org.bouncycastle.asn1.ASN1Sequence Maven / Gradle / Ivy
package org.bouncycastle.asn1;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.bouncycastle.util.Arrays;
/**
* ASN.1 SEQUENCE and SEQUENCE OF constructs.
*
* DER form is always definite form length fields, while
* BER support uses indefinite form.
*
* X.690
* 8: Basic encoding rules
* 8.9 Encoding of a sequence value
* 8.9.1 The encoding of a sequence value shall be constructed.
*
* 8.9.2 The contents octets shall consist of the complete
* encoding of one data value from each of the types listed in
* the ASN.1 definition of the sequence type, in the order of
* their appearance in the definition, unless the type was referenced
* with the keyword OPTIONAL or the keyword DEFAULT.
*
* 8.9.3 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.
* If present, it shall appear in the encoding at the point
* corresponding to the appearance of the type in the ASN.1 definition.
*
* 8.10 Encoding of a sequence-of value
*
* 8.10.1 The encoding of a sequence-of value shall be constructed.
*
* 8.10.2 The contents octets shall consist of zero,
* one or more complete encodings of data values from the type listed in
* the ASN.1 definition.
*
* 8.10.3 The order of the encodings of the data values shall be
* the same as the order of the data values in the sequence-of value to
* be encoded.
*
* 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).]
*
* 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.
*
*/
public abstract class ASN1Sequence
extends ASN1Primitive
implements org.bouncycastle.util.Iterable
{
// NOTE: Only non-final to support LazyEncodedSequence
ASN1Encodable[] elements;
/**
* Return an ASN1Sequence from the given object.
*
* @param obj the object we want converted.
* @exception IllegalArgumentException if the object cannot be converted.
* @return an ASN1Sequence instance, or null.
*/
public static ASN1Sequence getInstance(
Object obj)
{
if (obj == null || obj instanceof ASN1Sequence)
{
return (ASN1Sequence)obj;
}
else if (obj instanceof ASN1SequenceParser)
{
return ASN1Sequence.getInstance(((ASN1SequenceParser)obj).toASN1Primitive());
}
else if (obj instanceof byte[])
{
try
{
return ASN1Sequence.getInstance(fromByteArray((byte[])obj));
}
catch (IOException e)
{
throw new IllegalArgumentException("failed to construct sequence from byte[]: " + e.getMessage());
}
}
else if (obj instanceof ASN1Encodable)
{
ASN1Primitive primitive = ((ASN1Encodable)obj).toASN1Primitive();
if (primitive instanceof ASN1Sequence)
{
return (ASN1Sequence)primitive;
}
}
throw new IllegalArgumentException("unknown object in getInstance: " + obj.getClass().getName());
}
/**
* 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 should
* be using this method.
*
* @param taggedObject 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 ASN1Sequence instance.
*/
public static ASN1Sequence getInstance(
ASN1TaggedObject taggedObject,
boolean explicit)
{
if (explicit)
{
if (!taggedObject.isExplicit())
{
throw new IllegalArgumentException("object implicit - explicit expected.");
}
return getInstance(taggedObject.getObject());
}
ASN1Primitive o = taggedObject.getObject();
/*
* constructed object which appears to be explicitly tagged when it should be implicit means
* we have to add the surrounding sequence.
*/
if (taggedObject.isExplicit())
{
if (taggedObject instanceof BERTaggedObject)
{
return new BERSequence(o);
}
return new DLSequence(o);
}
if (o instanceof ASN1Sequence)
{
ASN1Sequence s = (ASN1Sequence)o;
if (taggedObject instanceof BERTaggedObject)
{
return s;
}
return (ASN1Sequence)s.toDLObject();
}
throw new IllegalArgumentException("unknown object in getInstance: " + taggedObject.getClass().getName());
}
/**
* Create an empty SEQUENCE
*/
protected ASN1Sequence()
{
this.elements = ASN1EncodableVector.EMPTY_ELEMENTS;
}
/**
* Create a SEQUENCE containing one object.
* @param element the object to be put in the SEQUENCE.
*/
protected ASN1Sequence(ASN1Encodable element)
{
if (null == element)
{
throw new NullPointerException("'element' cannot be null");
}
this.elements = new ASN1Encodable[]{ element };
}
/**
* Create a SEQUENCE containing a vector of objects.
* @param elementVector the vector of objects to be put in the SEQUENCE.
*/
protected ASN1Sequence(ASN1EncodableVector elementVector)
{
if (null == elementVector)
{
throw new NullPointerException("'elementVector' cannot be null");
}
this.elements = elementVector.takeElements();
}
/**
* Create a SEQUENCE containing an array of objects.
* @param elements the array of objects to be put in the SEQUENCE.
*/
protected ASN1Sequence(ASN1Encodable[] elements)
{
if (Arrays.isNullOrContainsNull(elements))
{
throw new NullPointerException("'elements' cannot be null, or contain null");
}
this.elements = ASN1EncodableVector.cloneElements(elements);
}
ASN1Sequence(ASN1Encodable[] elements, boolean clone)
{
this.elements = clone ? ASN1EncodableVector.cloneElements(elements) : elements;
}
public ASN1Encodable[] toArray()
{
return ASN1EncodableVector.cloneElements(elements);
}
ASN1Encodable[] toArrayInternal()
{
return elements;
}
public Enumeration getObjects()
{
return new Enumeration()
{
private int pos = 0;
public boolean hasMoreElements()
{
return pos < elements.length;
}
public Object nextElement()
{
if (pos < elements.length)
{
return elements[pos++];
}
throw new NoSuchElementException();
}
};
}
public ASN1SequenceParser parser()
{
// NOTE: Call size() here to 'force' a LazyEncodedSequence
final int count = size();
return new ASN1SequenceParser()
{
private int pos = 0;
public ASN1Encodable readObject() throws IOException
{
if (count == pos)
{
return null;
}
ASN1Encodable obj = elements[pos++];
if (obj instanceof ASN1Sequence)
{
return ((ASN1Sequence)obj).parser();
}
if (obj instanceof ASN1Set)
{
return ((ASN1Set)obj).parser();
}
return obj;
}
public ASN1Primitive getLoadedObject()
{
return ASN1Sequence.this;
}
public ASN1Primitive toASN1Primitive()
{
return ASN1Sequence.this;
}
};
}
/**
* Return the object at the sequence position indicated by index.
*
* @param index the sequence number (starting at zero) of the object
* @return the object at the sequence position indicated by index.
*/
public ASN1Encodable getObjectAt(int index)
{
return elements[index];
}
/**
* Return the number of objects in this sequence.
*
* @return the number of objects in this sequence.
*/
public int size()
{
return elements.length;
}
public int hashCode()
{
// return Arrays.hashCode(elements);
int i = elements.length;
int hc = i + 1;
while (--i >= 0)
{
hc *= 257;
hc ^= elements[i].toASN1Primitive().hashCode();
}
return hc;
}
boolean asn1Equals(ASN1Primitive other)
{
if (!(other instanceof ASN1Sequence))
{
return false;
}
ASN1Sequence that = (ASN1Sequence)other;
int count = this.size();
if (that.size() != count)
{
return false;
}
for (int i = 0; i < count; ++i)
{
ASN1Primitive p1 = this.elements[i].toASN1Primitive();
ASN1Primitive p2 = that.elements[i].toASN1Primitive();
if (p1 != p2 && !p1.asn1Equals(p2))
{
return false;
}
}
return true;
}
/**
* Change current SEQUENCE object to be encoded as {@link DERSequence}.
* This is part of Distinguished Encoding Rules form serialization.
*/
ASN1Primitive toDERObject()
{
return new DERSequence(elements, false);
}
/**
* Change current SEQUENCE object to be encoded as {@link DLSequence}.
* This is part of Direct Length form serialization.
*/
ASN1Primitive toDLObject()
{
return new DLSequence(elements, false);
}
boolean isConstructed()
{
return true;
}
abstract void encode(ASN1OutputStream out, boolean withTag) throws IOException;
public String toString()
{
// NOTE: Call size() here to 'force' a LazyEncodedSequence
int count = size();
if (0 == count)
{
return "[]";
}
StringBuffer sb = new StringBuffer();
sb.append('[');
for (int i = 0;;)
{
sb.append(elements[i]);
if (++i >= count)
{
break;
}
sb.append(", ");
}
sb.append(']');
return sb.toString();
}
public Iterator iterator()
{
return new Arrays.Iterator(elements);
}
}