1 files changed, 150 insertions, 0 deletions
diff --git a/java/security/DigestInputStream.java b/java/security/DigestInputStream.java
new file mode 100644
index 000000000..ed5978f96
--- /dev/null
+++ b/java/security/DigestInputStream.java
@@ -0,0 +1,150 @@
+/* DigestInputStream.java --- An Input stream tied to a message digest
+   
+  Copyright (c) 1999 by Free Software Foundation, Inc.
+  Written by Mark Benvenuto <ivymccough@worldnet.att.net>
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Library General Public License as published 
+  by the Free Software Foundation, version 2. (see COPYING.LIB)
+
+  This program 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 this program; if not, write to the Free Software Foundation
+  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307 USA. */
+
+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();
+}
+
+}
+\ No newline at end of file