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 "system/filesys.h"
  26 #include "smb_krb5.h"
  27 #include "../librpc/gen_ndr/ndr_misc.h"
  28 #include "libads/kerberos_proto.h"
  29 #include "libads/cldap.h"
  30 #include "secrets.h"
  31 #include "../lib/tsocket/tsocket.h"
  32
  33 #ifdef HAVE_KRB5
  34
  35 #define LIBADS_CCACHE_NAME "MEMORY:libads"
  36
  37 /*
  38   we use a prompter to avoid a crash bug in the kerberos libs when
  39   dealing with empty passwords
  40   this prompter is just a string copy ...
  41 */
  42 static krb5_error_code
  43 kerb_prompter(krb5_context ctx, void *data,
  44                const char *name,
  45                const char *banner,
  46                int num_prompts,
  47                krb5_prompt prompts[])
  48 {
  49         if (num_prompts == 0) return 0;
  50
  51         memset(prompts[0].reply->data, '\0', prompts[0].reply->length);
  52         if (prompts[0].reply->length > 0) {
  53                 if (data) {
  54                         strncpy((char *)prompts[0].reply->data, (const char *)data,
  55                                 prompts[0].reply->length-1);
  56                         prompts[0].reply->length = strlen((const char *)prompts[0].reply->data);
  57                 } else {
  58                         prompts[0].reply->length = 0;
  59                 }
  60         }
  61         return 0;
  62 }
  63
  64  static bool smb_krb5_get_ntstatus_from_krb5_error(krb5_error *error,
  65                                                    NTSTATUS *nt_status)
  66 {
  67         DATA_BLOB edata;
  68         DATA_BLOB unwrapped_edata;
  69         TALLOC_CTX *mem_ctx;
  70         struct KRB5_EDATA_NTSTATUS parsed_edata;
  71         enum ndr_err_code ndr_err;
  72
  73 #ifdef HAVE_E_DATA_POINTER_IN_KRB5_ERROR
  74         edata = data_blob(error->e_data->data, error->e_data->length);
  75 #else
  76         edata = data_blob(error->e_data.data, error->e_data.length);
  77 #endif /* HAVE_E_DATA_POINTER_IN_KRB5_ERROR */
  78
  79 #ifdef DEVELOPER
  80         dump_data(10, edata.data, edata.length);
  81 #endif /* DEVELOPER */
  82
  83         mem_ctx = talloc_init("smb_krb5_get_ntstatus_from_krb5_error");
  84         if (mem_ctx == NULL) {
  85                 data_blob_free(&edata);
  86                 return False;
  87         }
  88
  89         if (!unwrap_edata_ntstatus(mem_ctx, &edata, &unwrapped_edata)) {
  90                 data_blob_free(&edata);
  91                 TALLOC_FREE(mem_ctx);
  92                 return False;
  93         }
  94
  95         data_blob_free(&edata);
  96
  97         ndr_err = ndr_pull_struct_blob_all(&unwrapped_edata, mem_ctx,
  98                 &parsed_edata, (ndr_pull_flags_fn_t)ndr_pull_KRB5_EDATA_NTSTATUS);
  99         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 100                 data_blob_free(&unwrapped_edata);
 101                 TALLOC_FREE(mem_ctx);
 102                 return False;
 103         }
 104
 105         data_blob_free(&unwrapped_edata);
 106
 107         if (nt_status) {
 108                 *nt_status = parsed_edata.ntstatus;
 109         }
 110
 111         TALLOC_FREE(mem_ctx);
 112
 113         return True;
 114 }
 115
 116  static bool smb_krb5_get_ntstatus_from_krb5_error_init_creds_opt(krb5_context ctx,
 117                                                                   krb5_get_init_creds_opt *opt,
 118                                                                   NTSTATUS *nt_status)
 119 {
 120         bool ret = False;
 121         krb5_error *error = NULL;
 122
 123 #ifdef HAVE_KRB5_GET_INIT_CREDS_OPT_GET_ERROR
 124         ret = krb5_get_init_creds_opt_get_error(ctx, opt, &error);
 125         if (ret) {
 126                 DEBUG(1,("krb5_get_init_creds_opt_get_error gave: %s\n",
 127                         error_message(ret)));
 128                 return False;
 129         }
 130 #endif /* HAVE_KRB5_GET_INIT_CREDS_OPT_GET_ERROR */
 131
 132         if (!error) {
 133                 DEBUG(1,("no krb5_error\n"));
 134                 return False;
 135         }
 136
 137 #ifdef HAVE_E_DATA_POINTER_IN_KRB5_ERROR
 138         if (!error->e_data) {
 139 #else
 140         if (error->e_data.data == NULL) {
 141 #endif /* HAVE_E_DATA_POINTER_IN_KRB5_ERROR */
 142                 DEBUG(1,("no edata in krb5_error\n"));
 143                 krb5_free_error(ctx, error);
 144                 return False;
 145         }
 146
 147         ret = smb_krb5_get_ntstatus_from_krb5_error(error, nt_status);
 148
 149         krb5_free_error(ctx, error);
 150
 151         return ret;
 152 }
 153
 154 /*
 155   simulate a kinit, putting the tgt in the given cache location. If cache_name == NULL
 156   place in default cache location.
 157   remus@snapserver.com
 158 */
 159 int kerberos_kinit_password_ext(const char *principal,
 160                                 const char *password,
 161                                 int time_offset,
 162                                 time_t *expire_time,
 163                                 time_t *renew_till_time,
 164                                 const char *cache_name,
 165                                 bool request_pac,
 166                                 bool add_netbios_addr,
 167                                 time_t renewable_time,
 168                                 NTSTATUS *ntstatus)
 169 {
 170         krb5_context ctx = NULL;
 171         krb5_error_code code = 0;
 172         krb5_ccache cc = NULL;
 173         krb5_principal me = NULL;
 174         krb5_creds my_creds;
 175         krb5_get_init_creds_opt *opt = NULL;
 176         smb_krb5_addresses *addr = NULL;
 177
 178         ZERO_STRUCT(my_creds);
 179
 180         initialize_krb5_error_table();
 181         if ((code = krb5_init_context(&ctx)))
 182                 goto out;
 183
 184         if (time_offset != 0) {
 185                 krb5_set_real_time(ctx, time(NULL) + time_offset, 0);
 186         }
 187
 188         DEBUG(10,("kerberos_kinit_password: as %s using [%s] as ccache and config [%s]\n",
 189                         principal,
 190                         cache_name ? cache_name: krb5_cc_default_name(ctx),
 191                         getenv("KRB5_CONFIG")));
 192
 193         if ((code = krb5_cc_resolve(ctx, cache_name ? cache_name : krb5_cc_default_name(ctx), &cc))) {
 194                 goto out;
 195         }
 196
 197         if ((code = smb_krb5_parse_name(ctx, principal, &me))) {
 198                 goto out;
 199         }
 200
 201         if ((code = smb_krb5_get_init_creds_opt_alloc(ctx, &opt))) {
 202                 goto out;
 203         }
 204
 205         krb5_get_init_creds_opt_set_renew_life(opt, renewable_time);
 206         krb5_get_init_creds_opt_set_forwardable(opt, True);
 207 #if 0
 208         /* insane testing */
 209         krb5_get_init_creds_opt_set_tkt_life(opt, 60);
 210 #endif
 211
 212 #ifdef HAVE_KRB5_GET_INIT_CREDS_OPT_SET_PAC_REQUEST
 213         if (request_pac) {
 214                 if ((code = krb5_get_init_creds_opt_set_pac_request(ctx, opt, (krb5_boolean)request_pac))) {
 215                         goto out;
 216                 }
 217         }
 218 #endif
 219         if (add_netbios_addr) {
 220                 if ((code = smb_krb5_gen_netbios_krb5_address(&addr,
 221                                                         lp_netbios_name()))) {
 222                         goto out;
 223                 }
 224                 krb5_get_init_creds_opt_set_address_list(opt, addr->addrs);
 225         }
 226
 227         if ((code = krb5_get_init_creds_password(ctx, &my_creds, me, discard_const_p(char,password),
 228                                                  kerb_prompter, discard_const_p(char, password),
 229                                                  0, NULL, opt))) {
 230                 goto out;
 231         }
 232
 233         if ((code = krb5_cc_initialize(ctx, cc, me))) {
 234                 goto out;
 235         }
 236
 237         if ((code = krb5_cc_store_cred(ctx, cc, &my_creds))) {
 238                 goto out;
 239         }
 240
 241         if (expire_time) {
 242                 *expire_time = (time_t) my_creds.times.endtime;
 243         }
 244
 245         if (renew_till_time) {
 246                 *renew_till_time = (time_t) my_creds.times.renew_till;
 247         }
 248  out:
 249         if (ntstatus) {
 250
 251                 NTSTATUS status;
 252
 253                 /* fast path */
 254                 if (code == 0) {
 255                         *ntstatus = NT_STATUS_OK;
 256                         goto cleanup;
 257                 }
 258
 259                 /* try to get ntstatus code out of krb5_error when we have it
 260                  * inside the krb5_get_init_creds_opt - gd */
 261
 262                 if (opt && smb_krb5_get_ntstatus_from_krb5_error_init_creds_opt(ctx, opt, &status)) {
 263                         *ntstatus = status;
 264                         goto cleanup;
 265                 }
 266
 267                 /* fall back to self-made-mapping */
 268                 *ntstatus = krb5_to_nt_status(code);
 269         }
 270
 271  cleanup:
 272         krb5_free_cred_contents(ctx, &my_creds);
 273         if (me) {
 274                 krb5_free_principal(ctx, me);
 275         }
 276         if (addr) {
 277                 smb_krb5_free_addresses(ctx, addr);
 278         }
 279         if (opt) {
 280                 smb_krb5_get_init_creds_opt_free(ctx, opt);
 281         }
 282         if (cc) {
 283                 krb5_cc_close(ctx, cc);
 284         }
 285         if (ctx) {
 286                 krb5_free_context(ctx);
 287         }
 288         return code;
 289 }
 290
 291 int ads_kdestroy(const char *cc_name)
 292 {
 293         krb5_error_code code;
 294         krb5_context ctx = NULL;
 295         krb5_ccache cc = NULL;
 296
 297         initialize_krb5_error_table();
 298         if ((code = krb5_init_context (&ctx))) {
 299                 DEBUG(3, ("ads_kdestroy: kdb5_init_context failed: %s\n",
 300                         error_message(code)));
 301                 return code;
 302         }
 303
 304         if (!cc_name) {
 305                 if ((code = krb5_cc_default(ctx, &cc))) {
 306                         krb5_free_context(ctx);
 307                         return code;
 308                 }
 309         } else {
 310                 if ((code = krb5_cc_resolve(ctx, cc_name, &cc))) {
 311                         DEBUG(3, ("ads_kdestroy: krb5_cc_resolve failed: %s\n",
 312                                   error_message(code)));
 313                         krb5_free_context(ctx);
 314                         return code;
 315                 }
 316         }
 317
 318         if ((code = krb5_cc_destroy (ctx, cc))) {
 319                 DEBUG(3, ("ads_kdestroy: krb5_cc_destroy failed: %s\n",
 320                         error_message(code)));
 321         }
 322
 323         krb5_free_context (ctx);
 324         return code;
 325 }
 326
 327 /************************************************************************
 328  Routine to fetch the salting principal for a service.  Active
 329  Directory may use a non-obvious principal name to generate the salt
 330  when it determines the key to use for encrypting tickets for a service,
 331  and hopefully we detected that when we joined the domain.
 332  ************************************************************************/
 333
 334 static char *kerberos_secrets_fetch_salting_principal(const char *service, int enctype)
 335 {
 336         char *key = NULL;
 337         char *ret = NULL;
 338
 339         if (asprintf(&key, "%s/%s/enctype=%d",
 340                      SECRETS_SALTING_PRINCIPAL, service, enctype) == -1) {
 341                 return NULL;
 342         }
 343         ret = (char *)secrets_fetch(key, NULL);
 344         SAFE_FREE(key);
 345         return ret;
 346 }
 347
 348 /************************************************************************
 349  Return the standard DES salt key
 350 ************************************************************************/
 351
 352 char* kerberos_standard_des_salt( void )
 353 {
 354         fstring salt;
 355
 356         fstr_sprintf( salt, "host/%s.%s@", lp_netbios_name(), lp_realm() );
 357         (void)strlower_m( salt );
 358         fstrcat( salt, lp_realm() );
 359
 360         return SMB_STRDUP( salt );
 361 }
 362
 363 /************************************************************************
 364 ************************************************************************/
 365
 366 static char* des_salt_key( void )
 367 {
 368         char *key;
 369
 370         if (asprintf(&key, "%s/DES/%s", SECRETS_SALTING_PRINCIPAL,
 371                      lp_realm()) == -1) {
 372                 return NULL;
 373         }
 374
 375         return key;
 376 }
 377
 378 /************************************************************************
 379 ************************************************************************/
 380
 381 bool kerberos_secrets_store_des_salt( const char* salt )
 382 {
 383         char* key;
 384         bool ret;
 385
 386         if ( (key = des_salt_key()) == NULL ) {
 387                 DEBUG(0,("kerberos_secrets_store_des_salt: failed to generate key!\n"));
 388                 return False;
 389         }
 390
 391         if ( !salt ) {
 392                 DEBUG(8,("kerberos_secrets_store_des_salt: deleting salt\n"));
 393                 secrets_delete( key );
 394                 return True;
 395         }
 396
 397         DEBUG(3,("kerberos_secrets_store_des_salt: Storing salt \"%s\"\n", salt));
 398
 399         ret = secrets_store( key, salt, strlen(salt)+1 );
 400
 401         SAFE_FREE( key );
 402
 403         return ret;
 404 }
 405
 406 /************************************************************************
 407 ************************************************************************/
 408
 409 static
 410 char* kerberos_secrets_fetch_des_salt( void )
 411 {
 412         char *salt, *key;
 413
 414         if ( (key = des_salt_key()) == NULL ) {
 415                 DEBUG(0,("kerberos_secrets_fetch_des_salt: failed to generate key!\n"));
 416                 return NULL;
 417         }
 418
 419         salt = (char*)secrets_fetch( key, NULL );
 420
 421         SAFE_FREE( key );
 422
 423         return salt;
 424 }
 425
 426 /************************************************************************
 427  Routine to get the salting principal for this service.  This is
 428  maintained for backwards compatibilty with releases prior to 3.0.24.
 429  Since we store the salting principal string only at join, we may have
 430  to look for the older tdb keys.  Caller must free if return is not null.
 431  ************************************************************************/
 432
 433 static
 434 krb5_principal kerberos_fetch_salt_princ_for_host_princ(krb5_context context,
 435                                                         krb5_principal host_princ,
 436                                                         int enctype)
 437 {
 438         char *unparsed_name = NULL, *salt_princ_s = NULL;
 439         krb5_principal ret_princ = NULL;
 440
 441         /* lookup new key first */
 442
 443         if ( (salt_princ_s = kerberos_secrets_fetch_des_salt()) == NULL ) {
 444
 445                 /* look under the old key.  If this fails, just use the standard key */
 446
 447                 if (smb_krb5_unparse_name(talloc_tos(), context, host_princ, &unparsed_name) != 0) {
 448                         return (krb5_principal)NULL;
 449                 }
 450                 if ((salt_princ_s = kerberos_secrets_fetch_salting_principal(unparsed_name, enctype)) == NULL) {
 451                         /* fall back to host/machine.realm@REALM */
 452                         salt_princ_s = kerberos_standard_des_salt();
 453                 }
 454         }
 455
 456         if (smb_krb5_parse_name(context, salt_princ_s, &ret_princ) != 0) {
 457                 ret_princ = NULL;
 458         }
 459
 460         TALLOC_FREE(unparsed_name);
 461         SAFE_FREE(salt_princ_s);
 462
 463         return ret_princ;
 464 }
 465
 466 int create_kerberos_key_from_string(krb5_context context,
 467                                         krb5_principal host_princ,
 468                                         krb5_data *password,
 469                                         krb5_keyblock *key,
 470                                         krb5_enctype enctype,
 471                                         bool no_salt)
 472 {
 473         krb5_principal salt_princ = NULL;
 474         int ret;
 475         /*
 476          * Check if we've determined that the KDC is salting keys for this
 477          * principal/enctype in a non-obvious way.  If it is, try to match
 478          * its behavior.
 479          */
 480         if (no_salt) {
 481                 KRB5_KEY_DATA(key) = (KRB5_KEY_DATA_CAST *)SMB_MALLOC(password->length);
 482                 if (!KRB5_KEY_DATA(key)) {
 483                         return ENOMEM;
 484                 }
 485                 memcpy(KRB5_KEY_DATA(key), password->data, password->length);
 486                 KRB5_KEY_LENGTH(key) = password->length;
 487                 KRB5_KEY_TYPE(key) = enctype;
 488                 return 0;
 489         }
 490         salt_princ = kerberos_fetch_salt_princ_for_host_princ(context, host_princ, enctype);
 491         ret = smb_krb5_create_key_from_string(context,
 492                                               salt_princ ? salt_princ : host_princ,
 493                                               NULL,
 494                                               password,
 495                                               enctype,
 496                                               key);
 497         if (salt_princ) {
 498                 krb5_free_principal(context, salt_princ);
 499         }
 500         return ret;
 501 }
 502
 503 /************************************************************************
 504  Routine to set the salting principal for this service.  Active
 505  Directory may use a non-obvious principal name to generate the salt
 506  when it determines the key to use for encrypting tickets for a service,
 507  and hopefully we detected that when we joined the domain.
 508  Setting principal to NULL deletes this entry.
 509  ************************************************************************/
 510
 511 bool kerberos_secrets_store_salting_principal(const char *service,
 512                                               int enctype,
 513                                               const char *principal)
 514 {
 515         char *key = NULL;
 516         bool ret = False;
 517         krb5_context context = NULL;
 518         krb5_principal princ = NULL;
 519         char *princ_s = NULL;
 520         char *unparsed_name = NULL;
 521         krb5_error_code code;
 522
 523         if (((code = krb5_init_context(&context)) != 0) || (context == NULL)) {
 524                 DEBUG(5, ("kerberos_secrets_store_salting_pricipal: kdb5_init_context failed: %s\n",
 525                           error_message(code)));
 526                 return False;
 527         }
 528         if (strchr_m(service, '@')) {
 529                 if (asprintf(&princ_s, "%s", service) == -1) {
 530                         goto out;
 531                 }
 532         } else {
 533                 if (asprintf(&princ_s, "%s@%s", service, lp_realm()) == -1) {
 534                         goto out;
 535                 }
 536         }
 537
 538         if (smb_krb5_parse_name(context, princ_s, &princ) != 0) {
 539                 goto out;
 540         }
 541         if (smb_krb5_unparse_name(talloc_tos(), context, princ, &unparsed_name) != 0) {
 542                 goto out;
 543         }
 544
 545         if (asprintf(&key, "%s/%s/enctype=%d",
 546                      SECRETS_SALTING_PRINCIPAL, unparsed_name, enctype)
 547             == -1) {
 548                 goto out;
 549         }
 550
 551         if ((principal != NULL) && (strlen(principal) > 0)) {
 552                 ret = secrets_store(key, principal, strlen(principal) + 1);
 553         } else {
 554                 ret = secrets_delete(key);
 555         }
 556
 557  out:
 558
 559         SAFE_FREE(key);
 560         SAFE_FREE(princ_s);
 561         TALLOC_FREE(unparsed_name);
 562
 563         if (princ) {
 564                 krb5_free_principal(context, princ);
 565         }
 566
 567         if (context) {
 568                 krb5_free_context(context);
 569         }
 570
 571         return ret;
 572 }
 573
 574
 575 /************************************************************************
 576 ************************************************************************/
 577
 578 int kerberos_kinit_password(const char *principal,
 579                             const char *password,
 580                             int time_offset,
 581                             const char *cache_name)
 582 {
 583         return kerberos_kinit_password_ext(principal,
 584                                            password,
 585                                            time_offset,
 586                                            0,
 587                                            0,
 588                                            cache_name,
 589                                            False,
 590                                            False,
 591                                            0,
 592                                            NULL);
 593 }
 594
 595 /************************************************************************
 596 ************************************************************************/
 597
 598 /************************************************************************
 599  Create a string list of available kdc's, possibly searching by sitename.
 600  Does DNS queries.
 601
 602  If "sitename" is given, the DC's in that site are listed first.
 603
 604 ************************************************************************/
 605
 606 static void add_sockaddr_unique(struct sockaddr_storage *addrs, int *num_addrs,
 607                                 const struct sockaddr_storage *addr)
 608 {
 609         int i;
 610
 611         for (i=0; i<*num_addrs; i++) {
 612                 if (sockaddr_equal((const struct sockaddr *)&addrs[i],
 613                                    (const struct sockaddr *)addr)) {
 614                         return;
 615                 }
 616         }
 617         addrs[i] = *addr;
 618         *num_addrs += 1;
 619 }
 620
 621 /* print_canonical_sockaddr prints an ipv6 addr in the form of
 622 * [ipv6.addr]. This string, when put in a generated krb5.conf file is not
 623 * always properly dealt with by some older krb5 libraries. Adding the hard-coded
 624 * portnumber workarounds the issue. - gd */
 625
 626 static char *print_canonical_sockaddr_with_port(TALLOC_CTX *mem_ctx,
 627                                                 const struct sockaddr_storage *pss)
 628 {
 629         char *str = NULL;
 630
 631         str = print_canonical_sockaddr(mem_ctx, pss);
 632         if (str == NULL) {
 633                 return NULL;
 634         }
 635
 636         if (pss->ss_family != AF_INET6) {
 637                 return str;
 638         }
 639
 640 #if defined(HAVE_IPV6)
 641         str = talloc_asprintf_append(str, ":88");
 642 #endif
 643         return str;
 644 }
 645
 646 static char *get_kdc_ip_string(char *mem_ctx,
 647                 const char *realm,
 648                 const char *sitename,
 649                 const struct sockaddr_storage *pss)
 650 {
 651         TALLOC_CTX *frame = talloc_stackframe();
 652         int i;
 653         struct ip_service *ip_srv_site = NULL;
 654         struct ip_service *ip_srv_nonsite = NULL;
 655         int count_site = 0;
 656         int count_nonsite;
 657         int num_dcs;
 658         struct sockaddr_storage *dc_addrs;
 659         struct tsocket_address **dc_addrs2 = NULL;
 660         const struct tsocket_address * const *dc_addrs3 = NULL;
 661         char *result = NULL;
 662         struct netlogon_samlogon_response **responses = NULL;
 663         NTSTATUS status;
 664         char *kdc_str = talloc_asprintf(mem_ctx, "%s\t\tkdc = %s\n", "",
 665                                         print_canonical_sockaddr_with_port(mem_ctx, pss));
 666
 667         if (kdc_str == NULL) {
 668                 TALLOC_FREE(frame);
 669                 return NULL;
 670         }
 671
 672         /*
 673          * First get the KDC's only in this site, the rest will be
 674          * appended later
 675          */
 676
 677         if (sitename) {
 678                 get_kdc_list(realm, sitename, &ip_srv_site, &count_site);
 679                 DEBUG(10, ("got %d addresses from site %s search\n", count_site,
 680                            sitename));
 681         }
 682
 683         /* Get all KDC's. */
 684
 685         get_kdc_list(realm, NULL, &ip_srv_nonsite, &count_nonsite);
 686         DEBUG(10, ("got %d addresses from site-less search\n", count_nonsite));
 687
 688         dc_addrs = talloc_array(talloc_tos(), struct sockaddr_storage,
 689                                 count_site + count_nonsite);
 690         if (dc_addrs == NULL) {
 691                 goto out;
 692         }
 693
 694         num_dcs = 0;
 695
 696         for (i = 0; i < count_site; i++) {
 697                 if (!sockaddr_equal(
 698                         (const struct sockaddr *)pss,
 699                         (const struct sockaddr *)&ip_srv_site[i].ss)) {
 700                         add_sockaddr_unique(dc_addrs, &num_dcs,
 701                                             &ip_srv_site[i].ss);
 702                 }
 703         }
 704
 705         for (i = 0; i < count_nonsite; i++) {
 706                 if (!sockaddr_equal(
 707                         (const struct sockaddr *)pss,
 708                         (const struct sockaddr *)&ip_srv_nonsite[i].ss)) {
 709                         add_sockaddr_unique(dc_addrs, &num_dcs,
 710                                             &ip_srv_nonsite[i].ss);
 711                 }
 712         }
 713
 714         dc_addrs2 = talloc_zero_array(talloc_tos(),
 715                                       struct tsocket_address *,
 716                                       num_dcs);
 717
 718         DEBUG(10, ("%d additional KDCs to test\n", num_dcs));
 719         if (num_dcs == 0) {
 720                 goto out;
 721         }
 722         if (dc_addrs2 == NULL) {
 723                 goto out;
 724         }
 725
 726         for (i=0; i<num_dcs; i++) {
 727                 char addr[INET6_ADDRSTRLEN];
 728                 int ret;
 729
 730                 print_sockaddr(addr, sizeof(addr), &dc_addrs[i]);
 731
 732                 ret = tsocket_address_inet_from_strings(dc_addrs2, "ip",
 733                                                         addr, LDAP_PORT,
 734                                                         &dc_addrs2[i]);
 735                 if (ret != 0) {
 736                         status = map_nt_error_from_unix(errno);
 737                         DEBUG(2,("Failed to create tsocket_address for %s - %s\n",
 738                                  addr, nt_errstr(status)));
 739                         goto out;
 740                 }
 741         }
 742
 743         dc_addrs3 = (const struct tsocket_address * const *)dc_addrs2;
 744
 745         status = cldap_multi_netlogon(talloc_tos(),
 746                         dc_addrs3, num_dcs,
 747                         realm, lp_netbios_name(),
 748                         NETLOGON_NT_VERSION_5 | NETLOGON_NT_VERSION_5EX,
 749                         MIN(num_dcs, 3), timeval_current_ofs(3, 0), &responses);
 750         TALLOC_FREE(dc_addrs2);
 751         dc_addrs3 = NULL;
 752
 753         if (!NT_STATUS_IS_OK(status)) {
 754                 DEBUG(10,("get_kdc_ip_string: cldap_multi_netlogon failed: "
 755                           "%s\n", nt_errstr(status)));
 756                 goto out;
 757         }
 758
 759         for (i=0; i<num_dcs; i++) {
 760                 char *new_kdc_str;
 761
 762                 if (responses[i] == NULL) {
 763                         continue;
 764                 }
 765
 766                 /* Append to the string - inefficient but not done often. */
 767                 new_kdc_str = talloc_asprintf(mem_ctx, "%s\t\tkdc = %s\n",
 768                                               kdc_str,
 769                                               print_canonical_sockaddr_with_port(mem_ctx, &dc_addrs[i]));
 770                 if (new_kdc_str == NULL) {
 771                         goto out;
 772                 }
 773                 TALLOC_FREE(kdc_str);
 774                 kdc_str = new_kdc_str;
 775         }
 776
 777 out:
 778         DEBUG(10, ("get_kdc_ip_string: Returning %s\n", kdc_str));
 779
 780         result = kdc_str;
 781         SAFE_FREE(ip_srv_site);
 782         SAFE_FREE(ip_srv_nonsite);
 783         TALLOC_FREE(frame);
 784         return result;
 785 }
 786
 787 /************************************************************************
 788  Create  a specific krb5.conf file in the private directory pointing
 789  at a specific kdc for a realm. Keyed off domain name. Sets
 790  KRB5_CONFIG environment variable to point to this file. Must be
 791  run as root or will fail (which is a good thing :-).
 792 ************************************************************************/
 793
 794 bool create_local_private_krb5_conf_for_domain(const char *realm,
 795                                                 const char *domain,
 796                                                 const char *sitename,
 797                                                 const struct sockaddr_storage *pss)
 798 {
 799         char *dname;
 800         char *tmpname = NULL;
 801         char *fname = NULL;
 802         char *file_contents = NULL;
 803         char *kdc_ip_string = NULL;
 804         size_t flen = 0;
 805         ssize_t ret;
 806         int fd;
 807         char *realm_upper = NULL;
 808         bool result = false;
 809         char *aes_enctypes = NULL;
 810         mode_t mask;
 811
 812         if (!lp_create_krb5_conf()) {
 813                 return false;
 814         }
 815
 816         if (realm == NULL) {
 817                 DEBUG(0, ("No realm has been specified! Do you really want to "
 818                           "join an Active Directory server?\n"));
 819                 return false;
 820         }
 821
 822         if (domain == NULL || pss == NULL) {
 823                 return false;
 824         }
 825
 826         dname = lock_path("smb_krb5");
 827         if (!dname) {
 828                 return false;
 829         }
 830         if ((mkdir(dname, 0755)==-1) && (errno != EEXIST)) {
 831                 DEBUG(0,("create_local_private_krb5_conf_for_domain: "
 832                         "failed to create directory %s. Error was %s\n",
 833                         dname, strerror(errno) ));
 834                 goto done;
 835         }
 836
 837         tmpname = lock_path("smb_tmp_krb5.XXXXXX");
 838         if (!tmpname) {
 839                 goto done;
 840         }
 841
 842         fname = talloc_asprintf(dname, "%s/krb5.conf.%s", dname, domain);
 843         if (!fname) {
 844                 goto done;
 845         }
 846
 847         DEBUG(10,("create_local_private_krb5_conf_for_domain: fname = %s, realm = %s, domain = %s\n",
 848                 fname, realm, domain ));
 849
 850         realm_upper = talloc_strdup(fname, realm);
 851         if (!strupper_m(realm_upper)) {
 852                 goto done;
 853         }
 854
 855         kdc_ip_string = get_kdc_ip_string(dname, realm, sitename, pss);
 856         if (!kdc_ip_string) {
 857                 goto done;
 858         }
 859
 860         aes_enctypes = talloc_strdup(fname, "");
 861         if (aes_enctypes == NULL) {
 862                 goto done;
 863         }
 864
 865 #ifdef HAVE_ENCTYPE_AES256_CTS_HMAC_SHA1_96
 866         aes_enctypes = talloc_asprintf_append(aes_enctypes, "%s", "aes256-cts-hmac-sha1-96 ");
 867         if (aes_enctypes == NULL) {
 868                 goto done;
 869         }
 870 #endif
 871 #ifdef HAVE_ENCTYPE_AES128_CTS_HMAC_SHA1_96
 872         aes_enctypes = talloc_asprintf_append(aes_enctypes, "%s", "aes128-cts-hmac-sha1-96");
 873         if (aes_enctypes == NULL) {
 874                 goto done;
 875         }
 876 #endif
 877
 878         file_contents = talloc_asprintf(fname,
 879                                         "[libdefaults]\n\tdefault_realm = %s\n"
 880                                         "\tdefault_tgs_enctypes = %s RC4-HMAC DES-CBC-CRC DES-CBC-MD5\n"
 881                                         "\tdefault_tkt_enctypes = %s RC4-HMAC DES-CBC-CRC DES-CBC-MD5\n"
 882                                         "\tpreferred_enctypes = %s RC4-HMAC DES-CBC-CRC DES-CBC-MD5\n\n"
 883                                         "[realms]\n\t%s = {\n"
 884                                         "%s\t}\n",
 885                                         realm_upper, aes_enctypes, aes_enctypes, aes_enctypes,
 886                                         realm_upper, kdc_ip_string);
 887
 888         if (!file_contents) {
 889                 goto done;
 890         }
 891
 892         flen = strlen(file_contents);
 893
 894         mask = umask(S_IRWXO | S_IRWXG);
 895         fd = mkstemp(tmpname);
 896         umask(mask);
 897         if (fd == -1) {
 898                 DEBUG(0,("create_local_private_krb5_conf_for_domain: smb_mkstemp failed,"
 899                         " for file %s. Errno %s\n",
 900                         tmpname, strerror(errno) ));
 901                 goto done;
 902         }
 903
 904         if (fchmod(fd, 0644)==-1) {
 905                 DEBUG(0,("create_local_private_krb5_conf_for_domain: fchmod failed for %s."
 906                         " Errno %s\n",
 907                         tmpname, strerror(errno) ));
 908                 unlink(tmpname);
 909                 close(fd);
 910                 goto done;
 911         }
 912
 913         ret = write(fd, file_contents, flen);
 914         if (flen != ret) {
 915                 DEBUG(0,("create_local_private_krb5_conf_for_domain: write failed,"
 916                         " returned %d (should be %u). Errno %s\n",
 917                         (int)ret, (unsigned int)flen, strerror(errno) ));
 918                 unlink(tmpname);
 919                 close(fd);
 920                 goto done;
 921         }
 922         if (close(fd)==-1) {
 923                 DEBUG(0,("create_local_private_krb5_conf_for_domain: close failed."
 924                         " Errno %s\n", strerror(errno) ));
 925                 unlink(tmpname);
 926                 goto done;
 927         }
 928
 929         if (rename(tmpname, fname) == -1) {
 930                 DEBUG(0,("create_local_private_krb5_conf_for_domain: rename "
 931                         "of %s to %s failed. Errno %s\n",
 932                         tmpname, fname, strerror(errno) ));
 933                 unlink(tmpname);
 934                 goto done;
 935         }
 936
 937         DEBUG(5,("create_local_private_krb5_conf_for_domain: wrote "
 938                 "file %s with realm %s KDC list = %s\n",
 939                 fname, realm_upper, kdc_ip_string));
 940
 941         /* Set the environment variable to this file. */
 942         setenv("KRB5_CONFIG", fname, 1);
 943
 944         result = true;
 945
 946 #if defined(OVERWRITE_SYSTEM_KRB5_CONF)
 947
 948 #define SYSTEM_KRB5_CONF_PATH "/etc/krb5.conf"
 949         /* Insanity, sheer insanity..... */
 950
 951         if (strequal(realm, lp_realm())) {
 952                 SMB_STRUCT_STAT sbuf;
 953
 954                 if (sys_lstat(SYSTEM_KRB5_CONF_PATH, &sbuf, false) == 0) {
 955                         if (S_ISLNK(sbuf.st_ex_mode) && sbuf.st_ex_size) {
 956                                 int lret;
 957                                 size_t alloc_size = sbuf.st_ex_size + 1;
 958                                 char *linkpath = talloc_array(talloc_tos(), char,
 959                                                 alloc_size);
 960                                 if (!linkpath) {
 961                                         goto done;
 962                                 }
 963                                 lret = readlink(SYSTEM_KRB5_CONF_PATH, linkpath,
 964                                                 alloc_size - 1);
 965                                 if (lret == -1) {
 966                                         TALLOC_FREE(linkpath);
 967                                         goto done;
 968                                 }
 969                                 linkpath[lret] = '\0';
 970
 971                                 if (strcmp(linkpath, fname) == 0) {
 972                                         /* Symlink already exists. */
 973                                         TALLOC_FREE(linkpath);
 974                                         goto done;
 975                                 }
 976                                 TALLOC_FREE(linkpath);
 977                         }
 978                 }
 979
 980                 /* Try and replace with a symlink. */
 981                 if (symlink(fname, SYSTEM_KRB5_CONF_PATH) == -1) {
 982                         const char *newpath = SYSTEM_KRB5_CONF_PATH ".saved";
 983                         if (errno != EEXIST) {
 984                                 DEBUG(0,("create_local_private_krb5_conf_for_domain: symlink "
 985                                         "of %s to %s failed. Errno %s\n",
 986                                         fname, SYSTEM_KRB5_CONF_PATH, strerror(errno) ));
 987                                 goto done; /* Not a fatal error. */
 988                         }
 989
 990                         /* Yes, this is a race conditon... too bad. */
 991                         if (rename(SYSTEM_KRB5_CONF_PATH, newpath) == -1) {
 992                                 DEBUG(0,("create_local_private_krb5_conf_for_domain: rename "
 993                                         "of %s to %s failed. Errno %s\n",
 994                                         SYSTEM_KRB5_CONF_PATH, newpath,
 995                                         strerror(errno) ));
 996                                 goto done; /* Not a fatal error. */
 997                         }
 998
 999                         if (symlink(fname, SYSTEM_KRB5_CONF_PATH) == -1) {
1000                                 DEBUG(0,("create_local_private_krb5_conf_for_domain: "
1001                                         "forced symlink of %s to /etc/krb5.conf failed. Errno %s\n",
1002                                         fname, strerror(errno) ));
1003                                 goto done; /* Not a fatal error. */
1004                         }
1005                 }
1006         }
1007 #endif
1008
1009 done:
1010         TALLOC_FREE(tmpname);
1011         TALLOC_FREE(dname);
1012
1013         return result;
1014 }
1015 #endif