Linden's Blog

EncryptedLocalStore and applicationDirectory in AIR

The EncryptedLocalStore class provides methods for setting and getting objects in the encrypted local data store for an AIR application. And the encrypted files are put in a subdirectory of the user’s application data directory; the subdirectory path is Adobe/AIR/ELS/appFolder. The appFolder equals to the applicationID  that you wrote in application description xml (xxx-app.xml) when the application is not signed by any valid certificate.   If the AIR application is signed by a valid certificate,  the appFolder should look like ApplicationID.19863E06A76A…B73154839644F.1. The hex string followed the ApplicationID must be the hashed value of all the files in application directory when it was signed. The AIR application will hash their application directory when it starts up and check it with the original one. If it was not matched, the application’s Encrypted Local Store directory will be set to Adobe/AIR/ELS/ApplicationID. Therefore, the data stored in Encrypted Local Store directory seems lost from application view. The AIR application can’t read the data that it stored before. The result looks like below:

Figure 1. Normal

Figure2. Something Changes in Application Directory

When will this situation happen?
If  any modification was done at the files under application directory, the Encrypted Local Store directory will be change. The information you stored in Encrypted Local Store class will be no longer available.

What should we do?
Don’t write anything into application directory. Be careful when you are operating on File.applicationDirectory. Or never sign your application .

Adobe China Flash Platform Summit will be Broadcasted By Flash P2P

There will be a Flash Platform Summit at Beijing. This summit will start at 9:00 am at April 21 GMT+0800. And the keynote sessions will be broadcasted using flash p2p technology.  All you need is to download flash player 10.1 RC at http://labs.adobe.com/downloads/flashplayer10.html.  After installation completed, go to http://202.108.6.253/fmsp2p/VideoPlayer.html?47. Then you can watch the summit online when it begins. See you !

Using Tasksel in Ubuntu to simplify your work.

Tasksel is a useful tool to install or uninstall a set of software which is pre-defined by Ubuntu. If you want to install LAMP, use tasksel is very simple. Select the LAMP and press OK. Then tasksel will install all necessary files. That’s cool.

The post is brought to you by lekhonee v0.7

BackTrack: A Linux-based Penetration Testing Arsenal

BackTrack is the highest rated and acclaimed Linux security distribution to date. It is a Linux-based penetration testing arsenal that aids security professionals in the ability to perform assessments in a purely native environment dedicated to hacking. You can run it on Live CD or flash driver.  BackTrack has been customized down to every package, kernel configuration, script and patch solely for the purpose of the penetration tester.

Here is the link http://www.backtrack-linux.org/

Adobe Flash Builder 4, Flex 4 and ColdFusion Builder go GA!

Adobe was announced that the GA releases of Flash Builder 4, Flex 4, and ColdFusion Builder are ready for prime-time. Today (3/22) we released:

Flex 4 – Including the new Spark skinning and component architecture enabling a new level of expressiveness in RIAs in addition to supporting the new Flash Catalyst to Flash Builder workflow.

Flash Builder 4 – There are over 90 new features in this release, and you can use them with both Flex 3 and Flex 4 to gain big improvements in development time, integration and building more expressive apps. (Note: Please be sure to uninstall any FB4 beta SW before installing the release product)

ColdFusion Builder – This new Eclipse-based IDE for ColdFusion development is deeply integrated with ColdFusion 9 in addition to making it fast and easy for CF developers to create Flex applications with integration between ColdFusion Builder and Flash Builder。

• Read Andrew Shorten’s Flex Team Blog post

• Get Flash Builder 4 (remember to uninstall any FB4 beta SW first)

• AdobeTV: Learn what developers like about Flash Builder in this video from Flash Camp Boston from March 19th

• AdobeTV: David Wadhwani, VP and GM of Adobe’s Platform BU introduces new Flash Platform products

• Test drive Flex 4 – Take the Flex Test Drive: Build an application in an hour and learn about Flex 4 using this new guided, video tutorial

• Flex-in-a-week free video training – New for Flex 4

• Get ColdFusion Builder

• Video: ColdFusion Builder Feature Tour

• Flex product info on adobe.com

• ColdFusion product info on adobe.com

Technorati : ColdFusion, flash, flex

The easiest way to build a data collection server.

The easiest way to build a data collection server is using the apache’s access log. The access log can record all requests those are requested by clients. So the clients can upload its data to server by just calling a static page. At server side, all needs are a apache server and an empty page. Thus, the load for the server will be lowest.

127.0.0.1 - - [27/Jan/2010:17:48:24 +0800] "GET /abc/api.xml?msg=%22test%22 HTTP/1.1" 302 225

After the data has been collected, you can use various tools to analyze the data you got. You can write a script to put your data into a database or convert the log files to another format which your analytic tools can recognize.

There is a use full toll for you to analyze the log called loghetti. It allows you count your data.

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Flash player 10.1 beta 3 release!

The flash player 10.1 beta3 release in adobe Labs see http://labs.adobe.com/technologies/flashplayer10/

File Operation in Adobe AIR

In AIR application, the file operation is as the same as in other applications( application compiled from C++ etc.).  The size of the file that air can open only depends on the system.

Which class to handle file?

The FileStream Class is the major Class for operating content of a file. A FileStream object has two methods for opening a file. One is synchrony open, another is asynchrony. The open operation will decide the behavior of other file operation you perform on the FileStream object. If the object is opened in synchrony, the operations such as write and read will be also synchrony. It means that the application can’t do anything until the read is finished. If you open a file in asynchrony method by calling openAsync, all reading and writing operations will be asynchrony. The application should handle to get results of operation the events.

Why asynchrony open?

The asynchrony open is used when application need to write a large data fragment. These writing operations are time consuming. If you don’t want your application behaves like death, you should use asynchrony open. Or your application needs to read from a stream, the data is not all ready when the application open the stream file. The synchrony read can only read the data already exists.

Actually, When you open a file, the file is not loaded into memory, it just create a handle in system to identify the opened file. So there is no size limitation by AIR-self, but system.

Linden Liu’s flex series: Tips of Writing ASDoc

Tip 1: The sequence of the @param should be as the order of parameters defined in function.
For example, you defined a function like this public function foo(param1:Type1, param2:Type2, param3:Type3):void. The asdoc should be like this:
/**
* xxxxxxxxxxx description of the function.
* @param param1 xxxxx.
* @param param2 xxxxx.
* @param param3 xxxxx.
* xxxxxxxxxxxxxxxx.
*/
public function foo(param1:Type1, param2:Type2, param3:Type3):void
If parameters are not written in such order, the type of each parameter will misorder.

Tip 2: Every sentence should be ended with a dot “.”, if the asdoc is using the language which dosen’t terminate sentence with “.”.

Tip 3: Keep the special or escape characters in mind. The “&” mark is a logic operator and it is also a escape character in ASDoc just like it in html. So the “&&” is not allowed in ASDoc. If you do that, it will be OK in Flex 3, but it will be caused an error when using Flex4. So It is better to make all escape charaters replaced.

Technorati : asdoc, flex

The flash.net.URLLoader will change your request method to GET.

The URLLoader of flash will change your URLRequest method to GET if your request’s data property is empty. The test code is simple.

private function testPostWithEmptyData():void

{

var urlLoader:URLLoader = new URLLoader();

var req:URLRequest = new URLRequest();

req.url = “http://dict.cn/POSTWithoutData”;

req.method = URLRequestMethod.POST;

urlLoader.load(req);

}

private function testPostWithData():void

{

var urlLoader:URLLoader = new URLLoader();

var req:URLRequest = new URLRequest();

req.url = “http://dict.cn/POSTWithData”;

req.method = URLRequestMethod.POST;

req.data = new URLVariables(“q=hello”);

urlLoader.load(req);

}

Then you can capture the http request data in wireshark. The POST Request without data will be changed to GET, see follow snapshot

Figure 1. The POST Request Without any data.

Figure 2.The POST Request With Data.

There is a note in help

Note: If running in Flash Player and the referenced form has no body, Flash Player automatically uses a GET operation, even if the method is set to URLRequestMethod.POST. For this reason, it is recommended to always include a “dummy” body to ensure that the correct method is used. But actually in air application, the POST request will be treated as GET if there is no body.