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package javax.net.ssl;

import java.security.*;
import java.util.*;

import sun.security.jca.GetInstance;

Instances of this class represent a secure socket protocol
implementation which acts as a factory for secure socket
factories or SSLEngines. This class is initialized
with an optional set of key and trust managers and source of
secure random bytes.
 Every implementation of the Java platform is required to support the
following standard SSLContext protocol:

TLSv1

This protocol is described in the 
SSLContext section of the
Java Cryptography Architecture Standard Algorithm Name Documentation.
Consult the release documentation for your implementation to see if any
other algorithms are supported.
Since:
1.4/**
 * Instances of this class represent a secure socket protocol
 * implementation which acts as a factory for secure socket
 * factories or <code>SSLEngine</code>s. This class is initialized
 * with an optional set of key and trust managers and source of
 * secure random bytes.
 *
 * <p> Every implementation of the Java platform is required to support the
 * following standard <code>SSLContext</code> protocol:
 * <ul>
 * <li><tt>TLSv1</tt></li>
 * </ul>
 * This protocol is described in the <a href=
 * "{@docRoot}/../technotes/guides/security/StandardNames.html#SSLContext">
 * SSLContext section</a> of the
 * Java Cryptography Architecture Standard Algorithm Name Documentation.
 * Consult the release documentation for your implementation to see if any
 * other algorithms are supported.
 *
 * @since 1.4
 */
public class SSLContext {
    private final Provider provider;

    private final SSLContextSpi contextSpi;

    private final String protocol;

    
Creates an SSLContext object.
Params:
contextSpi – the delegate
provider – the provider
protocol – the protocol/**
     * Creates an SSLContext object.
     *
     * @param contextSpi the delegate
     * @param provider the provider
     * @param protocol the protocol
     */
    protected SSLContext(SSLContextSpi contextSpi, Provider provider,
            String protocol) {
        this.contextSpi = contextSpi;
        this.provider = provider;
        this.protocol = protocol;
    }

    private static SSLContext defaultContext;

    
Returns the default SSL context.
If a default context was set using the 
SSLContext.setDefault() method, it is returned. Otherwise, the first call of this method triggers the call SSLContext.getInstance("Default").
If successful, that object is made the default SSL context and returned.
The default context is immediately usable and does not require initialization. 
Throws:
NoSuchAlgorithmException – if the SSLContext.getInstance() call fails
Returns:
the default SSL context
Since:
1.6/**
     * Returns the default SSL context.
     *
     * <p>If a default context was set using the {@link #setDefault
     * SSLContext.setDefault()} method, it is returned. Otherwise, the first
     * call of this method triggers the call
     * <code>SSLContext.getInstance("Default")</code>.
     * If successful, that object is made the default SSL context and returned.
     *
     * <p>The default context is immediately
     * usable and does not require {@linkplain #init initialization}.
     *
     * @return the default SSL context
     * @throws NoSuchAlgorithmException if the
     *   {@link SSLContext#getInstance SSLContext.getInstance()} call fails
     * @since 1.6
     */
    public static synchronized SSLContext getDefault()
            throws NoSuchAlgorithmException {
        if (defaultContext == null) {
            defaultContext = SSLContext.getInstance("Default");
        }
        return defaultContext;
    }

    
Sets the default SSL context. It will be returned by subsequent calls to getDefault. The default context must be immediately usable and not require initialization. 
Params:
context – the SSLContext
Throws:
NullPointerException – if context is null
SecurityException – if a security manager exists and its
         checkPermission method does not allow
         SSLPermission("setDefaultSSLContext")
Since:
1.6/**
     * Sets the default SSL context. It will be returned by subsequent calls
     * to {@link #getDefault}. The default context must be immediately usable
     * and not require {@linkplain #init initialization}.
     *
     * @param context the SSLContext
     * @throws  NullPointerException if context is null
     * @throws  SecurityException if a security manager exists and its
     *          <code>checkPermission</code> method does not allow
     *          <code>SSLPermission("setDefaultSSLContext")</code>
     * @since 1.6
     */
    public static synchronized void setDefault(SSLContext context) {
        if (context == null) {
            throw new NullPointerException();
        }
        SecurityManager sm = System.getSecurityManager();
        if (sm != null) {
            sm.checkPermission(new SSLPermission("setDefaultSSLContext"));
        }
        defaultContext = context;
    }

    
Returns a SSLContext object that implements the
specified secure socket protocol.
 This method traverses the list of registered security Providers,
starting with the most preferred Provider.
A new SSLContext object encapsulating the
SSLContextSpi implementation from the first
Provider that supports the specified protocol is returned.
 Note that the list of registered providers may be retrieved via the Security.getProviders() method. 
Params:
protocol – the standard name of the requested protocol.
         See the SSLContext section in the 
         Java Cryptography Architecture Standard Algorithm Name
         Documentation
         for information about standard protocol names.
Throws:
NoSuchAlgorithmException – if no Provider supports a
         TrustManagerFactorySpi implementation for the
         specified protocol.
NullPointerException – if protocol is null.
See Also:
Provider
Returns:
the new SSLContext object./**
     * Returns a <code>SSLContext</code> object that implements the
     * specified secure socket protocol.
     *
     * <p> This method traverses the list of registered security Providers,
     * starting with the most preferred Provider.
     * A new SSLContext object encapsulating the
     * SSLContextSpi implementation from the first
     * Provider that supports the specified protocol is returned.
     *
     * <p> Note that the list of registered providers may be retrieved via
     * the {@link Security#getProviders() Security.getProviders()} method.
     *
     * @param protocol the standard name of the requested protocol.
     *          See the SSLContext section in the <a href=
     * "{@docRoot}/../technotes/guides/security/StandardNames.html#SSLContext">
     *          Java Cryptography Architecture Standard Algorithm Name
     *          Documentation</a>
     *          for information about standard protocol names.
     *
     * @return the new <code>SSLContext</code> object.
     *
     * @exception NoSuchAlgorithmException if no Provider supports a
     *          TrustManagerFactorySpi implementation for the
     *          specified protocol.
     * @exception NullPointerException if protocol is null.
     *
     * @see java.security.Provider
     */
    public static SSLContext getInstance(String protocol)
            throws NoSuchAlgorithmException {
        GetInstance.Instance instance = GetInstance.getInstance
                ("SSLContext", SSLContextSpi.class, protocol);
        return new SSLContext((SSLContextSpi)instance.impl, instance.provider,
                protocol);
    }

    
Returns a SSLContext object that implements the
specified secure socket protocol.
 A new SSLContext object encapsulating the
SSLContextSpi implementation from the specified provider
is returned.  The specified provider must be registered
in the security provider list.
 Note that the list of registered providers may be retrieved via the Security.getProviders() method. 
Params:
protocol – the standard name of the requested protocol.
         See the SSLContext section in the 
         Java Cryptography Architecture Standard Algorithm Name
         Documentation
         for information about standard protocol names.
provider – the name of the provider.
Throws:
NoSuchAlgorithmException – if a SSLContextSpi
         implementation for the specified protocol is not
         available from the specified provider.
NoSuchProviderException – if the specified provider is not
         registered in the security provider list.
IllegalArgumentException – if the provider name is null or empty.
NullPointerException – if protocol is null.
See Also:
Provider
Returns:
the new SSLContext object./**
     * Returns a <code>SSLContext</code> object that implements the
     * specified secure socket protocol.
     *
     * <p> A new SSLContext object encapsulating the
     * SSLContextSpi implementation from the specified provider
     * is returned.  The specified provider must be registered
     * in the security provider list.
     *
     * <p> Note that the list of registered providers may be retrieved via
     * the {@link Security#getProviders() Security.getProviders()} method.
     *
     * @param protocol the standard name of the requested protocol.
     *          See the SSLContext section in the <a href=
     * "{@docRoot}/../technotes/guides/security/StandardNames.html#SSLContext">
     *          Java Cryptography Architecture Standard Algorithm Name
     *          Documentation</a>
     *          for information about standard protocol names.
     *
     * @param provider the name of the provider.
     *
     * @return the new <code>SSLContext</code> object.
     *
     * @throws NoSuchAlgorithmException if a SSLContextSpi
     *          implementation for the specified protocol is not
     *          available from the specified provider.
     *
     * @throws NoSuchProviderException if the specified provider is not
     *          registered in the security provider list.
     *
     * @throws IllegalArgumentException if the provider name is null or empty.
     * @throws NullPointerException if protocol is null.
     *
     * @see java.security.Provider
     */
    public static SSLContext getInstance(String protocol, String provider)
            throws NoSuchAlgorithmException, NoSuchProviderException {
        GetInstance.Instance instance = GetInstance.getInstance
                ("SSLContext", SSLContextSpi.class, protocol, provider);
        return new SSLContext((SSLContextSpi)instance.impl, instance.provider,
                protocol);
    }

    
Returns a SSLContext object that implements the
specified secure socket protocol.
 A new SSLContext object encapsulating the
SSLContextSpi implementation from the specified Provider
object is returned.  Note that the specified Provider object
does not have to be registered in the provider list.
Params:
protocol – the standard name of the requested protocol.
         See the SSLContext section in the 
         Java Cryptography Architecture Standard Algorithm Name
         Documentation
         for information about standard protocol names.
provider – an instance of the provider.
Throws:
NoSuchAlgorithmException – if a KeyManagerFactorySpi
         implementation for the specified protocol is not available
         from the specified Provider object.
IllegalArgumentException – if the provider name is null.
NullPointerException – if protocol is null.
See Also:
Provider
Returns:
the new SSLContext object./**
     * Returns a <code>SSLContext</code> object that implements the
     * specified secure socket protocol.
     *
     * <p> A new SSLContext object encapsulating the
     * SSLContextSpi implementation from the specified Provider
     * object is returned.  Note that the specified Provider object
     * does not have to be registered in the provider list.
     *
     * @param protocol the standard name of the requested protocol.
     *          See the SSLContext section in the <a href=
     * "{@docRoot}/../technotes/guides/security/StandardNames.html#SSLContext">
     *          Java Cryptography Architecture Standard Algorithm Name
     *          Documentation</a>
     *          for information about standard protocol names.
     *
     * @param provider an instance of the provider.
     *
     * @return the new <code>SSLContext</code> object.
     *
     * @throws NoSuchAlgorithmException if a KeyManagerFactorySpi
     *          implementation for the specified protocol is not available
     *          from the specified Provider object.
     *
     * @throws IllegalArgumentException if the provider name is null.
     * @throws NullPointerException if protocol is null.
     *
     * @see java.security.Provider
     */
    public static SSLContext getInstance(String protocol, Provider provider)
            throws NoSuchAlgorithmException {
        GetInstance.Instance instance = GetInstance.getInstance
                ("SSLContext", SSLContextSpi.class, protocol, provider);
        return new SSLContext((SSLContextSpi)instance.impl, instance.provider,
                protocol);
    }

    
Returns the protocol name of this SSLContext object.
This is the same name that was specified in one of the
getInstance calls that created this
SSLContext object.
Returns:
the protocol name of this SSLContext object./**
     * Returns the protocol name of this <code>SSLContext</code> object.
     *
     * <p>This is the same name that was specified in one of the
     * <code>getInstance</code> calls that created this
     * <code>SSLContext</code> object.
     *
     * @return the protocol name of this <code>SSLContext</code> object.
     */
    public final String getProtocol() {
        return this.protocol;
    }

    
Returns the provider of this SSLContext object.
Returns:
the provider of this SSLContext object/**
     * Returns the provider of this <code>SSLContext</code> object.
     *
     * @return the provider of this <code>SSLContext</code> object
     */
    public final Provider getProvider() {
        return this.provider;
    }

    
Initializes this context. Either of the first two parameters
may be null in which case the installed security providers will
be searched for the highest priority implementation of the
appropriate factory. Likewise, the secure random parameter may
be null in which case the default implementation will be used.

Only the first instance of a particular key and/or trust manager
implementation type in the array is used.  (For example, only
the first javax.net.ssl.X509KeyManager in the array will be used.)
Params:
km – the sources of authentication keys or null
tm – the sources of peer authentication trust decisions or null
random – the source of randomness for this generator or null
Throws:
KeyManagementException – if this operation fails/**
     * Initializes this context. Either of the first two parameters
     * may be null in which case the installed security providers will
     * be searched for the highest priority implementation of the
     * appropriate factory. Likewise, the secure random parameter may
     * be null in which case the default implementation will be used.
     * <P>
     * Only the first instance of a particular key and/or trust manager
     * implementation type in the array is used.  (For example, only
     * the first javax.net.ssl.X509KeyManager in the array will be used.)
     *
     * @param km the sources of authentication keys or null
     * @param tm the sources of peer authentication trust decisions or null
     * @param random the source of randomness for this generator or null
     * @throws KeyManagementException if this operation fails
     */
    public final void init(KeyManager[] km, TrustManager[] tm,
                                SecureRandom random)
        throws KeyManagementException {
        contextSpi.engineInit(km, tm, random);
    }

    
Returns a SocketFactory object for this
context.
Throws:
IllegalStateException – if the SSLContextImpl requires
         initialization and the init() has not been called
Returns:
the SocketFactory object/**
     * Returns a <code>SocketFactory</code> object for this
     * context.
     *
     * @return the <code>SocketFactory</code> object
     * @throws IllegalStateException if the SSLContextImpl requires
     *          initialization and the <code>init()</code> has not been called
     */
    public final SSLSocketFactory getSocketFactory() {
        return contextSpi.engineGetSocketFactory();
    }

    
Returns a ServerSocketFactory object for
this context.
Throws:
IllegalStateException – if the SSLContextImpl requires
         initialization and the init() has not been called
Returns:
the ServerSocketFactory object/**
     * Returns a <code>ServerSocketFactory</code> object for
     * this context.
     *
     * @return the <code>ServerSocketFactory</code> object
     * @throws IllegalStateException if the SSLContextImpl requires
     *          initialization and the <code>init()</code> has not been called
     */
    public final SSLServerSocketFactory getServerSocketFactory() {
        return contextSpi.engineGetServerSocketFactory();
    }

    
Creates a new SSLEngine using this context.
 Applications using this factory method are providing no hints for an internal session reuse strategy. If hints are desired, createSSLEngine(String, int) should be used instead. 

Some cipher suites (such as Kerberos) require remote hostname
information, in which case this factory method should not be used.
Throws:
UnsupportedOperationException – if the underlying provider
         does not implement the operation.
IllegalStateException – if the SSLContextImpl requires
         initialization and the init() has not been called
Returns:
 the SSLEngine object
Since:
  1.5/**
     * Creates a new <code>SSLEngine</code> using this context.
     * <P>
     * Applications using this factory method are providing no hints
     * for an internal session reuse strategy. If hints are desired,
     * {@link #createSSLEngine(String, int)} should be used
     * instead.
     * <P>
     * Some cipher suites (such as Kerberos) require remote hostname
     * information, in which case this factory method should not be used.
     *
     * @return  the <code>SSLEngine</code> object
     * @throws  UnsupportedOperationException if the underlying provider
     *          does not implement the operation.
     * @throws  IllegalStateException if the SSLContextImpl requires
     *          initialization and the <code>init()</code> has not been called
     * @since   1.5
     */
    public final SSLEngine createSSLEngine() {
        try {
            return contextSpi.engineCreateSSLEngine();
        } catch (AbstractMethodError e) {
            UnsupportedOperationException unsup =
                new UnsupportedOperationException(
                    "Provider: " + getProvider() +
                    " doesn't support this operation");
            unsup.initCause(e);
            throw unsup;
        }
    }

    
Creates a new SSLEngine using this context using
advisory peer information.

Applications using this factory method are providing hints
for an internal session reuse strategy.

Some cipher suites (such as Kerberos) require remote hostname
information, in which case peerHost needs to be specified.
Params:
peerHost – the non-authoritative name of the host
peerPort – the non-authoritative port
Throws:
UnsupportedOperationException – if the underlying provider
         does not implement the operation.
IllegalStateException – if the SSLContextImpl requires
         initialization and the init() has not been called
Returns:
 the new SSLEngine object
Since:
  1.5/**
     * Creates a new <code>SSLEngine</code> using this context using
     * advisory peer information.
     * <P>
     * Applications using this factory method are providing hints
     * for an internal session reuse strategy.
     * <P>
     * Some cipher suites (such as Kerberos) require remote hostname
     * information, in which case peerHost needs to be specified.
     *
     * @param   peerHost the non-authoritative name of the host
     * @param   peerPort the non-authoritative port
     * @return  the new <code>SSLEngine</code> object
     * @throws  UnsupportedOperationException if the underlying provider
     *          does not implement the operation.
     * @throws  IllegalStateException if the SSLContextImpl requires
     *          initialization and the <code>init()</code> has not been called
     * @since   1.5
     */
    public final SSLEngine createSSLEngine(String peerHost, int peerPort) {
        try {
            return contextSpi.engineCreateSSLEngine(peerHost, peerPort);
        } catch (AbstractMethodError e) {
            UnsupportedOperationException unsup =
                new UnsupportedOperationException(
                    "Provider: " + getProvider() +
                    " does not support this operation");
            unsup.initCause(e);
            throw unsup;
        }
    }

    
Returns the server session context, which represents the set of
SSL sessions available for use during the handshake phase of
server-side SSL sockets.

This context may be unavailable in some environments, in which
case this method returns null. For example, when the underlying
SSL provider does not provide an implementation of SSLSessionContext
interface, this method returns null. A non-null session context
is returned otherwise.
Returns:
server session context bound to this SSL context/**
     * Returns the server session context, which represents the set of
     * SSL sessions available for use during the handshake phase of
     * server-side SSL sockets.
     * <P>
     * This context may be unavailable in some environments, in which
     * case this method returns null. For example, when the underlying
     * SSL provider does not provide an implementation of SSLSessionContext
     * interface, this method returns null. A non-null session context
     * is returned otherwise.
     *
     * @return server session context bound to this SSL context
     */
    public final SSLSessionContext getServerSessionContext() {
        return contextSpi.engineGetServerSessionContext();
    }

    
Returns the client session context, which represents the set of
SSL sessions available for use during the handshake phase of
client-side SSL sockets.

This context may be unavailable in some environments, in which
case this method returns null. For example, when the underlying
SSL provider does not provide an implementation of SSLSessionContext
interface, this method returns null. A non-null session context
is returned otherwise.
Returns:
client session context bound to this SSL context/**
     * Returns the client session context, which represents the set of
     * SSL sessions available for use during the handshake phase of
     * client-side SSL sockets.
     * <P>
     * This context may be unavailable in some environments, in which
     * case this method returns null. For example, when the underlying
     * SSL provider does not provide an implementation of SSLSessionContext
     * interface, this method returns null. A non-null session context
     * is returned otherwise.
     *
     * @return client session context bound to this SSL context
     */
    public final SSLSessionContext getClientSessionContext() {
        return contextSpi.engineGetClientSessionContext();
    }

    
Returns a copy of the SSLParameters indicating the default
settings for this SSL context.
The parameters will always have the ciphersuites and protocols
arrays set to non-null values.
Throws:
UnsupportedOperationException – if the default SSL parameters
  could not be obtained.
Returns:
a copy of the SSLParameters object with the default settings
Since:
1.6/**
     * Returns a copy of the SSLParameters indicating the default
     * settings for this SSL context.
     *
     * <p>The parameters will always have the ciphersuites and protocols
     * arrays set to non-null values.
     *
     * @return a copy of the SSLParameters object with the default settings
     * @throws UnsupportedOperationException if the default SSL parameters
     *   could not be obtained.
     * @since 1.6
     */
    public final SSLParameters getDefaultSSLParameters() {
        return contextSpi.engineGetDefaultSSLParameters();
    }

    
Returns a copy of the SSLParameters indicating the supported
settings for this SSL context.
The parameters will always have the ciphersuites and protocols
arrays set to non-null values.
Throws:
UnsupportedOperationException – if the supported SSL parameters
  could not be obtained.
Returns:
a copy of the SSLParameters object with the supported
  settings
Since:
1.6/**
     * Returns a copy of the SSLParameters indicating the supported
     * settings for this SSL context.
     *
     * <p>The parameters will always have the ciphersuites and protocols
     * arrays set to non-null values.
     *
     * @return a copy of the SSLParameters object with the supported
     *   settings
     * @throws UnsupportedOperationException if the supported SSL parameters
     *   could not be obtained.
     * @since 1.6
     */
    public final SSLParameters getSupportedSSLParameters() {
        return contextSpi.engineGetSupportedSSLParameters();
    }

}