/*
 * @(#)MyJCE.java	1.4 02/01/17
 *
 * Copyright 2002 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or 
 * without modification, are permitted provided that the following 
 * conditions are met:
 * 
 * -Redistributions of source code must retain the above copyright  
 * notice, this  list of conditions and the following disclaimer.
 * 
 * -Redistribution in binary form must reproduct the above copyright 
 * notice, this list of conditions and the following disclaimer in 
 * the documentation and/or other materials provided with the 
 * distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of 
 * contributors may be used to endorse or promote products derived 
 * from this software without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any 
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY 
 * EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY 
 * DAMAGES OR LIABILITIES  SUFFERED BY LICENSEE AS A RESULT OF  OR 
 * RELATING TO USE, MODIFICATION OR DISTRIBUTION OF THE SOFTWARE OR 
 * ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE 
 * FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, 
 * SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER 
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF 
 * THE USE OF OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN 
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * You acknowledge that Software is not designed, licensed or 
 * intended for use in the design, construction, operation or 
  * maintenance of any nuclear facility. 
 */

import java.io.*;
import java.net.*;
import java.security.cert.*;
import java.security.AccessController;
import java.security.CodeSource;
import java.security.PrivilegedAction;
import java.security.PrivilegedExceptionAction;
import java.security.PrivilegedActionException;
import java.security.Provider;
import java.security.PublicKey;
import java.util.*;
import java.util.jar.*;

public final class MyJCE extends Provider {

    // Flag for avoiding unnecessary self-integrity checking.
    private static boolean verifiedSelfIntegrity = false;

    // Provider's signing cert which is used to sign the jar.
    private static X509Certificate providerCert = null;

    // Raw bytes of provider's own code signing cert.
    // NOTE: YOU NEED TO CHANGE THIS TO YOUR OWN PROVIDER CERTIFICATE
    private static final byte[] bytesOfProviderCert = {
        (byte)0x30, (byte)0x82, (byte)0x03, (byte)0xB4, (byte)0x30, (byte)0x82, 
        (byte)0x03, (byte)0x72, (byte)0xA0, (byte)0x03, (byte)0x02, (byte)0x01, 
        (byte)0x02, (byte)0x02, (byte)0x02, (byte)0x01, (byte)0x04, (byte)0x30, 
        (byte)0x0B, (byte)0x06, (byte)0x07, (byte)0x2A, (byte)0x86, (byte)0x48, 
        (byte)0xCE, (byte)0x38, (byte)0x04, (byte)0x03, (byte)0x05, (byte)0x00, 
        (byte)0x30, (byte)0x81, (byte)0x90, (byte)0x31, (byte)0x0B, (byte)0x30, 
        (byte)0x09, (byte)0x06, (byte)0x03, (byte)0x55, (byte)0x04, (byte)0x06, 
        (byte)0x13, (byte)0x02, (byte)0x55, (byte)0x53, (byte)0x31, (byte)0x0B, 
        (byte)0x30, (byte)0x09, (byte)0x06, (byte)0x03, (byte)0x55, (byte)0x04, 
        (byte)0x08, (byte)0x13, (byte)0x02, (byte)0x43, (byte)0x41, (byte)0x31, 
        (byte)0x12, (byte)0x30, (byte)0x10, (byte)0x06, (byte)0x03, (byte)0x55, 
        (byte)0x04, (byte)0x07, (byte)0x13, (byte)0x09, (byte)0x50, (byte)0x61, 
        (byte)0x6C, (byte)0x6F, (byte)0x20, (byte)0x41, (byte)0x6C, (byte)0x74, 
        (byte)0x6F, (byte)0x31, (byte)0x1D, (byte)0x30, (byte)0x1B, (byte)0x06, 
        (byte)0x03, (byte)0x55, (byte)0x04, (byte)0x0A, (byte)0x13, (byte)0x14, 
        (byte)0x53, (byte)0x75, (byte)0x6E, (byte)0x20, (byte)0x4D, (byte)0x69, 
        (byte)0x63, (byte)0x72, (byte)0x6F, (byte)0x73, (byte)0x79, (byte)0x73, 
        (byte)0x74, (byte)0x65, (byte)0x6D, (byte)0x73, (byte)0x20, (byte)0x49, 
        (byte)0x6E, (byte)0x63, (byte)0x31, (byte)0x23, (byte)0x30, (byte)0x21, 
        (byte)0x06, (byte)0x03, (byte)0x55, (byte)0x04, (byte)0x0B, (byte)0x13, 
        (byte)0x1A, (byte)0x4A, (byte)0x61, (byte)0x76, (byte)0x61, (byte)0x20, 
        (byte)0x53, (byte)0x6F, (byte)0x66, (byte)0x74, (byte)0x77, (byte)0x61, 
        (byte)0x72, (byte)0x65, (byte)0x20, (byte)0x43, (byte)0x6F, (byte)0x64, 
        (byte)0x65, (byte)0x20, (byte)0x53, (byte)0x69, (byte)0x67, (byte)0x6E, 
        (byte)0x69, (byte)0x6E, (byte)0x67, (byte)0x31, (byte)0x1C, (byte)0x30, 
        (byte)0x1A, (byte)0x06, (byte)0x03, (byte)0x55, (byte)0x04, (byte)0x03, 
        (byte)0x13, (byte)0x13, (byte)0x4A, (byte)0x43, (byte)0x45, (byte)0x20, 
        (byte)0x43, (byte)0x6F, (byte)0x64, (byte)0x65, (byte)0x20, (byte)0x53, 
        (byte)0x69, (byte)0x67, (byte)0x6E, (byte)0x69, (byte)0x6E, (byte)0x67, 
        (byte)0x20, (byte)0x43, (byte)0x41, (byte)0x30, (byte)0x1E, (byte)0x17, 
        (byte)0x0D, (byte)0x30, (byte)0x31, (byte)0x31, (byte)0x30, (byte)0x31, 
        (byte)0x39, (byte)0x32, (byte)0x33, (byte)0x30, (byte)0x34, (byte)0x33, 
        (byte)0x31, (byte)0x5A, (byte)0x17, (byte)0x0D, (byte)0x30, (byte)0x36, 
        (byte)0x31, (byte)0x30, (byte)0x32, (byte)0x33, (byte)0x32, (byte)0x33, 
        (byte)0x30, (byte)0x34, (byte)0x33, (byte)0x31, (byte)0x5A, (byte)0x30, 
        (byte)0x63, (byte)0x31, (byte)0x1D, (byte)0x30, (byte)0x1B, (byte)0x06, 
        (byte)0x03, (byte)0x55, (byte)0x04, (byte)0x0A, (byte)0x0C, (byte)0x14, 
        (byte)0x53, (byte)0x75, (byte)0x6E, (byte)0x20, (byte)0x4D, (byte)0x69, 
        (byte)0x63, (byte)0x72, (byte)0x6F, (byte)0x73, (byte)0x79, (byte)0x73, 
        (byte)0x74, (byte)0x65, (byte)0x6D, (byte)0x73, (byte)0x20, (byte)0x49, 
        (byte)0x6E, (byte)0x63, (byte)0x31, (byte)0x23, (byte)0x30, (byte)0x21, 
        (byte)0x06, (byte)0x03, (byte)0x55, (byte)0x04, (byte)0x0B, (byte)0x0C, 
        (byte)0x1A, (byte)0x4A, (byte)0x61, (byte)0x76, (byte)0x61, (byte)0x20, 
        (byte)0x53, (byte)0x6F, (byte)0x66, (byte)0x74, (byte)0x77, (byte)0x61, 
        (byte)0x72, (byte)0x65, (byte)0x20, (byte)0x43, (byte)0x6F, (byte)0x64, 
        (byte)0x65, (byte)0x20, (byte)0x53, (byte)0x69, (byte)0x67, (byte)0x6E, 
        (byte)0x69, (byte)0x6E, (byte)0x67, (byte)0x31, (byte)0x1D, (byte)0x30, 
        (byte)0x1B, (byte)0x06, (byte)0x03, (byte)0x55, (byte)0x04, (byte)0x03, 
        (byte)0x0C, (byte)0x14, (byte)0x53, (byte)0x75, (byte)0x6E, (byte)0x20, 
        (byte)0x4D, (byte)0x69, (byte)0x63, (byte)0x72, (byte)0x6F, (byte)0x73, 
        (byte)0x79, (byte)0x73, (byte)0x74, (byte)0x65, (byte)0x6D, (byte)0x73, 
        (byte)0x20, (byte)0x49, (byte)0x6E, (byte)0x63, (byte)0x30, (byte)0x82, 
        (byte)0x01, (byte)0xB5, (byte)0x30, (byte)0x82, (byte)0x01, (byte)0x2A, 
        (byte)0x06, (byte)0x05, (byte)0x2B, (byte)0x0E, (byte)0x03, (byte)0x02, 
        (byte)0x0C, (byte)0x30, (byte)0x82, (byte)0x01, (byte)0x1F, (byte)0x02, 
        (byte)0x81, (byte)0x81, (byte)0x00, (byte)0xFD, (byte)0x7F, (byte)0x53, 
        (byte)0x81, (byte)0x1D, (byte)0x75, (byte)0x12, (byte)0x29, (byte)0x52, 
        (byte)0xDF, (byte)0x4A, (byte)0x9C, (byte)0x2E, (byte)0xEC, (byte)0xE4, 
        (byte)0xE7, (byte)0xF6, (byte)0x11, (byte)0xB7, (byte)0x52, (byte)0x3C, 
        (byte)0xEF, (byte)0x44, (byte)0x00, (byte)0xC3, (byte)0x1E, (byte)0x3F, 
        (byte)0x80, (byte)0xB6, (byte)0x51, (byte)0x26, (byte)0x69, (byte)0x45, 
        (byte)0x5D, (byte)0x40, (byte)0x22, (byte)0x51, (byte)0xFB, (byte)0x59, 
        (byte)0x3D, (byte)0x8D, (byte)0x58, (byte)0xFA, (byte)0xBF, (byte)0xC5, 
        (byte)0xF5, (byte)0xBA, (byte)0x30, (byte)0xF6, (byte)0xCB, (byte)0x9B, 
        (byte)0x55, (byte)0x6C, (byte)0xD7, (byte)0x81, (byte)0x3B, (byte)0x80, 
        (byte)0x1D, (byte)0x34, (byte)0x6F, (byte)0xF2, (byte)0x66, (byte)0x60, 
        (byte)0xB7, (byte)0x6B, (byte)0x99, (byte)0x50, (byte)0xA5, (byte)0xA4, 
        (byte)0x9F, (byte)0x9F, (byte)0xE8, (byte)0x04, (byte)0x7B, (byte)0x10, 
        (byte)0x22, (byte)0xC2, (byte)0x4F, (byte)0xBB, (byte)0xA9, (byte)0xD7, 
        (byte)0xFE, (byte)0xB7, (byte)0xC6, (byte)0x1B, (byte)0xF8, (byte)0x3B, 
        (byte)0x57, (byte)0xE7, (byte)0xC6, (byte)0xA8, (byte)0xA6, (byte)0x15, 
        (byte)0x0F, (byte)0x04, (byte)0xFB, (byte)0x83, (byte)0xF6, (byte)0xD3, 
        (byte)0xC5, (byte)0x1E, (byte)0xC3, (byte)0x02, (byte)0x35, (byte)0x54, 
        (byte)0x13, (byte)0x5A, (byte)0x16, (byte)0x91, (byte)0x32, (byte)0xF6, 
        (byte)0x75, (byte)0xF3, (byte)0xAE, (byte)0x2B, (byte)0x61, (byte)0xD7, 
        (byte)0x2A, (byte)0xEF, (byte)0xF2, (byte)0x22, (byte)0x03, (byte)0x19, 
        (byte)0x9D, (byte)0xD1, (byte)0x48, (byte)0x01, (byte)0xC7, (byte)0x02, 
        (byte)0x15, (byte)0x00, (byte)0x97, (byte)0x60, (byte)0x50, (byte)0x8F, 
        (byte)0x15, (byte)0x23, (byte)0x0B, (byte)0xCC, (byte)0xB2, (byte)0x92, 
        (byte)0xB9, (byte)0x82, (byte)0xA2, (byte)0xEB, (byte)0x84, (byte)0x0B, 
        (byte)0xF0, (byte)0x58, (byte)0x1C, (byte)0xF5, (byte)0x02, (byte)0x81, 
        (byte)0x81, (byte)0x00, (byte)0xF7, (byte)0xE1, (byte)0xA0, (byte)0x85, 
        (byte)0xD6, (byte)0x9B, (byte)0x3D, (byte)0xDE, (byte)0xCB, (byte)0xBC, 
        (byte)0xAB, (byte)0x5C, (byte)0x36, (byte)0xB8, (byte)0x57, (byte)0xB9, 
        (byte)0x79, (byte)0x94, (byte)0xAF, (byte)0xBB, (byte)0xFA, (byte)0x3A, 
        (byte)0xEA, (byte)0x82, (byte)0xF9, (byte)0x57, (byte)0x4C, (byte)0x0B, 
        (byte)0x3D, (byte)0x07, (byte)0x82, (byte)0x67, (byte)0x51, (byte)0x59, 
        (byte)0x57, (byte)0x8E, (byte)0xBA, (byte)0xD4, (byte)0x59, (byte)0x4F, 
        (byte)0xE6, (byte)0x71, (byte)0x07, (byte)0x10, (byte)0x81, (byte)0x80, 
        (byte)0xB4, (byte)0x49, (byte)0x16, (byte)0x71, (byte)0x23, (byte)0xE8, 
        (byte)0x4C, (byte)0x28, (byte)0x16, (byte)0x13, (byte)0xB7, (byte)0xCF, 
        (byte)0x09, (byte)0x32, (byte)0x8C, (byte)0xC8, (byte)0xA6, (byte)0xE1, 
        (byte)0x3C, (byte)0x16, (byte)0x7A, (byte)0x8B, (byte)0x54, (byte)0x7C, 
        (byte)0x8D, (byte)0x28, (byte)0xE0, (byte)0xA3, (byte)0xAE, (byte)0x1E, 
        (byte)0x2B, (byte)0xB3, (byte)0xA6, (byte)0x75, (byte)0x91, (byte)0x6E, 
        (byte)0xA3, (byte)0x7F, (byte)0x0B, (byte)0xFA, (byte)0x21, (byte)0x35, 
        (byte)0x62, (byte)0xF1, (byte)0xFB, (byte)0x62, (byte)0x7A, (byte)0x01, 
        (byte)0x24, (byte)0x3B, (byte)0xCC, (byte)0xA4, (byte)0xF1, (byte)0xBE, 
        (byte)0xA8, (byte)0x51, (byte)0x90, (byte)0x89, (byte)0xA8, (byte)0x83, 
        (byte)0xDF, (byte)0xE1, (byte)0x5A, (byte)0xE5, (byte)0x9F, (byte)0x06, 
        (byte)0x92, (byte)0x8B, (byte)0x66, (byte)0x5E, (byte)0x80, (byte)0x7B, 
        (byte)0x55, (byte)0x25, (byte)0x64, (byte)0x01, (byte)0x4C, (byte)0x3B, 
        (byte)0xFE, (byte)0xCF, (byte)0x49, (byte)0x2A, (byte)0x03, (byte)0x81, 
        (byte)0x84, (byte)0x00, (byte)0x02, (byte)0x81, (byte)0x80, (byte)0x07, 
        (byte)0xCC, (byte)0xF6, (byte)0x38, (byte)0x3A, (byte)0xCD, (byte)0xD3, 
        (byte)0x58, (byte)0x99, (byte)0x90, (byte)0x0F, (byte)0x71, (byte)0xAF, 
        (byte)0xAA, (byte)0xD0, (byte)0x03, (byte)0x27, (byte)0x3B, (byte)0x74, 
        (byte)0xE1, (byte)0x64, (byte)0x38, (byte)0x11, (byte)0xBF, (byte)0xFA, 
        (byte)0xB7, (byte)0xBF, (byte)0x2C, (byte)0xE7, (byte)0xBB, (byte)0xA7, 
        (byte)0x92, (byte)0x2F, (byte)0x08, (byte)0xCE, (byte)0x27, (byte)0xF8, 
        (byte)0xB4, (byte)0xFD, (byte)0xD8, (byte)0x14, (byte)0x1D, (byte)0xA3, 
        (byte)0x95, (byte)0xBB, (byte)0x03, (byte)0x16, (byte)0xA6, (byte)0xBA, 
        (byte)0xBC, (byte)0x35, (byte)0xC0, (byte)0xCD, (byte)0xF9, (byte)0xF5, 
        (byte)0x6C, (byte)0xA7, (byte)0x94, (byte)0x5B, (byte)0x23, (byte)0x01, 
        (byte)0xF9, (byte)0xAE, (byte)0xF5, (byte)0xC9, (byte)0xE0, (byte)0x81, 
        (byte)0x7A, (byte)0xE8, (byte)0xE4, (byte)0x69, (byte)0xEB, (byte)0xF8, 
        (byte)0xF5, (byte)0x80, (byte)0x25, (byte)0x04, (byte)0x2C, (byte)0x91, 
        (byte)0x73, (byte)0x96, (byte)0x59, (byte)0xB4, (byte)0x06, (byte)0x83, 
        (byte)0x17, (byte)0xB2, (byte)0x50, (byte)0xAC, (byte)0x4F, (byte)0xEB, 
        (byte)0x9D, (byte)0x51, (byte)0x25, (byte)0x3D, (byte)0xF7, (byte)0xEE, 
        (byte)0xB0, (byte)0x24, (byte)0x25, (byte)0x0E, (byte)0xFE, (byte)0xB4, 
        (byte)0x32, (byte)0xA1, (byte)0xC4, (byte)0x0E, (byte)0xB3, (byte)0x66, 
        (byte)0x41, (byte)0xE0, (byte)0x57, (byte)0xCE, (byte)0x9D, (byte)0xBE, 
        (byte)0x33, (byte)0x2E, (byte)0x93, (byte)0x9A, (byte)0xC9, (byte)0x7A, 
        (byte)0x57, (byte)0xDC, (byte)0xCD, (byte)0x88, (byte)0x60, (byte)0xA7, 
        (byte)0xCE, (byte)0xA3, (byte)0x81, (byte)0x88, (byte)0x30, (byte)0x81, 
        (byte)0x85, (byte)0x30, (byte)0x11, (byte)0x06, (byte)0x09, (byte)0x60, 
        (byte)0x86, (byte)0x48, (byte)0x01, (byte)0x86, (byte)0xF8, (byte)0x42, 
        (byte)0x01, (byte)0x01, (byte)0x04, (byte)0x04, (byte)0x03, (byte)0x02, 
        (byte)0x04, (byte)0x10, (byte)0x30, (byte)0x0E, (byte)0x06, (byte)0x03, 
        (byte)0x55, (byte)0x1D, (byte)0x0F, (byte)0x01, (byte)0x01, (byte)0xFF, 
        (byte)0x04, (byte)0x04, (byte)0x03, (byte)0x02, (byte)0x05, (byte)0xE0, 
        (byte)0x30, (byte)0x1D, (byte)0x06, (byte)0x03, (byte)0x55, (byte)0x1D, 
        (byte)0x0E, (byte)0x04, (byte)0x16, (byte)0x04, (byte)0x14, (byte)0x55, 
        (byte)0x8D, (byte)0x1F, (byte)0x2A, (byte)0x05, (byte)0xAB, (byte)0x9B, 
        (byte)0xCE, (byte)0x86, (byte)0x10, (byte)0xAE, (byte)0x3B, (byte)0x5D, 
        (byte)0xF6, (byte)0xBA, (byte)0x3F, (byte)0x22, (byte)0xC5, (byte)0x6A, 
        (byte)0xCA, (byte)0x30, (byte)0x1F, (byte)0x06, (byte)0x03, (byte)0x55, 
        (byte)0x1D, (byte)0x23, (byte)0x04, (byte)0x18, (byte)0x30, (byte)0x16, 
        (byte)0x80, (byte)0x14, (byte)0x65, (byte)0xE2, (byte)0xF4, (byte)0x86, 
        (byte)0xC9, (byte)0xD3, (byte)0x4E, (byte)0xF0, (byte)0x91, (byte)0x4E, 
        (byte)0x58, (byte)0xA2, (byte)0x6A, (byte)0xF5, (byte)0xD8, (byte)0x78, 
        (byte)0x5A, (byte)0x9A, (byte)0xC1, (byte)0xA6, (byte)0x30, (byte)0x20, 
        (byte)0x06, (byte)0x03, (byte)0x55, (byte)0x1D, (byte)0x11, (byte)0x04, 
        (byte)0x19, (byte)0x30, (byte)0x17, (byte)0x81, (byte)0x15, (byte)0x79, 
        (byte)0x75, (byte)0x2D, (byte)0x63, (byte)0x68, (byte)0x69, (byte)0x6E, 
        (byte)0x67, (byte)0x2E, (byte)0x70, (byte)0x65, (byte)0x6E, (byte)0x67, 
        (byte)0x40, (byte)0x73, (byte)0x75, (byte)0x6E, (byte)0x2E, (byte)0x63, 
        (byte)0x6F, (byte)0x6D, (byte)0x30, (byte)0x0B, (byte)0x06, (byte)0x07, 
        (byte)0x2A, (byte)0x86, (byte)0x48, (byte)0xCE, (byte)0x38, (byte)0x04, 
        (byte)0x03, (byte)0x05, (byte)0x00, (byte)0x03, (byte)0x2F, (byte)0x00, 
        (byte)0x30, (byte)0x2C, (byte)0x02, (byte)0x14, (byte)0x75, (byte)0x4B, 
        (byte)0xE8, (byte)0x21, (byte)0x37, (byte)0x78, (byte)0x79, (byte)0x0A, 
        (byte)0xD0, (byte)0xB5, (byte)0xDC, (byte)0x7E, (byte)0x36, (byte)0x75, 
        (byte)0xB9, (byte)0xE4, (byte)0x14, (byte)0xB5, (byte)0xD0, (byte)0x46, 
        (byte)0x02, (byte)0x14, (byte)0x6A, (byte)0x51, (byte)0xDC, (byte)0xBA, 
        (byte)0x6D, (byte)0x1A, (byte)0x6B, (byte)0x5C, (byte)0x18, (byte)0x23, 
        (byte)0x6A, (byte)0xF1, (byte)0xCA, (byte)0x21, (byte)0x8A, (byte)0x77, 
        (byte)0xC2, (byte)0x05, (byte)0x16, (byte)0x42
    };

    // UNCOMMENT FOR TESTING AFTER YOU'VE REPLACED THE ABOVE CERT
    // RAW BYTES WITH YOUR OWN.
    // public static void main(String[] argv) {
    // 	System.out.println("Integrity Checking? " 
    //                     + MyJCE.selfIntegrityChecking());
    // }

    public MyJCE() {
	// First, register provider name, version and description.
	super("MyJCE", 1.0, "sample provider which supports nothing");
	// Set up the provider properties here
	// For examples, reference the Appendix A and B of 
	// JCE "How to Implement a Provider" Guide.
	//   
	//    ...
	//
    }

    /** 
     * Perform self-integrity checking. Call this method in all 
     * the constructors of your SPI implementation classes.
     * NOTE: The following implementation assumes that all
     * your provider implementation is packaged inside ONE jar. 
     */
    public static final synchronized boolean selfIntegrityChecking() {
	if (verifiedSelfIntegrity) {
	    return true;
	}

	URL providerURL = (URL) AccessController.doPrivileged(
			        new PrivilegedAction() {
	    public Object run() {
	        CodeSource cs = MyJCE.class.getProtectionDomain().
					    getCodeSource();
	        return cs.getLocation();
	    }
	});

	if (providerURL == null) {
	    return false;
	}

	// Open a connnection to the provider JAR file
	JarVerifier jv = new JarVerifier(providerURL);

	// Make sure that the provider JAR file is signed with 
	// provider's own signing certificate.
	try {
	    if (providerCert == null) {
                providerCert = setupProviderCert();
            }
	    jv.verify(providerCert);  
        } catch (Exception e) {
	    e.printStackTrace();
	    return false;
	}
	
	verifiedSelfIntegrity = true;
	return true;    
    }

    /*
     * Set up 'providerCert' with the certificate bytes.
     */
    private static X509Certificate setupProviderCert()
	      throws IOException, CertificateException {
        CertificateFactory cf = CertificateFactory.getInstance("X.509");
	ByteArrayInputStream inStream = new ByteArrayInputStream(
					    bytesOfProviderCert);
	X509Certificate cert = (X509Certificate) 
	                        cf.generateCertificate(inStream);
	inStream.close();
        return cert;
    }

    public class JarVerifier {

	private URL jarURL = null;
	private JarFile jarFile = null;

	JarVerifier(URL jarURL) {
	    this.jarURL = jarURL;
	}

	/**
	 * Retrive the jar file from the specified url.
	 */
	private JarFile retrieveJarFileFromURL(URL url) 
	    throws PrivilegedActionException, MalformedURLException {
	    JarFile jf = null;

	    // Prep the url with the appropriate protocol.
	    jarURL = 
		url.getProtocol().equalsIgnoreCase("jar") ?
		url : 
		new URL("jar:" + url.toString() + "!/");
	    // Retrieve the jar file using JarURLConnection
	    jf = (JarFile) AccessController.doPrivileged(
		             new PrivilegedExceptionAction() {
                public Object run() throws Exception {
		    JarURLConnection conn = 
                       (JarURLConnection) jarURL.openConnection();
                    // Always get a fresh copy, so we don't have to
		    // worry about the stale file handle when the
		    // cached jar is closed by some other application.
		    conn.setUseCaches(false);
		    return conn.getJarFile();
		}
	    });
	    return jf;
	}

	/**
	 * First, retrieve the jar file from the URL passed in constructor.
	 * Then, compare it to the expected X509Certificate.
	 * If everything went well and the certificates are the same, no 
	 * exception is thrown.
	 */
	public void verify(X509Certificate targetCert)
	    throws IOException {
	    // Sanity checking
	    if (targetCert == null) {
		throw new SecurityException("Provider certificate is invalid");
	    }

	    try {
		if (jarFile == null) {
		    jarFile = retrieveJarFileFromURL(jarURL);
		}
	    } catch (Exception ex) {
		SecurityException se = new SecurityException();
		se.initCause(ex);
		throw se;
	    }

	    Vector entriesVec = new Vector();
	
	    // Ensure the jar file is signed.
	    Manifest man = jarFile.getManifest();
	    if (man == null) {
		throw new SecurityException("The provider is not signed");
	    }

	    // Ensure all the entries' signatures verify correctly
	    byte[] buffer = new byte[8192];
	    Enumeration entries = jarFile.entries();
	
	    while (entries.hasMoreElements()) {
		JarEntry je = (JarEntry) entries.nextElement();

		// Skip directories.
		if (je.isDirectory()) continue;
		entriesVec.addElement(je);
		InputStream is = jarFile.getInputStream(je);

		// Read in each jar entry. A security exception will
		// be thrown if a signature/digest check fails.
		int n;
		while ((n = is.read(buffer, 0, buffer.length)) != -1) {
		    // Don't care
		}
		is.close();
	    }
	
	    // Get the list of signer certificates 
	    Enumeration e = entriesVec.elements();

	    while (e.hasMoreElements()) {
		JarEntry je = (JarEntry) e.nextElement();

		// Every file must be signed except files in META-INF.
		Certificate[] certs = je.getCertificates();
		if ((certs == null) || (certs.length == 0)) {
		    if (!je.getName().startsWith("META-INF"))
			throw new SecurityException("The provider " +
						    "has unsigned " +
						    "class files.");
		} else {
		    // Check whether the file is signed by the expected
		    // signer. The jar may be signed by multiple signers.
		    // See if one of the signers is 'targetCert'.
		    int startIndex = 0;
		    X509Certificate[] certChain;
		    boolean signedAsExpected = false;
		
		    while ((certChain = getAChain(certs, startIndex)) != null) {
			if (certChain[0].equals(targetCert)) {
			    // Stop since one trusted signer is found.
			    signedAsExpected = true;
			    break;
			}
			// Proceed to the next chain.
			startIndex += certChain.length;
		    }
		
		    if (!signedAsExpected) {
			throw new SecurityException("The provider " +
						    "is not signed by a " +
						    "trusted signer");
		    }
		}
	    }
	}
    
	/**
	 * Extracts ONE certificate chain from the specified certificate array
	 * which may contain multiple certificate chains, starting from index
	 * 'startIndex'.
	 */
	private static X509Certificate[] getAChain(Certificate[] certs,
						   int startIndex) {	
	    if (startIndex > certs.length - 1)
		return null;
	
	    int i;
	    // Keep going until the next certificate is not the 
	    // issuer of this certificate.
	    for (i = startIndex; i < certs.length - 1; i++) {
		if (!((X509Certificate)certs[i + 1]).getSubjectDN().
		    equals(((X509Certificate)certs[i]).getIssuerDN())) {
		    break;
		}
	    }
	    // Construct and return the found certificate chain.
	    int certChainSize = (i-startIndex) + 1;
	    X509Certificate[] ret = new X509Certificate[certChainSize];
	    for (int j = 0; j < certChainSize; j++ ) {
		ret[j] = (X509Certificate) certs[startIndex + j];
	    }
	    return ret;
	}

	// Close the jar file once this object is no longer needed.
	protected void finalize() throws Throwable {
	    jarFile.close();
	}
    }
}
