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         DEBUG(10, ("BindSimple dn: %s\n",req->dn));
  77
  78         reply = ldapsrv_init_reply(call, LDAP_TAG_BindResponse);
  79         if (!reply) {
  80                 return NT_STATUS_NO_MEMORY;
  81         }
  82
  83         if (req->dn != NULL &&
  84             strlen(req->dn) != 0 &&
  85             call->conn->require_strong_auth > LDAP_SERVER_REQUIRE_STRONG_AUTH_NO &&
  86             call->conn->sockets.active != call->conn->sockets.tls)
  87         {
  88                 status = NT_STATUS_NETWORK_ACCESS_DENIED;
  89                 result = LDAP_STRONG_AUTH_REQUIRED;
  90                 errstr = talloc_asprintf(reply,
  91                                          "BindSimple: Transport encryption required.");
  92                 goto do_reply;
  93         }
  94
  95         status = authenticate_ldap_simple_bind(call,
  96                                                call->conn->connection->event.ctx,
  97                                                call->conn->connection->msg_ctx,
  98                                                call->conn->lp_ctx,
  99                                                call->conn->connection->remote_address,
 100                                                call->conn->connection->local_address,
 101                                                req->dn,
 102                                                req->creds.password,
 103                                                &session_info);
 104
 105         if (NT_STATUS_IS_OK(status)) {
 106                 result = LDAP_SUCCESS;
 107                 errstr = NULL;
 108
 109                 talloc_unlink(call->conn, call->conn->session_info);
 110                 call->conn->session_info = talloc_steal(call->conn, session_info);
 111
 112                 call->conn->authz_logged = true;
 113
 114                 /* don't leak the old LDB */
 115                 talloc_unlink(call->conn, call->conn->ldb);
 116
 117                 status = ldapsrv_backend_Init(call->conn);
 118
 119                 if (!NT_STATUS_IS_OK(status)) {
 120                         result = LDAP_OPERATIONS_ERROR;
 121                         errstr = talloc_asprintf(reply, "Simple Bind: Failed to advise ldb new credentials: %s", nt_errstr(status));
 122                 }
 123         } else {
 124                 status = nt_status_squash(status);
 125
 126                 result = LDAP_INVALID_CREDENTIALS;
 127                 errstr = ldapsrv_bind_error_msg(reply, HRES_SEC_E_INVALID_TOKEN,
 128                                                 0x0C0903A9, status);
 129         }
 130
 131 do_reply:
 132         resp = &reply->msg->r.BindResponse;
 133         resp->response.resultcode = result;
 134         resp->response.errormessage = errstr;
 135         resp->response.dn = NULL;
 136         resp->response.referral = NULL;
 137         resp->SASL.secblob = NULL;
 138
 139         ldapsrv_queue_reply(call, reply);
 140         return NT_STATUS_OK;
 141 }
 142
 143 struct ldapsrv_sasl_postprocess_context {
 144         struct ldapsrv_connection *conn;
 145         struct tstream_context *sasl;
 146 };
 147
 148 struct ldapsrv_sasl_postprocess_state {
 149         uint8_t dummy;
 150 };
 151
 152 static struct tevent_req *ldapsrv_sasl_postprocess_send(TALLOC_CTX *mem_ctx,
 153                                                 struct tevent_context *ev,
 154                                                 void *private_data)
 155 {
 156         struct ldapsrv_sasl_postprocess_context *context =
 157                 talloc_get_type_abort(private_data,
 158                 struct ldapsrv_sasl_postprocess_context);
 159         struct tevent_req *req;
 160         struct ldapsrv_sasl_postprocess_state *state;
 161
 162         req = tevent_req_create(mem_ctx, &state,
 163                                 struct ldapsrv_sasl_postprocess_state);
 164         if (req == NULL) {
 165                 return NULL;
 166         }
 167
 168         TALLOC_FREE(context->conn->sockets.sasl);
 169         context->conn->sockets.sasl = talloc_move(context->conn, &context->sasl);
 170         context->conn->sockets.active = context->conn->sockets.sasl;
 171
 172         tevent_req_done(req);
 173         return tevent_req_post(req, ev);
 174 }
 175
 176 static NTSTATUS ldapsrv_sasl_postprocess_recv(struct tevent_req *req)
 177 {
 178         return tevent_req_simple_recv_ntstatus(req);
 179 }
 180
 181 static NTSTATUS ldapsrv_setup_gensec(struct ldapsrv_connection *conn,
 182                                      const char *sasl_mech,
 183                                      struct gensec_security **_gensec_security)
 184 {
 185         NTSTATUS status;
 186
 187         struct gensec_security *gensec_security;
 188
 189         status = samba_server_gensec_start(conn,
 190                                            conn->connection->event.ctx,
 191                                            conn->connection->msg_ctx,
 192                                            conn->lp_ctx,
 193                                            conn->server_credentials,
 194                                            "ldap",
 195                                            &gensec_security);
 196         if (!NT_STATUS_IS_OK(status)) {
 197                 return status;
 198         }
 199
 200         status = gensec_set_target_service_description(gensec_security,
 201                                                        "LDAP");
 202         if (!NT_STATUS_IS_OK(status)) {
 203                 return status;
 204         }
 205
 206         status = gensec_set_remote_address(gensec_security,
 207                                            conn->connection->remote_address);
 208         if (!NT_STATUS_IS_OK(status)) {
 209                 return status;
 210         }
 211
 212         status = gensec_set_local_address(gensec_security,
 213                                           conn->connection->local_address);
 214         if (!NT_STATUS_IS_OK(status)) {
 215                 return status;
 216         }
 217
 218         gensec_want_feature(gensec_security, GENSEC_FEATURE_ASYNC_REPLIES);
 219         gensec_want_feature(gensec_security, GENSEC_FEATURE_LDAP_STYLE);
 220
 221         status = gensec_start_mech_by_sasl_name(gensec_security, sasl_mech);
 222
 223         if (!NT_STATUS_IS_OK(status)) {
 224                 return status;
 225         }
 226
 227         *_gensec_security = gensec_security;
 228         return status;
 229 }
 230
 231 static NTSTATUS ldapsrv_BindSASL(struct ldapsrv_call *call)
 232 {
 233         struct ldap_BindRequest *req = &call->request->r.BindRequest;
 234         struct ldapsrv_reply *reply;
 235         struct ldap_BindResponse *resp;
 236         struct ldapsrv_connection *conn;
 237         int result = 0;
 238         const char *errstr=NULL;
 239         NTSTATUS status = NT_STATUS_OK;
 240
 241         DEBUG(10, ("BindSASL dn: %s\n",req->dn));
 242
 243         reply = ldapsrv_init_reply(call, LDAP_TAG_BindResponse);
 244         if (!reply) {
 245                 return NT_STATUS_NO_MEMORY;
 246         }
 247         resp = &reply->msg->r.BindResponse;
 248
 249         conn = call->conn;
 250
 251         /*
 252          * TODO: a SASL bind with a different mechanism
 253          *       should cancel an inprogress SASL bind.
 254          *       (see RFC 4513)
 255          */
 256
 257         if (!conn->gensec) {
 258                 status = ldapsrv_setup_gensec(conn, req->creds.SASL.mechanism,
 259                                               &conn->gensec);
 260                 if (!NT_STATUS_IS_OK(status)) {
 261                         DEBUG(1, ("Failed to start GENSEC server for [%s] code: %s\n",
 262                                   ldb_binary_encode_string(call, req->creds.SASL.mechanism),
 263                                   nt_errstr(status)));
 264                         result = LDAP_OPERATIONS_ERROR;
 265                         errstr = talloc_asprintf(reply, "SASL: Failed to start authentication system: %s",
 266                                                  nt_errstr(status));
 267                 }
 268         }
 269
 270         if (NT_STATUS_IS_OK(status)) {
 271                 DATA_BLOB input = data_blob(NULL, 0);
 272                 DATA_BLOB output = data_blob(NULL, 0);
 273
 274                 if (req->creds.SASL.secblob) {
 275                         input = *req->creds.SASL.secblob;
 276                 }
 277
 278                 status = gensec_update_ev(conn->gensec, reply, conn->connection->event.ctx,
 279                                           input, &output);
 280
 281                 /* Windows 2000 mmc doesn't like secblob == NULL and reports a decoding error */
 282                 resp->SASL.secblob = talloc(reply, DATA_BLOB);
 283                 NT_STATUS_HAVE_NO_MEMORY(resp->SASL.secblob);
 284                 *resp->SASL.secblob = output;
 285         } else {
 286                 resp->SASL.secblob = NULL;
 287         }
 288
 289         if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
 290                 result = LDAP_SASL_BIND_IN_PROGRESS;
 291                 errstr = NULL;
 292         } else if (NT_STATUS_IS_OK(status)) {
 293                 struct ldapsrv_sasl_postprocess_context *context = NULL;
 294
 295                 result = LDAP_SUCCESS;
 296                 errstr = NULL;
 297
 298                 if (gensec_have_feature(conn->gensec, GENSEC_FEATURE_SIGN) ||
 299                     gensec_have_feature(conn->gensec, GENSEC_FEATURE_SEAL)) {
 300
 301                         context = talloc(call, struct ldapsrv_sasl_postprocess_context);
 302
 303                         if (!context) {
 304                                 status = NT_STATUS_NO_MEMORY;
 305                         }
 306                 }
 307
 308                 if (context && conn->sockets.tls) {
 309                         TALLOC_FREE(context);
 310                         status = NT_STATUS_NOT_SUPPORTED;
 311                         result = LDAP_UNWILLING_TO_PERFORM;
 312                         errstr = talloc_asprintf(reply,
 313                                                  "SASL:[%s]: Sign or Seal are not allowed if TLS is used",
 314                                                  req->creds.SASL.mechanism);
 315                 }
 316
 317                 if (context && conn->sockets.sasl) {
 318                         TALLOC_FREE(context);
 319                         status = NT_STATUS_NOT_SUPPORTED;
 320                         result = LDAP_UNWILLING_TO_PERFORM;
 321                         errstr = talloc_asprintf(reply,
 322                                                  "SASL:[%s]: Sign or Seal are not allowed if SASL encryption has already been set up",
 323                                                  req->creds.SASL.mechanism);
 324                 }
 325
 326                 if (context) {
 327                         context->conn = conn;
 328                         status = gensec_create_tstream(context,
 329                                                        context->conn->gensec,
 330                                                        context->conn->sockets.raw,
 331                                                        &context->sasl);
 332                         if (NT_STATUS_IS_OK(status)) {
 333                                 if (!talloc_reference(context->sasl, conn->gensec)) {
 334                                         status = NT_STATUS_NO_MEMORY;
 335                                 }
 336                         }
 337                 } else {
 338                         switch (call->conn->require_strong_auth) {
 339                         case LDAP_SERVER_REQUIRE_STRONG_AUTH_NO:
 340                                 break;
 341                         case LDAP_SERVER_REQUIRE_STRONG_AUTH_ALLOW_SASL_OVER_TLS:
 342                                 if (call->conn->sockets.active == call->conn->sockets.tls) {
 343                                         break;
 344                                 }
 345                                 status = NT_STATUS_NETWORK_ACCESS_DENIED;
 346                                 result = LDAP_STRONG_AUTH_REQUIRED;
 347                                 errstr = talloc_asprintf(reply,
 348                                                 "SASL:[%s]: not allowed if TLS is used.",
 349                                                  req->creds.SASL.mechanism);
 350                                 break;
 351                         case LDAP_SERVER_REQUIRE_STRONG_AUTH_YES:
 352                                 status = NT_STATUS_NETWORK_ACCESS_DENIED;
 353                                 result = LDAP_STRONG_AUTH_REQUIRED;
 354                                 errstr = talloc_asprintf(reply,
 355                                                  "SASL:[%s]: Sign or Seal are required.",
 356                                                  req->creds.SASL.mechanism);
 357                                 break;
 358                         }
 359                 }
 360
 361                 if (result != LDAP_SUCCESS) {
 362                 } else if (!NT_STATUS_IS_OK(status)) {
 363                         result = LDAP_OPERATIONS_ERROR;
 364                         errstr = talloc_asprintf(reply,
 365                                                  "SASL:[%s]: Failed to setup SASL socket: %s",
 366                                                  req->creds.SASL.mechanism, nt_errstr(status));
 367                 } else {
 368                         struct auth_session_info *old_session_info=NULL;
 369
 370                         old_session_info = conn->session_info;
 371                         conn->session_info = NULL;
 372                         status = gensec_session_info(conn->gensec, conn, &conn->session_info);
 373                         if (!NT_STATUS_IS_OK(status)) {
 374                                 conn->session_info = old_session_info;
 375                                 result = LDAP_OPERATIONS_ERROR;
 376                                 errstr = talloc_asprintf(reply,
 377                                                          "SASL:[%s]: Failed to get session info: %s",
 378                                                          req->creds.SASL.mechanism, nt_errstr(status));
 379                         } else {
 380                                 talloc_unlink(conn, old_session_info);
 381
 382                                 /* don't leak the old LDB */
 383                                 talloc_unlink(conn, conn->ldb);
 384
 385                                 call->conn->authz_logged = true;
 386
 387                                 status = ldapsrv_backend_Init(conn);
 388
 389                                 if (!NT_STATUS_IS_OK(status)) {
 390                                         result = LDAP_OPERATIONS_ERROR;
 391                                         errstr = talloc_asprintf(reply,
 392                                                                  "SASL:[%s]: Failed to advise samdb of new credentials: %s",
 393                                                                  req->creds.SASL.mechanism,
 394                                                                  nt_errstr(status));
 395                                 }
 396                         }
 397                 }
 398
 399                 if (NT_STATUS_IS_OK(status) && context) {
 400                         call->postprocess_send = ldapsrv_sasl_postprocess_send;
 401                         call->postprocess_recv = ldapsrv_sasl_postprocess_recv;
 402                         call->postprocess_private = context;
 403                 }
 404                 talloc_unlink(conn, conn->gensec);
 405                 conn->gensec = NULL;
 406         } else {
 407                 status = nt_status_squash(status);
 408                 if (result == 0) {
 409                         result = LDAP_INVALID_CREDENTIALS;
 410                         errstr = ldapsrv_bind_error_msg(reply, HRES_SEC_E_LOGON_DENIED,
 411                                                         0x0C0904DC, status);
 412                 }
 413                 talloc_unlink(conn, conn->gensec);
 414                 conn->gensec = NULL;
 415         }
 416
 417         resp->response.resultcode = result;
 418         resp->response.dn = NULL;
 419         resp->response.errormessage = errstr;
 420         resp->response.referral = NULL;
 421
 422         ldapsrv_queue_reply(call, reply);
 423         return NT_STATUS_OK;
 424 }
 425
 426 NTSTATUS ldapsrv_BindRequest(struct ldapsrv_call *call)
 427 {
 428         struct ldap_BindRequest *req = &call->request->r.BindRequest;
 429         struct ldapsrv_reply *reply;
 430         struct ldap_BindResponse *resp;
 431
 432         if (call->conn->pending_calls != NULL) {
 433                 reply = ldapsrv_init_reply(call, LDAP_TAG_BindResponse);
 434                 if (!reply) {
 435                         return NT_STATUS_NO_MEMORY;
 436                 }
 437
 438                 resp = &reply->msg->r.BindResponse;
 439                 resp->response.resultcode = LDAP_BUSY;
 440                 resp->response.dn = NULL;
 441                 resp->response.errormessage = talloc_asprintf(reply, "Pending requests on this LDAP session");
 442                 resp->response.referral = NULL;
 443                 resp->SASL.secblob = NULL;
 444
 445                 ldapsrv_queue_reply(call, reply);
 446                 return NT_STATUS_OK;
 447         }
 448
 449         /*
 450          * TODO: a simple bind should cancel an
 451          *       inprogress SASL bind.
 452          *       (see RFC 4513)
 453          */
 454         switch (req->mechanism) {
 455                 case LDAP_AUTH_MECH_SIMPLE:
 456                         return ldapsrv_BindSimple(call);
 457                 case LDAP_AUTH_MECH_SASL:
 458                         return ldapsrv_BindSASL(call);
 459         }
 460
 461         reply = ldapsrv_init_reply(call, LDAP_TAG_BindResponse);
 462         if (!reply) {
 463                 return NT_STATUS_NO_MEMORY;
 464         }
 465
 466         resp = &reply->msg->r.BindResponse;
 467         resp->response.resultcode = LDAP_AUTH_METHOD_NOT_SUPPORTED;
 468         resp->response.dn = NULL;
 469         resp->response.errormessage = talloc_asprintf(reply, "Bad AuthenticationChoice [%d]", req->mechanism);
 470         resp->response.referral = NULL;
 471         resp->SASL.secblob = NULL;
 472
 473         ldapsrv_queue_reply(call, reply);
 474         return NT_STATUS_OK;
 475 }
 476
 477 NTSTATUS ldapsrv_UnbindRequest(struct ldapsrv_call *call)
 478 {
 479         DEBUG(10, ("UnbindRequest\n"));
 480         return NT_STATUS_OK;
 481 }