ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Security
Security sandboxes
Flash Player 9 and later, Adobe AIR 1.0 and later
Client computers can obtain individual files containing code, content, and data from a number of sources, such as
from external websites, from a local file system, or from an installed AIR application. The Flash Player and AIR
runtimes individually assign code files and other resources, such as shared objects, bitmaps, sounds, videos, and data
files, to security sandboxes based on their origin when they are loaded. The following sections describe the rules,
enforced by the runtimes, that govern what a code or content executing within a given sandbox can access.
For more information on Flash Player security, see the Flash Player Developer Center topic “Security” at
www.adobe.com/go/devnet_security_en.
Remote sandboxes
Flash Player 9 and later, Adobe AIR 1.0 and later
The Flash Player and AIR runtimes classify assets (including SWF files) from the Internet in separate sandboxes that
correspond to their domain of origin. For example, assets loaded from example.com will be placed into a different
security sandbox than assets loaded from foo.org. By default, these files are authorized to access any resources from
their own server. Remote SWF files can be allowed to access additional data from other domains by explicit website
and author permissions, such as URL policy files and the Security.allowDomain() method. For details, see
“Website controls (policy files)” on page 1040 and “Author (developer) controls” on page 1043.
Remote SWF files cannot load any local files or resources.
For more information on Flash Player security, see the Flash Player Developer Center topic “Security” at
www.adobe.com/go/devnet_security_en.
Local sandboxes
Flash Player 9 and later, Adobe AIR 1.0 and later
Local file describes any file that is referenced by using the file: protocol or a Universal Naming Convention (UNC)
path. Local SWF files are placed into one of four local sandboxes:
The local-with-filesystem sandbox—For security purposes, the Flash Player and AIR runtimes place all local files
in the local-with-file-system sandbox, by default. From this sandbox, executable code can read local files (by using
the URLLoader class, for example), but cannot communicate with the network in any way. This assures the user
that local data cannot be leaked out to the network or otherwise inappropriately shared.
The local-with-networking sandbox—When compiling a SWF file, you can specify that it has network access when
run as a local file (see “Setting the sandbox type of local SWF files” on page 1036).These files are placed in the localwith-networking
sandbox. SWF files that are assigned to the local-with-networking sandbox forfeit their local file
access. In return, the SWF files are allowed to access data from the network. However, a local-with-networking
SWF file is still not allowed to read any network-derived data unless permissions are present for that action,
through a URL policy file or a call to the Security.allowDomain() method. In order to grant such permission, a
URL policy file must grant permission to all domains by using or by using
Security.allowDomain("*"). For more information, see “Website controls (policy files)” on page 1040 and
“Author (developer) controls” on page 1043.
Last updated 6/6/2012
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