question: public boolean verify ( X509Certificate cert , Provider sigProvider ) throws NoSuchAlgorithmException , CertificateExpiredException , CertificateNotYetValidException , CMSException { Time signingTime = getSigningTime ( ) ; if ( signingTime != null ) { cert . checkValidity ( signingTime . getDate ( ) ) ; } return doVerify ( cert . getPublicKey ( ) , sigProvider ) ; }
target:  verify that the given certificate successfully handles and confirms the signature associated with this signer and, if a signingTime attribute is available, that the certificate was valid at the time the signature was generated.