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
  40 static NTSTATUS auth3_generate_session_info_pac(struct auth4_context *auth_ctx,
  41                                                 TALLOC_CTX *mem_ctx,
  42                                                 struct smb_krb5_context *smb_krb5_context,
  43                                                 DATA_BLOB *pac_blob,
  44                                                 const char *princ_name,
  45                                                 const struct tsocket_address *remote_address,
  46                                                 uint32_t session_info_flags,
  47                                                 struct auth_session_info **session_info)
  48 {
  49         TALLOC_CTX *tmp_ctx;
  50         struct PAC_LOGON_INFO *logon_info = NULL;
  51         struct netr_SamInfo3 *info3_copy = NULL;
  52         bool is_mapped;
  53         bool is_guest;
  54         char *ntuser;
  55         char *ntdomain;
  56         char *username;
  57         char *rhost;
  58         struct passwd *pw;
  59         NTSTATUS status;
  60         int rc;
  61
  62         tmp_ctx = talloc_new(mem_ctx);
  63         if (!tmp_ctx) {
  64                 return NT_STATUS_NO_MEMORY;
  65         }
  66
  67         if (pac_blob) {
  68 #ifdef HAVE_KRB5
  69                 struct wbcAuthUserParams params = {};
  70                 struct wbcAuthUserInfo *info = NULL;
  71                 struct wbcAuthErrorInfo *err = NULL;
  72                 wbcErr wbc_err;
  73
  74                 /*
  75                  * Let winbind decode the PAC.
  76                  * This will also store the user
  77                  * data in the netsamlogon cache.
  78                  *
  79                  * We need to do this *before* we
  80                  * call get_user_from_kerberos_info()
  81                  * as that does a user lookup that
  82                  * expects info in the netsamlogon cache.
  83                  *
  84                  * See BUG: https://bugzilla.samba.org/show_bug.cgi?id=11259
  85                  */
  86                 params.level = WBC_AUTH_USER_LEVEL_PAC;
  87                 params.password.pac.data = pac_blob->data;
  88                 params.password.pac.length = pac_blob->length;
  89
  90                 become_root();
  91                 wbc_err = wbcAuthenticateUserEx(&params, &info, &err);
  92                 unbecome_root();
  93
  94                 /*
  95                  * As this is merely a cache prime
  96                  * WBC_ERR_WINBIND_NOT_AVAILABLE
  97                  * is not a fatal error, treat it
  98                  * as success.
  99                  */
 100
 101                 switch (wbc_err) {
 102                         case WBC_ERR_WINBIND_NOT_AVAILABLE:
 103                         case WBC_ERR_SUCCESS:
 104                                 break;
 105                         case WBC_ERR_AUTH_ERROR:
 106                                 status = NT_STATUS(err->nt_status);
 107                                 wbcFreeMemory(err);
 108                                 goto done;
 109                         default:
 110                                 status = NT_STATUS_LOGON_FAILURE;
 111                                 goto done;
 112                 }
 113
 114                 status = kerberos_pac_logon_info(tmp_ctx, *pac_blob, NULL, NULL,
 115                                                  NULL, NULL, 0, &logon_info);
 116 #else
 117                 status = NT_STATUS_ACCESS_DENIED;
 118 #endif
 119                 if (!NT_STATUS_IS_OK(status)) {
 120                         goto done;
 121                 }
 122         }
 123
 124         rc = get_remote_hostname(remote_address,
 125                                  &rhost,
 126                                  tmp_ctx);
 127         if (rc < 0) {
 128                 status = NT_STATUS_NO_MEMORY;
 129                 goto done;
 130         }
 131         if (strequal(rhost, "UNKNOWN")) {
 132                 rhost = tsocket_address_inet_addr_string(remote_address,
 133                                                          tmp_ctx);
 134                 if (rhost == NULL) {
 135                         status = NT_STATUS_NO_MEMORY;
 136                         goto done;
 137                 }
 138         }
 139
 140         status = get_user_from_kerberos_info(tmp_ctx, rhost,
 141                                              princ_name, logon_info,
 142                                              &is_mapped, &is_guest,
 143                                              &ntuser, &ntdomain,
 144                                              &username, &pw);
 145         if (!NT_STATUS_IS_OK(status)) {
 146                 DBG_NOTICE("Failed to map kerberos principal to system user "
 147                           "(%s)\n", nt_errstr(status));
 148                 status = NT_STATUS_ACCESS_DENIED;
 149                 goto done;
 150         }
 151
 152         /* Get the info3 from the PAC data if we have it */
 153         if (logon_info) {
 154                 status = create_info3_from_pac_logon_info(tmp_ctx,
 155                                         logon_info,
 156                                         &info3_copy);
 157                 if (!NT_STATUS_IS_OK(status)) {
 158                         goto done;
 159                 }
 160         }
 161
 162         /* setup the string used by %U */
 163         sub_set_smb_name(username);
 164
 165         /* reload services so that the new %U is taken into account */
 166         lp_load_with_shares(get_dyn_CONFIGFILE());
 167
 168         status = make_session_info_krb5(mem_ctx,
 169                                         ntuser, ntdomain, username, pw,
 170                                         info3_copy, is_guest, is_mapped, NULL /* No session key for now, caller will sort it out */,
 171                                         session_info);
 172         if (!NT_STATUS_IS_OK(status)) {
 173                 DEBUG(1, ("Failed to map kerberos pac to server info (%s)\n",
 174                           nt_errstr(status)));
 175                 status = NT_STATUS_ACCESS_DENIED;
 176                 goto done;
 177         }
 178
 179         DEBUG(5, (__location__ "OK: user: %s domain: %s client: %s\n",
 180                   ntuser, ntdomain, rhost));
 181
 182         status = NT_STATUS_OK;
 183
 184 done:
 185         TALLOC_FREE(tmp_ctx);
 186         return status;
 187 }
 188
 189 static struct auth4_context *make_auth4_context_s3(TALLOC_CTX *mem_ctx, struct auth_context *auth_context)
 190 {
 191         struct auth4_context *auth4_context = talloc_zero(mem_ctx, struct auth4_context);
 192         if (auth4_context == NULL) {
 193                 DEBUG(10, ("failed to allocate auth4_context failed\n"));
 194                 return NULL;
 195         }
 196         auth4_context->generate_session_info_pac = auth3_generate_session_info_pac;
 197         auth4_context->generate_session_info = auth3_generate_session_info;
 198         auth4_context->get_ntlm_challenge = auth3_get_challenge;
 199         auth4_context->set_ntlm_challenge = auth3_set_challenge;
 200         auth4_context->check_ntlm_password = auth3_check_password;
 201         auth4_context->private_data = talloc_steal(auth4_context, auth_context);
 202         return auth4_context;
 203 }
 204
 205 NTSTATUS make_auth4_context(TALLOC_CTX *mem_ctx, struct auth4_context **auth4_context_out)
 206 {
 207         struct auth_context *auth_context;
 208         NTSTATUS nt_status;
 209
 210         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 211         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 212
 213         nt_status = make_auth3_context_for_ntlm(tmp_ctx, &auth_context);
 214         if (!NT_STATUS_IS_OK(nt_status)) {
 215                 TALLOC_FREE(tmp_ctx);
 216                 return nt_status;
 217         }
 218
 219         if (auth_context->make_auth4_context) {
 220                 nt_status = auth_context->make_auth4_context(auth_context, mem_ctx, auth4_context_out);
 221                 TALLOC_FREE(tmp_ctx);
 222                 return nt_status;
 223
 224         } else {
 225                 struct auth4_context *auth4_context = make_auth4_context_s3(tmp_ctx, auth_context);
 226                 if (auth4_context == NULL) {
 227                         TALLOC_FREE(tmp_ctx);
 228                         return NT_STATUS_NO_MEMORY;
 229                 }
 230                 *auth4_context_out = talloc_steal(mem_ctx, auth4_context);
 231                 TALLOC_FREE(tmp_ctx);
 232                 return NT_STATUS_OK;
 233         }
 234 }
 235
 236 NTSTATUS auth_generic_prepare(TALLOC_CTX *mem_ctx,
 237                               const struct tsocket_address *remote_address,
 238                               const struct tsocket_address *local_address,
 239                               const char *service_description,
 240                               struct gensec_security **gensec_security_out)
 241 {
 242         struct gensec_security *gensec_security;
 243         struct auth_context *auth_context;
 244         NTSTATUS nt_status;
 245
 246         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 247         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 248
 249         nt_status = make_auth3_context_for_ntlm(tmp_ctx, &auth_context);
 250         if (!NT_STATUS_IS_OK(nt_status)) {
 251                 TALLOC_FREE(tmp_ctx);
 252                 return nt_status;
 253         }
 254
 255         if (auth_context->prepare_gensec) {
 256                 nt_status = auth_context->prepare_gensec(auth_context, tmp_ctx,
 257                                                          &gensec_security);
 258                 if (!NT_STATUS_IS_OK(nt_status)) {
 259                         TALLOC_FREE(tmp_ctx);
 260                         return nt_status;
 261                 }
 262         } else {
 263                 const struct gensec_security_ops **backends = NULL;
 264                 struct gensec_settings *gensec_settings;
 265                 struct loadparm_context *lp_ctx;
 266                 size_t idx = 0;
 267                 struct cli_credentials *server_credentials;
 268                 const char *dns_name;
 269                 const char *dns_domain;
 270                 struct auth4_context *auth4_context = make_auth4_context_s3(tmp_ctx, auth_context);
 271                 if (auth4_context == NULL) {
 272                         TALLOC_FREE(tmp_ctx);
 273                         return NT_STATUS_NO_MEMORY;
 274                 }
 275
 276                 lp_ctx = loadparm_init_s3(tmp_ctx, loadparm_s3_helpers());
 277                 if (lp_ctx == NULL) {
 278                         DEBUG(10, ("loadparm_init_s3 failed\n"));
 279                         TALLOC_FREE(tmp_ctx);
 280                         return NT_STATUS_INVALID_SERVER_STATE;
 281                 }
 282
 283                 gensec_settings = lpcfg_gensec_settings(tmp_ctx, lp_ctx);
 284                 if (lp_ctx == NULL) {
 285                         DEBUG(10, ("lpcfg_gensec_settings failed\n"));
 286                         TALLOC_FREE(tmp_ctx);
 287                         return NT_STATUS_NO_MEMORY;
 288                 }
 289
 290                 /*
 291                  * This should be a 'netbios domain -> DNS domain'
 292                  * mapping, and can currently validly return NULL on
 293                  * poorly configured systems.
 294                  *
 295                  * This is used for the NTLMSSP server
 296                  *
 297                  */
 298                 dns_name = get_mydnsfullname();
 299                 if (dns_name == NULL) {
 300                         dns_name = "";
 301                 }
 302
 303                 dns_domain = get_mydnsdomname(tmp_ctx);
 304                 if (dns_domain == NULL) {
 305                         dns_domain = "";
 306                 }
 307
 308                 gensec_settings->server_dns_name = strlower_talloc(gensec_settings, dns_name);
 309                 if (gensec_settings->server_dns_name == NULL) {
 310                         TALLOC_FREE(tmp_ctx);
 311                         return NT_STATUS_NO_MEMORY;
 312                 }
 313
 314                 gensec_settings->server_dns_domain = strlower_talloc(gensec_settings, dns_domain);
 315                 if (gensec_settings->server_dns_domain == NULL) {
 316                         TALLOC_FREE(tmp_ctx);
 317                         return NT_STATUS_NO_MEMORY;
 318                 }
 319
 320                 backends = talloc_zero_array(gensec_settings,
 321                                              const struct gensec_security_ops *, 6);
 322                 if (backends == NULL) {
 323                         TALLOC_FREE(tmp_ctx);
 324                         return NT_STATUS_NO_MEMORY;
 325                 }
 326                 gensec_settings->backends = backends;
 327
 328                 gensec_init();
 329
 330                 /* These need to be in priority order, krb5 before NTLMSSP */
 331 #if defined(HAVE_KRB5)
 332                 backends[idx++] = &gensec_gse_krb5_security_ops;
 333 #endif
 334
 335                 backends[idx++] = gensec_security_by_oid(NULL, GENSEC_OID_NTLMSSP);
 336
 337                 backends[idx++] = gensec_security_by_oid(NULL, GENSEC_OID_SPNEGO);
 338
 339                 backends[idx++] = gensec_security_by_auth_type(NULL, DCERPC_AUTH_TYPE_SCHANNEL);
 340
 341                 backends[idx++] = gensec_security_by_auth_type(NULL, DCERPC_AUTH_TYPE_NCALRPC_AS_SYSTEM);
 342
 343                 /*
 344                  * This is anonymous for now, because we just use it
 345                  * to set the kerberos state at the moment
 346                  */
 347                 server_credentials = cli_credentials_init_anon(tmp_ctx);
 348                 if (!server_credentials) {
 349                         DEBUG(0, ("auth_generic_prepare: Failed to init server credentials\n"));
 350                         return NT_STATUS_NO_MEMORY;
 351                 }
 352
 353                 cli_credentials_set_conf(server_credentials, lp_ctx);
 354
 355                 if (lp_security() == SEC_ADS || USE_KERBEROS_KEYTAB) {
 356                         cli_credentials_set_kerberos_state(server_credentials, CRED_AUTO_USE_KERBEROS);
 357                 } else {
 358                         cli_credentials_set_kerberos_state(server_credentials, CRED_DONT_USE_KERBEROS);
 359                 }
 360
 361                 nt_status = gensec_server_start(tmp_ctx, gensec_settings,
 362                                                 auth4_context, &gensec_security);
 363
 364                 if (!NT_STATUS_IS_OK(nt_status)) {
 365                         TALLOC_FREE(tmp_ctx);
 366                         return nt_status;
 367                 }
 368
 369                 gensec_set_credentials(gensec_security, server_credentials);
 370
 371                 talloc_unlink(tmp_ctx, lp_ctx);
 372                 talloc_unlink(tmp_ctx, server_credentials);
 373                 talloc_unlink(tmp_ctx, gensec_settings);
 374                 talloc_unlink(tmp_ctx, auth4_context);
 375         }
 376
 377         nt_status = gensec_set_remote_address(gensec_security,
 378                                               remote_address);
 379         if (!NT_STATUS_IS_OK(nt_status)) {
 380                 TALLOC_FREE(tmp_ctx);
 381                 return nt_status;
 382         }
 383
 384         nt_status = gensec_set_local_address(gensec_security,
 385                                              local_address);
 386         if (!NT_STATUS_IS_OK(nt_status)) {
 387                 TALLOC_FREE(tmp_ctx);
 388                 return nt_status;
 389         }
 390
 391         nt_status = gensec_set_target_service_description(gensec_security,
 392                                                           service_description);
 393
 394         if (!NT_STATUS_IS_OK(nt_status)) {
 395                 TALLOC_FREE(tmp_ctx);
 396                 return nt_status;
 397         }
 398
 399         *gensec_security_out = talloc_steal(mem_ctx, gensec_security);
 400         TALLOC_FREE(tmp_ctx);
 401         return NT_STATUS_OK;
 402 }
 403
 404 /*
 405  * Check a username and password, and return the final session_info.
 406  * We also log the authorization of the session here, just as
 407  * gensec_session_info() does.
 408  */
 409 NTSTATUS auth_check_password_session_info(struct auth4_context *auth_context,
 410                                           TALLOC_CTX *mem_ctx,
 411                                           struct auth_usersupplied_info *user_info,
 412                                           struct auth_session_info **session_info)
 413 {
 414         NTSTATUS nt_status;
 415         void *server_info;
 416         uint8_t authoritative = 0;
 417
 418         if (auth_context->check_ntlm_password_send != NULL) {
 419                 struct tevent_context *ev = NULL;
 420                 struct tevent_req *subreq = NULL;
 421                 bool ok;
 422
 423                 ev = samba_tevent_context_init(talloc_tos());
 424                 if (ev == NULL) {
 425                         return NT_STATUS_NO_MEMORY;
 426                 }
 427
 428                 subreq = auth_context->check_ntlm_password_send(ev, ev,
 429                                                                 auth_context,
 430                                                                 user_info);
 431                 if (subreq == NULL) {
 432                         TALLOC_FREE(ev);
 433                         return NT_STATUS_NO_MEMORY;
 434                 }
 435                 ok = tevent_req_poll_ntstatus(subreq, ev, &nt_status);
 436                 if (!ok) {
 437                         TALLOC_FREE(ev);
 438                         return nt_status;
 439                 }
 440                 nt_status = auth_context->check_ntlm_password_recv(subreq,
 441                                                                    talloc_tos(),
 442                                                                    &authoritative,
 443                                                                    &server_info,
 444                                                                    NULL, NULL);
 445                 TALLOC_FREE(ev);
 446                 if (!NT_STATUS_IS_OK(nt_status)) {
 447                         return nt_status;
 448                 }
 449         } else {
 450                 nt_status = auth_context->check_ntlm_password(auth_context,
 451                                                               talloc_tos(),
 452                                                               user_info,
 453                                                               &authoritative,
 454                                                               &server_info,
 455                                                               NULL, NULL);
 456                 if (!NT_STATUS_IS_OK(nt_status)) {
 457                         return nt_status;
 458                 }
 459         }
 460
 461         nt_status = auth_context->generate_session_info(auth_context,
 462                                                         mem_ctx,
 463                                                         server_info,
 464                                                         user_info->client.account_name,
 465                                                         AUTH_SESSION_INFO_UNIX_TOKEN |
 466                                                         AUTH_SESSION_INFO_DEFAULT_GROUPS |
 467                                                         AUTH_SESSION_INFO_NTLM,
 468                                                         session_info);
 469         TALLOC_FREE(server_info);
 470
 471         if (!NT_STATUS_IS_OK(nt_status)) {
 472                 return nt_status;
 473         }
 474
 475         /*
 476          * This is rather redundant (the authentication has just been
 477          * logged, with much the same details), but because we want to
 478          * log all authorizations consistently (be they NLTM, NTLMSSP
 479          * or krb5) we log this info again as an authorization.
 480          */
 481         log_successful_authz_event(auth_context->msg_ctx,
 482                                    auth_context->lp_ctx,
 483                                    user_info->remote_host,
 484                                    user_info->local_host,
 485                                    user_info->service_description,
 486                                    user_info->auth_description,
 487                                    AUTHZ_TRANSPORT_PROTECTION_SMB,
 488                                    *session_info);
 489
 490         return nt_status;
 491 }