public abstract class

KeyPairGeneratorSpi

extends Object
java.lang.Object
   ↳ java.security.KeyPairGeneratorSpi
Known Direct Subclasses
Known Indirect Subclasses

Class Overview

This class defines the Service Provider Interface (SPI) for the KeyPairGenerator class, which is used to generate pairs of public and private keys.

All the abstract methods in this class must be implemented by each cryptographic service provider who wishes to supply the implementation of a key pair generator for a particular algorithm.

In case the client does not explicitly initialize the KeyPairGenerator (via a call to an initialize method), each provider must supply (and document) a default initialization. For example, the Sun provider uses a default modulus size (keysize) of 1024 bits.

Summary

Public Constructors
KeyPairGeneratorSpi()
Public Methods
abstract KeyPair generateKeyPair()
Generates a key pair.
void initialize(AlgorithmParameterSpec params, SecureRandom random)
Initializes the key pair generator using the specified parameter set and user-provided source of randomness.
abstract void initialize(int keysize, SecureRandom random)
Initializes the key pair generator for a certain keysize, using the default parameter set.
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Inherited Methods
From class java.lang.Object

Public Constructors

public KeyPairGeneratorSpi ()

Public Methods

public abstract KeyPair generateKeyPair ()

Generates a key pair. Unless an initialization method is called using a KeyPairGenerator interface, algorithm-specific defaults will be used. This will generate a new key pair every time it is called.

Returns
  • the newly generated KeyPair

public void initialize (AlgorithmParameterSpec params, SecureRandom random)

Initializes the key pair generator using the specified parameter set and user-provided source of randomness.

This concrete method has been added to this previously-defined abstract class. (For backwards compatibility, it cannot be abstract.) It may be overridden by a provider to initialize the key pair generator. Such an override is expected to throw an InvalidAlgorithmParameterException if a parameter is inappropriate for this key pair generator. If this method is not overridden, it always throws an UnsupportedOperationException.

Parameters
params the parameter set used to generate the keys.
random the source of randomness for this generator.
Throws
InvalidAlgorithmParameterException if the given parameters are inappropriate for this key pair generator.

public abstract void initialize (int keysize, SecureRandom random)

Initializes the key pair generator for a certain keysize, using the default parameter set.

Parameters
keysize the keysize. This is an algorithm-specific metric, such as modulus length, specified in number of bits.
random the source of randomness for this generator.
Throws
InvalidParameterException if the keysize is not supported by this KeyPairGeneratorSpi object.