source3/libads/kerberos.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    kerberos utility library
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Remus Koos 2001
   6    Copyright (C) Nalin Dahyabhai <nalin@redhat.com> 2004.
   7    Copyright (C) Jeremy Allison 2004.
   8    Copyright (C) Gerald Carter 2006.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "smb_krb5.h"
  26
  27 #ifdef HAVE_KRB5
  28
  29 #define DEFAULT_KRB5_PORT 88
  30
  31 #define LIBADS_CCACHE_NAME "MEMORY:libads"
  32
  33 /*
  34   we use a prompter to avoid a crash bug in the kerberos libs when
  35   dealing with empty passwords
  36   this prompter is just a string copy ...
  37 */
  38 static krb5_error_code
  39 kerb_prompter(krb5_context ctx, void *data,
  40                const char *name,
  41                const char *banner,
  42                int num_prompts,
  43                krb5_prompt prompts[])
  44 {
  45         if (num_prompts == 0) return 0;
  46
  47         memset(prompts[0].reply->data, '\0', prompts[0].reply->length);
  48         if (prompts[0].reply->length > 0) {
  49                 if (data) {
  50                         strncpy((char *)prompts[0].reply->data, (const char *)data,
  51                                 prompts[0].reply->length-1);
  52                         prompts[0].reply->length = strlen((const char *)prompts[0].reply->data);
  53                 } else {
  54                         prompts[0].reply->length = 0;
  55                 }
  56         }
  57         return 0;
  58 }
  59
  60  static bool smb_krb5_get_ntstatus_from_krb5_error(krb5_error *error,
  61                                                    NTSTATUS *nt_status)
  62 {
  63         DATA_BLOB edata;
  64         DATA_BLOB unwrapped_edata;
  65         TALLOC_CTX *mem_ctx;
  66         struct KRB5_EDATA_NTSTATUS parsed_edata;
  67         enum ndr_err_code ndr_err;
  68
  69 #ifdef HAVE_E_DATA_POINTER_IN_KRB5_ERROR
  70         edata = data_blob(error->e_data->data, error->e_data->length);
  71 #else
  72         edata = data_blob(error->e_data.data, error->e_data.length);
  73 #endif /* HAVE_E_DATA_POINTER_IN_KRB5_ERROR */
  74
  75 #ifdef DEVELOPER
  76         dump_data(10, edata.data, edata.length);
  77 #endif /* DEVELOPER */
  78
  79         mem_ctx = talloc_init("smb_krb5_get_ntstatus_from_krb5_error");
  80         if (mem_ctx == NULL) {
  81                 data_blob_free(&edata);
  82                 return False;
  83         }
  84
  85         if (!unwrap_edata_ntstatus(mem_ctx, &edata, &unwrapped_edata)) {
  86                 data_blob_free(&edata);
  87                 TALLOC_FREE(mem_ctx);
  88                 return False;
  89         }
  90
  91         data_blob_free(&edata);
  92
  93         ndr_err = ndr_pull_struct_blob_all(&unwrapped_edata, mem_ctx, NULL,
  94                         &parsed_edata,
  95                         (ndr_pull_flags_fn_t)ndr_pull_KRB5_EDATA_NTSTATUS);
  96         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  97                 data_blob_free(&unwrapped_edata);
  98                 TALLOC_FREE(mem_ctx);
  99                 return False;
 100         }
 101
 102         data_blob_free(&unwrapped_edata);
 103
 104         if (nt_status) {
 105                 *nt_status = parsed_edata.ntstatus;
 106         }
 107
 108         TALLOC_FREE(mem_ctx);
 109
 110         return True;
 111 }
 112
 113  static bool smb_krb5_get_ntstatus_from_krb5_error_init_creds_opt(krb5_context ctx,
 114                                                                   krb5_get_init_creds_opt *opt,
 115                                                                   NTSTATUS *nt_status)
 116 {
 117         bool ret = False;
 118         krb5_error *error = NULL;
 119
 120 #ifdef HAVE_KRB5_GET_INIT_CREDS_OPT_GET_ERROR
 121         ret = krb5_get_init_creds_opt_get_error(ctx, opt, &error);
 122         if (ret) {
 123                 DEBUG(1,("krb5_get_init_creds_opt_get_error gave: %s\n",
 124                         error_message(ret)));
 125                 return False;
 126         }
 127 #endif /* HAVE_KRB5_GET_INIT_CREDS_OPT_GET_ERROR */
 128
 129         if (!error) {
 130                 DEBUG(1,("no krb5_error\n"));
 131                 return False;
 132         }
 133
 134 #ifdef HAVE_E_DATA_POINTER_IN_KRB5_ERROR
 135         if (!error->e_data) {
 136 #else
 137         if (error->e_data.data == NULL) {
 138 #endif /* HAVE_E_DATA_POINTER_IN_KRB5_ERROR */
 139                 DEBUG(1,("no edata in krb5_error\n"));
 140                 krb5_free_error(ctx, error);
 141                 return False;
 142         }
 143
 144         ret = smb_krb5_get_ntstatus_from_krb5_error(error, nt_status);
 145
 146         krb5_free_error(ctx, error);
 147
 148         return ret;
 149 }
 150
 151 /*
 152   simulate a kinit, putting the tgt in the given cache location. If cache_name == NULL
 153   place in default cache location.
 154   remus@snapserver.com
 155 */
 156 int kerberos_kinit_password_ext(const char *principal,
 157                                 const char *password,
 158                                 int time_offset,
 159                                 time_t *expire_time,
 160                                 time_t *renew_till_time,
 161                                 const char *cache_name,
 162                                 bool request_pac,
 163                                 bool add_netbios_addr,
 164                                 time_t renewable_time,
 165                                 NTSTATUS *ntstatus)
 166 {
 167         krb5_context ctx = NULL;
 168         krb5_error_code code = 0;
 169         krb5_ccache cc = NULL;
 170         krb5_principal me = NULL;
 171         krb5_creds my_creds;
 172         krb5_get_init_creds_opt *opt = NULL;
 173         smb_krb5_addresses *addr = NULL;
 174
 175         ZERO_STRUCT(my_creds);
 176
 177         initialize_krb5_error_table();
 178         if ((code = krb5_init_context(&ctx)))
 179                 goto out;
 180
 181         if (time_offset != 0) {
 182                 krb5_set_real_time(ctx, time(NULL) + time_offset, 0);
 183         }
 184
 185         DEBUG(10,("kerberos_kinit_password: as %s using [%s] as ccache and config [%s]\n",
 186                         principal,
 187                         cache_name ? cache_name: krb5_cc_default_name(ctx),
 188                         getenv("KRB5_CONFIG")));
 189
 190         if ((code = krb5_cc_resolve(ctx, cache_name ? cache_name : krb5_cc_default_name(ctx), &cc))) {
 191                 goto out;
 192         }
 193
 194         if ((code = smb_krb5_parse_name(ctx, principal, &me))) {
 195                 goto out;
 196         }
 197
 198         if ((code = smb_krb5_get_init_creds_opt_alloc(ctx, &opt))) {
 199                 goto out;
 200         }
 201
 202         krb5_get_init_creds_opt_set_renew_life(opt, renewable_time);
 203         krb5_get_init_creds_opt_set_forwardable(opt, True);
 204 #if 0
 205         /* insane testing */
 206         krb5_get_init_creds_opt_set_tkt_life(opt, 60);
 207 #endif
 208
 209 #ifdef HAVE_KRB5_GET_INIT_CREDS_OPT_SET_PAC_REQUEST
 210         if (request_pac) {
 211                 if ((code = krb5_get_init_creds_opt_set_pac_request(ctx, opt, (krb5_boolean)request_pac))) {
 212                         goto out;
 213                 }
 214         }
 215 #endif
 216         if (add_netbios_addr) {
 217                 if ((code = smb_krb5_gen_netbios_krb5_address(&addr))) {
 218                         goto out;
 219                 }
 220                 krb5_get_init_creds_opt_set_address_list(opt, addr->addrs);
 221         }
 222
 223         if ((code = krb5_get_init_creds_password(ctx, &my_creds, me, CONST_DISCARD(char *,password),
 224                                                  kerb_prompter, CONST_DISCARD(char *,password),
 225                                                  0, NULL, opt))) {
 226                 goto out;
 227         }
 228
 229         if ((code = krb5_cc_initialize(ctx, cc, me))) {
 230                 goto out;
 231         }
 232
 233         if ((code = krb5_cc_store_cred(ctx, cc, &my_creds))) {
 234                 goto out;
 235         }
 236
 237         if (expire_time) {
 238                 *expire_time = (time_t) my_creds.times.endtime;
 239         }
 240
 241         if (renew_till_time) {
 242                 *renew_till_time = (time_t) my_creds.times.renew_till;
 243         }
 244  out:
 245         if (ntstatus) {
 246
 247                 NTSTATUS status;
 248
 249                 /* fast path */
 250                 if (code == 0) {
 251                         *ntstatus = NT_STATUS_OK;
 252                         goto cleanup;
 253                 }
 254
 255                 /* try to get ntstatus code out of krb5_error when we have it
 256                  * inside the krb5_get_init_creds_opt - gd */
 257
 258                 if (opt && smb_krb5_get_ntstatus_from_krb5_error_init_creds_opt(ctx, opt, &status)) {
 259                         *ntstatus = status;
 260                         goto cleanup;
 261                 }
 262
 263                 /* fall back to self-made-mapping */
 264                 *ntstatus = krb5_to_nt_status(code);
 265         }
 266
 267  cleanup:
 268         krb5_free_cred_contents(ctx, &my_creds);
 269         if (me) {
 270                 krb5_free_principal(ctx, me);
 271         }
 272         if (addr) {
 273                 smb_krb5_free_addresses(ctx, addr);
 274         }
 275         if (opt) {
 276                 smb_krb5_get_init_creds_opt_free(ctx, opt);
 277         }
 278         if (cc) {
 279                 krb5_cc_close(ctx, cc);
 280         }
 281         if (ctx) {
 282                 krb5_free_context(ctx);
 283         }
 284         return code;
 285 }
 286
 287
 288
 289 /* run kinit to setup our ccache */
 290 int ads_kinit_password(ADS_STRUCT *ads)
 291 {
 292         char *s;
 293         int ret;
 294         const char *account_name;
 295         fstring acct_name;
 296
 297         if (ads->auth.flags & ADS_AUTH_USER_CREDS) {
 298                 account_name = ads->auth.user_name;
 299                 goto got_accountname;
 300         }
 301
 302         if ( IS_DC ) {
 303                 /* this will end up getting a ticket for DOMAIN@RUSTED.REA.LM */
 304                 account_name = lp_workgroup();
 305         } else {
 306                 /* always use the sAMAccountName for security = domain */
 307                 /* global_myname()$@REA.LM */
 308                 if ( lp_security() == SEC_DOMAIN ) {
 309                         fstr_sprintf( acct_name, "%s$", global_myname() );
 310                         account_name = acct_name;
 311                 }
 312                 else
 313                         /* This looks like host/global_myname()@REA.LM */
 314                         account_name = ads->auth.user_name;
 315         }
 316
 317  got_accountname:
 318         if (asprintf(&s, "%s@%s", account_name, ads->auth.realm) == -1) {
 319                 return KRB5_CC_NOMEM;
 320         }
 321
 322         if (!ads->auth.password) {
 323                 SAFE_FREE(s);
 324                 return KRB5_LIBOS_CANTREADPWD;
 325         }
 326
 327         ret = kerberos_kinit_password_ext(s, ads->auth.password, ads->auth.time_offset,
 328                         &ads->auth.tgt_expire, NULL, NULL, False, False, ads->auth.renewable,
 329                         NULL);
 330
 331         if (ret) {
 332                 DEBUG(0,("kerberos_kinit_password %s failed: %s\n",
 333                          s, error_message(ret)));
 334         }
 335         SAFE_FREE(s);
 336         return ret;
 337 }
 338
 339 int ads_kdestroy(const char *cc_name)
 340 {
 341         krb5_error_code code;
 342         krb5_context ctx = NULL;
 343         krb5_ccache cc = NULL;
 344
 345         initialize_krb5_error_table();
 346         if ((code = krb5_init_context (&ctx))) {
 347                 DEBUG(3, ("ads_kdestroy: kdb5_init_context failed: %s\n",
 348                         error_message(code)));
 349                 return code;
 350         }
 351
 352         if (!cc_name) {
 353                 if ((code = krb5_cc_default(ctx, &cc))) {
 354                         krb5_free_context(ctx);
 355                         return code;
 356                 }
 357         } else {
 358                 if ((code = krb5_cc_resolve(ctx, cc_name, &cc))) {
 359                         DEBUG(3, ("ads_kdestroy: krb5_cc_resolve failed: %s\n",
 360                                   error_message(code)));
 361                         krb5_free_context(ctx);
 362                         return code;
 363                 }
 364         }
 365
 366         if ((code = krb5_cc_destroy (ctx, cc))) {
 367                 DEBUG(3, ("ads_kdestroy: krb5_cc_destroy failed: %s\n",
 368                         error_message(code)));
 369         }
 370
 371         krb5_free_context (ctx);
 372         return code;
 373 }
 374
 375 /************************************************************************
 376  Routine to fetch the salting principal for a service.  Active
 377  Directory may use a non-obvious principal name to generate the salt
 378  when it determines the key to use for encrypting tickets for a service,
 379  and hopefully we detected that when we joined the domain.
 380  ************************************************************************/
 381
 382 static char *kerberos_secrets_fetch_salting_principal(const char *service, int enctype)
 383 {
 384         char *key = NULL;
 385         char *ret = NULL;
 386
 387         if (asprintf(&key, "%s/%s/enctype=%d",
 388                      SECRETS_SALTING_PRINCIPAL, service, enctype) == -1) {
 389                 return NULL;
 390         }
 391         ret = (char *)secrets_fetch(key, NULL);
 392         SAFE_FREE(key);
 393         return ret;
 394 }
 395
 396 /************************************************************************
 397  Return the standard DES salt key
 398 ************************************************************************/
 399
 400 char* kerberos_standard_des_salt( void )
 401 {
 402         fstring salt;
 403
 404         fstr_sprintf( salt, "host/%s.%s@", global_myname(), lp_realm() );
 405         strlower_m( salt );
 406         fstrcat( salt, lp_realm() );
 407
 408         return SMB_STRDUP( salt );
 409 }
 410
 411 /************************************************************************
 412 ************************************************************************/
 413
 414 static char* des_salt_key( void )
 415 {
 416         char *key;
 417
 418         if (asprintf(&key, "%s/DES/%s", SECRETS_SALTING_PRINCIPAL,
 419                      lp_realm()) == -1) {
 420                 return NULL;
 421         }
 422
 423         return key;
 424 }
 425
 426 /************************************************************************
 427 ************************************************************************/
 428
 429 bool kerberos_secrets_store_des_salt( const char* salt )
 430 {
 431         char* key;
 432         bool ret;
 433
 434         if ( (key = des_salt_key()) == NULL ) {
 435                 DEBUG(0,("kerberos_secrets_store_des_salt: failed to generate key!\n"));
 436                 return False;
 437         }
 438
 439         if ( !salt ) {
 440                 DEBUG(8,("kerberos_secrets_store_des_salt: deleting salt\n"));
 441                 secrets_delete( key );
 442                 return True;
 443         }
 444
 445         DEBUG(3,("kerberos_secrets_store_des_salt: Storing salt \"%s\"\n", salt));
 446
 447         ret = secrets_store( key, salt, strlen(salt)+1 );
 448
 449         SAFE_FREE( key );
 450
 451         return ret;
 452 }
 453
 454 /************************************************************************
 455 ************************************************************************/
 456
 457 char* kerberos_secrets_fetch_des_salt( void )
 458 {
 459         char *salt, *key;
 460
 461         if ( (key = des_salt_key()) == NULL ) {
 462                 DEBUG(0,("kerberos_secrets_fetch_des_salt: failed to generate key!\n"));
 463                 return False;
 464         }
 465
 466         salt = (char*)secrets_fetch( key, NULL );
 467
 468         SAFE_FREE( key );
 469
 470         return salt;
 471 }
 472
 473 /************************************************************************
 474  Routine to get the default realm from the kerberos credentials cache.
 475  Caller must free if the return value is not NULL.
 476 ************************************************************************/
 477
 478 char *kerberos_get_default_realm_from_ccache( void )
 479 {
 480         char *realm = NULL;
 481         krb5_context ctx = NULL;
 482         krb5_ccache cc = NULL;
 483         krb5_principal princ = NULL;
 484
 485         initialize_krb5_error_table();
 486         if (krb5_init_context(&ctx)) {
 487                 return NULL;
 488         }
 489
 490         DEBUG(5,("kerberos_get_default_realm_from_ccache: "
 491                 "Trying to read krb5 cache: %s\n",
 492                 krb5_cc_default_name(ctx)));
 493         if (krb5_cc_default(ctx, &cc)) {
 494                 DEBUG(0,("kerberos_get_default_realm_from_ccache: "
 495                         "failed to read default cache\n"));
 496                 goto out;
 497         }
 498         if (krb5_cc_get_principal(ctx, cc, &princ)) {
 499                 DEBUG(0,("kerberos_get_default_realm_from_ccache: "
 500                         "failed to get default principal\n"));
 501                 goto out;
 502         }
 503
 504 #if defined(HAVE_KRB5_PRINCIPAL_GET_REALM)
 505         realm = SMB_STRDUP(krb5_principal_get_realm(ctx, princ));
 506 #elif defined(HAVE_KRB5_PRINC_REALM)
 507         {
 508                 krb5_data *realm_data = krb5_princ_realm(ctx, princ);
 509                 realm = SMB_STRNDUP(realm_data->data, realm_data->length);
 510         }
 511 #endif
 512
 513   out:
 514
 515         if (ctx) {
 516                 if (princ) {
 517                         krb5_free_principal(ctx, princ);
 518                 }
 519                 if (cc) {
 520                         krb5_cc_close(ctx, cc);
 521                 }
 522                 krb5_free_context(ctx);
 523         }
 524
 525         return realm;
 526 }
 527
 528
 529 /************************************************************************
 530  Routine to get the salting principal for this service.  This is
 531  maintained for backwards compatibilty with releases prior to 3.0.24.
 532  Since we store the salting principal string only at join, we may have
 533  to look for the older tdb keys.  Caller must free if return is not null.
 534  ************************************************************************/
 535
 536 krb5_principal kerberos_fetch_salt_princ_for_host_princ(krb5_context context,
 537                                                         krb5_principal host_princ,
 538                                                         int enctype)
 539 {
 540         char *unparsed_name = NULL, *salt_princ_s = NULL;
 541         krb5_principal ret_princ = NULL;
 542
 543         /* lookup new key first */
 544
 545         if ( (salt_princ_s = kerberos_secrets_fetch_des_salt()) == NULL ) {
 546
 547                 /* look under the old key.  If this fails, just use the standard key */
 548
 549                 if (smb_krb5_unparse_name(talloc_tos(), context, host_princ, &unparsed_name) != 0) {
 550                         return (krb5_principal)NULL;
 551                 }
 552                 if ((salt_princ_s = kerberos_secrets_fetch_salting_principal(unparsed_name, enctype)) == NULL) {
 553                         /* fall back to host/machine.realm@REALM */
 554                         salt_princ_s = kerberos_standard_des_salt();
 555                 }
 556         }
 557
 558         if (smb_krb5_parse_name(context, salt_princ_s, &ret_princ) != 0) {
 559                 ret_princ = NULL;
 560         }
 561
 562         TALLOC_FREE(unparsed_name);
 563         SAFE_FREE(salt_princ_s);
 564
 565         return ret_princ;
 566 }
 567
 568 /************************************************************************
 569  Routine to set the salting principal for this service.  Active
 570  Directory may use a non-obvious principal name to generate the salt
 571  when it determines the key to use for encrypting tickets for a service,
 572  and hopefully we detected that when we joined the domain.
 573  Setting principal to NULL deletes this entry.
 574  ************************************************************************/
 575
 576 bool kerberos_secrets_store_salting_principal(const char *service,
 577                                               int enctype,
 578                                               const char *principal)
 579 {
 580         char *key = NULL;
 581         bool ret = False;
 582         krb5_context context = NULL;
 583         krb5_principal princ = NULL;
 584         char *princ_s = NULL;
 585         char *unparsed_name = NULL;
 586         krb5_error_code code;
 587
 588         if (((code = krb5_init_context(&context)) != 0) || (context == NULL)) {
 589                 DEBUG(5, ("kerberos_secrets_store_salting_pricipal: kdb5_init_context failed: %s\n",
 590                           error_message(code)));
 591                 return False;
 592         }
 593         if (strchr_m(service, '@')) {
 594                 if (asprintf(&princ_s, "%s", service) == -1) {
 595                         goto out;
 596                 }
 597         } else {
 598                 if (asprintf(&princ_s, "%s@%s", service, lp_realm()) == -1) {
 599                         goto out;
 600                 }
 601         }
 602
 603         if (smb_krb5_parse_name(context, princ_s, &princ) != 0) {
 604                 goto out;
 605
 606         }
 607         if (smb_krb5_unparse_name(talloc_tos(), context, princ, &unparsed_name) != 0) {
 608                 goto out;
 609         }
 610
 611         if (asprintf(&key, "%s/%s/enctype=%d",
 612                      SECRETS_SALTING_PRINCIPAL, unparsed_name, enctype)
 613             == -1) {
 614                 goto out;
 615         }
 616
 617         if ((principal != NULL) && (strlen(principal) > 0)) {
 618                 ret = secrets_store(key, principal, strlen(principal) + 1);
 619         } else {
 620                 ret = secrets_delete(key);
 621         }
 622
 623  out:
 624
 625         SAFE_FREE(key);
 626         SAFE_FREE(princ_s);
 627         TALLOC_FREE(unparsed_name);
 628
 629         if (princ) {
 630                 krb5_free_principal(context, princ);
 631         }
 632
 633         if (context) {
 634                 krb5_free_context(context);
 635         }
 636
 637         return ret;
 638 }
 639
 640
 641 /************************************************************************
 642 ************************************************************************/
 643
 644 int kerberos_kinit_password(const char *principal,
 645                             const char *password,
 646                             int time_offset,
 647                             const char *cache_name)
 648 {
 649         return kerberos_kinit_password_ext(principal,
 650                                            password,
 651                                            time_offset,
 652                                            0,
 653                                            0,
 654                                            cache_name,
 655                                            False,
 656                                            False,
 657                                            0,
 658                                            NULL);
 659 }
 660
 661 /************************************************************************
 662 ************************************************************************/
 663
 664 static char *print_kdc_line(char *mem_ctx,
 665                         const char *prev_line,
 666                         const struct sockaddr_storage *pss)
 667 {
 668         char *kdc_str = NULL;
 669
 670         if (pss->ss_family == AF_INET) {
 671                 kdc_str = talloc_asprintf(mem_ctx, "%s\tkdc = %s\n",
 672                                         prev_line,
 673                                         print_canonical_sockaddr(mem_ctx, pss));
 674         } else {
 675                 char addr[INET6_ADDRSTRLEN];
 676                 uint16_t port = get_sockaddr_port(pss);
 677
 678                 if (port != 0 && port != DEFAULT_KRB5_PORT) {
 679                         /* Currently for IPv6 we can't specify a non-default
 680                            krb5 port with an address, as this requires a ':'.
 681                            Resolve to a name. */
 682                         char hostname[MAX_DNS_NAME_LENGTH];
 683                         int ret = sys_getnameinfo((const struct sockaddr *)pss,
 684                                         sizeof(*pss),
 685                                         hostname, sizeof(hostname),
 686                                         NULL, 0,
 687                                         NI_NAMEREQD);
 688                         if (ret) {
 689                                 DEBUG(0,("print_kdc_line: can't resolve name "
 690                                         "for kdc with non-default port %s. "
 691                                         "Error %s\n.",
 692                                         print_canonical_sockaddr(mem_ctx, pss),
 693                                         gai_strerror(ret)));
 694                         }
 695                         /* Success, use host:port */
 696                         kdc_str = talloc_asprintf(mem_ctx,
 697                                         "%s\tkdc = %s:%u\n",
 698                                         prev_line,
 699                                         hostname,
 700                                         (unsigned int)port);
 701                 } else {
 702                         kdc_str = talloc_asprintf(mem_ctx, "%s\tkdc = %s\n",
 703                                         prev_line,
 704                                         print_sockaddr(addr,
 705                                                 sizeof(addr),
 706                                                 pss));
 707                 }
 708         }
 709         return kdc_str;
 710 }
 711
 712 /************************************************************************
 713  Create a string list of available kdc's, possibly searching by sitename.
 714  Does DNS queries.
 715
 716  If "sitename" is given, the DC's in that site are listed first.
 717
 718 ************************************************************************/
 719
 720 static char *get_kdc_ip_string(char *mem_ctx,
 721                 const char *realm,
 722                 const char *sitename,
 723                 struct sockaddr_storage *pss)
 724 {
 725         int i;
 726         struct ip_service *ip_srv_site = NULL;
 727         struct ip_service *ip_srv_nonsite = NULL;
 728         int count_site = 0;
 729         int count_nonsite;
 730         char *kdc_str = print_kdc_line(mem_ctx, "", pss);
 731
 732         if (kdc_str == NULL) {
 733                 return NULL;
 734         }
 735
 736         /*
 737          * First get the KDC's only in this site, the rest will be
 738          * appended later
 739          */
 740
 741         if (sitename) {
 742
 743                 get_kdc_list(realm, sitename, &ip_srv_site, &count_site);
 744
 745                 for (i = 0; i < count_site; i++) {
 746                         if (sockaddr_equal((struct sockaddr *)&ip_srv_site[i].ss,
 747                                                    (struct sockaddr *)pss)) {
 748                                 continue;
 749                         }
 750                         /* Append to the string - inefficient
 751                          * but not done often. */
 752                         kdc_str = print_kdc_line(mem_ctx,
 753                                                 kdc_str,
 754                                                 &ip_srv_site[i].ss);
 755                         if (!kdc_str) {
 756                                 SAFE_FREE(ip_srv_site);
 757                                 return NULL;
 758                         }
 759                 }
 760         }
 761
 762         /* Get all KDC's. */
 763
 764         get_kdc_list(realm, NULL, &ip_srv_nonsite, &count_nonsite);
 765
 766         for (i = 0; i < count_nonsite; i++) {
 767                 int j;
 768
 769                 if (sockaddr_equal((struct sockaddr *)&ip_srv_nonsite[i].ss, (struct sockaddr *)pss)) {
 770                         continue;
 771                 }
 772
 773                 /* Ensure this isn't an IP already seen (YUK! this is n*n....) */
 774                 for (j = 0; j < count_site; j++) {
 775                         if (sockaddr_equal((struct sockaddr *)&ip_srv_nonsite[i].ss,
 776                                                 (struct sockaddr *)&ip_srv_site[j].ss)) {
 777                                 break;
 778                         }
 779                         /* As the lists are sorted we can break early if nonsite > site. */
 780                         if (ip_service_compare(&ip_srv_nonsite[i], &ip_srv_site[j]) > 0) {
 781                                 break;
 782                         }
 783                 }
 784                 if (j != i) {
 785                         continue;
 786                 }
 787
 788                 /* Append to the string - inefficient but not done often. */
 789                 kdc_str = print_kdc_line(mem_ctx,
 790                                 kdc_str,
 791                                 &ip_srv_nonsite[i].ss);
 792                 if (!kdc_str) {
 793                         SAFE_FREE(ip_srv_site);
 794                         SAFE_FREE(ip_srv_nonsite);
 795                         return NULL;
 796                 }
 797         }
 798
 799
 800         SAFE_FREE(ip_srv_site);
 801         SAFE_FREE(ip_srv_nonsite);
 802
 803         DEBUG(10,("get_kdc_ip_string: Returning %s\n",
 804                 kdc_str ));
 805
 806         return kdc_str;
 807 }
 808
 809 /************************************************************************
 810  Create  a specific krb5.conf file in the private directory pointing
 811  at a specific kdc for a realm. Keyed off domain name. Sets
 812  KRB5_CONFIG environment variable to point to this file. Must be
 813  run as root or will fail (which is a good thing :-).
 814 ************************************************************************/
 815
 816 bool create_local_private_krb5_conf_for_domain(const char *realm,
 817                                                 const char *domain,
 818                                                 const char *sitename,
 819                                                 struct sockaddr_storage *pss)
 820 {
 821         char *dname;
 822         char *tmpname = NULL;
 823         char *fname = NULL;
 824         char *file_contents = NULL;
 825         char *kdc_ip_string = NULL;
 826         size_t flen = 0;
 827         ssize_t ret;
 828         int fd;
 829         char *realm_upper = NULL;
 830         bool result = false;
 831
 832         if (!lp_create_krb5_conf()) {
 833                 return false;
 834         }
 835
 836         dname = lock_path("smb_krb5");
 837         if (!dname) {
 838                 return false;
 839         }
 840         if ((mkdir(dname, 0755)==-1) && (errno != EEXIST)) {
 841                 DEBUG(0,("create_local_private_krb5_conf_for_domain: "
 842                         "failed to create directory %s. Error was %s\n",
 843                         dname, strerror(errno) ));
 844                 goto done;
 845         }
 846
 847         tmpname = lock_path("smb_tmp_krb5.XXXXXX");
 848         if (!tmpname) {
 849                 goto done;
 850         }
 851
 852         fname = talloc_asprintf(dname, "%s/krb5.conf.%s", dname, domain);
 853         if (!fname) {
 854                 goto done;
 855         }
 856
 857         DEBUG(10,("create_local_private_krb5_conf_for_domain: fname = %s, realm = %s, domain = %s\n",
 858                 fname, realm, domain ));
 859
 860         realm_upper = talloc_strdup(fname, realm);
 861         strupper_m(realm_upper);
 862
 863         kdc_ip_string = get_kdc_ip_string(dname, realm, sitename, pss);
 864         if (!kdc_ip_string) {
 865                 goto done;
 866         }
 867
 868         file_contents = talloc_asprintf(fname,
 869                                         "[libdefaults]\n\tdefault_realm = %s\n"
 870                                         "\tdefault_tgs_enctypes = RC4-HMAC DES-CBC-CRC DES-CBC-MD5\n"
 871                                         "\tdefault_tkt_enctypes = RC4-HMAC DES-CBC-CRC DES-CBC-MD5\n"
 872                                         "\tpreferred_enctypes = RC4-HMAC DES-CBC-CRC DES-CBC-MD5\n\n"
 873                                         "[realms]\n\t%s = {\n"
 874                                         "\t%s\t}\n",
 875                                         realm_upper, realm_upper, kdc_ip_string);
 876
 877         if (!file_contents) {
 878                 goto done;
 879         }
 880
 881         flen = strlen(file_contents);
 882
 883         fd = mkstemp(tmpname);
 884         if (fd == -1) {
 885                 DEBUG(0,("create_local_private_krb5_conf_for_domain: smb_mkstemp failed,"
 886                         " for file %s. Errno %s\n",
 887                         tmpname, strerror(errno) ));
 888                 goto done;
 889         }
 890
 891         if (fchmod(fd, 0644)==-1) {
 892                 DEBUG(0,("create_local_private_krb5_conf_for_domain: fchmod failed for %s."
 893                         " Errno %s\n",
 894                         tmpname, strerror(errno) ));
 895                 unlink(tmpname);
 896                 close(fd);
 897                 goto done;
 898         }
 899
 900         ret = write(fd, file_contents, flen);
 901         if (flen != ret) {
 902                 DEBUG(0,("create_local_private_krb5_conf_for_domain: write failed,"
 903                         " returned %d (should be %u). Errno %s\n",
 904                         (int)ret, (unsigned int)flen, strerror(errno) ));
 905                 unlink(tmpname);
 906                 close(fd);
 907                 goto done;
 908         }
 909         if (close(fd)==-1) {
 910                 DEBUG(0,("create_local_private_krb5_conf_for_domain: close failed."
 911                         " Errno %s\n", strerror(errno) ));
 912                 unlink(tmpname);
 913                 goto done;
 914         }
 915
 916         if (rename(tmpname, fname) == -1) {
 917                 DEBUG(0,("create_local_private_krb5_conf_for_domain: rename "
 918                         "of %s to %s failed. Errno %s\n",
 919                         tmpname, fname, strerror(errno) ));
 920                 unlink(tmpname);
 921                 goto done;
 922         }
 923
 924         DEBUG(5,("create_local_private_krb5_conf_for_domain: wrote "
 925                 "file %s with realm %s KDC list = %s\n",
 926                 fname, realm_upper, kdc_ip_string));
 927
 928         /* Set the environment variable to this file. */
 929         setenv("KRB5_CONFIG", fname, 1);
 930
 931         result = true;
 932
 933 #if defined(OVERWRITE_SYSTEM_KRB5_CONF)
 934
 935 #define SYSTEM_KRB5_CONF_PATH "/etc/krb5.conf"
 936         /* Insanity, sheer insanity..... */
 937
 938         if (strequal(realm, lp_realm())) {
 939                 char linkpath[PATH_MAX+1];
 940                 int lret;
 941
 942                 lret = readlink(SYSTEM_KRB5_CONF_PATH, linkpath, sizeof(linkpath)-1);
 943                 if (lret != -1) {
 944                         linkpath[lret] = '\0';
 945                 }
 946
 947                 if (lret != -1 || strcmp(linkpath, fname) == 0) {
 948                         /* Symlink already exists. */
 949                         goto done;
 950                 }
 951
 952                 /* Try and replace with a symlink. */
 953                 if (symlink(fname, SYSTEM_KRB5_CONF_PATH) == -1) {
 954                         const char *newpath = SYSTEM_KRB5_CONF_PATH ## ".saved";
 955                         if (errno != EEXIST) {
 956                                 DEBUG(0,("create_local_private_krb5_conf_for_domain: symlink "
 957                                         "of %s to %s failed. Errno %s\n",
 958                                         fname, SYSTEM_KRB5_CONF_PATH, strerror(errno) ));
 959                                 goto done; /* Not a fatal error. */
 960                         }
 961
 962                         /* Yes, this is a race conditon... too bad. */
 963                         if (rename(SYSTEM_KRB5_CONF_PATH, newpath) == -1) {
 964                                 DEBUG(0,("create_local_private_krb5_conf_for_domain: rename "
 965                                         "of %s to %s failed. Errno %s\n",
 966                                         SYSTEM_KRB5_CONF_PATH, newpath,
 967                                         strerror(errno) ));
 968                                 goto done; /* Not a fatal error. */
 969                         }
 970
 971                         if (symlink(fname, SYSTEM_KRB5_CONF_PATH) == -1) {
 972                                 DEBUG(0,("create_local_private_krb5_conf_for_domain: "
 973                                         "forced symlink of %s to /etc/krb5.conf failed. Errno %s\n",
 974                                         fname, strerror(errno) ));
 975                                 goto done; /* Not a fatal error. */
 976                         }
 977                 }
 978         }
 979 #endif
 980
 981 done:
 982         TALLOC_FREE(tmpname);
 983         TALLOC_FREE(dname);
 984
 985         return result;
 986 }
 987 #endif