0);
 233         } else {
 234                 /* could match windows client and return 'cannot logon from this workstation', but it just confuses everybody */
 235                 return NT_STATUS_INVALID_PARAMETER;
 236         }
 237
 238         *req = smb_raw_sesssetup_send(session, &state->setup);
 239         if (!*req) {
 240                 return NT_STATUS_NO_MEMORY;
 241         }
 242         return (*req)->status;
 243 }
 244
 245
 246 /*
 247   old style session setup (pre NT1 protocol level)
 248 */
 249 static NTSTATUS session_setup_old(struct composite_context *c,
 250                                   struct smbcli_session *session,
 251                                   struct smb_composite_sesssetup *io,
 252                                   struct smbcli_request **req)
 253 {
 254         struct sesssetup_state *state = talloc_get_type(c->private, struct sesssetup_state);
 255         const char *password = cli_credentials_get_password(io->in.credentials);
 256
 257         state->setup.old.level      = RAW_SESSSETUP_OLD;
 258         state->setup.old.in.bufsize = session->transport->options.max_xmit;
 259         state->setup.old.in.mpx_max = session->transport->options.max_mux;
 260         state->setup.old.in.vc_num  = 1;
 261         state->setup.old.in.sesskey = io->in.sesskey;
 262         state->setup.old.in.domain  = cli_credentials_get_domain(io->in.credentials);
 263         state->setup.old.in.user    = cli_credentials_get_username(io->in.credentials);
 264         state->setup.old.in.os      = "Unix";
 265         state->setup.old.in.lanman  = talloc_asprintf(state, "Samba %s", SAMBA_VERSION_STRING);
 266
 267         if (!password) {
 268                 state->setup.old.in.password = data_blob(NULL, 0);
 269         } else if (session->transport->negotiate.sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) {
 270                 state->setup.old.in.password = lanman_blob(state, password,
 271                                                            session->transport->negotiate.secblob);
 272         } else {
 273                 state->setup.old.in.password = data_blob_talloc(state,
 274                                                                 password,
 275                                                                 strlen(password));
 276         }
 277
 278         *req = smb_raw_sesssetup_send(session, &state->setup);
 279         if (!*req) {
 280                 return NT_STATUS_NO_MEMORY;
 281         }
 282         return (*req)->status;
 283 }
 284
 285
 286 /*
 287   Modern, all singing, all dancing extended security (and possibly SPNEGO) request
 288 */
 289 static NTSTATUS session_setup_spnego(struct composite_context *c,
 290                                      struct smbcli_session *session,
 291                                      struct smb_composite_sesssetup *io,
 292                                      struct smbcli_request **req)
 293 {
 294         struct sesssetup_state *state = talloc_get_type(c->private, struct sesssetup_state);
 295         NTSTATUS status, session_key_err;
 296         DATA_BLOB session_key = data_blob(NULL, 0);
 297         DATA_BLOB null_data_blob = data_blob(NULL, 0);
 298         const char *chosen_oid = NULL;
 299
 300         state->setup.spnego.level           = RAW_SESSSETUP_SPNEGO;
 301         state->setup.spnego.in.bufsize      = session->transport->options.max_xmit;
 302         state->setup.spnego.in.mpx_max      = session->transport->options.max_mux;
 303         state->setup.spnego.in.vc_num       = 1;
 304         state->setup.spnego.in.sesskey      = io->in.sesskey;
 305         state->setup.spnego.in.capabilities = io->in.capabilities;
 306         state->setup.spnego.in.os           = "Unix";
 307         state->setup.spnego.in.lanman       = talloc_asprintf(state, "Samba %s", SAMBA_VERSION_STRING);
 308         state->setup.spnego.in.workgroup    = io->in.workgroup;
 309
 310         state->setup.spnego.out.vuid        = session->vuid;
 311
 312         smbcli_temp_set_signing(session->transport);
 313
 314         status = gensec_client_start(session, &session->gensec, c->event_ctx);
 315         if (!NT_STATUS_IS_OK(status)) {
 316                 DEBUG(1, ("Failed to start GENSEC client mode: %s\n", nt_errstr(status)));
 317                 return status;
 318         }
 319
 320         gensec_want_feature(session->gensec, GENSEC_FEATURE_SESSION_KEY);
 321
 322         status = gensec_set_credentials(session->gensec, io->in.credentials);
 323         if (!NT_STATUS_IS_OK(status)) {
 324                 DEBUG(1, ("Failed to start set GENSEC client credentails: %s\n",
 325                           nt_errstr(status)));
 326                 return status;
 327         }
 328
 329         status = gensec_set_target_hostname(session->gensec, session->transport->socket->hostname);
 330         if (!NT_STATUS_IS_OK(status)) {
 331                 DEBUG(1, ("Failed to start set GENSEC target hostname: %s\n",
 332                           nt_errstr(status)));
 333                 return status;
 334         }
 335
 336         status = gensec_set_target_service(session->gensec, "cifs");
 337         if (!NT_STATUS_IS_OK(status)) {
 338                 DEBUG(1, ("Failed to start set GENSEC target service: %s\n",
 339                           nt_errstr(status)));
 340                 return status;
 341         }
 342
 343         if (session->transport->negotiate.secblob.length) {
 344                 chosen_oid = GENSEC_OID_SPNEGO;
 345         } else {
 346                 /* without a sec blob, means raw NTLMSSP */
 347                 chosen_oid = GENSEC_OID_NTLMSSP;
 348         }
 349
 350         status = gensec_start_mech_by_oid(session->gensec, chosen_oid);
 351         if (!NT_STATUS_IS_OK(status)) {
 352                 DEBUG(1, ("Failed to start set GENSEC client SPNEGO mechanism %s: %s\n",
 353                           gensec_get_name_by_oid(chosen_oid), nt_errstr(status)));
 354                 return status;
 355         }
 356
 357         status = gensec_update(session->gensec, state,
 358                                session->transport->negotiate.secblob,
 359                                &state->setup.spnego.in.secblob);
 360         if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
 361             !NT_STATUS_IS_OK(status)) {
 362                 DEBUG(1, ("Failed initial gensec_update with mechanism %s: %s\n",
 363                           gensec_get_name_by_oid(chosen_oid), nt_errstr(status)));
 364                 return status;
 365         }
 366         state->gensec_status = status;
 367
 368         session_key_err = gensec_session_key(session->gensec, &session_key);
 369         if (NT_STATUS_IS_OK(session_key_err)) {
 370                 smbcli_transport_simple_set_signing(session->transport, session_key, null_data_blob);
 371         }
 372
 373         *req = smb_raw_sesssetup_send(session, &state->setup);
 374         if (!*req) {
 375                 return NT_STATUS_NO_MEMORY;
 376         }
 377         return (*req)->status;
 378 }
 379
 380
 381 /*
 382   composite session setup function that hides the details of all the
 383   different session setup varients, including the multi-pass nature of
 384   the spnego varient
 385 */
 386 struct composite_context *smb_composite_sesssetup_send(struct smbcli_session *session,
 387                                                        struct smb_composite_sesssetup *io)
 388 {
 389         struct composite_context *c;
 390         struct sesssetup_state *state;
 391         NTSTATUS status;
 392
 393         c = talloc_zero(session, struct composite_context);
 394         if (c == NULL) return NULL;
 395
 396         state = talloc(c, struct sesssetup_state);
 397         if (state == NULL) {
 398                 c->state = SMBCLI_REQUEST_ERROR;
 399                 c->status = NT_STATUS_NO_MEMORY;
 400         }
 401
 402         state->io = io;
 403
 404         c->state = SMBCLI_REQUEST_SEND;
 405         c->private = state;
 406         c->event_ctx = session->transport->socket->event.ctx;
 407
 408         /* no session setup at all in earliest protocol varients */
 409         if (session->transport->negotiate.protocol < PROTOCOL_LANMAN1) {
 410                 ZERO_STRUCT(io->out);
 411                 c->state = SMBCLI_REQUEST_DONE;
 412                 return c;
 413         }
 414
 415         /* see what session setup interface we will use */
 416         if (session->transport->negotiate.protocol < PROTOCOL_NT1) {
 417                 status = session_setup_old(c, session, io, &state->req);
 418         } else if (!session->transport->options.use_spnego ||
 419                    !(io->in.capabilities & CAP_EXTENDED_SECURITY)) {
 420                 status = session_setup_nt1(c, session, io, &state->req);
 421         } else {
 422                 status = session_setup_spnego(c, session, io, &state->req);
 423         }
 424
 425         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) ||
 426             NT_STATUS_IS_OK(status)) {
 427                 state->req->async.fn = request_handler;
 428                 state->req->async.private = c;
 429                 return c;
 430         }
 431
 432         c->state = SMBCLI_REQUEST_ERROR;
 433         c->status = status;
 434         return c;
 435 }
 436
 437
 438 /*
 439   receive a composite session setup reply
 440 */
 441 NTSTATUS smb_composite_sesssetup_recv(struct composite_context *c)
 442 {
 443         NTSTATUS status;
 444         status = composite_wait(c);
 445         talloc_free(c);
 446         return status;
 447 }
 448
 449 /*
 450   sync version of smb_composite_sesssetup
 451 */
 452 NTSTATUS smb_composite_sesssetup(struct smbcli_session *session, struct smb_composite_sesssetup *io)
 453 {
 454         struct composite_context *c = smb_composite_sesssetup_send(session, io);
 455         return smb_composite_sesssetup_recv(c);
 456 }