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.decryption_verification;
017
018import javax.annotation.Nonnull;
019
020import org.bouncycastle.openpgp.PGPPublicKey;
021
022public interface MissingPublicKeyCallback {
023
024    /**
025     * This method gets called if we encounter a signature of an unknown key.
026     *
027     * Note: It would be super cool to provide the OpenPgp fingerprint here, but unfortunately signatures only contain
028     * the key id (see https://tools.ietf.org/html/rfc4880#section-5.2.3.5)
029     *
030     * @param keyId ID of the missing key
031     *
032     * @return the key or null
033     */
034    PGPPublicKey onMissingPublicKeyEncountered(@Nonnull Long keyId);
035
036}