package com.google.bitcoin.bouncycastle.asn1;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Vector;
abstract public class ASN1Set
extends ASN1Object
{
protected Vector set = new Vector();
/**
* return an ASN1Set from the given object.
*
* @param obj the object we want converted.
* @exception IllegalArgumentException if the object cannot be converted.
*/
public static ASN1Set getInstance(
Object obj)
{
if (obj == null || obj instanceof ASN1Set)
{
return (ASN1Set)obj;
}
throw new IllegalArgumentException("unknown object in getInstance: " + obj.getClass().getName());
}
/**
* Return an ASN1 set 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
* set - 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 sets you really <b>should</b>
* be using this method.
*
* @param obj the tagged object.
* @param explicit true if the object is meant to be explicitly tagged
* false otherwise.
* @exception IllegalArgumentException if the tagged object cannot
* be converted.
*/
public static ASN1Set getInstance(
ASN1TaggedObject obj,
boolean explicit)
{
if (explicit)
{
if (!obj.isExplicit())
{
throw new IllegalArgumentException("object implicit - explicit expected.");
}
return (ASN1Set)obj.getObject();
}
else
{
//
// constructed object which appears to be explicitly tagged
// and it's really implicit means we have to add the
// surrounding sequence.
//
if (obj.isExplicit())
{
ASN1Set set = new DERSet(obj.getObject());
return set;
}
else
{
if (obj.getObject() instanceof ASN1Set)
{
return (ASN1Set)obj.getObject();
}
//
// in this case the parser returns a sequence, convert it
// into a set.
//
ASN1EncodableVector v = new ASN1EncodableVector();
if (obj.getObject() instanceof ASN1Sequence)
{
ASN1Sequence s = (ASN1Sequence)obj.getObject();
Enumeration e = s.getObjects();
while (e.hasMoreElements())
{
v.add((DEREncodable)e.nextElement());
}
return new DERSet(v, false);
}
}
}
throw new IllegalArgumentException("unknown object in getInstance: " + obj.getClass().getName());
}
public ASN1Set()
{
}
public Enumeration getObjects()
{
return set.elements();
}
/**
* return the object at the set position indicated by index.
*
* @param index the set number (starting at zero) of the object
* @return the object at the set position indicated by index.
*/
public DEREncodable getObjectAt(
int index)
{
return (DEREncodable)set.elementAt(index);
}
/**
* return the number of objects in this set.
*
* @return the number of objects in this set.
*/
public int size()
{
return set.size();
}
public ASN1SetParser parser()
{
final ASN1Set outer = this;
return new ASN1SetParser()
{
private final int max = size();
private int index;
public DEREncodable readObject() throws IOException
{
if (index == max)
{
return null;
}
DEREncodable obj = getObjectAt(index++);
if (obj instanceof ASN1Sequence)
{
return ((ASN1Sequence)obj).parser();
}
if (obj instanceof ASN1Set)
{
return ((ASN1Set)obj).parser();
}
return obj;
}
public DERObject getDERObject()
{
return outer;
}
};
}
public int hashCode()
{
Enumeration e = this.getObjects();
int hashCode = size();
while (e.hasMoreElements())
{
Object o = e.nextElement();
hashCode *= 17;
if (o != null)
{
hashCode ^= o.hashCode();
}
}
return hashCode;
}
boolean asn1Equals(
DERObject o)
{
if (!(o instanceof ASN1Set))
{
return false;
}
ASN1Set other = (ASN1Set)o;
if (this.size() != other.size())
{
return false;
}
Enumeration s1 = this.getObjects();
Enumeration s2 = other.getObjects();
while (s1.hasMoreElements())
{
DERObject o1 = ((DEREncodable)s1.nextElement()).getDERObject();
DERObject o2 = ((DEREncodable)s2.nextElement()).getDERObject();
if (o1 == o2 || (o1 != null && o1.equals(o2)))
{
continue;
}
return false;
}
return true;
}
/**
* return true if a <= b (arrays are assumed padded with zeros).
*/
private boolean lessThanOrEqual(
byte[] a,
byte[] b)
{
if (a.length <= b.length)
{
for (int i = 0; i != a.length; i++)
{
int l = a[i] & 0xff;
int r = b[i] & 0xff;
if (r > l)
{
return true;
}
else if (l > r)
{
return false;
}
}
return true;
}
else
{
for (int i = 0; i != b.length; i++)
{
int l = a[i] & 0xff;
int r = b[i] & 0xff;
if (r > l)
{
return true;
}
else if (l > r)
{
return false;
}
}
return false;
}
}
private byte[] getEncoded(
DEREncodable obj)
{
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
ASN1OutputStream aOut = new ASN1OutputStream(bOut);
try
{
aOut.writeObject(obj);
}
catch (IOException e)
{
throw new IllegalArgumentException("cannot encode object added to SET");
}
return bOut.toByteArray();
}
protected void sort()
{
if (set.size() > 1)
{
boolean swapped = true;
int lastSwap = set.size() - 1;
while (swapped)
{
int index = 0;
int swapIndex = 0;
byte[] a = getEncoded((DEREncodable)set.elementAt(0));
swapped = false;
while (index != lastSwap)
{
byte[] b = getEncoded((DEREncodable)set.elementAt(index + 1));
if (lessThanOrEqual(a, b))
{
a = b;
}
else
{
Object o = set.elementAt(index);
set.setElementAt(set.elementAt(index + 1), index);
set.setElementAt(o, index + 1);
swapped = true;
swapIndex = index;
}
index++;
}
lastSwap = swapIndex;
}
}
}
protected void addObject(
DEREncodable obj)
{
set.addElement(obj);
}
abstract void encode(DEROutputStream out)
throws IOException;
public String toString()
{
return set.toString();
}
}