iaik.security.ec.common

Class X963KDFParameterSpec

java.lang.Object

iaik.security.ec.common.X963KDFParameterSpec

All Implemented Interfaces:

KDFParameterSpec, AlgorithmParameterSpec

public final class X963KDFParameterSpec
extends Object
implements KDFParameterSpec

Parameter class for key derivation functions (KDFs) as specified in [1] and [2].

References:

[1] ANSI X9.63-2001, "American National Standard for Financial Services - Key Agreement and Key Transport Using Elliptic Curve Cryptography" , November 2001.

[2] Certicom Research. 2009. Standards for Efficient Cryptography - SEC 1: Elliptic Curve Cryptography v2.0

Author:

Christian Hanser

See Also:

ECDHParameterSpec, ECDHKeyAgreement, ECDHWithCofactorKeyAgreement

Field Summary

Fields

Modifier and Type	Field and Description
static iaik.asn1.ObjectID	OID object identifier for the ASN.1 structure

Constructor Summary

Constructors

Constructor and Description
X963KDFParameterSpec(iaik.asn1.structures.AlgorithmID md) Creates a new parameter spec object without a key length and shared information.
X963KDFParameterSpec(iaik.asn1.structures.AlgorithmID md, byte[] sharedInformation) Creates a new parameter spec object without a key length.
X963KDFParameterSpec(iaik.asn1.structures.AlgorithmID md, int keyLength) Creates a new parameter spec object without adding shared information.
X963KDFParameterSpec(iaik.asn1.structures.AlgorithmID md, int keyLength, byte[] sharedInformation) Creates a new parameter spec object with shared information.
X963KDFParameterSpec(iaik.asn1.structures.AlgorithmID md, int keyLength, X963ASN1SharedInfo sharedInformation) Creates a new parameter spec object with shared information.

Method Summary

Modifier and Type	Method and Description
static X963KDFParameterSpec	decode(iaik.asn1.ASN1Object parameters) Creates a new X963KDFParameterSpec object from the specified ASN.1 structure.
boolean	equals(Object obj)
int	getKeyLength() Returns the length of the key to be generated.
int	getMaxHashBitLength() The maximum bitsize of the data to be hashed.
MessageDigest	getMessageDigest() Returns the message digest that will be used to generate the keying data.
byte[]	getSharedInformation() Returns the optional shared information.
int	hashCode()
iaik.asn1.ASN1Object	toASN1Object() This method returns the following ASN.1 structure (according to [2]):

Methods inherited from class java.lang.Object

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

Field Detail

OID

public static final iaik.asn1.ObjectID OID

object identifier for the ASN.1 structure

Constructor Detail

X963KDFParameterSpec

public X963KDFParameterSpec(iaik.asn1.structures.AlgorithmID md)

Creates a new parameter spec object without a key length and shared information.

Parameters:

md - the message digest that will be used to derive the keying data

X963KDFParameterSpec

public X963KDFParameterSpec(iaik.asn1.structures.AlgorithmID md,
                            byte[] sharedInformation)

Creates a new parameter spec object without a key length.

Parameters:

md - the message digest that will be used to derive the keying data

sharedInformation - an octet string holding the shared information

X963KDFParameterSpec

public X963KDFParameterSpec(iaik.asn1.structures.AlgorithmID md,
                            int keyLength)

Creates a new parameter spec object without adding shared information.

Parameters:

md - the message digest that will be used to derive the keying data

keyLength - the length of the key in bits

X963KDFParameterSpec

public X963KDFParameterSpec(iaik.asn1.structures.AlgorithmID md,
                            int keyLength,
                            byte[] sharedInformation)

Creates a new parameter spec object with shared information.

Parameters:

md - the message digest that will be used to derive the keying data

keyLength - the length of the key in bits

sharedInformation - an octet string holding the shared information

X963KDFParameterSpec

public X963KDFParameterSpec(iaik.asn1.structures.AlgorithmID md,
                            int keyLength,
                            X963ASN1SharedInfo sharedInformation)

Creates a new parameter spec object with shared information.

Parameters:

md - the message digest that will be used to derive the keying data

keyLength - the length of the key in bits

sharedInformation - an ASN1SharedInfo holding the non-encoded shared information

Method Detail

getMessageDigest

public MessageDigest getMessageDigest()

Returns the message digest that will be used to generate the keying data.

Returns:

the message digest

getKeyLength

public int getKeyLength()

Returns the length of the key to be generated.

Returns:

the length of the key in bits

getSharedInformation

public byte[] getSharedInformation()

Returns the optional shared information.

Returns:

either an octet-string holding the shared information or null if no shared information is available

getMaxHashBitLength

public int getMaxHashBitLength()

The maximum bitsize of the data to be hashed.

Returns:

the maximum bitsize of the data to be hashed.

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toASN1Object

public iaik.asn1.ASN1Object toASN1Object()

This method returns the following ASN.1 structure (according to [2]):

 KeyDerivationFunction ::= AlgorithmIdentifier {{KDFSet}}

 where

 KDFSet ALGORITHM ::= {
     {OID x9-63-kdf PARMS HashAlgorithm }
 }
 

Specified by:

toASN1Object in interface KDFParameterSpec

Returns:

an ASN1Object instance

decode

public static X963KDFParameterSpec decode(iaik.asn1.ASN1Object parameters)

Creates a new X963KDFParameterSpec object from the specified ASN.1 structure.

Parameters:

parameters - the ASN.1 object

Returns:

an X963KDFParameterSpec instance