/*

 * Copyright (c) 1996, 2012, Oracle and/or its affiliates. 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

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 */

package sun.security.ssl;

import java.security.SecureRandom;

/**

 * Encapsulates an SSL session ID.  SSL Session IDs are not reused by

 * servers during the lifetime of any sessions it created.  Sessions may

 * be used by many connections, either concurrently (for example, two

 * connections to a web server at the same time) or sequentially (over as

 * long a time period as is allowed by a given server).

 *

 * @author Satish Dharmaraj

 * @author David Brownell

 */

final

class SessionId

{

    private byte sessionId [];          // max 32 bytes

    /** Constructs a new session ID ... perhaps for a rejoinable session */

    SessionId (boolean isRejoinable, SecureRandom generator)

    {

        if (isRejoinable)

            // this will be unique, it's a timestamp plus much randomness

            sessionId = new RandomCookie (generator).random_bytes;

        else

            sessionId = new byte [0];

    }

    /** Constructs a session ID from a byte array (max size 32 bytes) */

    SessionId (byte sessionId [])

        { this.sessionId = sessionId; }

    /** Returns the length of the ID, in bytes */

    int length ()

        { return sessionId.length; }

    /** Returns the bytes in the ID.  May be an empty array.  */

    byte [] getId ()

    {

        return sessionId.clone ();

    }

    /** Returns the ID as a string */

    @Override

    public String toString ()

    {

        int             len = sessionId.length;

        StringBuilder    sb = new StringBuilder (10 + 2 * len);

        sb.append("{");

        for (int i = 0; i < len; i++) {

            sb.append(0x0ff & sessionId[i]);

            if (i != (len - 1))

                sb.append (", ");

        }

        sb.append("}");

        return sb.toString ();

    }

    /** Returns a value which is the same for session IDs which are equal */

    @Override

    public int hashCode ()

    {

        int     retval = 0;

        for (int i = 0; i < sessionId.length; i++)

            retval += sessionId [i];

        return retval;

    }

    /** Returns true if the parameter is the same session ID */

    @Override

    public boolean equals (Object obj)

    {

        if (!(obj instanceof SessionId))

            return false;

        SessionId s = (SessionId) obj;

        byte b [] = s.getId ();

        if (b.length != sessionId.length)

            return false;

        for (int i = 0; i < sessionId.length; i++) {

            if (b [i] != sessionId [i])

                return false;

        }

        return true;

    }

}