source4/kdc/pac-glue.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    PAC Glue between Samba and the KDC
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005-2009
   7    Copyright (C) Simo Sorce <idra@samba.org> 2010
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "../libds/common/flags.h"
  26 #include <ldb.h>
  27 #include "auth/auth.h"
  28 #include "auth/auth_sam_reply.h"
  29 #include "kdc/kdc-glue.h"
  30 #include "kdc/pac-glue.h"
  31 #include "param/param.h"
  32 #include "librpc/gen_ndr/ndr_krb5pac.h"
  33 #include "libcli/security/security.h"
  34 #include "dsdb/samdb/samdb.h"
  35
  36 static
  37 NTSTATUS samba_get_logon_info_pac_blob(TALLOC_CTX *mem_ctx,
  38                                        struct auth_user_info_dc *info,
  39                                        DATA_BLOB *pac_data)
  40 {
  41         struct netr_SamInfo3 *info3;
  42         union PAC_INFO pac_info;
  43         enum ndr_err_code ndr_err;
  44         NTSTATUS nt_status;
  45
  46         ZERO_STRUCT(pac_info);
  47
  48         nt_status = auth_convert_user_info_dc_saminfo3(mem_ctx, info, &info3);
  49         if (!NT_STATUS_IS_OK(nt_status)) {
  50                 DEBUG(1, ("Getting Samba info failed: %s\n",
  51                           nt_errstr(nt_status)));
  52                 return nt_status;
  53         }
  54
  55         pac_info.logon_info.info = talloc_zero(mem_ctx, struct PAC_LOGON_INFO);
  56         if (!pac_info.logon_info.info) {
  57                 return NT_STATUS_NO_MEMORY;
  58         }
  59
  60         pac_info.logon_info.info->info3 = *info3;
  61
  62         ndr_err = ndr_push_union_blob(pac_data, mem_ctx, &pac_info,
  63                                       PAC_TYPE_LOGON_INFO,
  64                                       (ndr_push_flags_fn_t)ndr_push_PAC_INFO);
  65         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  66                 nt_status = ndr_map_error2ntstatus(ndr_err);
  67                 DEBUG(1, ("PAC (presig) push failed: %s\n",
  68                           nt_errstr(nt_status)));
  69                 return nt_status;
  70         }
  71
  72         return NT_STATUS_OK;
  73 }
  74
  75 krb5_error_code samba_make_krb5_pac(krb5_context context,
  76                                     DATA_BLOB *pac_blob,
  77                                     DATA_BLOB *deleg_blob,
  78                                     krb5_pac *pac)
  79 {
  80         krb5_data pac_data;
  81         krb5_data deleg_data;
  82         krb5_error_code ret;
  83
  84         /* The user account may be set not to want the PAC */
  85         if (!pac_blob) {
  86                 return 0;
  87         }
  88
  89         ret = krb5_data_copy(&pac_data, pac_blob->data, pac_blob->length);
  90         if (ret != 0) {
  91                 return ret;
  92         }
  93
  94         ZERO_STRUCT(deleg_data);
  95         if (deleg_blob) {
  96                 ret = krb5_data_copy(&deleg_data,
  97                                      deleg_blob->data,
  98                                      deleg_blob->length);
  99                 if (ret != 0) {
 100                         krb5_data_free(&pac_data);
 101                         return ret;
 102                 }
 103         }
 104
 105         ret = krb5_pac_init(context, pac);
 106         if (ret != 0) {
 107                 krb5_data_free(&pac_data);
 108                 krb5_data_free(&deleg_data);
 109                 return ret;
 110         }
 111
 112         ret = krb5_pac_add_buffer(context, *pac, PAC_TYPE_LOGON_INFO, &pac_data);
 113         krb5_data_free(&pac_data);
 114         if (ret != 0) {
 115                 krb5_data_free(&deleg_data);
 116                 return ret;
 117         }
 118
 119         if (deleg_blob) {
 120                 ret = krb5_pac_add_buffer(context, *pac,
 121                                           PAC_TYPE_CONSTRAINED_DELEGATION,
 122                                           &deleg_data);
 123                 krb5_data_free(&deleg_data);
 124                 if (ret != 0) {
 125                         return ret;
 126                 }
 127         }
 128
 129         return ret;
 130 }
 131
 132 bool samba_princ_needs_pac(struct hdb_entry_ex *princ)
 133 {
 134
 135         struct samba_kdc_entry *p = talloc_get_type(princ->ctx, struct samba_kdc_entry);
 136         uint32_t userAccountControl;
 137
 138
 139         /* The service account may be set not to want the PAC */
 140         userAccountControl = ldb_msg_find_attr_as_uint(p->msg, "userAccountControl", 0);
 141         if (userAccountControl & UF_NO_AUTH_DATA_REQUIRED) {
 142                 return false;
 143         }
 144
 145         return true;
 146 }
 147
 148 /* Was the krbtgt in this DB (ie, should we check the incoming signature) and was it an RODC */
 149 int samba_krbtgt_is_in_db(struct hdb_entry_ex *princ, bool *is_in_db, bool *is_untrusted)
 150 {
 151         NTSTATUS status;
 152         struct samba_kdc_entry *p = talloc_get_type(princ->ctx, struct samba_kdc_entry);
 153         int rodc_krbtgt_number, trust_direction;
 154         uint32_t rid;
 155
 156         TALLOC_CTX *mem_ctx = talloc_new(NULL);
 157         if (!mem_ctx) {
 158                 return ENOMEM;
 159         }
 160
 161         trust_direction = ldb_msg_find_attr_as_int(p->msg, "trustDirection", 0);
 162
 163         if (trust_direction != 0) {
 164                 /* Domain trust - we cannot check the sig, but we trust it for a correct PAC
 165
 166                    This is exactly where we should flag for SID
 167                    validation when we do inter-foreest trusts
 168                  */
 169                 talloc_free(mem_ctx);
 170                 *is_untrusted = false;
 171                 *is_in_db = false;
 172                 return 0;
 173         }
 174
 175         /* The lack of password controls etc applies to krbtgt by
 176          * virtue of being that particular RID */
 177         status = dom_sid_split_rid(NULL, samdb_result_dom_sid(mem_ctx, p->msg, "objectSid"), NULL, &rid);
 178
 179         if (!NT_STATUS_IS_OK(status)) {
 180                 talloc_free(mem_ctx);
 181                 return EINVAL;
 182         }
 183
 184         rodc_krbtgt_number = ldb_msg_find_attr_as_int(p->msg, "msDS-SecondaryKrbTgtNumber", -1);
 185
 186         if (p->kdc_db_ctx->my_krbtgt_number == 0) {
 187                 if (rid == DOMAIN_RID_KRBTGT) {
 188                         *is_untrusted = false;
 189                         *is_in_db = true;
 190                         talloc_free(mem_ctx);
 191                         return 0;
 192                 } else if (rodc_krbtgt_number != -1) {
 193                         *is_in_db = true;
 194                         *is_untrusted = true;
 195                         talloc_free(mem_ctx);
 196                         return 0;
 197                 }
 198         } else if ((rid != DOMAIN_RID_KRBTGT) && (rodc_krbtgt_number == p->kdc_db_ctx->my_krbtgt_number)) {
 199                 talloc_free(mem_ctx);
 200                 *is_untrusted = false;
 201                 *is_in_db = true;
 202                 return 0;
 203         } else if (rid == DOMAIN_RID_KRBTGT) {
 204                 /* krbtgt viewed from an RODC */
 205                 talloc_free(mem_ctx);
 206                 *is_untrusted = false;
 207                 *is_in_db = false;
 208                 return 0;
 209         }
 210
 211         /* Another RODC */
 212         talloc_free(mem_ctx);
 213         *is_untrusted = true;
 214         *is_in_db = false;
 215         return 0;
 216 }
 217
 218 NTSTATUS samba_kdc_get_pac_blob(TALLOC_CTX *mem_ctx,
 219                                 struct hdb_entry_ex *client,
 220                                 DATA_BLOB **_pac_blob)
 221 {
 222         struct samba_kdc_entry *p = talloc_get_type(client->ctx, struct samba_kdc_entry);
 223         struct auth_user_info_dc *user_info_dc;
 224         DATA_BLOB *pac_blob;
 225         NTSTATUS nt_status;
 226
 227         /* The user account may be set not to want the PAC */
 228         if ( ! samba_princ_needs_pac(client)) {
 229                 *_pac_blob = NULL;
 230                 return NT_STATUS_OK;
 231         }
 232
 233         pac_blob = talloc_zero(mem_ctx, DATA_BLOB);
 234         if (!pac_blob) {
 235                 return NT_STATUS_NO_MEMORY;
 236         }
 237
 238         nt_status = authsam_make_user_info_dc(mem_ctx, p->kdc_db_ctx->samdb,
 239                                              lpcfg_netbios_name(p->kdc_db_ctx->lp_ctx),
 240                                              lpcfg_sam_name(p->kdc_db_ctx->lp_ctx),
 241                                              p->realm_dn,
 242                                              p->msg,
 243                                              data_blob(NULL, 0),
 244                                              data_blob(NULL, 0),
 245                                              &user_info_dc);
 246         if (!NT_STATUS_IS_OK(nt_status)) {
 247                 DEBUG(0, ("Getting user info for PAC failed: %s\n",
 248                           nt_errstr(nt_status)));
 249                 return nt_status;
 250         }
 251
 252         nt_status = samba_get_logon_info_pac_blob(mem_ctx, user_info_dc, pac_blob);
 253         if (!NT_STATUS_IS_OK(nt_status)) {
 254                 DEBUG(0, ("Building PAC failed: %s\n",
 255                           nt_errstr(nt_status)));
 256                 return nt_status;
 257         }
 258
 259         *_pac_blob = pac_blob;
 260         return NT_STATUS_OK;
 261 }
 262
 263 NTSTATUS samba_kdc_update_pac_blob(TALLOC_CTX *mem_ctx,
 264                                    krb5_context context,
 265                                    const krb5_pac pac, DATA_BLOB *pac_blob,
 266                                    struct PAC_SIGNATURE_DATA *pac_srv_sig,
 267                                    struct PAC_SIGNATURE_DATA *pac_kdc_sig)
 268 {
 269         struct auth_user_info_dc *user_info_dc;
 270         krb5_error_code ret;
 271         NTSTATUS nt_status;
 272
 273         ret = kerberos_pac_to_user_info_dc(mem_ctx, pac,
 274                                            context, &user_info_dc, pac_srv_sig, pac_kdc_sig);
 275         if (ret) {
 276                 return NT_STATUS_UNSUCCESSFUL;
 277         }
 278
 279         nt_status = samba_get_logon_info_pac_blob(mem_ctx,
 280                                                   user_info_dc, pac_blob);
 281
 282         return nt_status;
 283 }
 284
 285 NTSTATUS samba_kdc_update_delegation_info_blob(TALLOC_CTX *mem_ctx,
 286                                 krb5_context context,
 287                                 const krb5_pac pac,
 288                                 const krb5_principal server_principal,
 289                                 const krb5_principal proxy_principal,
 290                                 DATA_BLOB *new_blob)
 291 {
 292         krb5_data old_data;
 293         DATA_BLOB old_blob;
 294         krb5_error_code ret;
 295         NTSTATUS nt_status;
 296         enum ndr_err_code ndr_err;
 297         union PAC_INFO info;
 298         struct PAC_CONSTRAINED_DELEGATION _d;
 299         struct PAC_CONSTRAINED_DELEGATION *d = NULL;
 300         char *server = NULL;
 301         char *proxy = NULL;
 302         uint32_t i;
 303         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 304
 305         if (tmp_ctx == NULL) {
 306                 return NT_STATUS_NO_MEMORY;
 307         }
 308
 309         ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_CONSTRAINED_DELEGATION, &old_data);
 310         if (ret == ENOENT) {
 311                 ZERO_STRUCT(old_data);
 312         } else if (ret) {
 313                 talloc_free(tmp_ctx);
 314                 return NT_STATUS_UNSUCCESSFUL;
 315         }
 316
 317         old_blob.length = old_data.length;
 318         old_blob.data = (uint8_t *)old_data.data;
 319
 320         ZERO_STRUCT(info);
 321         if (old_blob.length > 0) {
 322                 ndr_err = ndr_pull_union_blob(&old_blob, mem_ctx,
 323                                 &info, PAC_TYPE_CONSTRAINED_DELEGATION,
 324                                 (ndr_pull_flags_fn_t)ndr_pull_PAC_INFO);
 325                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 326                         krb5_data_free(&old_data);
 327                         nt_status = ndr_map_error2ntstatus(ndr_err);
 328                         DEBUG(0,("can't parse the PAC LOGON_INFO: %s\n", nt_errstr(nt_status)));
 329                         talloc_free(tmp_ctx);
 330                         return nt_status;
 331                 }
 332         } else {
 333                 ZERO_STRUCT(_d);
 334                 info.constrained_delegation.info = &_d;
 335         }
 336         krb5_data_free(&old_data);
 337
 338         ret = krb5_unparse_name(context, server_principal, &server);
 339         if (ret) {
 340                 talloc_free(tmp_ctx);
 341                 return NT_STATUS_INTERNAL_ERROR;
 342         }
 343
 344         ret = krb5_unparse_name_flags(context, proxy_principal,
 345                                       KRB5_PRINCIPAL_UNPARSE_NO_REALM, &proxy);
 346         if (ret) {
 347                 SAFE_FREE(server);
 348                 talloc_free(tmp_ctx);
 349                 return NT_STATUS_INTERNAL_ERROR;
 350         }
 351
 352         d = info.constrained_delegation.info;
 353         i = d->num_transited_services;
 354         d->proxy_target.string = server;
 355         d->transited_services = talloc_realloc(mem_ctx, d->transited_services,
 356                                                struct lsa_String, i + 1);
 357         d->transited_services[i].string = proxy;
 358         d->num_transited_services = i + 1;
 359
 360         ndr_err = ndr_push_union_blob(new_blob, mem_ctx,
 361                                 &info, PAC_TYPE_CONSTRAINED_DELEGATION,
 362                                 (ndr_push_flags_fn_t)ndr_push_PAC_INFO);
 363         SAFE_FREE(server);
 364         SAFE_FREE(proxy);
 365         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 366                 krb5_data_free(&old_data);
 367                 nt_status = ndr_map_error2ntstatus(ndr_err);
 368                 DEBUG(0,("can't parse the PAC LOGON_INFO: %s\n", nt_errstr(nt_status)));
 369                 talloc_free(tmp_ctx);
 370                 return nt_status;
 371         }
 372
 373         talloc_free(tmp_ctx);
 374         return NT_STATUS_OK;
 375 }
 376
 377 /* this function allocates 'data' using malloc.
 378  * The caller is responsible for freeing it */
 379 void samba_kdc_build_edata_reply(NTSTATUS nt_status, DATA_BLOB *e_data)
 380 {
 381         PA_DATA pa;
 382         unsigned char *buf;
 383         size_t len;
 384         krb5_error_code ret = 0;
 385
 386         if (!e_data)
 387                 return;
 388
 389         pa.padata_type          = KRB5_PADATA_PW_SALT;
 390         pa.padata_value.length  = 12;
 391         pa.padata_value.data    = malloc(pa.padata_value.length);
 392         if (!pa.padata_value.data) {
 393                 e_data->length = 0;
 394                 e_data->data = NULL;
 395                 return;
 396         }
 397
 398         SIVAL(pa.padata_value.data, 0, NT_STATUS_V(nt_status));
 399         SIVAL(pa.padata_value.data, 4, 0);
 400         SIVAL(pa.padata_value.data, 8, 1);
 401
 402         ASN1_MALLOC_ENCODE(PA_DATA, buf, len, &pa, &len, ret);
 403         free(pa.padata_value.data);
 404
 405         e_data->data   = buf;
 406         e_data->length = len;
 407
 408         return;
 409 }
 410
 411 /* function to map policy errors */
 412 krb5_error_code samba_kdc_map_policy_err(NTSTATUS nt_status)
 413 {
 414         krb5_error_code ret;
 415
 416         if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_MUST_CHANGE))
 417                 ret = KRB5KDC_ERR_KEY_EXPIRED;
 418         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_EXPIRED))
 419                 ret = KRB5KDC_ERR_KEY_EXPIRED;
 420         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_EXPIRED))
 421                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 422         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_DISABLED))
 423                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 424         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_LOGON_HOURS))
 425                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 426         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_LOCKED_OUT))
 427                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 428         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_WORKSTATION))
 429                 ret = KRB5KDC_ERR_POLICY;
 430         else
 431                 ret = KRB5KDC_ERR_POLICY;
 432
 433         return ret;
 434 }
 435
 436 /* Given a kdc entry, consult the account_ok routine in auth/auth_sam.c
 437  * for consistency */
 438 NTSTATUS samba_kdc_check_client_access(struct samba_kdc_entry *kdc_entry,
 439                                        const char *client_name,
 440                                        const char *workstation,
 441                                        bool password_change)
 442 {
 443         TALLOC_CTX *tmp_ctx;
 444         NTSTATUS nt_status;
 445
 446         tmp_ctx = talloc_named(NULL, 0, "samba_kdc_check_client_access");
 447         if (!tmp_ctx) {
 448                 return NT_STATUS_NO_MEMORY;
 449         }
 450
 451         /* we allow all kinds of trusts here */
 452         nt_status = authsam_account_ok(tmp_ctx,
 453                                        kdc_entry->kdc_db_ctx->samdb,
 454                                        MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT |
 455                                        MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT,
 456                                        kdc_entry->realm_dn, kdc_entry->msg,
 457                                        workstation, client_name,
 458                                        true, password_change);
 459
 460         talloc_free(tmp_ctx);
 461         return nt_status;
 462 }
 463
 464 int kdc_check_pac(krb5_context context,
 465                   DATA_BLOB srv_sig,
 466                   struct PAC_SIGNATURE_DATA *kdc_sig,
 467                   hdb_entry_ex *ent)
 468 {
 469         krb5_enctype etype;
 470         int ret;
 471         krb5_keyblock keyblock;
 472         Key *key;
 473         if (kdc_sig->type == CKSUMTYPE_HMAC_MD5) {
 474                 etype = ETYPE_ARCFOUR_HMAC_MD5;
 475         } else {
 476                 ret = krb5_cksumtype_to_enctype(context,
 477                                                 kdc_sig->type,
 478                                                 &etype);
 479                 if (ret != 0) {
 480                         return ret;
 481                 }
 482         }
 483
 484         ret = hdb_enctype2key(context, &ent->entry, etype, &key);
 485
 486         if (ret != 0) {
 487                 return ret;
 488         }
 489
 490         keyblock = key->key;
 491
 492         return check_pac_checksum(srv_sig, kdc_sig,
 493                                  context, &keyblock);
 494 }
 495
 496
 497