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->pipe->conn->flags & DCERPC_HEADER_SIGNING) {
 141                 gensec_want_feature(sec->generic_state, GENSEC_FEATURE_SIGN_PKT_HEADER);
 142         }
 143
 144         if (state->credentials.length == 0) {
 145                 composite_done(c);
 146                 return;
 147         }
 148
 149         sec->auth_info->credentials = state->credentials;
 150
 151         if (!more_processing) {
 152                 /* NO reply expected, so just send it */
 153                 c->status = dcerpc_auth3(state->pipe, state);
 154                 if (!composite_is_ok(c)) return;
 155
 156                 composite_done(c);
 157                 return;
 158         }
 159
 160         /* We are demanding a reply, so use a request that will get us one */
 161
 162         creq = dcerpc_alter_context_send(state->pipe, state,
 163                                          &state->pipe->syntax,
 164                                          &state->pipe->transfer_syntax);
 165         if (composite_nomem(creq, c)) return;
 166
 167         composite_continue(c, creq, bind_auth_recv_alter, c);
 168 }
 169
 170
 171 static void bind_auth_recv_alter(struct composite_context *creq)
 172 {
 173         struct composite_context *c = talloc_get_type(creq->async.private_data,
 174                                                       struct composite_context);
 175
 176         c->status = dcerpc_alter_context_recv(creq);
 177         if (!composite_is_ok(c)) return;
 178
 179         bind_auth_next_step(c);
 180 }
 181
 182
 183 static void bind_auth_recv_bindreply(struct composite_context *creq)
 184 {
 185         struct composite_context *c = talloc_get_type(creq->async.private_data,
 186                                                       struct composite_context);
 187         struct bind_auth_state *state = talloc_get_type(c->private_data,
 188                                                         struct bind_auth_state);
 189
 190         c->status = dcerpc_bind_recv(creq);
 191         if (!composite_is_ok(c)) return;
 192
 193         if (!state->more_processing) {
 194                 /* The first gensec_update has not requested a second run, so
 195                  * we're done here. */
 196                 composite_done(c);
 197                 return;
 198         }
 199
 200         bind_auth_next_step(c);
 201 }
 202
 203
 204 /**
 205    Bind to a DCE/RPC pipe, send async request
 206    @param mem_ctx TALLOC_CTX for the allocation of the composite_context
 207    @param p The dcerpc_pipe to bind (must already be connected)
 208    @param table The interface table to use (the DCE/RPC bind both selects and interface and authenticates)
 209    @param credentials The credentials of the account to connect with
 210    @param auth_type Select the authentication scheme to use
 211    @param auth_level Chooses between unprotected (connect), signed or sealed
 212    @param service The service (used by Kerberos to select the service principal to contact)
 213    @retval A composite context describing the partial state of the bind
 214 */
 215
 216 struct composite_context *dcerpc_bind_auth_send(TALLOC_CTX *mem_ctx,
 217                                                 struct dcerpc_pipe *p,
 218                                                 const struct ndr_interface_table *table,
 219                                                 struct cli_credentials *credentials,
 220                                                 struct loadparm_context *lp_ctx,
 221                                                 uint8_t auth_type, uint8_t auth_level,
 222                                                 const char *service)
 223 {
 224         struct composite_context *c, *creq;
 225         struct bind_auth_state *state;
 226         struct dcerpc_security *sec;
 227
 228         struct ndr_syntax_id syntax, transfer_syntax;
 229
 230         /* composite context allocation and setup */
 231         c = composite_create(mem_ctx, p->conn->event_ctx);
 232         if (c == NULL) return NULL;
 233
 234         state = talloc(c, struct bind_auth_state);
 235         if (composite_nomem(state, c)) return c;
 236         c->private_data = state;
 237
 238         state->pipe = p;
 239
 240         c->status = dcerpc_init_syntaxes(table,
 241                                          &syntax,
 242                                          &transfer_syntax);
 243         if (!composite_is_ok(c)) return c;
 244
 245         sec = &p->conn->security_state;
 246
 247         c->status = gensec_client_start(p, &sec->generic_state,
 248                                         p->conn->event_ctx,
 249                                         lp_ctx);
 250         if (!NT_STATUS_IS_OK(c->status)) {
 251                 DEBUG(1, ("Failed to start GENSEC client mode: %s\n",
 252                           nt_errstr(c->status)));
 253                 composite_error(c, c->status);
 254                 return c;
 255         }
 256
 257         c->status = gensec_set_credentials(sec->generic_state, credentials);
 258         if (!NT_STATUS_IS_OK(c->status)) {
 259                 DEBUG(1, ("Failed to set GENSEC client credentials: %s\n",
 260                           nt_errstr(c->status)));
 261                 composite_error(c, c->status);
 262                 return c;
 263         }
 264
 265         c->status = gensec_set_target_hostname(sec->generic_state,
 266                                                p->conn->transport.target_hostname(p->conn));
 267         if (!NT_STATUS_IS_OK(c->status)) {
 268                 DEBUG(1, ("Failed to set GENSEC target hostname: %s\n",
 269                           nt_errstr(c->status)));
 270                 composite_error(c, c->status);
 271                 return c;
 272         }
 273
 274         if (service != NULL) {
 275                 c->status = gensec_set_target_service(sec->generic_state,
 276                                                       service);
 277                 if (!NT_STATUS_IS_OK(c->status)) {
 278                         DEBUG(1, ("Failed to set GENSEC target service: %s\n",
 279                                   nt_errstr(c->status)));
 280                         composite_error(c, c->status);
 281                         return c;
 282                 }
 283         }
 284
 285         c->status = gensec_start_mech_by_authtype(sec->generic_state,
 286                                                   auth_type, auth_level);
 287         if (!NT_STATUS_IS_OK(c->status)) {
 288                 DEBUG(1, ("Failed to start GENSEC client mechanism %s: %s\n",
 289                           gensec_get_name_by_authtype(auth_type),
 290                           nt_errstr(c->status)));
 291                 composite_error(c, c->status);
 292                 return c;
 293         }
 294
 295         sec->auth_info = talloc(p, struct dcerpc_auth);
 296         if (composite_nomem(sec->auth_info, c)) return c;
 297
 298         sec->auth_info->auth_type = auth_type;
 299         sec->auth_info->auth_level = auth_level,
 300         sec->auth_info->auth_pad_length = 0;
 301         sec->auth_info->auth_reserved = 0;
 302         sec->auth_info->auth_context_id = random();
 303         sec->auth_info->credentials = data_blob(NULL, 0);
 304
 305         /* The status value here, from GENSEC is vital to the security
 306          * of the system.  Even if the other end accepts, if GENSEC
 307          * claims 'MORE_PROCESSING_REQUIRED' then you must keep
 308          * feeding it blobs, or else the remote host/attacker might
 309          * avoid mutal authentication requirements.
 310          *
 311          * Likewise, you must not feed GENSEC too much (after the OK),
 312          * it doesn't like that either
 313          */
 314
 315         c->status = gensec_update(sec->generic_state, state,
 316                                   sec->auth_info->credentials,
 317                                   &state->credentials);
 318         if (!NT_STATUS_IS_OK(c->status) &&
 319             !NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 320                 composite_error(c, c->status);
 321                 return c;
 322         }
 323
 324         state->more_processing = NT_STATUS_EQUAL(c->status,
 325                                                  NT_STATUS_MORE_PROCESSING_REQUIRED);
 326
 327         if (state->credentials.length == 0) {
 328                 composite_done(c);
 329                 return c;
 330         }
 331
 332         sec->auth_info->credentials = state->credentials;
 333
 334         /* The first request always is a dcerpc_bind. The subsequent ones
 335          * depend on gensec results */
 336         creq = dcerpc_bind_send(p, state, &syntax, &transfer_syntax);
 337         if (composite_nomem(creq, c)) return c;
 338
 339         composite_continue(c, creq, bind_auth_recv_bindreply, c);
 340         return c;
 341 }
 342
 343
 344 /**
 345    Bind to a DCE/RPC pipe, receive result
 346    @param creq A composite context describing state of async call
 347    @retval NTSTATUS code
 348 */
 349
 350 NTSTATUS dcerpc_bind_auth_recv(struct composite_context *creq)
 351 {
 352         NTSTATUS result = composite_wait(creq);
 353         struct bind_auth_state *state = talloc_get_type(creq->private_data,
 354                                                         struct bind_auth_state);
 355
 356         if (NT_STATUS_IS_OK(result)) {
 357                 /*
 358                   after a successful authenticated bind the session
 359                   key reverts to the generic session key
 360                 */
 361                 state->pipe->conn->security_state.session_key = dcerpc_generic_session_key;
 362         }
 363
 364         talloc_free(creq);
 365         return result;
 366 }
 367
 368
 369 /**
 370    Perform a GENSEC authenticated bind to a DCE/RPC pipe, sync
 371    @param p The dcerpc_pipe to bind (must already be connected)
 372    @param table The interface table to use (the DCE/RPC bind both selects and interface and authenticates)
 373    @param credentials The credentials of the account to connect with
 374    @param auth_type Select the authentication scheme to use
 375    @param auth_level Chooses between unprotected (connect), signed or sealed
 376    @param service The service (used by Kerberos to select the service principal to contact)
 377    @retval NTSTATUS status code
 378 */
 379
 380 _PUBLIC_ NTSTATUS dcerpc_bind_auth(struct dcerpc_pipe *p,
 381                           const struct ndr_interface_table *table,
 382                           struct cli_credentials *credentials,
 383                           struct loadparm_context *lp_ctx,
 384                           uint8_t auth_type, uint8_t auth_level,
 385                           const char *service)
 386 {
 387         struct composite_context *creq;
 388         creq = dcerpc_bind_auth_send(p, p, table, credentials, lp_ctx,
 389                                      auth_type, auth_level, service);
 390         return dcerpc_bind_auth_recv(creq);
 391 }