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 #include "auth/kerberos/pac_utils.h"
  36
  37 static
  38 NTSTATUS samba_get_logon_info_pac_blob(TALLOC_CTX *mem_ctx,
  39                                        struct auth_user_info_dc *info,
  40                                        DATA_BLOB *pac_data)
  41 {
  42         struct netr_SamInfo3 *info3;
  43         union PAC_INFO pac_info;
  44         enum ndr_err_code ndr_err;
  45         NTSTATUS nt_status;
  46
  47         ZERO_STRUCT(pac_info);
  48
  49         nt_status = auth_convert_user_info_dc_saminfo3(mem_ctx, info, &info3);
  50         if (!NT_STATUS_IS_OK(nt_status)) {
  51                 DEBUG(1, ("Getting Samba info failed: %s\n",
  52                           nt_errstr(nt_status)));
  53                 return nt_status;
  54         }
  55
  56         pac_info.logon_info.info = talloc_zero(mem_ctx, struct PAC_LOGON_INFO);
  57         if (!pac_info.logon_info.info) {
  58                 return NT_STATUS_NO_MEMORY;
  59         }
  60
  61         pac_info.logon_info.info->info3 = *info3;
  62
  63         ndr_err = ndr_push_union_blob(pac_data, mem_ctx, &pac_info,
  64                                       PAC_TYPE_LOGON_INFO,
  65                                       (ndr_push_flags_fn_t)ndr_push_PAC_INFO);
  66         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  67                 nt_status = ndr_map_error2ntstatus(ndr_err);
  68                 DEBUG(1, ("PAC (presig) push failed: %s\n",
  69                           nt_errstr(nt_status)));
  70                 return nt_status;
  71         }
  72
  73         return NT_STATUS_OK;
  74 }
  75
  76 krb5_error_code samba_make_krb5_pac(krb5_context context,
  77                                     DATA_BLOB *pac_blob,
  78                                     DATA_BLOB *deleg_blob,
  79                                     krb5_pac *pac)
  80 {
  81         krb5_data pac_data;
  82         krb5_data deleg_data;
  83         krb5_error_code ret;
  84
  85         /* The user account may be set not to want the PAC */
  86         if (!pac_blob) {
  87                 return 0;
  88         }
  89
  90         ret = krb5_data_copy(&pac_data, pac_blob->data, pac_blob->length);
  91         if (ret != 0) {
  92                 return ret;
  93         }
  94
  95         ZERO_STRUCT(deleg_data);
  96         if (deleg_blob) {
  97                 ret = krb5_data_copy(&deleg_data,
  98                                      deleg_blob->data,
  99                                      deleg_blob->length);
 100                 if (ret != 0) {
 101                         krb5_data_free(&pac_data);
 102                         return ret;
 103                 }
 104         }
 105
 106         ret = krb5_pac_init(context, pac);
 107         if (ret != 0) {
 108                 krb5_data_free(&pac_data);
 109                 krb5_data_free(&deleg_data);
 110                 return ret;
 111         }
 112
 113         ret = krb5_pac_add_buffer(context, *pac, PAC_TYPE_LOGON_INFO, &pac_data);
 114         krb5_data_free(&pac_data);
 115         if (ret != 0) {
 116                 krb5_data_free(&deleg_data);
 117                 return ret;
 118         }
 119
 120         if (deleg_blob) {
 121                 ret = krb5_pac_add_buffer(context, *pac,
 122                                           PAC_TYPE_CONSTRAINED_DELEGATION,
 123                                           &deleg_data);
 124                 krb5_data_free(&deleg_data);
 125                 if (ret != 0) {
 126                         return ret;
 127                 }
 128         }
 129
 130         return ret;
 131 }
 132
 133 bool samba_princ_needs_pac(struct hdb_entry_ex *princ)
 134 {
 135
 136         struct samba_kdc_entry *p = talloc_get_type(princ->ctx, struct samba_kdc_entry);
 137         uint32_t userAccountControl;
 138
 139
 140         /* The service account may be set not to want the PAC */
 141         userAccountControl = ldb_msg_find_attr_as_uint(p->msg, "userAccountControl", 0);
 142         if (userAccountControl & UF_NO_AUTH_DATA_REQUIRED) {
 143                 return false;
 144         }
 145
 146         return true;
 147 }
 148
 149 /* Was the krbtgt in this DB (ie, should we check the incoming signature) and was it an RODC */
 150 int samba_krbtgt_is_in_db(struct hdb_entry_ex *princ, bool *is_in_db, bool *is_untrusted)
 151 {
 152         NTSTATUS status;
 153         struct samba_kdc_entry *p = talloc_get_type(princ->ctx, struct samba_kdc_entry);
 154         int rodc_krbtgt_number, trust_direction;
 155         uint32_t rid;
 156
 157         TALLOC_CTX *mem_ctx = talloc_new(NULL);
 158         if (!mem_ctx) {
 159                 return ENOMEM;
 160         }
 161
 162         trust_direction = ldb_msg_find_attr_as_int(p->msg, "trustDirection", 0);
 163
 164         if (trust_direction != 0) {
 165                 /* Domain trust - we cannot check the sig, but we trust it for a correct PAC
 166
 167                    This is exactly where we should flag for SID
 168                    validation when we do inter-foreest trusts
 169                  */
 170                 talloc_free(mem_ctx);
 171                 *is_untrusted = false;
 172                 *is_in_db = false;
 173                 return 0;
 174         }
 175
 176         /* The lack of password controls etc applies to krbtgt by
 177          * virtue of being that particular RID */
 178         status = dom_sid_split_rid(NULL, samdb_result_dom_sid(mem_ctx, p->msg, "objectSid"), NULL, &rid);
 179
 180         if (!NT_STATUS_IS_OK(status)) {
 181                 talloc_free(mem_ctx);
 182                 return EINVAL;
 183         }
 184
 185         rodc_krbtgt_number = ldb_msg_find_attr_as_int(p->msg, "msDS-SecondaryKrbTgtNumber", -1);
 186
 187         if (p->kdc_db_ctx->my_krbtgt_number == 0) {
 188                 if (rid == DOMAIN_RID_KRBTGT) {
 189                         *is_untrusted = false;
 190                         *is_in_db = true;
 191                         talloc_free(mem_ctx);
 192                         return 0;
 193                 } else if (rodc_krbtgt_number != -1) {
 194                         *is_in_db = true;
 195                         *is_untrusted = true;
 196                         talloc_free(mem_ctx);
 197                         return 0;
 198                 }
 199         } else if ((rid != DOMAIN_RID_KRBTGT) && (rodc_krbtgt_number == p->kdc_db_ctx->my_krbtgt_number)) {
 200                 talloc_free(mem_ctx);
 201                 *is_untrusted = false;
 202                 *is_in_db = true;
 203                 return 0;
 204         } else if (rid == DOMAIN_RID_KRBTGT) {
 205                 /* krbtgt viewed from an RODC */
 206                 talloc_free(mem_ctx);
 207                 *is_untrusted = false;
 208                 *is_in_db = false;
 209                 return 0;
 210         }
 211
 212         /* Another RODC */
 213         talloc_free(mem_ctx);
 214         *is_untrusted = true;
 215         *is_in_db = false;
 216         return 0;
 217 }
 218
 219 NTSTATUS samba_kdc_get_pac_blob(TALLOC_CTX *mem_ctx,
 220                                 struct hdb_entry_ex *client,
 221                                 DATA_BLOB **_pac_blob)
 222 {
 223         struct samba_kdc_entry *p = talloc_get_type(client->ctx, struct samba_kdc_entry);
 224         struct auth_user_info_dc *user_info_dc;
 225         DATA_BLOB *pac_blob;
 226         NTSTATUS nt_status;
 227
 228         /* The user account may be set not to want the PAC */
 229         if ( ! samba_princ_needs_pac(client)) {
 230                 *_pac_blob = NULL;
 231                 return NT_STATUS_OK;
 232         }
 233
 234         pac_blob = talloc_zero(mem_ctx, DATA_BLOB);
 235         if (!pac_blob) {
 236                 return NT_STATUS_NO_MEMORY;
 237         }
 238
 239         nt_status = authsam_make_user_info_dc(mem_ctx, p->kdc_db_ctx->samdb,
 240                                              lpcfg_netbios_name(p->kdc_db_ctx->lp_ctx),
 241                                              lpcfg_sam_name(p->kdc_db_ctx->lp_ctx),
 242                                              p->realm_dn,
 243                                              p->msg,
 244                                              data_blob(NULL, 0),
 245                                              data_blob(NULL, 0),
 246                                              &user_info_dc);
 247         if (!NT_STATUS_IS_OK(nt_status)) {
 248                 DEBUG(0, ("Getting user info for PAC failed: %s\n",
 249                           nt_errstr(nt_status)));
 250                 return nt_status;
 251         }
 252
 253         nt_status = samba_get_logon_info_pac_blob(mem_ctx, user_info_dc, pac_blob);
 254         if (!NT_STATUS_IS_OK(nt_status)) {
 255                 DEBUG(0, ("Building PAC failed: %s\n",
 256                           nt_errstr(nt_status)));
 257                 return nt_status;
 258         }
 259
 260         *_pac_blob = pac_blob;
 261         return NT_STATUS_OK;
 262 }
 263
 264 NTSTATUS samba_kdc_update_pac_blob(TALLOC_CTX *mem_ctx,
 265                                    krb5_context context,
 266                                    const krb5_pac pac, DATA_BLOB *pac_blob,
 267                                    struct PAC_SIGNATURE_DATA *pac_srv_sig,
 268                                    struct PAC_SIGNATURE_DATA *pac_kdc_sig)
 269 {
 270         struct auth_user_info_dc *user_info_dc;
 271         krb5_error_code ret;
 272         NTSTATUS nt_status;
 273
 274         ret = kerberos_pac_to_user_info_dc(mem_ctx, pac,
 275                                            context, &user_info_dc, pac_srv_sig, pac_kdc_sig);
 276         if (ret) {
 277                 return NT_STATUS_UNSUCCESSFUL;
 278         }
 279
 280         nt_status = samba_get_logon_info_pac_blob(mem_ctx,
 281                                                   user_info_dc, pac_blob);
 282
 283         return nt_status;
 284 }
 285
 286 NTSTATUS samba_kdc_update_delegation_info_blob(TALLOC_CTX *mem_ctx,
 287                                 krb5_context context,
 288                                 const krb5_pac pac,
 289                                 const krb5_principal server_principal,
 290                                 const krb5_principal proxy_principal,
 291                                 DATA_BLOB *new_blob)
 292 {
 293         krb5_data old_data;
 294         DATA_BLOB old_blob;
 295         krb5_error_code ret;
 296         NTSTATUS nt_status;
 297         enum ndr_err_code ndr_err;
 298         union PAC_INFO info;
 299         struct PAC_CONSTRAINED_DELEGATION _d;
 300         struct PAC_CONSTRAINED_DELEGATION *d = NULL;
 301         char *server = NULL;
 302         char *proxy = NULL;
 303         uint32_t i;
 304         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 305
 306         if (tmp_ctx == NULL) {
 307                 return NT_STATUS_NO_MEMORY;
 308         }
 309
 310         ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_CONSTRAINED_DELEGATION, &old_data);
 311         if (ret == ENOENT) {
 312                 ZERO_STRUCT(old_data);
 313         } else if (ret) {
 314                 talloc_free(tmp_ctx);
 315                 return NT_STATUS_UNSUCCESSFUL;
 316         }
 317
 318         old_blob.length = old_data.length;
 319         old_blob.data = (uint8_t *)old_data.data;
 320
 321         ZERO_STRUCT(info);
 322         if (old_blob.length > 0) {
 323                 ndr_err = ndr_pull_union_blob(&old_blob, mem_ctx,
 324                                 &info, PAC_TYPE_CONSTRAINED_DELEGATION,
 325                                 (ndr_pull_flags_fn_t)ndr_pull_PAC_INFO);
 326                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 327                         krb5_data_free(&old_data);
 328                         nt_status = ndr_map_error2ntstatus(ndr_err);
 329                         DEBUG(0,("can't parse the PAC LOGON_INFO: %s\n", nt_errstr(nt_status)));
 330                         talloc_free(tmp_ctx);
 331                         return nt_status;
 332                 }
 333         } else {
 334                 ZERO_STRUCT(_d);
 335                 info.constrained_delegation.info = &_d;
 336         }
 337         krb5_data_free(&old_data);
 338
 339         ret = krb5_unparse_name(context, server_principal, &server);
 340         if (ret) {
 341                 talloc_free(tmp_ctx);
 342                 return NT_STATUS_INTERNAL_ERROR;
 343         }
 344
 345         ret = krb5_unparse_name_flags(context, proxy_principal,
 346                                       KRB5_PRINCIPAL_UNPARSE_NO_REALM, &proxy);
 347         if (ret) {
 348                 SAFE_FREE(server);
 349                 talloc_free(tmp_ctx);
 350                 return NT_STATUS_INTERNAL_ERROR;
 351         }
 352
 353         d = info.constrained_delegation.info;
 354         i = d->num_transited_services;
 355         d->proxy_target.string = server;
 356         d->transited_services = talloc_realloc(mem_ctx, d->transited_services,
 357                                                struct lsa_String, i + 1);
 358         d->transited_services[i].string = proxy;
 359         d->num_transited_services = i + 1;
 360
 361         ndr_err = ndr_push_union_blob(new_blob, mem_ctx,
 362                                 &info, PAC_TYPE_CONSTRAINED_DELEGATION,
 363                                 (ndr_push_flags_fn_t)ndr_push_PAC_INFO);
 364         SAFE_FREE(server);
 365         SAFE_FREE(proxy);
 366         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 367                 krb5_data_free(&old_data);
 368                 nt_status = ndr_map_error2ntstatus(ndr_err);
 369                 DEBUG(0,("can't parse the PAC LOGON_INFO: %s\n", nt_errstr(nt_status)));
 370                 talloc_free(tmp_ctx);
 371                 return nt_status;
 372         }
 373
 374         talloc_free(tmp_ctx);
 375         return NT_STATUS_OK;
 376 }
 377
 378 /* this function allocates 'data' using malloc.
 379  * The caller is responsible for freeing it */
 380 void samba_kdc_build_edata_reply(NTSTATUS nt_status, DATA_BLOB *e_data)
 381 {
 382         PA_DATA pa;
 383         unsigned char *buf;
 384         size_t len;
 385         krb5_error_code ret = 0;
 386
 387         if (!e_data)
 388                 return;
 389
 390         pa.padata_type          = KRB5_PADATA_PW_SALT;
 391         pa.padata_value.length  = 12;
 392         pa.padata_value.data    = malloc(pa.padata_value.length);
 393         if (!pa.padata_value.data) {
 394                 e_data->length = 0;
 395                 e_data->data = NULL;
 396                 return;
 397         }
 398
 399         SIVAL(pa.padata_value.data, 0, NT_STATUS_V(nt_status));
 400         SIVAL(pa.padata_value.data, 4, 0);
 401         SIVAL(pa.padata_value.data, 8, 1);
 402
 403         ASN1_MALLOC_ENCODE(PA_DATA, buf, len, &pa, &len, ret);
 404         free(pa.padata_value.data);
 405
 406         e_data->data   = buf;
 407         e_data->length = len;
 408
 409         return;
 410 }
 411
 412 /* function to map policy errors */
 413 krb5_error_code samba_kdc_map_policy_err(NTSTATUS nt_status)
 414 {
 415         krb5_error_code ret;
 416
 417         if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_MUST_CHANGE))
 418                 ret = KRB5KDC_ERR_KEY_EXPIRED;
 419         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_EXPIRED))
 420                 ret = KRB5KDC_ERR_KEY_EXPIRED;
 421         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_EXPIRED))
 422                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 423         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_DISABLED))
 424                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 425         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_LOGON_HOURS))
 426                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 427         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_LOCKED_OUT))
 428                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 429         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_WORKSTATION))
 430                 ret = KRB5KDC_ERR_POLICY;
 431         else
 432                 ret = KRB5KDC_ERR_POLICY;
 433
 434         return ret;
 435 }
 436
 437 /* Given a kdc entry, consult the account_ok routine in auth/auth_sam.c
 438  * for consistency */
 439 NTSTATUS samba_kdc_check_client_access(struct samba_kdc_entry *kdc_entry,
 440                                        const char *client_name,
 441                                        const char *workstation,
 442                                        bool password_change)
 443 {
 444         TALLOC_CTX *tmp_ctx;
 445         NTSTATUS nt_status;
 446
 447         tmp_ctx = talloc_named(NULL, 0, "samba_kdc_check_client_access");
 448         if (!tmp_ctx) {
 449                 return NT_STATUS_NO_MEMORY;
 450         }
 451
 452         /* we allow all kinds of trusts here */
 453         nt_status = authsam_account_ok(tmp_ctx,
 454                                        kdc_entry->kdc_db_ctx->samdb,
 455                                        MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT |
 456                                        MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT,
 457                                        kdc_entry->realm_dn, kdc_entry->msg,
 458                                        workstation, client_name,
 459                                        true, password_change);
 460
 461         talloc_free(tmp_ctx);
 462         return nt_status;
 463 }
 464
 465 int kdc_check_pac(krb5_context context,
 466                   DATA_BLOB srv_sig,
 467                   struct PAC_SIGNATURE_DATA *kdc_sig,
 468                   hdb_entry_ex *ent)
 469 {
 470         krb5_enctype etype;
 471         int ret;
 472         krb5_keyblock keyblock;
 473         Key *key;
 474         if (kdc_sig->type == CKSUMTYPE_HMAC_MD5) {
 475                 etype = ETYPE_ARCFOUR_HMAC_MD5;
 476         } else {
 477                 ret = krb5_cksumtype_to_enctype(context,
 478                                                 kdc_sig->type,
 479                                                 &etype);
 480                 if (ret != 0) {
 481                         return ret;
 482                 }
 483         }
 484
 485 #if HDB_ENCTYPE2KEY_TAKES_KEYSET
 486         ret = hdb_enctype2key(context, &ent->entry, NULL, etype, &key);
 487 #else
 488         ret = hdb_enctype2key(context, &ent->entry, etype, &key);
 489 #endif
 490
 491         if (ret != 0) {
 492                 return ret;
 493         }
 494
 495         keyblock = key->key;
 496
 497         return check_pac_checksum(srv_sig, kdc_sig,
 498                                  context, &keyblock);
 499 }
 500
 501
 502