really fix the ssh_host_rsa_key.pub.gpg output.

[monkeysphere.git] / src / monkeysphere-ssh-proxycommand

diff --git a/src/monkeysphere-ssh-proxycommand b/src/monkeysphere-ssh-proxycommand
index a7b87ca76f9abff956e1f8a1ea885f963332c2c0..aeea30dcd976dbaef5770e317f41135ef879d7aa 100755 (executable)
--- a/src/monkeysphere-ssh-proxycommand
+++ b/src/monkeysphere-ssh-proxycommand
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # monkeysphere-ssh-proxycommand: MonkeySphere ssh ProxyCommand hook
 #
@@ -13,14 +13,88 @@
 # 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
 }
 
+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
@@ -35,7 +109,7 @@ HOST="$1"
 PORT="$2"
 
 if [ -z "$HOST" ] ; then
-    echo "Host not specified." >&2
+    log "Host not specified."
     usage
     exit 255
 fi
@@ -88,6 +162,30 @@ export MONKEYSPHERE_CHECK_KEYSERVER
 # update the known_hosts file for the host
 monkeysphere update-known_hosts "$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
     if (which nc 2>/dev/null >/dev/null); then