cr.engineInit(new ByteArrayInputStream(certsKey));
certs = cr.engineReadAll();
signCert = (X509Certificate)certs.iterator().next();
crls = new ArrayList();
ASN1InputStream in = new ASN1InputStream(new ByteArrayInputStream(contentsKey));
digest = ((DEROctetString)in.readObject()).getOctets();
if (provider == null)
sig = Signature.getInstance("SHA1withRSA");
else
sig = Signature.getInstance("SHA1withRSA", provider);
sig.initVerify(signCert.getPublicKey());