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 "../libcli/auth/libcli_auth.h"
  27 #include "smb_krb5.h"
  28 #include "libads/kerberos_proto.h"
  29 #include "libads/krb5_errs.h"
  30
  31 #undef DBGC_CLASS
  32 #define DBGC_CLASS DBGC_WINBIND
  33
  34 /* uncomment this to do fast debugging on the krb5 ticket renewal event */
  35 #ifdef DEBUG_KRB5_TKT_RENEWAL
  36 #undef DEBUG_KRB5_TKT_RENEWAL
  37 #endif
  38
  39 #define MAX_CCACHES 100
  40
  41 static struct WINBINDD_CCACHE_ENTRY *ccache_list;
  42 static void krb5_ticket_gain_handler(struct tevent_context *,
  43                                      struct tevent_timer *,
  44                                      struct timeval,
  45                                      void *);
  46 static void add_krb5_ticket_gain_handler_event(struct WINBINDD_CCACHE_ENTRY *,
  47                                      struct timeval);
  48
  49 /* The Krb5 ticket refresh handler should be scheduled
  50    at one-half of the period from now till the tkt
  51    expiration */
  52
  53 static time_t krb5_event_refresh_time(time_t end_time)
  54 {
  55         time_t rest = end_time - time(NULL);
  56         return end_time - rest/2;
  57 }
  58
  59 /****************************************************************
  60  Find an entry by name.
  61 ****************************************************************/
  62
  63 static struct WINBINDD_CCACHE_ENTRY *get_ccache_by_username(const char *username)
  64 {
  65         struct WINBINDD_CCACHE_ENTRY *entry;
  66
  67         for (entry = ccache_list; entry; entry = entry->next) {
  68                 if (strequal(entry->username, username)) {
  69                         return entry;
  70                 }
  71         }
  72         return NULL;
  73 }
  74
  75 /****************************************************************
  76  How many do we have ?
  77 ****************************************************************/
  78
  79 static int ccache_entry_count(void)
  80 {
  81         struct WINBINDD_CCACHE_ENTRY *entry;
  82         int i = 0;
  83
  84         for (entry = ccache_list; entry; entry = entry->next) {
  85                 i++;
  86         }
  87         return i;
  88 }
  89
  90 void ccache_remove_all_after_fork(void)
  91 {
  92         struct WINBINDD_CCACHE_ENTRY *cur, *next;
  93
  94         for (cur = ccache_list; cur; cur = next) {
  95                 next = cur->next;
  96                 DLIST_REMOVE(ccache_list, cur);
  97                 TALLOC_FREE(cur->event);
  98                 TALLOC_FREE(cur);
  99         }
 100
 101         return;
 102 }
 103
 104 /****************************************************************
 105  Do the work of refreshing the ticket.
 106 ****************************************************************/
 107
 108 static void krb5_ticket_refresh_handler(struct tevent_context *event_ctx,
 109                                         struct tevent_timer *te,
 110                                         struct timeval now,
 111                                         void *private_data)
 112 {
 113         struct WINBINDD_CCACHE_ENTRY *entry =
 114                 talloc_get_type_abort(private_data, struct WINBINDD_CCACHE_ENTRY);
 115 #ifdef HAVE_KRB5
 116         int ret;
 117         time_t new_start;
 118         time_t expire_time = 0;
 119         struct WINBINDD_MEMORY_CREDS *cred_ptr = entry->cred_ptr;
 120 #endif
 121
 122         DBG_DEBUG("event called for: %s, %s\n",
 123                   entry->ccname, entry->username);
 124
 125         TALLOC_FREE(entry->event);
 126
 127 #ifdef HAVE_KRB5
 128
 129         /* Kinit again if we have the user password and we can't renew the old
 130          * tgt anymore
 131          * NB
 132          * This happens when machine are put to sleep for a very long time. */
 133
 134         if (entry->renew_until < time(NULL)) {
 135 rekinit:
 136                 if (cred_ptr && cred_ptr->pass) {
 137
 138                         set_effective_uid(entry->uid);
 139
 140                         ret = kerberos_kinit_password_ext(entry->principal_name,
 141                                                           cred_ptr->pass,
 142                                                           0, /* hm, can we do time correction here ? */
 143                                                           &entry->refresh_time,
 144                                                           &entry->renew_until,
 145                                                           entry->ccname,
 146                                                           False, /* no PAC required anymore */
 147                                                           True,
 148                                                           WINBINDD_PAM_AUTH_KRB5_RENEW_TIME,
 149                                                           NULL);
 150                         gain_root_privilege();
 151
 152                         if (ret) {
 153                                 DEBUG(3,("krb5_ticket_refresh_handler: "
 154                                         "could not re-kinit: %s\n",
 155                                         error_message(ret)));
 156                                 /* destroy the ticket because we cannot rekinit
 157                                  * it, ignore error here */
 158                                 ads_kdestroy(entry->ccname);
 159
 160                                 /* Don't break the ticket refresh chain: retry
 161                                  * refreshing ticket sometime later when KDC is
 162                                  * unreachable -- BoYang. More error code handling
 163                                  * here?
 164                                  * */
 165
 166                                 if ((ret == KRB5_KDC_UNREACH)
 167                                     || (ret == KRB5_REALM_CANT_RESOLVE)) {
 168 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 169                                         new_start = time(NULL) + 30;
 170 #else
 171                                         new_start = time(NULL) +
 172                                                     MAX(30, lp_winbind_cache_time());
 173 #endif
 174                                         add_krb5_ticket_gain_handler_event(entry,
 175                                                         timeval_set(new_start, 0));
 176                                         return;
 177                                 }
 178                                 TALLOC_FREE(entry->event);
 179                                 return;
 180                         }
 181
 182                         DEBUG(10,("krb5_ticket_refresh_handler: successful re-kinit "
 183                                 "for: %s in ccache: %s\n",
 184                                 entry->principal_name, entry->ccname));
 185
 186 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 187                         new_start = time(NULL) + 30;
 188 #else
 189                         /* The tkt should be refreshed at one-half the period
 190                            from now to the expiration time */
 191                         expire_time = entry->refresh_time;
 192                         new_start = krb5_event_refresh_time(entry->refresh_time);
 193 #endif
 194                         goto done;
 195                 } else {
 196                                 /* can this happen?
 197                                  * No cached credentials
 198                                  * destroy ticket and refresh chain
 199                                  * */
 200                                 ads_kdestroy(entry->ccname);
 201                                 TALLOC_FREE(entry->event);
 202                                 return;
 203                 }
 204         }
 205
 206         set_effective_uid(entry->uid);
 207
 208         ret = smb_krb5_renew_ticket(entry->ccname,
 209                                     entry->principal_name,
 210                                     entry->service,
 211                                     &new_start);
 212 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 213         new_start = time(NULL) + 30;
 214 #else
 215         expire_time = new_start;
 216         new_start = krb5_event_refresh_time(new_start);
 217 #endif
 218
 219         gain_root_privilege();
 220
 221         if (ret) {
 222                 DEBUG(3,("krb5_ticket_refresh_handler: "
 223                         "could not renew tickets: %s\n",
 224                         error_message(ret)));
 225                 /* maybe we are beyond the renewing window */
 226
 227                 /* evil rises here, we refresh ticket failed,
 228                  * but the ticket might be expired. Therefore,
 229                  * When we refresh ticket failed, destory the
 230                  * ticket */
 231
 232                 ads_kdestroy(entry->ccname);
 233
 234                 /* avoid breaking the renewal chain: retry in
 235                  * lp_winbind_cache_time() seconds when the KDC was not
 236                  * available right now.
 237                  * the return code can be KRB5_REALM_CANT_RESOLVE.
 238                  * More error code handling here? */
 239
 240                 if ((ret == KRB5_KDC_UNREACH)
 241                     || (ret == KRB5_REALM_CANT_RESOLVE)) {
 242 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 243                         new_start = time(NULL) + 30;
 244 #else
 245                         new_start = time(NULL) +
 246                                     MAX(30, lp_winbind_cache_time());
 247 #endif
 248                         /* ticket is destroyed here, we have to regain it
 249                          * if it is possible */
 250                         add_krb5_ticket_gain_handler_event(entry,
 251                                                 timeval_set(new_start, 0));
 252                         return;
 253                 }
 254
 255                 /* This is evil, if the ticket was already expired.
 256                  * renew ticket function returns KRB5KRB_AP_ERR_TKT_EXPIRED.
 257                  * But there is still a chance that we can rekinit it.
 258                  *
 259                  * This happens when user login in online mode, and then network
 260                  * down or something cause winbind goes offline for a very long time,
 261                  * and then goes online again. ticket expired, renew failed.
 262                  * This happens when machine are put to sleep for a long time,
 263                  * but shorter than entry->renew_util.
 264                  * NB
 265                  * Looks like the KDC is reachable, we want to rekinit as soon as
 266                  * possible instead of waiting some time later. */
 267                 if ((ret == KRB5KRB_AP_ERR_TKT_EXPIRED)
 268                     || (ret == KRB5_FCC_NOFILE)) goto rekinit;
 269
 270                 return;
 271         }
 272
 273 done:
 274         /* in cases that ticket will be unrenewable soon, we don't try to renew ticket
 275          * but try to regain ticket if it is possible */
 276         if (entry->renew_until && expire_time
 277              && (entry->renew_until <= expire_time)) {
 278                 /* try to regain ticket 10 seconds before expiration */
 279                 expire_time -= 10;
 280                 add_krb5_ticket_gain_handler_event(entry,
 281                                         timeval_set(expire_time, 0));
 282                 return;
 283         }
 284
 285         if (entry->refresh_time == 0) {
 286                 entry->refresh_time = new_start;
 287         }
 288         entry->event = tevent_add_timer(global_event_context(), entry,
 289                                        timeval_set(new_start, 0),
 290                                        krb5_ticket_refresh_handler,
 291                                        entry);
 292
 293 #endif
 294 }
 295
 296 /****************************************************************
 297  Do the work of regaining a ticket when coming from offline auth.
 298 ****************************************************************/
 299
 300 static void krb5_ticket_gain_handler(struct tevent_context *event_ctx,
 301                                      struct tevent_timer *te,
 302                                      struct timeval now,
 303                                      void *private_data)
 304 {
 305         struct WINBINDD_CCACHE_ENTRY *entry =
 306                 talloc_get_type_abort(private_data, struct WINBINDD_CCACHE_ENTRY);
 307 #ifdef HAVE_KRB5
 308         int ret;
 309         struct timeval t;
 310         struct WINBINDD_MEMORY_CREDS *cred_ptr = entry->cred_ptr;
 311         struct winbindd_domain *domain = NULL;
 312 #endif
 313
 314         DBG_DEBUG("event called for: %s, %s\n",
 315                   entry->ccname, entry->username);
 316
 317         TALLOC_FREE(entry->event);
 318
 319 #ifdef HAVE_KRB5
 320
 321         if (!cred_ptr || !cred_ptr->pass) {
 322                 DEBUG(10,("krb5_ticket_gain_handler: no memory creds\n"));
 323                 return;
 324         }
 325
 326         if ((domain = find_domain_from_name(entry->realm)) == NULL) {
 327                 DEBUG(0,("krb5_ticket_gain_handler: unknown domain\n"));
 328                 return;
 329         }
 330
 331         if (!domain->online) {
 332                 goto retry_later;
 333         }
 334
 335         set_effective_uid(entry->uid);
 336
 337         ret = kerberos_kinit_password_ext(entry->principal_name,
 338                                           cred_ptr->pass,
 339                                           0, /* hm, can we do time correction here ? */
 340                                           &entry->refresh_time,
 341                                           &entry->renew_until,
 342                                           entry->ccname,
 343                                           False, /* no PAC required anymore */
 344                                           True,
 345                                           WINBINDD_PAM_AUTH_KRB5_RENEW_TIME,
 346                                           NULL);
 347         gain_root_privilege();
 348
 349         if (ret) {
 350                 DEBUG(3,("krb5_ticket_gain_handler: "
 351                         "could not kinit: %s\n",
 352                         error_message(ret)));
 353                 /* evil. If we cannot do it, destroy any the __maybe__
 354                  * __existing__ ticket */
 355                 ads_kdestroy(entry->ccname);
 356                 goto retry_later;
 357         }
 358
 359         DEBUG(10,("krb5_ticket_gain_handler: "
 360                 "successful kinit for: %s in ccache: %s\n",
 361                 entry->principal_name, entry->ccname));
 362
 363         goto got_ticket;
 364
 365   retry_later:
 366
 367 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 368         t = timeval_set(time(NULL) + 30, 0);
 369 #else
 370         t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 371 #endif
 372
 373         add_krb5_ticket_gain_handler_event(entry, t);
 374         return;
 375
 376   got_ticket:
 377
 378 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 379         t = timeval_set(time(NULL) + 30, 0);
 380 #else
 381         t = timeval_set(krb5_event_refresh_time(entry->refresh_time), 0);
 382 #endif
 383
 384         if (entry->refresh_time == 0) {
 385                 entry->refresh_time = t.tv_sec;
 386         }
 387         entry->event = tevent_add_timer(global_event_context(),
 388                                        entry,
 389                                        t,
 390                                        krb5_ticket_refresh_handler,
 391                                        entry);
 392
 393         return;
 394 #endif
 395 }
 396
 397 /**************************************************************
 398  The gain initial ticket case is recognised as entry->refresh_time
 399  is always zero.
 400 **************************************************************/
 401
 402 static void add_krb5_ticket_gain_handler_event(struct WINBINDD_CCACHE_ENTRY *entry,
 403                                      struct timeval t)
 404 {
 405         entry->refresh_time = 0;
 406         entry->event = tevent_add_timer(global_event_context(),
 407                                        entry,
 408                                        t,
 409                                        krb5_ticket_gain_handler,
 410                                        entry);
 411 }
 412
 413 void ccache_regain_all_now(void)
 414 {
 415         struct WINBINDD_CCACHE_ENTRY *cur;
 416         struct timeval t = timeval_current();
 417
 418         for (cur = ccache_list; cur; cur = cur->next) {
 419                 struct tevent_timer *new_event;
 420
 421                 /*
 422                  * if refresh_time is 0, we know that the
 423                  * the event has the krb5_ticket_gain_handler
 424                  */
 425                 if (cur->refresh_time == 0) {
 426                         new_event = tevent_add_timer(global_event_context(),
 427                                                     cur,
 428                                                     t,
 429                                                     krb5_ticket_gain_handler,
 430                                                     cur);
 431                 } else {
 432                         new_event = tevent_add_timer(global_event_context(),
 433                                                     cur,
 434                                                     t,
 435                                                     krb5_ticket_refresh_handler,
 436                                                     cur);
 437                 }
 438
 439                 if (!new_event) {
 440                         continue;
 441                 }
 442
 443                 TALLOC_FREE(cur->event);
 444                 cur->event = new_event;
 445         }
 446
 447         return;
 448 }
 449
 450 /****************************************************************
 451  Check if an ccache entry exists.
 452 ****************************************************************/
 453
 454 bool ccache_entry_exists(const char *username)
 455 {
 456         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 457         return (entry != NULL);
 458 }
 459
 460 /****************************************************************
 461  Ensure we're changing the correct entry.
 462 ****************************************************************/
 463
 464 bool ccache_entry_identical(const char *username,
 465                             uid_t uid,
 466                             const char *ccname)
 467 {
 468         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 469
 470         if (!entry) {
 471                 return False;
 472         }
 473
 474         if (entry->uid != uid) {
 475                 DEBUG(0,("cache_entry_identical: uid's differ: %u != %u\n",
 476                         (unsigned int)entry->uid, (unsigned int)uid));
 477                 return False;
 478         }
 479         if (!strcsequal(entry->ccname, ccname)) {
 480                 DEBUG(0,("cache_entry_identical: "
 481                         "ccnames differ: (cache) %s != (client) %s\n",
 482                         entry->ccname, ccname));
 483                 return False;
 484         }
 485         return True;
 486 }
 487
 488 NTSTATUS add_ccache_to_list(const char *princ_name,
 489                             const char *ccname,
 490                             const char *service,
 491                             const char *username,
 492                             const char *pass,
 493                             const char *realm,
 494                             uid_t uid,
 495                             time_t create_time,
 496                             time_t ticket_end,
 497                             time_t renew_until,
 498                             bool postponed_request)
 499 {
 500         struct WINBINDD_CCACHE_ENTRY *entry = NULL;
 501         struct timeval t;
 502         NTSTATUS ntret;
 503
 504         if ((username == NULL && princ_name == NULL) ||
 505             ccname == NULL || uid == (uid_t)-1) {
 506                 return NT_STATUS_INVALID_PARAMETER;
 507         }
 508
 509         if (ccache_entry_count() + 1 > MAX_CCACHES) {
 510                 DEBUG(10,("add_ccache_to_list: "
 511                         "max number of ccaches reached\n"));
 512                 return NT_STATUS_NO_MORE_ENTRIES;
 513         }
 514
 515         /* Reference count old entries */
 516         entry = get_ccache_by_username(username);
 517         if (entry) {
 518                 /* Check cached entries are identical. */
 519                 if (!ccache_entry_identical(username, uid, ccname)) {
 520                         return NT_STATUS_INVALID_PARAMETER;
 521                 }
 522                 entry->ref_count++;
 523                 DEBUG(10,("add_ccache_to_list: "
 524                         "ref count on entry %s is now %d\n",
 525                         username, entry->ref_count));
 526                 /* FIXME: in this case we still might want to have a krb5 cred
 527                  * event handler created - gd
 528                  * Add ticket refresh handler here */
 529
 530                 if (!lp_winbind_refresh_tickets() || renew_until <= 0) {
 531                         return NT_STATUS_OK;
 532                 }
 533
 534                 if (!entry->event) {
 535                         if (postponed_request) {
 536                                 t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 537                                 add_krb5_ticket_gain_handler_event(entry, t);
 538                         } else {
 539                                 /* Renew at 1/2 the ticket expiration time */
 540 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 541                                 t = timeval_set(time(NULL)+30, 0);
 542 #else
 543                                 t = timeval_set(krb5_event_refresh_time(ticket_end),
 544                                                 0);
 545 #endif
 546                                 if (!entry->refresh_time) {
 547                                         entry->refresh_time = t.tv_sec;
 548                                 }
 549                                 entry->event = tevent_add_timer(global_event_context(),
 550                                                                entry,
 551                                                                t,
 552                                                                krb5_ticket_refresh_handler,
 553                                                                entry);
 554                         }
 555
 556                         if (!entry->event) {
 557                                 ntret = remove_ccache(username);
 558                                 if (!NT_STATUS_IS_OK(ntret)) {
 559                                         DEBUG(0, ("add_ccache_to_list: Failed to remove krb5 "
 560                                                   "ccache %s for user %s\n", entry->ccname,
 561                                                   entry->username));
 562                                         DEBUG(0, ("add_ccache_to_list: error is %s\n",
 563                                                   nt_errstr(ntret)));
 564                                         return ntret;
 565                                 }
 566                                 return NT_STATUS_NO_MEMORY;
 567                         }
 568
 569                         DEBUG(10,("add_ccache_to_list: added krb5_ticket handler\n"));
 570
 571                 }
 572
 573                 /*
 574                  * If we're set up to renew our krb5 tickets, we must
 575                  * cache the credentials in memory for the ticket
 576                  * renew function (or increase the reference count
 577                  * if we're logging in more than once). Fix inspired
 578                  * by patch from Ian Gordon <ian.gordon@strath.ac.uk>
 579                  * for bugid #9098.
 580                  */
 581
 582                 ntret = winbindd_add_memory_creds(username, uid, pass);
 583                 DEBUG(10, ("winbindd_add_memory_creds returned: %s\n",
 584                         nt_errstr(ntret)));
 585
 586                 return NT_STATUS_OK;
 587         }
 588
 589         entry = talloc(NULL, struct WINBINDD_CCACHE_ENTRY);
 590         if (!entry) {
 591                 return NT_STATUS_NO_MEMORY;
 592         }
 593
 594         ZERO_STRUCTP(entry);
 595
 596         if (username) {
 597                 entry->username = talloc_strdup(entry, username);
 598                 if (!entry->username) {
 599                         goto no_mem;
 600                 }
 601         }
 602         if (princ_name) {
 603                 entry->principal_name = talloc_strdup(entry, princ_name);
 604                 if (!entry->principal_name) {
 605                         goto no_mem;
 606                 }
 607         }
 608         if (service) {
 609                 entry->service = talloc_strdup(entry, service);
 610                 if (!entry->service) {
 611                         goto no_mem;
 612                 }
 613         }
 614
 615         entry->ccname = talloc_strdup(entry, ccname);
 616         if (!entry->ccname) {
 617                 goto no_mem;
 618         }
 619
 620         entry->realm = talloc_strdup(entry, realm);
 621         if (!entry->realm) {
 622                 goto no_mem;
 623         }
 624
 625         entry->create_time = create_time;
 626         entry->renew_until = renew_until;
 627         entry->uid = uid;
 628         entry->ref_count = 1;
 629
 630         if (!lp_winbind_refresh_tickets() || renew_until <= 0) {
 631                 goto add_entry;
 632         }
 633
 634         if (postponed_request) {
 635                 t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 636                 add_krb5_ticket_gain_handler_event(entry, t);
 637         } else {
 638                 /* Renew at 1/2 the ticket expiration time */
 639 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 640                 t = timeval_set(time(NULL)+30, 0);
 641 #else
 642                 t = timeval_set(krb5_event_refresh_time(ticket_end), 0);
 643 #endif
 644                 if (entry->refresh_time == 0) {
 645                         entry->refresh_time = t.tv_sec;
 646                 }
 647                 entry->event = tevent_add_timer(global_event_context(),
 648                                                entry,
 649                                                t,
 650                                                krb5_ticket_refresh_handler,
 651                                                entry);
 652         }
 653
 654         if (!entry->event) {
 655                 goto no_mem;
 656         }
 657
 658         DEBUG(10,("add_ccache_to_list: added krb5_ticket handler\n"));
 659
 660  add_entry:
 661
 662         DLIST_ADD(ccache_list, entry);
 663
 664         DEBUG(10,("add_ccache_to_list: "
 665                 "added ccache [%s] for user [%s] to the list\n",
 666                 ccname, username));
 667
 668         if (entry->event) {
 669                 /*
 670                  * If we're set up to renew our krb5 tickets, we must
 671                  * cache the credentials in memory for the ticket
 672                  * renew function. Fix inspired by patch from
 673                  * Ian Gordon <ian.gordon@strath.ac.uk> for
 674                  * bugid #9098.
 675                  */
 676
 677                 ntret = winbindd_add_memory_creds(username, uid, pass);
 678                 DEBUG(10, ("winbindd_add_memory_creds returned: %s\n",
 679                         nt_errstr(ntret)));
 680         }
 681
 682         return NT_STATUS_OK;
 683
 684  no_mem:
 685
 686         TALLOC_FREE(entry);
 687         return NT_STATUS_NO_MEMORY;
 688 }
 689
 690 /*******************************************************************
 691  Remove a WINBINDD_CCACHE_ENTRY entry and the krb5 ccache if no longer
 692  referenced.
 693  *******************************************************************/
 694
 695 NTSTATUS remove_ccache(const char *username)
 696 {
 697         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 698         NTSTATUS status = NT_STATUS_OK;
 699 #ifdef HAVE_KRB5
 700         krb5_error_code ret;
 701 #endif
 702
 703         if (!entry) {
 704                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 705         }
 706
 707         if (entry->ref_count <= 0) {
 708                 DEBUG(0,("remove_ccache: logic error. "
 709                         "ref count for user %s = %d\n",
 710                         username, entry->ref_count));
 711                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 712         }
 713
 714         entry->ref_count--;
 715
 716         if (entry->ref_count > 0) {
 717                 DEBUG(10,("remove_ccache: entry %s ref count now %d\n",
 718                         username, entry->ref_count));
 719                 return NT_STATUS_OK;
 720         }
 721
 722         /* no references any more */
 723
 724         DLIST_REMOVE(ccache_list, entry);
 725         TALLOC_FREE(entry->event); /* unregisters events */
 726
 727 #ifdef HAVE_KRB5
 728         ret = ads_kdestroy(entry->ccname);
 729
 730         /* we ignore the error when there has been no credential cache */
 731         if (ret == KRB5_FCC_NOFILE) {
 732                 ret = 0;
 733         } else if (ret) {
 734                 DEBUG(0,("remove_ccache: "
 735                         "failed to destroy user krb5 ccache %s with: %s\n",
 736                         entry->ccname, error_message(ret)));
 737         } else {
 738                 DEBUG(10,("remove_ccache: "
 739                         "successfully destroyed krb5 ccache %s for user %s\n",
 740                         entry->ccname, username));
 741         }
 742         status = krb5_to_nt_status(ret);
 743 #endif
 744
 745         TALLOC_FREE(entry);
 746         DEBUG(10,("remove_ccache: removed ccache for user %s\n", username));
 747
 748         return status;
 749 }
 750
 751 /*******************************************************************
 752  In memory credentials cache code.
 753 *******************************************************************/
 754
 755 static struct WINBINDD_MEMORY_CREDS *memory_creds_list;
 756
 757 /***********************************************************
 758  Find an entry on the list by name.
 759 ***********************************************************/
 760
 761 struct WINBINDD_MEMORY_CREDS *find_memory_creds_by_name(const char *username)
 762 {
 763         struct WINBINDD_MEMORY_CREDS *p;
 764
 765         for (p = memory_creds_list; p; p = p->next) {
 766                 if (strequal(p->username, username)) {
 767                         return p;
 768                 }
 769         }
 770         return NULL;
 771 }
 772
 773 /***********************************************************
 774  Store the required creds and mlock them.
 775 ***********************************************************/
 776
 777 static NTSTATUS store_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp,
 778                                    const char *pass)
 779 {
 780 #if !defined(HAVE_MLOCK)
 781         return NT_STATUS_OK;
 782 #else
 783         /* new_entry->nt_hash is the base pointer for the block
 784            of memory pointed into by new_entry->lm_hash and
 785            new_entry->pass (if we're storing plaintext). */
 786
 787         memcredp->len = NT_HASH_LEN + LM_HASH_LEN;
 788         if (pass) {
 789                 memcredp->len += strlen(pass)+1;
 790         }
 791
 792
 793 #if defined(LINUX)
 794         /* aligning the memory on on x86_64 and compiling
 795            with gcc 4.1 using -O2 causes a segv in the
 796            next memset()  --jerry */
 797         memcredp->nt_hash = SMB_MALLOC_ARRAY(unsigned char, memcredp->len);
 798 #else
 799         /* On non-linux platforms, mlock()'d memory must be aligned */
 800         memcredp->nt_hash = SMB_MEMALIGN_ARRAY(unsigned char,
 801                                                getpagesize(), memcredp->len);
 802 #endif
 803         if (!memcredp->nt_hash) {
 804                 return NT_STATUS_NO_MEMORY;
 805         }
 806         memset(memcredp->nt_hash, 0x0, memcredp->len);
 807
 808         memcredp->lm_hash = memcredp->nt_hash + NT_HASH_LEN;
 809
 810 #ifdef DEBUG_PASSWORD
 811         DEBUG(10,("mlocking memory: %p\n", memcredp->nt_hash));
 812 #endif
 813         if ((mlock(memcredp->nt_hash, memcredp->len)) == -1) {
 814                 DEBUG(0,("failed to mlock memory: %s (%d)\n",
 815                         strerror(errno), errno));
 816                 SAFE_FREE(memcredp->nt_hash);
 817                 return map_nt_error_from_unix(errno);
 818         }
 819
 820 #ifdef DEBUG_PASSWORD
 821         DEBUG(10,("mlocked memory: %p\n", memcredp->nt_hash));
 822 #endif
 823
 824         if (pass) {
 825                 /* Create and store the password hashes. */
 826                 E_md4hash(pass, memcredp->nt_hash);
 827                 E_deshash(pass, memcredp->lm_hash);
 828
 829                 memcredp->pass = (char *)memcredp->lm_hash + LM_HASH_LEN;
 830                 memcpy(memcredp->pass, pass,
 831                        memcredp->len - NT_HASH_LEN - LM_HASH_LEN);
 832         }
 833
 834         return NT_STATUS_OK;
 835 #endif
 836 }
 837
 838 /***********************************************************
 839  Destroy existing creds.
 840 ***********************************************************/
 841
 842 static NTSTATUS delete_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp)
 843 {
 844 #if !defined(HAVE_MUNLOCK)
 845         return NT_STATUS_OK;
 846 #else
 847         if (munlock(memcredp->nt_hash, memcredp->len) == -1) {
 848                 DEBUG(0,("failed to munlock memory: %s (%d)\n",
 849                         strerror(errno), errno));
 850                 return map_nt_error_from_unix(errno);
 851         }
 852         memset(memcredp->nt_hash, '\0', memcredp->len);
 853         SAFE_FREE(memcredp->nt_hash);
 854         memcredp->nt_hash = NULL;
 855         memcredp->lm_hash = NULL;
 856         memcredp->pass = NULL;
 857         memcredp->len = 0;
 858         return NT_STATUS_OK;
 859 #endif
 860 }
 861
 862 /***********************************************************
 863  Replace the required creds with new ones (password change).
 864 ***********************************************************/
 865
 866 static NTSTATUS winbindd_replace_memory_creds_internal(struct WINBINDD_MEMORY_CREDS *memcredp,
 867                                                        const char *pass)
 868 {
 869         NTSTATUS status = delete_memory_creds(memcredp);
 870         if (!NT_STATUS_IS_OK(status)) {
 871                 return status;
 872         }
 873         return store_memory_creds(memcredp, pass);
 874 }
 875
 876 /*************************************************************
 877  Store credentials in memory in a list.
 878 *************************************************************/
 879
 880 static NTSTATUS winbindd_add_memory_creds_internal(const char *username,
 881                                                    uid_t uid,
 882                                                    const char *pass)
 883 {
 884         /* Shortcut to ensure we don't store if no mlock. */
 885 #if !defined(HAVE_MLOCK) || !defined(HAVE_MUNLOCK)
 886         return NT_STATUS_OK;
 887 #else
 888         NTSTATUS status;
 889         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
 890
 891         memcredp = find_memory_creds_by_name(username);
 892         if (uid == (uid_t)-1) {
 893                 DEBUG(0,("winbindd_add_memory_creds_internal: "
 894                         "invalid uid for user %s.\n", username));
 895                 return NT_STATUS_INVALID_PARAMETER;
 896         }
 897
 898         if (memcredp) {
 899                 /* Already exists. Increment the reference count and replace stored creds. */
 900                 if (uid != memcredp->uid) {
 901                         DEBUG(0,("winbindd_add_memory_creds_internal: "
 902                                 "uid %u for user %s doesn't "
 903                                 "match stored uid %u. Replacing.\n",
 904                                 (unsigned int)uid, username,
 905                                 (unsigned int)memcredp->uid));
 906                         memcredp->uid = uid;
 907                 }
 908                 memcredp->ref_count++;
 909                 DEBUG(10,("winbindd_add_memory_creds_internal: "
 910                         "ref count for user %s is now %d\n",
 911                         username, memcredp->ref_count));
 912                 return winbindd_replace_memory_creds_internal(memcredp, pass);
 913         }
 914
 915         memcredp = talloc_zero(NULL, struct WINBINDD_MEMORY_CREDS);
 916         if (!memcredp) {
 917                 return NT_STATUS_NO_MEMORY;
 918         }
 919         memcredp->username = talloc_strdup(memcredp, username);
 920         if (!memcredp->username) {
 921                 talloc_destroy(memcredp);
 922                 return NT_STATUS_NO_MEMORY;
 923         }
 924
 925         status = store_memory_creds(memcredp, pass);
 926         if (!NT_STATUS_IS_OK(status)) {
 927                 talloc_destroy(memcredp);
 928                 return status;
 929         }
 930
 931         memcredp->uid = uid;
 932         memcredp->ref_count = 1;
 933         DLIST_ADD(memory_creds_list, memcredp);
 934
 935         DEBUG(10,("winbindd_add_memory_creds_internal: "
 936                 "added entry for user %s\n", username));
 937
 938         return NT_STATUS_OK;
 939 #endif
 940 }
 941
 942 /*************************************************************
 943  Store users credentials in memory. If we also have a
 944  struct WINBINDD_CCACHE_ENTRY for this username with a
 945  refresh timer, then store the plaintext of the password
 946  and associate the new credentials with the struct WINBINDD_CCACHE_ENTRY.
 947 *************************************************************/
 948
 949 NTSTATUS winbindd_add_memory_creds(const char *username,
 950                                    uid_t uid,
 951                                    const char *pass)
 952 {
 953         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 954         NTSTATUS status;
 955
 956         status = winbindd_add_memory_creds_internal(username, uid, pass);
 957         if (!NT_STATUS_IS_OK(status)) {
 958                 return status;
 959         }
 960
 961         if (entry) {
 962                 struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
 963                 memcredp = find_memory_creds_by_name(username);
 964                 if (memcredp) {
 965                         entry->cred_ptr = memcredp;
 966                 }
 967         }
 968
 969         return status;
 970 }
 971
 972 /*************************************************************
 973  Decrement the in-memory ref count - delete if zero.
 974 *************************************************************/
 975
 976 NTSTATUS winbindd_delete_memory_creds(const char *username)
 977 {
 978         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
 979         struct WINBINDD_CCACHE_ENTRY *entry = NULL;
 980         NTSTATUS status = NT_STATUS_OK;
 981
 982         memcredp = find_memory_creds_by_name(username);
 983         entry = get_ccache_by_username(username);
 984
 985         if (!memcredp) {
 986                 DEBUG(10,("winbindd_delete_memory_creds: unknown user %s\n",
 987                         username));
 988                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 989         }
 990
 991         if (memcredp->ref_count <= 0) {
 992                 DEBUG(0,("winbindd_delete_memory_creds: logic error. "
 993                         "ref count for user %s = %d\n",
 994                         username, memcredp->ref_count));
 995                 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
 996         }
 997
 998         memcredp->ref_count--;
 999         if (memcredp->ref_count <= 0) {
1000                 delete_memory_creds(memcredp);
1001                 DLIST_REMOVE(memory_creds_list, memcredp);
1002                 talloc_destroy(memcredp);
1003                 DEBUG(10,("winbindd_delete_memory_creds: "
1004                         "deleted entry for user %s\n",
1005                         username));
1006         } else {
1007                 DEBUG(10,("winbindd_delete_memory_creds: "
1008                         "entry for user %s ref_count now %d\n",
1009                         username, memcredp->ref_count));
1010         }
1011
1012         if (entry) {
1013                 /* Ensure we have no dangling references to this. */
1014                 entry->cred_ptr = NULL;
1015         }
1016
1017         return status;
1018 }
1019
1020 /***********************************************************
1021  Replace the required creds with new ones (password change).
1022 ***********************************************************/
1023
1024 NTSTATUS winbindd_replace_memory_creds(const char *username,
1025                                        const char *pass)
1026 {
1027         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
1028
1029         memcredp = find_memory_creds_by_name(username);
1030         if (!memcredp) {
1031                 DEBUG(10,("winbindd_replace_memory_creds: unknown user %s\n",
1032                         username));
1033                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
1034         }
1035
1036         DEBUG(10,("winbindd_replace_memory_creds: replaced creds for user %s\n",
1037                 username));
1038
1039         return winbindd_replace_memory_creds_internal(memcredp, pass);
1040 }