iaik.security.md

Class SHA256Spi

java.lang.Object

java.security.MessageDigestSpi

iaik.security.md.SHA256Spi

All Implemented Interfaces:

java.lang.Cloneable

public class SHA256Spi
extends java.security.MessageDigestSpi
implements java.lang.Cloneable

Wraps around the IAIK-JCE SHA-256 implementation for fixing a JSSE MessageDigest Cloneable bug.

Some versions of JSSE (e.g. Java 11) may contain a bug (https://bugs.openjdk.java.net/browse/JDK-8214098) that may cause a TLS handshake to fail with an UnsupportedOperationException if an MessageDigest engine is used that implements the Cloneable interface and is extended from the java.security.MessageDigest class.

This class belongs to the "subsidiary" IAIK-MD provider and wraps around the SHA-256 MessageDigest implementation of the IAIK provider but is extended from the MessageDigestSpi class and therefore allows to use the IAIK provider with affected JSSE versions when installing the IAIK-MD provider as first provider in front of the IAIK provider:

 Security.insertProviderAt(new IAIKMD(), 1);
 Security.insertProviderAt(new IAIK(), 2);
 

See Also:

SHA256

Constructor Summary

Constructors

Constructor and Description
SHA256Spi() Default constructor.

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.Object	clone() Returns a clone of this message digest that can be used independently of this instance.
protected byte[]	engineDigest() Finishes the message digest computation.
protected void	engineReset() Resets this MessageDigest engine.
protected void	engineUpdate(byte input) Updates the message digest computation with the given data byte.
protected void	engineUpdate(byte[] input, int offset, int len) Updates the message digest computation with the given data.

Methods inherited from class java.security.MessageDigestSpi

engineDigest, engineGetDigestLength, engineUpdate

Methods inherited from class java.lang.Object

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

Constructor Detail

SHA256Spi

public SHA256Spi()

Default constructor.

Shall not be used by application. Applications shall use MessageDigest.getInstance() for creating a MessageDigest engine and shall use the MessageDigest engines of the IAIK provider:

 MessageDigest md = MessageDigest.getInstance("SHA-256", "IAIK");
 

Method Detail

clone

public java.lang.Object clone()

Returns a clone of this message digest that can be used independently of this instance.

Returns:

A clone of this message digest.

engineUpdate

protected void engineUpdate(byte input)

Updates the message digest computation with the given data byte.

Specified by:

engineUpdate in class java.security.MessageDigestSpi

Parameters:

input - the data byte

engineUpdate

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

Updates the message digest computation with the given data.

Specified by:

engineUpdate in class java.security.MessageDigestSpi

Parameters:

input - the input data

offset - the start offset in the input array

len - the len of the data

engineDigest

protected byte[] engineDigest()

Finishes the message digest computation.

Specified by:

engineDigest in class java.security.MessageDigestSpi

Returns:

the message digest value

engineReset

protected void engineReset()

Resets this MessageDigest engine.

Specified by:

engineReset in class java.security.MessageDigestSpi