source4/ldap_server/ldap_bind.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    LDAP server
   4    Copyright (C) Stefan Metzmacher 2004
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "ldap_server/ldap_server.h"
  22 #include "auth/auth.h"
  23 #include "smbd/service.h"
  24 #include <ldb.h>
  25 #include <ldb_errors.h>
  26 #include "dsdb/samdb/samdb.h"
  27 #include "auth/gensec/gensec.h"
  28 #include "auth/gensec/gensec_tstream.h"
  29 #include "param/param.h"
  30 #include "../lib/util/tevent_ntstatus.h"
  31
  32 static char *ldapsrv_bind_error_msg(TALLOC_CTX *mem_ctx,
  33                                     HRESULT hresult,
  34                                     uint32_t DSID,
  35                                     NTSTATUS status)
  36 {
  37         WERROR werr;
  38         char *msg = NULL;
  39
  40         status = nt_status_squash(status);
  41         werr = ntstatus_to_werror(status);
  42
  43         /*
  44          * There are 4 lower case hex digits following 'v' at the end,
  45          * but different Windows Versions return different values:
  46          *
  47          * Windows 2008R2 uses 'v1db1'
  48          * Windows 2012R2 uses 'v2580'
  49          *
  50          * We just match Windows 2008R2 as that's what was referenced
  51          * in https://bugzilla.samba.org/show_bug.cgi?id=9048
  52          */
  53         msg = talloc_asprintf(mem_ctx, "%08X: LdapErr: DSID-%08X, comment: "
  54                               "AcceptSecurityContext error, data %x, v1db1",
  55                               (unsigned)HRES_ERROR_V(hresult),
  56                               (unsigned)DSID,
  57                               (unsigned)W_ERROR_V(werr));
  58
  59         return msg;
  60 }
  61
  62
  63 static NTSTATUS ldapsrv_BindSimple(struct ldapsrv_call *call)
  64 {
  65         struct ldap_BindRequest *req = &call->request->r.BindRequest;
  66         struct ldapsrv_reply *reply;
  67         struct ldap_BindResponse *resp;
  68
  69         int result;
  70         const char *errstr;
  71
  72         struct auth_session_info *session_info;
  73
  74         NTSTATUS status;
  75
  76         bool using_tls = call->conn->sockets.active == call->conn->sockets.tls;
  77
  78         DEBUG(10, ("BindSimple dn: %s\n",req->dn));
  79
  80         reply = ldapsrv_init_reply(call, LDAP_TAG_BindResponse);
  81         if (!reply) {
  82                 return NT_STATUS_NO_MEMORY;
  83         }
  84
  85         if (req->dn != NULL &&
  86             strlen(req->dn) != 0 &&
  87             call->conn->require_strong_auth > LDAP_SERVER_REQUIRE_STRONG_AUTH_NO &&
  88             !using_tls)
  89         {
  90                 status = NT_STATUS_NETWORK_ACCESS_DENIED;
  91                 result = LDAP_STRONG_AUTH_REQUIRED;
  92                 errstr = talloc_asprintf(reply,
  93                                          "BindSimple: Transport encryption required.");
  94                 goto do_reply;
  95         }
  96
  97         status = authenticate_ldap_simple_bind(call,
  98                                                call->conn->connection->event.ctx,
  99                                                call->conn->connection->msg_ctx,
 100                                                call->conn->lp_ctx,
 101                                                call->conn->connection->remote_address,
 102                                                call->conn->connection->local_address,
 103                                                using_tls,
 104                                                req->dn,
 105                                                req->creds.password,
 106                                                &session_info);
 107
 108         if (NT_STATUS_IS_OK(status)) {
 109                 result = LDAP_SUCCESS;
 110                 errstr = NULL;
 111
 112                 talloc_unlink(call->conn, call->conn->session_info);
 113                 call->conn->session_info = talloc_steal(call->conn, session_info);
 114
 115                 call->conn->authz_logged = true;
 116
 117                 /* don't leak the old LDB */
 118                 talloc_unlink(call->conn, call->conn->ldb);
 119
 120                 status = ldapsrv_backend_Init(call->conn);
 121
 122                 if (!NT_STATUS_IS_OK(status)) {
 123                         result = LDAP_OPERATIONS_ERROR;
 124                         errstr = talloc_asprintf(reply, "Simple Bind: Failed to advise ldb new credentials: %s", nt_errstr(status));
 125                 }
 126         } else {
 127                 status = nt_status_squash(status);
 128
 129                 result = LDAP_INVALID_CREDENTIALS;
 130                 errstr = ldapsrv_bind_error_msg(reply, HRES_SEC_E_INVALID_TOKEN,
 131                                                 0x0C0903A9, status);
 132         }
 133
 134 do_reply:
 135         resp = &reply->msg->r.BindResponse;
 136         resp->response.resultcode = result;
 137         resp->response.errormessage = errstr;
 138         resp->response.dn = NULL;
 139         resp->response.referral = NULL;
 140         resp->SASL.secblob = NULL;
 141
 142         ldapsrv_queue_reply(call, reply);
 143         return NT_STATUS_OK;
 144 }
 145
 146 struct ldapsrv_sasl_postprocess_context {
 147         struct ldapsrv_connection *conn;
 148         struct tstream_context *sasl;
 149 };
 150
 151 struct ldapsrv_sasl_postprocess_state {
 152         uint8_t dummy;
 153 };
 154
 155 static struct tevent_req *ldapsrv_sasl_postprocess_send(TALLOC_CTX *mem_ctx,
 156                                                 struct tevent_context *ev,
 157                                                 void *private_data)
 158 {
 159         struct ldapsrv_sasl_postprocess_context *context =
 160                 talloc_get_type_abort(private_data,
 161                 struct ldapsrv_sasl_postprocess_context);
 162         struct tevent_req *req;
 163         struct ldapsrv_sasl_postprocess_state *state;
 164
 165         req = tevent_req_create(mem_ctx, &state,
 166                                 struct ldapsrv_sasl_postprocess_state);
 167         if (req == NULL) {
 168                 return NULL;
 169         }
 170
 171         TALLOC_FREE(context->conn->sockets.sasl);
 172         context->conn->sockets.sasl = talloc_move(context->conn, &context->sasl);
 173         context->conn->sockets.active = context->conn->sockets.sasl;
 174
 175         tevent_req_done(req);
 176         return tevent_req_post(req, ev);
 177 }
 178
 179 static NTSTATUS ldapsrv_sasl_postprocess_recv(struct tevent_req *req)
 180 {
 181         return tevent_req_simple_recv_ntstatus(req);
 182 }
 183
 184 static NTSTATUS ldapsrv_setup_gensec(struct ldapsrv_connection *conn,
 185                                      const char *sasl_mech,
 186                                      struct gensec_security **_gensec_security)
 187 {
 188         NTSTATUS status;
 189
 190         struct gensec_security *gensec_security;
 191
 192         status = samba_server_gensec_start(conn,
 193                                            conn->connection->event.ctx,
 194                                            conn->connection->msg_ctx,
 195                                            conn->lp_ctx,
 196                                            conn->server_credentials,
 197                                            "ldap",
 198                                            &gensec_security);
 199         if (!NT_STATUS_IS_OK(status)) {
 200                 return status;
 201         }
 202
 203         status = gensec_set_target_service_description(gensec_security,
 204                                                        "LDAP");
 205         if (!NT_STATUS_IS_OK(status)) {
 206                 return status;
 207         }
 208
 209         status = gensec_set_remote_address(gensec_security,
 210                                            conn->connection->remote_address);
 211         if (!NT_STATUS_IS_OK(status)) {
 212                 return status;
 213         }
 214
 215         status = gensec_set_local_address(gensec_security,
 216                                           conn->connection->local_address);
 217         if (!NT_STATUS_IS_OK(status)) {
 218                 return status;
 219         }
 220
 221         gensec_want_feature(gensec_security, GENSEC_FEATURE_ASYNC_REPLIES);
 222         gensec_want_feature(gensec_security, GENSEC_FEATURE_LDAP_STYLE);
 223
 224         if (conn->sockets.active == conn->sockets.tls) {
 225                 gensec_want_feature(gensec_security, GENSEC_FEATURE_LDAPS_TRANSPORT);
 226         }
 227
 228         status = gensec_start_mech_by_sasl_name(gensec_security, sasl_mech);
 229
 230         if (!NT_STATUS_IS_OK(status)) {
 231                 return status;
 232         }
 233
 234         *_gensec_security = gensec_security;
 235         return status;
 236 }
 237
 238 static NTSTATUS ldapsrv_BindSASL(struct ldapsrv_call *call)
 239 {
 240         struct ldap_BindRequest *req = &call->request->r.BindRequest;
 241         struct ldapsrv_reply *reply;
 242         struct ldap_BindResponse *resp;
 243         struct ldapsrv_connection *conn;
 244         int result = 0;
 245         const char *errstr=NULL;
 246         NTSTATUS status = NT_STATUS_OK;
 247
 248         DEBUG(10, ("BindSASL dn: %s\n",req->dn));
 249
 250         reply = ldapsrv_init_reply(call, LDAP_TAG_BindResponse);
 251         if (!reply) {
 252                 return NT_STATUS_NO_MEMORY;
 253         }
 254         resp = &reply->msg->r.BindResponse;
 255
 256         conn = call->conn;
 257
 258         /*
 259          * TODO: a SASL bind with a different mechanism
 260          *       should cancel an inprogress SASL bind.
 261          *       (see RFC 4513)
 262          */
 263
 264         if (!conn->gensec) {
 265                 status = ldapsrv_setup_gensec(conn, req->creds.SASL.mechanism,
 266                                               &conn->gensec);
 267                 if (!NT_STATUS_IS_OK(status)) {
 268                         DEBUG(1, ("Failed to start GENSEC server for [%s] code: %s\n",
 269                                   ldb_binary_encode_string(call, req->creds.SASL.mechanism),
 270                                   nt_errstr(status)));
 271                         result = LDAP_OPERATIONS_ERROR;
 272                         errstr = talloc_asprintf(reply, "SASL: Failed to start authentication system: %s",
 273                                                  nt_errstr(status));
 274                 }
 275         }
 276
 277         if (NT_STATUS_IS_OK(status)) {
 278                 DATA_BLOB input = data_blob(NULL, 0);
 279                 DATA_BLOB output = data_blob(NULL, 0);
 280
 281                 if (req->creds.SASL.secblob) {
 282                         input = *req->creds.SASL.secblob;
 283                 }
 284
 285                 status = gensec_update_ev(conn->gensec, reply, conn->connection->event.ctx,
 286                                           input, &output);
 287
 288                 /* Windows 2000 mmc doesn't like secblob == NULL and reports a decoding error */
 289                 resp->SASL.secblob = talloc(reply, DATA_BLOB);
 290                 NT_STATUS_HAVE_NO_MEMORY(resp->SASL.secblob);
 291                 *resp->SASL.secblob = output;
 292         } else {
 293                 resp->SASL.secblob = NULL;
 294         }
 295
 296         if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
 297                 result = LDAP_SASL_BIND_IN_PROGRESS;
 298                 errstr = NULL;
 299         } else if (NT_STATUS_IS_OK(status)) {
 300                 struct ldapsrv_sasl_postprocess_context *context = NULL;
 301
 302                 result = LDAP_SUCCESS;
 303                 errstr = NULL;
 304
 305                 if (gensec_have_feature(conn->gensec, GENSEC_FEATURE_SIGN) ||
 306                     gensec_have_feature(conn->gensec, GENSEC_FEATURE_SEAL)) {
 307
 308                         context = talloc(call, struct ldapsrv_sasl_postprocess_context);
 309
 310                         if (!context) {
 311                                 status = NT_STATUS_NO_MEMORY;
 312                         }
 313                 }
 314
 315                 if (context && conn->sockets.tls) {
 316                         TALLOC_FREE(context);
 317                         status = NT_STATUS_NOT_SUPPORTED;
 318                         result = LDAP_UNWILLING_TO_PERFORM;
 319                         errstr = talloc_asprintf(reply,
 320                                                  "SASL:[%s]: Sign or Seal are not allowed if TLS is used",
 321                                                  req->creds.SASL.mechanism);
 322                 }
 323
 324                 if (context && conn->sockets.sasl) {
 325                         TALLOC_FREE(context);
 326                         status = NT_STATUS_NOT_SUPPORTED;
 327                         result = LDAP_UNWILLING_TO_PERFORM;
 328                         errstr = talloc_asprintf(reply,
 329                                                  "SASL:[%s]: Sign or Seal are not allowed if SASL encryption has already been set up",
 330                                                  req->creds.SASL.mechanism);
 331                 }
 332
 333                 if (context) {
 334                         context->conn = conn;
 335                         status = gensec_create_tstream(context,
 336                                                        context->conn->gensec,
 337                                                        context->conn->sockets.raw,
 338                                                        &context->sasl);
 339                         if (NT_STATUS_IS_OK(status)) {
 340                                 if (!talloc_reference(context->sasl, conn->gensec)) {
 341                                         status = NT_STATUS_NO_MEMORY;
 342                                 }
 343                         }
 344                 } else {
 345                         switch (call->conn->require_strong_auth) {
 346                         case LDAP_SERVER_REQUIRE_STRONG_AUTH_NO:
 347                                 break;
 348                         case LDAP_SERVER_REQUIRE_STRONG_AUTH_ALLOW_SASL_OVER_TLS:
 349                                 if (call->conn->sockets.active == call->conn->sockets.tls) {
 350                                         break;
 351                                 }
 352                                 status = NT_STATUS_NETWORK_ACCESS_DENIED;
 353                                 result = LDAP_STRONG_AUTH_REQUIRED;
 354                                 errstr = talloc_asprintf(reply,
 355                                                 "SASL:[%s]: not allowed if TLS is used.",
 356                                                  req->creds.SASL.mechanism);
 357                                 break;
 358                         case LDAP_SERVER_REQUIRE_STRONG_AUTH_YES:
 359                                 status = NT_STATUS_NETWORK_ACCESS_DENIED;
 360                                 result = LDAP_STRONG_AUTH_REQUIRED;
 361                                 errstr = talloc_asprintf(reply,
 362                                                  "SASL:[%s]: Sign or Seal are required.",
 363                                                  req->creds.SASL.mechanism);
 364                                 break;
 365                         }
 366                 }
 367
 368                 if (result != LDAP_SUCCESS) {
 369                 } else if (!NT_STATUS_IS_OK(status)) {
 370                         result = LDAP_OPERATIONS_ERROR;
 371                         errstr = talloc_asprintf(reply,
 372                                                  "SASL:[%s]: Failed to setup SASL socket: %s",
 373                                                  req->creds.SASL.mechanism, nt_errstr(status));
 374                 } else {
 375                         struct auth_session_info *old_session_info=NULL;
 376
 377                         old_session_info = conn->session_info;
 378                         conn->session_info = NULL;
 379                         status = gensec_session_info(conn->gensec, conn, &conn->session_info);
 380                         if (!NT_STATUS_IS_OK(status)) {
 381                                 conn->session_info = old_session_info;
 382                                 result = LDAP_OPERATIONS_ERROR;
 383                                 errstr = talloc_asprintf(reply,
 384                                                          "SASL:[%s]: Failed to get session info: %s",
 385                                                          req->creds.SASL.mechanism, nt_errstr(status));
 386                         } else {
 387                                 talloc_unlink(conn, old_session_info);
 388
 389                                 /* don't leak the old LDB */
 390                                 talloc_unlink(conn, conn->ldb);
 391
 392                                 call->conn->authz_logged = true;
 393
 394                                 status = ldapsrv_backend_Init(conn);
 395
 396                                 if (!NT_STATUS_IS_OK(status)) {
 397                                         result = LDAP_OPERATIONS_ERROR;
 398                                         errstr = talloc_asprintf(reply,
 399                                                                  "SASL:[%s]: Failed to advise samdb of new credentials: %s",
 400                                                                  req->creds.SASL.mechanism,
 401                                                                  nt_errstr(status));
 402                                 }
 403                         }
 404                 }
 405
 406                 if (NT_STATUS_IS_OK(status) && context) {
 407                         call->postprocess_send = ldapsrv_sasl_postprocess_send;
 408                         call->postprocess_recv = ldapsrv_sasl_postprocess_recv;
 409                         call->postprocess_private = context;
 410                 }
 411                 talloc_unlink(conn, conn->gensec);
 412                 conn->gensec = NULL;
 413         } else {
 414                 status = nt_status_squash(status);
 415                 if (result == 0) {
 416                         result = LDAP_INVALID_CREDENTIALS;
 417                         errstr = ldapsrv_bind_error_msg(reply, HRES_SEC_E_LOGON_DENIED,
 418                                                         0x0C0904DC, status);
 419                 }
 420                 talloc_unlink(conn, conn->gensec);
 421                 conn->gensec = NULL;
 422         }
 423
 424         resp->response.resultcode = result;
 425         resp->response.dn = NULL;
 426         resp->response.errormessage = errstr;
 427         resp->response.referral = NULL;
 428
 429         ldapsrv_queue_reply(call, reply);
 430         return NT_STATUS_OK;
 431 }
 432
 433 NTSTATUS ldapsrv_BindRequest(struct ldapsrv_call *call)
 434 {
 435         struct ldap_BindRequest *req = &call->request->r.BindRequest;
 436         struct ldapsrv_reply *reply;
 437         struct ldap_BindResponse *resp;
 438
 439         if (call->conn->pending_calls != NULL) {
 440                 reply = ldapsrv_init_reply(call, LDAP_TAG_BindResponse);
 441                 if (!reply) {
 442                         return NT_STATUS_NO_MEMORY;
 443                 }
 444
 445                 resp = &reply->msg->r.BindResponse;
 446                 resp->response.resultcode = LDAP_BUSY;
 447                 resp->response.dn = NULL;
 448                 resp->response.errormessage = talloc_asprintf(reply, "Pending requests on this LDAP session");
 449                 resp->response.referral = NULL;
 450                 resp->SASL.secblob = NULL;
 451
 452                 ldapsrv_queue_reply(call, reply);
 453                 return NT_STATUS_OK;
 454         }
 455
 456         /*
 457          * TODO: a simple bind should cancel an
 458          *       inprogress SASL bind.
 459          *       (see RFC 4513)
 460          */
 461         switch (req->mechanism) {
 462                 case LDAP_AUTH_MECH_SIMPLE:
 463                         return ldapsrv_BindSimple(call);
 464                 case LDAP_AUTH_MECH_SASL:
 465                         return ldapsrv_BindSASL(call);
 466         }
 467
 468         reply = ldapsrv_init_reply(call, LDAP_TAG_BindResponse);
 469         if (!reply) {
 470                 return NT_STATUS_NO_MEMORY;
 471         }
 472
 473         resp = &reply->msg->r.BindResponse;
 474         resp->response.resultcode = LDAP_AUTH_METHOD_NOT_SUPPORTED;
 475         resp->response.dn = NULL;
 476         resp->response.errormessage = talloc_asprintf(reply, "Bad AuthenticationChoice [%d]", req->mechanism);
 477         resp->response.referral = NULL;
 478         resp->SASL.secblob = NULL;
 479
 480         ldapsrv_queue_reply(call, reply);
 481         return NT_STATUS_OK;
 482 }
 483
 484 NTSTATUS ldapsrv_UnbindRequest(struct ldapsrv_call *call)
 485 {
 486         DEBUG(10, ("UnbindRequest\n"));
 487         return NT_STATUS_OK;
 488 }