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 #include "librpc/gen_ndr/ndr_krb5pac.h"
  27 #include "smb_krb5.h"
  28 #include "authdata.h"
  29
  30 #ifdef HAVE_KRB5
  31
  32 /****************************************************************
  33 ****************************************************************/
  34
  35 static krb5_error_code check_pac_checksum(TALLOC_CTX *mem_ctx,
  36                                           DATA_BLOB pac_data,
  37                                           struct PAC_SIGNATURE_DATA *sig,
  38                                           krb5_context context,
  39                                           krb5_keyblock *keyblock)
  40 {
  41         krb5_error_code ret;
  42         krb5_checksum cksum;
  43         krb5_keyusage usage = 0;
  44
  45         smb_krb5_checksum_from_pac_sig(&cksum, sig);
  46
  47 #ifdef HAVE_KRB5_KU_OTHER_CKSUM /* Heimdal */
  48         usage = KRB5_KU_OTHER_CKSUM;
  49 #elif defined(HAVE_KRB5_KEYUSAGE_APP_DATA_CKSUM) /* MIT */
  50         usage = KRB5_KEYUSAGE_APP_DATA_CKSUM;
  51 #else
  52 #error UNKNOWN_KRB5_KEYUSAGE
  53 #endif
  54
  55         ret = smb_krb5_verify_checksum(context,
  56                                        keyblock,
  57                                        usage,
  58                                        &cksum,
  59                                        pac_data.data,
  60                                        pac_data.length);
  61
  62         if (ret) {
  63                 DEBUG(2,("check_pac_checksum: PAC Verification failed: %s (%d)\n",
  64                         error_message(ret), ret));
  65                 return ret;
  66         }
  67
  68         return ret;
  69 }
  70
  71 /****************************************************************
  72 ****************************************************************/
  73
  74  NTSTATUS decode_pac_data(TALLOC_CTX *mem_ctx,
  75                          DATA_BLOB *pac_data_blob,
  76                          krb5_context context,
  77                          krb5_keyblock *service_keyblock,
  78                          krb5_const_principal client_principal,
  79                          time_t tgs_authtime,
  80                          struct PAC_DATA **pac_data_out)
  81 {
  82         NTSTATUS status;
  83         enum ndr_err_code ndr_err;
  84         krb5_error_code ret;
  85         DATA_BLOB modified_pac_blob;
  86
  87         NTTIME tgs_authtime_nttime;
  88         krb5_principal client_principal_pac = NULL;
  89         int i;
  90
  91         struct PAC_SIGNATURE_DATA *srv_sig_ptr = NULL;
  92         struct PAC_SIGNATURE_DATA *kdc_sig_ptr = NULL;
  93         struct PAC_SIGNATURE_DATA *srv_sig_wipe = NULL;
  94         struct PAC_SIGNATURE_DATA *kdc_sig_wipe = NULL;
  95         struct PAC_LOGON_NAME *logon_name = NULL;
  96         struct PAC_LOGON_INFO *logon_info = NULL;
  97         struct PAC_DATA *pac_data = NULL;
  98         struct PAC_DATA_RAW *pac_data_raw = NULL;
  99
 100         DATA_BLOB *srv_sig_blob = NULL;
 101         DATA_BLOB *kdc_sig_blob = NULL;
 102
 103         *pac_data_out = NULL;
 104
 105         pac_data = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA);
 106         pac_data_raw = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA_RAW);
 107         kdc_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA);
 108         srv_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA);
 109         if (!pac_data_raw || !pac_data || !kdc_sig_wipe || !srv_sig_wipe) {
 110                 return NT_STATUS_NO_MEMORY;
 111         }
 112
 113         ndr_err = ndr_pull_struct_blob(pac_data_blob, pac_data,
 114                         NULL, pac_data,
 115                        (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 116         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 117                 status = ndr_map_error2ntstatus(ndr_err);
 118                 DEBUG(0,("can't parse the PAC: %s\n",
 119                         nt_errstr(status)));
 120                 return status;
 121         }
 122
 123         if (pac_data->num_buffers < 4) {
 124                 /* we need logon_ingo, service_key and kdc_key */
 125                 DEBUG(0,("less than 4 PAC buffers\n"));
 126                 return NT_STATUS_INVALID_PARAMETER;
 127         }
 128
 129         ndr_err = ndr_pull_struct_blob(pac_data_blob, pac_data_raw,
 130                                        NULL, pac_data_raw,
 131                                        (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA_RAW);
 132         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 133                 status = ndr_map_error2ntstatus(ndr_err);
 134                 DEBUG(0,("can't parse the PAC: %s\n",
 135                         nt_errstr(status)));
 136                 return status;
 137         }
 138
 139         if (pac_data_raw->num_buffers < 4) {
 140                 /* we need logon_ingo, service_key and kdc_key */
 141                 DEBUG(0,("less than 4 PAC buffers\n"));
 142                 return NT_STATUS_INVALID_PARAMETER;
 143         }
 144
 145         if (pac_data->num_buffers != pac_data_raw->num_buffers) {
 146                 /* we need logon_ingo, service_key and kdc_key */
 147                 DEBUG(0,("misparse!  PAC_DATA has %d buffers while PAC_DATA_RAW has %d\n",
 148                          pac_data->num_buffers, pac_data_raw->num_buffers));
 149                 return NT_STATUS_INVALID_PARAMETER;
 150         }
 151
 152         for (i=0; i < pac_data->num_buffers; i++) {
 153                 if (pac_data->buffers[i].type != pac_data_raw->buffers[i].type) {
 154                         DEBUG(0,("misparse!  PAC_DATA buffer %d has type %d while PAC_DATA_RAW has %d\n",
 155                                  i, pac_data->buffers[i].type, pac_data->buffers[i].type));
 156                         return NT_STATUS_INVALID_PARAMETER;
 157                 }
 158                 switch (pac_data->buffers[i].type) {
 159                         case PAC_TYPE_LOGON_INFO:
 160                                 if (!pac_data->buffers[i].info) {
 161                                         break;
 162                                 }
 163                                 logon_info = pac_data->buffers[i].info->logon_info.info;
 164                                 break;
 165                         case PAC_TYPE_SRV_CHECKSUM:
 166                                 if (!pac_data->buffers[i].info) {
 167                                         break;
 168                                 }
 169                                 srv_sig_ptr = &pac_data->buffers[i].info->srv_cksum;
 170                                 srv_sig_blob = &pac_data_raw->buffers[i].info->remaining;
 171                                 break;
 172                         case PAC_TYPE_KDC_CHECKSUM:
 173                                 if (!pac_data->buffers[i].info) {
 174                                         break;
 175                                 }
 176                                 kdc_sig_ptr = &pac_data->buffers[i].info->kdc_cksum;
 177                                 kdc_sig_blob = &pac_data_raw->buffers[i].info->remaining;
 178                                 break;
 179                         case PAC_TYPE_LOGON_NAME:
 180                                 logon_name = &pac_data->buffers[i].info->logon_name;
 181                                 break;
 182                         default:
 183                                 break;
 184                 }
 185         }
 186
 187         if (!logon_info) {
 188                 DEBUG(0,("PAC no logon_info\n"));
 189                 return NT_STATUS_INVALID_PARAMETER;
 190         }
 191
 192         if (!logon_name) {
 193                 DEBUG(0,("PAC no logon_name\n"));
 194                 return NT_STATUS_INVALID_PARAMETER;
 195         }
 196
 197         if (!srv_sig_ptr || !srv_sig_blob) {
 198                 DEBUG(0,("PAC no srv_key\n"));
 199                 return NT_STATUS_INVALID_PARAMETER;
 200         }
 201
 202         if (!kdc_sig_ptr || !kdc_sig_blob) {
 203                 DEBUG(0,("PAC no kdc_key\n"));
 204                 return NT_STATUS_INVALID_PARAMETER;
 205         }
 206
 207         /* Find and zero out the signatures, as required by the signing algorithm */
 208
 209         /* We find the data blobs above, now we parse them to get at the exact portion we should zero */
 210         ndr_err = ndr_pull_struct_blob(kdc_sig_blob, kdc_sig_wipe,
 211                                        NULL, kdc_sig_wipe,
 212                                        (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
 213         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 214                 status = ndr_map_error2ntstatus(ndr_err);
 215                 DEBUG(0,("can't parse the KDC signature: %s\n",
 216                         nt_errstr(status)));
 217                 return status;
 218         }
 219
 220         ndr_err = ndr_pull_struct_blob(srv_sig_blob, srv_sig_wipe,
 221                                        NULL, srv_sig_wipe,
 222                                        (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
 223         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 224                 status = ndr_map_error2ntstatus(ndr_err);
 225                 DEBUG(0,("can't parse the SRV signature: %s\n",
 226                         nt_errstr(status)));
 227                 return status;
 228         }
 229
 230         /* Now zero the decoded structure */
 231         memset(kdc_sig_wipe->signature.data, '\0', kdc_sig_wipe->signature.length);
 232         memset(srv_sig_wipe->signature.data, '\0', srv_sig_wipe->signature.length);
 233
 234         /* and reencode, back into the same place it came from */
 235         ndr_err = ndr_push_struct_blob(kdc_sig_blob, pac_data_raw,
 236                                        NULL, kdc_sig_wipe,
 237                                        (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
 238         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 239                 status = ndr_map_error2ntstatus(ndr_err);
 240                 DEBUG(0,("can't repack the KDC signature: %s\n",
 241                         nt_errstr(status)));
 242                 return status;
 243         }
 244         ndr_err = ndr_push_struct_blob(srv_sig_blob, pac_data_raw,
 245                                        NULL, srv_sig_wipe,
 246                                        (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
 247         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 248                 status = ndr_map_error2ntstatus(ndr_err);
 249                 DEBUG(0,("can't repack the SRV signature: %s\n",
 250                         nt_errstr(status)));
 251                 return status;
 252         }
 253
 254         /* push out the whole structure, but now with zero'ed signatures */
 255         ndr_err = ndr_push_struct_blob(&modified_pac_blob, pac_data_raw,
 256                                        NULL, pac_data_raw,
 257                                        (ndr_push_flags_fn_t)ndr_push_PAC_DATA_RAW);
 258         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 259                 status = ndr_map_error2ntstatus(ndr_err);
 260                 DEBUG(0,("can't repack the RAW PAC: %s\n",
 261                         nt_errstr(status)));
 262                 return status;
 263         }
 264
 265         /* verify by service_key */
 266         ret = check_pac_checksum(mem_ctx,
 267                                  modified_pac_blob, srv_sig_ptr,
 268                                  context,
 269                                  service_keyblock);
 270         if (ret) {
 271                 DEBUG(1, ("PAC Decode: Failed to verify the service signature: %s\n",
 272                           error_message(ret)));
 273                 return NT_STATUS_ACCESS_DENIED;
 274         }
 275
 276         /* Convert to NT time, so as not to loose accuracy in comparison */
 277         unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);
 278
 279         if (tgs_authtime_nttime != logon_name->logon_time) {
 280                 DEBUG(2, ("PAC Decode: Logon time mismatch between ticket and PAC!\n"));
 281                 DEBUG(2, ("PAC Decode: PAC: %s\n", nt_time_string(mem_ctx, logon_name->logon_time)));
 282                 DEBUG(2, ("PAC Decode: Ticket: %s\n", nt_time_string(mem_ctx, tgs_authtime_nttime)));
 283                 return NT_STATUS_ACCESS_DENIED;
 284         }
 285
 286         ret = smb_krb5_parse_name_norealm(context, logon_name->account_name,
 287                                     &client_principal_pac);
 288         if (ret) {
 289                 DEBUG(2, ("Could not parse name from incoming PAC: [%s]: %s\n",
 290                           logon_name->account_name,
 291                           error_message(ret)));
 292                 return NT_STATUS_INVALID_PARAMETER;
 293         }
 294
 295         if (!smb_krb5_principal_compare_any_realm(context, client_principal, client_principal_pac)) {
 296                 DEBUG(2, ("Name in PAC [%s] does not match principal name in ticket\n",
 297                           logon_name->account_name));
 298                 krb5_free_principal(context, client_principal_pac);
 299                 return NT_STATUS_ACCESS_DENIED;
 300         }
 301
 302         DEBUG(3,("Found account name from PAC: %s [%s]\n",
 303                  logon_info->info3.base.account_name.string,
 304                  logon_info->info3.base.full_name.string));
 305
 306         DEBUG(10,("Successfully validated Kerberos PAC\n"));
 307
 308         if (DEBUGLEVEL >= 10) {
 309                 const char *s;
 310                 s = NDR_PRINT_STRUCT_STRING(mem_ctx, PAC_DATA, pac_data);
 311                 if (s) {
 312                         DEBUGADD(10,("%s\n", s));
 313                 }
 314         }
 315
 316         *pac_data_out = pac_data;
 317
 318         return NT_STATUS_OK;
 319 }
 320
 321 /****************************************************************
 322 ****************************************************************/
 323
 324 struct PAC_LOGON_INFO *get_logon_info_from_pac(struct PAC_DATA *pac_data)
 325 {
 326         int i;
 327
 328         for (i=0; i < pac_data->num_buffers; i++) {
 329
 330                 if (pac_data->buffers[i].type != PAC_TYPE_LOGON_INFO) {
 331                         continue;
 332                 }
 333
 334                 return pac_data->buffers[i].info->logon_info.info;
 335         }
 336
 337         return NULL;
 338 }
 339
 340 /****************************************************************
 341 ****************************************************************/
 342
 343 NTSTATUS kerberos_return_pac(TALLOC_CTX *mem_ctx,
 344                              const char *name,
 345                              const char *pass,
 346                              time_t time_offset,
 347                              time_t *expire_time,
 348                              time_t *renew_till_time,
 349                              const char *cache_name,
 350                              bool request_pac,
 351                              bool add_netbios_addr,
 352                              time_t renewable_time,
 353                              const char *impersonate_princ_s,
 354                              struct PAC_DATA **pac_ret)
 355 {
 356         krb5_error_code ret;
 357         NTSTATUS status = NT_STATUS_INVALID_PARAMETER;
 358         DATA_BLOB tkt, ap_rep, sesskey1, sesskey2;
 359         struct PAC_DATA *pac_data = NULL;
 360         char *client_princ_out = NULL;
 361         const char *auth_princ = NULL;
 362         const char *local_service = NULL;
 363         const char *cc = "MEMORY:kerberos_return_pac";
 364
 365         ZERO_STRUCT(tkt);
 366         ZERO_STRUCT(ap_rep);
 367         ZERO_STRUCT(sesskey1);
 368         ZERO_STRUCT(sesskey2);
 369
 370         if (!name || !pass) {
 371                 return NT_STATUS_INVALID_PARAMETER;
 372         }
 373
 374         if (cache_name) {
 375                 cc = cache_name;
 376         }
 377
 378         if (!strchr_m(name, '@')) {
 379                 auth_princ = talloc_asprintf(mem_ctx, "%s@%s", name,
 380                         lp_realm());
 381         } else {
 382                 auth_princ = name;
 383         }
 384         NT_STATUS_HAVE_NO_MEMORY(auth_princ);
 385
 386         local_service = talloc_asprintf(mem_ctx, "%s$@%s",
 387                                         global_myname(), lp_realm());
 388         NT_STATUS_HAVE_NO_MEMORY(local_service);
 389
 390         ret = kerberos_kinit_password_ext(auth_princ,
 391                                           pass,
 392                                           time_offset,
 393                                           expire_time,
 394                                           renew_till_time,
 395                                           cc,
 396                                           request_pac,
 397                                           add_netbios_addr,
 398                                           renewable_time,
 399                                           &status);
 400         if (ret) {
 401                 DEBUG(1,("kinit failed for '%s' with: %s (%d)\n",
 402                         auth_princ, error_message(ret), ret));
 403                 /* status already set */
 404                 goto out;
 405         }
 406
 407         DEBUG(10,("got TGT for %s in %s\n", auth_princ, cc));
 408         if (expire_time) {
 409                 DEBUGADD(10,("\tvalid until: %s (%d)\n",
 410                         http_timestring(talloc_tos(), *expire_time),
 411                         (int)*expire_time));
 412         }
 413         if (renew_till_time) {
 414                 DEBUGADD(10,("\trenewable till: %s (%d)\n",
 415                         http_timestring(talloc_tos(), *renew_till_time),
 416                         (int)*renew_till_time));
 417         }
 418
 419         /* we cannot continue with krb5 when UF_DONT_REQUIRE_PREAUTH is set,
 420          * in that case fallback to NTLM - gd */
 421
 422         if (expire_time && renew_till_time &&
 423             (*expire_time == 0) && (*renew_till_time == 0)) {
 424                 return NT_STATUS_INVALID_LOGON_TYPE;
 425         }
 426
 427         ret = cli_krb5_get_ticket(local_service,
 428                                   time_offset,
 429                                   &tkt,
 430                                   &sesskey1,
 431                                   0,
 432                                   cc,
 433                                   NULL,
 434                                   impersonate_princ_s);
 435         if (ret) {
 436                 DEBUG(1,("failed to get ticket for %s: %s\n",
 437                         local_service, error_message(ret)));
 438                 if (impersonate_princ_s) {
 439                         DEBUGADD(1,("tried S4U2SELF impersonation as: %s\n",
 440                                 impersonate_princ_s));
 441                 }
 442                 status = krb5_to_nt_status(ret);
 443                 goto out;
 444         }
 445         status = ads_verify_ticket(mem_ctx,
 446                                    lp_realm(),
 447                                    time_offset,
 448                                    &tkt,
 449                                    &client_princ_out,
 450                                    &pac_data,
 451                                    &ap_rep,
 452                                    &sesskey2,
 453                                    False);
 454         if (!NT_STATUS_IS_OK(status)) {
 455                 DEBUG(1,("ads_verify_ticket failed: %s\n",
 456                         nt_errstr(status)));
 457                 goto out;
 458         }
 459
 460         if (!pac_data) {
 461                 DEBUG(1,("no PAC\n"));
 462                 status = NT_STATUS_INVALID_PARAMETER;
 463                 goto out;
 464         }
 465
 466         *pac_ret = pac_data;
 467
 468 out:
 469         if (cc != cache_name) {
 470                 ads_kdestroy(cc);
 471         }
 472
 473         data_blob_free(&tkt);
 474         data_blob_free(&ap_rep);
 475         data_blob_free(&sesskey1);
 476         data_blob_free(&sesskey2);
 477
 478         TALLOC_FREE(client_princ_out);
 479
 480         return status;
 481 }
 482
 483 /****************************************************************
 484 ****************************************************************/
 485
 486 static NTSTATUS kerberos_return_pac_logon_info(TALLOC_CTX *mem_ctx,
 487                                                const char *name,
 488                                                const char *pass,
 489                                                time_t time_offset,
 490                                                time_t *expire_time,
 491                                                time_t *renew_till_time,
 492                                                const char *cache_name,
 493                                                bool request_pac,
 494                                                bool add_netbios_addr,
 495                                                time_t renewable_time,
 496                                                const char *impersonate_princ_s,
 497                                                struct PAC_LOGON_INFO **logon_info)
 498 {
 499         NTSTATUS status;
 500         struct PAC_DATA *pac_data = NULL;
 501         struct PAC_LOGON_INFO *info = NULL;
 502
 503         status = kerberos_return_pac(mem_ctx,
 504                                      name,
 505                                      pass,
 506                                      time_offset,
 507                                      expire_time,
 508                                      renew_till_time,
 509                                      cache_name,
 510                                      request_pac,
 511                                      add_netbios_addr,
 512                                      renewable_time,
 513                                      impersonate_princ_s,
 514                                      &pac_data);
 515         if (!NT_STATUS_IS_OK(status)) {
 516                 return status;
 517         }
 518
 519         if (!pac_data) {
 520                 DEBUG(3,("no pac\n"));
 521                 return NT_STATUS_INVALID_USER_BUFFER;
 522         }
 523
 524         info = get_logon_info_from_pac(pac_data);
 525         if (!info) {
 526                 DEBUG(1,("no logon_info\n"));
 527                 return NT_STATUS_INVALID_USER_BUFFER;
 528         }
 529
 530         *logon_info = info;
 531
 532         return NT_STATUS_OK;
 533 }
 534
 535 /****************************************************************
 536 ****************************************************************/
 537
 538 NTSTATUS kerberos_return_info3_from_pac(TALLOC_CTX *mem_ctx,
 539                                         const char *name,
 540                                         const char *pass,
 541                                         time_t time_offset,
 542                                         time_t *expire_time,
 543                                         time_t *renew_till_time,
 544                                         const char *cache_name,
 545                                         bool request_pac,
 546                                         bool add_netbios_addr,
 547                                         time_t renewable_time,
 548                                         const char *impersonate_princ_s,
 549                                         struct netr_SamInfo3 **info3)
 550 {
 551         NTSTATUS status;
 552         struct PAC_LOGON_INFO *logon_info = NULL;
 553
 554         status = kerberos_return_pac_logon_info(mem_ctx,
 555                                                 name,
 556                                                 pass,
 557                                                 time_offset,
 558                                                 expire_time,
 559                                                 renew_till_time,
 560                                                 cache_name,
 561                                                 request_pac,
 562                                                 add_netbios_addr,
 563                                                 renewable_time,
 564                                                 impersonate_princ_s,
 565                                                 &logon_info);
 566         if (!NT_STATUS_IS_OK(status)) {
 567                 return status;
 568         }
 569
 570         *info3 = &logon_info->info3;
 571
 572         return NT_STATUS_OK;
 573 }
 574 #endif