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         c->status = gensec_update(sec->generic_state, state,
 155                                   state->pipe->conn->event_ctx,
 156                                   sec->auth_info->credentials,
 157                                   &state->credentials);
 158         data_blob_free(&sec->auth_info->credentials);
 159
 160         if (NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 161                 more_processing = true;
 162                 c->status = NT_STATUS_OK;
 163         }
 164
 165         if (!composite_is_ok(c)) return;
 166
 167         if (state->pipe->conn->flags & DCERPC_HEADER_SIGNING) {
 168                 gensec_want_feature(sec->generic_state, GENSEC_FEATURE_SIGN_PKT_HEADER);
 169         }
 170
 171         if (state->credentials.length == 0) {
 172                 composite_done(c);
 173                 return;
 174         }
 175
 176         sec->auth_info->credentials = state->credentials;
 177
 178         if (!more_processing) {
 179                 /* NO reply expected, so just send it */
 180                 c->status = dcerpc_auth3(state->pipe, state);
 181                 data_blob_free(&state->credentials);
 182                 sec->auth_info->credentials = data_blob(NULL, 0);
 183                 if (!composite_is_ok(c)) return;
 184
 185                 composite_done(c);
 186                 return;
 187         }
 188
 189         /* We are demanding a reply, so use a request that will get us one */
 190
 191         subreq = dcerpc_alter_context_send(state, state->pipe->conn->event_ctx,
 192                                            state->pipe,
 193                                            &state->pipe->syntax,
 194                                            &state->pipe->transfer_syntax);
 195         data_blob_free(&state->credentials);
 196         sec->auth_info->credentials = data_blob(NULL, 0);
 197         if (composite_nomem(subreq, c)) return;
 198         tevent_req_set_callback(subreq, bind_auth_recv_alter, c);
 199 }
 200
 201
 202 static void bind_auth_recv_alter(struct tevent_req *subreq)
 203 {
 204         struct composite_context *c =
 205                 tevent_req_callback_data(subreq,
 206                 struct composite_context);
 207
 208         c->status = dcerpc_alter_context_recv(subreq);
 209         TALLOC_FREE(subreq);
 210         if (!composite_is_ok(c)) return;
 211
 212         bind_auth_next_step(c);
 213 }
 214
 215
 216 static void bind_auth_recv_bindreply(struct tevent_req *subreq)
 217 {
 218         struct composite_context *c =
 219                 tevent_req_callback_data(subreq,
 220                 struct composite_context);
 221         struct bind_auth_state *state = talloc_get_type(c->private_data,
 222                                                         struct bind_auth_state);
 223
 224         c->status = dcerpc_bind_recv(subreq);
 225         TALLOC_FREE(subreq);
 226         if (!composite_is_ok(c)) return;
 227
 228         if (!state->more_processing) {
 229                 /* The first gensec_update has not requested a second run, so
 230                  * we're done here. */
 231                 composite_done(c);
 232                 return;
 233         }
 234
 235         bind_auth_next_step(c);
 236 }
 237
 238
 239 /**
 240    Bind to a DCE/RPC pipe, send async request
 241    @param mem_ctx TALLOC_CTX for the allocation of the composite_context
 242    @param p The dcerpc_pipe to bind (must already be connected)
 243    @param table The interface table to use (the DCE/RPC bind both selects and interface and authenticates)
 244    @param credentials The credentials of the account to connect with
 245    @param auth_type Select the authentication scheme to use
 246    @param auth_level Chooses between unprotected (connect), signed or sealed
 247    @param service The service (used by Kerberos to select the service principal to contact)
 248    @retval A composite context describing the partial state of the bind
 249 */
 250
 251 struct composite_context *dcerpc_bind_auth_send(TALLOC_CTX *mem_ctx,
 252                                                 struct dcerpc_pipe *p,
 253                                                 const struct ndr_interface_table *table,
 254                                                 struct cli_credentials *credentials,
 255                                                 struct gensec_settings *gensec_settings,
 256                                                 uint8_t auth_type, uint8_t auth_level,
 257                                                 const char *service)
 258 {
 259         struct composite_context *c;
 260         struct bind_auth_state *state;
 261         struct dcecli_security *sec;
 262         struct tevent_req *subreq;
 263
 264         struct ndr_syntax_id syntax, transfer_syntax;
 265
 266         /* composite context allocation and setup */
 267         c = composite_create(mem_ctx, p->conn->event_ctx);
 268         if (c == NULL) return NULL;
 269
 270         state = talloc(c, struct bind_auth_state);
 271         if (composite_nomem(state, c)) return c;
 272         c->private_data = state;
 273
 274         state->pipe = p;
 275
 276         c->status = dcerpc_init_syntaxes(table, p->conn->flags,
 277                                          &syntax,
 278                                          &transfer_syntax);
 279         if (!composite_is_ok(c)) return c;
 280
 281         sec = &p->conn->security_state;
 282
 283         c->status = gensec_client_start(p, &sec->generic_state,
 284                                         gensec_settings);
 285         if (!NT_STATUS_IS_OK(c->status)) {
 286                 DEBUG(1, ("Failed to start GENSEC client mode: %s\n",
 287                           nt_errstr(c->status)));
 288                 composite_error(c, c->status);
 289                 return c;
 290         }
 291
 292         c->status = gensec_set_credentials(sec->generic_state, credentials);
 293         if (!NT_STATUS_IS_OK(c->status)) {
 294                 DEBUG(1, ("Failed to set GENSEC client credentials: %s\n",
 295                           nt_errstr(c->status)));
 296                 composite_error(c, c->status);
 297                 return c;
 298         }
 299
 300         c->status = gensec_set_target_hostname(sec->generic_state,
 301                                                p->conn->transport.target_hostname(p->conn));
 302         if (!NT_STATUS_IS_OK(c->status)) {
 303                 DEBUG(1, ("Failed to set GENSEC target hostname: %s\n",
 304                           nt_errstr(c->status)));
 305                 composite_error(c, c->status);
 306                 return c;
 307         }
 308
 309         if (service != NULL) {
 310                 c->status = gensec_set_target_service(sec->generic_state,
 311                                                       service);
 312                 if (!NT_STATUS_IS_OK(c->status)) {
 313                         DEBUG(1, ("Failed to set GENSEC target service: %s\n",
 314                                   nt_errstr(c->status)));
 315                         composite_error(c, c->status);
 316                         return c;
 317                 }
 318         }
 319
 320         if (p->binding && p->binding->target_principal) {
 321                 c->status = gensec_set_target_principal(sec->generic_state,
 322                                                         p->binding->target_principal);
 323                 if (!NT_STATUS_IS_OK(c->status)) {
 324                         DEBUG(1, ("Failed to set GENSEC target principal to %s: %s\n",
 325                                   p->binding->target_principal, nt_errstr(c->status)));
 326                         composite_error(c, c->status);
 327                         return c;
 328                 }
 329         }
 330
 331         c->status = gensec_start_mech_by_authtype(sec->generic_state,
 332                                                   auth_type, auth_level);
 333         if (!NT_STATUS_IS_OK(c->status)) {
 334                 DEBUG(1, ("Failed to start GENSEC client mechanism %s: %s\n",
 335                           gensec_get_name_by_authtype(sec->generic_state, auth_type),
 336                           nt_errstr(c->status)));
 337                 composite_error(c, c->status);
 338                 return c;
 339         }
 340
 341         sec->auth_info = talloc(p, struct dcerpc_auth);
 342         if (composite_nomem(sec->auth_info, c)) return c;
 343
 344         sec->auth_info->auth_type = auth_type;
 345         sec->auth_info->auth_level = auth_level,
 346         sec->auth_info->auth_pad_length = 0;
 347         sec->auth_info->auth_reserved = 0;
 348         sec->auth_info->auth_context_id = random();
 349         sec->auth_info->credentials = data_blob(NULL, 0);
 350
 351         /* The status value here, from GENSEC is vital to the security
 352          * of the system.  Even if the other end accepts, if GENSEC
 353          * claims 'MORE_PROCESSING_REQUIRED' then you must keep
 354          * feeding it blobs, or else the remote host/attacker might
 355          * avoid mutal authentication requirements.
 356          *
 357          * Likewise, you must not feed GENSEC too much (after the OK),
 358          * it doesn't like that either
 359          */
 360
 361         c->status = gensec_update(sec->generic_state, state,
 362                                   p->conn->event_ctx,
 363                                   sec->auth_info->credentials,
 364                                   &state->credentials);
 365         if (!NT_STATUS_IS_OK(c->status) &&
 366             !NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 367                 composite_error(c, c->status);
 368                 return c;
 369         }
 370
 371         state->more_processing = NT_STATUS_EQUAL(c->status,
 372                                                  NT_STATUS_MORE_PROCESSING_REQUIRED);
 373
 374         if (state->credentials.length == 0) {
 375                 composite_done(c);
 376                 return c;
 377         }
 378
 379         sec->auth_info->credentials = state->credentials;
 380
 381         /* The first request always is a dcerpc_bind. The subsequent ones
 382          * depend on gensec results */
 383         subreq = dcerpc_bind_send(state, p->conn->event_ctx, p,
 384                                   &syntax, &transfer_syntax);
 385         data_blob_free(&state->credentials);
 386         sec->auth_info->credentials = data_blob(NULL, 0);
 387         if (composite_nomem(subreq, c)) return c;
 388         tevent_req_set_callback(subreq, bind_auth_recv_bindreply, c);
 389
 390         return c;
 391 }
 392
 393
 394 /**
 395    Bind to a DCE/RPC pipe, receive result
 396    @param creq A composite context describing state of async call
 397    @retval NTSTATUS code
 398 */
 399
 400 NTSTATUS dcerpc_bind_auth_recv(struct composite_context *creq)
 401 {
 402         NTSTATUS result = composite_wait(creq);
 403         struct bind_auth_state *state = talloc_get_type(creq->private_data,
 404                                                         struct bind_auth_state);
 405
 406         if (NT_STATUS_IS_OK(result)) {
 407                 /*
 408                   after a successful authenticated bind the session
 409                   key reverts to the generic session key
 410                 */
 411                 state->pipe->conn->security_state.session_key = dcerpc_generic_session_key;
 412         }
 413
 414         talloc_free(creq);
 415         return result;
 416 }
 417
 418
 419 /**
 420    Perform a GENSEC authenticated bind to a DCE/RPC pipe, sync
 421    @param p The dcerpc_pipe to bind (must already be connected)
 422    @param table The interface table to use (the DCE/RPC bind both selects and interface and authenticates)
 423    @param credentials The credentials of the account to connect with
 424    @param auth_type Select the authentication scheme to use
 425    @param auth_level Chooses between unprotected (connect), signed or sealed
 426    @param service The service (used by Kerberos to select the service principal to contact)
 427    @retval NTSTATUS status code
 428 */
 429
 430 _PUBLIC_ NTSTATUS dcerpc_bind_auth(struct dcerpc_pipe *p,
 431                           const struct ndr_interface_table *table,
 432                           struct cli_credentials *credentials,
 433                           struct gensec_settings *gensec_settings,
 434                           uint8_t auth_type, uint8_t auth_level,
 435                           const char *service)
 436 {
 437         struct composite_context *creq;
 438         creq = dcerpc_bind_auth_send(p, p, table, credentials, gensec_settings,
 439                                      auth_type, auth_level, service);
 440         return dcerpc_bind_auth_recv(creq);
 441 }