org.logi.crypto.protocols
Class DHKeyExClient

java.lang.Object
  |
  +--org.logi.crypto.Crypto
        |
        +--org.logi.crypto.protocols.DHKeyEx
              |
              +--org.logi.crypto.protocols.DHKeyExClient
All Implemented Interfaces:
InterKeyExClient, InterProtocolClient

public class DHKeyExClient
extends org.logi.crypto.protocols.DHKeyEx
implements InterKeyExClient

Diffie-Hellman key exchange client. It expects to talk to a DHKeyExServer object.

Author:
Logi Ragnarsson (logir@logi.org)
See Also:
DHKeyExServer

Fields inherited from class org.logi.crypto.Crypto
BIT, cdsPath, EMPTY_ARRAY, FOUR, keySource, NIBBLE, ONE, primeCertainty, random, TWO, ZERO
 
Constructor Summary
DHKeyExClient(DHPrivateKey pri, java.lang.String keyType)
          Create a new DHKeyExClient object.
DHKeyExClient(int n, java.lang.String keyType)
          Create a new DHKeyExClient object.
 
Method Summary
 boolean completed()
          Returns true iff this end of the protocol i completed.
 int maxMessageSize()
          Returns the maximum expected size of a message for this protocol.
 byte[] message(byte[] received)
          Get the next message in the protocol.
 Key sessionKey()
          Returns the key if it has been decided upon, or null otherwise.
 
Methods inherited from class org.logi.crypto.Crypto
binString, binString, ensureArrayLength, ensureArrayLength, equal, equalRelaxed, equalSub, fromHexNibble, fromHexString, fromString, fromString, hexString, hexString, hexString, hexString, hexString, initRandom, initRandom, makeClass, makeInt, makeLong, makeSessionKey, pastSpace, pickBits, pickBits, prettyPrint, prettyPrint, readBlock, readInt, trimArrayLength, trimArrayLength, trimLeadingZeroes, writeBytes, writeBytes, writeInt
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.logi.crypto.protocols.InterKeyExClient
sessionKey
 
Methods inherited from interface org.logi.crypto.protocols.InterProtocolClient
completed, maxMessageSize
 

Constructor Detail

DHKeyExClient

public DHKeyExClient(DHPrivateKey pri,
                     java.lang.String keyType)
              throws KeyException
Create a new DHKeyExClient object. It uses the private DH key from pri.
Throws:
KeyException - if the key is not private.

DHKeyExClient

public DHKeyExClient(int n,
                     java.lang.String keyType)
Create a new DHKeyExClient object. It uses an n bit modulus and the named key type.

There are pre-computed public modulus and gnerator pairs for these values of n: 256, 512, 1024, 2048. Using one of these values saves you from a rather long wait.

Method Detail

message

public byte[] message(byte[] received)
               throws CryptoProtocolException
Get the next message in the protocol.

received is the last message received form the server and has not yet been sent to the client.

The returned value is the next message to send to the server or null if no more messages need to be sent and the protocol is terminated.

Specified by:
message in interface InterProtocolClient
Throws:
CryptoProtocolException - if a problem arises with the protocol.

sessionKey

public Key sessionKey()
Returns the key if it has been decided upon, or null otherwise.

completed

public boolean completed()
Returns true iff this end of the protocol i completed.

maxMessageSize

public int maxMessageSize()
Returns the maximum expected size of a message for this protocol.


Copyright (c) 1997-2001 Logi Ragnarsson - Distributed under the GPL