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 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(sizeof(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         for (auth_method = auth_context->auth_method_list; auth_method; auth_method = auth_method->next) {
  92                 if (auth_method->get_chal == NULL) {
  93                         DEBUG(5, ("auth_get_challenge: module %s did not want to specify a challenge\n", auth_method->name));
  94                         continue;
  95                 }
  96
  97                 DEBUG(5, ("auth_get_challenge: getting challenge from module %s\n", auth_method->name));
  98                 if (challenge_set_by != NULL) {
  99                         DEBUG(1, ("auth_get_challenge: CONFIGURATION ERROR: authentication method %s has already specified a challenge.  Challenge by %s ignored.\n",
 100                                   challenge_set_by, auth_method->name));
 101                         continue;
 102                 }
 103
 104                 mem_ctx = talloc_init("auth_get_challenge for module %s", auth_method->name);
 105                 if (!mem_ctx) {
 106                         smb_panic("talloc_init() failed!");
 107                 }
 108
 109                 challenge = auth_method->get_chal(auth_context, &auth_method->private_data, mem_ctx);
 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: sucessfully 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                 talloc_destroy(mem_ctx);
 120         }
 121
 122         if (!challenge_set_by) {
 123                 uchar chal[8];
 124
 125                 generate_random_buffer(chal, sizeof(chal), False);
 126                 auth_context->challenge = data_blob_talloc(auth_context->mem_ctx,
 127                                                            chal, sizeof(chal));
 128
 129                 challenge_set_by = "random";
 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         return auth_context->challenge.data;
 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 SAM_ACCOUNT 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
 207         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 208         const char *pdb_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.str, user_info->smb_name.str, user_info->wksta_name.str));
 217
 218         DEBUG(3, ("check_ntlm_password:  mapped user is: [%s]\\[%s]@[%s]\n",
 219                   user_info->domain.str, user_info->internal_username.str, user_info->wksta_name.str));
 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                     user_info->lm_resp.length, 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.str, user_info->domain.str))
 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.str, user_info->smb_name.str);
 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.str));
 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.str, nt_errstr(nt_status)));
 269                 }
 270
 271                 talloc_destroy(mem_ctx);
 272
 273                 if (NT_STATUS_IS_OK(nt_status))
 274                         break;
 275         }
 276
 277         if (NT_STATUS_IS_OK(nt_status)) {
 278                 pdb_username = pdb_get_username((*server_info)->sam_account);
 279                 if (!(*server_info)->guest) {
 280                         /* We might not be root if we are an RPC call */
 281                         become_root();
 282                         nt_status = smb_pam_accountcheck(pdb_username);
 283                         unbecome_root();
 284
 285                         if (NT_STATUS_IS_OK(nt_status)) {
 286                                 DEBUG(5, ("check_ntlm_password:  PAM Account for user [%s] suceeded\n",
 287                                           pdb_username));
 288                         } else {
 289                                 DEBUG(3, ("check_ntlm_password:  PAM Account for user [%s] FAILED with error %s\n",
 290                                           pdb_username, nt_errstr(nt_status)));
 291                         }
 292                 }
 293
 294                 if (NT_STATUS_IS_OK(nt_status)) {
 295                         DEBUG((*server_info)->guest ? 5 : 2,
 296                               ("check_ntlm_password:  %sauthentication for user [%s] -> [%s] -> [%s] suceeded\n",
 297                                (*server_info)->guest ? "guest " : "",
 298                                user_info->smb_name.str,
 299                                user_info->internal_username.str,
 300                                pdb_username));
 301                 }
 302         }
 303
 304         if (!NT_STATUS_IS_OK(nt_status)) {
 305                 DEBUG(2, ("check_ntlm_password:  Authentication for user [%s] -> [%s] FAILED with error %s\n",
 306                           user_info->smb_name.str, user_info->internal_username.str,
 307                           nt_errstr(nt_status)));
 308                 ZERO_STRUCTP(server_info);
 309         }
 310         return nt_status;
 311 }
 312
 313 /***************************************************************************
 314  Clear out a auth_context, and destroy the attached TALLOC_CTX
 315 ***************************************************************************/
 316
 317 static void free_auth_context(struct auth_context **auth_context)
 318 {
 319         if (*auth_context != NULL)
 320                 talloc_destroy((*auth_context)->mem_ctx);
 321         *auth_context = NULL;
 322 }
 323
 324 /***************************************************************************
 325  Make a auth_info struct
 326 ***************************************************************************/
 327
 328 static NTSTATUS make_auth_context(struct auth_context **auth_context)
 329 {
 330         TALLOC_CTX *mem_ctx;
 331
 332         mem_ctx = talloc_init("authentication context");
 333
 334         *auth_context = talloc(mem_ctx, sizeof(**auth_context));
 335         if (!*auth_context) {
 336                 DEBUG(0,("make_auth_context: talloc failed!\n"));
 337                 talloc_destroy(mem_ctx);
 338                 return NT_STATUS_NO_MEMORY;
 339         }
 340         ZERO_STRUCTP(*auth_context);
 341
 342         (*auth_context)->mem_ctx = mem_ctx;
 343         (*auth_context)->check_ntlm_password = check_ntlm_password;
 344         (*auth_context)->get_ntlm_challenge = get_ntlm_challenge;
 345         (*auth_context)->free = free_auth_context;
 346
 347         return NT_STATUS_OK;
 348 }
 349
 350 BOOL load_auth_module(struct auth_context *auth_context,
 351                       const char *module, auth_methods **ret)
 352 {
 353         static BOOL initialised_static_modules = False;
 354
 355         struct auth_init_function_entry *entry;
 356         char *module_name = smb_xstrdup(module);
 357         char *module_params = NULL;
 358         char *p;
 359         BOOL good = False;
 360
 361         /* Initialise static modules if not done so yet */
 362         if(!initialised_static_modules) {
 363                 static_init_auth;
 364                 initialised_static_modules = True;
 365         }
 366
 367         DEBUG(5,("load_auth_module: Attempting to find an auth method to match %s\n",
 368                  module));
 369
 370         p = strchr(module_name, ':');
 371         if (p) {
 372                 *p = 0;
 373                 module_params = p+1;
 374                 trim_string(module_params, " ", " ");
 375         }
 376
 377         trim_string(module_name, " ", " ");
 378
 379         entry = auth_find_backend_entry(module_name);
 380
 381         if (entry == NULL) {
 382                 if (NT_STATUS_IS_OK(smb_probe_module("auth", module_name))) {
 383                         entry = auth_find_backend_entry(module_name);
 384                 }
 385         }
 386
 387         if (entry != NULL) {
 388                 if (!NT_STATUS_IS_OK(entry->init(auth_context, module_params, ret))) {
 389                         DEBUG(0,("load_auth_module: auth method %s did not correctly init\n",
 390                                  module_name));
 391                 } else {
 392                         DEBUG(5,("load_auth_module: auth method %s has a valid init\n",
 393                                  module_name));
 394                         good = True;
 395                 }
 396         } else {
 397                 DEBUG(0,("load_auth_module: can't find auth method %s!\n", module_name));
 398         }
 399
 400         SAFE_FREE(module_name);
 401         return good;
 402 }
 403
 404 /***************************************************************************
 405  Make a auth_info struct for the auth subsystem
 406 ***************************************************************************/
 407
 408 static NTSTATUS make_auth_context_text_list(struct auth_context **auth_context, char **text_list)
 409 {
 410         auth_methods *list = NULL;
 411         auth_methods *t = NULL;
 412         auth_methods *tmp;
 413         NTSTATUS nt_status;
 414
 415         if (!text_list) {
 416                 DEBUG(2,("make_auth_context_text_list: No auth method list!?\n"));
 417                 return NT_STATUS_UNSUCCESSFUL;
 418         }
 419
 420         if (!NT_STATUS_IS_OK(nt_status = make_auth_context(auth_context)))
 421                 return nt_status;
 422
 423         for (;*text_list; text_list++) {
 424                 if (load_auth_module(*auth_context, *text_list, &t)) {
 425                     DLIST_ADD_END(list, t, tmp);
 426                 }
 427         }
 428
 429         (*auth_context)->auth_method_list = list;
 430
 431         return nt_status;
 432 }
 433
 434 /***************************************************************************
 435  Make a auth_context struct for the auth subsystem
 436 ***************************************************************************/
 437
 438 NTSTATUS make_auth_context_subsystem(struct auth_context **auth_context)
 439 {
 440         char **auth_method_list = NULL;
 441         NTSTATUS nt_status;
 442
 443         if (lp_auth_methods() && !str_list_copy(&auth_method_list, lp_auth_methods())) {
 444                 return NT_STATUS_NO_MEMORY;
 445         }
 446
 447         if (auth_method_list == NULL) {
 448                 switch (lp_security())
 449                 {
 450                 case SEC_DOMAIN:
 451                         DEBUG(5,("Making default auth method list for security=domain\n"));
 452                         auth_method_list = str_list_make("guest sam winbind:ntdomain", NULL);
 453                         break;
 454                 case SEC_SERVER:
 455                         DEBUG(5,("Making default auth method list for security=server\n"));
 456                         auth_method_list = str_list_make("guest sam smbserver", NULL);
 457                         break;
 458                 case SEC_USER:
 459                         if (lp_encrypted_passwords()) {
 460                                 DEBUG(5,("Making default auth method list for security=user, encrypt passwords = yes\n"));
 461                                 auth_method_list = str_list_make("guest sam", NULL);
 462                         } else {
 463                                 DEBUG(5,("Making default auth method list for security=user, encrypt passwords = no\n"));
 464                                 auth_method_list = str_list_make("guest unix", NULL);
 465                         }
 466                         break;
 467                 case SEC_SHARE:
 468                         if (lp_encrypted_passwords()) {
 469                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = yes\n"));
 470                                 auth_method_list = str_list_make("guest sam", NULL);
 471                         } else {
 472                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = no\n"));
 473                                 auth_method_list = str_list_make("guest unix", NULL);
 474                         }
 475                         break;
 476                 case SEC_ADS:
 477                         DEBUG(5,("Making default auth method list for security=ADS\n"));
 478                         auth_method_list = str_list_make("guest sam winbind:ntdomain", NULL);
 479                         break;
 480                 default:
 481                         DEBUG(5,("Unknown auth method!\n"));
 482                         return NT_STATUS_UNSUCCESSFUL;
 483                 }
 484         } else {
 485                 DEBUG(5,("Using specified auth order\n"));
 486         }
 487
 488         if (!NT_STATUS_IS_OK(nt_status = make_auth_context_text_list(auth_context, auth_method_list))) {
 489                 str_list_free(&auth_method_list);
 490                 return nt_status;
 491         }
 492
 493         str_list_free(&auth_method_list);
 494         return nt_status;
 495 }
 496
 497 /***************************************************************************
 498  Make a auth_info struct with a fixed challenge
 499 ***************************************************************************/
 500
 501 NTSTATUS make_auth_context_fixed(struct auth_context **auth_context, uchar chal[8])
 502 {
 503         NTSTATUS nt_status;
 504         if (!NT_STATUS_IS_OK(nt_status = make_auth_context_subsystem(auth_context))) {
 505                 return nt_status;
 506         }
 507
 508         (*auth_context)->challenge = data_blob(chal, 8);
 509         (*auth_context)->challenge_set_by = "fixed";
 510         return nt_status;
 511 }
 512
 513