org.logi.crypto.protocols
Class DHKeyExServer

java.lang.Object
  |
  +--org.logi.crypto.Crypto
        |
        +--org.logi.crypto.protocols.DHKeyEx
              |
              +--org.logi.crypto.protocols.DHKeyExServer

All Implemented Interfaces:

InterKeyExServer, InterProtocolServer

public class DHKeyExServer

extends org.logi.crypto.protocols.DHKeyEx

implements InterKeyExServer

Diffie-Hellman key exchange server. It expects to talk to a DHKeyExClient object.

Author:

Logi Ragnarsson (logir@logi.org)

See Also:

DHKeyExClient

Fields inherited from class org.logi.crypto.Crypto

BIT, cdsPath, EMPTY_ARRAY, FOUR, keySource, NIBBLE, ONE, primeCertainty, random, TWO, ZERO

Constructor Summary

DHKeyExServer(DHPrivateKey pri, java.lang.String keyType)
Create a new DHKeyExServer object.

DHKeyExServer(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.InterKeyExServer

sessionKey

Methods inherited from interface org.logi.crypto.protocols.InterProtocolServer

completed, maxMessageSize

Constructor Detail

DHKeyExServer

public DHKeyExServer(DHPrivateKey pri,
                     java.lang.String keyType)
              throws KeyException

Create a new DHKeyExServer object. It uses the private DH key from pri.

Throws:

KeyException - if the key is not private.

DHKeyExServer

public DHKeyExServer(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 client and has not yet been sent to the client.

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

Specified by:

message in interface InterProtocolServer

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.