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 "system/kerberos.h"
  30 #include "auth/kerberos/kerberos.h"
  31 #include "kdc/samba_kdc.h"
  32 #include "kdc/pac-glue.h"
  33 #include "param/param.h"
  34 #include "librpc/gen_ndr/ndr_krb5pac.h"
  35 #include "libcli/security/security.h"
  36 #include "dsdb/samdb/samdb.h"
  37 #include "auth/kerberos/pac_utils.h"
  38
  39 static
  40 NTSTATUS samba_get_logon_info_pac_blob(TALLOC_CTX *mem_ctx,
  41                                        struct auth_user_info_dc *info,
  42                                        DATA_BLOB *pac_data)
  43 {
  44         struct netr_SamInfo3 *info3;
  45         union PAC_INFO pac_info;
  46         enum ndr_err_code ndr_err;
  47         NTSTATUS nt_status;
  48
  49         ZERO_STRUCT(pac_info);
  50
  51         nt_status = auth_convert_user_info_dc_saminfo3(mem_ctx, info, &info3);
  52         if (!NT_STATUS_IS_OK(nt_status)) {
  53                 DEBUG(1, ("Getting Samba info failed: %s\n",
  54                           nt_errstr(nt_status)));
  55                 return nt_status;
  56         }
  57
  58         pac_info.logon_info.info = talloc_zero(mem_ctx, struct PAC_LOGON_INFO);
  59         if (!pac_info.logon_info.info) {
  60                 return NT_STATUS_NO_MEMORY;
  61         }
  62
  63         pac_info.logon_info.info->info3 = *info3;
  64
  65         ndr_err = ndr_push_union_blob(pac_data, mem_ctx, &pac_info,
  66                                       PAC_TYPE_LOGON_INFO,
  67                                       (ndr_push_flags_fn_t)ndr_push_PAC_INFO);
  68         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  69                 nt_status = ndr_map_error2ntstatus(ndr_err);
  70                 DEBUG(1, ("PAC (presig) push failed: %s\n",
  71                           nt_errstr(nt_status)));
  72                 return nt_status;
  73         }
  74
  75         return NT_STATUS_OK;
  76 }
  77
  78 krb5_error_code samba_make_krb5_pac(krb5_context context,
  79                                     DATA_BLOB *pac_blob,
  80                                     DATA_BLOB *deleg_blob,
  81                                     krb5_pac *pac)
  82 {
  83         krb5_data pac_data;
  84         krb5_data deleg_data;
  85         krb5_error_code ret;
  86
  87         /* The user account may be set not to want the PAC */
  88         if (!pac_blob) {
  89                 return 0;
  90         }
  91
  92         ret = krb5_copy_data_contents(&pac_data,
  93                                       pac_blob->data,
  94                                       pac_blob->length);
  95         if (ret != 0) {
  96                 return ret;
  97         }
  98
  99         ZERO_STRUCT(deleg_data);
 100         if (deleg_blob) {
 101                 ret = krb5_copy_data_contents(&deleg_data,
 102                                               deleg_blob->data,
 103                                               deleg_blob->length);
 104                 if (ret != 0) {
 105                         kerberos_free_data_contents(context, &pac_data);
 106                         return ret;
 107                 }
 108         }
 109
 110         ret = krb5_pac_init(context, pac);
 111         if (ret != 0) {
 112                 kerberos_free_data_contents(context, &pac_data);
 113                 kerberos_free_data_contents(context, &deleg_data);
 114                 return ret;
 115         }
 116
 117         ret = krb5_pac_add_buffer(context, *pac, PAC_TYPE_LOGON_INFO, &pac_data);
 118         kerberos_free_data_contents(context, &pac_data);
 119         if (ret != 0) {
 120                 kerberos_free_data_contents(context, &deleg_data);
 121                 return ret;
 122         }
 123
 124         if (deleg_blob) {
 125                 ret = krb5_pac_add_buffer(context, *pac,
 126                                           PAC_TYPE_CONSTRAINED_DELEGATION,
 127                                           &deleg_data);
 128                 kerberos_free_data_contents(context, &deleg_data);
 129                 if (ret != 0) {
 130                         return ret;
 131                 }
 132         }
 133
 134         return ret;
 135 }
 136
 137 bool samba_princ_needs_pac(struct samba_kdc_entry *skdc_entry)
 138 {
 139
 140         uint32_t userAccountControl;
 141
 142         /* The service account may be set not to want the PAC */
 143         userAccountControl = ldb_msg_find_attr_as_uint(skdc_entry->msg, "userAccountControl", 0);
 144         if (userAccountControl & UF_NO_AUTH_DATA_REQUIRED) {
 145                 return false;
 146         }
 147
 148         return true;
 149 }
 150
 151 /* Was the krbtgt in this DB (ie, should we check the incoming signature) and was it an RODC */
 152 int samba_krbtgt_is_in_db(struct samba_kdc_entry *p,
 153                           bool *is_in_db,
 154                           bool *is_untrusted)
 155 {
 156         NTSTATUS status;
 157         int rodc_krbtgt_number, trust_direction;
 158         uint32_t rid;
 159
 160         TALLOC_CTX *mem_ctx = talloc_new(NULL);
 161         if (!mem_ctx) {
 162                 return ENOMEM;
 163         }
 164
 165         trust_direction = ldb_msg_find_attr_as_int(p->msg, "trustDirection", 0);
 166
 167         if (trust_direction != 0) {
 168                 /* Domain trust - we cannot check the sig, but we trust it for a correct PAC
 169
 170                    This is exactly where we should flag for SID
 171                    validation when we do inter-foreest trusts
 172                  */
 173                 talloc_free(mem_ctx);
 174                 *is_untrusted = false;
 175                 *is_in_db = false;
 176                 return 0;
 177         }
 178
 179         /* The lack of password controls etc applies to krbtgt by
 180          * virtue of being that particular RID */
 181         status = dom_sid_split_rid(NULL, samdb_result_dom_sid(mem_ctx, p->msg, "objectSid"), NULL, &rid);
 182
 183         if (!NT_STATUS_IS_OK(status)) {
 184                 talloc_free(mem_ctx);
 185                 return EINVAL;
 186         }
 187
 188         rodc_krbtgt_number = ldb_msg_find_attr_as_int(p->msg, "msDS-SecondaryKrbTgtNumber", -1);
 189
 190         if (p->kdc_db_ctx->my_krbtgt_number == 0) {
 191                 if (rid == DOMAIN_RID_KRBTGT) {
 192                         *is_untrusted = false;
 193                         *is_in_db = true;
 194                         talloc_free(mem_ctx);
 195                         return 0;
 196                 } else if (rodc_krbtgt_number != -1) {
 197                         *is_in_db = true;
 198                         *is_untrusted = true;
 199                         talloc_free(mem_ctx);
 200                         return 0;
 201                 }
 202         } else if ((rid != DOMAIN_RID_KRBTGT) && (rodc_krbtgt_number == p->kdc_db_ctx->my_krbtgt_number)) {
 203                 talloc_free(mem_ctx);
 204                 *is_untrusted = false;
 205                 *is_in_db = true;
 206                 return 0;
 207         } else if (rid == DOMAIN_RID_KRBTGT) {
 208                 /* krbtgt viewed from an RODC */
 209                 talloc_free(mem_ctx);
 210                 *is_untrusted = false;
 211                 *is_in_db = false;
 212                 return 0;
 213         }
 214
 215         /* Another RODC */
 216         talloc_free(mem_ctx);
 217         *is_untrusted = true;
 218         *is_in_db = false;
 219         return 0;
 220 }
 221
 222 NTSTATUS samba_kdc_get_pac_blob(TALLOC_CTX *mem_ctx,
 223                                 struct samba_kdc_entry *p,
 224                                 DATA_BLOB **_pac_blob)
 225 {
 226         struct auth_user_info_dc *user_info_dc;
 227         DATA_BLOB *pac_blob;
 228         NTSTATUS nt_status;
 229
 230         /* The user account may be set not to want the PAC */
 231         if ( ! samba_princ_needs_pac(p)) {
 232                 *_pac_blob = NULL;
 233                 return NT_STATUS_OK;
 234         }
 235
 236         pac_blob = talloc_zero(mem_ctx, DATA_BLOB);
 237         if (!pac_blob) {
 238                 return NT_STATUS_NO_MEMORY;
 239         }
 240
 241         nt_status = authsam_make_user_info_dc(mem_ctx, p->kdc_db_ctx->samdb,
 242                                              lpcfg_netbios_name(p->kdc_db_ctx->lp_ctx),
 243                                              lpcfg_sam_name(p->kdc_db_ctx->lp_ctx),
 244                                              p->realm_dn,
 245                                              p->msg,
 246                                              data_blob(NULL, 0),
 247                                              data_blob(NULL, 0),
 248                                              &user_info_dc);
 249         if (!NT_STATUS_IS_OK(nt_status)) {
 250                 DEBUG(0, ("Getting user info for PAC failed: %s\n",
 251                           nt_errstr(nt_status)));
 252                 return nt_status;
 253         }
 254
 255         nt_status = samba_get_logon_info_pac_blob(mem_ctx, user_info_dc, pac_blob);
 256         if (!NT_STATUS_IS_OK(nt_status)) {
 257                 DEBUG(0, ("Building PAC failed: %s\n",
 258                           nt_errstr(nt_status)));
 259                 return nt_status;
 260         }
 261
 262         *_pac_blob = pac_blob;
 263         return NT_STATUS_OK;
 264 }
 265
 266 NTSTATUS samba_kdc_update_pac_blob(TALLOC_CTX *mem_ctx,
 267                                    krb5_context context,
 268                                    const krb5_pac pac, DATA_BLOB *pac_blob,
 269                                    struct PAC_SIGNATURE_DATA *pac_srv_sig,
 270                                    struct PAC_SIGNATURE_DATA *pac_kdc_sig)
 271 {
 272         struct auth_user_info_dc *user_info_dc;
 273         krb5_error_code ret;
 274         NTSTATUS nt_status;
 275
 276         ret = kerberos_pac_to_user_info_dc(mem_ctx, pac,
 277                                            context, &user_info_dc, pac_srv_sig, pac_kdc_sig);
 278         if (ret) {
 279                 return NT_STATUS_UNSUCCESSFUL;
 280         }
 281
 282         nt_status = samba_get_logon_info_pac_blob(mem_ctx,
 283                                                   user_info_dc, pac_blob);
 284
 285         return nt_status;
 286 }
 287
 288 NTSTATUS samba_kdc_update_delegation_info_blob(TALLOC_CTX *mem_ctx,
 289                                 krb5_context context,
 290                                 const krb5_pac pac,
 291                                 const krb5_principal server_principal,
 292                                 const krb5_principal proxy_principal,
 293                                 DATA_BLOB *new_blob)
 294 {
 295         krb5_data old_data;
 296         DATA_BLOB old_blob;
 297         krb5_error_code ret;
 298         NTSTATUS nt_status;
 299         enum ndr_err_code ndr_err;
 300         union PAC_INFO info;
 301         struct PAC_CONSTRAINED_DELEGATION _d;
 302         struct PAC_CONSTRAINED_DELEGATION *d = NULL;
 303         char *server = NULL;
 304         char *proxy = NULL;
 305         uint32_t i;
 306         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 307
 308         if (tmp_ctx == NULL) {
 309                 return NT_STATUS_NO_MEMORY;
 310         }
 311
 312         ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_CONSTRAINED_DELEGATION, &old_data);
 313         if (ret == ENOENT) {
 314                 ZERO_STRUCT(old_data);
 315         } else if (ret) {
 316                 talloc_free(tmp_ctx);
 317                 return NT_STATUS_UNSUCCESSFUL;
 318         }
 319
 320         old_blob.length = old_data.length;
 321         old_blob.data = (uint8_t *)old_data.data;
 322
 323         ZERO_STRUCT(info);
 324         if (old_blob.length > 0) {
 325                 ndr_err = ndr_pull_union_blob(&old_blob, mem_ctx,
 326                                 &info, PAC_TYPE_CONSTRAINED_DELEGATION,
 327                                 (ndr_pull_flags_fn_t)ndr_pull_PAC_INFO);
 328                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 329                         kerberos_free_data_contents(context, &old_data);
 330                         nt_status = ndr_map_error2ntstatus(ndr_err);
 331                         DEBUG(0,("can't parse the PAC LOGON_INFO: %s\n", nt_errstr(nt_status)));
 332                         talloc_free(tmp_ctx);
 333                         return nt_status;
 334                 }
 335         } else {
 336                 ZERO_STRUCT(_d);
 337                 info.constrained_delegation.info = &_d;
 338         }
 339         kerberos_free_data_contents(context, &old_data);
 340
 341         ret = krb5_unparse_name(context, server_principal, &server);
 342         if (ret) {
 343                 talloc_free(tmp_ctx);
 344                 return NT_STATUS_INTERNAL_ERROR;
 345         }
 346
 347         ret = krb5_unparse_name_flags(context, proxy_principal,
 348                                       KRB5_PRINCIPAL_UNPARSE_NO_REALM, &proxy);
 349         if (ret) {
 350                 SAFE_FREE(server);
 351                 talloc_free(tmp_ctx);
 352                 return NT_STATUS_INTERNAL_ERROR;
 353         }
 354
 355         d = info.constrained_delegation.info;
 356         i = d->num_transited_services;
 357         d->proxy_target.string = server;
 358         d->transited_services = talloc_realloc(mem_ctx, d->transited_services,
 359                                                struct lsa_String, i + 1);
 360         d->transited_services[i].string = proxy;
 361         d->num_transited_services = i + 1;
 362
 363         ndr_err = ndr_push_union_blob(new_blob, mem_ctx,
 364                                 &info, PAC_TYPE_CONSTRAINED_DELEGATION,
 365                                 (ndr_push_flags_fn_t)ndr_push_PAC_INFO);
 366         SAFE_FREE(server);
 367         SAFE_FREE(proxy);
 368         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 369                 kerberos_free_data_contents(context, &old_data);
 370                 nt_status = ndr_map_error2ntstatus(ndr_err);
 371                 DEBUG(0,("can't parse the PAC LOGON_INFO: %s\n", nt_errstr(nt_status)));
 372                 talloc_free(tmp_ctx);
 373                 return nt_status;
 374         }
 375
 376         talloc_free(tmp_ctx);
 377         return NT_STATUS_OK;
 378 }
 379
 380 /* function to map policy errors */
 381 krb5_error_code samba_kdc_map_policy_err(NTSTATUS nt_status)
 382 {
 383         krb5_error_code ret;
 384
 385         if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_MUST_CHANGE))
 386                 ret = KRB5KDC_ERR_KEY_EXP;
 387         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_PASSWORD_EXPIRED))
 388                 ret = KRB5KDC_ERR_KEY_EXP;
 389         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_EXPIRED))
 390                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 391         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_DISABLED))
 392                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 393         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_LOGON_HOURS))
 394                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 395         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_LOCKED_OUT))
 396                 ret = KRB5KDC_ERR_CLIENT_REVOKED;
 397         else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_WORKSTATION))
 398                 ret = KRB5KDC_ERR_POLICY;
 399         else
 400                 ret = KRB5KDC_ERR_POLICY;
 401
 402         return ret;
 403 }
 404
 405 /* Given a kdc entry, consult the account_ok routine in auth/auth_sam.c
 406  * for consistency */
 407 NTSTATUS samba_kdc_check_client_access(struct samba_kdc_entry *kdc_entry,
 408                                        const char *client_name,
 409                                        const char *workstation,
 410                                        bool password_change)
 411 {
 412         TALLOC_CTX *tmp_ctx;
 413         NTSTATUS nt_status;
 414
 415         tmp_ctx = talloc_named(NULL, 0, "samba_kdc_check_client_access");
 416         if (!tmp_ctx) {
 417                 return NT_STATUS_NO_MEMORY;
 418         }
 419
 420         /* we allow all kinds of trusts here */
 421         nt_status = authsam_account_ok(tmp_ctx,
 422                                        kdc_entry->kdc_db_ctx->samdb,
 423                                        MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT |
 424                                        MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT,
 425                                        kdc_entry->realm_dn, kdc_entry->msg,
 426                                        workstation, client_name,
 427                                        true, password_change);
 428
 429         talloc_free(tmp_ctx);
 430         return nt_status;
 431 }