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.

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.

Inherited Method Summary

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

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

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

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

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

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

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 setNeedClientAuth(boolean) or setWantClientAuth(boolean).

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

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

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

public abstract String[] getSupportedProtocols ()

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

Returns
  • an array of protocol names supported

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.

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 setNeedClientAuth(boolean) or setWantClientAuth(boolean).

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

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.

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.

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.

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 setNeedClientAuth(boolean) or setWantClientAuth(boolean).

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

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.

Parameters
params the parameters
Throws
IllegalArgumentException if the setEnabledCipherSuites() or the setEnabledProtocols() call fails

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.

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 setNeedClientAuth(boolean) or setWantClientAuth(boolean).

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