-#!/bin/sh -e
+#!/usr/bin/env bash
-# MonkeySphere ssh ProxyCommand hook
-# Proxy command script to initiate a monkeysphere known_hosts update
-# before an ssh connection to host is established.
-# Can be added to ~/.ssh/config as follows:
-# ProxyCommand monkeysphere-ssh-proxycommand %h %p
+# monkeysphere-ssh-proxycommand: MonkeySphere ssh ProxyCommand hook
+#
+# The monkeysphere scripts are written by:
+# Jameson Rollins <jrollins@fifthhorseman.net>
+#
+# They are Copyright 2008, and are all released under the GPL, version 3
+# or later.
+
+# This is meant to be run as an ssh ProxyCommand to initiate a
+# monkeysphere known_hosts update before an ssh connection to host is
+# established. Can be added to ~/.ssh/config as follows:
+# ProxyCommand monkeysphere-ssh-proxycommand %h %p
+
+########################################################################
+
+usage() {
+cat <<EOF >&2
+usage: ssh -o ProxyCommand="$(basename $0) %h %p" ...
+EOF
+}
+
+########################################################################
+
+# export the monkeysphere log level
+export MONKEYSPHERE_LOG_LEVEL
+
+if [ "$1" = '--no-connect' ] ; then
+ NO_CONNECT='true'
+ shift 1
+fi
HOST="$1"
PORT="$2"
+if [ -z "$HOST" ] ; then
+ echo "Host not specified." >&2
+ usage
+ exit 255
+fi
+if [ -z "$PORT" ] ; then
+ PORT=22
+fi
+
+# set the host URI
+if [ "$PORT" != '22' ] ; then
+ HOSTP="${HOST}:${PORT}"
+else
+ HOSTP="${HOST}"
+fi
+URI="ssh://${HOSTP}"
+
+# specify keyserver checking. the behavior of this proxy command is
+# intentionally different than that of running monkeyesphere normally,
+# and keyserver checking is intentionally done under certain
+# circumstances. This can be overridden by setting the
+# MONKEYSPHERE_CHECK_KEYSERVER environment variable.
+
+# if the host is in the gpg keyring...
+if gpg --list-key ="${URI}" 2>&1 >/dev/null ; then
+ # do not check the keyserver
+ CHECK_KEYSERVER="false"
+
+# if the host is NOT in the keyring...
+else
+ # if the host key is found in the known_hosts file...
+ # FIXME: this only works for default known_hosts location
+ hostKey=$(ssh-keygen -F "$HOST" 2>/dev/null)
+
+ if [ "$hostKey" ] ; then
+ # do not check the keyserver
+ # FIXME: more nuanced checking should be done here to properly
+ # take into consideration hosts that join monkeysphere by
+ # converting an existing and known ssh key
+ CHECK_KEYSERVER="false"
+
+ # if the host key is not found in the known_hosts file...
+ else
+ # check the keyserver
+ CHECK_KEYSERVER="true"
+ fi
+fi
+# set and export the variable for use by monkeysphere
+MONKEYSPHERE_CHECK_KEYSERVER=${MONKEYSPHERE_CHECK_KEYSERVER:="$CHECK_KEYSERVER"}
+export MONKEYSPHERE_CHECK_KEYSERVER
+
# update the known_hosts file for the host
-monkeysphere update-known-hosts "$HOST"
+monkeysphere update-known_hosts "$HOSTP"
-# make a netcat connection to host for the ssh connection
-exec nc "$HOST" "$PORT"
+# exec a netcat passthrough to host for the ssh connection
+if [ -z "$NO_CONNECT" ] ; then
+ if (which nc 2>/dev/null >/dev/null); then
+ exec nc "$HOST" "$PORT"
+ elif (which socat 2>/dev/null >/dev/null); then
+ exec socat STDIO "TCP:$HOST:$PORT"
+ else
+ echo "Neither netcat nor socat found -- could not complete monkeysphere-ssh-proxycommand connection to $HOST:$PORT" >&2
+ exit 255
+ fi
+fi