#!/usr/bin/env bash # monkeysphere: MonkeySphere client tool # # The monkeysphere scripts are written by: # Jameson Rollins <jrollins@fifthhorseman.net> # Jamie McClelland <jm@mayfirst.org> # Daniel Kahn Gillmor <dkg@fifthhorseman.net> # # They are Copyright 2008, and are all released under the GPL, version 3 # or later. ######################################################################## PGRM=$(basename $0) SHARE=${MONKEYSPHERE_SHARE:-"/usr/share/monkeysphere"} export SHARE . "${SHARE}/common" || exit 1 # UTC date in ISO 8601 format if needed DATE=$(date -u '+%FT%T') # unset some environment variables that could screw things up unset GREP_OPTIONS # default return code RETURN=0 # set the file creation mask to be only owner rw umask 077 ######################################################################## # FUNCTIONS ######################################################################## usage() { cat <<EOF >&2 usage: $PGRM <subcommand> [options] [args] MonkeySphere client tool. subcommands: update-known_hosts (k) [HOST]... update known_hosts file update-authorized_keys (a) update authorized_keys file gen-subkey (g) [KEYID] generate an authentication subkey --length (-l) BITS key length in bits (2048) --expire (-e) EXPIRE date to expire subkey-to-ssh-agent (s) store authentication subkey in ssh-agent help (h,?) this help EOF } # generate a subkey with the 'a' usage flags set gen_subkey(){ local keyLength local keyExpire local keyID local gpgOut local userID # set default key parameter values keyLength= keyExpire= # get options TEMP=$(getopt -o l:e: -l length:,expire: -n "$PGRM" -- "$@") if [ $? != 0 ] ; then exit 1 fi # Note the quotes around `$TEMP': they are essential! eval set -- "$TEMP" while true ; do case "$1" in -l|--length) keyLength="$2" shift 2 ;; -e|--expire) keyExpire="$2" shift 2 ;; --) shift ;; *) break ;; esac done if [ -z "$1" ] ; then # find all secret keys keyID=$(gpg --with-colons --list-secret-keys | grep ^sec | cut -f5 -d: | sort -u) # if multiple sec keys exist, fail if (( $(echo "$keyID" | wc -l) > 1 )) ; then echo "Multiple secret keys found:" echo "$keyID" failure "Please specify which primary key to use." fi else keyID="$1" fi if [ -z "$keyID" ] ; then failure "You have no secret key available. You should create an OpenPGP key before joining the monkeysphere. You can do this with: gpg --gen-key" fi # get key output, and fail if not found gpgOut=$(gpg --quiet --fixed-list-mode --list-secret-keys --with-colons \ "$keyID") || failure # fail if multiple sec lines are returned, which means the id # given is not unique if [ $(echo "$gpgOut" | grep -c '^sec:') -gt '1' ] ; then failure "Key ID '$keyID' is not unique." fi # prompt if an authentication subkey already exists if echo "$gpgOut" | egrep "^(sec|ssb):" | cut -d: -f 12 | grep -q a ; then echo "An authentication subkey already exists for key '$keyID'." read -p "Are you sure you would like to generate another one? (y/N) " OK; OK=${OK:N} if [ "${OK/y/Y}" != 'Y' ] ; then failure "aborting." fi fi # set subkey defaults # prompt about key expiration if not specified keyExpire=$(get_gpg_expiration "$keyExpire") # generate the list of commands that will be passed to edit-key editCommands=$(cat <<EOF addkey 7 S E A Q $keyLength $keyExpire save EOF ) log verbose "generating subkey..." fifoDir=$(mktemp -d) (umask 077 && mkfifo "$fifoDir/pass") echo "$editCommands" | gpg --passphrase-fd 3 3< "$fifoDir/pass" --expert --command-fd 0 --edit-key "$keyID" & passphrase_prompt "Please enter your passphrase for $keyID: " "$fifoDir/pass" rm -rf "$fifoDir" wait log verbose "done." } function subkey_to_ssh_agent() { # try to add all authentication subkeys to the agent: local sshaddresponse local secretkeys local authsubkeys local workingdir local keysuccess local subkey local publine local kname if ! test_gnu_dummy_s2k_extension ; then failure "Your version of GnuTLS does not seem capable of using with gpg's exported subkeys. You may want to consider patching or upgrading. For more details, see: http://lists.gnu.org/archive/html/gnutls-devel/2008-08/msg00005.html" fi # if there's no agent running, don't bother: if [ -z "$SSH_AUTH_SOCK" ] || ! which ssh-add >/dev/null ; then failure "No ssh-agent available." fi # and if it looks like it's running, but we can't actually talk to # it, bail out: ssh-add -l >/dev/null sshaddresponse="$?" if [ "$sshaddresponse" = "2" ]; then failure "Could not connect to ssh-agent" fi # get list of secret keys (to work around https://bugs.g10code.com/gnupg/issue945): secretkeys=$(gpg --list-secret-keys --with-colons --fixed-list-mode --fingerprint | \ grep '^fpr:' | cut -f10 -d: | awk '{ print "0x" $1 "!" }') if [ -z "$secretkeys" ]; then failure "You have no secret keys in your keyring! You might want to run 'gpg --gen-key'." fi authsubkeys=$(gpg --list-secret-keys --with-colons --fixed-list-mode \ --fingerprint --fingerprint $secretkeys | \ cut -f1,5,10,12 -d: | grep -A1 '^ssb:[^:]*::[^:]*a[^:]*$' | \ grep '^fpr::' | cut -f3 -d: | sort -u) if [ -z "$authsubkeys" ]; then failure "no authentication-capable subkeys available. You might want to 'monkeysphere gen-subkey'" fi workingdir=$(mktemp -d) umask 077 mkfifo "$workingdir/passphrase" keysuccess=1 # FIXME: we're currently allowing any other options to get passed # through to ssh-add. should we limit it to known ones? For # example: -d or -c and/or -t <lifetime> for subkey in $authsubkeys; do # choose a label by which this key will be known in the agent: # we are labelling the key by User ID instead of by # fingerprint, but filtering out all / characters to make sure # the filename is legit. primaryuid=$(gpg --with-colons --list-key "0x${subkey}!" | grep '^pub:' | cut -f10 -d: | tr -d /) #kname="[monkeysphere] $primaryuid" kname="$primaryuid" if [ "$1" = '-d' ]; then # we're removing the subkey: gpg --export "0x${subkey}!" | openpgp2ssh "$subkey" > "$workingdir/$kname" (cd "$workingdir" && ssh-add -d "$kname") else # we're adding the subkey: mkfifo "$workingdir/$kname" gpg --quiet --passphrase-fd 3 3<"$workingdir/passphrase" \ --export-options export-reset-subkey-passwd,export-minimal,no-export-attributes \ --export-secret-subkeys "0x${subkey}!" | openpgp2ssh "$subkey" > "$workingdir/$kname" & (cd "$workingdir" && DISPLAY=nosuchdisplay SSH_ASKPASS=/bin/false ssh-add "$@" "$kname" </dev/null )& passphrase_prompt "Enter passphrase for key $kname: " "$workingdir/passphrase" wait %2 fi keysuccess="$?" rm -f "$workingdir/$kname" done rm -rf "$workingdir" # FIXME: sort out the return values: we're just returning the # success or failure of the final authentication subkey in this # case. What if earlier ones failed? exit "$keysuccess" } ######################################################################## # MAIN ######################################################################## # unset variables that should be defined only in config file unset KEYSERVER unset CHECK_KEYSERVER unset KNOWN_HOSTS unset HASH_KNOWN_HOSTS unset AUTHORIZED_KEYS # load global config [ -r "${ETC}/monkeysphere.conf" ] && . "${ETC}/monkeysphere.conf" # set monkeysphere home directory MONKEYSPHERE_HOME=${MONKEYSPHERE_HOME:="${HOME}/.monkeysphere"} mkdir -p -m 0700 "$MONKEYSPHERE_HOME" # load local config [ -e ${MONKEYSPHERE_CONFIG:="${MONKEYSPHERE_HOME}/monkeysphere.conf"} ] && . "$MONKEYSPHERE_CONFIG" # set empty config variables with ones from the environment, or from # config file, or with defaults LOG_LEVEL=${MONKEYSPHERE_LOG_LEVEL:=${LOG_LEVEL:="INFO"}} GNUPGHOME=${MONKEYSPHERE_GNUPGHOME:=${GNUPGHOME:="${HOME}/.gnupg"}} KEYSERVER=${MONKEYSPHERE_KEYSERVER:="$KEYSERVER"} # if keyserver not specified in env or monkeysphere.conf, # look in gpg.conf if [ -z "$KEYSERVER" ] ; then if [ -f "${GNUPGHOME}/gpg.conf" ] ; then KEYSERVER=$(grep -e "^[[:space:]]*keyserver " "${GNUPGHOME}/gpg.conf" | tail -1 | awk '{ print $2 }') fi fi # if it's still not specified, use the default KEYSERVER=${KEYSERVER:="subkeys.pgp.net"} CHECK_KEYSERVER=${MONKEYSPHERE_CHECK_KEYSERVER:=${CHECK_KEYSERVER:="true"}} KNOWN_HOSTS=${MONKEYSPHERE_KNOWN_HOSTS:=${KNOWN_HOSTS:="${HOME}/.ssh/known_hosts"}} HASH_KNOWN_HOSTS=${MONKEYSPHERE_HASH_KNOWN_HOSTS:=${HASH_KNOWN_HOSTS:="true"}} AUTHORIZED_KEYS=${MONKEYSPHERE_AUTHORIZED_KEYS:=${AUTHORIZED_KEYS:="${HOME}/.ssh/authorized_keys"}} # other variables not in config file AUTHORIZED_USER_IDS=${MONKEYSPHERE_AUTHORIZED_USER_IDS:="${MONKEYSPHERE_HOME}/authorized_user_ids"} REQUIRED_HOST_KEY_CAPABILITY=${MONKEYSPHERE_REQUIRED_HOST_KEY_CAPABILITY:="a"} REQUIRED_USER_KEY_CAPABILITY=${MONKEYSPHERE_REQUIRED_USER_KEY_CAPABILITY:="a"} # export GNUPGHOME and make sure gpg home exists with proper # permissions export GNUPGHOME mkdir -p -m 0700 "$GNUPGHOME" export LOG_LEVEL # get subcommand COMMAND="$1" [ "$COMMAND" ] || failure "Type '$PGRM help' for usage." shift case $COMMAND in 'update-known_hosts'|'update-known-hosts'|'k') MODE='known_hosts' # check permissions on the known_hosts file path if ! check_key_file_permissions "$USER" "$KNOWN_HOSTS" ; then failure "Improper permissions on known_hosts file path." fi # if hosts are specified on the command line, process just # those hosts if [ "$1" ] ; then update_known_hosts "$@" RETURN="$?" # otherwise, if no hosts are specified, process every host # in the user's known_hosts file else # exit if the known_hosts file does not exist if [ ! -e "$KNOWN_HOSTS" ] ; then log error "known_hosts file '$KNOWN_HOSTS' does not exist." exit fi process_known_hosts RETURN="$?" fi ;; 'update-authorized_keys'|'update-authorized-keys'|'a') MODE='authorized_keys' # check permissions on the authorized_user_ids file path if ! check_key_file_permissions "$USER" "$AUTHORIZED_USER_IDS" ; then failure "Improper permissions on authorized_user_ids file path." fi # check permissions on the authorized_keys file path if ! check_key_file_permissions "$USER" "$AUTHORIZED_KEYS" ; then failure "Improper permissions on authorized_keys file path." fi # exit if the authorized_user_ids file is empty if [ ! -e "$AUTHORIZED_USER_IDS" ] ; then log error "authorized_user_ids file '$AUTHORIZED_USER_IDS' does not exist." exit fi # process authorized_user_ids file process_authorized_user_ids "$AUTHORIZED_USER_IDS" RETURN="$?" ;; 'gen-subkey'|'g') gen_subkey "$@" ;; 'subkey-to-ssh-agent'|'s') subkey_to_ssh_agent "$@" ;; '--help'|'help'|'-h'|'h'|'?') usage ;; *) failure "Unknown command: '$COMMAND' Type '$PGRM help' for usage." ;; esac exit "$RETURN"