public AttributeTable getUnprotectedAttributes()
throws IOException
{
if (_unprotectedAttributes == null && _attrNotRead)
{
ASN1SetParser set = _envelopedData.getUnprotectedAttrs();
_attrNotRead = false;
if (set != null)
{
ASN1EncodableVector v = new ASN1EncodableVector();
DEREncodable o;
while ((o = set.readObject()) != null)
{
ASN1SequenceParser seq = (ASN1SequenceParser)o;
v.add(seq.getDERObject());
}