Module com.github.glusk.srp6_variables

Package com.github.glusk.srp6_variables

Class SRP6ScramblingParameter

java.lang.Object

com.github.glusk.srp6_variables.AbstractSRP6IntegerVariable

com.github.glusk.srp6_variables.SRP6ScramblingParameter

All Implemented Interfaces:

SRP6IntegerVariable

public final class SRP6ScramblingParameter
extends AbstractSRP6IntegerVariable

SRP-6 Random Scrambling Parameter (u).

This variable is computed as:

 u = H(A | B)
 

where H() is a one-way hash function, | a concatenation operator, A client's public key and B the server's public key.

Constructor Summary

Constructors

Constructor	Description
SRP6ScramblingParameter(ImmutableMessageDigest hashFunction, SRP6IntegerVariable clientPublicKey, SRP6IntegerVariable serverPublicKey, SRP6IntegerVariable prime, ByteOrder byteOrder)	Constructs a new SRP-6 Random Scrambling Parameter as specified in RFC 5054.

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

SRP6ScramblingParameter

public SRP6ScramblingParameter(ImmutableMessageDigest hashFunction,
                               SRP6IntegerVariable clientPublicKey,
                               SRP6IntegerVariable serverPublicKey,
                               SRP6IntegerVariable prime,
                               ByteOrder byteOrder)

Constructs a new SRP-6 Random Scrambling Parameter as specified in RFC 5054.

 u = H(PAD(A) | PAD(B))
 

Note: A and B are zero-padded to the byte length of N.

Parameters:

hashFunction - a one-way hash function - H()

clientPublicKey - SRP-6 variable: client public key (A)

serverPublicKey - SRP-6 variable: server public key (B)

prime - SRP-6 variable: prime (N)

byteOrder - the byte order to use when converting the resulting hash to integer and the byte order of public keys' byte sequences to feed to the hash function

Method Detail

bytes

public Bytes bytes(ByteOrder preferredOrder)
            throws IllegalStateException

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 byte length of N is shorter than the byte length of either A or B