SSLServerSocketFactorys create
* SSLServerSockets.
*
* @since 1.4
* @see SSLSocket
* @see SSLServerSocket
* @author David Brownell
*/
public abstract class SSLServerSocketFactory extends ServerSocketFactory
{
// Android-changed: Renamed field.
// Some apps rely on changing this field via reflection, so we can't change the name
// without introducing app compatibility problems. See http://b/62248930.
private static SSLServerSocketFactory defaultServerSocketFactory;
// Android-changed: Check Security.getVersion() on each update.
// If the set of providers or other such things changes, it may change the default
// factory, so we track the version returned from Security.getVersion() instead of
// only having a flag that says if we've ever initialized the default.
// private static boolean propertyChecked;
private static int lastVersion = -1;
private static void log(String msg) {
if (SSLSocketFactory.DEBUG) {
System.out.println(msg);
}
}
/**
* Constructor is used only by subclasses.
*/
protected SSLServerSocketFactory() { /* NOTHING */ }
/**
* Returns the default SSL server socket factory.
*
* The first time this method is called, the security property * "ssl.ServerSocketFactory.provider" is examined. If it is non-null, a * class by that name is loaded and instantiated. If that is successful and * the object is an instance of SSLServerSocketFactory, it is made the * default SSL server socket factory. * *
Otherwise, this method returns
* SSLContext.getDefault().getServerSocketFactory(). If that
* call fails, an inoperative factory is returned.
*
* @return the default ServerSocketFactory
* @see SSLContext#getDefault
*/
public static synchronized ServerSocketFactory getDefault() {
// Android-changed: Check Security.getVersion() on each update.
if (defaultServerSocketFactory != null && lastVersion == Security.getVersion()) {
return defaultServerSocketFactory;
}
lastVersion = Security.getVersion();
SSLServerSocketFactory previousDefaultServerSocketFactory = defaultServerSocketFactory;
defaultServerSocketFactory = null;
String clsName = SSLSocketFactory.getSecurityProperty
("ssl.ServerSocketFactory.provider");
if (clsName != null) {
// Android-changed: Check if we already have an instance of the default factory class.
// The instance for the default socket factory is checked for updates quite
// often (for instance, every time a security provider is added). Which leads
// to unnecessary overload and excessive error messages in case of class-loading
// errors. Avoid creating a new object if the class name is the same as before.
if (previousDefaultServerSocketFactory != null
&& clsName.equals(previousDefaultServerSocketFactory.getClass().getName())) {
defaultServerSocketFactory = previousDefaultServerSocketFactory;
return defaultServerSocketFactory;
}
log("setting up default SSLServerSocketFactory");
try {
Class cls = null;
try {
cls = Class.forName(clsName);
} catch (ClassNotFoundException e) {
// Android-changed; Try the contextClassLoader first.
ClassLoader cl = Thread.currentThread().getContextClassLoader();
if (cl == null) {
cl = ClassLoader.getSystemClassLoader();
}
if (cl != null) {
// Android-changed: Use Class.forName() so the class gets initialized.
cls = Class.forName(clsName, true, cl);
}
}
log("class " + clsName + " is loaded");
SSLServerSocketFactory fac = (SSLServerSocketFactory)cls.newInstance();
log("instantiated an instance of class " + clsName);
defaultServerSocketFactory = fac;
return fac;
} catch (Exception e) {
log("SSLServerSocketFactory instantiation failed: " + e);
// Android-changed: Fallback to the default SSLContext on exception.
}
}
try {
// Android-changed: Allow for {@code null} SSLContext.getDefault.
SSLContext context = SSLContext.getDefault();
if (context != null) {
defaultServerSocketFactory = context.getServerSocketFactory();
} else {
defaultServerSocketFactory = new DefaultSSLServerSocketFactory(new IllegalStateException("No factory found."));
}
return defaultServerSocketFactory;
} catch (NoSuchAlgorithmException e) {
return new DefaultSSLServerSocketFactory(e);
}
}
/**
* Returns the list of cipher suites which are enabled by default.
* Unless a different list is enabled, handshaking on an SSL connection
* will use one of these cipher suites. The minimum quality of service
* for these defaults requires confidentiality protection and server
* authentication (that is, no anonymous cipher suites).
*
* @see #getSupportedCipherSuites()
* @return array of the cipher suites enabled by default
*/
public abstract String [] getDefaultCipherSuites();
// Android-changed: Added warnings about misuse
/**
* Returns the names of the cipher suites which could be enabled for use
* on an SSL connection created by this factory.
* 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 {@code Arrays.asList(getSupportedCipherSuites()).contains(...)} * or to filter a desired list of cipher suites to only the supported ones via * {@code desiredSuiteSet.retainAll(Arrays.asList(getSupportedCipherSuites()))}. * * @return an array of cipher suite names * @see #getDefaultCipherSuites() */ public abstract String [] getSupportedCipherSuites(); } // // The default factory does NOTHING. // class DefaultSSLServerSocketFactory extends SSLServerSocketFactory { private final Exception reason; DefaultSSLServerSocketFactory(Exception reason) { this.reason = reason; } private ServerSocket throwException() throws SocketException { throw (SocketException) new SocketException(reason.toString()).initCause(reason); } @Override public ServerSocket createServerSocket() throws IOException { return throwException(); } @Override public ServerSocket createServerSocket(int port) throws IOException { return throwException(); } @Override public ServerSocket createServerSocket(int port, int backlog) throws IOException { return throwException(); } @Override public ServerSocket createServerSocket(int port, int backlog, InetAddress ifAddress) throws IOException { return throwException(); } @Override public String [] getDefaultCipherSuites() { return new String[0]; } @Override public String [] getSupportedCipherSuites() { return new String[0]; } }