Fix custom SSLSocketFactory not being set because of an unsafe lazy-i…

…nitialization in JDK (#4566)

* Avoid unsafe lazy-initialization for SSL sockets

This prevents calling HttpsURLConnection.getDefaultSSLSocketFactory() in
an unsafe manner due to the poorly implemented lazy-initialization on
the JDK.

When multiple threads call that method concurrently (calling
secureConnection()) the SSLSocketFactory is instantiated two times,
making one thread fail the check and overriding the custom socket
factory with the default one.

Also-by: Kevin Conaway <[email protected]>
Signed-off-by: Adrian Haasler García <[email protected]>

core-client/src/main/java/org/glassfish/jersey/client/internal/HttpUrlConnector.java

@@ -71,6 +71,9 @@ public class HttpUrlConnector implements Connector {
 
     private static final Logger LOGGER = Logger.getLogger(HttpUrlConnector.class.getName());
     private static final String ALLOW_RESTRICTED_HEADERS_SYSTEM_PROPERTY = "sun.net.http.allowRestrictedHeaders";
+    // Avoid multi-thread uses of HttpsURLConnection.getDefaultSSLSocketFactory() because it does not implement a
+    // proper lazy-initialization. See https://github.com/jersey/jersey/issues/3293
+    private static final SSLSocketFactory DEFAULT_SSL_SOCKET_FACTORY = HttpsURLConnection.getDefaultSSLSocketFactory();
     // The list of restricted headers is extracted from sun.net.www.protocol.http.HttpURLConnection
     private static final String[] restrictedHeaders = {
             "Access-Control-Request-Headers",
@@ -302,7 +305,7 @@ protected void secureConnection(final JerseyClient client, final HttpURLConnecti
                 suc.setHostnameVerifier(verifier);
             }
 
-            if (HttpsURLConnection.getDefaultSSLSocketFactory() == suc.getSSLSocketFactory()) {
+            if (DEFAULT_SSL_SOCKET_FACTORY == suc.getSSLSocketFactory()) {
                 // indicates that the custom socket factory was not set
                 suc.setSSLSocketFactory(sslSocketFactory.get());
             }

tests/e2e-client/src/test/java/org/glassfish/jersey/tests/e2e/client/connector/ssl/SslHttpUrlConnectorTest.java

@@ -17,10 +17,18 @@
 package org.glassfish.jersey.tests.e2e.client.connector.ssl;
 
 import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.net.HttpURLConnection;
 import java.net.InetAddress;
 import java.net.Socket;
 import java.net.URL;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 
 import javax.ws.rs.client.Client;
 import javax.ws.rs.client.ClientBuilder;
@@ -79,6 +87,61 @@ public HttpURLConnection getConnection(final URL url) throws IOException {
         assertTrue(socketFactory.isVisited());
     }
 
+    /**
+     * Test for https://github.com/jersey/jersey/issues/3293
+     *
+     * @author Kevin Conaway
+     */
+    @Test
+    public void testConcurrentRequestsWithCustomSSLContext() throws Exception {
+        final SSLContext sslContext = getSslContext();
+
+        final Client client = ClientBuilder.newBuilder()
+            .sslContext(sslContext)
+            .register(HttpAuthenticationFeature.basic("user", "password"))
+            .register(LoggingFeature.class)
+            .build();
+
+        int numThreads = 5;
+        CyclicBarrier barrier = new CyclicBarrier(numThreads);
+        ExecutorService service = Executors.newFixedThreadPool(numThreads);
+        List<Exception> exceptions = new CopyOnWriteArrayList<>();
+
+        for (int i = 0; i < numThreads; i++) {
+            service.submit(() -> {
+                try {
+                    barrier.await(1, TimeUnit.MINUTES);
+                    for (int call = 0; call < 10; call++) {
+                        final Response response = client.target(Server.BASE_URI).path("/").request().get();
+                        assertEquals(200, response.getStatus());
+                    }
+                } catch (Exception ex) {
+                    exceptions.add(ex);
+                }
+            });
+        }
+
+        service.shutdown();
+
+        assertTrue(
+            service.awaitTermination(1, TimeUnit.MINUTES)
+        );
+
+        assertTrue(
+            toString(exceptions),
+            exceptions.isEmpty()
+        );
+    }
+
+    private String toString(List<Exception> exceptions) {
+        StringWriter writer = new StringWriter();
+        PrintWriter printWriter = new PrintWriter(writer);
+
+        exceptions.forEach(e -> e.printStackTrace(printWriter));
+
+        return writer.toString();
+    }
+
     public static class CustomSSLSocketFactory extends SSLSocketFactory {
 
         private boolean visited = false;