org.spongycastle.crypto.prng.drbg

Class CTRSP800DRBG

java.lang.Object

org.spongycastle.crypto.prng.drbg.CTRSP800DRBG

All Implemented Interfaces:

SP80090DRBG

public class CTRSP800DRBG
extends java.lang.Object
implements SP80090DRBG

A SP800-90A CTR DRBG.

Constructor Summary

Constructors

Constructor and Description
CTRSP800DRBG(BlockCipher engine, int keySizeInBits, int securityStrength, EntropySource entropySource, byte[] personalizationString, byte[] nonce) Construct a SP800-90A CTR DRBG.

Method Summary

Modifier and Type	Method and Description
int	generate(byte[] output, byte[] additionalInput, boolean predictionResistant) Populate a passed in array with random data.
int	getBlockSize() Return the block size (in bits) of the DRBG.
void	reseed(byte[] additionalInput) Reseed the DRBG.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CTRSP800DRBG

public CTRSP800DRBG(BlockCipher engine,
                    int keySizeInBits,
                    int securityStrength,
                    EntropySource entropySource,
                    byte[] personalizationString,
                    byte[] nonce)

Construct a SP800-90A CTR DRBG.

Minimum entropy requirement is the security strength requested.

Parameters:

engine - underlying block cipher to use to support DRBG

keySizeInBits - size of the key to use with the block cipher.

securityStrength - security strength required (in bits)

entropySource - source of entropy to use for seeding/reseeding.

personalizationString - personalization string to distinguish this DRBG (may be null).

nonce - nonce to further distinguish this DRBG (may be null).

Method Detail

getBlockSize

public int getBlockSize()

Return the block size (in bits) of the DRBG.

Specified by:

getBlockSize in interface SP80090DRBG

Returns:

the number of bits produced on each internal round of the DRBG.

generate

public int generate(byte[] output,
                    byte[] additionalInput,
                    boolean predictionResistant)

Populate a passed in array with random data.

Specified by:

generate in interface SP80090DRBG

Parameters:

output - output array for generated bits.

additionalInput - additional input to be added to the DRBG in this step.

predictionResistant - true if a reseed should be forced, false otherwise.

Returns:

number of bits generated, -1 if a reseed required.

reseed

public void reseed(byte[] additionalInput)

Reseed the DRBG.

Specified by:

reseed in interface SP80090DRBG

Parameters:

additionalInput - additional input to be added to the DRBG in this step.