1 files changed, 29 insertions, 0 deletions
diff --git a/pkix/src/main/java/org/spongycastle/operator/InputExpander.java b/pkix/src/main/java/org/spongycastle/operator/InputExpander.java
new file mode 100644
index 00000000..870e4807
--- /dev/null
+++ b/pkix/src/main/java/org/spongycastle/operator/InputExpander.java
@@ -0,0 +1,29 @@
+package org.spongycastle.operator;
+
+import java.io.InputStream;
+
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+
+/**
+ * General interface for an operator that is able to produce
+ * an InputStream that will produce uncompressed data.
+ */
+public interface InputExpander
+{
+    /**
+     * Return the algorithm identifier describing the compression
+     * algorithm and parameters this expander supports.
+     *
+     * @return algorithm oid and parameters.
+     */
+    AlgorithmIdentifier getAlgorithmIdentifier();
+
+    /**
+     * Wrap the passed in input stream comIn, returning an input stream
+     * that expands anything read in from comIn.
+     *
+     * @param comIn the compressed input data stream..
+     * @return an expanding InputStream.
+     */
+    InputStream getInputStream(InputStream comIn);
+}