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