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<DIV><FONT face=Arial size=2>Hi,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I know I've already replied to this post once, but
I came across the following link the other day and thought that it might help
update some people, or at least remove some
misconceptions, about Policy Files for cross-domain Socket
access : -</FONT></DIV>
<DIV><FONT face=Arial size=2><A
href="http://www.adobe.com/devnet/flashplayer/articles/socket_policy_files.html">http://www.adobe.com/devnet/flashplayer/articles/socket_policy_files.html</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>It's dated 14 April 2008, and has some interesting
stuff that I (and evidently others) was not aware of: -</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>1) Port level granularity eg:</FONT></DIV>
<DIV><allow-access-from domain="swf.example.com" to-ports="123,456-458"
/><BR> </DIV>
<DIV><FONT face=Arial size=2>2) Standardizing a port number for the serving of
policy files (Couldn't see SSL option)</FONT><BR>Adobe has filed with IANA, the
<A href="http://www.iana.org/" target=_blank><FONT color=#0066cc>Internet
Assigned Numbers Authority</FONT></A>, to reserve port 843 for the purposes of
serving socket policy files. By introducing a centralized location for socket
policy files, Flash Player enables a system administrator to define what ports
are available through one master policy that overrides any other policy file on
the host. If Flash Player 9,0,124,0 cannot retrieve a master policy file from
port 843, then it requests a socket policy file on the port where it is trying
to connect. However, if a policy file is available from a service on TCP port
843, then Flash Player considers that to be the authoritative set of permissions
for that system.<BR></DIV>
<DIV><FONT face=Arial size=2>3) Lots of other useful stuff that I feel the
WebSocket people are dismissing too lightly </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I'm not saying that Adobe/Flex, SUN/Java, and
Microsoft/Silverlight can't all be wrong, but I just really hope that isn't one
of these Web "standards" where some one is being different just for the hell of
it.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>It's good to talk.</FONT></DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Cheers Richard Maher</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=shannon@arc.net.au href="mailto:shannon@arc.net.au">Shannon</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=maher_rj@hotmail.com
href="mailto:maher_rj@hotmail.com">Richard's Hotmail</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Cc:</B> <A title=whatwg@lists.whatwg.org
href="mailto:whatwg@lists.whatwg.org">WHAT working group</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, September 22, 2008 12:09
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [whatwg] WebSocket support
in HTML5</DIV>
<DIV><BR></DIV><BR><BR>Richard's Hotmail wrote:
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<DIV><FONT face=Arial size=2>My particular beef is with the intended
WebSocket support, and specifically the restrictive nature of its
implementation. I respectfully, yet forcefully, suggest that the intended
implementation is complete crap and you'd do better to look at existing
Socket support from SUN Java, Adobe Flex, and Microsoft Silverlight before
engraving anything into stone! What we need (and is a really great idea) is
native HTML/JavaScript support for Sockets - What we don't need is someone
re-inventing sockets 'cos they think they can do it better.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Anyway I find it difficult to not be
inflammatory so I'll stop now, but please look to the substance of my
complaint (and the original post in comp.lang.JavaScript attached below) and
at least question why it is that you are putting all these protocol
restriction on binary socket support.</FONT></DIV></BLOCKQUOTE>It's hard to
determine the substance of your complaint. It appears you don't really
understand the Java, Flex or Silverlight implementations. They are all quite
restrictive, just in different ways:<BR><BR>* Java raises a security exception
unless the user authorises the socket using an ugly and confusing popup
security dialog<BR>* Flex and Silverlight requires the remote server or device
also run a webserver (to serve crossdomain.xml). Flex supports connections
ONLY to port numbers higher than 1024. The crossdomain files for each platform
have different filenames and appear to already be partly incompatible between
the two companies, hardly a "standard".<BR><BR>Both Silverlight and Flash/Flex
are fundamentally flawed since they run on the assumption that a file hosted
on port 80 is an authorative security policy for a whole server. As someone
who works in an ISP I assure you this is an incorrect assumuption. Many ISPs
run additional services on their webserver, such as databases and email, to
save rack hosting costs or for simplicity or security reasons. I would not
want one of our virtual hosting customers authorising web visitors access to
those services. It is also fundamentally flawed to assume services on ports
greater than 1024 are automatically "safe".<BR><BR>These companies chose
convienience over security, which quite frankly is why their software is so
frequently exploited. However that's between them and their customers, this
group deals with standards that must be acceptable to the web community at
large.<BR><BR>The current approach the HTML spec is taking is that that policy
files are essentially untrustworthy so the service itself must arbitrate
access with a handshake. Most of the details of this handshake are hidden from
the Javascript author so your concerns about complexity seem unjustified. If
you are worried about the complexity of implementing the server end of the
service I can't see why, it's about 3-6 lines of output and some reasonably
straight-forward text parsing. It could easily be done with a wrapper for
existing services.<BR><BR>Other than that it behaves as an asynchronous binary
TCP socket. What exactly are you concerned
about?<BR><BR>Shannon<BR><BR></BLOCKQUOTE></BODY></HTML>