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 NTSTATUS auth_get_ntlm_challenge(struct auth_context *auth_context,
  82                                  uint8_t chal[8])
  83 {
  84         uchar tmp[8];
  85
  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         generate_random_buffer(tmp, sizeof(tmp));
  95         auth_context->challenge = data_blob_talloc(auth_context,
  96                                                    tmp, sizeof(tmp));
  97
  98         auth_context->challenge_set_by = "random";
  99
 100         memcpy(chal, auth_context->challenge.data, 8);
 101         return NT_STATUS_OK;
 102 }
 103
 104
 105 /**
 106  * Check user is in correct domain (if required)
 107  *
 108  * @param user Only used to fill in the debug message
 109  *
 110  * @param domain The domain to be verified
 111  *
 112  * @return True if the user can connect with that domain,
 113  *         False otherwise.
 114 **/
 115
 116 static bool check_domain_match(const char *user, const char *domain)
 117 {
 118         /*
 119          * If we aren't serving to trusted domains, we must make sure that
 120          * the validation request comes from an account in the same domain
 121          * as the Samba server
 122          */
 123
 124         if (!lp_allow_trusted_domains() &&
 125             !(strequal("", domain) ||
 126               strequal(lp_workgroup(), domain) ||
 127               is_myname(domain))) {
 128                 DEBUG(1, ("check_domain_match: Attempt to connect as user %s from domain %s denied.\n", user, domain));
 129                 return False;
 130         } else {
 131                 return True;
 132         }
 133 }
 134
 135 /**
 136  * Check a user's Plaintext, LM or NTLM password.
 137  *
 138  * Check a user's password, as given in the user_info struct and return various
 139  * interesting details in the server_info struct.
 140  *
 141  * This function does NOT need to be in a become_root()/unbecome_root() pair
 142  * as it makes the calls itself when needed.
 143  *
 144  * The return value takes precedence over the contents of the server_info
 145  * struct.  When the return is other than NT_STATUS_OK the contents
 146  * of that structure is undefined.
 147  *
 148  * @param user_info Contains the user supplied components, including the passwords.
 149  *                  Must be created with make_user_info() or one of its wrappers.
 150  *
 151  * @param auth_context Supplies the challenges and some other data.
 152  *                  Must be created with make_auth_context(), and the challenges should be
 153  *                  filled in, either at creation or by calling the challenge geneation
 154  *                  function auth_get_challenge().
 155  *
 156  * @param server_info If successful, contains information about the authentication,
 157  *                    including a struct samu struct describing the user.
 158  *
 159  * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.
 160  *
 161  **/
 162
 163 NTSTATUS auth_check_ntlm_password(TALLOC_CTX *mem_ctx,
 164                                   const struct auth_context *auth_context,
 165                                   const struct auth_usersupplied_info *user_info,
 166                                   struct auth_serversupplied_info **pserver_info)
 167 {
 168         /* if all the modules say 'not for me' this is reasonable */
 169         NTSTATUS nt_status = NT_STATUS_NO_SUCH_USER;
 170         const char *unix_username;
 171         auth_methods *auth_method;
 172
 173         if (user_info == NULL || auth_context == NULL || pserver_info == NULL) {
 174                 return NT_STATUS_LOGON_FAILURE;
 175         }
 176
 177         DEBUG(3, ("check_ntlm_password:  Checking password for unmapped user [%s]\\[%s]@[%s] with the new password interface\n",
 178                   user_info->client.domain_name, user_info->client.account_name, user_info->workstation_name));
 179
 180         DEBUG(3, ("check_ntlm_password:  mapped user is: [%s]\\[%s]@[%s]\n",
 181                   user_info->mapped.domain_name, user_info->mapped.account_name, user_info->workstation_name));
 182
 183         if (auth_context->challenge.length != 8) {
 184                 DEBUG(0, ("check_ntlm_password:  Invalid challenge stored for this auth context - cannot continue\n"));
 185                 return NT_STATUS_LOGON_FAILURE;
 186         }
 187
 188         if (auth_context->challenge_set_by)
 189                 DEBUG(10, ("check_ntlm_password: auth_context challenge created by %s\n",
 190                                         auth_context->challenge_set_by));
 191
 192         DEBUG(10, ("challenge is: \n"));
 193         dump_data(5, auth_context->challenge.data, auth_context->challenge.length);
 194
 195 #ifdef DEBUG_PASSWORD
 196         DEBUG(100, ("user_info has passwords of length %d and %d\n",
 197                     (int)user_info->password.response.lanman.length, (int)user_info->password.response.nt.length));
 198         DEBUG(100, ("lm:\n"));
 199         dump_data(100, user_info->password.response.lanman.data, user_info->password.response.lanman.length);
 200         DEBUG(100, ("nt:\n"));
 201         dump_data(100, user_info->password.response.nt.data, user_info->password.response.nt.length);
 202 #endif
 203
 204         /* This needs to be sorted:  If it doesn't match, what should we do? */
 205         if (!check_domain_match(user_info->client.account_name, user_info->mapped.domain_name))
 206                 return NT_STATUS_LOGON_FAILURE;
 207
 208         for (auth_method = auth_context->auth_method_list;auth_method; auth_method = auth_method->next) {
 209                 struct auth_serversupplied_info *server_info;
 210                 TALLOC_CTX *tmp_ctx;
 211                 NTSTATUS result;
 212
 213                 tmp_ctx = talloc_named(mem_ctx,
 214                                        0,
 215                                        "%s authentication for user %s\\%s",
 216                                        auth_method->name,
 217                                        user_info->mapped.domain_name,
 218                                        user_info->client.account_name);
 219
 220                 result = auth_method->auth(auth_context,
 221                                            auth_method->private_data,
 222                                            tmp_ctx,
 223                                            user_info,
 224                                            &server_info);
 225
 226                 /* check if the module did anything */
 227                 if ( NT_STATUS_V(result) == NT_STATUS_V(NT_STATUS_NOT_IMPLEMENTED) ) {
 228                         DEBUG(10,("check_ntlm_password: %s had nothing to say\n", auth_method->name));
 229                         TALLOC_FREE(tmp_ctx);
 230                         continue;
 231                 }
 232
 233                 nt_status = result;
 234
 235                 if (NT_STATUS_IS_OK(nt_status)) {
 236                         DEBUG(3, ("check_ntlm_password: %s authentication for user [%s] succeeded\n",
 237                                   auth_method->name, user_info->client.account_name));
 238                 } else {
 239                         DEBUG(5, ("check_ntlm_password: %s authentication for user [%s] FAILED with error %s\n",
 240                                   auth_method->name, user_info->client.account_name, nt_errstr(nt_status)));
 241                 }
 242
 243                 if (NT_STATUS_IS_OK(nt_status)) {
 244                         *pserver_info = talloc_steal(mem_ctx, server_info);
 245                         TALLOC_FREE(tmp_ctx);
 246                         break;
 247                 }
 248
 249                 TALLOC_FREE(tmp_ctx);
 250         }
 251
 252         /* successful authentication */
 253
 254         if (NT_STATUS_IS_OK(nt_status)) {
 255                 unix_username = (*pserver_info)->unix_name;
 256                 if (!(*pserver_info)->guest) {
 257                         const char *rhost;
 258
 259                         if (tsocket_address_is_inet(user_info->remote_host, "ip")) {
 260                                 rhost = tsocket_address_inet_addr_string(user_info->remote_host,
 261                                                                          talloc_tos());
 262                                 if (rhost == NULL) {
 263                                         return NT_STATUS_NO_MEMORY;
 264                                 }
 265                         } else {
 266                                 rhost = "127.0.0.1";
 267                         }
 268
 269                         /* We might not be root if we are an RPC call */
 270                         become_root();
 271                         nt_status = smb_pam_accountcheck(unix_username,
 272                                                          rhost);
 273                         unbecome_root();
 274
 275                         if (NT_STATUS_IS_OK(nt_status)) {
 276                                 DEBUG(5, ("check_ntlm_password:  PAM Account for user [%s] succeeded\n",
 277                                           unix_username));
 278                         } else {
 279                                 DEBUG(3, ("check_ntlm_password:  PAM Account for user [%s] FAILED with error %s\n",
 280                                           unix_username, nt_errstr(nt_status)));
 281                         }
 282                 }
 283
 284                 if (NT_STATUS_IS_OK(nt_status)) {
 285                         DEBUG((*pserver_info)->guest ? 5 : 2,
 286                               ("check_ntlm_password:  %sauthentication for user [%s] -> [%s] -> [%s] succeeded\n",
 287                                (*pserver_info)->guest ? "guest " : "",
 288                                user_info->client.account_name,
 289                                user_info->mapped.account_name,
 290                                unix_username));
 291                 }
 292
 293                 return nt_status;
 294         }
 295
 296         /* failed authentication; check for guest lapping */
 297
 298         DEBUG(2, ("check_ntlm_password:  Authentication for user [%s] -> [%s] FAILED with error %s\n",
 299                   user_info->client.account_name, user_info->mapped.account_name,
 300                   nt_errstr(nt_status)));
 301         ZERO_STRUCTP(pserver_info);
 302
 303         return nt_status;
 304 }
 305
 306 /***************************************************************************
 307  Clear out a auth_context, and destroy the attached TALLOC_CTX
 308 ***************************************************************************/
 309
 310 static int auth_context_destructor(void *ptr)
 311 {
 312         struct auth_context *ctx = talloc_get_type(ptr, struct auth_context);
 313         struct auth_methods *am;
 314
 315
 316         /* Free private data of context's authentication methods */
 317         for (am = ctx->auth_method_list; am; am = am->next) {
 318                 TALLOC_FREE(am->private_data);
 319         }
 320
 321         return 0;
 322 }
 323
 324 /***************************************************************************
 325  Make a auth_info struct
 326 ***************************************************************************/
 327
 328 static NTSTATUS make_auth_context(TALLOC_CTX *mem_ctx,
 329                                   struct auth_context **auth_context)
 330 {
 331         struct auth_context *ctx;
 332
 333         ctx = talloc_zero(mem_ctx, struct auth_context);
 334         if (!ctx) {
 335                 DEBUG(0,("make_auth_context: talloc failed!\n"));
 336                 return NT_STATUS_NO_MEMORY;
 337         }
 338
 339         talloc_set_destructor((TALLOC_CTX *)ctx, auth_context_destructor);
 340
 341         *auth_context = ctx;
 342         return NT_STATUS_OK;
 343 }
 344
 345 bool load_auth_module(struct auth_context *auth_context,
 346                       const char *module, auth_methods **ret)
 347 {
 348         static bool initialised_static_modules = False;
 349
 350         struct auth_init_function_entry *entry;
 351         char *module_name = smb_xstrdup(module);
 352         char *module_params = NULL;
 353         char *p;
 354         bool good = False;
 355
 356         /* Initialise static modules if not done so yet */
 357         if(!initialised_static_modules) {
 358                 static_init_auth;
 359                 initialised_static_modules = True;
 360         }
 361
 362         DEBUG(5,("load_auth_module: Attempting to find an auth method to match %s\n",
 363                  module));
 364
 365         p = strchr(module_name, ':');
 366         if (p) {
 367                 *p = 0;
 368                 module_params = p+1;
 369                 trim_char(module_params, ' ', ' ');
 370         }
 371
 372         trim_char(module_name, ' ', ' ');
 373
 374         entry = auth_find_backend_entry(module_name);
 375
 376         if (entry == NULL) {
 377                 if (NT_STATUS_IS_OK(smb_probe_module("auth", module_name))) {
 378                         entry = auth_find_backend_entry(module_name);
 379                 }
 380         }
 381
 382         if (entry != NULL) {
 383                 if (!NT_STATUS_IS_OK(entry->init(auth_context, module_params, ret))) {
 384                         DEBUG(0,("load_auth_module: auth method %s did not correctly init\n",
 385                                  module_name));
 386                 } else {
 387                         DEBUG(5,("load_auth_module: auth method %s has a valid init\n",
 388                                  module_name));
 389                         good = True;
 390                 }
 391         } else {
 392                 DEBUG(0,("load_auth_module: can't find auth method %s!\n", module_name));
 393         }
 394
 395         SAFE_FREE(module_name);
 396         return good;
 397 }
 398
 399 /***************************************************************************
 400  Make a auth_info struct for the auth subsystem
 401 ***************************************************************************/
 402
 403 static NTSTATUS make_auth_context_text_list(TALLOC_CTX *mem_ctx,
 404                                             struct auth_context **auth_context,
 405                                             char **text_list)
 406 {
 407         auth_methods *list = NULL;
 408         auth_methods *t, *method = NULL;
 409         NTSTATUS nt_status;
 410
 411         if (!text_list) {
 412                 DEBUG(2,("make_auth_context_text_list: No auth method list!?\n"));
 413                 return NT_STATUS_UNSUCCESSFUL;
 414         }
 415
 416         nt_status = make_auth_context(mem_ctx, auth_context);
 417
 418         if (!NT_STATUS_IS_OK(nt_status)) {
 419                 return nt_status;
 420         }
 421
 422         for (;*text_list; text_list++) {
 423                 if (load_auth_module(*auth_context, *text_list, &t)) {
 424                     DLIST_ADD_END(list, t, auth_methods *);
 425                 }
 426         }
 427
 428         (*auth_context)->auth_method_list = list;
 429
 430         /* Look for the first module to provide a prepare_gensec and
 431          * make_auth4_context hook, and set that if provided */
 432         for (method = (*auth_context)->auth_method_list; method; method = method->next) {
 433                 if (method->prepare_gensec && method->make_auth4_context) {
 434                         (*auth_context)->prepare_gensec = method->prepare_gensec;
 435                         (*auth_context)->make_auth4_context = method->make_auth4_context;
 436                         break;
 437                 }
 438         }
 439         return NT_STATUS_OK;
 440 }
 441
 442 /***************************************************************************
 443  Make a auth_context struct for the auth subsystem
 444 ***************************************************************************/
 445
 446 NTSTATUS make_auth_context_subsystem(TALLOC_CTX *mem_ctx,
 447                                      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_server_role())
 460                 {
 461                 case ROLE_DOMAIN_MEMBER:
 462                         DEBUG(5,("Making default auth method list for server role = 'domain member'\n"));
 463                         auth_method_list = str_list_make_v3(
 464                                 talloc_tos(), "guest sam winbind:ntdomain",
 465                                 NULL);
 466                         break;
 467                 case ROLE_DOMAIN_BDC:
 468                 case ROLE_DOMAIN_PDC:
 469                         DEBUG(5,("Making default auth method list for DC\n"));
 470                         auth_method_list = str_list_make_v3(
 471                                 talloc_tos(),
 472                                 "guest sam winbind:trustdomain",
 473                                 NULL);
 474                         break;
 475                 case ROLE_STANDALONE:
 476                         DEBUG(5,("Making default auth method list for server role = 'standalone server', encrypt passwords = yes\n"));
 477                         if (lp_encrypt_passwords()) {
 478                                 auth_method_list = str_list_make_v3(
 479                                                 talloc_tos(), "guest sam",
 480                                                 NULL);
 481                         } else {
 482                                 DEBUG(5,("Making default auth method list for server role = 'standalone server', encrypt passwords = no\n"));
 483                                 auth_method_list = str_list_make_v3(
 484                                         talloc_tos(), "guest unix", NULL);
 485                         }
 486                         break;
 487                 case ROLE_ACTIVE_DIRECTORY_DC:
 488                         DEBUG(5,("Making default auth method list for server role = 'active directory domain controller'\n"));
 489                         auth_method_list = str_list_make_v3(
 490                                 talloc_tos(),
 491                                 "samba4",
 492                                 NULL);
 493                         break;
 494                 default:
 495                         DEBUG(5,("Unknown auth method!\n"));
 496                         return NT_STATUS_UNSUCCESSFUL;
 497                 }
 498         } else {
 499                 DEBUG(5,("Using specified auth order\n"));
 500         }
 501
 502         nt_status = make_auth_context_text_list(mem_ctx, auth_context,
 503                                                 auth_method_list);
 504
 505         TALLOC_FREE(auth_method_list);
 506         return nt_status;
 507 }
 508
 509 /***************************************************************************
 510  Make a auth_info struct with a fixed challenge
 511 ***************************************************************************/
 512
 513 NTSTATUS make_auth_context_fixed(TALLOC_CTX *mem_ctx,
 514                                  struct auth_context **auth_context,
 515                                  uchar chal[8])
 516 {
 517         NTSTATUS nt_status;
 518         nt_status = make_auth_context_subsystem(mem_ctx, auth_context);
 519         if (!NT_STATUS_IS_OK(nt_status)) {
 520                 return nt_status;
 521         }
 522
 523         (*auth_context)->challenge = data_blob_talloc(*auth_context, chal, 8);
 524         (*auth_context)->challenge_set_by = "fixed";
 525         return nt_status;
 526 }
 527
 528