Module java.base
Package java.security

Enum DrbgParameters.Capability

  • All Implemented Interfaces:
    Serializable, Comparable<DrbgParameters.Capability>
    Enclosing class:
    DrbgParameters


    public static enum DrbgParameters.Capability
    extends Enum<DrbgParameters.Capability>
    The reseedable and prediction resistance capabilities of a DRBG.

    When this object is passed to a SecureRandom.getInstance() call, it is the requested minimum capability. When it's returned from SecureRandom.getParameters(), it is the effective capability.

    Please note that while the Instantiate_function defined in NIST SP 800-90Ar1 only includes a prediction_resistance_flag parameter, the Capability type includes an extra value RESEED_ONLY because reseeding is an optional function. If NONE is used in an Instantiation object in calling the SecureRandom.getInstance method, the returned DRBG instance is not guaranteed to support reseeding. If RESEED_ONLY or PR_AND_RESEED is used, the instance must support reseeding.

    The table below lists possible effective values if a certain capability is requested, i.e.

     Capability requested = ...;
     SecureRandom s = SecureRandom.getInstance("DRBG",
             DrbgParameters(-1, requested, null));
     Capability effective = ((DrbgParametes.Initiate) s.getParameters())
             .getCapability();
    requested and effective capabilities
    Requested Value Possible Effective Values
    NONENONE, RESEED_ONLY, PR_AND_RESEED
    RESEED_ONLYRESEED_ONLY, PR_AND_RESEED
    PR_AND_RESEEDPR_AND_RESEED

    A DRBG implementation supporting prediction resistance must also support reseeding.

    Since:
    9
    • Method Detail

      • values

        public static DrbgParameters.Capability[] values​()
        Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
        for (DrbgParameters.Capability c : DrbgParameters.Capability.values())
            System.out.println(c);
        
        Returns:
        an array containing the constants of this enum type, in the order they are declared
      • valueOf

        public static DrbgParameters.Capability valueOf​(String name)
        Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
        Parameters:
        name - the name of the enum constant to be returned.
        Returns:
        the enum constant with the specified name
        Throws:
        IllegalArgumentException - if this enum type has no constant with the specified name
        NullPointerException - if the argument is null
      • toString

        public String toString​()
        Description copied from class: Enum
        Returns the name of this enum constant, as contained in the declaration. This method may be overridden, though it typically isn't necessary or desirable. An enum type should override this method when a more "programmer-friendly" string form exists.
        Overrides:
        toString in class Enum<DrbgParameters.Capability>
        Returns:
        the name of this enum constant
      • supportsReseeding

        public boolean supportsReseeding​()
        Returns whether this capability supports reseeding.
        Returns:
        true for PR_AND_RESEED and RESEED_ONLY, and false for NONE
      • supportsPredictionResistance

        public boolean supportsPredictionResistance​()
        Returns whether this capability supports prediction resistance.
        Returns:
        true for PR_AND_RESEED, and false for RESEED_ONLY and NONE