src/monkeysphere-server

   1 #!/bin/bash
   2
   3 # monkeysphere-server: MonkeySphere server admin tool
   4 #
   5 # The monkeysphere scripts are written by:
   6 # Jameson Rollins <jrollins@fifthhorseman.net>
   7 #
   8 # They are Copyright 2008, and are all released under the GPL, version 3
   9 # or later.
  10
  11 ########################################################################
  12 PGRM=$(basename $0)
  13 PGRM_PATH=$(dirname $0)
  14
  15 SHARE=${SHARE:-"/usr/share/monkeysphere"}
  16 export SHARE
  17 . "${SHARE}/common"
  18
  19 VARLIB="/var/lib/monkeysphere"
  20 export VARLIB
  21
  22 # date in UTF format if needed
  23 DATE=$(date -u '+%FT%T')
  24
  25 # unset some environment variables that could screw things up
  26 GREP_OPTIONS=
  27
  28 # default return code
  29 ERR=0
  30
  31 ########################################################################
  32 # FUNCTIONS
  33 ########################################################################
  34
  35 usage() {
  36 cat <<EOF
  37 usage: $PGRM <subcommand> [args]
  38 MonkeySphere server admin tool.
  39
  40 subcommands:
  41   update-users (u) [USER]...            update users authorized_keys files
  42   gen-key (g) [HOSTNAME]                generate gpg key for the server
  43   show-fingerprint (f)                  show server's host key fingerprint
  44   publish-key (p)                       publish server's host key to keyserver
  45   trust-key (t) KEYID [LEVEL]           set owner trust for keyid
  46   help (h,?)                            this help
  47
  48 EOF
  49 }
  50
  51 # generate server gpg key
  52 gen_key() {
  53     local hostName
  54     local userID
  55     local keyParameters
  56     local fingerprint
  57
  58     hostName=${1:-$(hostname --fqdn)}
  59
  60     SERVICE=${SERVICE:-"ssh"}
  61     userID="${SERVICE}://${hostName}"
  62
  63     GNUPGHOME="$GNUPGHOME_HOST"
  64     if gpg --list-key ="$userID" > /dev/null 2>&1 ; then
  65         failure "Key for '$userID' already exists"
  66     fi
  67
  68     # set key defaults
  69     KEY_TYPE=${KEY_TYPE:-"RSA"}
  70     KEY_LENGTH=${KEY_LENGTH:-"2048"}
  71     KEY_USAGE=${KEY_USAGE:-"auth"}
  72     KEY_EXPIRE=${KEY_EXPIRE:-"0"}
  73     cat <<EOF
  74 Please specify how long the key should be valid.
  75          0 = key does not expire
  76       <n>  = key expires in n days
  77       <n>w = key expires in n weeks
  78       <n>m = key expires in n months
  79       <n>y = key expires in n years
  80 EOF
  81     read -p "Key is valid for? ($KEY_EXPIRE) " KEY_EXPIRE; KEY_EXPIRE=${KEY_EXPIRE:-"0"}
  82
  83     # set key parameters
  84     keyParameters=$(cat <<EOF
  85 Key-Type: $KEY_TYPE
  86 Key-Length: $KEY_LENGTH
  87 Key-Usage: $KEY_USAGE
  88 Name-Real: $userID
  89 Expire-Date: $KEY_EXPIRE
  90 EOF
  91 )
  92
  93     # add the revoker field if requested
  94     # FIXME: the "1:" below assumes that $REVOKER's key is an RSA key.  why?
  95     # FIXME: why is this marked "sensitive"?  how will this signature ever
  96     # be transmitted to the expected revoker?
  97     if [ "$REVOKER" ] ; then
  98         keyParameters="${keyParameters}"$(cat <<EOF
  99
 100 Revoker: 1:$REVOKER sensitive
 101 EOF
 102 )
 103     fi
 104
 105     echo "The following key parameters will be used:"
 106     echo "$keyParameters"
 107
 108     read -p "Generate key? [Y|n]: " OK; OK=${OK:=Y}
 109     if [ ${OK/y/Y} != 'Y' ] ; then
 110         failure "aborting."
 111     fi
 112
 113     # add commit command
 114     keyParameters="${keyParameters}"$(cat <<EOF
 115
 116 %commit
 117 %echo done
 118 EOF
 119 )
 120
 121     log "generating server key..."
 122     GNUPGHOME="$GNUPGHOME_HOST"
 123     echo "$keyParameters" | gpg --batch --gen-key
 124
 125     # output the server fingerprint
 126     fingerprint_server_key "=${userID}"
 127
 128     # find the key fingerprint of the server primary key
 129     GNUPGHOME="$GNUPGHOME_HOST"
 130     fingerprint=$(gpg --list-key --with-colons --with-fingerprint "=${userID}" | \
 131         grep '^fpr:' | head -1 | cut -d: -f10)
 132
 133     # export the host key to the authentication keyring
 134     GNUPGHOME="$GNUPGHOME_HOST" gpg --export "$fingerprint" | \
 135         su --preserve-environment "$MONKEYSPHERE_USER" -c -- \
 136         "GNUPGHOME=$GNUPGHOME_AUTHENTICATION gpg --import"
 137
 138     # set host key owner trust to ultimate in authentication keyring
 139     echo "${fingerprint}:6:" | \
 140         su --preserve-environment "$MONKEYSPHERE_USER" -c -- \
 141         "GNUPGHOME=$GNUPGHOME_AUTHENTICATION gpg --import-ownertrust"
 142
 143     # write the key to the file
 144     # NOTE: assumes that the primary key is the proper key to use
 145     GNUPGHOME="$GNUPGHOME_HOST"
 146     (umask 077 && gpgsecret2ssh "$fingerprint" > "${VARLIB}/ssh_host_rsa_key")
 147     log "Private SSH host key output to file: ${VARLIB}/ssh_host_rsa_key"
 148 }
 149
 150 # gpg output key fingerprint
 151 fingerprint_server_key() {
 152     local ID
 153
 154     if [ "$1" ] ; then
 155         ID="$1"
 156     else
 157         ID="=ssh://$(hostname --fqdn)"
 158     fi
 159
 160     gpg --fingerprint --list-secret-keys "$ID"
 161 }
 162
 163 # publish server key to keyserver
 164 publish_server_key() {
 165     read -p "really publish key to $KEYSERVER? [y|N]: " OK; OK=${OK:=N}
 166     if [ ${OK/y/Y} != 'Y' ] ; then
 167         failure "aborting."
 168     fi
 169
 170     # publish host key
 171     # FIXME: need to figure out better way to identify host key
 172     # dummy command so as not to publish fakes keys during testing
 173     # eventually:
 174     #gpg --keyserver "$KEYSERVER" --send-keys $(hostname -f)
 175     failure "NOT PUBLISHED (to avoid permanent publication errors during monkeysphere development).
 176 To publish manually, do: gpg --keyserver $KEYSERVER --send-keys $(hostname -f)"
 177 }
 178
 179
 180 # retrieve key from web of trust, and set owner trust to "full"
 181 # if key is found.
 182 trust_key() {
 183     local keyID
 184     local trustLevel
 185
 186     keyID="$1"
 187     trustLevel="$2"
 188
 189     if [ -z "$keyID" ] ; then
 190         failure "You must specify key to trust."
 191     fi
 192
 193     export keyID
 194
 195     # get the key from the key server
 196     GNUPGHOME="$GNUPGHOME_AUTHENTICATION"
 197     su --preserve-environment "$MONKEYSPHERE_USER" -c -- \
 198         "gpg --keyserver $KEYSERVER --recv-key $keyID"
 199     if [ "$?" != 0 ] ; then
 200         failure "Could not retrieve key '$keyID'."
 201     fi
 202
 203     # move the key from the authentication keyring to the host keyring
 204     GNUPGHOME="$GNUPGHOME_AUTHENTICATION"
 205     su --preserve-environment "$MONKEYSPHERE_USER" -c -- \
 206         "gpg --export $keyID" | \
 207         GNUPGHOME="$GNUPGHOME_HOST" gpg --import
 208
 209     # get key fingerprint
 210     GNUPGHOME="$GNUPGHOME_HOST"
 211     fingerprint=$(get_key_fingerprint "$keyID")
 212
 213     echo "key found:"
 214     GNUPGHOME="$GNUPGHOME_HOST"
 215     gpg --fingerprint "$fingerprint"
 216
 217     while [ -z "$trustLevel" ] ; do
 218         cat <<EOF
 219 Please decide how far you trust this user to correctly verify other users' keys
 220 (by looking at passports, checking fingerprints from different sources, etc.)
 221
 222   1 = I don't know or won't say
 223   2 = I do NOT trust
 224   3 = I trust marginally
 225   4 = I trust fully
 226   5 = I trust ultimately
 227
 228 EOF
 229         read -p "Your decision? " trustLevel
 230         if echo "$trustLevel" | grep -v "[1-5]" ; then
 231             echo "Unknown trust level '$trustLevel'."
 232             unset trustLevel
 233         elif [ "$trustLevel" = 'q' ] ; then
 234             failure "Aborting."
 235         fi
 236     done
 237
 238     # attach a "non-exportable" signature to the key
 239     # this is required for the key to have any validity at all
 240     # the 'y's on stdin indicates "yes, i really want to sign"
 241     GNUPGHOME="$GNUPGHOME_HOST"
 242     echo -e 'y\ny' | \
 243         gpg --quiet --lsign-key --command-fd 0 "$fingerprint"
 244
 245     # copy the host keyring into the authentication keyring
 246     mv "$GNUPGHOME_AUTHENTICATION"/pubring.gpg{,.old}
 247     cp "$GNUPGHOME_HOST"/pubring.gpg "$GNUPGHOME_AUTHENTICATION"/pubring.gpg
 248     chown "$MONKEYSPHERE_USER" "$GNUPGHOME_AUTHENTICATION"/pubring.gpg
 249     GNUPGHOME="$GNUPGHOME_AUTHENTICATION"
 250     su --preserve-environment "$MONKEYSPHERE_USER" -c -- \
 251         "gpg --import ${GNUPGHOME_AUTHENTICATION}/pubring.gpg.old"
 252
 253     # index trustLevel by one to difference between level in ui and level
 254     # internally
 255     trustLevel=$((trustLevel+1))
 256
 257     # import new owner trust level for key
 258     GNUPGHOME="$GNUPGHOME_AUTHENTICATION"
 259     echo "${fingerprint}:${trustLevel}:" | \
 260         su --preserve-environment "$MONKEYSPHERE_USER" -c -- \
 261         "GNUPGHOME=$GNUPGHOME_AUTHENTICATION gpg --import-ownertrust"
 262
 263     if [ $? = 0 ] ; then
 264         log "Owner trust updated."
 265     else
 266         failure "There was a problem changing owner trust."
 267     fi
 268 }
 269
 270 ########################################################################
 271 # MAIN
 272 ########################################################################
 273
 274 COMMAND="$1"
 275 [ "$COMMAND" ] || failure "Type '$PGRM help' for usage."
 276 shift
 277
 278 # set ms home directory
 279 MS_HOME=${MS_HOME:-"$ETC"}
 280
 281 # load configuration file
 282 MS_CONF=${MS_CONF:-"$MS_HOME"/monkeysphere-server.conf}
 283 [ -e "$MS_CONF" ] && . "$MS_CONF"
 284
 285 # set empty config variable with defaults
 286 MONKEYSPHERE_USER=${MONKEYSPHERE_USER:-"monkeysphere"}
 287 KEYSERVER=${KEYSERVER:-"subkeys.pgp.net"}
 288 CHECK_KEYSERVER=${CHECK_KEYSERVER:="true"}
 289 AUTHORIZED_USER_IDS=${AUTHORIZED_USER_IDS:-"%h/.config/monkeysphere/authorized_user_ids"}
 290 RAW_AUTHORIZED_KEYS=${RAW_AUTHORIZED_KEYS:-"%h/.ssh/authorized_keys"}
 291
 292 # other variables
 293 REQUIRED_USER_KEY_CAPABILITY=${REQUIRED_USER_KEY_CAPABILITY:-"a"}
 294 GNUPGHOME_HOST=${GNUPGHOME_HOST:-"${VARLIB}/gnupg-host"}
 295 GNUPGHOME_AUTHENTICATION=${GNUPGHOME_AUTHENTICATION:-"${VARLIB}/gnupg-authentication"}
 296
 297 # export variables
 298 export MODE
 299 export MONKEYSPHERE_USER
 300 export KEYSERVER
 301 export CHECK_KEYSERVER
 302 export REQUIRED_USER_KEY_CAPABILITY
 303 export GNUPGHOME_HOST
 304 export GNUPGHOME_AUTHENTICATION
 305 export GNUPGHOME
 306
 307 case $COMMAND in
 308     'update-users'|'update-user'|'u')
 309         if [ "$1" ] ; then
 310             # get users from command line
 311             unames="$@"
 312         else
 313             # or just look at all users if none specified
 314             unames=$(getent passwd | cut -d: -f1)
 315         fi
 316
 317         # set mode
 318         MODE="authorized_keys"
 319
 320         # set gnupg home
 321         GNUPGHOME="$GNUPGHOME_AUTHENTICATION"
 322
 323         # check to see if the gpg trust database has been initialized
 324         if [ ! -s "${GNUPGHOME}/trustdb.gpg" ] ; then
 325             failure "GNUPG trust database uninitialized.  Please see MONKEYSPHERE-SERVER(8)."
 326         fi
 327
 328         # make sure the authorized_keys directory exists
 329         mkdir -p "${VARLIB}/authorized_keys"
 330
 331         # loop over users
 332         for uname in $unames ; do
 333             # check all specified users exist
 334             if ! getent passwd "$uname" >/dev/null ; then
 335                 error "----- unknown user '$uname' -----"
 336                 continue
 337             fi
 338
 339             # set authorized_user_ids and raw authorized_keys variables,
 340             # translating ssh-style path variables
 341             authorizedUserIDs=$(translate_ssh_variables "$uname" "$AUTHORIZED_USER_IDS")
 342             rawAuthorizedKeys=$(translate_ssh_variables "$uname" "$RAW_AUTHORIZED_KEYS")
 343
 344             # if neither is found, skip user
 345             if [ ! -s "$authorizedUserIDs" ] ; then
 346                 if [ "$rawAuthorizedKeys" = '-' -o ! -s "$rawAuthorizedKeys" ] ; then
 347                     continue
 348                 fi
 349             fi
 350
 351             log "----- user: $uname -----"
 352
 353             # make temporary directory
 354             TMPDIR=$(mktemp -d)
 355
 356             # trap to delete temporary directory on exit
 357             trap "rm -rf $TMPDIR" EXIT
 358
 359             # create temporary authorized_user_ids file
 360             TMP_AUTHORIZED_USER_IDS="${TMPDIR}/authorized_user_ids"
 361             touch "$TMP_AUTHORIZED_USER_IDS"
 362
 363             # create temporary authorized_keys file
 364             AUTHORIZED_KEYS="${TMPDIR}/authorized_keys"
 365             touch "$AUTHORIZED_KEYS"
 366
 367             # set restrictive permissions on the temporary files
 368             # FIXME: is there a better way to do this?
 369             chmod 0700 "$TMPDIR"
 370             chmod 0600 "$AUTHORIZED_KEYS"
 371             chmod 0600 "$TMP_AUTHORIZED_USER_IDS"
 372             chown -R "$MONKEYSPHERE_USER" "$TMPDIR"
 373
 374             # if the authorized_user_ids file exists...
 375             if [ -s "$authorizedUserIDs" ] ; then
 376                 # copy user authorized_user_ids file to temporary
 377                 # location
 378                 cat "$authorizedUserIDs" > "$TMP_AUTHORIZED_USER_IDS"
 379
 380                 # export needed variables
 381                 export AUTHORIZED_KEYS
 382                 export TMP_AUTHORIZED_USER_IDS
 383
 384                 # process authorized_user_ids file, as monkeysphere
 385                 # user
 386                 su --preserve-environment "$MONKEYSPHERE_USER" -c -- \
 387                     ". ${SHARE}/common; process_authorized_user_ids $TMP_AUTHORIZED_USER_IDS"
 388             fi
 389
 390             # add user-controlled authorized_keys file path if specified
 391             if [ "$rawAuthorizedKeys" != '-' -a -s "$rawAuthorizedKeys" ] ; then
 392                 log -n "adding raw authorized_keys file... "
 393                 cat "$rawAuthorizedKeys" >> "$AUTHORIZED_KEYS"
 394                 loge "done."
 395             fi
 396
 397             # openssh appears to check the contents of the
 398             # authorized_keys file as the user in question, so the
 399             # file must be readable by that user at least.
 400             # FIXME: is there a better way to do this?
 401             chown root "$AUTHORIZED_KEYS"
 402             chgrp $(getent passwd "$uname" | cut -f4 -d:) "$AUTHORIZED_KEYS"
 403             chmod g+r "$AUTHORIZED_KEYS"
 404
 405             # if the resulting authorized_keys file is not empty, move
 406             # it into place
 407             mv -f "$AUTHORIZED_KEYS" "${VARLIB}/authorized_keys/${uname}"
 408
 409             log "authorized_keys file updated."
 410
 411             # destroy temporary directory
 412             rm -rf "$TMPDIR"
 413         done
 414         ;;
 415
 416     'gen-key'|'g')
 417         # set gnupg home
 418         GNUPGHOME="$GNUPGHOME_HOST"
 419         gen_key "$@"
 420         ;;
 421
 422     'show-fingerprint'|'f')
 423         # set gnupg home
 424         GNUPGHOME="$GNUPGHOME_HOST"
 425         fingerprint_server_key "$@"
 426         ;;
 427
 428     'publish-key'|'p')
 429         # set gnupg home
 430         GNUPGHOME="$GNUPGHOME_HOST"
 431         publish_server_key
 432         ;;
 433
 434     'trust-key'|'t')
 435         trust_key "$@"
 436         ;;
 437
 438     'help'|'h'|'?')
 439         usage
 440         ;;
 441
 442     *)
 443         failure "Unknown command: '$COMMAND'
 444 Type '$PGRM help' for usage."
 445         ;;
 446 esac
 447
 448 exit "$ERR"