X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=src%2Fmonkeysphere-server;h=0a2f04b00bcb9624b7b4fdfba23bfb197d339bf2;hb=dda1c93bc94daa24bf7b0f5671f8a222c0089efd;hp=a198c33c762e7dd005f7c2f80e164cc662c6d7b2;hpb=7d02db7106da26f7705563297544a4ba1edfc71b;p=monkeysphere.git diff --git a/src/monkeysphere-server b/src/monkeysphere-server index a198c33..0a2f04b 100755 --- a/src/monkeysphere-server +++ b/src/monkeysphere-server @@ -11,9 +11,9 @@ ######################################################################## PGRM=$(basename $0) -SHARE=${SHARE:-"/usr/share/monkeysphere"} +SHARE=${MONKEYSPHERE_SHARE:="/usr/share/monkeysphere"} export SHARE -. "${SHARE}/common" +. "${SHARE}/common" || exit 1 VARLIB="/var/lib/monkeysphere" export VARLIB @@ -22,10 +22,10 @@ export VARLIB DATE=$(date -u '+%FT%T') # unset some environment variables that could screw things up -GREP_OPTIONS= +unset GREP_OPTIONS # default return code -ERR=0 +RETURN=0 ######################################################################## # FUNCTIONS @@ -33,39 +33,252 @@ ERR=0 usage() { cat < [args] +usage: $PGRM [options] [args] MonkeySphere server admin tool. subcommands: - update-users (u) [USER]... update users authorized_keys files - gen-key (g) [HOSTNAME] generate gpg key for the server - show-fingerprint (f) show server's host key fingerprint - publish-key (p) publish server's host key to keyserver - trust-key (t) KEYID [LEVEL] set owner trust for keyid - help (h,?) this help - + update-users (u) [USER]... update user authorized_keys files + + gen-key (g) [HOSTNAME] generate gpg key for the server + -l|--length BITS key length in bits (2048) + -e|--expire EXPIRE date to expire + -r|--revoker FINGERPRINT add a revoker + show-fingerprint (f) show server's host key fingerprint + publish-key (p) publish server's host key to keyserver + diagnostics (d) report on the server's monkeysphere status + + add-identity-certifier (a) KEYID import and tsign a certification key + -n|--domain DOMAIN limit ID certifications to IDs in DOMAIN + -t|--trust TRUST trust level of certifier (full) + -d|--depth DEPTH trust depth for certifier (1) + remove-identity-certifier (r) KEYID remove a certification key + list-identity-certifiers (l) list certification keys + + gpg-authentication-cmd CMD gnupg-authentication command + + help (h,?) this help EOF } +su_monkeysphere_user() { + su --preserve-environment "$MONKEYSPHERE_USER" -- -c "$@" +} + +# function to interact with the host gnupg keyring +gpg_host() { + local returnCode + + GNUPGHOME="$GNUPGHOME_HOST" + export GNUPGHOME + + # NOTE: we supress this warning because we need the monkeysphere + # user to be able to read the host pubring. we realize this might + # be problematic, but it's the simplest solution, without too much + # loss of security. + gpg --no-permission-warning "$@" + returnCode="$?" + + # always reset the permissions on the host pubring so that the + # monkeysphere user can read the trust signatures + chgrp "$MONKEYSPHERE_USER" "${GNUPGHOME_HOST}/pubring.gpg" + chmod g+r "${GNUPGHOME_HOST}/pubring.gpg" + + return "$returnCode" +} + +# function to interact with the authentication gnupg keyring +# FIXME: this function requires basically accepts only a single +# argument because of problems with quote expansion. this needs to be +# fixed/improved. +gpg_authentication() { + GNUPGHOME="$GNUPGHOME_AUTHENTICATION" + export GNUPGHOME + + su_monkeysphere_user "gpg $@" +} + +# update authorized_keys for users +update_users() { + if [ "$1" ] ; then + # get users from command line + unames="$@" + else + # or just look at all users if none specified + unames=$(getent passwd | cut -d: -f1) + fi + + # set mode + MODE="authorized_keys" + + # set gnupg home + GNUPGHOME="$GNUPGHOME_AUTHENTICATION" + + # check to see if the gpg trust database has been initialized + if [ ! -s "${GNUPGHOME}/trustdb.gpg" ] ; then + failure "GNUPG trust database uninitialized. Please see MONKEYSPHERE-SERVER(8)." + fi + + # make sure the authorized_keys directory exists + mkdir -p "${VARLIB}/authorized_keys" + + # loop over users + for uname in $unames ; do + # check all specified users exist + if ! getent passwd "$uname" >/dev/null ; then + log "----- unknown user '$uname' -----" + continue + fi + + # set authorized_user_ids and raw authorized_keys variables, + # translating ssh-style path variables + authorizedUserIDs=$(translate_ssh_variables "$uname" "$AUTHORIZED_USER_IDS") + rawAuthorizedKeys=$(translate_ssh_variables "$uname" "$RAW_AUTHORIZED_KEYS") + + # if neither is found, skip user + if [ ! -s "$authorizedUserIDs" ] ; then + if [ "$rawAuthorizedKeys" = '-' -o ! -s "$rawAuthorizedKeys" ] ; then + continue + fi + fi + + log "----- user: $uname -----" + + # exit if the authorized_user_ids file is empty + if ! check_key_file_permissions "$uname" "$AUTHORIZED_USER_IDS" ; then + log "Improper permissions on authorized_user_ids file path." + continue + fi + + # check permissions on the authorized_keys file path + if ! check_key_file_permissions "$uname" "$RAW_AUTHORIZED_KEYS" ; then + log "Improper permissions on authorized_keys file path path." + continue + fi + + # make temporary directory + TMPDIR=$(mktemp -d) + + # trap to delete temporary directory on exit + trap "rm -rf $TMPDIR" EXIT + + # create temporary authorized_user_ids file + TMP_AUTHORIZED_USER_IDS="${TMPDIR}/authorized_user_ids" + touch "$TMP_AUTHORIZED_USER_IDS" + + # create temporary authorized_keys file + AUTHORIZED_KEYS="${TMPDIR}/authorized_keys" + touch "$AUTHORIZED_KEYS" + + # set restrictive permissions on the temporary files + # FIXME: is there a better way to do this? + chmod 0700 "$TMPDIR" + chmod 0600 "$AUTHORIZED_KEYS" + chmod 0600 "$TMP_AUTHORIZED_USER_IDS" + chown -R "$MONKEYSPHERE_USER" "$TMPDIR" + + # if the authorized_user_ids file exists... + if [ -s "$authorizedUserIDs" ] ; then + # copy user authorized_user_ids file to temporary + # location + cat "$authorizedUserIDs" > "$TMP_AUTHORIZED_USER_IDS" + + # export needed variables + export AUTHORIZED_KEYS + export TMP_AUTHORIZED_USER_IDS + + # process authorized_user_ids file, as monkeysphere + # user + su_monkeysphere_user \ + ". ${SHARE}/common; process_authorized_user_ids $TMP_AUTHORIZED_USER_IDS" + RETURN="$?" + fi + + # add user-controlled authorized_keys file path if specified + if [ "$rawAuthorizedKeys" != '-' -a -s "$rawAuthorizedKeys" ] ; then + log -n "adding raw authorized_keys file... " + cat "$rawAuthorizedKeys" >> "$AUTHORIZED_KEYS" + loge "done." + fi + + # openssh appears to check the contents of the + # authorized_keys file as the user in question, so the + # file must be readable by that user at least. + # FIXME: is there a better way to do this? + chown root "$AUTHORIZED_KEYS" + chgrp $(getent passwd "$uname" | cut -f4 -d:) "$AUTHORIZED_KEYS" + chmod g+r "$AUTHORIZED_KEYS" + + # move the resulting authorized_keys file into place + mv -f "$AUTHORIZED_KEYS" "${VARLIB}/authorized_keys/${uname}" + + # destroy temporary directory + rm -rf "$TMPDIR" + done +} + # generate server gpg key gen_key() { + local keyType + local keyLength + local keyUsage + local keyExpire + local revoker local hostName + local userID + local keyParameters + local fingerprint + + # set default key parameter values + keyType="RSA" + keyLength="2048" + keyUsage="auth" + keyExpire= + revoker= + + # get options + TEMP=$(getopt -o e:l:r -l expire:,length:,revoker: -n "$PGRM" -- "$@") + + if [ $? != 0 ] ; then + exit 1 + fi - hostName=${1:-$(hostname --fqdn)} + # Note the quotes around `$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 + ;; + -r|--revoker) + revoker="$2" + shift 2 + ;; + --) + shift + ;; + *) + break + ;; + esac + done - SERVICE=${SERVICE:-"ssh"} - userID="${SERVICE}://${hostName}" + hostName=${1:-$(hostname --fqdn)} + userID="ssh://${hostName}" - if gpg --list-key ="$userID" > /dev/null 2>&1 ; then + # check for presense of key with user ID + if gpg_host --list-key ="$userID" > /dev/null 2>&1 ; then failure "Key for '$userID' already exists" fi - # set key defaults - KEY_TYPE=${KEY_TYPE:-"RSA"} - KEY_LENGTH=${KEY_LENGTH:-"2048"} - KEY_USAGE=${KEY_USAGE:-"auth"} - KEY_EXPIRE=${KEY_EXPIRE:-"0"} - cat < = key expires in n days @@ -73,34 +286,41 @@ Please specify how long the key should be valid. m = key expires in n months y = key expires in n years EOF - read -p "Key is valid for? ($KEY_EXPIRE) " KEY_EXPIRE; KEY_EXPIRE=${KEY_EXPIRE:-"0"} + while [ -z "$keyExpire" ] ; do + read -p "Key is valid for? (0) " keyExpire + if ! test_gpg_expire ${keyExpire:=0} ; then + echo "invalid value" + unset keyExpire + fi + done + elif ! test_gpg_expire "$keyExpire" ; then + failure "invalid key expiration value '$keyExpire'." + fi # set key parameters keyParameters=$(cat < "${MS_HOME}/ssh_host_rsa_key") - log "Private SSH host key output to file: ${MS_HOME}/ssh_host_rsa_key" + (umask 077 && \ + gpg_host --export-secret-key "$fingerprint" | \ + openpgp2ssh "$fingerprint" > "${VARLIB}/ssh_host_rsa_key") + log "Private SSH host key output to file: ${VARLIB}/ssh_host_rsa_key" } # gpg output key fingerprint fingerprint_server_key() { - local ID + gpg_host --fingerprint --list-secret-keys +} - if [ -z "$1" ] ; then - ID="$1" - else - ID="=ssh://$(hostname --fqdn)" +# publish server key to keyserver +publish_server_key() { + read -p "Really publish key to $KEYSERVER? (y/N) " OK; OK=${OK:=N} + if [ ${OK/y/Y} != 'Y' ] ; then + failure "aborting." fi - gpg --fingerprint --list-secret-keys "$ID" + # publish host key + # FIXME: need to figure out better way to identify host key + # dummy command so as not to publish fakes keys during testing + # eventually: + #gpg_authentication "--keyserver $KEYSERVER --send-keys $(hostname -f)" + echo "NOT PUBLISHED (to avoid permanent publication errors during monkeysphere development)." + echo "The following command should publish the key:" + echo "monkeysphere-server gpg-authentication-cmd '--keyserver $KEYSERVER --send-keys $(hostname -f)'" + exit 255 } -######################################################################## -# MAIN -######################################################################## +diagnostics() { +# * check on the status and validity of the key and public certificates + local seckey + local keysfound + local curdate + local warnwindow + local warndate + local create + local expire + local uid + local fingerprint + local badhostkeys + + seckey=$(gpg_host --list-secret-keys --fingerprint --with-colons --fixed-list-mode) + keysfound=$(echo "$seckey" | grep -c ^sec:) + curdate=$(date +%s) + # warn when anything is 2 months away from expiration + warnwindow='2 months' + warndate=$(date +%s -d "$warnwindow") + + echo "Checking host GPG key..." + if (( "$keysfound" < 1 )); then + echo "! No host key found." + echo " - Recommendation: run 'monkeysphere-server gen-key'" + elif (( "$keysfound" > 1 )); then + echo "! More than one host key found?" + # FIXME: recommend a way to resolve this + else + create=$(echo "$seckey" | grep ^sec: | cut -f6 -d:) + expire=$(echo "$seckey" | grep ^sec: | cut -f7 -d:) + fingerprint=$(echo "$seckey" | grep ^fpr: | head -n1 | cut -f10 -d:) + # check for key expiration: + if [ "$expire" ]; then + if (( "$expire" < "$curdate" )); then + echo "! Host key is expired." + # FIXME: recommend a way to resolve this other than re-keying? + elif (( "$expire" < "$warndate" )); then + echo "! Host key expires in less than $warnwindow:" $(date -d "$(( $expire - $curdate )) seconds" +%F) + # FIXME: recommend a way to resolve this? + fi + fi -COMMAND="$1" -[ "$COMMAND" ] || failure "Type '$PGRM help' for usage." -shift + # and weirdnesses: + if [ "$create" ] && (( "$create" > "$curdate" )); then + echo "! Host key was created in the future(?!). Is your clock correct?" + echo " - Recommendation: Check clock ($(date +%F_%T)); use NTP?" + fi -# set ms home directory -MS_HOME=${MS_HOME:-"$ETC"} + # check for UserID expiration: + echo "$seckey" | grep ^uid: | cut -d: -f6,7,10 | \ + while IFS=: read create expire uid ; do + # FIXME: should we be doing any checking on the form + # of the User ID? Should we be unmangling it somehow? -# load configuration file -MS_CONF=${MS_CONF:-"$MS_HOME"/monkeysphere-server.conf} -[ -e "$MS_CONF" ] && . "$MS_CONF" + if [ "$create" ] && (( "$create" > "$curdate" )); then + echo "! User ID '$uid' was created in the future(?!). Is your clock correct?" + echo " - Recommendation: Check clock ($(date +%F_%T)); use NTP?" + fi + if [ "$expire" ] ; then + if (( "$expire" < "$curdate" )); then + echo "! User ID '$uid' is expired." + # FIXME: recommend a way to resolve this + elif (( "$expire" < "$warndate" )); then + echo "! User ID '$uid' expires in less than $warnwindow:" $(date -d "$(( $expire - $curdate )) seconds" +%F) + # FIXME: recommend a way to resolve this + fi + fi + done + +# FIXME: verify that the host key is properly published to the +# keyservers (do this with the non-privileged user) -# set empty config variable with defaults -KEYSERVER=${KEYSERVER:-"subkeys.pgp.net"} -CHECK_KEYSERVER=${CHECK_KEYSERVER:="true"} -AUTHORIZED_USER_IDS=${AUTHORIZED_USER_IDS:-"%h/.config/monkeysphere/authorized_user_ids"} -RAW_AUTHORIZED_KEYS=${RAW_AUTHORIZED_KEYS:-"%h/.ssh/authorized_keys"} +# FIXME: check that there are valid, non-expired certifying signatures +# attached to the host key after fetching from the public keyserver +# (do this with the non-privileged user as well) -# other variables -REQUIRED_USER_KEY_CAPABILITY=${REQUIRED_USER_KEY_CAPABILITY:-"a"} -GNUPGHOME_HOST=${GNUPGHOME_HOST:-"${VARLIB}/gnupg-host"} -GNUPGHOME_AUTHENTICATION=${GNUPGHOME_AUTHENTICATION:-"${VARLIB}/gnupg-authentication"} +# FIXME: propose adding a revoker to the host key if none exist (do we +# have a way to do that after key generation?) -# set default GNUPGHOME, and make sure the directory exists -GNUPGHOME="$GNUPGHOME_HOST" -export GNUPGHOME -mkdir -p -m 0700 "$GNUPGHOME" - -case $COMMAND in - 'update-users'|'update-user'|'u') - if [ "$1" ] ; then - # get users from command line - unames="$@" + # Ensure that the ssh_host_rsa_key file is present and non-empty: + echo "Checking host SSH key..." + if [ ! -s "${VARLIB}/ssh_host_rsa_key" ] ; then + echo "! The host key as prepared for SSH (${VARLIB}/ssh_host_rsa_key) is missing or empty." else - # or just look at all users if none specified - unames=$(getent passwd | cut -d: -f1) + if [ $(stat -c '%a' "${VARLIB}/ssh_host_rsa_key") != 600 ] ; then + echo "! Permissions seem wrong for ${VARLIB}/ssh_host_rsa_key -- should be 0600." + fi + + # propose changes needed for sshd_config (if any) + if ! grep -q "^HostKey ${VARLIB}/ssh_host_rsa_key$" /etc/ssh/sshd_config; then + echo "! /etc/ssh/sshd_config does not point to the monkeysphere host key (${VARLIB}/ssh_host_rsa_key)." + echo " - Recommendation: add a line to /etc/ssh/sshd_config: 'HostKey ${VARLIB}/ssh_host_rsa_key'" + fi + if badhostkeys=$(grep '^HostKey' | grep -q -v "^HostKey ${VARLIB}/ssh_host_rsa_key$") ; then + echo "! /etc/sshd_config refers to some non-monkeysphere host keys:" + echo "$badhostkeys" + echo "- Recommendation: remove the above HostKey lines from /etc/ssh/sshd_config" + fi fi + fi - # set mode - MODE="authorized_keys" +# FIXME: look at the ownership/privileges of the various keyrings, +# directories housing them, etc (what should those values be? can +# we make them as minimal as possible?) - # make sure the authorized_keys directory exists - mkdir -p "${VARLIB}/authorized_keys" +# FIXME: look to see that the ownertrust rules are set properly on the +# authentication keyring - # set GNUPGHOME, and make sure the directory exists - GNUPGHOME="$GNUPGHOME_AUTHENTICATION" - export GNUPGHOME - mkdir -p -m 0700 "$GNUPGHOME" +# FIXME: make sure that at least one identity certifier exists - # loop over users - for uname in $unames ; do - # check all specified users exist - if ! getent passwd "$uname" >/dev/null ; then - error "----- unknown user '$uname' -----" - continue - fi +} - # set authorized_user_ids and raw authorized_keys variables, - # translating ssh-style path variables - authorizedUserIDs=$(translate_ssh_variables "$uname" "$AUTHORIZED_USER_IDS") - rawAuthorizedKeys=$(translate_ssh_variables "$uname" "$RAW_AUTHORIZED_KEYS") +# retrieve key from web of trust, import it into the host keyring, and +# ltsign the key in the host keyring so that it may certify other keys +add_certifier() { + local domain + local trust + local depth + local keyID + local fingerprint + local ltsignCommand + local trustval + + # set default values for trust depth and domain + domain= + trust=full + depth=1 + + # get options + TEMP=$(getopt -o n:t:d: -l domain:,trust:,depth: -n "$PGRM" -- "$@") + + if [ $? != 0 ] ; then + exit 1 + fi - # if neither is found, skip user - if [ ! -s "$authorizedUserIDs" -a ! -s "$rawAuthorizedKeys" ] ; then - continue - fi + # Note the quotes around `$TEMP': they are essential! + eval set -- "$TEMP" + + while true ; do + case "$1" in + -n|--domain) + domain="$2" + shift 2 + ;; + -t|--trust) + trust="$2" + shift 2 + ;; + -d|--depth) + depth="$2" + shift 2 + ;; + --) + shift + ;; + *) + break + ;; + esac + done + + keyID="$1" + if [ -z "$keyID" ] ; then + failure "You must specify the key ID of a key to add." + fi + export keyID - log "----- user: $uname -----" + # get the key from the key server + gpg_authentication "--keyserver $KEYSERVER --recv-key '$keyID'" - # temporary authorized_keys file - AUTHORIZED_KEYS=$(mktemp) + # get the full fingerprint of a key ID + fingerprint=$(gpg_authentication "--list-key --with-colons --with-fingerprint $keyID" | \ + grep '^fpr:' | grep "$keyID" | cut -d: -f10) - # trap to delete file on exit - trap "rm -f $AUTHORIZE_KEYS" EXIT + echo "key found:" + gpg_authentication "--fingerprint $fingerprint" - # process authorized_user_ids file - if [ -s "$authorizedUserIDs" ] ; then - log "processing authorized_user_ids file..." - process_authorized_user_ids "$authorizedUserIDs" - fi + echo "Are you sure you want to add this key as a certifier of" + read -p "users on this system? (y/N) " OK; OK=${OK:-N} + if [ "${OK/y/Y}" != 'Y' ] ; then + failure "aborting." + fi - # add user-controlled authorized_keys file path if specified - if [ "$RAW_AUTHORIZED_KEYS" != '-' ] ; then - if [ -s "$rawAuthorizedKeys" ] ; then - log -n "adding raw authorized_keys file... " - cat "$rawAuthorizedKeys" >> "$AUTHORIZED_KEYS" - loge "done." - fi - fi + # export the key to the host keyring + gpg_authentication "--export $keyID" | gpg_host --import + + if [ "$trust" == marginal ]; then + trustval=1 + elif [ "$trust" == full ]; then + trustval=2 + else + failure "trust value requested ('$trust') was unclear (only 'marginal' or 'full' are supported)" + fi - # if the resulting authorized_keys file is not empty, move - # the temp authorized_keys file into place - if [ -s "$AUTHORIZED_KEYS" ] ; then - # openssh appears to check the contents of the - # authorized_keys file as the user in question, so the - # file must be readable by that user at least. - # FIXME: is there a better way to do this? - chgrp $(getent passwd "$uname" | cut -f4 -d:) "$AUTHORIZED_KEYS" - chmod g+r "$AUTHORIZED_KEYS" + # ltsign command + # NOTE: *all* user IDs will be ltsigned + ltsignCommand=$(cat <