Package zeroecho.core.alg.xdh

Class XdhKeyGenBuilder

java.lang.Object

zeroecho.core.alg.xdh.XdhKeyGenBuilder

All Implemented Interfaces:

AsymmetricKeyBuilder<XdhSpec>

public final class XdhKeyGenBuilder
extends Object
implements AsymmetricKeyBuilder<XdhSpec>

KeyPair generator for XDH curves using the JCA KeyPairGenerator SPI.

This builder produces XDH key pairs (e.g., X25519, X448 depending on the runtime provider) by instantiating a JCA KeyPairGenerator with the algorithm name supplied by XdhSpec.kpgName().

Design and scope

• Generation only: This builder supports key generation. Public/private import is intentionally unsupported and will throw UnsupportedOperationException.
• Provider resolution: The default JCA provider selection is used. If a specific provider is required, supply or register one that exposes the requested XDH algorithm name.
• Thread-safety: Instances are stateless and thread-safe.

Example

 // Generate an X25519 key pair
 XdhKeyGenBuilder builder = new XdhKeyGenBuilder();
 KeyPair kp = builder.generateKeyPair(XdhSpec.X25519);
 PublicKey pub = kp.getPublic();
 PrivateKey prv = kp.getPrivate();
 

Since:

1.0

Constructor Summary

Constructors

Constructor	Description
XdhKeyGenBuilder()

Method Summary

Modifier and Type	Method	Description
KeyPair	generateKeyPair(XdhSpec spec)	Generates a new XDH key pair using the JCA KeyPairGenerator.
PrivateKey	importPrivate(XdhSpec spec)	Not supported: importing XDH private keys is outside the scope of this builder.
PublicKey	importPublic(XdhSpec spec)	Not supported: importing XDH public keys is outside the scope of this builder.

Methods inherited from class java.lang.Object

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

Constructor Details

XdhKeyGenBuilder

public XdhKeyGenBuilder()

Method Details

generateKeyPair

public KeyPair generateKeyPair(XdhSpec spec)
                        throws GeneralSecurityException

Generates a new XDH key pair using the JCA KeyPairGenerator.

The generator instance is obtained via KeyPairGenerator.getInstance(String) with XdhSpec.kpgName() (for example, "XDH" or "X25519"). No additional initialization parameters are supplied; providers are expected to choose safe defaults for the requested curve.

Specified by:

generateKeyPair in interface AsymmetricKeyBuilder<XdhSpec>

Parameters:

spec - the XDH key specification indicating which XDH variant to use (e.g., X25519)

Returns:

a freshly generated KeyPair for the requested XDH variant

Throws:

GeneralSecurityException - if the algorithm is not available, the provider rejects the request, or key generation fails

importPublic

public PublicKey importPublic(XdhSpec spec)

Not supported: importing XDH public keys is outside the scope of this builder.

Use a dedicated import builder or provider-specific utilities if you need to wrap encoded public keys.

Specified by:

importPublic in interface AsymmetricKeyBuilder<XdhSpec>

Parameters:

spec - the XDH key specification

Returns:

never returns normally

Throws:

UnsupportedOperationException - always thrown to indicate unsupported operation

importPrivate

public PrivateKey importPrivate(XdhSpec spec)

Not supported: importing XDH private keys is outside the scope of this builder.

Use a dedicated import builder or provider-specific utilities if you need to wrap encoded private keys.

Specified by:

importPrivate in interface AsymmetricKeyBuilder<XdhSpec>

Parameters:

spec - the XDH key specification

Returns:

never returns normally

Throws:

UnsupportedOperationException - always thrown to indicate unsupported operation