org.linguafranca.pwdb.hashedblock

Class HashedBlockOutputStream

java.lang.Object

java.io.OutputStream

org.linguafranca.pwdb.hashedblock.HashedBlockOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public class HashedBlockOutputStream
extends OutputStream

Takes a stream of data and formats as Hashed Blocks to the underlying output 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
HashedBlockOutputStream(OutputStream outputStream) Create a BigEndian Hash Block Output Stream
HashedBlockOutputStream(OutputStream outputStream, boolean littleEndian) Create a Hash Block Output Stream with choice of endian encoding

Method Summary

Modifier and Type	Method and Description
void	close()
void	flush()
protected void	put(byte[] b, int offset, int length) Writes to the internal buffer, and writes to the underlying output stream as necessary as BLOCK_SIZE blocks
protected void	save() Saqve the internal buffer to the underlying stream as a hash block
void	write(@NotNull byte[] b, int offset, int count)
void	write(int i)
protected void	writeInt(int value) Write a 4 byte int value to the underlying stream in appropriate endian format

Methods inherited from class java.io.OutputStream

write

Methods inherited from class java.lang.Object

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

Constructor Detail

HashedBlockOutputStream

public HashedBlockOutputStream(OutputStream outputStream)

Create a BigEndian Hash Block Output Stream

Parameters:

outputStream - the output stream to receive the hash blocks

HashedBlockOutputStream

public HashedBlockOutputStream(OutputStream outputStream,
                               boolean littleEndian)

Create a Hash Block Output Stream with choice of endian encoding

Parameters:

outputStream - the output stream to receive the hash blocks

littleEndian - true to encode in a little endian way

Method Detail

write

public void write(int i)
           throws IOException

Specified by:

write in class OutputStream

Throws:

IOException

write

public void write(@NotNull
                  @NotNull byte[] b,
                  int offset,
                  int count)
           throws IOException

Overrides:

write in class OutputStream

Throws:

IOException

flush

public void flush()
           throws IOException

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class OutputStream

Throws:

IOException

put

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

Writes to the internal buffer, and writes to the underlying output stream as necessary as BLOCK_SIZE blocks

Parameters:

b - the byte array to write

offset - offset in the byte array

length - number of bytes to write

Throws:

IOException

save

protected void save()
             throws IOException

Saqve the internal buffer to the underlying stream as a hash block

Throws:

IOException

writeInt

protected void writeInt(int value)
                 throws IOException

Write a 4 byte int value to the underlying stream in appropriate endian format

Parameters:

value - the value to write

Throws:

IOException