1 files changed, 155 insertions, 0 deletions
diff --git a/libjava/java/security/DigestInputStream.java b/libjava/java/security/DigestInputStream.java
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+++ b/libjava/java/security/DigestInputStream.java
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+/* DigestInputStream.java --- An Input stream tied to a message digest
+   Copyright (C) 1999 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+As a special exception, if you link this library with other files to
+produce an executable, this library does not by itself cause the
+resulting executable to be covered by the GNU General Public License.
+This exception does not however invalidate any other reasons why the
+executable file might be covered by the GNU General Public License. */
+
+package java.security;
+//import java.security.MessageDigest;
+import java.io.InputStream;
+import java.io.FilterInputStream;
+import java.io.IOException;
+
+/**
+   DigestInputStream is a class that ties an InputStream with a 
+   MessageDigest. The Message Digest is used by the class to 
+   update it self as bytes are read from the InputStream.
+
+   The updating to the digest depends on the on flag which is set
+   to true by default to tell the class to update the data
+   in the message digest.
+
+   @version 0.0
+   @author Mark Benvenuto <ivymccough@worldnet.att.net>
+ */
+public class DigestInputStream extends FilterInputStream
+{
+  /**
+     The message digest for the DigestInputStream 
+   */
+  protected MessageDigest digest;
+
+  //Manages the on flag
+  private boolean state = true;
+
+  /**
+     Constructs a new DigestInputStream.
+     It associates a MessageDigest with the stream to 
+     compute the stream as data is written.
+
+     @param stream An InputStream to associate this stream with
+     @param digest A MessageDigest to hash the stream with
+   */
+  public DigestInputStream(InputStream stream, MessageDigest digest)
+  {
+    super(stream);
+    //this.in = stream;
+    this.digest = digest;
+  }
+
+  /**
+     Returns the MessageDigest associated with this DigestInputStream 
+
+     @return The MessageDigest used to hash this stream
+   */
+  public MessageDigest getMessageDigest()
+  {
+    return digest;
+  }
+
+  /**
+     Sets the current MessageDigest to current parameter
+
+     @param digest A MessageDigest to associate with this stream
+   */
+  public void setMessageDigest(MessageDigest digest)
+  {
+    this.digest = digest;
+  }
+
+  /** 
+     Reads a byte from the input stream and updates the digest.
+     This method reads the underlying input stream and if the 
+     on flag is true then updates the message digest.
+
+     @return Returns a byte from the input stream, -1 is returned to indicate that 
+     the end of stream was reached before this read call
+
+     @throws IOException if an IO error occurs in the underlying input stream,
+     this error is thrown
+   */
+  public int read() throws IOException
+  {
+    int temp = in.read();
+
+    if (state == true && temp != -1)
+      digest.update((byte) temp);
+
+    return temp;
+  }
+
+  /** 
+     Reads bytes from the input stream and updates the digest.
+     This method reads the underlying input stream and if the 
+     on flag is true then updates the message digest.
+
+     @param b a byte array to store the data from the input stream
+     @param off an offset to start at in the array
+     @param len length of data to read
+     @return Returns count of bytes read, -1 is returned to indicate that 
+     the end of stream was reached before this read call
+
+     @throws IOException if an IO error occurs in the underlying input stream,
+     this error is thrown
+   */
+  public int read(byte[]b, int off, int len) throws IOException
+  {
+    int temp = in.read(b, off, len);
+
+    if (state == true && temp != -1)
+      digest.update(b, off, len);
+
+    return temp;
+  }
+
+  /**
+     Sets the flag specifing if this DigestInputStream updates the
+     digest in the write() methods. The default is on;
+
+     @param on True means it digests stream, false means it does not
+   */
+  public void on(boolean on)
+  {
+    state = on;
+  }
+
+  /**
+     Converts the input stream and underlying message digest to a string.
+
+     @return A string representing the input stream and message digest.
+   */
+  public String toString()
+  {
+    return "[Digest Input Stream] " + digest.toString();
+  }
+}