SSLServerSocket

public abstract class SSLServerSocket extends ServerSocket

This class extends ServerSockets and provides secure server sockets using protocols such as the Secure Sockets Layer (SSL) or Transport Layer Security (TLS) protocols.

Instances of this class are generally created using a SSLServerSocketFactory. The primary function of SSLServerSockets is to create SSLSockets by accepting connections.

SSLServerSockets contain several pieces of state data which are inherited by the SSLSocket at socket creation. These include the enabled cipher suites and protocols, whether client authentication is necessary, and whether created sockets should begin handshaking in client or server mode. The state inherited by the created SSLSocket can be overriden by calling the appropriate methods.

See Also

• ServerSocket
• SSLSocket

Protected Constructor Summary

	SSLServerSocket() Used only by subclasses.
	SSLServerSocket(int port) Used only by subclasses.
	SSLServerSocket(int port, int backlog) Used only by subclasses.
	SSLServerSocket(int port, int backlog, InetAddress address) Used only by subclasses.

Public Method Summary

abstract boolean	getEnableSessionCreation() Returns true if new SSL sessions may be established by the sockets which are created from this server socket.
abstract String[]	getEnabledCipherSuites() Returns the list of cipher suites which are currently enabled for use by newly accepted connections.
abstract String[]	getEnabledProtocols() Returns the names of the protocols which are currently enabled for use by the newly accepted connections.
abstract boolean	getNeedClientAuth() Returns true if client authentication will be required on newly accepted server-mode SSLSockets.
SSLParameters	getSSLParameters() Returns the SSLParameters in effect for newly accepted connections.
abstract String[]	getSupportedCipherSuites() Returns the names of the cipher suites which could be enabled for use on an SSL connection.
abstract String[]	getSupportedProtocols() Returns the names of the protocols which could be enabled for use.
abstract boolean	getUseClientMode() Returns true if accepted connections will be in SSL client mode.
abstract boolean	getWantClientAuth() Returns true if client authentication will be requested on newly accepted server-mode connections.
abstract void	setEnableSessionCreation(boolean flag) Controls whether new SSL sessions may be established by the sockets which are created from this server socket.
abstract void	setEnabledCipherSuites(String[] suites) Sets the cipher suites enabled for use by accepted connections.
abstract void	setEnabledProtocols(String[] protocols) Controls which particular protocols are enabled for use by accepted connections.
abstract void	setNeedClientAuth(boolean need) Controls whether accepted server-mode SSLSockets will be initially configured to require client authentication.
void	setSSLParameters(SSLParameters params) Applies SSLParameters to newly accepted connections.
abstract void	setUseClientMode(boolean mode) Controls whether accepted connections are in the (default) SSL server mode, or the SSL client mode.
abstract void	setWantClientAuth(boolean want) Controls whether accepted server-mode SSLSockets will be initially configured to request client authentication.
String	toString() Returns the implementation address and implementation port of this socket as a String.

Inherited Method Summary

From class java.net.ServerSocket

Socket	accept() Listens for a connection to be made to this socket and accepts it.
void	bind(SocketAddress endpoint, int backlog) Binds the ServerSocket to a specific address (IP address and port number).
void	bind(SocketAddress endpoint) Binds the ServerSocket to a specific address (IP address and port number).
void	close() Closes this socket.
ServerSocketChannel	getChannel() Returns the unique ServerSocketChannel object associated with this socket, if any.
InetAddress	getInetAddress() Returns the local address of this server socket.
int	getLocalPort() Returns the port number on which this socket is listening.
SocketAddress	getLocalSocketAddress() Returns the address of the endpoint this socket is bound to.
synchronized int	getReceiveBufferSize() Gets the value of the SO_RCVBUF option for this ServerSocket, that is the proposed buffer size that will be used for Sockets accepted from this ServerSocket.
boolean	getReuseAddress() Tests if SO_REUSEADDR is enabled.
synchronized int	getSoTimeout() Retrieve setting for SO_TIMEOUT.
final void	implAccept(Socket s) Subclasses of ServerSocket use this method to override accept() to return their own subclass of socket.
boolean	isBound() Returns the binding state of the ServerSocket.
boolean	isClosed() Returns the closed state of the ServerSocket.
void	setPerformancePreferences(int connectionTime, int latency, int bandwidth) Sets performance preferences for this ServerSocket.
synchronized void	setReceiveBufferSize(int size) Sets a default proposed value for the SO_RCVBUF option for sockets accepted from this ServerSocket.
void	setReuseAddress(boolean on) Enable/disable the SO_REUSEADDR socket option.
synchronized void	setSoTimeout(int timeout) Enable/disable SO_TIMEOUT with the specified timeout, in milliseconds.
synchronized static void	setSocketFactory(SocketImplFactory fac) Sets the server socket implementation factory for the application.
String	toString() Returns the implementation address and implementation port of this socket as a String.

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

From interface java.io.Closeable

abstract void

close() Closes this stream and releases any system resources associated with it.

From interface java.lang.AutoCloseable

abstract void

close() Closes this resource, relinquishing any underlying resources.

Protected Constructors

protected SSLServerSocket ()

Used only by subclasses.

Create an unbound TCP server socket using the default authentication context.

Throws

IOException	if an I/O error occurs when creating the socket

protected SSLServerSocket (int port)

Used only by subclasses.

Create a TCP server socket on a port, using the default authentication context. The connection backlog defaults to fifty connections queued up before the system starts to reject new connection requests.

A port number of 0 creates a socket on any free port.

If there is a security manager, its checkListen method is called with the port argument as its argument to ensure the operation is allowed. This could result in a SecurityException.

Parameters

port	the port on which to listen

Throws

IOException	if an I/O error occurs when creating the socket
SecurityException	if a security manager exists and its checkListen method doesn't allow the operation.
IllegalArgumentException	if the port parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive.

See Also

• SecurityManager.checkListen(int)

protected SSLServerSocket (int port, int backlog)

Used only by subclasses.

Create a TCP server socket on a port, using the default authentication context and a specified backlog of connections.

A port number of 0 creates a socket on any free port.

The backlog argument is the requested maximum number of pending connections on the socket. Its exact semantics are implementation specific. In particular, an implementation may impose a maximum length or may choose to ignore the parameter altogther. The value provided should be greater than 0. If it is less than or equal to 0, then an implementation specific default will be used.

If there is a security manager, its checkListen method is called with the port argument as its argument to ensure the operation is allowed. This could result in a SecurityException.

Parameters

port	the port on which to listen
backlog	requested maximum length of the queue of incoming connections.

Throws

IOException	if an I/O error occurs when creating the socket
SecurityException	if a security manager exists and its checkListen method doesn't allow the operation.
IllegalArgumentException	if the port parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive.

See Also

• SecurityManager.checkListen(int)

protected SSLServerSocket (int port, int backlog, InetAddress address)

Used only by subclasses.

Create a TCP server socket on a port, using the default authentication context and a specified backlog of connections as well as a particular specified network interface. This constructor is used on multihomed hosts, such as those used for firewalls or as routers, to control through which interface a network service is provided.

If there is a security manager, its checkListen method is called with the port argument as its argument to ensure the operation is allowed. This could result in a SecurityException.

A port number of 0 creates a socket on any free port.

The backlog argument is the requested maximum number of pending connections on the socket. Its exact semantics are implementation specific. In particular, an implementation may impose a maximum length or may choose to ignore the parameter altogther. The value provided should be greater than 0. If it is less than or equal to 0, then an implementation specific default will be used.

If address is null, it will default accepting connections on any/all local addresses.

Parameters

port	the port on which to listen
backlog	requested maximum length of the queue of incoming connections.
address	the address of the network interface through which connections will be accepted

Throws

IOException	if an I/O error occurs when creating the socket
SecurityException	if a security manager exists and its checkListen method doesn't allow the operation.
IllegalArgumentException	if the port parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive.

See Also

• SecurityManager.checkListen(int)

Public Methods

public abstract boolean getEnableSessionCreation ()

Returns true if new SSL sessions may be established by the sockets which are created from this server socket.

Returns

• true indicates that sessions may be created; this is the default. false indicates that an existing session must be resumed

See Also

• setEnableSessionCreation(boolean)

public abstract String[] getEnabledCipherSuites ()

Returns the list of cipher suites which are currently enabled for use by newly accepted connections.

If this list has not been explicitly modified, a system-provided default guarantees a minimum quality of service in all enabled cipher suites.

There are several reasons why an enabled cipher suite might not actually be used. For example: the server socket might not have appropriate private keys available to it or the cipher suite might be anonymous, precluding the use of client authentication, while the server socket has been told to require that sort of authentication.

Returns

• an array of cipher suites enabled

See Also

• getSupportedCipherSuites()
• setEnabledCipherSuites(String[])

public abstract String[] getEnabledProtocols ()

Returns the names of the protocols which are currently enabled for use by the newly accepted connections.

Returns

• an array of protocol names

See Also

• getSupportedProtocols()
• setEnabledProtocols(String[])

public abstract boolean getNeedClientAuth ()

Returns true if client authentication will be required on newly accepted server-mode SSLSockets.

The initial inherited setting may be overridden by calling SSLSocket.setNeedClientAuth(boolean) or SSLSocket.setWantClientAuth(boolean).

Returns

• true if client authentication is required, or false if no client authentication is desired.

See Also

• setNeedClientAuth(boolean)
• setWantClientAuth(boolean)
• getWantClientAuth()
• setUseClientMode(boolean)

public SSLParameters getSSLParameters ()

Returns the SSLParameters in effect for newly accepted connections. The ciphersuites and protocols of the returned SSLParameters are always non-null.

Returns

• the SSLParameters in effect for newly accepted connections

See Also

• setSSLParameters(SSLParameters)

public abstract String[] getSupportedCipherSuites ()

Returns the names of the cipher suites which could be enabled for use on an SSL connection.

Normally, only a subset of these will actually be enabled by default, since this list may include cipher suites which do not meet quality of service requirements for those defaults. Such cipher suites are useful in specialized applications.

Returns

• an array of cipher suite names

See Also

• getEnabledCipherSuites()
• setEnabledCipherSuites(String[])

public abstract String[] getSupportedProtocols ()

Returns the names of the protocols which could be enabled for use.

Returns

• an array of protocol names supported

See Also

• getEnabledProtocols()
• setEnabledProtocols(String[])

public abstract boolean getUseClientMode ()

Returns true if accepted connections will be in SSL client mode.

Returns

• true if the connection should use SSL client mode.

See Also

• setUseClientMode(boolean)

public abstract boolean getWantClientAuth ()

Returns true if client authentication will be requested on newly accepted server-mode connections.

The initial inherited setting may be overridden by calling SSLSocket.setNeedClientAuth(boolean) or SSLSocket.setWantClientAuth(boolean).

Returns

• true if client authentication is requested, or false if no client authentication is desired.

See Also

• setWantClientAuth(boolean)
• setNeedClientAuth(boolean)
• getNeedClientAuth()
• setUseClientMode(boolean)

public abstract void setEnableSessionCreation (boolean flag)

Controls whether new SSL sessions may be established by the sockets which are created from this server socket.

SSLSockets returned from accept() inherit this setting.

Parameters

flag	true indicates that sessions may be created; this is the default. false indicates that an existing session must be resumed.

See Also

• getEnableSessionCreation()

public abstract void setEnabledCipherSuites (String[] suites)

Sets the cipher suites enabled for use by accepted connections.

The cipher suites must have been listed by getSupportedCipherSuites() as being supported. Following a successful call to this method, only suites listed in the suites parameter are enabled for use.

Suites that require authentication information which is not available in this ServerSocket's authentication context will not be used in any case, even if they are enabled.

SSLSockets returned from accept() inherit this setting.

Parameters

suites	Names of all the cipher suites to enable

Throws

IllegalArgumentException	when one or more of ciphers named by the parameter is not supported, or when the parameter is null.

See Also

• getSupportedCipherSuites()
• getEnabledCipherSuites()

public abstract void setEnabledProtocols (String[] protocols)

Controls which particular protocols are enabled for use by accepted connections.

The protocols must have been listed by getSupportedProtocols() as being supported. Following a successful call to this method, only protocols listed in the protocols parameter are enabled for use.

SSLSockets returned from accept() inherit this setting.

Parameters

protocols	Names of all the protocols to enable.

Throws

IllegalArgumentException	when one or more of the protocols named by the parameter is not supported or when the protocols parameter is null.

See Also

• getEnabledProtocols()
• getSupportedProtocols()

public abstract void setNeedClientAuth (boolean need)

Controls whether accepted server-mode SSLSockets will be initially configured to require client authentication.

A socket's client authentication setting is one of the following:

• client authentication required
• client authentication requested
• no client authentication desired

Unlike setWantClientAuth(boolean), if the accepted socket's option is set and the client chooses not to provide authentication information about itself, the negotiations will stop and the connection will be dropped.

Calling this method overrides any previous setting made by this method or setWantClientAuth(boolean).

The initial inherited setting may be overridden by calling SSLSocket.setNeedClientAuth(boolean) or SSLSocket.setWantClientAuth(boolean).

Parameters

need	set to true if client authentication is required, or false if no client authentication is desired.

See Also

• getNeedClientAuth()
• setWantClientAuth(boolean)
• getWantClientAuth()
• setUseClientMode(boolean)

public void setSSLParameters (SSLParameters params)

Applies SSLParameters to newly accepted connections.

This means:

• If params.getCipherSuites() is non-null, setEnabledCipherSuites() is called with that value.
• If params.getProtocols() is non-null, setEnabledProtocols() is called with that value.
• If params.getNeedClientAuth() or params.getWantClientAuth() return true, setNeedClientAuth(true) and setWantClientAuth(true) are called, respectively; otherwise setWantClientAuth(false) is called.
• If params.getServerNames() is non-null, the socket will configure its server names with that value.
• If params.getSNIMatchers() is non-null, the socket will configure its SNI matchers with that value.

Parameters

params	the parameters

Throws

IllegalArgumentException	if the setEnabledCipherSuites() or the setEnabledProtocols() call fails

See Also

• getSSLParameters()

public abstract void setUseClientMode (boolean mode)

Controls whether accepted connections are in the (default) SSL server mode, or the SSL client mode.

Servers normally authenticate themselves, and clients are not required to do so.

In rare cases, TCP servers need to act in the SSL client mode on newly accepted connections. For example, FTP clients acquire server sockets and listen there for reverse connections from the server. An FTP client would use an SSLServerSocket in "client" mode to accept the reverse connection while the FTP server uses an SSLSocket with "client" mode disabled to initiate the connection. During the resulting handshake, existing SSL sessions may be reused.

SSLSockets returned from accept() inherit this setting.

Parameters

mode	true if newly accepted connections should use SSL client mode.

See Also

• getUseClientMode()

public abstract void setWantClientAuth (boolean want)

Controls whether accepted server-mode SSLSockets will be initially configured to request client authentication.

A socket's client authentication setting is one of the following:

• client authentication required
• client authentication requested
• no client authentication desired

Unlike setNeedClientAuth(boolean), if the accepted socket's option is set and the client chooses not to provide authentication information about itself, the negotiations will continue.

Calling this method overrides any previous setting made by this method or setNeedClientAuth(boolean).

The initial inherited setting may be overridden by calling SSLSocket.setNeedClientAuth(boolean) or SSLSocket.setWantClientAuth(boolean).

Parameters

want	set to true if client authentication is requested, or false if no client authentication is desired.

See Also

• getWantClientAuth()
• setNeedClientAuth(boolean)
• getNeedClientAuth()
• setUseClientMode(boolean)

public String toString ()

Returns the implementation address and implementation port of this socket as a String.

If there is a security manager set, its checkConnect method is called with the local address and -1 as its arguments to see if the operation is allowed. If the operation is not allowed, an InetAddress representing the loopback address is returned as the implementation address.

Returns

• a string representation of this socket.