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         const char *nt4_domain, *nt4_account;
  72
  73         struct auth_session_info *session_info;
  74
  75         NTSTATUS status;
  76
  77         DEBUG(10, ("BindSimple dn: %s\n",req->dn));
  78
  79         reply = ldapsrv_init_reply(call, LDAP_TAG_BindResponse);
  80         if (!reply) {
  81                 return NT_STATUS_NO_MEMORY;
  82         }
  83
  84         if (req->dn != NULL &&
  85             strlen(req->dn) != 0 &&
  86             call->conn->require_strong_auth > LDAP_SERVER_REQUIRE_STRONG_AUTH_NO &&
  87             call->conn->sockets.active != call->conn->sockets.tls)
  88         {
  89                 status = NT_STATUS_NETWORK_ACCESS_DENIED;
  90                 result = LDAP_STRONG_AUTH_REQUIRED;
  91                 errstr = talloc_asprintf(reply,
  92                                          "BindSimple: Transport encryption required.");
  93                 goto do_reply;
  94         }
  95
  96         status = crack_auto_name_to_nt4_name(call, call->conn->connection->event.ctx, call->conn->lp_ctx, req->dn, &nt4_domain, &nt4_account);
  97         if (NT_STATUS_IS_OK(status)) {
  98                 status = authenticate_username_pw(call,
  99                                                   call->conn->connection->event.ctx,
 100                                                   call->conn->connection->msg_ctx,
 101                                                   call->conn->lp_ctx,
 102                                                   nt4_domain, nt4_account,
 103                                                   req->creds.password,
 104                                                   MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT |
 105                                                   MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT,
 106                                                   &session_info);
 107         }
 108
 109         if (NT_STATUS_IS_OK(status)) {
 110                 result = LDAP_SUCCESS;
 111                 errstr = NULL;
 112
 113                 talloc_unlink(call->conn, call->conn->session_info);
 114                 call->conn->session_info = talloc_steal(call->conn, session_info);
 115
 116                 /* don't leak the old LDB */
 117                 talloc_unlink(call->conn, call->conn->ldb);
 118
 119                 status = ldapsrv_backend_Init(call->conn);
 120
 121                 if (!NT_STATUS_IS_OK(status)) {
 122                         result = LDAP_OPERATIONS_ERROR;
 123                         errstr = talloc_asprintf(reply, "Simple Bind: Failed to advise ldb new credentials: %s", nt_errstr(status));
 124                 }
 125         } else {
 126                 status = nt_status_squash(status);
 127
 128                 result = LDAP_INVALID_CREDENTIALS;
 129                 errstr = ldapsrv_bind_error_msg(reply, HRES_SEC_E_INVALID_TOKEN,
 130                                                 0x0C0903A9, status);
 131         }
 132
 133 do_reply:
 134         resp = &reply->msg->r.BindResponse;
 135         resp->response.resultcode = result;
 136         resp->response.errormessage = errstr;
 137         resp->response.dn = NULL;
 138         resp->response.referral = NULL;
 139         resp->SASL.secblob = NULL;
 140
 141         ldapsrv_queue_reply(call, reply);
 142         return NT_STATUS_OK;
 143 }
 144
 145 struct ldapsrv_sasl_postprocess_context {
 146         struct ldapsrv_connection *conn;
 147         struct tstream_context *sasl;
 148 };
 149
 150 struct ldapsrv_sasl_postprocess_state {
 151         uint8_t dummy;
 152 };
 153
 154 static struct tevent_req *ldapsrv_sasl_postprocess_send(TALLOC_CTX *mem_ctx,
 155                                                 struct tevent_context *ev,
 156                                                 void *private_data)
 157 {
 158         struct ldapsrv_sasl_postprocess_context *context =
 159                 talloc_get_type_abort(private_data,
 160                 struct ldapsrv_sasl_postprocess_context);
 161         struct tevent_req *req;
 162         struct ldapsrv_sasl_postprocess_state *state;
 163
 164         req = tevent_req_create(mem_ctx, &state,
 165                                 struct ldapsrv_sasl_postprocess_state);
 166         if (req == NULL) {
 167                 return NULL;
 168         }
 169
 170         TALLOC_FREE(context->conn->sockets.sasl);
 171         context->conn->sockets.sasl = talloc_move(context->conn, &context->sasl);
 172         context->conn->sockets.active = context->conn->sockets.sasl;
 173
 174         tevent_req_done(req);
 175         return tevent_req_post(req, ev);
 176 }
 177
 178 static NTSTATUS ldapsrv_sasl_postprocess_recv(struct tevent_req *req)
 179 {
 180         return tevent_req_simple_recv_ntstatus(req);
 181 }
 182
 183 static NTSTATUS ldapsrv_setup_gensec(struct ldapsrv_connection *conn,
 184                                      const char *sasl_mech,
 185                                      struct gensec_security **_gensec_security)
 186 {
 187         NTSTATUS status;
 188
 189         struct gensec_security *gensec_security;
 190
 191         status = samba_server_gensec_start(conn,
 192                                            conn->connection->event.ctx,
 193                                            conn->connection->msg_ctx,
 194                                            conn->lp_ctx,
 195                                            conn->server_credentials,
 196                                            "ldap",
 197                                            &gensec_security);
 198         if (!NT_STATUS_IS_OK(status)) {
 199                 return status;
 200         }
 201
 202         status = gensec_set_remote_address(gensec_security,
 203                                            conn->connection->remote_address);
 204         if (!NT_STATUS_IS_OK(status)) {
 205                 return status;
 206         }
 207
 208         status = gensec_set_local_address(gensec_security,
 209                                           conn->connection->local_address);
 210         if (!NT_STATUS_IS_OK(status)) {
 211                 return status;
 212         }
 213
 214         gensec_want_feature(gensec_security, GENSEC_FEATURE_ASYNC_REPLIES);
 215         gensec_want_feature(gensec_security, GENSEC_FEATURE_LDAP_STYLE);
 216
 217         status = gensec_start_mech_by_sasl_name(gensec_security, sasl_mech);
 218
 219         if (!NT_STATUS_IS_OK(status)) {
 220                 return status;
 221         }
 222
 223         *_gensec_security = gensec_security;
 224         return status;
 225 }
 226
 227 static NTSTATUS ldapsrv_BindSASL(struct ldapsrv_call *call)
 228 {
 229         struct ldap_BindRequest *req = &call->request->r.BindRequest;
 230         struct ldapsrv_reply *reply;
 231         struct ldap_BindResponse *resp;
 232         struct ldapsrv_connection *conn;
 233         int result = 0;
 234         const char *errstr=NULL;
 235         NTSTATUS status = NT_STATUS_OK;
 236
 237         DEBUG(10, ("BindSASL dn: %s\n",req->dn));
 238
 239         reply = ldapsrv_init_reply(call, LDAP_TAG_BindResponse);
 240         if (!reply) {
 241                 return NT_STATUS_NO_MEMORY;
 242         }
 243         resp = &reply->msg->r.BindResponse;
 244
 245         conn = call->conn;
 246
 247         /*
 248          * TODO: a SASL bind with a different mechanism
 249          *       should cancel an inprogress SASL bind.
 250          *       (see RFC 4513)
 251          */
 252
 253         if (!conn->gensec) {
 254                 conn->session_info = NULL;
 255
 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 }