XTransferSecurityPolicy.java

/*
 Copyright 2012-2013, Polyvi Inc. (http://polyvi.github.io/openxface)
 This program is distributed under the terms of the GNU General Public License.

 This file is part of xFace.

 xFace is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 xFace is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with xFace.  If not, see <http://www.gnu.org/licenses/>.
*/

package com.polyvi.xface.app.transferpolicy;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.ArrayList;

import android.content.Context;
import android.content.SharedPreferences;

import com.polyvi.xface.XSecurityPolicy;
import com.polyvi.xface.app.XApplication;
import com.polyvi.xface.core.XAppCheckListener;
import com.polyvi.xface.core.XISystemContext;
import com.polyvi.xface.event.XEvent;
import com.polyvi.xface.event.XEventType;
import com.polyvi.xface.event.XSystemEventCenter;
import com.polyvi.xface.util.XConstant;
import com.polyvi.xface.util.XCryptor;
import com.polyvi.xface.util.XFileUtils;
import com.polyvi.xface.util.XFileVisitor;
import com.polyvi.xface.util.XLog;

/**
 * app转移的安全策略
 */
public class XTransferSecurityPolicy implements XSecurityPolicy, XFileVisitor {
    private static final String CLASS_NAME = XTransferSecurityPolicy.class
            .getSimpleName();
    private XISystemContext mSysCtx;
    private ArrayList<String> mMd5Array;
    private boolean mIsContinueTraverse;
    private XCryptor mCryptor;

    public XTransferSecurityPolicy(XISystemContext sysCtx) {
        mIsContinueTraverse = true;
        mSysCtx = sysCtx;
        mMd5Array = new ArrayList<String>();
        mCryptor = new XCryptor();
    }

    @Override
    public boolean checkAppStart(XApplication app, XAppCheckListener listener) {
        String transferedAppMd5 = calTransferedAppMd5(app.getAppInfo()
                .getSrcRoot());
        if (null != transferedAppMd5) {
            String prefMd5 = readPrefMd5(app.getAppId());
            if (transferedAppMd5.equals(prefMd5)) {
                listener.onCheckSuccess(app, mSysCtx);
                return true;
            }
        }
        sendMd5InvalidEvt(app);
        listener.onCheckSuccess(app, mSysCtx);
        return true;
    }

    @Override
    public boolean checkAppClose(XApplication app) {
        return true;
    }

    /**
     * 从apps.pref中读取对应app的md5值
     *
     * @param appId
     * @return
     */
    private String readPrefMd5(String appId) {
        SharedPreferences preference = mSysCtx.getContext()
                .getSharedPreferences(
                        XPreInstallAppsTransferPolicy.APPS_MD5_FILE_NAME,
                        Context.MODE_WORLD_READABLE
                                | Context.MODE_WORLD_WRITEABLE);
        String md5 = preference.getString(appId, null);
        if (null == md5) {
            XLog.d(CLASS_NAME, "App id: " + appId + " not found in "
                    + XPreInstallAppsTransferPolicy.APPS_MD5_FILE_NAME);
            return null;
        }
        return md5;
    }

    /**
     * 计算转移后的app的md5值
     *
     * @param appSrcRoot
     * @return
     */
    private String calTransferedAppMd5(String appSrcRoot) {
        if (null == appSrcRoot) {
            XLog.w(CLASS_NAME, "calTransferedAppMd5 app src_Root is null!");
            return null;
        }
        // src前面有file协议会无法找到相应路径，所以需要去掉file协议头
        appSrcRoot = appSrcRoot.split(XConstant.FILE_SCHEME)[1];
        XFileUtils.walkDirectory(appSrcRoot, this);
        String md5 = XTransferPolicyUtils.calAppMd5(mMd5Array, mCryptor);
        mMd5Array.clear();
        return md5;
    }

    /**
     * 同步发送md5值未匹配的事件
     *
     * @param app
     */
    private void sendMd5InvalidEvt(XApplication app) {
        XEvent evt = new XEvent(XEventType.MD5_INVALID, app.getAppId());
        mSysCtx.getEventCenter().sendEventSync(evt);
    }

    @Override
    public void visit(String filePath) {
        // 计算md5值
        try {
            if (filePath.endsWith(".html") || filePath.endsWith(".js")
                    || filePath.endsWith(".htm")) {
                FileInputStream is = new FileInputStream(new File(filePath));
                String md5 = mCryptor.calMD5Value(is);
                mMd5Array.add(md5);
            }
        } catch (FileNotFoundException e) {
            XLog.e(CLASS_NAME, filePath + " Not Found!");
            mMd5Array = null;
            mIsContinueTraverse = false;
        }
    }

    @Override
    public boolean isContinueTraverse() {
        return mIsContinueTraverse;
    }

}