source/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
  22 #undef DBGC_CLASS
  23 #define DBGC_CLASS DBGC_AUTH
  24
  25 static_decl_auth;
  26
  27 static struct auth_init_function_entry *backends = NULL;
  28
  29 static struct auth_init_function_entry *auth_find_backend_entry(const char *name);
  30
  31 NTSTATUS smb_register_auth(int version, const char *name, auth_init_function init)
  32 {
  33         struct auth_init_function_entry *entry = backends;
  34
  35         if (version != AUTH_INTERFACE_VERSION) {
  36                 DEBUG(0,("Can't register auth_method!\n"
  37                          "You tried to register an auth module with AUTH_INTERFACE_VERSION %d, while this version of samba uses %d\n",
  38                          version,AUTH_INTERFACE_VERSION));
  39                 return NT_STATUS_OBJECT_TYPE_MISMATCH;
  40         }
  41
  42         if (!name || !init) {
  43                 return NT_STATUS_INVALID_PARAMETER;
  44         }
  45
  46         DEBUG(5,("Attempting to register auth backend %s\n", name));
  47
  48         if (auth_find_backend_entry(name)) {
  49                 DEBUG(0,("There already is an auth method registered with the name %s!\n", name));
  50                 return NT_STATUS_OBJECT_NAME_COLLISION;
  51         }
  52
  53         entry = SMB_XMALLOC_P(struct auth_init_function_entry);
  54         entry->name = smb_xstrdup(name);
  55         entry->init = init;
  56
  57         DLIST_ADD(backends, entry);
  58         DEBUG(5,("Successfully added auth method '%s'\n", name));
  59         return NT_STATUS_OK;
  60 }
  61
  62 static struct auth_init_function_entry *auth_find_backend_entry(const char *name)
  63 {
  64         struct auth_init_function_entry *entry = backends;
  65
  66         while(entry) {
  67                 if (strcmp(entry->name, name)==0) return entry;
  68                 entry = entry->next;
  69         }
  70
  71         return NULL;
  72 }
  73
  74 /****************************************************************************
  75  Try to get a challenge out of the various authentication modules.
  76  Returns a const char of length 8 bytes.
  77 ****************************************************************************/
  78
  79 static const uint8 *get_ntlm_challenge(struct auth_context *auth_context)
  80 {
  81         DATA_BLOB challenge = data_blob_null;
  82         const char *challenge_set_by = NULL;
  83         auth_methods *auth_method;
  84         TALLOC_CTX *mem_ctx;
  85
  86         if (auth_context->challenge.length) {
  87                 DEBUG(5, ("get_ntlm_challenge (auth subsystem): returning previous challenge by module %s (normal)\n",
  88                           auth_context->challenge_set_by));
  89                 return auth_context->challenge.data;
  90         }
  91
  92         auth_context->challenge_may_be_modified = False;
  93
  94         for (auth_method = auth_context->auth_method_list; auth_method; auth_method = auth_method->next) {
  95                 if (auth_method->get_chal == NULL) {
  96                         DEBUG(5, ("auth_get_challenge: module %s did not want to specify a challenge\n", auth_method->name));
  97                         continue;
  98                 }
  99
 100                 DEBUG(5, ("auth_get_challenge: getting challenge from module %s\n", auth_method->name));
 101                 if (challenge_set_by != NULL) {
 102                         DEBUG(1, ("auth_get_challenge: CONFIGURATION ERROR: authentication method %s has already specified a challenge.  Challenge by %s ignored.\n",
 103                                   challenge_set_by, auth_method->name));
 104                         continue;
 105                 }
 106
 107                 mem_ctx = talloc_init("auth_get_challenge for module %s", auth_method->name);
 108                 if (!mem_ctx) {
 109                         smb_panic("talloc_init() failed!");
 110                 }
 111
 112                 challenge = auth_method->get_chal(auth_context, &auth_method->private_data, mem_ctx);
 113                 if (!challenge.length) {
 114                         DEBUG(3, ("auth_get_challenge: getting challenge from authentication method %s FAILED.\n",
 115                                   auth_method->name));
 116                 } else {
 117                         DEBUG(5, ("auth_get_challenge: successfully got challenge from module %s\n", auth_method->name));
 118                         auth_context->challenge = challenge;
 119                         challenge_set_by = auth_method->name;
 120                         auth_context->challenge_set_method = auth_method;
 121                 }
 122                 talloc_destroy(mem_ctx);
 123         }
 124
 125         if (!challenge_set_by) {
 126                 uchar chal[8];
 127
 128                 generate_random_buffer(chal, sizeof(chal));
 129                 auth_context->challenge = data_blob_talloc(auth_context->mem_ctx,
 130                                                            chal, sizeof(chal));
 131
 132                 challenge_set_by = "random";
 133                 auth_context->challenge_may_be_modified = True;
 134         }
 135
 136         DEBUG(5, ("auth_context challenge created by %s\n", challenge_set_by));
 137         DEBUG(5, ("challenge is: \n"));
 138         dump_data(5, auth_context->challenge.data, auth_context->challenge.length);
 139
 140         SMB_ASSERT(auth_context->challenge.length == 8);
 141
 142         auth_context->challenge_set_by=challenge_set_by;
 143
 144         return auth_context->challenge.data;
 145 }
 146
 147
 148 /**
 149  * Check user is in correct domain (if required)
 150  *
 151  * @param user Only used to fill in the debug message
 152  *
 153  * @param domain The domain to be verified
 154  *
 155  * @return True if the user can connect with that domain,
 156  *         False otherwise.
 157 **/
 158
 159 static bool check_domain_match(const char *user, const char *domain)
 160 {
 161         /*
 162          * If we aren't serving to trusted domains, we must make sure that
 163          * the validation request comes from an account in the same domain
 164          * as the Samba server
 165          */
 166
 167         if (!lp_allow_trusted_domains() &&
 168             !(strequal("", domain) ||
 169               strequal(lp_workgroup(), domain) ||
 170               is_myname(domain))) {
 171                 DEBUG(1, ("check_domain_match: Attempt to connect as user %s from domain %s denied.\n", user, domain));
 172                 return False;
 173         } else {
 174                 return True;
 175         }
 176 }
 177
 178 /**
 179  * Check a user's Plaintext, LM or NTLM password.
 180  *
 181  * Check a user's password, as given in the user_info struct and return various
 182  * interesting details in the server_info struct.
 183  *
 184  * This function does NOT need to be in a become_root()/unbecome_root() pair
 185  * as it makes the calls itself when needed.
 186  *
 187  * The return value takes precedence over the contents of the server_info
 188  * struct.  When the return is other than NT_STATUS_OK the contents
 189  * of that structure is undefined.
 190  *
 191  * @param user_info Contains the user supplied components, including the passwords.
 192  *                  Must be created with make_user_info() or one of its wrappers.
 193  *
 194  * @param auth_context Supplies the challenges and some other data.
 195  *                  Must be created with make_auth_context(), and the challenges should be
 196  *                  filled in, either at creation or by calling the challenge geneation
 197  *                  function auth_get_challenge().
 198  *
 199  * @param server_info If successful, contains information about the authentication,
 200  *                    including a struct samu struct describing the user.
 201  *
 202  * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.
 203  *
 204  **/
 205
 206 static NTSTATUS check_ntlm_password(const struct auth_context *auth_context,
 207                                     const struct auth_usersupplied_info *user_info,
 208                                     struct auth_serversupplied_info **server_info)
 209 {
 210         /* if all the modules say 'not for me' this is reasonable */
 211         NTSTATUS nt_status = NT_STATUS_NO_SUCH_USER;
 212         const char *unix_username;
 213         auth_methods *auth_method;
 214         TALLOC_CTX *mem_ctx;
 215
 216         if (!user_info || !auth_context || !server_info)
 217                 return NT_STATUS_LOGON_FAILURE;
 218
 219         DEBUG(3, ("check_ntlm_password:  Checking password for unmapped user [%s]\\[%s]@[%s] with the new password interface\n",
 220                   user_info->client_domain, user_info->smb_name, user_info->wksta_name));
 221
 222         DEBUG(3, ("check_ntlm_password:  mapped user is: [%s]\\[%s]@[%s]\n",
 223                   user_info->domain, user_info->internal_username, user_info->wksta_name));
 224
 225         if (auth_context->challenge.length != 8) {
 226                 DEBUG(0, ("check_ntlm_password:  Invalid challenge stored for this auth context - cannot continue\n"));
 227                 return NT_STATUS_LOGON_FAILURE;
 228         }
 229
 230         if (auth_context->challenge_set_by)
 231                 DEBUG(10, ("check_ntlm_password: auth_context challenge created by %s\n",
 232                                         auth_context->challenge_set_by));
 233
 234         DEBUG(10, ("challenge is: \n"));
 235         dump_data(5, auth_context->challenge.data, auth_context->challenge.length);
 236
 237 #ifdef DEBUG_PASSWORD
 238         DEBUG(100, ("user_info has passwords of length %d and %d\n",
 239                     (int)user_info->lm_resp.length, (int)user_info->nt_resp.length));
 240         DEBUG(100, ("lm:\n"));
 241         dump_data(100, user_info->lm_resp.data, user_info->lm_resp.length);
 242         DEBUG(100, ("nt:\n"));
 243         dump_data(100, user_info->nt_resp.data, user_info->nt_resp.length);
 244 #endif
 245
 246         /* This needs to be sorted:  If it doesn't match, what should we do? */
 247         if (!check_domain_match(user_info->smb_name, user_info->domain))
 248                 return NT_STATUS_LOGON_FAILURE;
 249
 250         for (auth_method = auth_context->auth_method_list;auth_method; auth_method = auth_method->next) {
 251                 NTSTATUS result;
 252
 253                 mem_ctx = talloc_init("%s authentication for user %s\\%s", auth_method->name,
 254                                             user_info->domain, user_info->smb_name);
 255
 256                 result = auth_method->auth(auth_context, auth_method->private_data, mem_ctx, user_info, server_info);
 257
 258                 /* check if the module did anything */
 259                 if ( NT_STATUS_V(result) == NT_STATUS_V(NT_STATUS_NOT_IMPLEMENTED) ) {
 260                         DEBUG(10,("check_ntlm_password: %s had nothing to say\n", auth_method->name));
 261                         talloc_destroy(mem_ctx);
 262                         continue;
 263                 }
 264
 265                 nt_status = result;
 266
 267                 if (NT_STATUS_IS_OK(nt_status)) {
 268                         DEBUG(3, ("check_ntlm_password: %s authentication for user [%s] succeeded\n",
 269                                   auth_method->name, user_info->smb_name));
 270                 } else {
 271                         DEBUG(5, ("check_ntlm_password: %s authentication for user [%s] FAILED with error %s\n",
 272                                   auth_method->name, user_info->smb_name, nt_errstr(nt_status)));
 273                 }
 274
 275                 talloc_destroy(mem_ctx);
 276
 277                 if ( NT_STATUS_IS_OK(nt_status))
 278                 {
 279                                 break;
 280                 }
 281         }
 282
 283         /* successful authentication */
 284
 285         if (NT_STATUS_IS_OK(nt_status)) {
 286                 unix_username = (*server_info)->unix_name;
 287                 if (!(*server_info)->guest) {
 288                         /* We might not be root if we are an RPC call */
 289                         become_root();
 290                         nt_status = smb_pam_accountcheck(unix_username);
 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->smb_name,
 307                                user_info->internal_username,
 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->smb_name, user_info->internal_username,
 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 void free_auth_context(struct auth_context **auth_context)
 329 {
 330         auth_methods *auth_method;
 331
 332         if (*auth_context) {
 333                 /* Free private data of context's authentication methods */
 334                 for (auth_method = (*auth_context)->auth_method_list; auth_method; auth_method = auth_method->next) {
 335                         TALLOC_FREE(auth_method->private_data);
 336                 }
 337
 338                 talloc_destroy((*auth_context)->mem_ctx);
 339                 *auth_context = NULL;
 340         }
 341 }
 342
 343 /***************************************************************************
 344  Make a auth_info struct
 345 ***************************************************************************/
 346
 347 static NTSTATUS make_auth_context(struct auth_context **auth_context)
 348 {
 349         TALLOC_CTX *mem_ctx;
 350
 351         mem_ctx = talloc_init("authentication context");
 352
 353         *auth_context = TALLOC_P(mem_ctx, struct auth_context);
 354         if (!*auth_context) {
 355                 DEBUG(0,("make_auth_context: talloc failed!\n"));
 356                 talloc_destroy(mem_ctx);
 357                 return NT_STATUS_NO_MEMORY;
 358         }
 359         ZERO_STRUCTP(*auth_context);
 360
 361         (*auth_context)->mem_ctx = mem_ctx;
 362         (*auth_context)->check_ntlm_password = check_ntlm_password;
 363         (*auth_context)->get_ntlm_challenge = get_ntlm_challenge;
 364         (*auth_context)->free = free_auth_context;
 365
 366         return NT_STATUS_OK;
 367 }
 368
 369 bool load_auth_module(struct auth_context *auth_context,
 370                       const char *module, auth_methods **ret)
 371 {
 372         static bool initialised_static_modules = False;
 373
 374         struct auth_init_function_entry *entry;
 375         char *module_name = smb_xstrdup(module);
 376         char *module_params = NULL;
 377         char *p;
 378         bool good = False;
 379
 380         /* Initialise static modules if not done so yet */
 381         if(!initialised_static_modules) {
 382                 static_init_auth;
 383                 initialised_static_modules = True;
 384         }
 385
 386         DEBUG(5,("load_auth_module: Attempting to find an auth method to match %s\n",
 387                  module));
 388
 389         p = strchr(module_name, ':');
 390         if (p) {
 391                 *p = 0;
 392                 module_params = p+1;
 393                 trim_char(module_params, ' ', ' ');
 394         }
 395
 396         trim_char(module_name, ' ', ' ');
 397
 398         entry = auth_find_backend_entry(module_name);
 399
 400         if (entry == NULL) {
 401                 if (NT_STATUS_IS_OK(smb_probe_module("auth", module_name))) {
 402                         entry = auth_find_backend_entry(module_name);
 403                 }
 404         }
 405
 406         if (entry != NULL) {
 407                 if (!NT_STATUS_IS_OK(entry->init(auth_context, module_params, ret))) {
 408                         DEBUG(0,("load_auth_module: auth method %s did not correctly init\n",
 409                                  module_name));
 410                 } else {
 411                         DEBUG(5,("load_auth_module: auth method %s has a valid init\n",
 412                                  module_name));
 413                         good = True;
 414                 }
 415         } else {
 416                 DEBUG(0,("load_auth_module: can't find auth method %s!\n", module_name));
 417         }
 418
 419         SAFE_FREE(module_name);
 420         return good;
 421 }
 422
 423 /***************************************************************************
 424  Make a auth_info struct for the auth subsystem
 425 ***************************************************************************/
 426
 427 static NTSTATUS make_auth_context_text_list(struct auth_context **auth_context, char **text_list)
 428 {
 429         auth_methods *list = NULL;
 430         auth_methods *t = NULL;
 431         NTSTATUS nt_status;
 432
 433         if (!text_list) {
 434                 DEBUG(2,("make_auth_context_text_list: No auth method list!?\n"));
 435                 return NT_STATUS_UNSUCCESSFUL;
 436         }
 437
 438         if (!NT_STATUS_IS_OK(nt_status = make_auth_context(auth_context)))
 439                 return nt_status;
 440
 441         for (;*text_list; text_list++) {
 442                 if (load_auth_module(*auth_context, *text_list, &t)) {
 443                     DLIST_ADD_END(list, t, auth_methods *);
 444                 }
 445         }
 446
 447         (*auth_context)->auth_method_list = list;
 448
 449         return nt_status;
 450 }
 451
 452 /***************************************************************************
 453  Make a auth_context struct for the auth subsystem
 454 ***************************************************************************/
 455
 456 NTSTATUS make_auth_context_subsystem(struct auth_context **auth_context)
 457 {
 458         char **auth_method_list = NULL;
 459         NTSTATUS nt_status;
 460
 461         if (lp_auth_methods()
 462             && !str_list_copy(talloc_tos(), &auth_method_list,
 463                               lp_auth_methods())) {
 464                 return NT_STATUS_NO_MEMORY;
 465         }
 466
 467         if (auth_method_list == NULL) {
 468                 switch (lp_security())
 469                 {
 470                 case SEC_DOMAIN:
 471                         DEBUG(5,("Making default auth method list for security=domain\n"));
 472                         auth_method_list = str_list_make(
 473                                 talloc_tos(), "guest sam winbind:ntdomain",
 474                                 NULL);
 475                         break;
 476                 case SEC_SERVER:
 477                         DEBUG(5,("Making default auth method list for security=server\n"));
 478                         auth_method_list = str_list_make(
 479                                 talloc_tos(), "guest sam smbserver",
 480                                 NULL);
 481                         break;
 482                 case SEC_USER:
 483                         if (lp_encrypted_passwords()) {
 484                                 if ((lp_server_role() == ROLE_DOMAIN_PDC) || (lp_server_role() == ROLE_DOMAIN_BDC)) {
 485                                         DEBUG(5,("Making default auth method list for DC, security=user, encrypt passwords = yes\n"));
 486                                         auth_method_list = str_list_make(
 487                                                 talloc_tos(),
 488                                                 "guest sam winbind:trustdomain",
 489                                                 NULL);
 490                                 } else {
 491                                         DEBUG(5,("Making default auth method list for standalone security=user, encrypt passwords = yes\n"));
 492                                         auth_method_list = str_list_make(
 493                                                 talloc_tos(), "guest sam",
 494                                                 NULL);
 495                                 }
 496                         } else {
 497                                 DEBUG(5,("Making default auth method list for security=user, encrypt passwords = no\n"));
 498                                 auth_method_list = str_list_make(
 499                                         talloc_tos(), "guest unix", NULL);
 500                         }
 501                         break;
 502                 case SEC_SHARE:
 503                         if (lp_encrypted_passwords()) {
 504                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = yes\n"));
 505                                 auth_method_list = str_list_make(
 506                                         talloc_tos(), "guest sam", NULL);
 507                         } else {
 508                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = no\n"));
 509                                 auth_method_list = str_list_make(
 510                                         talloc_tos(), "guest unix", NULL);
 511                         }
 512                         break;
 513                 case SEC_ADS:
 514                         DEBUG(5,("Making default auth method list for security=ADS\n"));
 515                         auth_method_list = str_list_make(
 516                                 talloc_tos(), "guest sam winbind:ntdomain",
 517                                 NULL);
 518                         break;
 519                 default:
 520                         DEBUG(5,("Unknown auth method!\n"));
 521                         return NT_STATUS_UNSUCCESSFUL;
 522                 }
 523         } else {
 524                 DEBUG(5,("Using specified auth order\n"));
 525         }
 526
 527         nt_status = make_auth_context_text_list(auth_context,
 528                                                 auth_method_list);
 529
 530         TALLOC_FREE(auth_method_list);
 531         return nt_status;
 532 }
 533
 534 /***************************************************************************
 535  Make a auth_info struct with a fixed challenge
 536 ***************************************************************************/
 537
 538 NTSTATUS make_auth_context_fixed(struct auth_context **auth_context, uchar chal[8])
 539 {
 540         NTSTATUS nt_status;
 541         if (!NT_STATUS_IS_OK(nt_status = make_auth_context_subsystem(auth_context))) {
 542                 return nt_status;
 543         }
 544
 545         (*auth_context)->challenge = data_blob_talloc((*auth_context)->mem_ctx, chal, 8);
 546         (*auth_context)->challenge_set_by = "fixed";
 547         return nt_status;
 548 }
 549
 550