windows-server-2003/ds/netapi/netlib/secobj2.c

/*++

Copyright (c) 1991-1992  Microsoft Corporation

Module Name:

    secobj.c

Abstract:

    This module provides support routines to simplify the creation of
    security descriptors for user-mode objects.

Author:

    Cliff Van Dyke (CliffV) 09-Feb-1994

Environment:

    Contains NT specific code.

Revision History:

    Cliff Van Dyke (CliffV) 09-Feb-1994
        Split off from secobj.c so NtLmSsp can reference secobj.c
        without loading the rpc libaries.

--*/

#include <nt.h>
#include <ntrtl.h>
#include <nturtl.h>

#include <windows.h>            // DWORD.
#include <lmcons.h>             // NET_API_STATUS.

#include <netlib.h>
#include <lmerr.h>

#include <netdebug.h>
#include <debuglib.h>

#include <rpc.h>
#include <rpcutil.h>

#include <secobj.h>



NET_API_STATUS
NetpAccessCheckAndAudit(
    IN  LPTSTR SubsystemName,
    IN  LPTSTR ObjectTypeName,
    IN  PSECURITY_DESCRIPTOR SecurityDescriptor,
    IN  ACCESS_MASK DesiredAccess,
    IN  PGENERIC_MAPPING GenericMapping
    )
/*++

Routine Description:

    This function impersonates the caller so that it can perform access
    validation using NtAccessCheckAndAuditAlarm; and reverts back to
    itself before returning.

Arguments:

    SubsystemName - Supplies a name string identifying the subsystem
        calling this routine.

    ObjectTypeName - Supplies the name of the type of the object being
        accessed.

    SecurityDescriptor - A pointer to the Security Descriptor against which
        acccess is to be checked.

    DesiredAccess - Supplies desired acccess mask.  This mask must have been
        previously mapped to contain no generic accesses.

    GenericMapping - Supplies a pointer to the generic mapping associated
        with this object type.

Return Value:

    NET_API_STATUS - NERR_Success or reason for failure.

--*/
{

    NTSTATUS NtStatus;
    RPC_STATUS RpcStatus;
    BOOLEAN fWasEnabled;

    UNICODE_STRING Subsystem;
    UNICODE_STRING ObjectType;
    UNICODE_STRING ObjectName;

#ifndef UNICODE
    OEM_STRING AnsiString;
#endif

    ACCESS_MASK GrantedAccess;
    BOOLEAN GenerateOnClose;
    NTSTATUS AccessStatus;


#ifdef UNICODE
    RtlInitUnicodeString(&Subsystem, SubsystemName);
    RtlInitUnicodeString(&ObjectType, ObjectTypeName);
#else
    NetpInitOemString( &AnsiString, SubsystemName );
    NtStatus = RtlOemStringToUnicodeString(
                   &Subsystem,
                   &AnsiString,
                   TRUE
                   );

    if ( !NT_SUCCESS( NtStatus )) {
        NetpKdPrint(("[Netlib] Error calling RtlOemStringToUnicodeString %08lx\n",
                     NtStatus));
        return NetpNtStatusToApiStatus( NtStatus );
    }

    NetpInitOemString( &AnsiString, ObjectTypeName );

    NtStatus = RtlOemStringToUnicodeString(&ObjectType,
                                           &AnsiString,
                                           TRUE);

    if ( !NT_SUCCESS( NtStatus )) {
        NetpKdPrint(("[Netlib] Error calling RtlOemStringToUnicodeString %08lx\n",
                     NtStatus));
        RtlFreeUnicodeString( &Subsystem );
        return NetpNtStatusToApiStatus( NtStatus );
    }
#endif

    //
    // Make sure SE_AUDIT_PRIVILEGE is enabled for this process (rather
    // than the thread) since the audit privilege is checked in the process
    // token (and not the thread token).  Leave it enabled since there's
    // no harm in doing so once it's been enabled (since the process needs
    // to have the privilege in the first place).
    //

    RtlAdjustPrivilege(SE_AUDIT_PRIVILEGE,
                       TRUE,
                       FALSE,
                       &fWasEnabled);

    RtlInitUnicodeString(&ObjectName, NULL);             // No object name

    if ((RpcStatus = RpcImpersonateClient(NULL)) != RPC_S_OK) {
        NetpKdPrint(("[Netlib] Failed to impersonate client %08lx\n",
                     RpcStatus));
        return NetpRpcStatusToApiStatus(RpcStatus);
    }

    NtStatus = NtAccessCheckAndAuditAlarm(
                   &Subsystem,
                   NULL,                        // No handle for object
                   &ObjectType,
                   &ObjectName,
                   SecurityDescriptor,
                   DesiredAccess,
                   GenericMapping,
                   FALSE,
                   &GrantedAccess,
                   &AccessStatus,
                   &GenerateOnClose
                   );

#ifndef UNICODE
    RtlFreeUnicodeString( &Subsystem );
    RtlFreeUnicodeString( &ObjectType );
#endif

    if ((RpcStatus = RpcRevertToSelf()) != RPC_S_OK) {
        NetpKdPrint(("[Netlib] Fail to revert to self %08lx\n", RpcStatus));
        NetpAssert(FALSE);
    }

    if (! NT_SUCCESS(NtStatus)) {
        NetpKdPrint(("[Netlib] Error calling NtAccessCheckAndAuditAlarm %08lx\n",
                     NtStatus));
        return ERROR_ACCESS_DENIED;
    }

    if (AccessStatus != STATUS_SUCCESS) {
        IF_DEBUG(SECURITY) {
            NetpKdPrint(("[Netlib] Access status is %08lx\n", AccessStatus));
        }
        return ERROR_ACCESS_DENIED;
    }

    return NERR_Success;
}



NET_API_STATUS
NetpAccessCheck(
    IN  PSECURITY_DESCRIPTOR SecurityDescriptor,
    IN  ACCESS_MASK DesiredAccess,
    IN  PGENERIC_MAPPING GenericMapping
    )
/*++

Routine Description:

    This function impersonates the caller so that it can perform access
    validation using NtAccessCheck; and reverts back to
    itself before returning.

    This routine differs from NetpAccessCheckAndAudit in that it doesn't require
    the caller to have SE_AUDIT_PRIVILEGE nor does it generate audits.
    That is typically fine since the passed in security descriptor typically doesn't
    have a SACL requesting an audit.

Arguments:

    SecurityDescriptor - A pointer to the Security Descriptor against which
        acccess is to be checked.

    DesiredAccess - Supplies desired acccess mask.  This mask must have been
        previously mapped to contain no generic accesses.

    GenericMapping - Supplies a pointer to the generic mapping associated
        with this object type.

Return Value:

    NET_API_STATUS - NERR_Success or reason for failure.

--*/
{
    NET_API_STATUS NetStatus;
    NET_API_STATUS TempStatus;

    HANDLE ClientToken = NULL;

    DWORD GrantedAccess;
    BOOL AccessStatus;
    BYTE PrivilegeSet[500]; // Large buffer
    DWORD PrivilegeSetSize;


    //
    // Impersonate the client.
    //

    NetStatus = RpcImpersonateClient(NULL);

    if ( NetStatus != RPC_S_OK ) {
        NetpKdPrint(("[Netlib] Failed to impersonate client %08lx\n",
                     NetStatus));
        return NetpRpcStatusToApiStatus(NetStatus);
    }

    //
    // Open the impersonated token.
    //

    if ( !OpenThreadToken( GetCurrentThread(),
                           TOKEN_QUERY,
                           TRUE, // Use NtLmSvc security context to open token
                           &ClientToken )) {

        NetStatus = GetLastError();
        NetpKdPrint(("[Netlib] Error calling GetCurrentThread %ld\n",
                     NetStatus));

        goto Cleanup;
    }

    //
    // Check if the client has the required access.
    //

    PrivilegeSetSize = sizeof(PrivilegeSet);

    if ( !AccessCheck( SecurityDescriptor,
                       ClientToken,
                       DesiredAccess,
                       GenericMapping,
                       (PPRIVILEGE_SET) PrivilegeSet,
                       &PrivilegeSetSize,
                       &GrantedAccess,
                       &AccessStatus ) ) {

        NetStatus = GetLastError();
        NetpKdPrint(("[Netlib] Error calling AccessCheck %ld\n",
                     NetStatus));

        goto Cleanup;

    }

    if ( !AccessStatus ) {
        NetStatus = GetLastError();
        IF_DEBUG(SECURITY) {
            NetpKdPrint(("[Netlib] Access status is %ld\n", NetStatus ));
        }
        goto Cleanup;
    }

    //
    // Success
    //

    NetStatus = NERR_Success;

    //
    // Free locally used resources
    //
Cleanup:
    TempStatus = RpcRevertToSelf();
    if ( TempStatus != RPC_S_OK ) {
        NetpKdPrint(("[Netlib] Fail to revert to self %08lx\n", TempStatus));
        NetpAssert(FALSE);
    }

    if ( ClientToken != NULL ) {
        CloseHandle( ClientToken );
    }

    return NetStatus;
}