iaik.security.cipher

Class GCMParameterSpec

java.lang.Object

iaik.security.cipher.GCMParameterSpec

All Implemented Interfaces:

java.security.spec.AlgorithmParameterSpec

Direct Known Subclasses:

GCMCMSParameterSpec

public class GCMParameterSpec
extends java.lang.Object
implements java.security.spec.AlgorithmParameterSpec

GCM (Galois/Counter mode) parameter specification.

This class holds the necessary inputs (additional data, nonce, MAC length or MAC block) for the encryption and decryption with the GCM mode.

If no parameters are passed to the constructor the IV is generated and the macLength is set to 12. If only macLength shall be specified, nonce and additional data have to be null.

Version:

File Revision 2

See Also:

AlgorithmParameterSpec

Constructor Summary

Constructors

Constructor and Description
GCMParameterSpec() Creates a GCM Parameter specification with default values.
GCMParameterSpec(byte[] aaData, byte[] nonce) Creates a GCM Parameter specification with the given additional data and nonce.
GCMParameterSpec(byte[] aaData, byte[] nonce, byte[] macBlock) Creates a GCM Parameter specification with the given additional data, nonce and MAC block.
GCMParameterSpec(byte[] aaData, byte[] nonce, int macLen) Creates a GCM Parameter specification with the given additional data, nonce and MAC length.

Method Summary

Methods

Modifier and Type	Method and Description
byte[]	getAAD() Returns the associated data used for authentication.
byte[]	getMac() Returns the authentication block used to authenticate the plaintext and additional data.
int	getMacLength() Returns the number of bytes used for the MAC block.
byte[]	getNonce() Returns the used bytes to generate the IV.
void	setMacLength(int macLength) Set number of bytes that should be used as MAC.

Methods inherited from class java.lang.Object

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

Constructor Detail

GCMParameterSpec

public GCMParameterSpec(byte[] aaData,
                byte[] nonce,
                int macLen)
                 throws java.security.InvalidAlgorithmParameterException

Creates a GCM Parameter specification with the given additional data, nonce and MAC length. This constructor shall be used to specify algorithm parameters for encryption. The MAC block is null. (No MAC block must be specified for encryption.)

Parameters:

aaData - the additional data that is authenticated

nonce - bytes used to generate the IV

macLen - number of bytes used as MAC

Throws:

java.security.InvalidAlgorithmParameterException

GCMParameterSpec

public GCMParameterSpec(byte[] aaData,
                byte[] nonce,
                byte[] macBlock)
                 throws java.security.InvalidAlgorithmParameterException

Creates a GCM Parameter specification with the given additional data, nonce and MAC block. This constructor shall be used to specify the algorithm parameters for decryption. Nonce and MAC block must be set for decryption.

Parameters:

aaData - the additional data that is authenticated

nonce - bytes used to generate the IV

macBlock - the MAC block used to verify authenticity

Throws:

java.security.InvalidAlgorithmParameterException

GCMParameterSpec

public GCMParameterSpec(byte[] aaData,
                byte[] nonce)
                 throws java.security.InvalidAlgorithmParameterException

Creates a GCM Parameter specification with the given additional data and nonce. MAC length will be set to 12 bytes.

Parameters:

aaData - the additional data that is authenticated

nonce - bytes used to generate the IV

Throws:

java.security.InvalidAlgorithmParameterException

GCMParameterSpec

public GCMParameterSpec()
                 throws java.security.InvalidAlgorithmParameterException

Creates a GCM Parameter specification with default values. The nonce will be generated and the MAC length will be set to 12 bytes.

Throws:

java.security.InvalidAlgorithmParameterException

Method Detail

setMacLength

public void setMacLength(int macLength)
                  throws java.security.InvalidAlgorithmParameterException

Set number of bytes that should be used as MAC.

Throws:

java.security.InvalidAlgorithmParameterException - if the specified MAC length is not valid

getAAD

public byte[] getAAD()

Returns the associated data used for authentication.

Returns:

associated data

getMacLength

public int getMacLength()

Returns the number of bytes used for the MAC block.

Returns:

number of bytes of the authentication block

getNonce

public byte[] getNonce()

Returns the used bytes to generate the IV.

Returns:

bytes used to generate the IV

getMac

public byte[] getMac()

Returns the authentication block used to authenticate the plaintext and additional data.

Returns:

macBlock