content: /*
   * 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.ambari.server.security.encryption;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.security.KeyStore;
  
  import org.apache.ambari.server.AmbariException;
  import org.apache.ambari.server.configuration.Configuration;
  import org.apache.commons.io.IOUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * FileBasedCredentialStore is a CredentialStore implementation that creates and manages
   * a JCEKS (Java Cryptography Extension KeyStore) file on disk.  The key store and its contents are
   * encrypted using the key from the supplied {@link MasterKeyService}.
   * <p/>
   * Most of the work for this implementation is handled by the {@link AbstractCredentialStore}.
   * This class handles the details of the storage location and associated input and output streams.
   */
  public class FileBasedCredentialStore extends AbstractCredentialStore {
    private static final Logger LOG = LoggerFactory.getLogger(FileBasedCredentialStore.class);
  
    /**
     * The directory to use for storing the key store file
     */
    private File keyStoreFile;
  
    /**
     * Constructs a new FileBasedCredentialStore using the specified key store directory
     *
     * @param keyStoreLocation a File pointing to the directory in which to store the key store file; or the file itself
     */
    public FileBasedCredentialStore(File keyStoreLocation) {
      if (keyStoreLocation == null) {
        // If the keyStoreLocation is not set, create the file (using the default filename)  in the
        // current working directory.
        LOG.warn("Writing key store to the current working directory of the running process");
        keyStoreLocation = new File(Configuration.MASTER_KEYSTORE_FILENAME_DEFAULT);
      } else if (keyStoreLocation.isDirectory()) {
        // If the keyStoreLocation is a directory, create the file (using the default filename) in
        // that directory.
        keyStoreLocation = new File(keyStoreLocation, Configuration.MASTER_KEYSTORE_FILENAME_DEFAULT);
      }
  
      if (keyStoreLocation.exists()) {
        if (!keyStoreLocation.canWrite()) {
          LOG.warn("The destination file is not writable. Failures may occur when writing the key store to disk: {}", keyStoreLocation.getAbsolutePath());
        }
      } else {
        File directory = keyStoreLocation.getParentFile();
        if ((directory != null) && !directory.canWrite()) {
          LOG.warn("The destination directory is not writable. Failures may occur when writing the key store to disk: {}", keyStoreLocation.getAbsolutePath());
        }
      }
  
      this.keyStoreFile = keyStoreLocation;
    }
  
    /**
     * Gets the path to this FileBasedCredentialStore's KeyStore file
     *
     * @return a file indicating the path to this FileBasedCredentialStore's KeyStore file
     */
    public File getKeyStorePath() {
      return keyStoreFile;
    }
  
  
    @Override
    protected void persistCredentialStore(KeyStore keyStore) throws AmbariException {
      putKeyStore(keyStore, this.keyStoreFile);
    }
  
  
    @Override
    protected KeyStore loadCredentialStore() throws AmbariException {
      return getKeyStore(this.keyStoreFile, DEFAULT_STORE_TYPE);
    }
  
    /**
     * Reads the key store data from the specified file. If the file does not exist, a new KeyStore
     * will be created.
     *
     * @param keyStoreFile a File pointing to the key store file
     * @param keyStoreType the type of key store data to read (or create)
     * @return the loaded KeyStore
     * @throws AmbariException if the Master Key Service is not set
     * @see AbstractCredentialStore#loadCredentialStore()
     */
    private KeyStore getKeyStore(final File keyStoreFile, String keyStoreType) throws AmbariException {
      KeyStore keyStore;
      FileInputStream inputStream;
  
      if (keyStoreFile.exists()) {
        if (keyStoreFile.length() > 0) {
          LOG.debug("Reading key store from {}", keyStoreFile.getAbsolutePath());
          try {
            inputStream = new FileInputStream(keyStoreFile);
          } catch (FileNotFoundException e) {
            throw new AmbariException(String.format("Failed to open the key store file: %s", e.getLocalizedMessage()), e);
          }
        } else {
          LOG.debug("The key store file found in {} is empty. Returning new (non-persisted) KeyStore", keyStoreFile.getAbsolutePath());
          inputStream = null;
        }
      } else {
        LOG.debug("Key store file not found in {}. Returning new (non-persisted) KeyStore", keyStoreFile.getAbsolutePath());
        inputStream = null;
      }
  
      try {
        keyStore = loadKeyStore(inputStream, keyStoreType);
      } finally {
        IOUtils.closeQuietly(inputStream);
      }
  
      return keyStore;
    }
  
    /**
     * Writes the specified KeyStore to a file.
     *
     * @param keyStore     the KeyStore to write to a file
     * @param keyStoreFile the File in which to store the KeyStore data
     * @throws AmbariException if an error occurs while writing the KeyStore data
     */
    private void putKeyStore(KeyStore keyStore, File keyStoreFile) throws AmbariException {
      LOG.debug("Writing key store to {}", keyStoreFile.getAbsolutePath());
  
      FileOutputStream outputStream = null;
  
      try {
        outputStream = new FileOutputStream(this.keyStoreFile);
        writeKeyStore(keyStore, outputStream);
      } catch (FileNotFoundException e) {
        throw new AmbariException(String.format("Failed to open the key store file: %s", e.getLocalizedMessage()), e);
      } finally {
        IOUtils.closeQuietly(outputStream);
      }
    }
  }
  