/* * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.net.ssl; import java.nio.ByteBuffer; import java.nio.ReadOnlyBufferException; /** * A class which enables secure communications using protocols such as * the Secure Sockets Layer (SSL) or * IETF RFC 2246 "Transport * Layer Security" (TLS) protocols, but is transport independent. *

* The secure communications modes 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 cipher suite 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 {@link #getSession()} method. *

* The SSLSocket class provides much of the same security * functionality, but all of the inbound and outbound data is * automatically transported using the underlying {@link * java.net.Socket Socket}, which by design uses a blocking model. * While this is appropriate for many applications, this model does not * provide the scalability required by large servers. *

* The primary distinction of an SSLEngine is that it * operates on inbound and outbound byte streams, independent of the * transport mechanism. It is the responsibility of the * SSLEngine user to arrange for reliable I/O transport to * the peer. By separating the SSL/TLS abstraction from the I/O * transport mechanism, the SSLEngine can be used for a * wide variety of I/O types, such as {@link * java.nio.channels.spi.AbstractSelectableChannel#configureBlocking(boolean) * non-blocking I/O (polling)}, {@link java.nio.channels.Selector * selectable non-blocking I/O}, {@link java.net.Socket Socket} and the * traditional Input/OutputStreams, local {@link java.nio.ByteBuffer * ByteBuffers} or byte arrays, future asynchronous * I/O models , and so on. *

* At a high level, the SSLEngine appears thus: * *

 *                   app data
 *
 *                |           ^
 *                |     |     |
 *                v     |     |
 *           +----+-----|-----+----+
 *           |          |          |
 *           |       SSL|Engine    |
 *   wrap()  |          |          |  unwrap()
 *           | OUTBOUND | INBOUND  |
 *           |          |          |
 *           +----+-----|-----+----+
 *                |     |     ^
 *                |     |     |
 *                v           |
 *
 *                   net data
 * 
* Application data (also known as plaintext or cleartext) is data which * is produced or consumed by an application. Its counterpart is * network data, which consists of either handshaking and/or ciphertext * (encrypted) data, and destined to be transported via an I/O * mechanism. Inbound data is data which has been received from the * peer, and outbound data is destined for the peer. *

* (In the context of an SSLEngine, the term "handshake * data" is taken to mean any data exchanged to establish and control a * secure connection. Handshake data includes the SSL/TLS messages * "alert", "change_cipher_spec," and "handshake.") *

* There are five distinct phases to an SSLEngine. * *

    *
  1. Creation - The SSLEngine has been created and * initialized, but has not yet been used. During this phase, an * application may set any SSLEngine-specific settings * (enabled cipher suites, whether the SSLEngine should * handshake in client or server mode, and so on). Once * handshaking has begun, though, any new settings (except * client/server mode, see below) will be used for * the next handshake. * *
  2. Initial Handshake - The initial handshake is a procedure by * which the two peers exchange communication parameters until an * SSLSession is established. Application data can not be sent during * this phase. * *
  3. Application Data - Once the communication parameters have * been established and the handshake is complete, application data * may flow through the SSLEngine. Outbound * application messages are encrypted and integrity protected, * and inbound messages reverse the process. * *
  4. Rehandshaking - Either side may request a renegotiation of * the session at any time during the Application Data phase. New * handshaking data can be intermixed among the application data. * Before starting the rehandshake phase, the application may * reset the SSL/TLS communication parameters such as the list of * enabled ciphersuites and whether to use client authentication, * but can not change between client/server modes. As before, once * handshaking has begun, any new SSLEngine * configuration settings will not be used until the next * handshake. * *
  5. Closure - When the connection is no longer needed, the * application should close the SSLEngine and should * send/receive any remaining messages to the peer before * closing the underlying transport mechanism. Once an engine is * closed, it is not reusable: a new SSLEngine must * be created. *
* An SSLEngine is created by calling {@link * SSLContext#createSSLEngine()} from an initialized * SSLContext. Any configuration * parameters should be set before making the first call to * wrap(), unwrap(), or * beginHandshake(). These methods all trigger the * initial handshake. *

* Data moves through the engine by calling {@link #wrap(ByteBuffer, * ByteBuffer) wrap()} or {@link #unwrap(ByteBuffer, ByteBuffer) * unwrap()} on outbound or inbound data, respectively. Depending on * the state of the SSLEngine, a wrap() call * may consume application data from the source buffer and may produce * network data in the destination buffer. The outbound data * may contain application and/or handshake data. A call to * unwrap() will examine the source buffer and may * advance the handshake if the data is handshaking information, or * may place application data in the destination buffer if the data * is application. The state of the underlying SSL/TLS algorithm * will determine when data is consumed and produced. *

* Calls to wrap() and unwrap() return an * SSLEngineResult which indicates the status of the * operation, and (optionally) how to interact with the engine to make * progress. *

* The SSLEngine produces/consumes complete SSL/TLS * packets only, and does not store application data internally between * calls to wrap()/unwrap(). Thus input and output * ByteBuffers must be sized appropriately to hold the * maximum record that can be produced. Calls to {@link * SSLSession#getPacketBufferSize()} and {@link * SSLSession#getApplicationBufferSize()} should be used to determine * the appropriate buffer sizes. The size of the outbound application * data buffer generally does not matter. If buffer conditions do not * allow for the proper consumption/production of data, the application * must determine (via {@link SSLEngineResult}) and correct the * problem, and then try the call again. *

* For example, unwrap() will return a {@link * SSLEngineResult.Status#BUFFER_OVERFLOW} result if the engine * determines that there is not enough destination buffer space available. * Applications should call {@link SSLSession#getApplicationBufferSize()} * and compare that value with the space available in the destination buffer, * enlarging the buffer if necessary. Similarly, if unwrap() * were to return a {@link SSLEngineResult.Status#BUFFER_UNDERFLOW}, the * application should call {@link SSLSession#getPacketBufferSize()} to ensure * that the source buffer has enough room to hold a record (enlarging if * necessary), and then obtain more inbound data. * *

 *   SSLEngineResult r = engine.unwrap(src, dst);
 *   switch (r.getStatus()) {
 *   BUFFER_OVERFLOW:
 *       // Could attempt to drain the dst buffer of any already obtained
 *       // data, but we'll just increase it to the size needed.
 *       int appSize = engine.getSession().getApplicationBufferSize();
 *       ByteBuffer b = ByteBuffer.allocate(appSize + dst.position());
 *       dst.flip();
 *       b.put(dst);
 *       dst = b;
 *       // retry the operation.
 *       break;
 *   BUFFER_UNDERFLOW:
 *       int netSize = engine.getSession().getPacketBufferSize();
 *       // Resize buffer if needed.
 *       if (netSize > dst.capacity()) {
 *           ByteBuffer b = ByteBuffer.allocate(netSize);
 *           src.flip();
 *           b.put(src);
 *           src = b;
 *       }
 *       // Obtain more inbound network data for src,
 *       // then retry the operation.
 *       break;
 *   // other cases: CLOSED, OK.
 *   }
 * 
* *

* Unlike SSLSocket, all methods of SSLEngine are * non-blocking. SSLEngine implementations may * require the results of tasks that may take an extended period of * time to complete, or may even block. For example, a TrustManager * may need to connect to a remote certificate validation service, * or a KeyManager might need to prompt a user to determine which * certificate to use as part of client authentication. Additionally, * creating cryptographic signatures and verifying them can be slow, * seemingly blocking. *

* For any operation which may potentially block, the * SSLEngine will create a {@link java.lang.Runnable} * delegated task. When SSLEngineResult indicates that a * delegated task result is needed, the application must call {@link * #getDelegatedTask()} to obtain an outstanding delegated task and * call its {@link java.lang.Runnable#run() run()} method (possibly using * a different thread depending on the compute strategy). The * application should continue obtaining delegated tasks until no more * exist, and try the original operation again. *

* At the end of a communication session, applications should properly * close the SSL/TLS link. The SSL/TLS protocols have closure handshake * messages, and these messages should be communicated to the peer * before releasing the SSLEngine and closing the * underlying transport mechanism. A close can be initiated by one of: * an SSLException, an inbound closure handshake message, or one of the * close methods. In all cases, closure handshake messages are * generated by the engine, and wrap() should be repeatedly * called until the resulting SSLEngineResult's status * returns "CLOSED", or {@link #isOutboundDone()} returns true. All * data obtained from the wrap() method should be sent to the * peer. *

* {@link #closeOutbound()} is used to signal the engine that the * application will not be sending any more data. *

* A peer will signal its intent to close by sending its own closure * handshake message. After this message has been received and * processed by the local SSLEngine's unwrap() * call, the application can detect the close by calling * unwrap() and looking for a SSLEngineResult * with status "CLOSED", or if {@link #isInboundDone()} returns true. * If for some reason the peer closes the communication link without * sending the proper SSL/TLS closure message, the application can * detect the end-of-stream and can signal the engine via {@link * #closeInbound()} that there will no more inbound messages to * process. Some applications might choose to require orderly shutdown * messages from a peer, in which case they can check that the closure * was generated by a handshake message and not by an end-of-stream * condition. *

* 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 * cipher suite be selected. *

* Each SSL/TLS connection must have one client and one server, thus * each endpoint must decide which role to assume. This choice determines * who begins the handshaking process as well as which type of messages * should be sent by each party. The method {@link * #setUseClientMode(boolean)} configures the mode. Once the initial * handshaking has started, an SSLEngine can not switch * between client and server modes, even when performing renegotiations. *

* Applications might choose to process delegated tasks in different * threads. When an SSLEngine * is created, the current {@link java.security.AccessControlContext} * is saved. All future delegated tasks will be processed using this * context: that is, all access control decisions will be made using the * context captured at engine creation. *

*


* * Concurrency Notes: * There are two concurrency issues to be aware of: * *
    *
  1. The wrap() and unwrap() methods * may execute concurrently of each other. * *
  2. The SSL/TLS protocols employ ordered packets. * Applications must take care to ensure that generated packets * are delivered in sequence. If packets arrive * out-of-order, unexpected or fatal results may occur. *

    * For example: *

    *

     *              synchronized (outboundLock) {
     *                  sslEngine.wrap(src, dst);
     *                  outboundQueue.put(dst);
     *              }
     *      
    * * As a corollary, two threads must not attempt to call the same method * (either wrap() or unwrap()) concurrently, * because there is no way to guarantee the eventual packet ordering. *
* *

Default configuration for different Android versions

*

{@code SSLEngine} instances obtained from default {@link SSLContext} are configured as * follows: * * * *

Protocols

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
ProtocolSupported (API Levels)Enabled by default (API Levels)
SSLv31+1–22
TLSv11+1+
TLSv1.120+20+
TLSv1.220+20+
* *

Cipher suites

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Cipher suiteSupported (API Levels)Enabled by default (API Levels)
SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA9–229–19
SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA9–229–19
SSL_DHE_DSS_WITH_DES_CBC_SHA9–229–19
SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA9–229–19
SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA9–229–19
SSL_DHE_RSA_WITH_DES_CBC_SHA9–229–19
SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA9–22
SSL_DH_anon_EXPORT_WITH_RC4_40_MD59–22
SSL_DH_anon_WITH_3DES_EDE_CBC_SHA9–22
SSL_DH_anon_WITH_DES_CBC_SHA9–22
SSL_DH_anon_WITH_RC4_128_MD59–22
SSL_RSA_EXPORT_WITH_DES40_CBC_SHA9–229–19
SSL_RSA_EXPORT_WITH_RC4_40_MD59–229–19
SSL_RSA_WITH_3DES_EDE_CBC_SHA9+9–19
SSL_RSA_WITH_DES_CBC_SHA9–229–19
SSL_RSA_WITH_NULL_MD59–22
SSL_RSA_WITH_NULL_SHA9–22
SSL_RSA_WITH_RC4_128_MD59+9–19
SSL_RSA_WITH_RC4_128_SHA9+9–23
TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA1–81–8
TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA1–81–8
TLS_DHE_DSS_WITH_AES_128_CBC_SHA9–229–22
TLS_DHE_DSS_WITH_AES_128_CBC_SHA25620–22
TLS_DHE_DSS_WITH_AES_128_GCM_SHA25620–22
TLS_DHE_DSS_WITH_AES_256_CBC_SHA9–2220–22
TLS_DHE_DSS_WITH_AES_256_CBC_SHA25620–22
TLS_DHE_DSS_WITH_AES_256_GCM_SHA38420–22
TLS_DHE_DSS_WITH_DES_CBC_SHA1–81–8
TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA1–81–8
TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA1–81–8
TLS_DHE_RSA_WITH_AES_128_CBC_SHA9+9+
TLS_DHE_RSA_WITH_AES_128_CBC_SHA25620+
TLS_DHE_RSA_WITH_AES_128_GCM_SHA25620+20+
TLS_DHE_RSA_WITH_AES_256_CBC_SHA9+20+
TLS_DHE_RSA_WITH_AES_256_CBC_SHA25620+
TLS_DHE_RSA_WITH_AES_256_GCM_SHA38420+20+
TLS_DHE_RSA_WITH_DES_CBC_SHA1–81–8
TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA1–8
TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA1–8
TLS_DH_DSS_WITH_DES_CBC_SHA1–8
TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA1–8
TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA1–8
TLS_DH_RSA_WITH_DES_CBC_SHA1–8
TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA1–8
TLS_DH_anon_WITH_3DES_EDE_CBC_SHA1–8
TLS_DH_anon_WITH_AES_128_CBC_SHA9–22
TLS_DH_anon_WITH_AES_128_CBC_SHA25620–22
TLS_DH_anon_WITH_AES_128_GCM_SHA25620–22
TLS_DH_anon_WITH_AES_256_CBC_SHA9–22
TLS_DH_anon_WITH_AES_256_CBC_SHA25620–22
TLS_DH_anon_WITH_AES_256_GCM_SHA38420–22
TLS_DH_anon_WITH_DES_CBC_SHA1–8
TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA20–22
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA20+20+
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA25620+
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA25620+20+
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA20+20+
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA38420+
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA38420+20+
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA25624+24+
TLS_ECDHE_ECDSA_WITH_NULL_SHA20–22
TLS_ECDHE_ECDSA_WITH_RC4_128_SHA20+20–23
TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA21+21+
TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA21+21+
TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA25624+24+
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA20–22
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA20+20+
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA25620+
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA25620+20+
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA20+20+
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA38420+
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA38420+20+
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA25624+24+
TLS_ECDHE_RSA_WITH_NULL_SHA20–22
TLS_ECDHE_RSA_WITH_RC4_128_SHA20+20–23
TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA20–22
TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA20–22
TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA25620–22
TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA25620–22
TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA20–22
TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA38420–22
TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA38420–22
TLS_ECDH_ECDSA_WITH_NULL_SHA20–22
TLS_ECDH_ECDSA_WITH_RC4_128_SHA20–22
TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA20–22
TLS_ECDH_RSA_WITH_AES_128_CBC_SHA20–22
TLS_ECDH_RSA_WITH_AES_128_CBC_SHA25620–22
TLS_ECDH_RSA_WITH_AES_128_GCM_SHA25620–22
TLS_ECDH_RSA_WITH_AES_256_CBC_SHA20–22
TLS_ECDH_RSA_WITH_AES_256_CBC_SHA38420–22
TLS_ECDH_RSA_WITH_AES_256_GCM_SHA38420–22
TLS_ECDH_RSA_WITH_NULL_SHA20–22
TLS_ECDH_RSA_WITH_RC4_128_SHA20–22
TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA20–22
TLS_ECDH_anon_WITH_AES_128_CBC_SHA20–22
TLS_ECDH_anon_WITH_AES_256_CBC_SHA20–22
TLS_ECDH_anon_WITH_NULL_SHA20–22
TLS_ECDH_anon_WITH_RC4_128_SHA20–22
TLS_EMPTY_RENEGOTIATION_INFO_SCSV20+20+
TLS_FALLBACK_SCSV21+
TLS_NULL_WITH_NULL_NULL1–8
TLS_PSK_WITH_3DES_EDE_CBC_SHA21–22
TLS_PSK_WITH_AES_128_CBC_SHA21+21+
TLS_PSK_WITH_AES_256_CBC_SHA21+21+
TLS_PSK_WITH_RC4_128_SHA21+
TLS_RSA_EXPORT_WITH_DES40_CBC_SHA1–81–8
TLS_RSA_WITH_3DES_EDE_CBC_SHA1–81–8
TLS_RSA_WITH_AES_128_CBC_SHA9+9+
TLS_RSA_WITH_AES_128_CBC_SHA25620+
TLS_RSA_WITH_AES_128_GCM_SHA25620+20+
TLS_RSA_WITH_AES_256_CBC_SHA9+20+
TLS_RSA_WITH_AES_256_CBC_SHA25620+
TLS_RSA_WITH_AES_256_GCM_SHA38420+20+
TLS_RSA_WITH_DES_CBC_SHA1–81–8
TLS_RSA_WITH_NULL_MD51–8
TLS_RSA_WITH_NULL_SHA1–8
TLS_RSA_WITH_NULL_SHA25620–22
* *

NOTE: PSK cipher suites are enabled by default only if the {@code SSLContext} through * which the engine was created has been initialized with a {@code PSKKeyManager}. * * @see SSLContext * @see SSLSocket * @see SSLServerSocket * @see SSLSession * @see java.net.Socket * * @since 1.5 * @author Brad R. Wetmore */ public abstract class SSLEngine { private String peerHost = null; private int peerPort = -1; /** * Constructor for an SSLEngine providing no hints * for an internal session reuse strategy. * * @see SSLContext#createSSLEngine() * @see SSLSessionContext */ protected SSLEngine() { } /** * Constructor for an SSLEngine. *

* SSLEngine implementations may use the * peerHost and peerPort parameters as hints * for their internal session reuse strategy. *

* Some cipher suites (such as Kerberos) require remote hostname * information. Implementations of this class should use this * constructor to use Kerberos. *

* The parameters are not authenticated by the * SSLEngine. * * @param peerHost the name of the peer host * @param peerPort the port number of the peer * @see SSLContext#createSSLEngine(String, int) * @see SSLSessionContext */ protected SSLEngine(String peerHost, int peerPort) { this.peerHost = peerHost; this.peerPort = peerPort; } /** * Returns the host name of the peer. *

* Note that the value is not authenticated, and should not be * relied upon. * * @return the host name of the peer, or null if nothing is * available. */ public String getPeerHost() { return peerHost; } /** * Returns the port number of the peer. *

* Note that the value is not authenticated, and should not be * relied upon. * * @return the port number of the peer, or -1 if nothing is * available. */ public int getPeerPort() { return peerPort; } /** * Attempts to encode a buffer of plaintext application data into * SSL/TLS network data. *

* An invocation of this method behaves in exactly the same manner * as the invocation: *

     * {@link #wrap(ByteBuffer [], int, int, ByteBuffer)
     *     engine.wrap(new ByteBuffer [] { src }, 0, 1, dst);}
     * 
     *
     * @param   src
     *          a ByteBuffer containing outbound application data
     * @param   dst
     *          a ByteBuffer to hold outbound network data
     * @return  an SSLEngineResult describing the result
     *          of this operation.
     * @throws  SSLException
     *          A problem was encountered while processing the
     *          data that caused the SSLEngine to abort.
     *          See the class description for more information on
     *          engine closure.
     * @throws  ReadOnlyBufferException
     *          if the dst buffer is read-only.
     * @throws  IllegalArgumentException
     *          if either src or dst
     *          is null.
     * @throws  IllegalStateException if the client/server mode
     *          has not yet been set.
     * @see     #wrap(ByteBuffer [], int, int, ByteBuffer)
     */
    public SSLEngineResult wrap(ByteBuffer src,
            ByteBuffer dst) throws SSLException {
        return wrap(new ByteBuffer [] { src }, 0, 1, dst);
    }

    /**
     * Attempts to encode plaintext bytes from a sequence of data
     * buffers into SSL/TLS network data.
     * 

* An invocation of this method behaves in exactly the same manner * as the invocation: *

     * {@link #wrap(ByteBuffer [], int, int, ByteBuffer)
     *     engine.wrap(srcs, 0, srcs.length, dst);}
     * 
     *
     * @param   srcs
     *          an array of ByteBuffers containing the
     *          outbound application data
     * @param   dst
     *          a ByteBuffer to hold outbound network data
     * @return  an SSLEngineResult describing the result
     *          of this operation.
     * @throws  SSLException
     *          A problem was encountered while processing the
     *          data that caused the SSLEngine to abort.
     *          See the class description for more information on
     *          engine closure.
     * @throws  ReadOnlyBufferException
     *          if the dst buffer is read-only.
     * @throws  IllegalArgumentException
     *          if either srcs or dst
     *          is null, or if any element in srcs is null.
     * @throws  IllegalStateException if the client/server mode
     *          has not yet been set.
     * @see     #wrap(ByteBuffer [], int, int, ByteBuffer)
     */
    public SSLEngineResult wrap(ByteBuffer [] srcs,
            ByteBuffer dst) throws SSLException {
        if (srcs == null) {
            throw new IllegalArgumentException("src == null");
        }
        return wrap(srcs, 0, srcs.length, dst);
    }


    /**
     * Attempts to encode plaintext bytes from a subsequence of data
     * buffers into SSL/TLS network data.  This "gathering"
     * operation encodes, in a single invocation, a sequence of bytes
     * from one or more of a given sequence of buffers.  Gathering
     * wraps are often useful when implementing network protocols or
     * file formats that, for example, group data into segments
     * consisting of one or more fixed-length headers followed by a
     * variable-length body.  See
     * {@link java.nio.channels.GatheringByteChannel} for more
     * information on gathering, and {@link
     * java.nio.channels.GatheringByteChannel#write(ByteBuffer[],
     * int, int)} for more information on the subsequence
     * behavior.
     * 

* Depending on the state of the SSLEngine, this method may produce * network data without consuming any application data (for example, * it may generate handshake data.) *

* The application is responsible for reliably transporting the * network data to the peer, and for ensuring that data created by * multiple calls to wrap() is transported in the same order in which * it was generated. The application must properly synchronize * multiple calls to this method. *

* If this SSLEngine has not yet started its initial * handshake, this method will automatically start the handshake. *

* This method will attempt to produce one SSL/TLS packet, and will * consume as much source data as possible, but will never consume * more than the sum of the bytes remaining in each buffer. Each * ByteBuffer's position is updated to reflect the * amount of data consumed or produced. The limits remain the * same. *

* The underlying memory used by the srcs and * dst ByteBuffers must not be the same. *

* See the class description for more information on engine closure. * * @param srcs * an array of ByteBuffers containing the * outbound application data * @param offset * The offset within the buffer array of the first buffer from * which bytes are to be retrieved; it must be non-negative * and no larger than srcs.length * @param length * The maximum number of buffers to be accessed; it must be * non-negative and no larger than * srcs.length - offset * @param dst * a ByteBuffer to hold outbound network data * @return an SSLEngineResult describing the result * of this operation. * @throws SSLException * A problem was encountered while processing the * data that caused the SSLEngine to abort. * See the class description for more information on * engine closure. * @throws IndexOutOfBoundsException * if the preconditions on the offset and * length parameters do not hold. * @throws ReadOnlyBufferException * if the dst buffer is read-only. * @throws IllegalArgumentException * if either srcs or dst * is null, or if any element in the srcs * subsequence specified is null. * @throws IllegalStateException if the client/server mode * has not yet been set. * @see java.nio.channels.GatheringByteChannel * @see java.nio.channels.GatheringByteChannel#write( * ByteBuffer[], int, int) */ public abstract SSLEngineResult wrap(ByteBuffer [] srcs, int offset, int length, ByteBuffer dst) throws SSLException; /** * Attempts to decode SSL/TLS network data into a plaintext * application data buffer. *

* An invocation of this method behaves in exactly the same manner * as the invocation: *

     * {@link #unwrap(ByteBuffer, ByteBuffer [], int, int)
     *     engine.unwrap(src, new ByteBuffer [] { dst }, 0, 1);}
     * 
     *
     * @param   src
     *          a ByteBuffer containing inbound network data.
     * @param   dst
     *          a ByteBuffer to hold inbound application data.
     * @return  an SSLEngineResult describing the result
     *          of this operation.
     * @throws  SSLException
     *          A problem was encountered while processing the
     *          data that caused the SSLEngine to abort.
     *          See the class description for more information on
     *          engine closure.
     * @throws  ReadOnlyBufferException
     *          if the dst buffer is read-only.
     * @throws  IllegalArgumentException
     *          if either src or dst
     *          is null.
     * @throws  IllegalStateException if the client/server mode
     *          has not yet been set.
     * @see     #unwrap(ByteBuffer, ByteBuffer [], int, int)
     */
    public SSLEngineResult unwrap(ByteBuffer src,
            ByteBuffer dst) throws SSLException {
        return unwrap(src, new ByteBuffer [] { dst }, 0, 1);
    }

    /**
     * Attempts to decode SSL/TLS network data into a sequence of plaintext
     * application data buffers.
     * 

* An invocation of this method behaves in exactly the same manner * as the invocation: *

     * {@link #unwrap(ByteBuffer, ByteBuffer [], int, int)
     *     engine.unwrap(src, dsts, 0, dsts.length);}
     * 
     *
     * @param   src
     *          a ByteBuffer containing inbound network data.
     * @param   dsts
     *          an array of ByteBuffers to hold inbound
     *          application data.
     * @return  an SSLEngineResult describing the result
     *          of this operation.
     * @throws  SSLException
     *          A problem was encountered while processing the
     *          data that caused the SSLEngine to abort.
     *          See the class description for more information on
     *          engine closure.
     * @throws  ReadOnlyBufferException
     *          if any of the dst buffers are read-only.
     * @throws  IllegalArgumentException
     *          if either src or dsts
     *          is null, or if any element in dsts is null.
     * @throws  IllegalStateException if the client/server mode
     *          has not yet been set.
     * @see     #unwrap(ByteBuffer, ByteBuffer [], int, int)
     */
    public SSLEngineResult unwrap(ByteBuffer src,
            ByteBuffer [] dsts) throws SSLException {
        if (dsts == null) {
            throw new IllegalArgumentException("dsts == null");
        }
        return unwrap(src, dsts, 0, dsts.length);
    }

    /**
     * Attempts to decode SSL/TLS network data into a subsequence of
     * plaintext application data buffers.  This "scattering"
     * operation decodes, in a single invocation, a sequence of bytes
     * into one or more of a given sequence of buffers.  Scattering
     * unwraps are often useful when implementing network protocols or
     * file formats that, for example, group data into segments
     * consisting of one or more fixed-length headers followed by a
     * variable-length body.  See
     * {@link java.nio.channels.ScatteringByteChannel} for more
     * information on scattering, and {@link
     * java.nio.channels.ScatteringByteChannel#read(ByteBuffer[],
     * int, int)} for more information on the subsequence
     * behavior.
     * 

* Depending on the state of the SSLEngine, this method may consume * network data without producing any application data (for example, * it may consume handshake data.) *

* The application is responsible for reliably obtaining the network * data from the peer, and for invoking unwrap() on the data in the * order it was received. The application must properly synchronize * multiple calls to this method. *

* If this SSLEngine has not yet started its initial * handshake, this method will automatically start the handshake. *

* This method will attempt to consume one complete SSL/TLS network * packet, but will never consume more than the sum of the bytes * remaining in the buffers. Each ByteBuffer's * position is updated to reflect the amount of data consumed or * produced. The limits remain the same. *

* The underlying memory used by the src and * dsts ByteBuffers must not be the same. *

* The inbound network buffer may be modified as a result of this * call: therefore if the network data packet is required for some * secondary purpose, the data should be duplicated before calling this * method. Note: the network data will not be useful to a second * SSLEngine, as each SSLEngine contains unique random state which * influences the SSL/TLS messages. *

* See the class description for more information on engine closure. * * @param src * a ByteBuffer containing inbound network data. * @param dsts * an array of ByteBuffers to hold inbound * application data. * @param offset * The offset within the buffer array of the first buffer from * which bytes are to be transferred; it must be non-negative * and no larger than dsts.length. * @param length * The maximum number of buffers to be accessed; it must be * non-negative and no larger than * dsts.length - offset. * @return an SSLEngineResult describing the result * of this operation. * @throws SSLException * A problem was encountered while processing the * data that caused the SSLEngine to abort. * See the class description for more information on * engine closure. * @throws IndexOutOfBoundsException * If the preconditions on the offset and * length parameters do not hold. * @throws ReadOnlyBufferException * if any of the dst buffers are read-only. * @throws IllegalArgumentException * if either src or dsts * is null, or if any element in the dsts * subsequence specified is null. * @throws IllegalStateException if the client/server mode * has not yet been set. * @see java.nio.channels.ScatteringByteChannel * @see java.nio.channels.ScatteringByteChannel#read( * ByteBuffer[], int, int) */ public abstract SSLEngineResult unwrap(ByteBuffer src, ByteBuffer [] dsts, int offset, int length) throws SSLException; /** * Returns a delegated Runnable task for * this SSLEngine. *

* SSLEngine operations may require the results of * operations that block, or may take an extended period of time to * complete. This method is used to obtain an outstanding {@link * java.lang.Runnable} operation (task). Each task must be assigned * a thread (possibly the current) to perform the {@link * java.lang.Runnable#run() run} operation. Once the * run method returns, the Runnable object * is no longer needed and may be discarded. *

* Delegated tasks run in the AccessControlContext * in place when this object was created. *

* A call to this method will return each outstanding task * exactly once. *

* Multiple delegated tasks can be run in parallel. * * @return a delegated Runnable task, or null * if none are available. */ public abstract Runnable getDelegatedTask(); /** * Signals that no more inbound network data will be sent * to this SSLEngine. *

* If the application initiated the closing process by calling * {@link #closeOutbound()}, under some circumstances it is not * required that the initiator wait for the peer's corresponding * close message. (See section 7.2.1 of the TLS specification (RFC 2246) for more * information on waiting for closure alerts.) In such cases, this * method need not be called. *

* But if the application did not initiate the closure process, or * if the circumstances above do not apply, this method should be * called whenever the end of the SSL/TLS data stream is reached. * This ensures closure of the inbound side, and checks that the * peer followed the SSL/TLS close procedure properly, thus * detecting possible truncation attacks. *

* This method is idempotent: if the inbound side has already * been closed, this method does not do anything. *

* {@link #wrap(ByteBuffer, ByteBuffer) wrap()} should be * called to flush any remaining handshake data. * * @throws SSLException * if this engine has not received the proper SSL/TLS close * notification message from the peer. * * @see #isInboundDone() * @see #isOutboundDone() */ public abstract void closeInbound() throws SSLException; /** * Returns whether {@link #unwrap(ByteBuffer, ByteBuffer)} will * accept any more inbound data messages. * * @return true if the SSLEngine will not * consume anymore network data (and by implication, * will not produce any more application data.) * @see #closeInbound() */ public abstract boolean isInboundDone(); /** * Signals that no more outbound application data will be sent * on this SSLEngine. *

* This method is idempotent: if the outbound side has already * been closed, this method does not do anything. *

* {@link #wrap(ByteBuffer, ByteBuffer)} should be * called to flush any remaining handshake data. * * @see #isOutboundDone() */ public abstract void closeOutbound(); /** * Returns whether {@link #wrap(ByteBuffer, ByteBuffer)} will * produce any more outbound data messages. *

* Note that during the closure phase, a SSLEngine may * generate handshake closure data that must be sent to the peer. * wrap() must be called to generate this data. When * this method returns true, no more outbound data will be created. * * @return true if the SSLEngine will not produce * any more network data * * @see #closeOutbound() * @see #closeInbound() */ public abstract boolean isOutboundDone(); /** * Returns the names of the cipher suites which could be enabled for use * on this engine. 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. * * @return an array of cipher suite names * @see #getEnabledCipherSuites() * @see #setEnabledCipherSuites(String []) */ public abstract String [] getSupportedCipherSuites(); /** * Returns the names of the SSL cipher suites which are currently * enabled for use on this engine. When an SSLEngine 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/private keys for the suite are not available, or an * anonymous suite is enabled but authentication is required.) * * @return an array of cipher suite names * @see #getSupportedCipherSuites() * @see #setEnabledCipherSuites(String []) */ public abstract String [] getEnabledCipherSuites(); /** * Sets the cipher suites enabled for use on this engine. *

* 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 {@link #getEnabledCipherSuites()} for more information * on why a specific cipher suite may never be used on a engine. * * @param suites Names of all the cipher suites to enable * @throws IllegalArgumentException when one or more of the ciphers * named by the parameter is not supported, or when the * parameter is null. * @see #getSupportedCipherSuites() * @see #getEnabledCipherSuites() */ public abstract void setEnabledCipherSuites(String suites []); /** * Returns the names of the protocols which could be enabled for use * with this SSLEngine. * * @return an array of protocols supported */ public abstract String [] getSupportedProtocols(); /** * Returns the names of the protocol versions which are currently * enabled for use with this SSLEngine. * * @return an array of protocols * @see #setEnabledProtocols(String []) */ public abstract String [] getEnabledProtocols(); /** * Set the protocol versions enabled for use on this engine. *

* 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. * * @param protocols Names of all the protocols to enable. * @throws IllegalArgumentException when one or more of * the protocols named by the parameter is not supported or * when the protocols parameter is null. * @see #getEnabledProtocols() */ public abstract void setEnabledProtocols(String protocols[]); /** * Returns the SSLSession in use in this * SSLEngine. *

* 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. *

* Unlike {@link SSLSocket#getSession()} * this method does not block until handshaking is complete. *

* Until the initial handshake has completed, this method returns * a session object which reports an invalid cipher suite of * "SSL_NULL_WITH_NULL_NULL". * * @return the SSLSession for this SSLEngine * @see SSLSession */ public abstract SSLSession getSession(); /** * 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. * * @see SSLSocket * @see SSLSession * @see ExtendedSSLSession * @see X509ExtendedKeyManager * @see X509ExtendedTrustManager * * @return null if this instance is not currently handshaking, or * if the current handshake has not progressed far enough to * create a basic SSLSession. Otherwise, this method returns the * {@code SSLSession} currently being negotiated. * @throws UnsupportedOperationException if the underlying provider * does not implement the operation. * * @since 1.7 */ public SSLSession getHandshakeSession() { throw new UnsupportedOperationException(); } /** * Initiates handshaking (initial or renegotiation) on this SSLEngine. *

* This method is not needed for the initial handshake, as the * wrap() and unwrap() methods will * implicitly call this method if handshaking has not already begun. *

* Note that the peer may also request a session renegotiation with * this SSLEngine by sending the appropriate * session renegotiate handshake message. *

* Unlike the {@link SSLSocket#startHandshake() * SSLSocket#startHandshake()} method, this method does not block * until handshaking is completed. *

* To force a complete SSL/TLS session renegotiation, the current * session should be invalidated prior to calling this method. *

* Some protocols may not support multiple handshakes on an existing * engine and may throw an SSLException. * * @throws SSLException * if a problem was encountered while signaling the * SSLEngine to begin a new handshake. * See the class description for more information on * engine closure. * @throws IllegalStateException if the client/server mode * has not yet been set. * @see SSLSession#invalidate() */ public abstract void beginHandshake() throws SSLException; /** * Returns the current handshake status for this SSLEngine. * * @return the current SSLEngineResult.HandshakeStatus. */ public abstract SSLEngineResult.HandshakeStatus getHandshakeStatus(); /** * Configures the engine 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 engine. *

* Servers normally authenticate themselves, and clients * are not required to do so. * * @param mode true if the engine should start its handshaking * in "client" mode * @throws IllegalArgumentException if a mode change is attempted * after the initial handshake has begun. * @see #getUseClientMode() */ public abstract void setUseClientMode(boolean mode); /** * Returns true if the engine is set to use client mode when * handshaking. * * @return true if the engine should do handshaking * in "client" mode * @see #setUseClientMode(boolean) */ public abstract boolean getUseClientMode(); /** * Configures the engine to require client authentication. This * option is only useful for engines in the server mode. *

* An engine's client authentication setting is one of the following: *

    *
  • client authentication required *
  • client authentication requested *
  • no client authentication desired *
*

* Unlike {@link #setWantClientAuth(boolean)}, if this option is set and * the client chooses not to provide authentication information * about itself, the negotiations will stop and the engine will * begin its closure procedure. *

* Calling this method overrides any previous setting made by * this method or {@link #setWantClientAuth(boolean)}. * * @param need set to true if client authentication is required, * or false if no client authentication is desired. * @see #getNeedClientAuth() * @see #setWantClientAuth(boolean) * @see #getWantClientAuth() * @see #setUseClientMode(boolean) */ public abstract void setNeedClientAuth(boolean need); /** * Returns true if the engine will require client authentication. * This option is only useful to engines in the server mode. * * @return true if client authentication is required, * or false if no client authentication is desired. * @see #setNeedClientAuth(boolean) * @see #setWantClientAuth(boolean) * @see #getWantClientAuth() * @see #setUseClientMode(boolean) */ public abstract boolean getNeedClientAuth(); /** * Configures the engine to request client authentication. * This option is only useful for engines in the server mode. *

* An engine's client authentication setting is one of the following: *

    *
  • client authentication required *
  • client authentication requested *
  • no client authentication desired *
*

* Unlike {@link #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 {@link #setNeedClientAuth(boolean)}. * * @param want set to true if client authentication is requested, * or false if no client authentication is desired. * @see #getWantClientAuth() * @see #setNeedClientAuth(boolean) * @see #getNeedClientAuth() * @see #setUseClientMode(boolean) */ public abstract void setWantClientAuth(boolean want); /** * Returns true if the engine will request client authentication. * This option is only useful for engines in the server mode. * * @return true if client authentication is requested, * or false if no client authentication is desired. * @see #setNeedClientAuth(boolean) * @see #getNeedClientAuth() * @see #setWantClientAuth(boolean) * @see #setUseClientMode(boolean) */ public abstract boolean getWantClientAuth(); /** * Controls whether new SSL sessions may be established by this engine. * If session creations are not allowed, and there are no * existing sessions to resume, there will be no successful * handshaking. * * @param flag true indicates that sessions may be created; this * is the default. false indicates that an existing session * must be resumed * @see #getEnableSessionCreation() */ public abstract void setEnableSessionCreation(boolean flag); /** * Returns true if new SSL sessions may be established by this engine. * * @return true indicates that sessions may be created; this * is the default. false indicates that an existing session * must be resumed * @see #setEnableSessionCreation(boolean) */ public abstract boolean getEnableSessionCreation(); /** * Returns the SSLParameters in effect for this SSLEngine. * The ciphersuites and protocols of the returned SSLParameters * are always non-null. * * @return the SSLParameters in effect for this SSLEngine. * @since 1.6 */ 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; } /** * Applies SSLParameters to this engine. * *

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. *
* * @param params the parameters * @throws IllegalArgumentException if the setEnabledCipherSuites() or * the setEnabledProtocols() call fails * @since 1.6 */ 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); } } }