BigInteger version = ((DERInteger)seq.getObjectAt(0)).getValue();
if (version.intValue() != 3)
{
throw new IllegalArgumentException("wrong version for PFX PDU");
}
contentInfo = ContentInfo.getInstance(seq.getObjectAt(1));
if (seq.size() == 3)
{
macData = MacData.getInstance(seq.getObjectAt(2));
}