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 event_context *,
  42                                      struct timed_event *,
  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 event_context *event_ctx,
 108                                         struct timed_event *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         DEBUG(10,("krb5_ticket_refresh_handler called\n"));
 122         DEBUGADD(10,("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 = event_add_timed(winbind_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 event_context *event_ctx,
 301                                      struct timed_event *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         DEBUG(10,("krb5_ticket_gain_handler called\n"));
 315         DEBUGADD(10,("event called for: %s, %s\n",
 316                 entry->ccname, entry->username));
 317
 318         TALLOC_FREE(entry->event);
 319
 320 #ifdef HAVE_KRB5
 321
 322         if (!cred_ptr || !cred_ptr->pass) {
 323                 DEBUG(10,("krb5_ticket_gain_handler: no memory creds\n"));
 324                 return;
 325         }
 326
 327         if ((domain = find_domain_from_name(entry->realm)) == NULL) {
 328                 DEBUG(0,("krb5_ticket_gain_handler: unknown domain\n"));
 329                 return;
 330         }
 331
 332         if (!domain->online) {
 333                 goto retry_later;
 334         }
 335
 336         set_effective_uid(entry->uid);
 337
 338         ret = kerberos_kinit_password_ext(entry->principal_name,
 339                                           cred_ptr->pass,
 340                                           0, /* hm, can we do time correction here ? */
 341                                           &entry->refresh_time,
 342                                           &entry->renew_until,
 343                                           entry->ccname,
 344                                           False, /* no PAC required anymore */
 345                                           True,
 346                                           WINBINDD_PAM_AUTH_KRB5_RENEW_TIME,
 347                                           NULL);
 348         gain_root_privilege();
 349
 350         if (ret) {
 351                 DEBUG(3,("krb5_ticket_gain_handler: "
 352                         "could not kinit: %s\n",
 353                         error_message(ret)));
 354                 /* evil. If we cannot do it, destroy any the __maybe__
 355                  * __existing__ ticket */
 356                 ads_kdestroy(entry->ccname);
 357                 goto retry_later;
 358         }
 359
 360         DEBUG(10,("krb5_ticket_gain_handler: "
 361                 "successful kinit for: %s in ccache: %s\n",
 362                 entry->principal_name, entry->ccname));
 363
 364         goto got_ticket;
 365
 366   retry_later:
 367
 368 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 369         t = timeval_set(time(NULL) + 30, 0);
 370 #else
 371         t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 372 #endif
 373
 374         add_krb5_ticket_gain_handler_event(entry, t);
 375         return;
 376
 377   got_ticket:
 378
 379 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 380         t = timeval_set(time(NULL) + 30, 0);
 381 #else
 382         t = timeval_set(krb5_event_refresh_time(entry->refresh_time), 0);
 383 #endif
 384
 385         if (entry->refresh_time == 0) {
 386                 entry->refresh_time = t.tv_sec;
 387         }
 388         entry->event = event_add_timed(winbind_event_context(),
 389                                        entry,
 390                                        t,
 391                                        krb5_ticket_refresh_handler,
 392                                        entry);
 393
 394         return;
 395 #endif
 396 }
 397
 398 /**************************************************************
 399  The gain initial ticket case is recognised as entry->refresh_time
 400  is always zero.
 401 **************************************************************/
 402
 403 static void add_krb5_ticket_gain_handler_event(struct WINBINDD_CCACHE_ENTRY *entry,
 404                                      struct timeval t)
 405 {
 406         entry->refresh_time = 0;
 407         entry->event = event_add_timed(winbind_event_context(),
 408                                        entry,
 409                                        t,
 410                                        krb5_ticket_gain_handler,
 411                                        entry);
 412 }
 413
 414 void ccache_regain_all_now(void)
 415 {
 416         struct WINBINDD_CCACHE_ENTRY *cur;
 417         struct timeval t = timeval_current();
 418
 419         for (cur = ccache_list; cur; cur = cur->next) {
 420                 struct timed_event *new_event;
 421
 422                 /*
 423                  * if refresh_time is 0, we know that the
 424                  * the event has the krb5_ticket_gain_handler
 425                  */
 426                 if (cur->refresh_time == 0) {
 427                         new_event = event_add_timed(winbind_event_context(),
 428                                                     cur,
 429                                                     t,
 430                                                     krb5_ticket_gain_handler,
 431                                                     cur);
 432                 } else {
 433                         new_event = event_add_timed(winbind_event_context(),
 434                                                     cur,
 435                                                     t,
 436                                                     krb5_ticket_refresh_handler,
 437                                                     cur);
 438                 }
 439
 440                 if (!new_event) {
 441                         continue;
 442                 }
 443
 444                 TALLOC_FREE(cur->event);
 445                 cur->event = new_event;
 446         }
 447
 448         return;
 449 }
 450
 451 /****************************************************************
 452  Check if an ccache entry exists.
 453 ****************************************************************/
 454
 455 bool ccache_entry_exists(const char *username)
 456 {
 457         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 458         return (entry != NULL);
 459 }
 460
 461 /****************************************************************
 462  Ensure we're changing the correct entry.
 463 ****************************************************************/
 464
 465 bool ccache_entry_identical(const char *username,
 466                             uid_t uid,
 467                             const char *ccname)
 468 {
 469         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 470
 471         if (!entry) {
 472                 return False;
 473         }
 474
 475         if (entry->uid != uid) {
 476                 DEBUG(0,("cache_entry_identical: uid's differ: %u != %u\n",
 477                         (unsigned int)entry->uid, (unsigned int)uid));
 478                 return False;
 479         }
 480         if (!strcsequal(entry->ccname, ccname)) {
 481                 DEBUG(0,("cache_entry_identical: "
 482                         "ccnames differ: (cache) %s != (client) %s\n",
 483                         entry->ccname, ccname));
 484                 return False;
 485         }
 486         return True;
 487 }
 488
 489 NTSTATUS add_ccache_to_list(const char *princ_name,
 490                             const char *ccname,
 491                             const char *service,
 492                             const char *username,
 493                             const char *pass,
 494                             const char *realm,
 495                             uid_t uid,
 496                             time_t create_time,
 497                             time_t ticket_end,
 498                             time_t renew_until,
 499                             bool postponed_request)
 500 {
 501         struct WINBINDD_CCACHE_ENTRY *entry = NULL;
 502         struct timeval t;
 503         NTSTATUS ntret;
 504 #ifdef HAVE_KRB5
 505         int ret;
 506 #endif
 507
 508         if ((username == NULL && princ_name == NULL) ||
 509             ccname == NULL || uid < 0) {
 510                 return NT_STATUS_INVALID_PARAMETER;
 511         }
 512
 513         if (ccache_entry_count() + 1 > MAX_CCACHES) {
 514                 DEBUG(10,("add_ccache_to_list: "
 515                         "max number of ccaches reached\n"));
 516                 return NT_STATUS_NO_MORE_ENTRIES;
 517         }
 518
 519         /* If it is cached login, destroy krb5 ticket
 520          * to avoid surprise. */
 521 #ifdef HAVE_KRB5
 522         if (postponed_request) {
 523                 /* ignore KRB5_FCC_NOFILE error here */
 524                 ret = ads_kdestroy(ccname);
 525                 if (ret == KRB5_FCC_NOFILE) {
 526                         ret = 0;
 527                 }
 528                 if (ret) {
 529                         DEBUG(0, ("add_ccache_to_list: failed to destroy "
 530                                    "user krb5 ccache %s with %s\n", ccname,
 531                                    error_message(ret)));
 532                         return krb5_to_nt_status(ret);
 533                 }
 534                 DEBUG(10, ("add_ccache_to_list: successfully destroyed "
 535                            "krb5 ccache %s for user %s\n", ccname,
 536                            username));
 537         }
 538 #endif
 539
 540         /* Reference count old entries */
 541         entry = get_ccache_by_username(username);
 542         if (entry) {
 543                 /* Check cached entries are identical. */
 544                 if (!ccache_entry_identical(username, uid, ccname)) {
 545                         return NT_STATUS_INVALID_PARAMETER;
 546                 }
 547                 entry->ref_count++;
 548                 DEBUG(10,("add_ccache_to_list: "
 549                         "ref count on entry %s is now %d\n",
 550                         username, entry->ref_count));
 551                 /* FIXME: in this case we still might want to have a krb5 cred
 552                  * event handler created - gd
 553                  * Add ticket refresh handler here */
 554
 555                 if (!lp_winbind_refresh_tickets() || renew_until <= 0) {
 556                         return NT_STATUS_OK;
 557                 }
 558
 559                 if (!entry->event) {
 560                         if (postponed_request) {
 561                                 t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 562                                 add_krb5_ticket_gain_handler_event(entry, t);
 563                         } else {
 564                                 /* Renew at 1/2 the ticket expiration time */
 565 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 566                                 t = timeval_set(time(NULL)+30, 0);
 567 #else
 568                                 t = timeval_set(krb5_event_refresh_time(ticket_end),
 569                                                 0);
 570 #endif
 571                                 if (!entry->refresh_time) {
 572                                         entry->refresh_time = t.tv_sec;
 573                                 }
 574                                 entry->event = event_add_timed(winbind_event_context(),
 575                                                                entry,
 576                                                                t,
 577                                                                krb5_ticket_refresh_handler,
 578                                                                entry);
 579                         }
 580
 581                         if (!entry->event) {
 582                                 ntret = remove_ccache(username);
 583                                 if (!NT_STATUS_IS_OK(ntret)) {
 584                                         DEBUG(0, ("add_ccache_to_list: Failed to remove krb5 "
 585                                                   "ccache %s for user %s\n", entry->ccname,
 586                                                   entry->username));
 587                                         DEBUG(0, ("add_ccache_to_list: error is %s\n",
 588                                                   nt_errstr(ntret)));
 589                                         return ntret;
 590                                 }
 591                                 return NT_STATUS_NO_MEMORY;
 592                         }
 593
 594                         DEBUG(10,("add_ccache_to_list: added krb5_ticket handler\n"));
 595
 596                 }
 597
 598                 /*
 599                  * If we're set up to renew our krb5 tickets, we must
 600                  * cache the credentials in memory for the ticket
 601                  * renew function (or increase the reference count
 602                  * if we're logging in more than once). Fix inspired
 603                  * by patch from Ian Gordon <ian.gordon@strath.ac.uk>
 604                  * for bugid #9098.
 605                  */
 606
 607                 ntret = winbindd_add_memory_creds(username, uid, pass);
 608                 DEBUG(10, ("winbindd_add_memory_creds returned: %s\n",
 609                         nt_errstr(ntret)));
 610
 611                 return NT_STATUS_OK;
 612         }
 613
 614         entry = TALLOC_P(NULL, struct WINBINDD_CCACHE_ENTRY);
 615         if (!entry) {
 616                 return NT_STATUS_NO_MEMORY;
 617         }
 618
 619         ZERO_STRUCTP(entry);
 620
 621         if (username) {
 622                 entry->username = talloc_strdup(entry, username);
 623                 if (!entry->username) {
 624                         goto no_mem;
 625                 }
 626         }
 627         if (princ_name) {
 628                 entry->principal_name = talloc_strdup(entry, princ_name);
 629                 if (!entry->principal_name) {
 630                         goto no_mem;
 631                 }
 632         }
 633         if (service) {
 634                 entry->service = talloc_strdup(entry, service);
 635                 if (!entry->service) {
 636                         goto no_mem;
 637                 }
 638         }
 639
 640         entry->ccname = talloc_strdup(entry, ccname);
 641         if (!entry->ccname) {
 642                 goto no_mem;
 643         }
 644
 645         entry->realm = talloc_strdup(entry, realm);
 646         if (!entry->realm) {
 647                 goto no_mem;
 648         }
 649
 650         entry->create_time = create_time;
 651         entry->renew_until = renew_until;
 652         entry->uid = uid;
 653         entry->ref_count = 1;
 654
 655         if (!lp_winbind_refresh_tickets() || renew_until <= 0) {
 656                 goto add_entry;
 657         }
 658
 659         if (postponed_request) {
 660                 t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0);
 661                 add_krb5_ticket_gain_handler_event(entry, t);
 662         } else {
 663                 /* Renew at 1/2 the ticket expiration time */
 664 #if defined(DEBUG_KRB5_TKT_RENEWAL)
 665                 t = timeval_set(time(NULL)+30, 0);
 666 #else
 667                 t = timeval_set(krb5_event_refresh_time(ticket_end), 0);
 668 #endif
 669                 if (entry->refresh_time == 0) {
 670                         entry->refresh_time = t.tv_sec;
 671                 }
 672                 entry->event = event_add_timed(winbind_event_context(),
 673                                                entry,
 674                                                t,
 675                                                krb5_ticket_refresh_handler,
 676                                                entry);
 677         }
 678
 679         if (!entry->event) {
 680                 goto no_mem;
 681         }
 682
 683         DEBUG(10,("add_ccache_to_list: added krb5_ticket handler\n"));
 684
 685  add_entry:
 686
 687         DLIST_ADD(ccache_list, entry);
 688
 689         DEBUG(10,("add_ccache_to_list: "
 690                 "added ccache [%s] for user [%s] to the list\n",
 691                 ccname, username));
 692
 693         if (entry->event) {
 694                 /*
 695                  * If we're set up to renew our krb5 tickets, we must
 696                  * cache the credentials in memory for the ticket
 697                  * renew function. Fix inspired by patch from
 698                  * Ian Gordon <ian.gordon@strath.ac.uk> for
 699                  * bugid #9098.
 700                  */
 701
 702                 ntret = winbindd_add_memory_creds(username, uid, pass);
 703                 DEBUG(10, ("winbindd_add_memory_creds returned: %s\n",
 704                         nt_errstr(ntret)));
 705         }
 706
 707         return NT_STATUS_OK;
 708
 709  no_mem:
 710
 711         TALLOC_FREE(entry);
 712         return NT_STATUS_NO_MEMORY;
 713 }
 714
 715 /*******************************************************************
 716  Remove a WINBINDD_CCACHE_ENTRY entry and the krb5 ccache if no longer
 717  referenced.
 718  *******************************************************************/
 719
 720 NTSTATUS remove_ccache(const char *username)
 721 {
 722         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 723         NTSTATUS status = NT_STATUS_OK;
 724 #ifdef HAVE_KRB5
 725         krb5_error_code ret;
 726 #endif
 727
 728         if (!entry) {
 729                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 730         }
 731
 732         if (entry->ref_count <= 0) {
 733                 DEBUG(0,("remove_ccache: logic error. "
 734                         "ref count for user %s = %d\n",
 735                         username, entry->ref_count));
 736                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 737         }
 738
 739         entry->ref_count--;
 740
 741         if (entry->ref_count > 0) {
 742                 DEBUG(10,("remove_ccache: entry %s ref count now %d\n",
 743                         username, entry->ref_count));
 744                 return NT_STATUS_OK;
 745         }
 746
 747         /* no references any more */
 748
 749         DLIST_REMOVE(ccache_list, entry);
 750         TALLOC_FREE(entry->event); /* unregisters events */
 751
 752 #ifdef HAVE_KRB5
 753         ret = ads_kdestroy(entry->ccname);
 754
 755         /* we ignore the error when there has been no credential cache */
 756         if (ret == KRB5_FCC_NOFILE) {
 757                 ret = 0;
 758         } else if (ret) {
 759                 DEBUG(0,("remove_ccache: "
 760                         "failed to destroy user krb5 ccache %s with: %s\n",
 761                         entry->ccname, error_message(ret)));
 762         } else {
 763                 DEBUG(10,("remove_ccache: "
 764                         "successfully destroyed krb5 ccache %s for user %s\n",
 765                         entry->ccname, username));
 766         }
 767         status = krb5_to_nt_status(ret);
 768 #endif
 769
 770         TALLOC_FREE(entry);
 771         DEBUG(10,("remove_ccache: removed ccache for user %s\n", username));
 772
 773         return status;
 774 }
 775
 776 /*******************************************************************
 777  In memory credentials cache code.
 778 *******************************************************************/
 779
 780 static struct WINBINDD_MEMORY_CREDS *memory_creds_list;
 781
 782 /***********************************************************
 783  Find an entry on the list by name.
 784 ***********************************************************/
 785
 786 struct WINBINDD_MEMORY_CREDS *find_memory_creds_by_name(const char *username)
 787 {
 788         struct WINBINDD_MEMORY_CREDS *p;
 789
 790         for (p = memory_creds_list; p; p = p->next) {
 791                 if (strequal(p->username, username)) {
 792                         return p;
 793                 }
 794         }
 795         return NULL;
 796 }
 797
 798 /***********************************************************
 799  Store the required creds and mlock them.
 800 ***********************************************************/
 801
 802 static NTSTATUS store_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp,
 803                                    const char *pass)
 804 {
 805 #if !defined(HAVE_MLOCK)
 806         return NT_STATUS_OK;
 807 #else
 808         /* new_entry->nt_hash is the base pointer for the block
 809            of memory pointed into by new_entry->lm_hash and
 810            new_entry->pass (if we're storing plaintext). */
 811
 812         memcredp->len = NT_HASH_LEN + LM_HASH_LEN;
 813         if (pass) {
 814                 memcredp->len += strlen(pass)+1;
 815         }
 816
 817
 818 #if defined(LINUX)
 819         /* aligning the memory on on x86_64 and compiling
 820            with gcc 4.1 using -O2 causes a segv in the
 821            next memset()  --jerry */
 822         memcredp->nt_hash = SMB_MALLOC_ARRAY(unsigned char, memcredp->len);
 823 #else
 824         /* On non-linux platforms, mlock()'d memory must be aligned */
 825         memcredp->nt_hash = SMB_MEMALIGN_ARRAY(unsigned char,
 826                                                getpagesize(), memcredp->len);
 827 #endif
 828         if (!memcredp->nt_hash) {
 829                 return NT_STATUS_NO_MEMORY;
 830         }
 831         memset(memcredp->nt_hash, 0x0, memcredp->len);
 832
 833         memcredp->lm_hash = memcredp->nt_hash + NT_HASH_LEN;
 834
 835 #ifdef DEBUG_PASSWORD
 836         DEBUG(10,("mlocking memory: %p\n", memcredp->nt_hash));
 837 #endif
 838         if ((mlock(memcredp->nt_hash, memcredp->len)) == -1) {
 839                 DEBUG(0,("failed to mlock memory: %s (%d)\n",
 840                         strerror(errno), errno));
 841                 SAFE_FREE(memcredp->nt_hash);
 842                 return map_nt_error_from_unix(errno);
 843         }
 844
 845 #ifdef DEBUG_PASSWORD
 846         DEBUG(10,("mlocked memory: %p\n", memcredp->nt_hash));
 847 #endif
 848
 849         /* Create and store the password hashes. */
 850         E_md4hash(pass, memcredp->nt_hash);
 851         E_deshash(pass, memcredp->lm_hash);
 852
 853         if (pass) {
 854                 memcredp->pass = (char *)memcredp->lm_hash + LM_HASH_LEN;
 855                 memcpy(memcredp->pass, pass,
 856                        memcredp->len - NT_HASH_LEN - LM_HASH_LEN);
 857         }
 858
 859         return NT_STATUS_OK;
 860 #endif
 861 }
 862
 863 /***********************************************************
 864  Destroy existing creds.
 865 ***********************************************************/
 866
 867 static NTSTATUS delete_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp)
 868 {
 869 #if !defined(HAVE_MUNLOCK)
 870         return NT_STATUS_OK;
 871 #else
 872         if (munlock(memcredp->nt_hash, memcredp->len) == -1) {
 873                 DEBUG(0,("failed to munlock memory: %s (%d)\n",
 874                         strerror(errno), errno));
 875                 return map_nt_error_from_unix(errno);
 876         }
 877         memset(memcredp->nt_hash, '\0', memcredp->len);
 878         SAFE_FREE(memcredp->nt_hash);
 879         memcredp->nt_hash = NULL;
 880         memcredp->lm_hash = NULL;
 881         memcredp->pass = NULL;
 882         memcredp->len = 0;
 883         return NT_STATUS_OK;
 884 #endif
 885 }
 886
 887 /***********************************************************
 888  Replace the required creds with new ones (password change).
 889 ***********************************************************/
 890
 891 static NTSTATUS winbindd_replace_memory_creds_internal(struct WINBINDD_MEMORY_CREDS *memcredp,
 892                                                        const char *pass)
 893 {
 894         NTSTATUS status = delete_memory_creds(memcredp);
 895         if (!NT_STATUS_IS_OK(status)) {
 896                 return status;
 897         }
 898         return store_memory_creds(memcredp, pass);
 899 }
 900
 901 /*************************************************************
 902  Store credentials in memory in a list.
 903 *************************************************************/
 904
 905 static NTSTATUS winbindd_add_memory_creds_internal(const char *username,
 906                                                    uid_t uid,
 907                                                    const char *pass)
 908 {
 909         /* Shortcut to ensure we don't store if no mlock. */
 910 #if !defined(HAVE_MLOCK) || !defined(HAVE_MUNLOCK)
 911         return NT_STATUS_OK;
 912 #else
 913         NTSTATUS status;
 914         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
 915
 916         memcredp = find_memory_creds_by_name(username);
 917         if (uid == (uid_t)-1) {
 918                 DEBUG(0,("winbindd_add_memory_creds_internal: "
 919                         "invalid uid for user %s.\n", username));
 920                 return NT_STATUS_INVALID_PARAMETER;
 921         }
 922
 923         if (memcredp) {
 924                 /* Already exists. Increment the reference count and replace stored creds. */
 925                 if (uid != memcredp->uid) {
 926                         DEBUG(0,("winbindd_add_memory_creds_internal: "
 927                                 "uid %u for user %s doesn't "
 928                                 "match stored uid %u. Replacing.\n",
 929                                 (unsigned int)uid, username,
 930                                 (unsigned int)memcredp->uid));
 931                         memcredp->uid = uid;
 932                 }
 933                 memcredp->ref_count++;
 934                 DEBUG(10,("winbindd_add_memory_creds_internal: "
 935                         "ref count for user %s is now %d\n",
 936                         username, memcredp->ref_count));
 937                 return winbindd_replace_memory_creds_internal(memcredp, pass);
 938         }
 939
 940         memcredp = TALLOC_ZERO_P(NULL, struct WINBINDD_MEMORY_CREDS);
 941         if (!memcredp) {
 942                 return NT_STATUS_NO_MEMORY;
 943         }
 944         memcredp->username = talloc_strdup(memcredp, username);
 945         if (!memcredp->username) {
 946                 talloc_destroy(memcredp);
 947                 return NT_STATUS_NO_MEMORY;
 948         }
 949
 950         status = store_memory_creds(memcredp, pass);
 951         if (!NT_STATUS_IS_OK(status)) {
 952                 talloc_destroy(memcredp);
 953                 return status;
 954         }
 955
 956         memcredp->uid = uid;
 957         memcredp->ref_count = 1;
 958         DLIST_ADD(memory_creds_list, memcredp);
 959
 960         DEBUG(10,("winbindd_add_memory_creds_internal: "
 961                 "added entry for user %s\n", username));
 962
 963         return NT_STATUS_OK;
 964 #endif
 965 }
 966
 967 /*************************************************************
 968  Store users credentials in memory. If we also have a
 969  struct WINBINDD_CCACHE_ENTRY for this username with a
 970  refresh timer, then store the plaintext of the password
 971  and associate the new credentials with the struct WINBINDD_CCACHE_ENTRY.
 972 *************************************************************/
 973
 974 NTSTATUS winbindd_add_memory_creds(const char *username,
 975                                    uid_t uid,
 976                                    const char *pass)
 977 {
 978         struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username);
 979         NTSTATUS status;
 980
 981         status = winbindd_add_memory_creds_internal(username, uid, pass);
 982         if (!NT_STATUS_IS_OK(status)) {
 983                 return status;
 984         }
 985
 986         if (entry) {
 987                 struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
 988                 memcredp = find_memory_creds_by_name(username);
 989                 if (memcredp) {
 990                         entry->cred_ptr = memcredp;
 991                 }
 992         }
 993
 994         return status;
 995 }
 996
 997 /*************************************************************
 998  Decrement the in-memory ref count - delete if zero.
 999 *************************************************************/
1000
1001 NTSTATUS winbindd_delete_memory_creds(const char *username)
1002 {
1003         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
1004         struct WINBINDD_CCACHE_ENTRY *entry = NULL;
1005         NTSTATUS status = NT_STATUS_OK;
1006
1007         memcredp = find_memory_creds_by_name(username);
1008         entry = get_ccache_by_username(username);
1009
1010         if (!memcredp) {
1011                 DEBUG(10,("winbindd_delete_memory_creds: unknown user %s\n",
1012                         username));
1013                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
1014         }
1015
1016         if (memcredp->ref_count <= 0) {
1017                 DEBUG(0,("winbindd_delete_memory_creds: logic error. "
1018                         "ref count for user %s = %d\n",
1019                         username, memcredp->ref_count));
1020                 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
1021         }
1022
1023         memcredp->ref_count--;
1024         if (memcredp->ref_count <= 0) {
1025                 delete_memory_creds(memcredp);
1026                 DLIST_REMOVE(memory_creds_list, memcredp);
1027                 talloc_destroy(memcredp);
1028                 DEBUG(10,("winbindd_delete_memory_creds: "
1029                         "deleted entry for user %s\n",
1030                         username));
1031         } else {
1032                 DEBUG(10,("winbindd_delete_memory_creds: "
1033                         "entry for user %s ref_count now %d\n",
1034                         username, memcredp->ref_count));
1035         }
1036
1037         if (entry) {
1038                 /* Ensure we have no dangling references to this. */
1039                 entry->cred_ptr = NULL;
1040         }
1041
1042         return status;
1043 }
1044
1045 /***********************************************************
1046  Replace the required creds with new ones (password change).
1047 ***********************************************************/
1048
1049 NTSTATUS winbindd_replace_memory_creds(const char *username,
1050                                        const char *pass)
1051 {
1052         struct WINBINDD_MEMORY_CREDS *memcredp = NULL;
1053
1054         memcredp = find_memory_creds_by_name(username);
1055         if (!memcredp) {
1056                 DEBUG(10,("winbindd_replace_memory_creds: unknown user %s\n",
1057                         username));
1058                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
1059         }
1060
1061         DEBUG(10,("winbindd_replace_memory_creds: replaced creds for user %s\n",
1062                 username));
1063
1064         return winbindd_replace_memory_creds_internal(memcredp, pass);
1065 }