November 2001
Intermediate to advanced
788 pages
27h 27m
English
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Chapter 16. Securing Web Applications
Web servers are fine programs for displaying static information such as brochures, FAQs, and product catalogs. But applications that are customized for the user or that implement business logic (such as shopping carts) require that servers be extended with specialized code that executes each time the web page is fetched. This code most often takes the form of scripts or programs that are run when a particular URL is accessed. There is no limit to what a good programming team can do with a web server, a programming language, and enough time. Unfortunately, programs that provide additional functionality over the Web can have flaws that allow attackers to compromise the system on which the web server is running. These flaws are rarely evident when the program is run as intended.
This chapter focuses on programming techniques that you can use to make web programs more secure.
A Legacy of Extensibility and Risk
There are four primary techniques that web developers can use to create web-based applications:
- CGI
The Common Gateway Interface (CGI) was the first means of extending web servers. When a URL referencing a CGI program is requested from the web server, the web server runs the CGI program in a separate process, captures the program’s output, and sends the results to the requesting web browser. Parameters to the CGI programs are encoded as environment variables and also provided to the program on standard input.
CGI programs can perform database ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.