keyinfofactory.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

/*
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 */
/*
 * $Id: KeyInfoFactory.java,v 1.12 2005/05/10 16:35:35 mullan Exp $
 */
package javax.xml.crypto.dsig.keyinfo;

import java.math.BigInteger;
import java.security.KeyException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.Provider;
import java.security.PublicKey;
import java.security.Security;
import java.security.cert.X509CRL;
import java.util.List;
import javax.xml.crypto.MarshalException;
import javax.xml.crypto.NoSuchMechanismException;
import javax.xml.crypto.URIDereferencer;
import javax.xml.crypto.XMLStructure;
import javax.xml.crypto.dom.DOMStructure;
import javax.xml.crypto.dsig.*;

import sun.security.jca.*;
import sun.security.jca.GetInstance.Instance;

/**
 * A factory for creating {@link KeyInfo} objects from scratch or for
 * unmarshalling a <code>KeyInfo</code> object from a corresponding XML 
 * representation.
 *
 * <p>Each instance of <code>KeyInfoFactory</code> supports a specific
 * XML mechanism type. To create a <code>KeyInfoFactory</code>, call one of the
 * static {@link #getInstance getInstance} methods, passing in the XML 
 * mechanism type desired, for example:
 *
 * <blockquote><code>
 *   KeyInfoFactory factory = KeyInfoFactory.getInstance("DOM");
 * </code></blockquote>
 *
 * <p>The objects that this factory produces will be based
 * on DOM and abide by the DOM interoperability requirements as defined in the
 * <a href="../../../../../../technotes/guides/security/xmldsig/overview.html#DOM Mechanism Requirements">
 * DOM Mechanism Requirements</a> section of the API overview. See the
 * <a href="../../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
 * Service Providers</a> section of the API overview for a list of standard 
 * mechanism types.
 *
 * <p><code>KeyInfoFactory</code> implementations are registered and loaded
 * using the {@link java.security.Provider} mechanism.
 * For example, a service provider that supports the
 * DOM mechanism would be specified in the <code>Provider</code> subclass as:
 * <pre>
 *     put("KeyInfoFactory.DOM", "org.example.DOMKeyInfoFactory");
 * </pre>
 *
 * <p>Also, the <code>XMLStructure</code>s that are created by this factory
 * may contain state specific to the <code>KeyInfo</code> and are not
 * intended to be reusable.
 *
 * <p>An implementation MUST minimally support the default mechanism type: DOM.
 *
 * <p>Note that a caller must use the same <code>KeyInfoFactory</code>
 * instance to create the <code>XMLStructure</code>s of a particular
 * <code>KeyInfo</code> object. The behavior is undefined if 
 * <code>XMLStructure</code>s from different providers or different mechanism 
 * types are used together.
 *
 * <p><b>Concurrent Access</b>
 * <p>The static methods of this class are guaranteed to be thread-safe. 
 * Multiple threads may concurrently invoke the static methods defined in this 
 * class with no ill effects.
 *
 * <p>However, this is not true for the non-static methods defined by this 
 * class. Unless otherwise documented by a specific provider, threads that 
 * need to access a single <code>KeyInfoFactory</code> instance concurrently 
 * should synchronize amongst themselves and provide the necessary locking. 
 * Multiple threads each manipulating a different <code>KeyInfoFactory</code> 
 * instance need not synchronize.
 *
 * @author Sean Mullan
 * @author JSR 105 Expert Group
 * @since 1.6
 */
public abstract class KeyInfoFactory {

    private String mechanismType;
    private Provider provider;

    /**
     * Default constructor, for invocation by subclasses.
     */
    protected KeyInfoFactory() {}

    /**
     * Returns a <code>KeyInfoFactory</code> that supports the
     * specified XML processing mechanism and representation type (ex: "DOM").
     *
     * <p>This method uses the standard JCA provider lookup mechanism to 
     * locate and instantiate a <code>KeyInfoFactory</code> implementation of 
     * the desired mechanism type. It traverses the list of registered security 
     * <code>Provider</code>s, starting with the most preferred 
     * <code>Provider</code>. A new <code>KeyInfoFactory</code> object 
     * from the first <code>Provider</code> that supports the specified 
     * mechanism is returned. 
     * 
     * <p> Note that the list of registered providers may be retrieved via 
     * the {@link Security#getProviders() Security.getProviders()} method. 
     *
     * @param mechanismType the type of the XML processing mechanism and
     *    representation. See the <a 
     *    href="../../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
     *    Service Providers</a> section of the API overview for a list of 
     *    standard mechanism types.
     * @return a new <code>KeyInfoFactory</code>
     * @throws NullPointerException if <code>mechanismType</code> is
     *    <code>null</code>
     * @throws NoSuchMechanismException if no <code>Provider</code> supports a
     *    <code>KeyInfoFactory</code> implementation for the specified mechanism
     * @see Provider
     */
    public static KeyInfoFactory getInstance(String mechanismType) {
	if (mechanismType == null) {
            throw new NullPointerException("mechanismType cannot be null");
	}
        Instance instance;
        try {
            instance = GetInstance.getInstance
                ("KeyInfoFactory", null, mechanismType);
        } catch (NoSuchAlgorithmException nsae) {
            throw new NoSuchMechanismException(nsae);
        }
        KeyInfoFactory factory = (KeyInfoFactory) instance.impl;
        factory.mechanismType = mechanismType;
        factory.provider = instance.provider;
        return factory;
    }

    /**
     * Returns a <code>KeyInfoFactory</code> that supports the
     * requested XML processing mechanism and representation type (ex: "DOM"),
     * as supplied by the specified provider. Note that the specified 
     * <code>Provider</code> object does not have to be registered in the 
     * provider list. 
     *
     * @param mechanismType the type of the XML processing mechanism and
     *    representation. See the <a 
     *    href="../../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
     *    Service Providers</a> section of the API overview for a list of 
     *    standard mechanism types.
     * @param provider the <code>Provider</code> object
     * @return a new <code>KeyInfoFactory</code>
     * @throws NullPointerException if <code>mechanismType</code> or
     *    <code>provider</code> are <code>null</code>
     * @throws NoSuchMechanismException if a <code>KeyInfoFactory</code> 
     *    implementation for the specified mechanism is not available from the 
     *    specified <code>Provider</code> object
     * @see Provider
     */
    public static KeyInfoFactory getInstance(String mechanismType,
	Provider provider) {
	if (mechanismType == null) {
            throw new NullPointerException("mechanismType cannot be null");
	} else if (provider == null) {
	    throw new NullPointerException("provider cannot be null");
	}

        Instance instance;
        try {
            instance = GetInstance.getInstance
                ("KeyInfoFactory", null, mechanismType, provider);
        } catch (NoSuchAlgorithmException nsae) {
            throw new NoSuchMechanismException(nsae);
        }
        KeyInfoFactory factory = (KeyInfoFactory) instance.impl;
        factory.mechanismType = mechanismType;
        factory.provider = instance.provider;
        return factory;
    }

    /**
     * Returns a <code>KeyInfoFactory</code> that supports the
     * requested XML processing mechanism and representation type (ex: "DOM"),
     * as supplied by the specified provider. The specified provider must be 
     * registered in the security provider list. 
     *
     * <p>Note that the list of registered providers may be retrieved via 
     * the {@link Security#getProviders() Security.getProviders()} method. 
     *
     * @param mechanismType the type of the XML processing mechanism and
     *    representation. See the <a 
     *    href="../../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
     *    Service Providers</a> section of the API overview for a list of 
     *    standard mechanism types.
     * @param provider the string name of the provider
     * @return a new <code>KeyInfoFactory</code>
     * @throws NoSuchProviderException if the specified provider is not 
     *    registered in the security provider list
     * @throws NullPointerException if <code>mechanismType</code> or
     *    <code>provider</code> are <code>null</code>
     * @throws NoSuchMechanismException if a <code>KeyInfoFactory</code> 
     *    implementation for the specified mechanism is not available from the 
     *    specified provider
     * @see Provider
     */
    public static KeyInfoFactory getInstance(String mechanismType,
	String provider) throws NoSuchProviderException {
	if (mechanismType == null) {
            throw new NullPointerException("mechanismType cannot be null");
	} else if (provider == null) {
            throw new NullPointerException("provider cannot be null");
	} else if (provider.length() == 0) {
	    throw new NoSuchProviderException();
	}

        Instance instance;
        try {
            instance = GetInstance.getInstance
                ("KeyInfoFactory", null, mechanismType, provider);
        } catch (NoSuchAlgorithmException nsae) {
            throw new NoSuchMechanismException(nsae);
        }
        KeyInfoFactory factory = (KeyInfoFactory) instance.impl;
        factory.mechanismType = mechanismType;
        factory.provider = instance.provider;
        return factory;
    }

    /**
     * Returns a <code>KeyInfoFactory</code> that supports the
     * default XML processing mechanism and representation type ("DOM").
     *
     * <p>This method uses the standard JCA provider lookup mechanism to 
     * locate and instantiate a <code>KeyInfoFactory</code> implementation of 
     * the default mechanism type. It traverses the list of registered security 
     * <code>Provider</code>s, starting with the most preferred
     * <code>Provider</code>.  A new <code>KeyInfoFactory</code> object
     * from the first <code>Provider</code> that supports the DOM mechanism is 
     * returned. 
     * 
     * <p> Note that the list of registered providers may be retrieved via 
     * the {@link Security#getProviders() Security.getProviders()} method. 
     *
     * @return a new <code>KeyInfoFactory</code>
     * @throws NoSuchMechanismException if no <code>Provider</code> supports a 
     *    <code>KeyInfoFactory</code> implementation for the DOM mechanism
     * @see Provider
     */
    public static KeyInfoFactory getInstance() {
        return getInstance("DOM");