source3/libads/kerberos_keytab.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    kerberos keytab utility library
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Remus Koos 2001
   6    Copyright (C) Luke Howard 2003
   7    Copyright (C) Jim McDonough (jmcd@us.ibm.com) 2003
   8    Copyright (C) Guenther Deschner 2003
   9    Copyright (C) Rakesh Patel 2004
  10    Copyright (C) Dan Perry 2004
  11    Copyright (C) Jeremy Allison 2004
  12    Copyright (C) Gerald Carter 2006
  13
  14    This program is free software; you can redistribute it and/or modify
  15    it under the terms of the GNU General Public License as published by
  16    the Free Software Foundation; either version 3 of the License, or
  17    (at your option) any later version.
  18
  19    This program is distributed in the hope that it will be useful,
  20    but WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22    GNU General Public License for more details.
  23
  24    You should have received a copy of the GNU General Public License
  25    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  26 */
  27
  28 #include "includes.h"
  29 #include "smb_krb5.h"
  30 #include "ads.h"
  31 #include "secrets.h"
  32
  33 #ifdef HAVE_KRB5
  34
  35 /**********************************************************************
  36 **********************************************************************/
  37
  38 static krb5_error_code seek_and_delete_old_entries(krb5_context context,
  39                                                    krb5_keytab keytab,
  40                                                    krb5_kvno kvno,
  41                                                    const char *princ_s,
  42                                                    krb5_principal princ,
  43                                                    bool flush,
  44                                                    bool keep_old_entries)
  45 {
  46         krb5_error_code ret;
  47         krb5_kt_cursor cursor;
  48         krb5_kt_cursor zero_csr;
  49         krb5_keytab_entry kt_entry;
  50         krb5_keytab_entry zero_kt_entry;
  51         char *ktprinc = NULL;
  52         krb5_kvno old_kvno = kvno - 1;
  53
  54         ZERO_STRUCT(cursor);
  55         ZERO_STRUCT(zero_csr);
  56         ZERO_STRUCT(kt_entry);
  57         ZERO_STRUCT(zero_kt_entry);
  58
  59         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
  60         if (ret == KRB5_KT_END || ret == ENOENT ) {
  61                 /* no entries */
  62                 return 0;
  63         }
  64
  65         DEBUG(3, (__location__ ": Will try to delete old keytab entries\n"));
  66         while (!krb5_kt_next_entry(context, keytab, &kt_entry, &cursor)) {
  67                 bool name_ok = false;
  68
  69                 if (!flush && (princ_s != NULL)) {
  70                         ret = smb_krb5_unparse_name(talloc_tos(), context,
  71                                                     kt_entry.principal,
  72                                                     &ktprinc);
  73                         if (ret) {
  74                                 DEBUG(1, (__location__
  75                                           ": smb_krb5_unparse_name failed "
  76                                           "(%s)\n", error_message(ret)));
  77                                 goto out;
  78                         }
  79
  80 #ifdef HAVE_KRB5_KT_COMPARE
  81                         name_ok = krb5_kt_compare(context, &kt_entry,
  82                                                   princ, 0, 0);
  83 #else
  84                         name_ok = (strcmp(ktprinc, princ_s) == 0);
  85 #endif
  86
  87                         if (!name_ok) {
  88                                 DEBUG(10, (__location__ ": ignoring keytab "
  89                                            "entry principal %s, kvno = %d\n",
  90                                            ktprinc, kt_entry.vno));
  91
  92                                 /* Not a match,
  93                                  * just free this entry and continue. */
  94                                 ret = smb_krb5_kt_free_entry(context,
  95                                                              &kt_entry);
  96                                 ZERO_STRUCT(kt_entry);
  97                                 if (ret) {
  98                                         DEBUG(1, (__location__
  99                                                   ": smb_krb5_kt_free_entry "
 100                                                   "failed (%s)\n",
 101                                                   error_message(ret)));
 102                                         goto out;
 103                                 }
 104
 105                                 TALLOC_FREE(ktprinc);
 106                                 continue;
 107                         }
 108
 109                         TALLOC_FREE(ktprinc);
 110                 }
 111
 112                 /*------------------------------------------------------------
 113                  * Save the entries with kvno - 1. This is what microsoft does
 114                  * to allow people with existing sessions that have kvno - 1
 115                  * to still work. Otherwise, when the password for the machine
 116                  * changes, all kerberizied sessions will 'break' until either
 117                  * the client reboots or the client's session key expires and
 118                  * they get a new session ticket with the new kvno.
 119                  * Some keytab files only store the kvno in 8bits, limit
 120                  * the compare accordingly.
 121                  */
 122
 123                 if (!flush && ((kt_entry.vno & 0xff) == (old_kvno & 0xff))) {
 124                         DEBUG(5, (__location__ ": Saving previous (kvno %d) "
 125                                   "entry for principal: %s.\n",
 126                                   old_kvno, princ_s));
 127                         continue;
 128                 }
 129
 130                 if (keep_old_entries) {
 131                         DEBUG(5, (__location__ ": Saving old (kvno %d) "
 132                                   "entry for principal: %s.\n",
 133                                   kvno, princ_s));
 134                         continue;
 135                 }
 136
 137                 DEBUG(5, (__location__ ": Found old entry for principal: %s "
 138                           "(kvno %d) - trying to remove it.\n",
 139                           princ_s, kt_entry.vno));
 140
 141                 ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 142                 ZERO_STRUCT(cursor);
 143                 if (ret) {
 144                         DEBUG(1, (__location__ ": krb5_kt_end_seq_get() "
 145                                   "failed (%s)\n", error_message(ret)));
 146                         goto out;
 147                 }
 148                 ret = krb5_kt_remove_entry(context, keytab, &kt_entry);
 149                 if (ret) {
 150                         DEBUG(1, (__location__ ": krb5_kt_remove_entry() "
 151                                   "failed (%s)\n", error_message(ret)));
 152                         goto out;
 153                 }
 154
 155                 DEBUG(5, (__location__ ": removed old entry for principal: "
 156                           "%s (kvno %d).\n", princ_s, kt_entry.vno));
 157
 158                 ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 159                 if (ret) {
 160                         DEBUG(1, (__location__ ": krb5_kt_start_seq() failed "
 161                                   "(%s)\n", error_message(ret)));
 162                         goto out;
 163                 }
 164                 ret = smb_krb5_kt_free_entry(context, &kt_entry);
 165                 ZERO_STRUCT(kt_entry);
 166                 if (ret) {
 167                         DEBUG(1, (__location__ ": krb5_kt_remove_entry() "
 168                                   "failed (%s)\n", error_message(ret)));
 169                         goto out;
 170                 }
 171         }
 172
 173 out:
 174         if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
 175                 smb_krb5_kt_free_entry(context, &kt_entry);
 176         }
 177         if (keytab) {
 178                 if (memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) {
 179                         krb5_kt_end_seq_get(context, keytab, &cursor);
 180                 }
 181         }
 182
 183         return ret;
 184 }
 185
 186 static int smb_krb5_kt_add_entry(krb5_context context,
 187                                  krb5_keytab keytab,
 188                                  krb5_kvno kvno,
 189                                  const char *princ_s,
 190                                  const char *salt_principal,
 191                                  krb5_enctype enctype,
 192                                  krb5_data *password,
 193                                  bool no_salt,
 194                                  bool keep_old_entries)
 195 {
 196         krb5_error_code ret;
 197         krb5_keytab_entry kt_entry;
 198         krb5_principal princ = NULL;
 199         krb5_keyblock *keyp;
 200
 201         ZERO_STRUCT(kt_entry);
 202
 203         ret = smb_krb5_parse_name(context, princ_s, &princ);
 204         if (ret) {
 205                 DEBUG(1, (__location__ ": smb_krb5_parse_name(%s) "
 206                           "failed (%s)\n", princ_s, error_message(ret)));
 207                 goto out;
 208         }
 209
 210         /* Seek and delete old keytab entries */
 211         ret = seek_and_delete_old_entries(context, keytab, kvno,
 212                                           princ_s, princ, false,
 213                                           keep_old_entries);
 214         if (ret) {
 215                 goto out;
 216         }
 217
 218         /* If we get here, we have deleted all the old entries with kvno's
 219          * not equal to the current kvno-1. */
 220
 221         keyp = KRB5_KT_KEY(&kt_entry);
 222
 223         if (no_salt) {
 224                 KRB5_KEY_DATA(keyp) = (KRB5_KEY_DATA_CAST *)SMB_MALLOC(password->length);
 225                 if (KRB5_KEY_DATA(keyp) == NULL) {
 226                         ret = ENOMEM;
 227                         goto out;
 228                 }
 229                 memcpy(KRB5_KEY_DATA(keyp), password->data, password->length);
 230                 KRB5_KEY_LENGTH(keyp) = password->length;
 231                 KRB5_KEY_TYPE(keyp) = enctype;
 232         } else {
 233                 krb5_principal salt_princ = NULL;
 234
 235                 ret = smb_krb5_parse_name(context, salt_principal, &salt_princ);
 236                 if (ret) {
 237                         DBG_WARNING("krb5_parse_name(%s) failed (%s)\n",
 238                                     salt_principal, error_message(ret));
 239                         goto out;
 240                 }
 241
 242                 ret = smb_krb5_create_key_from_string(context,
 243                                                       salt_princ,
 244                                                       NULL,
 245                                                       password,
 246                                                       enctype,
 247                                                       keyp);
 248                 krb5_free_principal(context, salt_princ);
 249                 if (ret != 0) {
 250                         goto out;
 251                 }
 252         }
 253
 254         kt_entry.principal = princ;
 255         kt_entry.vno       = kvno;
 256
 257         DEBUG(3, (__location__ ": adding keytab entry for (%s) with "
 258                   "encryption type (%d) and version (%d)\n",
 259                   princ_s, enctype, kt_entry.vno));
 260         ret = krb5_kt_add_entry(context, keytab, &kt_entry);
 261         krb5_free_keyblock_contents(context, keyp);
 262         ZERO_STRUCT(kt_entry);
 263         if (ret) {
 264                 DEBUG(1, (__location__ ": adding entry to keytab "
 265                           "failed (%s)\n", error_message(ret)));
 266                 goto out;
 267         }
 268
 269 out:
 270         if (princ) {
 271                 krb5_free_principal(context, princ);
 272         }
 273
 274         return (int)ret;
 275 }
 276
 277 #ifdef HAVE_ADS
 278
 279 /**********************************************************************
 280  Adds a single service principal, i.e. 'host' to the system keytab
 281 ***********************************************************************/
 282
 283 int ads_keytab_add_entry(ADS_STRUCT *ads, const char *srvPrinc)
 284 {
 285         krb5_error_code ret = 0;
 286         krb5_context context = NULL;
 287         krb5_keytab keytab = NULL;
 288         krb5_data password;
 289         krb5_kvno kvno;
 290         krb5_enctype enctypes[6] = {
 291                 ENCTYPE_DES_CBC_CRC,
 292                 ENCTYPE_DES_CBC_MD5,
 293 #ifdef HAVE_ENCTYPE_AES128_CTS_HMAC_SHA1_96
 294                 ENCTYPE_AES128_CTS_HMAC_SHA1_96,
 295 #endif
 296 #ifdef HAVE_ENCTYPE_AES256_CTS_HMAC_SHA1_96
 297                 ENCTYPE_AES256_CTS_HMAC_SHA1_96,
 298 #endif
 299                 ENCTYPE_ARCFOUR_HMAC,
 300                 0
 301         };
 302         char *princ_s = NULL;
 303         char *short_princ_s = NULL;
 304         char *salt_princ_s = NULL;
 305         char *password_s = NULL;
 306         char *my_fqdn;
 307         TALLOC_CTX *tmpctx = NULL;
 308         char *machine_name;
 309         ADS_STATUS aderr;
 310         int i;
 311
 312         initialize_krb5_error_table();
 313         ret = krb5_init_context(&context);
 314         if (ret) {
 315                 DEBUG(1, (__location__ ": could not krb5_init_context: %s\n",
 316                           error_message(ret)));
 317                 return -1;
 318         }
 319
 320         ret = smb_krb5_open_keytab(context, NULL, True, &keytab);
 321         if (ret) {
 322                 DEBUG(1, (__location__ ": smb_krb5_open_keytab failed (%s)\n",
 323                           error_message(ret)));
 324                 goto out;
 325         }
 326
 327         /* retrieve the password */
 328         if (!secrets_init()) {
 329                 DEBUG(1, (__location__ ": secrets_init failed\n"));
 330                 ret = -1;
 331                 goto out;
 332         }
 333         password_s = secrets_fetch_machine_password(lp_workgroup(), NULL, NULL);
 334         if (!password_s) {
 335                 DEBUG(1, (__location__ ": failed to fetch machine password\n"));
 336                 ret = -1;
 337                 goto out;
 338         }
 339         ZERO_STRUCT(password);
 340         password.data = password_s;
 341         password.length = strlen(password_s);
 342
 343         /* we need the dNSHostName value here */
 344         tmpctx = talloc_init(__location__);
 345         if (!tmpctx) {
 346                 DEBUG(0, (__location__ ": talloc_init() failed!\n"));
 347                 ret = -1;
 348                 goto out;
 349         }
 350
 351         my_fqdn = ads_get_dnshostname(ads, tmpctx, lp_netbios_name());
 352         if (!my_fqdn) {
 353                 DEBUG(0, (__location__ ": unable to determine machine "
 354                           "account's dns name in AD!\n"));
 355                 ret = -1;
 356                 goto out;
 357         }
 358
 359         machine_name = ads_get_samaccountname(ads, tmpctx, lp_netbios_name());
 360         if (!machine_name) {
 361                 DEBUG(0, (__location__ ": unable to determine machine "
 362                           "account's short name in AD!\n"));
 363                 ret = -1;
 364                 goto out;
 365         }
 366         /*strip the trailing '$' */
 367         machine_name[strlen(machine_name)-1] = '\0';
 368
 369         /* Construct our principal */
 370         if (strchr_m(srvPrinc, '@')) {
 371                 /* It's a fully-named principal. */
 372                 princ_s = talloc_asprintf(tmpctx, "%s", srvPrinc);
 373                 if (!princ_s) {
 374                         ret = -1;
 375                         goto out;
 376                 }
 377         } else if (srvPrinc[strlen(srvPrinc)-1] == '$') {
 378                 /* It's the machine account, as used by smbclient clients. */
 379                 princ_s = talloc_asprintf(tmpctx, "%s@%s",
 380                                           srvPrinc, lp_realm());
 381                 if (!princ_s) {
 382                         ret = -1;
 383                         goto out;
 384                 }
 385         } else {
 386                 /* It's a normal service principal.  Add the SPN now so that we
 387                  * can obtain credentials for it and double-check the salt value
 388                  * used to generate the service's keys. */
 389
 390                 princ_s = talloc_asprintf(tmpctx, "%s/%s@%s",
 391                                           srvPrinc, my_fqdn, lp_realm());
 392                 if (!princ_s) {
 393                         ret = -1;
 394                         goto out;
 395                 }
 396                 short_princ_s = talloc_asprintf(tmpctx, "%s/%s@%s",
 397                                                 srvPrinc, machine_name,
 398                                                 lp_realm());
 399                 if (short_princ_s == NULL) {
 400                         ret = -1;
 401                         goto out;
 402                 }
 403
 404                 /* According to http://support.microsoft.com/kb/326985/en-us,
 405                    certain principal names are automatically mapped to the
 406                    host/... principal in the AD account.
 407                    So only create these in the keytab, not in AD.  --jerry */
 408
 409                 if (!strequal(srvPrinc, "cifs") &&
 410                     !strequal(srvPrinc, "host")) {
 411                         DEBUG(3, (__location__ ": Attempting to add/update "
 412                                   "'%s'\n", princ_s));
 413
 414                         aderr = ads_add_service_principal_name(ads,
 415                                         lp_netbios_name(), my_fqdn, srvPrinc);
 416                         if (!ADS_ERR_OK(aderr)) {
 417                                 DEBUG(1, (__location__ ": failed to "
 418                                          "ads_add_service_principal_name.\n"));
 419                                 goto out;
 420                         }
 421                 }
 422         }
 423
 424         kvno = (krb5_kvno)ads_get_machine_kvno(ads, lp_netbios_name());
 425         if (kvno == -1) {
 426                 /* -1 indicates failure, everything else is OK */
 427                 DEBUG(1, (__location__ ": ads_get_machine_kvno failed to "
 428                          "determine the system's kvno.\n"));
 429                 ret = -1;
 430                 goto out;
 431         }
 432
 433         for (i = 0; enctypes[i]; i++) {
 434                 salt_princ_s = kerberos_fetch_salt_princ_for_host_princ(context,
 435                                                                         princ_s,
 436                                                                         enctypes[i]);
 437
 438                 /* add the fqdn principal to the keytab */
 439                 ret = smb_krb5_kt_add_entry(context,
 440                                             keytab,
 441                                             kvno,
 442                                             princ_s,
 443                                             salt_princ_s,
 444                                             enctypes[i],
 445                                             &password,
 446                                             false,
 447                                             false);
 448                 if (ret) {
 449                         DEBUG(1, (__location__ ": Failed to add entry to keytab\n"));
 450                         SAFE_FREE(salt_princ_s);
 451                         goto out;
 452                 }
 453
 454                 /* add the short principal name if we have one */
 455                 if (short_princ_s) {
 456                         ret = smb_krb5_kt_add_entry(context,
 457                                                     keytab,
 458                                                     kvno,
 459                                                     short_princ_s,
 460                                                     salt_princ_s,
 461                                                     enctypes[i],
 462                                                     &password,
 463                                                     false,
 464                                                     false);
 465                         if (ret) {
 466                                 DEBUG(1, (__location__
 467                                           ": Failed to add short entry to keytab\n"));
 468                                 SAFE_FREE(salt_princ_s);
 469                                 goto out;
 470                         }
 471                 }
 472                 SAFE_FREE(salt_princ_s);
 473         }
 474
 475 out:
 476         TALLOC_FREE(tmpctx);
 477
 478         if (keytab) {
 479                 krb5_kt_close(context, keytab);
 480         }
 481         if (context) {
 482                 krb5_free_context(context);
 483         }
 484         return (int)ret;
 485 }
 486
 487 /**********************************************************************
 488  Flushes all entries from the system keytab.
 489 ***********************************************************************/
 490
 491 int ads_keytab_flush(ADS_STRUCT *ads)
 492 {
 493         krb5_error_code ret = 0;
 494         krb5_context context = NULL;
 495         krb5_keytab keytab = NULL;
 496         krb5_kvno kvno;
 497         ADS_STATUS aderr;
 498
 499         initialize_krb5_error_table();
 500         ret = krb5_init_context(&context);
 501         if (ret) {
 502                 DEBUG(1, (__location__ ": could not krb5_init_context: %s\n",
 503                           error_message(ret)));
 504                 return ret;
 505         }
 506
 507         ret = smb_krb5_open_keytab(context, NULL, True, &keytab);
 508         if (ret) {
 509                 DEBUG(1, (__location__ ": smb_krb5_open_keytab failed (%s)\n",
 510                           error_message(ret)));
 511                 goto out;
 512         }
 513
 514         kvno = (krb5_kvno)ads_get_machine_kvno(ads, lp_netbios_name());
 515         if (kvno == -1) {
 516                 /* -1 indicates a failure */
 517                 DEBUG(1, (__location__ ": Error determining the kvno.\n"));
 518                 goto out;
 519         }
 520
 521         /* Seek and delete old keytab entries */
 522         ret = seek_and_delete_old_entries(context, keytab, kvno,
 523                                           NULL, NULL, true, false);
 524         if (ret) {
 525                 goto out;
 526         }
 527
 528         aderr = ads_clear_service_principal_names(ads, lp_netbios_name());
 529         if (!ADS_ERR_OK(aderr)) {
 530                 DEBUG(1, (__location__ ": Error while clearing service "
 531                           "principal listings in LDAP.\n"));
 532                 goto out;
 533         }
 534
 535 out:
 536         if (keytab) {
 537                 krb5_kt_close(context, keytab);
 538         }
 539         if (context) {
 540                 krb5_free_context(context);
 541         }
 542         return ret;
 543 }
 544
 545 /**********************************************************************
 546  Adds all the required service principals to the system keytab.
 547 ***********************************************************************/
 548
 549 int ads_keytab_create_default(ADS_STRUCT *ads)
 550 {
 551         krb5_error_code ret = 0;
 552         krb5_context context = NULL;
 553         krb5_keytab keytab = NULL;
 554         krb5_kt_cursor cursor = {0};
 555         krb5_keytab_entry kt_entry = {0};
 556         krb5_kvno kvno;
 557         size_t found = 0;
 558         char *sam_account_name, *upn;
 559         char **oldEntries = NULL, *princ_s[26];
 560         TALLOC_CTX *frame;
 561         char *machine_name;
 562         char **spn_array;
 563         size_t num_spns;
 564         size_t i;
 565         ADS_STATUS status;
 566
 567         ZERO_STRUCT(kt_entry);
 568         ZERO_STRUCT(cursor);
 569
 570         frame = talloc_stackframe();
 571         if (frame == NULL) {
 572                 ret = -1;
 573                 goto done;
 574         }
 575
 576         status = ads_get_service_principal_names(frame,
 577                                                  ads,
 578                                                  lp_netbios_name(),
 579                                                  &spn_array,
 580                                                  &num_spns);
 581         if (!ADS_ERR_OK(status)) {
 582                 ret = -1;
 583                 goto done;
 584         }
 585
 586         for (i = 0; i < num_spns; i++) {
 587                 char *srv_princ;
 588                 char *p;
 589
 590                 srv_princ = strlower_talloc(frame, spn_array[i]);
 591                 if (srv_princ == NULL) {
 592                         ret = -1;
 593                         goto done;
 594                 }
 595
 596                 p = strchr_m(srv_princ, '/');
 597                 if (p == NULL) {
 598                         continue;
 599                 }
 600                 p[0] = '\0';
 601
 602                 /* Add the SPNs found on the DC */
 603                 ret = ads_keytab_add_entry(ads, srv_princ);
 604                 if (ret != 0) {
 605                         DEBUG(1, ("ads_keytab_add_entry failed while "
 606                                   "adding '%s' principal.\n",
 607                                   spn_array[i]));
 608                         goto done;
 609                 }
 610         }
 611
 612 #if 0   /* don't create the CIFS/... keytab entries since no one except smbd
 613            really needs them and we will fall back to verifying against
 614            secrets.tdb */
 615
 616         ret = ads_keytab_add_entry(ads, "cifs"));
 617         if (ret != 0 ) {
 618                 DEBUG(1, (__location__ ": ads_keytab_add_entry failed while "
 619                           "adding 'cifs'.\n"));
 620                 return ret;
 621         }
 622 #endif
 623
 624         memset(princ_s, '\0', sizeof(princ_s));
 625
 626         initialize_krb5_error_table();
 627         ret = krb5_init_context(&context);
 628         if (ret) {
 629                 DEBUG(1, (__location__ ": could not krb5_init_context: %s\n",
 630                           error_message(ret)));
 631                 goto done;
 632         }
 633
 634         machine_name = talloc_strdup(frame, lp_netbios_name());
 635         if (!machine_name) {
 636                 ret = -1;
 637                 goto done;
 638         }
 639
 640         /* now add the userPrincipalName and sAMAccountName entries */
 641         sam_account_name = ads_get_samaccountname(ads, frame, machine_name);
 642         if (!sam_account_name) {
 643                 DEBUG(0, (__location__ ": unable to determine machine "
 644                           "account's name in AD!\n"));
 645                 ret = -1;
 646                 goto done;
 647         }
 648
 649         /* upper case the sAMAccountName to make it easier for apps to
 650            know what case to use in the keytab file */
 651         if (!strupper_m(sam_account_name)) {
 652                 ret = -1;
 653                 goto done;
 654         }
 655
 656         ret = ads_keytab_add_entry(ads, sam_account_name);
 657         if (ret != 0) {
 658                 DEBUG(1, (__location__ ": ads_keytab_add_entry() failed "
 659                           "while adding sAMAccountName (%s)\n",
 660                           sam_account_name));
 661                 goto done;
 662         }
 663
 664         /* remember that not every machine account will have a upn */
 665         upn = ads_get_upn(ads, frame, machine_name);
 666         if (upn) {
 667                 ret = ads_keytab_add_entry(ads, upn);
 668                 if (ret != 0) {
 669                         DEBUG(1, (__location__ ": ads_keytab_add_entry() "
 670                                   "failed while adding UPN (%s)\n", upn));
 671                         goto done;
 672                 }
 673         }
 674
 675         /* Now loop through the keytab and update any other existing entries */
 676         kvno = (krb5_kvno)ads_get_machine_kvno(ads, machine_name);
 677         if (kvno == (krb5_kvno)-1) {
 678                 DEBUG(1, (__location__ ": ads_get_machine_kvno() failed to "
 679                           "determine the system's kvno.\n"));
 680                 goto done;
 681         }
 682
 683         DEBUG(3, (__location__ ": Searching for keytab entries to preserve "
 684                   "and update.\n"));
 685
 686         ret = smb_krb5_open_keytab(context, NULL, True, &keytab);
 687         if (ret) {
 688                 DEBUG(1, (__location__ ": smb_krb5_open_keytab failed (%s)\n",
 689                           error_message(ret)));
 690                 goto done;
 691         }
 692
 693         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 694         if (ret != KRB5_KT_END && ret != ENOENT ) {
 695                 while ((ret = krb5_kt_next_entry(context, keytab,
 696                                                  &kt_entry, &cursor)) == 0) {
 697                         smb_krb5_kt_free_entry(context, &kt_entry);
 698                         ZERO_STRUCT(kt_entry);
 699                         found++;
 700                 }
 701         }
 702         krb5_kt_end_seq_get(context, keytab, &cursor);
 703         ZERO_STRUCT(cursor);
 704
 705         /*
 706          * Hmmm. There is no "rewind" function for the keytab. This means we
 707          * have a race condition where someone else could add entries after
 708          * we've counted them. Re-open asap to minimise the race. JRA.
 709          */
 710         DEBUG(3, (__location__ ": Found %zd entries in the keytab.\n", found));
 711         if (!found) {
 712                 goto done;
 713         }
 714
 715         oldEntries = talloc_zero_array(frame, char *, found + 1);
 716         if (!oldEntries) {
 717                 DEBUG(1, (__location__ ": Failed to allocate space to store "
 718                           "the old keytab entries (talloc failed?).\n"));
 719                 ret = -1;
 720                 goto done;
 721         }
 722
 723         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 724         if (ret == KRB5_KT_END || ret == ENOENT) {
 725                 krb5_kt_end_seq_get(context, keytab, &cursor);
 726                 ZERO_STRUCT(cursor);
 727                 goto done;
 728         }
 729
 730         while (krb5_kt_next_entry(context, keytab, &kt_entry, &cursor) == 0) {
 731                 if (kt_entry.vno != kvno) {
 732                         char *ktprinc = NULL;
 733                         char *p;
 734
 735                         /* This returns a malloc'ed string in ktprinc. */
 736                         ret = smb_krb5_unparse_name(oldEntries, context,
 737                                                     kt_entry.principal,
 738                                                     &ktprinc);
 739                         if (ret) {
 740                                 DEBUG(1, (__location__
 741                                          ": smb_krb5_unparse_name failed "
 742                                          "(%s)\n", error_message(ret)));
 743                                 goto done;
 744                         }
 745                         /*
 746                          * From looking at the krb5 source they don't seem to
 747                          * take locale or mb strings into account.
 748                          * Maybe this is because they assume utf8 ?
 749                          * In this case we may need to convert from utf8 to
 750                          * mb charset here ? JRA.
 751                          */
 752                         p = strchr_m(ktprinc, '@');
 753                         if (p) {
 754                                 *p = '\0';
 755                         }
 756
 757                         p = strchr_m(ktprinc, '/');
 758                         if (p) {
 759                                 *p = '\0';
 760                         }
 761                         for (i = 0; i < found; i++) {
 762                                 if (!oldEntries[i]) {
 763                                         oldEntries[i] = ktprinc;
 764                                         break;
 765                                 }
 766                                 if (!strcmp(oldEntries[i], ktprinc)) {
 767                                         TALLOC_FREE(ktprinc);
 768                                         break;
 769                                 }
 770                         }
 771                         if (i == found) {
 772                                 TALLOC_FREE(ktprinc);
 773                         }
 774                 }
 775                 smb_krb5_kt_free_entry(context, &kt_entry);
 776                 ZERO_STRUCT(kt_entry);
 777         }
 778         krb5_kt_end_seq_get(context, keytab, &cursor);
 779         ZERO_STRUCT(cursor);
 780
 781         ret = 0;
 782         for (i = 0; oldEntries[i]; i++) {
 783                 ret |= ads_keytab_add_entry(ads, oldEntries[i]);
 784                 TALLOC_FREE(oldEntries[i]);
 785         }
 786
 787 done:
 788         TALLOC_FREE(oldEntries);
 789         TALLOC_FREE(frame);
 790
 791         {
 792                 krb5_keytab_entry zero_kt_entry;
 793                 ZERO_STRUCT(zero_kt_entry);
 794                 if (memcmp(&zero_kt_entry, &kt_entry,
 795                                 sizeof(krb5_keytab_entry))) {
 796                         smb_krb5_kt_free_entry(context, &kt_entry);
 797                 }
 798         }
 799         {
 800                 krb5_kt_cursor zero_csr;
 801                 ZERO_STRUCT(zero_csr);
 802                 if ((memcmp(&cursor, &zero_csr,
 803                                 sizeof(krb5_kt_cursor)) != 0) && keytab) {
 804                         krb5_kt_end_seq_get(context, keytab, &cursor);
 805                 }
 806         }
 807         if (keytab) {
 808                 krb5_kt_close(context, keytab);
 809         }
 810         if (context) {
 811                 krb5_free_context(context);
 812         }
 813         return ret;
 814 }
 815
 816 #endif /* HAVE_ADS */
 817
 818 /**********************************************************************
 819  List system keytab.
 820 ***********************************************************************/
 821
 822 int ads_keytab_list(const char *keytab_name)
 823 {
 824         krb5_error_code ret = 0;
 825         krb5_context context = NULL;
 826         krb5_keytab keytab = NULL;
 827         krb5_kt_cursor cursor;
 828         krb5_keytab_entry kt_entry;
 829
 830         ZERO_STRUCT(kt_entry);
 831         ZERO_STRUCT(cursor);
 832
 833         initialize_krb5_error_table();
 834         ret = krb5_init_context(&context);
 835         if (ret) {
 836                 DEBUG(1, (__location__ ": could not krb5_init_context: %s\n",
 837                           error_message(ret)));
 838                 return ret;
 839         }
 840
 841         ret = smb_krb5_open_keytab(context, keytab_name, False, &keytab);
 842         if (ret) {
 843                 DEBUG(1, (__location__ ": smb_krb5_open_keytab failed (%s)\n",
 844                           error_message(ret)));
 845                 goto out;
 846         }
 847
 848         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 849         if (ret) {
 850                 ZERO_STRUCT(cursor);
 851                 goto out;
 852         }
 853
 854         printf("Vno  Type                                        Principal\n");
 855
 856         while (krb5_kt_next_entry(context, keytab, &kt_entry, &cursor) == 0) {
 857
 858                 char *princ_s = NULL;
 859                 char *etype_s = NULL;
 860                 krb5_enctype enctype = 0;
 861
 862                 ret = smb_krb5_unparse_name(talloc_tos(), context,
 863                                             kt_entry.principal, &princ_s);
 864                 if (ret) {
 865                         goto out;
 866                 }
 867
 868                 enctype = smb_get_enctype_from_kt_entry(&kt_entry);
 869
 870                 ret = smb_krb5_enctype_to_string(context, enctype, &etype_s);
 871                 if (ret &&
 872                     (asprintf(&etype_s, "UNKNOWN: %d\n", enctype) == -1)) {
 873                         TALLOC_FREE(princ_s);
 874                         goto out;
 875                 }
 876
 877                 printf("%3d  %-43s %s\n", kt_entry.vno, etype_s, princ_s);
 878
 879                 TALLOC_FREE(princ_s);
 880                 SAFE_FREE(etype_s);
 881
 882                 ret = smb_krb5_kt_free_entry(context, &kt_entry);
 883                 if (ret) {
 884                         goto out;
 885                 }
 886         }
 887
 888         ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 889         if (ret) {
 890                 goto out;
 891         }
 892
 893         /* Ensure we don't double free. */
 894         ZERO_STRUCT(kt_entry);
 895         ZERO_STRUCT(cursor);
 896 out:
 897
 898         {
 899                 krb5_keytab_entry zero_kt_entry;
 900                 ZERO_STRUCT(zero_kt_entry);
 901                 if (memcmp(&zero_kt_entry, &kt_entry,
 902                                 sizeof(krb5_keytab_entry))) {
 903                         smb_krb5_kt_free_entry(context, &kt_entry);
 904                 }
 905         }
 906         {
 907                 krb5_kt_cursor zero_csr;
 908                 ZERO_STRUCT(zero_csr);
 909                 if ((memcmp(&cursor, &zero_csr,
 910                                 sizeof(krb5_kt_cursor)) != 0) && keytab) {
 911                         krb5_kt_end_seq_get(context, keytab, &cursor);
 912                 }
 913         }
 914
 915         if (keytab) {
 916                 krb5_kt_close(context, keytab);
 917         }
 918         if (context) {
 919                 krb5_free_context(context);
 920         }
 921         return ret;
 922 }
 923
 924 #endif /* HAVE_KRB5 */