Package net.schmizz.sshj.transport

Class TransportImpl

java.lang.Object

net.schmizz.sshj.transport.TransportImpl

All Implemented Interfaces:

RemoteAddressProvider, SSHPacketHandler, DisconnectListener, Transport

public final class TransportImpl
extends java.lang.Object
implements Transport, DisconnectListener

A thread-safe Transport implementation.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	TransportImpl.ConnInfo
private static class	TransportImpl.NullService

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	authed
private java.lang.String	clientID	Client version identification string
private Event<TransportException>	close
private Config	config
private TransportImpl.ConnInfo	connInfo
private Decoder	decoder
private DisconnectListener	disconnectListener
private Encoder	encoder
private KeyAlgorithm	hostKeyAlgorithm
private KeyExchanger	kexer
private org.slf4j.Logger	log
private LoggerFactory	loggerFactory
private Message	msg	Message identifier of last packet received
private Service	nextService	The next service that will be activated, only set when sending an SSH_MSG_SERVICE_REQUEST
private Service	nullService
private Reader	reader
private java.lang.String	serverID	Server version identification string
private Service	service	Currently active service e.g.
private Event<TransportException>	serviceAccept
private int	timeoutMs
private java.util.concurrent.locks.ReentrantLock	writeLock

Constructor Summary

Constructors

Constructor	Description
TransportImpl(Config config)

Method Summary

Modifier and Type	Method	Description
void	addAlgorithmsVerifier(AlgorithmsVerifier verifier)	Adds the specified verifier.
void	addHostKeyVerifier(HostKeyVerifier hkv)	Adds the specified verifier.
void	die(java.lang.Exception ex)	Kill the transport in an exceptional way.
void	disconnect()	Send a disconnection packet with reason as DisconnectReason.BY_APPLICATION, and closes this transport.
void	disconnect(DisconnectReason reason)	Send a disconnect packet with the given reason, and closes this transport.
void	disconnect(DisconnectReason reason, java.lang.String message)	Send a disconnect packet with the given reason and message, and closes this transport.
void	doKex()	Do key exchange and algorithm negotiation.
private void	finishOff()
(package private) java.lang.String	getClientID()
java.util.List<KeyAlgorithm>	getClientKeyAlgorithms(KeyType keyType)
java.lang.String	getClientVersion()
Config	getConfig()
(package private) TransportImpl.ConnInfo	getConnInfo()
(package private) Decoder	getDecoder()
DisconnectListener	getDisconnectListener()
(package private) Encoder	getEncoder()
KeyAlgorithm	getHostKeyAlgorithm()
java.lang.String	getRemoteHost()
int	getRemotePort()
java.net.InetSocketAddress	getRemoteSocketAddress()	Get Remote Socket Address using Connection Information
(package private) java.lang.String	getServerID()
java.lang.String	getServerVersion()	Returns the version string as sent by the SSH server for identification purposes, e.g.
Service	getService()
byte[]	getSessionID()
int	getTimeoutMs()
(package private) java.util.concurrent.locks.ReentrantLock	getWriteLock()
private void	gotDebug(SSHPacket buf)
private void	gotDisconnect(SSHPacket buf)
private void	gotServiceAccept()
private void	gotUnimplemented(SSHPacket packet)	Got an SSH_MSG_UNIMPLEMENTED, so lets see where we're at and act accordingly.
void	handle(Message msg, SSHPacket buf)	This is where all incoming packets are handled.
void	init(java.lang.String remoteHost, int remotePort, java.io.InputStream in, java.io.OutputStream out)	Sets the host information and the streams to be used by this transport.
boolean	isAuthenticated()
boolean	isKexDone()
private static boolean	isKexerPacket(Message msg)
boolean	isRunning()
void	join()	Joins the thread calling this method to the transport's death.
void	join(int timeout, java.util.concurrent.TimeUnit unit)	Joins the thread calling this method to the transport's death.
void	notifyDisconnect(DisconnectReason reason, java.lang.String message)	TransportImpl implements its own default DisconnectListener.
private java.lang.String	readIdentification(Buffer.PlainBuffer buffer)	Reads the identification string from the SSH server.
private void	receiveServerIdent()
void	reqService(Service service)	Request a SSH service represented by a Service instance.
private void	sendClientIdent()	Receive the server identification string.
private void	sendDisconnect(DisconnectReason reason, java.lang.String message)
private void	sendServiceRequest(java.lang.String serviceName)	Sends a service request for the specified service
long	sendUnimplemented()	Sends SSH_MSG_UNIMPLEMENTED in response to the last packet received.
void	setAuthenticated()	Informs this transport that authentication has been completed.
void	setDisconnectListener(DisconnectListener listener)	Specify a listener that will be notified upon disconnection.
void	setHostKeyAlgorithm(KeyAlgorithm keyAlgorithm)
void	setService(Service service)	Sets the currently active Service.
void	setTimeoutMs(int timeoutMs)	Set a timeout for methods that may block.
long	write(SSHPacket payload)	Write a packet over this transport.

Methods inherited from class java.lang.Object

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

Field Detail

loggerFactory

private final LoggerFactory loggerFactory

log

private final org.slf4j.Logger log

nullService

private final Service nullService

config

private final Config config

kexer

private final KeyExchanger kexer

reader

private final Reader reader

encoder

private final Encoder encoder

decoder

private final Decoder decoder

hostKeyAlgorithm

private KeyAlgorithm hostKeyAlgorithm

serviceAccept

private final Event<TransportException> serviceAccept

close

private final Event<TransportException> close

clientID

private final java.lang.String clientID

Client version identification string

timeoutMs

private volatile int timeoutMs

authed

private volatile boolean authed

service

private volatile Service service

Currently active service e.g. UserAuthService, ConnectionService

nextService

private volatile Service nextService

The next service that will be activated, only set when sending an SSH_MSG_SERVICE_REQUEST

disconnectListener

private DisconnectListener disconnectListener

connInfo

private TransportImpl.ConnInfo connInfo

serverID

private java.lang.String serverID

Server version identification string

msg

private Message msg

Message identifier of last packet received

writeLock

private final java.util.concurrent.locks.ReentrantLock writeLock

Constructor Detail

TransportImpl

public TransportImpl(Config config)

Method Detail

init

public void init(java.lang.String remoteHost,
                 int remotePort,
                 java.io.InputStream in,
                 java.io.OutputStream out)
          throws TransportException

Description copied from interface: Transport

Sets the host information and the streams to be used by this transport. Identification information is exchanged with the server. A TransportException is thrown in case of SSH protocol version incompatibility.

Specified by:

init in interface Transport

Parameters:

remoteHost - server's hostname

remotePort - server's port

in - input stream for the connection

out - output stream for the connection

Throws:

TransportException - if there is an error during exchange of identification information

getRemoteSocketAddress

public java.net.InetSocketAddress getRemoteSocketAddress()

Get Remote Socket Address using Connection Information

Specified by:

getRemoteSocketAddress in interface RemoteAddressProvider

Returns:

Remote Socket Address or null when not connected

notifyDisconnect

public void notifyDisconnect(DisconnectReason reason,
                             java.lang.String message)

TransportImpl implements its own default DisconnectListener.

Specified by:

notifyDisconnect in interface DisconnectListener

receiveServerIdent

private void receiveServerIdent()
                         throws java.io.IOException

Throws:

java.io.IOException

sendClientIdent

private void sendClientIdent()
                      throws java.io.IOException

Receive the server identification string.

Throws:

java.io.IOException - If there was an error writing to the outputstream.

readIdentification

private java.lang.String readIdentification(Buffer.PlainBuffer buffer)
                                     throws java.io.IOException

Reads the identification string from the SSH server. This is the very first string that is sent upon connection by the server. It takes the form of, e.g. "SSH-2.0-OpenSSH_ver".

Several concerns are taken care of here, e.g. verifying protocol version, correct line endings as specified in RFC and such.

This is not efficient but is only done once.

Parameters:

buffer - The buffer to read from.

Returns:

empty string if full ident string has not yet been received

Throws:

java.io.IOException - Thrown when protocol version is not supported

addHostKeyVerifier

public void addHostKeyVerifier(HostKeyVerifier hkv)

Description copied from interface: Transport

Adds the specified verifier.

Specified by:

addHostKeyVerifier in interface Transport

Parameters:

hkv - the host key verifier

addAlgorithmsVerifier

public void addAlgorithmsVerifier(AlgorithmsVerifier verifier)

Description copied from interface: Transport

Adds the specified verifier.

Specified by:

addAlgorithmsVerifier in interface Transport

Parameters:

verifier - The verifier to call with negotiated algorithms

doKex

public void doKex()
           throws TransportException

Description copied from interface: Transport

Do key exchange and algorithm negotiation. This can be the initial one or for algorithm renegotiation.

Specified by:

doKex in interface Transport

Throws:

TransportException - if there was an error during key exchange

isKexDone

public boolean isKexDone()

getTimeoutMs

public int getTimeoutMs()

Specified by:

getTimeoutMs in interface Transport

Returns:

the timeout that is currently set for blocking operations.

setTimeoutMs

public void setTimeoutMs(int timeoutMs)

Description copied from interface: Transport

Set a timeout for methods that may block.

Specified by:

setTimeoutMs in interface Transport

Parameters:

timeoutMs - the timeout in milliseconds

getRemoteHost

public java.lang.String getRemoteHost()

Specified by:

getRemoteHost in interface Transport

Returns:

the hostname to which this transport is connected.

getRemotePort

public int getRemotePort()

Specified by:

getRemotePort in interface Transport

Returns:

the port number on the remote host to which this transport is connected.

getClientVersion

public java.lang.String getClientVersion()

Specified by:

getClientVersion in interface Transport

Returns:

the version string used by this client to identify itself to an SSH server, e.g. "SSHJ_3_0"

getConfig

public Config getConfig()

Specified by:

getConfig in interface Transport

Returns:

the Config associated with this transport.

getServerVersion

public java.lang.String getServerVersion()

Description copied from interface: Transport

Returns the version string as sent by the SSH server for identification purposes, e.g. "OpenSSH_$version".

If the transport has not yet been initialized via Transport.init(java.lang.String, int, java.io.InputStream, java.io.OutputStream), it will be null.

Specified by:

getServerVersion in interface Transport

Returns:

server's version string (may be null)

getSessionID

public byte[] getSessionID()

Specified by:

getSessionID in interface Transport

Returns:

the session identifier assigned by server

getService

public Service getService()

Specified by:

getService in interface Transport

Returns:

the currently active Service instance.

setService

public void setService(Service service)

Description copied from interface: Transport

Sets the currently active Service. Handling of non-transport-layer packets is delegated to that service.

For this method to be successful, at least one service request via Transport.reqService(net.schmizz.sshj.Service) must have been successful (not necessarily for the service being set).

Specified by:

setService in interface Transport

Parameters:

service - (null-ok) the Service

reqService

public void reqService(Service service)
                throws TransportException

Description copied from interface: Transport

Request a SSH service represented by a Service instance. A separate call to Transport.setService(net.schmizz.sshj.Service) is not needed.

Specified by:

reqService in interface Transport

Parameters:

service - the SSH service to be requested

Throws:

TransportException - if the request failed for any reason

sendServiceRequest

private void sendServiceRequest(java.lang.String serviceName)
                         throws TransportException

Sends a service request for the specified service

Parameters:

serviceName - name of the service being requested

Throws:

TransportException - if there is an error while sending the request

setAuthenticated

public void setAuthenticated()

Description copied from interface: Transport

Informs this transport that authentication has been completed. This method must be called after successful authentication, so that delayed compression may become effective if applicable.

Specified by:

setAuthenticated in interface Transport

isAuthenticated

public boolean isAuthenticated()

Specified by:

isAuthenticated in interface Transport

Returns:

whether the transport thinks it is authenticated.

sendUnimplemented

public long sendUnimplemented()
                       throws TransportException

Description copied from interface: Transport

Sends SSH_MSG_UNIMPLEMENTED in response to the last packet received.

Specified by:

sendUnimplemented in interface Transport

Returns:

the sequence number of the packet sent

Throws:

TransportException - if an error occurred sending the packet

join

public void join()
          throws TransportException

Description copied from interface: Transport

Joins the thread calling this method to the transport's death.

Specified by:

join in interface Transport

Throws:

TransportException - if the transport dies of an exception

join

public void join(int timeout,
                 java.util.concurrent.TimeUnit unit)
          throws TransportException

Description copied from interface: Transport

Joins the thread calling this method to the transport's death.

Specified by:

join in interface Transport

Throws:

TransportException - if the transport dies of an exception

isRunning

public boolean isRunning()

Specified by:

isRunning in interface Transport

Returns:

whether this transport is active.

The transport is considered to be running if it has been initialized without error via Transport.init(java.lang.String, int, java.io.InputStream, java.io.OutputStream) and has not been disconnected.

disconnect

public void disconnect()

Description copied from interface: Transport

Send a disconnection packet with reason as DisconnectReason.BY_APPLICATION, and closes this transport.

Specified by:

disconnect in interface Transport

disconnect

public void disconnect(DisconnectReason reason)

Description copied from interface: Transport

Send a disconnect packet with the given reason, and closes this transport.

Specified by:

disconnect in interface Transport

Parameters:

reason - reason for disconnecting

disconnect

public void disconnect(DisconnectReason reason,
                       java.lang.String message)

Description copied from interface: Transport

Send a disconnect packet with the given reason and message, and closes this transport.

Specified by:

disconnect in interface Transport

Parameters:

reason - the reason code for this disconnect

message - the text message

setDisconnectListener

public void setDisconnectListener(DisconnectListener listener)

Description copied from interface: Transport

Specify a listener that will be notified upon disconnection.

Specified by:

setDisconnectListener in interface Transport

Parameters:

listener - Disconnect Listener to be configured

getDisconnectListener

public DisconnectListener getDisconnectListener()

Specified by:

getDisconnectListener in interface Transport

Returns:

the current disconnect listener.

write

public long write(SSHPacket payload)
           throws TransportException

Description copied from interface: Transport

Write a packet over this transport.

The payload SSHPacket should have 5 bytes free at the beginning to avoid a performance penalty associated with making space for header bytes (packet length, padding length).

Specified by:

write in interface Transport

Parameters:

payload - the SSHPacket containing data to send

Returns:

sequence number of the sent packet

Throws:

TransportException - if an error occurred sending the packet

sendDisconnect

private void sendDisconnect(DisconnectReason reason,
                            java.lang.String message)

handle

public void handle(Message msg,
                   SSHPacket buf)
            throws SSHException

This is where all incoming packets are handled. If they pertain to the transport layer, they are handled here; otherwise they are delegated to the active service instance if any via SSHPacketHandler.handle(net.schmizz.sshj.common.Message, net.schmizz.sshj.common.SSHPacket).

Even among the transport layer specific packets, key exchange packets are delegated to KeyExchanger.handle(net.schmizz.sshj.common.Message, net.schmizz.sshj.common.SSHPacket).

This method is called in the context of the reader thread via Decoder.received(byte[], int) when a full packet has been decoded.

Specified by:

handle in interface SSHPacketHandler

Parameters:

msg - the message identifier

buf - buffer containing rest of the packet

Throws:

SSHException - if an error occurs during handling (unrecoverable)

isKexerPacket

private static boolean isKexerPacket(Message msg)

gotDebug

private void gotDebug(SSHPacket buf)
               throws TransportException

Throws:

TransportException

gotDisconnect

private void gotDisconnect(SSHPacket buf)
                    throws TransportException

Throws:

TransportException

gotServiceAccept

private void gotServiceAccept()
                       throws TransportException

Throws:

TransportException

gotUnimplemented

private void gotUnimplemented(SSHPacket packet)
                       throws SSHException

Got an SSH_MSG_UNIMPLEMENTED, so lets see where we're at and act accordingly.

Parameters:

packet - The 'unimplemented' packet received

Throws:

TransportException - Thrown when key exchange is ongoing

SSHException

finishOff

private void finishOff()

die

public void die(java.lang.Exception ex)

Description copied from interface: Transport

Kill the transport in an exceptional way.

Specified by:

die in interface Transport

Parameters:

ex - The exception that occurred.

getClientID

java.lang.String getClientID()

getServerID

java.lang.String getServerID()

getEncoder

Encoder getEncoder()

getDecoder

Decoder getDecoder()

getWriteLock

java.util.concurrent.locks.ReentrantLock getWriteLock()

getConnInfo

TransportImpl.ConnInfo getConnInfo()

setHostKeyAlgorithm

public void setHostKeyAlgorithm(KeyAlgorithm keyAlgorithm)

getHostKeyAlgorithm

public KeyAlgorithm getHostKeyAlgorithm()

Specified by:

getHostKeyAlgorithm in interface Transport

getClientKeyAlgorithms

public java.util.List<KeyAlgorithm> getClientKeyAlgorithms(KeyType keyType)
                                                    throws TransportException

Specified by:

getClientKeyAlgorithms in interface Transport

Throws:

TransportException