javax.net.ssl: abstract public class: SSLSocket

javax.net.ssl
abstract public class: SSLSocket [javadoc | source]

java.lang.Object
   java.net.Socket
      javax.net.ssl.SSLSocket

All Implemented Interfaces:
Closeable

This class extends Sockets and provides secure socket using protocols such as the "Secure Sockets Layer" (SSL) or IETF "Transport Layer Security" (TLS) protocols.

Such sockets are normal stream sockets, but they add a layer of security protections over the underlying network transport protocol, such as TCP. Those protections include:

Integrity Protection. SSL protects against modification of messages by an active wiretapper.
Authentication. In most modes, SSL provides peer authentication. Servers are usually authenticated, and clients may be authenticated as requested by servers.
Confidentiality (Privacy Protection). In most modes, SSL encrypts data being sent between client and server. This protects the confidentiality of data, so that passive wiretappers won't see sensitive data such as financial information or personal information of many kinds.

These kinds of protection are specified by a "cipher suite", which is a combination of cryptographic algorithms used by a given SSL connection. During the negotiation process, the two endpoints must agree on a ciphersuite that is available in both environments. If there is no such suite in common, no SSL connection can be established, and no data can be exchanged.

The cipher suite used is established by a negotiation process called "handshaking". The goal of this process is to create or rejoin a "session", which may protect many connections over time. After handshaking has completed, you can access session attributes by using the getSession method. The initial handshake on this connection can be initiated in one of three ways:

calling startHandshake which explicitly begins handshakes, or
any attempt to read or write application data on this socket causes an implicit handshake, or
a call to getSession tries to set up a session if there is no currently valid session, and an implicit handshake is done.

If handshaking fails for any reason, the SSLSocket is closed, and no futher communications can be done.

There are two groups of cipher suites which you will need to know about when managing cipher suites:

Supported cipher suites: all the suites which are supported by the SSL implementation. This list is reported using getSupportedCipherSuites.
Enabled cipher suites, which may be fewer than the full set of supported suites. This group is set using the setEnabledCipherSuites method, and queried using the getEnabledCipherSuites method. Initially, a default set of cipher suites will be enabled on a new socket that represents the minimum suggested configuration.

Implementation defaults require that only cipher suites which authenticate servers and provide confidentiality be enabled by default. Only if both sides explicitly agree to unauthenticated and/or non-private (unencrypted) communications will such a ciphersuite be selected.

When SSLSockets are first created, no handshaking is done so that applications may first set their communication preferences: what cipher suites to use, whether the socket should be in client or server mode, etc. However, security is always provided by the time that application data is sent over the connection.

You may register to receive event notification of handshake completion. This involves the use of two additional classes. HandshakeCompletedEvent objects are passed to HandshakeCompletedListener instances, which are registered by users of this API. SSLSockets are created by SSLSocketFactorys, or by accepting a connection from a SSLServerSocket.

A SSL socket must choose to operate in the client or server mode. This will determine who begins the handshaking process, as well as which messages should be sent by each party. Each connection must have one client and one server, or handshaking will not progress properly. Once the initial handshaking has started, a socket can not switch between client and server modes, even when performing renegotiations.

Also see:

java.net.Socket

SSLServerSocket

SSLSocketFactory

since: 1.4 -

author: David - Brownell

Fields inherited from java.net.Socket:
impl

Constructor:

Constructor:
protected SSLSocket() { super(); } Used only by subclasses. Constructs an uninitialized, unconnected TCP socket.
protected SSLSocket(String host, int port) throws IOException, UnknownHostException { super(host, port); } Used only by subclasses. Constructs a TCP connection to a named host at a specified port. This acts as the SSL client. If there is a security manager, its `checkConnect` method is called with the host address and `port` as its arguments. This could result in a SecurityException. Parameters: `host` - name of the host with which to connect, or `null` for the loopback address. `port` - number of the server's port Throws: `IOException` - if an I/O error occurs when creating the socket `SecurityException` - if a security manager exists and its `checkConnect` method doesn't allow the operation. `UnknownHostException` - if the host is not known `IllegalArgumentException` - if the port parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive. Also see: SecurityManager#checkConnect
protected SSLSocket(InetAddress address, int port) throws IOException { super(address, port); } Used only by subclasses. Constructs a TCP connection to a server at a specified address and port. This acts as the SSL client. If there is a security manager, its `checkConnect` method is called with the host address and `port` as its arguments. This could result in a SecurityException. Parameters: `address` - the server's host `port` - its port Throws: `IOException` - if an I/O error occurs when creating the socket `SecurityException` - if a security manager exists and its `checkConnect` 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. `NullPointerException` - if `address` is null. Also see: SecurityManager#checkConnect
protected SSLSocket(String host, int port, InetAddress clientAddress, int clientPort) throws IOException, UnknownHostException { super(host, port, clientAddress, clientPort); } Used only by subclasses. Constructs an SSL connection to a named host at a specified port, binding the client side of the connection a given address and port. This acts as the SSL client. If there is a security manager, its `checkConnect` method is called with the host address and `port` as its arguments. This could result in a SecurityException. Parameters: `host` - name of the host with which to connect, or `null` for the loopback address. `port` - number of the server's port `clientAddress` - the client's address the socket is bound to, or `null` for the `anyLocal` address. `clientPort` - the client's port the socket is bound to, or `zero` for a system selected free port. Throws: `IOException` - if an I/O error occurs when creating the socket `SecurityException` - if a security manager exists and its `checkConnect` method doesn't allow the operation. `UnknownHostException` - if the host is not known `IllegalArgumentException` - if the port parameter or clientPort parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive. Also see: SecurityManager#checkConnect
protected SSLSocket(InetAddress address, int port, InetAddress clientAddress, int clientPort) throws IOException { super(address, port, clientAddress, clientPort); } Used only by subclasses. Constructs an SSL connection to a server at a specified address and TCP port, binding the client side of the connection a given address and port. This acts as the SSL client. If there is a security manager, its `checkConnect` method is called with the host address and `port` as its arguments. This could result in a SecurityException. Parameters: `address` - the server's host `port` - its port `clientAddress` - the client's address the socket is bound to, or `null` for the `anyLocal` address. `clientPort` - the client's port the socket is bound to, or `zero` for a system selected free port. Throws: `IOException` - if an I/O error occurs when creating the socket `SecurityException` - if a security manager exists and its `checkConnect` method doesn't allow the operation. `IllegalArgumentException` - if the port parameter or clientPort parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive. `NullPointerException` - if `address` is null. Also see: SecurityManager#checkConnect

 protected SSLSocket() {
 super();
}

Used only by subclasses. Constructs an uninitialized, unconnected TCP socket.

 protected SSLSocket(String host,
    int port) throws IOException, UnknownHostException {
 super(host, port);
}

If there is a security manager, its checkConnect method is called with the host address and port as its arguments. This could result in a SecurityException.

Parameters:

host - name of the host with which to connect, or null for the loopback address.

port - number of the server's port

Throws:

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

SecurityException - if a security manager exists and its checkConnect method doesn't allow the operation.

UnknownHostException - if the host is not known

IllegalArgumentException - if the port parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive.

Also see:

SecurityManager#checkConnect

 protected SSLSocket(InetAddress address,
    int port) throws IOException {
 super(address, port);
}

If there is a security manager, its checkConnect method is called with the host address and port as its arguments. This could result in a SecurityException.

Parameters:

address - the server's host

port - its port

Throws:

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

SecurityException - if a security manager exists and its checkConnect 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.

NullPointerException - if address is null.

Also see:

SecurityManager#checkConnect

 protected SSLSocket(String host,
    int port,
    InetAddress clientAddress,
    int clientPort) throws IOException, UnknownHostException {
 super(host, port, clientAddress, clientPort);
}

If there is a security manager, its checkConnect method is called with the host address and port as its arguments. This could result in a SecurityException.

Parameters:

host - name of the host with which to connect, or null for the loopback address.

port - number of the server's port

clientAddress - the client's address the socket is bound to, or null for the anyLocal address.

clientPort - the client's port the socket is bound to, or zero for a system selected free port.

Throws:

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

SecurityException - if a security manager exists and its checkConnect method doesn't allow the operation.

UnknownHostException - if the host is not known

IllegalArgumentException - if the port parameter or clientPort parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive.

Also see:

SecurityManager#checkConnect

 protected SSLSocket(InetAddress address,
    int port,
    InetAddress clientAddress,
    int clientPort) throws IOException {
 super(address, port, clientAddress, clientPort);
}

If there is a security manager, its checkConnect method is called with the host address and port as its arguments. This could result in a SecurityException.

Parameters:

address - the server's host

port - its port

clientAddress - the client's address the socket is bound to, or null for the anyLocal address.

clientPort - the client's port the socket is bound to, or zero for a system selected free port.

Throws:

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

SecurityException - if a security manager exists and its checkConnect method doesn't allow the operation.

IllegalArgumentException - if the port parameter or clientPort parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive.

NullPointerException - if address is null.

Also see:

SecurityManager#checkConnect

Method from javax.net.ssl.SSLSocket Summary:
addHandshakeCompletedListener, getEnableSessionCreation, getEnabledCipherSuites, getEnabledProtocols, getHandshakeSession, getNeedClientAuth, getSSLParameters, getSession, getSupportedCipherSuites, getSupportedProtocols, getUseClientMode, getWantClientAuth, removeHandshakeCompletedListener, setEnableSessionCreation, setEnabledCipherSuites, setEnabledProtocols, setNeedClientAuth, setSSLParameters, setUseClientMode, setWantClientAuth, startHandshake

Method from javax.net.ssl.SSLSocket Summary:

addHandshakeCompletedListener, getEnableSessionCreation, getEnabledCipherSuites, getEnabledProtocols, getHandshakeSession, getNeedClientAuth, getSSLParameters, getSession, getSupportedCipherSuites, getSupportedProtocols, getUseClientMode, getWantClientAuth, removeHandshakeCompletedListener, setEnableSessionCreation, setEnabledCipherSuites, setEnabledProtocols, setNeedClientAuth, setSSLParameters, setUseClientMode, setWantClientAuth, startHandshake

Methods from java.net.Socket:
bind, close, connect, connect, createImpl, getChannel, getImpl, getInetAddress, getInputStream, getKeepAlive, getLocalAddress, getLocalPort, getLocalSocketAddress, getOOBInline, getOutputStream, getPort, getReceiveBufferSize, getRemoteSocketAddress, getReuseAddress, getSendBufferSize, getSoLinger, getSoTimeout, getTcpNoDelay, getTrafficClass, isBound, isClosed, isConnected, isInputShutdown, isOutputShutdown, postAccept, sendUrgentData, setBound, setConnected, setCreated, setImpl, setKeepAlive, setOOBInline, setPerformancePreferences, setReceiveBufferSize, setReuseAddress, setSendBufferSize, setSoLinger, setSoTimeout, setSocketImplFactory, setTcpNoDelay, setTrafficClass, shutdownInput, shutdownOutput, toString

Methods from java.net.Socket:

bind, close, connect, connect, createImpl, getChannel, getImpl, getInetAddress, getInputStream, getKeepAlive, getLocalAddress, getLocalPort, getLocalSocketAddress, getOOBInline, getOutputStream, getPort, getReceiveBufferSize, getRemoteSocketAddress, getReuseAddress, getSendBufferSize, getSoLinger, getSoTimeout, getTcpNoDelay, getTrafficClass, isBound, isClosed, isConnected, isInputShutdown, isOutputShutdown, postAccept, sendUrgentData, setBound, setConnected, setCreated, setImpl, setKeepAlive, setOOBInline, setPerformancePreferences, setReceiveBufferSize, setReuseAddress, setSendBufferSize, setSoLinger, setSoTimeout, setSocketImplFactory, setTcpNoDelay, setTrafficClass, shutdownInput, shutdownOutput, toString

Methods from java.lang.Object:
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from javax.net.ssl.SSLSocket Detail:
abstract public void addHandshakeCompletedListener(HandshakeCompletedListener listener) Registers an event listener to receive notifications that an SSL handshake has completed on this connection.
abstract public boolean getEnableSessionCreation() Returns true if new SSL sessions may be established by this socket.
abstract public String[] getEnabledCipherSuites() Returns the names of the SSL cipher suites which are currently enabled for use on this connection. When an SSLSocket is first created, all enabled cipher suites support a minimum quality of service. Thus, in some environments this value might be empty. Even if a suite has been enabled, it might never be used. (For example, the peer does not support it, the requisite certificates (and private keys) for the suite are not available, or an anonymous suite is enabled but authentication is required.
abstract public String[] getEnabledProtocols() Returns the names of the protocol versions which are currently enabled for use on this connection.
public SSLSession getHandshakeSession() { throw new UnsupportedOperationException(); } Returns the {@code SSLSession} being constructed during a SSL/TLS handshake. TLS protocols may negotiate parameters that are needed when using an instance of this class, but before the {@code SSLSession} has been completely initialized and made available via {@code getSession}. For example, the list of valid signature algorithms may restrict the type of certificates that can used during TrustManager decisions, or the maximum TLS fragment packet sizes can be resized to better support the network environment. This method provides early access to the {@code SSLSession} being constructed. Depending on how far the handshake has progressed, some data may not yet be available for use. For example, if a remote server will be sending a Certificate chain, but that chain has yet not been processed, the {@code getPeerCertificates} method of {@code SSLSession} will throw a SSLPeerUnverifiedException. Once that chain has been processed, {@code getPeerCertificates} will return the proper value. Unlike #getSession() , this method does not initiate the initial handshake and does not block until handshaking is complete.
abstract public boolean getNeedClientAuth() Returns true if the socket will require client authentication. This option is only useful to sockets in the server mode.
public SSLParameters getSSLParameters() { SSLParameters params = new SSLParameters(); params.setCipherSuites(getEnabledCipherSuites()); params.setProtocols(getEnabledProtocols()); if (getNeedClientAuth()) { params.setNeedClientAuth(true); } else if (getWantClientAuth()) { params.setWantClientAuth(true); } return params; } Returns the SSLParameters in effect for this SSLSocket. The ciphersuites and protocols of the returned SSLParameters are always non-null.
abstract public SSLSession getSession() Returns the SSL Session in use by this connection. These can be long lived, and frequently correspond to an entire login session for some user. The session specifies a particular cipher suite which is being actively used by all connections in that session, as well as the identities of the session's client and server. This method will initiate the initial handshake if necessary and then block until the handshake has been established. If an error occurs during the initial handshake, this method returns an invalid session object which reports an invalid cipher suite of "SSL_NULL_WITH_NULL_NULL".
abstract public String[] getSupportedCipherSuites() Returns the names of the cipher suites which could be enabled for use on this 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 might be useful in specialized applications.
abstract public String[] getSupportedProtocols() Returns the names of the protocols which could be enabled for use on an SSL connection.
abstract public boolean getUseClientMode() Returns true if the socket is set to use client mode when handshaking.
abstract public boolean getWantClientAuth() Returns true if the socket will request client authentication. This option is only useful for sockets in the server mode.
abstract public void removeHandshakeCompletedListener(HandshakeCompletedListener listener) Removes a previously registered handshake completion listener.
abstract public void setEnableSessionCreation(boolean flag) Controls whether new SSL sessions may be established by this socket. If session creations are not allowed, and there are no existing sessions to resume, there will be no successful handshaking.
abstract public void setEnabledCipherSuites(String[] suites) Sets the cipher suites enabled for use on this connection. Each cipher suite in the `suites` parameter must have been listed by getSupportedCipherSuites(), or the method will fail. Following a successful call to this method, only suites listed in the `suites` parameter are enabled for use. See #getEnabledCipherSuites() for more information on why a specific ciphersuite may never be used on a connection.
abstract public void setEnabledProtocols(String[] protocols) Sets the protocol versions enabled for use on this connection. 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.
abstract public void setNeedClientAuth(boolean need) Configures the socket to require client authentication. This option is only useful for sockets in the server mode. 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 this 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) .
public void setSSLParameters(SSLParameters params) { String[] s; s = params.getCipherSuites(); if (s != null) { setEnabledCipherSuites(s); } s = params.getProtocols(); if (s != null) { setEnabledProtocols(s); } if (params.getNeedClientAuth()) { setNeedClientAuth(true); } else if (params.getWantClientAuth()) { setWantClientAuth(true); } else { setWantClientAuth(false); } } Applies SSLParameters to this socket. 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.
abstract public void setUseClientMode(boolean mode) Configures the socket to use client (or server) mode when handshaking. This method must be called before any handshaking occurs. Once handshaking has begun, the mode can not be reset for the life of this socket. Servers normally authenticate themselves, and clients are not required to do so.
abstract public void setWantClientAuth(boolean want) Configures the socket to request client authentication. This option is only useful for sockets in the server mode. 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 this 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) .
abstract public void startHandshake() throws IOException Starts an SSL handshake on this connection. Common reasons include a need to use new encryption keys, to change cipher suites, or to initiate a new session. To force complete reauthentication, the current session could be invalidated before starting this handshake. If data has already been sent on the connection, it continues to flow during this handshake. When the handshake completes, this will be signaled with an event. This method is synchronous for the initial handshake on a connection and returns when the negotiated handshake is complete. Some protocols may not support multiple handshakes on an existing socket and may throw an IOException.