SSLServerSocket

public abstract class SSLServerSocket
extends ServerSocket

java.lang.Object
   ↳ java.net.ServerSocket
     ↳ javax.net.ssl.SSLServerSocket


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.

Summary

Protected constructors

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 methods

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 methods

Protected constructors

SSLServerSocket

Added in API level 1
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

SSLServerSocket

Added in API level 1
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 int: 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.

SSLServerSocket

Added in API level 1
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 int: the port on which to listen

backlog int: 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.

SSLServerSocket

Added in API level 1
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 int: the port on which to listen

backlog int: requested maximum length of the queue of incoming connections.

address InetAddress: 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.

Public methods

getEnableSessionCreation

Added in API level 1
public abstract boolean getEnableSessionCreation ()

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

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

getEnabledCipherSuites

Added in API level 1
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
String[] an array of cipher suites enabled

getEnabledProtocols

Added in API level 1
public abstract String[] getEnabledProtocols ()

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

Returns
String[] an array of protocol names

getNeedClientAuth

Added in API level 1
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
boolean true if client authentication is required, or false if no client authentication is desired.

getSSLParameters

Added in API level 24
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
SSLParameters the SSLParameters in effect for newly accepted connections

getSupportedCipherSuites

Added in API level 1
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.

Applications should not blindly enable all supported cipher suites. The supported cipher suites can include signaling cipher suite values that can cause connection problems if enabled inappropriately.

The proper way to use this method is to either check if a specific cipher suite is supported via Arrays.asList(getSupportedCipherSuites()).contains(...) or to filter a desired list of cipher suites to only the supported ones via desiredSuiteSet.retainAll(Arrays.asList(getSupportedCipherSuites())).

Returns
String[] an array of cipher suite names

getSupportedProtocols

Added in API level 1
public abstract String[] getSupportedProtocols ()

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

Returns
String[] an array of protocol names supported

getUseClientMode

Added in API level 1
public abstract boolean getUseClientMode ()

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

Returns
boolean true if the connection should use SSL client mode.

getWantClientAuth

Added in API level 1
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
boolean true if client authentication is requested, or false if no client authentication is desired.

setEnableSessionCreation

Added in API level 1
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 boolean: true indicates that sessions may be created; this is the default. false indicates that an existing session must be resumed.

setEnabledCipherSuites

Added in API level 1
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 String: 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.

setEnabledProtocols

Added in API level 1
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.

Because of the way the protocol version is negotiated, connections will only be able to use a member of the lowest set of contiguous enabled protocol versions. For example, enabling TLSv1.2 and TLSv1 will result in connections only being able to use TLSv1.

SSLSockets returned from accept() inherit this setting.

Parameters
protocols String: 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.

setNeedClientAuth

Added in API level 1
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 boolean: set to true if client authentication is required, or false if no client authentication is desired.

setSSLParameters

Added in API level 24
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 SSLParameters: the parameters

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

See also:

setUseClientMode

Added in API level 1
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 boolean: true if newly accepted connections should use SSL client mode.

See also:

setWantClientAuth

Added in API level 1
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 boolean: set to true if client authentication is requested, or false if no client authentication is desired.

toString

Added in API level 1
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
String a string representation of this socket.