This class defines the CRL Extensions. It is used for both CRL Extensions and CRL Entry Extensions, which are defined are follows: <pre> TBSCertList ::= SEQUENCE { version Version OPTIONAL, -- if present, must be v2 signature AlgorithmIdentifier, issuer Name, thisUpdate Time, nextUpdate Time OPTIONAL, revokedCertificates SEQUENCE OF SEQUENCE { userCertificate CertificateSerialNumber, revocationDate Time, crlEntryExtensions Extensions OPTIONAL -- if present, must be v2 } OPTIONAL, crlExtensions [0] EXPLICIT Extensions OPTIONAL -- if present, must be v2 } </pre>