source4/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         { "samstrict_dc", auth_init_samstrict_dc },
  35         { "unix", auth_init_unix },
  36 /*      { "smbserver", auth_init_smbserver }, */
  37 /*      { "ntdomain", auth_init_ntdomain }, */
  38 /*      { "trustdomain", auth_init_trustdomain }, */
  39 /*      { "winbind", auth_init_winbind }, */
  40 #ifdef DEVELOPER
  41         { "name_to_ntstatus", auth_init_name_to_ntstatus },
  42         { "fixed_challenge", auth_init_fixed_challenge },
  43 #endif
  44         { "plugin", auth_init_plugin },
  45         { NULL, NULL}
  46 };
  47
  48 /****************************************************************************
  49  Try to get a challenge out of the various authentication modules.
  50  Returns a const char of length 8 bytes.
  51 ****************************************************************************/
  52
  53 static const uint8 *get_ntlm_challenge(struct auth_context *auth_context)
  54 {
  55         DATA_BLOB challenge = data_blob(NULL, 0);
  56         const char *challenge_set_by = NULL;
  57         auth_methods *auth_method;
  58         TALLOC_CTX *mem_ctx;
  59
  60         if (auth_context->challenge.length) {
  61                 DEBUG(5, ("get_ntlm_challenge (auth subsystem): returning previous challenge by module %s (normal)\n",
  62                           auth_context->challenge_set_by));
  63                 return auth_context->challenge.data;
  64         }
  65
  66         for (auth_method = auth_context->auth_method_list; auth_method; auth_method = auth_method->next) {
  67                 if (auth_method->get_chal == NULL) {
  68                         DEBUG(5, ("auth_get_challenge: module %s did not want to specify a challenge\n", auth_method->name));
  69                         continue;
  70                 }
  71
  72                 DEBUG(5, ("auth_get_challenge: getting challenge from module %s\n", auth_method->name));
  73                 if (challenge_set_by != NULL) {
  74                         DEBUG(1, ("auth_get_challenge: CONFIGURATION ERROR: authentication method %s has already specified a challenge.  Challenge by %s ignored.\n",
  75                                   challenge_set_by, auth_method->name));
  76                         continue;
  77                 }
  78
  79                 mem_ctx = talloc_init("auth_get_challenge for module %s", auth_method->name);
  80                 if (!mem_ctx) {
  81                         smb_panic("talloc_init() failed!");
  82                 }
  83
  84                 challenge = auth_method->get_chal(auth_context, &auth_method->private_data, mem_ctx);
  85                 if (!challenge.length) {
  86                         DEBUG(3, ("auth_get_challenge: getting challenge from authentication method %s FAILED.\n",
  87                                   auth_method->name));
  88                 } else {
  89                         DEBUG(5, ("auth_get_challenge: sucessfully got challenge from module %s\n", auth_method->name));
  90                         auth_context->challenge = challenge;
  91                         challenge_set_by = auth_method->name;
  92                         auth_context->challenge_set_method = auth_method;
  93                 }
  94                 talloc_destroy(mem_ctx);
  95         }
  96
  97         if (!challenge_set_by) {
  98                 uchar chal[8];
  99
 100                 generate_random_buffer(chal, sizeof(chal), False);
 101                 auth_context->challenge = data_blob_talloc(auth_context->mem_ctx,
 102                                                            chal, sizeof(chal));
 103
 104                 challenge_set_by = "random";
 105         }
 106
 107         DEBUG(5, ("auth_context challenge created by %s\n", challenge_set_by));
 108         DEBUG(5, ("challenge is: \n"));
 109         dump_data(5, (const char*)auth_context->challenge.data, auth_context->challenge.length);
 110
 111         SMB_ASSERT(auth_context->challenge.length == 8);
 112
 113         auth_context->challenge_set_by=challenge_set_by;
 114
 115         return auth_context->challenge.data;
 116 }
 117
 118
 119 /**
 120  * Check user is in correct domain (if required)
 121  *
 122  * @param user Only used to fill in the debug message
 123  *
 124  * @param domain The domain to be verified
 125  *
 126  * @return True if the user can connect with that domain,
 127  *         False otherwise.
 128 **/
 129
 130 static BOOL check_domain_match(const char *user, const char *domain)
 131 {
 132         /*
 133          * If we aren't serving to trusted domains, we must make sure that
 134          * the validation request comes from an account in the same domain
 135          * as the Samba server
 136          */
 137
 138         if (!lp_allow_trusted_domains() &&
 139             !(strequal("", domain) ||
 140               strequal(lp_workgroup(), domain) ||
 141               is_myname(domain))) {
 142                 DEBUG(1, ("check_domain_match: Attempt to connect as user %s from domain %s denied.\n", user, domain));
 143                 return False;
 144         } else {
 145                 return True;
 146         }
 147 }
 148
 149 /**
 150  * Check a user's Plaintext, LM or NTLM password.
 151  *
 152  * Check a user's password, as given in the user_info struct and return various
 153  * interesting details in the server_info struct.
 154  *
 155  * This function does NOT need to be in a become_root()/unbecome_root() pair
 156  * as it makes the calls itself when needed.
 157  *
 158  * The return value takes precedence over the contents of the server_info
 159  * struct.  When the return is other than NT_STATUS_OK the contents
 160  * of that structure is undefined.
 161  *
 162  * @param user_info Contains the user supplied components, including the passwords.
 163  *                  Must be created with make_user_info() or one of its wrappers.
 164  *
 165  * @param auth_context Supplies the challenges and some other data.
 166  *                  Must be created with make_auth_context(), and the challenges should be
 167  *                  filled in, either at creation or by calling the challenge geneation
 168  *                  function auth_get_challenge().
 169  *
 170  * @param server_info If successful, contains information about the authentication,
 171  *                    including a SAM_ACCOUNT struct describing the user.
 172  *
 173  * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.
 174  *
 175  **/
 176
 177 static NTSTATUS check_ntlm_password(const struct auth_context *auth_context,
 178                                     const struct auth_usersupplied_info *user_info,
 179                                     struct auth_serversupplied_info **server_info)
 180 {
 181
 182         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 183         const char *pdb_username;
 184         auth_methods *auth_method;
 185         TALLOC_CTX *mem_ctx;
 186
 187         if (!user_info || !auth_context || !server_info)
 188                 return NT_STATUS_LOGON_FAILURE;
 189
 190         DEBUG(3, ("check_ntlm_password:  Checking password for unmapped user [%s]\\[%s]@[%s] with the new password interface\n",
 191                   user_info->client_domain.str, user_info->smb_name.str, user_info->wksta_name.str));
 192
 193         DEBUG(3, ("check_ntlm_password:  mapped user is: [%s]\\[%s]@[%s]\n",
 194                   user_info->domain.str, user_info->internal_username.str, user_info->wksta_name.str));
 195
 196         if (auth_context->challenge.length != 8) {
 197                 DEBUG(0, ("check_ntlm_password:  Invalid challenge stored for this auth context - cannot continue\n"));
 198                 return NT_STATUS_LOGON_FAILURE;
 199         }
 200
 201         if (auth_context->challenge_set_by)
 202                 DEBUG(10, ("check_ntlm_password: auth_context challenge created by %s\n",
 203                                         auth_context->challenge_set_by));
 204
 205         DEBUG(10, ("challenge is: \n"));
 206         dump_data(5, (const char*)auth_context->challenge.data, auth_context->challenge.length);
 207
 208 #ifdef DEBUG_PASSWORD
 209         DEBUG(100, ("user_info has passwords of length %d and %d\n",
 210                     user_info->lm_resp.length, user_info->nt_resp.length));
 211         DEBUG(100, ("lm:\n"));
 212         dump_data(100, user_info->lm_resp.data, user_info->lm_resp.length);
 213         DEBUG(100, ("nt:\n"));
 214         dump_data(100, user_info->nt_resp.data, user_info->nt_resp.length);
 215 #endif
 216
 217         /* This needs to be sorted:  If it doesn't match, what should we do? */
 218         if (!check_domain_match(user_info->smb_name.str, user_info->domain.str))
 219                 return NT_STATUS_LOGON_FAILURE;
 220
 221         for (auth_method = auth_context->auth_method_list;auth_method; auth_method = auth_method->next) {
 222                 mem_ctx = talloc_init("%s authentication for user %s\\%s", auth_method->name,
 223                                             user_info->domain.str, user_info->smb_name.str);
 224
 225                 nt_status = auth_method->auth(auth_context, auth_method->private_data, mem_ctx, user_info, server_info);
 226                 if (NT_STATUS_IS_OK(nt_status)) {
 227                         DEBUG(3, ("check_ntlm_password: %s authentication for user [%s] suceeded\n",
 228                                   auth_method->name, user_info->smb_name.str));
 229                 } else {
 230                         DEBUG(5, ("check_ntlm_password: %s authentication for user [%s] FAILED with error %s\n",
 231                                   auth_method->name, user_info->smb_name.str, nt_errstr(nt_status)));
 232                 }
 233
 234                 talloc_destroy(mem_ctx);
 235
 236                 if (NT_STATUS_IS_OK(nt_status))
 237                         break;
 238         }
 239
 240         /* This is one of the few places the *relies* (rather than just sets defaults
 241            on the value of lp_security().  This needs to change.  A new paramater
 242            perhaps? */
 243         if (lp_security() >= SEC_SERVER)
 244                 smb_user_control(user_info, *server_info, nt_status);
 245
 246         if (NT_STATUS_IS_OK(nt_status)) {
 247                 pdb_username = pdb_get_username((*server_info)->sam_account);
 248                 if (!(*server_info)->guest) {
 249                         /* We might not be root if we are an RPC call */
 250                         become_root();
 251                         nt_status = smb_pam_accountcheck(pdb_username);
 252                         unbecome_root();
 253
 254                         if (NT_STATUS_IS_OK(nt_status)) {
 255                                 DEBUG(5, ("check_ntlm_password:  PAM Account for user [%s] suceeded\n",
 256                                           pdb_username));
 257                         } else {
 258                                 DEBUG(3, ("check_ntlm_password:  PAM Account for user [%s] FAILED with error %s\n",
 259                                           pdb_username, nt_errstr(nt_status)));
 260                         }
 261                 }
 262
 263                 if (NT_STATUS_IS_OK(nt_status)) {
 264                         DEBUG((*server_info)->guest ? 5 : 2,
 265                               ("check_ntlm_password:  %sauthentication for user [%s] -> [%s] -> [%s] suceeded\n",
 266                                (*server_info)->guest ? "guest " : "",
 267                                user_info->smb_name.str,
 268                                user_info->internal_username.str,
 269                                pdb_username));
 270                 }
 271         }
 272
 273         if (!NT_STATUS_IS_OK(nt_status)) {
 274                 DEBUG(2, ("check_ntlm_password:  Authentication for user [%s] -> [%s] FAILED with error %s\n",
 275                           user_info->smb_name.str, user_info->internal_username.str,
 276                           nt_errstr(nt_status)));
 277                 ZERO_STRUCTP(server_info);
 278         }
 279         return nt_status;
 280 }
 281
 282 /***************************************************************************
 283  Clear out a auth_context, and destroy the attached TALLOC_CTX
 284 ***************************************************************************/
 285
 286 static void free_auth_context(struct auth_context **auth_context)
 287 {
 288         if (*auth_context != NULL)
 289                 talloc_destroy((*auth_context)->mem_ctx);
 290         *auth_context = NULL;
 291 }
 292
 293 /***************************************************************************
 294  Make a auth_info struct
 295 ***************************************************************************/
 296
 297 static NTSTATUS make_auth_context(struct auth_context **auth_context)
 298 {
 299         TALLOC_CTX *mem_ctx;
 300
 301         mem_ctx = talloc_init("authentication context");
 302
 303         *auth_context = talloc(mem_ctx, sizeof(**auth_context));
 304         if (!*auth_context) {
 305                 DEBUG(0,("make_auth_context: talloc failed!\n"));
 306                 talloc_destroy(mem_ctx);
 307                 return NT_STATUS_NO_MEMORY;
 308         }
 309         ZERO_STRUCTP(*auth_context);
 310
 311         (*auth_context)->mem_ctx = mem_ctx;
 312         (*auth_context)->check_ntlm_password = check_ntlm_password;
 313         (*auth_context)->get_ntlm_challenge = get_ntlm_challenge;
 314         (*auth_context)->free = free_auth_context;
 315
 316         return NT_STATUS_OK;
 317 }
 318
 319 /***************************************************************************
 320  Make a auth_info struct for the auth subsystem
 321 ***************************************************************************/
 322
 323 static NTSTATUS make_auth_context_text_list(struct auth_context **auth_context, char **text_list)
 324 {
 325         auth_methods *list = NULL;
 326         auth_methods *t = NULL;
 327         auth_methods *tmp;
 328         int i;
 329         NTSTATUS nt_status;
 330
 331         if (!text_list) {
 332                 DEBUG(2,("make_auth_context_text_list: No auth method list!?\n"));
 333                 return NT_STATUS_UNSUCCESSFUL;
 334         }
 335
 336         if (!NT_STATUS_IS_OK(nt_status = make_auth_context(auth_context)))
 337                 return nt_status;
 338
 339         for (;*text_list; text_list++) {
 340                 DEBUG(5,("make_auth_context_text_list: Attempting to find an auth method to match %s\n",
 341                                         *text_list));
 342                 for (i = 0; builtin_auth_init_functions[i].name; i++) {
 343                         char *module_name = smb_xstrdup(*text_list);
 344                         char *module_params = NULL;
 345                         char *p;
 346
 347                         p = strchr(module_name, ':');
 348                         if (p) {
 349                                 *p = 0;
 350                                 module_params = p+1;
 351                                 trim_string(module_params, " ", " ");
 352                         }
 353
 354                         trim_string(module_name, " ", " ");
 355
 356                         if (strequal(builtin_auth_init_functions[i].name, module_name)) {
 357                                 DEBUG(5,("make_auth_context_text_list: Found auth method %s (at pos %d)\n", *text_list, i));
 358                                 if (NT_STATUS_IS_OK(builtin_auth_init_functions[i].init(*auth_context, module_params, &t))) {
 359                                         DEBUG(5,("make_auth_context_text_list: auth method %s has a valid init\n",
 360                                                                 *text_list));
 361                                         DLIST_ADD_END(list, t, tmp);
 362                                 } else {
 363                                         DEBUG(0,("make_auth_context_text_list: auth method %s did not correctly init\n",
 364                                                                 *text_list));
 365                                 }
 366                                 break;
 367                         }
 368                         SAFE_FREE(module_name);
 369                 }
 370         }
 371
 372         (*auth_context)->auth_method_list = list;
 373
 374         return nt_status;
 375 }
 376
 377 /***************************************************************************
 378  Make a auth_context struct for the auth subsystem
 379 ***************************************************************************/
 380
 381 NTSTATUS make_auth_context_subsystem(struct auth_context **auth_context)
 382 {
 383         char **auth_method_list = NULL;
 384         NTSTATUS nt_status;
 385
 386         if (lp_auth_methods() && !str_list_copy(&auth_method_list, lp_auth_methods())) {
 387                 return NT_STATUS_NO_MEMORY;
 388         }
 389
 390         if (auth_method_list == NULL) {
 391                 switch (lp_security())
 392                 {
 393                 case SEC_DOMAIN:
 394                         DEBUG(5,("Making default auth method list for security=domain\n"));
 395                         auth_method_list = str_list_make("guest sam winbind ntdomain", NULL);
 396                         break;
 397                 case SEC_SERVER:
 398                         DEBUG(5,("Making default auth method list for security=server\n"));
 399                         auth_method_list = str_list_make("guest sam smbserver", NULL);
 400                         break;
 401                 case SEC_USER:
 402                         if (lp_encrypted_passwords()) {
 403                                 DEBUG(5,("Making default auth method list for security=user, encrypt passwords = yes\n"));
 404                                 auth_method_list = str_list_make("guest sam", NULL);
 405                         } else {
 406                                 DEBUG(5,("Making default auth method list for security=user, encrypt passwords = no\n"));
 407                                 auth_method_list = str_list_make("guest unix", NULL);
 408                         }
 409                         break;
 410                 case SEC_SHARE:
 411                         if (lp_encrypted_passwords()) {
 412                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = yes\n"));
 413                                 auth_method_list = str_list_make("guest sam", NULL);
 414                         } else {
 415                                 DEBUG(5,("Making default auth method list for security=share, encrypt passwords = no\n"));
 416                                 auth_method_list = str_list_make("guest unix", NULL);
 417                         }
 418                         break;
 419                 case SEC_ADS:
 420                         DEBUG(5,("Making default auth method list for security=ADS\n"));
 421                         auth_method_list = str_list_make("guest sam ads winbind ntdomain", NULL);
 422                         break;
 423                 default:
 424                         DEBUG(5,("Unknown auth method!\n"));
 425                         return NT_STATUS_UNSUCCESSFUL;
 426                 }
 427         } else {
 428                 DEBUG(5,("Using specified auth order\n"));
 429         }
 430
 431         if (!NT_STATUS_IS_OK(nt_status = make_auth_context_text_list(auth_context, auth_method_list))) {
 432                 str_list_free(&auth_method_list);
 433                 return nt_status;
 434         }
 435
 436         str_list_free(&auth_method_list);
 437         return nt_status;
 438 }
 439
 440 /***************************************************************************
 441  Make a auth_info struct with a fixed challenge
 442 ***************************************************************************/
 443
 444 NTSTATUS make_auth_context_fixed(struct auth_context **auth_context, uchar chal[8])
 445 {
 446         NTSTATUS nt_status;
 447         if (!NT_STATUS_IS_OK(nt_status = make_auth_context_subsystem(auth_context))) {
 448                 return nt_status;
 449         }
 450
 451         (*auth_context)->challenge = data_blob(chal, 8);
 452         (*auth_context)->challenge_set_by = "fixed";
 453         return nt_status;
 454 }
 455
 456