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Ok, so this is the last revision of my Flex Thanksgiving homework. Thanks to everyone for the tips. My only purpose here was to learn a bit and I've definitely done that - thanks to you guys out there. So - enough kissing up. Let me talk about what I did in this last build.

First I expanded core.cfc to include a few new methods: unsecure and secure. They simply return random strings with the secure method adding a static string in front:

<cffunction name="unsecure" access="remote" returnType="numeric" output="false">
   <cfreturn randRange(1,10000)>
</cffunction>

<cffunction name="secure" access="remote" returnType="string" output="false" roles="admin">
   <cfreturn "secure function " & randRange(1,10000)>
</cffunction>

You may be wondering why I bothered with the unsecure method. I mean - I've done it before easily enough. My authenticate method wasn't secured. Frankly there was no good reason - I just wanted to be complete. Ignore the roles equals part. I'll be getting to that in a second.

To my main stage (remember I was using a ViewStack and I named my different pages as stages) I added two buttons:

<mx:Button id="unsecureButton" label="Call unsecured method." click="callUnsecure()" />   

<mx:Button id="secureButton" label="Call secured method." click="callSecure()" />

These two buttons were what I used to test my methods. Now lets talk security. I started off this series saying I wanted to avoid ColdFusion's roles based security. I am not of fan of it. It is probably the only thing about ColdFusion I don't like. Turns out though that it is very darn handy when working with Flex. So handy that I decided to swallow my pride a little and just use it. How difficult is it to use in Flex? Incredibly difficult. Very complex. In fact, I shouldn't even tell you how to do this. I should charge outrageous consulting fees instead. (Actually more than a few people posted this.)

Basically what you do is set login information into your RemoteObject tag. I moved my username/password values out of the old method and into the global scope. I then used setRemoteCredentials. Here is my new function that is run after authentication:

private function checkAuthResult(event):void {
   var result = event.result;
   if(result == 'false') {
      Alert.show("Authentication failed", "Errors", mx.controls.Alert.OK);            
   } else {
      core.setRemoteCredentials(usernameValue,passwordValue);   
      mainView.selectedChild = mainStage;
   }
}

The only real difference here from the last version is the setRemoteCredentials function. You can think of it like adding a badge to your remoteObject. Now all calls will also pass along authentication information. How do you use that? With the CFLOGIN scope. I added an Application.cfc file to the project and used this onRequestStart:

<cffunction name="onRequestStart" returnType="boolean" output="false">
   <cfargument name="thePage" type="string" required="true">
   
   <cflogin>
      <cfif isDefined("cflogin.name") and isDefined("cflogin.password")>
         <cfif application.core.authenticate(cflogin.name, cflogin.password)>
            <cfloginuser name="#cflogin.name#" password="#cflogin.password#" roles="#application.core.getRoles(cflogin.name)#">
         </cfif>
      </cfif>
   </cflogin>
   
   <cfreturn true>
</cffunction>

So for those of you who have not used CFLOGIN, the basic thing to remember is that it can auto detect calls made with authentication data (not just from Flash/Flex) and will give you access to the username and password. I took these values and passed them to the authentication method. If it returns true (which it should), then I grab the roles (hard coded in my CFC as "admin") and run the CFLOGINUSER tag. So remember my secured method above that had roles=admin? It will now work correctly since the CFLOGINUSER tag will end up giving me a role of "admin."

So I said this was the last entry, but earlier today J Fernandes showed me a good way to make my source attribute dynamic based on FlashVars. So I'll do one more build tomorrow demonstrating that.

I'm happy this was so easy in the end. But - I'm not happy that I ended up using CFLOGIN. To me it is almost as bad as Evaluate(). How could I get around it? One idea would be to build a proxy CFC. This CFC would have contain the methods I need to run remotely, and each method would

• have a username and password attribute. These would get passed to an authenticate() method and logic would only continue if the authentication passed
• any other arguments would be passed in as a structure and then expanded as arguments to the "real" CFC behind the scenes

This seems like extra work. But it does get rid of CFLOGIN. It also lets me keep my original CFC a bit slimmer and more focused on business logic while my proxy can worry about security.

For those of you out there doing Flex 2 development - how do you handle security?

p.s. Oops, forgot to link to the new build. You can view it here: http://ray.camdenfamily.com/demos/flexsec4/SimpleRemotingTest.html

Comments (18) Nov 25, 2006 9:15 PM Views: 6521

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