javax.crypto.spec.DHParameterSpec Maven / Gradle / Ivy
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package javax.crypto.spec;
import java.math.BigInteger;
import java.security.spec.AlgorithmParameterSpec;
/**
* This class specifies the set of parameters used with the Diffie-Hellman
* algorithm, as specified in PKCS #3: Diffie-Hellman Key-Agreement
* Standard.
*
* A central authority generates parameters and gives them to the two
* entities seeking to generate a secret key. The parameters are a prime
* p, a base g, and optionally the length
* in bits of the private value, l.
*
*
It is possible that more than one instance of parameters may be
* generated by a given central authority, and that there may be more than
* one central authority. Indeed, each individual may be its own central
* authority, with different entities having different parameters.
*
*
Note that this class does not perform any validation on specified
* parameters. Thus, the specified values are returned directly even
* if they are null.
*
* @author Jan Luehe
*
* @see javax.crypto.KeyAgreement
* @since 1.4
*/
public class DHParameterSpec implements AlgorithmParameterSpec {
// The prime modulus
private BigInteger p;
// The base generator
private BigInteger g;
// The size in bits of the random exponent (private value) (optional)
private int l;
/**
* Constructs a parameter set for Diffie-Hellman, using a prime modulus
* p and a base generator g.
*
* @param p the prime modulus
* @param g the base generator
*/
public DHParameterSpec(BigInteger p, BigInteger g) {
this.p = p;
this.g = g;
this.l = 0;
}
/**
* Constructs a parameter set for Diffie-Hellman, using a prime modulus
* p, a base generator g,
* and the size in bits, l, of the random exponent
* (private value).
*
* @param p the prime modulus
* @param g the base generator
* @param l the size in bits of the random exponent (private value)
*/
public DHParameterSpec(BigInteger p, BigInteger g, int l) {
this.p = p;
this.g = g;
this.l = l;
}
/**
* Returns the prime modulus p.
*
* @return the prime modulus p
*/
public BigInteger getP() {
return this.p;
}
/**
* Returns the base generator g.
*
* @return the base generator g
*/
public BigInteger getG() {
return this.g;
}
/**
* Returns the size in bits, l, of the random exponent
* (private value).
*
* @return the size in bits, l, of the random exponent
* (private value), or 0 if this size has not been set
*/
public int getL() {
return this.l;
}
}