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