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