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 2003,2007
   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  * Open a krb5 keytab with flags, handles readonly or readwrite access and
  40  * allows to process non-default keytab names.
  41  * @param context krb5_context
  42  * @param keytab_name_req string
  43  * @param write_access BOOL if writable keytab is required
  44  * @param krb5_keytab pointer to krb5_keytab (close with krb5_kt_close())
  45  * @return krb5_error_code
  46 **********************************************************************/
  47
  48  krb5_error_code smb_krb5_open_keytab(krb5_context context,
  49                                       const char *keytab_name_req,
  50                                       BOOL write_access,
  51                                       krb5_keytab *keytab)
  52 {
  53         krb5_error_code ret = 0;
  54         TALLOC_CTX *mem_ctx;
  55         char keytab_string[MAX_KEYTAB_NAME_LEN];
  56         BOOL found_valid_name = False;
  57         const char *pragma = "FILE";
  58         const char *tmp = NULL;
  59
  60         if (!write_access && !keytab_name_req) {
  61                 /* caller just wants to read the default keytab readonly, so be it */
  62                 return krb5_kt_default(context, keytab);
  63         }
  64
  65         mem_ctx = talloc_init("smb_krb5_open_keytab");
  66         if (!mem_ctx) {
  67                 return ENOMEM;
  68         }
  69
  70 #ifdef HAVE_WRFILE_KEYTAB
  71         if (write_access) {
  72                 pragma = "WRFILE";
  73         }
  74 #endif
  75
  76         if (keytab_name_req) {
  77
  78                 if (strlen(keytab_name_req) > MAX_KEYTAB_NAME_LEN) {
  79                         ret = KRB5_CONFIG_NOTENUFSPACE;
  80                         goto out;
  81                 }
  82
  83                 if ((strncmp(keytab_name_req, "WRFILE:/", 8) == 0) ||
  84                     (strncmp(keytab_name_req, "FILE:/", 6) == 0)) {
  85                         tmp = keytab_name_req;
  86                         goto resolve;
  87                 }
  88
  89                 if (keytab_name_req[0] != '/') {
  90                         ret = KRB5_KT_BADNAME;
  91                         goto out;
  92                 }
  93
  94                 tmp = talloc_asprintf(mem_ctx, "%s:%s", pragma, keytab_name_req);
  95                 if (!tmp) {
  96                         ret = ENOMEM;
  97                         goto out;
  98                 }
  99
 100                 goto resolve;
 101         }
 102
 103         /* we need to handle more complex keytab_strings, like:
 104          * "ANY:FILE:/etc/krb5.keytab,krb4:/etc/srvtab" */
 105
 106         ret = krb5_kt_default_name(context, &keytab_string[0], MAX_KEYTAB_NAME_LEN - 2);
 107         if (ret) {
 108                 goto out;
 109         }
 110
 111         DEBUG(10,("smb_krb5_open_keytab: krb5_kt_default_name returned %s\n", keytab_string));
 112
 113         tmp = talloc_strdup(mem_ctx, keytab_string);
 114         if (!tmp) {
 115                 ret = ENOMEM;
 116                 goto out;
 117         }
 118
 119         if (strncmp(tmp, "ANY:", 4) == 0) {
 120                 tmp += 4;
 121         }
 122
 123         memset(&keytab_string, '\0', sizeof(keytab_string));
 124
 125         while (next_token(&tmp, keytab_string, ",", sizeof(keytab_string))) {
 126
 127                 if (strncmp(keytab_string, "WRFILE:", 7) == 0) {
 128                         found_valid_name = True;
 129                         tmp = keytab_string;
 130                         tmp += 7;
 131                 }
 132
 133                 if (strncmp(keytab_string, "FILE:", 5) == 0) {
 134                         found_valid_name = True;
 135                         tmp = keytab_string;
 136                         tmp += 5;
 137                 }
 138
 139                 if (found_valid_name) {
 140
 141                         if (tmp[0] != '/') {
 142                                 ret = KRB5_KT_BADNAME;
 143                                 goto out;
 144                         }
 145
 146                         tmp = talloc_asprintf(mem_ctx, "%s:%s", pragma, tmp);
 147                         if (!tmp) {
 148                                 ret = ENOMEM;
 149                                 goto out;
 150                         }
 151                         break;
 152                 }
 153         }
 154
 155         if (!found_valid_name) {
 156                 ret = KRB5_KT_UNKNOWN_TYPE;
 157                 goto out;
 158         }
 159
 160  resolve:
 161         DEBUG(10,("smb_krb5_open_keytab: resolving: %s\n", tmp));
 162         ret = krb5_kt_resolve(context, tmp, keytab);
 163
 164  out:
 165         TALLOC_FREE(mem_ctx);
 166         return ret;
 167 }
 168
 169 /**********************************************************************
 170 **********************************************************************/
 171
 172 static int smb_krb5_kt_add_entry( krb5_context context, krb5_keytab keytab,
 173                                   krb5_kvno kvno, const char *princ_s,
 174                                   krb5_enctype *enctypes, krb5_data password )
 175 {
 176         krb5_error_code ret = 0;
 177         krb5_kt_cursor cursor;
 178         krb5_keytab_entry kt_entry;
 179         krb5_principal princ = NULL;
 180         int i;
 181         char *ktprinc = NULL;
 182
 183         ZERO_STRUCT(kt_entry);
 184         ZERO_STRUCT(cursor);
 185
 186         ret = smb_krb5_parse_name(context, princ_s, &princ);
 187         if (ret) {
 188                 DEBUG(1,("smb_krb5_kt_add_entry: smb_krb5_parse_name(%s) failed (%s)\n", princ_s, error_message(ret)));
 189                 goto out;
 190         }
 191
 192         /* Seek and delete old keytab entries */
 193         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 194         if (ret != KRB5_KT_END && ret != ENOENT ) {
 195                 DEBUG(3,("smb_krb5_kt_add_entry: Will try to delete old keytab entries\n"));
 196                 while(!krb5_kt_next_entry(context, keytab, &kt_entry, &cursor)) {
 197                         BOOL compare_name_ok = False;
 198
 199                         ret = smb_krb5_unparse_name(context, kt_entry.principal, &ktprinc);
 200                         if (ret) {
 201                                 DEBUG(1,("smb_krb5_kt_add_entry: smb_krb5_unparse_name failed (%s)\n",
 202                                         error_message(ret)));
 203                                 goto out;
 204                         }
 205
 206                         /*---------------------------------------------------------------------------
 207                          * Save the entries with kvno - 1.   This is what microsoft does
 208                          * to allow people with existing sessions that have kvno - 1 to still
 209                          * work.   Otherwise, when the password for the machine changes, all
 210                          * kerberizied sessions will 'break' until either the client reboots or
 211                          * the client's session key expires and they get a new session ticket
 212                          * with the new kvno.
 213                          */
 214
 215 #ifdef HAVE_KRB5_KT_COMPARE
 216                         compare_name_ok = (krb5_kt_compare(context, &kt_entry, princ, 0, 0) == True);
 217 #else
 218                         compare_name_ok = (strcmp(ktprinc, princ_s) == 0);
 219 #endif
 220
 221                         if (!compare_name_ok) {
 222                                 DEBUG(10,("smb_krb5_kt_add_entry: ignoring keytab entry principal %s, kvno = %d\n",
 223                                         ktprinc, kt_entry.vno));
 224                         }
 225
 226                         SAFE_FREE(ktprinc);
 227
 228                         if (compare_name_ok) {
 229                                 if (kt_entry.vno == kvno - 1) {
 230                                         DEBUG(5,("smb_krb5_kt_add_entry: Saving previous (kvno %d) entry for principal: %s.\n",
 231                                                 kvno - 1, princ_s));
 232                                 } else {
 233
 234                                         DEBUG(5,("smb_krb5_kt_add_entry: Found old entry for principal: %s (kvno %d) - trying to remove it.\n",
 235                                                 princ_s, kt_entry.vno));
 236                                         ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 237                                         ZERO_STRUCT(cursor);
 238                                         if (ret) {
 239                                                 DEBUG(1,("smb_krb5_kt_add_entry: krb5_kt_end_seq_get() failed (%s)\n",
 240                                                         error_message(ret)));
 241                                                 goto out;
 242                                         }
 243                                         ret = krb5_kt_remove_entry(context, keytab, &kt_entry);
 244                                         if (ret) {
 245                                                 DEBUG(1,("smb_krb5_kt_add_entry: krb5_kt_remove_entry failed (%s)\n",
 246                                                         error_message(ret)));
 247                                                 goto out;
 248                                         }
 249
 250                                         DEBUG(5,("smb_krb5_kt_add_entry: removed old entry for principal: %s (kvno %d).\n",
 251                                                 princ_s, kt_entry.vno));
 252
 253                                         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 254                                         if (ret) {
 255                                                 DEBUG(1,("smb_krb5_kt_add_entry: krb5_kt_start_seq failed (%s)\n",
 256                                                         error_message(ret)));
 257                                                 goto out;
 258                                         }
 259                                         ret = smb_krb5_kt_free_entry(context, &kt_entry);
 260                                         ZERO_STRUCT(kt_entry);
 261                                         if (ret) {
 262                                                 DEBUG(1,("smb_krb5_kt_add_entry: krb5_kt_remove_entry failed (%s)\n",
 263                                                         error_message(ret)));
 264                                                 goto out;
 265                                         }
 266                                         continue;
 267                                 }
 268                         }
 269
 270                         /* Not a match, just free this entry and continue. */
 271                         ret = smb_krb5_kt_free_entry(context, &kt_entry);
 272                         ZERO_STRUCT(kt_entry);
 273                         if (ret) {
 274                                 DEBUG(1,("smb_krb5_kt_add_entry: smb_krb5_kt_free_entry failed (%s)\n", error_message(ret)));
 275                                 goto out;
 276                         }
 277                 }
 278
 279                 ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 280                 ZERO_STRUCT(cursor);
 281                 if (ret) {
 282                         DEBUG(1,("smb_krb5_kt_add_entry: krb5_kt_end_seq_get failed (%s)\n",error_message(ret)));
 283                         goto out;
 284                 }
 285         }
 286
 287         /* Ensure we don't double free. */
 288         ZERO_STRUCT(kt_entry);
 289         ZERO_STRUCT(cursor);
 290
 291         /* If we get here, we have deleted all the old entries with kvno's not equal to the current kvno-1. */
 292
 293         /* Now add keytab entries for all encryption types */
 294         for (i = 0; enctypes[i]; i++) {
 295                 krb5_keyblock *keyp;
 296
 297 #if !defined(HAVE_KRB5_KEYTAB_ENTRY_KEY) && !defined(HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK)
 298 #error krb5_keytab_entry has no key or keyblock member
 299 #endif
 300 #ifdef HAVE_KRB5_KEYTAB_ENTRY_KEY               /* MIT */
 301                 keyp = &kt_entry.key;
 302 #endif
 303 #ifdef HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK          /* Heimdal */
 304                 keyp = &kt_entry.keyblock;
 305 #endif
 306                 if (create_kerberos_key_from_string(context, princ, &password, keyp, enctypes[i])) {
 307                         continue;
 308                 }
 309
 310                 kt_entry.principal = princ;
 311                 kt_entry.vno       = kvno;
 312
 313                 DEBUG(3,("smb_krb5_kt_add_entry: adding keytab entry for (%s) with encryption type (%d) and version (%d)\n",
 314                         princ_s, enctypes[i], kt_entry.vno));
 315                 ret = krb5_kt_add_entry(context, keytab, &kt_entry);
 316                 krb5_free_keyblock_contents(context, keyp);
 317                 ZERO_STRUCT(kt_entry);
 318                 if (ret) {
 319                         DEBUG(1,("smb_krb5_kt_add_entry: adding entry to keytab failed (%s)\n", error_message(ret)));
 320                         goto out;
 321                 }
 322         }
 323
 324
 325 out:
 326         {
 327                 krb5_keytab_entry zero_kt_entry;
 328                 ZERO_STRUCT(zero_kt_entry);
 329                 if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
 330                         smb_krb5_kt_free_entry(context, &kt_entry);
 331                 }
 332         }
 333         if (princ) {
 334                 krb5_free_principal(context, princ);
 335         }
 336
 337         {
 338                 krb5_kt_cursor zero_csr;
 339                 ZERO_STRUCT(zero_csr);
 340                 if ((memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
 341                         krb5_kt_end_seq_get(context, keytab, &cursor);
 342                 }
 343         }
 344
 345         return (int)ret;
 346 }
 347
 348
 349 /**********************************************************************
 350  Adds a single service principal, i.e. 'host' to the system keytab
 351 ***********************************************************************/
 352
 353 int ads_keytab_add_entry(ADS_STRUCT *ads, const char *srvPrinc)
 354 {
 355         krb5_error_code ret = 0;
 356         krb5_context context = NULL;
 357         krb5_keytab keytab = NULL;
 358         krb5_data password;
 359         krb5_kvno kvno;
 360         krb5_enctype enctypes[4] = { ENCTYPE_DES_CBC_CRC, ENCTYPE_DES_CBC_MD5, 0, 0 };
 361         char *princ_s = NULL, *short_princ_s = NULL;
 362         char *password_s = NULL;
 363         char *my_fqdn;
 364         TALLOC_CTX *ctx = NULL;
 365         char *machine_name;
 366
 367 #if defined(ENCTYPE_ARCFOUR_HMAC)
 368         enctypes[2] = ENCTYPE_ARCFOUR_HMAC;
 369 #endif
 370
 371         initialize_krb5_error_table();
 372         ret = krb5_init_context(&context);
 373         if (ret) {
 374                 DEBUG(1,("ads_keytab_add_entry: could not krb5_init_context: %s\n",error_message(ret)));
 375                 return -1;
 376         }
 377
 378         ret = smb_krb5_open_keytab(context, NULL, True, &keytab);
 379         if (ret) {
 380                 DEBUG(1,("ads_keytab_add_entry: smb_krb5_open_keytab failed (%s)\n", error_message(ret)));
 381                 goto out;
 382         }
 383
 384         /* retrieve the password */
 385         if (!secrets_init()) {
 386                 DEBUG(1,("ads_keytab_add_entry: secrets_init failed\n"));
 387                 ret = -1;
 388                 goto out;
 389         }
 390         password_s = secrets_fetch_machine_password(lp_workgroup(), NULL, NULL);
 391         if (!password_s) {
 392                 DEBUG(1,("ads_keytab_add_entry: failed to fetch machine password\n"));
 393                 ret = -1;
 394                 goto out;
 395         }
 396         password.data = password_s;
 397         password.length = strlen(password_s);
 398
 399         /* we need the dNSHostName value here */
 400
 401         if ( (ctx = talloc_init("ads_keytab_add_entry")) == NULL ) {
 402                 DEBUG(0,("ads_keytab_add_entry: talloc() failed!\n"));
 403                 ret = -1;
 404                 goto out;
 405         }
 406
 407         if ( (my_fqdn = ads_get_dnshostname( ads, ctx, global_myname())) == NULL ) {
 408                 DEBUG(0,("ads_keytab_add_entry: unable to determine machine account's dns name in AD!\n"));
 409                 ret = -1;
 410                 goto out;
 411         }
 412
 413         if ( (machine_name = ads_get_samaccountname( ads, ctx, global_myname())) == NULL ) {
 414                 DEBUG(0,("ads_keytab_add_entry: unable to determine machine account's short name in AD!\n"));
 415                 ret = -1;
 416                 goto out;
 417         }
 418         /*strip the trailing '$' */
 419         machine_name[strlen(machine_name)-1] = '\0';
 420
 421         /* Construct our principal */
 422
 423         if (strchr_m(srvPrinc, '@')) {
 424                 /* It's a fully-named principal. */
 425                 asprintf(&princ_s, "%s", srvPrinc);
 426         } else if (srvPrinc[strlen(srvPrinc)-1] == '$') {
 427                 /* It's the machine account, as used by smbclient clients. */
 428                 asprintf(&princ_s, "%s@%s", srvPrinc, lp_realm());
 429         } else {
 430                 /* It's a normal service principal.  Add the SPN now so that we
 431                  * can obtain credentials for it and double-check the salt value
 432                  * used to generate the service's keys. */
 433
 434                 asprintf(&princ_s, "%s/%s@%s", srvPrinc, my_fqdn, lp_realm());
 435                 asprintf(&short_princ_s, "%s/%s@%s", srvPrinc, machine_name, lp_realm());
 436
 437                 /* According to http://support.microsoft.com/kb/326985/en-us,
 438                    certain principal names are automatically mapped to the host/...
 439                    principal in the AD account.  So only create these in the
 440                    keytab, not in AD.  --jerry */
 441
 442                 if ( !strequal( srvPrinc, "cifs" ) && !strequal(srvPrinc, "host" ) ) {
 443                         DEBUG(3,("ads_keytab_add_entry: Attempting to add/update '%s'\n", princ_s));
 444
 445                         if (!ADS_ERR_OK(ads_add_service_principal_name(ads, global_myname(), my_fqdn, srvPrinc))) {
 446                                 DEBUG(1,("ads_keytab_add_entry: ads_add_service_principal_name failed.\n"));
 447                                 goto out;
 448                         }
 449                 }
 450         }
 451
 452         kvno = (krb5_kvno) ads_get_kvno(ads, global_myname());
 453         if (kvno == -1) {       /* -1 indicates failure, everything else is OK */
 454                 DEBUG(1,("ads_keytab_add_entry: ads_get_kvno failed to determine the system's kvno.\n"));
 455                 ret = -1;
 456                 goto out;
 457         }
 458
 459         /* add the fqdn principal to the keytab */
 460
 461         ret = smb_krb5_kt_add_entry( context, keytab, kvno, princ_s, enctypes, password );
 462         if ( ret ) {
 463                 DEBUG(1,("ads_keytab_add_entry: Failed to add entry to keytab file\n"));
 464                 goto out;
 465         }
 466
 467         /* add the short principal name if we have one */
 468
 469         if ( short_princ_s ) {
 470                 ret = smb_krb5_kt_add_entry( context, keytab, kvno, short_princ_s, enctypes, password );
 471                 if ( ret ) {
 472                         DEBUG(1,("ads_keytab_add_entry: Failed to add short entry to keytab file\n"));
 473                         goto out;
 474                 }
 475         }
 476
 477 out:
 478         SAFE_FREE( princ_s );
 479         SAFE_FREE( short_princ_s );
 480         TALLOC_FREE( ctx );
 481
 482         if (keytab) {
 483                 krb5_kt_close(context, keytab);
 484         }
 485         if (context) {
 486                 krb5_free_context(context);
 487         }
 488         return (int)ret;
 489 }
 490
 491 /**********************************************************************
 492  Flushes all entries from the system keytab.
 493 ***********************************************************************/
 494
 495 int ads_keytab_flush(ADS_STRUCT *ads)
 496 {
 497         krb5_error_code ret = 0;
 498         krb5_context context = NULL;
 499         krb5_keytab keytab = NULL;
 500         krb5_kt_cursor cursor;
 501         krb5_keytab_entry kt_entry;
 502         krb5_kvno kvno;
 503
 504         ZERO_STRUCT(kt_entry);
 505         ZERO_STRUCT(cursor);
 506
 507         initialize_krb5_error_table();
 508         ret = krb5_init_context(&context);
 509         if (ret) {
 510                 DEBUG(1,("ads_keytab_flush: could not krb5_init_context: %s\n",error_message(ret)));
 511                 return ret;
 512         }
 513
 514         ret = smb_krb5_open_keytab(context, NULL, True, &keytab);
 515         if (ret) {
 516                 DEBUG(1,("ads_keytab_flush: smb_krb5_open_keytab failed (%s)\n", error_message(ret)));
 517                 goto out;
 518         }
 519
 520         kvno = (krb5_kvno) ads_get_kvno(ads, global_myname());
 521         if (kvno == -1) {       /* -1 indicates a failure */
 522                 DEBUG(1,("ads_keytab_flush: Error determining the system's kvno.\n"));
 523                 goto out;
 524         }
 525
 526         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 527         if (ret != KRB5_KT_END && ret != ENOENT) {
 528                 while (!krb5_kt_next_entry(context, keytab, &kt_entry, &cursor)) {
 529                         ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 530                         ZERO_STRUCT(cursor);
 531                         if (ret) {
 532                                 DEBUG(1,("ads_keytab_flush: krb5_kt_end_seq_get() failed (%s)\n",error_message(ret)));
 533                                 goto out;
 534                         }
 535                         ret = krb5_kt_remove_entry(context, keytab, &kt_entry);
 536                         if (ret) {
 537                                 DEBUG(1,("ads_keytab_flush: krb5_kt_remove_entry failed (%s)\n",error_message(ret)));
 538                                 goto out;
 539                         }
 540                         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 541                         if (ret) {
 542                                 DEBUG(1,("ads_keytab_flush: krb5_kt_start_seq failed (%s)\n",error_message(ret)));
 543                                 goto out;
 544                         }
 545                         ret = smb_krb5_kt_free_entry(context, &kt_entry);
 546                         ZERO_STRUCT(kt_entry);
 547                         if (ret) {
 548                                 DEBUG(1,("ads_keytab_flush: krb5_kt_remove_entry failed (%s)\n",error_message(ret)));
 549                                 goto out;
 550                         }
 551                 }
 552         }
 553
 554         /* Ensure we don't double free. */
 555         ZERO_STRUCT(kt_entry);
 556         ZERO_STRUCT(cursor);
 557
 558         if (!ADS_ERR_OK(ads_clear_service_principal_names(ads, global_myname()))) {
 559                 DEBUG(1,("ads_keytab_flush: Error while clearing service principal listings in LDAP.\n"));
 560                 goto out;
 561         }
 562
 563 out:
 564
 565         {
 566                 krb5_keytab_entry zero_kt_entry;
 567                 ZERO_STRUCT(zero_kt_entry);
 568                 if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
 569                         smb_krb5_kt_free_entry(context, &kt_entry);
 570                 }
 571         }
 572         {
 573                 krb5_kt_cursor zero_csr;
 574                 ZERO_STRUCT(zero_csr);
 575                 if ((memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
 576                         krb5_kt_end_seq_get(context, keytab, &cursor);
 577                 }
 578         }
 579         if (keytab) {
 580                 krb5_kt_close(context, keytab);
 581         }
 582         if (context) {
 583                 krb5_free_context(context);
 584         }
 585         return ret;
 586 }
 587
 588 /**********************************************************************
 589  Adds all the required service principals to the system keytab.
 590 ***********************************************************************/
 591
 592 int ads_keytab_create_default(ADS_STRUCT *ads)
 593 {
 594         krb5_error_code ret = 0;
 595         krb5_context context = NULL;
 596         krb5_keytab keytab = NULL;
 597         krb5_kt_cursor cursor;
 598         krb5_keytab_entry kt_entry;
 599         krb5_kvno kvno;
 600         int i, found = 0;
 601         char *sam_account_name, *upn;
 602         char **oldEntries = NULL, *princ_s[26];
 603         TALLOC_CTX *ctx = NULL;
 604         fstring machine_name;
 605
 606         memset(princ_s, '\0', sizeof(princ_s));
 607
 608         fstrcpy( machine_name, global_myname() );
 609
 610         /* these are the main ones we need */
 611
 612         if ( (ret = ads_keytab_add_entry(ads, "host") ) != 0 ) {
 613                 DEBUG(1,("ads_keytab_create_default: ads_keytab_add_entry failed while adding 'host'.\n"));
 614                 return ret;
 615         }
 616
 617
 618 #if 0   /* don't create the CIFS/... keytab entries since no one except smbd
 619            really needs them and we will fall back to verifying against secrets.tdb */
 620
 621         if ( (ret = ads_keytab_add_entry(ads, "cifs")) != 0 ) {
 622                 DEBUG(1,("ads_keytab_create_default: ads_keytab_add_entry failed while adding 'cifs'.\n"));
 623                 return ret;
 624         }
 625 #endif
 626
 627         if ( (ctx = talloc_init("ads_keytab_create_default")) == NULL ) {
 628                 DEBUG(0,("ads_keytab_create_default: talloc() failed!\n"));
 629                 return -1;
 630         }
 631
 632         /* now add the userPrincipalName and sAMAccountName entries */
 633
 634         if ( (sam_account_name = ads_get_samaccountname( ads, ctx, machine_name)) == NULL ) {
 635                 DEBUG(0,("ads_keytab_add_entry: unable to determine machine account's name in AD!\n"));
 636                 TALLOC_FREE( ctx );
 637                 return -1;
 638         }
 639
 640         /* upper case the sAMAccountName to make it easier for apps to
 641            know what case to use in the keytab file */
 642
 643         strupper_m( sam_account_name );
 644
 645         if ( (ret = ads_keytab_add_entry(ads, sam_account_name )) != 0 ) {
 646                 DEBUG(1,("ads_keytab_create_default: ads_keytab_add_entry failed while adding sAMAccountName (%s)\n",
 647                         sam_account_name));
 648                 return ret;
 649         }
 650
 651         /* remember that not every machine account will have a upn */
 652
 653         upn = ads_get_upn( ads, ctx, machine_name);
 654         if ( upn ) {
 655                 if ( (ret = ads_keytab_add_entry(ads, upn)) != 0 ) {
 656                         DEBUG(1,("ads_keytab_create_default: ads_keytab_add_entry failed while adding UPN (%s)\n",
 657                                 upn));
 658                         TALLOC_FREE( ctx );
 659                         return ret;
 660                 }
 661         }
 662
 663         TALLOC_FREE( ctx );
 664
 665         /* Now loop through the keytab and update any other existing entries... */
 666
 667         kvno = (krb5_kvno) ads_get_kvno(ads, machine_name);
 668         if (kvno == -1) {
 669                 DEBUG(1,("ads_keytab_create_default: ads_get_kvno failed to determine the system's kvno.\n"));
 670                 return -1;
 671         }
 672
 673         DEBUG(3,("ads_keytab_create_default: Searching for keytab entries to "
 674                 "preserve and update.\n"));
 675
 676         ZERO_STRUCT(kt_entry);
 677         ZERO_STRUCT(cursor);
 678
 679         initialize_krb5_error_table();
 680         ret = krb5_init_context(&context);
 681         if (ret) {
 682                 DEBUG(1,("ads_keytab_create_default: could not krb5_init_context: %s\n",error_message(ret)));
 683                 return ret;
 684         }
 685         ret = krb5_kt_default(context, &keytab);
 686         if (ret) {
 687                 DEBUG(1,("ads_keytab_create_default: krb5_kt_default failed (%s)\n",error_message(ret)));
 688                 goto done;
 689         }
 690
 691         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 692         if (ret != KRB5_KT_END && ret != ENOENT ) {
 693                 while ((ret = krb5_kt_next_entry(context, keytab, &kt_entry, &cursor)) == 0) {
 694                         smb_krb5_kt_free_entry(context, &kt_entry);
 695                         ZERO_STRUCT(kt_entry);
 696                         found++;
 697                 }
 698         }
 699         krb5_kt_end_seq_get(context, keytab, &cursor);
 700         ZERO_STRUCT(cursor);
 701
 702         /*
 703          * Hmmm. There is no "rewind" function for the keytab. This means we have a race condition
 704          * where someone else could add entries after we've counted them. Re-open asap to minimise
 705          * the race. JRA.
 706          */
 707
 708         DEBUG(3, ("ads_keytab_create_default: Found %d entries in the keytab.\n", found));
 709         if (!found) {
 710                 goto done;
 711         }
 712         oldEntries = SMB_MALLOC_ARRAY(char *, found );
 713         if (!oldEntries) {
 714                 DEBUG(1,("ads_keytab_create_default: Failed to allocate space to store the old keytab entries (malloc failed?).\n"));
 715                 ret = -1;
 716                 goto done;
 717         }
 718         memset(oldEntries, '\0', found * sizeof(char *));
 719
 720         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 721         if (ret != KRB5_KT_END && ret != ENOENT ) {
 722                 while (krb5_kt_next_entry(context, keytab, &kt_entry, &cursor) == 0) {
 723                         if (kt_entry.vno != kvno) {
 724                                 char *ktprinc = NULL;
 725                                 char *p;
 726
 727                                 /* This returns a malloc'ed string in ktprinc. */
 728                                 ret = smb_krb5_unparse_name(context, kt_entry.principal, &ktprinc);
 729                                 if (ret) {
 730                                         DEBUG(1,("smb_krb5_unparse_name failed (%s)\n", error_message(ret)));
 731                                         goto done;
 732                                 }
 733                                 /*
 734                                  * From looking at the krb5 source they don't seem to take locale
 735                                  * or mb strings into account. Maybe this is because they assume utf8 ?
 736                                  * In this case we may need to convert from utf8 to mb charset here ? JRA.
 737                                  */
 738                                 p = strchr_m(ktprinc, '@');
 739                                 if (p) {
 740                                         *p = '\0';
 741                                 }
 742
 743                                 p = strchr_m(ktprinc, '/');
 744                                 if (p) {
 745                                         *p = '\0';
 746                                 }
 747                                 for (i = 0; i < found; i++) {
 748                                         if (!oldEntries[i]) {
 749                                                 oldEntries[i] = ktprinc;
 750                                                 break;
 751                                         }
 752                                         if (!strcmp(oldEntries[i], ktprinc)) {
 753                                                 SAFE_FREE(ktprinc);
 754                                                 break;
 755                                         }
 756                                 }
 757                                 if (i == found) {
 758                                         SAFE_FREE(ktprinc);
 759                                 }
 760                         }
 761                         smb_krb5_kt_free_entry(context, &kt_entry);
 762                         ZERO_STRUCT(kt_entry);
 763                 }
 764                 ret = 0;
 765                 for (i = 0; oldEntries[i]; i++) {
 766                         ret |= ads_keytab_add_entry(ads, oldEntries[i]);
 767                         SAFE_FREE(oldEntries[i]);
 768                 }
 769                 krb5_kt_end_seq_get(context, keytab, &cursor);
 770         }
 771         ZERO_STRUCT(cursor);
 772
 773 done:
 774
 775         SAFE_FREE(oldEntries);
 776
 777         {
 778                 krb5_keytab_entry zero_kt_entry;
 779                 ZERO_STRUCT(zero_kt_entry);
 780                 if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
 781                         smb_krb5_kt_free_entry(context, &kt_entry);
 782                 }
 783         }
 784         {
 785                 krb5_kt_cursor zero_csr;
 786                 ZERO_STRUCT(zero_csr);
 787                 if ((memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
 788                         krb5_kt_end_seq_get(context, keytab, &cursor);
 789                 }
 790         }
 791         if (keytab) {
 792                 krb5_kt_close(context, keytab);
 793         }
 794         if (context) {
 795                 krb5_free_context(context);
 796         }
 797         return ret;
 798 }
 799
 800 /**********************************************************************
 801  List system keytab.
 802 ***********************************************************************/
 803
 804 int ads_keytab_list(void)
 805 {
 806         krb5_error_code ret = 0;
 807         krb5_context context = NULL;
 808         krb5_keytab keytab = NULL;
 809         krb5_kt_cursor cursor;
 810         krb5_keytab_entry kt_entry;
 811
 812         ZERO_STRUCT(kt_entry);
 813         ZERO_STRUCT(cursor);
 814
 815         initialize_krb5_error_table();
 816         ret = krb5_init_context(&context);
 817         if (ret) {
 818                 DEBUG(1,("ads_keytab_list: could not krb5_init_context: %s\n",error_message(ret)));
 819                 return ret;
 820         }
 821
 822         ret = smb_krb5_open_keytab(context, NULL, False, &keytab);
 823         if (ret) {
 824                 DEBUG(1,("ads_keytab_list: smb_krb5_open_keytab failed (%s)\n", error_message(ret)));
 825                 goto out;
 826         }
 827
 828         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
 829         if (ret) {
 830                 goto out;
 831         }
 832
 833         printf("Vno  Type        Principal\n");
 834
 835         while (krb5_kt_next_entry(context, keytab, &kt_entry, &cursor) == 0) {
 836
 837                 char *princ_s = NULL;
 838                 char *etype_s = NULL;
 839                 krb5_enctype enctype = 0;
 840
 841                 ret = smb_krb5_unparse_name(context, kt_entry.principal, &princ_s);
 842                 if (ret) {
 843                         goto out;
 844                 }
 845
 846                 enctype = smb_get_enctype_from_kt_entry(&kt_entry);
 847
 848                 ret = smb_krb5_enctype_to_string(context, enctype, &etype_s);
 849                 if (ret) {
 850                         SAFE_FREE(princ_s);
 851                         goto out;
 852                 }
 853
 854                 printf("%3d  %s\t\t %s\n", kt_entry.vno, etype_s, princ_s);
 855
 856                 SAFE_FREE(princ_s);
 857                 SAFE_FREE(etype_s);
 858
 859                 ret = smb_krb5_kt_free_entry(context, &kt_entry);
 860                 if (ret) {
 861                         goto out;
 862                 }
 863         }
 864
 865         ret = krb5_kt_end_seq_get(context, keytab, &cursor);
 866         if (ret) {
 867                 goto out;
 868         }
 869
 870         /* Ensure we don't double free. */
 871         ZERO_STRUCT(kt_entry);
 872         ZERO_STRUCT(cursor);
 873 out:
 874
 875         {
 876                 krb5_keytab_entry zero_kt_entry;
 877                 ZERO_STRUCT(zero_kt_entry);
 878                 if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
 879                         smb_krb5_kt_free_entry(context, &kt_entry);
 880                 }
 881         }
 882         {
 883                 krb5_kt_cursor zero_csr;
 884                 ZERO_STRUCT(zero_csr);
 885                 if ((memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
 886                         krb5_kt_end_seq_get(context, keytab, &cursor);
 887                 }
 888         }
 889
 890         if (keytab) {
 891                 krb5_kt_close(context, keytab);
 892         }
 893         if (context) {
 894                 krb5_free_context(context);
 895         }
 896         return ret;
 897 }
 898
 899 #endif /* HAVE_KRB5 */