source3/winbindd/winbindd_cred_cache.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Winbind daemon - krb5 credential cache functions
   5    and in-memory cache functions.
   6
   7    Copyright (C) Guenther Deschner 2005-2006
   8    Copyright (C) Jeremy Allison 2006
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "winbindd.h"
  26 #undef DBGC_CLASS
  27 #define DBGC_CLASS DBGC_WINBIND
  28
  29 /* uncomment this to do fast debugging on the krb5 ticket renewal event */
  30 #ifdef DEBUG_KRB5_TKT_RENEWAL
  31 #undef DEBUG_KRB5_TKT_RENEWAL
  32 #endif
  33
  34 #define MAX_CCACHES 100
  35
  36 static struct WINBINDD_CCACHE_ENTRY *ccache_list;
  37 static void krb5_ticket_gain_handler(struct event_context *,
  38                                      struct timed_event *,
  39                                      struct timeval,
  40                                      void *);
  41
  42 /* The Krb5 ticket refresh handler should be scheduled
  43    at one-half of the period from now till the tkt
  44    expiration */
  45 #define KRB5_EVENT_REFRESH_TIME(x) ((x) - (((x) - time(NULL))/2))
  46
  47 /****************************************************************
  48  Find an entry by name.
  49 ****************************************************************/
  50
  51 static struct WINBINDD_CCACHE_ENTRY *get_ccache_by_username(const char *username)
  52 {
  53         struct WINBINDD_CCACHE_ENTRY *entry;
  54
  55         for (entry = ccache_list; entry; entry = entry->next) {
  56                 if (strequal(entry->username, username)) {
  57                         return entry;
  58                 }
  59         }
  60         return NULL;
  61 }
  62
  63 /****************************************************************
  64  How many do we have ?
  65 ****************************************************************/
  66
  67 static int ccache_entry_count(void)
  68 {
  69         struct WINBINDD_CCACHE_ENTRY *entry;
  70         int i = 0;
  71
  72         for (entry = ccache_list; entry; entry = entry->next) {
  73                 i++;
  74         }
  75         return i;
  76 }
  77
  78 void ccache_remove_all_after_fork(void)
  79 {
  80         struct WINBINDD_CCACHE_ENTRY *cur, *next;
  81
  82         for (cur = ccache_list; cur; cur = next) {
  83                 next = cur->next;
  84                 DLIST_REMOVE(ccache_list, cur);
  85                 TALLOC_FREE(cur->event);
  86                 TALLOC_FREE(cur);
  87         }
  88
  89         return;
  90 }
  91
  92 /****************************************************************
  93  Do the work of refreshing the ticket.
  94 ****************************************************************/
  95
  96 static void krb5_ticket_refresh_handler(struct event_context *event_ctx,
  97                                         struct timed_event *te,
  98                                         struct timeval now,
  99                                         void *private_data)
 100 {
 101         struct WINBINDD_CCACHE_ENTRY *entry =
 102                 talloc_get_type_abort(private_data, struct WINBINDD_CCACHE_ENTRY);
 103 #ifdef HAVE_KRB5
 104         int ret;
 105         time_t new_start;
 106         time_t expire_time = 0;
 107         struct WINBINDD_MEMORY_CREDS *cred_ptr = entry->cred_ptr;
 108 #endif
 109
 110         DEBUG(10,("krb5_ticket_refresh_handler called\n"));
 111         DEBUGADD(10,("event called for: %s, %s\n",
 112                 entry->ccname, entry->username));
 113
 114         TALLOC_FREE(entry->event);
 115
 116 #ifdef HAVE_KRB5
 117
 118         /* Kinit again if we have the user password and we can't renew the old
 119          * tgt anymore
 120          * NB
 121          * This happens when machine are put to sleep for a very long time. */
 122
 123         if (entry->renew_until < time(NULL)) {
 124 rekinit:
 125                 if (cred_ptr && cred_ptr->pass) {
 126
 127                         set_effective_uid(entry->uid);
 128
 129                         ret = kerberos_kinit_password_ext(entry->principal_name,
 130                                                           cred_ptr->pass,
 131                                                           0, /* hm, can we do time correction here ? */
 132                                                           &entry->refresh_time,
 133                                                           &entry->renew_until,
 134                                                           entry->ccname,
 135                                                           False, /* no PAC required anymore */
 136                                                           True,
 137                                                           WINBINDD_PAM_AUTH_KRB5_RENEW_TIME,
 138                                                           NULL);
 139                         gain_root_privilege();
 140
 141                         if (ret) {
 142                                 DEBUG(3,("krb5_ticket_refresh_handler: "
 143                                         "could not re-kinit: %s\n",
 144                                         error_message(ret)));
 145                                 /* destroy the ticket because we cannot rekinit
 146                                  * it, ignore error here */
 147                                 ads_kdestroy(entry->ccname);
 148
 149                                 /* Don't break the ticket refresh chain: retry
 150                                  * refreshing ticket sometime later when KDC is
 151                                  * unreachable -- BoYang. More error code handling
 152                                  * here?
 153                                  * */
 154
 155                                 if ((ret == KRB5_KDC_UNREACH)
 156                                     || (ret == KRB5_REALM_CANT_RESOLVE)) {
 157 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 158                                         new_start = time(NULL) + 30;
 159 #else
 160                                         new_start = time(NULL) +
 161                                                     MAX(30, lp_winbind_cache_time());
 162 #endif
 163                                         entry->refresh_time = 0;
 164                                         /* try to regain ticket here */
 165                                         entry->event = event_add_timed(winbind_event_context(),
 166                                                                        entry,
 167                                                                        timeval_set(new_start, 0),
 168                                                                        krb5_ticket_gain_handler,
 169                                                                        entry);
 170                                         return;
 171                                 }
 172                                 TALLOC_FREE(entry->event);
 173                                 return;
 174                         }
 175
 176                         DEBUG(10,("krb5_ticket_refresh_handler: successful re-kinit "
 177                                 "for: %s in ccache: %s\n",
 178                                 entry->principal_name, entry->ccname));
 179
 180 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 181                         new_start = time(NULL) + 30;
 182 #else
 183                         /* The tkt should be refreshed at one-half the period
 184                            from now to the expiration time */
 185                         expire_time = entry->refresh_time;
 186                         new_start = KRB5_EVENT_REFRESH_TIME(entry->refresh_time);
 187 #endif
 188                         goto done;
 189                 } else {
 190                                 /* can this happen?
 191                                  * No cached credentials
 192                                  * destroy ticket and refresh chain
 193                                  * */
 194                                 ads_kdestroy(entry->ccname);
 195                                 TALLOC_FREE(entry->event);
 196                                 return;
 197                 }
 198         }
 199
 200         set_effective_uid(entry->uid);
 201
 202         ret = smb_krb5_renew_ticket(entry->ccname,
 203                                     entry->principal_name,
 204                                     entry->service,
 205                                     &new_start);
 206 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 207         new_start = time(NULL) + 30;
 208 #else
 209         expire_time = new_start;
 210         new_start = KRB5_EVENT_REFRESH_TIME(new_start);
 211 #endif
 212
 213         gain_root_privilege();
 214
 215         if (ret) {
 216                 DEBUG(3,("krb5_ticket_refresh_handler: "
 217                         "could not renew tickets: %s\n",
 218                         error_message(ret)));
 219                 /* maybe we are beyond the renewing window */
 220
 221                 /* evil rises here, we refresh ticket failed,
 222                  * but the ticket might be expired. Therefore,
 223                  * When we refresh ticket failed, destory the
 224                  * ticket */
 225
 226                 ads_kdestroy(entry->ccname);
 227
 228                 /* avoid breaking the renewal chain: retry in
 229                  * lp_winbind_cache_time() seconds when the KDC was not
 230                  * available right now.
 231                  * the return code can be KRB5_REALM_CANT_RESOLVE.
 232                  * More error code handling here? */
 233
 234                 if ((ret == KRB5_KDC_UNREACH)
 235                     || (ret == KRB5_REALM_CANT_RESOLVE)) {
 236 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 237                         new_start = time(NULL) + 30;
 238 #else
 239                         new_start = time(NULL) +
 240                                     MAX(30, lp_winbind_cache_time());
 241 #endif
 242                         /* ticket is destroyed here, we have to regain it
 243                          * if it is possible */
 244                         entry->refresh_time = 0;
 245                         entry->event = event_add_timed(winbind_event_context(),
 246                                                         entry,
 247                                                         timeval_set(new_start, 0),
 248                                                         krb5_ticket_gain_handler,
 249                                                         entry);
 250                         return;
 251                 }
 252
 253                 /* This is evil, if the ticket was already expired.
 254                  * renew ticket function returns KRB5KRB_AP_ERR_TKT_EXPIRED.
 255                  * But there is still a chance that we can rekinit it.
 256                  *
 257                  * This happens when user login in online mode, and then network
 258                  * down or something cause winbind goes offline for a very long time,
 259                  * and then goes online again. ticket expired, renew failed.
 260                  * This happens when machine are put to sleep for a long time,
 261                  * but shorter than entry->renew_util.
 262                  * NB
 263                  * Looks like the KDC is reachable, we want to rekinit as soon as
 264                  * possible instead of waiting some time later. */
 265                 if ((ret == KRB5KRB_AP_ERR_TKT_EXPIRED)
 266                     || (ret == KRB5_FCC_NOFILE)) goto rekinit;
 267
 268                 return;
 269         }
 270
 271 done:
 272         /* in cases that ticket will be unrenewable soon, we don't try to renew ticket
 273          * but try to regain ticket if it is possible */
 274         if (entry->renew_until && expire_time
 275              && (entry->renew_until <= expire_time)) {
 276                 /* try to regain ticket 10 seconds beforre expiration */
 277                 expire_time -= 10;
 278                 entry->refresh_time = 0;
 279                 entry->event = event_add_timed(winbind_event_context(), entry,
 280                                                 timeval_set(expire_time, 0),
 281                                                 krb5_ticket_gain_handler,
 282                                                 entry);
 283                 return;
 284         }
 285
 286         if (entry->refresh_time == 0) {
 287                 entry->refresh_time = new_start;
 288         }
 289         entry->event = event_add_timed(winbind_event_context(), entry,
 290                                        timeval_set(new_start, 0),
 291                                        krb5_ticket_refresh_handler,
 292                                        entry);
 293
 294 #endif
 295 }
 296
 297 /****************************************************************
 298  Do the work of regaining a ticket when coming from offline auth.
 299 ****************************************************************/
 300
 301 static void krb5_ticket_gain_handler(struct event_context *event_ctx,
 302                                      struct timed_event *te,
 303                                      struct timeval now,
 304                                      void *private_data)
 305 {
 306         struct WINBINDD_CCACHE_ENTRY *entry =
 307                 talloc_get_type_abort(private_data, struct WINBINDD_CCACHE_ENTRY);
 308 #ifdef HAVE_KRB5
 309         int ret;
 310         struct timeval t;
 311         struct WINBINDD_MEMORY_CREDS *cred_ptr = entry->cred_ptr;
 312         struct winbindd_domain *domain = NULL;
 313 #endif
 314
 315         DEBUG(10,("krb5_ticket_gain_handler called\n"));
 316         DEBUGADD(10,("event called for: %s, %s\n",
 317                 entry->ccname, entry->username));
 318
 319         TALLOC_FREE(entry->event);
 320
 321 #ifdef HAVE_KRB5
 322
 323         if (!cred_ptr || !cred_ptr->pass) {
 324                 DEBUG(10,("krb5_ticket_gain_handler: no memory creds\n"));
 325                 return;
 326         }
 327
 328         if ((domain = find_domain_from_name(entry->realm)) == NULL) {
 329                 DEBUG(0,("krb5_ticket_gain_handler: unknown domain\n"));
 330                 return;
 331         }
 332
 333         if (!domain->online) {
 334                 goto retry_later;
 335         }
 336
 337         set_effective_uid(entry->uid);
 338
 339         ret = kerberos_kinit_password_ext(entry->principal_name,
 340                                           cred_ptr->pass,
 341                                           0, /* hm, can we do time correction here ? */
 342                                           &entry->refresh_time,
 343                                           &entry->renew_until,
 344                                           entry->ccname,
 345                                           False, /* no PAC required anymore */
 346                                           True,
 347                                           WINBINDD_PAM_AUTH_KRB5_RENEW_TIME,
 348                                           NULL);
 349         gain_root_privilege();
 350
 351         if (ret) {
 352                 DEBUG(3,("krb5_ticket_gain_handler: "
 353                         "could not kinit: %s\n",
 354                         error_message(ret)));
 355                 /* evil. If we cannot do it, destroy any the __maybe__
 356                  * __existing__ ticket */
 357                 ads_kdestroy(entry->ccname);
 358                 goto retry_later;
 359         }
 360
 361         DEBUG(10,("krb5_ticket_gain_handler: "
 362                 "successful kinit for: %s in ccache: %s\n",
 363                 entry->principal_name, entry->ccname));
 364
 365         goto got_ticket;
 366
 367   retry_later:
 368
 369 #if defined(DEBUG_KRB5_TKT_REGAIN)
 370         t = timeval_set(time(NULL) + 30, 0);
 371 #else
 372         t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 373 #endif
 374
 375         entry->refresh_time = 0;
 376         entry->event = event_add_timed(winbind_event_context(),
 377                                        entry,
 378                                        t,
 379                                        krb5_ticket_gain_handler,
 380                                        entry);
 381
 382         return;
 383
 384   got_ticket:
 385
 386 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 387         t = timeval_set(time(NULL) + 30, 0);
 388 #else
 389         t = timeval_set(KRB5_EVENT_REFRESH_TIME(entry->refresh_time), 0);
 390 #endif
 391
 392         if (entry->refresh_time == 0) {
 393                 entry->refresh_time = t.tv_sec;
 394         }
 395         entry->event = event_add_timed(winbind_event_context(),
 396                                        entry,
 397                                        t,
 398                                        krb5_ticket_refresh_handler,
 399                                        entry);
 400
 401         return;
 402 #endif
 403 }
 404
 405 void ccache_regain_all_now(void)
 406 {
 407         struct WINBINDD_CCACHE_ENTRY *cur;
 408         struct timeval t = timeval_current();
 409
 410         for (cur = ccache_list; cur; cur = cur->next) {
 411                 struct timed_event *new_event;
 412
 413                 /*
 414                  * if refresh_time is 0, we know that the
 415                  * the event has the krb5_ticket_gain_handler
 416                  */
 417                 if (cur->refresh_time == 0) {
 418                         new_event = event_add_timed(winbind_event_context(),
 419                                                     cur,
 420                                                     t,
 421                                                     krb5_ticket_gain_handler,
 422                                                     cur);
 423                 } else {
 424                         new_event = event_add_timed(winbind_event_context(),
 425                                                     cur,
 426                                                     t,
 427                                                     krb5_ticket_refresh_handler,
 428                                                     cur);
 429                 }
 430
 431                 if (!new_event) {
 432                         continue;
 433                 }
 434
 435                 TALLOC_FREE(cur->event);
 436                 cur->event = new_event;
 437         }
 438
 439         return;
 440 }
 441
 442 /****************************************************************
 443  Check if an ccache entry exists.
 444 ****************************************************************/
 445
 446 bool ccache_entry_exists(const char *username)
 447 {
 448         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 449         return (entry != NULL);
 450 }
 451
 452 /****************************************************************
 453  Ensure we're changing the correct entry.
 454 ****************************************************************/
 455
 456 bool ccache_entry_identical(const char *username,
 457                             uid_t uid,
 458                             const char *ccname)
 459 {
 460         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 461
 462         if (!entry) {
 463                 return False;
 464         }
 465
 466         if (entry->uid != uid) {
 467                 DEBUG(0,("cache_entry_identical: uid's differ: %u != %u\n",
 468                         (unsigned int)entry->uid, (unsigned int)uid));
 469                 return False;
 470         }
 471         if (!strcsequal(entry->ccname, ccname)) {
 472                 DEBUG(0,("cache_entry_identical: "
 473                         "ccnames differ: (cache) %s != (client) %s\n",
 474                         entry->ccname, ccname));
 475                 return False;
 476         }
 477         return True;
 478 }
 479
 480 NTSTATUS add_ccache_to_list(const char *princ_name,
 481                             const char *ccname,
 482                             const char *service,
 483                             const char *username,
 484                             const char *realm,
 485                             uid_t uid,
 486                             time_t create_time,
 487                             time_t ticket_end,
 488                             time_t renew_until,
 489                             bool postponed_request)
 490 {
 491         struct WINBINDD_CCACHE_ENTRY *entry = NULL;
 492         struct timeval t;
 493         NTSTATUS ntret;
 494 #ifdef HAVE_KRB5
 495         int ret;
 496 #endif
 497
 498         if ((username == NULL && princ_name == NULL) ||
 499             ccname == NULL || uid < 0) {
 500                 return NT_STATUS_INVALID_PARAMETER;
 501         }
 502
 503         if (ccache_entry_count() + 1 > MAX_CCACHES) {
 504                 DEBUG(10,("add_ccache_to_list: "
 505                         "max number of ccaches reached\n"));
 506                 return NT_STATUS_NO_MORE_ENTRIES;
 507         }
 508
 509         /* If it is cached login, destroy krb5 ticket
 510          * to avoid surprise. */
 511 #ifdef HAVE_KRB5
 512         if (postponed_request) {
 513                 /* ignore KRB5_FCC_NOFILE error here */
 514                 ret = ads_kdestroy(ccname);
 515                 if (ret == KRB5_FCC_NOFILE) {
 516                         ret = 0;
 517                 }
 518                 if (ret) {
 519                         DEBUG(0, ("add_ccache_to_list: failed to destroy "
 520                                    "user krb5 ccache %s with %s\n", ccname,
 521                                    error_message(ret)));
 522                         return krb5_to_nt_status(ret);
 523                 } else {
 524                         DEBUG(10, ("add_ccache_to_list: successfully destroyed "
 525                                    "krb5 ccache %s for user %s\n", ccname,
 526                                    username));
 527                 }
 528         }
 529 #endif
 530
 531         /* Reference count old entries */
 532         entry = get_ccache_by_username(username);
 533         if (entry) {
 534                 /* Check cached entries are identical. */
 535                 if (!ccache_entry_identical(username, uid, ccname)) {
 536                         return NT_STATUS_INVALID_PARAMETER;
 537                 }
 538                 entry->ref_count++;
 539                 DEBUG(10,("add_ccache_to_list: "
 540                         "ref count on entry %s is now %d\n",
 541                         username, entry->ref_count));
 542                 /* FIXME: in this case we still might want to have a krb5 cred
 543                  * event handler created - gd
 544                  * Add ticket refresh handler here */
 545
 546                 if (!lp_winbind_refresh_tickets() || renew_until <= 0) {
 547                         return NT_STATUS_OK;
 548                 }
 549
 550                 if (!entry->event) {
 551                         if (postponed_request) {
 552                                 t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 553                                 entry->refresh_time = 0;
 554                                 entry->event = event_add_timed(winbind_event_context(),
 555                                                                entry,
 556                                                                t,
 557                                                                krb5_ticket_gain_handler,
 558                                                                entry);
 559                         } else {
 560                                 /* Renew at 1/2 the ticket expiration time */
 561 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 562                                 t = timeval_set(time(NULL)+30, 0);
 563 #else
 564                                 t = timeval_set(KRB5_EVENT_REFRESH_TIME(ticket_end), 0);
 565 #endif
 566                                 if (!entry->refresh_time) {
 567                                         entry->refresh_time = t.tv_sec;
 568                                 }
 569                                 entry->event = event_add_timed(winbind_event_context(),
 570                                                                entry,
 571                                                                t,
 572                                                                krb5_ticket_refresh_handler,
 573                                                                entry);
 574                         }
 575
 576                         if (!entry->event) {
 577                                 ntret = remove_ccache(username);
 578                                 if (!NT_STATUS_IS_OK(ntret)) {
 579                                         DEBUG(0, ("add_ccache_to_list: Failed to remove krb5 "
 580                                                   "ccache %s for user %s\n", entry->ccname,
 581                                                   entry->username));
 582                                         DEBUG(0, ("add_ccache_to_list: error is %s\n",
 583                                                   nt_errstr(ntret)));
 584                                         return ntret;
 585                                 }
 586                                 return NT_STATUS_NO_MEMORY;
 587                         }
 588
 589                         DEBUG(10,("add_ccache_to_list: added krb5_ticket handler\n"));
 590                 }
 591
 592                 return NT_STATUS_OK;
 593         }
 594
 595         entry = TALLOC_P(NULL, struct WINBINDD_CCACHE_ENTRY);
 596         if (!entry) {
 597                 return NT_STATUS_NO_MEMORY;
 598         }
 599
 600         ZERO_STRUCTP(entry);
 601
 602         if (username) {
 603                 entry->username = talloc_strdup(entry, username);
 604                 if (!entry->username) {
 605                         goto no_mem;
 606                 }
 607         }
 608         if (princ_name) {
 609                 entry->principal_name = talloc_strdup(entry, princ_name);
 610                 if (!entry->principal_name) {
 611                         goto no_mem;
 612                 }
 613         }
 614         if (service) {
 615                 entry->service = talloc_strdup(entry, service);
 616                 if (!entry->service) {
 617                         goto no_mem;
 618                 }
 619         }
 620
 621         entry->ccname = talloc_strdup(entry, ccname);
 622         if (!entry->ccname) {
 623                 goto no_mem;
 624         }
 625
 626         entry->realm = talloc_strdup(entry, realm);
 627         if (!entry->realm) {
 628                 goto no_mem;
 629         }
 630
 631         entry->create_time = create_time;
 632         entry->renew_until = renew_until;
 633         entry->uid = uid;
 634         entry->ref_count = 1;
 635
 636         if (!lp_winbind_refresh_tickets() || renew_until <= 0) {
 637                 goto add_entry;
 638         }
 639
 640         if (postponed_request) {
 641                 t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 642                 entry->refresh_time = 0;
 643                 entry->event = event_add_timed(winbind_event_context(),
 644                                                entry,
 645                                                t,
 646                                                krb5_ticket_gain_handler,
 647                                                entry);
 648         } else {
 649                 /* Renew at 1/2 the ticket expiration time */
 650 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 651                 t = timeval_set(time(NULL)+30, 0);
 652 #else
 653                 t = timeval_set(KRB5_EVENT_REFRESH_TIME(ticket_end), 0);
 654 #endif
 655                 if (entry->refresh_time == 0) {
 656                         entry->refresh_time = t.tv_sec;
 657                 }
 658                 entry->event = event_add_timed(winbind_event_context(),
 659                                                entry,
 660                                                t,
 661                                                krb5_ticket_refresh_handler,
 662                                                entry);
 663         }
 664
 665         if (!entry->event) {
 666                 goto no_mem;
 667         }
 668
 669         DEBUG(10,("add_ccache_to_list: added krb5_ticket handler\n"));
 670
 671  add_entry:
 672
 673         DLIST_ADD(ccache_list, entry);
 674
 675         DEBUG(10,("add_ccache_to_list: "
 676                 "added ccache [%s] for user [%s] to the list\n",
 677                 ccname, username));
 678
 679         return NT_STATUS_OK;
 680
 681  no_mem:
 682
 683         TALLOC_FREE(entry);
 684         return NT_STATUS_NO_MEMORY;
 685 }
 686
 687 /*******************************************************************
 688  Remove a WINBINDD_CCACHE_ENTRY entry and the krb5 ccache if no longer
 689  referenced.
 690  *******************************************************************/
 691
 692 NTSTATUS remove_ccache(const char *username)
 693 {
 694         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 695         NTSTATUS status = NT_STATUS_OK;
 696         #ifdef HAVE_KRB5
 697         krb5_error_code ret;
 698 #endif
 699
 700         if (!entry) {
 701                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 702         }
 703
 704         if (entry->ref_count <= 0) {
 705                 DEBUG(0,("remove_ccache: logic error. "
 706                         "ref count for user %s = %d\n",
 707                         username, entry->ref_count));
 708                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 709         }
 710
 711         entry->ref_count--;
 712
 713         if (entry->ref_count > 0) {
 714                 DEBUG(10,("remove_ccache: entry %s ref count now %d\n",
 715                         username, entry->ref_count));
 716                 return NT_STATUS_OK;
 717         }
 718
 719         /* no references any more */
 720
 721         DLIST_REMOVE(ccache_list, entry);
 722         TALLOC_FREE(entry->event); /* unregisters events */
 723
 724 #ifdef HAVE_KRB5
 725         ret = ads_kdestroy(entry->ccname);
 726
 727         /* we ignore the error when there has been no credential cache */
 728         if (ret == KRB5_FCC_NOFILE) {
 729                 ret = 0;
 730         } else if (ret) {
 731                 DEBUG(0,("remove_ccache: "
 732                         "failed to destroy user krb5 ccache %s with: %s\n",
 733                         entry->ccname, error_message(ret)));
 734         } else {
 735                 DEBUG(10,("remove_ccache: "
 736                         "successfully destroyed krb5 ccache %s for user %s\n",
 737                         entry->ccname, username));
 738         }
 739         status = krb5_to_nt_status(ret);
 740 #endif
 741
 742         TALLOC_FREE(entry);
 743         DEBUG(10,("remove_ccache: removed ccache for user %s\n", username));
 744
 745         return status;
 746 }
 747
 748 /*******************************************************************
 749  In memory credentials cache code.
 750 *******************************************************************/
 751
 752 static struct WINBINDD_MEMORY_CREDS *memory_creds_list;
 753
 754 /***********************************************************
 755  Find an entry on the list by name.
 756 ***********************************************************/
 757
 758 struct WINBINDD_MEMORY_CREDS *find_memory_creds_by_name(const char *username)
 759 {
 760         struct WINBINDD_MEMORY_CREDS *p;
 761
 762         for (p = memory_creds_list; p; p = p->next) {
 763                 if (strequal(p->username, username)) {
 764                         return p;
 765                 }
 766         }
 767         return NULL;
 768 }
 769
 770 /***********************************************************
 771  Store the required creds and mlock them.
 772 ***********************************************************/
 773
 774 static NTSTATUS store_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp,
 775                                    const char *pass)
 776 {
 777 #if !defined(HAVE_MLOCK)
 778         return NT_STATUS_OK;
 779 #else
 780         /* new_entry->nt_hash is the base pointer for the block
 781            of memory pointed into by new_entry->lm_hash and
 782            new_entry->pass (if we're storing plaintext). */
 783
 784         memcredp->len = NT_HASH_LEN + LM_HASH_LEN;
 785         if (pass) {
 786                 memcredp->len += strlen(pass)+1;
 787         }
 788
 789
 790 #if defined(LINUX)
 791         /* aligning the memory on on x86_64 and compiling
 792            with gcc 4.1 using -O2 causes a segv in the
 793            next memset()  --jerry */
 794         memcredp->nt_hash = SMB_MALLOC_ARRAY(unsigned char, memcredp->len);
 795 #else
 796         /* On non-linux platforms, mlock()'d memory must be aligned */
 797         memcredp->nt_hash = SMB_MEMALIGN_ARRAY(unsigned char,
 798                                                getpagesize(), memcredp->len);
 799 #endif
 800         if (!memcredp->nt_hash) {
 801                 return NT_STATUS_NO_MEMORY;
 802         }
 803         memset(memcredp->nt_hash, 0x0, memcredp->len);
 804
 805         memcredp->lm_hash = memcredp->nt_hash + NT_HASH_LEN;
 806
 807 #ifdef DEBUG_PASSWORD
 808         DEBUG(10,("mlocking memory: %p\n", memcredp->nt_hash));
 809 #endif
 810         if ((mlock(memcredp->nt_hash, memcredp->len)) == -1) {
 811                 DEBUG(0,("failed to mlock memory: %s (%d)\n",
 812                         strerror(errno), errno));
 813                 SAFE_FREE(memcredp->nt_hash);
 814                 return map_nt_error_from_unix(errno);
 815         }
 816
 817 #ifdef DEBUG_PASSWORD
 818         DEBUG(10,("mlocked memory: %p\n", memcredp->nt_hash));
 819 #endif
 820
 821         /* Create and store the password hashes. */
 822         E_md4hash(pass, memcredp->nt_hash);
 823         E_deshash(pass, memcredp->lm_hash);
 824
 825         if (pass) {
 826                 memcredp->pass = (char *)memcredp->lm_hash + LM_HASH_LEN;
 827                 memcpy(memcredp->pass, pass,
 828                        memcredp->len - NT_HASH_LEN - LM_HASH_LEN);
 829         }
 830
 831         return NT_STATUS_OK;
 832 #endif
 833 }
 834
 835 /***********************************************************
 836  Destroy existing creds.
 837 ***********************************************************/
 838
 839 static NTSTATUS delete_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp)
 840 {
 841 #if !defined(HAVE_MUNLOCK)
 842         return NT_STATUS_OK;
 843 #else
 844         if (munlock(memcredp->nt_hash, memcredp->len) == -1) {
 845                 DEBUG(0,("failed to munlock memory: %s (%d)\n",
 846                         strerror(errno), errno));
 847                 return map_nt_error_from_unix(errno);
 848         }
 849         memset(memcredp->nt_hash, '\0', memcredp->len);
 850         SAFE_FREE(memcredp->nt_hash);
 851         memcredp->nt_hash = NULL;
 852         memcredp->lm_hash = NULL;
 853         memcredp->pass = NULL;
 854         memcredp->len = 0;
 855         return NT_STATUS_OK;
 856 #endif
 857 }
 858
 859 /***********************************************************
 860  Replace the required creds with new ones (password change).
 861 ***********************************************************/
 862
 863 static NTSTATUS winbindd_replace_memory_creds_internal(struct WINBINDD_MEMORY_CREDS *memcredp,
 864                                                        const char *pass)
 865 {
 866         NTSTATUS status = delete_memory_creds(memcredp);
 867         if (!NT_STATUS_IS_OK(status)) {
 868                 return status;
 869         }
 870         return store_memory_creds(memcredp, pass);
 871 }
 872
 873 /*************************************************************
 874  Store credentials in memory in a list.
 875 *************************************************************/
 876
 877 static NTSTATUS winbindd_add_memory_creds_internal(const char *username,
 878                                                    uid_t uid,
 879                                                    const char *pass)
 880 {
 881         /* Shortcut to ensure we don't store if no mlock. */
 882 #if !defined(HAVE_MLOCK) || !defined(HAVE_MUNLOCK)
 883         return NT_STATUS_OK;
 884 #else
 885         NTSTATUS status;
 886         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
 887
 888         memcredp = find_memory_creds_by_name(username);
 889         if (uid == (uid_t)-1) {
 890                 DEBUG(0,("winbindd_add_memory_creds_internal: "
 891                         "invalid uid for user %s.\n", username));
 892                 return NT_STATUS_INVALID_PARAMETER;
 893         }
 894
 895         if (memcredp) {
 896                 /* Already exists. Increment the reference count and replace stored creds. */
 897                 if (uid != memcredp->uid) {
 898                         DEBUG(0,("winbindd_add_memory_creds_internal: "
 899                                 "uid %u for user %s doesn't "
 900                                 "match stored uid %u. Replacing.\n",
 901                                 (unsigned int)uid, username,
 902                                 (unsigned int)memcredp->uid));
 903                         memcredp->uid = uid;
 904                 }
 905                 memcredp->ref_count++;
 906                 DEBUG(10,("winbindd_add_memory_creds_internal: "
 907                         "ref count for user %s is now %d\n",
 908                         username, memcredp->ref_count));
 909                 return winbindd_replace_memory_creds_internal(memcredp, pass);
 910         }
 911
 912         memcredp = TALLOC_ZERO_P(NULL, struct WINBINDD_MEMORY_CREDS);
 913         if (!memcredp) {
 914                 return NT_STATUS_NO_MEMORY;
 915         }
 916         memcredp->username = talloc_strdup(memcredp, username);
 917         if (!memcredp->username) {
 918                 talloc_destroy(memcredp);
 919                 return NT_STATUS_NO_MEMORY;
 920         }
 921
 922         status = store_memory_creds(memcredp, pass);
 923         if (!NT_STATUS_IS_OK(status)) {
 924                 talloc_destroy(memcredp);
 925                 return status;
 926         }
 927
 928         memcredp->uid = uid;
 929         memcredp->ref_count = 1;
 930         DLIST_ADD(memory_creds_list, memcredp);
 931
 932         DEBUG(10,("winbindd_add_memory_creds_internal: "
 933                 "added entry for user %s\n", username));
 934
 935         return NT_STATUS_OK;
 936 #endif
 937 }
 938
 939 /*************************************************************
 940  Store users credentials in memory. If we also have a
 941  struct WINBINDD_CCACHE_ENTRY for this username with a
 942  refresh timer, then store the plaintext of the password
 943  and associate the new credentials with the struct WINBINDD_CCACHE_ENTRY.
 944 *************************************************************/
 945
 946 NTSTATUS winbindd_add_memory_creds(const char *username,
 947                                    uid_t uid,
 948                                    const char *pass)
 949 {
 950         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 951         NTSTATUS status;
 952
 953         status = winbindd_add_memory_creds_internal(username, uid, pass);
 954         if (!NT_STATUS_IS_OK(status)) {
 955                 return status;
 956         }
 957
 958         if (entry) {
 959                 struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
 960                 memcredp = find_memory_creds_by_name(username);
 961                 if (memcredp) {
 962                         entry->cred_ptr = memcredp;
 963                 }
 964         }
 965
 966         return status;
 967 }
 968
 969 /*************************************************************
 970  Decrement the in-memory ref count - delete if zero.
 971 *************************************************************/
 972
 973 NTSTATUS winbindd_delete_memory_creds(const char *username)
 974 {
 975         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
 976         struct WINBINDD_CCACHE_ENTRY *entry = NULL;
 977         NTSTATUS status = NT_STATUS_OK;
 978
 979         memcredp = find_memory_creds_by_name(username);
 980         entry = get_ccache_by_username(username);
 981
 982         if (!memcredp) {
 983                 DEBUG(10,("winbindd_delete_memory_creds: unknown user %s\n",
 984                         username));
 985                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 986         }
 987
 988         if (memcredp->ref_count <= 0) {
 989                 DEBUG(0,("winbindd_delete_memory_creds: logic error. "
 990                         "ref count for user %s = %d\n",
 991                         username, memcredp->ref_count));
 992                 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
 993         }
 994
 995         memcredp->ref_count--;
 996         if (memcredp->ref_count <= 0) {
 997                 delete_memory_creds(memcredp);
 998                 DLIST_REMOVE(memory_creds_list, memcredp);
 999                 talloc_destroy(memcredp);
1000                 DEBUG(10,("winbindd_delete_memory_creds: "
1001                         "deleted entry for user %s\n",
1002                         username));
1003         } else {
1004                 DEBUG(10,("winbindd_delete_memory_creds: "
1005                         "entry for user %s ref_count now %d\n",
1006                         username, memcredp->ref_count));
1007         }
1008
1009         if (entry) {
1010                 /* Ensure we have no dangling references to this. */
1011                 entry->cred_ptr = NULL;
1012         }
1013
1014         return status;
1015 }
1016
1017 /***********************************************************
1018  Replace the required creds with new ones (password change).
1019 ***********************************************************/
1020
1021 NTSTATUS winbindd_replace_memory_creds(const char *username,
1022                                        const char *pass)
1023 {
1024         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
1025
1026         memcredp = find_memory_creds_by_name(username);
1027         if (!memcredp) {
1028                 DEBUG(10,("winbindd_replace_memory_creds: unknown user %s\n",
1029                         username));
1030                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
1031         }
1032
1033         DEBUG(10,("winbindd_replace_memory_creds: replaced creds for user %s\n",
1034                 username));
1035
1036         return winbindd_replace_memory_creds_internal(memcredp, pass);
1037 }