com.ibm.crypto.fips.provider

Class GhashMD

java.lang.Object

java.security.MessageDigestSpi

com.ibm.crypto.fips.provider.GhashMD

public final class GhashMD
extends java.security.MessageDigestSpi

Implementation of the GHASH function from NIST SP 800-38D. http://csrc.nist.gov/publications/nistpubs/800-38D/SP-800-38D.pdf

Constructor Summary

Constructors

Constructor and Description
GhashMD() Standard constructor.

Method Summary

Methods

Modifier and Type	Method and Description
protected byte[]	engineDigest() Completes the digest by padding and running the final compression.
protected int	engineDigest(byte[] buf, int offset, int len) Completes the digest by padding and running the final compression.
protected int	engineGetDigestLength() Return the digest length in bytes
protected void	engineReset() Returns the message digest object to its original state.
protected void	engineUpdate(byte input) Adds a byte of data to be processed by the message digest algorithm.
protected void	engineUpdate(byte[] input, int offset, int len) Adds len bytes of data from input to be processed by the message digest algorithm.
void	setupH(byte[] h)

Methods inherited from class java.security.MessageDigestSpi

clone, engineUpdate

Methods inherited from class java.lang.Object

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

Constructor Detail

GhashMD

public GhashMD()

Standard constructor.

Method Detail

engineGetDigestLength

protected int engineGetDigestLength()

Return the digest length in bytes

Overrides:

engineGetDigestLength in class java.security.MessageDigestSpi

Returns:

the digest length in bytes

engineDigest

protected byte[] engineDigest()

Completes the digest by padding and running the final compression. Resulting digest is returned.

Specified by:

engineDigest in class java.security.MessageDigestSpi

Returns:

byte[] - the resulting message digest

engineDigest

protected int engineDigest(byte[] buf,
               int offset,
               int len)
                    throws java.security.DigestException

Completes the digest by padding and running the final compression. The resultant message digest is then placed in the byte array buf starting at position offset.

Overrides:

engineDigest in class java.security.MessageDigestSpi

Parameters:

buf - - byte array for storing the message digest

offset - - beginning index of the digest in buf

len - - max number of bytes of digest accepted, must be greater than digest size

Returns:

int - length of message digest written into buf

Throws:

java.security.DigestException - - if there is not enough room in buf for the full message digest

engineReset

protected void engineReset()

Returns the message digest object to its original state.

Specified by:

engineReset in class java.security.MessageDigestSpi

engineUpdate

protected void engineUpdate(byte input)

Adds a byte of data to be processed by the message digest algorithm.

Specified by:

engineUpdate in class java.security.MessageDigestSpi

Parameters:

input - - data to be processed

engineUpdate

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

Adds len bytes of data from input to be processed by the message digest algorithm.

Specified by:

engineUpdate in class java.security.MessageDigestSpi

Parameters:

input - - array that data bytes are taken from

offset - - index of input to start taking data from

len - - number of bytes to be processed

setupH

public void setupH(byte[] h)