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 "libcli/composite/composite.h"
  26 #include "auth/gensec/gensec.h"
  27 #include "librpc/rpc/dcerpc.h"
  28 #include "librpc/rpc/dcerpc_proto.h"
  29 #include "param/param.h"
  30
  31 /*
  32   return the rpc syntax and transfer syntax given the pipe uuid and version
  33 */
  34 static NTSTATUS dcerpc_init_syntaxes(const struct ndr_interface_table *table,
  35                                      uint32_t pipe_flags,
  36                                      struct ndr_syntax_id *syntax,
  37                                      struct ndr_syntax_id *transfer_syntax)
  38 {
  39         syntax->uuid = table->syntax_id.uuid;
  40         syntax->if_version = table->syntax_id.if_version;
  41
  42         if (pipe_flags & DCERPC_NDR64) {
  43                 *transfer_syntax = ndr64_transfer_syntax;
  44         } else {
  45                 *transfer_syntax = ndr_transfer_syntax;
  46         }
  47
  48         return NT_STATUS_OK;
  49 }
  50
  51
  52 /*
  53   Send request to do a non-authenticated dcerpc bind
  54 */
  55 struct composite_context *dcerpc_bind_auth_none_send(TALLOC_CTX *mem_ctx,
  56                                                      struct dcerpc_pipe *p,
  57                                                      const struct ndr_interface_table *table)
  58 {
  59         struct ndr_syntax_id syntax;
  60         struct ndr_syntax_id transfer_syntax;
  61
  62         struct composite_context *c;
  63
  64         c = composite_create(mem_ctx, p->conn->event_ctx);
  65         if (c == NULL) return NULL;
  66
  67         c->status = dcerpc_init_syntaxes(table, p->conn->flags,
  68                                          &syntax, &transfer_syntax);
  69         if (!NT_STATUS_IS_OK(c->status)) {
  70                 DEBUG(2,("Invalid uuid string in "
  71                          "dcerpc_bind_auth_none_send\n"));
  72                 composite_error(c, c->status);
  73                 return c;
  74         }
  75
  76         /* c was only allocated as a container for a possible error */
  77         talloc_free(c);
  78
  79         return dcerpc_bind_send(p, mem_ctx, &syntax, &transfer_syntax);
  80 }
  81
  82
  83 /*
  84   Receive result of a non-authenticated dcerpc bind
  85 */
  86 NTSTATUS dcerpc_bind_auth_none_recv(struct composite_context *ctx)
  87 {
  88         return dcerpc_bind_recv(ctx);
  89 }
  90
  91
  92 /*
  93   Perform sync non-authenticated dcerpc bind
  94 */
  95 _PUBLIC_ NTSTATUS dcerpc_bind_auth_none(struct dcerpc_pipe *p,
  96                                const struct ndr_interface_table *table)
  97 {
  98         struct composite_context *ctx;
  99
 100         ctx = dcerpc_bind_auth_none_send(p, p, table);
 101         return dcerpc_bind_auth_none_recv(ctx);
 102 }
 103
 104
 105 struct bind_auth_state {
 106         struct dcerpc_pipe *pipe;
 107         DATA_BLOB credentials;
 108         bool more_processing;   /* Is there anything more to do after the
 109                                  * first bind itself received? */
 110 };
 111
 112 static void bind_auth_recv_alter(struct composite_context *creq);
 113
 114 static void bind_auth_next_step(struct composite_context *c)
 115 {
 116         struct bind_auth_state *state;
 117         struct dcerpc_security *sec;
 118         struct composite_context *creq;
 119         bool more_processing = false;
 120
 121         state = talloc_get_type(c->private_data, struct bind_auth_state);
 122         sec = &state->pipe->conn->security_state;
 123
 124         /* The status value here, from GENSEC is vital to the security
 125          * of the system.  Even if the other end accepts, if GENSEC
 126          * claims 'MORE_PROCESSING_REQUIRED' then you must keep
 127          * feeding it blobs, or else the remote host/attacker might
 128          * avoid mutal authentication requirements.
 129          *
 130          * Likewise, you must not feed GENSEC too much (after the OK),
 131          * it doesn't like that either
 132          */
 133
 134         c->status = gensec_update(sec->generic_state, state,
 135                                   sec->auth_info->credentials,
 136                                   &state->credentials);
 137         data_blob_free(&sec->auth_info->credentials);
 138
 139         if (NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 140                 more_processing = true;
 141                 c->status = NT_STATUS_OK;
 142         }
 143
 144         if (!composite_is_ok(c)) return;
 145
 146         if (state->pipe->conn->flags & DCERPC_HEADER_SIGNING) {
 147                 gensec_want_feature(sec->generic_state, GENSEC_FEATURE_SIGN_PKT_HEADER);
 148         }
 149
 150         if (state->credentials.length == 0) {
 151                 composite_done(c);
 152                 return;
 153         }
 154
 155         sec->auth_info->credentials = state->credentials;
 156
 157         if (!more_processing) {
 158                 /* NO reply expected, so just send it */
 159                 c->status = dcerpc_auth3(state->pipe, state);
 160                 data_blob_free(&state->credentials);
 161                 sec->auth_info->credentials = data_blob(NULL, 0);
 162                 if (!composite_is_ok(c)) return;
 163
 164                 composite_done(c);
 165                 return;
 166         }
 167
 168         /* We are demanding a reply, so use a request that will get us one */
 169
 170         creq = dcerpc_alter_context_send(state->pipe, state,
 171                                          &state->pipe->syntax,
 172                                          &state->pipe->transfer_syntax);
 173         data_blob_free(&state->credentials);
 174         sec->auth_info->credentials = data_blob(NULL, 0);
 175         if (composite_nomem(creq, c)) return;
 176
 177         composite_continue(c, creq, bind_auth_recv_alter, c);
 178 }
 179
 180
 181 static void bind_auth_recv_alter(struct composite_context *creq)
 182 {
 183         struct composite_context *c = talloc_get_type(creq->async.private_data,
 184                                                       struct composite_context);
 185
 186         c->status = dcerpc_alter_context_recv(creq);
 187         if (!composite_is_ok(c)) return;
 188
 189         bind_auth_next_step(c);
 190 }
 191
 192
 193 static void bind_auth_recv_bindreply(struct composite_context *creq)
 194 {
 195         struct composite_context *c = talloc_get_type(creq->async.private_data,
 196                                                       struct composite_context);
 197         struct bind_auth_state *state = talloc_get_type(c->private_data,
 198                                                         struct bind_auth_state);
 199
 200         c->status = dcerpc_bind_recv(creq);
 201         if (!composite_is_ok(c)) return;
 202
 203         if (!state->more_processing) {
 204                 /* The first gensec_update has not requested a second run, so
 205                  * we're done here. */
 206                 composite_done(c);
 207                 return;
 208         }
 209
 210         bind_auth_next_step(c);
 211 }
 212
 213
 214 /**
 215    Bind to a DCE/RPC pipe, send async request
 216    @param mem_ctx TALLOC_CTX for the allocation of the composite_context
 217    @param p The dcerpc_pipe to bind (must already be connected)
 218    @param table The interface table to use (the DCE/RPC bind both selects and interface and authenticates)
 219    @param credentials The credentials of the account to connect with
 220    @param auth_type Select the authentication scheme to use
 221    @param auth_level Chooses between unprotected (connect), signed or sealed
 222    @param service The service (used by Kerberos to select the service principal to contact)
 223    @retval A composite context describing the partial state of the bind
 224 */
 225
 226 struct composite_context *dcerpc_bind_auth_send(TALLOC_CTX *mem_ctx,
 227                                                 struct dcerpc_pipe *p,
 228                                                 const struct ndr_interface_table *table,
 229                                                 struct cli_credentials *credentials,
 230                                                 struct gensec_settings *gensec_settings,
 231                                                 uint8_t auth_type, uint8_t auth_level,
 232                                                 const char *service)
 233 {
 234         struct composite_context *c, *creq;
 235         struct bind_auth_state *state;
 236         struct dcerpc_security *sec;
 237
 238         struct ndr_syntax_id syntax, transfer_syntax;
 239
 240         /* composite context allocation and setup */
 241         c = composite_create(mem_ctx, p->conn->event_ctx);
 242         if (c == NULL) return NULL;
 243
 244         state = talloc(c, struct bind_auth_state);
 245         if (composite_nomem(state, c)) return c;
 246         c->private_data = state;
 247
 248         state->pipe = p;
 249
 250         c->status = dcerpc_init_syntaxes(table, p->conn->flags,
 251                                          &syntax,
 252                                          &transfer_syntax);
 253         if (!composite_is_ok(c)) return c;
 254
 255         sec = &p->conn->security_state;
 256
 257         c->status = gensec_client_start(p, &sec->generic_state,
 258                                         p->conn->event_ctx,
 259                                         gensec_settings);
 260         if (!NT_STATUS_IS_OK(c->status)) {
 261                 DEBUG(1, ("Failed to start GENSEC client mode: %s\n",
 262                           nt_errstr(c->status)));
 263                 composite_error(c, c->status);
 264                 return c;
 265         }
 266
 267         c->status = gensec_set_credentials(sec->generic_state, credentials);
 268         if (!NT_STATUS_IS_OK(c->status)) {
 269                 DEBUG(1, ("Failed to set GENSEC client credentials: %s\n",
 270                           nt_errstr(c->status)));
 271                 composite_error(c, c->status);
 272                 return c;
 273         }
 274
 275         c->status = gensec_set_target_hostname(sec->generic_state,
 276                                                p->conn->transport.target_hostname(p->conn));
 277         if (!NT_STATUS_IS_OK(c->status)) {
 278                 DEBUG(1, ("Failed to set GENSEC target hostname: %s\n",
 279                           nt_errstr(c->status)));
 280                 composite_error(c, c->status);
 281                 return c;
 282         }
 283
 284         if (service != NULL) {
 285                 c->status = gensec_set_target_service(sec->generic_state,
 286                                                       service);
 287                 if (!NT_STATUS_IS_OK(c->status)) {
 288                         DEBUG(1, ("Failed to set GENSEC target service: %s\n",
 289                                   nt_errstr(c->status)));
 290                         composite_error(c, c->status);
 291                         return c;
 292                 }
 293         }
 294
 295         c->status = gensec_start_mech_by_authtype(sec->generic_state,
 296                                                   auth_type, auth_level);
 297         if (!NT_STATUS_IS_OK(c->status)) {
 298                 DEBUG(1, ("Failed to start GENSEC client mechanism %s: %s\n",
 299                           gensec_get_name_by_authtype(sec->generic_state, auth_type),
 300                           nt_errstr(c->status)));
 301                 composite_error(c, c->status);
 302                 return c;
 303         }
 304
 305         sec->auth_info = talloc(p, struct dcerpc_auth);
 306         if (composite_nomem(sec->auth_info, c)) return c;
 307
 308         sec->auth_info->auth_type = auth_type;
 309         sec->auth_info->auth_level = auth_level,
 310         sec->auth_info->auth_pad_length = 0;
 311         sec->auth_info->auth_reserved = 0;
 312         sec->auth_info->auth_context_id = random();
 313         sec->auth_info->credentials = data_blob(NULL, 0);
 314
 315         /* The status value here, from GENSEC is vital to the security
 316          * of the system.  Even if the other end accepts, if GENSEC
 317          * claims 'MORE_PROCESSING_REQUIRED' then you must keep
 318          * feeding it blobs, or else the remote host/attacker might
 319          * avoid mutal authentication requirements.
 320          *
 321          * Likewise, you must not feed GENSEC too much (after the OK),
 322          * it doesn't like that either
 323          */
 324
 325         c->status = gensec_update(sec->generic_state, state,
 326                                   sec->auth_info->credentials,
 327                                   &state->credentials);
 328         if (!NT_STATUS_IS_OK(c->status) &&
 329             !NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 330                 composite_error(c, c->status);
 331                 return c;
 332         }
 333
 334         state->more_processing = NT_STATUS_EQUAL(c->status,
 335                                                  NT_STATUS_MORE_PROCESSING_REQUIRED);
 336
 337         if (state->credentials.length == 0) {
 338                 composite_done(c);
 339                 return c;
 340         }
 341
 342         sec->auth_info->credentials = state->credentials;
 343
 344         /* The first request always is a dcerpc_bind. The subsequent ones
 345          * depend on gensec results */
 346         creq = dcerpc_bind_send(p, state, &syntax, &transfer_syntax);
 347         data_blob_free(&state->credentials);
 348         sec->auth_info->credentials = data_blob(NULL, 0);
 349         if (composite_nomem(creq, c)) return c;
 350
 351         composite_continue(c, creq, bind_auth_recv_bindreply, c);
 352         return c;
 353 }
 354
 355
 356 /**
 357    Bind to a DCE/RPC pipe, receive result
 358    @param creq A composite context describing state of async call
 359    @retval NTSTATUS code
 360 */
 361
 362 NTSTATUS dcerpc_bind_auth_recv(struct composite_context *creq)
 363 {
 364         NTSTATUS result = composite_wait(creq);
 365         struct bind_auth_state *state = talloc_get_type(creq->private_data,
 366                                                         struct bind_auth_state);
 367
 368         if (NT_STATUS_IS_OK(result)) {
 369                 /*
 370                   after a successful authenticated bind the session
 371                   key reverts to the generic session key
 372                 */
 373                 state->pipe->conn->security_state.session_key = dcerpc_generic_session_key;
 374         }
 375
 376         talloc_free(creq);
 377         return result;
 378 }
 379
 380
 381 /**
 382    Perform a GENSEC authenticated bind to a DCE/RPC pipe, sync
 383    @param p The dcerpc_pipe to bind (must already be connected)
 384    @param table The interface table to use (the DCE/RPC bind both selects and interface and authenticates)
 385    @param credentials The credentials of the account to connect with
 386    @param auth_type Select the authentication scheme to use
 387    @param auth_level Chooses between unprotected (connect), signed or sealed
 388    @param service The service (used by Kerberos to select the service principal to contact)
 389    @retval NTSTATUS status code
 390 */
 391
 392 _PUBLIC_ NTSTATUS dcerpc_bind_auth(struct dcerpc_pipe *p,
 393                           const struct ndr_interface_table *table,
 394                           struct cli_credentials *credentials,
 395                           struct gensec_settings *gensec_settings,
 396                           uint8_t auth_type, uint8_t auth_level,
 397                           const char *service)
 398 {
 399         struct composite_context *creq;
 400         creq = dcerpc_bind_auth_send(p, p, table, credentials, gensec_settings,
 401                                      auth_type, auth_level, service);
 402         return dcerpc_bind_auth_recv(creq);
 403 }