source/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 2 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, write to the Free Software
  26    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  27 */
  28
  29 #include "includes.h"
  30
  31 #ifdef HAVE_KRB5
  32
  33 /* This MAX_NAME_LEN is a constant defined in krb5.h */
  34 #ifndef MAX_KEYTAB_NAME_LEN
  35 #define MAX_KEYTAB_NAME_LEN 1100
  36 #endif
  37
  38
  39 /**********************************************************************
  40 **********************************************************************/
  41
  42 static int smb_krb5_kt_add_entry( krb5_context context, krb5_keytab keytab,
  43                                   krb5_kvno kvno, const char *princ_s,
  44                                   krb5_enctype *enctypes, krb5_data password )
  45 {
  46         krb5_error_code ret = 0;
  47         krb5_kt_cursor cursor;
  48         krb5_keytab_entry kt_entry;
  49         krb5_principal princ = NULL;
  50         int i;
  51         char *ktprinc = NULL;
  52
  53         ZERO_STRUCT(kt_entry);
  54         ZERO_STRUCT(cursor);
  55
  56         ret = smb_krb5_parse_name(context, princ_s, &princ);
  57         if (ret) {
  58                 DEBUG(1,("smb_krb5_kt_add_entry: smb_krb5_parse_name(%s) failed (%s)\n", princ_s, error_message(ret)));
  59                 goto out;
  60         }
  61
  62         /* Seek and delete old keytab entries */
  63         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
  64         if (ret != KRB5_KT_END && ret != ENOENT ) {
  65                 DEBUG(3,("smb_krb5_kt_add_entry: Will try to delete old keytab entries\n"));
  66                 while(!krb5_kt_next_entry(context, keytab, &kt_entry, &cursor)) {
  67                         BOOL compare_name_ok = False;
  68
  69                         ret = smb_krb5_unparse_name(context, kt_entry.principal, &ktprinc);
  70                         if (ret) {
  71                                 DEBUG(1,("smb_krb5_kt_add_entry: smb_krb5_unparse_name failed (%s)\n",
  72                                         error_message(ret)));
  73                                 goto out;
  74                         }
  75
  76                         /*---------------------------------------------------------------------------
  77                          * Save the entries with kvno - 1.   This is what microsoft does
  78                          * to allow people with existing sessions that have kvno - 1 to still
  79                          * work.   Otherwise, when the password for the machine changes, all
  80                          * kerberizied sessions will 'break' until either the client reboots or
  81                          * the client's session key expires and they get a new session ticket
  82                          * with the new kvno.
  83                          */
  84
  85 #ifdef HAVE_KRB5_KT_COMPARE
  86                         compare_name_ok = (krb5_kt_compare(context, &kt_entry, princ, 0, 0) == True);
  87 #else
  88                         compare_name_ok = (strcmp(ktprinc, princ_s) == 0);
  89 #endif
  90
  91                         if (!compare_name_ok) {
  92                                 DEBUG(10,("smb_krb5_kt_add_entry: ignoring keytab entry principal %s, kvno = %d\n",
  93                                         ktprinc, kt_entry.vno));
  94                         }
  95
  96                         SAFE_FREE(ktprinc);
  97
  98                         if (compare_name_ok) {
  99                                 if (kt_entry.vno == kvno - 1) {
 100                                         DEBUG(5,("smb_krb5_kt_add_entry: Saving previous (kvno %d) entry for principal: %s.\n",
 101                                                 kvno - 1, princ_s));
 102                                 } else {
 103
 104                                         DEBUG(5,("smb_krb5_kt_add_entry: Found old entry for principal: %s (kvno %d) - trying to remove it.\n",
 105                                                 princ_s, kt_entry.vno));
 106                                         ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 107                                         ZERO_STRUCT(cursor);
 108                                         if (ret) {
 109                                                 DEBUG(1,("smb_krb5_kt_add_entry: krb5_kt_end_seq_get() failed (%s)\n",
 110                                                         error_message(ret)));
 111                                                 goto out;
 112                                         }
 113                                         ret = krb5_kt_remove_entry(context, keytab, &kt_entry);
 114                                         if (ret) {
 115                                                 DEBUG(1,("smb_krb5_kt_add_entry: krb5_kt_remove_entry failed (%s)\n",
 116                                                         error_message(ret)));
 117                                                 goto out;
 118                                         }
 119
 120                                         DEBUG(5,("smb_krb5_kt_add_entry: removed old entry for principal: %s (kvno %d).\n",
 121                                                 princ_s, kt_entry.vno));
 122
 123                                         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 124                                         if (ret) {
 125                                                 DEBUG(1,("smb_krb5_kt_add_entry: krb5_kt_start_seq failed (%s)\n",
 126                                                         error_message(ret)));
 127                                                 goto out;
 128                                         }
 129                                         ret = smb_krb5_kt_free_entry(context, &kt_entry);
 130                                         ZERO_STRUCT(kt_entry);
 131                                         if (ret) {
 132                                                 DEBUG(1,("smb_krb5_kt_add_entry: krb5_kt_remove_entry failed (%s)\n",
 133                                                         error_message(ret)));
 134                                                 goto out;
 135                                         }
 136                                         continue;
 137                                 }
 138                         }
 139
 140                         /* Not a match, just free this entry and continue. */
 141                         ret = smb_krb5_kt_free_entry(context, &kt_entry);
 142                         ZERO_STRUCT(kt_entry);
 143                         if (ret) {
 144                                 DEBUG(1,("smb_krb5_kt_add_entry: smb_krb5_kt_free_entry failed (%s)\n", error_message(ret)));
 145                                 goto out;
 146                         }
 147                 }
 148
 149                 ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 150                 ZERO_STRUCT(cursor);
 151                 if (ret) {
 152                         DEBUG(1,("smb_krb5_kt_add_entry: krb5_kt_end_seq_get failed (%s)\n",error_message(ret)));
 153                         goto out;
 154                 }
 155         }
 156
 157         /* Ensure we don't double free. */
 158         ZERO_STRUCT(kt_entry);
 159         ZERO_STRUCT(cursor);
 160
 161         /* If we get here, we have deleted all the old entries with kvno's not equal to the current kvno-1. */
 162
 163         /* Now add keytab entries for all encryption types */
 164         for (i = 0; enctypes[i]; i++) {
 165                 krb5_keyblock *keyp;
 166
 167 #if !defined(HAVE_KRB5_KEYTAB_ENTRY_KEY) && !defined(HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK)
 168 #error krb5_keytab_entry has no key or keyblock member
 169 #endif
 170 #ifdef HAVE_KRB5_KEYTAB_ENTRY_KEY               /* MIT */
 171                 keyp = &kt_entry.key;
 172 #endif
 173 #ifdef HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK          /* Heimdal */
 174                 keyp = &kt_entry.keyblock;
 175 #endif
 176                 if (create_kerberos_key_from_string(context, princ, &password, keyp, enctypes[i])) {
 177                         continue;
 178                 }
 179
 180                 kt_entry.principal = princ;
 181                 kt_entry.vno       = kvno;
 182
 183                 DEBUG(3,("smb_krb5_kt_add_entry: adding keytab entry for (%s) with encryption type (%d) and version (%d)\n",
 184                         princ_s, enctypes[i], kt_entry.vno));
 185                 ret = krb5_kt_add_entry(context, keytab, &kt_entry);
 186                 krb5_free_keyblock_contents(context, keyp);
 187                 ZERO_STRUCT(kt_entry);
 188                 if (ret) {
 189                         DEBUG(1,("smb_krb5_kt_add_entry: adding entry to keytab failed (%s)\n", error_message(ret)));
 190                         goto out;
 191                 }
 192         }
 193
 194
 195 out:
 196         {
 197                 krb5_keytab_entry zero_kt_entry;
 198                 ZERO_STRUCT(zero_kt_entry);
 199                 if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
 200                         smb_krb5_kt_free_entry(context, &kt_entry);
 201                 }
 202         }
 203         if (princ) {
 204                 krb5_free_principal(context, princ);
 205         }
 206
 207         {
 208                 krb5_kt_cursor zero_csr;
 209                 ZERO_STRUCT(zero_csr);
 210                 if ((memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
 211                         krb5_kt_end_seq_get(context, keytab, &cursor);
 212                 }
 213         }
 214
 215         return (int)ret;
 216 }
 217
 218
 219 /**********************************************************************
 220  Adds a single service principal, i.e. 'host' to the system keytab
 221 ***********************************************************************/
 222
 223 int ads_keytab_add_entry(ADS_STRUCT *ads, const char *srvPrinc)
 224 {
 225         krb5_error_code ret = 0;
 226         krb5_context context = NULL;
 227         krb5_keytab keytab = NULL;
 228         krb5_data password;
 229         krb5_kvno kvno;
 230         krb5_enctype enctypes[4] = { ENCTYPE_DES_CBC_CRC, ENCTYPE_DES_CBC_MD5, 0, 0 };
 231         char *princ_s = NULL, *short_princ_s = NULL;
 232         char *password_s = NULL;
 233         char *my_fqdn;
 234         char keytab_name[MAX_KEYTAB_NAME_LEN];
 235         TALLOC_CTX *ctx = NULL;
 236         char *machine_name;
 237
 238 #if defined(ENCTYPE_ARCFOUR_HMAC)
 239         enctypes[2] = ENCTYPE_ARCFOUR_HMAC;
 240 #endif
 241
 242         initialize_krb5_error_table();
 243         ret = krb5_init_context(&context);
 244         if (ret) {
 245                 DEBUG(1,("ads_keytab_add_entry: could not krb5_init_context: %s\n",error_message(ret)));
 246                 return -1;
 247         }
 248
 249 #ifdef HAVE_WRFILE_KEYTAB       /* MIT */
 250         keytab_name[0] = 'W';
 251         keytab_name[1] = 'R';
 252         ret = krb5_kt_default_name(context, (char *) &keytab_name[2], MAX_KEYTAB_NAME_LEN - 4);
 253 #else                           /* Heimdal */
 254         ret = krb5_kt_default_name(context, (char *) &keytab_name[0], MAX_KEYTAB_NAME_LEN - 2);
 255 #endif
 256         if (ret) {
 257                 DEBUG(1,("ads_keytab_add_entry: krb5_kt_default_name failed (%s)\n", error_message(ret)));
 258                 goto out;
 259         }
 260         DEBUG(2,("ads_keytab_add_entry: Using default system keytab: %s\n", (char *) &keytab_name));
 261         ret = krb5_kt_resolve(context, (char *) &keytab_name, &keytab);
 262         if (ret) {
 263                 DEBUG(1,("ads_keytab_add_entry: krb5_kt_resolve failed (%s)\n", error_message(ret)));
 264                 goto out;
 265         }
 266
 267         /* retrieve the password */
 268         if (!secrets_init()) {
 269                 DEBUG(1,("ads_keytab_add_entry: secrets_init failed\n"));
 270                 ret = -1;
 271                 goto out;
 272         }
 273         password_s = secrets_fetch_machine_password(lp_workgroup(), NULL, NULL);
 274         if (!password_s) {
 275                 DEBUG(1,("ads_keytab_add_entry: failed to fetch machine password\n"));
 276                 ret = -1;
 277                 goto out;
 278         }
 279         password.data = password_s;
 280         password.length = strlen(password_s);
 281
 282         /* we need the dNSHostName value here */
 283
 284         if ( (ctx = talloc_init("ads_keytab_add_entry")) == NULL ) {
 285                 DEBUG(0,("ads_keytab_add_entry: talloc() failed!\n"));
 286                 ret = -1;
 287                 goto out;
 288         }
 289
 290         if ( (my_fqdn = ads_get_dnshostname( ads, ctx, global_myname())) == NULL ) {
 291                 DEBUG(0,("ads_keytab_add_entry: unable to determine machine account's dns name in AD!\n"));
 292                 ret = -1;
 293                 goto out;
 294         }
 295
 296         if ( (machine_name = ads_get_samaccountname( ads, ctx, global_myname())) == NULL ) {
 297                 DEBUG(0,("ads_keytab_add_entry: unable to determine machine account's short name in AD!\n"));
 298                 ret = -1;
 299                 goto out;
 300         }
 301         /*strip the trailing '$' */
 302         machine_name[strlen(machine_name)-1] = '\0';
 303
 304         /* Construct our principal */
 305
 306         if (strchr_m(srvPrinc, '@')) {
 307                 /* It's a fully-named principal. */
 308                 asprintf(&princ_s, "%s", srvPrinc);
 309         } else if (srvPrinc[strlen(srvPrinc)-1] == '$') {
 310                 /* It's the machine account, as used by smbclient clients. */
 311                 asprintf(&princ_s, "%s@%s", srvPrinc, lp_realm());
 312         } else {
 313                 /* It's a normal service principal.  Add the SPN now so that we
 314                  * can obtain credentials for it and double-check the salt value
 315                  * used to generate the service's keys. */
 316
 317                 asprintf(&princ_s, "%s/%s@%s", srvPrinc, my_fqdn, lp_realm());
 318                 asprintf(&short_princ_s, "%s/%s@%s", srvPrinc, machine_name, lp_realm());
 319
 320                 /* According to http://support.microsoft.com/kb/326985/en-us,
 321                    certain principal names are automatically mapped to the host/...
 322                    principal in the AD account.  So only create these in the
 323                    keytab, not in AD.  --jerry */
 324
 325                 if ( !strequal( srvPrinc, "cifs" ) && !strequal(srvPrinc, "host" ) ) {
 326                         DEBUG(3,("ads_keytab_add_entry: Attempting to add/update '%s'\n", princ_s));
 327
 328                         if (!ADS_ERR_OK(ads_add_service_principal_name(ads, global_myname(), my_fqdn, srvPrinc))) {
 329                                 DEBUG(1,("ads_keytab_add_entry: ads_add_service_principal_name failed.\n"));
 330                                 goto out;
 331                         }
 332                 }
 333         }
 334
 335         kvno = (krb5_kvno) ads_get_kvno(ads, global_myname());
 336         if (kvno == -1) {       /* -1 indicates failure, everything else is OK */
 337                 DEBUG(1,("ads_keytab_add_entry: ads_get_kvno failed to determine the system's kvno.\n"));
 338                 ret = -1;
 339                 goto out;
 340         }
 341
 342         /* add the fqdn principal to the keytab */
 343
 344         ret = smb_krb5_kt_add_entry( context, keytab, kvno, princ_s, enctypes, password );
 345         if ( ret ) {
 346                 DEBUG(1,("ads_keytab_add_entry: Failed to add entry to keytab file\n"));
 347                 goto out;
 348         }
 349
 350         /* add the short principal name if we have one */
 351
 352         if ( short_princ_s ) {
 353                 ret = smb_krb5_kt_add_entry( context, keytab, kvno, short_princ_s, enctypes, password );
 354                 if ( ret ) {
 355                         DEBUG(1,("ads_keytab_add_entry: Failed to add short entry to keytab file\n"));
 356                         goto out;
 357                 }
 358         }
 359
 360 out:
 361         SAFE_FREE( princ_s );
 362         SAFE_FREE( short_princ_s );
 363         TALLOC_FREE( ctx );
 364
 365         if (keytab) {
 366                 krb5_kt_close(context, keytab);
 367         }
 368         if (context) {
 369                 krb5_free_context(context);
 370         }
 371         return (int)ret;
 372 }
 373
 374 /**********************************************************************
 375  Flushes all entries from the system keytab.
 376 ***********************************************************************/
 377
 378 int ads_keytab_flush(ADS_STRUCT *ads)
 379 {
 380         krb5_error_code ret = 0;
 381         krb5_context context = NULL;
 382         krb5_keytab keytab = NULL;
 383         krb5_kt_cursor cursor;
 384         krb5_keytab_entry kt_entry;
 385         krb5_kvno kvno;
 386         char keytab_name[MAX_KEYTAB_NAME_LEN];
 387
 388         ZERO_STRUCT(kt_entry);
 389         ZERO_STRUCT(cursor);
 390
 391         initialize_krb5_error_table();
 392         ret = krb5_init_context(&context);
 393         if (ret) {
 394                 DEBUG(1,("ads_keytab_flush: could not krb5_init_context: %s\n",error_message(ret)));
 395                 return ret;
 396         }
 397 #ifdef HAVE_WRFILE_KEYTAB
 398         keytab_name[0] = 'W';
 399         keytab_name[1] = 'R';
 400         ret = krb5_kt_default_name(context, (char *) &keytab_name[2], MAX_KEYTAB_NAME_LEN - 4);
 401 #else
 402         ret = krb5_kt_default_name(context, (char *) &keytab_name[0], MAX_KEYTAB_NAME_LEN - 2);
 403 #endif
 404         if (ret) {
 405                 DEBUG(1,("ads_keytab_flush: krb5_kt_default failed (%s)\n", error_message(ret)));
 406                 goto out;
 407         }
 408         DEBUG(3,("ads_keytab_flush: Using default keytab: %s\n", (char *) &keytab_name));
 409         ret = krb5_kt_resolve(context, (char *) &keytab_name, &keytab);
 410         if (ret) {
 411                 DEBUG(1,("ads_keytab_flush: krb5_kt_resolve failed (%s)\n", error_message(ret)));
 412                 goto out;
 413         }
 414
 415         kvno = (krb5_kvno) ads_get_kvno(ads, global_myname());
 416         if (kvno == -1) {       /* -1 indicates a failure */
 417                 DEBUG(1,("ads_keytab_flush: Error determining the system's kvno.\n"));
 418                 goto out;
 419         }
 420
 421         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 422         if (ret != KRB5_KT_END && ret != ENOENT) {
 423                 while (!krb5_kt_next_entry(context, keytab, &kt_entry, &cursor)) {
 424                         ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 425                         ZERO_STRUCT(cursor);
 426                         if (ret) {
 427                                 DEBUG(1,("ads_keytab_flush: krb5_kt_end_seq_get() failed (%s)\n",error_message(ret)));
 428                                 goto out;
 429                         }
 430                         ret = krb5_kt_remove_entry(context, keytab, &kt_entry);
 431                         if (ret) {
 432                                 DEBUG(1,("ads_keytab_flush: krb5_kt_remove_entry failed (%s)\n",error_message(ret)));
 433                                 goto out;
 434                         }
 435                         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 436                         if (ret) {
 437                                 DEBUG(1,("ads_keytab_flush: krb5_kt_start_seq failed (%s)\n",error_message(ret)));
 438                                 goto out;
 439                         }
 440                         ret = smb_krb5_kt_free_entry(context, &kt_entry);
 441                         ZERO_STRUCT(kt_entry);
 442                         if (ret) {
 443                                 DEBUG(1,("ads_keytab_flush: krb5_kt_remove_entry failed (%s)\n",error_message(ret)));
 444                                 goto out;
 445                         }
 446                 }
 447         }
 448
 449         /* Ensure we don't double free. */
 450         ZERO_STRUCT(kt_entry);
 451         ZERO_STRUCT(cursor);
 452
 453         if (!ADS_ERR_OK(ads_clear_service_principal_names(ads, global_myname()))) {
 454                 DEBUG(1,("ads_keytab_flush: Error while clearing service principal listings in LDAP.\n"));
 455                 goto out;
 456         }
 457
 458 out:
 459
 460         {
 461                 krb5_keytab_entry zero_kt_entry;
 462                 ZERO_STRUCT(zero_kt_entry);
 463                 if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
 464                         smb_krb5_kt_free_entry(context, &kt_entry);
 465                 }
 466         }
 467         {
 468                 krb5_kt_cursor zero_csr;
 469                 ZERO_STRUCT(zero_csr);
 470                 if ((memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
 471                         krb5_kt_end_seq_get(context, keytab, &cursor);
 472                 }
 473         }
 474         if (keytab) {
 475                 krb5_kt_close(context, keytab);
 476         }
 477         if (context) {
 478                 krb5_free_context(context);
 479         }
 480         return ret;
 481 }
 482
 483 /**********************************************************************
 484  Adds all the required service principals to the system keytab.
 485 ***********************************************************************/
 486
 487 int ads_keytab_create_default(ADS_STRUCT *ads)
 488 {
 489         krb5_error_code ret = 0;
 490         krb5_context context = NULL;
 491         krb5_keytab keytab = NULL;
 492         krb5_kt_cursor cursor;
 493         krb5_keytab_entry kt_entry;
 494         krb5_kvno kvno;
 495         int i, found = 0;
 496         char *sam_account_name, *upn;
 497         char **oldEntries = NULL, *princ_s[26];
 498         TALLOC_CTX *ctx = NULL;
 499         fstring machine_name;
 500
 501         memset(princ_s, '\0', sizeof(princ_s));
 502
 503         fstrcpy( machine_name, global_myname() );
 504
 505         /* these are the main ones we need */
 506
 507         if ( (ret = ads_keytab_add_entry(ads, "host") ) != 0 ) {
 508                 DEBUG(1,("ads_keytab_create_default: ads_keytab_add_entry failed while adding 'host'.\n"));
 509                 return ret;
 510         }
 511
 512
 513 #if 0   /* don't create the CIFS/... keytab entries since no one except smbd
 514            really needs them and we will fall back to verifying against secrets.tdb */
 515
 516         if ( (ret = ads_keytab_add_entry(ads, "cifs")) != 0 ) {
 517                 DEBUG(1,("ads_keytab_create_default: ads_keytab_add_entry failed while adding 'cifs'.\n"));
 518                 return ret;
 519         }
 520 #endif
 521
 522         if ( (ctx = talloc_init("ads_keytab_create_default")) == NULL ) {
 523                 DEBUG(0,("ads_keytab_create_default: talloc() failed!\n"));
 524                 return -1;
 525         }
 526
 527         /* now add the userPrincipalName and sAMAccountName entries */
 528
 529         if ( (sam_account_name = ads_get_samaccountname( ads, ctx, machine_name)) == NULL ) {
 530                 DEBUG(0,("ads_keytab_add_entry: unable to determine machine account's name in AD!\n"));
 531                 TALLOC_FREE( ctx );
 532                 return -1;
 533         }
 534
 535         /* upper case the sAMAccountName to make it easier for apps to
 536            know what case to use in the keytab file */
 537
 538         strupper_m( sam_account_name );
 539
 540         if ( (ret = ads_keytab_add_entry(ads, sam_account_name )) != 0 ) {
 541                 DEBUG(1,("ads_keytab_create_default: ads_keytab_add_entry failed while adding sAMAccountName (%s)\n",
 542                         sam_account_name));
 543                 return ret;
 544         }
 545
 546         /* remember that not every machine account will have a upn */
 547
 548         upn = ads_get_upn( ads, ctx, machine_name);
 549         if ( upn ) {
 550                 if ( (ret = ads_keytab_add_entry(ads, upn)) != 0 ) {
 551                         DEBUG(1,("ads_keytab_create_default: ads_keytab_add_entry failed while adding UPN (%s)\n",
 552                                 upn));
 553                         TALLOC_FREE( ctx );
 554                         return ret;
 555                 }
 556         }
 557
 558         TALLOC_FREE( ctx );
 559
 560         /* Now loop through the keytab and update any other existing entries... */
 561
 562         kvno = (krb5_kvno) ads_get_kvno(ads, machine_name);
 563         if (kvno == -1) {
 564                 DEBUG(1,("ads_keytab_create_default: ads_get_kvno failed to determine the system's kvno.\n"));
 565                 return -1;
 566         }
 567
 568         DEBUG(3,("ads_keytab_create_default: Searching for keytab entries to "
 569                 "preserve and update.\n"));
 570
 571         ZERO_STRUCT(kt_entry);
 572         ZERO_STRUCT(cursor);
 573
 574         initialize_krb5_error_table();
 575         ret = krb5_init_context(&context);
 576         if (ret) {
 577                 DEBUG(1,("ads_keytab_create_default: could not krb5_init_context: %s\n",error_message(ret)));
 578                 return ret;
 579         }
 580         ret = krb5_kt_default(context, &keytab);
 581         if (ret) {
 582                 DEBUG(1,("ads_keytab_create_default: krb5_kt_default failed (%s)\n",error_message(ret)));
 583                 goto done;
 584         }
 585
 586         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 587         if (ret != KRB5_KT_END && ret != ENOENT ) {
 588                 while ((ret = krb5_kt_next_entry(context, keytab, &kt_entry, &cursor)) == 0) {
 589                         smb_krb5_kt_free_entry(context, &kt_entry);
 590                         ZERO_STRUCT(kt_entry);
 591                         found++;
 592                 }
 593         }
 594         krb5_kt_end_seq_get(context, keytab, &cursor);
 595         ZERO_STRUCT(cursor);
 596
 597         /*
 598          * Hmmm. There is no "rewind" function for the keytab. This means we have a race condition
 599          * where someone else could add entries after we've counted them. Re-open asap to minimise
 600          * the race. JRA.
 601          */
 602
 603         DEBUG(3, ("ads_keytab_create_default: Found %d entries in the keytab.\n", found));
 604         if (!found) {
 605                 goto done;
 606         }
 607         oldEntries = SMB_MALLOC_ARRAY(char *, found );
 608         if (!oldEntries) {
 609                 DEBUG(1,("ads_keytab_create_default: Failed to allocate space to store the old keytab entries (malloc failed?).\n"));
 610                 ret = -1;
 611                 goto done;
 612         }
 613         memset(oldEntries, '\0', found * sizeof(char *));
 614
 615         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 616         if (ret != KRB5_KT_END && ret != ENOENT ) {
 617                 while (krb5_kt_next_entry(context, keytab, &kt_entry, &cursor) == 0) {
 618                         if (kt_entry.vno != kvno) {
 619                                 char *ktprinc = NULL;
 620                                 char *p;
 621
 622                                 /* This returns a malloc'ed string in ktprinc. */
 623                                 ret = smb_krb5_unparse_name(context, kt_entry.principal, &ktprinc);
 624                                 if (ret) {
 625                                         DEBUG(1,("smb_krb5_unparse_name failed (%s)\n", error_message(ret)));
 626                                         goto done;
 627                                 }
 628                                 /*
 629                                  * From looking at the krb5 source they don't seem to take locale
 630                                  * or mb strings into account. Maybe this is because they assume utf8 ?
 631                                  * In this case we may need to convert from utf8 to mb charset here ? JRA.
 632                                  */
 633                                 p = strchr_m(ktprinc, '@');
 634                                 if (p) {
 635                                         *p = '\0';
 636                                 }
 637
 638                                 p = strchr_m(ktprinc, '/');
 639                                 if (p) {
 640                                         *p = '\0';
 641                                 }
 642                                 for (i = 0; i < found; i++) {
 643                                         if (!oldEntries[i]) {
 644                                                 oldEntries[i] = ktprinc;
 645                                                 break;
 646                                         }
 647                                         if (!strcmp(oldEntries[i], ktprinc)) {
 648                                                 SAFE_FREE(ktprinc);
 649                                                 break;
 650                                         }
 651                                 }
 652                                 if (i == found) {
 653                                         SAFE_FREE(ktprinc);
 654                                 }
 655                         }
 656                         smb_krb5_kt_free_entry(context, &kt_entry);
 657                         ZERO_STRUCT(kt_entry);
 658                 }
 659                 ret = 0;
 660                 for (i = 0; oldEntries[i]; i++) {
 661                         ret |= ads_keytab_add_entry(ads, oldEntries[i]);
 662                         SAFE_FREE(oldEntries[i]);
 663                 }
 664                 krb5_kt_end_seq_get(context, keytab, &cursor);
 665         }
 666         ZERO_STRUCT(cursor);
 667
 668 done:
 669
 670         SAFE_FREE(oldEntries);
 671
 672         {
 673                 krb5_keytab_entry zero_kt_entry;
 674                 ZERO_STRUCT(zero_kt_entry);
 675                 if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
 676                         smb_krb5_kt_free_entry(context, &kt_entry);
 677                 }
 678         }
 679         {
 680                 krb5_kt_cursor zero_csr;
 681                 ZERO_STRUCT(zero_csr);
 682                 if ((memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
 683                         krb5_kt_end_seq_get(context, keytab, &cursor);
 684                 }
 685         }
 686         if (keytab) {
 687                 krb5_kt_close(context, keytab);
 688         }
 689         if (context) {
 690                 krb5_free_context(context);
 691         }
 692         return ret;
 693 }
 694 #endif /* HAVE_KRB5 */