Specifications

37ADOBE FLEX 3
Building and Deploying Adobe Flex 3 Applications
You can also assign a SWF file to be in the local-trusted sandbox when you load it from the local file system. To
do this, you configure a directory as trusted by Flash Player (which results in the SWF file being put in the local-
trusted sandbox) by adding a FlashPlayerTrust configuration file that specifies the directory to trust. This requires
administrator access privileges to the client system, so it is typically used in controlled environments. Users can
also define a directory as trusted by using the Flash Player User Settings Manager. For more information, see Flash
Player documentation.
Deploying secure applications
When you deploy an application, you make the application accessible to your users. The process of deploying an
application is dependent on your application, your application requirements, and your deployment environment.
You can employ some of the following strategies to ensure that the application you deploy is secure.
Deploying local SWF files versus network SWF files
Client computers can obtain individual SWF files from a number of sources, such as from an external website or
a local file system. When SWF files are loaded into Flash Player, they are individually assigned to security
sandboxes based on their origin.
Flash Player classifies SWF files downloaded from the network (such as from external websites) in separate
sandboxes that correspond to their website origin domains. By default, these files are authorized to access
additional network resources that come from the specific (exact domain name match) site. Network SWF files can
be allowed to access additional data from other domains by explicit website and author permissions.
A local SWF file describes any file referenced by using the “file:\\” protocol or a UNC path, which does not include
an IP address or a qualifying domain. For example, “\\test\test.swf ” and “file:\\test.swf” are considered local files,
while “\\test.com\test.swf” and “\\192.168.0.1\test.swf” are not considered local files.
Local SWF files from local origins, such as local file systems or UNC network paths, are placed into one of three
sandboxes: local-with-networking, local-with-filesystem, and local-trusted.
When you compile the Flex application, if you set the
use-network compiler option to false, local SWF files are
placed in the local-with-filesystem sandbox. If you set the
use-network compiler option to true, local SWF files
are placed in the local-with-networking sandbox.
Local SWF files that are registered as trusted (by users or by installer programs) are placed in the local-trusted
sandbox. Users can also reassign (move) a local SWF file to or from the local-trusted sandbox based on their
security considerations.