-\versionid $Id: pageant.but,v 1.7 2001/12/20 15:27:40 simon Exp $
+\define{versionidpageant} \versionid $Id$
-\C{pageant} Using Pageant for authentication
+\C{pageant} Using \i{Pageant} for authentication
\cfg{winhelp-topic}{pageant.general}
-Pageant is an SSH authentication agent. It holds your private keys
-in memory, already decoded, so that you can use them often without
-needing to type a passphrase.
+Pageant is an SSH \i{authentication agent}. It holds your \i{private key}s
+in memory, already decoded, so that you can use them often
+\I{passwordless login}without needing to type a \i{passphrase}.
\H{pageant-start} Getting started with Pageant
-Before you run Pageant, you need to have a private key. See
-\k{pubkey} to find out how to generate and use one.
+Before you run Pageant, you need to have a private key in \c{*.\i{PPK}}
+format. See \k{pubkey} to find out how to generate and use one.
When you run Pageant, it will put an icon of a computer wearing a
-hat into the System tray. It will then sit and do nothing, until you
+hat into the \ii{System tray}. It will then sit and do nothing, until you
load a private key into it.
If you click the Pageant icon with the right mouse button, you will
open as many PuTTY sessions as you like without having to type your
passphrase again.
+(PuTTY can be configured not to try to use Pageant, but it will try
+by default. See \k{config-ssh-tryagent} and
+\k{using-cmdline-agentauth} for more information.)
+
When you want to shut down Pageant, click the right button on the
Pageant icon in the System tray, and select \q{Exit} from the menu.
Closing the Pageant main window does \e{not} shut down Pageant.
that are currently loaded into Pageant. The list might look
something like this:
-\c ssh1 1024 22:c3:68:3b:09:41:36:c3:39:83:91:ae:71:b2:0f:04 key1
-\c ssh-rsa 1023 74:63:08:82:95:75:e1:7c:33:31:bb:cb:00:c0:89:8b key2
+\c ssh1 1024 22:c3:68:3b:09:41:36:c3:39:83:91:ae:71:b2:0f:04 k1
+\c ssh-rsa 1023 74:63:08:82:95:75:e1:7c:33:31:bb:cb:00:c0:89:8b k2
For each key, the list box will tell you:
\b The type of the key. Currently, this can be \c{ssh1} (an RSA key
-for use with the SSH v1 protocol), \c{ssh-rsa} (an RSA key for use
-with the SSH v2 protocol), or \c{ssh-dss} (a DSA key for use with
-the SSH v2 protocol).
+for use with the SSH-1 protocol), \c{ssh-rsa} (an RSA key for use
+with the SSH-2 protocol), or \c{ssh-dss} (a DSA key for use with
+the SSH-2 protocol).
\b The size (in bits) of the key.
-\b The fingerprint for the public key. This should be the same
-fingerprint given by PuTTYgen, and (hopefully) also the same
-fingerprint shown by remote utilities such as \c{ssh-keygen} when
+\b The \I{key fingerprint}fingerprint for the public key. This should be
+the same fingerprint given by PuTTYgen, and (hopefully) also the same
+fingerprint shown by remote utilities such as \i\c{ssh-keygen} when
applied to your \c{authorized_keys} file.
\b The comment attached to the key.
\H{pageant-cmdline} The Pageant command line
Pageant can be made to do things automatically when it starts up, by
-specifying instructions on its command line. If you're starting
-Pageant from the Windows GUI, you can arrange this by editing the
-properties of the Windows shortcut that it was started from.
+\I{command-line arguments}specifying instructions on its command line.
+If you're starting Pageant from the Windows GUI, you can arrange this
+by editing the properties of the \i{Windows shortcut} that it was
+started from.
+
+If Pageant is already running, invoking it again with the options
+below causes actions to be performed with the existing instance, not a
+new one.
\S{pageant-cmdline-loadkey} Making Pageant automatically load keys
on startup
starts up, if you provide them on the Pageant command line. Your
command line might then look like:
-\c C:\PuTTY\pageant.exe d:\main.key d:\secondary.key
+\c C:\PuTTY\pageant.exe d:\main.ppk d:\secondary.ppk
If the keys are stored encrypted, Pageant will request the
passphrases on startup.
+If Pageant is already running, this syntax loads keys into the
+existing Pageant.
+
\S{pageant-cmdline-command} Making Pageant run another program
You can arrange for Pageant to start another program once it has
Plink, or whatever) will then be able to use the keys Pageant has
loaded.
-You do this by specifying the \c{-c} option followed by the command,
-like this:
+You do this by specifying the \I{-c-pageant}\c{-c} option followed
+by the command, like this:
-\c C:\PuTTY\pageant.exe d:\main.key -c C:\PuTTY\putty.exe
+\c C:\PuTTY\pageant.exe d:\main.ppk -c C:\PuTTY\putty.exe
-\H{pageant-forward} Using agent forwarding
+\H{pageant-forward} Using \i{agent forwarding}
Agent forwarding is a mechanism that allows applications on your SSH
server machine to talk to the agent on your client machine.
-Note that at present, agent forwarding in SSH2 is only available
-when your SSH server is OpenSSH. The \cw{ssh.com} server uses a
-different agent protocol which they have not published. If you would
-like PuTTY to be able to support agent forwarding to an \cw{ssh.com}
-server, please write to \cw{ssh.com} and explain to them that they
-are hurting themselves and their users by keeping their protocol
-secret.
+Note that at present, agent forwarding in SSH-2 is only available
+when your SSH server is \i{OpenSSH}. The \i\cw{ssh.com} server uses a
+different agent protocol, which PuTTY does not yet support.
To enable agent forwarding, first start Pageant. Then set up a PuTTY
SSH session in which \q{Allow agent forwarding} is enabled (see
-\k{config-ssh-agentfwd}). Open the session as normal.
+\k{config-ssh-agentfwd}). Open the session as normal. (Alternatively,
+you can use the \c{-A} command line option; see
+\k{using-cmdline-agent} for details.)
If this has worked, your applications on the server should now have
access to a Unix domain socket which the SSH server will forward
In addition, if you have a private key on one of the SSH servers,
you can send it all the way back to Pageant using the local
-\c{ssh-add} command:
+\i\c{ssh-add} command:
\c unixbox:~$ ssh-add ~/.ssh/id_rsa
\c Need passphrase for /home/fred/.ssh/id_rsa
\H{pageant-security} Security considerations
-Using Pageant for public-key authentication gives you the
+\I{security risk}Using Pageant for public-key authentication gives you the
convenience of being able to open multiple SSH sessions without
having to type a passphrase every time, but also gives you the
security benefit of never storing a decrypted private key on disk.
for two reasons:
\b Windows unfortunately provides no way to protect pieces of memory
-from being written to the system swap file. So if Pageant is holding
+from being written to the system \i{swap file}. So if Pageant is holding
your private keys for a long period of time, it's possible that
decrypted private key data may be written to the system swap file,
and an attacker who gained access to your hard disk later on might
However, the sysadmin of the server machine can always pretend to be
you \e{on that machine}. So if you forward your agent to a server
machine, then the sysadmin of that machine can access the forwarded
-agent connection and request signatures from your public keys, and
+agent connection and request signatures from your private keys, and
can therefore log in to other machines as you. They can only do this
to a limited extent - when the agent forwarding disappears they lose
the ability - but using Pageant doesn't actually \e{prevent} the
projects / u / mdw / putty / blobdiff