source3/libads/authdata.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    kerberos authorization data (PAC) utility library
   4    Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003
   5    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   6    Copyright (C) Andrew Tridgell 2001
   7    Copyright (C) Luke Howard 2002-2003
   8    Copyright (C) Stefan Metzmacher 2004-2005
   9    Copyright (C) Guenther Deschner 2005,2007,2008
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 3 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 #include "includes.h"
  26
  27 #ifdef HAVE_KRB5
  28
  29 /****************************************************************
  30 ****************************************************************/
  31
  32 static krb5_error_code check_pac_checksum(TALLOC_CTX *mem_ctx,
  33                                           DATA_BLOB pac_data,
  34                                           struct PAC_SIGNATURE_DATA *sig,
  35                                           krb5_context context,
  36                                           krb5_keyblock *keyblock)
  37 {
  38         krb5_error_code ret;
  39         krb5_checksum cksum;
  40         krb5_keyusage usage = 0;
  41
  42         smb_krb5_checksum_from_pac_sig(&cksum, sig);
  43
  44 #ifdef HAVE_KRB5_KU_OTHER_CKSUM /* Heimdal */
  45         usage = KRB5_KU_OTHER_CKSUM;
  46 #elif defined(HAVE_KRB5_KEYUSAGE_APP_DATA_CKSUM) /* MIT */
  47         usage = KRB5_KEYUSAGE_APP_DATA_CKSUM;
  48 #else
  49 #error UNKNOWN_KRB5_KEYUSAGE
  50 #endif
  51
  52         ret = smb_krb5_verify_checksum(context,
  53                                        keyblock,
  54                                        usage,
  55                                        &cksum,
  56                                        pac_data.data,
  57                                        pac_data.length);
  58
  59         if (ret) {
  60                 DEBUG(2,("check_pac_checksum: PAC Verification failed: %s (%d)\n",
  61                         error_message(ret), ret));
  62                 return ret;
  63         }
  64
  65         return ret;
  66 }
  67
  68 /****************************************************************
  69 ****************************************************************/
  70
  71  NTSTATUS decode_pac_data(TALLOC_CTX *mem_ctx,
  72                          DATA_BLOB *pac_data_blob,
  73                          krb5_context context,
  74                          krb5_keyblock *service_keyblock,
  75                          krb5_const_principal client_principal,
  76                          time_t tgs_authtime,
  77                          struct PAC_DATA **pac_data_out)
  78 {
  79         NTSTATUS status;
  80         enum ndr_err_code ndr_err;
  81         krb5_error_code ret;
  82         DATA_BLOB modified_pac_blob;
  83
  84         NTTIME tgs_authtime_nttime;
  85         krb5_principal client_principal_pac = NULL;
  86         int i;
  87
  88         struct PAC_SIGNATURE_DATA *srv_sig_ptr = NULL;
  89         struct PAC_SIGNATURE_DATA *kdc_sig_ptr = NULL;
  90         struct PAC_SIGNATURE_DATA *srv_sig_wipe = NULL;
  91         struct PAC_SIGNATURE_DATA *kdc_sig_wipe = NULL;
  92         struct PAC_LOGON_NAME *logon_name = NULL;
  93         struct PAC_LOGON_INFO *logon_info = NULL;
  94         struct PAC_DATA *pac_data = NULL;
  95         struct PAC_DATA_RAW *pac_data_raw = NULL;
  96
  97         DATA_BLOB *srv_sig_blob = NULL;
  98         DATA_BLOB *kdc_sig_blob = NULL;
  99
 100         *pac_data_out = NULL;
 101
 102         pac_data = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA);
 103         pac_data_raw = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA_RAW);
 104         kdc_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA);
 105         srv_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA);
 106         if (!pac_data_raw || !pac_data || !kdc_sig_wipe || !srv_sig_wipe) {
 107                 return NT_STATUS_NO_MEMORY;
 108         }
 109
 110         ndr_err = ndr_pull_struct_blob(pac_data_blob, pac_data,
 111                         NULL, pac_data,
 112                        (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 113         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 114                 status = ndr_map_error2ntstatus(ndr_err);
 115                 DEBUG(0,("can't parse the PAC: %s\n",
 116                         nt_errstr(status)));
 117                 return status;
 118         }
 119
 120         if (pac_data->num_buffers < 4) {
 121                 /* we need logon_ingo, service_key and kdc_key */
 122                 DEBUG(0,("less than 4 PAC buffers\n"));
 123                 return NT_STATUS_INVALID_PARAMETER;
 124         }
 125
 126         ndr_err = ndr_pull_struct_blob(pac_data_blob, pac_data_raw,
 127                                        NULL, pac_data_raw,
 128                                        (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA_RAW);
 129         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 130                 status = ndr_map_error2ntstatus(ndr_err);
 131                 DEBUG(0,("can't parse the PAC: %s\n",
 132                         nt_errstr(status)));
 133                 return status;
 134         }
 135
 136         if (pac_data_raw->num_buffers < 4) {
 137                 /* we need logon_ingo, service_key and kdc_key */
 138                 DEBUG(0,("less than 4 PAC buffers\n"));
 139                 return NT_STATUS_INVALID_PARAMETER;
 140         }
 141
 142         if (pac_data->num_buffers != pac_data_raw->num_buffers) {
 143                 /* we need logon_ingo, service_key and kdc_key */
 144                 DEBUG(0,("misparse!  PAC_DATA has %d buffers while PAC_DATA_RAW has %d\n",
 145                          pac_data->num_buffers, pac_data_raw->num_buffers));
 146                 return NT_STATUS_INVALID_PARAMETER;
 147         }
 148
 149         for (i=0; i < pac_data->num_buffers; i++) {
 150                 if (pac_data->buffers[i].type != pac_data_raw->buffers[i].type) {
 151                         DEBUG(0,("misparse!  PAC_DATA buffer %d has type %d while PAC_DATA_RAW has %d\n",
 152                                  i, pac_data->buffers[i].type, pac_data->buffers[i].type));
 153                         return NT_STATUS_INVALID_PARAMETER;
 154                 }
 155                 switch (pac_data->buffers[i].type) {
 156                         case PAC_TYPE_LOGON_INFO:
 157                                 if (!pac_data->buffers[i].info) {
 158                                         break;
 159                                 }
 160                                 logon_info = pac_data->buffers[i].info->logon_info.info;
 161                                 break;
 162                         case PAC_TYPE_SRV_CHECKSUM:
 163                                 if (!pac_data->buffers[i].info) {
 164                                         break;
 165                                 }
 166                                 srv_sig_ptr = &pac_data->buffers[i].info->srv_cksum;
 167                                 srv_sig_blob = &pac_data_raw->buffers[i].info->remaining;
 168                                 break;
 169                         case PAC_TYPE_KDC_CHECKSUM:
 170                                 if (!pac_data->buffers[i].info) {
 171                                         break;
 172                                 }
 173                                 kdc_sig_ptr = &pac_data->buffers[i].info->kdc_cksum;
 174                                 kdc_sig_blob = &pac_data_raw->buffers[i].info->remaining;
 175                                 break;
 176                         case PAC_TYPE_LOGON_NAME:
 177                                 logon_name = &pac_data->buffers[i].info->logon_name;
 178                                 break;
 179                         default:
 180                                 break;
 181                 }
 182         }
 183
 184         if (!logon_info) {
 185                 DEBUG(0,("PAC no logon_info\n"));
 186                 return NT_STATUS_INVALID_PARAMETER;
 187         }
 188
 189         if (!logon_name) {
 190                 DEBUG(0,("PAC no logon_name\n"));
 191                 return NT_STATUS_INVALID_PARAMETER;
 192         }
 193
 194         if (!srv_sig_ptr || !srv_sig_blob) {
 195                 DEBUG(0,("PAC no srv_key\n"));
 196                 return NT_STATUS_INVALID_PARAMETER;
 197         }
 198
 199         if (!kdc_sig_ptr || !kdc_sig_blob) {
 200                 DEBUG(0,("PAC no kdc_key\n"));
 201                 return NT_STATUS_INVALID_PARAMETER;
 202         }
 203
 204         /* Find and zero out the signatures, as required by the signing algorithm */
 205
 206         /* We find the data blobs above, now we parse them to get at the exact portion we should zero */
 207         ndr_err = ndr_pull_struct_blob(kdc_sig_blob, kdc_sig_wipe,
 208                                        NULL, kdc_sig_wipe,
 209                                        (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
 210         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 211                 status = ndr_map_error2ntstatus(ndr_err);
 212                 DEBUG(0,("can't parse the KDC signature: %s\n",
 213                         nt_errstr(status)));
 214                 return status;
 215         }
 216
 217         ndr_err = ndr_pull_struct_blob(srv_sig_blob, srv_sig_wipe,
 218                                        NULL, srv_sig_wipe,
 219                                        (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
 220         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 221                 status = ndr_map_error2ntstatus(ndr_err);
 222                 DEBUG(0,("can't parse the SRV signature: %s\n",
 223                         nt_errstr(status)));
 224                 return status;
 225         }
 226
 227         /* Now zero the decoded structure */
 228         memset(kdc_sig_wipe->signature.data, '\0', kdc_sig_wipe->signature.length);
 229         memset(srv_sig_wipe->signature.data, '\0', srv_sig_wipe->signature.length);
 230
 231         /* and reencode, back into the same place it came from */
 232         ndr_err = ndr_push_struct_blob(kdc_sig_blob, pac_data_raw,
 233                                        NULL, kdc_sig_wipe,
 234                                        (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
 235         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 236                 status = ndr_map_error2ntstatus(ndr_err);
 237                 DEBUG(0,("can't repack the KDC signature: %s\n",
 238                         nt_errstr(status)));
 239                 return status;
 240         }
 241         ndr_err = ndr_push_struct_blob(srv_sig_blob, pac_data_raw,
 242                                        NULL, srv_sig_wipe,
 243                                        (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
 244         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 245                 status = ndr_map_error2ntstatus(ndr_err);
 246                 DEBUG(0,("can't repack the SRV signature: %s\n",
 247                         nt_errstr(status)));
 248                 return status;
 249         }
 250
 251         /* push out the whole structure, but now with zero'ed signatures */
 252         ndr_err = ndr_push_struct_blob(&modified_pac_blob, pac_data_raw,
 253                                        NULL, pac_data_raw,
 254                                        (ndr_push_flags_fn_t)ndr_push_PAC_DATA_RAW);
 255         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 256                 status = ndr_map_error2ntstatus(ndr_err);
 257                 DEBUG(0,("can't repack the RAW PAC: %s\n",
 258                         nt_errstr(status)));
 259                 return status;
 260         }
 261
 262         /* verify by service_key */
 263         ret = check_pac_checksum(mem_ctx,
 264                                  modified_pac_blob, srv_sig_ptr,
 265                                  context,
 266                                  service_keyblock);
 267         if (ret) {
 268                 DEBUG(1, ("PAC Decode: Failed to verify the service signature: %s\n",
 269                           error_message(ret)));
 270                 return NT_STATUS_ACCESS_DENIED;
 271         }
 272
 273         /* Convert to NT time, so as not to loose accuracy in comparison */
 274         unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);
 275
 276         if (tgs_authtime_nttime != logon_name->logon_time) {
 277                 DEBUG(2, ("PAC Decode: Logon time mismatch between ticket and PAC!\n"));
 278                 DEBUG(2, ("PAC Decode: PAC: %s\n", nt_time_string(mem_ctx, logon_name->logon_time)));
 279                 DEBUG(2, ("PAC Decode: Ticket: %s\n", nt_time_string(mem_ctx, tgs_authtime_nttime)));
 280                 return NT_STATUS_ACCESS_DENIED;
 281         }
 282
 283         ret = smb_krb5_parse_name_norealm(context, logon_name->account_name,
 284                                     &client_principal_pac);
 285         if (ret) {
 286                 DEBUG(2, ("Could not parse name from incoming PAC: [%s]: %s\n",
 287                           logon_name->account_name,
 288                           error_message(ret)));
 289                 return NT_STATUS_INVALID_PARAMETER;
 290         }
 291
 292         if (!smb_krb5_principal_compare_any_realm(context, client_principal, client_principal_pac)) {
 293                 DEBUG(2, ("Name in PAC [%s] does not match principal name in ticket\n",
 294                           logon_name->account_name));
 295                 krb5_free_principal(context, client_principal_pac);
 296                 return NT_STATUS_ACCESS_DENIED;
 297         }
 298
 299         DEBUG(3,("Found account name from PAC: %s [%s]\n",
 300                  logon_info->info3.base.account_name.string,
 301                  logon_info->info3.base.full_name.string));
 302
 303         DEBUG(10,("Successfully validated Kerberos PAC\n"));
 304
 305         if (DEBUGLEVEL >= 10) {
 306                 const char *s;
 307                 s = NDR_PRINT_STRUCT_STRING(mem_ctx, PAC_DATA, pac_data);
 308                 if (s) {
 309                         DEBUGADD(10,("%s\n", s));
 310                 }
 311         }
 312
 313         *pac_data_out = pac_data;
 314
 315         return NT_STATUS_OK;
 316 }
 317
 318 /****************************************************************
 319 ****************************************************************/
 320
 321 struct PAC_LOGON_INFO *get_logon_info_from_pac(struct PAC_DATA *pac_data)
 322 {
 323         int i;
 324
 325         for (i=0; i < pac_data->num_buffers; i++) {
 326
 327                 if (pac_data->buffers[i].type != PAC_TYPE_LOGON_INFO) {
 328                         continue;
 329                 }
 330
 331                 return pac_data->buffers[i].info->logon_info.info;
 332         }
 333
 334         return NULL;
 335 }
 336
 337 /****************************************************************
 338 ****************************************************************/
 339
 340 NTSTATUS kerberos_return_pac(TALLOC_CTX *mem_ctx,
 341                              const char *name,
 342                              const char *pass,
 343                              time_t time_offset,
 344                              time_t *expire_time,
 345                              time_t *renew_till_time,
 346                              const char *cache_name,
 347                              bool request_pac,
 348                              bool add_netbios_addr,
 349                              time_t renewable_time,
 350                              struct PAC_DATA **pac_ret)
 351 {
 352         krb5_error_code ret;
 353         NTSTATUS status = NT_STATUS_INVALID_PARAMETER;
 354         DATA_BLOB tkt, ap_rep, sesskey1, sesskey2;
 355         struct PAC_DATA *pac_data = NULL;
 356         char *client_princ_out = NULL;
 357         const char *auth_princ = NULL;
 358         const char *local_service = NULL;
 359         const char *cc = "MEMORY:kerberos_return_pac";
 360
 361         ZERO_STRUCT(tkt);
 362         ZERO_STRUCT(ap_rep);
 363         ZERO_STRUCT(sesskey1);
 364         ZERO_STRUCT(sesskey2);
 365
 366         if (!name || !pass) {
 367                 return NT_STATUS_INVALID_PARAMETER;
 368         }
 369
 370         if (cache_name) {
 371                 cc = cache_name;
 372         }
 373
 374         if (!strchr_m(name, '@')) {
 375                 auth_princ = talloc_asprintf(mem_ctx, "%s@%s", name,
 376                         lp_realm());
 377         } else {
 378                 auth_princ = name;
 379         }
 380         NT_STATUS_HAVE_NO_MEMORY(auth_princ);
 381
 382         local_service = talloc_asprintf(mem_ctx, "%s$@%s",
 383                                         global_myname(), lp_realm());
 384         NT_STATUS_HAVE_NO_MEMORY(local_service);
 385
 386         ret = kerberos_kinit_password_ext(auth_princ,
 387                                           pass,
 388                                           time_offset,
 389                                           expire_time,
 390                                           renew_till_time,
 391                                           cc,
 392                                           request_pac,
 393                                           add_netbios_addr,
 394                                           renewable_time,
 395                                           &status);
 396         if (ret) {
 397                 DEBUG(1,("kinit failed for '%s' with: %s (%d)\n",
 398                         auth_princ, error_message(ret), ret));
 399                 /* status already set */
 400                 goto out;
 401         }
 402
 403         DEBUG(10,("got TGT for %s in %s\n", auth_princ, cc));
 404         if (expire_time) {
 405                 DEBUGADD(10,("\tvalid until: %s (%d)\n",
 406                         http_timestring(*expire_time),
 407                         (int)*expire_time));
 408         }
 409         if (renew_till_time) {
 410                 DEBUGADD(10,("\trenewable till: %s (%d)\n",
 411                         http_timestring(*renew_till_time),
 412                         (int)*renew_till_time));
 413         }
 414
 415         /* we cannot continue with krb5 when UF_DONT_REQUIRE_PREAUTH is set,
 416          * in that case fallback to NTLM - gd */
 417
 418         if (expire_time && renew_till_time &&
 419             (*expire_time == 0) && (*renew_till_time == 0)) {
 420                 return NT_STATUS_INVALID_LOGON_TYPE;
 421         }
 422
 423
 424         ret = cli_krb5_get_ticket(local_service,
 425                                   time_offset,
 426                                   &tkt,
 427                                   &sesskey1,
 428                                   0,
 429                                   cc,
 430                                   NULL);
 431         if (ret) {
 432                 DEBUG(1,("failed to get ticket for %s: %s\n",
 433                         local_service, error_message(ret)));
 434                 status = krb5_to_nt_status(ret);
 435                 goto out;
 436         }
 437
 438         status = ads_verify_ticket(mem_ctx,
 439                                    lp_realm(),
 440                                    time_offset,
 441                                    &tkt,
 442                                    &client_princ_out,
 443                                    &pac_data,
 444                                    &ap_rep,
 445                                    &sesskey2,
 446                                    False);
 447         if (!NT_STATUS_IS_OK(status)) {
 448                 DEBUG(1,("ads_verify_ticket failed: %s\n",
 449                         nt_errstr(status)));
 450                 goto out;
 451         }
 452
 453         if (!pac_data) {
 454                 DEBUG(1,("no PAC\n"));
 455                 status = NT_STATUS_INVALID_PARAMETER;
 456                 goto out;
 457         }
 458
 459         *pac_ret = pac_data;
 460
 461 out:
 462         if (cc != cache_name) {
 463                 ads_kdestroy(cc);
 464         }
 465
 466         data_blob_free(&tkt);
 467         data_blob_free(&ap_rep);
 468         data_blob_free(&sesskey1);
 469         data_blob_free(&sesskey2);
 470
 471         SAFE_FREE(client_princ_out);
 472
 473         return status;
 474 }
 475
 476 /****************************************************************
 477 ****************************************************************/
 478
 479 static NTSTATUS kerberos_return_pac_logon_info(TALLOC_CTX *mem_ctx,
 480                                                const char *name,
 481                                                const char *pass,
 482                                                time_t time_offset,
 483                                                time_t *expire_time,
 484                                                time_t *renew_till_time,
 485                                                const char *cache_name,
 486                                                bool request_pac,
 487                                                bool add_netbios_addr,
 488                                                time_t renewable_time,
 489                                                struct PAC_LOGON_INFO **logon_info)
 490 {
 491         NTSTATUS status;
 492         struct PAC_DATA *pac_data = NULL;
 493         struct PAC_LOGON_INFO *info = NULL;
 494
 495         status = kerberos_return_pac(mem_ctx,
 496                                      name,
 497                                      pass,
 498                                      time_offset,
 499                                      expire_time,
 500                                      renew_till_time,
 501                                      cache_name,
 502                                      request_pac,
 503                                      add_netbios_addr,
 504                                      renewable_time,
 505                                      &pac_data);
 506         if (!NT_STATUS_IS_OK(status)) {
 507                 return status;
 508         }
 509
 510         if (!pac_data) {
 511                 DEBUG(3,("no pac\n"));
 512                 return NT_STATUS_INVALID_USER_BUFFER;
 513         }
 514
 515         info = get_logon_info_from_pac(pac_data);
 516         if (!info) {
 517                 DEBUG(1,("no logon_info\n"));
 518                 return NT_STATUS_INVALID_USER_BUFFER;
 519         }
 520
 521         *logon_info = info;
 522
 523         return NT_STATUS_OK;
 524 }
 525
 526 /****************************************************************
 527 ****************************************************************/
 528
 529 NTSTATUS kerberos_return_info3_from_pac(TALLOC_CTX *mem_ctx,
 530                                         const char *name,
 531                                         const char *pass,
 532                                         time_t time_offset,
 533                                         time_t *expire_time,
 534                                         time_t *renew_till_time,
 535                                         const char *cache_name,
 536                                         bool request_pac,
 537                                         bool add_netbios_addr,
 538                                         time_t renewable_time,
 539                                         struct netr_SamInfo3 **info3)
 540 {
 541         NTSTATUS status;
 542         struct PAC_LOGON_INFO *logon_info = NULL;
 543
 544         status = kerberos_return_pac_logon_info(mem_ctx,
 545                                                 name,
 546                                                 pass,
 547                                                 time_offset,
 548                                                 expire_time,
 549                                                 renew_till_time,
 550                                                 cache_name,
 551                                                 request_pac,
 552                                                 add_netbios_addr,
 553                                                 renewable_time,
 554                                                 &logon_info);
 555         if (!NT_STATUS_IS_OK(status)) {
 556                 return status;
 557         }
 558
 559         *info3 = &logon_info->info3;
 560
 561         return NT_STATUS_OK;
 562 }
 563 #endif