+# retrieve all keys with given user id from keyserver
+# FIXME: need to figure out how to retrieve all matching keys
+# (not just first 5)
+gpg_fetch_keys() {
+ local id="$1"
+ echo 1,2,3,4,5 | \
+ gpg --quiet --batch --command-fd 0 --with-colons \
+ --keyserver "$KEYSERVER" \
+ --search ="$id" >/dev/null 2>&1
+}
+
+# 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/:/'
+}
+
+# stand in until we get dkg's gpg2ssh program
+gpg2ssh_tmp() {
+ local mode
+ local keyID
+
+ mode="$1"
+ keyID="$2"
+ userID="$3"
+
+ if [ "$mode" = '--authorized_keys' -o "$mode" = '-a' ] ; then
+ gpgkey2ssh "$keyID" | sed -e "s/COMMENT/$userID/"
+ elif [ "$mode" = '--known_hosts' -o "$mode" = '-k' ] ; then
+ echo -n "$userID "; gpgkey2ssh "$keyID" | sed -e 's/ COMMENT//'
+ fi
+}
+
+# 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 appropriate capability (E|A)
+# - checks that particular desired user id has appropriate validity
+# see /usr/share/doc/gnupg/DETAILS.gz
+# FIXME: add some more status output
+# expects global variable: "mode"
+process_user_id() {
+ local userID
+ local cacheDir
+ local keyOK
+ local keyCapability
+ local keyFingerprint
+ local userIDHash
+
+ userID="$1"
+ cacheDir="$2"
+
+ # fetch all keys from keyserver
+ # if none found, break
+ if ! gpg_fetch_keys "$userID" ; then
+ echo " no keys found."
+ return
+ fi
+
+ # some crazy piping here that takes the output of gpg and
+ # pipes it into a "while read" loop that reads each line
+ # of standard input one-by-one.
+ gpg --fixed-list-mode --list-key --with-colons \
+ --with-fingerprint ="$userID" 2> /dev/null | \
+ cut -d : -f 1,2,5,10,12 | \
+ while IFS=: read -r type validity keyid uidfpr capability ; do
+ # process based on record type
+ case $type in
+ 'pub')
+ # new key, wipe the slate
+ keyOK=
+ keyCapability=
+ keyFingerprint=
+ # check primary key validity
+ if [ "$validity" != 'u' -a "$validity" != 'f' ] ; then
+ continue
+ fi
+ # check capability is not Disabled...
+ if echo "$capability" | grep -q 'D' ; then
+ continue
+ fi
+ # check capability is Encryption and Authentication
+ # FIXME: make more flexible capability specification
+ # (ie. in conf file)
+ if echo "$capability" | grep -q -v 'E' ; then
+ if echo "$capability" | grep -q -v 'A' ; then
+ continue
+ fi
+ fi
+ keyCapability="$capability"
+ keyOK=true
+ keyID="$keyid"
+ ;;
+ 'fpr')
+ # if key ok, get fingerprint
+ if [ "$keyOK" ] ; then
+ keyFingerprint="$uidfpr"
+ fi
+ ;;
+ 'uid')
+ # check key ok and we have key fingerprint
+ if [ -z "$keyOK" -o -z "$keyFingerprint" ] ; then
+ continue
+ fi
+ # check key validity
+ if [ "$validity" != 'u' -a "$validity" != 'f' ] ; then
+ continue
+ fi
+ # check the uid matches
+ if [ "$(unescape "$uidfpr")" != "$userID" ] ; then
+ continue
+ fi
+ # convert the key
+ # FIXME: needs to apply extra options if specified
+ echo -n " valid key found; generating ssh key(s)... "
+ userIDHash=$(echo "$userID" | sha1sum | awk '{ print $1 }')
+ # export the key with gpg2ssh
+ #gpg --export "$keyFingerprint" | gpg2ssh "$mode" > "$cacheDir"/"$userIDHash"."$keyFingerprint"
+ # stand in until we get dkg's gpg2ssh program
+ gpg2ssh_tmp "$mode" "$keyID" "$userID" > "$cacheDir"/"$userIDHash"."$keyFingerprint"
+ if [ "$?" = 0 ] ; then
+ echo "done."
+ else
+ echo "error."
+ fi
+ ;;
+ esac
+ done
+}
+
+# process the auth_*_ids file
+# go through line-by-line, extracting and processing each user id
+# expects global variable: "mode"
+process_auth_file() {
+ local authIDsFile
+ local cacheDir
+ local nLines
+ local line
+ local userID
+
+ authIDsFile="$1"
+ cacheDir="$2"
+
+ # find number of user ids in auth_user_ids file
+ nLines=$(meat <"$authIDsFile" | wc -l)
+
+ # make sure gpg home exists with proper permissions
+ mkdir -p -m 0700 "$GNUPGHOME"
+
+ # clean out keys file and remake keys directory
+ rm -rf "$cacheDir"
+ mkdir -p "$cacheDir"
+
+ # loop through all user ids
+ for line in $(seq 1 $nLines) ; do
+ # get user id
+ # FIXME: needs to handle extra options if necessary
+ userID=$(meat <"$authIDsFile" | cutline "$line" )
+
+ # process the user id and extract keys
+ log "processing user id: '$userID'"
+ process_user_id "$userID" "$cacheDir"
+ done
+}
+
+
+########################################################################
+# MAIN
+########################################################################