org.linguafranca.pwdb.hashedblock

Class HashedBlockInputStream

java.lang.Object

java.io.InputStream

org.linguafranca.pwdb.hashedblock.HashedBlockInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class HashedBlockInputStream
extends InputStream

Takes an underlying input stream formatted as Hashed Blocks and provides the content of the blocks as an input stream

A Hashed block consists of:

1. A 4 byte block sequence number, increments from 0
2. A 32 byte MD5 hash of the content
3. A 4 byte length field
4. Content

The stream of blocks is terminated with a 0 length 0 hash block.

Originally developed for KeePass. A KeePass hash block stream is little endian, i.e. the sequence number and length fields are low order byte first.

Author:

Jo

Constructor Summary

Constructors

Constructor and Description
HashedBlockInputStream(InputStream inputStream) Create a Big Endian Hash Block Input Stream
HashedBlockInputStream(InputStream inputStream, boolean littleEndian) Create a Hash Block Input Stream with choice of endian encoding

Method Summary

Modifier and Type	Method and Description
void	close()
protected int	get(byte[] b, int offset, int length) Gets bytes from the internal buffer and replenishes the buffer as necessary
protected void	load() Reload the internal buffer from the underlying input stream
int	read()
int	read(@NotNull byte[] b, int offset, int length)

Methods inherited from class java.io.InputStream

available, mark, markSupported, read, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

HashedBlockInputStream

public HashedBlockInputStream(InputStream inputStream)

Create a Big Endian Hash Block Input Stream

Parameters:

inputStream - the input stream containing the hash blocks

HashedBlockInputStream

public HashedBlockInputStream(InputStream inputStream,
                              boolean littleEndian)

Create a Hash Block Input Stream with choice of endian encoding

Parameters:

inputStream - the input stream containing the hash blocks

littleEndian - true if the stream is little endian encoded

Method Detail

read

public int read(@NotNull
                @NotNull byte[] b,
                int offset,
                int length)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class InputStream

Throws:

IOException

get

protected int get(byte[] b,
                  int offset,
                  int length)
           throws IOException

Gets bytes from the internal buffer and replenishes the buffer as necessary

Parameters:

b - a byte array to fill

offset - the offset to strat from

length - the number of bytes to return

Returns:

the number of bytes actually returned, , -1 if end of file

Throws:

IOException

load

protected void load()
             throws IOException

Reload the internal buffer from the underlying input stream

Throws:

IOException