AlgorithmParameterGeneratorSpi (Java SE 22 & JDK 22)
Description: declaration: module: java.base, package: java.security, class: AlgorithmParameterGeneratorSpi
Keywords: java.security.AlgorithmParameterGeneratorSpi class

Module java.base
Package java.security

# Class AlgorithmParameterGeneratorSpi

java.lang.Object
java.security.AlgorithmParameterGeneratorSpi

public abstract class AlgorithmParameterGeneratorSpi extends Object
This class defines the Service Provider Interface (SPI) for the `AlgorithmParameterGenerator` class, which is used to generate a set of parameters to be used with a certain algorithm.

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

In case the client does not explicitly initialize the AlgorithmParameterGenerator (via a call to an `engineInit` method), each provider must supply (and document) a default initialization. See the Keysize Restriction sections of the JDK Providers document for information on the AlgorithmParameterGenerator defaults used by JDK providers. However, note that defaults may vary across different providers. Additionally, the default value for a provider may change in a future version. Therefore, it is recommended to explicitly initialize the `AlgorithmParameterGenerator` instead of relying on provider-specific defaults.

Since:
  1.2
See Also:
  - `AlgorithmParameterGenerator`
  - `AlgorithmParameters`
  - `AlgorithmParameterSpec`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `AlgorithmParameterGeneratorSpi()`
  Constructor for subclasses to call.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected abstract AlgorithmParameters`
  `engineGenerateParameters()`
  Generates the parameters.
  `protected abstract void`
  `engineInit(int size, SecureRandom random)`
  Initializes this parameter generator for a certain size and source of randomness.
  `protected abstract void`
  `engineInit(AlgorithmParameterSpec genParamSpec, SecureRandom random)`
  Initializes this parameter generator with a set of algorithm-specific parameter generation values.

  ### Methods declared in class java.lang.Object

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

- ## Constructor Details

  - ### AlgorithmParameterGeneratorSpi

    public AlgorithmParameterGeneratorSpi()
    Constructor for subclasses to call.

- ## Method Details

  - ### engineInit

    protected abstract void engineInit(int size, SecureRandom random)
    Initializes this parameter generator for a certain size and source of randomness.
    Parameters:
      `size` - the size (number of bits).
      `random` - the source of randomness.

  - ### engineInit

    protected abstract void engineInit(AlgorithmParameterSpec genParamSpec, SecureRandom random) throws InvalidAlgorithmParameterException
    Initializes this parameter generator with a set of algorithm-specific parameter generation values.
    Parameters:
      `genParamSpec` - the set of algorithm-specific parameter generation values.
      `random` - the source of randomness.
    Throws:
      `InvalidAlgorithmParameterException` - if the given parameter generation values are inappropriate for this parameter generator.

  - ### engineGenerateParameters

    protected abstract AlgorithmParameters engineGenerateParameters()
    Generates the parameters.
    Returns:
      the new `AlgorithmParameters` object.