1 files changed, 75 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/asn1/ASN1Null.java b/core/src/main/java/org/spongycastle/asn1/ASN1Null.java
new file mode 100644
index 00000000..f1bd726a
--- /dev/null
+++ b/core/src/main/java/org/spongycastle/asn1/ASN1Null.java
@@ -0,0 +1,75 @@
+package org.spongycastle.asn1;
+
+import java.io.IOException;
+
+/**
+ * A NULL object - use DERNull.INSTANCE for populating structures.
+ */
+public abstract class ASN1Null
+    extends ASN1Primitive
+{
+    /**
+     * Return an instance of ASN.1 NULL from the passed in object.
+     * <p>
+     * Accepted inputs:
+     * <ul>
+     * <li> null &rarr; null
+     * <li> {@link ASN1Null} object
+     * <li> a byte[] containing ASN.1 NULL object
+     * </ul>
+     * </p>
+     *
+     * @param o object to be converted.
+     * @return an instance of ASN1Null, or null.
+     * @exception IllegalArgumentException if the object cannot be converted.
+     */
+    public static ASN1Null getInstance(Object o)
+    {
+        if (o instanceof ASN1Null)
+        {
+            return (ASN1Null)o;
+        }
+
+        if (o != null)
+        {
+            try
+            {
+                return ASN1Null.getInstance(ASN1Primitive.fromByteArray((byte[])o));
+            }
+            catch (IOException e)
+            {
+                throw new IllegalArgumentException("failed to construct NULL from byte[]: " + e.getMessage());
+            }
+            catch (ClassCastException e)
+            {
+                throw new IllegalArgumentException("unknown object in getInstance(): " + o.getClass().getName());
+            }
+        }
+
+        return null;
+    }
+
+    public int hashCode()
+    {
+        return -1;
+    }
+
+    boolean asn1Equals(
+        ASN1Primitive o)
+    {
+        if (!(o instanceof ASN1Null))
+        {
+            return false;
+        }
+        
+        return true;
+    }
+
+    abstract void encode(ASN1OutputStream out)
+        throws IOException;
+
+    public String toString()
+    {
+         return "NULL";
+    }
+}