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