The ASN.1 definition is as follows:

   PolicyQualifierInfo ::= SEQUENCE {
        policyQualifierId       PolicyQualifierId,
        qualifier               ANY DEFINED BY policyQualifierId }
 

A certificate policies extension, if present in an X.509 version 3 certificate, contains a sequence of one or more policy information terms, each of which consists of an object identifier (OID) and optional qualifiers. In an end-entity certificate, these policy information terms indicate the policy under which the certificate has been issued and the purposes for which the certificate may be used. In a CA certificate, these policy information terms limit the set of policies for certification paths which include this certificate.

A Set of PolicyQualifierInfo objects are returned by the PolicyNode.getPolicyQualifiers method. This allows applications with specific policy requirements to process and validate each policy qualifier. Applications that need to process policy qualifiers should explicitly set the policyQualifiersRejected flag to false (by calling the PKIXParameters.setPolicyQualifiersRejected method) before validating a certification path.

Note that the PKIX certification path validation algorithm specifies that any policy qualifier in a certificate policies extension that is marked critical must be processed and validated. Otherwise, the certification path must be rejected. If the policyQualifiersRejected flag is set to false, it is up to the application to validate all policy qualifiers in this manner in order to be PKIX compliant.

Concurrent Access

All PolicyQualifierInfo objects must be immutable and thread-safe. That is, multiple threads may concurrently invoke the methods defined in this class on a single PolicyQualifierInfo object (or more than one) with no ill effects. Requiring PolicyQualifierInfo objects to be immutable and thread-safe allows them to be passed around to various pieces of code without worrying about coordinating access.