1 files changed, 107 insertions, 0 deletions
diff --git a/crypto/src/cms/CMSCompressedData.cs b/crypto/src/cms/CMSCompressedData.cs
new file mode 100644
index 000000000..2d0107e88
--- /dev/null
+++ b/crypto/src/cms/CMSCompressedData.cs
@@ -0,0 +1,107 @@
+using System;
+using System.IO;
+
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Asn1.Cms;
+using Org.BouncyCastle.Utilities.Zlib;
+
+namespace Org.BouncyCastle.Cms
+{
+    /**
+    * containing class for an CMS Compressed Data object
+    */
+    public class CmsCompressedData
+    {
+        internal ContentInfo contentInfo;
+
+		public CmsCompressedData(
+            byte[] compressedData)
+            : this(CmsUtilities.ReadContentInfo(compressedData))
+        {
+        }
+
+		public CmsCompressedData(
+            Stream compressedDataStream)
+            : this(CmsUtilities.ReadContentInfo(compressedDataStream))
+        {
+        }
+
+		public CmsCompressedData(
+            ContentInfo contentInfo)
+        {
+            this.contentInfo = contentInfo;
+        }
+
+		/**
+		 * Return the uncompressed content.
+		 *
+		 * @return the uncompressed content
+		 * @throws CmsException if there is an exception uncompressing the data.
+		 */
+		public byte[] GetContent()
+        {
+            CompressedData comData = CompressedData.GetInstance(contentInfo.Content);
+            ContentInfo content = comData.EncapContentInfo;
+
+			Asn1OctetString bytes = (Asn1OctetString) content.Content;
+			ZInputStream zIn = new ZInputStream(bytes.GetOctetStream());
+
+			try
+			{
+				return CmsUtilities.StreamToByteArray(zIn);
+			}
+			catch (IOException e)
+			{
+				throw new CmsException("exception reading compressed stream.", e);
+			}
+			finally
+			{
+				zIn.Close();
+			}
+        }
+
+	    /**
+	     * Return the uncompressed content, throwing an exception if the data size
+	     * is greater than the passed in limit. If the content is exceeded getCause()
+	     * on the CMSException will contain a StreamOverflowException
+	     *
+	     * @param limit maximum number of bytes to read
+	     * @return the content read
+	     * @throws CMSException if there is an exception uncompressing the data.
+	     */
+		public byte[] GetContent(int limit)
+		{
+			CompressedData  comData = CompressedData.GetInstance(contentInfo.Content);
+			ContentInfo     content = comData.EncapContentInfo;
+
+			Asn1OctetString bytes = (Asn1OctetString)content.Content;
+
+			ZInputStream zIn = new ZInputStream(new MemoryStream(bytes.GetOctets(), false));
+
+			try
+			{
+				return CmsUtilities.StreamToByteArray(zIn, limit);
+			}
+			catch (IOException e)
+			{
+				throw new CmsException("exception reading compressed stream.", e);
+			}
+		}
+
+		/**
+		 * return the ContentInfo 
+		 */
+		public ContentInfo ContentInfo
+		{
+			get { return contentInfo; }
+		}
+
+		/**
+        * return the ASN.1 encoded representation of this object.
+        */
+        public byte[] GetEncoded()
+        {
+			return contentInfo.GetEncoded();
+        }
+    }
+}