--- /dev/null
+package org.bouncycastle.crypto.io;
+
+import java.io.*;
+
+import org.bouncycastle.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;
+ }
+}