private KekRecipientInfo GetKekInfo(
Asn1TaggedObject o)
{
// For compatibility with erroneous version, we don't always pass 'false' here
return KekRecipientInfo.GetInstance(o, o.IsExplicit());
}
/**
* Return an ASN1 sequence from a tagged object. There is a special
* case here, if an object appears to have been explicitly tagged on
* reading but we were expecting it to be implicitly tagged in the
* normal course of events it indicates that we lost the surrounding
* sequence - so we need to add it back (this will happen if the tagged
* object is a sequence that contains other sequences). If you are
* dealing with implicitly tagged sequences you really <b>should</b>
* be using this method.
*
* @param obj the tagged object.
* @param explicitly true if the object is meant to be explicitly tagged,
* false otherwise.
* @exception ArgumentException if the tagged object cannot
* be converted.
*/
public static Asn1Sequence GetInstance(
Asn1TaggedObject obj,
bool explicitly)
{
Asn1Object inner = obj.GetObject();
if (explicitly)
{
if (!obj.IsExplicit())
throw new ArgumentException("object implicit - explicit expected.");
return (Asn1Sequence) inner;
}
//
// constructed object which appears to be explicitly tagged
// when it should be implicit means we have to add the
// surrounding sequence.
//
if (obj.IsExplicit())
{
if (obj is BerTaggedObject)
{
return new BerSequence(inner);
}
return new DerSequence(inner);
}
if (inner is Asn1Sequence)
{
return (Asn1Sequence) inner;
}
throw new ArgumentException("Unknown object in GetInstance: " + obj.GetType().FullName, "obj");
}
