public abstract class SSLSocket extends Socket
Socket
s 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:
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:
startHandshake
which explicitly
begins handshakes, or
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:
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 SSLSocket
s 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.
SSLSocket
s are created by SSLSocketFactory
s,
or by accept
ing 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.
Socket
,
SSLServerSocket
,
SSLSocketFactory
Modifier | Constructor and Description |
---|---|
protected |
SSLSocket()
Used only by subclasses.
|
protected |
SSLSocket(InetAddress address,
int port)
Used only by subclasses.
|
protected |
SSLSocket(InetAddress address,
int port,
InetAddress clientAddress,
int clientPort)
Used only by subclasses.
|
protected |
SSLSocket(String host,
int port)
Used only by subclasses.
|
protected |
SSLSocket(String host,
int port,
InetAddress clientAddress,
int clientPort)
Used only by subclasses.
|
Modifier and Type | Method and Description |
---|---|
abstract void |
addHandshakeCompletedListener(HandshakeCompletedListener listener)
Registers an event listener to receive notifications that an
SSL handshake has completed on this connection.
|
abstract String[] |
getEnabledCipherSuites()
Returns the names of the SSL cipher suites which are currently
enabled for use on this connection.
|
abstract String[] |
getEnabledProtocols()
Returns the names of the protocol versions which are currently
enabled for use on this connection.
|
abstract boolean |
getEnableSessionCreation()
Returns true if new SSL sessions may be established by this socket.
|
SSLSession |
getHandshakeSession()
Returns the
SSLSession being constructed during a SSL/TLS
handshake. |
abstract boolean |
getNeedClientAuth()
Returns true if the socket will require client authentication.
|
abstract SSLSession |
getSession()
Returns the SSL Session in use by this connection.
|
SSLParameters |
getSSLParameters()
Returns the SSLParameters in effect for this SSLSocket.
|
abstract String[] |
getSupportedCipherSuites()
Returns the names of the cipher suites which could be enabled for use
on this connection.
|
abstract String[] |
getSupportedProtocols()
Returns the names of the protocols which could be enabled for use
on an SSL connection.
|
abstract boolean |
getUseClientMode()
Returns true if the socket is set to use client mode when
handshaking.
|
abstract boolean |
getWantClientAuth()
Returns true if the socket will request client authentication.
|
abstract void |
removeHandshakeCompletedListener(HandshakeCompletedListener listener)
Removes a previously registered handshake completion listener.
|
abstract void |
setEnabledCipherSuites(String[] suites)
Sets the cipher suites enabled for use on this connection.
|
abstract void |
setEnabledProtocols(String[] protocols)
Sets the protocol versions enabled for use on this connection.
|
abstract void |
setEnableSessionCreation(boolean flag)
Controls whether new SSL sessions may be established by this socket.
|
abstract void |
setNeedClientAuth(boolean need)
Configures the socket to require client authentication.
|
void |
setSSLParameters(SSLParameters params)
Applies SSLParameters to this socket.
|
abstract void |
setUseClientMode(boolean mode)
Configures the socket to use client (or server) mode when
handshaking.
|
abstract void |
setWantClientAuth(boolean want)
Configures the socket to request client authentication.
|
abstract void |
startHandshake()
Starts an SSL handshake on this connection.
|
bind, close, connect, connect, getChannel, getInetAddress, getInputStream, getKeepAlive, getLocalAddress, getLocalPort, getLocalSocketAddress, getOOBInline, getOutputStream, getPort, getReceiveBufferSize, getRemoteSocketAddress, getReuseAddress, getSendBufferSize, getSoLinger, getSoTimeout, getTcpNoDelay, getTrafficClass, isBound, isClosed, isConnected, isInputShutdown, isOutputShutdown, sendUrgentData, setKeepAlive, setOOBInline, setPerformancePreferences, setReceiveBufferSize, setReuseAddress, setSendBufferSize, setSocketImplFactory, setSoLinger, setSoTimeout, setTcpNoDelay, setTrafficClass, shutdownInput, shutdownOutput, toString
protected SSLSocket()
protected SSLSocket(String host, int port) throws IOException, UnknownHostException
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.
host
- name of the host with which to connect, or
null
for the loopback address.port
- number of the server's portIOException
- if an I/O error occurs when creating the socketSecurityException
- if a security manager exists and its
checkConnect
method doesn't allow the operation.UnknownHostException
- if the host is not knownIllegalArgumentException
- if the port parameter is outside the
specified range of valid port values, which is between 0 and
65535, inclusive.SecurityManager.checkConnect(java.lang.String, int)
protected SSLSocket(InetAddress address, int port) throws IOException
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.
address
- the server's hostport
- its portIOException
- if an I/O error occurs when creating the socketSecurityException
- 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.SecurityManager.checkConnect(java.lang.String, int)
protected SSLSocket(String host, int port, InetAddress clientAddress, int clientPort) throws IOException, UnknownHostException
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.
host
- name of the host with which to connect, or
null
for the loopback address.port
- number of the server's portclientAddress
- 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.IOException
- if an I/O error occurs when creating the socketSecurityException
- if a security manager exists and its
checkConnect
method doesn't allow the operation.UnknownHostException
- if the host is not knownIllegalArgumentException
- if the port parameter or clientPort
parameter is outside the specified range of valid port values,
which is between 0 and 65535, inclusive.SecurityManager.checkConnect(java.lang.String, int)
protected SSLSocket(InetAddress address, int port, InetAddress clientAddress, int clientPort) throws IOException
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.
address
- the server's hostport
- its portclientAddress
- 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.IOException
- if an I/O error occurs when creating the socketSecurityException
- 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.SecurityManager.checkConnect(java.lang.String, int)
public abstract String[] getSupportedCipherSuites()
getEnabledCipherSuites()
,
setEnabledCipherSuites(String [])
public abstract String[] getEnabledCipherSuites()
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.
getSupportedCipherSuites()
,
setEnabledCipherSuites(String [])
public abstract void setEnabledCipherSuites(String[] suites)
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.
suites
- Names of all the cipher suites to enableIllegalArgumentException
- when one or more of the ciphers
named by the parameter is not supported, or when the
parameter is null.getSupportedCipherSuites()
,
getEnabledCipherSuites()
public abstract String[] getSupportedProtocols()
public abstract String[] getEnabledProtocols()
setEnabledProtocols(String [])
public abstract void setEnabledProtocols(String[] protocols)
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.
protocols
- Names of all the protocols to enable.IllegalArgumentException
- when one or more of
the protocols named by the parameter is not supported or
when the protocols parameter is null.getEnabledProtocols()
public abstract SSLSession getSession()
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".
SSLSession
public SSLSession getHandshakeSession()
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 SSLSession
has
been completely initialized and made available via 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 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 getPeerCertificates
method of SSLSession
will throw a
SSLPeerUnverifiedException. Once that chain has been processed,
getPeerCertificates
will return the proper value.
Unlike getSession()
, this method does not initiate the
initial handshake and does not block until handshaking is
complete.
SSLSession
currently being negotiated.UnsupportedOperationException
- if the underlying provider
does not implement the operation.SSLEngine
,
SSLSession
,
ExtendedSSLSession
,
X509ExtendedKeyManager
,
X509ExtendedTrustManager
public abstract void addHandshakeCompletedListener(HandshakeCompletedListener listener)
listener
- the HandShake Completed event listenerIllegalArgumentException
- if the argument is null.startHandshake()
,
removeHandshakeCompletedListener(HandshakeCompletedListener)
public abstract void removeHandshakeCompletedListener(HandshakeCompletedListener listener)
listener
- the HandShake Completed event listenerIllegalArgumentException
- if the listener is not registered,
or the argument is null.addHandshakeCompletedListener(HandshakeCompletedListener)
public abstract void startHandshake() throws IOException
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.
IOException
- on a network level erroraddHandshakeCompletedListener(HandshakeCompletedListener)
public abstract void setUseClientMode(boolean mode)
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.
mode
- true if the socket should start its handshaking
in "client" modeIllegalArgumentException
- if a mode change is attempted
after the initial handshake has begun.getUseClientMode()
public abstract boolean getUseClientMode()
setUseClientMode(boolean)
public abstract void setNeedClientAuth(boolean need)
A socket's client authentication setting is one of the following:
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)
.
need
- set to true if client authentication is required,
or false if no client authentication is desired.getNeedClientAuth()
,
setWantClientAuth(boolean)
,
getWantClientAuth()
,
setUseClientMode(boolean)
public abstract boolean getNeedClientAuth()
setNeedClientAuth(boolean)
,
setWantClientAuth(boolean)
,
getWantClientAuth()
,
setUseClientMode(boolean)
public abstract void setWantClientAuth(boolean want)
A socket's client authentication setting is one of the following:
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)
.
want
- set to true if client authentication is requested,
or false if no client authentication is desired.getWantClientAuth()
,
setNeedClientAuth(boolean)
,
getNeedClientAuth()
,
setUseClientMode(boolean)
public abstract boolean getWantClientAuth()
setNeedClientAuth(boolean)
,
getNeedClientAuth()
,
setWantClientAuth(boolean)
,
setUseClientMode(boolean)
public abstract void setEnableSessionCreation(boolean flag)
flag
- true indicates that sessions may be created; this
is the default. false indicates that an existing session
must be resumedgetEnableSessionCreation()
public abstract boolean getEnableSessionCreation()
setEnableSessionCreation(boolean)
public SSLParameters getSSLParameters()
public void setSSLParameters(SSLParameters params)
This means:
params.getCipherSuites()
is non-null,
setEnabledCipherSuites()
is called with that value
params.getProtocols()
is non-null,
setEnabledProtocols()
is called with that value
params.getNeedClientAuth()
or
params.getWantClientAuth()
return true
,
setNeedClientAuth(true)
and
setWantClientAuth(true)
are called, respectively;
otherwise setWantClientAuth(false)
is called.
params
- the parametersIllegalArgumentException
- if the setEnabledCipherSuites() or
the setEnabledProtocols() call fails Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2020, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.
Scripting on this page tracks web page traffic, but does not change the content in any way.