/**
  * add a signer - no attributes other than the default ones will be
  * provided here.
  *
  * @param key signing key to use
  * @param cert certificate containing corresponding public key
  * @param digestOID digest algorithm OID
  */
 public void AddSigner(
     AsymmetricKeyParameter privateKey,
     X509Certificate cert,
     string digestOID)
 {
     AddSigner(privateKey, cert, Helper.GetEncOid(privateKey, digestOID), digestOID);
 }
 public void AddSigner(AsymmetricKeyParameter privateKey, X509Certificate cert, string digestOid, CmsAttributeTableGenerator signedAttrGenerator, CmsAttributeTableGenerator unsignedAttrGenerator)
 {
     AddSigner(privateKey, cert, Helper.GetEncOid(privateKey, digestOid), digestOid, signedAttrGenerator, unsignedAttrGenerator);
 }