1 files changed, 52 insertions, 0 deletions
diff --git a/crypto/src/cms/CMSProcessableInputStream.cs b/crypto/src/cms/CMSProcessableInputStream.cs
new file mode 100644
index 000000000..7fdd1dfef
--- /dev/null
+++ b/crypto/src/cms/CMSProcessableInputStream.cs
@@ -0,0 +1,52 @@
+using System;
+using System.IO;
+
+using Org.BouncyCastle.Utilities.IO;
+
+namespace Org.BouncyCastle.Cms
+{
+	public class CmsProcessableInputStream
+		: CmsProcessable, CmsReadable
+	{
+		private Stream input;
+		private bool used = false;
+
+		public CmsProcessableInputStream(
+			Stream input)
+		{
+			this.input = input;
+		}
+
+		public Stream GetInputStream()
+		{
+			CheckSingleUsage();
+
+			return input;
+		}
+
+		public void Write(Stream output)
+		{
+			CheckSingleUsage();
+
+			Streams.PipeAll(input, output);
+			input.Close();
+		}
+
+		[Obsolete]
+		public object GetContent()
+		{
+			return GetInputStream();
+		}
+
+		private void CheckSingleUsage()
+		{
+			lock (this)
+			{
+				if (used)
+					throw new InvalidOperationException("CmsProcessableInputStream can only be used once");
+
+				used = true;
+			}
+		}
+	}
+}