2003/02/12 06:21:04

[org.ibex.core.git] / src / org / bouncycastle / asn1 / ASN1TaggedObject.java

diff --git a/src/org/bouncycastle/asn1/ASN1TaggedObject.java b/src/org/bouncycastle/asn1/ASN1TaggedObject.java
new file mode 100644 (file)
index 0000000..deadcdb
--- /dev/null
+++ b/src/org/bouncycastle/asn1/ASN1TaggedObject.java
@@ -0,0 +1,122 @@
+package org.bouncycastle.asn1;
+
+import java.io.*;
+
+/**
+ * ASN.1 TaggedObject - in ASN.1 nottation this is any object proceeded by
+ * a [n] where n is some number - these are assume to follow the construction
+ * rules (as with sequences).
+ */
+public abstract class ASN1TaggedObject
+    extends DERObject
+{
+    int             tagNo;
+    boolean         empty = false;
+    boolean         explicit = true;
+    DEREncodable    obj = null;
+
+    /**
+     * @param tagNo the tag number for this object.
+     * @param obj the tagged object.
+     */
+    public ASN1TaggedObject(
+        int             tagNo,
+        DEREncodable    obj)
+    {
+        this.explicit = true;
+        this.tagNo = tagNo;
+        this.obj = obj;
+    }
+
+    /**
+     * @param explicit true if the object is explicitly tagged.
+     * @param tagNo the tag number for this object.
+     * @param obj the tagged object.
+     */
+    public ASN1TaggedObject(
+        boolean         explicit,
+        int             tagNo,
+        DEREncodable    obj)
+    {
+        this.explicit = explicit;
+        this.tagNo = tagNo;
+        this.obj = obj;
+    }
+       
+       public boolean equals(
+               Object o)
+       {
+        if (o == null || !(o instanceof ASN1TaggedObject))
+        {
+            return false;
+        }
+        
+        ASN1TaggedObject other = (ASN1TaggedObject)o;
+        
+        if(tagNo != other.tagNo || empty != other.empty || explicit != other.explicit)
+        {
+                       return false;
+               }
+               
+               if(obj == null)
+               {
+                       if(other.obj != null)
+                       {
+                               return false;
+                       }
+               }
+               else
+               {
+                       if(!(obj.equals(other.obj)))
+                       {
+                               return false;
+                       }
+               }
+               
+               return true;
+       }
+       
+    public int getTagNo()
+    {
+        return tagNo;
+    }
+
+    /**
+     * return whether or not the object may be explicitly tagged. 
+     * <p>
+     * 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()
+    {
+        return explicit;
+    }
+
+    public boolean isEmpty()
+    {
+        return empty;
+    }
+
+    /**
+     * return whatever was following the tag.
+     * <p>
+     * Note: tagged objects are generally context dependent if you're
+     * trying to extract a tagged object you should be going via the
+     * appropriate getInstance method.
+     */
+    public DERObject getObject()
+    {
+        if (obj != null)
+        {
+            return obj.getDERObject();
+        }
+
+        return null;
+    }
+
+    abstract void encode(DEROutputStream  out)
+        throws IOException;
+}