From e571c4d7ffa1cf60330ac0c7e3fb8b62533ff60e Mon Sep 17 00:00:00 2001 From: simon Date: Fri, 13 Apr 2001 09:39:08 +0000 Subject: [PATCH] Some introductory blurb in the docs git-svn-id: svn://svn.tartarus.org/sgt/putty@1038 cda61777-01e9-0310-a592-d414129be87e --- doc/intro.but | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 90 insertions(+), 7 deletions(-) diff --git a/doc/intro.but b/doc/intro.but index bc1c49a2..b1f0ddbf 100644 --- a/doc/intro.but +++ b/doc/intro.but @@ -1,11 +1,94 @@ \C{intro} Introduction to PuTTY -\# PuTTY is an SSH and Telnet client +PuTTY is a free SSH, Telnet and Rlogin client for 32-bit Windows +systems. -\# Section on `what is Telnet? what is SSH?' for the people who -\# don't have the first clue what they are. Explain what they're -\# good for and why you might want to use one, and explain under -\# what conditions you might _not_ want to use one. +\H{you-what} What are SSH, Telnet and Rlogin? -\# Section on `what's the difference between Telnet and SSH?' where -\# we evangelise - POLITELY! - about SSH and security +If you already know what SSH, Telnet and Rlogin are, you can safely +skip on to the next section. + +SSH, Telnet and Rlogin are three ways of doing the same thing: +logging in to a multi-user computer from another computer, over a +network. + +Multi-user operating systems, such as Unix and VMS, usually present +a command-line interface to the user, much like the \q{Command +Prompt} or \q{MS-DOS Prompt} in Windows. The system prints a prompt, +and you type commands which the system will obey. + +Using this type of interface, there is no need for you to be sitting +at the same machine you are typing commands to. The commands, and +responses, can be sent over a network, so you can sit at one +computer and give commands to another one, or even to more than one. + +SSH, Telnet and Rlogin are \e{network protocols} that allow you to +do this. On the computer you sit at, you run a \e{client}, which +makes a network connection to the other computer (the \e{server}). +The network connection carries your keystrokes and commands from the +client to the server, and carries the server's responses back to +you. + +These protocols can also be used for other types of keyboard-based +interactive session. In particular, there are a lot of bulletin +boards, talker systems and MUDs (Multi-User Dungeons) which support +access using Telnet. There are even a few that support SSH. + +You might want to use SSH, Telnet or Rlogin if: + +\b you have an account on a Unix or VMS system which you want to be +able to access from somewhere else + +\b your Internet Service Provider provides you with a login account +on a web server. (This might also be known as a \e{shell account}. +A \e{shell} is the program that runs on the server and interprets +your commands for you.) + +\b you want to use a bulletin board system, talker or MUD which can +be accessed using Telnet. + +You probably do \e{not} want to use SSH, Telnet or Rlogin if: + +\b you only use Windows machines. Windows machines have their own +ways of networking between themselves, and unless you are doing +something fairly unusual, you will not need to use any of these +remote login protocols. + +\H{which-one} How do SSH, Telnet and Rlogin differ? + +This list summarises some of the differences between SSH, Telnet and +Rlogin. + +\b SSH is a recently designed, high-security protocol. It uses +strong cryptography to protect your connection against +eavesdropping, hijacking and other attacks. Telnet and Rlogin are +both older protocols offering minimal security. + +\b Telnet allows you to pass some settings on to the server, such as +environment variables. (These control various aspects of the +server's behaviour. You can usually set them by entering commands +into the server once you're connected, but it's easier to have +Telnet do it automatically.) SSH and Rlogin do not support this. +However, most modern Telnet servers don't allow it either, because +it has been a constant source of security problems. + +\b SSH and Rlogin both allow you to log in to the server without +having to type a password. (Rlogin's method of doing this is +insecure, and can allow an attacker to access your account on the +server. SSH's method is much more secure, and typically requires the +attacker to have gained access to your actual client machine.) + +\b SSH allows you to connect to the server and automatically send a +command, so that the server will run that command and then +disconnect. So you can use it in automated processing. + +The Internet is a hostile environment and security is everybody's +responsibility. If you are connecting across the open Internet, then +we recommend you use SSH. If the server you want to connect to +doesn't support SSH, it might be worth trying to persuade the +administrator to install it. + +If you are behind a good firewall, it is more likely to be safe to +use Telnet or Rlogin, but we still recommend you use SSH. + +\# perhaps a section on terminal emulation? -- 2.11.0