1 files changed, 74 insertions, 0 deletions
diff --git a/pkix/src/main/java/org/spongycastle/cms/CMSCompressedDataGenerator.java b/pkix/src/main/java/org/spongycastle/cms/CMSCompressedDataGenerator.java
new file mode 100644
index 00000000..b26e84a3
--- /dev/null
+++ b/pkix/src/main/java/org/spongycastle/cms/CMSCompressedDataGenerator.java
@@ -0,0 +1,74 @@
+package org.spongycastle.cms;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+import org.spongycastle.asn1.ASN1OctetString;
+import org.spongycastle.asn1.BEROctetString;
+import org.spongycastle.asn1.cms.CMSObjectIdentifiers;
+import org.spongycastle.asn1.cms.CompressedData;
+import org.spongycastle.asn1.cms.ContentInfo;
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.operator.OutputCompressor;
+
+/**
+ * General class for generating a compressed CMS message.
+ * <p>
+ * A simple example of usage.
+ * <p>
+ * <pre>
+ *      CMSCompressedDataGenerator  fact = new CMSCompressedDataGenerator();
+ *
+ *      CMSCompressedData           data = fact.generate(content, new ZlibCompressor());
+ * </pre>
+ */
+public class CMSCompressedDataGenerator
+{
+    public static final String  ZLIB    = "1.2.840.113549.1.9.16.3.8";
+
+    /**
+     * base constructor
+     */
+    public CMSCompressedDataGenerator()
+    {
+    }
+
+    /**
+     * generate an object that contains an CMS Compressed Data
+     */
+    public CMSCompressedData generate(
+        CMSTypedData content,
+        OutputCompressor compressor)
+        throws CMSException
+    {
+        AlgorithmIdentifier     comAlgId;
+        ASN1OctetString         comOcts;
+
+        try
+        {
+            ByteArrayOutputStream bOut = new ByteArrayOutputStream();
+            OutputStream zOut = compressor.getOutputStream(bOut);
+
+            content.write(zOut);
+
+            zOut.close();
+
+            comAlgId = compressor.getAlgorithmIdentifier();
+            comOcts = new BEROctetString(bOut.toByteArray());
+        }
+        catch (IOException e)
+        {
+            throw new CMSException("exception encoding data.", e);
+        }
+
+        ContentInfo     comContent = new ContentInfo(
+                                    content.getContentType(), comOcts);
+
+        ContentInfo     contentInfo = new ContentInfo(
+                                    CMSObjectIdentifiers.compressedData,
+                                    new CompressedData(comAlgId, comContent));
+
+        return new CMSCompressedData(contentInfo);
+    }
+}