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4d8782e74f
I've shifted away from using the SVN revision number as a monotonic version identifier (replacing it in the Windows version resource with a count of days since an arbitrary epoch), and I've removed all uses of SVN keyword expansion (replacing them with version information written out by Buildscr). While I'm at it, I've done a major rewrite of the affected code which centralises all the computation of the assorted version numbers and strings into Buildscr, so that they're all more or less alongside each other rather than scattered across multiple source files. I've also retired the MD5-based manifest file system. A long time ago, it seemed like a good idea to arrange that binaries of PuTTY would automatically cease to identify themselves as a particular upstream version number if any changes were made to the source code, so that if someone made a local tweak and distributed the result then I wouldn't get blamed for the results. Since then I've decided the whole idea is more trouble than it's worth, so now distribution tarballs will have version information baked in and people can just cope with that. [originally from svn r10262]
87 lines
3.6 KiB
Plaintext
87 lines
3.6 KiB
Plaintext
\C{intro} Introduction to PuTTY
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PuTTY is a free SSH, Telnet and Rlogin client for 32-bit Windows
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systems.
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\H{you-what} What are SSH, Telnet and Rlogin?
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If you already know what SSH, Telnet and Rlogin are, you can safely
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skip on to the next section.
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SSH, Telnet and Rlogin are three ways of doing the same thing:
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logging in to a multi-user computer from another computer, over a
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network.
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Multi-user operating systems, such as Unix and VMS, usually present
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a \i{command-line interface} to the user, much like the \q{\i{Command
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Prompt}} or \q{\i{MS-DOS Prompt}} in Windows. The system prints a
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prompt, and you type commands which the system will obey.
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Using this type of interface, there is no need for you to be sitting
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at the same machine you are typing commands to. The commands, and
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responses, can be sent over a network, so you can sit at one
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computer and give commands to another one, or even to more than one.
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SSH, Telnet and Rlogin are \i\e{network protocols} that allow you to
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do this. On the computer you sit at, you run a \i\e{client}, which
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makes a network connection to the other computer (the \i\e{server}).
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The network connection carries your keystrokes and commands from the
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client to the server, and carries the server's responses back to
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you.
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These protocols can also be used for other types of keyboard-based
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interactive session. In particular, there are a lot of bulletin
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boards, \i{talker systems} and \i{MUDs} (Multi-User Dungeons) which support
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access using Telnet. There are even a few that support SSH.
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You might want to use SSH, Telnet or Rlogin if:
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\b you have an account on a Unix or VMS system which you want to be
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able to access from somewhere else
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\b your Internet Service Provider provides you with a login account
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on a \i{web server}. (This might also be known as a \i\e{shell account}.
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A \e{shell} is the program that runs on the server and interprets
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your commands for you.)
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\b you want to use a \i{bulletin board system}, talker or MUD which can
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be accessed using Telnet.
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You probably do \e{not} want to use SSH, Telnet or Rlogin if:
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\b you only use Windows. Windows computers have their own
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ways of networking between themselves, and unless you are doing
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something fairly unusual, you will not need to use any of these
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remote login protocols.
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\H{which-one} How do SSH, Telnet and Rlogin differ?
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This list summarises some of the \i{differences between SSH, Telnet
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and Rlogin}.
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\b SSH (which stands for \q{\i{secure shell}}) is a recently designed,
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high-security protocol. It uses strong cryptography to protect your
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connection against eavesdropping, hijacking and other attacks. Telnet
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and Rlogin are both older protocols offering minimal security.
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\b SSH and Rlogin both allow you to \I{passwordless login}log in to the
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server without having to type a password. (Rlogin's method of doing this is
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insecure, and can allow an attacker to access your account on the
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server. SSH's method is much more secure, and typically breaking the
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security requires the attacker to have gained access to your actual
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client machine.)
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\b SSH allows you to connect to the server and automatically send a
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command, so that the server will run that command and then
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disconnect. So you can use it in automated processing.
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The Internet is a hostile environment and security is everybody's
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responsibility. If you are connecting across the open Internet, then
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we recommend you use SSH. If the server you want to connect to
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doesn't support SSH, it might be worth trying to persuade the
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administrator to install it.
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If your client and server are both behind the same (good) firewall,
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it is more likely to be safe to use Telnet or Rlogin, but we still
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recommend you use SSH.
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