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.util.Set;
  
  import org.apache.ambari.server.AmbariException;
  import org.apache.ambari.server.security.credential.Credential;
  
  public interface CredentialStore {
    /**
     * Adds a new credential to this CredentialStore
     * <p/>
     * The supplied key will be converted into UTF-8 bytes before being stored.
     *
     * @param alias      a string declaring the alias (or name) of the credential
     * @param credential the credential to store
     * @throws AmbariException if an error occurs while storing the new credential
     */
    void addCredential(String alias, Credential credential) throws AmbariException;
  
    /**
     * Retrieves the specified credential from this CredentialStore
     *
     * @param alias a string declaring the alias (or name) of the credential
     * @return a Credential or null of not found
     * @throws AmbariException if an error occurs while retrieving the new credential
     */
    Credential getCredential(String alias) throws AmbariException;
  
    /**
     * Removes the specified credential from this CredentialStore
     *
     * @param alias a string declaring the alias (or name) of the credential
     * @throws AmbariException if an error occurs while removing the new credential
     */
    void removeCredential(String alias) throws AmbariException;
  
    /**
     * Returns a list of the alias names for the credentials stored in the CredentialStore
     *
     * @return a Set of Strings representing alias names for the credentials stored in the CredentialStore
     * @throws AmbariException if an error occurs while searching forthe credential
     */
    Set<String> listCredentials() throws AmbariException;
  
    /**
     * Tests this CredentialStore for the existence of a credential with the specified alias
     *
     * @param alias a string declaring the alias (or name) of the credential
     * @return true if the alias exists; otherwise false
     * @throws AmbariException if an error occurs while searching forthe credential
     */
    boolean containsCredential(String alias) throws AmbariException;
  
    /**
     * Sets the MasterKeyService for this CredentialStore
     *
     * @param masterKeyService the MasterKeyService
     */
    void setMasterKeyService(MasterKeyService masterKeyService);
  }
  