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 /** List of various built-in authentication modules */
  27
  28 static const struct auth_init_function_entry builtin_auth_init_functions[] = {
  29         { "guest", auth_init_guest },
  30         { "rhosts", auth_init_rhosts },
  31         { "hostsequiv", auth_init_hostsequiv },
  32         { "sam", auth_init_sam },
  33         { "samstrict", auth_init_samstrict },
  34         { "unix", auth_init_unix },
  35         { "smbserver", auth_init_smbserver },
  36         { "ntdomain", auth_init_ntdomain },
  37         { "trustdomain", auth_init_trustdomain },
  38         { "winbind", auth_init_winbind },
  39 #ifdef DEVELOPER
  40         { "name_to_ntstatus", auth_init_name_to_ntstatus },
  41         { "fixed_challenge", auth_init_fixed_challenge },
  42 #endif
  43         { "plugin", auth_init_plugin },
  44         { NULL, NULL}
  45 };
  46
  47 /****************************************************************************
  48  Try to get a challenge out of the various authentication modules.
  49  Returns a const char of length 8 bytes.
  50 ****************************************************************************/
  51
  52 static const uint8 *get_ntlm_challenge(struct auth_context *auth_context)
  53 {
  54         DATA_BLOB challenge = data_blob(NULL, 0);
  55         const char *challenge_set_by = NULL;
  56         auth_methods *auth_method;
  57         TALLOC_CTX *mem_ctx;
  58
  59         if (auth_context->challenge.length) {
  60                 DEBUG(5, ("get_ntlm_challenge (auth subsystem): returning previous challenge by module %s (normal)\n",
  61                           auth_context->challenge_set_by));
  62                 return auth_context->challenge.data;
  63         }
  64
  65         for (auth_method = auth_context->auth_method_list; auth_method; auth_method = auth_method->next) {
  66                 if (auth_method->get_chal == NULL) {
  67                         DEBUG(5, ("auth_get_challenge: module %s did not want to specify a challenge\n", auth_method->name));
  68                         continue;
  69                 }
  70
  71                 DEBUG(5, ("auth_get_challenge: getting challenge from module %s\n", auth_method->name));
  72                 if (challenge_set_by != NULL) {
  73                         DEBUG(1, ("auth_get_challenge: CONFIGURATION ERROR: authentication method %s has already specified a challenge.  Challenge by %s ignored.\n",
  74                                   challenge_set_by, auth_method->name));
  75                         continue;
  76                 }
  77
  78                 mem_ctx = talloc_init("auth_get_challenge for module %s", auth_method->name);
  79                 if (!mem_ctx) {
  80                         smb_panic("talloc_init() failed!");
  81                 }
  82
  83                 challenge = auth_method->get_chal(auth_context, &auth_method->private_data, mem_ctx);
  84                 if (!challenge.length) {
  85                         DEBUG(3, ("auth_get_challenge: getting challenge from authentication method %s FAILED.\n",
  86                                   auth_method->name));
  87                 } else {
  88                         DEBUG(5, ("auth_get_challenge: sucessfully got challenge from module %s\n", auth_method->name));
  89                         auth_context->challenge = challenge;
  90                         challenge_set_by = auth_method->name;
  91                         auth_context->challenge_set_method = auth_method;
  92                 }
  93                 talloc_destroy(mem_ctx);
  94         }
  95
  96         if (!challenge_set_by) {
  97                 uchar chal[8];
  98
  99                 generate_random_buffer(chal, sizeof(chal), False);
 100                 auth_context->challenge = data_blob_talloc(auth_context->mem_ctx,
 101                                                            chal, sizeof(chal));
 102
 103                 challenge_set_by = "random";
 104         }
 105
 106         DEBUG(5, ("auth_context challenge created by %s\n", challenge_set_by));
 107         DEBUG(5, ("challenge is: \n"));
 108         dump_data(5, auth_context->challenge.data, auth_context->challenge.length);
 109
 110         SMB_ASSERT(auth_context->challenge.length == 8);
 111
 112         auth_context->challenge_set_by=challenge_set_by;
 113
 114         return auth_context->challenge.data;
 115 }
 116
 117
 118 /**
 119  * Check user is in correct domain (if required)
 120  *
 121  * @param user Only used to fill in the debug message
 122  *
 123  * @param domain The domain to be verified
 124  *
 125  * @return True if the user can connect with that domain,
 126  *         False otherwise.
 127 **/
 128
 129 static BOOL check_domain_match(const char *user, const char *domain)
 130 {
 131         /*
 132          * If we aren't serving to trusted domains, we must make sure that
 133          * the validation request comes from an account in the same domain
 134          * as the Samba server
 135          */
 136
 137         if (!lp_allow_trusted_domains() &&
 138             !(strequal("", domain) ||
 139               strequal(lp_workgroup(), domain) ||
 140               is_myname(domain))) {
 141                 DEBUG(1, ("check_domain_match: Attempt to connect as user %s from domain %s denied.\n", user, domain));
 142                 return False;
 143         } else {
 144                 return True;
 145         }
 146 }
 147
 148 /**
 149  * Check a user's Plaintext, LM or NTLM password.
 150  *
 151  * Check a user's password, as given in the user_info struct and return various
 152  * interesting details in the server_info struct.
 153  *
 154  * This function does NOT need to be in a become_root()/unbecome_root() pair
 155  * as it makes the calls itself when needed.
 156  *
 157  * The return value takes precedence over the contents of the server_info
 158  * struct.  When the return is other than NT_STATUS_OK the contents
 159  * of that structure is undefined.
 160  *
 161  * @param user_info Contains the user supplied components, including the passwords.
 162  *                  Must be created with make_user_info() or one of its wrappers.
 163  *
 164  * @param auth_context Supplies the challenges and some other data.
 165  *                  Must be created with make_auth_context(), and the challenges should be
 166  *                  filled in, either at creation or by calling the challenge geneation
 167  *                  function auth_get_challenge().
 168  *
 169  * @param server_info If successful, contains information about the authentication,
 170  *                    including a SAM_ACCOUNT struct describing the user.
 171  *
 172  * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.
 173  *
 174  **/
 175
 176 static NTSTATUS check_ntlm_password(const struct auth_context *auth_context,
 177                                     const struct auth_usersupplied_info *user_info,
 178                                     struct auth_serversupplied_info **server_info)
 179 {
 180
 181         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 182         const char *pdb_username;
 183         auth_methods *auth_method;
 184         TALLOC_CTX *mem_ctx;
 185
 186         if (!user_info || !auth_context || !server_info)
 187                 return NT_STATUS_LOGON_FAILURE;
 188
 189         DEBUG(3, ("check_ntlm_password:  Checking password for unmapped user [%s]\\[%s]@[%s] with the new password interface\n",
 190                   user_info->client_domain.str, user_info->smb_name.str, user_info->wksta_name.str));
 191
 192         DEBUG(3, ("check_ntlm_password:  mapped user is: [%s]\\[%s]@[%s]\n",
 193                   user_info->domain.str, user_info->internal_username.str, user_info->wksta_name.str));
 194
 195         if (auth_context->challenge.length != 8) {
 196                 DEBUG(0, ("check_ntlm_password:  Invalid challenge stored for this auth context - cannot continue\n"));
 197                 return NT_STATUS_LOGON_FAILURE;
 198         }
 199
 200         if (auth_context->challenge_set_by)
 201                 DEBUG(10, ("check_ntlm_password: auth_context challenge created by %s\n",
 202                                         auth_context->challenge_set_by));
 203
 204         DEBUG(10, ("challenge is: \n"));
 205         dump_data(5, auth_context->challenge.data, auth_context->challenge.length);
 206
 207 #ifdef DEBUG_PASSWORD
 208         DEBUG(100, ("user_info has passwords of length %d and %d\n",
 209                     user_info->lm_resp.length, user_info->nt_resp.length));
 210         DEBUG(100, ("lm:\n"));
 211         dump_data(100, user_info->lm_resp.data, user_info->lm_resp.length);
 212         DEBUG(100, ("nt:\n"));
 213         dump_data(100, user_info->nt_resp.data, user_info->nt_resp.length);
 214 #endif
 215
 216         /* This needs to be sorted:  If it doesn't match, what should we do? */
 217         if (!check_domain_match(user_info->smb_name.str, user_info->domain.str))
 218                 return NT_STATUS_LOGON_FAILURE;
 219
 220         for (auth_method = auth_context->auth_method_list;auth_method; auth_method = auth_method->next) {
 221                 mem_ctx = talloc_init("%s authentication for user %s\\%s", auth_method->name,
 222                                             user_info->domain.str, user_info->smb_name.str);
 223
 224                 nt_status = auth_method->auth(auth_context, auth_method->private_data, mem_ctx, user_info, server_info);
 225                 if (NT_STATUS_IS_OK(nt_status)) {
 226                         DEBUG(3, ("check_ntlm_password: %s authentication for user [%s] suceeded\n",
 227                                   auth_method->name, user_info->smb_name.str));
 228                 } else {
 229                         DEBUG(5, ("check_ntlm_password: %s authentication for user [%s] FAILED with error %s\n",
 230                                   auth_method->name, user_info->smb_name.str, nt_errstr(nt_status)));
 231                 }
 232
 233                 talloc_destroy(mem_ctx);
 234
 235                 if (NT_STATUS_IS_OK(nt_status))
 236                         break;
 237         }
 238
 239         /* This is one of the few places the *relies* (rather than just sets defaults
 240            on the value of lp_security().  This needs to change.  A new paramater
 241            perhaps? */
 242         if (lp_security() >= SEC_SERVER)
 243                 smb_user_control(user_info, *server_info, nt_status);
 244
 245         if (NT_STATUS_IS_OK(nt_status)) {
 246                 pdb_username = pdb_get_username((*server_info)->sam_account);
 247                 if (!(*server_info)->guest) {
 248                         /* We might not be root if we are an RPC call */
 249                         become_root();
 250                         nt_status = smb_pam_accountcheck(pdb_username);
 251                         unbecome_root();
 252
 253                         if (NT_STATUS_IS_OK(nt_status)) {
 254                                 DEBUG(5, ("check_ntlm_password:  PAM Account for user [%s] suceeded\n",
 255                                           pdb_username));
 256                         } else {
 257                                 DEBUG(3, ("check_ntlm_password:  PAM Account for user [%s] FAILED with error %s\n",
 258                                           pdb_username, nt_errstr(nt_status)));
 259                         }
 260                 }
 261
 262                 if (NT_STATUS_IS_OK(nt_status)) {
 263                         DEBUG((*server_info)->guest ? 5 : 2,
 264                               ("check_ntlm_password:  %sauthentication for user [%s] -> [%s] -> [%s] suceeded\n",
 265                                (*server_info)->guest ? "guest " : "",
 266                                user_info->smb_name.str,
 267                                user_info->internal_username.str,
 268                                pdb_username));
 269                 }
 270         }
 271
 272         if (!NT_STATUS_IS_OK(nt_status)) {
 273                 DEBUG(2, ("check_ntlm_password:  Authentication for user [%s] -> [%s] FAILED with error %s\n",
 274                           user_info->smb_name.str, user_info->internal_username.str,
 275                           nt_errstr(nt_status)));
 276                 ZERO_STRUCTP(server_info);
 277         }
 278         return nt_status;
 279 }
 280
 281 /***************************************************************************
 282  Clear out a auth_context, and destroy the attached TALLOC_CTX
 283 ***************************************************************************/
 284
 285 static void free_auth_context(struct auth_context **auth_context)
 286 {
 287         if (*auth_context != NULL)
 288                 talloc_destroy((*auth_context)->mem_ctx);
 289         *auth_context = NULL;
 290 }
 291
 292 /***************************************************************************
 293  Make a auth_info struct
 294 ***************************************************************************/
 295
 296 static NTSTATUS make_auth_context(struct auth_context **auth_context)
 297 {
 298         TALLOC_CTX *mem_ctx;
 299
 300         mem_ctx = talloc_init("authentication context");
 301
 302         *auth_context = talloc(mem_ctx, sizeof(**auth_context));
 303         if (!*auth_context) {
 304                 DEBUG(0,("make_auth_context: talloc failed!\n"));
 305                 talloc_destroy(mem_ctx);
 306                 return NT_STATUS_NO_MEMORY;
 307         }
 308         ZERO_STRUCTP(*auth_context);
 309
 310         (*auth_context)->mem_ctx = mem_ctx;
 311         (*auth_context)->check_ntlm_password = check_ntlm_password;
 312         (*auth_context)->get_ntlm_challenge = get_ntlm_challenge;
 313         (*auth_context)->free = free_auth_context;
 314
 315         return NT_STATUS_OK;
 316 }
 317
 318 /***************************************************************************
 319  Make a auth_info struct for the auth subsystem
 320 ***************************************************************************/
 321
 322 static NTSTATUS make_auth_context_text_list(struct auth_context **auth_context, char **text_list)
 323 {
 324         auth_methods *list = NULL;
 325         auth_methods *t = NULL;
 326         auth_methods *tmp;
 327         int i;
 328         NTSTATUS nt_status;
 329
 330         if (!text_list) {
 331                 DEBUG(2,("make_auth_context_text_list: No auth method list!?\n"));
 332                 return NT_STATUS_UNSUCCESSFUL;
 333         }
 334
 335         if (!NT_STATUS_IS_OK(nt_status = make_auth_context(auth_context)))
 336                 return nt_status;
 337
 338         for (;*text_list; text_list++) {
 339                 DEBUG(5,("make_auth_context_text_list: Attempting to find an auth method to match %s\n",
 340                                         *text_list));
 341                 for (i = 0; builtin_auth_init_functions[i].name; i++) {
 342                         char *module_name = smb_xstrdup(*text_list);
 343                         char *module_params = NULL;
 344                         char *p;
 345
 346                         p = strchr(module_name, ':');
 347                         if (p) {
 348                                 *p = 0;
 349                                 module_params = p+1;
 350                                 trim_string(module_params, " ", " ");
 351                         }
 352
 353                         trim_string(module_name, " ", " ");
 354
 355                         if (strequal(builtin_auth_init_functions[i].name, module_name)) {
 356                                 DEBUG(5,("make_auth_context_text_list: Found auth method %s (at pos %d)\n", *text_list, i));
 357                                 if (NT_STATUS_IS_OK(builtin_auth_init_functions[i].init(*auth_context, module_params, &t))) {
 358                                         DEBUG(5,("make_auth_context_text_list: auth method %s has a valid init\n",
 359                                                                 *text_list));
 360                                         DLIST_ADD_END(list, t, tmp);
 361                                 } else {
 362                                         DEBUG(0,("make_auth_context_text_list: auth method %s did not correctly init\n",
 363                                                                 *text_list));
 364                                 }
 365                                 break;
 366                         }
 367                         SAFE_FREE(module_name);
 368                 }
 369         }
 370
 371         (*auth_context)->auth_method_list = list;
 372
 373         return nt_status;
 374 }
 375
 376 /***************************************************************************
 377  Make a auth_context struct for the auth subsystem
 378 ***************************************************************************/
 379
 380 NTSTATUS make_auth_context_subsystem(struct auth_context **auth_context)
 381 {
 382         char **auth_method_list = NULL;
 383         NTSTATUS nt_status;
 384
 385         if (lp_auth_methods() && !str_list_copy(&auth_method_list, lp_auth_methods())) {
 386                 return NT_STATUS_NO_MEMORY;
 387         }
 388
 389         if (auth_method_list == NULL) {
 390                 switch (lp_security())
 391                 {
 392                 case SEC_DOMAIN:
 393                         DEBUG(5,("Making default auth method list for security=domain\n"));
 394                         auth_method_list = str_list_make("guest sam winbind ntdomain", NULL);
 395                         break;
 396                 case SEC_SERVER:
 397                         DEBUG(5,("Making default auth method list for security=server\n"));
 398                         auth_method_list = str_list_make("guest sam smbserver", NULL);
 399                         break;
 400                 case SEC_USER:
 401                         if (lp_encrypted_passwords()) {
 402                                 DEBUG(5,("Making default auth method list for security=user, encrypt passwords = yes\n"));
 403                                 auth_method_list = str_list_make("guest sam", NULL);
 404                         } else {
 405                                 DEBUG(5,("Making default auth method list for security=user, encrypt passwords = no\n"));
 406                                 auth_method_list = str_list_make("guest unix", NULL);
 407                         }
 408                         break;
 409                 case SEC_SHARE:
 410                         if (lp_encrypted_passwords()) {
 411                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = yes\n"));
 412                                 auth_method_list = str_list_make("guest sam", NULL);
 413                         } else {
 414                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = no\n"));
 415                                 auth_method_list = str_list_make("guest unix", NULL);
 416                         }
 417                         break;
 418                 case SEC_ADS:
 419                         DEBUG(5,("Making default auth method list for security=ADS\n"));
 420                         auth_method_list = str_list_make("guest sam ads winbind ntdomain", NULL);
 421                         break;
 422                 default:
 423                         DEBUG(5,("Unknown auth method!\n"));
 424                         return NT_STATUS_UNSUCCESSFUL;
 425                 }
 426         } else {
 427                 DEBUG(5,("Using specified auth order\n"));
 428         }
 429
 430         if (!NT_STATUS_IS_OK(nt_status = make_auth_context_text_list(auth_context, auth_method_list))) {
 431                 str_list_free(&auth_method_list);
 432                 return nt_status;
 433         }
 434
 435         str_list_free(&auth_method_list);
 436         return nt_status;
 437 }
 438
 439 /***************************************************************************
 440  Make a auth_info struct with a fixed challenge
 441 ***************************************************************************/
 442
 443 NTSTATUS make_auth_context_fixed(struct auth_context **auth_context, uchar chal[8])
 444 {
 445         NTSTATUS nt_status;
 446         if (!NT_STATUS_IS_OK(nt_status = make_auth_context_subsystem(auth_context))) {
 447                 return nt_status;
 448         }
 449
 450         (*auth_context)->challenge = data_blob(chal, 8);
 451         (*auth_context)->challenge_set_by = "fixed";
 452         return nt_status;
 453 }
 454
 455