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sun.security.provider

public abstract Class AbstractHashDrbg

extends AbstractDrbg
Class Inheritance
Known Direct Subclasses
sun.security.provider.HashDrbg, sun.security.provider.HmacDrbg
Imports
sun.security.util.HexDumpEncoder, java.util.ArrayList, .List, .Locale

Field Summary

Modifier and TypeField and Description
protected int
outLen

protected int
seedLen

Inherited from sun.security.provider.AbstractDrbg:
algorithmdebugDEFAULT_STRENGTHhighestSupportedSecurityStrengthmaxAdditionalInputLengthmaxLengthmaxNumberOfBytesPerRequestmaxPersonalizationStringLengthmechNameminLengthnoncepersonalizationStringrequestedAlgorithmrequestedInstantiationSecurityStrengthreseedCounterreseedIntervalsecurityStrengthsupportPredictionResistancesupportReseedingusedf

Constructor Summary

AccessConstructor and Description
public
AbstractHashDrbg()

Method Summary

Modifier and TypeMethod and Description
private static int
alg2strength(String algorithm)

protected void
chooseAlgorithmAndStrength()

Implements abstract sun.security.provider.AbstractDrbg.chooseAlgorithmAndStrength.

Decides what algorithm and strength to use (SHA-256 or AES-256, 128 or 256).

protected abstract void
hashReseedInternal(List<byte[]>
not null, each element neither null
inputs)

Operates on multiple inputs.

public void
instantiateAlgorithm(byte[]
the entropy input, its length is already conditioned to be between minLength and maxLength.
entropy)

Implements abstract sun.security.provider.AbstractDrbg.instantiateAlgorithm.

Instantiates a DRBG.

protected void
reseedAlgorithm(byte[]
the entropy input, its length is already conditioned to be between minLength and maxLength.
ei, byte[]
additional input, can be null. If not null, its length is smaller than maxAdditionalInputLength
additionalInput)

Overrides sun.security.provider.AbstractDrbg.reseedAlgorithm.

The reseed function.

Inherited from sun.security.provider.AbstractDrbg:
configureengineGenerateSeedengineGetParametersengineNextBytesengineNextBytesengineReseedengineSetSeedgenerateAlgorithmgetStandardStrengthinitEnginetoString

Field Detail

outLenback to summary
protected int outLen
seedLenback to summary
protected int seedLen

Constructor Detail

AbstractHashDrbgback to summary
public AbstractHashDrbg()

Method Detail

alg2strengthback to summary
private static int alg2strength(String algorithm)
chooseAlgorithmAndStrengthback to summary
protected void chooseAlgorithmAndStrength()

Implements abstract sun.security.provider.AbstractDrbg.chooseAlgorithmAndStrength.

Doc from sun.security.provider.AbstractDrbg.chooseAlgorithmAndStrength.

Decides what algorithm and strength to use (SHA-256 or AES-256, 128 or 256). Strength related fields must also be defined or redefined here. Called in configure. A mechanism uses requestedAlgorithm, requestedInstantiationSecurityStrength, and DEFAULT_STRENGTH to decide which algorithm and strength to use.

If requestedAlgorithm is provided, it will always be used. If requestedInstantiationSecurityStrength is also provided, the algorithm will use the strength (an exception will be thrown if the strength is not supported), otherwise, the smaller one of the highest supported strength of the algorithm and the default strength will be used.

If requestedAlgorithm is not provided, an algorithm will be chosen that supports requestedInstantiationSecurityStrength (or DEFAULT_STRENGTH if there is no request).

Since every call to configure will call this method, make sure to the calls do not contradict with each other.

Here are some examples of the algorithm and strength chosen (suppose DEFAULT_STRENGTH is 128) for HashDRBG: 

requested             effective
(SHA-224, 256)        IAE
(SHA-256, -1)         (SHA-256,128)
(SHA-256, 112)        (SHA-256,112)
(SHA-256, 128)        (SHA-256,128)
(SHA-3, -1)           IAE
(null, -1)            (SHA-256,128)
(null, 112)           (SHA-256,112)
(null, 192)           (SHA-256,192)
(null, 256)           (SHA-256,256)
(null, 384)           IAE
hashReseedInternalback to summary
protected abstract void hashReseedInternal(List<byte[]> inputs)

Operates on multiple inputs.

Parameters
inputs:List<byte[]>

not null, each element neither null

instantiateAlgorithmback to summary
public void instantiateAlgorithm(byte[] entropy)

Implements abstract sun.security.provider.AbstractDrbg.instantiateAlgorithm.

Doc from sun.security.provider.AbstractDrbg.instantiateAlgorithm.

Instantiates a DRBG. Called automatically before the first nextBytes call.

Note that the other parameters (nonce, strength, ps) are already stored inside at configuration.

Parameters
entropy:byte[]

the entropy input, its length is already conditioned to be between minLength and maxLength.

Annotations
@Override
reseedAlgorithmback to summary
protected void reseedAlgorithm(byte[] ei, byte[] additionalInput)

Overrides sun.security.provider.AbstractDrbg.reseedAlgorithm.

Doc from sun.security.provider.AbstractDrbg.reseedAlgorithm.

The reseed function.

Parameters
ei:byte[]

the entropy input, its length is already conditioned to be between minLength and maxLength.

additionalInput:byte[]

additional input, can be null. If not null, its length is smaller than maxAdditionalInputLength

Annotations
@Override