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                 *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16);
  82                 if (!user_sess_key->data) {
  83                         return NT_STATUS_NO_MEMORY;
  84                 }
  85                 SMBsesskeygen_ntv1(nt_pw, user_sess_key->data);
  86                 return hash_password_check(mem_ctx, lp_lanman_auth(),
  87                                            client_lm_hash,
  88                                            client_nt_hash,
  89                                            username,
  90                                            lm_hash,
  91                                            nt_hash);
  92         } else {
  93                 return ntlm_password_check(mem_ctx, lp_lanman_auth(),
  94                                            lp_ntlm_auth(),
  95                                            user_info->logon_parameters,
  96                                            challenge,
  97                                            &user_info->lm_resp, &user_info->nt_resp,
  98                                            username,
  99                                            user_info->smb_name,
 100                                            user_info->client_domain,
 101                                            lm_hash,
 102                                            nt_hash,
 103                                            user_sess_key, lm_sess_key);
 104         }
 105 }
 106
 107 /****************************************************************************
 108  Check if a user is allowed to logon at this time. Note this is the
 109  servers local time, as logon hours are just specified as a weekly
 110  bitmask.
 111 ****************************************************************************/
 112
 113 static bool logon_hours_ok(struct samu *sampass)
 114 {
 115         /* In logon hours first bit is Sunday from 12AM to 1AM */
 116         const uint8 *hours;
 117         struct tm *utctime;
 118         time_t lasttime;
 119         const char *asct;
 120         uint8 bitmask, bitpos;
 121
 122         hours = pdb_get_hours(sampass);
 123         if (!hours) {
 124                 DEBUG(5,("logon_hours_ok: No hours restrictions for user %s\n",pdb_get_username(sampass)));
 125                 return True;
 126         }
 127
 128         lasttime = time(NULL);
 129         utctime = gmtime(&lasttime);
 130         if (!utctime) {
 131                 DEBUG(1, ("logon_hours_ok: failed to get gmtime. Failing logon for user %s\n",
 132                         pdb_get_username(sampass) ));
 133                 return False;
 134         }
 135
 136         /* find the corresponding byte and bit */
 137         bitpos = (utctime->tm_wday * 24 + utctime->tm_hour) % 168;
 138         bitmask = 1 << (bitpos % 8);
 139
 140         if (! (hours[bitpos/8] & bitmask)) {
 141                 struct tm *t = localtime(&lasttime);
 142                 if (!t) {
 143                         asct = "INVALID TIME";
 144                 } else {
 145                         asct = asctime(t);
 146                         if (!asct) {
 147                                 asct = "INVALID TIME";
 148                         }
 149                 }
 150
 151                 DEBUG(1, ("logon_hours_ok: Account for user %s not allowed to "
 152                           "logon at this time (%s).\n",
 153                           pdb_get_username(sampass), asct ));
 154                 return False;
 155         }
 156
 157         asct = asctime(utctime);
 158         DEBUG(5,("logon_hours_ok: user %s allowed to logon at this time (%s)\n",
 159                 pdb_get_username(sampass), asct ? asct : "UNKNOWN TIME" ));
 160
 161         return True;
 162 }
 163
 164 /****************************************************************************
 165  Do a specific test for a struct samu being valid for this connection
 166  (ie not disabled, expired and the like).
 167 ****************************************************************************/
 168
 169 static NTSTATUS sam_account_ok(TALLOC_CTX *mem_ctx,
 170                                struct samu *sampass,
 171                                const struct auth_usersupplied_info *user_info)
 172 {
 173         uint32  acct_ctrl = pdb_get_acct_ctrl(sampass);
 174         char *workstation_list;
 175         time_t kickoff_time;
 176
 177         DEBUG(4,("sam_account_ok: Checking SMB password for user %s\n",pdb_get_username(sampass)));
 178
 179         /* Quit if the account was disabled. */
 180         if (acct_ctrl & ACB_DISABLED) {
 181                 DEBUG(1,("sam_account_ok: Account for user '%s' was disabled.\n", pdb_get_username(sampass)));
 182                 return NT_STATUS_ACCOUNT_DISABLED;
 183         }
 184
 185         /* Quit if the account was locked out. */
 186         if (acct_ctrl & ACB_AUTOLOCK) {
 187                 DEBUG(1,("sam_account_ok: Account for user %s was locked out.\n", pdb_get_username(sampass)));
 188                 return NT_STATUS_ACCOUNT_LOCKED_OUT;
 189         }
 190
 191         /* Quit if the account is not allowed to logon at this time. */
 192         if (! logon_hours_ok(sampass)) {
 193                 return NT_STATUS_INVALID_LOGON_HOURS;
 194         }
 195
 196         /* Test account expire time */
 197
 198         kickoff_time = pdb_get_kickoff_time(sampass);
 199         if (kickoff_time != 0 && time(NULL) > kickoff_time) {
 200                 DEBUG(1,("sam_account_ok: Account for user '%s' has expired.\n", pdb_get_username(sampass)));
 201                 DEBUG(3,("sam_account_ok: Account expired at '%ld' unix time.\n", (long)kickoff_time));
 202                 return NT_STATUS_ACCOUNT_EXPIRED;
 203         }
 204
 205         if (!(pdb_get_acct_ctrl(sampass) & ACB_PWNOEXP) && !(pdb_get_acct_ctrl(sampass) & ACB_PWNOTREQ)) {
 206                 time_t must_change_time = pdb_get_pass_must_change_time(sampass);
 207                 time_t last_set_time = pdb_get_pass_last_set_time(sampass);
 208
 209                 /* check for immediate expiry "must change at next logon"
 210                  * for a user account. */
 211                 if (((acct_ctrl & (ACB_WSTRUST|ACB_SVRTRUST)) == 0) && (last_set_time == 0)) {
 212                         DEBUG(1,("sam_account_ok: Account for user '%s' password must change!\n", pdb_get_username(sampass)));
 213                         return NT_STATUS_PASSWORD_MUST_CHANGE;
 214                 }
 215
 216                 /* check for expired password */
 217                 if (must_change_time < time(NULL) && must_change_time != 0) {
 218                         DEBUG(1,("sam_account_ok: Account for user '%s' password expired!\n", pdb_get_username(sampass)));
 219                         DEBUG(1,("sam_account_ok: Password expired at '%s' (%ld) unix time.\n", http_timestring(talloc_tos(), must_change_time), (long)must_change_time));
 220                         return NT_STATUS_PASSWORD_EXPIRED;
 221                 }
 222         }
 223
 224         /* Test workstation. Workstation list is comma separated. */
 225
 226         workstation_list = talloc_strdup(mem_ctx, pdb_get_workstations(sampass));
 227         if (!workstation_list)
 228                 return NT_STATUS_NO_MEMORY;
 229
 230         if (*workstation_list) {
 231                 bool invalid_ws = True;
 232                 char *tok = NULL;
 233                 const char *s = workstation_list;
 234                 char *machine_name = talloc_asprintf(mem_ctx, "%s$", user_info->wksta_name);
 235
 236                 if (machine_name == NULL)
 237                         return NT_STATUS_NO_MEMORY;
 238
 239                 while (next_token_talloc(mem_ctx, &s, &tok, ",")) {
 240                         DEBUG(10,("sam_account_ok: checking for workstation match %s and %s\n",
 241                                   tok, user_info->wksta_name));
 242                         if(strequal(tok, user_info->wksta_name)) {
 243                                 invalid_ws = False;
 244                                 break;
 245                         }
 246                         if (tok[0] == '+') {
 247                                 DEBUG(10,("sam_account_ok: checking for workstation %s in group: %s\n",
 248                                         machine_name, tok + 1));
 249                                 if (user_in_group(machine_name, tok + 1)) {
 250                                         invalid_ws = False;
 251                                         break;
 252                                 }
 253                         }
 254                         TALLOC_FREE(tok);
 255                 }
 256                 TALLOC_FREE(tok);
 257                 TALLOC_FREE(machine_name);
 258
 259                 if (invalid_ws)
 260                         return NT_STATUS_INVALID_WORKSTATION;
 261         }
 262
 263         if (acct_ctrl & ACB_DOMTRUST) {
 264                 DEBUG(2,("sam_account_ok: Domain trust account %s denied by server\n", pdb_get_username(sampass)));
 265                 return NT_STATUS_NOLOGON_INTERDOMAIN_TRUST_ACCOUNT;
 266         }
 267
 268         if (acct_ctrl & ACB_SVRTRUST) {
 269                 if (!(user_info->logon_parameters & MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT)) {
 270                         DEBUG(2,("sam_account_ok: Server trust account %s denied by server\n", pdb_get_username(sampass)));
 271                         return NT_STATUS_NOLOGON_SERVER_TRUST_ACCOUNT;
 272                 }
 273         }
 274
 275         if (acct_ctrl & ACB_WSTRUST) {
 276                 if (!(user_info->logon_parameters & MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT)) {
 277                         DEBUG(2,("sam_account_ok: Wksta trust account %s denied by server\n", pdb_get_username(sampass)));
 278                         return NT_STATUS_NOLOGON_WORKSTATION_TRUST_ACCOUNT;
 279                 }
 280         }
 281         return NT_STATUS_OK;
 282 }
 283
 284 /**
 285  * Check whether the given password is one of the last two
 286  * password history entries. If so, the bad pwcount should
 287  * not be incremented even thought the actual password check
 288  * failed.
 289  */
 290 static bool need_to_increment_bad_pw_count(
 291         const DATA_BLOB *challenge,
 292         struct samu* sampass,
 293         const struct auth_usersupplied_info *user_info)
 294 {
 295         uint8_t i;
 296         const uint8_t *pwhistory;
 297         uint32_t pwhistory_len;
 298         uint32_t policy_pwhistory_len;
 299         uint32_t acct_ctrl;
 300         const char *username;
 301         TALLOC_CTX *mem_ctx = talloc_stackframe();
 302         bool result = true;
 303
 304         pdb_get_account_policy(PDB_POLICY_PASSWORD_HISTORY,
 305                                &policy_pwhistory_len);
 306         if (policy_pwhistory_len == 0) {
 307                 goto done;
 308         }
 309
 310         pwhistory = pdb_get_pw_history(sampass, &pwhistory_len);
 311         if (!pwhistory || pwhistory_len == 0) {
 312                 goto done;
 313         }
 314
 315         acct_ctrl = pdb_get_acct_ctrl(sampass);
 316         username = pdb_get_username(sampass);
 317
 318         for (i=1; i < MIN(MIN(3, policy_pwhistory_len), pwhistory_len); i++) {
 319                 static const uint8_t zero16[SALTED_MD5_HASH_LEN];
 320                 const uint8_t *salt;
 321                 const uint8_t *nt_pw;
 322                 NTSTATUS status;
 323                 DATA_BLOB user_sess_key = data_blob_null;
 324                 DATA_BLOB lm_sess_key = data_blob_null;
 325
 326                 salt = &pwhistory[i*PW_HISTORY_ENTRY_LEN];
 327                 nt_pw = salt + PW_HISTORY_SALT_LEN;
 328
 329                 if (memcmp(zero16, nt_pw, NT_HASH_LEN) == 0) {
 330                         /* skip zero password hash */
 331                         continue;
 332                 }
 333
 334                 if (memcmp(zero16, salt, PW_HISTORY_SALT_LEN) != 0) {
 335                         /* skip nonzero salt (old format entry) */
 336                         continue;
 337                 }
 338
 339                 status = sam_password_ok(mem_ctx,
 340                                          username, acct_ctrl,
 341                                          challenge,
 342                                          NULL, nt_pw,
 343                                          user_info, &user_sess_key, &lm_sess_key);
 344                 if (NT_STATUS_IS_OK(status)) {
 345                         result = false;
 346                         break;
 347                 }
 348         }
 349
 350 done:
 351         TALLOC_FREE(mem_ctx);
 352         return result;
 353 }
 354
 355 /****************************************************************************
 356 check if a username/password is OK assuming the password is a 24 byte
 357 SMB hash supplied in the user_info structure
 358 return an NT_STATUS constant.
 359 ****************************************************************************/
 360
 361 NTSTATUS check_sam_security(const DATA_BLOB *challenge,
 362                             TALLOC_CTX *mem_ctx,
 363                             const struct auth_usersupplied_info *user_info,
 364                             struct auth_serversupplied_info **server_info)
 365 {
 366         struct samu *sampass=NULL;
 367         bool ret;
 368         NTSTATUS nt_status;
 369         NTSTATUS update_login_attempts_status;
 370         DATA_BLOB user_sess_key = data_blob_null;
 371         DATA_BLOB lm_sess_key = data_blob_null;
 372         bool updated_autolock = False, updated_badpw = False;
 373         const char *username;
 374         const uint8_t *nt_pw;
 375         const uint8_t *lm_pw;
 376
 377         /* the returned struct gets kept on the server_info, by means
 378            of a steal further down */
 379
 380         sampass = samu_new(mem_ctx);
 381         if (sampass == NULL) {
 382                 return NT_STATUS_NO_MEMORY;
 383         }
 384
 385         /* get the account information */
 386
 387         become_root();
 388         ret = pdb_getsampwnam(sampass, user_info->internal_username);
 389         unbecome_root();
 390
 391         if (ret == False) {
 392                 DEBUG(3,("check_sam_security: Couldn't find user '%s' in "
 393                          "passdb.\n", user_info->internal_username));
 394                 TALLOC_FREE(sampass);
 395                 return NT_STATUS_NO_SUCH_USER;
 396         }
 397
 398         username = pdb_get_username(sampass);
 399         nt_pw = pdb_get_nt_passwd(sampass);
 400         lm_pw = pdb_get_lanman_passwd(sampass);
 401
 402         /* see if autolock flag needs to be updated */
 403         if (pdb_get_acct_ctrl(sampass) & ACB_NORMAL)
 404                 pdb_update_autolock_flag(sampass, &updated_autolock);
 405         /* Quit if the account was locked out. */
 406         if (pdb_get_acct_ctrl(sampass) & ACB_AUTOLOCK) {
 407                 DEBUG(3,("check_sam_security: Account for user %s was locked out.\n", username));
 408                 return NT_STATUS_ACCOUNT_LOCKED_OUT;
 409         }
 410
 411         nt_status = sam_password_ok(mem_ctx,
 412                                     username, pdb_get_acct_ctrl(sampass),
 413                                     challenge, lm_pw, nt_pw,
 414                                     user_info, &user_sess_key, &lm_sess_key);
 415
 416         /* Notify passdb backend of login success/failure. If not
 417            NT_STATUS_OK the backend doesn't like the login */
 418
 419         update_login_attempts_status = pdb_update_login_attempts(sampass, NT_STATUS_IS_OK(nt_status));
 420
 421         if (!NT_STATUS_IS_OK(nt_status)) {
 422                 bool increment_bad_pw_count = false;
 423
 424                 if (NT_STATUS_EQUAL(nt_status,NT_STATUS_WRONG_PASSWORD) &&
 425                     pdb_get_acct_ctrl(sampass) & ACB_NORMAL &&
 426                     NT_STATUS_IS_OK(update_login_attempts_status))
 427                 {
 428                         increment_bad_pw_count =
 429                                 need_to_increment_bad_pw_count(
 430                                         challenge, sampass, user_info);
 431                 }
 432
 433                 if (increment_bad_pw_count) {
 434                         pdb_increment_bad_password_count(sampass);
 435                         updated_badpw = True;
 436                 } else {
 437                         pdb_update_bad_password_count(sampass,
 438                                                       &updated_badpw);
 439                 }
 440                 if (updated_autolock || updated_badpw){
 441                         NTSTATUS status;
 442
 443                         become_root();
 444                         status = pdb_update_sam_account(sampass);
 445                         unbecome_root();
 446
 447                         if (!NT_STATUS_IS_OK(status)) {
 448                                 DEBUG(1, ("Failed to modify entry: %s\n",
 449                                           nt_errstr(status)));
 450                         }
 451                 }
 452                 goto done;
 453         }
 454
 455         if ((pdb_get_acct_ctrl(sampass) & ACB_NORMAL) &&
 456             (pdb_get_bad_password_count(sampass) > 0)){
 457                 pdb_set_bad_password_count(sampass, 0, PDB_CHANGED);
 458                 pdb_set_bad_password_time(sampass, 0, PDB_CHANGED);
 459                 updated_badpw = True;
 460         }
 461
 462         if (updated_autolock || updated_badpw){
 463                 NTSTATUS status;
 464
 465                 become_root();
 466                 status = pdb_update_sam_account(sampass);
 467                 unbecome_root();
 468
 469                 if (!NT_STATUS_IS_OK(status)) {
 470                         DEBUG(1, ("Failed to modify entry: %s\n",
 471                                   nt_errstr(status)));
 472                 }
 473         }
 474
 475         nt_status = sam_account_ok(mem_ctx, sampass, user_info);
 476
 477         if (!NT_STATUS_IS_OK(nt_status)) {
 478                 goto done;
 479         }
 480
 481         become_root();
 482         nt_status = make_server_info_sam(server_info, sampass);
 483         unbecome_root();
 484         /*
 485          * sampass has been stolen to server_info.
 486          * So NULL it out to prevent segfaults.
 487          */
 488         sampass = NULL;
 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 }