source/auth/auth.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Password and authentication handling
   4    Copyright (C) Andrew Bartlett         2001-2002
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 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, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 #undef DBGC_CLASS
  24 #define DBGC_CLASS DBGC_AUTH
  25
  26 static struct auth_init_function_entry *backends = NULL;
  27
  28 static struct auth_init_function_entry *auth_find_backend_entry(const char *name);
  29
  30 NTSTATUS smb_register_auth(int version, const char *name, auth_init_function init)
  31 {
  32         struct auth_init_function_entry *entry = backends;
  33
  34         if (version != AUTH_INTERFACE_VERSION) {
  35                 DEBUG(0,("Can't register auth_method!\n"
  36                          "You tried to register an auth module with AUTH_INTERFACE_VERSION %d, while this version of samba uses %d\n",
  37                          version,AUTH_INTERFACE_VERSION));
  38                 return NT_STATUS_OBJECT_TYPE_MISMATCH;
  39         }
  40
  41         if (!name || !init) {
  42                 return NT_STATUS_INVALID_PARAMETER;
  43         }
  44
  45         DEBUG(5,("Attempting to register auth backend %s\n", name));
  46
  47         if (auth_find_backend_entry(name)) {
  48                 DEBUG(0,("There already is an auth method registered with the name %s!\n", name));
  49                 return NT_STATUS_OBJECT_NAME_COLLISION;
  50         }
  51
  52         entry = SMB_XMALLOC_P(struct auth_init_function_entry);
  53         entry->name = smb_xstrdup(name);
  54         entry->init = init;
  55
  56         DLIST_ADD(backends, entry);
  57         DEBUG(5,("Successfully added auth method '%s'\n", name));
  58         return NT_STATUS_OK;
  59 }
  60
  61 static struct auth_init_function_entry *auth_find_backend_entry(const char *name)
  62 {
  63         struct auth_init_function_entry *entry = backends;
  64
  65         while(entry) {
  66                 if (strcmp(entry->name, name)==0) return entry;
  67                 entry = entry->next;
  68         }
  69
  70         return NULL;
  71 }
  72
  73 /****************************************************************************
  74  Try to get a challenge out of the various authentication modules.
  75  Returns a const char of length 8 bytes.
  76 ****************************************************************************/
  77
  78 static const uint8 *get_ntlm_challenge(struct auth_context *auth_context)
  79 {
  80         DATA_BLOB challenge = data_blob(NULL, 0);
  81         const char *challenge_set_by = NULL;
  82         auth_methods *auth_method;
  83         TALLOC_CTX *mem_ctx;
  84
  85         if (auth_context->challenge.length) {
  86                 DEBUG(5, ("get_ntlm_challenge (auth subsystem): returning previous challenge by module %s (normal)\n",
  87                           auth_context->challenge_set_by));
  88                 return auth_context->challenge.data;
  89         }
  90
  91         auth_context->challenge_may_be_modified = False;
  92
  93         for (auth_method = auth_context->auth_method_list; auth_method; auth_method = auth_method->next) {
  94                 if (auth_method->get_chal == NULL) {
  95                         DEBUG(5, ("auth_get_challenge: module %s did not want to specify a challenge\n", auth_method->name));
  96                         continue;
  97                 }
  98
  99                 DEBUG(5, ("auth_get_challenge: getting challenge from module %s\n", auth_method->name));
 100                 if (challenge_set_by != NULL) {
 101                         DEBUG(1, ("auth_get_challenge: CONFIGURATION ERROR: authentication method %s has already specified a challenge.  Challenge by %s ignored.\n",
 102                                   challenge_set_by, auth_method->name));
 103                         continue;
 104                 }
 105
 106                 mem_ctx = talloc_init("auth_get_challenge for module %s", auth_method->name);
 107                 if (!mem_ctx) {
 108                         smb_panic("talloc_init() failed!");
 109                 }
 110
 111                 challenge = auth_method->get_chal(auth_context, &auth_method->private_data, mem_ctx);
 112                 if (!challenge.length) {
 113                         DEBUG(3, ("auth_get_challenge: getting challenge from authentication method %s FAILED.\n",
 114                                   auth_method->name));
 115                 } else {
 116                         DEBUG(5, ("auth_get_challenge: sucessfully got challenge from module %s\n", auth_method->name));
 117                         auth_context->challenge = challenge;
 118                         challenge_set_by = auth_method->name;
 119                         auth_context->challenge_set_method = auth_method;
 120                 }
 121                 talloc_destroy(mem_ctx);
 122         }
 123
 124         if (!challenge_set_by) {
 125                 uchar chal[8];
 126
 127                 generate_random_buffer(chal, sizeof(chal));
 128                 auth_context->challenge = data_blob_talloc(auth_context->mem_ctx,
 129                                                            chal, sizeof(chal));
 130
 131                 challenge_set_by = "random";
 132                 auth_context->challenge_may_be_modified = True;
 133         }
 134
 135         DEBUG(5, ("auth_context challenge created by %s\n", challenge_set_by));
 136         DEBUG(5, ("challenge is: \n"));
 137         dump_data(5, (const char *)auth_context->challenge.data, auth_context->challenge.length);
 138
 139         SMB_ASSERT(auth_context->challenge.length == 8);
 140
 141         auth_context->challenge_set_by=challenge_set_by;
 142
 143         return auth_context->challenge.data;
 144 }
 145
 146
 147 /**
 148  * Check user is in correct domain (if required)
 149  *
 150  * @param user Only used to fill in the debug message
 151  *
 152  * @param domain The domain to be verified
 153  *
 154  * @return True if the user can connect with that domain,
 155  *         False otherwise.
 156 **/
 157
 158 static BOOL check_domain_match(const char *user, const char *domain)
 159 {
 160         /*
 161          * If we aren't serving to trusted domains, we must make sure that
 162          * the validation request comes from an account in the same domain
 163          * as the Samba server
 164          */
 165
 166         if (!lp_allow_trusted_domains() &&
 167             !(strequal("", domain) ||
 168               strequal(lp_workgroup(), domain) ||
 169               is_myname(domain))) {
 170                 DEBUG(1, ("check_domain_match: Attempt to connect as user %s from domain %s denied.\n", user, domain));
 171                 return False;
 172         } else {
 173                 return True;
 174         }
 175 }
 176
 177 /**
 178  * Check a user's Plaintext, LM or NTLM password.
 179  *
 180  * Check a user's password, as given in the user_info struct and return various
 181  * interesting details in the server_info struct.
 182  *
 183  * This function does NOT need to be in a become_root()/unbecome_root() pair
 184  * as it makes the calls itself when needed.
 185  *
 186  * The return value takes precedence over the contents of the server_info
 187  * struct.  When the return is other than NT_STATUS_OK the contents
 188  * of that structure is undefined.
 189  *
 190  * @param user_info Contains the user supplied components, including the passwords.
 191  *                  Must be created with make_user_info() or one of its wrappers.
 192  *
 193  * @param auth_context Supplies the challenges and some other data.
 194  *                  Must be created with make_auth_context(), and the challenges should be
 195  *                  filled in, either at creation or by calling the challenge geneation
 196  *                  function auth_get_challenge().
 197  *
 198  * @param server_info If successful, contains information about the authentication,
 199  *                    including a SAM_ACCOUNT struct describing the user.
 200  *
 201  * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.
 202  *
 203  **/
 204
 205 static NTSTATUS check_ntlm_password(const struct auth_context *auth_context,
 206                                     const struct auth_usersupplied_info *user_info,
 207                                     struct auth_serversupplied_info **server_info)
 208 {
 209         /* if all the modules say 'not for me' this is reasonable */
 210         NTSTATUS nt_status = NT_STATUS_NO_SUCH_USER;
 211         const char *unix_username;
 212         auth_methods *auth_method;
 213         TALLOC_CTX *mem_ctx;
 214
 215         if (!user_info || !auth_context || !server_info)
 216                 return NT_STATUS_LOGON_FAILURE;
 217
 218         DEBUG(3, ("check_ntlm_password:  Checking password for unmapped user [%s]\\[%s]@[%s] with the new password interface\n",
 219                   user_info->client_domain.str, user_info->smb_name.str, user_info->wksta_name.str));
 220
 221         DEBUG(3, ("check_ntlm_password:  mapped user is: [%s]\\[%s]@[%s]\n",
 222                   user_info->domain.str, user_info->internal_username.str, user_info->wksta_name.str));
 223
 224         if (auth_context->challenge.length != 8) {
 225                 DEBUG(0, ("check_ntlm_password:  Invalid challenge stored for this auth context - cannot continue\n"));
 226                 return NT_STATUS_LOGON_FAILURE;
 227         }
 228
 229         if (auth_context->challenge_set_by)
 230                 DEBUG(10, ("check_ntlm_password: auth_context challenge created by %s\n",
 231                                         auth_context->challenge_set_by));
 232
 233         DEBUG(10, ("challenge is: \n"));
 234         dump_data(5, (const char *)auth_context->challenge.data, auth_context->challenge.length);
 235
 236 #ifdef DEBUG_PASSWORD
 237         DEBUG(100, ("user_info has passwords of length %d and %d\n",
 238                     user_info->lm_resp.length, user_info->nt_resp.length));
 239         DEBUG(100, ("lm:\n"));
 240         dump_data(100, user_info->lm_resp.data, user_info->lm_resp.length);
 241         DEBUG(100, ("nt:\n"));
 242         dump_data(100, user_info->nt_resp.data, user_info->nt_resp.length);
 243 #endif
 244
 245         /* This needs to be sorted:  If it doesn't match, what should we do? */
 246         if (!check_domain_match(user_info->smb_name.str, user_info->domain.str))
 247                 return NT_STATUS_LOGON_FAILURE;
 248
 249         for (auth_method = auth_context->auth_method_list;auth_method; auth_method = auth_method->next) {
 250                 NTSTATUS result;
 251
 252                 mem_ctx = talloc_init("%s authentication for user %s\\%s", auth_method->name,
 253                                             user_info->domain.str, user_info->smb_name.str);
 254
 255                 result = auth_method->auth(auth_context, auth_method->private_data, mem_ctx, user_info, server_info);
 256
 257                 /* check if the module did anything */
 258                 if ( NT_STATUS_V(result) == NT_STATUS_V(NT_STATUS_NOT_IMPLEMENTED) ) {
 259                         DEBUG(10,("check_ntlm_password: %s had nothing to say\n", auth_method->name));
 260                         talloc_destroy(mem_ctx);
 261                         continue;
 262                 }
 263
 264                 nt_status = result;
 265
 266                 if (NT_STATUS_IS_OK(nt_status)) {
 267                         DEBUG(3, ("check_ntlm_password: %s authentication for user [%s] succeeded\n",
 268                                   auth_method->name, user_info->smb_name.str));
 269                 } else {
 270                         DEBUG(5, ("check_ntlm_password: %s authentication for user [%s] FAILED with error %s\n",
 271                                   auth_method->name, user_info->smb_name.str, nt_errstr(nt_status)));
 272                 }
 273
 274                 talloc_destroy(mem_ctx);
 275
 276                 if ( NT_STATUS_IS_OK(nt_status))
 277                 {
 278                                 break;
 279                 }
 280         }
 281
 282         /* successful authentication */
 283
 284         if (NT_STATUS_IS_OK(nt_status)) {
 285                 unix_username = (*server_info)->unix_name;
 286                 if (!(*server_info)->guest) {
 287                         /* We might not be root if we are an RPC call */
 288                         become_root();
 289                         nt_status = smb_pam_accountcheck(unix_username);
 290                         unbecome_root();
 291
 292                         if (NT_STATUS_IS_OK(nt_status)) {
 293                                 DEBUG(5, ("check_ntlm_password:  PAM Account for user [%s] succeeded\n",
 294                                           unix_username));
 295                         } else {
 296                                 DEBUG(3, ("check_ntlm_password:  PAM Account for user [%s] FAILED with error %s\n",
 297                                           unix_username, nt_errstr(nt_status)));
 298                         }
 299                 }
 300
 301                 if (NT_STATUS_IS_OK(nt_status)) {
 302                         DEBUG((*server_info)->guest ? 5 : 2,
 303                               ("check_ntlm_password:  %sauthentication for user [%s] -> [%s] -> [%s] succeeded\n",
 304                                (*server_info)->guest ? "guest " : "",
 305                                user_info->smb_name.str,
 306                                user_info->internal_username.str,
 307                                unix_username));
 308                 }
 309
 310                 return nt_status;
 311         }
 312
 313         /* failed authentication; check for guest lapping */
 314
 315         DEBUG(2, ("check_ntlm_password:  Authentication for user [%s] -> [%s] FAILED with error %s\n",
 316         user_info->smb_name.str, user_info->internal_username.str,
 317         nt_errstr(nt_status)));
 318         ZERO_STRUCTP(server_info);
 319
 320         return nt_status;
 321 }
 322
 323 /***************************************************************************
 324  Clear out a auth_context, and destroy the attached TALLOC_CTX
 325 ***************************************************************************/
 326
 327 static void free_auth_context(struct auth_context **auth_context)
 328 {
 329         auth_methods *auth_method;
 330
 331         if (*auth_context) {
 332                 /* Free private data of context's authentication methods */
 333                 for (auth_method = (*auth_context)->auth_method_list; auth_method; auth_method = auth_method->next) {
 334                         if (auth_method->free_private_data) {
 335                                 auth_method->free_private_data (&auth_method->private_data);
 336                                 auth_method->private_data = NULL;
 337                         }
 338                 }
 339
 340                 talloc_destroy((*auth_context)->mem_ctx);
 341                 *auth_context = NULL;
 342         }
 343 }
 344
 345 /***************************************************************************
 346  Make a auth_info struct
 347 ***************************************************************************/
 348
 349 static NTSTATUS make_auth_context(struct auth_context **auth_context)
 350 {
 351         TALLOC_CTX *mem_ctx;
 352
 353         mem_ctx = talloc_init("authentication context");
 354
 355         *auth_context = TALLOC_P(mem_ctx, struct auth_context);
 356         if (!*auth_context) {
 357                 DEBUG(0,("make_auth_context: talloc failed!\n"));
 358                 talloc_destroy(mem_ctx);
 359                 return NT_STATUS_NO_MEMORY;
 360         }
 361         ZERO_STRUCTP(*auth_context);
 362
 363         (*auth_context)->mem_ctx = mem_ctx;
 364         (*auth_context)->check_ntlm_password = check_ntlm_password;
 365         (*auth_context)->get_ntlm_challenge = get_ntlm_challenge;
 366         (*auth_context)->free = free_auth_context;
 367
 368         return NT_STATUS_OK;
 369 }
 370
 371 BOOL load_auth_module(struct auth_context *auth_context,
 372                       const char *module, auth_methods **ret)
 373 {
 374         static BOOL initialised_static_modules = False;
 375
 376         struct auth_init_function_entry *entry;
 377         char *module_name = smb_xstrdup(module);
 378         char *module_params = NULL;
 379         char *p;
 380         BOOL good = False;
 381
 382         /* Initialise static modules if not done so yet */
 383         if(!initialised_static_modules) {
 384                 static_init_auth;
 385                 initialised_static_modules = True;
 386         }
 387
 388         DEBUG(5,("load_auth_module: Attempting to find an auth method to match %s\n",
 389                  module));
 390
 391         p = strchr(module_name, ':');
 392         if (p) {
 393                 *p = 0;
 394                 module_params = p+1;
 395                 trim_char(module_params, ' ', ' ');
 396         }
 397
 398         trim_char(module_name, ' ', ' ');
 399
 400         entry = auth_find_backend_entry(module_name);
 401
 402         if (entry == NULL) {
 403                 if (NT_STATUS_IS_OK(smb_probe_module("auth", module_name))) {
 404                         entry = auth_find_backend_entry(module_name);
 405                 }
 406         }
 407
 408         if (entry != NULL) {
 409                 if (!NT_STATUS_IS_OK(entry->init(auth_context, module_params, ret))) {
 410                         DEBUG(0,("load_auth_module: auth method %s did not correctly init\n",
 411                                  module_name));
 412                 } else {
 413                         DEBUG(5,("load_auth_module: auth method %s has a valid init\n",
 414                                  module_name));
 415                         good = True;
 416                 }
 417         } else {
 418                 DEBUG(0,("load_auth_module: can't find auth method %s!\n", module_name));
 419         }
 420
 421         SAFE_FREE(module_name);
 422         return good;
 423 }
 424
 425 /***************************************************************************
 426  Make a auth_info struct for the auth subsystem
 427 ***************************************************************************/
 428
 429 static NTSTATUS make_auth_context_text_list(struct auth_context **auth_context, char **text_list)
 430 {
 431         auth_methods *list = NULL;
 432         auth_methods *t = NULL;
 433         auth_methods *tmp;
 434         NTSTATUS nt_status;
 435
 436         if (!text_list) {
 437                 DEBUG(2,("make_auth_context_text_list: No auth method list!?\n"));
 438                 return NT_STATUS_UNSUCCESSFUL;
 439         }
 440
 441         if (!NT_STATUS_IS_OK(nt_status = make_auth_context(auth_context)))
 442                 return nt_status;
 443
 444         for (;*text_list; text_list++) {
 445                 if (load_auth_module(*auth_context, *text_list, &t)) {
 446                     DLIST_ADD_END(list, t, tmp);
 447                 }
 448         }
 449
 450         (*auth_context)->auth_method_list = list;
 451
 452         return nt_status;
 453 }
 454
 455 /***************************************************************************
 456  Make a auth_context struct for the auth subsystem
 457 ***************************************************************************/
 458
 459 NTSTATUS make_auth_context_subsystem(struct auth_context **auth_context)
 460 {
 461         char **auth_method_list = NULL;
 462         NTSTATUS nt_status;
 463
 464         if (lp_auth_methods() && !str_list_copy(&auth_method_list, lp_auth_methods())) {
 465                 return NT_STATUS_NO_MEMORY;
 466         }
 467
 468         if (auth_method_list == NULL) {
 469                 switch (lp_security())
 470                 {
 471                 case SEC_DOMAIN:
 472                         DEBUG(5,("Making default auth method list for security=domain\n"));
 473                         auth_method_list = str_list_make("guest sam winbind:ntdomain", NULL);
 474                         break;
 475                 case SEC_SERVER:
 476                         DEBUG(5,("Making default auth method list for security=server\n"));
 477                         auth_method_list = str_list_make("guest sam smbserver", NULL);
 478                         break;
 479                 case SEC_USER:
 480                         if (lp_encrypted_passwords()) {
 481                                 if ((lp_server_role() == ROLE_DOMAIN_PDC) || (lp_server_role() == ROLE_DOMAIN_BDC)) {
 482                                         DEBUG(5,("Making default auth method list for DC, security=user, encrypt passwords = yes\n"));
 483                                         auth_method_list = str_list_make("guest sam winbind:trustdomain", NULL);
 484                                 } else {
 485                                         DEBUG(5,("Making default auth method list for standalone security=user, encrypt passwords = yes\n"));
 486                                         auth_method_list = str_list_make("guest sam", NULL);
 487                                 }
 488                         } else {
 489                                 DEBUG(5,("Making default auth method list for security=user, encrypt passwords = no\n"));
 490                                 auth_method_list = str_list_make("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("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("guest unix", NULL);
 500                         }
 501                         break;
 502                 case SEC_ADS:
 503                         DEBUG(5,("Making default auth method list for security=ADS\n"));
 504                         auth_method_list = str_list_make("guest sam winbind:ntdomain", NULL);
 505                         break;
 506                 default:
 507                         DEBUG(5,("Unknown auth method!\n"));
 508                         return NT_STATUS_UNSUCCESSFUL;
 509                 }
 510         } else {
 511                 DEBUG(5,("Using specified auth order\n"));
 512         }
 513
 514         if (!NT_STATUS_IS_OK(nt_status = make_auth_context_text_list(auth_context, auth_method_list))) {
 515                 str_list_free(&auth_method_list);
 516                 return nt_status;
 517         }
 518
 519         str_list_free(&auth_method_list);
 520         return nt_status;
 521 }
 522
 523 /***************************************************************************
 524  Make a auth_info struct with a fixed challenge
 525 ***************************************************************************/
 526
 527 NTSTATUS make_auth_context_fixed(struct auth_context **auth_context, uchar chal[8])
 528 {
 529         NTSTATUS nt_status;
 530         if (!NT_STATUS_IS_OK(nt_status = make_auth_context_subsystem(auth_context))) {
 531                 return nt_status;
 532         }
 533
 534         (*auth_context)->challenge = data_blob_talloc((*auth_context)->mem_ctx, chal, 8);
 535         (*auth_context)->challenge_set_by = "fixed";
 536         return nt_status;
 537 }
 538
 539