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 "auth.h"
  26 #include "../lib/tsocket/tsocket.h"
  27 #include "auth/gensec/gensec.h"
  28 #include "lib/param/param.h"
  29 #ifdef HAVE_KRB5
  30 #include "auth/kerberos/pac_utils.h"
  31 #include "nsswitch/libwbclient/wbclient.h"
  32 #endif
  33 #include "librpc/crypto/gse.h"
  34 #include "auth/credentials/credentials.h"
  35 #include "lib/param/loadparm.h"
  36 #include "librpc/gen_ndr/dcerpc.h"
  37
  38 static NTSTATUS auth3_generate_session_info_pac(struct auth4_context *auth_ctx,
  39                                                 TALLOC_CTX *mem_ctx,
  40                                                 struct smb_krb5_context *smb_krb5_context,
  41                                                 DATA_BLOB *pac_blob,
  42                                                 const char *princ_name,
  43                                                 const struct tsocket_address *remote_address,
  44                                                 uint32_t session_info_flags,
  45                                                 struct auth_session_info **session_info)
  46 {
  47         TALLOC_CTX *tmp_ctx;
  48         struct PAC_LOGON_INFO *logon_info = NULL;
  49         struct netr_SamInfo3 *info3_copy = NULL;
  50         bool is_mapped;
  51         bool is_guest;
  52         char *ntuser;
  53         char *ntdomain;
  54         char *username;
  55         char *rhost;
  56         struct passwd *pw;
  57         NTSTATUS status;
  58         int rc;
  59
  60         tmp_ctx = talloc_new(mem_ctx);
  61         if (!tmp_ctx) {
  62                 return NT_STATUS_NO_MEMORY;
  63         }
  64
  65         if (pac_blob) {
  66 #ifdef HAVE_KRB5
  67                 struct wbcAuthUserParams params = {};
  68                 struct wbcAuthUserInfo *info = NULL;
  69                 struct wbcAuthErrorInfo *err = NULL;
  70                 wbcErr wbc_err;
  71
  72                 /*
  73                  * Let winbind decode the PAC.
  74                  * This will also store the user
  75                  * data in the netsamlogon cache.
  76                  *
  77                  * We need to do this *before* we
  78                  * call get_user_from_kerberos_info()
  79                  * as that does a user lookup that
  80                  * expects info in the netsamlogon cache.
  81                  *
  82                  * See BUG: https://bugzilla.samba.org/show_bug.cgi?id=11259
  83                  */
  84                 params.level = WBC_AUTH_USER_LEVEL_PAC;
  85                 params.password.pac.data = pac_blob->data;
  86                 params.password.pac.length = pac_blob->length;
  87
  88                 become_root();
  89                 wbc_err = wbcAuthenticateUserEx(&params, &info, &err);
  90                 unbecome_root();
  91
  92                 /*
  93                  * As this is merely a cache prime
  94                  * WBC_ERR_WINBIND_NOT_AVAILABLE
  95                  * is not a fatal error, treat it
  96                  * as success.
  97                  */
  98
  99                 switch (wbc_err) {
 100                         case WBC_ERR_WINBIND_NOT_AVAILABLE:
 101                         case WBC_ERR_SUCCESS:
 102                                 break;
 103                         case WBC_ERR_AUTH_ERROR:
 104                                 status = NT_STATUS(err->nt_status);
 105                                 wbcFreeMemory(err);
 106                                 goto done;
 107                         default:
 108                                 status = NT_STATUS_LOGON_FAILURE;
 109                                 goto done;
 110                 }
 111
 112                 status = kerberos_pac_logon_info(tmp_ctx, *pac_blob, NULL, NULL,
 113                                                  NULL, NULL, 0, &logon_info);
 114 #else
 115                 status = NT_STATUS_ACCESS_DENIED;
 116 #endif
 117                 if (!NT_STATUS_IS_OK(status)) {
 118                         goto done;
 119                 }
 120         }
 121
 122         rc = get_remote_hostname(remote_address,
 123                                  &rhost,
 124                                  tmp_ctx);
 125         if (rc < 0) {
 126                 status = NT_STATUS_NO_MEMORY;
 127                 goto done;
 128         }
 129         if (strequal(rhost, "UNKNOWN")) {
 130                 rhost = tsocket_address_inet_addr_string(remote_address,
 131                                                          tmp_ctx);
 132                 if (rhost == NULL) {
 133                         status = NT_STATUS_NO_MEMORY;
 134                         goto done;
 135                 }
 136         }
 137
 138         status = get_user_from_kerberos_info(tmp_ctx, rhost,
 139                                              princ_name, logon_info,
 140                                              &is_mapped, &is_guest,
 141                                              &ntuser, &ntdomain,
 142                                              &username, &pw);
 143         if (!NT_STATUS_IS_OK(status)) {
 144                 DBG_NOTICE("Failed to map kerberos principal to system user "
 145                           "(%s)\n", nt_errstr(status));
 146                 status = NT_STATUS_ACCESS_DENIED;
 147                 goto done;
 148         }
 149
 150         /* Get the info3 from the PAC data if we have it */
 151         if (logon_info) {
 152                 status = create_info3_from_pac_logon_info(tmp_ctx,
 153                                         logon_info,
 154                                         &info3_copy);
 155                 if (!NT_STATUS_IS_OK(status)) {
 156                         goto done;
 157                 }
 158         }
 159
 160         /* setup the string used by %U */
 161         sub_set_smb_name(username);
 162
 163         /* reload services so that the new %U is taken into account */
 164         lp_load_with_shares(get_dyn_CONFIGFILE());
 165
 166         status = make_session_info_krb5(mem_ctx,
 167                                         ntuser, ntdomain, username, pw,
 168                                         info3_copy, is_guest, is_mapped, NULL /* No session key for now, caller will sort it out */,
 169                                         session_info);
 170         if (!NT_STATUS_IS_OK(status)) {
 171                 DEBUG(1, ("Failed to map kerberos pac to server info (%s)\n",
 172                           nt_errstr(status)));
 173                 status = NT_STATUS_ACCESS_DENIED;
 174                 goto done;
 175         }
 176
 177         DEBUG(5, (__location__ "OK: user: %s domain: %s client: %s\n",
 178                   ntuser, ntdomain, rhost));
 179
 180         status = NT_STATUS_OK;
 181
 182 done:
 183         TALLOC_FREE(tmp_ctx);
 184         return status;
 185 }
 186
 187 static struct auth4_context *make_auth4_context_s3(TALLOC_CTX *mem_ctx, struct auth_context *auth_context)
 188 {
 189         struct auth4_context *auth4_context = talloc_zero(mem_ctx, struct auth4_context);
 190         if (auth4_context == NULL) {
 191                 DEBUG(10, ("failed to allocate auth4_context failed\n"));
 192                 return NULL;
 193         }
 194         auth4_context->generate_session_info_pac = auth3_generate_session_info_pac;
 195         auth4_context->generate_session_info = auth3_generate_session_info;
 196         auth4_context->get_ntlm_challenge = auth3_get_challenge;
 197         auth4_context->set_ntlm_challenge = auth3_set_challenge;
 198         auth4_context->check_ntlm_password = auth3_check_password;
 199         auth4_context->private_data = talloc_steal(auth4_context, auth_context);
 200         return auth4_context;
 201 }
 202
 203 NTSTATUS make_auth4_context(TALLOC_CTX *mem_ctx, struct auth4_context **auth4_context_out)
 204 {
 205         struct auth_context *auth_context;
 206         NTSTATUS nt_status;
 207
 208         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 209         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 210
 211         nt_status = make_auth3_context_for_ntlm(tmp_ctx, &auth_context);
 212         if (!NT_STATUS_IS_OK(nt_status)) {
 213                 TALLOC_FREE(tmp_ctx);
 214                 return nt_status;
 215         }
 216
 217         if (auth_context->make_auth4_context) {
 218                 nt_status = auth_context->make_auth4_context(auth_context, mem_ctx, auth4_context_out);
 219                 TALLOC_FREE(tmp_ctx);
 220                 return nt_status;
 221
 222         } else {
 223                 struct auth4_context *auth4_context = make_auth4_context_s3(tmp_ctx, auth_context);
 224                 if (auth4_context == NULL) {
 225                         TALLOC_FREE(tmp_ctx);
 226                         return NT_STATUS_NO_MEMORY;
 227                 }
 228                 *auth4_context_out = talloc_steal(mem_ctx, auth4_context);
 229                 TALLOC_FREE(tmp_ctx);
 230                 return NT_STATUS_OK;
 231         }
 232 }
 233
 234 NTSTATUS auth_generic_prepare(TALLOC_CTX *mem_ctx,
 235                               const struct tsocket_address *remote_address,
 236                               const struct tsocket_address *local_address,
 237                               const char *service_description,
 238                               struct gensec_security **gensec_security_out)
 239 {
 240         struct gensec_security *gensec_security;
 241         struct auth_context *auth_context;
 242         NTSTATUS nt_status;
 243
 244         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 245         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 246
 247         nt_status = make_auth3_context_for_ntlm(tmp_ctx, &auth_context);
 248         if (!NT_STATUS_IS_OK(nt_status)) {
 249                 TALLOC_FREE(tmp_ctx);
 250                 return nt_status;
 251         }
 252
 253         if (auth_context->prepare_gensec) {
 254                 nt_status = auth_context->prepare_gensec(auth_context, tmp_ctx,
 255                                                          &gensec_security);
 256                 if (!NT_STATUS_IS_OK(nt_status)) {
 257                         TALLOC_FREE(tmp_ctx);
 258                         return nt_status;
 259                 }
 260         } else {
 261                 const struct gensec_security_ops **backends = NULL;
 262                 struct gensec_settings *gensec_settings;
 263                 struct loadparm_context *lp_ctx;
 264                 size_t idx = 0;
 265                 struct cli_credentials *server_credentials;
 266                 const char *dns_name;
 267                 const char *dns_domain;
 268                 struct auth4_context *auth4_context = make_auth4_context_s3(tmp_ctx, auth_context);
 269                 if (auth4_context == NULL) {
 270                         TALLOC_FREE(tmp_ctx);
 271                         return NT_STATUS_NO_MEMORY;
 272                 }
 273
 274                 lp_ctx = loadparm_init_s3(tmp_ctx, loadparm_s3_helpers());
 275                 if (lp_ctx == NULL) {
 276                         DEBUG(10, ("loadparm_init_s3 failed\n"));
 277                         TALLOC_FREE(tmp_ctx);
 278                         return NT_STATUS_INVALID_SERVER_STATE;
 279                 }
 280
 281                 gensec_settings = lpcfg_gensec_settings(tmp_ctx, lp_ctx);
 282                 if (lp_ctx == NULL) {
 283                         DEBUG(10, ("lpcfg_gensec_settings failed\n"));
 284                         TALLOC_FREE(tmp_ctx);
 285                         return NT_STATUS_NO_MEMORY;
 286                 }
 287
 288                 /*
 289                  * This should be a 'netbios domain -> DNS domain'
 290                  * mapping, and can currently validly return NULL on
 291                  * poorly configured systems.
 292                  *
 293                  * This is used for the NTLMSSP server
 294                  *
 295                  */
 296                 dns_name = get_mydnsfullname();
 297                 if (dns_name == NULL) {
 298                         dns_name = "";
 299                 }
 300
 301                 dns_domain = get_mydnsdomname(tmp_ctx);
 302                 if (dns_domain == NULL) {
 303                         dns_domain = "";
 304                 }
 305
 306                 gensec_settings->server_dns_name = strlower_talloc(gensec_settings, dns_name);
 307                 if (gensec_settings->server_dns_name == NULL) {
 308                         TALLOC_FREE(tmp_ctx);
 309                         return NT_STATUS_NO_MEMORY;
 310                 }
 311
 312                 gensec_settings->server_dns_domain = strlower_talloc(gensec_settings, dns_domain);
 313                 if (gensec_settings->server_dns_domain == NULL) {
 314                         TALLOC_FREE(tmp_ctx);
 315                         return NT_STATUS_NO_MEMORY;
 316                 }
 317
 318                 backends = talloc_zero_array(gensec_settings,
 319                                              const struct gensec_security_ops *, 6);
 320                 if (backends == NULL) {
 321                         TALLOC_FREE(tmp_ctx);
 322                         return NT_STATUS_NO_MEMORY;
 323                 }
 324                 gensec_settings->backends = backends;
 325
 326                 gensec_init();
 327
 328                 /* These need to be in priority order, krb5 before NTLMSSP */
 329 #if defined(HAVE_KRB5)
 330                 backends[idx++] = &gensec_gse_krb5_security_ops;
 331 #endif
 332
 333                 backends[idx++] = gensec_security_by_oid(NULL, GENSEC_OID_NTLMSSP);
 334
 335                 backends[idx++] = gensec_security_by_oid(NULL, GENSEC_OID_SPNEGO);
 336
 337                 backends[idx++] = gensec_security_by_auth_type(NULL, DCERPC_AUTH_TYPE_SCHANNEL);
 338
 339                 backends[idx++] = gensec_security_by_auth_type(NULL, DCERPC_AUTH_TYPE_NCALRPC_AS_SYSTEM);
 340
 341                 /*
 342                  * This is anonymous for now, because we just use it
 343                  * to set the kerberos state at the moment
 344                  */
 345                 server_credentials = cli_credentials_init_anon(tmp_ctx);
 346                 if (!server_credentials) {
 347                         DEBUG(0, ("auth_generic_prepare: Failed to init server credentials\n"));
 348                         return NT_STATUS_NO_MEMORY;
 349                 }
 350
 351                 cli_credentials_set_conf(server_credentials, lp_ctx);
 352
 353                 if (lp_security() == SEC_ADS || USE_KERBEROS_KEYTAB) {
 354                         cli_credentials_set_kerberos_state(server_credentials, CRED_AUTO_USE_KERBEROS);
 355                 } else {
 356                         cli_credentials_set_kerberos_state(server_credentials, CRED_DONT_USE_KERBEROS);
 357                 }
 358
 359                 nt_status = gensec_server_start(tmp_ctx, gensec_settings,
 360                                                 auth4_context, &gensec_security);
 361
 362                 if (!NT_STATUS_IS_OK(nt_status)) {
 363                         TALLOC_FREE(tmp_ctx);
 364                         return nt_status;
 365                 }
 366
 367                 gensec_set_credentials(gensec_security, server_credentials);
 368
 369                 talloc_unlink(tmp_ctx, lp_ctx);
 370                 talloc_unlink(tmp_ctx, server_credentials);
 371                 talloc_unlink(tmp_ctx, gensec_settings);
 372                 talloc_unlink(tmp_ctx, auth4_context);
 373         }
 374
 375         nt_status = gensec_set_remote_address(gensec_security,
 376                                               remote_address);
 377         if (!NT_STATUS_IS_OK(nt_status)) {
 378                 TALLOC_FREE(tmp_ctx);
 379                 return nt_status;
 380         }
 381
 382         nt_status = gensec_set_local_address(gensec_security,
 383                                              local_address);
 384         if (!NT_STATUS_IS_OK(nt_status)) {
 385                 TALLOC_FREE(tmp_ctx);
 386                 return nt_status;
 387         }
 388
 389         nt_status = gensec_set_target_service_description(gensec_security,
 390                                                           service_description);
 391
 392         if (!NT_STATUS_IS_OK(nt_status)) {
 393                 TALLOC_FREE(tmp_ctx);
 394                 return nt_status;
 395         }
 396
 397         *gensec_security_out = talloc_steal(mem_ctx, gensec_security);
 398         TALLOC_FREE(tmp_ctx);
 399         return NT_STATUS_OK;
 400 }
 401
 402 /*
 403  * Check a username and password, and return the final session_info.
 404  * We also log the authorization of the session here, just as
 405  * gensec_session_info() does.
 406  */
 407 NTSTATUS auth_check_password_session_info(struct auth4_context *auth_context,
 408                                           TALLOC_CTX *mem_ctx,
 409                                           struct auth_usersupplied_info *user_info,
 410                                           struct auth_session_info **session_info)
 411 {
 412         NTSTATUS nt_status;
 413         void *server_info;
 414         uint8_t authoritative = 0;
 415
 416         nt_status = auth_context->check_ntlm_password(auth_context,
 417                                                       talloc_tos(),
 418                                                       user_info,
 419                                                       &authoritative,
 420                                                       &server_info, NULL, NULL);
 421
 422         if (!NT_STATUS_IS_OK(nt_status)) {
 423                 return nt_status;
 424         }
 425
 426         nt_status = auth_context->generate_session_info(auth_context,
 427                                                         mem_ctx,
 428                                                         server_info,
 429                                                         user_info->client.account_name,
 430                                                         AUTH_SESSION_INFO_UNIX_TOKEN |
 431                                                         AUTH_SESSION_INFO_DEFAULT_GROUPS |
 432                                                         AUTH_SESSION_INFO_NTLM,
 433                                                         session_info);
 434         TALLOC_FREE(server_info);
 435
 436         if (!NT_STATUS_IS_OK(nt_status)) {
 437                 return nt_status;
 438         }
 439
 440         /*
 441          * This is rather redundant (the authentication has just been
 442          * logged, with much the same details), but because we want to
 443          * log all authorizations consistently (be they NLTM, NTLMSSP
 444          * or krb5) we log this info again as an authorization.
 445          */
 446         log_successful_authz_event(auth_context->msg_ctx,
 447                                    auth_context->lp_ctx,
 448                                    user_info->remote_host,
 449                                    user_info->local_host,
 450                                    user_info->service_description,
 451                                    user_info->auth_description,
 452                                    AUTHZ_TRANSPORT_PROTECTION_SMB,
 453                                    *session_info);
 454
 455         return nt_status;
 456 }