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 "smbd/globals.h"
  22
  23 #undef DBGC_CLASS
  24 #define DBGC_CLASS DBGC_AUTH
  25
  26 static_decl_auth;
  27
  28 static struct auth_init_function_entry *auth_backends = NULL;
  29
  30 static struct auth_init_function_entry *auth_find_backend_entry(const char *name);
  31
  32 NTSTATUS smb_register_auth(int version, const char *name, auth_init_function init)
  33 {
  34         struct auth_init_function_entry *entry = auth_backends;
  35
  36         if (version != AUTH_INTERFACE_VERSION) {
  37                 DEBUG(0,("Can't register auth_method!\n"
  38                          "You tried to register an auth module with AUTH_INTERFACE_VERSION %d, while this version of samba uses %d\n",
  39                          version,AUTH_INTERFACE_VERSION));
  40                 return NT_STATUS_OBJECT_TYPE_MISMATCH;
  41         }
  42
  43         if (!name || !init) {
  44                 return NT_STATUS_INVALID_PARAMETER;
  45         }
  46
  47         DEBUG(5,("Attempting to register auth backend %s\n", name));
  48
  49         if (auth_find_backend_entry(name)) {
  50                 DEBUG(0,("There already is an auth method registered with the name %s!\n", name));
  51                 return NT_STATUS_OBJECT_NAME_COLLISION;
  52         }
  53
  54         entry = SMB_XMALLOC_P(struct auth_init_function_entry);
  55         entry->name = smb_xstrdup(name);
  56         entry->init = init;
  57
  58         DLIST_ADD(auth_backends, entry);
  59         DEBUG(5,("Successfully added auth method '%s'\n", name));
  60         return NT_STATUS_OK;
  61 }
  62
  63 static struct auth_init_function_entry *auth_find_backend_entry(const char *name)
  64 {
  65         struct auth_init_function_entry *entry = auth_backends;
  66
  67         while(entry) {
  68                 if (strcmp(entry->name, name)==0) return entry;
  69                 entry = entry->next;
  70         }
  71
  72         return NULL;
  73 }
  74
  75 /****************************************************************************
  76  Try to get a challenge out of the various authentication modules.
  77  Returns a const char of length 8 bytes.
  78 ****************************************************************************/
  79
  80 static NTSTATUS get_ntlm_challenge(struct auth_context *auth_context,
  81                                uint8_t chal[8])
  82 {
  83         DATA_BLOB challenge = data_blob_null;
  84         const char *challenge_set_by = NULL;
  85         auth_methods *auth_method;
  86
  87         if (auth_context->challenge.length) {
  88                 DEBUG(5, ("get_ntlm_challenge (auth subsystem): returning previous challenge by module %s (normal)\n",
  89                           auth_context->challenge_set_by));
  90                 memcpy(chal, auth_context->challenge.data, 8);
  91                 return NT_STATUS_OK;
  92         }
  93
  94         auth_context->challenge_may_be_modified = False;
  95
  96         for (auth_method = auth_context->auth_method_list; auth_method; auth_method = auth_method->next) {
  97                 if (auth_method->get_chal == NULL) {
  98                         DEBUG(5, ("auth_get_challenge: module %s did not want to specify a challenge\n", auth_method->name));
  99                         continue;
 100                 }
 101
 102                 DEBUG(5, ("auth_get_challenge: getting challenge from module %s\n", auth_method->name));
 103                 if (challenge_set_by != NULL) {
 104                         DEBUG(1, ("auth_get_challenge: CONFIGURATION ERROR: authentication method %s has already specified a challenge.  Challenge by %s ignored.\n",
 105                                   challenge_set_by, auth_method->name));
 106                         continue;
 107                 }
 108
 109                 challenge = auth_method->get_chal(auth_context, &auth_method->private_data,
 110                                                   auth_context);
 111                 if (!challenge.length) {
 112                         DEBUG(3, ("auth_get_challenge: getting challenge from authentication method %s FAILED.\n",
 113                                   auth_method->name));
 114                 } else {
 115                         DEBUG(5, ("auth_get_challenge: successfully got challenge from module %s\n", auth_method->name));
 116                         auth_context->challenge = challenge;
 117                         challenge_set_by = auth_method->name;
 118                         auth_context->challenge_set_method = auth_method;
 119                 }
 120         }
 121
 122         if (!challenge_set_by) {
 123                 uchar tmp[8];
 124
 125                 generate_random_buffer(tmp, sizeof(tmp));
 126                 auth_context->challenge = data_blob_talloc(auth_context,
 127                                                            tmp, sizeof(tmp));
 128
 129                 challenge_set_by = "random";
 130                 auth_context->challenge_may_be_modified = True;
 131         }
 132
 133         DEBUG(5, ("auth_context challenge created by %s\n", challenge_set_by));
 134         DEBUG(5, ("challenge is: \n"));
 135         dump_data(5, auth_context->challenge.data, auth_context->challenge.length);
 136
 137         SMB_ASSERT(auth_context->challenge.length == 8);
 138
 139         auth_context->challenge_set_by=challenge_set_by;
 140
 141         memcpy(chal, auth_context->challenge.data, 8);
 142         return NT_STATUS_OK;
 143 }
 144
 145
 146 /**
 147  * Check user is in correct domain (if required)
 148  *
 149  * @param user Only used to fill in the debug message
 150  *
 151  * @param domain The domain to be verified
 152  *
 153  * @return True if the user can connect with that domain,
 154  *         False otherwise.
 155 **/
 156
 157 static bool check_domain_match(const char *user, const char *domain)
 158 {
 159         /*
 160          * If we aren't serving to trusted domains, we must make sure that
 161          * the validation request comes from an account in the same domain
 162          * as the Samba server
 163          */
 164
 165         if (!lp_allow_trusted_domains() &&
 166             !(strequal("", domain) ||
 167               strequal(lp_workgroup(), domain) ||
 168               is_myname(domain))) {
 169                 DEBUG(1, ("check_domain_match: Attempt to connect as user %s from domain %s denied.\n", user, domain));
 170                 return False;
 171         } else {
 172                 return True;
 173         }
 174 }
 175
 176 /**
 177  * Check a user's Plaintext, LM or NTLM password.
 178  *
 179  * Check a user's password, as given in the user_info struct and return various
 180  * interesting details in the server_info struct.
 181  *
 182  * This function does NOT need to be in a become_root()/unbecome_root() pair
 183  * as it makes the calls itself when needed.
 184  *
 185  * The return value takes precedence over the contents of the server_info
 186  * struct.  When the return is other than NT_STATUS_OK the contents
 187  * of that structure is undefined.
 188  *
 189  * @param user_info Contains the user supplied components, including the passwords.
 190  *                  Must be created with make_user_info() or one of its wrappers.
 191  *
 192  * @param auth_context Supplies the challenges and some other data.
 193  *                  Must be created with make_auth_context(), and the challenges should be
 194  *                  filled in, either at creation or by calling the challenge geneation
 195  *                  function auth_get_challenge().
 196  *
 197  * @param server_info If successful, contains information about the authentication,
 198  *                    including a struct samu struct describing the user.
 199  *
 200  * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.
 201  *
 202  **/
 203
 204 static NTSTATUS check_ntlm_password(const struct auth_context *auth_context,
 205                                     const struct auth_usersupplied_info *user_info,
 206                                     struct auth_serversupplied_info **server_info)
 207 {
 208         /* if all the modules say 'not for me' this is reasonable */
 209         NTSTATUS nt_status = NT_STATUS_NO_SUCH_USER;
 210         const char *unix_username;
 211         auth_methods *auth_method;
 212         TALLOC_CTX *mem_ctx;
 213
 214         if (!user_info || !auth_context || !server_info)
 215                 return NT_STATUS_LOGON_FAILURE;
 216
 217         DEBUG(3, ("check_ntlm_password:  Checking password for unmapped user [%s]\\[%s]@[%s] with the new password interface\n",
 218                   user_info->client.domain_name, user_info->client.account_name, user_info->workstation_name));
 219
 220         DEBUG(3, ("check_ntlm_password:  mapped user is: [%s]\\[%s]@[%s]\n",
 221                   user_info->mapped.domain_name, user_info->mapped.account_name, user_info->workstation_name));
 222
 223         if (auth_context->challenge.length != 8) {
 224                 DEBUG(0, ("check_ntlm_password:  Invalid challenge stored for this auth context - cannot continue\n"));
 225                 return NT_STATUS_LOGON_FAILURE;
 226         }
 227
 228         if (auth_context->challenge_set_by)
 229                 DEBUG(10, ("check_ntlm_password: auth_context challenge created by %s\n",
 230                                         auth_context->challenge_set_by));
 231
 232         DEBUG(10, ("challenge is: \n"));
 233         dump_data(5, auth_context->challenge.data, auth_context->challenge.length);
 234
 235 #ifdef DEBUG_PASSWORD
 236         DEBUG(100, ("user_info has passwords of length %d and %d\n",
 237                     (int)user_info->password.response.lanman.length, (int)user_info->password.response.nt.length));
 238         DEBUG(100, ("lm:\n"));
 239         dump_data(100, user_info->password.response.lanman.data, user_info->password.response.lanman.length);
 240         DEBUG(100, ("nt:\n"));
 241         dump_data(100, user_info->password.response.nt.data, user_info->password.response.nt.length);
 242 #endif
 243
 244         /* This needs to be sorted:  If it doesn't match, what should we do? */
 245         if (!check_domain_match(user_info->client.account_name, user_info->mapped.domain_name))
 246                 return NT_STATUS_LOGON_FAILURE;
 247
 248         for (auth_method = auth_context->auth_method_list;auth_method; auth_method = auth_method->next) {
 249                 NTSTATUS result;
 250
 251                 mem_ctx = talloc_init("%s authentication for user %s\\%s", auth_method->name,
 252                                       user_info->mapped.domain_name, user_info->client.account_name);
 253
 254                 result = auth_method->auth(auth_context, auth_method->private_data, mem_ctx, user_info, server_info);
 255
 256                 /* check if the module did anything */
 257                 if ( NT_STATUS_V(result) == NT_STATUS_V(NT_STATUS_NOT_IMPLEMENTED) ) {
 258                         DEBUG(10,("check_ntlm_password: %s had nothing to say\n", auth_method->name));
 259                         talloc_destroy(mem_ctx);
 260                         continue;
 261                 }
 262
 263                 nt_status = result;
 264
 265                 if (NT_STATUS_IS_OK(nt_status)) {
 266                         DEBUG(3, ("check_ntlm_password: %s authentication for user [%s] succeeded\n",
 267                                   auth_method->name, user_info->client.account_name));
 268                 } else {
 269                         DEBUG(5, ("check_ntlm_password: %s authentication for user [%s] FAILED with error %s\n",
 270                                   auth_method->name, user_info->client.account_name, nt_errstr(nt_status)));
 271                 }
 272
 273                 talloc_destroy(mem_ctx);
 274
 275                 if ( NT_STATUS_IS_OK(nt_status))
 276                 {
 277                                 break;
 278                 }
 279         }
 280
 281         /* successful authentication */
 282
 283         if (NT_STATUS_IS_OK(nt_status)) {
 284                 unix_username = (*server_info)->unix_name;
 285                 if (!(*server_info)->guest) {
 286                         /* We might not be root if we are an RPC call */
 287                         become_root();
 288                         nt_status = smb_pam_accountcheck(
 289                                 unix_username,
 290                                 smbd_server_conn->client_id.name);
 291                         unbecome_root();
 292
 293                         if (NT_STATUS_IS_OK(nt_status)) {
 294                                 DEBUG(5, ("check_ntlm_password:  PAM Account for user [%s] succeeded\n",
 295                                           unix_username));
 296                         } else {
 297                                 DEBUG(3, ("check_ntlm_password:  PAM Account for user [%s] FAILED with error %s\n",
 298                                           unix_username, nt_errstr(nt_status)));
 299                         }
 300                 }
 301
 302                 if (NT_STATUS_IS_OK(nt_status)) {
 303                         DEBUG((*server_info)->guest ? 5 : 2,
 304                               ("check_ntlm_password:  %sauthentication for user [%s] -> [%s] -> [%s] succeeded\n",
 305                                (*server_info)->guest ? "guest " : "",
 306                                user_info->client.account_name,
 307                                user_info->mapped.account_name,
 308                                unix_username));
 309                 }
 310
 311                 return nt_status;
 312         }
 313
 314         /* failed authentication; check for guest lapping */
 315
 316         DEBUG(2, ("check_ntlm_password:  Authentication for user [%s] -> [%s] FAILED with error %s\n",
 317                   user_info->client.account_name, user_info->mapped.account_name,
 318                   nt_errstr(nt_status)));
 319         ZERO_STRUCTP(server_info);
 320
 321         return nt_status;
 322 }
 323
 324 /***************************************************************************
 325  Clear out a auth_context, and destroy the attached TALLOC_CTX
 326 ***************************************************************************/
 327
 328 static int auth_context_destructor(void *ptr)
 329 {
 330         struct auth_context *ctx = talloc_get_type(ptr, struct auth_context);
 331         struct auth_methods *am;
 332
 333
 334         /* Free private data of context's authentication methods */
 335         for (am = ctx->auth_method_list; am; am = am->next) {
 336                 TALLOC_FREE(am->private_data);
 337         }
 338
 339         return 0;
 340 }
 341
 342 /***************************************************************************
 343  Make a auth_info struct
 344 ***************************************************************************/
 345
 346 static NTSTATUS make_auth_context(TALLOC_CTX *mem_ctx,
 347                                   struct auth_context **auth_context)
 348 {
 349         struct auth_context *ctx;
 350
 351         ctx = talloc_zero(mem_ctx, struct auth_context);
 352         if (!ctx) {
 353                 DEBUG(0,("make_auth_context: talloc failed!\n"));
 354                 return NT_STATUS_NO_MEMORY;
 355         }
 356
 357         ctx->check_ntlm_password = check_ntlm_password;
 358         ctx->get_ntlm_challenge = get_ntlm_challenge;
 359
 360         talloc_set_destructor((TALLOC_CTX *)ctx, auth_context_destructor);
 361
 362         *auth_context = ctx;
 363         return NT_STATUS_OK;
 364 }
 365
 366 bool load_auth_module(struct auth_context *auth_context,
 367                       const char *module, auth_methods **ret)
 368 {
 369         static bool initialised_static_modules = False;
 370
 371         struct auth_init_function_entry *entry;
 372         char *module_name = smb_xstrdup(module);
 373         char *module_params = NULL;
 374         char *p;
 375         bool good = False;
 376
 377         /* Initialise static modules if not done so yet */
 378         if(!initialised_static_modules) {
 379                 static_init_auth;
 380                 initialised_static_modules = True;
 381         }
 382
 383         DEBUG(5,("load_auth_module: Attempting to find an auth method to match %s\n",
 384                  module));
 385
 386         p = strchr(module_name, ':');
 387         if (p) {
 388                 *p = 0;
 389                 module_params = p+1;
 390                 trim_char(module_params, ' ', ' ');
 391         }
 392
 393         trim_char(module_name, ' ', ' ');
 394
 395         entry = auth_find_backend_entry(module_name);
 396
 397         if (entry == NULL) {
 398                 if (NT_STATUS_IS_OK(smb_probe_module("auth", module_name))) {
 399                         entry = auth_find_backend_entry(module_name);
 400                 }
 401         }
 402
 403         if (entry != NULL) {
 404                 if (!NT_STATUS_IS_OK(entry->init(auth_context, module_params, ret))) {
 405                         DEBUG(0,("load_auth_module: auth method %s did not correctly init\n",
 406                                  module_name));
 407                 } else {
 408                         DEBUG(5,("load_auth_module: auth method %s has a valid init\n",
 409                                  module_name));
 410                         good = True;
 411                 }
 412         } else {
 413                 DEBUG(0,("load_auth_module: can't find auth method %s!\n", module_name));
 414         }
 415
 416         SAFE_FREE(module_name);
 417         return good;
 418 }
 419
 420 /***************************************************************************
 421  Make a auth_info struct for the auth subsystem
 422 ***************************************************************************/
 423
 424 static NTSTATUS make_auth_context_text_list(TALLOC_CTX *mem_ctx,
 425                                             struct auth_context **auth_context,
 426                                             char **text_list)
 427 {
 428         auth_methods *list = NULL;
 429         auth_methods *t = NULL;
 430         NTSTATUS nt_status;
 431
 432         if (!text_list) {
 433                 DEBUG(2,("make_auth_context_text_list: No auth method list!?\n"));
 434                 return NT_STATUS_UNSUCCESSFUL;
 435         }
 436
 437         nt_status = make_auth_context(mem_ctx, auth_context);
 438
 439         if (!NT_STATUS_IS_OK(nt_status)) {
 440                 return nt_status;
 441         }
 442
 443         for (;*text_list; text_list++) {
 444                 if (load_auth_module(*auth_context, *text_list, &t)) {
 445                     DLIST_ADD_END(list, t, auth_methods *);
 446                 }
 447         }
 448
 449         (*auth_context)->auth_method_list = list;
 450
 451         return nt_status;
 452 }
 453
 454 /***************************************************************************
 455  Make a auth_context struct for the auth subsystem
 456 ***************************************************************************/
 457
 458 NTSTATUS make_auth_context_subsystem(TALLOC_CTX *mem_ctx,
 459                                      struct auth_context **auth_context)
 460 {
 461         char **auth_method_list = NULL;
 462         NTSTATUS nt_status;
 463
 464         if (lp_auth_methods()
 465             && !(auth_method_list = str_list_copy(talloc_tos(),
 466                               lp_auth_methods()))) {
 467                 return NT_STATUS_NO_MEMORY;
 468         }
 469
 470         if (auth_method_list == NULL) {
 471                 switch (lp_security())
 472                 {
 473                 case SEC_DOMAIN:
 474                         DEBUG(5,("Making default auth method list for security=domain\n"));
 475                         auth_method_list = str_list_make_v3(
 476                                 talloc_tos(), "guest sam winbind:ntdomain",
 477                                 NULL);
 478                         break;
 479                 case SEC_SERVER:
 480                         DEBUG(5,("Making default auth method list for security=server\n"));
 481                         auth_method_list = str_list_make_v3(
 482                                 talloc_tos(), "guest sam smbserver",
 483                                 NULL);
 484                         break;
 485                 case SEC_USER:
 486                         if (lp_encrypted_passwords()) {
 487                                 if ((lp_server_role() == ROLE_DOMAIN_PDC) || (lp_server_role() == ROLE_DOMAIN_BDC)) {
 488                                         DEBUG(5,("Making default auth method list for DC, security=user, encrypt passwords = yes\n"));
 489                                         auth_method_list = str_list_make_v3(
 490                                                 talloc_tos(),
 491                                                 "guest sam winbind:trustdomain",
 492                                                 NULL);
 493                                 } else {
 494                                         DEBUG(5,("Making default auth method list for standalone security=user, encrypt passwords = yes\n"));
 495                                         auth_method_list = str_list_make_v3(
 496                                                 talloc_tos(), "guest sam",
 497                                                 NULL);
 498                                 }
 499                         } else {
 500                                 DEBUG(5,("Making default auth method list for security=user, encrypt passwords = no\n"));
 501                                 auth_method_list = str_list_make_v3(
 502                                         talloc_tos(), "guest unix", NULL);
 503                         }
 504                         break;
 505                 case SEC_SHARE:
 506                         if (lp_encrypted_passwords()) {
 507                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = yes\n"));
 508                                 auth_method_list = str_list_make_v3(
 509                                         talloc_tos(), "guest sam", NULL);
 510                         } else {
 511                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = no\n"));
 512                                 auth_method_list = str_list_make_v3(
 513                                         talloc_tos(), "guest unix", NULL);
 514                         }
 515                         break;
 516                 case SEC_ADS:
 517                         DEBUG(5,("Making default auth method list for security=ADS\n"));
 518                         auth_method_list = str_list_make_v3(
 519                                 talloc_tos(), "guest sam winbind:ntdomain",
 520                                 NULL);
 521                         break;
 522                 default:
 523                         DEBUG(5,("Unknown auth method!\n"));
 524                         return NT_STATUS_UNSUCCESSFUL;
 525                 }
 526         } else {
 527                 DEBUG(5,("Using specified auth order\n"));
 528         }
 529
 530         nt_status = make_auth_context_text_list(mem_ctx, auth_context,
 531                                                 auth_method_list);
 532
 533         TALLOC_FREE(auth_method_list);
 534         return nt_status;
 535 }
 536
 537 /***************************************************************************
 538  Make a auth_info struct with a fixed challenge
 539 ***************************************************************************/
 540
 541 NTSTATUS make_auth_context_fixed(TALLOC_CTX *mem_ctx,
 542                                  struct auth_context **auth_context,
 543                                  uchar chal[8])
 544 {
 545         NTSTATUS nt_status;
 546         nt_status = make_auth_context_subsystem(mem_ctx, auth_context);
 547         if (!NT_STATUS_IS_OK(nt_status)) {
 548                 return nt_status;
 549         }
 550
 551         (*auth_context)->challenge = data_blob_talloc(*auth_context, chal, 8);
 552         (*auth_context)->challenge_set_by = "fixed";
 553         return nt_status;
 554 }
 555
 556