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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
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package com.sun.org.apache.xml.internal.security.keys.keyresolver;

import java.security.PublicKey;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

import javax.crypto.SecretKey;

import com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations.DEREncodedKeyValueResolver;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations.DSAKeyValueResolver;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations.KeyInfoReferenceResolver;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations.RSAKeyValueResolver;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations.RetrievalMethodResolver;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations.X509CertificateResolver;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations.X509DigestResolver;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations.X509IssuerSerialResolver;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations.X509SKIResolver;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations.X509SubjectNameResolver;
import com.sun.org.apache.xml.internal.security.keys.storage.StorageResolver;
import com.sun.org.apache.xml.internal.security.utils.JavaUtils;
import org.w3c.dom.Element;
import org.w3c.dom.Node;

KeyResolver is factory class for subclass of KeyResolverSpi that
represent child element of KeyInfo.
/**
 * KeyResolver is factory class for subclass of KeyResolverSpi that
 * represent child element of KeyInfo.
 */
public class KeyResolver {

    private static final com.sun.org.slf4j.internal.Logger LOG =
        com.sun.org.slf4j.internal.LoggerFactory.getLogger(KeyResolver.class);

    
Field resolverVector /** Field resolverVector */
    private static List<KeyResolver> resolverVector = new CopyOnWriteArrayList<KeyResolver>();

    
Field resolverSpi /** Field resolverSpi */
    private final KeyResolverSpi resolverSpi;

    
Constructor.
Params:
keyResolverSpi – a KeyResolverSpi instance/**
     * Constructor.
     *
     * @param keyResolverSpi a KeyResolverSpi instance
     */
    private KeyResolver(KeyResolverSpi keyResolverSpi) {
        resolverSpi = keyResolverSpi;
    }

    
Method length
Returns:
the length of resolvers registered/**
     * Method length
     *
     * @return the length of resolvers registered
     */
    public static int length() {
        return resolverVector.size();
    }

    
Method getX509Certificate
Params:
element – 
baseURI – 
storage – 
Throws:
KeyResolverException – 
Returns:
The certificate represented by the element./**
     * Method getX509Certificate
     *
     * @param element
     * @param baseURI
     * @param storage
     * @return The certificate represented by the element.
     *
     * @throws KeyResolverException
     */
    public static final X509Certificate getX509Certificate(
        Element element, String baseURI, StorageResolver storage
    ) throws KeyResolverException {
        for (KeyResolver resolver : resolverVector) {
            if (resolver == null) {
                Object exArgs[] = {
                                   element != null
                                       && element.getNodeType() == Node.ELEMENT_NODE
                                       ? element.getTagName() : "null"
                };

                throw new KeyResolverException("utils.resolver.noClass", exArgs);
            }
            LOG.debug("check resolvability by class {}", resolver.getClass());

            X509Certificate cert = resolver.resolveX509Certificate(element, baseURI, storage);
            if (cert != null) {
                return cert;
            }
        }

        Object exArgs[] = {
                           element != null && element.getNodeType() == Node.ELEMENT_NODE
                           ? element.getTagName() : "null"
                          };

        throw new KeyResolverException("utils.resolver.noClass", exArgs);
    }

    
Method getPublicKey
Params:
element – 
baseURI – 
storage – 
Throws:
KeyResolverException – 
Returns:
the public key contained in the element/**
     * Method getPublicKey
     *
     * @param element
     * @param baseURI
     * @param storage
     * @return the public key contained in the element
     *
     * @throws KeyResolverException
     */
    public static final PublicKey getPublicKey(
        Element element, String baseURI, StorageResolver storage
    ) throws KeyResolverException {
        for (KeyResolver resolver : resolverVector) {
            if (resolver == null) {
                Object exArgs[] = {
                                   element != null
                                       && element.getNodeType() == Node.ELEMENT_NODE
                                       ? element.getTagName() : "null"
                };

                throw new KeyResolverException("utils.resolver.noClass", exArgs);
            }
            LOG.debug("check resolvability by class {}", resolver.getClass());

            PublicKey cert = resolver.resolvePublicKey(element, baseURI, storage);
            if (cert != null) {
                return cert;
            }
        }

        Object exArgs[] = {
                           element != null && element.getNodeType() == Node.ELEMENT_NODE
                           ? element.getTagName() : "null"
                          };

        throw new KeyResolverException("utils.resolver.noClass", exArgs);
    }

    
This method is used for registering KeyResolverSpis which are available to all KeyInfo objects. This means that personalized KeyResolverSpis should only be registered directly to the KeyInfo using KeyInfo.registerInternalKeyResolver. Please note that this method will create a new copy of the underlying array, as the underlying collection is a CopyOnWriteArrayList. 
Params:
className – 
globalResolver – Whether the KeyResolverSpi is a global resolver or not
Throws:
InstantiationException – 
IllegalAccessException – 
ClassNotFoundException – 
SecurityException – if a security manager is installed and the
   caller does not have permission to register the key resolver/**
     * This method is used for registering {@link KeyResolverSpi}s which are
     * available to <I>all</I> {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo} objects. This means that
     * personalized {@link KeyResolverSpi}s should only be registered directly
     * to the {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo} using
     * {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo#registerInternalKeyResolver}.
     * Please note that this method will create a new copy of the underlying array, as the
     * underlying collection is a CopyOnWriteArrayList.
     *
     * @param className
     * @param globalResolver Whether the KeyResolverSpi is a global resolver or not
     * @throws InstantiationException
     * @throws IllegalAccessException
     * @throws ClassNotFoundException
     * @throws SecurityException if a security manager is installed and the
     *    caller does not have permission to register the key resolver
     */
    public static void register(String className, boolean globalResolver)
        throws ClassNotFoundException, IllegalAccessException, InstantiationException {
        JavaUtils.checkRegisterPermission();
        KeyResolverSpi keyResolverSpi =
            (KeyResolverSpi) ClassLoaderUtils.loadClass(className, KeyResolver.class).newInstance();
        keyResolverSpi.setGlobalResolver(globalResolver);
        register(keyResolverSpi, false);
    }

    
This method is used for registering KeyResolverSpis which are available to all KeyInfo objects. This means that personalized KeyResolverSpis should only be registered directly to the KeyInfo using KeyInfo.registerInternalKeyResolver. Please note that this method will create a new copy of the underlying array, as the underlying collection is a CopyOnWriteArrayList. 
Params:
className – 
globalResolver – Whether the KeyResolverSpi is a global resolver or not
Throws:
SecurityException – if a security manager is installed and the
   caller does not have permission to register the key resolver/**
     * This method is used for registering {@link KeyResolverSpi}s which are
     * available to <I>all</I> {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo} objects. This means that
     * personalized {@link KeyResolverSpi}s should only be registered directly
     * to the {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo} using
     * {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo#registerInternalKeyResolver}.
     * Please note that this method will create a new copy of the underlying array, as the
     * underlying collection is a CopyOnWriteArrayList.
     *
     * @param className
     * @param globalResolver Whether the KeyResolverSpi is a global resolver or not
     * @throws SecurityException if a security manager is installed and the
     *    caller does not have permission to register the key resolver
     */
    public static void registerAtStart(String className, boolean globalResolver) {
        JavaUtils.checkRegisterPermission();
        KeyResolverSpi keyResolverSpi = null;
        Exception ex = null;
        try {
            KeyResolverSpi tmp = (KeyResolverSpi) ClassLoaderUtils.loadClass(className, KeyResolver.class).newInstance();
            keyResolverSpi = tmp;
            keyResolverSpi.setGlobalResolver(globalResolver);
            register(keyResolverSpi, true);
        } catch (ClassNotFoundException e) {
            ex = e;
        } catch (IllegalAccessException e) {
            ex = e;
        } catch (InstantiationException e) {
            ex = e;
        }

        if (ex != null) {
            throw (IllegalArgumentException) new
            IllegalArgumentException("Invalid KeyResolver class name").initCause(ex);
        }
    }

    
This method is used for registering KeyResolverSpis which are available to all KeyInfo objects. This means that personalized KeyResolverSpis should only be registered directly to the KeyInfo using KeyInfo.registerInternalKeyResolver. Please note that this method will create a new copy of the underlying array, as the underlying collection is a CopyOnWriteArrayList. 
Params:
keyResolverSpi – a KeyResolverSpi instance to register
start – whether to register the KeyResolverSpi at the start of the list or not
Throws:
SecurityException – if a security manager is installed and the
   caller does not have permission to register the key resolver/**
     * This method is used for registering {@link KeyResolverSpi}s which are
     * available to <I>all</I> {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo} objects. This means that
     * personalized {@link KeyResolverSpi}s should only be registered directly
     * to the {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo} using
     * {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo#registerInternalKeyResolver}.
     * Please note that this method will create a new copy of the underlying array, as the
     * underlying collection is a CopyOnWriteArrayList.
     *
     * @param keyResolverSpi a KeyResolverSpi instance to register
     * @param start whether to register the KeyResolverSpi at the start of the list or not
     * @throws SecurityException if a security manager is installed and the
     *    caller does not have permission to register the key resolver
     */
    public static void register(
        KeyResolverSpi keyResolverSpi,
        boolean start
    ) {
        JavaUtils.checkRegisterPermission();
        KeyResolver resolver = new KeyResolver(keyResolverSpi);
        if (start) {
            resolverVector.add(0, resolver);
        } else {
            resolverVector.add(resolver);
        }
    }

    
This method is used for registering KeyResolverSpis which are available to all KeyInfo objects. This means that personalized KeyResolverSpis should only be registered directly to the KeyInfo using KeyInfo.registerInternalKeyResolver. The KeyResolverSpi instances are not registered as a global resolver. 
Params:
classNames – 
Throws:
InstantiationException – 
IllegalAccessException – 
ClassNotFoundException – 
SecurityException – if a security manager is installed and the
   caller does not have permission to register the key resolver/**
     * This method is used for registering {@link KeyResolverSpi}s which are
     * available to <I>all</I> {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo} objects. This means that
     * personalized {@link KeyResolverSpi}s should only be registered directly
     * to the {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo} using
     * {@link com.sun.org.apache.xml.internal.security.keys.KeyInfo#registerInternalKeyResolver}.
     * The KeyResolverSpi instances are not registered as a global resolver.
     *
     *
     * @param classNames
     * @throws InstantiationException
     * @throws IllegalAccessException
     * @throws ClassNotFoundException
     * @throws SecurityException if a security manager is installed and the
     *    caller does not have permission to register the key resolver
     */
    public static void registerClassNames(List<String> classNames)
        throws ClassNotFoundException, IllegalAccessException, InstantiationException {
        JavaUtils.checkRegisterPermission();
        List<KeyResolver> keyResolverList = new ArrayList<>(classNames.size());
        for (String className : classNames) {
            KeyResolverSpi keyResolverSpi =
                (KeyResolverSpi)ClassLoaderUtils.loadClass(className, KeyResolver.class).newInstance();
            keyResolverSpi.setGlobalResolver(false);
            keyResolverList.add(new KeyResolver(keyResolverSpi));
        }
        resolverVector.addAll(keyResolverList);
    }

    
This method registers the default resolvers.
/**
     * This method registers the default resolvers.
     */
    public static void registerDefaultResolvers() {

        List<KeyResolver> keyResolverList = new ArrayList<>();
        keyResolverList.add(new KeyResolver(new RSAKeyValueResolver()));
        keyResolverList.add(new KeyResolver(new DSAKeyValueResolver()));
        keyResolverList.add(new KeyResolver(new X509CertificateResolver()));
        keyResolverList.add(new KeyResolver(new X509SKIResolver()));
        keyResolverList.add(new KeyResolver(new RetrievalMethodResolver()));
        keyResolverList.add(new KeyResolver(new X509SubjectNameResolver()));
        keyResolverList.add(new KeyResolver(new X509IssuerSerialResolver()));
        keyResolverList.add(new KeyResolver(new DEREncodedKeyValueResolver()));
        keyResolverList.add(new KeyResolver(new KeyInfoReferenceResolver()));
        keyResolverList.add(new KeyResolver(new X509DigestResolver()));

        resolverVector.addAll(keyResolverList);
    }

    
Method resolvePublicKey
Params:
element – 
baseURI – 
storage – 
Throws:
KeyResolverException – 
Returns:
resolved public key from the registered from the elements/**
     * Method resolvePublicKey
     *
     * @param element
     * @param baseURI
     * @param storage
     * @return resolved public key from the registered from the elements
     *
     * @throws KeyResolverException
     */
    public PublicKey resolvePublicKey(
        Element element, String baseURI, StorageResolver storage
    ) throws KeyResolverException {
        return resolverSpi.engineLookupAndResolvePublicKey(element, baseURI, storage);
    }

    
Method resolveX509Certificate
Params:
element – 
baseURI – 
storage – 
Throws:
KeyResolverException – 
Returns:
resolved X509certificate key from the registered from the elements/**
     * Method resolveX509Certificate
     *
     * @param element
     * @param baseURI
     * @param storage
     * @return resolved X509certificate key from the registered from the elements
     *
     * @throws KeyResolverException
     */
    public X509Certificate resolveX509Certificate(
        Element element, String baseURI, StorageResolver storage
    ) throws KeyResolverException {
        return resolverSpi.engineLookupResolveX509Certificate(element, baseURI, storage);
    }

    
Params:
element – 
baseURI – 
storage – 
Throws:
KeyResolverException – 
Returns:
resolved SecretKey key from the registered from the elements/**
     * @param element
     * @param baseURI
     * @param storage
     * @return resolved SecretKey key from the registered from the elements
     * @throws KeyResolverException
     */
    public SecretKey resolveSecretKey(
        Element element, String baseURI, StorageResolver storage
    ) throws KeyResolverException {
        return resolverSpi.engineLookupAndResolveSecretKey(element, baseURI, storage);
    }

    
Method setProperty
Params:
key – 
value – /**
     * Method setProperty
     *
     * @param key
     * @param value
     */
    public void setProperty(String key, String value) {
        resolverSpi.engineSetProperty(key, value);
    }

    
Method getProperty
Params:
key – 
Returns:
the property set for this resolver/**
     * Method getProperty
     *
     * @param key
     * @return the property set for this resolver
     */
    public String getProperty(String key) {
        return resolverSpi.engineGetProperty(key);
    }


    
Method understandsProperty
Params:
propertyToTest – 
Returns:
true if the resolver understands property propertyToTest/**
     * Method understandsProperty
     *
     * @param propertyToTest
     * @return true if the resolver understands property propertyToTest
     */
    public boolean understandsProperty(String propertyToTest) {
        return resolverSpi.understandsProperty(propertyToTest);
    }


    
Method resolverClassName
Returns:
the name of the resolver./**
     * Method resolverClassName
     *
     * @return the name of the resolver.
     */
    public String resolverClassName() {
        return resolverSpi.getClass().getName();
    }

    
Iterate over the KeyResolverSpi instances
/**
     * Iterate over the KeyResolverSpi instances
     */
    static class ResolverIterator implements Iterator<KeyResolverSpi> {
        List<KeyResolver> res;
        Iterator<KeyResolver> it;

        public ResolverIterator(List<KeyResolver> list) {
            res = list;
            it = res.iterator();
        }

        public boolean hasNext() {
            return it.hasNext();
        }

        public KeyResolverSpi next() {
            KeyResolver resolver = it.next();
            if (resolver == null) {
                throw new RuntimeException("utils.resolver.noClass");
            }

            return resolver.resolverSpi;
        }

        public void remove() {
            throw new UnsupportedOperationException("Can't remove resolvers using the iterator");
        }
    }

    public static Iterator<KeyResolverSpi> iterator() {
        return new ResolverIterator(resolverVector);
    }
}