1 files changed, 39 insertions, 0 deletions
diff --git a/crypto/src/util/io/TeeOutputStream.cs b/crypto/src/util/io/TeeOutputStream.cs
new file mode 100644
index 000000000..fe3a7586a
--- /dev/null
+++ b/crypto/src/util/io/TeeOutputStream.cs
@@ -0,0 +1,39 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+
+namespace Org.BouncyCastle.Utilities.IO
+{
+    public class TeeOutputStream
+		: BaseOutputStream
+	{
+		private readonly Stream output, tee;
+
+		public TeeOutputStream(Stream output, Stream tee)
+		{
+			Debug.Assert(output.CanWrite);
+			Debug.Assert(tee.CanWrite);
+
+			this.output = output;
+			this.tee = tee;
+		}
+
+		public override void Close()
+		{
+			output.Close();
+			tee.Close();
+		}
+
+		public override void Write(byte[] buffer, int offset, int count)
+		{
+			output.Write(buffer, offset, count);
+			tee.Write(buffer, offset, count);
+		}
+
+		public override void WriteByte(byte b)
+		{
+			output.WriteByte(b);
+			tee.WriteByte(b);
+		}
+	}
+}