Package com.sshtools.client

Class SshKeyExchangeClient

java.lang.Object

com.sshtools.client.SshKeyExchangeClient

All Implemented Interfaces:

Component, SshComponent, SecureComponent, SshKeyExchange<SshClientContext>

Direct Known Subclasses:

Curve25519SHA256Client, DiffieHellmanEcdh, DiffieHellmanGroup, DiffieHellmanGroupExchange, Rsa1024Sha1, Rsa2048Sha256

public abstract class SshKeyExchangeClient
extends Object
implements SshKeyExchange<SshClientContext>

An abstract base class for all key exchange implementations.

Field Summary

Fields

Modifier and Type	Field	Description
protected String	clientId
protected byte[]	clientKexInit
protected BigInteger	e
protected byte[]	exchangeHash	The exchange hash produced during key exchange.
protected BigInteger	f
protected boolean	firstPacketFollows
protected byte[]	hostKey	The server's host key.
protected SshPublicKey	key
protected BigInteger	secret	The secret value produced during key exchange.
protected String	serverId
protected byte[]	serverKexInit
protected byte[]	signature	The signature generated over the exchange hash
protected SshTransport<SshClientContext>	transport	The transport protocol for sending/receiving messages
protected boolean	useFirstPacket

Constructor Summary

Constructors

Constructor	Description
SshKeyExchangeClient(String hashAlgorithm, SecurityLevel securityLevel, int priority)	Contruct an uninitialized key exchange

Method Summary

Modifier and Type	Method	Description
protected void	calculateExchangeHash()	Calculates the exchange hash as an SHA1 hash of the following data.
byte[]	getExchangeHash()	Get the output of the key exchange
String	getHashAlgorithm()
byte[]	getHostKey()	Get the host key supplied during key exchange.
int	getPriority()
BigInteger	getSecret()	Get the secret value produced during key exchange.
SecurityLevel	getSecurityLevel()
byte[]	getSignature()	Get the signature produced during key exchange.
boolean	hasReceivedNewKeys()
boolean	hasSentNewKeys()
boolean	isComplete()
abstract boolean	processMessage(byte[] msg)	Process a key exchange message
void	reset()	Reset the key exchange.
void	setReceivedNewKeys(boolean receivedNewKeys)
void	setSentNewKeys(boolean sentNewKeys)

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.sshtools.synergy.ssh.components.SshKeyExchange

getAlgorithm, getProvider, init, test

Field Details

secret

protected BigInteger secret

The secret value produced during key exchange.

exchangeHash

protected byte[] exchangeHash

The exchange hash produced during key exchange.

hostKey

protected byte[] hostKey

The server's host key.

signature

protected byte[] signature

The signature generated over the exchange hash

clientId

protected String clientId

serverId

protected String serverId

clientKexInit

protected byte[] clientKexInit

serverKexInit

protected byte[] serverKexInit

key

protected SshPublicKey key

firstPacketFollows

protected boolean firstPacketFollows

useFirstPacket

protected boolean useFirstPacket

e

protected BigInteger e

f

protected BigInteger f

transport

protected SshTransport<SshClientContext> transport

The transport protocol for sending/receiving messages

Constructor Details

SshKeyExchangeClient

public SshKeyExchangeClient(String hashAlgorithm,
 SecurityLevel securityLevel,
 int priority)

Contruct an uninitialized key exchange

Method Details

getSecurityLevel

public SecurityLevel getSecurityLevel()

Specified by:

getSecurityLevel in interface SecureComponent

getPriority

public int getPriority()

Specified by:

getPriority in interface SecureComponent

setReceivedNewKeys

public void setReceivedNewKeys(boolean receivedNewKeys)

Specified by:

setReceivedNewKeys in interface SshKeyExchange<SshClientContext>

setSentNewKeys

public void setSentNewKeys(boolean sentNewKeys)

Specified by:

setSentNewKeys in interface SshKeyExchange<SshClientContext>

hasSentNewKeys

public boolean hasSentNewKeys()

Specified by:

hasSentNewKeys in interface SshKeyExchange<SshClientContext>

hasReceivedNewKeys

public boolean hasReceivedNewKeys()

Specified by:

hasReceivedNewKeys in interface SshKeyExchange<SshClientContext>

getExchangeHash

public byte[] getExchangeHash()

Get the output of the key exchange

Specified by:

getExchangeHash in interface SshKeyExchange<SshClientContext>

Returns:

the exchange hash output.

getHostKey

public byte[] getHostKey()

Get the host key supplied during key exchange.

Specified by:

getHostKey in interface SshKeyExchange<SshClientContext>

Returns:

the server's host key

getSecret

public BigInteger getSecret()

Get the secret value produced during key exchange.

Specified by:

getSecret in interface SshKeyExchange<SshClientContext>

Returns:

The secret value produced during key exchange

getSignature

public byte[] getSignature()

Get the signature produced during key exchange.

Specified by:

getSignature in interface SshKeyExchange<SshClientContext>

Returns:

the signature produced from the exchange hash.

processMessage

public abstract boolean processMessage(byte[] msg)
                                throws SshException,
IOException

Process a key exchange message

Specified by:

processMessage in interface SshKeyExchange<SshClientContext>

Parameters:

msg -

Returns:

boolean, indicating whether it has processed the message or not

Throws:

IOException

SshException

reset

public void reset()

Reset the key exchange.

isComplete

public boolean isComplete()

getHashAlgorithm

public String getHashAlgorithm()

Specified by:

getHashAlgorithm in interface SshKeyExchange<SshClientContext>

calculateExchangeHash

protected void calculateExchangeHash()
                              throws SshException

Calculates the exchange hash as an SHA1 hash of the following data.

  String         the client's version string (CR and NL excluded)
  String         the server's version string (CR and NL excluded)
  String         the payload of the client's SSH_MSG_KEXINIT
  String         the payload of the server's SSH_MSG_KEXINIT
  String         the host key
  BigInteger     e, exchange value sent by the client
  BigInteger     f, exchange value sent by the server
  BigInteger     K, the shared secret
 

Throws:

IOException

SshException