InvalidKeyException, NoSuchProviderException,
SignatureException
{
if ( !c.getSignatureAlgorithm().equals(c.getTBSCertList().getSignature()) )
{
throw new CRLException("Signature algorithm on CertifcateList does not match TBSCertList.");
}
Signature sig = Signature.getInstance(getSigAlgName(), sigProvider);
sig.initVerify(key);