# established. Can be added to ~/.ssh/config as follows:
# ProxyCommand monkeysphere ssh-proxycommand %h %p
+# output the key info, including the RSA fingerprint
+show_key_info() {
+ local keyid="$1"
+ local sshKeyGPGFile
+ local sshFingerprint
+ local gpgSigOut
+ local otherUids
+
+ # get the ssh key of the gpg key
+ sshKeyGPGFile=$(msmktempfile)
+ gpg2ssh "$keyid" >"$sshKeyGPGFile"
+ sshFingerprint=$(ssh-keygen -l -f "$sshKeyGPGFile" | \
+ awk '{ print $2 }')
+ rm -f "$sshKeyGPGFile"
+
+ # get the sigs for the matching key
+ gpgSigOut=$(gpg_user --check-sigs \
+ --list-options show-uid-validity \
+ "$keyid")
+
+ echo | log info
+
+ # output the sigs, but only those on the user ID
+ # we are looking for
+ echo "$gpgSigOut" | awk '
+{
+if (match($0,"^pub")) { print; }
+if (match($0,"^uid")) { ok=0; }
+if (match($0,"^uid.*'$userID'$")) { ok=1; print; }
+if (ok) { if (match($0,"^sig")) { print; } }
+}
+'
+
+ # output ssh fingerprint
+ cat <<EOF
+RSA key fingerprint is ${sshFingerprint}.
+EOF
+
+ # output the other user IDs for reference
+ otherUids=$(echo "$gpgSigOut" | grep "^uid" | grep -v "$userID")
+ if [ "$otherUids" ] ; then
+ log info <<EOF
+Other user IDs on this key:
+EOF
+ echo "$otherUids" | log info
+ fi
+
+}
+
# "marginal case" ouput in the case that there is not a full
# validation path to the host
output_no_valid_key() {
- local sshKeyOffered
local userID
+ local sshKeyOffered
+ local gpgOut
local type
local validity
local keyid
local usage
local sshKeyGPG
local tmpkey
- local sshFingerprint
- local gpgSigOut
+ local returnCode=0
userID="ssh://${HOSTP}"
- cat <<EOF | log info
--------------------- Monkeysphere warning -------------------
-Monkeysphere found OpenPGP keys for this hostname, but none had full validity.
-EOF
+ LOG_PREFIX=
- # retrieve the actual ssh key
- sshKeyOffered=$(ssh-keyscan -t rsa -p "$PORT" "$HOST" 2>/dev/null | awk '{ print $2, $3 }')
- # FIXME: should we do any checks for failed keyscans, eg. host not
- # found?
+ # retrieve the ssh key being offered by the host
+ sshKeyOffered=$(ssh-keyscan -t rsa -p "$PORT" "$HOST" 2>/dev/null \
+ | awk '{ print $2, $3 }')
# get the gpg info for userid
gpgOut=$(gpg_user --list-key --fixed-list-mode --with-colon \
--with-fingerprint --with-fingerprint \
="$userID" 2>/dev/null)
+ # output header
+ log info <<EOF
+-------------------- Monkeysphere warning -------------------
+Monkeysphere found OpenPGP keys for this hostname, but none had full validity.
+EOF
+
+ # output message if host key could not be retrieved from the host
+ if [ -z "$sshKeyOffered" ] ; then
+ log info <<EOF
+Could not retrieve RSA host key from $HOST.
+The following keys were found with marginal validity:
+EOF
+ fi
+
# find all 'pub' and 'sub' lines in the gpg output, which each
# represent a retrieved key for the user ID
echo "$gpgOut" | cut -d: -f1,2,5,10,12 | \
# 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
- cat <<EOF | log info
-An OpenPGP key matching the ssh key offered by the host was found:
+ # if a key was retrieved from the host...
+ if [ "$sshKeyOffered" ] ; then
+ # if one of keys found matches the one offered by the
+ # host, then output info
+ if [ "$sshKeyGPG" = "$sshKeyOffered" ] ; then
+ log info <<EOF
+An OpenPGP key matching the ssh key offered by the host was found:
EOF
- sshKeyGPGFile=$(msmktempfile)
- printf "%s" "$sshKeyGPG" >"$sshKeyGPGFile"
- sshFingerprint=$(ssh-keygen -l -f "$sshKeyGPGFile" \
- awk '{ print $2 }')
- rm -f "$sshKeyGPGFile"
+ show_key_info "$keyid" | log info
- # get the sigs for the matching key
- gpgSigOut=$(gpg_user --check-sigs \
- --list-options show-uid-validity \
- "$keyid")
-
- # output the sigs, but only those on the user ID
- # we are looking for
- echo "$gpgSigOut" | awk '
-{
-if (match($0,"^pub")) { print; }
-if (match($0,"^uid")) { ok=0; }
-if (match($0,"^uid.*'$userID'$")) { ok=1; print; }
-if (ok) { if (match($0,"^sig")) { print; } }
-}
-' | log info
- echo | log info
-
- # output the other user IDs for reference
- if (echo "$gpgSigOut" | grep "^uid" | grep -v -q "$userID") ; then
- cat <<EOF | log info
-Other user IDs on this key:
-
-EOF
- echo "$gpgSigOut" | grep "^uid" | grep -v "$userID" | log info
- echo | log info
+ # this whole process is in a "while read"
+ # subshell. the only way to get information
+ # out of the subshell is to change the return
+ # code. therefore we return 1 here to
+ # indicate that a matching gpg key was found
+ # for the ssh key offered by the host
+ return 1
fi
- # output ssh fingerprint
- cat <<EOF | log info
-RSA key fingerprint is ${sshFingerprint}.
-EOF
+ # else if a key was not retrieved from the host
+ else
+
+ # if the current key is marginal, show info
+ if [ "$validity" = 'm' -o "$validity" = 'f' ] ; then
+ show_key_info "$keyid" | log info
+ fi
- # this whole process is in a "while read"
- # subshell. the only way to get information out
- # of the subshell is to change the return code.
- # therefore we return 1 here to indicate that a
- # matching gpg key was found for the ssh key
- # offered by the host
- return 1
fi
;;
esac
- done
+ done || returnCode="$?"
+
+ # if no key match was made (and the "while read" subshell
+ # returned 1) output how many keys were found
+ if (( returnCode != 1 )) ; then
+
+ echo | log info
- # if no key match was made (and the "while read" subshell returned
- # 1) output how many keys were found
- if (($? != 1)) ; then
- cat <<EOF | log info
+ # output different footer messages depending on if a key had
+ # been retrieved from the host
+ if [ "$sshKeyOffered" ] ; then
+ log info <<EOF
None of the found keys matched the key offered by the host.
+EOF
+ else
+ log info <<EOF
+There may be other keys with less than marginal validity for this hostname.
+EOF
+ fi
+
+ log info <<EOF
Run the following command for more info about the found keys:
gpg --check-sigs --list-options show-uid-validity =${userID}
EOF
# prompted?
fi
- cat <<EOF | log info
+ # output footer
+ log info <<EOF
-------------------- ssh continues below --------------------
EOF
}
# CHECK_KEYSERVER variable in the monkeysphere.conf file.
# if the host is in the gpg keyring...
-if gpg_user --list-key ="${URI}" 2>&1 >/dev/null ; then
+if gpg_user --list-key ="${URI}" &>/dev/null ; then
# do not check the keyserver
CHECK_KEYSERVER=${CHECK_KEYSERVER:="false"}
CHECK_KEYSERVER=${MONKEYSPHERE_CHECK_KEYSERVER:=$CHECK_KEYSERVER}
# update the known_hosts file for the host
-update_known_hosts "$HOSTP"
+local returnCode=0
+update_known_hosts "$HOSTP" || returnCode="$?"
# 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 $? in
+case "$returnCode" in
0)
# acceptable host key found so continue to ssh
true
# exec a netcat passthrough to host for the ssh connection
if [ -z "$NO_CONNECT" ] ; then
- if (which nc 2>/dev/null >/dev/null); then
+ if (type nc &>/dev/null); then
exec nc "$HOST" "$PORT"
- elif (which socat 2>/dev/null >/dev/null); then
+ elif (type socat &>/dev/null); then
exec socat STDIO "TCP:$HOST:$PORT"
else
echo "Neither netcat nor socat found -- could not complete monkeysphere-ssh-proxycommand connection to $HOST:$PORT" >&2
projects / monkeysphere.git / blobdiff