# Class SSLContext

java.lang.Object
javax.net.ssl.SSLContext

public class SSLContext extends Object
Instances of this class represent a secure socket protocol implementation which acts as a factory for secure socket factories or `SSLEngine`s. 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` protocols:

- `TLSv1.2`
- `TLSv1.3`

These protocols are described in the SSLContext section of the Java Security Standard Algorithm Names Specification. Consult the release documentation for your implementation to see if any other protocols are supported.

Since:
  1.4
External Specifications
  - Java Security Standard Algorithm Names

- ## Constructor Summary

  Constructors
  Modifier
  Constructor
  Description
  `protected`
  `SSLContext(SSLContextSpi contextSpi, Provider provider, String protocol)`
  Creates an SSLContext object.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `final SSLEngine`
  `createSSLEngine()`
  Creates a new `SSLEngine` using this context.
  `final SSLEngine`
  `createSSLEngine(String peerHost, int peerPort)`
  Creates a new `SSLEngine` using this context using advisory peer information.
  `final SSLSessionContext`
  `getClientSessionContext()`
  Returns the client session context, which represents the set of SSL sessions available for use during the handshake phase of client-side SSL sockets.
  `static SSLContext`
  `getDefault()`
  Returns the default SSL context.
  `final SSLParameters`
  `getDefaultSSLParameters()`
  Returns a copy of the SSLParameters indicating the default settings for this SSL context.
  `static SSLContext`
  `getInstance(String protocol)`
  Returns a `SSLContext` object that implements the specified secure socket protocol.
  `static SSLContext`
  `getInstance(String protocol, String provider)`
  Returns a `SSLContext` object that implements the specified secure socket protocol.
  `static SSLContext`
  `getInstance(String protocol, Provider provider)`
  Returns a `SSLContext` object that implements the specified secure socket protocol.
  `final String`
  `getProtocol()`
  Returns the protocol name of this `SSLContext` object.
  `final Provider`
  `getProvider()`
  Returns the provider of this `SSLContext` object.
  `final SSLSessionContext`
  `getServerSessionContext()`
  Returns the server session context, which represents the set of SSL sessions available for use during the handshake phase of server-side SSL sockets.
  `final SSLServerSocketFactory`
  `getServerSocketFactory()`
  Returns a `ServerSocketFactory` object for this context.
  `final SSLSocketFactory`
  `getSocketFactory()`
  Returns a `SocketFactory` object for this context.
  `final SSLParameters`
  `getSupportedSSLParameters()`
  Returns a copy of the SSLParameters indicating the supported settings for this SSL context.
  `final void`
  `init(KeyManager[] km, TrustManager[] tm, SecureRandom random)`
  Initializes this context.
  `static void`
  `setDefault(SSLContext context)`
  Sets the default SSL context.

  ### Methods declared in class Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Constructor Details

  - ### SSLContext

    protected SSLContext(SSLContextSpi contextSpi, Provider provider, String protocol)
    Creates an SSLContext object.
    Parameters:
      `contextSpi` - the delegate
      `provider` - the provider
      `protocol` - the protocol

- ## Method Details

  - ### getDefault

    public static SSLContext getDefault() throws NoSuchAlgorithmException
    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.

    Returns:
      the default SSL context
    Throws:
      `NoSuchAlgorithmException` - if the `SSLContext.getInstance()` call fails
    Since:
      1.6

  - ### setDefault

    public static void setDefault(SSLContext context)
    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.
    Parameters:
      `context` - the SSLContext
    Throws:
      `NullPointerException` - if context is null
    Since:
      1.6

  - ### getInstance

    public static SSLContext getInstance(String protocol) throws NoSuchAlgorithmException
    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.

    Implementation Note:
      The JDK Reference Implementation additionally uses the `jdk.security.provider.preferred` `Security` property to determine the preferred provider order for the specified algorithm. This may be different from the order of providers returned by `Security.getProviders()`.
    Parameters:
      `protocol` - the standard name of the requested protocol. See the SSLContext section in the Java Security Standard Algorithm Names Specification for information about standard protocol names.
    Returns:
      the new `SSLContext` object
    Throws:
      `NoSuchAlgorithmException` - if no `Provider` supports a `SSLContextSpi` implementation for the specified protocol
      `NullPointerException` - if `protocol` is `null`
    External Specifications
      - Java Security Standard Algorithm Names
    See Also:
      - `Provider`

  - ### getInstance

    public static SSLContext getInstance(String protocol, String provider) throws NoSuchAlgorithmException, NoSuchProviderException
    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.

    Parameters:
      `protocol` - the standard name of the requested protocol. See the SSLContext section in the Java Security Standard Algorithm Names Specification for information about standard protocol names.
      `provider` - the name of the provider.
    Returns:
      the new `SSLContext` object
    Throws:
      `IllegalArgumentException` - if the provider name is `null` or empty
      `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
      `NullPointerException` - if `protocol` is `null`
    External Specifications
      - Java Security Standard Algorithm Names
    See Also:
      - `Provider`

  - ### getInstance

    public static SSLContext getInstance(String protocol, Provider provider) throws NoSuchAlgorithmException
    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.

    Parameters:
      `protocol` - the standard name of the requested protocol. See the SSLContext section in the Java Security Standard Algorithm Names Specification for information about standard protocol names.
      `provider` - an instance of the provider.
    Returns:
      the new `SSLContext` object
    Throws:
      `IllegalArgumentException` - if the provider is `null`
      `NoSuchAlgorithmException` - if a `SSLContextSpi` implementation for the specified protocol is not available from the specified `Provider` object
      `NullPointerException` - if `protocol` is `null`
    External Specifications
      - Java Security Standard Algorithm Names
    See Also:
      - `Provider`

  - ### getProtocol

    public final String getProtocol()
    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.

  - ### getProvider

    public final Provider getProvider()
    Returns the provider of this `SSLContext` object.
    Returns:
      the provider of this `SSLContext` object

  - ### init

    public final void init(KeyManager[] km, TrustManager[] tm, SecureRandom random) throws KeyManagementException
    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.)

    Parameters:
      `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

  - ### getSocketFactory

    public final SSLSocketFactory getSocketFactory()
    Returns a `SocketFactory` object for this context.
    Returns:
      the `SocketFactory` object
    Throws:
      `UnsupportedOperationException` - if the underlying provider does not implement the operation.
      `IllegalStateException` - if the SSLContextImpl requires initialization and the `init()` has not been called

  - ### getServerSocketFactory

    public final SSLServerSocketFactory getServerSocketFactory()
    Returns a `ServerSocketFactory` object for this context.
    Returns:
      the `ServerSocketFactory` object
    Throws:
      `UnsupportedOperationException` - if the underlying provider does not implement the operation.
      `IllegalStateException` - if the SSLContextImpl requires initialization and the `init()` has not been called

  - ### createSSLEngine

    public final SSLEngine createSSLEngine()
    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.

    Implementation Note:
      It is provider-specific if the returned SSLEngine uses client or server mode by default for the (D)TLS connection. The JDK SunJSSE provider implementation uses server mode by default. However, it is recommended to always set the desired mode explicitly by calling `SSLEngine.setUseClientMode()` before invoking other methods of the SSLEngine.
    Returns:
      the `SSLEngine` object
    Throws:
      `UnsupportedOperationException` - if the underlying provider does not implement the operation.
      `IllegalStateException` - if the SSLContextImpl requires initialization and the `init()` has not been called
    Since:
      1.5

  - ### createSSLEngine

    public final SSLEngine createSSLEngine(String peerHost, int peerPort)
    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.

    Implementation Note:
      It is provider-specific if the returned SSLEngine uses client or server mode by default for the (D)TLS connection. The JDK SunJSSE provider implementation uses server mode by default. However, it is recommended to always set the desired mode explicitly by calling `SSLEngine.setUseClientMode()` before invoking other methods of the SSLEngine.
    Parameters:
      `peerHost` - the non-authoritative name of the host
      `peerPort` - the non-authoritative port
    Returns:
      the new `SSLEngine` object
    Throws:
      `UnsupportedOperationException` - if the underlying provider does not implement the operation.
      `IllegalStateException` - if the SSLContextImpl requires initialization and the `init()` has not been called
    Since:
      1.5

  - ### getServerSessionContext

    public final SSLSessionContext getServerSessionContext()
    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

  - ### getClientSessionContext

    public final SSLSessionContext getClientSessionContext()
    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

  - ### getDefaultSSLParameters

    public final SSLParameters getDefaultSSLParameters()
    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.

    Returns:
      a copy of the SSLParameters object with the default settings
    Throws:
      `UnsupportedOperationException` - if the default SSL parameters could not be obtained.
    Since:
      1.6

  - ### getSupportedSSLParameters

    public final SSLParameters getSupportedSSLParameters()
    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.

    Returns:
      a copy of the SSLParameters object with the supported settings
    Throws:
      `UnsupportedOperationException` - if the supported SSL parameters could not be obtained.
    Since:
      1.6