1 files changed, 72 insertions, 0 deletions
diff --git a/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/CMSCompressedDataParser.java b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/CMSCompressedDataParser.java
new file mode 100644
index 000000000..bc853f2ac
--- /dev/null
+++ b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/CMSCompressedDataParser.java
@@ -0,0 +1,72 @@
+package org.spongycastle.cms;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.spongycastle.asn1.ASN1OctetStringParser;
+import org.spongycastle.asn1.ASN1SequenceParser;
+import org.spongycastle.asn1.BERTags;
+import org.spongycastle.asn1.cms.CompressedDataParser;
+import org.spongycastle.asn1.cms.ContentInfoParser;
+import org.spongycastle.operator.InputExpander;
+import org.spongycastle.operator.InputExpanderProvider;
+
+/**
+ * Class for reading a CMS Compressed Data stream.
+ * <pre>
+ *     CMSCompressedDataParser cp = new CMSCompressedDataParser(inputStream);
+ *      
+ *     process(cp.getContent(new ZlibExpanderProvider()).getContentStream());
+ * </pre>
+ *  Note: this class does not introduce buffering - if you are processing large files you should create
+ *  the parser with:
+ *  <pre>
+ *      CMSCompressedDataParser     ep = new CMSCompressedDataParser(new BufferedInputStream(inputStream, bufSize));
+ *  </pre>
+ *  where bufSize is a suitably large buffer size.
+ */
+public class CMSCompressedDataParser
+    extends CMSContentInfoParser
+{
+    public CMSCompressedDataParser(
+        byte[]    compressedData) 
+        throws CMSException
+    {
+        this(new ByteArrayInputStream(compressedData));
+    }
+
+    public CMSCompressedDataParser(
+        InputStream    compressedData) 
+        throws CMSException
+    {
+        super(compressedData);
+    }
+
+    /**
+     * Return a typed stream which will allow the reading of the compressed content in
+     * expanded form.
+     *
+     * @param expanderProvider a provider of expander algorithm implementations.
+     * @return a type stream which will yield the un-compressed content.
+     * @throws CMSException if there is an exception parsing the CompressedData object.
+     */
+    public CMSTypedStream  getContent(InputExpanderProvider expanderProvider)
+        throws CMSException
+    {
+        try
+        {
+            CompressedDataParser  comData = new CompressedDataParser((ASN1SequenceParser)_contentInfo.getContent(BERTags.SEQUENCE));
+            ContentInfoParser     content = comData.getEncapContentInfo();
+            InputExpander expander = expanderProvider.get(comData.getCompressionAlgorithmIdentifier());
+
+            ASN1OctetStringParser bytes = (ASN1OctetStringParser)content.getContent(BERTags.OCTET_STRING);
+
+            return new CMSTypedStream(content.getContentType().getId(), expander.getInputStream(bytes.getOctetStream()));
+        }
+        catch (IOException e)
+        {
+            throw new CMSException("IOException reading compressed content.", e);
+        }
+    }
+}