X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=src%2Fmonkeysphere-ssh-proxycommand;h=aeea30dcd976dbaef5770e317f41135ef879d7aa;hb=11a42a66941cc1bb4c1268895ac4522ecb5fb6e6;hp=15153d8d2a112d5baf9c1e926eac943da67df388;hpb=f5409b72c5635ff77c2cd49422206b14b2827893;p=monkeysphere.git

diff --git a/src/monkeysphere-ssh-proxycommand b/src/monkeysphere-ssh-proxycommand
index 15153d8..aeea30d 100755
--- a/src/monkeysphere-ssh-proxycommand
+++ b/src/monkeysphere-ssh-proxycommand
@@ -1,4 +1,4 @@
-#!/bin/sh -e
+#!/usr/bin/env bash
 
 # monkeysphere-ssh-proxycommand: MonkeySphere ssh ProxyCommand hook
 #
@@ -13,8 +13,19 @@
 # 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
+. "${SYSSHAREDIR}/common" || exit 1
+
+########################################################################
+# FUNCTIONS
+########################################################################
+
 usage() {
-cat <<EOF >&2
+    cat <<EOF >&2
 usage: ssh -o ProxyCommand="$(basename $0) %h %p" ...
 EOF
 }
@@ -23,6 +34,72 @@ log() {
     echo "$@" >&2
 }
 
+output_no_valid_key() {
+    local sshKeyOffered
+    local userID
+    local type
+    local validity
+    local keyid
+    local uidfpr
+    local usage
+    local sshKeyGPG
+    local sshFingerprint
+
+    userID="ssh://${HOSTP}"
+
+    log "Monkeysphere found only OpenPGP keys for this host with*out* full validity."
+    log "host:                $userID"
+    log
+
+    # retrieve the actual ssh key
+    sshKeyOffered=$(ssh-keyscan -t rsa -p "$PORT" "$HOST" 2>/dev/null | awk '{ print $2, $3 }')
+    # FIXME: should we do any checks for failed keyscans, eg host not
+    # found?
+
+    # output gpg info for userid and store
+    gpgOut=$(gpg --list-key --fixed-list-mode --with-colon \
+	--with-fingerprint --with-fingerprint \
+	="$userID" 2>/dev/null)
+
+    # find all 'pub' and 'sub' lines in the gpg output, which each
+    # represent a retrieved key for the user ID
+    echo "$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
@@ -31,22 +108,28 @@ fi
 HOST="$1"
 PORT="$2"
 
-MS_HOME=${MS_HOME:-"${HOME}/.config/monkeysphere"}
-
 if [ -z "$HOST" ] ; then
-    log "host must be specified."
+    log "Host not specified."
     usage
-    exit 1
+    exit 255
 fi
 if [ -z "$PORT" ] ; then
     PORT=22
 fi
 
 # set the host URI
-URI="ssh://${HOST}"
 if [ "$PORT" != '22' ] ; then
-    URI="${URI}:${PORT}"
+    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 ="${URI}" 2>&1 >/dev/null ; then
@@ -57,7 +140,8 @@ if gpg --list-key ="${URI}" 2>&1 >/dev/null ; then
 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")
+    hostKey=$(ssh-keygen -F "$HOST" 2>/dev/null)
+
     if [ "$hostKey" ] ; then
 	# do not check the keyserver
 	# FIXME: more nuanced checking should be done here to properly
@@ -71,12 +155,45 @@ else
 	CHECK_KEYSERVER="true"
     fi
 fi
-export CHECK_KEYSERVER
+# set and export the variable for use by monkeysphere
+MONKEYSPHERE_CHECK_KEYSERVER=${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
 
 # exec a netcat passthrough to host for the ssh connection
 if [ -z "$NO_CONNECT" ] ; then
-    exec nc "$HOST" "$PORT"
+    if (which nc 2>/dev/null >/dev/null); then
+	exec nc "$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