iaik.security.mac

Class Poly1305

java.lang.Object

javax.crypto.MacSpi

iaik.security.mac.Poly1305

public class Poly1305
extends javax.crypto.MacSpi

This class implements the Poly1305 MAC as specified in RFC 8439

An application wishing to perform a MAC computation, at first has to create a Mac object by instantiating the Mac class through a proper getInstance factory method thereby specifying the MAC algorithm to be used. Calculating a MAC based on the Poly1305 algorithm, may be initiated as follows:

 Mac poly1305Mac = Mac.getInstance("Poly1305");
 

After properly initializing the Mac object with one entities secret key, the data to be processed is applied by one (or more) calls to the update methods. The MAC computation is concluded by using doFinal. If the data can be processed without calling any update method, doFinal can be called immediately after initializing the MAC object:

 poly1305Mac.init(secret_key);
 byte[] mac_data = poly1305Mac.doFinal(data);
 

After the MAC finally has been calculated, the Mac object automatically is reset for being able to be used for further MAC computations, either by using the same secret key again, or using a new key by properly re-initializing this Mac object.

Constructor Summary

Constructors

Constructor and Description
Poly1305() Default constructor.

Method Summary

Methods

Modifier and Type	Method and Description
protected byte[]	engineDoFinal() Calculate the MAC and reset this Mac object to be ready for further MAC calculations.
protected int	engineGetMacLength()
protected void	engineInit(java.security.Key key, java.security.spec.AlgorithmParameterSpec params) Initialize the Mac with the given 32 byte key.
protected void	engineReset() Reset this Mac object to be ready for a new MAC computation.
protected void	engineUpdate(byte input) Feed a single byte into the Mac.
protected void	engineUpdate(byte[] input, int offset, int len) Feed in a block of bytes into this Mac.

Methods inherited from class javax.crypto.MacSpi

clone, engineUpdate

Methods inherited from class java.lang.Object

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

Constructor Detail

Poly1305

public Poly1305()

Default constructor.

Applications shall not use this constructor. They shall use

 Mac.getInstance("Poly1305", "IAIK");
 

for creating a Mac object for the Poly1305 algorithm.

Throws:

NoSuchAlgorithmException - if there is no implementation for SHA

Method Detail

engineGetMacLength

protected int engineGetMacLength()

Specified by:

engineGetMacLength in class javax.crypto.MacSpi

Returns:

The MAC length in bytes

engineInit

protected void engineInit(java.security.Key key,
              java.security.spec.AlgorithmParameterSpec params)
                   throws java.security.InvalidKeyException,
                          java.security.InvalidAlgorithmParameterException

Initialize the Mac with the given 32 byte key.

Specified by:

engineInit in class javax.crypto.MacSpi

Parameters:

key - The MAC key.

params - This implementation ignores this parameter.

Throws:

java.security.InvalidKeyException

java.security.InvalidAlgorithmParameterException

engineUpdate

protected void engineUpdate(byte input)

Feed a single byte into the Mac.

For better performance, use engineUpdate(byte[], int, int) and feed in larger blocks.

Specified by:

engineUpdate in class javax.crypto.MacSpi

Parameters:

input - The input byte.

engineUpdate

protected void engineUpdate(byte[] input,
                int offset,
                int len)

Feed in a block of bytes into this Mac.

Specified by:

engineUpdate in class javax.crypto.MacSpi

Parameters:

input - The data buffer.

offset - The start index in the buffer.

len - The length of the data block in the buffer.

engineDoFinal

protected byte[] engineDoFinal()

Calculate the MAC and reset this Mac object to be ready for further MAC calculations.

Specified by:

engineDoFinal in class javax.crypto.MacSpi

Returns:

The MAC value.

engineReset

protected void engineReset()

Reset this Mac object to be ready for a new MAC computation.

Specified by:

engineReset in class javax.crypto.MacSpi