Module com.github.glusk.srp6_variables

Package com.github.glusk.srp6_variables

Class SRP6RandomEphemeral

java.lang.Object

com.github.glusk.srp6_variables.AbstractSRP6IntegerVariable

com.github.glusk.srp6_variables.SRP6RandomEphemeral

All Implemented Interfaces:

SRP6IntegerVariable

public final class SRP6RandomEphemeral
extends AbstractSRP6IntegerVariable

SRP-6 Random Ephemeral (a, b).

Use this class to generate random private ephemeral values a and b (see package docs).

This class generates a random value r of the form:

 1 < r < N
 

where N is the SRP-6 "prime" variable.

The bit-length of this variable will be at least 256 bits, as recommended in: RFC 5054 | 3. Security Considerations.

This class is not thread-safe.

Constructor Summary

Constructors

Constructor	Description
SRP6RandomEphemeral(SecureRandom rng, int desiredBitLength, SRP6IntegerVariable prime)	Creates a new SRP-6 Random Ephemeral.
SRP6RandomEphemeral(SecureRandom rng, SRP6IntegerVariable prime)	Creates a new SRP-6 Random Ephemeral with default bit-length (256 bits).

Method Summary

Modifier and Type	Method	Description
Bytes	bytes(ByteOrder preferredOrder)	Returns this SRP-6 Integer Variable as a byte sequence in the preferred byte order.

Methods inherited from class com.github.glusk.srp6_variables.AbstractSRP6IntegerVariable

equals, hashCode

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.github.glusk.srp6_variables.SRP6IntegerVariable

asNonNegativeBigInteger, bytes

Constructor Detail

SRP6RandomEphemeral

public SRP6RandomEphemeral(SecureRandom rng,
                           SRP6IntegerVariable prime)

Creates a new SRP-6 Random Ephemeral with default bit-length (256 bits).

Parameters:

rng - source of randomness

prime - SRP-6 Integer Variable: prime (N)

SRP6RandomEphemeral

public SRP6RandomEphemeral(SecureRandom rng,
                           int desiredBitLength,
                           SRP6IntegerVariable prime)
                    throws IllegalArgumentException

Creates a new SRP-6 Random Ephemeral.

Parameters:

rng - source of randomness

desiredBitLength - the desired bit-length of this variable

prime - SRP-6 Integer Variable: prime (N)

Throws:

IllegalArgumentException

Method Detail

bytes

public Bytes bytes(ByteOrder preferredOrder)

Returns this SRP-6 Integer Variable as a byte sequence in the preferred byte order.

The representation returned must be minimal. That is, all leading (or trailing, depending on the preferredOrder) zero bytes have to be trimmed.

Number zero is hence defined as an empty byte sequence.

Parameters:

preferredOrder - the preferred byte order of the byte sequence that represents this SRP-6 Integer Variable

Returns:

the byte sequence that represents this SRP-6 Integer Variable in the preferred byte order

Throws:

IllegalStateException - If the set bit length is greater than the bit length of prime. More formally if: Math.max(desiredBitLength, 256) > bitlength(prime)