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Spongy Castle is a package-rename (org.bouncycastle.* to org.spongycastle.*) of Bouncy Castle
intended for the Android platform. Android unfortunately ships with a stripped-down version of
Bouncy Castle, which prevents easy upgrades - Spongy Castle overcomes this and provides a full,
up-to-date version of the Bouncy Castle cryptographic libs.
package org.spongycastle.asn1;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Vector;
import org.spongycastle.util.Arrays;
/**
* ASN.1 SET and SET OF constructs.
*
* Note: This does not know which syntax the set is!
* (The difference: ordering of SET elements or not ordering.)
*
* DER form is always definite form length fields, while
* BER support uses indefinite form.
*
* The CER form support does not exist.
*
*
* X.690
* 8: Basic encoding rules
* 8.11 Encoding of a set value
* 8.11.1 The encoding of a set value shall be constructed
*
* 8.11.2 The contents octets shall consist of the complete
* encoding of a data value from each of the types listed in the
* ASN.1 definition of the set type, in an order chosen by the sender,
* unless the type was referenced with the keyword
* OPTIONAL or the keyword DEFAULT.
*
* 8.11.3 The encoding of a data value may, but need not,
* be present for a type which was referenced with the keyword
* OPTIONAL or the keyword DEFAULT.
*
* NOTE — The order of data values in a set value is not significant,
* and places no constraints on the order during transfer
*
* 8.12 Encoding of a set-of value
* 8.12.1 The encoding of a set-of value shall be constructed.
*
* 8.12.2 The text of 8.10.2 applies:
* The contents octets shall consist of zero,
* one or more complete encodings of data values from the type listed in
* the ASN.1 definition.
*
* 8.12.3 The order of data values need not be preserved by
* the encoding and subsequent decoding.
*
*
9: Canonical encoding rules
* 9.1 Length forms
* If the encoding is constructed, it shall employ the indefinite-length form.
* If the encoding is primitive, it shall include the fewest length octets necessary.
* [Contrast with 8.1.3.2 b).]
* 9.3 Set components
* The encodings of the component values of a set value shall
* appear in an order determined by their tags as specified
* in 8.6 of ITU-T Rec. X.680 | ISO/IEC 8824-1.
* Additionally, for the purposes of determining the order in which
* components are encoded when one or more component is an untagged
* choice type, each untagged choice type is ordered as though it
* has a tag equal to that of the smallest tag in that choice type
* or any untagged choice types nested within.
*
* 10: Distinguished encoding rules
* 10.1 Length forms
* The definite form of length encoding shall be used,
* encoded in the minimum number of octets.
* [Contrast with 8.1.3.2 b).]
* 10.3 Set components
* The encodings of the component values of a set value shall appear
* in an order determined by their tags as specified
* in 8.6 of ITU-T Rec. X.680 | ISO/IEC 8824-1.
*
* NOTE — Where a component of the set is an untagged choice type,
* the location of that component in the ordering will depend on
* the tag of the choice component being encoded.
*
*
* 11: Restrictions on BER employed by both CER and DER
* 11.5 Set and sequence components with default value
* The encoding of a set value or sequence value shall not include
* an encoding for any component value which is equal to
* its default value.
* 11.6 Set-of components
*
* The encodings of the component values of a set-of value
* shall appear in ascending order, the encodings being compared
* as octet strings with the shorter components being padded at
* their trailing end with 0-octets.
*
* NOTE — The padding octets are for comparison purposes only
* and do not appear in the encodings.
*
*/
public abstract class ASN1Set
extends ASN1Primitive
implements org.spongycastle.util.Iterable
{
private Vector set = new Vector();
private boolean isSorted = false;
/**
* return an ASN1Set from the given object.
*
* @param obj the object we want converted.
* @exception IllegalArgumentException if the object cannot be converted.
* @return an ASN1Set instance, or null.
*/
public static ASN1Set getInstance(
Object obj)
{
if (obj == null || obj instanceof ASN1Set)
{
return (ASN1Set)obj;
}
else if (obj instanceof ASN1SetParser)
{
return ASN1Set.getInstance(((ASN1SetParser)obj).toASN1Primitive());
}
else if (obj instanceof byte[])
{
try
{
return ASN1Set.getInstance(ASN1Primitive.fromByteArray((byte[])obj));
}
catch (IOException e)
{
throw new IllegalArgumentException("failed to construct set from byte[]: " + e.getMessage());
}
}
else if (obj instanceof ASN1Encodable)
{
ASN1Primitive primitive = ((ASN1Encodable)obj).toASN1Primitive();
if (primitive instanceof ASN1Set)
{
return (ASN1Set)primitive;
}
}
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 should
* 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.
* @return an ASN1Set instance.
*/
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 set.
//
if (obj.isExplicit())
{
if (obj instanceof BERTaggedObject)
{
return new BERSet(obj.getObject());
}
else
{
return new DLSet(obj.getObject());
}
}
else
{
if (obj.getObject() instanceof ASN1Set)
{
return (ASN1Set)obj.getObject();
}
//
// in this case the parser returns a sequence, convert it
// into a set.
//
if (obj.getObject() instanceof ASN1Sequence)
{
ASN1Sequence s = (ASN1Sequence)obj.getObject();
if (obj instanceof BERTaggedObject)
{
return new BERSet(s.toArray());
}
else
{
return new DLSet(s.toArray());
}
}
}
}
throw new IllegalArgumentException("unknown object in getInstance: " + obj.getClass().getName());
}
protected ASN1Set()
{
}
/**
* create a sequence containing one object
* @param obj object to be added to the SET.
*/
protected ASN1Set(
ASN1Encodable obj)
{
set.addElement(obj);
}
/**
* create a sequence containing a vector of objects.
* @param v a vector of objects to make up the SET.
* @param doSort true if should be sorted DER style, false otherwise.
*/
protected ASN1Set(
ASN1EncodableVector v,
boolean doSort)
{
for (int i = 0; i != v.size(); i++)
{
set.addElement(v.get(i));
}
if (doSort)
{
this.sort();
}
}
/*
* create a sequence containing a vector of objects.
*/
protected ASN1Set(
ASN1Encodable[] array,
boolean doSort)
{
for (int i = 0; i != array.length; i++)
{
set.addElement(array[i]);
}
if (doSort)
{
this.sort();
}
}
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 ASN1Encodable getObjectAt(
int index)
{
return (ASN1Encodable)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 ASN1Encodable[] toArray()
{
ASN1Encodable[] values = new ASN1Encodable[this.size()];
for (int i = 0; i != this.size(); i++)
{
values[i] = this.getObjectAt(i);
}
return values;
}
public ASN1SetParser parser()
{
final ASN1Set outer = this;
return new ASN1SetParser()
{
private final int max = size();
private int index;
public ASN1Encodable readObject() throws IOException
{
if (index == max)
{
return null;
}
ASN1Encodable obj = getObjectAt(index++);
if (obj instanceof ASN1Sequence)
{
return ((ASN1Sequence)obj).parser();
}
if (obj instanceof ASN1Set)
{
return ((ASN1Set)obj).parser();
}
return obj;
}
public ASN1Primitive getLoadedObject()
{
return outer;
}
public ASN1Primitive toASN1Primitive()
{
return outer;
}
};
}
public int hashCode()
{
Enumeration e = this.getObjects();
int hashCode = size();
while (e.hasMoreElements())
{
Object o = getNext(e);
hashCode *= 17;
hashCode ^= o.hashCode();
}
return hashCode;
}
/**
* Change current SET object to be encoded as {@link DERSet}.
* This is part of Distinguished Encoding Rules form serialization.
*/
ASN1Primitive toDERObject()
{
if (isSorted)
{
ASN1Set derSet = new DERSet();
derSet.set = this.set;
return derSet;
}
else
{
Vector v = new Vector();
for (int i = 0; i != set.size(); i++)
{
v.addElement(set.elementAt(i));
}
ASN1Set derSet = new DERSet();
derSet.set = v;
derSet.sort();
return derSet;
}
}
/**
* Change current SET object to be encoded as {@link DLSet}.
* This is part of Direct Length form serialization.
*/
ASN1Primitive toDLObject()
{
ASN1Set derSet = new DLSet();
derSet.set = this.set;
return derSet;
}
boolean asn1Equals(
ASN1Primitive 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())
{
ASN1Encodable obj1 = getNext(s1);
ASN1Encodable obj2 = getNext(s2);
ASN1Primitive o1 = obj1.toASN1Primitive();
ASN1Primitive o2 = obj2.toASN1Primitive();
if (o1 == o2 || o1.equals(o2))
{
continue;
}
return false;
}
return true;
}
private ASN1Encodable getNext(Enumeration e)
{
ASN1Encodable encObj = (ASN1Encodable)e.nextElement();
// unfortunately null was allowed as a substitute for DER null
if (encObj == null)
{
return DERNull.INSTANCE;
}
return encObj;
}
/**
* return true if a <= b (arrays are assumed padded with zeros).
*/
private boolean lessThanOrEqual(
byte[] a,
byte[] b)
{
int len = Math.min(a.length, b.length);
for (int i = 0; i != len; ++i)
{
if (a[i] != b[i])
{
return (a[i] & 0xff) < (b[i] & 0xff);
}
}
return len == a.length;
}
private byte[] getDEREncoded(
ASN1Encodable obj)
{
try
{
return obj.toASN1Primitive().getEncoded(ASN1Encoding.DER);
}
catch (IOException e)
{
throw new IllegalArgumentException("cannot encode object added to SET");
}
}
protected void sort()
{
if (!isSorted)
{
isSorted = true;
if (set.size() > 1)
{
boolean swapped = true;
int lastSwap = set.size() - 1;
while (swapped)
{
int index = 0;
int swapIndex = 0;
byte[] a = getDEREncoded((ASN1Encodable)set.elementAt(0));
swapped = false;
while (index != lastSwap)
{
byte[] b = getDEREncoded((ASN1Encodable)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;
}
}
}
}
boolean isConstructed()
{
return true;
}
abstract void encode(ASN1OutputStream out)
throws IOException;
public String toString()
{
return set.toString();
}
public Iterator iterator()
{
return new Arrays.Iterator(toArray());
}
}