iaik.security.ecc.ecdsa
Class ECDSAParameter

java.lang.Object
  iaik.security.ecc.ecdsa.ECDSAParameter

All Implemented Interfaces:

ECDSAParams

public class ECDSAParameter

extends java.lang.Object

implements ECDSAParams

Specifies the domain parameter for the ecc algorithms. This class doesn't perform a parameter validation. Subclasses may add this feature.

The domain parameters are:

the base point G, which is a generator of the subgroup

the order of the subgroup r

if known, the co-factor k which is #E / r. (#E defines the number of points on the elliptic curve) Use the provided parameter factories in this package to get an instance of this class.

Field Summary

protected java.math.BigInteger	c_ the output c of the SHA-1 based algorithm
protected static boolean	DEFAULT_OID_ENCODING Indicates if the domain parameters should be referenced by their oids (whenever possible) or explicitely specified.
static iaik.asn1.INTEGER	ECDSA_PARAMETER_VERSION The version field in the ECDSA ASN.1 structure
protected ECPoint	g_ the base point
protected java.math.BigInteger	k_ the cofactor = #E / r
protected java.lang.String	oid_ The Object Identifier for these domain parameters or null if not defined.
protected java.math.BigInteger	r_ the order of the base point g_
protected java.math.BigInteger	s_ the 160-bit input seed s to the SHA-1 based algorithm

Constructor Summary

protected	ECDSAParameter() Subclasses use this constructor
	ECDSAParameter(ECCParameterSpec parameter) Creates an ECDSA parameter set from the given ECC parameters.
	ECDSAParameter(ECCParameterSpec parameter, int coordinates) Creates an ECDSA parameter set from the given ECC parameters.

Method Summary

boolean	equals(java.lang.Object other) Compares 2 Parameters.
java.math.BigInteger	getC()
static boolean	getDefaultOIDEncoding() This method returns the default encoding policy (ECDSA domain parameters may be specified either explicitely or just as oid).
ECPoint	getG() The generator of the subgroub of order r.
java.math.BigInteger	getK()
java.lang.String	getOID()
java.math.BigInteger	getR()
java.math.BigInteger	getS()
int	hashCode() Returns the hash code of this ECDSAParameters.
static void	setDefaultOIDEncoding(boolean useOID) Sets the default parameter encoding.
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 }
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

ECDSA_PARAMETER_VERSION

public static final iaik.asn1.INTEGER ECDSA_PARAMETER_VERSION

The version field in the ECDSA ASN.1 structure

See Also:

toASN1Object()

DEFAULT_OID_ENCODING

protected static boolean DEFAULT_OID_ENCODING

Indicates if the domain parameters should be referenced by their oids (whenever possible) or explicitely specified. The default settings use reference by oid.

c_

protected java.math.BigInteger c_

the output c of the SHA-1 based algorithm

g_

protected ECPoint g_

the base point

k_

protected java.math.BigInteger k_

the cofactor = #E / r

oid_

protected java.lang.String oid_

The Object Identifier for these domain parameters or null if not defined.

r_

protected java.math.BigInteger r_

the order of the base point g_

s_

protected java.math.BigInteger s_

the 160-bit input seed s to the SHA-1 based algorithm

Constructor Detail

ECDSAParameter

public ECDSAParameter(ECCParameterSpec parameter)
               throws ECCException

Creates an ECDSA parameter set from the given ECC parameters. The default coordinates will be used.

Parameters:

parameter - the given parameters (must be a valid set of parameters !!)

Throws:

ECCException - if the ec group instantiation failed.

ECDSAParameter

public ECDSAParameter(ECCParameterSpec parameter,
                      int coordinates)
               throws ECCException

Creates an ECDSA parameter set from the given ECC parameters.

Parameters:

parameter - the given parameters (must be a valid set of parameters !!)

coordinates - decides, which type of coordinates to use. One of the constants defined in this class.

Throws:

ECCException - if the ec group instantiation failed.

ECDSAParameter

protected ECDSAParameter()

Subclasses use this constructor

Method Detail

getDefaultOIDEncoding

public static boolean getDefaultOIDEncoding()

This method returns the default encoding policy (ECDSA domain parameters may be specified either explicitely or just as oid). The start-up setting is rferencing parameters by their oid.

Returns:

true if the parameters are referenced by oid (whenever possible)

setDefaultOIDEncoding

public static void setDefaultOIDEncoding(boolean useOID)

Sets the default parameter encoding.

Parameters:

useOID - if true (default) the domain parameters are referenced by their oid (if possible)

equals

public boolean equals(java.lang.Object other)

Compares 2 Parameters.

Parameters:

other - the other parameter, must be an instance of this class otherwise false will be returned.

Returns:

true if the base points G and both orders r are equal.

getC

public java.math.BigInteger getC()

Specified by:

getC in interface ECDSAParams

Returns:

the output c of the SHA-1 based algorithm or null if unkonown

getG

public ECPoint getG()

Description copied from interface: ECDSAParams

The generator of the subgroub of order r.

Specified by:

getG in interface ECDSAParams

Returns:

the base point G of order r.

See Also:

ECDSAParams.getR()

getK

public java.math.BigInteger getK()

Specified by:

getK in interface ECDSAParams

Returns:

the cofactor k = #E / r or null if not known.

getOID

public java.lang.String getOID()

Specified by:

getOID in interface ECDSAParams

Returns:

the oid of this parameter set or null if unknown

getR

public java.math.BigInteger getR()

Specified by:

getR in interface ECDSAParams

Returns:

the order r of the base point G.

getS

public java.math.BigInteger getS()

Specified by:

getS in interface ECDSAParams

Returns:

the 160-bit input seed s to the SHA-1 based algorithm or null if unknown

hashCode

public int hashCode()

Returns the hash code of this ECDSAParameters.

Returns:

the hash code of this ECDSAParameters.

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
 }
 

toString

public java.lang.String toString()

Returns:

a human readable string containing the base point, the order r, and the elliptic curve.