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