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                                  krb5_enctype *enctypes,
 191                                  krb5_data password,
 192                                  bool no_salt,
 193                                  bool keep_old_entries)
 194 {
 195         krb5_error_code ret;
 196         krb5_keytab_entry kt_entry;
 197         krb5_principal princ = NULL;
 198         int i;
 199
 200         ZERO_STRUCT(kt_entry);
 201
 202         ret = smb_krb5_parse_name(context, princ_s, &princ);
 203         if (ret) {
 204                 DEBUG(1, (__location__ ": smb_krb5_parse_name(%s) "
 205                           "failed (%s)\n", princ_s, error_message(ret)));
 206                 goto out;
 207         }
 208
 209         /* Seek and delete old keytab entries */
 210         ret = seek_and_delete_old_entries(context, keytab, kvno,
 211                                           princ_s, princ, false,
 212                                           keep_old_entries);
 213         if (ret) {
 214                 goto out;
 215         }
 216
 217         /* If we get here, we have deleted all the old entries with kvno's
 218          * not equal to the current kvno-1. */
 219
 220         /* Now add keytab entries for all encryption types */
 221         for (i = 0; enctypes[i]; i++) {
 222                 krb5_keyblock *keyp;
 223
 224                 keyp = KRB5_KT_KEY(&kt_entry);
 225
 226                 if (create_kerberos_key_from_string(context, princ,
 227                                                     &password, keyp,
 228                                                     enctypes[i], no_salt)) {
 229                         continue;
 230                 }
 231
 232                 kt_entry.principal = princ;
 233                 kt_entry.vno       = kvno;
 234
 235                 DEBUG(3, (__location__ ": adding keytab entry for (%s) with "
 236                           "encryption type (%d) and version (%d)\n",
 237                           princ_s, enctypes[i], kt_entry.vno));
 238                 ret = krb5_kt_add_entry(context, keytab, &kt_entry);
 239                 krb5_free_keyblock_contents(context, keyp);
 240                 ZERO_STRUCT(kt_entry);
 241                 if (ret) {
 242                         DEBUG(1, (__location__ ": adding entry to keytab "
 243                                   "failed (%s)\n", error_message(ret)));
 244                         goto out;
 245                 }
 246         }
 247
 248 out:
 249         if (princ) {
 250                 krb5_free_principal(context, princ);
 251         }
 252
 253         return (int)ret;
 254 }
 255
 256 #ifdef HAVE_ADS
 257
 258 /**********************************************************************
 259  Adds a single service principal, i.e. 'host' to the system keytab
 260 ***********************************************************************/
 261
 262 int ads_keytab_add_entry(ADS_STRUCT *ads, const char *srvPrinc)
 263 {
 264         krb5_error_code ret = 0;
 265         krb5_context context = NULL;
 266         krb5_keytab keytab = NULL;
 267         krb5_data password;
 268         krb5_kvno kvno;
 269         krb5_enctype enctypes[6] = {
 270                 ENCTYPE_DES_CBC_CRC,
 271                 ENCTYPE_DES_CBC_MD5,
 272 #ifdef HAVE_ENCTYPE_AES128_CTS_HMAC_SHA1_96
 273                 ENCTYPE_AES128_CTS_HMAC_SHA1_96,
 274 #endif
 275 #ifdef HAVE_ENCTYPE_AES256_CTS_HMAC_SHA1_96
 276                 ENCTYPE_AES256_CTS_HMAC_SHA1_96,
 277 #endif
 278                 ENCTYPE_ARCFOUR_HMAC,
 279                 0
 280         };
 281         char *princ_s = NULL;
 282         char *short_princ_s = NULL;
 283         char *password_s = NULL;
 284         char *my_fqdn;
 285         TALLOC_CTX *tmpctx = NULL;
 286         char *machine_name;
 287         ADS_STATUS aderr;
 288
 289         initialize_krb5_error_table();
 290         ret = krb5_init_context(&context);
 291         if (ret) {
 292                 DEBUG(1, (__location__ ": could not krb5_init_context: %s\n",
 293                           error_message(ret)));
 294                 return -1;
 295         }
 296
 297         ret = smb_krb5_open_keytab(context, NULL, True, &keytab);
 298         if (ret) {
 299                 DEBUG(1, (__location__ ": smb_krb5_open_keytab failed (%s)\n",
 300                           error_message(ret)));
 301                 goto out;
 302         }
 303
 304         /* retrieve the password */
 305         if (!secrets_init()) {
 306                 DEBUG(1, (__location__ ": secrets_init failed\n"));
 307                 ret = -1;
 308                 goto out;
 309         }
 310         password_s = secrets_fetch_machine_password(lp_workgroup(), NULL, NULL);
 311         if (!password_s) {
 312                 DEBUG(1, (__location__ ": failed to fetch machine password\n"));
 313                 ret = -1;
 314                 goto out;
 315         }
 316         ZERO_STRUCT(password);
 317         password.data = password_s;
 318         password.length = strlen(password_s);
 319
 320         /* we need the dNSHostName value here */
 321         tmpctx = talloc_init(__location__);
 322         if (!tmpctx) {
 323                 DEBUG(0, (__location__ ": talloc_init() failed!\n"));
 324                 ret = -1;
 325                 goto out;
 326         }
 327
 328         my_fqdn = ads_get_dnshostname(ads, tmpctx, lp_netbios_name());
 329         if (!my_fqdn) {
 330                 DEBUG(0, (__location__ ": unable to determine machine "
 331                           "account's dns name in AD!\n"));
 332                 ret = -1;
 333                 goto out;
 334         }
 335
 336         machine_name = ads_get_samaccountname(ads, tmpctx, lp_netbios_name());
 337         if (!machine_name) {
 338                 DEBUG(0, (__location__ ": unable to determine machine "
 339                           "account's short name in AD!\n"));
 340                 ret = -1;
 341                 goto out;
 342         }
 343         /*strip the trailing '$' */
 344         machine_name[strlen(machine_name)-1] = '\0';
 345
 346         /* Construct our principal */
 347         if (strchr_m(srvPrinc, '@')) {
 348                 /* It's a fully-named principal. */
 349                 princ_s = talloc_asprintf(tmpctx, "%s", srvPrinc);
 350                 if (!princ_s) {
 351                         ret = -1;
 352                         goto out;
 353                 }
 354         } else if (srvPrinc[strlen(srvPrinc)-1] == '$') {
 355                 /* It's the machine account, as used by smbclient clients. */
 356                 princ_s = talloc_asprintf(tmpctx, "%s@%s",
 357                                           srvPrinc, lp_realm());
 358                 if (!princ_s) {
 359                         ret = -1;
 360                         goto out;
 361                 }
 362         } else {
 363                 /* It's a normal service principal.  Add the SPN now so that we
 364                  * can obtain credentials for it and double-check the salt value
 365                  * used to generate the service's keys. */
 366
 367                 princ_s = talloc_asprintf(tmpctx, "%s/%s@%s",
 368                                           srvPrinc, my_fqdn, lp_realm());
 369                 if (!princ_s) {
 370                         ret = -1;
 371                         goto out;
 372                 }
 373                 short_princ_s = talloc_asprintf(tmpctx, "%s/%s@%s",
 374                                                 srvPrinc, machine_name,
 375                                                 lp_realm());
 376                 if (short_princ_s == NULL) {
 377                         ret = -1;
 378                         goto out;
 379                 }
 380
 381                 /* According to http://support.microsoft.com/kb/326985/en-us,
 382                    certain principal names are automatically mapped to the
 383                    host/... principal in the AD account.
 384                    So only create these in the keytab, not in AD.  --jerry */
 385
 386                 if (!strequal(srvPrinc, "cifs") &&
 387                     !strequal(srvPrinc, "host")) {
 388                         DEBUG(3, (__location__ ": Attempting to add/update "
 389                                   "'%s'\n", princ_s));
 390
 391                         aderr = ads_add_service_principal_name(ads,
 392                                         lp_netbios_name(), my_fqdn, srvPrinc);
 393                         if (!ADS_ERR_OK(aderr)) {
 394                                 DEBUG(1, (__location__ ": failed to "
 395                                          "ads_add_service_principal_name.\n"));
 396                                 goto out;
 397                         }
 398                 }
 399         }
 400
 401         kvno = (krb5_kvno)ads_get_machine_kvno(ads, lp_netbios_name());
 402         if (kvno == -1) {
 403                 /* -1 indicates failure, everything else is OK */
 404                 DEBUG(1, (__location__ ": ads_get_machine_kvno failed to "
 405                          "determine the system's kvno.\n"));
 406                 ret = -1;
 407                 goto out;
 408         }
 409
 410         /* add the fqdn principal to the keytab */
 411         ret = smb_krb5_kt_add_entry(context, keytab, kvno,
 412                                     princ_s, enctypes, password,
 413                                     false, false);
 414         if (ret) {
 415                 DEBUG(1, (__location__ ": Failed to add entry to keytab\n"));
 416                 goto out;
 417         }
 418
 419         /* add the short principal name if we have one */
 420         if (short_princ_s) {
 421                 ret = smb_krb5_kt_add_entry(context, keytab, kvno,
 422                                             short_princ_s, enctypes, password,
 423                                             false, false);
 424                 if (ret) {
 425                         DEBUG(1, (__location__
 426                                   ": Failed to add short entry to keytab\n"));
 427                         goto out;
 428                 }
 429         }
 430
 431 out:
 432         TALLOC_FREE(tmpctx);
 433
 434         if (keytab) {
 435                 krb5_kt_close(context, keytab);
 436         }
 437         if (context) {
 438                 krb5_free_context(context);
 439         }
 440         return (int)ret;
 441 }
 442
 443 /**********************************************************************
 444  Flushes all entries from the system keytab.
 445 ***********************************************************************/
 446
 447 int ads_keytab_flush(ADS_STRUCT *ads)
 448 {
 449         krb5_error_code ret = 0;
 450         krb5_context context = NULL;
 451         krb5_keytab keytab = NULL;
 452         krb5_kvno kvno;
 453         ADS_STATUS aderr;
 454
 455         initialize_krb5_error_table();
 456         ret = krb5_init_context(&context);
 457         if (ret) {
 458                 DEBUG(1, (__location__ ": could not krb5_init_context: %s\n",
 459                           error_message(ret)));
 460                 return ret;
 461         }
 462
 463         ret = smb_krb5_open_keytab(context, NULL, True, &keytab);
 464         if (ret) {
 465                 DEBUG(1, (__location__ ": smb_krb5_open_keytab failed (%s)\n",
 466                           error_message(ret)));
 467                 goto out;
 468         }
 469
 470         kvno = (krb5_kvno)ads_get_machine_kvno(ads, lp_netbios_name());
 471         if (kvno == -1) {
 472                 /* -1 indicates a failure */
 473                 DEBUG(1, (__location__ ": Error determining the kvno.\n"));
 474                 goto out;
 475         }
 476
 477         /* Seek and delete old keytab entries */
 478         ret = seek_and_delete_old_entries(context, keytab, kvno,
 479                                           NULL, NULL, true, false);
 480         if (ret) {
 481                 goto out;
 482         }
 483
 484         aderr = ads_clear_service_principal_names(ads, lp_netbios_name());
 485         if (!ADS_ERR_OK(aderr)) {
 486                 DEBUG(1, (__location__ ": Error while clearing service "
 487                           "principal listings in LDAP.\n"));
 488                 goto out;
 489         }
 490
 491 out:
 492         if (keytab) {
 493                 krb5_kt_close(context, keytab);
 494         }
 495         if (context) {
 496                 krb5_free_context(context);
 497         }
 498         return ret;
 499 }
 500
 501 /**********************************************************************
 502  Adds all the required service principals to the system keytab.
 503 ***********************************************************************/
 504
 505 int ads_keytab_create_default(ADS_STRUCT *ads)
 506 {
 507         krb5_error_code ret = 0;
 508         krb5_context context = NULL;
 509         krb5_keytab keytab = NULL;
 510         krb5_kt_cursor cursor;
 511         krb5_keytab_entry kt_entry;
 512         krb5_kvno kvno;
 513         size_t found = 0;
 514         char *sam_account_name, *upn;
 515         char **oldEntries = NULL, *princ_s[26];
 516         TALLOC_CTX *frame;
 517         char *machine_name;
 518         char **spn_array;
 519         size_t num_spns;
 520         size_t i;
 521         ADS_STATUS status;
 522
 523         frame = talloc_stackframe();
 524         if (frame == NULL) {
 525                 ret = -1;
 526                 goto done;
 527         }
 528
 529         status = ads_get_service_principal_names(frame,
 530                                                  ads,
 531                                                  lp_netbios_name(),
 532                                                  &spn_array,
 533                                                  &num_spns);
 534         if (!ADS_ERR_OK(status)) {
 535                 ret = -1;
 536                 goto done;
 537         }
 538
 539         for (i = 0; i < num_spns; i++) {
 540                 char *srv_princ;
 541                 char *p;
 542
 543                 srv_princ = strlower_talloc(frame, spn_array[i]);
 544                 if (srv_princ == NULL) {
 545                         ret = -1;
 546                         goto done;
 547                 }
 548
 549                 p = strchr_m(srv_princ, '/');
 550                 if (p == NULL) {
 551                         continue;
 552                 }
 553                 p[0] = '\0';
 554
 555                 /* Add the SPNs found on the DC */
 556                 ret = ads_keytab_add_entry(ads, srv_princ);
 557                 if (ret != 0) {
 558                         DEBUG(1, ("ads_keytab_add_entry failed while "
 559                                   "adding '%s' principal.\n",
 560                                   spn_array[i]));
 561                         goto done;
 562                 }
 563         }
 564
 565 #if 0   /* don't create the CIFS/... keytab entries since no one except smbd
 566            really needs them and we will fall back to verifying against
 567            secrets.tdb */
 568
 569         ret = ads_keytab_add_entry(ads, "cifs"));
 570         if (ret != 0 ) {
 571                 DEBUG(1, (__location__ ": ads_keytab_add_entry failed while "
 572                           "adding 'cifs'.\n"));
 573                 return ret;
 574         }
 575 #endif
 576
 577         memset(princ_s, '\0', sizeof(princ_s));
 578         ZERO_STRUCT(kt_entry);
 579         ZERO_STRUCT(cursor);
 580
 581         initialize_krb5_error_table();
 582         ret = krb5_init_context(&context);
 583         if (ret) {
 584                 DEBUG(1, (__location__ ": could not krb5_init_context: %s\n",
 585                           error_message(ret)));
 586                 goto done;
 587         }
 588
 589         machine_name = talloc_strdup(frame, lp_netbios_name());
 590         if (!machine_name) {
 591                 ret = -1;
 592                 goto done;
 593         }
 594
 595         /* now add the userPrincipalName and sAMAccountName entries */
 596         sam_account_name = ads_get_samaccountname(ads, frame, machine_name);
 597         if (!sam_account_name) {
 598                 DEBUG(0, (__location__ ": unable to determine machine "
 599                           "account's name in AD!\n"));
 600                 ret = -1;
 601                 goto done;
 602         }
 603
 604         /* upper case the sAMAccountName to make it easier for apps to
 605            know what case to use in the keytab file */
 606         if (!strupper_m(sam_account_name)) {
 607                 ret = -1;
 608                 goto done;
 609         }
 610
 611         ret = ads_keytab_add_entry(ads, sam_account_name);
 612         if (ret != 0) {
 613                 DEBUG(1, (__location__ ": ads_keytab_add_entry() failed "
 614                           "while adding sAMAccountName (%s)\n",
 615                           sam_account_name));
 616                 goto done;
 617         }
 618
 619         /* remember that not every machine account will have a upn */
 620         upn = ads_get_upn(ads, frame, machine_name);
 621         if (upn) {
 622                 ret = ads_keytab_add_entry(ads, upn);
 623                 if (ret != 0) {
 624                         DEBUG(1, (__location__ ": ads_keytab_add_entry() "
 625                                   "failed while adding UPN (%s)\n", upn));
 626                         goto done;
 627                 }
 628         }
 629
 630         /* Now loop through the keytab and update any other existing entries */
 631         kvno = (krb5_kvno)ads_get_machine_kvno(ads, machine_name);
 632         if (kvno == (krb5_kvno)-1) {
 633                 DEBUG(1, (__location__ ": ads_get_machine_kvno() failed to "
 634                           "determine the system's kvno.\n"));
 635                 goto done;
 636         }
 637
 638         DEBUG(3, (__location__ ": Searching for keytab entries to preserve "
 639                   "and update.\n"));
 640
 641         ret = smb_krb5_open_keytab(context, NULL, True, &keytab);
 642         if (ret) {
 643                 DEBUG(1, (__location__ ": smb_krb5_open_keytab failed (%s)\n",
 644                           error_message(ret)));
 645                 goto done;
 646         }
 647
 648         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 649         if (ret != KRB5_KT_END && ret != ENOENT ) {
 650                 while ((ret = krb5_kt_next_entry(context, keytab,
 651                                                  &kt_entry, &cursor)) == 0) {
 652                         smb_krb5_kt_free_entry(context, &kt_entry);
 653                         ZERO_STRUCT(kt_entry);
 654                         found++;
 655                 }
 656         }
 657         krb5_kt_end_seq_get(context, keytab, &cursor);
 658         ZERO_STRUCT(cursor);
 659
 660         /*
 661          * Hmmm. There is no "rewind" function for the keytab. This means we
 662          * have a race condition where someone else could add entries after
 663          * we've counted them. Re-open asap to minimise the race. JRA.
 664          */
 665         DEBUG(3, (__location__ ": Found %zd entries in the keytab.\n", found));
 666         if (!found) {
 667                 goto done;
 668         }
 669
 670         oldEntries = talloc_array(frame, char *, found);
 671         if (!oldEntries) {
 672                 DEBUG(1, (__location__ ": Failed to allocate space to store "
 673                           "the old keytab entries (talloc failed?).\n"));
 674                 ret = -1;
 675                 goto done;
 676         }
 677         memset(oldEntries, '\0', found * sizeof(char *));
 678
 679         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 680         if (ret == KRB5_KT_END || ret == ENOENT) {
 681                 krb5_kt_end_seq_get(context, keytab, &cursor);
 682                 ZERO_STRUCT(cursor);
 683                 goto done;
 684         }
 685
 686         while (krb5_kt_next_entry(context, keytab, &kt_entry, &cursor) == 0) {
 687                 if (kt_entry.vno != kvno) {
 688                         char *ktprinc = NULL;
 689                         char *p;
 690
 691                         /* This returns a malloc'ed string in ktprinc. */
 692                         ret = smb_krb5_unparse_name(oldEntries, context,
 693                                                     kt_entry.principal,
 694                                                     &ktprinc);
 695                         if (ret) {
 696                                 DEBUG(1, (__location__
 697                                          ": smb_krb5_unparse_name failed "
 698                                          "(%s)\n", error_message(ret)));
 699                                 goto done;
 700                         }
 701                         /*
 702                          * From looking at the krb5 source they don't seem to
 703                          * take locale or mb strings into account.
 704                          * Maybe this is because they assume utf8 ?
 705                          * In this case we may need to convert from utf8 to
 706                          * mb charset here ? JRA.
 707                          */
 708                         p = strchr_m(ktprinc, '@');
 709                         if (p) {
 710                                 *p = '\0';
 711                         }
 712
 713                         p = strchr_m(ktprinc, '/');
 714                         if (p) {
 715                                 *p = '\0';
 716                         }
 717                         for (i = 0; i < found; i++) {
 718                                 if (!oldEntries[i]) {
 719                                         oldEntries[i] = ktprinc;
 720                                         break;
 721                                 }
 722                                 if (!strcmp(oldEntries[i], ktprinc)) {
 723                                         TALLOC_FREE(ktprinc);
 724                                         break;
 725                                 }
 726                         }
 727                         if (i == found) {
 728                                 TALLOC_FREE(ktprinc);
 729                         }
 730                 }
 731                 smb_krb5_kt_free_entry(context, &kt_entry);
 732                 ZERO_STRUCT(kt_entry);
 733         }
 734         ret = 0;
 735         for (i = 0; oldEntries[i]; i++) {
 736                 ret |= ads_keytab_add_entry(ads, oldEntries[i]);
 737                 TALLOC_FREE(oldEntries[i]);
 738         }
 739         krb5_kt_end_seq_get(context, keytab, &cursor);
 740         ZERO_STRUCT(cursor);
 741
 742 done:
 743         TALLOC_FREE(oldEntries);
 744         TALLOC_FREE(frame);
 745
 746         {
 747                 krb5_keytab_entry zero_kt_entry;
 748                 ZERO_STRUCT(zero_kt_entry);
 749                 if (memcmp(&zero_kt_entry, &kt_entry,
 750                                 sizeof(krb5_keytab_entry))) {
 751                         smb_krb5_kt_free_entry(context, &kt_entry);
 752                 }
 753         }
 754         {
 755                 krb5_kt_cursor zero_csr;
 756                 ZERO_STRUCT(zero_csr);
 757                 if ((memcmp(&cursor, &zero_csr,
 758                                 sizeof(krb5_kt_cursor)) != 0) && keytab) {
 759                         krb5_kt_end_seq_get(context, keytab, &cursor);
 760                 }
 761         }
 762         if (keytab) {
 763                 krb5_kt_close(context, keytab);
 764         }
 765         if (context) {
 766                 krb5_free_context(context);
 767         }
 768         return ret;
 769 }
 770
 771 #endif /* HAVE_ADS */
 772
 773 /**********************************************************************
 774  List system keytab.
 775 ***********************************************************************/
 776
 777 int ads_keytab_list(const char *keytab_name)
 778 {
 779         krb5_error_code ret = 0;
 780         krb5_context context = NULL;
 781         krb5_keytab keytab = NULL;
 782         krb5_kt_cursor cursor;
 783         krb5_keytab_entry kt_entry;
 784
 785         ZERO_STRUCT(kt_entry);
 786         ZERO_STRUCT(cursor);
 787
 788         initialize_krb5_error_table();
 789         ret = krb5_init_context(&context);
 790         if (ret) {
 791                 DEBUG(1, (__location__ ": could not krb5_init_context: %s\n",
 792                           error_message(ret)));
 793                 return ret;
 794         }
 795
 796         ret = smb_krb5_open_keytab(context, keytab_name, False, &keytab);
 797         if (ret) {
 798                 DEBUG(1, (__location__ ": smb_krb5_open_keytab failed (%s)\n",
 799                           error_message(ret)));
 800                 goto out;
 801         }
 802
 803         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 804         if (ret) {
 805                 ZERO_STRUCT(cursor);
 806                 goto out;
 807         }
 808
 809         printf("Vno  Type                                        Principal\n");
 810
 811         while (krb5_kt_next_entry(context, keytab, &kt_entry, &cursor) == 0) {
 812
 813                 char *princ_s = NULL;
 814                 char *etype_s = NULL;
 815                 krb5_enctype enctype = 0;
 816
 817                 ret = smb_krb5_unparse_name(talloc_tos(), context,
 818                                             kt_entry.principal, &princ_s);
 819                 if (ret) {
 820                         goto out;
 821                 }
 822
 823                 enctype = smb_get_enctype_from_kt_entry(&kt_entry);
 824
 825                 ret = smb_krb5_enctype_to_string(context, enctype, &etype_s);
 826                 if (ret &&
 827                     (asprintf(&etype_s, "UNKNOWN: %d\n", enctype) == -1)) {
 828                         TALLOC_FREE(princ_s);
 829                         goto out;
 830                 }
 831
 832                 printf("%3d  %-43s %s\n", kt_entry.vno, etype_s, princ_s);
 833
 834                 TALLOC_FREE(princ_s);
 835                 SAFE_FREE(etype_s);
 836
 837                 ret = smb_krb5_kt_free_entry(context, &kt_entry);
 838                 if (ret) {
 839                         goto out;
 840                 }
 841         }
 842
 843         ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 844         if (ret) {
 845                 goto out;
 846         }
 847
 848         /* Ensure we don't double free. */
 849         ZERO_STRUCT(kt_entry);
 850         ZERO_STRUCT(cursor);
 851 out:
 852
 853         {
 854                 krb5_keytab_entry zero_kt_entry;
 855                 ZERO_STRUCT(zero_kt_entry);
 856                 if (memcmp(&zero_kt_entry, &kt_entry,
 857                                 sizeof(krb5_keytab_entry))) {
 858                         smb_krb5_kt_free_entry(context, &kt_entry);
 859                 }
 860         }
 861         {
 862                 krb5_kt_cursor zero_csr;
 863                 ZERO_STRUCT(zero_csr);
 864                 if ((memcmp(&cursor, &zero_csr,
 865                                 sizeof(krb5_kt_cursor)) != 0) && keytab) {
 866                         krb5_kt_end_seq_get(context, keytab, &cursor);
 867                 }
 868         }
 869
 870         if (keytab) {
 871                 krb5_kt_close(context, keytab);
 872         }
 873         if (context) {
 874                 krb5_free_context(context);
 875         }
 876         return ret;
 877 }
 878
 879 #endif /* HAVE_KRB5 */