HTML5 will be one of the hottest topics this year (and may continue for next 2 years). One of the features is called WebSocket. WebSocket is a technology providing for bi-directional, full-duplex communications channels, over a single Transmission Control Protocol (TCP) socket. It is designed to be implemented in web browsers and web servers but it can be used by any client or server application.
Due to a desgin vulnerability in WebSocket protocol, Mozilla Foundation has disabled it in the forthcoming Firefox 4 Beta 8 release. The vulnerability, in the code for transparent proxies, can potentially be exploited to poison the proxy cache and inject manipulated pages.
A group of researchers described the problem on the IETF mailing list in November. In their POC, it could allow attackers to inject a specially crafted JavaScript for Google Analytics into the proxy's cache that will be returned to clients and executed in their browsers after every subsequent request.
In conventional connections, a client prompts a server to send data via GET or POST. WebSockets allow permanent connections between clients and servers and enable servers to independently send data to a client.
Currently, WebSocket (ver. 76) is already supported by Chrome and Safari.
Showing posts with label WebSocket. Show all posts
Showing posts with label WebSocket. Show all posts
Dec 13, 2010
What is HTML5 WebSocket
One of the cool new features of HTML5 is WebSockets. It allows clients connect to the server without using AJAX requests.
Many Ajax applications makes use of the above – this can often be attributed to poor resource utilization.
Wouldn’t it be great if the server could wake up one morning and send its data to clients who are willing to listen without some sort of pre established connection? Welcome to the world of PUSH technology!
Here's a short tutorial, that review the process of running a WebSocket server in PHP, and then building a client to send and receive messages to it over the WebSocket protocol.
Other reference:
WebSockets is a technique for two-way communication over one (TCP) socket, a type of PUSH technology. At the moment, it’s still being standardized by the W3C; however, the latest versions of Chrome and Safari have support for WebSockets.Websockets can replace long-polling. This is an interesting concept; the client sends a request to the server – now, rather than the server responding with data it may not have, it essentially keeps the connection open until the fresh, up-to-date data is ready to be sent – the client next receives this, and sends another request. This has its benefits: decreased latency being one of them, as a connection which has already been opened does not require a new connection to be established. However, long-polling isn’t really a piece of fancy technology: it’s also possible for a request to time-out, and thus a new connection will be needed anyway.
Many Ajax applications makes use of the above – this can often be attributed to poor resource utilization.
Wouldn’t it be great if the server could wake up one morning and send its data to clients who are willing to listen without some sort of pre established connection? Welcome to the world of PUSH technology!
Here's a short tutorial, that review the process of running a WebSocket server in PHP, and then building a client to send and receive messages to it over the WebSocket protocol.
Other reference:
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