Capability

class Capability
kotlin.Any
   ↳ kotlin.Enum<java.security.DrbgParameters.Capability>
   ↳ java.security.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.

Summary

Enum values

Neither prediction resistance nor reseed.

Both prediction resistance and reseed.

Reseed but no prediction resistance.
Public methods
Boolean

Returns whether this capability supports prediction resistance.
Boolean

Returns whether this capability supports reseeding.
String

Enum values

NONE

Added in API level VanillaIceCream
enum val NONE : DrbgParameters.Capability

Neither prediction resistance nor reseed.

PR_AND_RESEED

Added in API level VanillaIceCream
enum val PR_AND_RESEED : DrbgParameters.Capability

Both prediction resistance and reseed.

RESEED_ONLY

Added in API level VanillaIceCream
enum val RESEED_ONLY : DrbgParameters.Capability

Reseed but no prediction resistance.

Public methods

supportsPredictionResistance

Added in API level VanillaIceCream
fun supportsPredictionResistance(): Boolean

Returns whether this capability supports prediction resistance.

Return
Boolean true for PR_AND_RESEED, and false for RESEED_ONLY and NONE

supportsReseeding

Added in API level VanillaIceCream
fun supportsReseeding(): Boolean

Returns whether this capability supports reseeding.

Return
Boolean true for PR_AND_RESEED and RESEED_ONLY, and false for NONE

toString

Added in API level VanillaIceCream
fun toString(): String
Return
String the name of this enum constant