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                         data_blob_free(&lmv2_session_key);
 203                         state->setup.nt1.in.password1 = lmv2_response;
 204                         state->setup.nt1.in.password2 = ntlmv2_response;
 205
 206                 } else {
 207
 208                         state->setup.nt1.in.password2 = nt_blob(state, nt_hash,
 209                                                                 session->transport->negotiate.secblob);
 210                         if (lp_client_lanman_auth()) {
 211                                 state->setup.nt1.in.password1 = lanman_blob(state, password,
 212                                                                             session->transport->negotiate.secblob);
 213                         } else {
 214                                 /* if not sending the LM password, send the NT password twice */
 215                                 state->setup.nt1.in.password1 = state->setup.nt1.in.password2;
 216                         }
 217
 218                         session_key = data_blob_talloc(session, NULL, 16);
 219                         SMBsesskeygen_ntv1(nt_hash->hash, session_key.data);
 220                 }
 221
 222                 smbcli_transport_simple_set_signing(session->transport, session_key,
 223                                                     state->setup.nt1.in.password2);
 224                 set_user_session_key(session, &session_key);
 225
 226                 data_blob_free(&session_key);
 227
 228         } else if (lp_client_plaintext_auth()) {
 229                 state->setup.nt1.in.password1 = data_blob_talloc(state, password, strlen(password));
 230                 state->setup.nt1.in.password2 = data_blob(NULL, 0);
 231         } else {
 232                 /* could match windows client and return 'cannot logon from this workstation', but it just confuses everybody */
 233                 return NT_STATUS_INVALID_PARAMETER;
 234         }
 235
 236         *req = smb_raw_sesssetup_send(session, &state->setup);
 237         if (!*req) {
 238                 return NT_STATUS_NO_MEMORY;
 239         }
 240         return (*req)->status;
 241 }
 242
 243
 244 /*
 245   old style session setup (pre NT1 protocol level)
 246 */
 247 static NTSTATUS session_setup_old(struct composite_context *c,
 248                                   struct smbcli_session *session,
 249                                   struct smb_composite_sesssetup *io,
 250                                   struct smbcli_request **req)
 251 {
 252         struct sesssetup_state *state = talloc_get_type(c->private_data, struct sesssetup_state);
 253         const char *password = cli_credentials_get_password(io->in.credentials);
 254
 255         state->setup.old.level      = RAW_SESSSETUP_OLD;
 256         state->setup.old.in.bufsize = session->transport->options.max_xmit;
 257         state->setup.old.in.mpx_max = session->transport->options.max_mux;
 258         state->setup.old.in.vc_num  = 1;
 259         state->setup.old.in.sesskey = io->in.sesskey;
 260         state->setup.old.in.os      = "Unix";
 261         state->setup.old.in.lanman  = talloc_asprintf(state, "Samba %s", SAMBA_VERSION_STRING);
 262         cli_credentials_get_ntlm_username_domain(io->in.credentials, state,
 263                                                  &state->setup.old.in.user,
 264                                                  &state->setup.old.in.domain);
 265
 266         if (!password) {
 267                 state->setup.old.in.password = data_blob(NULL, 0);
 268         } else if (session->transport->negotiate.sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) {
 269                 state->setup.old.in.password = lanman_blob(state, password,
 270                                                            session->transport->negotiate.secblob);
 271         } else {
 272                 state->setup.old.in.password = data_blob_talloc(state,
 273                                                                 password,
 274                                                                 strlen(password));
 275         }
 276
 277         *req = smb_raw_sesssetup_send(session, &state->setup);
 278         if (!*req) {
 279                 return NT_STATUS_NO_MEMORY;
 280         }
 281         return (*req)->status;
 282 }
 283
 284
 285 /*
 286   Modern, all singing, all dancing extended security (and possibly SPNEGO) request
 287 */
 288 static NTSTATUS session_setup_spnego(struct composite_context *c,
 289                                      struct smbcli_session *session,
 290                                      struct smb_composite_sesssetup *io,
 291                                      struct smbcli_request **req)
 292 {
 293         struct sesssetup_state *state = talloc_get_type(c->private_data, struct sesssetup_state);
 294         NTSTATUS status, session_key_err;
 295         DATA_BLOB session_key = data_blob(NULL, 0);
 296         DATA_BLOB null_data_blob = data_blob(NULL, 0);
 297         const char *chosen_oid = NULL;
 298
 299         state->setup.spnego.level           = RAW_SESSSETUP_SPNEGO;
 300         state->setup.spnego.in.bufsize      = session->transport->options.max_xmit;
 301         state->setup.spnego.in.mpx_max      = session->transport->options.max_mux;
 302         state->setup.spnego.in.vc_num       = 1;
 303         state->setup.spnego.in.sesskey      = io->in.sesskey;
 304         state->setup.spnego.in.capabilities = io->in.capabilities;
 305         state->setup.spnego.in.os           = "Unix";
 306         state->setup.spnego.in.lanman       = talloc_asprintf(state, "Samba %s", SAMBA_VERSION_STRING);
 307         state->setup.spnego.in.workgroup    = io->in.workgroup;
 308
 309         state->setup.spnego.out.vuid        = session->vuid;
 310
 311         smbcli_temp_set_signing(session->transport);
 312
 313         status = gensec_client_start(session, &session->gensec, c->event_ctx);
 314         if (!NT_STATUS_IS_OK(status)) {
 315                 DEBUG(1, ("Failed to start GENSEC client mode: %s\n", nt_errstr(status)));
 316                 return status;
 317         }
 318
 319         gensec_want_feature(session->gensec, GENSEC_FEATURE_SESSION_KEY);
 320
 321         status = gensec_set_credentials(session->gensec, io->in.credentials);
 322         if (!NT_STATUS_IS_OK(status)) {
 323                 DEBUG(1, ("Failed to start set GENSEC client credentails: %s\n",
 324                           nt_errstr(status)));
 325                 return status;
 326         }
 327
 328         status = gensec_set_target_hostname(session->gensec, session->transport->socket->hostname);
 329         if (!NT_STATUS_IS_OK(status)) {
 330                 DEBUG(1, ("Failed to start set GENSEC target hostname: %s\n",
 331                           nt_errstr(status)));
 332                 return status;
 333         }
 334
 335         status = gensec_set_target_service(session->gensec, "cifs");
 336         if (!NT_STATUS_IS_OK(status)) {
 337                 DEBUG(1, ("Failed to start set GENSEC target service: %s\n",
 338                           nt_errstr(status)));
 339                 return status;
 340         }
 341
 342         if (session->transport->negotiate.secblob.length) {
 343                 chosen_oid = GENSEC_OID_SPNEGO;
 344         } else {
 345                 /* without a sec blob, means raw NTLMSSP */
 346                 chosen_oid = GENSEC_OID_NTLMSSP;
 347         }
 348
 349         status = gensec_start_mech_by_oid(session->gensec, chosen_oid);
 350         if (!NT_STATUS_IS_OK(status)) {
 351                 DEBUG(1, ("Failed to start set GENSEC client SPNEGO mechanism %s: %s\n",
 352                           gensec_get_name_by_oid(chosen_oid), nt_errstr(status)));
 353                 return status;
 354         }
 355
 356         status = gensec_update(session->gensec, state,
 357                                session->transport->negotiate.secblob,
 358                                &state->setup.spnego.in.secblob);
 359         if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
 360             !NT_STATUS_IS_OK(status)) {
 361                 DEBUG(1, ("Failed initial gensec_update with mechanism %s: %s\n",
 362                           gensec_get_name_by_oid(chosen_oid), nt_errstr(status)));
 363                 return status;
 364         }
 365         state->gensec_status = status;
 366
 367         session_key_err = gensec_session_key(session->gensec, &session_key);
 368         if (NT_STATUS_IS_OK(session_key_err)) {
 369                 smbcli_transport_simple_set_signing(session->transport, session_key, null_data_blob);
 370         }
 371
 372         *req = smb_raw_sesssetup_send(session, &state->setup);
 373         if (!*req) {
 374                 return NT_STATUS_NO_MEMORY;
 375         }
 376         return (*req)->status;
 377 }
 378
 379
 380 /*
 381   composite session setup function that hides the details of all the
 382   different session setup varients, including the multi-pass nature of
 383   the spnego varient
 384 */
 385 struct composite_context *smb_composite_sesssetup_send(struct smbcli_session *session,
 386                                                        struct smb_composite_sesssetup *io)
 387 {
 388         struct composite_context *c;
 389         struct sesssetup_state *state;
 390         NTSTATUS status;
 391
 392         c = talloc_zero(session, struct composite_context);
 393         if (c == NULL) return NULL;
 394
 395         state = talloc(c, struct sesssetup_state);
 396         if (state == NULL) {
 397                 c->state = COMPOSITE_STATE_ERROR;
 398                 c->status = NT_STATUS_NO_MEMORY;
 399         }
 400
 401         state->io = io;
 402
 403         c->state = COMPOSITE_STATE_IN_PROGRESS;
 404         c->private_data = state;
 405         c->event_ctx = session->transport->socket->event.ctx;
 406
 407         /* no session setup at all in earliest protocol varients */
 408         if (session->transport->negotiate.protocol < PROTOCOL_LANMAN1) {
 409                 ZERO_STRUCT(io->out);
 410                 c->state = COMPOSITE_STATE_DONE;
 411                 return c;
 412         }
 413
 414         /* see what session setup interface we will use */
 415         if (session->transport->negotiate.protocol < PROTOCOL_NT1) {
 416                 status = session_setup_old(c, session, io, &state->req);
 417         } else if (!session->transport->options.use_spnego ||
 418                    !(io->in.capabilities & CAP_EXTENDED_SECURITY)) {
 419                 status = session_setup_nt1(c, session, io, &state->req);
 420         } else {
 421                 status = session_setup_spnego(c, session, io, &state->req);
 422         }
 423
 424         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) ||
 425             NT_STATUS_IS_OK(status)) {
 426                 state->req->async.fn = request_handler;
 427                 state->req->async.private = c;
 428                 return c;
 429         }
 430
 431         c->state = COMPOSITE_STATE_ERROR;
 432         c->status = status;
 433         return c;
 434 }
 435
 436
 437 /*
 438   receive a composite session setup reply
 439 */
 440 NTSTATUS smb_composite_sesssetup_recv(struct composite_context *c)
 441 {
 442         NTSTATUS status;
 443         status = composite_wait(c);
 444         talloc_free(c);
 445         return status;
 446 }
 447
 448 /*
 449   sync version of smb_composite_sesssetup
 450 */
 451 NTSTATUS smb_composite_sesssetup(struct smbcli_session *session, struct smb_composite_sesssetup *io)
 452 {
 453         struct composite_context *c = smb_composite_sesssetup_send(session, io);
 454         return smb_composite_sesssetup_recv(c);
 455 }