Chapter 25: Organizing a Remote Shell Under UNIX and Windows NT

Overview

Not only hackers but also administrators need a remote shell. After all, administrators do not want to traipse through the whole city on a rainy day only to fix a malfunctioning Windows NT server.

UNIX-like operating systems have a native shell. Under Windows NT, it is necessary to implement it independently. How is it possible to do this? Horrible code roams the network, redirecting the entire input and output of the generated process into descriptors of nonoverlapping sockets. Because nonoverlapping sockets in many respects behave like normal file handles, many believe that the operating system won't notice the deception and the command interpreter will work with the remote terminal like it would with the local console. Rarely, this technique might work in some Windows versions; however, in all contemporary systems, the generated process simply doesn't know what to do with socket descriptors, and the entire input and output fails.