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                 if (user_info->flags & USER_INFO_LOCAL_SAM_ONLY
 214                     && !(auth_method->flags & AUTH_METHOD_LOCAL_SAM)) {
 215                         continue;
 216                 }
 217
 218                 tmp_ctx = talloc_named(mem_ctx,
 219                                        0,
 220                                        "%s authentication for user %s\\%s",
 221                                        auth_method->name,
 222                                        user_info->mapped.domain_name,
 223                                        user_info->client.account_name);
 224
 225                 result = auth_method->auth(auth_context,
 226                                            auth_method->private_data,
 227                                            tmp_ctx,
 228                                            user_info,
 229                                            &server_info);
 230
 231                 /* check if the module did anything */
 232                 if ( NT_STATUS_V(result) == NT_STATUS_V(NT_STATUS_NOT_IMPLEMENTED) ) {
 233                         DEBUG(10,("check_ntlm_password: %s had nothing to say\n", auth_method->name));
 234                         TALLOC_FREE(tmp_ctx);
 235                         if (user_info->flags & USER_INFO_LOCAL_SAM_ONLY) {
 236                                 /* we don't expose the NT_STATUS_NOT_IMPLEMENTED
 237                                  * internals, except when the caller is only probing
 238                                  * one method, as they may do the fallback
 239                                  */
 240                                 nt_status = result;
 241                         }
 242                         continue;
 243                 }
 244
 245                 nt_status = result;
 246
 247                 if (NT_STATUS_IS_OK(nt_status)) {
 248                         DEBUG(3, ("check_ntlm_password: %s authentication for user [%s] succeeded\n",
 249                                   auth_method->name, user_info->client.account_name));
 250                 } else {
 251                         DEBUG(5, ("check_ntlm_password: %s authentication for user [%s] FAILED with error %s\n",
 252                                   auth_method->name, user_info->client.account_name, nt_errstr(nt_status)));
 253                 }
 254
 255                 if (NT_STATUS_IS_OK(nt_status)) {
 256                         *pserver_info = talloc_steal(mem_ctx, server_info);
 257                         TALLOC_FREE(tmp_ctx);
 258                         break;
 259                 }
 260
 261                 TALLOC_FREE(tmp_ctx);
 262         }
 263
 264         /* successful authentication */
 265
 266         if (NT_STATUS_IS_OK(nt_status)) {
 267                 unix_username = (*pserver_info)->unix_name;
 268
 269                 /* We skip doing this step if the caller asked us not to */
 270                 if (!(user_info->flags & USER_INFO_INFO3_AND_NO_AUTHZ)
 271                     && !(*pserver_info)->guest) {
 272                         const char *rhost;
 273
 274                         if (tsocket_address_is_inet(user_info->remote_host, "ip")) {
 275                                 rhost = tsocket_address_inet_addr_string(user_info->remote_host,
 276                                                                          talloc_tos());
 277                                 if (rhost == NULL) {
 278                                         return NT_STATUS_NO_MEMORY;
 279                                 }
 280                         } else {
 281                                 rhost = "127.0.0.1";
 282                         }
 283
 284                         /* We might not be root if we are an RPC call */
 285                         become_root();
 286                         nt_status = smb_pam_accountcheck(unix_username,
 287                                                          rhost);
 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((*pserver_info)->guest ? 5 : 2,
 301                               ("check_ntlm_password:  %sauthentication for user [%s] -> [%s] -> [%s] succeeded\n",
 302                                (*pserver_info)->guest ? "guest " : "",
 303                                user_info->client.account_name,
 304                                user_info->mapped.account_name,
 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->client.account_name, user_info->mapped.account_name,
 315                   nt_errstr(nt_status)));
 316         ZERO_STRUCTP(pserver_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 int auth_context_destructor(void *ptr)
 326 {
 327         struct auth_context *ctx = talloc_get_type(ptr, struct auth_context);
 328         struct auth_methods *am;
 329
 330
 331         /* Free private data of context's authentication methods */
 332         for (am = ctx->auth_method_list; am; am = am->next) {
 333                 TALLOC_FREE(am->private_data);
 334         }
 335
 336         return 0;
 337 }
 338
 339 /***************************************************************************
 340  Make a auth_info struct
 341 ***************************************************************************/
 342
 343 static NTSTATUS make_auth_context(TALLOC_CTX *mem_ctx,
 344                                   struct auth_context **auth_context)
 345 {
 346         struct auth_context *ctx;
 347
 348         ctx = talloc_zero(mem_ctx, struct auth_context);
 349         if (!ctx) {
 350                 DEBUG(0,("make_auth_context: talloc failed!\n"));
 351                 return NT_STATUS_NO_MEMORY;
 352         }
 353
 354         talloc_set_destructor((TALLOC_CTX *)ctx, auth_context_destructor);
 355
 356         *auth_context = ctx;
 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(TALLOC_CTX *mem_ctx,
 419                                             struct auth_context **auth_context,
 420                                             char **text_list)
 421 {
 422         auth_methods *list = NULL;
 423         auth_methods *t, *method = NULL;
 424         NTSTATUS nt_status;
 425
 426         if (!text_list) {
 427                 DEBUG(2,("make_auth_context_text_list: No auth method list!?\n"));
 428                 return NT_STATUS_UNSUCCESSFUL;
 429         }
 430
 431         nt_status = make_auth_context(mem_ctx, auth_context);
 432
 433         if (!NT_STATUS_IS_OK(nt_status)) {
 434                 return nt_status;
 435         }
 436
 437         for (;*text_list; text_list++) {
 438                 if (load_auth_module(*auth_context, *text_list, &t)) {
 439                     DLIST_ADD_END(list, t, auth_methods *);
 440                 }
 441         }
 442
 443         (*auth_context)->auth_method_list = list;
 444
 445         /* Look for the first module to provide a prepare_gensec and
 446          * make_auth4_context hook, and set that if provided */
 447         for (method = (*auth_context)->auth_method_list; method; method = method->next) {
 448                 if (method->prepare_gensec && method->make_auth4_context) {
 449                         (*auth_context)->prepare_gensec = method->prepare_gensec;
 450                         (*auth_context)->make_auth4_context = method->make_auth4_context;
 451                         break;
 452                 }
 453         }
 454         return NT_STATUS_OK;
 455 }
 456
 457 /***************************************************************************
 458  Make a auth_context struct for the auth subsystem
 459 ***************************************************************************/
 460
 461 NTSTATUS make_auth_context_subsystem(TALLOC_CTX *mem_ctx,
 462                                      struct auth_context **auth_context)
 463 {
 464         char **auth_method_list = NULL;
 465         NTSTATUS nt_status;
 466
 467         if (lp_auth_methods()
 468             && !(auth_method_list = str_list_copy(talloc_tos(),
 469                               lp_auth_methods()))) {
 470                 return NT_STATUS_NO_MEMORY;
 471         }
 472
 473         if (auth_method_list == NULL) {
 474                 switch (lp_server_role())
 475                 {
 476                 case ROLE_DOMAIN_MEMBER:
 477                         DEBUG(5,("Making default auth method list for server role = 'domain member'\n"));
 478                         auth_method_list = str_list_make_v3(
 479                                 talloc_tos(), "guest sam winbind:ntdomain",
 480                                 NULL);
 481                         break;
 482                 case ROLE_DOMAIN_BDC:
 483                 case ROLE_DOMAIN_PDC:
 484                         DEBUG(5,("Making default auth method list for DC\n"));
 485                         auth_method_list = str_list_make_v3(
 486                                 talloc_tos(),
 487                                 "guest sam winbind:trustdomain",
 488                                 NULL);
 489                         break;
 490                 case ROLE_STANDALONE:
 491                         DEBUG(5,("Making default auth method list for server role = 'standalone server', encrypt passwords = yes\n"));
 492                         if (lp_encrypt_passwords()) {
 493                                 auth_method_list = str_list_make_v3(
 494                                                 talloc_tos(), "guest sam",
 495                                                 NULL);
 496                         } else {
 497                                 DEBUG(5,("Making default auth method list for server role = 'standalone server', encrypt passwords = no\n"));
 498                                 auth_method_list = str_list_make_v3(
 499                                         talloc_tos(), "guest unix", NULL);
 500                         }
 501                         break;
 502                 case ROLE_ACTIVE_DIRECTORY_DC:
 503                         DEBUG(5,("Making default auth method list for server role = 'active directory domain controller'\n"));
 504                         auth_method_list = str_list_make_v3(
 505                                 talloc_tos(),
 506                                 "samba4",
 507                                 NULL);
 508                         break;
 509                 default:
 510                         DEBUG(5,("Unknown auth method!\n"));
 511                         return NT_STATUS_UNSUCCESSFUL;
 512                 }
 513         } else {
 514                 DEBUG(5,("Using specified auth order\n"));
 515         }
 516
 517         nt_status = make_auth_context_text_list(mem_ctx, auth_context,
 518                                                 auth_method_list);
 519
 520         TALLOC_FREE(auth_method_list);
 521         return nt_status;
 522 }
 523
 524 /***************************************************************************
 525  Make a auth_info struct with a fixed challenge
 526 ***************************************************************************/
 527
 528 NTSTATUS make_auth_context_fixed(TALLOC_CTX *mem_ctx,
 529                                  struct auth_context **auth_context,
 530                                  uchar chal[8])
 531 {
 532         NTSTATUS nt_status;
 533         nt_status = make_auth_context_subsystem(mem_ctx, auth_context);
 534         if (!NT_STATUS_IS_OK(nt_status)) {
 535                 return nt_status;
 536         }
 537
 538         (*auth_context)->challenge = data_blob_talloc(*auth_context, chal, 8);
 539         (*auth_context)->challenge_set_by = "fixed";
 540         return nt_status;
 541 }
 542
 543