Java XPath Get getPublicKeyFromKeyInfo(Node keyInfoNode)

Description

get Public Key From Key Info

License

Apache License

Declaration

public static PublicKey getPublicKeyFromKeyInfo(Node keyInfoNode)
            throws ParserConfigurationException, SAXException, IOException 

Method Source Code

//package com.java2s;
/*//from  w  w w . j av  a  2s  .  c o m
 * Copyright 2010 University of Chicago
 *
 * Licensed 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.
 *
 * NOTE: This is a _PROTOTYPE_ implementation and is not intended for
 *       production use.
 * @src https://svn.cagrid.org/trunk/cagrid/restsecurity/cagrid-restsecurity-common/src/main/java/org/cagrid/security/rest/util/SecurityUtil.java
 */

import java.io.IOException;
import java.math.BigInteger;

import java.security.KeyFactory;

import java.security.PublicKey;

import java.security.spec.InvalidKeySpecException;
import java.security.spec.RSAPublicKeySpec;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;

import org.apache.commons.codec.binary.Base64;

import org.w3c.dom.Node;

import org.xml.sax.SAXException;

public class Main {
    static XPathExpression keyModulusPath = null;
    static XPathExpression keyExponentPath = null;
    static KeyFactory rsaKeyFactory = null;

    public static PublicKey getPublicKeyFromKeyInfo(Node keyInfoNode)
            throws ParserConfigurationException, SAXException, IOException {
        PublicKey publicKey = null;

        try {
            String modulusString = keyModulusPath.evaluate(keyInfoNode);
            String exponentString = keyExponentPath.evaluate(keyInfoNode);
            if (modulusString == null || exponentString == null) {
                return null;
            }
            byte[] modulusBytes = Base64.decodeBase64(modulusString);
            BigInteger modulus = new BigInteger(1, modulusBytes);
            byte[] exponentBytes = Base64.decodeBase64(exponentString);
            BigInteger exponent = new BigInteger(1, exponentBytes);
            RSAPublicKeySpec keySpec = new RSAPublicKeySpec(modulus, exponent);
            publicKey = rsaKeyFactory.generatePublic(keySpec);
        } catch (XPathExpressionException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (InvalidKeySpecException e) {
            e.printStackTrace();
        }
        return publicKey;
    }
}

Related

1. getNodeText(XPath xpath, String xp, Node n)
2. getNodeTextByXPath(Document doc, String xpath)
3. getNogeList(String path, Node node)
4. getORSVersion()
5. getProcessIdFromBpmn(final String bpmn)
6. getResultXpathstring(String expr, InputSource inputSource)
7. getScrProperties(String componentName)
8. getSearchHandlerNode(final File solrconfig)
9. getSharedXPath()