keyusage.java

这是linux下ssl vpn的实现程序

/*
 *  SSL-Explorer
 *
 *  Copyright (C) 2003-2006 3SP LTD. All Rights Reserved
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2 of
 *  the License, or (at your option) any later version.
 *  This program 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 for more details.
 *
 *  You should have received a copy of the GNU General Public
 *  License along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
			
package com.maverick.crypto.asn1.x509;


import com.maverick.crypto.asn1.DERBitString;

/**
 * The KeyUsage object.
 * <pre>
 *    id-ce-keyUsage OBJECT IDENTIFIER ::=  { id-ce 15 }
 *
 *    KeyUsage ::= BIT STRING {
 *         digitalSignature        (0),
 *         nonRepudiation          (1),
 *         keyEncipherment         (2),
 *         dataEncipherment        (3),
 *         keyAgreement            (4),
 *         keyCertSign             (5),
 *         cRLSign                 (6),
 *         encipherOnly            (7),
 *         decipherOnly            (8) }
 * </pre>
 */
public class KeyUsage
    extends DERBitString
{
    public static final int        digitalSignature = (1 << 7);
    public static final int        nonRepudiation   = (1 << 6);
    public static final int        keyEncipherment  = (1 << 5);
    public static final int        dataEncipherment = (1 << 4);
    public static final int        keyAgreement     = (1 << 3);
    public static final int        keyCertSign      = (1 << 2);
    public static final int        cRLSign          = (1 << 1);
    public static final int        encipherOnly     = (1 << 0);
    public static final int        decipherOnly     = (1 << 15);

    /**
     * Basic constructor.
     *
     * @param usage - the bitwise OR of the Key Usage flags giving the
     * allowed uses for the key.
     * e.g. (KeyUsage.keyEncipherment | KeyUsage.dataEncipherment)
     */
    public KeyUsage(
        int usage)
    {
        super(getBytes(usage), getPadBits(usage));
    }

    public KeyUsage(
        DERBitString usage)
    {
        super(usage.getBytes(), usage.getPadBits());
    }

    public String toString()
    {
    	if (data.length == 1)
    	{
        	return "KeyUsage: 0x" + Integer.toHexString(data[0] & 0xff);
    	}
		return "KeyUsage: 0x" + Integer.toHexString((data[1] & 0xff) << 8 | (data[0] & 0xff));
    }
}