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package org.bouncycastle.asn1;
import java.io.IOException;
/**
* ASN.1 TaggedObject - in ASN.1 notation this is any object preceded by
* a [n] where n is some number - these are assumed to follow the construction
* rules (as with sequences).
*/
public abstract class ASN1TaggedObject
extends ASN1Primitive
implements ASN1TaggedObjectParser
{
int tagNo;
boolean empty = false;
boolean explicit = true;
ASN1Encodable obj = null;
static public ASN1TaggedObject getInstance(
ASN1TaggedObject obj,
boolean explicit)
{
if (explicit)
{
return (ASN1TaggedObject)obj.getObject();
}
throw new IllegalArgumentException("implicitly tagged tagged object");
}
static public ASN1TaggedObject getInstance(
Object obj)
{
if (obj == null || obj instanceof ASN1TaggedObject)
{
return (ASN1TaggedObject)obj;
}
else if (obj instanceof byte[])
{
try
{
return ASN1TaggedObject.getInstance(fromByteArray((byte[])obj));
}
catch (IOException e)
{
throw new IllegalArgumentException("failed to construct tagged object from byte[]: " + e.getMessage());
}
}
throw new IllegalArgumentException("unknown object in getInstance: " + obj.getClass().getName());
}
/**
* Create a tagged object with the style given by the value of explicit.
*
* If the object implements ASN1Choice the tag style will always be changed
* to explicit in accordance with the ASN.1 encoding rules.
*
* @param explicit true if the object is explicitly tagged.
* @param tagNo the tag number for this object.
* @param obj the tagged object.
*/
public ASN1TaggedObject(
boolean explicit,
int tagNo,
ASN1Encodable obj)
{
if (obj instanceof ASN1Choice)
{
this.explicit = true;
}
else
{
this.explicit = explicit;
}
this.tagNo = tagNo;
if (this.explicit)
{
this.obj = obj;
}
else
{
ASN1Primitive prim = obj.toASN1Primitive();
if (prim instanceof ASN1Set)
{
ASN1Set s = null;
}
this.obj = obj;
}
}
boolean asn1Equals(
ASN1Primitive o)
{
if (!(o instanceof ASN1TaggedObject))
{
return false;
}
ASN1TaggedObject other = (ASN1TaggedObject)o;
if (tagNo != other.tagNo || empty != other.empty || explicit != other.explicit)
{
return false;
}
if(obj == null)
{
if (other.obj != null)
{
return false;
}
}
else
{
if (!(obj.toASN1Primitive().equals(other.obj.toASN1Primitive())))
{
return false;
}
}
return true;
}
public int hashCode()
{
int code = tagNo;
// TODO: actually this is wrong - the problem is that a re-encoded
// object may end up with a different hashCode due to implicit
// tagging. As implicit tagging is ambiguous if a sequence is involved
// it seems the only correct method for both equals and hashCode is to
// compare the encodings...
if (obj != null)
{
code ^= obj.hashCode();
}
return code;
}
/**
* Return the tag number associated with this object.
*
* @return the tag number.
*/
public int getTagNo()
{
return tagNo;
}
/**
* return whether or not the object may be explicitly tagged.
*
* Note: if the object has been read from an input stream, the only
* time you can be sure if isExplicit is returning the true state of
* affairs is if it returns false. An implicitly tagged object may appear
* to be explicitly tagged, so you need to understand the context under
* which the reading was done as well, see getObject below.
*/
public boolean isExplicit()
{
return explicit;
}
public boolean isEmpty()
{
return empty;
}
/**
* Return whatever was following the tag.
*
* Note: tagged objects are generally context dependent if you're
* trying to extract a tagged object you should be going via the
* appropriate getInstance method.
*/
public ASN1Primitive getObject()
{
if (obj != null)
{
return obj.toASN1Primitive();
}
return null;
}
/**
* Return the object held in this tagged object as a parser assuming it has
* the type of the passed in tag. If the object doesn't have a parser
* associated with it, the base object is returned.
*/
public ASN1Encodable getObjectParser(
int tag,
boolean isExplicit)
throws IOException
{
switch (tag)
{
case BERTags.SET:
return ASN1Set.getInstance(this, isExplicit).parser();
case BERTags.SEQUENCE:
return ASN1Sequence.getInstance(this, isExplicit).parser();
case BERTags.OCTET_STRING:
return ASN1OctetString.getInstance(this, isExplicit).parser();
}
if (isExplicit)
{
return getObject();
}
throw new ASN1Exception("implicit tagging not implemented for tag: " + tag);
}
public ASN1Primitive getLoadedObject()
{
return this.toASN1Primitive();
}
ASN1Primitive toDERObject()
{
return new DERTaggedObject(explicit, tagNo, obj);
}
ASN1Primitive toDLObject()
{
return new DLTaggedObject(explicit, tagNo, obj);
}
abstract void encode(ASN1OutputStream out)
throws IOException;
public String toString()
{
return "[" + tagNo + "]" + obj;
}
}