1 files changed, 72 insertions, 0 deletions
diff --git a/crypto/src/asn1/DerTaggedObject.cs b/crypto/src/asn1/DerTaggedObject.cs
new file mode 100644
index 000000000..717d724b6
--- /dev/null
+++ b/crypto/src/asn1/DerTaggedObject.cs
@@ -0,0 +1,72 @@
+namespace Org.BouncyCastle.Asn1
+{
+	/**
+	 * DER 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 class DerTaggedObject
+		: Asn1TaggedObject
+	{
+		/**
+		 * @param tagNo the tag number for this object.
+		 * @param obj the tagged object.
+		 */
+		public DerTaggedObject(
+			int				tagNo,
+			Asn1Encodable	obj)
+			: base(tagNo, obj)
+		{
+		}
+
+		/**
+		 * @param explicitly true if an explicitly tagged object.
+		 * @param tagNo the tag number for this object.
+		 * @param obj the tagged object.
+		 */
+		public DerTaggedObject(
+			bool			explicitly,
+			int				tagNo,
+			Asn1Encodable	obj)
+			: base(explicitly, tagNo, obj)
+		{
+		}
+
+		/**
+		 * create an implicitly tagged object that contains a zero
+		 * length sequence.
+		 */
+		public DerTaggedObject(
+			int tagNo)
+			: base(false, tagNo, DerSequence.Empty)
+		{
+		}
+
+		internal override void Encode(
+			DerOutputStream derOut)
+		{
+			if (!IsEmpty())
+			{
+				byte[] bytes = obj.GetDerEncoded();
+
+				if (explicitly)
+				{
+					derOut.WriteEncoded(Asn1Tags.Constructed | Asn1Tags.Tagged, tagNo, bytes);
+				}
+				else
+				{
+					//
+					// need to mark constructed types... (preserve Constructed tag)
+					//
+					int flags = (bytes[0] & Asn1Tags.Constructed) | Asn1Tags.Tagged;
+					derOut.WriteTag(flags, tagNo);
+					derOut.Write(bytes, 1, bytes.Length - 1);
+				}
+			}
+			else
+			{
+				derOut.WriteEncoded(Asn1Tags.Constructed | Asn1Tags.Tagged, tagNo, new byte[0]);
+			}
+		}
+	}
+}