source3/auth/auth_generic.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 3.0
   4    handle GENSEC authentication, server side
   5
   6    Copyright (C) Andrew Tridgell      2001
   7    Copyright (C) Andrew Bartlett 2001-2003,2011
   8    Copyright (C) Simo Sorce 2010.
   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 <tevent.h>
  26 #include "../lib/util/tevent_ntstatus.h"
  27 #include "auth.h"
  28 #include "../lib/tsocket/tsocket.h"
  29 #include "auth/gensec/gensec.h"
  30 #include "lib/param/param.h"
  31 #ifdef HAVE_KRB5
  32 #include "auth/kerberos/pac_utils.h"
  33 #include "nsswitch/libwbclient/wbclient.h"
  34 #endif
  35 #include "librpc/crypto/gse.h"
  36 #include "auth/credentials/credentials.h"
  37 #include "lib/param/loadparm.h"
  38 #include "librpc/gen_ndr/dcerpc.h"
  39 #include "source3/lib/substitute.h"
  40
  41 static NTSTATUS auth3_generate_session_info_pac(struct auth4_context *auth_ctx,
  42                                                 TALLOC_CTX *mem_ctx,
  43                                                 struct smb_krb5_context *smb_krb5_context,
  44                                                 DATA_BLOB *pac_blob,
  45                                                 const char *princ_name,
  46                                                 const struct tsocket_address *remote_address,
  47                                                 uint32_t session_info_flags,
  48                                                 struct auth_session_info **session_info)
  49 {
  50         enum server_role server_role = lp_server_role();
  51         TALLOC_CTX *tmp_ctx;
  52         bool is_mapped;
  53         bool is_guest;
  54         char *ntuser;
  55         char *ntdomain;
  56         char *username;
  57         const char *rhost;
  58         struct passwd *pw;
  59         NTSTATUS status;
  60
  61         tmp_ctx = talloc_new(mem_ctx);
  62         if (!tmp_ctx) {
  63                 return NT_STATUS_NO_MEMORY;
  64         }
  65
  66         if (tsocket_address_is_inet(remote_address, "ip")) {
  67                 rhost = tsocket_address_inet_addr_string(
  68                         remote_address, tmp_ctx);
  69                 if (rhost == NULL) {
  70                         status = NT_STATUS_NO_MEMORY;
  71                         goto done;
  72                 }
  73         } else {
  74                 rhost = "127.0.0.1";
  75         }
  76
  77         if (server_role != ROLE_STANDALONE) {
  78                 struct wbcAuthUserParams params = { 0 };
  79                 struct wbcAuthUserInfo *info = NULL;
  80                 struct wbcAuthErrorInfo *err = NULL;
  81                 struct auth_serversupplied_info *server_info = NULL;
  82                 char *original_user_name = NULL;
  83                 char *p = NULL;
  84                 wbcErr wbc_err;
  85
  86                 if (pac_blob == NULL) {
  87                         /*
  88                          * This should already be catched at the main
  89                          * gensec layer, but better check twice
  90                          */
  91                         status = NT_STATUS_INTERNAL_ERROR;
  92                         goto done;
  93                 }
  94
  95                 /*
  96                  * Let winbind decode the PAC.
  97                  * This will also store the user
  98                  * data in the netsamlogon cache.
  99                  *
 100                  * This used to be a cache prime
 101                  * optimization, but now we delegate
 102                  * all logic to winbindd, as we require
 103                  * winbindd as domain member anyway.
 104                  */
 105                 params.level = WBC_AUTH_USER_LEVEL_PAC;
 106                 params.password.pac.data = pac_blob->data;
 107                 params.password.pac.length = pac_blob->length;
 108
 109                 /* we are contacting the privileged pipe */
 110                 become_root();
 111                 wbc_err = wbcAuthenticateUserEx(&params, &info, &err);
 112                 unbecome_root();
 113
 114                 /*
 115                  * As this is merely a cache prime
 116                  * WBC_ERR_WINBIND_NOT_AVAILABLE
 117                  * is not a fatal error, treat it
 118                  * as success.
 119                  */
 120
 121                 switch (wbc_err) {
 122                         case WBC_ERR_SUCCESS:
 123                                 break;
 124                         case WBC_ERR_WINBIND_NOT_AVAILABLE:
 125                                 status = NT_STATUS_NO_LOGON_SERVERS;
 126                                 DBG_ERR("winbindd not running - "
 127                                         "but required as domain member: %s\n",
 128                                         nt_errstr(status));
 129                                 goto done;
 130                         case WBC_ERR_AUTH_ERROR:
 131                                 status = NT_STATUS(err->nt_status);
 132                                 wbcFreeMemory(err);
 133                                 goto done;
 134                         case WBC_ERR_NO_MEMORY:
 135                                 status = NT_STATUS_NO_MEMORY;
 136                                 goto done;
 137                         default:
 138                                 status = NT_STATUS_LOGON_FAILURE;
 139                                 goto done;
 140                 }
 141
 142                 status = make_server_info_wbcAuthUserInfo(tmp_ctx,
 143                                                           info->account_name,
 144                                                           info->domain_name,
 145                                                           info, &server_info);
 146                 if (!NT_STATUS_IS_OK(status)) {
 147                         DEBUG(10, ("make_server_info_wbcAuthUserInfo failed: %s\n",
 148                                    nt_errstr(status)));
 149                         goto done;
 150                 }
 151
 152                 /* We skip doing this step if the caller asked us not to */
 153                 if (!(server_info->guest)) {
 154                         const char *unix_username = server_info->unix_name;
 155
 156                         /* We might not be root if we are an RPC call */
 157                         become_root();
 158                         status = smb_pam_accountcheck(unix_username, rhost);
 159                         unbecome_root();
 160
 161                         if (!NT_STATUS_IS_OK(status)) {
 162                                 DEBUG(3, ("check_ntlm_password:  PAM Account for user [%s] "
 163                                           "FAILED with error %s\n",
 164                                           unix_username, nt_errstr(status)));
 165                                 goto done;
 166                         }
 167
 168                         DEBUG(5, ("check_ntlm_password:  PAM Account for user [%s] "
 169                                   "succeeded\n", unix_username));
 170                 }
 171
 172                 DEBUG(3, ("Kerberos ticket principal name is [%s]\n", princ_name));
 173
 174                 p = strchr_m(princ_name, '@');
 175                 if (!p) {
 176                         DEBUG(3, ("[%s] Doesn't look like a valid principal\n",
 177                                   princ_name));
 178                         status = NT_STATUS_LOGON_FAILURE;
 179                         goto done;
 180                 }
 181
 182                 original_user_name = talloc_strndup(tmp_ctx, princ_name, p - princ_name);
 183                 if (original_user_name == NULL) {
 184                         status = NT_STATUS_NO_MEMORY;
 185                         goto done;
 186                 }
 187
 188                 status = create_local_token(mem_ctx,
 189                                             server_info,
 190                                             NULL,
 191                                             original_user_name,
 192                                             session_info);
 193                 if (!NT_STATUS_IS_OK(status)) {
 194                         DEBUG(10, ("create_local_token failed: %s\n",
 195                                    nt_errstr(status)));
 196                         goto done;
 197                 }
 198
 199                 goto session_info_ready;
 200         }
 201
 202         /* This is the standalone legacy code path */
 203
 204         if (pac_blob != NULL) {
 205                 /*
 206                  * In standalone mode we don't expect a PAC!
 207                  * we only support MIT realms
 208                  */
 209                 status = NT_STATUS_BAD_TOKEN_TYPE;
 210                 DBG_WARNING("Unexpected PAC for [%s] in standalone mode - %s\n",
 211                             princ_name, nt_errstr(status));
 212                 if (!NT_STATUS_IS_OK(status)) {
 213                         goto done;
 214                 }
 215         }
 216
 217         status = get_user_from_kerberos_info(tmp_ctx, rhost,
 218                                              princ_name,
 219                                              &is_mapped, &is_guest,
 220                                              &ntuser, &ntdomain,
 221                                              &username, &pw);
 222         if (!NT_STATUS_IS_OK(status)) {
 223                 DBG_NOTICE("Failed to map kerberos principal to system user "
 224                           "(%s)\n", nt_errstr(status));
 225                 status = NT_STATUS_ACCESS_DENIED;
 226                 goto done;
 227         }
 228
 229         status = make_session_info_krb5(mem_ctx,
 230                                         ntuser, ntdomain, username, pw,
 231                                         is_guest, is_mapped,
 232                                         session_info);
 233         if (!NT_STATUS_IS_OK(status)) {
 234                 DEBUG(1, ("Failed to map kerberos pac to server info (%s)\n",
 235                           nt_errstr(status)));
 236                 status = nt_status_squash(status);
 237                 goto done;
 238         }
 239
 240 session_info_ready:
 241
 242         /* setup the string used by %U */
 243         set_current_user_info((*session_info)->unix_info->sanitized_username,
 244                               (*session_info)->unix_info->unix_name,
 245                               (*session_info)->info->domain_name);
 246
 247         /* reload services so that the new %U is taken into account */
 248         lp_load_with_shares(get_dyn_CONFIGFILE());
 249
 250         DEBUG(5, (__location__ "OK: user: %s domain: %s client: %s\n",
 251                   (*session_info)->info->account_name,
 252                   (*session_info)->info->domain_name,
 253                   rhost));
 254
 255         status = NT_STATUS_OK;
 256
 257 done:
 258         TALLOC_FREE(tmp_ctx);
 259         return status;
 260 }
 261
 262 static struct auth4_context *make_auth4_context_s3(TALLOC_CTX *mem_ctx, struct auth_context *auth_context)
 263 {
 264         struct auth4_context *auth4_context = talloc_zero(mem_ctx, struct auth4_context);
 265         if (auth4_context == NULL) {
 266                 DEBUG(10, ("failed to allocate auth4_context failed\n"));
 267                 return NULL;
 268         }
 269         auth4_context->generate_session_info_pac = auth3_generate_session_info_pac;
 270         auth4_context->generate_session_info = auth3_generate_session_info;
 271         auth4_context->get_ntlm_challenge = auth3_get_challenge;
 272         auth4_context->set_ntlm_challenge = auth3_set_challenge;
 273         auth4_context->check_ntlm_password_send = auth3_check_password_send;
 274         auth4_context->check_ntlm_password_recv = auth3_check_password_recv;
 275         auth4_context->private_data = talloc_steal(auth4_context, auth_context);
 276         return auth4_context;
 277 }
 278
 279 NTSTATUS make_auth4_context(TALLOC_CTX *mem_ctx, struct auth4_context **auth4_context_out)
 280 {
 281         struct auth_context *auth_context;
 282         NTSTATUS nt_status;
 283
 284         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 285         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 286
 287         nt_status = make_auth3_context_for_ntlm(tmp_ctx, &auth_context);
 288         if (!NT_STATUS_IS_OK(nt_status)) {
 289                 TALLOC_FREE(tmp_ctx);
 290                 return nt_status;
 291         }
 292
 293         if (auth_context->make_auth4_context) {
 294                 nt_status = auth_context->make_auth4_context(auth_context, mem_ctx, auth4_context_out);
 295                 TALLOC_FREE(tmp_ctx);
 296                 return nt_status;
 297
 298         } else {
 299                 struct auth4_context *auth4_context = make_auth4_context_s3(tmp_ctx, auth_context);
 300                 if (auth4_context == NULL) {
 301                         TALLOC_FREE(tmp_ctx);
 302                         return NT_STATUS_NO_MEMORY;
 303                 }
 304                 *auth4_context_out = talloc_steal(mem_ctx, auth4_context);
 305                 TALLOC_FREE(tmp_ctx);
 306                 return NT_STATUS_OK;
 307         }
 308 }
 309
 310 NTSTATUS auth_generic_prepare(TALLOC_CTX *mem_ctx,
 311                               const struct tsocket_address *remote_address,
 312                               const struct tsocket_address *local_address,
 313                               const char *service_description,
 314                               struct gensec_security **gensec_security_out)
 315 {
 316         struct gensec_security *gensec_security;
 317         struct auth_context *auth_context = NULL;
 318         NTSTATUS nt_status;
 319
 320         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 321         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 322
 323         nt_status = make_auth3_context_for_ntlm(tmp_ctx, &auth_context);
 324         if (!NT_STATUS_IS_OK(nt_status)) {
 325                 goto done;
 326         }
 327
 328         if (auth_context->prepare_gensec) {
 329                 nt_status = auth_context->prepare_gensec(auth_context, tmp_ctx,
 330                                                          &gensec_security);
 331                 if (!NT_STATUS_IS_OK(nt_status)) {
 332                         goto done;
 333                 }
 334         } else {
 335                 const struct gensec_security_ops **backends = NULL;
 336                 struct gensec_settings *gensec_settings;
 337                 struct loadparm_context *lp_ctx;
 338                 size_t idx = 0;
 339                 struct cli_credentials *server_credentials;
 340                 const char *dns_name;
 341                 const char *dns_domain;
 342                 bool ok;
 343                 struct auth4_context *auth4_context = make_auth4_context_s3(tmp_ctx, auth_context);
 344                 if (auth4_context == NULL) {
 345                         goto nomem;
 346                 }
 347
 348                 lp_ctx = loadparm_init_s3(tmp_ctx, loadparm_s3_helpers());
 349                 if (lp_ctx == NULL) {
 350                         DEBUG(10, ("loadparm_init_s3 failed\n"));
 351                         nt_status = NT_STATUS_INVALID_SERVER_STATE;
 352                         goto done;
 353                 }
 354
 355                 gensec_settings = lpcfg_gensec_settings(tmp_ctx, lp_ctx);
 356                 if (lp_ctx == NULL) {
 357                         DEBUG(10, ("lpcfg_gensec_settings failed\n"));
 358                         goto nomem;
 359                 }
 360
 361                 /*
 362                  * This should be a 'netbios domain -> DNS domain'
 363                  * mapping, and can currently validly return NULL on
 364                  * poorly configured systems.
 365                  *
 366                  * This is used for the NTLMSSP server
 367                  *
 368                  */
 369                 dns_name = get_mydnsfullname();
 370                 if (dns_name == NULL) {
 371                         dns_name = "";
 372                 }
 373
 374                 dns_domain = get_mydnsdomname(tmp_ctx);
 375                 if (dns_domain == NULL) {
 376                         dns_domain = "";
 377                 }
 378
 379                 gensec_settings->server_dns_name = strlower_talloc(gensec_settings, dns_name);
 380                 if (gensec_settings->server_dns_name == NULL) {
 381                         goto nomem;
 382                 }
 383
 384                 gensec_settings->server_dns_domain = strlower_talloc(gensec_settings, dns_domain);
 385                 if (gensec_settings->server_dns_domain == NULL) {
 386                         goto nomem;
 387                 }
 388
 389                 backends = talloc_zero_array(gensec_settings,
 390                                              const struct gensec_security_ops *, 6);
 391                 if (backends == NULL) {
 392                         goto nomem;
 393                 }
 394                 gensec_settings->backends = backends;
 395
 396                 gensec_init();
 397
 398                 /* These need to be in priority order, krb5 before NTLMSSP */
 399 #if defined(HAVE_KRB5)
 400                 backends[idx++] = &gensec_gse_krb5_security_ops;
 401 #endif
 402
 403                 backends[idx++] = gensec_security_by_oid(NULL, GENSEC_OID_NTLMSSP);
 404
 405                 backends[idx++] = gensec_security_by_oid(NULL, GENSEC_OID_SPNEGO);
 406
 407                 backends[idx++] = gensec_security_by_auth_type(NULL, DCERPC_AUTH_TYPE_SCHANNEL);
 408
 409                 backends[idx++] = gensec_security_by_auth_type(NULL, DCERPC_AUTH_TYPE_NCALRPC_AS_SYSTEM);
 410
 411                 /*
 412                  * This is anonymous for now, because we just use it
 413                  * to set the kerberos state at the moment
 414                  */
 415                 server_credentials = cli_credentials_init_anon(tmp_ctx);
 416                 if (!server_credentials) {
 417                         DEBUG(0, ("auth_generic_prepare: Failed to init server credentials\n"));
 418                         goto nomem;
 419                 }
 420
 421                 ok = cli_credentials_set_conf(server_credentials, lp_ctx);
 422                 if (!ok) {
 423                         DBG_ERR("Failed to set server credentials defaults "
 424                                 "from smb.conf.\n");
 425                         goto nomem;
 426                 }
 427
 428                 if (lp_security() == SEC_ADS || USE_KERBEROS_KEYTAB) {
 429                         cli_credentials_set_kerberos_state(server_credentials,
 430                                                            CRED_USE_KERBEROS_DESIRED,
 431                                                            CRED_SPECIFIED);
 432                 } else {
 433                         cli_credentials_set_kerberos_state(server_credentials,
 434                                                            CRED_USE_KERBEROS_DISABLED,
 435                                                            CRED_SPECIFIED);
 436                 }
 437
 438                 nt_status = gensec_server_start(tmp_ctx, gensec_settings,
 439                                                 auth4_context, &gensec_security);
 440
 441                 if (!NT_STATUS_IS_OK(nt_status)) {
 442                         goto done;
 443                 }
 444
 445                 nt_status = gensec_set_credentials(
 446                         gensec_security, server_credentials);
 447                 if (!NT_STATUS_IS_OK(nt_status)) {
 448                         goto done;
 449                 }
 450         }
 451
 452         nt_status = gensec_set_remote_address(gensec_security,
 453                                               remote_address);
 454         if (!NT_STATUS_IS_OK(nt_status)) {
 455                 goto done;
 456         }
 457
 458         nt_status = gensec_set_local_address(gensec_security,
 459                                              local_address);
 460         if (!NT_STATUS_IS_OK(nt_status)) {
 461                 goto done;
 462         }
 463
 464         nt_status = gensec_set_target_service_description(gensec_security,
 465                                                           service_description);
 466         if (!NT_STATUS_IS_OK(nt_status)) {
 467                 goto done;
 468         }
 469
 470         *gensec_security_out = talloc_move(mem_ctx, &gensec_security);
 471         nt_status = NT_STATUS_OK;
 472         goto done;
 473 nomem:
 474         nt_status = NT_STATUS_NO_MEMORY;
 475 done:
 476         TALLOC_FREE(tmp_ctx);
 477         return nt_status;
 478 }
 479
 480 /*
 481  * Check a username and password, and return the final session_info.
 482  * We also log the authorization of the session here, just as
 483  * gensec_session_info() does.
 484  */
 485 NTSTATUS auth_check_password_session_info(struct auth4_context *auth_context,
 486                                           TALLOC_CTX *mem_ctx,
 487                                           struct auth_usersupplied_info *user_info,
 488                                           struct auth_session_info **session_info)
 489 {
 490         NTSTATUS nt_status;
 491         void *server_info;
 492         uint8_t authoritative = 1;
 493         struct tevent_context *ev = NULL;
 494         struct tevent_req *subreq = NULL;
 495         bool ok;
 496
 497         ev = samba_tevent_context_init(talloc_tos());
 498         if (ev == NULL) {
 499                 return NT_STATUS_NO_MEMORY;
 500         }
 501
 502         subreq = auth_context->check_ntlm_password_send(ev, ev,
 503                                                         auth_context,
 504                                                         user_info);
 505         if (subreq == NULL) {
 506                 TALLOC_FREE(ev);
 507                 return NT_STATUS_NO_MEMORY;
 508         }
 509         ok = tevent_req_poll_ntstatus(subreq, ev, &nt_status);
 510         if (!ok) {
 511                 TALLOC_FREE(ev);
 512                 return nt_status;
 513         }
 514         nt_status = auth_context->check_ntlm_password_recv(subreq,
 515                                                            talloc_tos(),
 516                                                            &authoritative,
 517                                                            &server_info,
 518                                                            NULL, NULL);
 519         TALLOC_FREE(ev);
 520         if (!NT_STATUS_IS_OK(nt_status)) {
 521                 return nt_status;
 522         }
 523
 524         nt_status = auth_context->generate_session_info(auth_context,
 525                                                         mem_ctx,
 526                                                         server_info,
 527                                                         user_info->client.account_name,
 528                                                         AUTH_SESSION_INFO_UNIX_TOKEN |
 529                                                         AUTH_SESSION_INFO_DEFAULT_GROUPS |
 530                                                         AUTH_SESSION_INFO_NTLM,
 531                                                         session_info);
 532         TALLOC_FREE(server_info);
 533
 534         if (!NT_STATUS_IS_OK(nt_status)) {
 535                 return nt_status;
 536         }
 537
 538         /*
 539          * This is rather redundant (the authentication has just been
 540          * logged, with much the same details), but because we want to
 541          * log all authorizations consistently (be they NLTM, NTLMSSP
 542          * or krb5) we log this info again as an authorization.
 543          */
 544         log_successful_authz_event(auth_context->msg_ctx,
 545                                    auth_context->lp_ctx,
 546                                    user_info->remote_host,
 547                                    user_info->local_host,
 548                                    user_info->service_description,
 549                                    user_info->auth_description,
 550                                    AUTHZ_TRANSPORT_PROTECTION_SMB,
 551                                    *session_info);
 552
 553         return nt_status;
 554 }