Chapter 2. Basic Client Use
SSH is a simple idea, but it has many complex parts. This chapter is
designed to get you started with SSH quickly. We cover the basics of
SSH's most immediately useful features:
- Logging into a remote computer over a secure connection
- Transferring files between computers over a secure connection
We also introduce authentication with cryptographic keys, a more
secure alternative to ordinary passwords. Advanced uses of client
programs, such as multiple keys, client configuration files, and TCP
port forwarding, will be covered in later chapters.
We use SSH1 and SSH2 (and occasionally OpenSSH) for all examples. If
the syntax differs among the products, we'll discuss each of
them.
2.1. A Running Example
Suppose you're out of town on a business trip and want to read
your email, which sits on a Unix machine belonging to your ISP,
shell.isp.com. A friend at a
nearby university agrees to let you log into her Unix account on the
machine
local.university.edu, and then remotely
log into yours. For the remote login you could use the
telnet or
rlogin programs, but
as we've seen, this connection between the machines is
insecure. (No doubt some subversive college student would grab your
password and turn your account into a renegade web server for pirated
software and Ani DiFranco MP3s.) Fortunately, both your
friend's Unix machine and your ISP's have an SSH product
installed.
In the example running through the chapter, we represent the shell
prompt of the local machine,
local.university.edu, as a dollar sign
(
$) and the prompt on
shell.isp.com as
shell.isp.com>.
| | |
1.7. Summary | | 2.2. Remote Terminal Sessions with ssh |