org.taverna.server.master.utils.X500Utils.java Source code

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Here is the source code for org.taverna.server.master.utils.X500Utils.java

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/*
 * Copyright (C) 2010-2011 The University of Manchester
 * 
 * See the file "LICENSE.txt" for license terms.
 */
package org.taverna.server.master.utils;

import static javax.security.auth.x500.X500Principal.RFC2253;

import java.math.BigInteger;
import java.security.cert.X509Certificate;
import java.util.HashMap;

import javax.annotation.PreDestroy;
import javax.security.auth.x500.X500Principal;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Support class that factors out some of the messier parts of working with
 * X.500 identities and X.509 certificates.
 * 
 * @author Donal Fellows
 */
public class X500Utils {
    private Log log = LogFactory.getLog("Taverna.Server.Utils");

    @PreDestroy
    void closeLog() {
        log = null;
    }

    private static final char DN_SEPARATOR = ',';
    private static final char DN_ESCAPE = '\\';
    private static final char DN_QUOTE = '"';

    /**
     * Parse the DN from the Principal and extract the CN field.
     * 
     * @param id
     *            The identity to extract the distinguished name from.
     * @param fields
     *            The names to look at when finding the field to return. Each
     *            should be an upper-cased string.
     * @return The common-name part of the distinguished name, or the literal
     *         string "<tt>none</tt>" if there is no CN.
     */
    public String getName(X500Principal id, String... fields) {
        String dn = id.getName(RFC2253);

        int i = 0;
        int startIndex = 0;
        boolean ignoreThisChar = false;
        boolean inQuotes = false;
        HashMap<String, String> tokenized = new HashMap<String, String>();

        for (i = 0; i < dn.length(); i++)
            if (ignoreThisChar)
                ignoreThisChar = false;
            else if (dn.charAt(i) == DN_QUOTE)
                inQuotes = !inQuotes;
            else if (inQuotes)
                continue;
            else if (dn.charAt(i) == DN_ESCAPE)
                ignoreThisChar = true;
            else if ((dn.charAt(i) == DN_SEPARATOR) && !ignoreThisChar) {
                storeDNField(tokenized, dn.substring(startIndex, i).trim().split("=", 2));
                startIndex = i + 1;
            }
        if (inQuotes || ignoreThisChar)
            log.warn("was parsing invalid DN format");
        // Add last token - after the last delimiter
        storeDNField(tokenized, dn.substring(startIndex).trim().split("=", 2));

        for (String field : fields) {
            String value = tokenized.get(field);
            if (value != null)
                return value;
        }
        return "none";
    }

    private void storeDNField(HashMap<String, String> container, String[] split) {
        if (split == null || split.length != 2)
            return;
        String key = split[0].toUpperCase();
        if (container.containsKey(key))
            log.warn("duplicate field in DN: " + key);
        // LATER: Should the field be de-quoted?
        container.put(key, split[1]);
    }

    /**
     * Get the serial number from a certificate as a hex string.
     * 
     * @param cert
     *            The certificate to extract from.
     * @return A hex string, in upper-case.
     */
    public String getSerial(X509Certificate cert) {
        return new BigInteger(1, cert.getSerialNumber().toByteArray()).toString(16).toUpperCase();
    }
}