com.tangosol.net.security
Class BlockCipherInputStream

java.lang.Object
  java.io.InputStream
      java.io.FilterInputStream
          com.tangosol.net.security.BlockCipherInputStream

All Implemented Interfaces:

Closeable

public class BlockCipherInputStream
extends FilterInputStream

InputStream which supports block ciphers, and data sizes which exceed the Cipher's block size.

Author:

mf 2006.08.08

Field Summary

static byte[]	EMPTY_BYTE_ARRAY Initial value for m_abBlockClear
protected byte[]	m_abBlockClear The current block of unencrypted data
protected byte[]	m_abBlockEncrypted The current block of encrypted data
protected Cipher	m_cipher The Cipher to use to decrypt data
protected boolean	m_fEof Marker indicating if the end of the wrapped stream has been reached
protected int	m_nBlockIndex The index into the next unread byte of unencrypted data
protected int	m_nBlockSize The Cipher's block size

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

BlockCipherInputStream(InputStream stream, Cipher cipher)
Construct a BlockCipherInputStream around the supplied stream and decrypt output data with the supplied cipher.

Method Summary

int	available()
protected int	ensureData() Ensure that there is some data available for read, blocking on the wrapped stream if necessary.
boolean	markSupported()
int	read()
int	read(byte[] abData)
int	read(byte[] abData, int nOffset, int nLength)
long	skip(long lBytes)

Methods inherited from class java.io.FilterInputStream

close, mark, reset

Field Detail

m_cipher

protected Cipher m_cipher

The Cipher to use to decrypt data

m_nBlockSize

protected int m_nBlockSize

The Cipher's block size

m_abBlockEncrypted

protected byte[] m_abBlockEncrypted

The current block of encrypted data

m_abBlockClear

protected byte[] m_abBlockClear

The current block of unencrypted data

m_nBlockIndex

protected int m_nBlockIndex

The index into the next unread byte of unencrypted data

m_fEof

protected boolean m_fEof

Marker indicating if the end of the wrapped stream has been reached

EMPTY_BYTE_ARRAY

public static final byte[] EMPTY_BYTE_ARRAY

Initial value for m_abBlockClear

Constructor Detail

BlockCipherInputStream

public BlockCipherInputStream(InputStream stream,
                              Cipher cipher)

Construct a BlockCipherInputStream around the supplied stream and decrypt output data with the supplied cipher.

Parameters:

stream - the stream to read encrypted data to

cipher - the cipher to use to decrypt data

Method Detail

read

public int read()
         throws IOException

Overrides:

read in class FilterInputStream

Throws:

IOException

read

public int read(byte[] abData)
         throws IOException

Overrides:

read in class FilterInputStream

Throws:

IOException

read

public int read(byte[] abData,
                int nOffset,
                int nLength)
         throws IOException

Overrides:

read in class FilterInputStream

Throws:

IOException

skip

public long skip(long lBytes)
          throws IOException

Overrides:

skip in class FilterInputStream

Throws:

IOException

available

public int available()
              throws IOException

Overrides:

available in class FilterInputStream

Throws:

IOException

markSupported

public boolean markSupported()

Overrides:

markSupported in class FilterInputStream

ensureData

protected int ensureData()
                  throws IOException

Ensure that there is some data available for read, blocking on the wrapped stream if necessary. As a side effect a call to this method may change m_abBlockClear and m_nBlockIndex.

Returns:

the number of bytes now available

Throws:

IOException