NIO SSL

Unlike blocking IO, the JVM does not provide standard SSLSocketChannel and SSLServerSocketChannel classes that extend the base socket channel classes. Instead the SSL exchanges must be manually orchestrated using a SSLEngine. This project provides implementations for SSLSocketChannel and SSLServerSocketChannel that can be used like SSLSocket and SSLServerSocket.

Getting Started

Direct Download

You can download niossl-0.2.jar directly and place in your project.

Using Maven

Add the following dependency into your Maven project:

<dependency>
    <groupId>org.baswell</groupId>
    <artifactId>niossl</artifactId>
    <version>0.2</version>
</dependency>

Copy Source

This project is only a couple of source files with no external dependencies. You can just copy these source files directly in your project.

Using SSLSocketChannel

SSLSocketChannel is constructed from a normal SocketChannel and the necessary SSL related information. Once the SSLSocketChannel is created its read and write methods can be used to receive and send data over a SSL network connection.

SocketChannel socketChannel = SocketChannel.open(new InetSocketAddress("test.com", 443););
socketChannel.configureBlocking(false);

SSLContext sslContext = SSLContext.getInstance("TLS");
SSLEngine sslEngine = sslContext.createSSLEngine();
sslEngine.setUseClientMode(true); 

ThreadPoolExecutor sslThreadPool = new ThreadPoolExecutor(250, 2000, 25, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>()); // Thread pool for executing long-running SSL tasks
NioSslLogger logger = null; // null disables logging

SSLSocketChannel sslSocketChannel = new SSLSocketChannel(socketChannel, sslEngine, sslThreadPool, getLogger());

// At this point you can use sslSocketChannel like you would a normal SocketChannel

Registering With Selectors

SSLSocketChannel cannot be registered directly with a Selector. Instead you must use the real SocketChannel instance that the SSLSocketChannel was constructed with.

SelectionKey selectionKey = sslSocketChannel.getWrappedSocketChannel().register(selector, SelectionKey.OP_READ);
selectionKey.attach(sslSocketChannel);

Application Buffer Size

The application buffers you pass in on calls to SSLSocketChannel.read and SSLSocketChannel.write must be of a minimum size to ensure that the SSLEngine has enough buffer to perform the SSL exchanges. An IllegalArgumentException will thrown from either of these read or write methods if the application buffer size passed in is smaller than the current size of the largest expected data packet sent or received.

SSLContext sslContext = SSLContext.getInstance("TLS");
SSLEngine sslEngine = sslContext.createSSLEngine();
sslEngine.setUseClientMode(true); 

int minAppBufferSize = sslEngine.getSession().getApplicationBufferSize(); // Your buffers must be at least this big.

Using SSLServerSocketChannel

SSLServerSocketChannel is used like a normal ServerSocketChannel. Once the SSLServerSocketChannel is constructed with the required SSL parameters, blocking calls to accept() or acceptOverSSL() can be made to process incoming requests. The SocketChannel objects returned from accept() are instances of SSLSocketChannel.

ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
serverSocketChannel.socket().bind(new InetSocketAddress(443));

SSLContext sslContext = SSLContext.getInstance("TLS");
ThreadPoolExecutor sslThreadPool = new ThreadPoolExecutor(250, 2000, 25, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>()); // Thread pool for executing long-running SSL tasks

NioSslLogger logger = null; // null disables logging

SSLServerSocketChannel sslServerSocketChannel = new SSLServerSocketChannel(serverSocketChannel, serverContext, sslThreadPool, logger);

while (true)
{
  SSLSocketChannel sslSocketChannel = sslServerSocketChannel.acceptOverSSL(); // blocks until a SocketChannel is ready
  dispatch(sslSocketChannel);
}

Additional Documentation

• Javadoc

Developed By

Corey Baswell - corey.baswell@gmail.com

License

Copyright 2015 Corey Baswell

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.