org.spongycastle.asn1.x9

Class DomainParameters

java.lang.Object

org.spongycastle.asn1.ASN1Object

org.spongycastle.asn1.x9.DomainParameters

All Implemented Interfaces:

ASN1Encodable, Encodable

public class DomainParameters
extends ASN1Object

X9.44 Diffie-Hellman domain parameters.

    DomainParameters ::= SEQUENCE {
       p                INTEGER,           -- odd prime, p=jq +1
       g                INTEGER,           -- generator, g
       q                INTEGER,           -- factor of p-1
       j                INTEGER OPTIONAL,  -- subgroup factor, j>= 2
       validationParams  ValidationParams OPTIONAL
    }
 

Constructor Summary

Constructors

Constructor and Description
DomainParameters(java.math.BigInteger p, java.math.BigInteger g, java.math.BigInteger q, java.math.BigInteger j, ValidationParams validationParams) Base constructor - the full domain parameter set.

Method Summary

Modifier and Type	Method and Description
java.math.BigInteger	getG() Return the generator of the multiplicative subgroup of order g.
static DomainParameters	getInstance(ASN1TaggedObject obj, boolean explicit) Return a DomainParameters object from the passed in tagged object.
static DomainParameters	getInstance(java.lang.Object obj) Return a DomainParameters object from the passed in object.
java.math.BigInteger	getJ() Return the value that satisfies the equation p = jq+1 (if present).
java.math.BigInteger	getP() Return the prime p defining the Galois field.
java.math.BigInteger	getQ() Return q, the prime factor of p - 1
ValidationParams	getValidationParams() Return the validation parameters for this set (if present).
ASN1Primitive	toASN1Primitive() Return an ASN.1 primitive representation of this object.

Methods inherited from class org.spongycastle.asn1.ASN1Object

equals, getEncoded, getEncoded, hasEncodedTagValue, hashCode, toASN1Object

Methods inherited from class java.lang.Object

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

Constructor Detail

DomainParameters

public DomainParameters(java.math.BigInteger p,
                        java.math.BigInteger g,
                        java.math.BigInteger q,
                        java.math.BigInteger j,
                        ValidationParams validationParams)

Base constructor - the full domain parameter set.

Parameters:

p - the prime p defining the Galois field.

g - the generator of the multiplicative subgroup of order g.

q - specifies the prime factor of p - 1

j - optionally specifies the value that satisfies the equation p = jq+1

validationParams - parameters for validating these domain parameters.

Method Detail

getInstance

public static DomainParameters getInstance(ASN1TaggedObject obj,
                                           boolean explicit)

Return a DomainParameters object from the passed in tagged object.

Parameters:

obj - a tagged object.

explicit - true if the contents of the object is explictly tagged, false otherwise.

Returns:

a DomainParameters

getInstance

public static DomainParameters getInstance(java.lang.Object obj)

Return a DomainParameters object from the passed in object.

Parameters:

obj - an object for conversion or a byte[].

Returns:

a DomainParameters

getP

public java.math.BigInteger getP()

Return the prime p defining the Galois field.

Returns:

the prime p.

getG

public java.math.BigInteger getG()

Return the generator of the multiplicative subgroup of order g.

Returns:

the generator g.

getQ

public java.math.BigInteger getQ()

Return q, the prime factor of p - 1

Returns:

q value

getJ

public java.math.BigInteger getJ()

Return the value that satisfies the equation p = jq+1 (if present).

Returns:

j value or null.

getValidationParams

public ValidationParams getValidationParams()

Return the validation parameters for this set (if present).

Returns:

validation parameters, or null if absent.

toASN1Primitive

public ASN1Primitive toASN1Primitive()

Return an ASN.1 primitive representation of this object.

Specified by:

toASN1Primitive in interface ASN1Encodable

Specified by:

toASN1Primitive in class ASN1Object

Returns:

a DERSequence containing the parameter values.