iaik.security.ec.common

Class ECParameterSpec

java.lang.Object

java.security.spec.ECParameterSpec

iaik.security.ec.common.ECParameterSpec

All Implemented Interfaces:

Cloneable, AlgorithmParameterSpec

Direct Known Subclasses:

ECDHParameterSpec, EdParameterSpec

public class ECParameterSpec
extends ECParameterSpec
implements Cloneable

This class specifies the set of domain parameters for use with the IAIK ECCelerate™ library.

References:

[1] ANSI X9.62-2005, "American National Standard for Financial Services - The Elliptic Curve Digital Signature Algorithm (ECDSA)" , ASC X9, November 2005.

Author:

Christian Hanser, Sebastian Ramacher

See Also:

AlgorithmParameterSpec, ECStandardizedParameterFactory

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ECParameterSpec(EllipticCurve curve, ECPoint g, BigInteger order, int h, iaik.asn1.structures.AlgorithmID hashAlgorithm, String oid) Creates a new ECParameterSpec instance.
protected	ECParameterSpec(EllipticCurve curve, ECPoint g, BigInteger order, int h, iaik.asn1.structures.AlgorithmID hashAlgorithm, String oid, BigInteger endomorphismAux0, BigInteger endomorphismAux1) Creates a new ECParameterSpec instance.

Method Summary

Modifier and Type	Method and Description
ECParameterSpec	clone() Creates a clone of this ECParameterSpec.
static ECParameterSpec	decode(iaik.asn1.ASN1Object parameters) Creates a new ECParameterSpec object from the specified ASN.1 structure.
boolean	equals(Object obj)
EllipticCurve	getCurve()
BigInteger	getEndomorphismAux0() Returns the first auxiliary value for various endomorphisms.
BigInteger	getEndomorphismAux1() Returns the first auxiliary value for various endomorphisms.
iaik.asn1.structures.AlgorithmID	getHashAlgorithmID() Returns the algorithm identifier of the hash algorithm that was used to create the curve and/or the generator.
String	getOID() Returns the object identifier of the specified curve.
static ECParameterSpec	getParameterSpec(ECParameterSpec params) Returns a new ECParameterSpec instance.
static ECParameterSpec	getParameterSpec(EllipticCurve curve, ECPoint g, BigInteger order, int h, iaik.asn1.structures.AlgorithmID hashAlgorithm, String oid) Returns a new ECParameterSpec instance.
int	hashCode()
static void	setDefaultOIDEncoding(boolean enable) Allows the user to set, whether domain parameters should be encoded as OID wherever possible, by default.
iaik.asn1.ASN1Object	toASN1Object() If the default encoding is set to oid encoding this method just returns the ObjectID otherwise the following ASN.1 structure:
String	toString() Returns a human readable String containing the base point, the order, and the elliptic curve.
static boolean	usesDefaultOIDEncoding() Returns true, if OID encoding is switched on.

Methods inherited from class java.security.spec.ECParameterSpec

getCofactor, getGenerator, getOrder

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ECParameterSpec

protected ECParameterSpec(EllipticCurve curve,
                          ECPoint g,
                          BigInteger order,
                          int h,
                          iaik.asn1.structures.AlgorithmID hashAlgorithm,
                          String oid)

Creates a new ECParameterSpec instance.

Parameters:

curve - the elliptic curve

g - the generator

order - the order of the generator

h - the cofactor

hashAlgorithm - the hashAlgorithm that was used to generate the curve and/or the generator

oid - a String representing the object identifier of the curve

ECParameterSpec

protected ECParameterSpec(EllipticCurve curve,
                          ECPoint g,
                          BigInteger order,
                          int h,
                          iaik.asn1.structures.AlgorithmID hashAlgorithm,
                          String oid,
                          BigInteger endomorphismAux0,
                          BigInteger endomorphismAux1)

Creates a new ECParameterSpec instance.

Parameters:

curve - the elliptic curve

g - the generator

order - the order of the generator

h - the cofactor

hashAlgorithm - the hashAlgorithm that was used to generate the curve and/or the generator

oid - a String representing the object identifier of the curve

endomorphismAux0 - the auxiliary value for different endomorphisms

endomorphismAux1 - the auxiliary value for different endomorphisms

Method Detail

getParameterSpec

public static ECParameterSpec getParameterSpec(EllipticCurve curve,
                                               ECPoint g,
                                               BigInteger order,
                                               int h,
                                               iaik.asn1.structures.AlgorithmID hashAlgorithm,
                                               String oid)
                                        throws InvalidCurveParameterSpecException

Returns a new ECParameterSpec instance.

Parameters:

curve - the elliptic curve

g - the generator of the curve group

order - the order of the generator

h - the cofactor of the curve

hashAlgorithm - the hashAlgorithm that was used to generate the curve and/or the generator

oid - a String representing the object identifier of the curve

Returns:

an IAIK parameter spec for the given curve

Throws:

InvalidCurveParameterSpecException - in case the curve parameter validation failed

getParameterSpec

public static ECParameterSpec getParameterSpec(ECParameterSpec params)
                                        throws InvalidCurveParameterSpecException

Returns a new ECParameterSpec instance.

Parameters:

params - a JDK parameter spec

Returns:

an IAIK parameter spec for the given curve

Throws:

InvalidCurveParameterSpecException - in case the curve parameter validation failed

getCurve

public EllipticCurve getCurve()

Overrides:

getCurve in class ECParameterSpec

getHashAlgorithmID

public iaik.asn1.structures.AlgorithmID getHashAlgorithmID()

Returns the algorithm identifier of the hash algorithm that was used to create the curve and/or the generator.

Returns:

an algorithm identifier

getOID

public String getOID()

Returns the object identifier of the specified curve.

Returns:

a String holding the object identifier

toASN1Object

public iaik.asn1.ASN1Object toASN1Object()

If the default encoding is set to oid encoding this method just returns the ObjectID otherwise the following ASN.1 structure:

 ECParameters  ::= SEQUENCE {          -- Elliptic curve parameters
  version   ECPVer,
  fieldID   FieldID,
  curve     Curve,
  base      ECPoint,                   -- Base point G
  order     INTEGER,                   -- Order n of the base point
  cofactor  INTEGER  OPTIONAL,         -- The integer h = #E(Fq)/n
  hash      HashAlgorithm OPTIONAL     -- The hash algorithm that was used to generate the curve and/or the generator
 }
 

Returns:

an ASN1Object instance

decode

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

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

Parameters:

parameters - the ASN.1 object

Returns:

an ASN1Object instance

Throws:

IllegalArgumentException - if the ASN.1 structure doen't contain valid parameters

See Also:

toASN1Object()

setDefaultOIDEncoding

public static void setDefaultOIDEncoding(boolean enable)

Allows the user to set, whether domain parameters should be encoded as OID wherever possible, by default.

Parameters:

enable - if true, it enables the OID encoding of parameters

usesDefaultOIDEncoding

public static boolean usesDefaultOIDEncoding()

Returns true, if OID encoding is switched on.

Returns:

true, if OID encoding is switched on

toString

public String toString()

Returns a human readable String containing the base point, the order, and the elliptic curve.

Overrides:

toString in class Object

Returns:

a human readable String containing the base point, the order, and the elliptic curve

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

getEndomorphismAux0

public BigInteger getEndomorphismAux0()

Returns the first auxiliary value for various endomorphisms.

Returns:

the first auxiliary value for various endomorphisms

getEndomorphismAux1

public BigInteger getEndomorphismAux1()

Returns the first auxiliary value for various endomorphisms.

Returns:

the second auxiliary value for various endomorphisms

clone

public ECParameterSpec clone()

Creates a clone of this ECParameterSpec.

The clone is not deep, i.e. the fields of this ECParameterSpec are only copied, not cloned.

Overrides:

clone in class Object

Returns:

the ECParameterSpec clone