public sealed class CSSecurityDescriptor : CSGenericSecurityDescriptor

Public NotInheritable Class CSSecurityDescriptor
	Inherits CSGenericSecurityDescriptor

using System;
using System.Xml;
using System.Text;
using System.Security.Principal;
using System.Security.AccessControl;
using ContentStudio;
using ContentStudio.Security;
using ContentStudio.Security.AccessControlEdit;

public class TheClass
{
    public void Main()
    {
        const int CONNECTION_ID = 1;
        //Create a new session.
        SessionManager sman = new SessionManager();
        int SessionID = sman.OpenSession(CONNECTION_ID);
        ContentStudio.Security.AccessControl acc = new AccessControl();
        //Get the security descriptor on document id 2558.
        string sd = acc.GetObjectSecurity(CONNECTION_ID,
                                          SessionID,
                                          2558,
                                          CSSecurableObjects.DocumentItem);
        /*
        Use the ContentStudio.Security.AccessControlEdit.CSSecurityDescriptor object.
        This object is not executed over remoting.
        */
        CSSecurityDescriptor secDesc = new CSSecurityDescriptor(sd);
        /*
        Add two new permission entries with the AddAccess method on the DiscretionaryAccessControlList
        of the CSSecurityDescriptor object.  Let's use Everyone - read, and CONTENTSTUDIO\Editors - modify.
        */
        SecurityIdentifier SID = new SecurityIdentifier(WellKnownSidType.WorldSid, null);
        secDesc.DiscretionaryAccessControlList.AddAccess(SID,
                                                         AccessControlType.Allow,
                                                         CSObjectPermissions.Read ,
                                                         AceFlags.None);
        const CSObjectPermissions MODIFY = CSObjectPermissions.Write | 
                                           CSObjectPermissions.Create | 
                                           CSObjectPermissions.Read | 
                                           CSObjectPermissions.SendForRevision;
        /*
        A SecurityIdentifier can also be created if you have the user name in the 
        format Domain\Username or the UPN-format (e.g. Editors@contentstudio.com).
        */
        NTAccount ntac = new NTAccount("CONTENTSTUDIO\\Editors");
        //Translate to a SecurityIdentifier
        SID = (SecurityIdentifier)ntac.Translate(typeof(SecurityIdentifier));
        secDesc.DiscretionaryAccessControlList.AddAccess(SID,
                                                         AccessControlType.Allow,
                                                         MODIFY,
                                                         AceFlags.None);
        //Get the the security descriptor in the Xml format.
        StringBuilder sbu = new StringBuilder();
        XmlWriter XWriter = XmlWriter.Create(sbu);
        secDesc.WriteXml(XWriter);
        XWriter.Flush();
        sd = sbu.ToString();
        //Save the security back to the object that provided it.
        acc.SetObjectSecurity(CONNECTION_ID, SessionID, AccessControl.SecurityInfoClass.DACL, sd);
    }
}

Imports System
Imports System.Xml
Imports System.Text
Imports System.Security.Principal
Imports System.Security.AccessControl
Imports ContentStudio
Imports ContentStudio.Security
Imports ContentStudio.Security.AccessControlEdit

Public Class TheClass
{
    Public Sub Main()
        Const CONNECTION_ID As Integer = 1
        'Create a new session.
        Dim sman SessionManager As New SessionManager()
        Dim SessionID As Integer = sman.OpenSession(CONNECTION_ID)
        Dim acc As ContentStudio.Security.AccessControl = New AccessControl()
        'Get the security descriptor on document id 2558.
        Dim sd As String = acc.GetObjectSecurity(CONNECTION_ID, _
                                                 SessionID, _
                                                 2558, _
                                                 CSSecurableObjects.DocumentItem)

        'Use the ContentStudio.Security.AccessControlEdit.CSSecurityDescriptor object.

        Dim secDesc As New CSSecurityDescriptor(sd)

        'Add a new permission with the AddAccess method on the DiscretionaryAccessControlList
        'of the CSSecurityDescriptor object. Let's use Everyone - read, and CONTENTSTUDIO\Editors - modify.
        Dim SID As New SecurityIdentifier(WellKnownSidType.WorldSid, Nothing)
        secDesc.DiscretionaryAccessControlList.AddAccess(SID, _
                                                         AccessControlType.Allow, _
                                                         MODIFY, _
                                                         AceFlags.None)
        Const MODIFY As CSObjectPermissions = CSObjectPermissions.Write Or _
                                              CSObjectPermissions.Create Or _
                                              CSObjectPermissions.Read Or _
                                              CSObjectPermissions.SendForRevision

        'A SecurityIdentifier can also be created if you have the user name in the 
        'format Domain\Username or the UPN-format (e.g. Editors@contentstudio.com).
        Dim ntac = New NTAccount("CONTENTSTUDIO\Editors")
        'Translate into a SecurityIdentifier
        SID = DirectCast(ntac.Translate(GetType(SecurityIdentifier)), SecurityIdentifier)
        secDesc.DiscretionaryAccessControlList.AddAccess(SID, _
                                                         AccessControlType.Allow, _
                                                         MODIFY, _
                                                         AceFlags.None)
        'Get the the security descriptor in the Xml format.
        Dim sbu As New StringBuilder()
        Dim XWriter AsXmlWriter = XmlWriter.Create(sbu)
        secDesc.WriteXml(XWriter)
        XWriter.Flush()
        sd = sbu.ToString()
        'Save the security back to the object that provided it.
        acc.SetObjectSecurity(CONNECTION_ID, SessionID, AccessControl.SecurityInfoClass.DACL, sd)
    End Sub
End Class