iaik.utils

Class MacOutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

iaik.utils.MacOutputStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable

public class MacOutputStream
extends java.io.FilterOutputStream

A stream implementation for MACing the data written to an output stream. This is similar to the java.security.DigestOutputStream.

Version:

File Revision 3

See Also:

MacInputStream, DigestOutputStream

Field Summary

Fields

Modifier and Type	Field and Description
protected javax.crypto.Mac	macEngine_ The MAC engine to use for MACing the data.
protected boolean	macingActive_ Indicates, if this objects sends data written to this stream to the Mac engine.

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

Constructors

Constructor and Description
MacOutputStream(java.io.OutputStream stream, javax.crypto.Mac macEngine) Creates a MAC output stream, using the specified output stream and MAC engine.

Method Summary

Methods

Modifier and Type	Method and Description
javax.crypto.Mac	getMac() Get the MAC engine used for MACing the data.
void	on(boolean macingActive) Turns the MACing on or off.
void	setMac(javax.crypto.Mac macEngine) Set the MAC engine to use for MACing the data.
java.lang.String	toString() Returns a string representation of this MAC output stream.
void	write(byte[] dataByteArray, int offset, int length) This methods updates the MAC, if the MACing is active.
void	write(int dataByte) This methods updates the MAC, if the MACing is active.

Methods inherited from class java.io.FilterOutputStream

close, flush, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

macingActive_

protected boolean macingActive_

Indicates, if this objects sends data written to this stream to the Mac engine.

macEngine_

protected javax.crypto.Mac macEngine_

The MAC engine to use for MACing the data.

Constructor Detail

MacOutputStream

public MacOutputStream(java.io.OutputStream stream,
               javax.crypto.Mac macEngine)

Creates a MAC output stream, using the specified output stream and MAC engine.

Parameters:

stream - The output stream to write the data though.

macEngine - The MAC engine to use for MACing the data.

Method Detail

getMac

public javax.crypto.Mac getMac()

Get the MAC engine used for MACing the data.

Returns:

The MAC engine used for MACing the data.

setMac

public void setMac(javax.crypto.Mac macEngine)

Set the MAC engine to use for MACing the data.

Parameters:

macEngine - The MAC engine to use for MACing the data.

write

public void write(int dataByte)
           throws java.io.IOException

This methods updates the MAC, if the MACing is active. Susequently, this method writes the data to the underlying stream.

Overrides:

write in class java.io.FilterOutputStream

Parameters:

dataByte - A single data byte.

Throws:

java.io.IOException - If writing to the underlaying stream fails.

write

public void write(byte[] dataByteArray,
         int offset,
         int length)
           throws java.io.IOException

This methods updates the MAC, if the MACing is active. Susequently, this method writes the data to the underlying stream.

Overrides:

write in class java.io.FilterOutputStream

Parameters:

dataByteArray - The array containing the data bytes.

offset - The offset in the data byte array to start reading the data bytes.

length - The number of bytes to read the array starting from offset.

Throws:

java.io.IOException - If writing to the underlaying stream fails.

on

public void on(boolean macingActive)

Turns the MACing on or off. If set to false, all data is just written through to the underlying stream but not to the MAC. Otherwise, if set to true, this object writes all data to the MAC as well as to the underlying stream.

Parameters:

macingActive - True, to MAC all data before writing to the underlying stream.

toString

public java.lang.String toString()

Returns a string representation of this MAC output stream.

Overrides:

toString in class java.lang.Object

Returns:

A string representation of this MAC output stream.