com.ibm.crypto.fips.provider

Class GCTR

java.lang.Object

com.ibm.crypto.fips.provider.GCTR

All Implemented Interfaces:

GCMConstants

public class GCTR
extends java.lang.Object
implements GCMConstants

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

Author:

Kevin Driver, Ben Hawks

Field Summary

Fields

Modifier and Type	Field and Description
static int	AES_BLOCK_SIZE
static int[]	AES_KEYSIZES

Fields inherited from interface com.ibm.crypto.fips.provider.GCMConstants

DEFAULT_TAG_LENGTH, GCM_TAG_LENGTHS

Constructor Summary

Constructors

Constructor and Description
GCTR()

Method Summary

Methods

Modifier and Type	Method and Description
byte[]	gcm_ad(byte[] IV, byte[] C, byte[] A, byte[] T) Performs an AES GCM decryption.
byte[]	gcm_ae(byte[] IV, byte[] P, byte[] A, byte[] C_out) Performs an AES GCM encryption.
void	initKey(java.security.Key k) Initializes the key.
void	setT(int t) Sets the length of the tag in bits.

Methods inherited from class java.lang.Object

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

Field Detail

AES_BLOCK_SIZE

public static final int AES_BLOCK_SIZE

See Also:

Constant Field Values

AES_KEYSIZES

public static final int[] AES_KEYSIZES

Constructor Detail

GCTR

public GCTR()

Method Detail

initKey

public void initKey(java.security.Key k)
             throws java.security.InvalidKeyException

Initializes the key.

Parameters:

k - the key

Throws:

java.security.InvalidKeyException

setT

public void setT(int t)

Sets the length of the tag in bits.

Parameters:

t - the length of the tag in bits

gcm_ae

public byte[] gcm_ae(byte[] IV,
            byte[] P,
            byte[] A,
            byte[] C_out)
              throws javax.crypto.IllegalBlockSizeException

Performs an AES GCM encryption.

Parameters:

IV - initialization vector

P - plain text

A - additional authentication data

C_out - cipher text

Returns:

the tag

Throws:

javax.crypto.IllegalBlockSizeException

gcm_ad

public byte[] gcm_ad(byte[] IV,
            byte[] C,
            byte[] A,
            byte[] T)
              throws javax.crypto.IllegalBlockSizeException,
                     java.security.InvalidAlgorithmParameterException,
                     javax.crypto.BadPaddingException

Performs an AES GCM decryption.

Parameters:

IV - initialization vector

C - cipher text

A - additional authentication data

T - tag

Returns:

the plain text

Throws:

javax.crypto.IllegalBlockSizeException

java.security.InvalidAlgorithmParameterException

javax.crypto.BadPaddingException