Merge pull request #149 from clue-labs/tls

Support explicitly choosing TLS version to negotiate with remote side

Author: WyriHaximus

README.md

@@ -460,6 +460,19 @@ $server = new Server('tls://127.0.0.1:8000', $loop, array(
 ));
 ```
 
+By default, this server supports TLSv1.0+ and excludes support for legacy
+SSLv2/SSLv3. As of PHP 5.6+ you can also explicitly choose the TLS version you
+want to negotiate with the remote side:
+
+```php
+$server = new Server('tls://127.0.0.1:8000', $loop, array(
+    'tls' => array(
+        'local_cert' => 'server.pem',
+        'crypto_method' => STREAM_CRYPTO_METHOD_TLSv1_2_SERVER
+    )
+));
+```
+
 > Note that available [TLS context options](http://php.net/manual/en/context.ssl.php),
   their defaults and effects of changing these may vary depending on your system
   and/or PHP version.
@@ -612,6 +625,18 @@ $server = new SecureServer($server, $loop, array(
 ));
 ```
 
+By default, this server supports TLSv1.0+ and excludes support for legacy
+SSLv2/SSLv3. As of PHP 5.6+ you can also explicitly choose the TLS version you
+want to negotiate with the remote side:
+
+```php
+$server = new TcpServer(8000, $loop);
+$server = new SecureServer($server, $loop, array(
+    'local_cert' => 'server.pem',
+    'crypto_method' => STREAM_CRYPTO_METHOD_TLSv1_2_SERVER
+));
+```
+
 > Note that available [TLS context options](http://php.net/manual/en/context.ssl.php),
 their defaults and effects of changing these may vary depending on your system
 and/or PHP version.
@@ -1000,6 +1025,18 @@ $connector->connect('tls://localhost:443')->then(function (ConnectionInterface $
 });
 ```
 
+By default, this connector supports TLSv1.0+ and excludes support for legacy
+SSLv2/SSLv3. As of PHP 5.6+ you can also explicitly choose the TLS version you
+want to negotiate with the remote side:
+
+```php
+$connector = new Connector($loop, array(
+    'tls' => array(
+        'crypto_method' => STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT
+    )
+));
+```
+
 > For more details about context options, please refer to the PHP documentation
   about [socket context options](http://php.net/manual/en/context.socket.php)
   and [SSL context options](http://php.net/manual/en/context.ssl.php).
@@ -1189,7 +1226,7 @@ $promise->cancel();
 ```
 
 Calling `cancel()` on a pending promise will cancel the underlying TCP/IP
-connection and/or the SSL/TLS negonation and reject the resulting promise.
+connection and/or the SSL/TLS negotiation and reject the resulting promise.
 
 You can optionally pass additional
 [SSL context options](http://php.net/manual/en/context.ssl.php)
@@ -1202,6 +1239,16 @@ $secureConnector = new React\Socket\SecureConnector($dnsConnector, $loop, array(
 ));
 ```
 
+By default, this connector supports TLSv1.0+ and excludes support for legacy
+SSLv2/SSLv3. As of PHP 5.6+ you can also explicitly choose the TLS version you
+want to negotiate with the remote side:
+
+```php
+$secureConnector = new React\Socket\SecureConnector($dnsConnector, $loop, array(
+    'crypto_method' => STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT
+));
+```
+
 > Advanced usage: Internally, the `SecureConnector` relies on setting up the
 required *context options* on the underlying stream resource.
 It should therefor be used with a `TcpConnector` somewhere in the connector

src/StreamEncryption.php

@@ -27,6 +27,13 @@ public function __construct(LoopInterface $loop, $server = true)
         $this->loop = $loop;
         $this->server = $server;
 
+        // support TLSv1.0+ by default and exclude legacy SSLv2/SSLv3.
+        // PHP 5.6+ supports bitmasks, legacy PHP only supports predefined
+        // constants, so apply accordingly below.
+        // Also, since PHP 5.6.7 up until before PHP 7.2.0 the main constant did
+        // only support TLSv1.0, so we explicitly apply all versions.
+        // @link http://php.net/manual/en/migration56.openssl.php#migration56.openssl.crypto-method
+        // @link https://3v4l.org/plbFn
         if ($server) {
             $this->method = STREAM_CRYPTO_METHOD_TLS_SERVER;
 
@@ -79,9 +86,16 @@ public function toggle(Connection $stream, $toggle)
         // get actual stream socket from stream instance
         $socket = $stream->stream;
 
+        // get crypto method from context options or use global setting from constructor
+        $method = $this->method;
+        $context = stream_context_get_options($socket);
+        if (isset($context['ssl']['crypto_method'])) {
+            $method = $context['ssl']['crypto_method'];
+        }
+
         $that = $this;
-        $toggleCrypto = function () use ($socket, $deferred, $toggle, $that) {
-            $that->toggleCrypto($socket, $deferred, $toggle);
+        $toggleCrypto = function () use ($socket, $deferred, $toggle, $method, $that) {
+            $that->toggleCrypto($socket, $deferred, $toggle, $method);
         };
 
         $this->loop->addReadStream($socket, $toggleCrypto);
@@ -106,10 +120,10 @@ public function toggle(Connection $stream, $toggle)
         });
     }
 
-    public function toggleCrypto($socket, Deferred $deferred, $toggle)
+    public function toggleCrypto($socket, Deferred $deferred, $toggle, $method)
     {
         set_error_handler(array($this, 'handleError'));
-        $result = stream_socket_enable_crypto($socket, $toggle, $this->method);
+        $result = stream_socket_enable_crypto($socket, $toggle, $method);
         restore_error_handler();
 
         if (true === $result) {

tests/FunctionalSecureServerTest.php

@@ -224,6 +224,54 @@ public function testPipesDataBackInMultipleChunksFromConnection()
         $this->assertEquals(400000, $received);
     }
 
+    /**
+     * @requires PHP 5.6
+     */
+    public function testEmitsConnectionForNewTlsv11Connection()
+    {
+        $loop = Factory::create();
+
+        $server = new TcpServer(0, $loop);
+        $server = new SecureServer($server, $loop, array(
+            'local_cert' => __DIR__ . '/../examples/localhost.pem',
+            'crypto_method' => STREAM_CRYPTO_METHOD_TLSv1_1_SERVER
+        ));
+        $server->on('connection', $this->expectCallableOnce());
+
+        $connector = new SecureConnector(new TcpConnector($loop), $loop, array(
+            'verify_peer' => false,
+            'crypto_method' => STREAM_CRYPTO_METHOD_TLSv1_1_CLIENT
+        ));
+        $promise = $connector->connect($server->getAddress());
+
+        Block\await($promise, $loop, self::TIMEOUT);
+    }
+
+    /**
+     * @requires PHP 5.6
+     */
+    public function testEmitsErrorForClientWithTlsVersionMismatch()
+    {
+        $loop = Factory::create();
+
+        $server = new TcpServer(0, $loop);
+        $server = new SecureServer($server, $loop, array(
+            'local_cert' => __DIR__ . '/../examples/localhost.pem',
+            'crypto_method' => STREAM_CRYPTO_METHOD_TLSv1_1_SERVER|STREAM_CRYPTO_METHOD_TLSv1_2_SERVER
+        ));
+        $server->on('connection', $this->expectCallableNever());
+        $server->on('error', $this->expectCallableOnce());
+
+        $connector = new SecureConnector(new TcpConnector($loop), $loop, array(
+            'verify_peer' => false,
+            'crypto_method' => STREAM_CRYPTO_METHOD_TLSv1_0_CLIENT
+        ));
+        $promise = $connector->connect($server->getAddress());
+
+        $this->setExpectedException('RuntimeException', 'handshake');
+        Block\await($promise, $loop, self::TIMEOUT);
+    }
+
     public function testEmitsConnectionForNewConnectionWithEncryptedCertificate()
     {
         $loop = Factory::create();