source3/rpc_server/srv_access_check.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *  RPC Pipe client / server routines
   4  *  Copyright (C) Andrew Tridgell                   1992-1997,
   5  *  Copyright (C) Luke Kenneth Casson Leighton      1996-1997,
   6  *  Copyright (C) Paul Ashton                       1997,
   7  *  Copyright (C) Marc Jacobsen                     1999,
   8  *  Copyright (C) Jeremy Allison                    2001-2008,
   9  *  Copyright (C) Jean François Micouleau           1998-2001,
  10  *  Copyright (C) Jim McDonough <jmcd@us.ibm.com>   2002,
  11  *  Copyright (C) Gerald (Jerry) Carter             2003-2004,
  12  *  Copyright (C) Simo Sorce                        2003.
  13  *  Copyright (C) Volker Lendecke                   2005.
  14  *  Copyright (C) Guenther Deschner                 2008.
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License as published by
  18  *  the Free Software Foundation; either version 3 of the License, or
  19  *  (at your option) any later version.
  20  *
  21  *  This program is distributed in the hope that it will be useful,
  22  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *  GNU General Public License for more details.
  25  *
  26  *  You should have received a copy of the GNU General Public License
  27  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  28  */
  29
  30 #include "includes.h"
  31 #include "rpc_server/srv_access_check.h"
  32 #include "../libcli/security/security.h"
  33 #include "passdb/machine_sid.h"
  34
  35 /*******************************************************************
  36  Checks if access to an object should be granted, and returns that
  37  level of access for further checks.
  38
  39  If the user has either of needed_priv_1 or needed_priv_2 then they
  40  get the rights in rights_mask in addition to any calulated rights.
  41
  42  This handles the unusual case where we need to allow two different
  43  privileges to obtain exactly the same rights, which occours only in
  44  SAMR.
  45 ********************************************************************/
  46
  47 NTSTATUS access_check_object( struct security_descriptor *psd, struct security_token *token,
  48                               enum sec_privilege needed_priv_1, enum sec_privilege needed_priv_2,
  49                               uint32 rights_mask,
  50                               uint32 des_access, uint32 *acc_granted,
  51                               const char *debug )
  52 {
  53         NTSTATUS status = NT_STATUS_ACCESS_DENIED;
  54         uint32 saved_mask = 0;
  55         bool priv_granted = false;
  56
  57         /* check privileges; certain SAM access bits should be overridden
  58            by privileges (mostly having to do with creating/modifying/deleting
  59            users and groups) */
  60
  61         if ((needed_priv_1 != SEC_PRIV_INVALID && security_token_has_privilege(token, needed_priv_1)) ||
  62             (needed_priv_2 != SEC_PRIV_INVALID && security_token_has_privilege(token, needed_priv_2))) {
  63                 priv_granted = true;
  64                 saved_mask = (des_access & rights_mask);
  65                 des_access &= ~saved_mask;
  66
  67                 DEBUG(4,("access_check_object: user rights access mask [0x%x]\n",
  68                         rights_mask));
  69         }
  70
  71
  72         /* check the security descriptor first */
  73
  74         status = se_access_check(psd, token, des_access, acc_granted);
  75         if (NT_STATUS_IS_OK(status)) {
  76                 goto done;
  77         }
  78
  79         /* give root a free pass */
  80
  81         if ( geteuid() == sec_initial_uid() ) {
  82
  83                 DEBUG(4,("%s: ACCESS should be DENIED  (requested: %#010x)\n", debug, des_access));
  84                 DEBUGADD(4,("but overritten by euid == sec_initial_uid()\n"));
  85
  86                 priv_granted = true;
  87                 *acc_granted = des_access;
  88
  89                 status = NT_STATUS_OK;
  90                 goto done;
  91         }
  92
  93
  94 done:
  95         if (priv_granted) {
  96                 /* add in any bits saved during the privilege check (only
  97                    matters if status is ok) */
  98
  99                 *acc_granted |= rights_mask;
 100         }
 101
 102         DEBUG(4,("%s: access %s (requested: 0x%08x, granted: 0x%08x)\n",
 103                 debug, NT_STATUS_IS_OK(status) ? "GRANTED" : "DENIED",
 104                 des_access, *acc_granted));
 105
 106         return status;
 107 }
 108
 109
 110 /*******************************************************************
 111  Map any MAXIMUM_ALLOWED_ACCESS request to a valid access set.
 112 ********************************************************************/
 113
 114 void map_max_allowed_access(const struct security_token *nt_token,
 115                             const struct security_unix_token *unix_token,
 116                             uint32_t *pacc_requested)
 117 {
 118         if (!((*pacc_requested) & MAXIMUM_ALLOWED_ACCESS)) {
 119                 return;
 120         }
 121         *pacc_requested &= ~MAXIMUM_ALLOWED_ACCESS;
 122
 123         /* At least try for generic read|execute - Everyone gets that. */
 124         *pacc_requested = GENERIC_READ_ACCESS|GENERIC_EXECUTE_ACCESS;
 125
 126         /* root gets anything. */
 127         if (unix_token->uid == sec_initial_uid()) {
 128                 *pacc_requested |= GENERIC_ALL_ACCESS;
 129                 return;
 130         }
 131
 132         /* Full Access for 'BUILTIN\Administrators' and 'BUILTIN\Account Operators */
 133
 134         if (security_token_has_sid(nt_token, &global_sid_Builtin_Administrators) ||
 135                         security_token_has_sid(nt_token, &global_sid_Builtin_Account_Operators)) {
 136                 *pacc_requested |= GENERIC_ALL_ACCESS;
 137                 return;
 138         }
 139
 140         /* Full access for DOMAIN\Domain Admins. */
 141         if ( IS_DC ) {
 142                 struct dom_sid domadmin_sid;
 143                 sid_compose(&domadmin_sid, get_global_sam_sid(),
 144                             DOMAIN_RID_ADMINS);
 145                 if (security_token_has_sid(nt_token, &domadmin_sid)) {
 146                         *pacc_requested |= GENERIC_ALL_ACCESS;
 147                         return;
 148                 }
 149         }
 150         /* TODO ! Check privileges. */
 151 }