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#JAVASCRIPT GET MAC ADDRESS WITH SIGNED APPLET FREE#The spawned thread will have the correct security context so it will be free to do whatever it needs to. For example, have the applet's start() function spawn a thread that can watch for and act upon events received by public methods called by scripts. I can't say I disagree with this design decision but if your goal is to create a signed applet that wants to expose a few elevated-privilege methods to unsigned scripts it's very easy to engineer around any limitations you might face. Even though the applet is signed, the script calling it isn't - and in this scenario Java becomes paranoid and executes bytecode as if it weren't signed. Its public methods that performed things like DNS lookups fell on its face due to a bunch of security exceptions. #JAVASCRIPT GET MAC ADDRESS WITH SIGNED APPLET CODE#Once the applet was built in a simple (synchronous) manner for testing purposes, my JavaScript code calling (In theory you can also do JNI but that's downright impossible from an applet - and requires a lot of work for every supported platform.) The only way you can really do a ping from Java code is to call the native operating system's ping executable and parse its output. ICMP support is nonexistent in Java, save for a single castrated and utterly useless isReachable call. Using the InetAddress class in any interesting manner (such as reverse DNS lookups) is only available to signed applets.Ģ. Unfortunately it had to be signed code (therefore the user must explicitlyĪllow it to run with elevated privileges) for two main reasons:ġ. The simplest way to do this is to build a state machine that has a single entry point (the nextstep() function in this code), and keeps track of what it's supposed to do via a bunch of global variables.įeel free to check out the source code of the page - the JavaScript is all inline and not obfuscated. Scripts in the running state effectively block the browser therefore everything has to be asynchronous. Low-level stuff like the actual pings or reverse DNS lookups have to be punted to a Java applet.ĭ("The application, of course, cannot run for extended periods of time: it can't just send off a ping and wait for a response that might never come. The JavaScript component talks to the server using asynchronous HTTP calls. To get at the latitude/longitude coordinates that belong to a specific IP address we use a database back on the server. Map = new GMap2(document.getElementById("map")) The map itself was a piece of cake to implement (the Google Maps API is a joy to work with): ![]() To make things look a bit more interesting we display a Google Map with markers for known hops. Finally, we enter an infinite loop and start pinging the IP address alongside the route, displaying the results. Once we arrive at the destination we resolve the IP addresses to host names in a separate pass. #JAVASCRIPT GET MAC ADDRESS WITH SIGNED APPLET SERIES#The idea is that once the user clicks the "Traceroute" button, we discover the route to the destination using a series of TTL-limited pings. The JavaScript application is probably the most complex of the four components. A form, a few tables, an OnLoad() handler to check for It's really just some (hopefully not entirely unaesthetic) cobweb that holds together the rest. This is arguably the simplest component of the four. TRACEROUTE.V has four major components: an HTLM page, a JavaScript state machine, a Java applet and a simple I wanted to play with a bunch of interesting and new (or neglected) technologies like the Google Maps API, asynchronous communication between JavaScript and a HTTP server, asynchronousĬommunication between a Java applet and JavaScript, IP address to location mapping, dynamic page updates, This started off as an experiment for me. ![]()
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