X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=src%2Fmonkeysphere-ssh-proxycommand;h=b03984449316d039ba1d971d221be60a2496ff88;hb=5d9949335aeb1dec04f530cbb3dfcac24288706a;hp=17249667879ca7e5b6f37eb7d314a1ba89e35f9d;hpb=4793624c65673268128fb0146cd9bd1b3cfeb6c4;p=monkeysphere.git

diff --git a/src/monkeysphere-ssh-proxycommand b/src/monkeysphere-ssh-proxycommand
index 1724966..b039844 100755
--- a/src/monkeysphere-ssh-proxycommand
+++ b/src/monkeysphere-ssh-proxycommand
@@ -1,16 +1,195 @@
-#!/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
+
+########################################################################
+PGRM=$(basename $0)
+
+SYSSHAREDIR=${MONKEYSPHERE_SYSSHAREDIR:-"/usr/share/monkeysphere"}
+export SYSSHAREDIR
+. "${SYSSHAREDIR}/common" || exit 1
+
+########################################################################
+# FUNCTIONS
+########################################################################
+
+usage() {
+    cat <<EOF >&2
+usage: ssh -o ProxyCommand="$(basename $0) %h %p" ...
+EOF
+}
+
+log() {
+    echo "$@" >&2
+}
+
+output_no_valid_key() {
+    local sshKeyOffered
+    local userID
+    local type
+    local validity
+    local keyid
+    local uidfpr
+    local usage
+    local sshKeyGPG
+    local sshFingerprint
+
+    log "OpenPGP keys with*out* full validity found for this host:"
+    log
+
+    # retrieve the actual ssh key
+    sshKeyOffered=$(ssh-keyscan -t rsa -p "$PORT" "$HOST" 2>/dev/null | awk '{ print $2, $3 }')
+
+    userID="ssh://${HOSTP}"
+
+    # output gpg info for (exact) userid and store
+    gpgOut=$(gpg --list-key --fixed-list-mode --with-colon \
+	--with-fingerprint --with-fingerprint \
+	="$userID" 2>/dev/null)
+
+    # loop over all lines in the gpg output and process.
+    echo "$gpgOut" | cut -d: -f1,2,5,10,12 | \
+    while IFS=: read -r type validity keyid uidfpr usage ; do
+	case $type in
+	    'pub'|'sub')
+		# get the ssh key of the gpg key
+		sshKeyGPG=$(gpg2ssh "$keyid")
+
+		# if one of keys found matches the one offered by the
+		# host, then output info
+		if [ "$sshKeyGPG" = "$sshKeyOffered" ] ; then
+
+		    # get the fingerprint of the ssh key
+		    tmpkey=$(mktemp ${TMPDIR:-/tmp}/tmp.XXXXXXXXXX)
+		    echo "$sshKeyGPG" > "$tmpkey"
+		    sshFingerprint=$(ssh-keygen -l -f "$tmpkey" | awk '{ print $2 }')
+		    rm -rf "$tmpkey"
+
+		    # output gpg info
+		    gpg --check-sigs \
+			--list-options show-uid-validity \
+			"$keyid" >&2
+
+		    # output ssh fingerprint
+		    log "RSA key fingerprint is ${sshFingerprint}."
+		    log "Falling through to standard ssh host checking."
+		    log
+		fi
+		;;
+	esac
+    done
+}
+
+########################################################################
+
+# 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 "$HOST" ] ; then
+    log "Host not specified."
+    usage
+    exit 255
+fi
+if [ -z "$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"
+
+# output on depending on the return of the update-known_hosts
+# subcommand, which is (ultimately) the return code of the
+# update_known_hosts function in common
+case $? in
+    0)
+	# acceptable host key found so continue to ssh
+	true
+	;;
+    1)
+	# no hosts at all found so also continue (drop through to
+	# regular ssh host verification)
+	true
+	;;
+    2)
+	# at least one *bad* host key (and no good host keys) was
+	# found, so output some usefull information
+	output_no_valid_key
+	;;
+    *)
+	# anything else drop through
+	true
+	;;
+esac
 
-# 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