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 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
  22    You should have received a copy of the GNU General Public License
  23    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  24 */
  25
  26 #include "includes.h"
  27 #include "system/kerberos.h"
  28 #include "auth/kerberos/kerberos.h"
  29 #include "librpc/gen_ndr/ndr_krb5pac.h"
  30 #include "lib/ldb/include/ldb.h"
  31 #include "auth/auth_sam.h"
  32
  33 static krb5_error_code check_pac_checksum(TALLOC_CTX *mem_ctx,
  34                                           DATA_BLOB pac_data,
  35                                           struct PAC_SIGNATURE_DATA *sig,
  36                                           krb5_context context,
  37                                           const krb5_keyblock *keyblock)
  38 {
  39         krb5_error_code ret;
  40         krb5_crypto crypto;
  41         Checksum cksum;
  42
  43         cksum.cksumtype         = (CKSUMTYPE)sig->type;
  44         cksum.checksum.length   = sig->signature.length;
  45         cksum.checksum.data     = sig->signature.data;
  46
  47         ret = krb5_crypto_init(context,
  48                                keyblock,
  49                                0,
  50                                &crypto);
  51         if (ret) {
  52                 DEBUG(0,("krb5_crypto_init() failed: %s\n",
  53                           smb_get_krb5_error_message(context, ret, mem_ctx)));
  54                 return ret;
  55         }
  56         ret = krb5_verify_checksum(context,
  57                                    crypto,
  58                                    KRB5_KU_OTHER_CKSUM,
  59                                    pac_data.data,
  60                                    pac_data.length,
  61                                    &cksum);
  62         krb5_crypto_destroy(context, crypto);
  63
  64         return ret;
  65 }
  66
  67  NTSTATUS kerberos_decode_pac(TALLOC_CTX *mem_ctx,
  68                               struct PAC_DATA **pac_data_out,
  69                               DATA_BLOB blob,
  70                               krb5_context context,
  71                               const krb5_keyblock *krbtgt_keyblock,
  72                               const krb5_keyblock *service_keyblock,
  73                               krb5_const_principal client_principal,
  74                               time_t tgs_authtime,
  75                               krb5_error_code *k5ret)
  76 {
  77         krb5_error_code ret;
  78         NTSTATUS status;
  79         struct PAC_SIGNATURE_DATA *srv_sig_ptr = NULL;
  80         struct PAC_SIGNATURE_DATA *kdc_sig_ptr = NULL;
  81         struct PAC_SIGNATURE_DATA *srv_sig_wipe = NULL;
  82         struct PAC_SIGNATURE_DATA *kdc_sig_wipe = NULL;
  83         struct PAC_LOGON_INFO *logon_info = NULL;
  84         struct PAC_LOGON_NAME *logon_name = NULL;
  85         struct PAC_DATA *pac_data;
  86         struct PAC_DATA_RAW *pac_data_raw;
  87
  88         DATA_BLOB *srv_sig_blob = NULL;
  89         DATA_BLOB *kdc_sig_blob = NULL;
  90
  91         DATA_BLOB modified_pac_blob;
  92         NTTIME tgs_authtime_nttime;
  93         krb5_principal client_principal_pac;
  94         int i;
  95
  96         krb5_clear_error_string(context);
  97
  98         if (k5ret) {
  99                 *k5ret = KRB5_PARSE_MALFORMED;
 100         }
 101
 102         pac_data = talloc(mem_ctx, struct PAC_DATA);
 103         pac_data_raw = talloc(mem_ctx, struct PAC_DATA_RAW);
 104         kdc_sig_wipe = talloc(mem_ctx, struct PAC_SIGNATURE_DATA);
 105         srv_sig_wipe = talloc(mem_ctx, struct PAC_SIGNATURE_DATA);
 106         if (!pac_data_raw || !pac_data || !kdc_sig_wipe || !srv_sig_wipe) {
 107                 if (k5ret) {
 108                         *k5ret = ENOMEM;
 109                 }
 110                 return NT_STATUS_NO_MEMORY;
 111         }
 112
 113         status = ndr_pull_struct_blob(&blob, pac_data, pac_data,
 114                                       (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
 115         if (!NT_STATUS_IS_OK(status)) {
 116                 DEBUG(0,("can't parse the PAC\n"));
 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         status = ndr_pull_struct_blob(&blob, pac_data_raw, pac_data_raw,
 127                                       (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA_RAW);
 128         if (!NT_STATUS_IS_OK(status)) {
 129                 DEBUG(0,("can't parse the PAC\n"));
 130                 return status;
 131         }
 132
 133         if (pac_data_raw->num_buffers < 4) {
 134                 /* we need logon_ingo, service_key and kdc_key */
 135                 DEBUG(0,("less than 4 PAC buffers\n"));
 136                 return NT_STATUS_INVALID_PARAMETER;
 137         }
 138
 139         if (pac_data->num_buffers != pac_data_raw->num_buffers) {
 140                 /* we need logon_ingo, service_key and kdc_key */
 141                 DEBUG(0,("misparse!  PAC_DATA has %d buffers while PAC_DATA_RAW has %d\n",
 142                          pac_data->num_buffers, pac_data_raw->num_buffers));
 143                 return NT_STATUS_INVALID_PARAMETER;
 144         }
 145
 146         for (i=0; i < pac_data->num_buffers; i++) {
 147                 if (pac_data->buffers[i].type != pac_data_raw->buffers[i].type) {
 148                         DEBUG(0,("misparse!  PAC_DATA buffer %d has type %d while PAC_DATA_RAW has %d\n",
 149                                  i, pac_data->buffers[i].type, pac_data->buffers[i].type));
 150                         return NT_STATUS_INVALID_PARAMETER;
 151                 }
 152                 switch (pac_data->buffers[i].type) {
 153                         case PAC_TYPE_LOGON_INFO:
 154                                 if (!pac_data->buffers[i].info) {
 155                                         break;
 156                                 }
 157                                 logon_info = pac_data->buffers[i].info->logon_info.info;
 158                                 break;
 159                         case PAC_TYPE_SRV_CHECKSUM:
 160                                 if (!pac_data->buffers[i].info) {
 161                                         break;
 162                                 }
 163                                 srv_sig_ptr = &pac_data->buffers[i].info->srv_cksum;
 164                                 srv_sig_blob = &pac_data_raw->buffers[i].info->remaining;
 165                                 break;
 166                         case PAC_TYPE_KDC_CHECKSUM:
 167                                 if (!pac_data->buffers[i].info) {
 168                                         break;
 169                                 }
 170                                 kdc_sig_ptr = &pac_data->buffers[i].info->kdc_cksum;
 171                                 kdc_sig_blob = &pac_data_raw->buffers[i].info->remaining;
 172                                 break;
 173                         case PAC_TYPE_LOGON_NAME:
 174                                 logon_name = &pac_data->buffers[i].info->logon_name;
 175                                 break;
 176                         default:
 177                                 break;
 178                 }
 179         }
 180
 181         if (!logon_info) {
 182                 DEBUG(0,("PAC no logon_info\n"));
 183                 return NT_STATUS_INVALID_PARAMETER;
 184         }
 185
 186         if (!logon_name) {
 187                 DEBUG(0,("PAC no logon_name\n"));
 188                 return NT_STATUS_INVALID_PARAMETER;
 189         }
 190
 191         if (!srv_sig_ptr || !srv_sig_blob) {
 192                 DEBUG(0,("PAC no srv_key\n"));
 193                 return NT_STATUS_INVALID_PARAMETER;
 194         }
 195
 196         if (!kdc_sig_ptr || !kdc_sig_blob) {
 197                 DEBUG(0,("PAC no kdc_key\n"));
 198                 return NT_STATUS_INVALID_PARAMETER;
 199         }
 200
 201         /* Find and zero out the signatures, as required by the signing algorithm */
 202
 203         /* We find the data blobs above, now we parse them to get at the exact portion we should zero */
 204         status = ndr_pull_struct_blob(kdc_sig_blob, kdc_sig_wipe, kdc_sig_wipe,
 205                                       (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
 206         if (!NT_STATUS_IS_OK(status)) {
 207                 DEBUG(0,("can't parse the KDC signature\n"));
 208                 return status;
 209         }
 210
 211         status = ndr_pull_struct_blob(srv_sig_blob, srv_sig_wipe, srv_sig_wipe,
 212                                       (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
 213         if (!NT_STATUS_IS_OK(status)) {
 214                 DEBUG(0,("can't parse the SRV signature\n"));
 215                 return status;
 216         }
 217
 218         /* Now zero the decoded structure */
 219         memset(kdc_sig_wipe->signature.data, '\0', kdc_sig_wipe->signature.length);
 220         memset(srv_sig_wipe->signature.data, '\0', srv_sig_wipe->signature.length);
 221
 222         /* and reencode, back into the same place it came from */
 223         status = ndr_push_struct_blob(kdc_sig_blob, pac_data_raw, kdc_sig_wipe,
 224                                       (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
 225         if (!NT_STATUS_IS_OK(status)) {
 226                 DEBUG(0,("can't repack the KDC signature\n"));
 227                 return status;
 228         }
 229         status = ndr_push_struct_blob(srv_sig_blob, pac_data_raw, srv_sig_wipe,
 230                                       (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
 231         if (!NT_STATUS_IS_OK(status)) {
 232                 DEBUG(0,("can't repack the SRV signature\n"));
 233                 return status;
 234         }
 235
 236         /* push out the whole structure, but now with zero'ed signatures */
 237         status = ndr_push_struct_blob(&modified_pac_blob, pac_data_raw, pac_data_raw,
 238                                          (ndr_push_flags_fn_t)ndr_push_PAC_DATA_RAW);
 239         if (!NT_STATUS_IS_OK(status)) {
 240                 DEBUG(0,("can't repack the RAW PAC\n"));
 241                 return status;
 242         }
 243
 244         /* verify by service_key */
 245         ret = check_pac_checksum(mem_ctx,
 246                                  modified_pac_blob, srv_sig_ptr,
 247                                  context,
 248                                  service_keyblock);
 249         if (ret) {
 250                 DEBUG(1, ("PAC Decode: Failed to verify the service signature: %s\n",
 251                           smb_get_krb5_error_message(context, ret, mem_ctx)));
 252                 if (k5ret) {
 253                         *k5ret = ret;
 254                 }
 255                 return NT_STATUS_ACCESS_DENIED;
 256         }
 257
 258         if (krbtgt_keyblock) {
 259                 ret = check_pac_checksum(mem_ctx,
 260                                             srv_sig_ptr->signature, kdc_sig_ptr,
 261                                             context, krbtgt_keyblock);
 262                 if (ret) {
 263                         DEBUG(1, ("PAC Decode: Failed to verify the KDC signature: %s\n",
 264                                   smb_get_krb5_error_message(context, ret, mem_ctx)));
 265                         if (k5ret) {
 266                                 *k5ret = ret;
 267                         }
 268                         return NT_STATUS_ACCESS_DENIED;
 269                 }
 270         }
 271
 272         /* Convert to NT time, so as not to loose accuracy in comparison */
 273         unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);
 274
 275         if (tgs_authtime_nttime != logon_name->logon_time) {
 276                 DEBUG(2, ("PAC Decode: Logon time mismatch between ticket and PAC!\n"));
 277                 DEBUG(2, ("PAC Decode: PAC: %s\n", nt_time_string(mem_ctx, logon_name->logon_time)));
 278                 DEBUG(2, ("PAC Decode: Ticket: %s\n", nt_time_string(mem_ctx, tgs_authtime_nttime)));
 279                 return NT_STATUS_ACCESS_DENIED;
 280         }
 281
 282         ret = krb5_parse_name_flags(context, logon_name->account_name, KRB5_PRINCIPAL_PARSE_NO_REALM,
 283                                     &client_principal_pac);
 284         if (ret) {
 285                 DEBUG(2, ("Could not parse name from incoming PAC: [%s]: %s\n",
 286                           logon_name->account_name,
 287                           smb_get_krb5_error_message(context, ret, mem_ctx)));
 288                 if (k5ret) {
 289                         *k5ret = ret;
 290                 }
 291                 return NT_STATUS_INVALID_PARAMETER;
 292         }
 293
 294         if (!krb5_principal_compare_any_realm(context, client_principal, client_principal_pac)) {
 295                 DEBUG(2, ("Name in PAC [%s] does not match principal name in ticket\n",
 296                           logon_name->account_name));
 297                 return NT_STATUS_ACCESS_DENIED;
 298         }
 299
 300 #if 0
 301         if (strcasecmp(logon_info->info3.base.account_name.string,
 302                        "Administrator")== 0) {
 303                 file_save("tmp_pac_data-admin.dat",blob.data,blob.length);
 304         }
 305 #endif
 306
 307         DEBUG(3,("Found account name from PAC: %s [%s]\n",
 308                  logon_info->info3.base.account_name.string,
 309                  logon_info->info3.base.full_name.string));
 310         *pac_data_out = pac_data;
 311
 312         return status;
 313 }
 314
 315 _PUBLIC_  NTSTATUS kerberos_pac_logon_info(TALLOC_CTX *mem_ctx,
 316                                   struct PAC_LOGON_INFO **logon_info,
 317                                   DATA_BLOB blob,
 318                                   krb5_context context,
 319                                   const krb5_keyblock *krbtgt_keyblock,
 320                                   const krb5_keyblock *service_keyblock,
 321                                   krb5_const_principal client_principal,
 322                                   time_t tgs_authtime,
 323                                   krb5_error_code *k5ret)
 324 {
 325         NTSTATUS nt_status;
 326         struct PAC_DATA *pac_data;
 327         int i;
 328         nt_status = kerberos_decode_pac(mem_ctx, &pac_data,
 329                                         blob,
 330                                         context,
 331                                         krbtgt_keyblock,
 332                                         service_keyblock,
 333                                         client_principal,
 334                                         tgs_authtime,
 335                                         k5ret);
 336         if (!NT_STATUS_IS_OK(nt_status)) {
 337                 return nt_status;
 338         }
 339
 340         *logon_info = NULL;
 341         for (i=0; i < pac_data->num_buffers; i++) {
 342                 if (pac_data->buffers[i].type != PAC_TYPE_LOGON_INFO) {
 343                         continue;
 344                 }
 345                 *logon_info = pac_data->buffers[i].info->logon_info.info;
 346         }
 347         if (!*logon_info) {
 348                 return NT_STATUS_INVALID_PARAMETER;
 349         }
 350         return NT_STATUS_OK;
 351 }
 352
 353 static krb5_error_code make_pac_checksum(TALLOC_CTX *mem_ctx,
 354                                          DATA_BLOB *pac_data,
 355                                          struct PAC_SIGNATURE_DATA *sig,
 356                                          krb5_context context,
 357                                          const krb5_keyblock *keyblock)
 358 {
 359         krb5_error_code ret;
 360         krb5_crypto crypto;
 361         Checksum cksum;
 362
 363
 364         ret = krb5_crypto_init(context,
 365                                keyblock,
 366                                0,
 367                                &crypto);
 368         if (ret) {
 369                 DEBUG(0,("krb5_crypto_init() failed: %s\n",
 370                           smb_get_krb5_error_message(context, ret, mem_ctx)));
 371                 return ret;
 372         }
 373         ret = krb5_create_checksum(context,
 374                                    crypto,
 375                                    KRB5_KU_OTHER_CKSUM,
 376                                    0,
 377                                    pac_data->data,
 378                                    pac_data->length,
 379                                    &cksum);
 380         if (ret) {
 381                 DEBUG(2, ("PAC Verification failed: %s\n",
 382                           smb_get_krb5_error_message(context, ret, mem_ctx)));
 383         }
 384
 385         krb5_crypto_destroy(context, crypto);
 386
 387         if (ret) {
 388                 return ret;
 389         }
 390
 391         sig->type = cksum.cksumtype;
 392         sig->signature = data_blob_talloc(mem_ctx, cksum.checksum.data, cksum.checksum.length);
 393         free_Checksum(&cksum);
 394
 395         return 0;
 396 }
 397
 398  krb5_error_code kerberos_encode_pac(TALLOC_CTX *mem_ctx,
 399                                     struct PAC_DATA *pac_data,
 400                                     krb5_context context,
 401                                     const krb5_keyblock *krbtgt_keyblock,
 402                                     const krb5_keyblock *service_keyblock,
 403                                     DATA_BLOB *pac)
 404 {
 405         NTSTATUS nt_status;
 406         krb5_error_code ret;
 407         DATA_BLOB zero_blob = data_blob(NULL, 0);
 408         DATA_BLOB tmp_blob = data_blob(NULL, 0);
 409         struct PAC_SIGNATURE_DATA *kdc_checksum = NULL;
 410         struct PAC_SIGNATURE_DATA *srv_checksum = NULL;
 411         int i;
 412
 413         /* First, just get the keytypes filled in (and lengths right, eventually) */
 414         for (i=0; i < pac_data->num_buffers; i++) {
 415                 if (pac_data->buffers[i].type != PAC_TYPE_KDC_CHECKSUM) {
 416                         continue;
 417                 }
 418                 kdc_checksum = &pac_data->buffers[i].info->kdc_cksum,
 419                 ret = make_pac_checksum(mem_ctx, &zero_blob,
 420                                         kdc_checksum,
 421                                         context, krbtgt_keyblock);
 422                 if (ret) {
 423                         DEBUG(2, ("making krbtgt PAC checksum failed: %s\n",
 424                                   smb_get_krb5_error_message(context, ret, mem_ctx)));
 425                         talloc_free(pac_data);
 426                         return ret;
 427                 }
 428         }
 429
 430         for (i=0; i < pac_data->num_buffers; i++) {
 431                 if (pac_data->buffers[i].type != PAC_TYPE_SRV_CHECKSUM) {
 432                         continue;
 433                 }
 434                 srv_checksum = &pac_data->buffers[i].info->srv_cksum;
 435                 ret = make_pac_checksum(mem_ctx, &zero_blob,
 436                                         srv_checksum,
 437                                         context, service_keyblock);
 438                 if (ret) {
 439                         DEBUG(2, ("making service PAC checksum failed: %s\n",
 440                                   smb_get_krb5_error_message(context, ret, mem_ctx)));
 441                         talloc_free(pac_data);
 442                         return ret;
 443                 }
 444         }
 445
 446         if (!kdc_checksum) {
 447                 DEBUG(2, ("Invalid PAC constructed for signing, no KDC checksum present!"));
 448                 return EINVAL;
 449         }
 450         if (!srv_checksum) {
 451                 DEBUG(2, ("Invalid PAC constructed for signing, no SRV checksum present!"));
 452                 return EINVAL;
 453         }
 454
 455         /* But wipe out the actual signatures */
 456         memset(kdc_checksum->signature.data, '\0', kdc_checksum->signature.length);
 457         memset(srv_checksum->signature.data, '\0', srv_checksum->signature.length);
 458
 459         nt_status = ndr_push_struct_blob(&tmp_blob, mem_ctx, pac_data,
 460                                          (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
 461         if (!NT_STATUS_IS_OK(nt_status)) {
 462                 DEBUG(1, ("PAC (presig) push failed: %s\n", nt_errstr(nt_status)));
 463                 talloc_free(pac_data);
 464                 return EINVAL;
 465         }
 466
 467         /* Then sign the result of the previous push, where the sig was zero'ed out */
 468         ret = make_pac_checksum(mem_ctx, &tmp_blob, srv_checksum,
 469                                 context, service_keyblock);
 470
 471         /* Then sign Server checksum */
 472         ret = make_pac_checksum(mem_ctx, &srv_checksum->signature, kdc_checksum, context, krbtgt_keyblock);
 473         if (ret) {
 474                 DEBUG(2, ("making krbtgt PAC checksum failed: %s\n",
 475                           smb_get_krb5_error_message(context, ret, mem_ctx)));
 476                 talloc_free(pac_data);
 477                 return ret;
 478         }
 479
 480         /* And push it out again, this time to the world.  This relies on determanistic pointer values */
 481         nt_status = ndr_push_struct_blob(&tmp_blob, mem_ctx, pac_data,
 482                                          (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
 483         if (!NT_STATUS_IS_OK(nt_status)) {
 484                 DEBUG(1, ("PAC (final) push failed: %s\n", nt_errstr(nt_status)));
 485                 talloc_free(pac_data);
 486                 return EINVAL;
 487         }
 488
 489         *pac = tmp_blob;
 490
 491         return ret;
 492 }
 493
 494
 495  krb5_error_code kerberos_create_pac(TALLOC_CTX *mem_ctx,
 496                                      struct auth_serversupplied_info *server_info,
 497                                      krb5_context context,
 498                                      const krb5_keyblock *krbtgt_keyblock,
 499                                      const krb5_keyblock *service_keyblock,
 500                                      krb5_principal client_principal,
 501                                      time_t tgs_authtime,
 502                                      DATA_BLOB *pac)
 503 {
 504         NTSTATUS nt_status;
 505         krb5_error_code ret;
 506         struct PAC_DATA *pac_data = talloc(mem_ctx, struct PAC_DATA);
 507         struct netr_SamInfo3 *sam3;
 508         union PAC_INFO *u_LOGON_INFO;
 509         struct PAC_LOGON_INFO *LOGON_INFO;
 510         union PAC_INFO *u_LOGON_NAME;
 511         struct PAC_LOGON_NAME *LOGON_NAME;
 512         union PAC_INFO *u_KDC_CHECKSUM;
 513         union PAC_INFO *u_SRV_CHECKSUM;
 514
 515         char *name;
 516
 517         enum {
 518                 PAC_BUF_LOGON_INFO = 0,
 519                 PAC_BUF_LOGON_NAME = 1,
 520                 PAC_BUF_SRV_CHECKSUM = 2,
 521                 PAC_BUF_KDC_CHECKSUM = 3,
 522                 PAC_BUF_NUM_BUFFERS = 4
 523         };
 524
 525         if (!pac_data) {
 526                 return ENOMEM;
 527         }
 528
 529         pac_data->num_buffers = PAC_BUF_NUM_BUFFERS;
 530         pac_data->version = 0;
 531
 532         pac_data->buffers = talloc_array(pac_data,
 533                                          struct PAC_BUFFER,
 534                                          pac_data->num_buffers);
 535         if (!pac_data->buffers) {
 536                 talloc_free(pac_data);
 537                 return ENOMEM;
 538         }
 539
 540         /* LOGON_INFO */
 541         u_LOGON_INFO = talloc_zero(pac_data->buffers, union PAC_INFO);
 542         if (!u_LOGON_INFO) {
 543                 talloc_free(pac_data);
 544                 return ENOMEM;
 545         }
 546         pac_data->buffers[PAC_BUF_LOGON_INFO].type = PAC_TYPE_LOGON_INFO;
 547         pac_data->buffers[PAC_BUF_LOGON_INFO].info = u_LOGON_INFO;
 548
 549         /* LOGON_NAME */
 550         u_LOGON_NAME = talloc_zero(pac_data->buffers, union PAC_INFO);
 551         if (!u_LOGON_NAME) {
 552                 talloc_free(pac_data);
 553                 return ENOMEM;
 554         }
 555         pac_data->buffers[PAC_BUF_LOGON_NAME].type = PAC_TYPE_LOGON_NAME;
 556         pac_data->buffers[PAC_BUF_LOGON_NAME].info = u_LOGON_NAME;
 557         LOGON_NAME = &u_LOGON_NAME->logon_name;
 558
 559         /* SRV_CHECKSUM */
 560         u_SRV_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
 561         if (!u_SRV_CHECKSUM) {
 562                 talloc_free(pac_data);
 563                 return ENOMEM;
 564         }
 565         pac_data->buffers[PAC_BUF_SRV_CHECKSUM].type = PAC_TYPE_SRV_CHECKSUM;
 566         pac_data->buffers[PAC_BUF_SRV_CHECKSUM].info = u_SRV_CHECKSUM;
 567
 568         /* KDC_CHECKSUM */
 569         u_KDC_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
 570         if (!u_KDC_CHECKSUM) {
 571                 talloc_free(pac_data);
 572                 return ENOMEM;
 573         }
 574         pac_data->buffers[PAC_BUF_KDC_CHECKSUM].type = PAC_TYPE_KDC_CHECKSUM;
 575         pac_data->buffers[PAC_BUF_KDC_CHECKSUM].info = u_KDC_CHECKSUM;
 576
 577         /* now the real work begins... */
 578
 579         LOGON_INFO = talloc_zero(u_LOGON_INFO, struct PAC_LOGON_INFO);
 580         if (!LOGON_INFO) {
 581                 talloc_free(pac_data);
 582                 return ENOMEM;
 583         }
 584         nt_status = auth_convert_server_info_saminfo3(LOGON_INFO, server_info, &sam3);
 585         if (!NT_STATUS_IS_OK(nt_status)) {
 586                 DEBUG(1, ("Getting Samba info failed: %s\n", nt_errstr(nt_status)));
 587                 talloc_free(pac_data);
 588                 return EINVAL;
 589         }
 590
 591         u_LOGON_INFO->logon_info.info           = LOGON_INFO;
 592         LOGON_INFO->info3 = *sam3;
 593
 594         ret = krb5_unparse_name_flags(context, client_principal,
 595                                       KRB5_PRINCIPAL_UNPARSE_NO_REALM, &name);
 596         if (ret) {
 597                 return ret;
 598         }
 599         LOGON_NAME->account_name        = talloc_strdup(LOGON_NAME, name);
 600         free(name);
 601         /*
 602           this logon_time field is absolutely critical. This is what
 603           caused all our PAC troubles :-)
 604         */
 605         unix_to_nt_time(&LOGON_NAME->logon_time, tgs_authtime);
 606
 607         ret = kerberos_encode_pac(mem_ctx,
 608                                   pac_data,
 609                                   context,
 610                                   krbtgt_keyblock,
 611                                   service_keyblock,
 612                                   pac);
 613         talloc_free(pac_data);
 614         return ret;
 615 }
 616