Enum DrbgParameters.Capability

java.lang.Object
- java.lang.Enum<DrbgParameters.Capability>
- - java.security.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
NONE	NONE, RESEED_ONLY, PR_AND_RESEED
RESEED_ONLY	RESEED_ONLY, PR_AND_RESEED
PR_AND_RESEED	PR_AND_RESEED

A DRBG implementation supporting prediction resistance must also support reseeding.

Since:: 9

Enum Constant Summary

Enum Constants
Enum Constant	Description
`NONE`	Neither prediction resistance nor reseed.
`PR_AND_RESEED`	Both prediction resistance and reseed.
`RESEED_ONLY`	Reseed but no prediction resistance.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`supportsPredictionResistance()`	Returns whether this capability supports prediction resistance.
`boolean`	`supportsReseeding()`	Returns whether this capability supports reseeding.
`static DrbgParameters.Capability`	`valueOf(String name)`	Returns the enum constant of this type with the specified name.
`static DrbgParameters.Capability[]`	`values()`	Returns an array containing the constants of this enum type, in the order they are declared.

Methods declared in class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods declared in class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

PR_AND_RESEED

public static final DrbgParameters.Capability PR_AND_RESEED

Both prediction resistance and reseed.

RESEED_ONLY

public static final DrbgParameters.Capability RESEED_ONLY

Reseed but no prediction resistance.

NONE

public static final DrbgParameters.Capability NONE

Neither prediction resistance nor reseed.

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

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