org.jboss.security.srp
Class SRPClientSession

java.lang.Object
  org.jboss.security.srp.SRPClientSession

public class SRPClientSession
extends Object

The client side logic to the SRP protocol. The class is intended to be used with a SRPServerSession object via the SRPServerInterface. The SRP algorithm using these classes consists of: 1. Get server, SRPServerInterface server = (SRPServerInterface) Naming.lookup(...); 2. Get SRP parameters, SRPParameters params = server.getSRPParameters(username); 3. Create a client session, SRPClientSession client = new SRPClientSession(username, password, params); 4. Exchange public keys, byte[] A = client.exponential(); byte[] B = server.init(username, A); 5. Exchange challenges, byte[] M1 = client.response(B); byte[] M2 = server.verify(username, M1); 6. Verify the server response, if( client.verify(M2) == false ) throw new SecurityException("Failed to validate server reply"); 7. Validation complete Note that these steps are stateful. They must be performed in order and a step cannot be repeated to update the session state. This product uses the 'Secure Remote Password' cryptographic authentication system developed by Tom Wu (tjw@CS.Stanford.EDU).

Version:

$Revision: 57210 $

Author:

Scott.Stark@jboss.org

Constructor Summary

SRPClientSession(String username, char[] password, SRPParameters params)
Creates a new SRP server session object from the username, password verifier,

SRPClientSession(String username, char[] password, SRPParameters params, byte[] abytes)
Creates a new SRP server session object from the username, password verifier,

Method Summary

byte[]	exponential()
byte[]	getSessionKey() Returns the negotiated session K, K = SHA_Interleave(S)
byte[]	response(byte[] Bbytes)
boolean	verify(byte[] M2)

Methods inherited from class java.lang.Object

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

Constructor Detail

SRPClientSession

public SRPClientSession(String username,
                        char[] password,
                        SRPParameters params)

Creates a new SRP server session object from the username, password verifier,

Parameters:

username, - the user ID

password, - the user clear text password

params, - the SRP parameters for the session

SRPClientSession

public SRPClientSession(String username,
                        char[] password,
                        SRPParameters params,
                        byte[] abytes)

Creates a new SRP server session object from the username, password verifier,

Parameters:

username, - the user ID

password, - the user clear text password

params, - the SRP parameters for the session

abytes, - the random exponent used in the A public key. This must be 8 bytes in length.

Method Detail

exponential

public byte[] exponential()

response

public byte[] response(byte[] Bbytes)
                throws NoSuchAlgorithmException

Throws:

NoSuchAlgorithmException - thrown if the session key MessageDigest algorithm cannot be found.

verify

public boolean verify(byte[] M2)

Parameters:

M2 - The server's response to the client's challenge

getSessionKey

public byte[] getSessionKey()
                     throws SecurityException

Returns the negotiated session K, K = SHA_Interleave(S)

Returns:

the private session K byte[]

Throws:

SecurityException - - if the current thread does not have an getSessionKey SRPPermission.