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_decl_auth;
  27
  28 static struct auth_init_function_entry *backends = NULL;
  29
  30 static struct auth_init_function_entry *auth_find_backend_entry(const char *name);
  31
  32 NTSTATUS smb_register_auth(int version, const char *name, auth_init_function init)
  33 {
  34         struct auth_init_function_entry *entry = backends;
  35
  36         if (version != AUTH_INTERFACE_VERSION) {
  37                 DEBUG(0,("Can't register auth_method!\n"
  38                          "You tried to register an auth module with AUTH_INTERFACE_VERSION %d, while this version of samba uses %d\n",
  39                          version,AUTH_INTERFACE_VERSION));
  40                 return NT_STATUS_OBJECT_TYPE_MISMATCH;
  41         }
  42
  43         if (!name || !init) {
  44                 return NT_STATUS_INVALID_PARAMETER;
  45         }
  46
  47         DEBUG(5,("Attempting to register auth backend %s\n", name));
  48
  49         if (auth_find_backend_entry(name)) {
  50                 DEBUG(0,("There already is an auth method registered with the name %s!\n", name));
  51                 return NT_STATUS_OBJECT_NAME_COLLISION;
  52         }
  53
  54         entry = SMB_XMALLOC_P(struct auth_init_function_entry);
  55         entry->name = smb_xstrdup(name);
  56         entry->init = init;
  57
  58         DLIST_ADD(backends, entry);
  59         DEBUG(5,("Successfully added auth method '%s'\n", name));
  60         return NT_STATUS_OK;
  61 }
  62
  63 static struct auth_init_function_entry *auth_find_backend_entry(const char *name)
  64 {
  65         struct auth_init_function_entry *entry = backends;
  66
  67         while(entry) {
  68                 if (strcmp(entry->name, name)==0) return entry;
  69                 entry = entry->next;
  70         }
  71
  72         return NULL;
  73 }
  74
  75 /****************************************************************************
  76  Try to get a challenge out of the various authentication modules.
  77  Returns a const char of length 8 bytes.
  78 ****************************************************************************/
  79
  80 static const uint8 *get_ntlm_challenge(struct auth_context *auth_context)
  81 {
  82         DATA_BLOB challenge = data_blob(NULL, 0);
  83         const char *challenge_set_by = NULL;
  84         auth_methods *auth_method;
  85         TALLOC_CTX *mem_ctx;
  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                 return auth_context->challenge.data;
  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                 mem_ctx = talloc_init("auth_get_challenge for module %s", auth_method->name);
 109                 if (!mem_ctx) {
 110                         smb_panic("talloc_init() failed!");
 111                 }
 112
 113                 challenge = auth_method->get_chal(auth_context, &auth_method->private_data, mem_ctx);
 114                 if (!challenge.length) {
 115                         DEBUG(3, ("auth_get_challenge: getting challenge from authentication method %s FAILED.\n",
 116                                   auth_method->name));
 117                 } else {
 118                         DEBUG(5, ("auth_get_challenge: sucessfully got challenge from module %s\n", auth_method->name));
 119                         auth_context->challenge = challenge;
 120                         challenge_set_by = auth_method->name;
 121                         auth_context->challenge_set_method = auth_method;
 122                 }
 123                 talloc_destroy(mem_ctx);
 124         }
 125
 126         if (!challenge_set_by) {
 127                 uchar chal[8];
 128
 129                 generate_random_buffer(chal, sizeof(chal));
 130                 auth_context->challenge = data_blob_talloc(auth_context->mem_ctx,
 131                                                            chal, sizeof(chal));
 132
 133                 challenge_set_by = "random";
 134                 auth_context->challenge_may_be_modified = True;
 135         }
 136
 137         DEBUG(5, ("auth_context challenge created by %s\n", challenge_set_by));
 138         DEBUG(5, ("challenge is: \n"));
 139         dump_data(5, (const char *)auth_context->challenge.data, auth_context->challenge.length);
 140
 141         SMB_ASSERT(auth_context->challenge.length == 8);
 142
 143         auth_context->challenge_set_by=challenge_set_by;
 144
 145         return auth_context->challenge.data;
 146 }
 147
 148
 149 /**
 150  * Check user is in correct domain (if required)
 151  *
 152  * @param user Only used to fill in the debug message
 153  *
 154  * @param domain The domain to be verified
 155  *
 156  * @return True if the user can connect with that domain,
 157  *         False otherwise.
 158 **/
 159
 160 static BOOL check_domain_match(const char *user, const char *domain)
 161 {
 162         /*
 163          * If we aren't serving to trusted domains, we must make sure that
 164          * the validation request comes from an account in the same domain
 165          * as the Samba server
 166          */
 167
 168         if (!lp_allow_trusted_domains() &&
 169             !(strequal("", domain) ||
 170               strequal(lp_workgroup(), domain) ||
 171               is_myname(domain))) {
 172                 DEBUG(1, ("check_domain_match: Attempt to connect as user %s from domain %s denied.\n", user, domain));
 173                 return False;
 174         } else {
 175                 return True;
 176         }
 177 }
 178
 179 /**
 180  * Check a user's Plaintext, LM or NTLM password.
 181  *
 182  * Check a user's password, as given in the user_info struct and return various
 183  * interesting details in the server_info struct.
 184  *
 185  * This function does NOT need to be in a become_root()/unbecome_root() pair
 186  * as it makes the calls itself when needed.
 187  *
 188  * The return value takes precedence over the contents of the server_info
 189  * struct.  When the return is other than NT_STATUS_OK the contents
 190  * of that structure is undefined.
 191  *
 192  * @param user_info Contains the user supplied components, including the passwords.
 193  *                  Must be created with make_user_info() or one of its wrappers.
 194  *
 195  * @param auth_context Supplies the challenges and some other data.
 196  *                  Must be created with make_auth_context(), and the challenges should be
 197  *                  filled in, either at creation or by calling the challenge geneation
 198  *                  function auth_get_challenge().
 199  *
 200  * @param server_info If successful, contains information about the authentication,
 201  *                    including a struct samu struct describing the user.
 202  *
 203  * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.
 204  *
 205  **/
 206
 207 static NTSTATUS check_ntlm_password(const struct auth_context *auth_context,
 208                                     const struct auth_usersupplied_info *user_info,
 209                                     struct auth_serversupplied_info **server_info)
 210 {
 211         /* if all the modules say 'not for me' this is reasonable */
 212         NTSTATUS nt_status = NT_STATUS_NO_SUCH_USER;
 213         const char *unix_username;
 214         auth_methods *auth_method;
 215         TALLOC_CTX *mem_ctx;
 216
 217         if (!user_info || !auth_context || !server_info)
 218                 return NT_STATUS_LOGON_FAILURE;
 219
 220         DEBUG(3, ("check_ntlm_password:  Checking password for unmapped user [%s]\\[%s]@[%s] with the new password interface\n",
 221                   user_info->client_domain, user_info->smb_name, user_info->wksta_name));
 222
 223         DEBUG(3, ("check_ntlm_password:  mapped user is: [%s]\\[%s]@[%s]\n",
 224                   user_info->domain, user_info->internal_username, user_info->wksta_name));
 225
 226         if (auth_context->challenge.length != 8) {
 227                 DEBUG(0, ("check_ntlm_password:  Invalid challenge stored for this auth context - cannot continue\n"));
 228                 return NT_STATUS_LOGON_FAILURE;
 229         }
 230
 231         if (auth_context->challenge_set_by)
 232                 DEBUG(10, ("check_ntlm_password: auth_context challenge created by %s\n",
 233                                         auth_context->challenge_set_by));
 234
 235         DEBUG(10, ("challenge is: \n"));
 236         dump_data(5, (const char *)auth_context->challenge.data, auth_context->challenge.length);
 237
 238 #ifdef DEBUG_PASSWORD
 239         DEBUG(100, ("user_info has passwords of length %d and %d\n",
 240                     (int)user_info->lm_resp.length, (int)user_info->nt_resp.length));
 241         DEBUG(100, ("lm:\n"));
 242         dump_data(100, (const char *)user_info->lm_resp.data, user_info->lm_resp.length);
 243         DEBUG(100, ("nt:\n"));
 244         dump_data(100, (const char *)user_info->nt_resp.data, user_info->nt_resp.length);
 245 #endif
 246
 247         /* This needs to be sorted:  If it doesn't match, what should we do? */
 248         if (!check_domain_match(user_info->smb_name, user_info->domain))
 249                 return NT_STATUS_LOGON_FAILURE;
 250
 251         for (auth_method = auth_context->auth_method_list;auth_method; auth_method = auth_method->next) {
 252                 NTSTATUS result;
 253
 254                 mem_ctx = talloc_init("%s authentication for user %s\\%s", auth_method->name,
 255                                             user_info->domain, user_info->smb_name);
 256
 257                 result = auth_method->auth(auth_context, auth_method->private_data, mem_ctx, user_info, server_info);
 258
 259                 /* check if the module did anything */
 260                 if ( NT_STATUS_V(result) == NT_STATUS_V(NT_STATUS_NOT_IMPLEMENTED) ) {
 261                         DEBUG(10,("check_ntlm_password: %s had nothing to say\n", auth_method->name));
 262                         talloc_destroy(mem_ctx);
 263                         continue;
 264                 }
 265
 266                 nt_status = result;
 267
 268                 if (NT_STATUS_IS_OK(nt_status)) {
 269                         DEBUG(3, ("check_ntlm_password: %s authentication for user [%s] succeeded\n",
 270                                   auth_method->name, user_info->smb_name));
 271                 } else {
 272                         DEBUG(5, ("check_ntlm_password: %s authentication for user [%s] FAILED with error %s\n",
 273                                   auth_method->name, user_info->smb_name, nt_errstr(nt_status)));
 274                 }
 275
 276                 talloc_destroy(mem_ctx);
 277
 278                 if ( NT_STATUS_IS_OK(nt_status))
 279                 {
 280                                 break;
 281                 }
 282         }
 283
 284         /* successful authentication */
 285
 286         if (NT_STATUS_IS_OK(nt_status)) {
 287                 unix_username = (*server_info)->unix_name;
 288                 if (!(*server_info)->guest) {
 289                         /* We might not be root if we are an RPC call */
 290                         become_root();
 291                         nt_status = smb_pam_accountcheck(unix_username);
 292                         unbecome_root();
 293
 294                         if (NT_STATUS_IS_OK(nt_status)) {
 295                                 DEBUG(5, ("check_ntlm_password:  PAM Account for user [%s] succeeded\n",
 296                                           unix_username));
 297                         } else {
 298                                 DEBUG(3, ("check_ntlm_password:  PAM Account for user [%s] FAILED with error %s\n",
 299                                           unix_username, nt_errstr(nt_status)));
 300                         }
 301                 }
 302
 303                 if (NT_STATUS_IS_OK(nt_status)) {
 304                         DEBUG((*server_info)->guest ? 5 : 2,
 305                               ("check_ntlm_password:  %sauthentication for user [%s] -> [%s] -> [%s] succeeded\n",
 306                                (*server_info)->guest ? "guest " : "",
 307                                user_info->smb_name,
 308                                user_info->internal_username,
 309                                unix_username));
 310                 }
 311
 312                 return nt_status;
 313         }
 314
 315         /* failed authentication; check for guest lapping */
 316
 317         DEBUG(2, ("check_ntlm_password:  Authentication for user [%s] -> [%s] FAILED with error %s\n",
 318                   user_info->smb_name, user_info->internal_username,
 319                   nt_errstr(nt_status)));
 320         ZERO_STRUCTP(server_info);
 321
 322         return nt_status;
 323 }
 324
 325 /***************************************************************************
 326  Clear out a auth_context, and destroy the attached TALLOC_CTX
 327 ***************************************************************************/
 328
 329 static void free_auth_context(struct auth_context **auth_context)
 330 {
 331         auth_methods *auth_method;
 332
 333         if (*auth_context) {
 334                 /* Free private data of context's authentication methods */
 335                 for (auth_method = (*auth_context)->auth_method_list; auth_method; auth_method = auth_method->next) {
 336                         if (auth_method->free_private_data) {
 337                                 auth_method->free_private_data (&auth_method->private_data);
 338                                 auth_method->private_data = NULL;
 339                         }
 340                 }
 341
 342                 talloc_destroy((*auth_context)->mem_ctx);
 343                 *auth_context = NULL;
 344         }
 345 }
 346
 347 /***************************************************************************
 348  Make a auth_info struct
 349 ***************************************************************************/
 350
 351 static NTSTATUS make_auth_context(struct auth_context **auth_context)
 352 {
 353         TALLOC_CTX *mem_ctx;
 354
 355         mem_ctx = talloc_init("authentication context");
 356
 357         *auth_context = TALLOC_P(mem_ctx, struct auth_context);
 358         if (!*auth_context) {
 359                 DEBUG(0,("make_auth_context: talloc failed!\n"));
 360                 talloc_destroy(mem_ctx);
 361                 return NT_STATUS_NO_MEMORY;
 362         }
 363         ZERO_STRUCTP(*auth_context);
 364
 365         (*auth_context)->mem_ctx = mem_ctx;
 366         (*auth_context)->check_ntlm_password = check_ntlm_password;
 367         (*auth_context)->get_ntlm_challenge = get_ntlm_challenge;
 368         (*auth_context)->free = free_auth_context;
 369
 370         return NT_STATUS_OK;
 371 }
 372
 373 BOOL load_auth_module(struct auth_context *auth_context,
 374                       const char *module, auth_methods **ret)
 375 {
 376         static BOOL initialised_static_modules = False;
 377
 378         struct auth_init_function_entry *entry;
 379         char *module_name = smb_xstrdup(module);
 380         char *module_params = NULL;
 381         char *p;
 382         BOOL good = False;
 383
 384         /* Initialise static modules if not done so yet */
 385         if(!initialised_static_modules) {
 386                 static_init_auth;
 387                 initialised_static_modules = True;
 388         }
 389
 390         DEBUG(5,("load_auth_module: Attempting to find an auth method to match %s\n",
 391                  module));
 392
 393         p = strchr(module_name, ':');
 394         if (p) {
 395                 *p = 0;
 396                 module_params = p+1;
 397                 trim_char(module_params, ' ', ' ');
 398         }
 399
 400         trim_char(module_name, ' ', ' ');
 401
 402         entry = auth_find_backend_entry(module_name);
 403
 404         if (entry == NULL) {
 405                 if (NT_STATUS_IS_OK(smb_probe_module("auth", module_name))) {
 406                         entry = auth_find_backend_entry(module_name);
 407                 }
 408         }
 409
 410         if (entry != NULL) {
 411                 if (!NT_STATUS_IS_OK(entry->init(auth_context, module_params, ret))) {
 412                         DEBUG(0,("load_auth_module: auth method %s did not correctly init\n",
 413                                  module_name));
 414                 } else {
 415                         DEBUG(5,("load_auth_module: auth method %s has a valid init\n",
 416                                  module_name));
 417                         good = True;
 418                 }
 419         } else {
 420                 DEBUG(0,("load_auth_module: can't find auth method %s!\n", module_name));
 421         }
 422
 423         SAFE_FREE(module_name);
 424         return good;
 425 }
 426
 427 /***************************************************************************
 428  Make a auth_info struct for the auth subsystem
 429 ***************************************************************************/
 430
 431 static NTSTATUS make_auth_context_text_list(struct auth_context **auth_context, char **text_list)
 432 {
 433         auth_methods *list = NULL;
 434         auth_methods *t = NULL;
 435         NTSTATUS nt_status;
 436
 437         if (!text_list) {
 438                 DEBUG(2,("make_auth_context_text_list: No auth method list!?\n"));
 439                 return NT_STATUS_UNSUCCESSFUL;
 440         }
 441
 442         if (!NT_STATUS_IS_OK(nt_status = make_auth_context(auth_context)))
 443                 return nt_status;
 444
 445         for (;*text_list; text_list++) {
 446                 if (load_auth_module(*auth_context, *text_list, &t)) {
 447                     DLIST_ADD_END(list, t, auth_methods *);
 448                 }
 449         }
 450
 451         (*auth_context)->auth_method_list = list;
 452
 453         return nt_status;
 454 }
 455
 456 /***************************************************************************
 457  Make a auth_context struct for the auth subsystem
 458 ***************************************************************************/
 459
 460 NTSTATUS make_auth_context_subsystem(struct auth_context **auth_context)
 461 {
 462         char **auth_method_list = NULL;
 463         NTSTATUS nt_status;
 464
 465         if (lp_auth_methods() && !str_list_copy(&auth_method_list, lp_auth_methods())) {
 466                 return NT_STATUS_NO_MEMORY;
 467         }
 468
 469         if (auth_method_list == NULL) {
 470                 switch (lp_security())
 471                 {
 472                 case SEC_DOMAIN:
 473                         DEBUG(5,("Making default auth method list for security=domain\n"));
 474                         auth_method_list = str_list_make("guest sam winbind:ntdomain", NULL);
 475                         break;
 476                 case SEC_SERVER:
 477                         DEBUG(5,("Making default auth method list for security=server\n"));
 478                         auth_method_list = str_list_make("guest sam smbserver", NULL);
 479                         break;
 480                 case SEC_USER:
 481                         if (lp_encrypted_passwords()) {
 482                                 if ((lp_server_role() == ROLE_DOMAIN_PDC) || (lp_server_role() == ROLE_DOMAIN_BDC)) {
 483                                         DEBUG(5,("Making default auth method list for DC, security=user, encrypt passwords = yes\n"));
 484                                         auth_method_list = str_list_make("guest sam winbind:trustdomain", NULL);
 485                                 } else {
 486                                         DEBUG(5,("Making default auth method list for standalone security=user, encrypt passwords = yes\n"));
 487                                         auth_method_list = str_list_make("guest sam", NULL);
 488                                 }
 489                         } else {
 490                                 DEBUG(5,("Making default auth method list for security=user, encrypt passwords = no\n"));
 491                                 auth_method_list = str_list_make("guest unix", NULL);
 492                         }
 493                         break;
 494                 case SEC_SHARE:
 495                         if (lp_encrypted_passwords()) {
 496                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = yes\n"));
 497                                 auth_method_list = str_list_make("guest sam", NULL);
 498                         } else {
 499                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = no\n"));
 500                                 auth_method_list = str_list_make("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("guest sam winbind:ntdomain", NULL);
 506                         break;
 507                 default:
 508                         DEBUG(5,("Unknown auth method!\n"));
 509                         return NT_STATUS_UNSUCCESSFUL;
 510                 }
 511         } else {
 512                 DEBUG(5,("Using specified auth order\n"));
 513         }
 514
 515         if (!NT_STATUS_IS_OK(nt_status = make_auth_context_text_list(auth_context, auth_method_list))) {
 516                 str_list_free(&auth_method_list);
 517                 return nt_status;
 518         }
 519
 520         str_list_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)->mem_ctx, chal, 8);
 536         (*auth_context)->challenge_set_by = "fixed";
 537         return nt_status;
 538 }
 539
 540