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+# -*-shell-script-*-
+
+# Shared sh functions for the monkeysphere
+#
+# Written by
+# Jameson Rollins <jrollins@fifthhorseman.net>
+#
+# Copyright 2008, released under the GPL, version 3 or later
+
+# all-caps variables are meant to be user supplied (ie. from config
+# file) and are considered global
+
+########################################################################
+### COMMON VARIABLES
+
+# managed directories
+ETC="/etc/monkeysphere"
+export ETC
+CACHE="/var/cache/monkeysphere"
+export CACHE
+
+########################################################################
+### UTILITY FUNCTIONS
+
+failure() {
+ echo "$1" >&2
+ exit ${2:-'1'}
+}
+
+# write output to stderr
+log() {
+ echo -n "ms: " 1>&2
+ echo "$@" 1>&2
+}
+
+loge() {
+ echo "$@" 1>&2
+}
+
+# cut out all comments(#) and blank lines from standard input
+meat() {
+ grep -v -e "^[[:space:]]*#" -e '^$'
+}
+
+# cut a specified line from standard input
+cutline() {
+ head --line="$1" | tail -1
+}
+
+# check that characters are in a string (in an AND fashion).
+# used for checking key capability
+# check_capability capability a [b...]
+check_capability() {
+ local usage
+ local capcheck
+
+ usage="$1"
+ shift 1
+
+ for capcheck ; do
+ if echo "$usage" | grep -q -v "$capcheck" ; then
+ return 1
+ fi
+ done
+ return 0
+}
+
+# convert escaped characters from gpg output back into original
+# character
+# FIXME: undo all escape character translation in with-colons gpg output
+unescape() {
+ echo "$1" | sed 's/\\x3a/:/'
+}
+
+# remove all lines with specified string from specified file
+remove_file_line() {
+ local file
+ local string
+
+ file="$1"
+ string="$2"
+
+ if [ "$file" -a "$string" ] ; then
+ grep -v "$string" "$file" | sponge "$file"
+ fi
+}
+
+### CONVERTION UTILITIES
+
+# output the ssh key for a given key ID
+gpg2ssh() {
+ local keyID
+
+ #keyID="$1" #TMP
+ # only use last 16 characters until openpgp2ssh can take all 40 #TMP
+ keyID=$(echo "$1" | cut -c 25-) #TMP
+
+ gpg --export "$keyID" | openpgp2ssh "$keyID" 2> /dev/null
+}
+
+# output known_hosts line from ssh key
+ssh2known_hosts() {
+ local host
+ local key
+
+ host="$1"
+ key="$2"
+
+ echo -n "$host "
+ echo -n "$key" | tr -d '\n'
+ echo " MonkeySphere${DATE}"
+}
+
+# output authorized_keys line from ssh key
+ssh2authorized_keys() {
+ local userID
+ local key
+
+ userID="$1"
+ key="$2"
+
+ echo -n "$key" | tr -d '\n'
+ echo " MonkeySphere${DATE}: ${userID}"
+}
+
+# convert key from gpg to ssh known_hosts format
+gpg2known_hosts() {
+ local host
+ local keyID
+
+ host="$1"
+ keyID="$2"
+
+ # NOTE: it seems that ssh-keygen -R removes all comment fields from
+ # all lines in the known_hosts file. why?
+ # NOTE: just in case, the COMMENT can be matched with the
+ # following regexp:
+ # '^MonkeySphere[[:digit:]]{4}(-[[:digit:]]{2}){2}T[[:digit:]]{2}(:[[:digit:]]{2}){2}$'
+ echo -n "$host "
+ gpg2ssh "$keyID" | tr -d '\n'
+ echo " MonkeySphere${DATE}"
+}
+
+# convert key from gpg to ssh authorized_keys format
+gpg2authorized_keys() {
+ local userID
+ local keyID
+
+ userID="$1"
+ keyID="$2"
+
+ # NOTE: just in case, the COMMENT can be matched with the
+ # following regexp:
+ # '^MonkeySphere[[:digit:]]{4}(-[[:digit:]]{2}){2}T[[:digit:]]{2}(:[[:digit:]]{2}){2}$'
+ gpg2ssh "$keyID" | tr -d '\n'
+ echo " MonkeySphere${DATE}: ${userID}"
+}
+
+### GPG UTILITIES
+
+# retrieve all keys with given user id from keyserver
+# FIXME: need to figure out how to retrieve all matching keys
+# (not just first N (5 in this case))
+gpg_fetch_userid() {
+ local userID
+
+ userID="$1"
+
+ log -n " checking keyserver $KEYSERVER... "
+ echo 1,2,3,4,5 | \
+ gpg --quiet --batch --with-colons \
+ --command-fd 0 --keyserver "$KEYSERVER" \
+ --search ="$userID" > /dev/null 2>&1
+ loge "done."
+}
+
+# get the full fingerprint of a key ID
+get_key_fingerprint() {
+ local keyID
+
+ keyID="$1"
+
+ gpg --list-key --with-colons --fixed-list-mode \
+ --with-fingerprint "$keyID" | grep "$keyID" | \
+ grep '^fpr:' | cut -d: -f10
+}
+
+########################################################################
+### PROCESSING FUNCTIONS
+
+# userid and key policy checking
+# the following checks policy on the returned keys
+# - checks that full key has appropriate valididy (u|f)
+# - checks key has specified capability (REQUIRED_*_KEY_CAPABILITY)
+# - checks that requested user ID has appropriate validity
+# (see /usr/share/doc/gnupg/DETAILS.gz)
+# output is one line for every found key, in the following format:
+#
+# flag fingerprint
+#
+# "flag" is an acceptability flag, 0 = ok, 1 = bad
+# "fingerprint" is the fingerprint of the key
+#
+# expects global variable: "MODE"
+process_user_id() {
+ local userID
+ local requiredCapability
+ local requiredPubCapability
+ local gpgOut
+ local type
+ local validity
+ local keyid
+ local uidfpr
+ local usage
+ local keyOK
+ local uidOK
+ local lastKey
+ local lastKeyOK
+ local fingerprint
+
+ userID="$1"
+
+ # set the required key capability based on the mode
+ if [ "$MODE" = 'known_hosts' ] ; then
+ requiredCapability="$REQUIRED_HOST_KEY_CAPABILITY"
+ elif [ "$MODE" = 'authorized_keys' ] ; then
+ requiredCapability="$REQUIRED_USER_KEY_CAPABILITY"
+ fi
+ requiredPubCapability=$(echo "$requiredCapability" | tr "[:lower:]" "[:upper:]")
+
+ # if CHECK_KEYSERVER variable set, check the keyserver
+ # for the user ID
+ if [ "$CHECK_KEYSERVER" = "true" ] ; then
+ gpg_fetch_userid "$userID"
+ fi
+
+ # output gpg info for (exact) userid and store
+ gpgOut=$(gpg --list-key --fixed-list-mode --with-colon \
+ --with-fingerprint --with-fingerprint \
+ ="$userID" 2>/dev/null)
+
+ # if the gpg query return code is not 0, return 1
+ if [ "$?" -ne 0 ] ; then
+ log " - key not found."
+ return 1
+ fi
+
+ # loop over all lines in the gpg output and process.
+ # need to do it this way (as opposed to "while read...") so that
+ # variables set in loop will be visible outside of loop
+ echo "$gpgOut" | cut -d: -f1,2,5,10,12 | \
+ while IFS=: read -r type validity keyid uidfpr usage ; do
+ # process based on record type
+ case $type in
+ 'pub') # primary keys
+ # new key, wipe the slate
+ keyOK=
+ uidOK=
+ lastKey=pub
+ lastKeyOK=
+ fingerprint=
+
+ log " primary key found: $keyid"
+
+ # if overall key is not valid, skip
+ if [ "$validity" != 'u' -a "$validity" != 'f' ] ; then
+ log " - unacceptable primary key validity ($validity)."
+ continue
+ fi
+ # if overall key is disabled, skip
+ if check_capability "$usage" 'D' ; then
+ log " - key disabled."
+ continue
+ fi
+ # if overall key capability is not ok, skip
+ if ! check_capability "$usage" $requiredPubCapability ; then
+ log " - unacceptable primary key capability ($usage)."
+ continue
+ fi
+
+ # mark overall key as ok
+ keyOK=true
+
+ # mark primary key as ok if capability is ok
+ if check_capability "$usage" $requiredCapability ; then
+ lastKeyOK=true
+ fi
+ ;;
+ 'uid') # user ids
+ # if an acceptable user ID was already found, skip
+ if [ "$uidOK" ] ; then
+ continue
+ fi
+ # if the user ID does not match, skip
+ if [ "$(unescape "$uidfpr")" != "$userID" ] ; then
+ continue
+ fi
+ # if the user ID validity is not ok, skip
+ if [ "$validity" != 'u' -a "$validity" != 'f' ] ; then
+ continue
+ fi
+
+ # mark user ID acceptable
+ uidOK=true
+
+ # output a line for the primary key
+ # 0 = ok, 1 = bad
+ if [ "$keyOK" -a "$uidOK" -a "$lastKeyOK" ] ; then
+ log " * acceptable key found."
+ echo 0 "$fingerprint"
+ else
+ echo 1 "$fingerprint"
+ fi
+ ;;
+ 'sub') # sub keys
+ # unset acceptability of last key
+ lastKey=sub
+ lastKeyOK=
+ fingerprint=
+
+ # if sub key validity is not ok, skip
+ if [ "$validity" != 'u' -a "$validity" != 'f' ] ; then
+ continue
+ fi
+ # if sub key capability is not ok, skip
+ if ! check_capability "$usage" $requiredCapability ; then
+ continue
+ fi
+
+ # mark sub key as ok
+ lastKeyOK=true
+ ;;
+ 'fpr') # key fingerprint
+ fingerprint="$uidfpr"
+
+ # if the last key was the pub key, skip
+ if [ "$lastKey" = pub ] ; then
+ continue
+ fi
+
+ # output a line for the last subkey
+ # 0 = ok, 1 = bad
+ if [ "$keyOK" -a "$uidOK" -a "$lastKeyOK" ] ; then
+ log " * acceptable key found."
+ echo 0 "$fingerprint"
+ else
+ echo 1 "$fingerprint"
+ fi
+ ;;
+ esac
+ done
+}
+
+# update the cache for userid, and prompt to add file to
+# authorized_user_ids file if the userid is found in gpg
+# and not already in file.
+update_userid() {
+ local userID
+
+ userID="$1"
+
+ log "processing userid: '$userID'"
+
+ # process the user ID to pull it from keyserver
+ process_user_id "$userID" | grep -q "^0 "
+
+ # check if user ID is in the authorized_user_ids file
+ if ! grep -q "^${userID}\$" "$AUTHORIZED_USER_IDS" ; then
+ read -p "user ID not currently authorized. authorize? [Y|n]: " OK; OK=${OK:=Y}
+ if [ ${OK/y/Y} = 'Y' ] ; then
+ # add if specified
+ log -n " adding user ID to authorized_user_ids file... "
+ echo "$userID" >> "$AUTHORIZED_USER_IDS"
+ loge "done."
+ else
+ # else do nothing
+ log " authorized_user_ids file untouched."
+ fi
+ fi
+}
+
+# remove a userid from the authorized_user_ids file
+remove_userid() {
+ local userID
+
+ userID="$1"
+
+ log "processing userid: '$userID'"
+
+ # check if user ID is in the authorized_user_ids file
+ if ! grep -q "^${userID}\$" "$AUTHORIZED_USER_IDS" ; then
+ log " user ID not currently authorized."
+ return 1
+ fi
+
+ # remove user ID from file
+ log -n " removing user ID '$userID'... "
+ remove_file_line "$AUTHORIZED_USER_IDS" "^${userID}$"
+ loge "done."
+}
+
+# process a host in known_host file
+process_host_known_hosts() {
+ local host
+ local userID
+ local ok
+ local keyid
+ local tmpfile
+
+ host="$1"
+ userID="ssh://${host}"
+
+ log "processing host: $host"
+
+ process_user_id "ssh://${host}" | \
+ while read -r ok keyid ; do
+ sshKey=$(gpg2ssh "$keyid")
+ # remove the old host key line
+ remove_file_line "$KNOWN_HOSTS" "$sshKey"
+ # if key OK, add new host line
+ if [ "$ok" -eq '0' ] ; then
+ # hash if specified
+ if [ "$HASH_KNOWN_HOSTS" = 'true' ] ; then
+ # FIXME: this is really hackish cause ssh-keygen won't
+ # hash from stdin to stdout
+ tmpfile=$(mktemp)
+ ssh2known_hosts "$host" "$sshKey" > "$tmpfile"
+ ssh-keygen -H -f "$tmpfile" 2> /dev/null
+ cat "$tmpfile" >> "$KNOWN_HOSTS"
+ rm -f "$tmpfile" "${tmpfile}.old"
+ else
+ ssh2known_hosts "$host" "$sshKey" >> "$KNOWN_HOSTS"
+ fi
+ fi
+ done
+}
+
+# process a uid in an authorized_keys file
+process_uid_authorized_keys() {
+ local userID
+ local ok
+ local keyid
+
+ userID="$1"
+
+ log "processing user ID: $userID"
+
+ process_user_id "$userID" | \
+ while read -r ok keyid ; do
+ sshKey=$(gpg2ssh "$keyid")
+ # remove the old host key line
+ remove_file_line "$AUTHORIZED_KEYS" "$sshKey"
+ # if key OK, add new host line
+ if [ "$ok" -eq '0' ] ; then
+ ssh2authorized_keys "$userID" "$sshKey" >> "$AUTHORIZED_KEYS"
+ fi
+ done
+}
+
+# process known_hosts file
+# go through line-by-line, extract each host, and process with the
+# host processing function
+process_known_hosts() {
+ local hosts
+ local host
+
+ # take all the hosts from the known_hosts file (first field),
+ # grep out all the hashed hosts (lines starting with '|')...
+ cat "$KNOWN_HOSTS" | meat | \
+ cut -d ' ' -f 1 | grep -v '^|.*$' | \
+ while IFS=, read -r -a hosts ; do
+ # and process each host
+ for host in ${hosts[*]} ; do
+ process_host_known_hosts "$host"
+ done
+ done
+}
+
+# process an authorized_user_ids file for authorized_keys
+process_authorized_user_ids() {
+ local userid
+
+ cat "$AUTHORIZED_USER_IDS" | meat | \
+ while read -r userid ; do
+ process_uid_authorized_keys "$userid"
+ done
+}
+
+# EXPERIMENTAL (unused) process userids found in authorized_keys file
+# go through line-by-line, extract monkeysphere userids from comment
+# fields, and process each userid
+# NOT WORKING
+process_authorized_keys() {
+ local authorizedKeys
+ local userID
+
+ authorizedKeys="$1"
+
+ # take all the monkeysphere userids from the authorized_keys file
+ # comment field (third field) that starts with "MonkeySphere uid:"
+ # FIXME: needs to handle authorized_keys options (field 0)
+ cat "$authorizedKeys" | meat | \
+ while read -r options keytype key comment ; do
+ # if the comment field is empty, assume the third field was
+ # the comment
+ if [ -z "$comment" ] ; then
+ comment="$key"
+ fi
+
+ if echo "$comment" | egrep -v -q '^MonkeySphere[[:digit:]]{4}(-[[:digit:]]{2}){2}T[[:digit:]]{2}(:[[:digit:]]{2}){2}:' ; then
+ continue
+ fi
+ userID=$(echo "$comment" | awk "{ print $2 }")
+ if [ -z "$userID" ] ; then
+ continue
+ fi
+
+ # process the userid
+ log "processing userid: '$userID'"
+ process_user_id "$userID" > /dev/null
+ done
+}
+
+##################################################
+### GPG HELPER FUNCTIONS
+
+# retrieve key from web of trust, and set owner trust to "full"
+# if key is found.
+trust_key() {
+ # get the key from the key server
+ if ! gpg --keyserver "$KEYSERVER" --recv-key "$keyID" ; then
+ log "could not retrieve key '$keyID'"
+ return 1
+ fi
+
+ # get key fingerprint
+ fingerprint=$(get_key_fingerprint "$keyID")
+
+ # attach a "non-exportable" signature to the key
+ # this is required for the key to have any validity at all
+ # the 'y's on stdin indicates "yes, i really want to sign"
+ echo -e 'y\ny' | gpg --lsign-key --command-fd 0 "$fingerprint"
+
+ # import "full" trust for fingerprint into gpg
+ echo ${fingerprint}:5: | gpg --import-ownertrust
+ if [ $? = 0 ] ; then
+ log "owner trust updated."
+ else
+ failure "there was a problem changing owner trust."
+ fi
+}
+
+# publish server key to keyserver
+publish_server_key() {
+ read -p "really publish key to $KEYSERVER? [y|N]: " OK; OK=${OK:=N}
+ if [ ${OK/y/Y} != 'Y' ] ; then
+ failure "aborting."
+ fi
+
+ # publish host key
+ # FIXME: need to figure out better way to identify host key
+ # dummy command so as not to publish fakes keys during testing
+ # eventually:
+ #gpg --send-keys --keyserver "$KEYSERVER" $(hostname -f)
+ echo "NOT PUBLISHED: gpg --send-keys --keyserver $KEYSERVER $(hostname -f)"
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-04 16:43:32 +0000