source3/auth/auth.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Password and authentication handling
   4    Copyright (C) Andrew Bartlett         2001-2002
   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 "auth.h"
  22 #include "../lib/tsocket/tsocket.h"
  23
  24 #include "param/param.h"
  25 #include "../lib/messaging/messaging.h"
  26 #include "lib/global_contexts.h"
  27
  28 #undef DBGC_CLASS
  29 #define DBGC_CLASS DBGC_AUTH
  30
  31 static_decl_auth;
  32
  33 static struct auth_init_function_entry *auth_backends = NULL;
  34
  35 static struct auth_init_function_entry *auth_find_backend_entry(const char *name);
  36
  37 NTSTATUS smb_register_auth(int version, const char *name, auth_init_function init)
  38 {
  39         struct auth_init_function_entry *entry = NULL;
  40
  41         if (version != AUTH_INTERFACE_VERSION) {
  42                 DEBUG(0,("Can't register auth_method!\n"
  43                          "You tried to register an auth module with AUTH_INTERFACE_VERSION %d, while this version of samba uses %d\n",
  44                          version,AUTH_INTERFACE_VERSION));
  45                 return NT_STATUS_OBJECT_TYPE_MISMATCH;
  46         }
  47
  48         if (!name || !init) {
  49                 return NT_STATUS_INVALID_PARAMETER;
  50         }
  51
  52         DEBUG(5,("Attempting to register auth backend %s\n", name));
  53
  54         if (auth_find_backend_entry(name)) {
  55                 DEBUG(0,("There already is an auth method registered with the name %s!\n", name));
  56                 return NT_STATUS_OBJECT_NAME_COLLISION;
  57         }
  58
  59         entry = SMB_XMALLOC_P(struct auth_init_function_entry);
  60         entry->name = smb_xstrdup(name);
  61         entry->init = init;
  62
  63         DLIST_ADD(auth_backends, entry);
  64         DEBUG(5,("Successfully added auth method '%s'\n", name));
  65         return NT_STATUS_OK;
  66 }
  67
  68 static struct auth_init_function_entry *auth_find_backend_entry(const char *name)
  69 {
  70         struct auth_init_function_entry *entry = auth_backends;
  71
  72         while(entry) {
  73                 if (strcmp(entry->name, name)==0) return entry;
  74                 entry = entry->next;
  75         }
  76
  77         return NULL;
  78 }
  79
  80 /****************************************************************************
  81  Try to get a challenge out of the various authentication modules.
  82  Returns a const char of length 8 bytes.
  83 ****************************************************************************/
  84
  85 NTSTATUS auth_get_ntlm_challenge(struct auth_context *auth_context,
  86                                  uint8_t chal[8])
  87 {
  88         if (auth_context->challenge.length) {
  89                 DBG_INFO("get_ntlm_challenge (auth subsystem): returning "
  90                          "previous challenge by module %s (normal)\n",
  91                           auth_context->challenge_set_by);
  92                 memcpy(chal, auth_context->challenge.data, 8);
  93                 return NT_STATUS_OK;
  94         }
  95
  96         auth_context->challenge = data_blob_talloc(auth_context, NULL, 8);
  97         if (auth_context->challenge.data == NULL) {
  98                 DBG_WARNING("data_blob_talloc failed\n");
  99                 return NT_STATUS_NO_MEMORY;
 100         }
 101         generate_random_buffer(
 102                 auth_context->challenge.data, auth_context->challenge.length);
 103
 104         auth_context->challenge_set_by = "random";
 105
 106         memcpy(chal, auth_context->challenge.data, 8);
 107         return NT_STATUS_OK;
 108 }
 109
 110
 111 /**
 112  * Check user is in correct domain (if required)
 113  *
 114  * @param user Only used to fill in the debug message
 115  *
 116  * @param domain The domain to be verified
 117  *
 118  * @return True if the user can connect with that domain,
 119  *         False otherwise.
 120 **/
 121
 122 static bool check_domain_match(const char *user, const char *domain)
 123 {
 124         /*
 125          * If we aren't serving to trusted domains, we must make sure that
 126          * the validation request comes from an account in the same domain
 127          * as the Samba server
 128          */
 129
 130         if (!lp_allow_trusted_domains() &&
 131             !(strequal("", domain) ||
 132               strequal(lp_workgroup(), domain) ||
 133               is_myname(domain))) {
 134                 DEBUG(1, ("check_domain_match: Attempt to connect as user %s from domain %s denied.\n", user, domain));
 135                 return False;
 136         } else {
 137                 return True;
 138         }
 139 }
 140
 141 /**
 142  * Check a user's Plaintext, LM or NTLM password.
 143  *
 144  * Check a user's password, as given in the user_info struct and return various
 145  * interesting details in the server_info struct.
 146  *
 147  * This function does NOT need to be in a become_root()/unbecome_root() pair
 148  * as it makes the calls itself when needed.
 149  *
 150  * The return value takes precedence over the contents of the server_info
 151  * struct.  When the return is other than NT_STATUS_OK the contents
 152  * of that structure is undefined.
 153  *
 154  * @param user_info Contains the user supplied components, including the passwords.
 155  *                  Must be created with make_user_info() or one of its wrappers.
 156  *
 157  * @param auth_context Supplies the challenges and some other data.
 158  *                  Must be created with make_auth_context(), and the challenges should be
 159  *                  filled in, either at creation or by calling the challenge generation
 160  *                  function auth_get_challenge().
 161  *
 162  * @param pserver_info If successful, contains information about the authentication,
 163  *                     including a struct samu struct describing the user.
 164  *
 165  * @param pauthoritative Indicates if the result should be treated as final
 166  *                       result.
 167  *
 168  * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.
 169  *
 170  **/
 171 NTSTATUS auth_check_ntlm_password(TALLOC_CTX *mem_ctx,
 172                                   const struct auth_context *auth_context,
 173                                   const struct auth_usersupplied_info *user_info,
 174                                   struct auth_serversupplied_info **pserver_info,
 175                                   uint8_t *pauthoritative)
 176 {
 177         TALLOC_CTX *frame;
 178         const char *auth_method_name = "";
 179         /* if all the modules say 'not for me' this is reasonable */
 180         NTSTATUS nt_status = NT_STATUS_NOT_IMPLEMENTED;
 181         const char *unix_username;
 182         struct auth_methods *auth_method;
 183         struct auth_serversupplied_info *server_info = NULL;
 184         struct dom_sid sid = {0};
 185         struct imessaging_context *msg_ctx = NULL;
 186         struct loadparm_context *lp_ctx = NULL;
 187
 188         if (user_info == NULL || auth_context == NULL || pserver_info == NULL) {
 189                 return NT_STATUS_LOGON_FAILURE;
 190         }
 191
 192         frame = talloc_stackframe();
 193
 194         if (lp_auth_event_notification()) {
 195                 lp_ctx = loadparm_init_s3(frame, loadparm_s3_helpers());
 196                 msg_ctx = imessaging_client_init(
 197                     frame, lp_ctx, global_event_context());
 198         }
 199
 200         *pauthoritative = 1;
 201
 202         DBG_NOTICE("check_ntlm_password:  Checking password for unmapped user "
 203                    "[%s]\\[%s]@[%s] with the new password interface\n",
 204                    user_info->client.domain_name,
 205                    user_info->client.account_name,
 206                    user_info->workstation_name);
 207
 208         DBG_NOTICE("check_ntlm_password:  mapped user is: [%s]\\[%s]@[%s]\n",
 209                    user_info->mapped.domain_name,
 210                    user_info->mapped.account_name,
 211                    user_info->workstation_name);
 212
 213         if (auth_context->challenge.length != 8) {
 214                 DEBUG(0, ("check_ntlm_password:  Invalid challenge stored for this auth context - cannot continue\n"));
 215                 nt_status = NT_STATUS_LOGON_FAILURE;
 216                 goto fail;
 217         }
 218
 219         if (auth_context->challenge_set_by)
 220                 DEBUG(10, ("check_ntlm_password: auth_context challenge created by %s\n",
 221                                         auth_context->challenge_set_by));
 222
 223         DEBUG(10, ("challenge is: \n"));
 224         dump_data(5, auth_context->challenge.data, auth_context->challenge.length);
 225
 226 #ifdef DEBUG_PASSWORD
 227         DEBUG(100, ("user_info has passwords of length %d and %d\n",
 228                     (int)user_info->password.response.lanman.length, (int)user_info->password.response.nt.length));
 229         DEBUG(100, ("lm:\n"));
 230         dump_data(100, user_info->password.response.lanman.data, user_info->password.response.lanman.length);
 231         DEBUG(100, ("nt:\n"));
 232         dump_data(100, user_info->password.response.nt.data, user_info->password.response.nt.length);
 233 #endif
 234
 235         /* This needs to be sorted:  If it doesn't match, what should we do? */
 236         if (!check_domain_match(user_info->client.account_name,
 237                                 user_info->mapped.domain_name)) {
 238                 nt_status = NT_STATUS_LOGON_FAILURE;
 239                 goto fail;
 240         }
 241
 242         for (auth_method = auth_context->auth_method_list;auth_method; auth_method = auth_method->next) {
 243
 244                 auth_method_name = auth_method->name;
 245
 246                 nt_status = auth_method->auth(auth_context,
 247                                               auth_method->private_data,
 248                                               talloc_tos(),
 249                                               user_info,
 250                                               &server_info);
 251
 252                 if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_NOT_IMPLEMENTED)) {
 253                         break;
 254                 }
 255
 256                 DBG_DEBUG("%s had nothing to say\n", auth_method->name);
 257         }
 258
 259         if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NOT_IMPLEMENTED)) {
 260                 *pauthoritative = 0;
 261                 nt_status = NT_STATUS_NO_SUCH_USER;
 262         }
 263
 264         if (!NT_STATUS_IS_OK(nt_status)) {
 265                 DBG_INFO("%s authentication for user [%s] FAILED with "
 266                          "error %s, authoritative=%u\n",
 267                          auth_method_name,
 268                          user_info->client.account_name,
 269                          nt_errstr(nt_status),
 270                          *pauthoritative);
 271                 goto fail;
 272         }
 273
 274         DBG_NOTICE("%s authentication for user [%s] succeeded\n",
 275                    auth_method_name, user_info->client.account_name);
 276
 277         unix_username = server_info->unix_name;
 278
 279         /* We skip doing this step if the caller asked us not to */
 280         if (!(user_info->flags & USER_INFO_INFO3_AND_NO_AUTHZ)
 281             && !(server_info->guest)) {
 282                 const char *rhost;
 283
 284                 if (tsocket_address_is_inet(user_info->remote_host, "ip")) {
 285                         rhost = tsocket_address_inet_addr_string(
 286                                 user_info->remote_host, talloc_tos());
 287                         if (rhost == NULL) {
 288                                 nt_status = NT_STATUS_NO_MEMORY;
 289                                 goto fail;
 290                         }
 291                 } else {
 292                         rhost = "127.0.0.1";
 293                 }
 294
 295                 /* We might not be root if we are an RPC call */
 296                 become_root();
 297                 nt_status = smb_pam_accountcheck(unix_username, rhost);
 298                 unbecome_root();
 299
 300                 if (NT_STATUS_IS_OK(nt_status)) {
 301                         DEBUG(5, ("check_ntlm_password:  PAM Account for user [%s] "
 302                                   "succeeded\n", unix_username));
 303                 } else {
 304                         DEBUG(3, ("check_ntlm_password:  PAM Account for user [%s] "
 305                                   "FAILED with error %s\n",
 306                                   unix_username, nt_errstr(nt_status)));
 307                 }
 308         }
 309
 310         if (!NT_STATUS_IS_OK(nt_status)) {
 311                 goto fail;
 312         }
 313
 314         nt_status = get_user_sid_info3_and_extra(server_info->info3,
 315                                                  &server_info->extra,
 316                                                  &sid);
 317         if (!NT_STATUS_IS_OK(nt_status)) {
 318                 sid = (struct dom_sid) {0};
 319         }
 320
 321         log_authentication_event(msg_ctx,
 322                                  lp_ctx,
 323                                  &auth_context->start_time,
 324                                  user_info,
 325                                  nt_status,
 326                                  server_info->info3->base.logon_domain.string,
 327                                  server_info->info3->base.account_name.string,
 328                                  &sid,
 329                                  NULL /* client_audit_info */,
 330                                  NULL /* server_audit_info */);
 331
 332         DEBUG(server_info->guest ? 5 : 2,
 333               ("check_ntlm_password:  %sauthentication for user "
 334                "[%s] -> [%s] -> [%s] succeeded\n",
 335                server_info->guest ? "guest " : "",
 336                user_info->client.account_name,
 337                user_info->mapped.account_name,
 338                unix_username));
 339
 340         *pserver_info = talloc_move(mem_ctx, &server_info);
 341
 342         TALLOC_FREE(frame);
 343         return NT_STATUS_OK;
 344
 345 fail:
 346
 347         /* failed authentication; check for guest lapping */
 348
 349         /*
 350          * Please try not to change this string, it is probably in use
 351          * in audit logging tools
 352          */
 353         DEBUG(2, ("check_ntlm_password:  Authentication for user "
 354                   "[%s] -> [%s] FAILED with error %s, authoritative=%u\n",
 355                   user_info->client.account_name, user_info->mapped.account_name,
 356                   nt_errstr(nt_status), *pauthoritative));
 357
 358         log_authentication_event(msg_ctx,
 359                                  lp_ctx,
 360                                  &auth_context->start_time,
 361                                  user_info,
 362                                  nt_status,
 363                                  NULL,
 364                                  NULL,
 365                                  NULL,
 366                                  NULL /* client_audit_info */,
 367                                  NULL /* server_audit_info */);
 368
 369         ZERO_STRUCTP(pserver_info);
 370
 371         TALLOC_FREE(frame);
 372
 373         return nt_status;
 374 }
 375
 376 /***************************************************************************
 377  Clear out a auth_context, and destroy the attached TALLOC_CTX
 378 ***************************************************************************/
 379
 380 static int auth_context_destructor(void *ptr)
 381 {
 382         struct auth_context *ctx = talloc_get_type(ptr, struct auth_context);
 383         struct auth_methods *am;
 384
 385
 386         /* Free private data of context's authentication methods */
 387         for (am = ctx->auth_method_list; am; am = am->next) {
 388                 TALLOC_FREE(am->private_data);
 389         }
 390
 391         return 0;
 392 }
 393
 394 /***************************************************************************
 395  Make a auth_info struct
 396 ***************************************************************************/
 397
 398 static NTSTATUS make_auth_context(TALLOC_CTX *mem_ctx,
 399                                   struct auth_context **auth_context)
 400 {
 401         struct auth_context *ctx;
 402
 403         ctx = talloc_zero(mem_ctx, struct auth_context);
 404         if (!ctx) {
 405                 DEBUG(0,("make_auth_context: talloc failed!\n"));
 406                 return NT_STATUS_NO_MEMORY;
 407         }
 408
 409         ctx->start_time = timeval_current();
 410
 411         talloc_set_destructor((TALLOC_CTX *)ctx, auth_context_destructor);
 412
 413         *auth_context = ctx;
 414         return NT_STATUS_OK;
 415 }
 416
 417 static bool load_auth_module(
 418         struct auth_context *auth_context,
 419         const char *module,
 420         struct auth_methods **ret)
 421 {
 422         static bool initialised_static_modules = False;
 423
 424         struct auth_init_function_entry *entry;
 425         char *module_name = smb_xstrdup(module);
 426         char *module_params = NULL;
 427         char *p;
 428         bool good = False;
 429
 430         /* Initialise static modules if not done so yet */
 431         if(!initialised_static_modules) {
 432                 static_init_auth(NULL);
 433                 initialised_static_modules = True;
 434         }
 435
 436         DEBUG(5,("load_auth_module: Attempting to find an auth method to match %s\n",
 437                  module));
 438
 439         p = strchr(module_name, ':');
 440         if (p) {
 441                 *p = 0;
 442                 module_params = p+1;
 443                 trim_char(module_params, ' ', ' ');
 444         }
 445
 446         trim_char(module_name, ' ', ' ');
 447
 448         entry = auth_find_backend_entry(module_name);
 449
 450         if (entry == NULL) {
 451                 if (NT_STATUS_IS_OK(smb_probe_module("auth", module_name))) {
 452                         entry = auth_find_backend_entry(module_name);
 453                 }
 454         }
 455
 456         if (entry != NULL) {
 457                 if (!NT_STATUS_IS_OK(entry->init(auth_context, module_params, ret))) {
 458                         DEBUG(0,("load_auth_module: auth method %s did not correctly init\n",
 459                                  module_name));
 460                 } else {
 461                         DEBUG(5,("load_auth_module: auth method %s has a valid init\n",
 462                                  module_name));
 463                         good = True;
 464                 }
 465         } else {
 466                 DEBUG(0,("load_auth_module: can't find auth method %s!\n", module_name));
 467         }
 468
 469         SAFE_FREE(module_name);
 470         return good;
 471 }
 472
 473 /***************************************************************************
 474  Make a auth_info struct for the auth subsystem
 475 ***************************************************************************/
 476
 477 static NTSTATUS make_auth_context_text_list(TALLOC_CTX *mem_ctx,
 478                                             struct auth_context **auth_context,
 479                                             char **text_list)
 480 {
 481         struct auth_methods *list = NULL;
 482         struct auth_methods *t, *method = NULL;
 483         NTSTATUS nt_status;
 484
 485         if (!text_list) {
 486                 DEBUG(2,("make_auth_context_text_list: No auth method list!?\n"));
 487                 return NT_STATUS_UNSUCCESSFUL;
 488         }
 489
 490         nt_status = make_auth_context(mem_ctx, auth_context);
 491
 492         if (!NT_STATUS_IS_OK(nt_status)) {
 493                 return nt_status;
 494         }
 495
 496         for (;*text_list; text_list++) {
 497                 if (load_auth_module(*auth_context, *text_list, &t)) {
 498                     DLIST_ADD_END(list, t);
 499                 }
 500         }
 501
 502         (*auth_context)->auth_method_list = list;
 503
 504         /* Look for the first module to provide a prepare_gensec and
 505          * make_auth4_context hook, and set that if provided */
 506         for (method = (*auth_context)->auth_method_list; method; method = method->next) {
 507                 if (method->prepare_gensec && method->make_auth4_context) {
 508                         (*auth_context)->prepare_gensec = method->prepare_gensec;
 509                         (*auth_context)->make_auth4_context = method->make_auth4_context;
 510                         break;
 511                 }
 512         }
 513         return NT_STATUS_OK;
 514 }
 515
 516 static NTSTATUS make_auth_context_specific(TALLOC_CTX *mem_ctx,
 517                                            struct auth_context **auth_context,
 518                                            const char *methods)
 519 {
 520         char **method_list;
 521         NTSTATUS status;
 522
 523         method_list = str_list_make_v3(talloc_tos(), methods, NULL);
 524         if (method_list == NULL) {
 525                 return NT_STATUS_NO_MEMORY;
 526         }
 527
 528         status = make_auth_context_text_list(
 529                 mem_ctx, auth_context, method_list);
 530
 531         TALLOC_FREE(method_list);
 532
 533         return status;
 534 }
 535
 536 /***************************************************************************
 537  Make a auth_context struct for the auth subsystem
 538 ***************************************************************************/
 539
 540 NTSTATUS make_auth3_context_for_ntlm(TALLOC_CTX *mem_ctx,
 541                                      struct auth_context **auth_context)
 542 {
 543         const char *methods = NULL;
 544         const char *role = NULL;
 545
 546         switch (lp_server_role()) {
 547         case ROLE_ACTIVE_DIRECTORY_DC:
 548                 role = "'active directory domain controller'";
 549                 methods = "samba4";
 550                 break;
 551         case ROLE_DOMAIN_MEMBER:
 552                 role = "'domain member'";
 553                 methods = "anonymous sam winbind sam_ignoredomain";
 554                 break;
 555         case ROLE_DOMAIN_BDC:
 556         case ROLE_DOMAIN_PDC:
 557         case ROLE_IPA_DC:
 558                 role = "'DC'";
 559                 methods = "anonymous sam winbind sam_ignoredomain";
 560                 break;
 561         case ROLE_STANDALONE:
 562                 if (lp_encrypt_passwords()) {
 563                         role = "'standalone server', encrypt passwords = yes";
 564                         methods = "anonymous sam_ignoredomain";
 565                 } else {
 566                         role = "'standalone server', encrypt passwords = no";
 567                         methods = "anonymous unix";
 568                 }
 569                 break;
 570         default:
 571                 DEBUG(5,("Unknown auth method!\n"));
 572                 return NT_STATUS_UNSUCCESSFUL;
 573         }
 574
 575         DBG_INFO("Making default auth method list for server role = %s\n",
 576                  role);
 577
 578         return make_auth_context_specific(mem_ctx, auth_context, methods);
 579 }
 580
 581 NTSTATUS make_auth3_context_for_netlogon(TALLOC_CTX *mem_ctx,
 582                                          struct auth_context **auth_context)
 583 {
 584         const char *methods = NULL;
 585
 586         switch (lp_server_role()) {
 587         case ROLE_DOMAIN_BDC:
 588         case ROLE_DOMAIN_PDC:
 589         case ROLE_IPA_DC:
 590                 methods = "sam_netlogon3 winbind";
 591                 break;
 592
 593         default:
 594                 DBG_ERR("Invalid server role!\n");
 595                 return NT_STATUS_INVALID_SERVER_STATE;
 596         }
 597
 598         return make_auth_context_specific(mem_ctx, auth_context, methods);
 599 }
 600
 601 NTSTATUS make_auth3_context_for_winbind(TALLOC_CTX *mem_ctx,
 602                                         struct auth_context **auth_context)
 603 {
 604         const char *methods = NULL;
 605
 606         switch (lp_server_role()) {
 607         case ROLE_STANDALONE:
 608         case ROLE_DOMAIN_MEMBER:
 609         case ROLE_DOMAIN_BDC:
 610         case ROLE_DOMAIN_PDC:
 611         case ROLE_IPA_DC:
 612                 methods = "sam";
 613                 break;
 614         case ROLE_ACTIVE_DIRECTORY_DC:
 615                 methods = "samba4:sam";
 616                 break;
 617         default:
 618                 DEBUG(5,("Unknown auth method!\n"));
 619                 return NT_STATUS_UNSUCCESSFUL;
 620         }
 621
 622         return make_auth_context_specific(mem_ctx, auth_context, methods);
 623 }
 624
 625 bool auth3_context_set_challenge(
 626         struct auth_context *ctx,
 627         const uint8_t chal[8],
 628         const char *challenge_set_by)
 629 {
 630         ctx->challenge = data_blob_talloc(ctx, chal, 8);
 631         if (ctx->challenge.data == NULL) {
 632                 return false;
 633         }
 634         ctx->challenge_set_by = talloc_strdup(ctx, challenge_set_by);
 635         if (ctx->challenge_set_by == NULL) {
 636                 return false;
 637         }
 638         return true;
 639 }