/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.hadoop.security.ssl;

import static org.junit.Assert.assertTrue;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.security.alias.CredentialProviderFactory;
import org.apache.hadoop.security.alias.JavaKeyStoreProvider;
import org.apache.hadoop.test.GenericTestUtils;
import org.apache.hadoop.util.StringUtils;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.event.Level;

import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLEngineResult;
import javax.net.ssl.SSLHandshakeException;
import javax.net.ssl.SSLSession;
import java.io.File;
import java.net.URL;
import java.nio.ByteBuffer;
import java.security.GeneralSecurityException;
import java.security.KeyPair;
import java.security.cert.X509Certificate;
import java.util.Collections;
import java.util.Map;

public class TestSSLFactory {
  private static final Logger LOG = LoggerFactory
      .getLogger(TestSSLFactory.class);
  private static final String BASEDIR =
      GenericTestUtils.getTempPath(TestSSLFactory.class.getSimpleName());
  private static final String KEYSTORES_DIR =
    new File(BASEDIR).getAbsolutePath();
  private String sslConfsDir;
  private static final String excludeCiphers = "TLS_ECDHE_RSA_WITH_RC4_128_SHA,"
      + "SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA,  \n"
      + "SSL_RSA_WITH_DES_CBC_SHA,"
      + "SSL_DHE_RSA_WITH_DES_CBC_SHA,  "
      + "SSL_RSA_EXPORT_WITH_RC4_40_MD5,\t \n"
      + "SSL_RSA_EXPORT_WITH_DES40_CBC_SHA,"
      + "SSL_RSA_WITH_RC4_128_MD5,"
      + "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA";

  @BeforeClass
  public static void setUp() throws Exception {
    File base = new File(BASEDIR);
    FileUtil.fullyDelete(base);
    base.mkdirs();
  }

  private Configuration createConfiguration(boolean clientCert,
      boolean trustStore)
    throws Exception {
    Configuration conf = new Configuration();
    KeyStoreTestUtil.setupSSLConfig(KEYSTORES_DIR, sslConfsDir, conf,
      clientCert, trustStore, excludeCiphers);
    return conf;
  }

  @After
  @Before
  public void cleanUp() throws Exception {
    sslConfsDir = KeyStoreTestUtil.getClasspathDir(TestSSLFactory.class);
    KeyStoreTestUtil.cleanupSSLConfig(KEYSTORES_DIR, sslConfsDir);
  }

  @Test(expected = IllegalStateException.class)
  public void clientMode() throws Exception {
    Configuration conf = createConfiguration(false, true);
    SSLFactory sslFactory = new SSLFactory(SSLFactory.Mode.CLIENT, conf);
    try {
      sslFactory.init();
      Assert.assertNotNull(sslFactory.createSSLSocketFactory());
      Assert.assertNotNull(sslFactory.getHostnameVerifier());
      sslFactory.createSSLServerSocketFactory();
    } finally {
      sslFactory.destroy();
    }
  }

  private void serverMode(boolean clientCert, boolean socket) throws Exception {
    Configuration conf = createConfiguration(clientCert, true);
    SSLFactory sslFactory = new SSLFactory(SSLFactory.Mode.SERVER, conf);
    try {
      sslFactory.init();
      Assert.assertNotNull(sslFactory.createSSLServerSocketFactory());
      Assert.assertEquals(clientCert, sslFactory.isClientCertRequired());
      if (socket) {
        sslFactory.createSSLSocketFactory();
      } else {
        sslFactory.getHostnameVerifier();
      }
    } finally {
      sslFactory.destroy();
    }
  }


  @Test(expected = IllegalStateException.class)
  public void serverModeWithoutClientCertsSocket() throws Exception {
    serverMode(false, true);
  }

  @Test(expected = IllegalStateException.class)
  public void serverModeWithClientCertsSocket() throws Exception {
    serverMode(true, true);
  }

  @Test(expected = IllegalStateException.class)
  public void serverModeWithoutClientCertsVerifier() throws Exception {
    serverMode(false, false);
  }

  @Test(expected = IllegalStateException.class)
  public void serverModeWithClientCertsVerifier() throws Exception {
    serverMode(true, false);
  }

  private void runDelegatedTasks(SSLEngineResult result, SSLEngine engine)
    throws Exception {
    Runnable runnable;
    if (result.getHandshakeStatus() ==
        SSLEngineResult.HandshakeStatus.NEED_TASK) {
      while ((runnable = engine.getDelegatedTask()) != null) {
        LOG.info("running delegated task...");
        runnable.run();
      }
      SSLEngineResult.HandshakeStatus hsStatus = engine.getHandshakeStatus();
      if (hsStatus == SSLEngineResult.HandshakeStatus.NEED_TASK) {
        throw new Exception("handshake shouldn't need additional tasks");
      }
    }
  }

  private static boolean isEngineClosed(SSLEngine engine) {
    return engine.isOutboundDone() && engine.isInboundDone();
  }

  private static void checkTransfer(ByteBuffer a, ByteBuffer b)
    throws Exception {
    a.flip();
    b.flip();
    assertTrue("transfer did not complete", a.equals(b));

    a.position(a.limit());
    b.position(b.limit());
    a.limit(a.capacity());
    b.limit(b.capacity());
  }
  @Test
  public void testServerWeakCiphers() throws Exception {
    // a simple test case to verify that SSL server rejects weak cipher suites,
    // inspired by https://docs.oracle.com/javase/8/docs/technotes/guides/
    //            security/jsse/samples/sslengine/SSLEngineSimpleDemo.java

    // set up a client and a server SSLEngine object, and let them exchange
    // data over ByteBuffer instead of network socket.
    GenericTestUtils.setLogLevel(SSLFactory.LOG, Level.DEBUG);
    final Configuration conf = createConfiguration(true, true);

    SSLFactory serverSSLFactory = new SSLFactory(SSLFactory.Mode.SERVER, conf);
    SSLFactory clientSSLFactory = new SSLFactory(SSLFactory.Mode.CLIENT, conf);

    serverSSLFactory.init();
    clientSSLFactory.init();

    SSLEngine serverSSLEngine = serverSSLFactory.createSSLEngine();
    SSLEngine clientSSLEngine = clientSSLFactory.createSSLEngine();
    // client selects cipher suites excluded by server
    clientSSLEngine.setEnabledCipherSuites(
        StringUtils.getTrimmedStrings(excludeCiphers));

    // use the same buffer size for server and client.
    SSLSession session = clientSSLEngine.getSession();
    int appBufferMax = session.getApplicationBufferSize();
    int netBufferMax = session.getPacketBufferSize();

    ByteBuffer clientOut = ByteBuffer.wrap("client".getBytes());
    ByteBuffer clientIn = ByteBuffer.allocate(appBufferMax);
    ByteBuffer serverOut = ByteBuffer.wrap("server".getBytes());
    ByteBuffer serverIn = ByteBuffer.allocate(appBufferMax);

    // send data from client to server
    ByteBuffer cTOs = ByteBuffer.allocateDirect(netBufferMax);
    // send data from server to client
    ByteBuffer sTOc = ByteBuffer.allocateDirect(netBufferMax);

    boolean dataDone = false;
    try {
      /**
       * Server and client engines call wrap()/unwrap() to perform handshaking,
       * until both engines are closed.
       */
      while (!isEngineClosed(clientSSLEngine) ||
          !isEngineClosed(serverSSLEngine)) {
        LOG.info("client wrap " + wrap(clientSSLEngine, clientOut, cTOs));
        LOG.info("server wrap " + wrap(serverSSLEngine, serverOut, sTOc));
        cTOs.flip();
        sTOc.flip();
        LOG.info("client unwrap " + unwrap(clientSSLEngine, sTOc, clientIn));
        LOG.info("server unwrap " + unwrap(serverSSLEngine, cTOs, serverIn));
        cTOs.compact();
        sTOc.compact();
        if (!dataDone && (clientOut.limit() == serverIn.position()) &&
            (serverOut.limit() == clientIn.position())) {
          checkTransfer(serverOut, clientIn);
          checkTransfer(clientOut, serverIn);

          LOG.info("closing client");
          clientSSLEngine.closeOutbound();
          dataDone = true;
        }
      }
      Assert.fail("The exception was not thrown");
    } catch (SSLHandshakeException e) {
      GenericTestUtils.assertExceptionContains("no cipher suites in common", e);
    }
  }

  private SSLEngineResult wrap(SSLEngine engine, ByteBuffer from,
      ByteBuffer to) throws Exception {
    SSLEngineResult result = engine.wrap(from, to);
    runDelegatedTasks(result, engine);
    return result;
  }

  private SSLEngineResult unwrap(SSLEngine engine, ByteBuffer from,
      ByteBuffer to) throws Exception {
    SSLEngineResult result = engine.unwrap(from, to);
    runDelegatedTasks(result, engine);
    return result;
  }

  @Test
  public void validHostnameVerifier() throws Exception {
    Configuration conf = createConfiguration(false, true);
    conf.unset(SSLFactory.SSL_HOSTNAME_VERIFIER_KEY);
    SSLFactory sslFactory = new
      SSLFactory(SSLFactory.Mode.CLIENT, conf);
    sslFactory.init();
    Assert.assertEquals("DEFAULT", sslFactory.getHostnameVerifier().toString());
    sslFactory.destroy();

    conf.set(SSLFactory.SSL_HOSTNAME_VERIFIER_KEY, "ALLOW_ALL");
    sslFactory = new SSLFactory(SSLFactory.Mode.CLIENT, conf);
    sslFactory.init();
    Assert.assertEquals("ALLOW_ALL",
                        sslFactory.getHostnameVerifier().toString());
    sslFactory.destroy();

    conf.set(SSLFactory.SSL_HOSTNAME_VERIFIER_KEY, "DEFAULT_AND_LOCALHOST");
    sslFactory = new SSLFactory(SSLFactory.Mode.CLIENT, conf);
    sslFactory.init();
    Assert.assertEquals("DEFAULT_AND_LOCALHOST",
                        sslFactory.getHostnameVerifier().toString());
    sslFactory.destroy();

    conf.set(SSLFactory.SSL_HOSTNAME_VERIFIER_KEY, "STRICT");
    sslFactory = new SSLFactory(SSLFactory.Mode.CLIENT, conf);
    sslFactory.init();
    Assert.assertEquals("STRICT", sslFactory.getHostnameVerifier().toString());
    sslFactory.destroy();

    conf.set(SSLFactory.SSL_HOSTNAME_VERIFIER_KEY, "STRICT_IE6");
    sslFactory = new SSLFactory(SSLFactory.Mode.CLIENT, conf);
    sslFactory.init();
    Assert.assertEquals("STRICT_IE6",
                        sslFactory.getHostnameVerifier().toString());
    sslFactory.destroy();
  }

  @Test(expected = GeneralSecurityException.class)
  public void invalidHostnameVerifier() throws Exception {
    Configuration conf = createConfiguration(false, true);
    conf.set(SSLFactory.SSL_HOSTNAME_VERIFIER_KEY, "foo");
    SSLFactory sslFactory = new SSLFactory(SSLFactory.Mode.CLIENT, conf);
    try {
      sslFactory.init();
    } finally {
      sslFactory.destroy();
    }
  }

  @Test
  public void testConnectionConfigurator() throws Exception {
    Configuration conf = createConfiguration(false, true);
    conf.set(SSLFactory.SSL_HOSTNAME_VERIFIER_KEY, "STRICT_IE6");
    SSLFactory sslFactory = new SSLFactory(SSLFactory.Mode.CLIENT, conf);
    try {
      sslFactory.init();
      HttpsURLConnection sslConn =
          (HttpsURLConnection) new URL("https://foo").openConnection();
      Assert.assertNotSame("STRICT_IE6",
                           sslConn.getHostnameVerifier().toString());
      sslFactory.configure(sslConn);
      Assert.assertEquals("STRICT_IE6",
                          sslConn.getHostnameVerifier().toString());
    } finally {
      sslFactory.destroy();
    }
  }

  @Test
  public void testServerDifferentPasswordAndKeyPassword() throws Exception {
    checkSSLFactoryInitWithPasswords(SSLFactory.Mode.SERVER, "password",
      "keyPassword", "password", "keyPassword");
  }

  @Test
  public void testServerKeyPasswordDefaultsToPassword() throws Exception {
    checkSSLFactoryInitWithPasswords(SSLFactory.Mode.SERVER, "password",
      "password", "password", null);
  }

  @Test
  public void testClientDifferentPasswordAndKeyPassword() throws Exception {
    checkSSLFactoryInitWithPasswords(SSLFactory.Mode.CLIENT, "password",
      "keyPassword", "password", "keyPassword");
  }

  @Test
  public void testClientKeyPasswordDefaultsToPassword() throws Exception {
    checkSSLFactoryInitWithPasswords(SSLFactory.Mode.CLIENT, "password",
      "password", "password", null);
  }

  @Test
  public void testServerCredProviderPasswords() throws Exception {
    KeyStoreTestUtil.provisionPasswordsToCredentialProvider();
    checkSSLFactoryInitWithPasswords(SSLFactory.Mode.SERVER,
        "storepass", "keypass", null, null, true);
  }

  /**
   * Checks that SSLFactory initialization is successful with the given
   * arguments.  This is a helper method for writing test cases that cover
   * different combinations of settings for the store password and key password.
   * It takes care of bootstrapping a keystore, a truststore, and SSL client or
   * server configuration.  Then, it initializes an SSLFactory.  If no exception
   * is thrown, then initialization was successful.
   *
   * @param mode SSLFactory.Mode mode to test
   * @param password String store password to set on keystore
   * @param keyPassword String key password to set on keystore
   * @param confPassword String store password to set in SSL config file, or null
   *   to avoid setting in SSL config file
   * @param confKeyPassword String key password to set in SSL config file, or
   *   null to avoid setting in SSL config file
   * @throws Exception for any error
   */
  private void checkSSLFactoryInitWithPasswords(SSLFactory.Mode mode,
      String password, String keyPassword, String confPassword,
      String confKeyPassword) throws Exception {
    checkSSLFactoryInitWithPasswords(mode, password, keyPassword,
        confPassword, confKeyPassword, false);
  }

 /**
   * Checks that SSLFactory initialization is successful with the given
   * arguments.  This is a helper method for writing test cases that cover
   * different combinations of settings for the store password and key password.
   * It takes care of bootstrapping a keystore, a truststore, and SSL client or
   * server configuration.  Then, it initializes an SSLFactory.  If no exception
   * is thrown, then initialization was successful.
   *
   * @param mode SSLFactory.Mode mode to test
   * @param password String store password to set on keystore
   * @param keyPassword String key password to set on keystore
   * @param confPassword String store password to set in SSL config file, or null
   *   to avoid setting in SSL config file
   * @param confKeyPassword String key password to set in SSL config file, or
   *   null to avoid setting in SSL config file
   * @param useCredProvider boolean to indicate whether passwords should be set
   * into the config or not. When set to true nulls are set and aliases are
   * expected to be resolved through credential provider API through the
   * Configuration.getPassword method
   * @throws Exception for any error
   */
  private void checkSSLFactoryInitWithPasswords(SSLFactory.Mode mode,
      String password, String keyPassword, String confPassword,
      String confKeyPassword, boolean useCredProvider) throws Exception {
    String keystore = new File(KEYSTORES_DIR, "keystore.jks").getAbsolutePath();
    String truststore = new File(KEYSTORES_DIR, "truststore.jks")
      .getAbsolutePath();
    String trustPassword = "trustP";

    // Create keys, certs, keystore, and truststore.
    KeyPair keyPair = KeyStoreTestUtil.generateKeyPair("RSA");
    X509Certificate cert = KeyStoreTestUtil.generateCertificate("CN=Test",
      keyPair, 30, "SHA1withRSA");
    KeyStoreTestUtil.createKeyStore(keystore, password, keyPassword, "Test",
      keyPair.getPrivate(), cert);
    Map<String, X509Certificate> certs = Collections.singletonMap("server",
      cert);
    KeyStoreTestUtil.createTrustStore(truststore, trustPassword, certs);

    // Create SSL configuration file, for either server or client.
    final String sslConfFileName;
    final Configuration sslConf;

    // if the passwords are provisioned in a cred provider then don't set them
    // in the configuration properly - expect them to be resolved through the
    // provider
    if (useCredProvider) {
      confPassword = null;
      confKeyPassword = null;
    }
    if (mode == SSLFactory.Mode.SERVER) {
      sslConfFileName = "ssl-server.xml";
      sslConf = KeyStoreTestUtil.createServerSSLConfig(keystore, confPassword,
        confKeyPassword, truststore);
      if (useCredProvider) {
        File testDir = GenericTestUtils.getTestDir();
        final Path jksPath = new Path(testDir.toString(), "test.jks");
        final String ourUrl =
            JavaKeyStoreProvider.SCHEME_NAME + "://file" + jksPath.toUri();
        sslConf.set(CredentialProviderFactory.CREDENTIAL_PROVIDER_PATH, ourUrl);
      }
    } else {
      sslConfFileName = "ssl-client.xml";
      sslConf = KeyStoreTestUtil.createClientSSLConfig(keystore, confPassword,
        confKeyPassword, truststore);
    }
    KeyStoreTestUtil.saveConfig(new File(sslConfsDir, sslConfFileName), sslConf);

    // Create the master configuration for use by the SSLFactory, which by
    // default refers to the ssl-server.xml or ssl-client.xml created above.
    Configuration conf = new Configuration();
    conf.setBoolean(SSLFactory.SSL_REQUIRE_CLIENT_CERT_KEY, true);

    // Try initializing an SSLFactory.
    SSLFactory sslFactory = new SSLFactory(mode, conf);
    try {
      sslFactory.init();
    } finally {
      sslFactory.destroy();
    }
  }

  @Test
  public void testNoClientCertsInitialization() throws Exception {
    Configuration conf = createConfiguration(false, true);
    conf.unset(SSLFactory.SSL_REQUIRE_CLIENT_CERT_KEY);
    SSLFactory sslFactory = new SSLFactory(SSLFactory.Mode.CLIENT, conf);
    try {
      sslFactory.init();
    } finally {
      sslFactory.destroy();
    }
  }

  @Test
  public void testNoTrustStore() throws Exception {
    Configuration conf = createConfiguration(false, false);
    conf.unset(SSLFactory.SSL_REQUIRE_CLIENT_CERT_KEY);
    SSLFactory sslFactory = new SSLFactory(SSLFactory.Mode.SERVER, conf);
    try {
      sslFactory.init();
    } finally {
      sslFactory.destroy();
    }
  }

}