SMRMessage.java :  » App » ampted » com » unitvectory » securemessagerelay » client » model » Android Open Source

/*
 * Copyright 2010 Jared Hatfield
 * SecureMessageReplay Java Client Library
 * 
 * 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.
 */
package com.unitvectory.securemessagerelay.client.model;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.StringWriter;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import com.unitvectory.securemessagerelay.client.SMRException;
import com.unitvectory.securemessagerelay.client.SMRGuid;
import com.unitvectory.securemessagerelay.client.encryption.AESDecryptor;
import com.unitvectory.securemessagerelay.client.encryption.AESEncryptor;

public class SMRMessage {

    /**
     * 
     */
    private String mid;

    /**
     * 
     */
    private String cid;

    /**
     * 
     */
    private String descriptor;

    /**
     * 
     */
    private String body;

    /**
     * 
     * @param descriptor
     * @param body
     * @param password
     */
    public SMRMessage(String descriptor, String body, String password) {
        this.mid = SMRGuid.NewGuid();
        this.cid = SMRGuid.NewPassword();
        this.descriptor = descriptor;
        AESEncryptor encryptor = new AESEncryptor(password);
        this.body = encryptor.encrypt(body);
    }

    public SMRMessage(String xmlcontent) throws SMRException {
        try {
            InputStream is = new ByteArrayInputStream(
                    xmlcontent.getBytes("UTF-8"));
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            Document doc = db.parse(is);
            doc.getDocumentElement().normalize();
            NodeList nodeLst = doc.getElementsByTagName("message");
            Node fstNode = nodeLst.item(0);

            this.mid = ParseXMLValueFromElement(fstNode, "mid");

            // NOTE: the message may not have a CID if it is retrieved from
            // the server
            try {
                this.cid = ParseXMLValueFromElement(fstNode, "cid");
            } catch (Exception e) {
                this.cid = null;
            }

            this.descriptor = ParseXMLValueFromElement(fstNode, "descriptor");
            this.body = ParseXMLValueFromElement(fstNode, "body");

        } catch (Exception e) {
            throw new SMRException();
        }
    }

    private static String ParseXMLValueFromElement(Node fstNode, String name) {
        Element fstElmnt = (Element) fstNode;
        NodeList fstNmElmntLst = fstElmnt.getElementsByTagName(name);
        Element fstNmElmnt = (Element) fstNmElmntLst.item(0);
        NodeList fstNm = fstNmElmnt.getChildNodes();
        return (fstNm.item(0)).getNodeValue();
    }

    /**
     * @return the mid
     */
    public String getMid() {
        return this.mid;
    }

    /**
     * @return the cid
     */
    public String getCid() {
        return this.cid;
    }

    /**
     * @return the descriptor
     */
    public String getDescriptor() {
        return this.descriptor;
    }

    /**
     * @return the body
     */
    public String getBody() {
        return this.body;
    }

    /**
     * 
     * @param password
     * @return
     */
    public String getDecryptedBody(String password) {
        AESDecryptor decryptor = new AESDecryptor(password);
        return decryptor.decrypt(this.getBody());
    }

    public String toXML() {
        String xmlString;
        try {
            // Create the document Document
            DocumentBuilderFactory dbfac = DocumentBuilderFactory.newInstance();
            DocumentBuilder docBuilder = dbfac.newDocumentBuilder();
            Document doc = docBuilder.newDocument();

            // Generate the XML content
            org.w3c.dom.Element root = doc.createElement("smr");
            doc.appendChild(root);
            org.w3c.dom.Element message = doc.createElement("message");
            root.appendChild(message);

            // Add all of the fields to the message
            org.w3c.dom.Element midElement = doc.createElement("mid");
            message.appendChild(midElement);
            org.w3c.dom.Text midXML = doc.createTextNode(this.getMid());
            midElement.appendChild(midXML);
            if (this.cid != null) {
                org.w3c.dom.Element cidElement = doc.createElement("cid");
                message.appendChild(cidElement);
                org.w3c.dom.Text cidXML = doc.createTextNode(this.getCid());
                cidElement.appendChild(cidXML);
            }

            org.w3c.dom.Element descriptorElement = doc
                    .createElement("descriptor");
            message.appendChild(descriptorElement);
            org.w3c.dom.Text descriptorXML = doc.createTextNode(this
                    .getDescriptor());
            descriptorElement.appendChild(descriptorXML);
            org.w3c.dom.Element bodyElement = doc.createElement("body");
            message.appendChild(bodyElement);
            org.w3c.dom.Text bodyXML = doc.createTextNode(this.getBody());
            bodyElement.appendChild(bodyXML);

            // Output the XML
            TransformerFactory tfac = TransformerFactory.newInstance();
            Transformer trans = tfac.newTransformer();
            trans.setOutputProperty(OutputKeys.INDENT, "yes");

            // Generate the string that will be returned
            StringWriter sw = new StringWriter();
            StreamResult result = new StreamResult(sw);
            DOMSource source = new DOMSource(doc);
            trans.transform(source, result);
            xmlString = sw.toString();

        } catch (Exception e) {
            xmlString = "<message>Fail</message>";
        }
        return xmlString;
    }
}