1 files changed, 70 insertions, 0 deletions
diff --git a/libraries/spongycastle/pkix/src/main/java/org/spongycastle/operator/BufferingContentSigner.java b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/operator/BufferingContentSigner.java
new file mode 100644
index 000000000..e96a906c3
--- /dev/null
+++ b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/operator/BufferingContentSigner.java
@@ -0,0 +1,70 @@
+package org.spongycastle.operator;
+
+import java.io.OutputStream;
+
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.util.io.BufferingOutputStream;
+
+/**
+ * A class that explicitly buffers the data to be signed, sending it in one
+ * block when ready for signing.
+ */
+public class BufferingContentSigner
+    implements ContentSigner
+{
+    private final ContentSigner contentSigner;
+    private final OutputStream  output;
+
+    /**
+     * Base constructor.
+     *
+     * @param contentSigner the content signer to be wrapped.
+     */
+    public BufferingContentSigner(ContentSigner contentSigner)
+    {
+        this.contentSigner = contentSigner;
+        this.output = new BufferingOutputStream(contentSigner.getOutputStream());
+    }
+
+    /**
+     * Base constructor.
+     *
+     * @param contentSigner the content signer to be wrapped.
+     * @param bufferSize the size of the internal buffer to use.
+     */
+    public BufferingContentSigner(ContentSigner contentSigner, int bufferSize)
+    {
+        this.contentSigner = contentSigner;
+        this.output = new BufferingOutputStream(contentSigner.getOutputStream(), bufferSize);
+    }
+
+    /**
+     * Return the algorithm identifier supported by this signer.
+     *
+     * @return algorithm identifier for the signature generated.
+     */
+    public AlgorithmIdentifier getAlgorithmIdentifier()
+    {
+        return contentSigner.getAlgorithmIdentifier();
+    }
+
+    /**
+     * Return the buffering stream.
+     *
+     * @return the output stream used to accumulate the data.
+     */
+    public OutputStream getOutputStream()
+    {
+        return output;
+    }
+
+    /**
+     * Generate signature from internally buffered data.
+     *
+     * @return the signature calculated from the bytes written to the buffering stream.
+     */
+    public byte[] getSignature()
+    {
+        return contentSigner.getSignature();
+    }
+}