/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
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
Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied. See the License for the
specific language governing permissions and limitations
under the License.
/**
 * 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
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations;

import java.io.IOException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.cert.X509Certificate;

import javax.crypto.SecretKey;
import javax.xml.namespace.QName;
import javax.xml.parsers.ParserConfigurationException;

import com.sun.org.apache.xml.internal.security.c14n.CanonicalizationException;
import com.sun.org.apache.xml.internal.security.exceptions.XMLSecurityException;
import com.sun.org.apache.xml.internal.security.keys.KeyInfo;
import com.sun.org.apache.xml.internal.security.keys.content.KeyInfoReference;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.KeyResolverException;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.KeyResolverSpi;
import com.sun.org.apache.xml.internal.security.keys.storage.StorageResolver;
import com.sun.org.apache.xml.internal.security.signature.XMLSignatureInput;
import com.sun.org.apache.xml.internal.security.utils.Constants;
import com.sun.org.apache.xml.internal.security.utils.XMLUtils;
import com.sun.org.apache.xml.internal.security.utils.resolver.ResourceResolver;
import org.w3c.dom.Attr;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;

KeyResolverSpi implementation which resolves public keys, private keys, secret keys, and X.509 certificates from a dsig11:KeyInfoReference element. /**
 * KeyResolverSpi implementation which resolves public keys, private keys, secret keys, and X.509 certificates from a
 * {@code dsig11:KeyInfoReference} element.
 *
 */
public class KeyInfoReferenceResolver extends KeyResolverSpi {

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

    
{{@inheritDoc}}. /** {{@inheritDoc}}. */
    public boolean engineCanResolve(Element element, String baseURI, StorageResolver storage) {
        return XMLUtils.elementIsInSignature11Space(element, Constants._TAG_KEYINFOREFERENCE);
    }

    
{{@inheritDoc}}. /** {{@inheritDoc}}. */
    public PublicKey engineLookupAndResolvePublicKey(Element element, String baseURI, StorageResolver storage)
        throws KeyResolverException {

        LOG.debug("Can I resolve {}", element.getTagName());

        if (!engineCanResolve(element, baseURI, storage)) {
            return null;
        }

        try {
            KeyInfo referent = resolveReferentKeyInfo(element, baseURI, storage);
            if (referent != null) {
                return referent.getPublicKey();
            }
        } catch (XMLSecurityException e) {
            LOG.debug("XMLSecurityException", e);
        }

        return null;
    }

    
{{@inheritDoc}}. /** {{@inheritDoc}}. */
    public X509Certificate engineLookupResolveX509Certificate(Element element, String baseURI, StorageResolver storage)
        throws KeyResolverException {

        LOG.debug("Can I resolve {}", element.getTagName());

        if (!engineCanResolve(element, baseURI, storage)) {
            return null;
        }

        try {
            KeyInfo referent = resolveReferentKeyInfo(element, baseURI, storage);
            if (referent != null) {
                return referent.getX509Certificate();
            }
        } catch (XMLSecurityException e) {
            LOG.debug("XMLSecurityException", e);
        }

        return null;
    }

    
{{@inheritDoc}}. /** {{@inheritDoc}}. */
    public SecretKey engineLookupAndResolveSecretKey(Element element, String baseURI, StorageResolver storage)
        throws KeyResolverException {

        LOG.debug("Can I resolve {}", element.getTagName());

        if (!engineCanResolve(element, baseURI, storage)) {
            return null;
        }

        try {
            KeyInfo referent = resolveReferentKeyInfo(element, baseURI, storage);
            if (referent != null) {
                return referent.getSecretKey();
            }
        } catch (XMLSecurityException e) {
            LOG.debug("XMLSecurityException", e);
        }

        return null;
    }

    
{{@inheritDoc}}. /** {{@inheritDoc}}. */
    public PrivateKey engineLookupAndResolvePrivateKey(Element element, String baseURI, StorageResolver storage)
        throws KeyResolverException {

        LOG.debug("Can I resolve " + element.getTagName());

        if (!engineCanResolve(element, baseURI, storage)) {
            return null;
        }

        try {
            KeyInfo referent = resolveReferentKeyInfo(element, baseURI, storage);
            if (referent != null) {
                return referent.getPrivateKey();
            }
        } catch (XMLSecurityException e) {
            LOG.debug("XMLSecurityException", e);
        }

        return null;
    }

    
Resolve the KeyInfoReference Element's URI attribute into a KeyInfo instance.
Params:
element – 
baseURI – 
storage – 
Throws:
XMLSecurityException – 
Returns:
the KeyInfo which is referred to by this KeyInfoReference, or null if can not be resolved/**
     * Resolve the KeyInfoReference Element's URI attribute into a KeyInfo instance.
     *
     * @param element
     * @param baseURI
     * @param storage
     * @return the KeyInfo which is referred to by this KeyInfoReference, or null if can not be resolved
     * @throws XMLSecurityException
     */
    private KeyInfo resolveReferentKeyInfo(Element element, String baseURI, StorageResolver storage) throws XMLSecurityException {
        KeyInfoReference reference = new KeyInfoReference(element, baseURI);
        Attr uriAttr = reference.getURIAttr();

        XMLSignatureInput resource = resolveInput(uriAttr, baseURI, secureValidation);

        Element referentElement = null;
        try {
            referentElement = obtainReferenceElement(resource);
        } catch (Exception e) {
            LOG.debug("XMLSecurityException", e);
            return null;
        }

        if (referentElement == null) {
            LOG.debug("De-reference of KeyInfoReference URI returned null: {}", uriAttr.getValue());
            return null;
        }

        validateReference(referentElement);

        KeyInfo referent = new KeyInfo(referentElement, baseURI);
        referent.addStorageResolver(storage);
        return referent;
    }

    
Validate the Element referred to by the KeyInfoReference.
Params:
referentElement – 
Throws:
XMLSecurityException – /**
     * Validate the Element referred to by the KeyInfoReference.
     *
     * @param referentElement
     *
     * @throws XMLSecurityException
     */
    private void validateReference(Element referentElement) throws XMLSecurityException {
        if (!XMLUtils.elementIsInSignatureSpace(referentElement, Constants._TAG_KEYINFO)) {
            Object exArgs[] = { new QName(referentElement.getNamespaceURI(), referentElement.getLocalName()) };
            throw new XMLSecurityException("KeyInfoReferenceResolver.InvalidReferentElement.WrongType", exArgs);
        }

        KeyInfo referent = new KeyInfo(referentElement, "");
        if (referent.containsKeyInfoReference()) {
            if (secureValidation) {
                throw new XMLSecurityException("KeyInfoReferenceResolver.InvalidReferentElement.ReferenceWithSecure");
            } else {
                // Don't support chains of references at this time. If do support in the future, this is where the code
                // would go to validate that don't have a cycle, resulting in an infinite loop. This may be unrealistic
                // to implement, and/or very expensive given remote URI references.
                throw new XMLSecurityException("KeyInfoReferenceResolver.InvalidReferentElement.ReferenceWithoutSecure");
            }
        }

    }

    
Resolve the XML signature input represented by the specified URI.
Params:
uri – 
baseURI – 
secureValidation – 
Throws:
XMLSecurityException – 
Returns:
the XML signature input represented by the specified URI./**
     * Resolve the XML signature input represented by the specified URI.
     *
     * @param uri
     * @param baseURI
     * @param secureValidation
     * @return the XML signature input represented by the specified URI.
     * @throws XMLSecurityException
     */
    private XMLSignatureInput resolveInput(Attr uri, String baseURI, boolean secureValidation)
        throws XMLSecurityException {
        ResourceResolver resRes = ResourceResolver.getInstance(uri, baseURI, secureValidation);
        return resRes.resolve(uri, baseURI, secureValidation);
    }

    
Resolve the Element effectively represented by the XML signature input source.
Params:
resource – 
Throws:
CanonicalizationException – 
ParserConfigurationException – 
IOException – 
SAXException – 
KeyResolverException – 
Returns:
the Element effectively represented by the XML signature input source./**
     * Resolve the Element effectively represented by the XML signature input source.
     *
     * @param resource
     * @return the Element effectively represented by the XML signature input source.
     * @throws CanonicalizationException
     * @throws ParserConfigurationException
     * @throws IOException
     * @throws SAXException
     * @throws KeyResolverException
     */
    private Element obtainReferenceElement(XMLSignatureInput resource)
        throws CanonicalizationException, ParserConfigurationException,
        IOException, SAXException, KeyResolverException {

        Element e;
        if (resource.isElement()){
            e = (Element) resource.getSubNode();
        } else if (resource.isNodeSet()) {
            LOG.debug("De-reference of KeyInfoReference returned an unsupported NodeSet");
            return null;
        } else {
            // Retrieved resource is a byte stream
            byte inputBytes[] = resource.getBytes();
            e = getDocFromBytes(inputBytes, this.secureValidation);
        }
        return e;
    }
}