Java example source code file (ValidateCertPath.java)

This example Java source code file (ValidateCertPath.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

base, bytearrayoutputstream, certificatefactory, certpath, certpathvalidatorexception, exception, file, fileinputstream, ioexception, pkixparameters, string, trustanchor, util, validatecertpath, x509certificate

The ValidateCertPath.java Java example source code

/*
 * Copyright (c) 2002, 2010, 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.
 *
 * 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
 * questions.
 */

/*
 * @test
 * @bug 4684810 6994717
 * @summary Verify that RFC822 name constraints are checked correctly
 */

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.IOException;

import java.security.cert.*;
import java.security.cert.PKIXReason;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.Set;

/**
 * ValidateCertPath performs a simple validation of a certification path.
 * On success, it prints the CertPathValidatorResult. On failure, it
 * prints the error.
 *
 * Synopsis:
 * <pre>
 *   ValidateCertPath trustAnchor [certFile ...]
 *       where each argument is the path to a file that contains a
 *       certificate. Each certificate should have an issuer equal to
 *       the subject of the preceding certificate.
 *</pre>
 *
 * @author      Steve Hanna
 */
public final class ValidateCertPath {

    private final static String BASE = System.getProperty("test.src", "./");

    private static CertPath path;
    private static PKIXParameters params;

    public static void main(String[] args) throws Exception {

        try {
            parseArgs(args);
            validate(path, params);
            throw new Exception("Successfully validated invalid path.");
        } catch (CertPathValidatorException e) {
            if (e.getReason() != PKIXReason.INVALID_NAME) {
                throw new Exception("unexpected reason: " + e.getReason());
            }
            System.out.println("Path rejected as expected: " + e);
        }
    }

    /**
     * Parse the command line arguments. Populate the static
     * class fields based on the values of the arugments. In
     * case of bad arguments, print usage and exit. In case of
     * other error, throw an exception.
     *
     * @param args command line arguments
     * @throws Exception on error
     */
    public static void parseArgs(String[] args) throws Exception {
        args = new String[] {"jane2jane.cer", "jane2steve.cer", "steve2tom.cer"};

        TrustAnchor anchor = new TrustAnchor(getCertFromFile(args[0]), null);
        List<X509Certificate> list = new ArrayList();
        for (int i = 1; i < args.length; i++) {
            list.add(0, getCertFromFile(args[i]));
        }
        CertificateFactory cf = CertificateFactory.getInstance("X509");
        path = cf.generateCertPath(list);

        Set<TrustAnchor> anchors = Collections.singleton(anchor);
        params = new PKIXParameters(anchors);
        params.setRevocationEnabled(false);
        // The certificates expired on 10/22/10, so set the validity date to
        // 05/01/2009 to avoid expiration failures
        params.setDate(new Date(1243828800000l));
    }

    /*
     * Reads the entire input stream into a byte array.
     */
    private static byte[] getTotalBytes(InputStream is) throws IOException {
        byte[] buffer = new byte[8192];
        ByteArrayOutputStream baos = new ByteArrayOutputStream(2048);
        int n;
        baos.reset();
        while ((n = is.read(buffer, 0, buffer.length)) != -1) {
            baos.write(buffer, 0, n);
        }
        return baos.toByteArray();
    }

    /**
     * Get a DER-encoded X.509 certificate from a file.
     *
     * @param certFilePath path to file containing DER-encoded certificate
     * @return X509Certificate
     * @throws IOException on error
     */
    public static X509Certificate getCertFromFile(String certFilePath)
        throws IOException {
            X509Certificate cert = null;
            try {
                File certFile = new File(BASE, certFilePath);
                if (!certFile.canRead())
                    throw new IOException("File " +
                                          certFile.toString() +
                                          " is not a readable file.");
                FileInputStream certFileInputStream =
                    new FileInputStream(certFile);
                CertificateFactory cf = CertificateFactory.getInstance("X509");
                cert = (X509Certificate)
                    cf.generateCertificate(certFileInputStream);
            } catch (Exception e) {
                e.printStackTrace();
                throw new IOException("Can't construct X509Certificate: " +
                                      e.getMessage());
            }
            return cert;
    }

    /**
     * Perform a PKIX validation. On success, print the
     * CertPathValidatorResult on System.out. On failure,
     * throw an exception.
     *
     * @param path CertPath to validate
     * @param params PKIXParameters to use in validation
     * @throws Exception on error
     */
    public static void validate(CertPath path, PKIXParameters params)
        throws Exception {
        CertPathValidator validator =
            CertPathValidator.getInstance("PKIX");
        CertPathValidatorResult cpvr = validator.validate(path, params);
        System.out.println("ValidateCertPath successful.");
    }
}