libgpo/gpo_sec.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *  Group Policy Object Support
   4  *  Copyright (C) Guenther Deschner 2007
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "includes.h"
  21 #include "libcli/security/security.h"
  22 #include "../libgpo/gpo.h"
  23 #include "auth.h"
  24 #include "../librpc/ndr/libndr.h"
  25
  26 /****************************************************************
  27 ****************************************************************/
  28
  29 static bool gpo_sd_check_agp_object_guid(const struct security_ace_object *object)
  30 {
  31         struct GUID ext_right_apg_guid;
  32         NTSTATUS status;
  33
  34         if (!object) {
  35                 return false;
  36         }
  37
  38         status = GUID_from_string(ADS_EXTENDED_RIGHT_APPLY_GROUP_POLICY,
  39                                   &ext_right_apg_guid);
  40         if (!NT_STATUS_IS_OK(status)) {
  41                 return false;
  42         }
  43
  44         switch (object->flags) {
  45                 case SEC_ACE_OBJECT_TYPE_PRESENT:
  46                         if (GUID_equal(&object->type.type,
  47                                        &ext_right_apg_guid)) {
  48                                 return true;
  49                         }
  50                 case SEC_ACE_INHERITED_OBJECT_TYPE_PRESENT:
  51                         if (GUID_equal(&object->inherited_type.inherited_type,
  52                                        &ext_right_apg_guid)) {
  53                                 return true;
  54                         }
  55                 default:
  56                         break;
  57         }
  58
  59         return false;
  60 }
  61
  62 /****************************************************************
  63 ****************************************************************/
  64
  65 static bool gpo_sd_check_agp_object(const struct security_ace *ace)
  66 {
  67         if (!sec_ace_object(ace->type)) {
  68                 return false;
  69         }
  70
  71         return gpo_sd_check_agp_object_guid(&ace->object.object);
  72 }
  73
  74 /****************************************************************
  75 ****************************************************************/
  76
  77 static bool gpo_sd_check_agp_access_bits(uint32_t access_mask)
  78 {
  79         return (access_mask & SEC_ADS_CONTROL_ACCESS);
  80 }
  81
  82 #if 0
  83 /****************************************************************
  84 ****************************************************************/
  85
  86 static bool gpo_sd_check_read_access_bits(uint32_t access_mask)
  87 {
  88         uint32_t read_bits = SEC_RIGHTS_LIST_CONTENTS |
  89                            SEC_RIGHTS_READ_ALL_PROP |
  90                            SEC_RIGHTS_READ_PERMS;
  91
  92         return (read_bits == (access_mask & read_bits));
  93 }
  94 #endif
  95
  96 /****************************************************************
  97 ****************************************************************/
  98
  99 static NTSTATUS gpo_sd_check_ace_denied_object(const struct security_ace *ace,
 100                                                const struct security_token *token)
 101 {
 102         char *sid_str;
 103
 104         if (gpo_sd_check_agp_object(ace) &&
 105             gpo_sd_check_agp_access_bits(ace->access_mask) &&
 106             security_token_has_sid(token, &ace->trustee)) {
 107                 sid_str = dom_sid_string(NULL, &ace->trustee);
 108                 DEBUG(10,("gpo_sd_check_ace_denied_object: "
 109                         "Access denied as of ace for %s\n",
 110                         sid_str));
 111                 talloc_free(sid_str);
 112                 return NT_STATUS_ACCESS_DENIED;
 113         }
 114
 115         return STATUS_MORE_ENTRIES;
 116 }
 117
 118 /****************************************************************
 119 ****************************************************************/
 120
 121 static NTSTATUS gpo_sd_check_ace_allowed_object(const struct security_ace *ace,
 122                                                 const struct security_token *token)
 123 {
 124         char *sid_str;
 125
 126         if (gpo_sd_check_agp_object(ace) &&
 127             gpo_sd_check_agp_access_bits(ace->access_mask) &&
 128             security_token_has_sid(token, &ace->trustee)) {
 129                 sid_str = dom_sid_string(NULL, &ace->trustee);
 130                 DEBUG(10,("gpo_sd_check_ace_allowed_object: "
 131                         "Access granted as of ace for %s\n",
 132                         sid_str));
 133                 talloc_free(sid_str);
 134
 135                 return NT_STATUS_OK;
 136         }
 137
 138         return STATUS_MORE_ENTRIES;
 139 }
 140
 141 /****************************************************************
 142 ****************************************************************/
 143
 144 static NTSTATUS gpo_sd_check_ace(const struct security_ace *ace,
 145                                  const struct security_token *token)
 146 {
 147         switch (ace->type) {
 148                 case SEC_ACE_TYPE_ACCESS_DENIED_OBJECT:
 149                         return gpo_sd_check_ace_denied_object(ace, token);
 150                 case SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT:
 151                         return gpo_sd_check_ace_allowed_object(ace, token);
 152                 default:
 153                         return STATUS_MORE_ENTRIES;
 154         }
 155 }
 156
 157 /****************************************************************
 158 ****************************************************************/
 159
 160 NTSTATUS gpo_apply_security_filtering(const struct GROUP_POLICY_OBJECT *gpo,
 161                                       const struct security_token *token)
 162 {
 163         struct security_descriptor *sd = gpo->security_descriptor;
 164         struct security_acl *dacl = NULL;
 165         NTSTATUS status = NT_STATUS_ACCESS_DENIED;
 166         int i;
 167
 168         if (!token) {
 169                 return NT_STATUS_INVALID_USER_BUFFER;
 170         }
 171
 172         if (!sd) {
 173                 return NT_STATUS_INVALID_SECURITY_DESCR;
 174         }
 175
 176         dacl = sd->dacl;
 177         if (!dacl) {
 178                 return NT_STATUS_INVALID_SECURITY_DESCR;
 179         }
 180
 181         /* check all aces and only return NT_STATUS_OK (== Access granted) or
 182          * NT_STATUS_ACCESS_DENIED ( == Access denied) - the default is to
 183          * deny access */
 184
 185         for (i = 0; i < dacl->num_aces; i ++) {
 186
 187                 status = gpo_sd_check_ace(&dacl->aces[i], token);
 188
 189                 if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
 190                         return status;
 191                 } else if (NT_STATUS_IS_OK(status)) {
 192                         return status;
 193                 }
 194
 195                 continue;
 196         }
 197
 198         return NT_STATUS_ACCESS_DENIED;
 199 }