org.cryptimeleon.math.hash

Class ByteAccumulator

java.lang.Object

org.cryptimeleon.math.hash.ByteAccumulator

All Implemented Interfaces:

java.lang.Comparable<ByteAccumulator>

Direct Known Subclasses:

ByteArrayAccumulator, EscapingByteAccumulator, HashAccumulator

public abstract class ByteAccumulator
extends java.lang.Object
implements java.lang.Comparable<ByteAccumulator>

A ByteAccumulator takes a (large) byte-string x as input and outputs a byte array representing f(x) for some function f. The function f depends on the concrete instantiation of this class. It can be, for example, the identity function ByteArrayAccumulator.

The input x can be given to the ByteAccumulator in substrings, so if x = x_1 || x_2 (|| denotes concatenation), then after calling append(x_1) and append(x_2), extractBytes() will output f(x) = f(x_1 || x_2).

Usually, this class will be used in the context of the UniqueByteRepresentable interface. To that end, it contains some helper methods to make it easier to insert certain x into this.

Field Summary

Fields

Modifier and Type	Field and Description
static byte	SEPARATOR

Constructor Summary

Constructors

Constructor and Description
ByteAccumulator()

Method Summary

Modifier and Type	Method and Description
void	append(byte singleByte) Appends a single byte to the accumulator.
abstract void	append(byte[] bytes) Appends bytes to the input x of this accumulator.
void	append(int integer) Appends the given integer as four bytes to the accumulator.
void	append(java.lang.String str) Appends the given String encoded as UTF-8 to the accumulator
void	append(UniqueByteRepresentable ubr) Updates the ByteAccumulator with bytes from a UniqueByteRepresentable.
void	appendAndSeparate(byte[] bytes) Appends the input and then appends a separator byte.
void	appendAndSeparate(java.lang.String str) Appends the input and then appends a separator byte.
void	appendPadded(int length, byte[] bytes) Pads the bytes with leading zero bytes to the desired length and then appends that to the accumulator.
void	appendSeperator() Appends a special separator symbol to the accumulator.
int	compareTo(ByteAccumulator byteAccumulator)
void	escapeAndAppend(byte[] bytes) Escapes any occurrence of the separator symbol and appends the escaped string to the byte accumulator.
void	escapeAndAppend(java.lang.String str) Escapes any occurrence of the separator symbol and appends the escaped string to the byte accumulator.
void	escapeAndAppend(UniqueByteRepresentable ubr) Escapes any occurrence of the separator symbol and appends the escaped string to the byte accumulator.
void	escapeAndSeparate(byte[] bytes) Escapes the separator symbol, appends the escaped bytes, then appends a separator symbol.
void	escapeAndSeparate(java.lang.String str) Escapes the separator symbol in the given string, appends the escaped bytes, then appends a separator symbol.
void	escapeAndSeparate(UniqueByteRepresentable ubr) Escapes the separator symbol, appends the escaped bytes, then appends a separator symbol.
abstract byte[]	extractBytes() Extracts f(x) from the accumulator, where x was input by append() calls.

Methods inherited from class java.lang.Object

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

Field Detail

SEPARATOR

public static byte SEPARATOR

Constructor Detail

ByteAccumulator

public ByteAccumulator()

Method Detail

append

public abstract void append(byte[] bytes)

Appends bytes to the input x of this accumulator.

extractBytes

public abstract byte[] extractBytes()

Extracts f(x) from the accumulator, where x was input by append() calls.

Returns:

f(x)

appendAndSeparate

public void appendAndSeparate(byte[] bytes)

Appends the input and then appends a separator byte.

appendAndSeparate

public void appendAndSeparate(java.lang.String str)

Appends the input and then appends a separator byte.

escapeAndAppend

public void escapeAndAppend(byte[] bytes)

Escapes any occurrence of the separator symbol and appends the escaped string to the byte accumulator.

escapeAndAppend

public void escapeAndAppend(java.lang.String str)

Escapes any occurrence of the separator symbol and appends the escaped string to the byte accumulator.

escapeAndAppend

public void escapeAndAppend(UniqueByteRepresentable ubr)

Escapes any occurrence of the separator symbol and appends the escaped string to the byte accumulator.

escapeAndSeparate

public void escapeAndSeparate(byte[] bytes)

Escapes the separator symbol, appends the escaped bytes, then appends a separator symbol.

escapeAndSeparate

public void escapeAndSeparate(java.lang.String str)

Escapes the separator symbol in the given string, appends the escaped bytes, then appends a separator symbol.

escapeAndSeparate

public void escapeAndSeparate(UniqueByteRepresentable ubr)

Escapes the separator symbol, appends the escaped bytes, then appends a separator symbol.

appendSeperator

public void appendSeperator()

Appends a special separator symbol to the accumulator.

appendPadded

public void appendPadded(int length,
                         byte[] bytes)

Pads the bytes with leading zero bytes to the desired length and then appends that to the accumulator.

Parameters:

length - the desired length of the appended byte string

bytes - the bytes to update

append

public void append(UniqueByteRepresentable ubr)

Updates the ByteAccumulator with bytes from a UniqueByteRepresentable.

append

public void append(byte singleByte)

Appends a single byte to the accumulator.

append

public void append(int integer)

Appends the given integer as four bytes to the accumulator.

append

public void append(java.lang.String str)

Appends the given String encoded as UTF-8 to the accumulator

compareTo

public int compareTo(ByteAccumulator byteAccumulator)

Specified by:

compareTo in interface java.lang.Comparable<ByteAccumulator>