source4/librpc/rpc/dcerpc_auth.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Generic Authentication Interface
   5
   6    Copyright (C) Andrew Tridgell 2003
   7    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   8    Copyright (C) Stefan Metzmacher 2004
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include <tevent.h>
  26 #include "libcli/composite/composite.h"
  27 #include "auth/gensec/gensec.h"
  28 #include "librpc/rpc/dcerpc.h"
  29 #include "librpc/rpc/dcerpc_proto.h"
  30 #include "param/param.h"
  31
  32 /*
  33   return the rpc syntax and transfer syntax given the pipe uuid and version
  34 */
  35 static NTSTATUS dcerpc_init_syntaxes(const struct ndr_interface_table *table,
  36                                      uint32_t pipe_flags,
  37                                      struct ndr_syntax_id *syntax,
  38                                      struct ndr_syntax_id *transfer_syntax)
  39 {
  40         syntax->uuid = table->syntax_id.uuid;
  41         syntax->if_version = table->syntax_id.if_version;
  42
  43         if (pipe_flags & DCERPC_NDR64) {
  44                 *transfer_syntax = ndr_transfer_syntax_ndr64;
  45         } else {
  46                 *transfer_syntax = ndr_transfer_syntax_ndr;
  47         }
  48
  49         return NT_STATUS_OK;
  50 }
  51
  52
  53 /*
  54   Send request to do a non-authenticated dcerpc bind
  55 */
  56 static void dcerpc_bind_auth_none_done(struct tevent_req *subreq);
  57
  58 struct composite_context *dcerpc_bind_auth_none_send(TALLOC_CTX *mem_ctx,
  59                                                      struct dcerpc_pipe *p,
  60                                                      const struct ndr_interface_table *table)
  61 {
  62         struct ndr_syntax_id syntax;
  63         struct ndr_syntax_id transfer_syntax;
  64
  65         struct composite_context *c;
  66         struct tevent_req *subreq;
  67
  68         c = composite_create(mem_ctx, p->conn->event_ctx);
  69         if (c == NULL) return NULL;
  70
  71         c->status = dcerpc_init_syntaxes(table, p->conn->flags,
  72                                          &syntax, &transfer_syntax);
  73         if (!NT_STATUS_IS_OK(c->status)) {
  74                 DEBUG(2,("Invalid uuid string in "
  75                          "dcerpc_bind_auth_none_send\n"));
  76                 composite_error(c, c->status);
  77                 return c;
  78         }
  79
  80         subreq = dcerpc_bind_send(mem_ctx, p->conn->event_ctx, p,
  81                                   &syntax, &transfer_syntax);
  82         if (composite_nomem(subreq, c)) return c;
  83         tevent_req_set_callback(subreq, dcerpc_bind_auth_none_done, c);
  84
  85         return c;
  86 }
  87
  88 static void dcerpc_bind_auth_none_done(struct tevent_req *subreq)
  89 {
  90         struct composite_context *ctx =
  91                 tevent_req_callback_data(subreq,
  92                 struct composite_context);
  93
  94         ctx->status = dcerpc_bind_recv(subreq);
  95         TALLOC_FREE(subreq);
  96         if (!composite_is_ok(ctx)) return;
  97
  98         composite_done(ctx);
  99 }
 100
 101 /*
 102   Receive result of a non-authenticated dcerpc bind
 103 */
 104 NTSTATUS dcerpc_bind_auth_none_recv(struct composite_context *ctx)
 105 {
 106         NTSTATUS result = composite_wait(ctx);
 107         TALLOC_FREE(ctx);
 108         return result;
 109 }
 110
 111
 112 /*
 113   Perform sync non-authenticated dcerpc bind
 114 */
 115 _PUBLIC_ NTSTATUS dcerpc_bind_auth_none(struct dcerpc_pipe *p,
 116                                const struct ndr_interface_table *table)
 117 {
 118         struct composite_context *ctx;
 119
 120         ctx = dcerpc_bind_auth_none_send(p, p, table);
 121         return dcerpc_bind_auth_none_recv(ctx);
 122 }
 123
 124
 125 struct bind_auth_state {
 126         struct dcerpc_pipe *pipe;
 127         DATA_BLOB credentials;
 128         bool more_processing;   /* Is there anything more to do after the
 129                                  * first bind itself received? */
 130 };
 131
 132 static void bind_auth_recv_alter(struct tevent_req *subreq);
 133
 134 static void bind_auth_next_step(struct composite_context *c)
 135 {
 136         struct bind_auth_state *state;
 137         struct dcecli_security *sec;
 138         struct tevent_req *subreq;
 139         bool more_processing = false;
 140
 141         state = talloc_get_type(c->private_data, struct bind_auth_state);
 142         sec = &state->pipe->conn->security_state;
 143
 144         /* The status value here, from GENSEC is vital to the security
 145          * of the system.  Even if the other end accepts, if GENSEC
 146          * claims 'MORE_PROCESSING_REQUIRED' then you must keep
 147          * feeding it blobs, or else the remote host/attacker might
 148          * avoid mutal authentication requirements.
 149          *
 150          * Likewise, you must not feed GENSEC too much (after the OK),
 151          * it doesn't like that either
 152          */
 153
 154         state->pipe->inhibit_timeout_processing = true;
 155         state->pipe->timed_out = false;
 156
 157         c->status = gensec_update(sec->generic_state, state,
 158                                   state->pipe->conn->event_ctx,
 159                                   sec->auth_info->credentials,
 160                                   &state->credentials);
 161         if (state->pipe->timed_out) {
 162                 composite_error(c, NT_STATUS_IO_TIMEOUT);
 163                 return;
 164         }
 165         state->pipe->inhibit_timeout_processing = false;
 166
 167         data_blob_free(&sec->auth_info->credentials);
 168
 169         if (NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 170                 more_processing = true;
 171                 c->status = NT_STATUS_OK;
 172         }
 173
 174         if (!composite_is_ok(c)) return;
 175
 176         if (state->pipe->conn->flags & DCERPC_HEADER_SIGNING) {
 177                 gensec_want_feature(sec->generic_state, GENSEC_FEATURE_SIGN_PKT_HEADER);
 178         }
 179
 180         if (state->credentials.length == 0) {
 181                 composite_done(c);
 182                 return;
 183         }
 184
 185         sec->auth_info->credentials = state->credentials;
 186
 187         if (!more_processing) {
 188                 /* NO reply expected, so just send it */
 189                 c->status = dcerpc_auth3(state->pipe, state);
 190                 data_blob_free(&state->credentials);
 191                 sec->auth_info->credentials = data_blob(NULL, 0);
 192                 if (!composite_is_ok(c)) return;
 193
 194                 composite_done(c);
 195                 return;
 196         }
 197
 198         /* We are demanding a reply, so use a request that will get us one */
 199
 200         subreq = dcerpc_alter_context_send(state, state->pipe->conn->event_ctx,
 201                                            state->pipe,
 202                                            &state->pipe->syntax,
 203                                            &state->pipe->transfer_syntax);
 204         data_blob_free(&state->credentials);
 205         sec->auth_info->credentials = data_blob(NULL, 0);
 206         if (composite_nomem(subreq, c)) return;
 207         tevent_req_set_callback(subreq, bind_auth_recv_alter, c);
 208 }
 209
 210
 211 static void bind_auth_recv_alter(struct tevent_req *subreq)
 212 {
 213         struct composite_context *c =
 214                 tevent_req_callback_data(subreq,
 215                 struct composite_context);
 216
 217         c->status = dcerpc_alter_context_recv(subreq);
 218         TALLOC_FREE(subreq);
 219         if (!composite_is_ok(c)) return;
 220
 221         bind_auth_next_step(c);
 222 }
 223
 224
 225 static void bind_auth_recv_bindreply(struct tevent_req *subreq)
 226 {
 227         struct composite_context *c =
 228                 tevent_req_callback_data(subreq,
 229                 struct composite_context);
 230         struct bind_auth_state *state = talloc_get_type(c->private_data,
 231                                                         struct bind_auth_state);
 232
 233         c->status = dcerpc_bind_recv(subreq);
 234         TALLOC_FREE(subreq);
 235         if (!composite_is_ok(c)) return;
 236
 237         if (!state->more_processing) {
 238                 /* The first gensec_update has not requested a second run, so
 239                  * we're done here. */
 240                 composite_done(c);
 241                 return;
 242         }
 243
 244         bind_auth_next_step(c);
 245 }
 246
 247
 248 /**
 249    Bind to a DCE/RPC pipe, send async request
 250    @param mem_ctx TALLOC_CTX for the allocation of the composite_context
 251    @param p The dcerpc_pipe to bind (must already be connected)
 252    @param table The interface table to use (the DCE/RPC bind both selects and interface and authenticates)
 253    @param credentials The credentials of the account to connect with
 254    @param auth_type Select the authentication scheme to use
 255    @param auth_level Chooses between unprotected (connect), signed or sealed
 256    @param service The service (used by Kerberos to select the service principal to contact)
 257    @retval A composite context describing the partial state of the bind
 258 */
 259
 260 struct composite_context *dcerpc_bind_auth_send(TALLOC_CTX *mem_ctx,
 261                                                 struct dcerpc_pipe *p,
 262                                                 const struct ndr_interface_table *table,
 263                                                 struct cli_credentials *credentials,
 264                                                 struct gensec_settings *gensec_settings,
 265                                                 uint8_t auth_type, uint8_t auth_level,
 266                                                 const char *service)
 267 {
 268         struct composite_context *c;
 269         struct bind_auth_state *state;
 270         struct dcecli_security *sec;
 271         struct tevent_req *subreq;
 272
 273         struct ndr_syntax_id syntax, transfer_syntax;
 274
 275         /* composite context allocation and setup */
 276         c = composite_create(mem_ctx, p->conn->event_ctx);
 277         if (c == NULL) return NULL;
 278
 279         state = talloc(c, struct bind_auth_state);
 280         if (composite_nomem(state, c)) return c;
 281         c->private_data = state;
 282
 283         state->pipe = p;
 284
 285         c->status = dcerpc_init_syntaxes(table, p->conn->flags,
 286                                          &syntax,
 287                                          &transfer_syntax);
 288         if (!composite_is_ok(c)) return c;
 289
 290         sec = &p->conn->security_state;
 291
 292         c->status = gensec_client_start(p, &sec->generic_state,
 293                                         gensec_settings);
 294         if (!NT_STATUS_IS_OK(c->status)) {
 295                 DEBUG(1, ("Failed to start GENSEC client mode: %s\n",
 296                           nt_errstr(c->status)));
 297                 composite_error(c, c->status);
 298                 return c;
 299         }
 300
 301         c->status = gensec_set_credentials(sec->generic_state, credentials);
 302         if (!NT_STATUS_IS_OK(c->status)) {
 303                 DEBUG(1, ("Failed to set GENSEC client credentials: %s\n",
 304                           nt_errstr(c->status)));
 305                 composite_error(c, c->status);
 306                 return c;
 307         }
 308
 309         c->status = gensec_set_target_hostname(sec->generic_state,
 310                                                p->conn->transport.target_hostname(p->conn));
 311         if (!NT_STATUS_IS_OK(c->status)) {
 312                 DEBUG(1, ("Failed to set GENSEC target hostname: %s\n",
 313                           nt_errstr(c->status)));
 314                 composite_error(c, c->status);
 315                 return c;
 316         }
 317
 318         if (service != NULL) {
 319                 c->status = gensec_set_target_service(sec->generic_state,
 320                                                       service);
 321                 if (!NT_STATUS_IS_OK(c->status)) {
 322                         DEBUG(1, ("Failed to set GENSEC target service: %s\n",
 323                                   nt_errstr(c->status)));
 324                         composite_error(c, c->status);
 325                         return c;
 326                 }
 327         }
 328
 329         if (p->binding && p->binding->target_principal) {
 330                 c->status = gensec_set_target_principal(sec->generic_state,
 331                                                         p->binding->target_principal);
 332                 if (!NT_STATUS_IS_OK(c->status)) {
 333                         DEBUG(1, ("Failed to set GENSEC target principal to %s: %s\n",
 334                                   p->binding->target_principal, nt_errstr(c->status)));
 335                         composite_error(c, c->status);
 336                         return c;
 337                 }
 338         }
 339
 340         c->status = gensec_start_mech_by_authtype(sec->generic_state,
 341                                                   auth_type, auth_level);
 342         if (!NT_STATUS_IS_OK(c->status)) {
 343                 DEBUG(1, ("Failed to start GENSEC client mechanism %s: %s\n",
 344                           gensec_get_name_by_authtype(sec->generic_state, auth_type),
 345                           nt_errstr(c->status)));
 346                 composite_error(c, c->status);
 347                 return c;
 348         }
 349
 350         sec->auth_info = talloc(p, struct dcerpc_auth);
 351         if (composite_nomem(sec->auth_info, c)) return c;
 352
 353         sec->auth_info->auth_type = auth_type;
 354         sec->auth_info->auth_level = auth_level,
 355         sec->auth_info->auth_pad_length = 0;
 356         sec->auth_info->auth_reserved = 0;
 357         sec->auth_info->auth_context_id = random();
 358         sec->auth_info->credentials = data_blob(NULL, 0);
 359
 360         /* The status value here, from GENSEC is vital to the security
 361          * of the system.  Even if the other end accepts, if GENSEC
 362          * claims 'MORE_PROCESSING_REQUIRED' then you must keep
 363          * feeding it blobs, or else the remote host/attacker might
 364          * avoid mutal authentication requirements.
 365          *
 366          * Likewise, you must not feed GENSEC too much (after the OK),
 367          * it doesn't like that either
 368          */
 369
 370         state->pipe->inhibit_timeout_processing = true;
 371         state->pipe->timed_out = false;
 372         c->status = gensec_update(sec->generic_state, state,
 373                                   p->conn->event_ctx,
 374                                   sec->auth_info->credentials,
 375                                   &state->credentials);
 376         if (state->pipe->timed_out) {
 377                 composite_error(c, NT_STATUS_IO_TIMEOUT);
 378                 return c;
 379         }
 380         state->pipe->inhibit_timeout_processing = false;
 381
 382         if (!NT_STATUS_IS_OK(c->status) &&
 383             !NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 384                 composite_error(c, c->status);
 385                 return c;
 386         }
 387
 388         state->more_processing = NT_STATUS_EQUAL(c->status,
 389                                                  NT_STATUS_MORE_PROCESSING_REQUIRED);
 390
 391         if (state->credentials.length == 0) {
 392                 composite_done(c);
 393                 return c;
 394         }
 395
 396         sec->auth_info->credentials = state->credentials;
 397
 398         /* The first request always is a dcerpc_bind. The subsequent ones
 399          * depend on gensec results */
 400         subreq = dcerpc_bind_send(state, p->conn->event_ctx, p,
 401                                   &syntax, &transfer_syntax);
 402         data_blob_free(&state->credentials);
 403         sec->auth_info->credentials = data_blob(NULL, 0);
 404         if (composite_nomem(subreq, c)) return c;
 405         tevent_req_set_callback(subreq, bind_auth_recv_bindreply, c);
 406
 407         return c;
 408 }
 409
 410
 411 /**
 412    Bind to a DCE/RPC pipe, receive result
 413    @param creq A composite context describing state of async call
 414    @retval NTSTATUS code
 415 */
 416
 417 NTSTATUS dcerpc_bind_auth_recv(struct composite_context *creq)
 418 {
 419         NTSTATUS result = composite_wait(creq);
 420         struct bind_auth_state *state = talloc_get_type(creq->private_data,
 421                                                         struct bind_auth_state);
 422
 423         if (NT_STATUS_IS_OK(result)) {
 424                 /*
 425                   after a successful authenticated bind the session
 426                   key reverts to the generic session key
 427                 */
 428                 state->pipe->conn->security_state.session_key = dcerpc_generic_session_key;
 429         }
 430
 431         talloc_free(creq);
 432         return result;
 433 }
 434
 435
 436 /**
 437    Perform a GENSEC authenticated bind to a DCE/RPC pipe, sync
 438    @param p The dcerpc_pipe to bind (must already be connected)
 439    @param table The interface table to use (the DCE/RPC bind both selects and interface and authenticates)
 440    @param credentials The credentials of the account to connect with
 441    @param auth_type Select the authentication scheme to use
 442    @param auth_level Chooses between unprotected (connect), signed or sealed
 443    @param service The service (used by Kerberos to select the service principal to contact)
 444    @retval NTSTATUS status code
 445 */
 446
 447 _PUBLIC_ NTSTATUS dcerpc_bind_auth(struct dcerpc_pipe *p,
 448                           const struct ndr_interface_table *table,
 449                           struct cli_credentials *credentials,
 450                           struct gensec_settings *gensec_settings,
 451                           uint8_t auth_type, uint8_t auth_level,
 452                           const char *service)
 453 {
 454         struct composite_context *creq;
 455         creq = dcerpc_bind_auth_send(p, p, table, credentials, gensec_settings,
 456                                      auth_type, auth_level, service);
 457         return dcerpc_bind_auth_recv(creq);
 458 }