18 May 2009
As a mobile architect, I've spent some time researching the solutions to deliver Flash Lite content protected with digital rights management (DRM). Recently I authored a Developer Center article titled How to protect Flash Lite content with OMA DRM 1.0. To follow up on that research to protect Flash Lite media, I went a step further and found a way to protect Flash Lite content that is packaged using a Symbian installer, which uses the .sis file format.
A Symbian installer for Flash Lite content offers two major functionalities:
To learn more about working with OMA DRM 1.0, please refer to the article referenced above.
You can use the method described here to protect Flash Lite content packaged into .sis format (also known as a SIS installer) on the following platforms:
In this article, I'll provide information on how to package your Flash Lite mobile content into a Symbian installer, which is the first important step. I'll also cover how to create a Protected Installation Package (PIP) and describe the process for applying and testing the PIP package. For the purposes of this article, we'll be using the Nokia Mobile Internet Toolkit.
The first step to protect Flash Lite mobile content is to create a Symbian (also known as SIS) installer file (that uses a .sis file extension). This process allows you to package Flash Lite content into a single file that is ready for installation on a mobile phone.
The following article on the Adobe Developer Connection provides all of the code you need: Making a simple SWF launcher with Nokia Carbide.c++ IDE (for Symbian 3rd Edition).
In addition to the information listed above, you may also find the following online resources helpful:
A Protected Installation Package (PIP) allows you to protect content packaged in a SIS installer (.sis file) and uses the file extension .pip.
For the purposes of this discussion, let's imagine that you've created a Flash Lite application (test.swf) that contains content you wish to protect, and that you've packaged the SWF file into a Symbian installer named test.sis.
At this point, you'll also need to create a definition file with the .def file extension. The definition file (named datafiles.def) should contain the following text:
application test.swf application/x-shockwave-flash c:\DATA\Others\test.swf
The creation of the definition file is necessary because it defines which file will be protected, the protected file's MIME type and the location where the protected file will be stored on the mobile phone after it is installed.
Note: In order to successfully protect your Flash Lite content (test.swf) you must know the location where the SWF file will be installed on the device. The location (the path to a directory) must be defined in the datafiles.def file as shown above.
The next step involves creating a PIP file—which is basically a ZIP file. (It really is as simple as creating an archive (.zip file) that contains the files listed below, and then renaming the file extension from .zip to .pip).
In this theoretical example, the ZIP file you create would contain the following files:
For more information and details about creating PIP files format, see the S60 Platform: Implementing OTA Application Delivery and Protection white paper posted on Forum Nokia.
In order to apply OMA DRM 1.0, you'll need to use one of the delivery methods outlined in the OMA DRM specification. The simplest way to do this is to create a mobile web page.
The following MIME types are defined for OMA DRM; you will need to configure them into your web server to ensure that OMA DRM protected files will be recognized by the mobile phone after they are downloaded.
application/vnd.oma.drm.rights+xml .dr application/vnd.oma.drm.rights+wbxml .drc application/vnd.oma.drm.content .dcf application/vnd.oma.drm.message .dm application/vnd.oma.drm.dd+xml .dd
application/vnd.oma.drm.message .dm is the only MIME type specifically required for OMA DRM Forward Lock 1.0.
Additionally, you'll need to set the following MIME types in order to support .pip and .sis file types:
application/x-pip pip x-epoc/x-sisx-app sis x-epoc/x-sisx-app sisx
To learn more about setting MIME types on your web server, see the following online documentation:
In this section, I'll describe the process of using the Nokia Mobile Internet Toolkit (version 4.1) to apply OMA DRM Forward Lock 1.0 to a .pip file.
Describing the details for every option is outside the scope of this article, but if you have questions, you can refer to the Nokia Mobile Internet Toolkit 4.1 User Guide. The user guide contains a great deal of information to help you learn more about all the capabilities and features of the toolkit.
Follow the steps below to apply the OMA DRM 1.0 Forward Lock:
After making these changes, the DRM definition window should look similar to the screenshot shown below (see Figure 3).
At this point, you've created a DRM message file that is ready for deployment. The next step involves uploading it to your web server so that it is available to be downloaded and installed on your mobile device.
Note: The digital rights protection will only be applied once a user downloads the test.dm file from the mobile website and installs it on the device.
To test the protected PIP package (the content contained in the .pip file) you can follow the step-by-step instructions outlined in a previous article Developer Center article I authored, titled: How to protect Flash Lite content with OMA DRM 1.0. Use the steps provided and adapt them to test your mobile content.
In order to test the protection, you must first upload your test.pip file and generate the test.dm file using the Nokia Mobile Internet Toolkit as described in the previous section.
Search for specific topics in the Forum Nokia Library to get more details about specific tasks and help with troubleshooting issues. The Forum Nokia Documentation page also contains a wealth of information to help you get started and answer any questions you may encounter.
Check out the Mobile and Devices Developer Center, where you'll find helpful articles and sample files to learn more about developing mobile applications. And be sure to visit the Flash Lite section of the Mobile and Devices Developer Center to learn more about programming strategies and techniques for delivering mobile content.
And if you haven't already, be sure to read the following related articles:
This work is licensed under a Creative Commons Attribution-Noncommercial 3.0 Unported License.