# -*-shell-script-*-
# This should be sourced by bash (though we welcome changes to make it POSIX sh compliant)

# Monkeysphere authentication update-users subcommand
#
# The monkeysphere scripts are written by:
# Jameson Rollins <jrollins@finestructure.net>
# Jamie McClelland <jm@mayfirst.org>
# Daniel Kahn Gillmor <dkg@fifthhorseman.net>
#
# They are Copyright 2008-2009, and are all released under the GPL,
# version 3 or later.

update_users() {

local returnCode=0
local unames
local uname
local authorizedKeysDir
local tmpAuthorizedKeys
local authorizedUserIDs

if [ "$1" ] ; then
    # get users from command line
    unames="$@"
else	     
    # or just look at all users if none specified
    unames=$(list_users)
fi

# set gnupg home
GNUPGHOME="$GNUPGHOME_SPHERE"

# the authorized_keys directory
authorizedKeysDir="${SYSDATADIR}/authorized_keys"

# 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 "${authorizedKeysDir}"

# loop over users
for uname in $unames ; do
    # check all specified users exist
    if ! id "$uname" >/dev/null ; then
	log error "----- unknown user '$uname' -----"
	continue
    fi

    log verbose "----- user: $uname -----"

    # make temporary directory
    TMPLOC=$(mktemp -d ${MATMPDIR}/tmp.XXXXXXXXXX) || failure "Could not create temporary directory!"

    # trap to delete temporary directory on exit
    trap "rm -rf $TMPLOC" EXIT

     # create temporary authorized_keys file
    tmpAuthorizedKeys="${TMPLOC}/authorized_keys"
    touch "$tmpAuthorizedKeys"

    # set restrictive permissions on the temporary files
    # FIXME: is there a better way to do this?
    chmod 0700 "$TMPLOC"
    chmod 0600 "$tmpAuthorizedKeys"
    chown -R "$MONKEYSPHERE_USER" "$TMPLOC"

    # process authorized_user_ids file
    log debug "checking for authorized_user_ids..."
    # translating ssh-style path variables
    authorizedUserIDs=$(translate_ssh_variables "$uname" "$AUTHORIZED_USER_IDS")
    if [ -s "$authorizedUserIDs" ] ; then
	# check permissions on the authorized_user_ids file path
	if check_key_file_permissions "$uname" "$authorizedUserIDs" ; then
	    log verbose "processing authorized_user_ids..."

	    # process authorized_user_ids file, as monkeysphere user
	    su_monkeysphere_user \
		. "${SYSSHAREDIR}/process_authorized_user_ids" "'$STRICT_MODES'" - \
		< "$authorizedUserIDs" \
		> "$tmpAuthorizedKeys"

	else
	    log debug "not processing authorized_user_ids."
	fi
    else
	log debug "empty or absent authorized_user_ids file."
    fi

    # add user-controlled authorized_keys file if specified translate
    # ssh-style path variables
    rawAuthorizedKeys=$(translate_ssh_variables "$uname" "$RAW_AUTHORIZED_KEYS")
    if [ "$rawAuthorizedKeys" != 'none' ] ; then
	log debug "checking for raw authorized_keys..."
	if [ -s "$rawAuthorizedKeys" ] ; then
	    # check permissions on the authorized_keys file path
	    if check_key_file_permissions "$uname" "$rawAuthorizedKeys" ; then
		log verbose "adding raw authorized_keys..."

		cat "$rawAuthorizedKeys" >> "$tmpAuthorizedKeys"

	    else
		log debug "not adding raw authorized_keys."
	    fi
	else
	    log debug "empty or absent authorized_keys file."
	fi
    fi

    # move the new authorized_keys file into place
    if [ -s "$tmpAuthorizedKeys" ] ; 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.

	# but in general, we don't want the user tampering with this
	# file directly, so we'll adopt this approach: Own the file by
	# the monkeysphere-server invoker (usually root, but should be
	# the same uid that sshd is launched as); change the group of
	# the file so that members of the user's group can read it.

	if [ "$OUTPUT_STDOUT" ] ; then
	    log debug "outputting keys to stdout..."
	    cat "$tmpAuthorizedKeys"
	else
	    log debug "moving new file to ${authorizedKeysDir}/${uname}..."
	    # FIXME: is there a better way to do this?
	    chown $(whoami) "$tmpAuthorizedKeys" && \
		chgrp $(id -g "$uname") "$tmpAuthorizedKeys" && \
		chmod g+r "$tmpAuthorizedKeys" && \
		mv -f "$tmpAuthorizedKeys" "${authorizedKeysDir}/${uname}" || \
		{
		log error "Failed to install authorized_keys for '$uname'!"
		rm -f "${authorizedKeysDir}/${uname}"
		# indicate that there has been a failure:
		returnCode=1
	    }
	fi
    else
	rm -f "${authorizedKeysDir}/${uname}"
    fi

    # unset the trap
    trap - EXIT

    # destroy temporary directory
    rm -rf "$TMPLOC"
done

return $returnCode
}