/*
 * 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.kex.dh;

import org.apache.sshd.common.digest.Digest;
import org.apache.sshd.common.kex.KeyExchange;
import org.apache.sshd.common.session.Session;
import org.apache.sshd.common.session.SessionHolder;
import org.apache.sshd.common.session.helpers.AbstractSession;
import org.apache.sshd.common.util.ValidateUtils;
import org.apache.sshd.common.util.logging.AbstractLoggingBean;

/**
 * @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
 */
public abstract class AbstractDHKeyExchange extends AbstractLoggingBean implements KeyExchange, SessionHolder<AbstractSession> {

    protected byte[] v_s;
    protected byte[] v_c;
    protected byte[] i_s;
    protected byte[] i_c;
    protected Digest hash;
    protected byte[] e;
    protected byte[] f;
    protected byte[] k;
    protected byte[] h;

    private AbstractSession session;

    protected AbstractDHKeyExchange() {
        super();
    }

    @Override
    public void init(Session s, byte[] v_s, byte[] v_c, byte[] i_s, byte[] i_c) throws Exception {
        this.session = ValidateUtils.checkInstanceOf(s, AbstractSession.class, "Not an abstract session: %s", s);
        this.v_s = ValidateUtils.checkNotNullAndNotEmpty(v_s, "No v_s value");
        this.v_c = ValidateUtils.checkNotNullAndNotEmpty(v_c, "No v_c value");
        this.i_s = ValidateUtils.checkNotNullAndNotEmpty(i_s, "No i_s value");
        this.i_c = ValidateUtils.checkNotNullAndNotEmpty(i_c, "No i_c value");
    }

    @Override
    public AbstractSession getSession() {
        return session;
    }

    @Override
    public Digest getHash() {
        return hash;
    }

    @Override
    public byte[] getH() {
        return h;
    }

    @Override
    public byte[] getK() {
        return k;
    }

    @Override
    public String toString() {
        return getClass().getSimpleName() + "[" + getName() + "]";
    }
}