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