Module java.base
Package java.security

Class SecureRandomSpi

  • All Implemented Interfaces:
    Serializable
    public abstract class SecureRandomSpi
extends Object
implements Serializable
    This class defines the Service Provider Interface (SPI) for the SecureRandom class.

    All the abstract methods in this class must be implemented by each service provider who wishes to supply the implementation of a cryptographically strong pseudo-random number generator.

    Since:
    1.2
    See Also:
    Serialized Form

    • Constructor Detail

      • SecureRandomSpi

        public SecureRandomSpi()
        Constructor without a parameter.

    • Method Detail

      • engineSetSeed

        protected abstract void engineSetSeed​(byte[] seed)
        Reseeds this random object with the given seed. The seed supplements, rather than replaces, the existing seed. Thus, repeated calls are guaranteed never to reduce randomness.
        Parameters:
        seed - the seed.

      • engineNextBytes

        protected abstract void engineNextBytes​(byte[] bytes)
        Generates a user-specified number of random bytes.

        Some random number generators can only generate a limited amount of random bytes per invocation. If the size of bytes is greater than this limit, the implementation should invoke its generation process multiple times to completely fill the buffer before returning from this method.

        Parameters:
        bytes - the array to be filled in with random bytes.

      • engineNextBytes

        protected void engineNextBytes​(byte[] bytes,
                               SecureRandomParameters params)
        Generates a user-specified number of random bytes with additional parameters.

        Some random number generators can only generate a limited amount of random bytes per invocation. If the size of bytes is greater than this limit, the implementation should invoke its generation process multiple times to completely fill the buffer before returning from this method.

        Parameters:
        bytes - the array to be filled in with random bytes
        params - additional parameters
        Throws:
        UnsupportedOperationException - if the implementation has not overridden this method
        IllegalArgumentException - if params is null, illegal or unsupported by this SecureRandom
        Since:
        9

      • engineGenerateSeed

        protected abstract byte[] engineGenerateSeed​(int numBytes)
        Returns the given number of seed bytes. This call may be used to seed other random number generators.
        Parameters:
        numBytes - the number of seed bytes to generate.
        Returns:
        the seed bytes.

      • engineReseed

        protected void engineReseed​(SecureRandomParameters params)
        Reseeds this random object with entropy input read from its entropy source with additional parameters.

        If this method is called by SecureRandom.reseed(), params will be null.

        Do not override this method if the implementation does not support reseeding.

        Parameters:
        params - extra parameters, can be null.
        Throws:
        UnsupportedOperationException - if the implementation has not overridden this method
        IllegalArgumentException - if params is illegal or unsupported by this SecureRandom
        Since:
        9

      • toString

        public String toString()
        Returns a Human-readable string representation of this SecureRandom.
        Overrides:
        toString in class Object
        Returns:
        the string representation