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 #include "smb_krb5.h"
  27
  28 #undef DBGC_CLASS
  29 #define DBGC_CLASS DBGC_WINBIND
  30
  31 /* uncomment this to do fast debugging on the krb5 ticket renewal event */
  32 #ifdef DEBUG_KRB5_TKT_RENEWAL
  33 #undef DEBUG_KRB5_TKT_RENEWAL
  34 #endif
  35
  36 #define MAX_CCACHES 100
  37
  38 static struct WINBINDD_CCACHE_ENTRY *ccache_list;
  39 static void krb5_ticket_gain_handler(struct event_context *,
  40                                      struct timed_event *,
  41                                      struct timeval,
  42                                      void *);
  43 static void add_krb5_ticket_gain_handler_event(struct WINBINDD_CCACHE_ENTRY *,
  44                                      struct timeval);
  45
  46 /* The Krb5 ticket refresh handler should be scheduled
  47    at one-half of the period from now till the tkt
  48    expiration */
  49 #define KRB5_EVENT_REFRESH_TIME(x) ((x) - (((x) - time(NULL))/2))
  50
  51 /****************************************************************
  52  Find an entry by name.
  53 ****************************************************************/
  54
  55 static struct WINBINDD_CCACHE_ENTRY *get_ccache_by_username(const char *username)
  56 {
  57         struct WINBINDD_CCACHE_ENTRY *entry;
  58
  59         for (entry = ccache_list; entry; entry = entry->next) {
  60                 if (strequal(entry->username, username)) {
  61                         return entry;
  62                 }
  63         }
  64         return NULL;
  65 }
  66
  67 /****************************************************************
  68  How many do we have ?
  69 ****************************************************************/
  70
  71 static int ccache_entry_count(void)
  72 {
  73         struct WINBINDD_CCACHE_ENTRY *entry;
  74         int i = 0;
  75
  76         for (entry = ccache_list; entry; entry = entry->next) {
  77                 i++;
  78         }
  79         return i;
  80 }
  81
  82 void ccache_remove_all_after_fork(void)
  83 {
  84         struct WINBINDD_CCACHE_ENTRY *cur, *next;
  85
  86         for (cur = ccache_list; cur; cur = next) {
  87                 next = cur->next;
  88                 DLIST_REMOVE(ccache_list, cur);
  89                 TALLOC_FREE(cur->event);
  90                 TALLOC_FREE(cur);
  91         }
  92
  93         return;
  94 }
  95
  96 /****************************************************************
  97  Do the work of refreshing the ticket.
  98 ****************************************************************/
  99
 100 static void krb5_ticket_refresh_handler(struct event_context *event_ctx,
 101                                         struct timed_event *te,
 102                                         struct timeval now,
 103                                         void *private_data)
 104 {
 105         struct WINBINDD_CCACHE_ENTRY *entry =
 106                 talloc_get_type_abort(private_data, struct WINBINDD_CCACHE_ENTRY);
 107 #ifdef HAVE_KRB5
 108         int ret;
 109         time_t new_start;
 110         time_t expire_time = 0;
 111         struct WINBINDD_MEMORY_CREDS *cred_ptr = entry->cred_ptr;
 112 #endif
 113
 114         DEBUG(10,("krb5_ticket_refresh_handler called\n"));
 115         DEBUGADD(10,("event called for: %s, %s\n",
 116                 entry->ccname, entry->username));
 117
 118         TALLOC_FREE(entry->event);
 119
 120 #ifdef HAVE_KRB5
 121
 122         /* Kinit again if we have the user password and we can't renew the old
 123          * tgt anymore
 124          * NB
 125          * This happens when machine are put to sleep for a very long time. */
 126
 127         if (entry->renew_until < time(NULL)) {
 128 rekinit:
 129                 if (cred_ptr && cred_ptr->pass) {
 130
 131                         set_effective_uid(entry->uid);
 132
 133                         ret = kerberos_kinit_password_ext(entry->principal_name,
 134                                                           cred_ptr->pass,
 135                                                           0, /* hm, can we do time correction here ? */
 136                                                           &entry->refresh_time,
 137                                                           &entry->renew_until,
 138                                                           entry->ccname,
 139                                                           False, /* no PAC required anymore */
 140                                                           True,
 141                                                           WINBINDD_PAM_AUTH_KRB5_RENEW_TIME,
 142                                                           NULL);
 143                         gain_root_privilege();
 144
 145                         if (ret) {
 146                                 DEBUG(3,("krb5_ticket_refresh_handler: "
 147                                         "could not re-kinit: %s\n",
 148                                         error_message(ret)));
 149                                 /* destroy the ticket because we cannot rekinit
 150                                  * it, ignore error here */
 151                                 ads_kdestroy(entry->ccname);
 152
 153                                 /* Don't break the ticket refresh chain: retry
 154                                  * refreshing ticket sometime later when KDC is
 155                                  * unreachable -- BoYang. More error code handling
 156                                  * here?
 157                                  * */
 158
 159                                 if ((ret == KRB5_KDC_UNREACH)
 160                                     || (ret == KRB5_REALM_CANT_RESOLVE)) {
 161 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 162                                         new_start = time(NULL) + 30;
 163 #else
 164                                         new_start = time(NULL) +
 165                                                     MAX(30, lp_winbind_cache_time());
 166 #endif
 167                                         add_krb5_ticket_gain_handler_event(entry,
 168                                                         timeval_set(new_start, 0));
 169                                         return;
 170                                 }
 171                                 TALLOC_FREE(entry->event);
 172                                 return;
 173                         }
 174
 175                         DEBUG(10,("krb5_ticket_refresh_handler: successful re-kinit "
 176                                 "for: %s in ccache: %s\n",
 177                                 entry->principal_name, entry->ccname));
 178
 179 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 180                         new_start = time(NULL) + 30;
 181 #else
 182                         /* The tkt should be refreshed at one-half the period
 183                            from now to the expiration time */
 184                         expire_time = entry->refresh_time;
 185                         new_start = KRB5_EVENT_REFRESH_TIME(entry->refresh_time);
 186 #endif
 187                         goto done;
 188                 } else {
 189                                 /* can this happen?
 190                                  * No cached credentials
 191                                  * destroy ticket and refresh chain
 192                                  * */
 193                                 ads_kdestroy(entry->ccname);
 194                                 TALLOC_FREE(entry->event);
 195                                 return;
 196                 }
 197         }
 198
 199         set_effective_uid(entry->uid);
 200
 201         ret = smb_krb5_renew_ticket(entry->ccname,
 202                                     entry->principal_name,
 203                                     entry->service,
 204                                     &new_start);
 205 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 206         new_start = time(NULL) + 30;
 207 #else
 208         expire_time = new_start;
 209         new_start = KRB5_EVENT_REFRESH_TIME(new_start);
 210 #endif
 211
 212         gain_root_privilege();
 213
 214         if (ret) {
 215                 DEBUG(3,("krb5_ticket_refresh_handler: "
 216                         "could not renew tickets: %s\n",
 217                         error_message(ret)));
 218                 /* maybe we are beyond the renewing window */
 219
 220                 /* evil rises here, we refresh ticket failed,
 221                  * but the ticket might be expired. Therefore,
 222                  * When we refresh ticket failed, destory the
 223                  * ticket */
 224
 225                 ads_kdestroy(entry->ccname);
 226
 227                 /* avoid breaking the renewal chain: retry in
 228                  * lp_winbind_cache_time() seconds when the KDC was not
 229                  * available right now.
 230                  * the return code can be KRB5_REALM_CANT_RESOLVE.
 231                  * More error code handling here? */
 232
 233                 if ((ret == KRB5_KDC_UNREACH)
 234                     || (ret == KRB5_REALM_CANT_RESOLVE)) {
 235 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 236                         new_start = time(NULL) + 30;
 237 #else
 238                         new_start = time(NULL) +
 239                                     MAX(30, lp_winbind_cache_time());
 240 #endif
 241                         /* ticket is destroyed here, we have to regain it
 242                          * if it is possible */
 243                         add_krb5_ticket_gain_handler_event(entry,
 244                                                 timeval_set(new_start, 0));
 245                         return;
 246                 }
 247
 248                 /* This is evil, if the ticket was already expired.
 249                  * renew ticket function returns KRB5KRB_AP_ERR_TKT_EXPIRED.
 250                  * But there is still a chance that we can rekinit it.
 251                  *
 252                  * This happens when user login in online mode, and then network
 253                  * down or something cause winbind goes offline for a very long time,
 254                  * and then goes online again. ticket expired, renew failed.
 255                  * This happens when machine are put to sleep for a long time,
 256                  * but shorter than entry->renew_util.
 257                  * NB
 258                  * Looks like the KDC is reachable, we want to rekinit as soon as
 259                  * possible instead of waiting some time later. */
 260                 if ((ret == KRB5KRB_AP_ERR_TKT_EXPIRED)
 261                     || (ret == KRB5_FCC_NOFILE)) goto rekinit;
 262
 263                 return;
 264         }
 265
 266 done:
 267         /* in cases that ticket will be unrenewable soon, we don't try to renew ticket
 268          * but try to regain ticket if it is possible */
 269         if (entry->renew_until && expire_time
 270              && (entry->renew_until <= expire_time)) {
 271                 /* try to regain ticket 10 seconds beforre expiration */
 272                 expire_time -= 10;
 273                 add_krb5_ticket_gain_handler_event(entry,
 274                                         timeval_set(expire_time, 0));
 275                 return;
 276         }
 277
 278         if (entry->refresh_time == 0) {
 279                 entry->refresh_time = new_start;
 280         }
 281         entry->event = event_add_timed(winbind_event_context(), entry,
 282                                        timeval_set(new_start, 0),
 283                                        krb5_ticket_refresh_handler,
 284                                        entry);
 285
 286 #endif
 287 }
 288
 289 /****************************************************************
 290  Do the work of regaining a ticket when coming from offline auth.
 291 ****************************************************************/
 292
 293 static void krb5_ticket_gain_handler(struct event_context *event_ctx,
 294                                      struct timed_event *te,
 295                                      struct timeval now,
 296                                      void *private_data)
 297 {
 298         struct WINBINDD_CCACHE_ENTRY *entry =
 299                 talloc_get_type_abort(private_data, struct WINBINDD_CCACHE_ENTRY);
 300 #ifdef HAVE_KRB5
 301         int ret;
 302         struct timeval t;
 303         struct WINBINDD_MEMORY_CREDS *cred_ptr = entry->cred_ptr;
 304         struct winbindd_domain *domain = NULL;
 305 #endif
 306
 307         DEBUG(10,("krb5_ticket_gain_handler called\n"));
 308         DEBUGADD(10,("event called for: %s, %s\n",
 309                 entry->ccname, entry->username));
 310
 311         TALLOC_FREE(entry->event);
 312
 313 #ifdef HAVE_KRB5
 314
 315         if (!cred_ptr || !cred_ptr->pass) {
 316                 DEBUG(10,("krb5_ticket_gain_handler: no memory creds\n"));
 317                 return;
 318         }
 319
 320         if ((domain = find_domain_from_name(entry->realm)) == NULL) {
 321                 DEBUG(0,("krb5_ticket_gain_handler: unknown domain\n"));
 322                 return;
 323         }
 324
 325         if (!domain->online) {
 326                 goto retry_later;
 327         }
 328
 329         set_effective_uid(entry->uid);
 330
 331         ret = kerberos_kinit_password_ext(entry->principal_name,
 332                                           cred_ptr->pass,
 333                                           0, /* hm, can we do time correction here ? */
 334                                           &entry->refresh_time,
 335                                           &entry->renew_until,
 336                                           entry->ccname,
 337                                           False, /* no PAC required anymore */
 338                                           True,
 339                                           WINBINDD_PAM_AUTH_KRB5_RENEW_TIME,
 340                                           NULL);
 341         gain_root_privilege();
 342
 343         if (ret) {
 344                 DEBUG(3,("krb5_ticket_gain_handler: "
 345                         "could not kinit: %s\n",
 346                         error_message(ret)));
 347                 /* evil. If we cannot do it, destroy any the __maybe__
 348                  * __existing__ ticket */
 349                 ads_kdestroy(entry->ccname);
 350                 goto retry_later;
 351         }
 352
 353         DEBUG(10,("krb5_ticket_gain_handler: "
 354                 "successful kinit for: %s in ccache: %s\n",
 355                 entry->principal_name, entry->ccname));
 356
 357         goto got_ticket;
 358
 359   retry_later:
 360
 361 #if defined(DEBUG_KRB5_TKT_REGAIN)
 362         t = timeval_set(time(NULL) + 30, 0);
 363 #else
 364         t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 365 #endif
 366
 367         add_krb5_ticket_gain_handler_event(entry, t);
 368         return;
 369
 370   got_ticket:
 371
 372 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 373         t = timeval_set(time(NULL) + 30, 0);
 374 #else
 375         t = timeval_set(KRB5_EVENT_REFRESH_TIME(entry->refresh_time), 0);
 376 #endif
 377
 378         if (entry->refresh_time == 0) {
 379                 entry->refresh_time = t.tv_sec;
 380         }
 381         entry->event = event_add_timed(winbind_event_context(),
 382                                        entry,
 383                                        t,
 384                                        krb5_ticket_refresh_handler,
 385                                        entry);
 386
 387         return;
 388 #endif
 389 }
 390
 391 /**************************************************************
 392  The gain initial ticket case is recognised as entry->refresh_time
 393  is always zero.
 394 **************************************************************/
 395
 396 static void add_krb5_ticket_gain_handler_event(struct WINBINDD_CCACHE_ENTRY *entry,
 397                                      struct timeval t)
 398 {
 399         entry->refresh_time = 0;
 400         entry->event = event_add_timed(winbind_event_context(),
 401                                        entry,
 402                                        t,
 403                                        krb5_ticket_gain_handler,
 404                                        entry);
 405 }
 406
 407 void ccache_regain_all_now(void)
 408 {
 409         struct WINBINDD_CCACHE_ENTRY *cur;
 410         struct timeval t = timeval_current();
 411
 412         for (cur = ccache_list; cur; cur = cur->next) {
 413                 struct timed_event *new_event;
 414
 415                 /*
 416                  * if refresh_time is 0, we know that the
 417                  * the event has the krb5_ticket_gain_handler
 418                  */
 419                 if (cur->refresh_time == 0) {
 420                         new_event = event_add_timed(winbind_event_context(),
 421                                                     cur,
 422                                                     t,
 423                                                     krb5_ticket_gain_handler,
 424                                                     cur);
 425                 } else {
 426                         new_event = event_add_timed(winbind_event_context(),
 427                                                     cur,
 428                                                     t,
 429                                                     krb5_ticket_refresh_handler,
 430                                                     cur);
 431                 }
 432
 433                 if (!new_event) {
 434                         continue;
 435                 }
 436
 437                 TALLOC_FREE(cur->event);
 438                 cur->event = new_event;
 439         }
 440
 441         return;
 442 }
 443
 444 /****************************************************************
 445  Check if an ccache entry exists.
 446 ****************************************************************/
 447
 448 bool ccache_entry_exists(const char *username)
 449 {
 450         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 451         return (entry != NULL);
 452 }
 453
 454 /****************************************************************
 455  Ensure we're changing the correct entry.
 456 ****************************************************************/
 457
 458 bool ccache_entry_identical(const char *username,
 459                             uid_t uid,
 460                             const char *ccname)
 461 {
 462         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 463
 464         if (!entry) {
 465                 return False;
 466         }
 467
 468         if (entry->uid != uid) {
 469                 DEBUG(0,("cache_entry_identical: uid's differ: %u != %u\n",
 470                         (unsigned int)entry->uid, (unsigned int)uid));
 471                 return False;
 472         }
 473         if (!strcsequal(entry->ccname, ccname)) {
 474                 DEBUG(0,("cache_entry_identical: "
 475                         "ccnames differ: (cache) %s != (client) %s\n",
 476                         entry->ccname, ccname));
 477                 return False;
 478         }
 479         return True;
 480 }
 481
 482 NTSTATUS add_ccache_to_list(const char *princ_name,
 483                             const char *ccname,
 484                             const char *service,
 485                             const char *username,
 486                             const char *realm,
 487                             uid_t uid,
 488                             time_t create_time,
 489                             time_t ticket_end,
 490                             time_t renew_until,
 491                             bool postponed_request)
 492 {
 493         struct WINBINDD_CCACHE_ENTRY *entry = NULL;
 494         struct timeval t;
 495         NTSTATUS ntret;
 496 #ifdef HAVE_KRB5
 497         int ret;
 498 #endif
 499
 500         if ((username == NULL && princ_name == NULL) ||
 501             ccname == NULL || uid < 0) {
 502                 return NT_STATUS_INVALID_PARAMETER;
 503         }
 504
 505         if (ccache_entry_count() + 1 > MAX_CCACHES) {
 506                 DEBUG(10,("add_ccache_to_list: "
 507                         "max number of ccaches reached\n"));
 508                 return NT_STATUS_NO_MORE_ENTRIES;
 509         }
 510
 511         /* If it is cached login, destroy krb5 ticket
 512          * to avoid surprise. */
 513 #ifdef HAVE_KRB5
 514         if (postponed_request) {
 515                 /* ignore KRB5_FCC_NOFILE error here */
 516                 ret = ads_kdestroy(ccname);
 517                 if (ret == KRB5_FCC_NOFILE) {
 518                         ret = 0;
 519                 }
 520                 if (ret) {
 521                         DEBUG(0, ("add_ccache_to_list: failed to destroy "
 522                                    "user krb5 ccache %s with %s\n", ccname,
 523                                    error_message(ret)));
 524                         return krb5_to_nt_status(ret);
 525                 } else {
 526                         DEBUG(10, ("add_ccache_to_list: successfully destroyed "
 527                                    "krb5 ccache %s for user %s\n", ccname,
 528                                    username));
 529                 }
 530         }
 531 #endif
 532
 533         /* Reference count old entries */
 534         entry = get_ccache_by_username(username);
 535         if (entry) {
 536                 /* Check cached entries are identical. */
 537                 if (!ccache_entry_identical(username, uid, ccname)) {
 538                         return NT_STATUS_INVALID_PARAMETER;
 539                 }
 540                 entry->ref_count++;
 541                 DEBUG(10,("add_ccache_to_list: "
 542                         "ref count on entry %s is now %d\n",
 543                         username, entry->ref_count));
 544                 /* FIXME: in this case we still might want to have a krb5 cred
 545                  * event handler created - gd
 546                  * Add ticket refresh handler here */
 547
 548                 if (!lp_winbind_refresh_tickets() || renew_until <= 0) {
 549                         return NT_STATUS_OK;
 550                 }
 551
 552                 if (!entry->event) {
 553                         if (postponed_request) {
 554                                 t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 555                                 add_krb5_ticket_gain_handler_event(entry, t);
 556                         } else {
 557                                 /* Renew at 1/2 the ticket expiration time */
 558 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 559                                 t = timeval_set(time(NULL)+30, 0);
 560 #else
 561                                 t = timeval_set(KRB5_EVENT_REFRESH_TIME(ticket_end), 0);
 562 #endif
 563                                 if (!entry->refresh_time) {
 564                                         entry->refresh_time = t.tv_sec;
 565                                 }
 566                                 entry->event = event_add_timed(winbind_event_context(),
 567                                                                entry,
 568                                                                t,
 569                                                                krb5_ticket_refresh_handler,
 570                                                                entry);
 571                         }
 572
 573                         if (!entry->event) {
 574                                 ntret = remove_ccache(username);
 575                                 if (!NT_STATUS_IS_OK(ntret)) {
 576                                         DEBUG(0, ("add_ccache_to_list: Failed to remove krb5 "
 577                                                   "ccache %s for user %s\n", entry->ccname,
 578                                                   entry->username));
 579                                         DEBUG(0, ("add_ccache_to_list: error is %s\n",
 580                                                   nt_errstr(ntret)));
 581                                         return ntret;
 582                                 }
 583                                 return NT_STATUS_NO_MEMORY;
 584                         }
 585
 586                         DEBUG(10,("add_ccache_to_list: added krb5_ticket handler\n"));
 587                 }
 588
 589                 return NT_STATUS_OK;
 590         }
 591
 592         entry = TALLOC_P(NULL, struct WINBINDD_CCACHE_ENTRY);
 593         if (!entry) {
 594                 return NT_STATUS_NO_MEMORY;
 595         }
 596
 597         ZERO_STRUCTP(entry);
 598
 599         if (username) {
 600                 entry->username = talloc_strdup(entry, username);
 601                 if (!entry->username) {
 602                         goto no_mem;
 603                 }
 604         }
 605         if (princ_name) {
 606                 entry->principal_name = talloc_strdup(entry, princ_name);
 607                 if (!entry->principal_name) {
 608                         goto no_mem;
 609                 }
 610         }
 611         if (service) {
 612                 entry->service = talloc_strdup(entry, service);
 613                 if (!entry->service) {
 614                         goto no_mem;
 615                 }
 616         }
 617
 618         entry->ccname = talloc_strdup(entry, ccname);
 619         if (!entry->ccname) {
 620                 goto no_mem;
 621         }
 622
 623         entry->realm = talloc_strdup(entry, realm);
 624         if (!entry->realm) {
 625                 goto no_mem;
 626         }
 627
 628         entry->create_time = create_time;
 629         entry->renew_until = renew_until;
 630         entry->uid = uid;
 631         entry->ref_count = 1;
 632
 633         if (!lp_winbind_refresh_tickets() || renew_until <= 0) {
 634                 goto add_entry;
 635         }
 636
 637         if (postponed_request) {
 638                 t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 639                 add_krb5_ticket_gain_handler_event(entry, t);
 640         } else {
 641                 /* Renew at 1/2 the ticket expiration time */
 642 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 643                 t = timeval_set(time(NULL)+30, 0);
 644 #else
 645                 t = timeval_set(KRB5_EVENT_REFRESH_TIME(ticket_end), 0);
 646 #endif
 647                 if (entry->refresh_time == 0) {
 648                         entry->refresh_time = t.tv_sec;
 649                 }
 650                 entry->event = event_add_timed(winbind_event_context(),
 651                                                entry,
 652                                                t,
 653                                                krb5_ticket_refresh_handler,
 654                                                entry);
 655         }
 656
 657         if (!entry->event) {
 658                 goto no_mem;
 659         }
 660
 661         DEBUG(10,("add_ccache_to_list: added krb5_ticket handler\n"));
 662
 663  add_entry:
 664
 665         DLIST_ADD(ccache_list, entry);
 666
 667         DEBUG(10,("add_ccache_to_list: "
 668                 "added ccache [%s] for user [%s] to the list\n",
 669                 ccname, username));
 670
 671         return NT_STATUS_OK;
 672
 673  no_mem:
 674
 675         TALLOC_FREE(entry);
 676         return NT_STATUS_NO_MEMORY;
 677 }
 678
 679 /*******************************************************************
 680  Remove a WINBINDD_CCACHE_ENTRY entry and the krb5 ccache if no longer
 681  referenced.
 682  *******************************************************************/
 683
 684 NTSTATUS remove_ccache(const char *username)
 685 {
 686         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 687         NTSTATUS status = NT_STATUS_OK;
 688         #ifdef HAVE_KRB5
 689         krb5_error_code ret;
 690 #endif
 691
 692         if (!entry) {
 693                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 694         }
 695
 696         if (entry->ref_count <= 0) {
 697                 DEBUG(0,("remove_ccache: logic error. "
 698                         "ref count for user %s = %d\n",
 699                         username, entry->ref_count));
 700                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 701         }
 702
 703         entry->ref_count--;
 704
 705         if (entry->ref_count > 0) {
 706                 DEBUG(10,("remove_ccache: entry %s ref count now %d\n",
 707                         username, entry->ref_count));
 708                 return NT_STATUS_OK;
 709         }
 710
 711         /* no references any more */
 712
 713         DLIST_REMOVE(ccache_list, entry);
 714         TALLOC_FREE(entry->event); /* unregisters events */
 715
 716 #ifdef HAVE_KRB5
 717         ret = ads_kdestroy(entry->ccname);
 718
 719         /* we ignore the error when there has been no credential cache */
 720         if (ret == KRB5_FCC_NOFILE) {
 721                 ret = 0;
 722         } else if (ret) {
 723                 DEBUG(0,("remove_ccache: "
 724                         "failed to destroy user krb5 ccache %s with: %s\n",
 725                         entry->ccname, error_message(ret)));
 726         } else {
 727                 DEBUG(10,("remove_ccache: "
 728                         "successfully destroyed krb5 ccache %s for user %s\n",
 729                         entry->ccname, username));
 730         }
 731         status = krb5_to_nt_status(ret);
 732 #endif
 733
 734         TALLOC_FREE(entry);
 735         DEBUG(10,("remove_ccache: removed ccache for user %s\n", username));
 736
 737         return status;
 738 }
 739
 740 /*******************************************************************
 741  In memory credentials cache code.
 742 *******************************************************************/
 743
 744 static struct WINBINDD_MEMORY_CREDS *memory_creds_list;
 745
 746 /***********************************************************
 747  Find an entry on the list by name.
 748 ***********************************************************/
 749
 750 struct WINBINDD_MEMORY_CREDS *find_memory_creds_by_name(const char *username)
 751 {
 752         struct WINBINDD_MEMORY_CREDS *p;
 753
 754         for (p = memory_creds_list; p; p = p->next) {
 755                 if (strequal(p->username, username)) {
 756                         return p;
 757                 }
 758         }
 759         return NULL;
 760 }
 761
 762 /***********************************************************
 763  Store the required creds and mlock them.
 764 ***********************************************************/
 765
 766 static NTSTATUS store_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp,
 767                                    const char *pass)
 768 {
 769 #if !defined(HAVE_MLOCK)
 770         return NT_STATUS_OK;
 771 #else
 772         /* new_entry->nt_hash is the base pointer for the block
 773            of memory pointed into by new_entry->lm_hash and
 774            new_entry->pass (if we're storing plaintext). */
 775
 776         memcredp->len = NT_HASH_LEN + LM_HASH_LEN;
 777         if (pass) {
 778                 memcredp->len += strlen(pass)+1;
 779         }
 780
 781
 782 #if defined(LINUX)
 783         /* aligning the memory on on x86_64 and compiling
 784            with gcc 4.1 using -O2 causes a segv in the
 785            next memset()  --jerry */
 786         memcredp->nt_hash = SMB_MALLOC_ARRAY(unsigned char, memcredp->len);
 787 #else
 788         /* On non-linux platforms, mlock()'d memory must be aligned */
 789         memcredp->nt_hash = SMB_MEMALIGN_ARRAY(unsigned char,
 790                                                getpagesize(), memcredp->len);
 791 #endif
 792         if (!memcredp->nt_hash) {
 793                 return NT_STATUS_NO_MEMORY;
 794         }
 795         memset(memcredp->nt_hash, 0x0, memcredp->len);
 796
 797         memcredp->lm_hash = memcredp->nt_hash + NT_HASH_LEN;
 798
 799 #ifdef DEBUG_PASSWORD
 800         DEBUG(10,("mlocking memory: %p\n", memcredp->nt_hash));
 801 #endif
 802         if ((mlock(memcredp->nt_hash, memcredp->len)) == -1) {
 803                 DEBUG(0,("failed to mlock memory: %s (%d)\n",
 804                         strerror(errno), errno));
 805                 SAFE_FREE(memcredp->nt_hash);
 806                 return map_nt_error_from_unix(errno);
 807         }
 808
 809 #ifdef DEBUG_PASSWORD
 810         DEBUG(10,("mlocked memory: %p\n", memcredp->nt_hash));
 811 #endif
 812
 813         /* Create and store the password hashes. */
 814         E_md4hash(pass, memcredp->nt_hash);
 815         E_deshash(pass, memcredp->lm_hash);
 816
 817         if (pass) {
 818                 memcredp->pass = (char *)memcredp->lm_hash + LM_HASH_LEN;
 819                 memcpy(memcredp->pass, pass,
 820                        memcredp->len - NT_HASH_LEN - LM_HASH_LEN);
 821         }
 822
 823         return NT_STATUS_OK;
 824 #endif
 825 }
 826
 827 /***********************************************************
 828  Destroy existing creds.
 829 ***********************************************************/
 830
 831 static NTSTATUS delete_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp)
 832 {
 833 #if !defined(HAVE_MUNLOCK)
 834         return NT_STATUS_OK;
 835 #else
 836         if (munlock(memcredp->nt_hash, memcredp->len) == -1) {
 837                 DEBUG(0,("failed to munlock memory: %s (%d)\n",
 838                         strerror(errno), errno));
 839                 return map_nt_error_from_unix(errno);
 840         }
 841         memset(memcredp->nt_hash, '\0', memcredp->len);
 842         SAFE_FREE(memcredp->nt_hash);
 843         memcredp->nt_hash = NULL;
 844         memcredp->lm_hash = NULL;
 845         memcredp->pass = NULL;
 846         memcredp->len = 0;
 847         return NT_STATUS_OK;
 848 #endif
 849 }
 850
 851 /***********************************************************
 852  Replace the required creds with new ones (password change).
 853 ***********************************************************/
 854
 855 static NTSTATUS winbindd_replace_memory_creds_internal(struct WINBINDD_MEMORY_CREDS *memcredp,
 856                                                        const char *pass)
 857 {
 858         NTSTATUS status = delete_memory_creds(memcredp);
 859         if (!NT_STATUS_IS_OK(status)) {
 860                 return status;
 861         }
 862         return store_memory_creds(memcredp, pass);
 863 }
 864
 865 /*************************************************************
 866  Store credentials in memory in a list.
 867 *************************************************************/
 868
 869 static NTSTATUS winbindd_add_memory_creds_internal(const char *username,
 870                                                    uid_t uid,
 871                                                    const char *pass)
 872 {
 873         /* Shortcut to ensure we don't store if no mlock. */
 874 #if !defined(HAVE_MLOCK) || !defined(HAVE_MUNLOCK)
 875         return NT_STATUS_OK;
 876 #else
 877         NTSTATUS status;
 878         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
 879
 880         memcredp = find_memory_creds_by_name(username);
 881         if (uid == (uid_t)-1) {
 882                 DEBUG(0,("winbindd_add_memory_creds_internal: "
 883                         "invalid uid for user %s.\n", username));
 884                 return NT_STATUS_INVALID_PARAMETER;
 885         }
 886
 887         if (memcredp) {
 888                 /* Already exists. Increment the reference count and replace stored creds. */
 889                 if (uid != memcredp->uid) {
 890                         DEBUG(0,("winbindd_add_memory_creds_internal: "
 891                                 "uid %u for user %s doesn't "
 892                                 "match stored uid %u. Replacing.\n",
 893                                 (unsigned int)uid, username,
 894                                 (unsigned int)memcredp->uid));
 895                         memcredp->uid = uid;
 896                 }
 897                 memcredp->ref_count++;
 898                 DEBUG(10,("winbindd_add_memory_creds_internal: "
 899                         "ref count for user %s is now %d\n",
 900                         username, memcredp->ref_count));
 901                 return winbindd_replace_memory_creds_internal(memcredp, pass);
 902         }
 903
 904         memcredp = TALLOC_ZERO_P(NULL, struct WINBINDD_MEMORY_CREDS);
 905         if (!memcredp) {
 906                 return NT_STATUS_NO_MEMORY;
 907         }
 908         memcredp->username = talloc_strdup(memcredp, username);
 909         if (!memcredp->username) {
 910                 talloc_destroy(memcredp);
 911                 return NT_STATUS_NO_MEMORY;
 912         }
 913
 914         status = store_memory_creds(memcredp, pass);
 915         if (!NT_STATUS_IS_OK(status)) {
 916                 talloc_destroy(memcredp);
 917                 return status;
 918         }
 919
 920         memcredp->uid = uid;
 921         memcredp->ref_count = 1;
 922         DLIST_ADD(memory_creds_list, memcredp);
 923
 924         DEBUG(10,("winbindd_add_memory_creds_internal: "
 925                 "added entry for user %s\n", username));
 926
 927         return NT_STATUS_OK;
 928 #endif
 929 }
 930
 931 /*************************************************************
 932  Store users credentials in memory. If we also have a
 933  struct WINBINDD_CCACHE_ENTRY for this username with a
 934  refresh timer, then store the plaintext of the password
 935  and associate the new credentials with the struct WINBINDD_CCACHE_ENTRY.
 936 *************************************************************/
 937
 938 NTSTATUS winbindd_add_memory_creds(const char *username,
 939                                    uid_t uid,
 940                                    const char *pass)
 941 {
 942         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 943         NTSTATUS status;
 944
 945         status = winbindd_add_memory_creds_internal(username, uid, pass);
 946         if (!NT_STATUS_IS_OK(status)) {
 947                 return status;
 948         }
 949
 950         if (entry) {
 951                 struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
 952                 memcredp = find_memory_creds_by_name(username);
 953                 if (memcredp) {
 954                         entry->cred_ptr = memcredp;
 955                 }
 956         }
 957
 958         return status;
 959 }
 960
 961 /*************************************************************
 962  Decrement the in-memory ref count - delete if zero.
 963 *************************************************************/
 964
 965 NTSTATUS winbindd_delete_memory_creds(const char *username)
 966 {
 967         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
 968         struct WINBINDD_CCACHE_ENTRY *entry = NULL;
 969         NTSTATUS status = NT_STATUS_OK;
 970
 971         memcredp = find_memory_creds_by_name(username);
 972         entry = get_ccache_by_username(username);
 973
 974         if (!memcredp) {
 975                 DEBUG(10,("winbindd_delete_memory_creds: unknown user %s\n",
 976                         username));
 977                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 978         }
 979
 980         if (memcredp->ref_count <= 0) {
 981                 DEBUG(0,("winbindd_delete_memory_creds: logic error. "
 982                         "ref count for user %s = %d\n",
 983                         username, memcredp->ref_count));
 984                 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
 985         }
 986
 987         memcredp->ref_count--;
 988         if (memcredp->ref_count <= 0) {
 989                 delete_memory_creds(memcredp);
 990                 DLIST_REMOVE(memory_creds_list, memcredp);
 991                 talloc_destroy(memcredp);
 992                 DEBUG(10,("winbindd_delete_memory_creds: "
 993                         "deleted entry for user %s\n",
 994                         username));
 995         } else {
 996                 DEBUG(10,("winbindd_delete_memory_creds: "
 997                         "entry for user %s ref_count now %d\n",
 998                         username, memcredp->ref_count));
 999         }
1000
1001         if (entry) {
1002                 /* Ensure we have no dangling references to this. */
1003                 entry->cred_ptr = NULL;
1004         }
1005
1006         return status;
1007 }
1008
1009 /***********************************************************
1010  Replace the required creds with new ones (password change).
1011 ***********************************************************/
1012
1013 NTSTATUS winbindd_replace_memory_creds(const char *username,
1014                                        const char *pass)
1015 {
1016         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
1017
1018         memcredp = find_memory_creds_by_name(username);
1019         if (!memcredp) {
1020                 DEBUG(10,("winbindd_replace_memory_creds: unknown user %s\n",
1021                         username));
1022                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
1023         }
1024
1025         DEBUG(10,("winbindd_replace_memory_creds: replaced creds for user %s\n",
1026                 username));
1027
1028         return winbindd_replace_memory_creds_internal(memcredp, pass);
1029 }