source3/auth/check_samsec.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Password and authentication handling
   4    Copyright (C) Andrew Tridgell              1992-2000
   5    Copyright (C) Luke Kenneth Casson Leighton 1996-2000
   6    Copyright (C) Andrew Bartlett              2001-2003
   7    Copyright (C) Gerald Carter                2003
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "../libcli/auth/libcli_auth.h"
  25
  26 #undef DBGC_CLASS
  27 #define DBGC_CLASS DBGC_AUTH
  28
  29 /****************************************************************************
  30  Do a specific test for an smb password being correct, given a smb_password and
  31  the lanman and NT responses.
  32 ****************************************************************************/
  33
  34 static NTSTATUS sam_password_ok(TALLOC_CTX *mem_ctx,
  35                                 const char *username,
  36                                 uint32_t acct_ctrl,
  37                                 const DATA_BLOB *challenge,
  38                                 const uint8_t *lm_pw,
  39                                 const uint8_t *nt_pw,
  40                                 const struct auth_usersupplied_info *user_info,
  41                                 DATA_BLOB *user_sess_key,
  42                                 DATA_BLOB *lm_sess_key)
  43 {
  44         struct samr_Password _lm_hash, _nt_hash, _client_lm_hash, _client_nt_hash;
  45         struct samr_Password *lm_hash = NULL;
  46         struct samr_Password *nt_hash = NULL;
  47         struct samr_Password *client_lm_hash = NULL;
  48         struct samr_Password *client_nt_hash = NULL;
  49
  50         *user_sess_key = data_blob_null;
  51         *lm_sess_key = data_blob_null;
  52
  53         if (acct_ctrl & ACB_PWNOTREQ) {
  54                 if (lp_null_passwords()) {
  55                         DEBUG(3,("Account for user '%s' has no password and null passwords are allowed.\n", username));
  56                         return NT_STATUS_OK;
  57                 } else {
  58                         DEBUG(3,("Account for user '%s' has no password and null passwords are NOT allowed.\n", username));
  59                         return NT_STATUS_LOGON_FAILURE;
  60                 }
  61         }
  62
  63         if (lm_pw) {
  64                 memcpy(_lm_hash.hash, lm_pw, sizeof(_lm_hash.hash));
  65                 lm_hash = &_lm_hash;
  66         }
  67         if (nt_pw) {
  68                 memcpy(_nt_hash.hash, nt_pw, sizeof(_nt_hash.hash));
  69                 nt_hash = &_nt_hash;
  70         }
  71         if (user_info->lm_interactive_pwd.data && sizeof(_client_lm_hash.hash) == user_info->lm_interactive_pwd.length) {
  72                 memcpy(_client_lm_hash.hash, user_info->lm_interactive_pwd.data, sizeof(_lm_hash.hash));
  73                 client_lm_hash = &_client_lm_hash;
  74         }
  75         if (user_info->nt_interactive_pwd.data && sizeof(_client_nt_hash.hash) == user_info->nt_interactive_pwd.length) {
  76                 memcpy(_client_nt_hash.hash, user_info->nt_interactive_pwd.data, sizeof(_nt_hash.hash));
  77                 client_nt_hash = &_client_nt_hash;
  78         }
  79
  80         if (client_lm_hash || client_nt_hash) {
  81                 if (!nt_pw) {
  82                         return NT_STATUS_WRONG_PASSWORD;
  83                 }
  84                 *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16);
  85                 if (!user_sess_key->data) {
  86                         return NT_STATUS_NO_MEMORY;
  87                 }
  88                 SMBsesskeygen_ntv1(nt_pw, user_sess_key->data);
  89                 return hash_password_check(mem_ctx, lp_lanman_auth(),
  90                                            client_lm_hash,
  91                                            client_nt_hash,
  92                                            username,
  93                                            lm_hash,
  94                                            nt_hash);
  95         } else {
  96                 return ntlm_password_check(mem_ctx, lp_lanman_auth(),
  97                                            lp_ntlm_auth(),
  98                                            user_info->logon_parameters,
  99                                            challenge,
 100                                            &user_info->lm_resp, &user_info->nt_resp,
 101                                            username,
 102                                            user_info->client.account_name,
 103                                            user_info->client.domain_name,
 104                                            lm_hash,
 105                                            nt_hash,
 106                                            user_sess_key, lm_sess_key);
 107         }
 108 }
 109
 110 /****************************************************************************
 111  Check if a user is allowed to logon at this time. Note this is the
 112  servers local time, as logon hours are just specified as a weekly
 113  bitmask.
 114 ****************************************************************************/
 115
 116 static bool logon_hours_ok(struct samu *sampass)
 117 {
 118         /* In logon hours first bit is Sunday from 12AM to 1AM */
 119         const uint8 *hours;
 120         struct tm *utctime;
 121         time_t lasttime;
 122         const char *asct;
 123         uint8 bitmask, bitpos;
 124
 125         hours = pdb_get_hours(sampass);
 126         if (!hours) {
 127                 DEBUG(5,("logon_hours_ok: No hours restrictions for user %s\n",pdb_get_username(sampass)));
 128                 return True;
 129         }
 130
 131         lasttime = time(NULL);
 132         utctime = gmtime(&lasttime);
 133         if (!utctime) {
 134                 DEBUG(1, ("logon_hours_ok: failed to get gmtime. Failing logon for user %s\n",
 135                         pdb_get_username(sampass) ));
 136                 return False;
 137         }
 138
 139         /* find the corresponding byte and bit */
 140         bitpos = (utctime->tm_wday * 24 + utctime->tm_hour) % 168;
 141         bitmask = 1 << (bitpos % 8);
 142
 143         if (! (hours[bitpos/8] & bitmask)) {
 144                 struct tm *t = localtime(&lasttime);
 145                 if (!t) {
 146                         asct = "INVALID TIME";
 147                 } else {
 148                         asct = asctime(t);
 149                         if (!asct) {
 150                                 asct = "INVALID TIME";
 151                         }
 152                 }
 153
 154                 DEBUG(1, ("logon_hours_ok: Account for user %s not allowed to "
 155                           "logon at this time (%s).\n",
 156                           pdb_get_username(sampass), asct ));
 157                 return False;
 158         }
 159
 160         asct = asctime(utctime);
 161         DEBUG(5,("logon_hours_ok: user %s allowed to logon at this time (%s)\n",
 162                 pdb_get_username(sampass), asct ? asct : "UNKNOWN TIME" ));
 163
 164         return True;
 165 }
 166
 167 /****************************************************************************
 168  Do a specific test for a struct samu being valid for this connection
 169  (ie not disabled, expired and the like).
 170 ****************************************************************************/
 171
 172 static NTSTATUS sam_account_ok(TALLOC_CTX *mem_ctx,
 173                                struct samu *sampass,
 174                                const struct auth_usersupplied_info *user_info)
 175 {
 176         uint32  acct_ctrl = pdb_get_acct_ctrl(sampass);
 177         char *workstation_list;
 178         time_t kickoff_time;
 179
 180         DEBUG(4,("sam_account_ok: Checking SMB password for user %s\n",pdb_get_username(sampass)));
 181
 182         /* Quit if the account was disabled. */
 183         if (acct_ctrl & ACB_DISABLED) {
 184                 DEBUG(1,("sam_account_ok: Account for user '%s' was disabled.\n", pdb_get_username(sampass)));
 185                 return NT_STATUS_ACCOUNT_DISABLED;
 186         }
 187
 188         /* Quit if the account was locked out. */
 189         if (acct_ctrl & ACB_AUTOLOCK) {
 190                 DEBUG(1,("sam_account_ok: Account for user %s was locked out.\n", pdb_get_username(sampass)));
 191                 return NT_STATUS_ACCOUNT_LOCKED_OUT;
 192         }
 193
 194         /* Quit if the account is not allowed to logon at this time. */
 195         if (! logon_hours_ok(sampass)) {
 196                 return NT_STATUS_INVALID_LOGON_HOURS;
 197         }
 198
 199         /* Test account expire time */
 200
 201         kickoff_time = pdb_get_kickoff_time(sampass);
 202         if (kickoff_time != 0 && time(NULL) > kickoff_time) {
 203                 DEBUG(1,("sam_account_ok: Account for user '%s' has expired.\n", pdb_get_username(sampass)));
 204                 DEBUG(3,("sam_account_ok: Account expired at '%ld' unix time.\n", (long)kickoff_time));
 205                 return NT_STATUS_ACCOUNT_EXPIRED;
 206         }
 207
 208         if (!(pdb_get_acct_ctrl(sampass) & ACB_PWNOEXP) && !(pdb_get_acct_ctrl(sampass) & ACB_PWNOTREQ)) {
 209                 time_t must_change_time = pdb_get_pass_must_change_time(sampass);
 210                 time_t last_set_time = pdb_get_pass_last_set_time(sampass);
 211
 212                 /* check for immediate expiry "must change at next logon"
 213                  * for a user account. */
 214                 if (((acct_ctrl & (ACB_WSTRUST|ACB_SVRTRUST)) == 0) && (last_set_time == 0)) {
 215                         DEBUG(1,("sam_account_ok: Account for user '%s' password must change!\n", pdb_get_username(sampass)));
 216                         return NT_STATUS_PASSWORD_MUST_CHANGE;
 217                 }
 218
 219                 /* check for expired password */
 220                 if (must_change_time < time(NULL) && must_change_time != 0) {
 221                         DEBUG(1,("sam_account_ok: Account for user '%s' password expired!\n", pdb_get_username(sampass)));
 222                         DEBUG(1,("sam_account_ok: Password expired at '%s' (%ld) unix time.\n", http_timestring(talloc_tos(), must_change_time), (long)must_change_time));
 223                         return NT_STATUS_PASSWORD_EXPIRED;
 224                 }
 225         }
 226
 227         /* Test workstation. Workstation list is comma separated. */
 228
 229         workstation_list = talloc_strdup(mem_ctx, pdb_get_workstations(sampass));
 230         if (!workstation_list)
 231                 return NT_STATUS_NO_MEMORY;
 232
 233         if (*workstation_list) {
 234                 bool invalid_ws = True;
 235                 char *tok = NULL;
 236                 const char *s = workstation_list;
 237                 char *machine_name = talloc_asprintf(mem_ctx, "%s$", user_info->workstation_name);
 238
 239                 if (machine_name == NULL)
 240                         return NT_STATUS_NO_MEMORY;
 241
 242                 while (next_token_talloc(mem_ctx, &s, &tok, ",")) {
 243                         DEBUG(10,("sam_account_ok: checking for workstation match %s and %s\n",
 244                                   tok, user_info->workstation_name));
 245                         if(strequal(tok, user_info->workstation_name)) {
 246                                 invalid_ws = False;
 247                                 break;
 248                         }
 249                         if (tok[0] == '+') {
 250                                 DEBUG(10,("sam_account_ok: checking for workstation %s in group: %s\n",
 251                                         machine_name, tok + 1));
 252                                 if (user_in_group(machine_name, tok + 1)) {
 253                                         invalid_ws = False;
 254                                         break;
 255                                 }
 256                         }
 257                         TALLOC_FREE(tok);
 258                 }
 259                 TALLOC_FREE(tok);
 260                 TALLOC_FREE(machine_name);
 261
 262                 if (invalid_ws)
 263                         return NT_STATUS_INVALID_WORKSTATION;
 264         }
 265
 266         if (acct_ctrl & ACB_DOMTRUST) {
 267                 DEBUG(2,("sam_account_ok: Domain trust account %s denied by server\n", pdb_get_username(sampass)));
 268                 return NT_STATUS_NOLOGON_INTERDOMAIN_TRUST_ACCOUNT;
 269         }
 270
 271         if (acct_ctrl & ACB_SVRTRUST) {
 272                 if (!(user_info->logon_parameters & MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT)) {
 273                         DEBUG(2,("sam_account_ok: Server trust account %s denied by server\n", pdb_get_username(sampass)));
 274                         return NT_STATUS_NOLOGON_SERVER_TRUST_ACCOUNT;
 275                 }
 276         }
 277
 278         if (acct_ctrl & ACB_WSTRUST) {
 279                 if (!(user_info->logon_parameters & MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT)) {
 280                         DEBUG(2,("sam_account_ok: Wksta trust account %s denied by server\n", pdb_get_username(sampass)));
 281                         return NT_STATUS_NOLOGON_WORKSTATION_TRUST_ACCOUNT;
 282                 }
 283         }
 284         return NT_STATUS_OK;
 285 }
 286
 287 /**
 288  * Check whether the given password is one of the last two
 289  * password history entries. If so, the bad pwcount should
 290  * not be incremented even thought the actual password check
 291  * failed.
 292  */
 293 static bool need_to_increment_bad_pw_count(
 294         const DATA_BLOB *challenge,
 295         struct samu* sampass,
 296         const struct auth_usersupplied_info *user_info)
 297 {
 298         uint8_t i;
 299         const uint8_t *pwhistory;
 300         uint32_t pwhistory_len;
 301         uint32_t policy_pwhistory_len;
 302         uint32_t acct_ctrl;
 303         const char *username;
 304         TALLOC_CTX *mem_ctx = talloc_stackframe();
 305         bool result = true;
 306
 307         pdb_get_account_policy(PDB_POLICY_PASSWORD_HISTORY,
 308                                &policy_pwhistory_len);
 309         if (policy_pwhistory_len == 0) {
 310                 goto done;
 311         }
 312
 313         pwhistory = pdb_get_pw_history(sampass, &pwhistory_len);
 314         if (!pwhistory || pwhistory_len == 0) {
 315                 goto done;
 316         }
 317
 318         acct_ctrl = pdb_get_acct_ctrl(sampass);
 319         username = pdb_get_username(sampass);
 320
 321         for (i=1; i < MIN(MIN(3, policy_pwhistory_len), pwhistory_len); i++) {
 322                 static const uint8_t zero16[SALTED_MD5_HASH_LEN];
 323                 const uint8_t *salt;
 324                 const uint8_t *nt_pw;
 325                 NTSTATUS status;
 326                 DATA_BLOB user_sess_key = data_blob_null;
 327                 DATA_BLOB lm_sess_key = data_blob_null;
 328
 329                 salt = &pwhistory[i*PW_HISTORY_ENTRY_LEN];
 330                 nt_pw = salt + PW_HISTORY_SALT_LEN;
 331
 332                 if (memcmp(zero16, nt_pw, NT_HASH_LEN) == 0) {
 333                         /* skip zero password hash */
 334                         continue;
 335                 }
 336
 337                 if (memcmp(zero16, salt, PW_HISTORY_SALT_LEN) != 0) {
 338                         /* skip nonzero salt (old format entry) */
 339                         continue;
 340                 }
 341
 342                 status = sam_password_ok(mem_ctx,
 343                                          username, acct_ctrl,
 344                                          challenge,
 345                                          NULL, nt_pw,
 346                                          user_info, &user_sess_key, &lm_sess_key);
 347                 if (NT_STATUS_IS_OK(status)) {
 348                         result = false;
 349                         break;
 350                 }
 351         }
 352
 353 done:
 354         TALLOC_FREE(mem_ctx);
 355         return result;
 356 }
 357
 358 /****************************************************************************
 359 check if a username/password is OK assuming the password is a 24 byte
 360 SMB hash supplied in the user_info structure
 361 return an NT_STATUS constant.
 362 ****************************************************************************/
 363
 364 NTSTATUS check_sam_security(const DATA_BLOB *challenge,
 365                             TALLOC_CTX *mem_ctx,
 366                             const struct auth_usersupplied_info *user_info,
 367                             struct auth_serversupplied_info **server_info)
 368 {
 369         struct samu *sampass=NULL;
 370         bool ret;
 371         NTSTATUS nt_status;
 372         NTSTATUS update_login_attempts_status;
 373         DATA_BLOB user_sess_key = data_blob_null;
 374         DATA_BLOB lm_sess_key = data_blob_null;
 375         bool updated_autolock = False, updated_badpw = False;
 376         const char *username;
 377         const uint8_t *nt_pw;
 378         const uint8_t *lm_pw;
 379
 380         /* the returned struct gets kept on the server_info, by means
 381            of a steal further down */
 382
 383         sampass = samu_new(mem_ctx);
 384         if (sampass == NULL) {
 385                 return NT_STATUS_NO_MEMORY;
 386         }
 387
 388         /* get the account information */
 389
 390         become_root();
 391         ret = pdb_getsampwnam(sampass, user_info->mapped.account_name);
 392         unbecome_root();
 393
 394         if (ret == False) {
 395                 DEBUG(3,("check_sam_security: Couldn't find user '%s' in "
 396                          "passdb.\n", user_info->mapped.account_name));
 397                 TALLOC_FREE(sampass);
 398                 return NT_STATUS_NO_SUCH_USER;
 399         }
 400
 401         username = pdb_get_username(sampass);
 402         nt_pw = pdb_get_nt_passwd(sampass);
 403         lm_pw = pdb_get_lanman_passwd(sampass);
 404
 405         /* see if autolock flag needs to be updated */
 406         if (pdb_get_acct_ctrl(sampass) & ACB_NORMAL)
 407                 pdb_update_autolock_flag(sampass, &updated_autolock);
 408         /* Quit if the account was locked out. */
 409         if (pdb_get_acct_ctrl(sampass) & ACB_AUTOLOCK) {
 410                 DEBUG(3,("check_sam_security: Account for user %s was locked out.\n", username));
 411                 return NT_STATUS_ACCOUNT_LOCKED_OUT;
 412         }
 413
 414         nt_status = sam_password_ok(mem_ctx,
 415                                     username, pdb_get_acct_ctrl(sampass),
 416                                     challenge, lm_pw, nt_pw,
 417                                     user_info, &user_sess_key, &lm_sess_key);
 418
 419         /* Notify passdb backend of login success/failure. If not
 420            NT_STATUS_OK the backend doesn't like the login */
 421
 422         update_login_attempts_status = pdb_update_login_attempts(sampass, NT_STATUS_IS_OK(nt_status));
 423
 424         if (!NT_STATUS_IS_OK(nt_status)) {
 425                 bool increment_bad_pw_count = false;
 426
 427                 if (NT_STATUS_EQUAL(nt_status,NT_STATUS_WRONG_PASSWORD) &&
 428                     pdb_get_acct_ctrl(sampass) & ACB_NORMAL &&
 429                     NT_STATUS_IS_OK(update_login_attempts_status))
 430                 {
 431                         increment_bad_pw_count =
 432                                 need_to_increment_bad_pw_count(
 433                                         challenge, sampass, user_info);
 434                 }
 435
 436                 if (increment_bad_pw_count) {
 437                         pdb_increment_bad_password_count(sampass);
 438                         updated_badpw = True;
 439                 } else {
 440                         pdb_update_bad_password_count(sampass,
 441                                                       &updated_badpw);
 442                 }
 443                 if (updated_autolock || updated_badpw){
 444                         NTSTATUS status;
 445
 446                         become_root();
 447                         status = pdb_update_sam_account(sampass);
 448                         unbecome_root();
 449
 450                         if (!NT_STATUS_IS_OK(status)) {
 451                                 DEBUG(1, ("Failed to modify entry: %s\n",
 452                                           nt_errstr(status)));
 453                         }
 454                 }
 455                 goto done;
 456         }
 457
 458         if ((pdb_get_acct_ctrl(sampass) & ACB_NORMAL) &&
 459             (pdb_get_bad_password_count(sampass) > 0)){
 460                 pdb_set_bad_password_count(sampass, 0, PDB_CHANGED);
 461                 pdb_set_bad_password_time(sampass, 0, PDB_CHANGED);
 462                 updated_badpw = True;
 463         }
 464
 465         if (updated_autolock || updated_badpw){
 466                 NTSTATUS status;
 467
 468                 become_root();
 469                 status = pdb_update_sam_account(sampass);
 470                 unbecome_root();
 471
 472                 if (!NT_STATUS_IS_OK(status)) {
 473                         DEBUG(1, ("Failed to modify entry: %s\n",
 474                                   nt_errstr(status)));
 475                 }
 476         }
 477
 478         nt_status = sam_account_ok(mem_ctx, sampass, user_info);
 479
 480         if (!NT_STATUS_IS_OK(nt_status)) {
 481                 goto done;
 482         }
 483
 484         become_root();
 485         nt_status = make_server_info_sam(server_info, sampass);
 486         unbecome_root();
 487
 488         TALLOC_FREE(sampass);
 489
 490         if (!NT_STATUS_IS_OK(nt_status)) {
 491                 DEBUG(0,("check_sam_security: make_server_info_sam() failed with '%s'\n", nt_errstr(nt_status)));
 492                 goto done;
 493         }
 494
 495         (*server_info)->user_session_key =
 496                 data_blob_talloc(*server_info, user_sess_key.data,
 497                                  user_sess_key.length);
 498         data_blob_free(&user_sess_key);
 499
 500         (*server_info)->lm_session_key =
 501                 data_blob_talloc(*server_info, lm_sess_key.data,
 502                                  lm_sess_key.length);
 503         data_blob_free(&lm_sess_key);
 504
 505         (*server_info)->nss_token |= user_info->was_mapped;
 506
 507 done:
 508         TALLOC_FREE(sampass);
 509         data_blob_free(&user_sess_key);
 510         data_blob_free(&lm_sess_key);
 511         return nt_status;
 512 }