1 files changed, 52 insertions, 0 deletions
diff --git a/crypto/src/asn1/DLExternal.cs b/crypto/src/asn1/DLExternal.cs
new file mode 100644
index 000000000..912ead579
--- /dev/null
+++ b/crypto/src/asn1/DLExternal.cs
@@ -0,0 +1,52 @@
+namespace Org.BouncyCastle.Asn1
+{
+    internal class DLExternal
+        : DerExternal
+    {
+        internal DLExternal(Asn1EncodableVector vector)
+            : base(vector)
+        {
+        }
+
+        internal DLExternal(Asn1Sequence sequence)
+            : base(sequence)
+        {
+        }
+
+        internal DLExternal(DerObjectIdentifier directReference, DerInteger indirectReference,
+            Asn1ObjectDescriptor dataValueDescriptor, Asn1TaggedObject externalData)
+            : base(directReference, indirectReference, dataValueDescriptor, externalData)
+        {
+        }
+
+        internal DLExternal(DerObjectIdentifier directReference, DerInteger indirectReference,
+            Asn1ObjectDescriptor dataValueDescriptor, int encoding, Asn1Object externalData)
+            : base(directReference, indirectReference, dataValueDescriptor, encoding, externalData)
+        {
+        }
+
+        internal override Asn1Sequence BuildSequence()
+        {
+            Asn1EncodableVector v = new Asn1EncodableVector(4);
+            v.AddOptional(directReference, indirectReference, dataValueDescriptor);
+            v.Add(new DLTaggedObject(0 == encoding, encoding, externalContent));
+            return new DLSequence(v);
+        }
+
+        internal override IAsn1Encoding GetEncoding(int encoding)
+        {
+            if (Asn1OutputStream.EncodingDer == encoding)
+                return base.GetEncoding(encoding);
+
+            return BuildSequence().GetEncodingImplicit(encoding, Asn1Tags.Universal, Asn1Tags.External);
+        }
+
+        internal override IAsn1Encoding GetEncodingImplicit(int encoding, int tagClass, int tagNo)
+        {
+            if (Asn1OutputStream.EncodingDer == encoding)
+                return base.GetEncodingImplicit(encoding, tagClass, tagNo);
+
+            return BuildSequence().GetEncodingImplicit(encoding, tagClass, tagNo);
+        }
+    }
+}