Add the missing psftp-pubkey section, shamelessly cribbed from the

corresponding section in the PSCP chapter.

[originally from svn r1487]

doc/psftp.but

@@ -1,4 +1,4 @@
-\versionid $Id: psftp.but,v 1.1 2001/12/14 12:15:43 simon Exp $
+\versionid $Id: psftp.but,v 1.2 2001/12/14 12:22:09 simon Exp $
 
 \C{psftp} Using PSFTP to transfer files securely
 
@@ -362,3 +362,31 @@ name, and then the new file name:
 
 The \c{rename} and \c{mv} commands work exactly the same way as
 \c{ren}.
+
+\H{psftp-pubkey} Using public key authentication with PSFTP
+
+Like PuTTY, PSFTP can authenticate using a public key instead of a
+password. There are two ways you can do this.
+
+Firstly, PSFTP can use PuTTY saved sessions in place of hostnames.
+So you might do this:
+
+\b Run PuTTY, and create a PuTTY saved session (see
+\k{config-saving}) which specifies your private key file (see
+\k{config-ssh-privkey}). You will probably also want to specify a
+username to log in as (see \k{config-username}).
+
+\b In PSFTP, you can now use the name of the session instead of a
+hostname: type \c{psftp sessionname}, where \c{sessionname} is
+replaced by the name of your saved session.
+
+Secondly, PSFTP will attempt to authenticate using Pageant if Pageant
+is running (see \k{pageant}). So you would do this:
+
+\b Ensure Pageant is running, and has your private key stored in it.
+
+\b Specify a user and host name to PSFTP as normal. PSFTP will
+automatically detect Pageant and try to use the keys within it.
+
+For more general information on public-key authentication, see
+\k{pubkey}.