org.gudy.bouncycastle.crypto.agreement.srp
Class SRP6Client

java.lang.Object
  org.gudy.bouncycastle.crypto.agreement.srp.SRP6Client

public class SRP6Client
extends Object

Implements the client side SRP-6a protocol. Note that this class is stateful, and therefore NOT threadsafe. This implementation of SRP is based on the optimized message sequence put forth by Thomas Wu in the paper "SRP-6: Improvements and Refinements to the Secure Remote Password Protocol, 2002"

Field Summary

protected BigInteger	a
protected BigInteger	A
protected BigInteger	B
protected Digest	digest
protected BigInteger	g
protected BigInteger	N
protected SecureRandom	random
protected BigInteger	S
protected BigInteger	u
protected BigInteger	x

Constructor Summary

SRP6Client()

Method Summary

BigInteger	calculateSecret(BigInteger serverB) Generates client's verification message given the server's credentials
BigInteger	generateClientCredentials(byte[] salt, byte[] identity, byte[] password) Generates client's credentials given the client's salt, identity and password
void	init(BigInteger N, BigInteger g, Digest digest, SecureRandom random) Initialises the client to begin new authentication attempt
protected BigInteger	selectPrivateValue()

Methods inherited from class java.lang.Object

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

Field Detail

N

protected BigInteger N

g

protected BigInteger g

a

protected BigInteger a

A

protected BigInteger A

B

protected BigInteger B

x

protected BigInteger x

u

protected BigInteger u

S

protected BigInteger S

digest

protected Digest digest

random

protected SecureRandom random

Constructor Detail

SRP6Client

public SRP6Client()

Method Detail

init

public void init(BigInteger N,
                 BigInteger g,
                 Digest digest,
                 SecureRandom random)

Initialises the client to begin new authentication attempt

Parameters:

N - The safe prime associated with the client's verifier

g - The group parameter associated with the client's verifier

digest - The digest algorithm associated with the client's verifier

random - For key generation

generateClientCredentials

public BigInteger generateClientCredentials(byte[] salt,
                                            byte[] identity,
                                            byte[] password)

Generates client's credentials given the client's salt, identity and password

Parameters:

salt - The salt used in the client's verifier.

identity - The user's identity (eg. username)

password - The user's password

Returns:

Client's public value to send to server

calculateSecret

public BigInteger calculateSecret(BigInteger serverB)
                           throws CryptoException

Generates client's verification message given the server's credentials

Parameters:

serverB - The server's credentials

Returns:

Client's verification message for the server

Throws:

CryptoException - If server's credentials are invalid

selectPrivateValue

protected BigInteger selectPrivateValue()