1 files changed, 52 insertions, 0 deletions
diff --git a/core/src/main/java/org/bouncycastle/crypto/io/MacInputStream.java b/core/src/main/java/org/bouncycastle/crypto/io/MacInputStream.java
new file mode 100644
index 00000000..b78548c6
--- /dev/null
+++ b/core/src/main/java/org/bouncycastle/crypto/io/MacInputStream.java
@@ -0,0 +1,52 @@
+package org.bouncycastle.crypto.io;
+
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.bouncycastle.crypto.Mac;
+
+public class MacInputStream
+    extends FilterInputStream
+{
+    protected Mac mac;
+
+    public MacInputStream(
+        InputStream stream,
+        Mac         mac)
+    {
+        super(stream);
+        this.mac = mac;
+    }
+
+    public int read()
+        throws IOException
+    {
+        int b = in.read();
+
+        if (b >= 0)
+        {
+            mac.update((byte)b);
+        }
+        return b;
+    }
+
+    public int read(
+        byte[] b,
+        int off,
+        int len)
+        throws IOException
+    {
+        int n = in.read(b, off, len);
+        if (n >= 0)
+        {
+            mac.update(b, off, n);
+        }
+        return n;
+    }
+
+    public Mac getMac()
+    {
+        return mac;
+    }
+}