/*
 * 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.sshd.common.keyprovider;

import java.io.IOException;
import java.security.GeneralSecurityException;
import java.util.Objects;
import java.util.stream.StreamSupport;

import org.apache.sshd.common.config.keys.OpenSshCertificate;
import org.apache.sshd.common.session.SessionContext;

/**
 * @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
 */
@FunctionalInterface
public interface HostKeyCertificateProvider {

    Iterable<OpenSshCertificate> loadCertificates(SessionContext session) throws IOException, GeneralSecurityException;

    default OpenSshCertificate loadCertificate(SessionContext session, String keyType)
            throws IOException, GeneralSecurityException {
        Iterable<OpenSshCertificate> certificates = loadCertificates(session);
        return StreamSupport.stream(certificates.spliterator(), false)
                .filter(pubKey -> Objects.equals(pubKey.getKeyType(), keyType))
                .findFirst()
                .orElse(null);
    }
}
