001/*
002 * Copyright 2018 Paul Schaub.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.pgpainless.key.protection;
017
018import javax.annotation.Nullable;
019
020import org.pgpainless.util.Passphrase;
021
022/**
023 * Interface to allow the user to provide a passphrase for an encrypted OpenPGP secret key.
024 */
025public interface SecretKeyPassphraseProvider {
026
027    /**
028     * Return a passphrase for the given key. If no record has been found, return null.
029     * Note: In case of an unprotected secret key, this method must may not return null, but a {@link Passphrase} with
030     * a content of null.
031     *
032     * @param keyId id of the key
033     * @return passphrase or null, if no passphrase record has been found.
034     */
035    @Nullable Passphrase getPassphraseFor(Long keyId);
036}