source4/auth/kerberos/kerberos_pac.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Create and parse the krb5 PAC
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   7    Copyright (C) Andrew Tridgell 2001
   8    Copyright (C) Luke Howard 2002-2003
   9    Copyright (C) Stefan Metzmacher 2004-2005
  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 2 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
  22    You should have received a copy of the GNU General Public License
  23    along with this program; if not, write to the Free Software
  24    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25 */
  26
  27 #include "includes.h"
  28 #include "system/kerberos.h"
  29 #include "system/time.h"
  30 #include "system/network.h"
  31 #include "auth/auth.h"
  32 #include "auth/kerberos/kerberos.h"
  33 #include "librpc/gen_ndr/ndr_krb5pac.h"
  34 #include "auth/auth.h"
  35
  36 static krb5_error_code check_pac_checksum(TALLOC_CTX *mem_ctx,
  37                                           DATA_BLOB pac_data,
  38                                           struct PAC_SIGNATURE_DATA *sig,
  39                                           krb5_context context,
  40                                           krb5_keyblock *keyblock)
  41 {
  42         krb5_error_code ret;
  43         krb5_crypto crypto;
  44         Checksum cksum;
  45
  46         cksum.cksumtype         = (CKSUMTYPE)sig->type;
  47         cksum.checksum.length   = sig->signature.length;
  48         cksum.checksum.data     = sig->signature.data;
  49
  50         ret = krb5_crypto_init(context,
  51                                keyblock,
  52                                0,
  53                                &crypto);
  54         if (ret) {
  55                 DEBUG(0,("krb5_crypto_init() failed: %s\n",
  56                           smb_get_krb5_error_message(context, ret, mem_ctx)));
  57                 return ret;
  58         }
  59         ret = krb5_verify_checksum(context,
  60                                    crypto,
  61                                    KRB5_KU_OTHER_CKSUM,
  62                                    pac_data.data,
  63                                    pac_data.length,
  64                                    &cksum);
  65         krb5_crypto_destroy(context, crypto);
  66
  67         return ret;
  68 }
  69
  70  NTSTATUS kerberos_decode_pac(TALLOC_CTX *mem_ctx,
  71                               struct PAC_DATA **pac_data_out,
  72                               DATA_BLOB blob,
  73                               krb5_context context,
  74                               krb5_keyblock *krbtgt_keyblock,
  75                               krb5_keyblock *service_keyblock,
  76                               krb5_const_principal client_principal,
  77                               time_t tgs_authtime,
  78                               krb5_error_code *k5ret)
  79 {
  80         krb5_error_code ret;
  81         NTSTATUS status;
  82         struct PAC_SIGNATURE_DATA *srv_sig_ptr = NULL;
  83         struct PAC_SIGNATURE_DATA *kdc_sig_ptr = NULL;
  84         struct PAC_SIGNATURE_DATA *srv_sig_wipe = NULL;
  85         struct PAC_SIGNATURE_DATA *kdc_sig_wipe = NULL;
  86         struct PAC_LOGON_INFO *logon_info = NULL;
  87         struct PAC_LOGON_NAME *logon_name = NULL;
  88         struct PAC_DATA *pac_data;
  89         struct PAC_DATA_RAW *pac_data_raw;
  90
  91         DATA_BLOB *srv_sig_blob = NULL;
  92         DATA_BLOB *kdc_sig_blob = NULL;
  93
  94         DATA_BLOB modified_pac_blob;
  95         NTTIME tgs_authtime_nttime;
  96         krb5_principal client_principal_pac;
  97         int i;
  98
  99         krb5_clear_error_string(context);
 100
 101         if (k5ret) {
 102                 *k5ret = KRB5_PARSE_MALFORMED;
 103         }
 104
 105         pac_data = talloc(mem_ctx, struct PAC_DATA);
 106         pac_data_raw = talloc(mem_ctx, struct PAC_DATA_RAW);
 107         kdc_sig_wipe = talloc(mem_ctx, struct PAC_SIGNATURE_DATA);
 108         srv_sig_wipe = talloc(mem_ctx, struct PAC_SIGNATURE_DATA);
 109         if (!pac_data_raw || !pac_data || !kdc_sig_wipe || !srv_sig_wipe) {
 110                 if (k5ret) {
 111                         *k5ret = ENOMEM;
 112                 }
 113                 return NT_STATUS_NO_MEMORY;
 114         }
 115
 116         status = ndr_pull_struct_blob(&blob, pac_data, pac_data,
 117                                       (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 118         if (!NT_STATUS_IS_OK(status)) {
 119                 DEBUG(0,("can't parse the PAC\n"));
 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         status = ndr_pull_struct_blob(&blob, pac_data_raw, pac_data_raw,
 130                                       (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA_RAW);
 131         if (!NT_STATUS_IS_OK(status)) {
 132                 DEBUG(0,("can't parse the PAC\n"));
 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         status = ndr_pull_struct_blob(kdc_sig_blob, kdc_sig_wipe, kdc_sig_wipe,
 208                                       (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
 209         if (!NT_STATUS_IS_OK(status)) {
 210                 DEBUG(0,("can't parse the KDC signature\n"));
 211                 return status;
 212         }
 213
 214         status = ndr_pull_struct_blob(srv_sig_blob, srv_sig_wipe, srv_sig_wipe,
 215                                       (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
 216         if (!NT_STATUS_IS_OK(status)) {
 217                 DEBUG(0,("can't parse the SRV signature\n"));
 218                 return status;
 219         }
 220
 221         /* Now zero the decoded structure */
 222         memset(kdc_sig_wipe->signature.data, '\0', kdc_sig_wipe->signature.length);
 223         memset(srv_sig_wipe->signature.data, '\0', srv_sig_wipe->signature.length);
 224
 225         /* and reencode, back into the same place it came from */
 226         status = ndr_push_struct_blob(kdc_sig_blob, pac_data_raw, kdc_sig_wipe,
 227                                       (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
 228         if (!NT_STATUS_IS_OK(status)) {
 229                 DEBUG(0,("can't repack the KDC signature\n"));
 230                 return status;
 231         }
 232         status = ndr_push_struct_blob(srv_sig_blob, pac_data_raw, srv_sig_wipe,
 233                                       (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
 234         if (!NT_STATUS_IS_OK(status)) {
 235                 DEBUG(0,("can't repack the SRV signature\n"));
 236                 return status;
 237         }
 238
 239         /* push out the whole structure, but now with zero'ed signatures */
 240         status = ndr_push_struct_blob(&modified_pac_blob, pac_data_raw, pac_data_raw,
 241                                          (ndr_push_flags_fn_t)ndr_push_PAC_DATA_RAW);
 242         if (!NT_STATUS_IS_OK(status)) {
 243                 DEBUG(0,("can't repack the RAW PAC\n"));
 244                 return status;
 245         }
 246
 247         /* verify by service_key */
 248         ret = check_pac_checksum(mem_ctx,
 249                                  modified_pac_blob, srv_sig_ptr,
 250                                  context,
 251                                  service_keyblock);
 252         if (ret) {
 253                 DEBUG(1, ("PAC Decode: Failed to verify the service signature: %s\n",
 254                           smb_get_krb5_error_message(context, ret, mem_ctx)));
 255                 if (k5ret) {
 256                         *k5ret = ret;
 257                 }
 258                 return NT_STATUS_ACCESS_DENIED;
 259         }
 260
 261         if (krbtgt_keyblock) {
 262                 ret = check_pac_checksum(mem_ctx,
 263                                             srv_sig_ptr->signature, kdc_sig_ptr,
 264                                             context, krbtgt_keyblock);
 265                 if (ret) {
 266                         DEBUG(1, ("PAC Decode: Failed to verify the KDC signature: %s\n",
 267                                   smb_get_krb5_error_message(context, ret, mem_ctx)));
 268                         if (k5ret) {
 269                                 *k5ret = ret;
 270                         }
 271                         return NT_STATUS_ACCESS_DENIED;
 272                 }
 273         }
 274
 275         /* Convert to NT time, so as not to loose accuracy in comparison */
 276         unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);
 277
 278         if (tgs_authtime_nttime != logon_name->logon_time) {
 279                 DEBUG(2, ("PAC Decode: Logon time mismatch between ticket and PAC!\n"));
 280                 DEBUG(2, ("PAC Decode: PAC: %s\n", nt_time_string(mem_ctx, logon_name->logon_time)));
 281                 DEBUG(2, ("PAC Decode: Ticket: %s\n", nt_time_string(mem_ctx, tgs_authtime_nttime)));
 282                 return NT_STATUS_ACCESS_DENIED;
 283         }
 284
 285         ret = krb5_parse_name_norealm(context, logon_name->account_name, &client_principal_pac);
 286         if (ret) {
 287                 DEBUG(2, ("Could not parse name from incoming PAC: [%s]: %s\n",
 288                           logon_name->account_name,
 289                           smb_get_krb5_error_message(context, ret, mem_ctx)));
 290                 if (k5ret) {
 291                         *k5ret = ret;
 292                 }
 293                 return NT_STATUS_INVALID_PARAMETER;
 294         }
 295
 296         if (!krb5_principal_compare_any_realm(context, client_principal, client_principal_pac)) {
 297                 DEBUG(2, ("Name in PAC [%s] does not match principal name in ticket\n",
 298                           logon_name->account_name));
 299                 return NT_STATUS_ACCESS_DENIED;
 300         }
 301
 302 #if 0
 303         if (strcasecmp(logon_info->info3.base.account_name.string,
 304                        "Administrator")== 0) {
 305                 file_save("tmp_pac_data-admin.dat",blob.data,blob.length);
 306         }
 307 #endif
 308
 309         DEBUG(0,("account_name: %s [%s]\n",
 310                  logon_info->info3.base.account_name.string,
 311                  logon_info->info3.base.full_name.string));
 312         *pac_data_out = pac_data;
 313
 314         return status;
 315 }
 316
 317  NTSTATUS kerberos_pac_logon_info(TALLOC_CTX *mem_ctx,
 318                                   struct PAC_LOGON_INFO **logon_info,
 319                                   DATA_BLOB blob,
 320                                   krb5_context context,
 321                                   krb5_keyblock *krbtgt_keyblock,
 322                                   krb5_keyblock *service_keyblock,
 323                                   krb5_const_principal client_principal,
 324                                   time_t tgs_authtime,
 325                                   krb5_error_code *k5ret)
 326 {
 327         NTSTATUS nt_status;
 328         struct PAC_DATA *pac_data;
 329         int i;
 330         nt_status = kerberos_decode_pac(mem_ctx, &pac_data,
 331                                         blob,
 332                                         context,
 333                                         krbtgt_keyblock,
 334                                         service_keyblock,
 335                                         client_principal,
 336                                         tgs_authtime,
 337                                         k5ret);
 338         if (!NT_STATUS_IS_OK(nt_status)) {
 339                 return nt_status;
 340         }
 341
 342         *logon_info = NULL;
 343         for (i=0; i < pac_data->num_buffers; i++) {
 344                 if (pac_data->buffers[i].type != PAC_TYPE_LOGON_INFO) {
 345                         continue;
 346                 }
 347                 *logon_info = pac_data->buffers[i].info->logon_info.info;
 348         }
 349         if (!*logon_info) {
 350                 return NT_STATUS_INVALID_PARAMETER;
 351         }
 352         return NT_STATUS_OK;
 353 }
 354
 355 static krb5_error_code make_pac_checksum(TALLOC_CTX *mem_ctx,
 356                                          DATA_BLOB *pac_data,
 357                                          struct PAC_SIGNATURE_DATA *sig,
 358                                          krb5_context context,
 359                                          krb5_keyblock *keyblock)
 360 {
 361         krb5_error_code ret;
 362         krb5_crypto crypto;
 363         Checksum cksum;
 364
 365
 366         ret = krb5_crypto_init(context,
 367                                keyblock,
 368                                0,
 369                                &crypto);
 370         if (ret) {
 371                 DEBUG(0,("krb5_crypto_init() failed: %s\n",
 372                           smb_get_krb5_error_message(context, ret, mem_ctx)));
 373                 return ret;
 374         }
 375         ret = krb5_create_checksum(context,
 376                                    crypto,
 377                                    KRB5_KU_OTHER_CKSUM,
 378                                    0,
 379                                    pac_data->data,
 380                                    pac_data->length,
 381                                    &cksum);
 382         if (ret) {
 383                 DEBUG(2, ("PAC Verification failed: %s\n",
 384                           smb_get_krb5_error_message(context, ret, mem_ctx)));
 385         }
 386
 387         krb5_crypto_destroy(context, crypto);
 388
 389         if (ret) {
 390                 return ret;
 391         }
 392
 393         sig->type = cksum.cksumtype;
 394         sig->signature = data_blob_talloc(mem_ctx, cksum.checksum.data, cksum.checksum.length);
 395         free_Checksum(&cksum);
 396
 397         return 0;
 398 }
 399
 400  krb5_error_code kerberos_encode_pac(TALLOC_CTX *mem_ctx,
 401                                     struct PAC_DATA *pac_data,
 402                                     krb5_context context,
 403                                     krb5_keyblock *krbtgt_keyblock,
 404                                     krb5_keyblock *service_keyblock,
 405                                     DATA_BLOB *pac)
 406 {
 407         NTSTATUS nt_status;
 408         krb5_error_code ret;
 409         DATA_BLOB zero_blob = data_blob(NULL, 0);
 410         DATA_BLOB tmp_blob = data_blob(NULL, 0);
 411         struct PAC_SIGNATURE_DATA *kdc_checksum = NULL;
 412         struct PAC_SIGNATURE_DATA *srv_checksum = NULL;
 413         int i;
 414
 415         /* First, just get the keytypes filled in (and lengths right, eventually) */
 416         for (i=0; i < pac_data->num_buffers; i++) {
 417                 if (pac_data->buffers[i].type != PAC_TYPE_KDC_CHECKSUM) {
 418                         continue;
 419                 }
 420                 kdc_checksum = &pac_data->buffers[i].info->kdc_cksum,
 421                 ret = make_pac_checksum(mem_ctx, &zero_blob,
 422                                         kdc_checksum,
 423                                         context, krbtgt_keyblock);
 424                 if (ret) {
 425                         DEBUG(2, ("making krbtgt PAC checksum failed: %s\n",
 426                                   smb_get_krb5_error_message(context, ret, mem_ctx)));
 427                         talloc_free(pac_data);
 428                         return ret;
 429                 }
 430         }
 431
 432         for (i=0; i < pac_data->num_buffers; i++) {
 433                 if (pac_data->buffers[i].type != PAC_TYPE_SRV_CHECKSUM) {
 434                         continue;
 435                 }
 436                 srv_checksum = &pac_data->buffers[i].info->srv_cksum;
 437                 ret = make_pac_checksum(mem_ctx, &zero_blob,
 438                                         srv_checksum,
 439                                         context, service_keyblock);
 440                 if (ret) {
 441                         DEBUG(2, ("making service PAC checksum failed: %s\n",
 442                                   smb_get_krb5_error_message(context, ret, mem_ctx)));
 443                         talloc_free(pac_data);
 444                         return ret;
 445                 }
 446         }
 447
 448         if (!kdc_checksum) {
 449                 DEBUG(2, ("Invalid PAC constructed for signing, no KDC checksum present!"));
 450                 return EINVAL;
 451         }
 452         if (!srv_checksum) {
 453                 DEBUG(2, ("Invalid PAC constructed for signing, no SRV checksum present!"));
 454                 return EINVAL;
 455         }
 456
 457         /* But wipe out the actual signatures */
 458         memset(kdc_checksum->signature.data, '\0', kdc_checksum->signature.length);
 459         memset(srv_checksum->signature.data, '\0', srv_checksum->signature.length);
 460
 461         nt_status = ndr_push_struct_blob(&tmp_blob, mem_ctx, pac_data,
 462                                          (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
 463         if (!NT_STATUS_IS_OK(nt_status)) {
 464                 DEBUG(1, ("PAC (presig) push failed: %s\n", nt_errstr(nt_status)));
 465                 talloc_free(pac_data);
 466                 return EINVAL;
 467         }
 468
 469         /* Then sign the result of the previous push, where the sig was zero'ed out */
 470         ret = make_pac_checksum(mem_ctx, &tmp_blob, srv_checksum,
 471                                 context, service_keyblock);
 472
 473         /* Then sign Server checksum */
 474         ret = make_pac_checksum(mem_ctx, &srv_checksum->signature, kdc_checksum, context, krbtgt_keyblock);
 475         if (ret) {
 476                 DEBUG(2, ("making krbtgt PAC checksum failed: %s\n",
 477                           smb_get_krb5_error_message(context, ret, mem_ctx)));
 478                 talloc_free(pac_data);
 479                 return ret;
 480         }
 481
 482         /* And push it out again, this time to the world.  This relies on determanistic pointer values */
 483         nt_status = ndr_push_struct_blob(&tmp_blob, mem_ctx, pac_data,
 484                                          (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
 485         if (!NT_STATUS_IS_OK(nt_status)) {
 486                 DEBUG(1, ("PAC (final) push failed: %s\n", nt_errstr(nt_status)));
 487                 talloc_free(pac_data);
 488                 return EINVAL;
 489         }
 490
 491         *pac = tmp_blob;
 492
 493         return ret;
 494 }
 495
 496
 497  krb5_error_code kerberos_create_pac(TALLOC_CTX *mem_ctx,
 498                                      struct auth_serversupplied_info *server_info,
 499                                      krb5_context context,
 500                                      krb5_keyblock *krbtgt_keyblock,
 501                                      krb5_keyblock *service_keyblock,
 502                                      krb5_principal client_principal,
 503                                      time_t tgs_authtime,
 504                                      DATA_BLOB *pac)
 505 {
 506         NTSTATUS nt_status;
 507         krb5_error_code ret;
 508         struct PAC_DATA *pac_data = talloc(mem_ctx, struct PAC_DATA);
 509         struct netr_SamInfo3 *sam3;
 510         union PAC_INFO *u_LOGON_INFO;
 511         struct PAC_LOGON_INFO *LOGON_INFO;
 512         union PAC_INFO *u_LOGON_NAME;
 513         struct PAC_LOGON_NAME *LOGON_NAME;
 514         union PAC_INFO *u_KDC_CHECKSUM;
 515         union PAC_INFO *u_SRV_CHECKSUM;
 516
 517         char *name;
 518
 519         enum {
 520                 PAC_BUF_LOGON_INFO = 0,
 521                 PAC_BUF_LOGON_NAME = 1,
 522                 PAC_BUF_SRV_CHECKSUM = 2,
 523                 PAC_BUF_KDC_CHECKSUM = 3,
 524                 PAC_BUF_NUM_BUFFERS = 4
 525         };
 526
 527         if (!pac_data) {
 528                 return ENOMEM;
 529         }
 530
 531         pac_data->num_buffers = PAC_BUF_NUM_BUFFERS;
 532         pac_data->version = 0;
 533
 534         pac_data->buffers = talloc_array(pac_data,
 535                                          struct PAC_BUFFER,
 536                                          pac_data->num_buffers);
 537         if (!pac_data->buffers) {
 538                 talloc_free(pac_data);
 539                 return ENOMEM;
 540         }
 541
 542         /* LOGON_INFO */
 543         u_LOGON_INFO = talloc_zero(pac_data->buffers, union PAC_INFO);
 544         if (!u_LOGON_INFO) {
 545                 talloc_free(pac_data);
 546                 return ENOMEM;
 547         }
 548         pac_data->buffers[PAC_BUF_LOGON_INFO].type = PAC_TYPE_LOGON_INFO;
 549         pac_data->buffers[PAC_BUF_LOGON_INFO].info = u_LOGON_INFO;
 550
 551         /* LOGON_NAME */
 552         u_LOGON_NAME = talloc_zero(pac_data->buffers, union PAC_INFO);
 553         if (!u_LOGON_NAME) {
 554                 talloc_free(pac_data);
 555                 return ENOMEM;
 556         }
 557         pac_data->buffers[PAC_BUF_LOGON_NAME].type = PAC_TYPE_LOGON_NAME;
 558         pac_data->buffers[PAC_BUF_LOGON_NAME].info = u_LOGON_NAME;
 559         LOGON_NAME = &u_LOGON_NAME->logon_name;
 560
 561         /* SRV_CHECKSUM */
 562         u_SRV_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
 563         if (!u_SRV_CHECKSUM) {
 564                 talloc_free(pac_data);
 565                 return ENOMEM;
 566         }
 567         pac_data->buffers[PAC_BUF_SRV_CHECKSUM].type = PAC_TYPE_SRV_CHECKSUM;
 568         pac_data->buffers[PAC_BUF_SRV_CHECKSUM].info = u_SRV_CHECKSUM;
 569
 570         /* KDC_CHECKSUM */
 571         u_KDC_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
 572         if (!u_KDC_CHECKSUM) {
 573                 talloc_free(pac_data);
 574                 return ENOMEM;
 575         }
 576         pac_data->buffers[PAC_BUF_KDC_CHECKSUM].type = PAC_TYPE_KDC_CHECKSUM;
 577         pac_data->buffers[PAC_BUF_KDC_CHECKSUM].info = u_KDC_CHECKSUM;
 578
 579         /* now the real work begins... */
 580
 581         LOGON_INFO = talloc_zero(u_LOGON_INFO, struct PAC_LOGON_INFO);
 582         if (!LOGON_INFO) {
 583                 talloc_free(pac_data);
 584                 return ENOMEM;
 585         }
 586         nt_status = auth_convert_server_info_saminfo3(LOGON_INFO, server_info, &sam3);
 587         if (!NT_STATUS_IS_OK(nt_status)) {
 588                 DEBUG(1, ("Getting Samba info failed: %s\n", nt_errstr(nt_status)));
 589                 talloc_free(pac_data);
 590                 return EINVAL;
 591         }
 592
 593         u_LOGON_INFO->logon_info.info           = LOGON_INFO;
 594         LOGON_INFO->info3 = *sam3;
 595
 596         ret = krb5_unparse_name_norealm(context, client_principal, &name);
 597         if (ret) {
 598                 return ret;
 599         }
 600         LOGON_NAME->account_name        = talloc_strdup(LOGON_NAME, name);
 601         free(name);
 602         /*
 603           this logon_time field is absolutely critical. This is what
 604           caused all our PAC troubles :-)
 605         */
 606         unix_to_nt_time(&LOGON_NAME->logon_time, tgs_authtime);
 607
 608         ret = kerberos_encode_pac(mem_ctx,
 609                                   pac_data,
 610                                   context,
 611                                   krbtgt_keyblock,
 612                                   service_keyblock,
 613                                   pac);
 614         talloc_free(pac_data);
 615         return ret;
 616 }
 617