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package org.bouncycastle.asn1;
import java.io.IOException;
import org.bouncycastle.util.Arrays;
/**
* 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
{
private static final int DECLARED_EXPLICIT = 1;
private static final int DECLARED_IMPLICIT = 2;
// TODO It will probably be better to track parsing constructed vs primitive instead
private static final int PARSED_EXPLICIT = 3;
private static final int PARSED_IMPLICIT = 4;
public static ASN1TaggedObject getInstance(Object obj)
{
if (obj == null || obj instanceof ASN1TaggedObject)
{
return (ASN1TaggedObject)obj;
}
// else if (obj instanceof ASN1TaggedObjectParser)
else if (obj instanceof ASN1Encodable)
{
ASN1Primitive primitive = ((ASN1Encodable)obj).toASN1Primitive();
if (primitive instanceof ASN1TaggedObject)
{
return (ASN1TaggedObject)primitive;
}
}
else if (obj instanceof byte[])
{
try
{
return checkedCast(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());
}
public static ASN1TaggedObject getInstance(Object obj, int tagClass)
{
if (obj == null)
{
throw new NullPointerException("'obj' cannot be null");
}
ASN1TaggedObject taggedObject = getInstance(obj);
if (tagClass != taggedObject.getTagClass())
{
throw new IllegalArgumentException("unexpected tag in getInstance: " + ASN1Util.getTagText(taggedObject));
}
return taggedObject;
}
public static ASN1TaggedObject getInstance(Object obj, int tagClass, int tagNo)
{
if (obj == null)
{
throw new NullPointerException("'obj' cannot be null");
}
ASN1TaggedObject taggedObject = getInstance(obj);
if (!taggedObject.hasTag(tagClass, tagNo))
{
throw new IllegalArgumentException("unexpected tag in getInstance: " + ASN1Util.getTagText(taggedObject));
}
return taggedObject;
}
public static ASN1TaggedObject getInstance(ASN1TaggedObject taggedObject, boolean declaredExplicit)
{
if (BERTags.CONTEXT_SPECIFIC != taggedObject.getTagClass())
{
throw new IllegalStateException("this method only valid for CONTEXT_SPECIFIC tags");
}
if (declaredExplicit)
{
return taggedObject.getExplicitBaseTagged();
}
throw new IllegalArgumentException("this method not valid for implicitly tagged tagged objects");
}
final int explicitness;
final int tagClass;
final int tagNo;
final ASN1Encodable obj;
/**
* 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.
*/
protected ASN1TaggedObject(boolean explicit, int tagNo, ASN1Encodable obj)
{
this(explicit, BERTags.CONTEXT_SPECIFIC, tagNo, obj);
}
protected ASN1TaggedObject(boolean explicit, int tagClass, int tagNo, ASN1Encodable obj)
{
this(explicit ? DECLARED_EXPLICIT : DECLARED_IMPLICIT, tagClass, tagNo, obj);
}
ASN1TaggedObject(int explicitness, int tagClass, int tagNo, ASN1Encodable obj)
{
if (null == obj)
{
throw new NullPointerException("'obj' cannot be null");
}
if (tagClass == BERTags.UNIVERSAL || (tagClass & BERTags.PRIVATE) != tagClass)
{
throw new IllegalArgumentException("invalid tag class: " + tagClass);
}
this.explicitness = (obj instanceof ASN1Choice) ? DECLARED_EXPLICIT : explicitness;
this.tagClass = tagClass;
this.tagNo = tagNo;
this.obj = obj;
}
final boolean asn1Equals(ASN1Primitive other)
{
if (!(other instanceof ASN1TaggedObject))
{
return false;
}
ASN1TaggedObject that = (ASN1TaggedObject)other;
if (this.tagNo != that.tagNo ||
this.tagClass != that.tagClass)
{
return false;
}
if (this.explicitness != that.explicitness)
{
/*
* TODO This seems incorrect for some cases of implicit tags e.g. if one is a
* declared-implicit SET and the other a parsed object.
*/
if (this.isExplicit() != that.isExplicit())
{
return false;
}
}
ASN1Primitive p1 = this.obj.toASN1Primitive();
ASN1Primitive p2 = that.obj.toASN1Primitive();
if (p1 == p2)
{
return true;
}
if (!this.isExplicit())
{
try
{
byte[] d1 = this.getEncoded();
byte[] d2 = that.getEncoded();
return Arrays.areEqual(d1, d2);
}
catch (IOException e)
{
return false;
}
}
return p1.asn1Equals(p2);
}
public int hashCode()
{
return (tagClass * 7919) ^ tagNo ^ (isExplicit() ? 0x0F : 0xF0) ^ obj.toASN1Primitive().hashCode();
}
public int getTagClass()
{
return tagClass;
}
/**
* Return the tag number associated with this object.
*
* @return the tag number.
*/
public int getTagNo()
{
return tagNo;
}
public boolean hasContextTag()
{
return this.tagClass == BERTags.CONTEXT_SPECIFIC;
}
public boolean hasContextTag(int tagNo)
{
return this.tagClass == BERTags.CONTEXT_SPECIFIC && this.tagNo == tagNo;
}
public boolean hasTag(int tagClass, int tagNo)
{
return this.tagClass == tagClass && this.tagNo == tagNo;
}
public boolean hasTagClass(int tagClass)
{
return this.tagClass == tagClass;
}
/**
* 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()
{
// TODO New methods like 'isKnownExplicit' etc. to distinguish uncertain cases?
switch (explicitness)
{
case DECLARED_EXPLICIT:
case PARSED_EXPLICIT:
return true;
default:
return false;
}
}
boolean isParsed()
{
switch (explicitness)
{
case PARSED_EXPLICIT:
case PARSED_IMPLICIT:
return true;
default:
return false;
}
}
/**
* Needed for open types, until we have better type-guided parsing support. Use sparingly for other
* purposes, and prefer {@link #getExplicitBaseTagged()}, {@link #getImplicitBaseTagged(int, int)} or
* {@link #getBaseUniversal(boolean, int)} where possible. Before using, check for matching tag
* {@link #getTagClass() class} and {@link #getTagNo() number}.
*/
public ASN1Object getBaseObject()
{
return obj instanceof ASN1Object ? (ASN1Object)obj : obj.toASN1Primitive();
}
/**
* Needed for open types, until we have better type-guided parsing support. Use
* sparingly for other purposes, and prefer {@link #getExplicitBaseTagged()} or
* {@link #getBaseUniversal(boolean, int)} where possible. Before using, check
* for matching tag {@link #getTagClass() class} and {@link #getTagNo() number}.
*/
public ASN1Object getExplicitBaseObject()
{
if (!isExplicit())
{
throw new IllegalStateException("object implicit - explicit expected.");
}
return obj instanceof ASN1Object ? (ASN1Object)obj : obj.toASN1Primitive();
}
public ASN1TaggedObject getExplicitBaseTagged()
{
if (!isExplicit())
{
throw new IllegalStateException("object implicit - explicit expected.");
}
return checkedCast(obj.toASN1Primitive());
}
public ASN1TaggedObject getImplicitBaseTagged(int baseTagClass, int baseTagNo)
{
if (baseTagClass == BERTags.UNIVERSAL || (baseTagClass & BERTags.PRIVATE) != baseTagClass)
{
throw new IllegalArgumentException("invalid base tag class: " + baseTagClass);
}
switch (explicitness)
{
case DECLARED_EXPLICIT:
throw new IllegalStateException("object explicit - implicit expected.");
case DECLARED_IMPLICIT:
{
ASN1TaggedObject declared = checkedCast(obj.toASN1Primitive());
return ASN1Util.checkTag(declared, baseTagClass, baseTagNo);
}
// Parsed; return a virtual tag (i.e. that couldn't have been present in the encoding)
default:
return replaceTag(baseTagClass, baseTagNo);
}
}
/**
* Note: tagged objects are generally context dependent. Before trying to
* extract a tagged object this way, make sure you have checked that both the
* {@link #getTagClass() tag class} and {@link #getTagNo() tag number} match
* what you are looking for.
*
* @param declaredExplicit Whether the tagged type for this object was declared
* EXPLICIT.
* @param tagNo The universal {@link BERTags tag number} of the
* expected base object.
*/
public ASN1Primitive getBaseUniversal(boolean declaredExplicit, int tagNo)
{
ASN1UniversalType universalType = ASN1UniversalTypes.get(tagNo);
if (null == universalType)
{
throw new IllegalArgumentException("unsupported UNIVERSAL tag number: " + tagNo);
}
return getBaseUniversal(declaredExplicit, universalType);
}
ASN1Primitive getBaseUniversal(boolean declaredExplicit, ASN1UniversalType universalType)
{
if (declaredExplicit)
{
if (!isExplicit())
{
throw new IllegalStateException("object explicit - implicit expected.");
}
return universalType.checkedCast(obj.toASN1Primitive());
}
if (DECLARED_EXPLICIT == explicitness)
{
throw new IllegalStateException("object explicit - implicit expected.");
}
ASN1Primitive primitive = obj.toASN1Primitive();
switch (explicitness)
{
case PARSED_EXPLICIT:
return universalType.fromImplicitConstructed(rebuildConstructed(primitive));
case PARSED_IMPLICIT:
{
if (primitive instanceof ASN1Sequence)
{
return universalType.fromImplicitConstructed((ASN1Sequence)primitive);
}
return universalType.fromImplicitPrimitive((DEROctetString)primitive);
}
default:
return universalType.checkedCast(primitive);
}
}
public ASN1Encodable parseBaseUniversal(boolean declaredExplicit, int baseTagNo) throws IOException
{
ASN1Primitive primitive = getBaseUniversal(declaredExplicit, baseTagNo);
switch (baseTagNo)
{
case BERTags.BIT_STRING:
return ((ASN1BitString)primitive).parser();
case BERTags.OCTET_STRING:
return ((ASN1OctetString)primitive).parser();
case BERTags.SEQUENCE:
return ((ASN1Sequence)primitive).parser();
case BERTags.SET:
return ((ASN1Set)primitive).parser();
}
return primitive;
}
public ASN1Encodable parseExplicitBaseObject() throws IOException
{
return getExplicitBaseObject();
}
public ASN1TaggedObjectParser parseExplicitBaseTagged() throws IOException
{
return getExplicitBaseTagged();
}
public ASN1TaggedObjectParser parseImplicitBaseTagged(int baseTagClass, int baseTagNo) throws IOException
{
return getImplicitBaseTagged(baseTagClass, baseTagNo);
}
public final ASN1Primitive getLoadedObject()
{
return this;
}
abstract ASN1Sequence rebuildConstructed(ASN1Primitive primitive);
abstract ASN1TaggedObject replaceTag(int tagClass, int tagNo);
ASN1Primitive toDERObject()
{
return new DERTaggedObject(explicitness, tagClass, tagNo, obj);
}
ASN1Primitive toDLObject()
{
return new DLTaggedObject(explicitness, tagClass, tagNo, obj);
}
public String toString()
{
return ASN1Util.getTagText(tagClass, tagNo) + obj;
}
static ASN1Primitive createConstructedDL(int tagClass, int tagNo, ASN1EncodableVector contentsElements)
{
boolean maybeExplicit = (contentsElements.size() == 1);
return maybeExplicit
? new DLTaggedObject(PARSED_EXPLICIT, tagClass, tagNo, contentsElements.get(0))
: new DLTaggedObject(PARSED_IMPLICIT, tagClass, tagNo, DLFactory.createSequence(contentsElements));
}
static ASN1Primitive createConstructedIL(int tagClass, int tagNo, ASN1EncodableVector contentsElements)
{
boolean maybeExplicit = (contentsElements.size() == 1);
return maybeExplicit
? new BERTaggedObject(PARSED_EXPLICIT, tagClass, tagNo, contentsElements.get(0))
: new BERTaggedObject(PARSED_IMPLICIT, tagClass, tagNo, BERFactory.createSequence(contentsElements));
}
static ASN1Primitive createPrimitive(int tagClass, int tagNo, byte[] contentsOctets)
{
// Note: !CONSTRUCTED => IMPLICIT
return new DLTaggedObject(PARSED_IMPLICIT, tagClass, tagNo, new DEROctetString(contentsOctets));
}
private static ASN1TaggedObject checkedCast(ASN1Primitive primitive)
{
if (primitive instanceof ASN1TaggedObject)
{
return (ASN1TaggedObject)primitive;
}
throw new IllegalStateException("unexpected object: " + primitive.getClass().getName());
}
}