Class KeyGeneratorSpi

java.lang.Object
javax.crypto.KeyGeneratorSpi
public abstract class KeyGeneratorSpi extends Object
This class defines the Service Provider Interface (SPI) for the KeyGenerator class. All the abstract methods in this class must be implemented by each cryptographic service provider who wishes to supply the implementation of a key generator for a particular algorithm.

In case the client does not explicitly initialize the KeyGenerator (via a call to an init method), each provider must supply (and document) a default initialization. See the Keysize Restriction sections of the JDK Providers document for information on the KeyGenerator 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 KeyGenerator instead of relying on provider-specific defaults.

Since:
1.4
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    KeyGeneratorSpi()
    Constructor for subclasses to call.

  • Method Summary

    Modifier and Type
    Method
    Description
    protected abstract SecretKey
    engineGenerateKey()
    Generates a secret key.
    protected abstract void
    engineInit(int keysize, SecureRandom random)
    Initializes this key generator for a certain keysize, using the given source of randomness.
    protected abstract void
    engineInit(SecureRandom random)
    Initializes the key generator.
    protected abstract void
    engineInit(AlgorithmParameterSpec params, SecureRandom random)
    Initializes the key generator with the specified parameter set and a user-provided source of randomness.

    Methods declared in class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Creates and returns a copy of this object.
    boolean
    equals(Object obj)
    Indicates whether some other object is "equal to" this one.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    Finalization is deprecated and subject to removal in a future release.
    final Class<?>
    getClass()
    Returns the runtime class of this Object.
    int
    hashCode()
    Returns a hash code value for this object.
    final void
    notify()
    Wakes up a single thread that is waiting on this object's monitor.
    final void
    notifyAll()
    Wakes up all threads that are waiting on this object's monitor.
    String
    toString()
    Returns a string representation of the object.
    final void
    wait()
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
    final void
    wait(long timeoutMillis)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
    final void
    wait(long timeoutMillis, int nanos)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

  • Constructor Details

    • KeyGeneratorSpi

      public KeyGeneratorSpi()
      Constructor for subclasses to call.

  • Method Details

    • engineInit

      protected abstract void engineInit(SecureRandom random)
      Initializes the key generator.
      Parameters:
      random - the source of randomness for this generator

    • engineInit

      protected abstract void engineInit(AlgorithmParameterSpec params, SecureRandom random) throws InvalidAlgorithmParameterException
      Initializes the key generator with the specified parameter set and a user-provided source of randomness.
      Parameters:
      params - the key generation parameters
      random - the source of randomness for this key generator
      Throws:
      InvalidAlgorithmParameterException - if params is inappropriate for this key generator

    • engineInit

      protected abstract void engineInit(int keysize, SecureRandom random)
      Initializes this key generator for a certain keysize, using the given source of randomness.
      Parameters:
      keysize - the keysize. This is an algorithm-specific metric, specified in number of bits.
      random - the source of randomness for this key generator
      Throws:
      InvalidParameterException - if the keysize is wrong or not supported.

    • engineGenerateKey

      protected abstract SecretKey engineGenerateKey()
      Generates a secret key.
      Returns:
      the new key