default client: use custom HostnameVerifier if overridden

Sometimes, it's useful to override the hostname verifier for SSL connections.
One example, would be when you're developing against a test server managed by
another company that's using a self-signed certificate with a mis-matched
hostname. This patch enables that usage by overriding the default
HostnameVerifier in a Dagger module.

Adding test coverage required switching the TrustingSSLSocketFactory from
using an anonymous cipher suite to one that authenticates.  A test keystore is
used for this purpose.  It contains two self-signed certificates, one
each with alias (and CN) "localhost" and "bad.example.com".  The
TrustingSSLSocketFactory is no longer a singleton; it now
optionally takes a key alias as an argument.

NOTICE

@@ -0,0 +1,4 @@
+Feign
+Copyright 2013 Netflix, Inc.
+
+Portions of this software developed by Commerce Technologies, Inc.

core/src/main/java/feign/Client.java

@@ -28,6 +28,7 @@ import java.util.List;
 import java.util.Map;
 
 import javax.inject.Inject;
+import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.HttpsURLConnection;
 import javax.net.ssl.SSLSocketFactory;
 
@@ -55,9 +56,11 @@ public interface Client {
 
   public static class Default implements Client {
     private final Lazy<SSLSocketFactory> sslContextFactory;
+    private final Lazy<HostnameVerifier> hostnameVerifier;
 
-    @Inject public Default(Lazy<SSLSocketFactory> sslContextFactory) {
+    @Inject public Default(Lazy<SSLSocketFactory> sslContextFactory, Lazy<HostnameVerifier> hostnameVerifier) {
       this.sslContextFactory = sslContextFactory;
+      this.hostnameVerifier = hostnameVerifier;
     }
 
     @Override public Response execute(Request request, Options options) throws IOException {
@@ -70,6 +73,7 @@ public interface Client {
       if (connection instanceof HttpsURLConnection) {
         HttpsURLConnection sslCon = (HttpsURLConnection) connection;
         sslCon.setSSLSocketFactory(sslContextFactory.get());
+        sslCon.setHostnameVerifier(hostnameVerifier.get());
       }
       connection.setConnectTimeout(options.connectTimeoutMillis());
       connection.setReadTimeout(options.readTimeoutMillis());

core/src/main/java/feign/Feign.java

@@ -29,6 +29,8 @@ import feign.codec.IncrementalDecoder;
 
 import javax.inject.Named;
 import javax.inject.Singleton;
+import javax.net.ssl.HostnameVerifier;
+import javax.net.ssl.HttpsURLConnection;
 import javax.net.ssl.SSLSocketFactory;
 import java.io.Closeable;
 import java.lang.reflect.Method;
@@ -104,6 +106,11 @@ public abstract class Feign implements Closeable {
       return SSLSocketFactory.class.cast(SSLSocketFactory.getDefault());
     }
 
+    @Provides
+    HostnameVerifier hostnameVerifier() {
+        return HttpsURLConnection.getDefaultHostnameVerifier();
+    }
+
     @Provides Client httpClient(Client.Default client) {
       return client;
     }

core/src/test/java/feign/AcceptAllHostnameVerifier.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2013 Netflix, Inc.
+ *
+ * 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.
+ */
+package feign;
+
+import javax.net.ssl.HostnameVerifier;
+import javax.net.ssl.SSLSession;
+
+final class AcceptAllHostnameVerifier implements HostnameVerifier {
+  @Override
+  public boolean verify(String s, SSLSession sslSession) {
+    return true;
+  }
+}

core/src/test/java/feign/FeignTest.java

@@ -31,6 +31,7 @@ import org.testng.annotations.Test;
 
 import javax.inject.Named;
 import javax.inject.Singleton;
+import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.SSLSocketFactory;
 import java.io.IOException;
 import java.io.Reader;
@@ -522,7 +523,7 @@ public class FeignTest {
     }
   }
 
-  @Module(injects = Client.Default.class, overrides = true)
+  @Module(injects = Client.Default.class, overrides = true, addsTo = Feign.Defaults.class)
   static class TrustSSLSockets {
     @Provides SSLSocketFactory trustingSSLSocketFactory() {
       return TrustingSSLSocketFactory.get();
@@ -531,7 +532,7 @@ public class FeignTest {
 
   @Test public void canOverrideSSLSocketFactory() throws IOException, InterruptedException {
     MockWebServer server = new MockWebServer();
-    server.useHttps(TrustingSSLSocketFactory.get(), false);
+    server.useHttps(TrustingSSLSocketFactory.get("localhost"), false);
     server.enqueue(new MockResponse().setResponseCode(200).setBody("success!".getBytes()));
     server.play();
 
@@ -544,9 +545,31 @@ public class FeignTest {
     }
   }
 
+  @Module(injects = Client.Default.class, overrides = true, addsTo = Feign.Defaults.class)
+  static class DisableHostnameVerification {
+    @Provides HostnameVerifier acceptAllHostnameVerifier() {
+      return new AcceptAllHostnameVerifier();
+    }
+  }
+
+  @Test public void canOverrideHostnameVerifier() throws IOException, InterruptedException {
+    MockWebServer server = new MockWebServer();
+    server.useHttps(TrustingSSLSocketFactory.get("bad.example.com"), false);
+    server.enqueue(new MockResponse().setResponseCode(200).setBody("success!".getBytes()));
+    server.play();
+
+    try {
+      TestInterface api = Feign.create(TestInterface.class, "https://localhost:" + server.getPort(),
+          new TestInterface.Module(), new TrustSSLSockets(), new DisableHostnameVerification());
+      api.post();
+    } finally {
+      server.shutdown();
+    }
+  }
+
   @Test public void retriesFailedHandshake() throws IOException, InterruptedException {
     MockWebServer server = new MockWebServer();
-    server.useHttps(TrustingSSLSocketFactory.get(), false);
+    server.useHttps(TrustingSSLSocketFactory.get("localhost"), false);
     server.enqueue(new MockResponse().setSocketPolicy(SocketPolicy.FAIL_HANDSHAKE));
     server.enqueue(new MockResponse().setResponseCode(200).setBody("success!".getBytes()));
     server.play();

core/src/test/java/feign/TrustingSSLSocketFactory.java

@@ -15,11 +15,24 @@
  */
 package feign;
 
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+import com.google.common.io.Closer;
+import com.google.common.io.InputSupplier;
+import com.google.common.io.Resources;
+
 import java.io.IOException;
+import java.io.InputStream;
 import java.net.InetAddress;
 import java.net.Socket;
+import java.security.KeyStore;
+import java.security.Principal;
+import java.security.PrivateKey;
 import java.security.SecureRandom;
+import java.security.cert.Certificate;
 import java.security.cert.X509Certificate;
+import java.util.Arrays;
 
 import javax.inject.Provider;
 import javax.net.ssl.KeyManager;
@@ -27,22 +40,40 @@ import javax.net.ssl.SSLContext;
 import javax.net.ssl.SSLSocket;
 import javax.net.ssl.SSLSocketFactory;
 import javax.net.ssl.TrustManager;
+import javax.net.ssl.X509KeyManager;
 import javax.net.ssl.X509TrustManager;
 
 import static com.google.common.base.Throwables.propagate;
 
 /**
- * used for ssl tests so that they can avoid having to read a keystore.
+ * Used for ssl tests to simplify setup.
  */
-final class TrustingSSLSocketFactory extends SSLSocketFactory implements X509TrustManager, KeyManager {
+final class TrustingSSLSocketFactory extends SSLSocketFactory implements X509TrustManager, X509KeyManager {
+
+  private static LoadingCache<String, SSLSocketFactory> sslSocketFactories =
+      CacheBuilder.newBuilder().build(new CacheLoader<String, SSLSocketFactory>() {
+    @Override
+    public SSLSocketFactory load(String serverAlias) throws Exception {
+      return new TrustingSSLSocketFactory(serverAlias);
+    }
+  });
 
   public static SSLSocketFactory get() {
-    return Singleton.INSTANCE.get();
+    return get("");
   }
 
+  public static SSLSocketFactory get(String serverAlias) {
+    return sslSocketFactories.getUnchecked(serverAlias);
+  }
+
+  private static final char[] KEYSTORE_PASSWORD = "password".toCharArray();
+
   private final SSLSocketFactory delegate;
+  private final String serverAlias;
+  private final PrivateKey privateKey;
+  private final X509Certificate[] certificateChain;
 
-  private TrustingSSLSocketFactory() {
+  private TrustingSSLSocketFactory(String serverAlias) {
     try {
       SSLContext sc = SSLContext.getInstance("SSL");
       sc.init(new KeyManager[]{this}, new TrustManager[]{this}, new SecureRandom());
@@ -50,6 +81,20 @@ final class TrustingSSLSocketFactory extends SSLSocketFactory implements X509Tru
     } catch (Exception e) {
       throw propagate(e);
     }
+    this.serverAlias = serverAlias;
+    if (serverAlias.isEmpty()) {
+      this.privateKey = null;
+      this.certificateChain = null;
+    } else {
+      try {
+        KeyStore keyStore = loadKeyStore(Resources.newInputStreamSupplier(Resources.getResource("keystore.jks")));
+        this.privateKey = (PrivateKey) keyStore.getKey(serverAlias, KEYSTORE_PASSWORD);
+        Certificate[] rawChain = keyStore.getCertificateChain(serverAlias);
+        this.certificateChain = Arrays.copyOf(rawChain, rawChain.length, X509Certificate[].class);
+      } catch (Exception e) {
+        throw propagate(e);
+      }
+    }
   }
 
   @Override public String[] getDefaultCipherSuites() {
@@ -100,15 +145,49 @@ final class TrustingSSLSocketFactory extends SSLSocketFactory implements X509Tru
   public void checkServerTrusted(X509Certificate[] certs, String authType) {
   }
 
-  private final static String[] ENABLED_CIPHER_SUITES = {"SSL_DH_anon_WITH_RC4_128_MD5"};
+  @Override
+  public String[] getClientAliases(String keyType, Principal[] issuers) {
+    return null;
+  }
 
-  private static enum Singleton implements Provider<SSLSocketFactory> {
-    INSTANCE;
+  @Override
+  public String chooseClientAlias(String[] keyType, Principal[] issuers, Socket socket) {
+    return null;
+  }
 
-    private final SSLSocketFactory sslSocketFactory = new TrustingSSLSocketFactory();
+  @Override
+  public String[] getServerAliases(String keyType, Principal[] issuers) {
+    return null;
+  }
 
-    @Override public SSLSocketFactory get() {
-      return sslSocketFactory;
+  @Override
+  public String chooseServerAlias(String keyType, Principal[] issuers, Socket socket) {
+    return serverAlias;
+  }
+
+  @Override
+  public X509Certificate[] getCertificateChain(String alias) {
+    return certificateChain;
+  }
+
+  @Override
+  public PrivateKey getPrivateKey(String alias) {
+    return privateKey;
+  }
+
+  private static KeyStore loadKeyStore(InputSupplier<InputStream> inputStreamSupplier) throws IOException {
+    Closer closer = Closer.create();
+    try {
+      InputStream inputStream = closer.register(inputStreamSupplier.getInput());
+      KeyStore keyStore = KeyStore.getInstance("JKS");
+      keyStore.load(inputStream, KEYSTORE_PASSWORD);
+      return keyStore;
+    } catch (Throwable e) {
+      throw closer.rethrow(e);
+    } finally {
+      closer.close();
     }
   }
+
+  private final static String[] ENABLED_CIPHER_SUITES = {"SSL_RSA_WITH_RC4_128_MD5"};
 }