special gpg functions for host/authentication.
[monkeysphere.git] / src / monkeysphere-server
index f68f3911fe8255bf8fd8ac07f7716b0d3b01333a..615f4948d02e30f9f9724d7fd00c69b85b685b5c 100755 (executable)
 
 ########################################################################
 PGRM=$(basename $0)
+PGRM_PATH=$(dirname $0)
 
-SHAREDIR=${SHAREDIR:-"/usr/share/monkeysphere"}
-export SHAREDIR
-. "${SHAREDIR}/common"
+SHARE=${SHARE:-"/usr/share/monkeysphere"}
+export SHARE
+. "${SHARE}/common"
+
+VARLIB="/var/lib/monkeysphere"
+export VARLIB
 
 # date in UTF format if needed
 DATE=$(date -u '+%FT%T')
@@ -21,6 +25,9 @@ DATE=$(date -u '+%FT%T')
 # unset some environment variables that could screw things up
 GREP_OPTIONS=
 
+# default return code
+ERR=0
+
 ########################################################################
 # FUNCTIONS
 ########################################################################
@@ -31,7 +38,7 @@ usage: $PGRM <subcommand> [args]
 MonkeySphere server admin tool.
 
 subcommands:
-  update-users (s) [USER]...            update users authorized_keys files
+  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
@@ -41,15 +48,33 @@ subcommands:
 EOF
 }
 
+gpg_host() {
+    GNUPGHOME="$GNUPGHOME_HOST"
+    export GNUPGHOME
+
+    gpg "$@"
+}
+
+gpg_authentication() {
+    GNUPGHOME="$GNUPGHOME_AUTHENTICATION"
+    export GNUPGHOME
+
+    su --preserve-environment "$MONKEYSPHERE_USER" -c -- "gpg $@"
+}
+
 # generate server gpg key
 gen_key() {
     local hostName
+    local userID
+    local keyParameters
+    local fingerprint
 
     hostName=${1:-$(hostname --fqdn)}
-    service=${SERVICE:-"ssh"}
-    userID="${service}://${hostName}"
 
-    if gpg --list-key ="$userID" > /dev/null 2>&1 ; then
+    SERVICE=${SERVICE:-"ssh"}
+    userID="${SERVICE}://${hostName}"
+
+    if gpg_host --list-key ="$userID" > /dev/null 2>&1 ; then
        failure "Key for '$userID' already exists"
     fi
 
@@ -106,27 +131,35 @@ EOF
 EOF
 )
 
-    log "generating server key... "
-    echo "$keyParameters" | gpg --batch --gen-key
+    log "generating server key..."
+    echo "$keyParameters" | gpg_host --batch --gen-key
 
     # output the server fingerprint
     fingerprint_server_key "=${userID}"
 
     # find the key fingerprint of the server primary key
-    keyID=$(gpg --list-key --with-colons --with-fingerprint "=${userID}" | \
+    fingerprint=$(gpg_host --list-key --with-colons --with-fingerprint "=${userID}" | \
        grep '^fpr:' | head -1 | cut -d: -f10)
 
+    # export the host key to the authentication keyring
+    gpg_host --export "$fingerprint" | gpg_authentication --import
+
+    # set host key owner trust to ultimate in authentication keyring
+    echo "${fingerprint}:6:" | \
+       gpg_authentication "--import-ownertrust"
+
     # write the key to the file
     # NOTE: assumes that the primary key is the proper key to use
-    (umask 077 && gpgsecret2ssh "$keyID" > "${MS_HOME}/ssh_host_rsa_key")
-    log "Private SSH host key output to file: ${MS_HOME}/ssh_host_rsa_key"
+    GNUPGHOME="$GNUPGHOME_HOST"
+    (umask 077 && gpgsecret2ssh "$fingerprint" > "${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
 
-    if [ -z "$1" ] ; then
+    if [ "$1" ] ; then
        ID="$1"
     else
        ID="=ssh://$(hostname --fqdn)"
@@ -135,6 +168,100 @@ fingerprint_server_key() {
     gpg --fingerprint --list-secret-keys "$ID"
 }
 
+# publish server key to keyserver
+publish_server_key() {
+    read -p "really publish key to $KEYSERVER? [y|N]: " OK; OK=${OK:=N}
+    if [ ${OK/y/Y} != 'Y' ] ; then
+       failure "aborting."
+    fi
+
+    # publish host key
+    # FIXME: need to figure out better way to identify host key
+    # dummy command so as not to publish fakes keys during testing
+    # eventually:
+    #gpg --keyserver "$KEYSERVER" --send-keys $(hostname -f)
+    failure "NOT PUBLISHED (to avoid permanent publication errors during monkeysphere development).
+To publish manually, do: gpg --keyserver $KEYSERVER --send-keys $(hostname -f)"
+}
+
+# retrieve key from web of trust, and set owner trust to "full"
+# if key is found.
+trust_key() {
+    local keyID
+    local trustLevel
+
+    keyID="$1"
+    trustLevel="$2"
+
+    if [ -z "$keyID" ] ; then
+       failure "You must specify key to trust."
+    fi
+
+    export keyID
+
+    # get the key from the key server
+    if ! su_monkeysphere_user "gpg --keyserver $KEYSERVER --recv-key $keyID" ; then
+       failure "Could not retrieve key '$keyID'."
+    fi
+
+    # move the key from the authentication keyring to the host keyring
+    gpg_authentication --export "$keyID" | gpg_host --import
+
+    # get key fingerprint
+    GNUPGHOME="$GNUPGHOME_HOST"
+    fingerprint=$(get_key_fingerprint "$keyID")
+
+    echo "key found:"
+    gpg_host --fingerprint "$fingerprint"
+
+    while [ -z "$trustLevel" ] ; do
+       cat <<EOF
+Please decide how far you trust this user to correctly verify other users' keys
+(by looking at passports, checking fingerprints from different sources, etc.)
+
+  1 = I don't know or won't say
+  2 = I do NOT trust
+  3 = I trust marginally
+  4 = I trust fully
+  5 = I trust ultimately
+
+EOF
+       read -p "Your decision? " trustLevel
+       if echo "$trustLevel" | grep -v "[1-5]" ; then
+           echo "Unknown trust level '$trustLevel'."
+           unset trustLevel
+       elif [ "$trustLevel" = 'q' ] ; then
+           failure "Aborting."
+       fi
+    done
+
+    # attach a "non-exportable" signature to the key
+    # this is required for the key to have any validity at all
+    # the 'y's on stdin indicates "yes, i really want to sign"
+    echo -e 'y\ny' | \
+       gpg_host --quiet --lsign-key --command-fd 0 "$fingerprint"
+
+    # copy the host keyring into the authentication keyring
+    mv "$GNUPGHOME_AUTHENTICATION"/pubring.gpg{,.old}
+    cp "$GNUPGHOME_HOST"/pubring.gpg "$GNUPGHOME_AUTHENTICATION"/pubring.gpg
+    chown "$MONKEYSPHERE_USER" "$GNUPGHOME_AUTHENTICATION"/pubring.gpg
+    gpg_authentication --import "$GNUPGHOME_AUTHENTICATION"/pubring.gpg.old
+
+    # index trustLevel by one to difference between level in ui and level
+    # internally
+    trustLevel=$((trustLevel+1))
+
+    # import new owner trust level for key
+    echo "${fingerprint}:${trustLevel}:" | \
+        gpg_authentication --import-ownertrust
+
+    if [ $? = 0 ] ; then
+       log "Owner trust updated."
+    else
+       failure "There was a problem changing owner trust."
+    fi
+}
+
 ########################################################################
 # MAIN
 ########################################################################
@@ -151,24 +278,29 @@ MS_CONF=${MS_CONF:-"$MS_HOME"/monkeysphere-server.conf}
 [ -e "$MS_CONF" ] && . "$MS_CONF"
 
 # set empty config variable with defaults
-GNUPGHOME=${GNUPGHOME:-"${MS_HOME}/gnupg"}
+MONKEYSPHERE_USER=${MONKEYSPHERE_USER:-"monkeysphere"}
 KEYSERVER=${KEYSERVER:-"subkeys.pgp.net"}
 CHECK_KEYSERVER=${CHECK_KEYSERVER:="true"}
-REQUIRED_USER_KEY_CAPABILITY=${REQUIRED_USER_KEY_CAPABILITY:-"a"}
 AUTHORIZED_USER_IDS=${AUTHORIZED_USER_IDS:-"%h/.config/monkeysphere/authorized_user_ids"}
-USER_CONTROLLED_AUTHORIZED_KEYS=${USER_CONTROLLED_AUTHORIZED_KEYS:-"%h/.ssh/authorized_keys"}
+RAW_AUTHORIZED_KEYS=${RAW_AUTHORIZED_KEYS:-"%h/.ssh/authorized_keys"}
 
+# 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"}
+
+# export variables
+export MODE
+export MONKEYSPHERE_USER
+export KEYSERVER
+export CHECK_KEYSERVER
+export REQUIRED_USER_KEY_CAPABILITY
+export GNUPGHOME_HOST
+export GNUPGHOME_AUTHENTICATION
 export GNUPGHOME
 
-# make sure the monkeysphere home directory exists
-mkdir -p "${MS_HOME}/authorized_user_ids"
-# make sure gpg home exists with proper permissions
-mkdir -p -m 0700 "$GNUPGHOME"
-# make sure the authorized_keys directory exists
-mkdir -p "${CACHE}/authorized_keys"
-
 case $COMMAND in
-    'update-users'|'update-user'|'s')
+    'update-users'|'update-user'|'u')
        if [ "$1" ] ; then
            # get users from command line
            unames="$@"
@@ -177,70 +309,124 @@ case $COMMAND in
            unames=$(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 $unames ; do
-           MODE="authorized_keys"
-
            # check all specified users exist
            if ! getent passwd "$uname" >/dev/null ; then
                error "----- unknown user '$uname' -----"
                continue
            fi
 
-           # set authorized_user_ids variable,
-           # translate ssh-style path variables
+           # 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")
 
-           # skip user if authorized_user_ids file does not exist
-           if [ ! -f "$authorizedUserIDs" ] ; then
-               continue
+           # if neither is found, skip user
+           if [ ! -s "$authorizedUserIDs" ] ; then
+               if [ "$rawAuthorizedKeys" = '-' -o ! -s "$rawAuthorizedKeys" ] ; then
+                   continue
+               fi
            fi
 
            log "----- user: $uname -----"
 
-           # temporary authorized_keys file
-           AUTHORIZED_KEYS=$(mktemp)
-
-           # skip if the user's authorized_user_ids file is empty
-           if [ ! -s "$authorizedUserIDs" ] ; then
-               log "authorized_user_ids file '$authorizedUserIDs' is empty."
-               continue
+            # make temporary directory
+            TMPDIR=$(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" > "$TMP_AUTHORIZED_USER_IDS"
+
+               # export needed variables
+               export AUTHORIZED_KEYS
+               export TMP_AUTHORIZED_USER_IDS
+
+               # process authorized_user_ids file, as monkeysphere
+               # user
+               su --preserve-environment "$MONKEYSPHERE_USER" -c -- \
+                   ". ${SHARE}/common; process_authorized_user_ids $TMP_AUTHORIZED_USER_IDS"
            fi
 
-           # process authorized_user_ids file
-           log "processing authorized_user_ids file..."
-           process_authorized_user_ids "$authorizedUserIDs"
-
            # add user-controlled authorized_keys file path if specified
-           if [ "$USER_CONTROLLED_AUTHORIZED_KEYS" != '-' ] ; then
-               userAuthorizedKeys=$(translate_ssh_variables "$uname" "$USER_CONTROLLED_AUTHORIZED_KEYS")
-               if [ -f "$userAuthorizedKeys" ] ; then
-                   log -n "adding user's authorized_keys file... "
-                   cat "$userAuthorizedKeys" >> "$AUTHORIZED_KEYS"
-                   loge "done."
-               fi
+           if [ "$rawAuthorizedKeys" != '-' -a -s "$rawAuthorizedKeys" ] ; then
+               log -n "adding raw authorized_keys file... "
+               cat "$rawAuthorizedKeys" >> "$AUTHORIZED_KEYS"
+               loge "done."
            fi
 
-           # move the temp authorized_keys file into place
-           mv -f "$AUTHORIZED_KEYS" "${CACHE}/authorized_keys/${uname}"
+           # openssh appears to check the contents of the
+            # authorized_keys file as the user in question, so the
+            # file must be readable by that user at least.
+           # FIXME: is there a better way to do this?
+           chown root "$AUTHORIZED_KEYS"
+           chgrp $(getent passwd "$uname" | cut -f4 -d:) "$AUTHORIZED_KEYS"
+           chmod g+r "$AUTHORIZED_KEYS"
+
+           # if the resulting authorized_keys file is not empty, move
+           # it into place
+           mv -f "$AUTHORIZED_KEYS" "${VARLIB}/authorized_keys/${uname}"
 
            log "authorized_keys file updated."
+           
+           # destroy temporary directory
+           rm -rf "$TMPDIR"
        done
        ;;
 
     'gen-key'|'g')
-       gen_key "$1"
+       # set gnupg home
+       GNUPGHOME="$GNUPGHOME_HOST"
+       gen_key "$@"
        ;;
 
     'show-fingerprint'|'f')
+       # set gnupg home
+       GNUPGHOME="$GNUPGHOME_HOST"
        fingerprint_server_key "$@"
        ;;
 
     'publish-key'|'p')
+       # set gnupg home
+       GNUPGHOME="$GNUPGHOME_HOST"
        publish_server_key
        ;;
 
-    'trust-key'|'trust-key'|'t')
+    'trust-key'|'t')
        trust_key "$@"
        ;;