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
  51                         FALL_THROUGH;
  52                 case SEC_ACE_INHERITED_OBJECT_TYPE_PRESENT:
  53                         if (GUID_equal(&object->inherited_type.inherited_type,
  54                                        &ext_right_apg_guid)) {
  55                                 return true;
  56                         }
  57
  58                         FALL_THROUGH;
  59                 default:
  60                         break;
  61         }
  62
  63         return false;
  64 }
  65
  66 /****************************************************************
  67 ****************************************************************/
  68
  69 static bool gpo_sd_check_agp_object(const struct security_ace *ace)
  70 {
  71         if (!sec_ace_object(ace->type)) {
  72                 return false;
  73         }
  74
  75         return gpo_sd_check_agp_object_guid(&ace->object.object);
  76 }
  77
  78 /****************************************************************
  79 ****************************************************************/
  80
  81 static bool gpo_sd_check_agp_access_bits(uint32_t access_mask)
  82 {
  83         return (access_mask & SEC_ADS_CONTROL_ACCESS);
  84 }
  85
  86 #if 0
  87 /****************************************************************
  88 ****************************************************************/
  89
  90 static bool gpo_sd_check_read_access_bits(uint32_t access_mask)
  91 {
  92         uint32_t read_bits = SEC_RIGHTS_LIST_CONTENTS |
  93                            SEC_RIGHTS_READ_ALL_PROP |
  94                            SEC_RIGHTS_READ_PERMS;
  95
  96         return (read_bits == (access_mask & read_bits));
  97 }
  98 #endif
  99
 100 /****************************************************************
 101 ****************************************************************/
 102
 103 static NTSTATUS gpo_sd_check_ace_denied_object(const struct security_ace *ace,
 104                                                const struct security_token *token)
 105 {
 106         if (gpo_sd_check_agp_object(ace) &&
 107             gpo_sd_check_agp_access_bits(ace->access_mask) &&
 108             security_token_has_sid(token, &ace->trustee)) {
 109                 struct dom_sid_buf sid_str;
 110                 DEBUG(10,("gpo_sd_check_ace_denied_object: "
 111                         "Access denied as of ace for %s\n",
 112                         dom_sid_str_buf(&ace->trustee, &sid_str)));
 113                 return NT_STATUS_ACCESS_DENIED;
 114         }
 115
 116         return STATUS_MORE_ENTRIES;
 117 }
 118
 119 /****************************************************************
 120 ****************************************************************/
 121
 122 static NTSTATUS gpo_sd_check_ace_allowed_object(const struct security_ace *ace,
 123                                                 const struct security_token *token)
 124 {
 125         if (gpo_sd_check_agp_object(ace) &&
 126             gpo_sd_check_agp_access_bits(ace->access_mask) &&
 127             security_token_has_sid(token, &ace->trustee)) {
 128                 struct dom_sid_buf sid_str;
 129                 DEBUG(10,("gpo_sd_check_ace_allowed_object: "
 130                         "Access granted as of ace for %s\n",
 131                         dom_sid_str_buf(&ace->trustee, &sid_str)));
 132                 return NT_STATUS_OK;
 133         }
 134
 135         return STATUS_MORE_ENTRIES;
 136 }
 137
 138 /****************************************************************
 139 ****************************************************************/
 140
 141 static NTSTATUS gpo_sd_check_ace(const struct security_ace *ace,
 142                                  const struct security_token *token)
 143 {
 144         switch (ace->type) {
 145                 case SEC_ACE_TYPE_ACCESS_DENIED_OBJECT:
 146                         return gpo_sd_check_ace_denied_object(ace, token);
 147                 case SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT:
 148                         return gpo_sd_check_ace_allowed_object(ace, token);
 149                 default:
 150                         return STATUS_MORE_ENTRIES;
 151         }
 152 }
 153
 154 /****************************************************************
 155 ****************************************************************/
 156
 157 NTSTATUS gpo_apply_security_filtering(const struct GROUP_POLICY_OBJECT *gpo,
 158                                       const struct security_token *token)
 159 {
 160         struct security_descriptor *sd = gpo->security_descriptor;
 161         struct security_acl *dacl = NULL;
 162         NTSTATUS status = NT_STATUS_ACCESS_DENIED;
 163         int i;
 164
 165         if (!token) {
 166                 return NT_STATUS_INVALID_USER_BUFFER;
 167         }
 168
 169         if (!sd) {
 170                 return NT_STATUS_INVALID_SECURITY_DESCR;
 171         }
 172
 173         dacl = sd->dacl;
 174         if (!dacl) {
 175                 return NT_STATUS_INVALID_SECURITY_DESCR;
 176         }
 177
 178         /* check all aces and only return NT_STATUS_OK (== Access granted) or
 179          * NT_STATUS_ACCESS_DENIED ( == Access denied) - the default is to
 180          * deny access */
 181
 182         for (i = 0; i < dacl->num_aces; i ++) {
 183
 184                 status = gpo_sd_check_ace(&dacl->aces[i], token);
 185
 186                 if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
 187                         return status;
 188                 } else if (NT_STATUS_IS_OK(status)) {
 189                         return status;
 190                 }
 191
 192                 continue;
 193         }
 194
 195         return NT_STATUS_ACCESS_DENIED;
 196 }