path: root/man/man1/monkeysphere-ssh-proxycommand.1

.TH MONKEYSPHERE-SSH-PROXYCOMMAND "1" "June 2008" "monkeysphere 0.1" "User Commands"

.SH NAME

monkeysphere-ssh-proxycommand \- MonkeySphere ssh ProxyCommand script

.SH DESCRIPTION

\fBmonkeysphere-ssh-proxy\fP is an ssh proxy command that can be used
to trigger a monkeysphere update of the ssh known_hosts file for a
host that is being connected to with ssh.  This works by updating the
known_hosts file for the host first, before an attempted connection to
the host is made.  Once the known_hosts file has been updated, a TCP
connection to the host is made by exec'ing netcat(1).  Regular ssh
communication is then done over this netcat TCP connection (see
ProxyCommand in ssh_config(5) for more info).

This command is meant to be run as the ssh "ProxyCommand".  This can
either be done by specifying the proxy command on the command line:

.B ssh -o ProxyCommand="monkeysphere-ssh-proxycommand %h %p" ...

or by adding the following line to your ~/.ssh/config script:

.B ProxyCommand monkeysphere-ssh-proxycommand %h %p

The script can easily be incorporated into other ProxyCommand scripts
by calling it with the "--no-connect" option, i.e.:

.B monkeysphere-ssh-proxycommand --no-connect "$HOST" "$PORT"

This will run everything except the final exec of netcat to make the
TCP connection to the host.  In this way this command can be added to
another proxy command that does other stuff, and then makes the
connection to the host itself.

.SH KEYSERVER CHECKING

The proxy command has a fairly nuanced policy for when keyservers are
queried when processing host.  If the host userID is not found in
either the user's keyring or in the known_hosts file, then the
keyserver is queried for the host userID.  If the host userID is found
in the user's keyring, then the keyserver is not checked.  This
assumes that the keyring is kept up-to-date, in a cronjob or the like,
so that revocations are properly handled.  If the host userID is not
found in the user's keyring, but the host is listed in the known_hosts
file, then the keyserver is not checked.  This last policy might
change in the future, possibly by adding a deferred check, so that
hosts that go from non-monkeysphere-enabled to monkeysphere-enabled
will be properly checked.

.SH ENVIRONMENT VARIABLES

All environment variables defined in monkeysphere(1) can also be used
for the proxy command, with one note:

.TP
MONKEYSPHERE_CHECK_KEYSERVER
Setting this variable (to `true' or `false') will override the policy
defined in KEYSERVER CHECKING above.

.SH AUTHOR

Written by Jameson Rollins <jrollins@fifthhorseman.net>

.SH SEE ALSO

.BR monkeysphere (1),
.BR ssh (1),
.BR ssh_config (5),
.BR netcat (1),
.BR gpg (1)