System.Security.AccessControl.CommonSecurityDescriptor.AddSystemAcl C# (CSharp) Method

        public void AddSystemAcl(byte revision, int trusted)
        {
            this.SystemAcl = new SystemAcl(this.IsContainer, this.IsDS, revision, trusted);
            this.AddControlFlags(ControlFlags.SystemAclPresent);
        }

        //
        // Modifies the SACL
        //
        private bool ModifyAudit(AccessControlModification modification, ObjectAuditRule rule, out bool modified)
        {
            bool result = true;

            if (_securityDescriptor.SystemAcl == null)
            {
                if (modification == AccessControlModification.Remove || modification == AccessControlModification.RemoveAll || modification == AccessControlModification.RemoveSpecific)
                {
                    modified = false;
                    return(result);
                }

                //_securityDescriptor.SystemAcl = new SystemAcl(IsContainer, IsDS, GenericAcl.AclRevisionDS, 1);
                //_securityDescriptor.AddControlFlags(ControlFlags.SystemAclPresent);
                _securityDescriptor.AddSystemAcl(GenericAcl.AclRevisionDS, 1);
            }
            else if ((modification == AccessControlModification.Add || modification == AccessControlModification.Set || modification == AccessControlModification.Reset) &&
                     (rule.ObjectFlags != ObjectAceFlags.None))
            {
                //
                // This will result in an object ace being added to the sacl, so the sacl revision must be AclRevisionDS
                //
                if (_securityDescriptor.SystemAcl.Revision < GenericAcl.AclRevisionDS)
                {
                    //
                    // we need to create a new sacl with the same aces as the existing one but the revision should be AclRevisionDS
                    //
                    byte[] binaryForm = new byte[_securityDescriptor.SystemAcl.BinaryLength];
                    _securityDescriptor.SystemAcl.GetBinaryForm(binaryForm, 0);
                    binaryForm[0] = GenericAcl.AclRevisionDS; // revision is the first byte of the binary form

                    _securityDescriptor.SystemAcl = new SystemAcl(IsContainer, IsDS, new RawAcl(binaryForm, 0));
                }
            }

            SecurityIdentifier sid = rule.IdentityReference.Translate(typeof(SecurityIdentifier)) as SecurityIdentifier;

            switch (modification)
            {
            case AccessControlModification.Add:
                //_securityDescriptor.SystemAcl.AddAudit(rule.AuditFlags, sid, rule.AccessMask, rule.InheritanceFlags, rule.PropagationFlags, rule.ObjectFlags, rule.ObjectType, rule.InheritedObjectType);
                _securityDescriptor.SystemAcl.AddAudit(sid, rule);
                break;

            case AccessControlModification.Set:
                //_securityDescriptor.SystemAcl.SetAudit(rule.AuditFlags, sid, rule.AccessMask, rule.InheritanceFlags, rule.PropagationFlags, rule.ObjectFlags, rule.ObjectType, rule.InheritedObjectType);
                _securityDescriptor.SystemAcl.SetAudit(sid, rule);
                break;

            case AccessControlModification.Reset:
                _securityDescriptor.SystemAcl.RemoveAudit(AuditFlags.Failure | AuditFlags.Success, sid, -1, InheritanceFlags.ContainerInherit, 0, ObjectAceFlags.None, Guid.Empty, Guid.Empty);
                //_securityDescriptor.SystemAcl.SetAudit(rule.AuditFlags, sid, rule.AccessMask, rule.InheritanceFlags, rule.PropagationFlags, rule.ObjectFlags, rule.ObjectType, rule.InheritedObjectType);
                _securityDescriptor.SystemAcl.SetAudit(sid, rule);
                break;

            case AccessControlModification.Remove:
                //result = _securityDescriptor.SystemAcl.RemoveAudit(rule.AuditFlags, sid, rule.AccessMask, rule.InheritanceFlags, rule.PropagationFlags, rule.ObjectFlags, rule.ObjectType, rule.InheritedObjectType);
                result = _securityDescriptor.SystemAcl.RemoveAudit(sid, rule);
                break;

            case AccessControlModification.RemoveAll:
                result = _securityDescriptor.SystemAcl.RemoveAudit(AuditFlags.Failure | AuditFlags.Success, sid, -1, InheritanceFlags.ContainerInherit, 0, ObjectAceFlags.None, Guid.Empty, Guid.Empty);
                if (result == false)
                {
                    Debug.Assert(false, "Invalid operation");
                    throw new Exception();
                }

                break;

            case AccessControlModification.RemoveSpecific:
                //_securityDescriptor.SystemAcl.RemoveAuditSpecific(rule.AuditFlags, sid, rule.AccessMask, rule.InheritanceFlags, rule.PropagationFlags, rule.ObjectFlags, rule.ObjectType, rule.InheritedObjectType);
                _securityDescriptor.SystemAcl.RemoveAuditSpecific(sid, rule);
                break;

            default:
                throw new ArgumentOutOfRangeException(
                          "modification",
                          SR.ArgumentOutOfRange_Enum);
            }

            modified            = result;
            AuditRulesModified |= modified;
            return(result);
        }