# Certificate Validity

## Contents
Overview Configuration

## Overview
The validity period of an X.509 certificate is encoded in the certificate. The Certificate Validity performs a simple check on a certificate to ensure that it has not expired. By default, the Certificate Validity filter searches for the X.509 certificate in the `certificate` message attribute, which must be set by a predecessor filter in the circuit (for example, by an SSL Authentication filter).
## Configuration
Configure the following fields on the Certificate Validity screen: Name: Enter an appropriate name for the filter. Certificate Attribute: Enter or select the name of the message attribute that you expect to hold the certificate. The filter checks the validity of the certificate contained in this attribute. If no certificate is found, the filter returns an error.