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.