org.bouncycastle.asn1.ASN1Set 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 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.bouncycastle.util.Iterable
{
protected final ASN1Encodable[] elements;
protected final boolean isSorted;
/**
* 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 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 ASN1Set instance.
*/
public static ASN1Set 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 and it's really implicit means
* we have to add the surrounding set.
*/
if (taggedObject.isExplicit())
{
if (taggedObject instanceof BERTaggedObject)
{
return new BERSet(o);
}
return new DLSet(o);
}
if (o instanceof ASN1Set)
{
ASN1Set s = (ASN1Set)o;
if (taggedObject instanceof BERTaggedObject)
{
return s;
}
return (ASN1Set)s.toDLObject();
}
/*
* in this case the parser returns a sequence, convert it into a set.
*/
if (o instanceof ASN1Sequence)
{
ASN1Sequence s = (ASN1Sequence)o;
// NOTE: Will force() a LazyEncodedSequence
ASN1Encodable[] elements = s.toArrayInternal();
if (taggedObject instanceof BERTaggedObject)
{
return new BERSet(false, elements);
}
return new DLSet(false, elements);
}
throw new IllegalArgumentException("unknown object in getInstance: " + taggedObject.getClass().getName());
}
protected ASN1Set()
{
this.elements = ASN1EncodableVector.EMPTY_ELEMENTS;
this.isSorted = true;
}
/**
* Create a SET containing one object
* @param element object to be added to the SET.
*/
protected ASN1Set(ASN1Encodable element)
{
if (null == element)
{
throw new NullPointerException("'element' cannot be null");
}
this.elements = new ASN1Encodable[]{ element };
this.isSorted = true;
}
/**
* Create a SET containing a vector of objects.
* @param elementVector a vector of objects to make up the SET.
* @param doSort true if should be sorted DER style, false otherwise.
*/
protected ASN1Set(ASN1EncodableVector elementVector, boolean doSort)
{
if (null == elementVector)
{
throw new NullPointerException("'elementVector' cannot be null");
}
ASN1Encodable[] tmp;
if (doSort && elementVector.size() >= 2)
{
tmp = elementVector.copyElements();
sort(tmp);
}
else
{
tmp = elementVector.takeElements();
}
this.elements = tmp;
this.isSorted = doSort || tmp.length < 2;
}
/**
* Create a SET containing an array of objects.
* @param elements an array of objects to make up the SET.
* @param doSort true if should be sorted DER style, false otherwise.
*/
protected ASN1Set(ASN1Encodable[] elements, boolean doSort)
{
if (Arrays.isNullOrContainsNull(elements))
{
throw new NullPointerException("'elements' cannot be null, or contain null");
}
ASN1Encodable[] tmp = ASN1EncodableVector.cloneElements(elements);
if (doSort && tmp.length >= 2)
{
sort(tmp);
}
this.elements = tmp;
this.isSorted = doSort || tmp.length < 2;
}
ASN1Set(boolean isSorted, ASN1Encodable[] elements)
{
this.elements = elements;
this.isSorted = isSorted || elements.length < 2;
}
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();
}
};
}
/**
* 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 elements[index];
}
/**
* return the number of objects in this set.
*
* @return the number of objects in this set.
*/
public int size()
{
return elements.length;
}
public ASN1Encodable[] toArray()
{
return ASN1EncodableVector.cloneElements(elements);
}
public ASN1SetParser parser()
{
final int count = size();
return new ASN1SetParser()
{
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 ASN1Set.this;
}
public ASN1Primitive toASN1Primitive()
{
return ASN1Set.this;
}
};
}
public int hashCode()
{
// return Arrays.hashCode(elements);
int i = elements.length;
int hc = i + 1;
// NOTE: Order-independent contribution of elements to avoid sorting
while (--i >= 0)
{
hc += elements[i].toASN1Primitive().hashCode();
}
return hc;
}
/**
* Change current SET object to be encoded as {@link DERSet}.
* This is part of Distinguished Encoding Rules form serialization.
*/
ASN1Primitive toDERObject()
{
ASN1Encodable[] tmp;
if (isSorted)
{
tmp = elements;
}
else
{
tmp = (ASN1Encodable[])elements.clone();
sort(tmp);
}
return new DERSet(true, tmp);
}
/**
* Change current SET object to be encoded as {@link DLSet}.
* This is part of Direct Length form serialization.
*/
ASN1Primitive toDLObject()
{
return new DLSet(isSorted, elements);
}
boolean asn1Equals(ASN1Primitive other)
{
if (!(other instanceof ASN1Set))
{
return false;
}
ASN1Set that = (ASN1Set)other;
int count = this.size();
if (that.size() != count)
{
return false;
}
DERSet dis = (DERSet)this.toDERObject();
DERSet dat = (DERSet)that.toDERObject();
for (int i = 0; i < count; ++i)
{
ASN1Primitive p1 = dis.elements[i].toASN1Primitive();
ASN1Primitive p2 = dat.elements[i].toASN1Primitive();
if (p1 != p2 && !p1.asn1Equals(p2))
{
return false;
}
}
return true;
}
boolean isConstructed()
{
return true;
}
abstract void encode(ASN1OutputStream out, boolean withTag) throws IOException;
public String toString()
{
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(toArray());
}
private static byte[] getDEREncoded(ASN1Encodable obj)
{
try
{
return obj.toASN1Primitive().getEncoded(ASN1Encoding.DER);
}
catch (IOException e)
{
throw new IllegalArgumentException("cannot encode object added to SET");
}
}
/**
* return true if a <= b (arrays are assumed padded with zeros).
*/
private static boolean lessThanOrEqual(byte[] a, byte[] b)
{
// assert a.length >= 2 && b.length >= 2;
/*
* NOTE: Set elements in DER encodings are ordered first according to their tags (class and
* number); the CONSTRUCTED bit is not part of the tag.
*
* For SET-OF, this is unimportant. All elements have the same tag and DER requires them to
* either all be in constructed form or all in primitive form, according to that tag. The
* elements are effectively ordered according to their content octets.
*
* For SET, the elements will have distinct tags, and each will be in constructed or
* primitive form accordingly. Failing to ignore the CONSTRUCTED bit could therefore lead to
* ordering inversions.
*/
int a0 = a[0] & ~BERTags.CONSTRUCTED;
int b0 = b[0] & ~BERTags.CONSTRUCTED;
if (a0 != b0)
{
return a0 < b0;
}
int last = Math.min(a.length, b.length) - 1;
for (int i = 1; i < last; ++i)
{
if (a[i] != b[i])
{
return (a[i] & 0xFF) < (b[i] & 0xFF);
}
}
return (a[last] & 0xFF) <= (b[last] & 0xFF);
}
private static void sort(ASN1Encodable[] t)
{
int count = t.length;
if (count < 2)
{
return;
}
ASN1Encodable eh = t[0], ei = t[1];
byte[] bh = getDEREncoded(eh), bi = getDEREncoded(ei);;
if (lessThanOrEqual(bi, bh))
{
ASN1Encodable et = ei; ei = eh; eh = et;
byte[] bt = bi; bi = bh; bh = bt;
}
for (int i = 2; i < count; ++i)
{
ASN1Encodable e2 = t[i];
byte[] b2 = getDEREncoded(e2);
if (lessThanOrEqual(bi, b2))
{
t[i - 2] = eh;
eh = ei; bh = bi;
ei = e2; bi = b2;
continue;
}
if (lessThanOrEqual(bh, b2))
{
t[i - 2] = eh;
eh = e2; bh = b2;
continue;
}
int j = i - 1;
while (--j > 0)
{
ASN1Encodable e1 = t[j - 1];
byte[] b1 = getDEREncoded(e1);
if (lessThanOrEqual(b1, b2))
{
break;
}
t[j] = e1;
}
t[j] = e2;
}
t[count - 2] = eh;
t[count - 1] = ei;
}
}