1 files changed, 102 insertions, 0 deletions
diff --git a/crypto/src/asn1/BERGenerator.cs b/crypto/src/asn1/BERGenerator.cs
new file mode 100644
index 000000000..271572c02
--- /dev/null
+++ b/crypto/src/asn1/BERGenerator.cs
@@ -0,0 +1,102 @@
+using System.IO;
+
+using Org.BouncyCastle.Utilities.IO;
+
+namespace Org.BouncyCastle.Asn1
+{
+    public class BerGenerator
+        : Asn1Generator
+    {
+        private bool      _tagged = false;
+        private bool      _isExplicit;
+        private int          _tagNo;
+
+        protected BerGenerator(
+            Stream outStream)
+            : base(outStream)
+        {
+        }
+
+        public BerGenerator(
+            Stream outStream,
+            int tagNo,
+            bool isExplicit)
+            : base(outStream)
+        {
+            _tagged = true;
+            _isExplicit = isExplicit;
+            _tagNo = tagNo;
+        }
+
+		public override void AddObject(
+			Asn1Encodable obj)
+		{
+			new BerOutputStream(Out).WriteObject(obj);
+		}
+
+		public override Stream GetRawOutputStream()
+        {
+            return Out;
+        }
+
+		public override void Close()
+		{
+			WriteBerEnd();
+		}
+
+        private void WriteHdr(
+            int tag)
+        {
+            Out.WriteByte((byte) tag);
+            Out.WriteByte(0x80);
+        }
+
+        protected void WriteBerHeader(
+            int tag)
+        {
+            if (_tagged)
+            {
+                int tagNum = _tagNo | Asn1Tags.Tagged;
+
+                if (_isExplicit)
+                {
+                    WriteHdr(tagNum | Asn1Tags.Constructed);
+                    WriteHdr(tag);
+                }
+                else
+                {
+                    if ((tag & Asn1Tags.Constructed) != 0)
+                    {
+                        WriteHdr(tagNum | Asn1Tags.Constructed);
+                    }
+                    else
+                    {
+                        WriteHdr(tagNum);
+                    }
+                }
+            }
+            else
+            {
+                WriteHdr(tag);
+            }
+        }
+
+		protected void WriteBerBody(
+            Stream contentStream)
+        {
+			Streams.PipeAll(contentStream, Out);
+        }
+
+		protected void WriteBerEnd()
+        {
+            Out.WriteByte(0x00);
+            Out.WriteByte(0x00);
+
+            if (_tagged && _isExplicit)  // write extra end for tag header
+            {
+                Out.WriteByte(0x00);
+                Out.WriteByte(0x00);
+            }
+        }
+    }
+}