/*
 * Copyright 2002-2003 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */
package com.sun.jmx.snmp;

/**
 * This interface allows you to compute key localization and delta generation. It is useful when adding user in USM MIB. An instance of <CODE> SnmpUsmKeyHandler </CODE> is associated to each <CODE> SnmpEngine </CODE> object.
 * When computing key, an authentication algorithm is needed. The supported ones are : usmHMACMD5AuthProtocol and usmHMACSHAAuthProtocol.
 * <p><b>This API is a Sun Microsystems internal API  and is subject
 * to change without notice.</b></p>
 * @since 1.5
 */
public interface SnmpUsmKeyHandler {

    /**
     * DES privacy algorithm key size. To be used when localizing privacy key
     */
    public static int DES_KEY_SIZE = 16;

    /**
     * DES privacy algorithm delta size. To be used when calculing privacy key delta.
     */
    public static int DES_DELTA_SIZE = 16;

    /**
     * Translate a password to a key. It MUST be compliant to RFC 2574 description.
     * @param algoName The authentication algorithm to use.
     * @param password Password to convert.
     * @return The key.
     * @exception IllegalArgumentException If the algorithm is unknown.
     */
    public byte[] password_to_key(String algoName, String password) throws IllegalArgumentException;
    /**
     * Localize the passed key using the passed <CODE>SnmpEngineId</CODE>. It MUST be compliant to RFC 2574 description.
     * @param algoName The authentication algorithm to use.
     * @param key The key to localize;
     * @param engineId The Id used to localize the key.
     * @return The localized key.
     * @exception IllegalArgumentException If the algorithm is unknown.
     */
    public byte[] localizeAuthKey(String algoName, byte[] key, SnmpEngineId engineId) throws IllegalArgumentException;

    /**
     * Localize the passed privacy key using the passed <CODE>SnmpEngineId</CODE>. It MUST be compliant to RFC 2574 description.
     * @param algoName The authentication algorithm to use.
     * @param key The key to localize;
     * @param engineId The Id used to localize the key.
     * @param keysize The privacy algorithm key size.
     * @return The localized key.
     * @exception IllegalArgumentException If the algorithm is unknown.
     */
    public byte[] localizePrivKey(String algoName, byte[] key, SnmpEngineId engineId,int keysize) throws IllegalArgumentException;

    /**
     * Calculate the delta parameter needed when processing key change. This computation is done by the key change initiator. It MUST be compliant to RFC 2574 description.
     * @param algoName The authentication algorithm to use.
     * @param oldKey The old key.
     * @param newKey The new key.
     * @param random The random value.
     * @return The delta.
     * @exception IllegalArgumentException If the algorithm is unknown.
     */
    public byte[] calculateAuthDelta(String algoName, byte[] oldKey, byte[] newKey, byte[] random) throws IllegalArgumentException;

    /**
     * Calculate the delta parameter needed when processing key change for a privacy algorithm. This computation is done by the key change initiator. It MUST be compliant to RFC 2574 description.
     * @param algoName The authentication algorithm to use.
     * @param oldKey The old key.
     * @param newKey The new key.
     * @param random The random value.
     * @param deltaSize The algo delta size.
     * @return The delta.
     * @exception IllegalArgumentException If the algorithm is unknown.
     */
    public byte[] calculatePrivDelta(String algoName, byte[] oldKey, byte[] newKey, byte[] random, int deltaSize) throws IllegalArgumentException;

}
