MACROMEDIA FLASH 8-LEARNING ACTIONSCRIPT 2.0 IN FLASH, Manual

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680 Understanding Security
Access to the local file system and the network A local SWF file can read from the local
file system where it is installed, read and write to and from servers, and can cross-script other
SWF files on either the network or the local file system. These files are trusted, and behave
like they did in Flash Player 7. For more information on local and network access SWF files,
see
“Access file system and network” on page 687 .
For more information on local file security in Flash 8 as it pertains to the authoring tool, see
the following sections:
■
“Understanding local security sandboxes” on page 680
■
“About Flash Player security settings” on page 681
■
“About local file security and projector files” on page 683
■
“About troubleshooting legacy SWF files” on page 684
■
“Fixing legacy content deployed on local computers” on page 684
■
“Publishing files for local deployment” on page 685
For information about local file security for users, see “About Flash Player security settings”
on page 681 . For more information on security, see www.macromedia.com/devnet/security/
and www.macromedia.com/software/flashplayer/security/ .
Understanding local security sandboxes
There are several different security sandboxes in the Flash Player. Each one determines how a
SWF file can interact with the local file system, the network, or both the local file system and
network at the same time. Restricting how a file can interact with the local file system, or the
network helps keep your computer and files safe. Understanding security sandboxes helps you
develop and test Flash applications on your computer without encountering unexpected
errors.
Local-with-file-system
For security purposes, Flash Player 8 places all local SWF files, including all legacy local SWF
files, in the local-with-file-system sandbox, by default (unless some other setting is made). For
some legacy (earlier than Flash Player 8) SWF files, operations could be affected by enforcing
restrictions on their access (no outside network access), but this provides the most secure
default for the users’ protection.
From this sandbox, SWF files may read from files on local file systems or UNC network paths
(by using the
XML.load()
method, for example), but they may not 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.