1 files changed, 52 insertions, 0 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/io/DigestInputStream.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/io/DigestInputStream.java
new file mode 100644
index 000000000..23a719640
--- /dev/null
+++ b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/io/DigestInputStream.java
@@ -0,0 +1,52 @@
+package org.spongycastle.crypto.io;
+
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.spongycastle.crypto.Digest;
+
+public class DigestInputStream
+    extends FilterInputStream
+{
+    protected Digest digest;
+
+    public DigestInputStream(
+        InputStream stream,
+        Digest      digest)
+    {
+        super(stream);
+        this.digest = digest;
+    }
+
+    public int read()
+        throws IOException
+    {
+        int b = in.read();
+
+        if (b >= 0)
+        {
+            digest.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)
+        {
+            digest.update(b, off, n);
+        }
+        return n;
+    }
+
+    public Digest getDigest()
+    {
+        return digest;
+    }
+}