#!/bin/sh
# Copyright (c) 1999-2020 Philip Hands <phil@hands.com>
# 2017 Sebastien Boyron <seb@boyron.eu>
# 2013 Martin Kletzander <mkletzan@redhat.com>
# 2010 Adeodato =?iso-8859-1?Q?Sim=F3?= <asp16@alu.ua.es>
# 2010 Eric Moret <eric.moret@gmail.com>
# 2009 Xr <xr@i-jeuxvideo.com>
# 2007 Justin Pryzby <justinpryzby@users.sourceforge.net>
# 2004 Reini Urban <rurban@x-ray.at>
# 2003 Colin Watson <cjwatson@debian.org>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
# Shell script to install your public key(s) on a remote machine
# See the ssh-copy-id(1) man page for details
# shellcheck shell=dash
# check that we have something mildly sane as our shell, or try to find something better
if false ^ printf "%s: WARNING: ancient shell, hunting for a more modern one... " "$0"
then
SANE_SH=${SANE_SH:-/usr/bin/ksh}
if printf 'true ^ false\n' | "$SANE_SH"
then
printf "'%s' seems viable.\\n" "$SANE_SH"
exec "$SANE_SH" "$0" "$@"
else
cat <<-EOF
oh dear.
If you have a more recent shell available, that supports \$(...) etc.
please try setting the environment variable SANE_SH to the path of that
shell, and then retry running this script. If that works, please report
a bug describing your setup, and the shell you used to make it work.
EOF
printf '%s: ERROR: Less dimwitted shell required.\n' "$0"
exit 1
fi
fi
# shellcheck disable=SC2010
DEFAULT_PUB_ID_FILE=$(ls -t "${HOME}"/.ssh/id*.pub 2>/dev/null | grep -v -- '-cert.pub$' | head -n 1)
usage () {
printf 'Usage: %s [-h|-?|-f|-n] [-i [identity_file]] [-p port] [-F alternative ssh_config file] [[-o <ssh -o options>] ...] [user@]hostname\n' "$0" >&2
printf '\t-f: force mode -- copy keys without trying to check if they are already installed\n' >&2
printf '\t-n: dry run -- no keys are actually copied\n' >&2
printf '\t-h|-?: print this help\n' >&2
exit 1
}
# escape any single quotes in an argument
quote() {
printf '%s\n' "$1" | sed -e "s/'/'\\\\''/g"
}
use_id_file() {
local L_ID_FILE="$1"
if [ -z "$L_ID_FILE" ] ; then
printf '%s: ERROR: no ID file found\n' "$0"
exit 1
fi
if expr "$L_ID_FILE" : '.*\.pub$' >/dev/null ; then
PUB_ID_FILE="$L_ID_FILE"
else
PUB_ID_FILE="$L_ID_FILE.pub"
fi
[ "$FORCED" ] || PRIV_ID_FILE=$(dirname "$PUB_ID_FILE")/$(basename "$PUB_ID_FILE" .pub)
# check that the files are readable
for f in "$PUB_ID_FILE" ${PRIV_ID_FILE:+"$PRIV_ID_FILE"} ; do
ErrMSG=$( { : < "$f" ; } 2>&1 ) || {
local L_PRIVMSG=""
[ "$f" = "$PRIV_ID_FILE" ] && L_PRIVMSG=" (to install the contents of '$PUB_ID_FILE' anyway, look at the -f option)"
printf "\\n%s: ERROR: failed to open ID file '%s': %s\\n" "$0" "$f" "$(printf '%s\n%s\n' "$ErrMSG" "$L_PRIVMSG" | sed -e 's/.*: *//')"
exit 1
}
done
printf '%s: INFO: Source of key(s) to be installed: "%s"\n' "$0" "$PUB_ID_FILE" >&2
GET_ID="cat \"$PUB_ID_FILE\""
}
if [ -n "$SSH_AUTH_SOCK" ] && ssh-add -L >/dev/null 2>&1 ; then
GET_ID="ssh-add -L"
fi
while getopts "i:o:p:F:fnh?" OPT
do
case "$OPT" in
i)
[ "${SEEN_OPT_I}" ] && {
printf '\n%s: ERROR: -i option must not be specified more than once\n\n' "$0"
usage
}
SEEN_OPT_I="yes"
use_id_file "${OPTARG:-$DEFAULT_PUB_ID_FILE}"
;;
o|p|F)
SSH_OPTS="${SSH_OPTS:+$SSH_OPTS }-$OPT '$(quote "${OPTARG}")'"
;;
f)
FORCED=1
;;
n)
DRY_RUN=1
;;
h|\?)
usage
;;
esac
done
#shift all args to keep only USER_HOST
shift $((OPTIND-1))
if [ $# = 0 ] ; then
usage
fi
if [ $# != 1 ] ; then
printf '%s: ERROR: Too many arguments. Expecting a target hostname, got: %s\n\n' "$0" "$SAVEARGS" >&2
usage
fi
# drop trailing colon
USER_HOST="$*"
# tack the hostname onto SSH_OPTS
SSH_OPTS="${SSH_OPTS:+$SSH_OPTS }'$(quote "$USER_HOST")'"
# and populate "$@" for later use (only way to get proper quoting of options)
eval set -- "$SSH_OPTS"
# shellcheck disable=SC2086
if [ -z "$(eval $GET_ID)" ] && [ -r "${PUB_ID_FILE:=$DEFAULT_PUB_ID_FILE}" ] ; then
use_id_file "$PUB_ID_FILE"
fi
# shellcheck disable=SC2086
if [ -z "$(eval $GET_ID)" ] ; then
printf '%s: ERROR: No identities found\n' "$0" >&2
exit 1
fi
# populate_new_ids() uses several global variables ($USER_HOST, $SSH_OPTS ...)
# and has the side effect of setting $NEW_IDS
populate_new_ids() {
local L_SUCCESS="$1"
# shellcheck disable=SC2086
if [ "$FORCED" ] ; then
NEW_IDS=$(eval $GET_ID)
return
fi
# repopulate "$@" inside this function
eval set -- "$SSH_OPTS"
umask 0177
local L_TMP_ID_FILE
L_TMP_ID_FILE=$(mktemp ~/.ssh/ssh-copy-id_id.XXXXXXXXXX)
if test $? -ne 0 || test "x$L_TMP_ID_FILE" = "x" ; then
printf '%s: ERROR: mktemp failed\n' "$0" >&2
exit 1
fi
local L_CLEANUP="rm -f \"$L_TMP_ID_FILE\" \"${L_TMP_ID_FILE}.stderr\""
# shellcheck disable=SC2064
trap "$L_CLEANUP" EXIT TERM INT QUIT
printf '%s: INFO: attempting to log in with the new key(s), to filter out any that are already installed\n' "$0" >&2
# shellcheck disable=SC2086
NEW_IDS=$(
eval $GET_ID | {
while read -r ID || [ "$ID" ] ; do
printf '%s\n' "$ID" > "$L_TMP_ID_FILE"
# the next line assumes $PRIV_ID_FILE only set if using a single id file - this
# assumption will break if we implement the possibility of multiple -i options.
# The point being that if file based, ssh needs the private key, which it cannot
# find if only given the contents of the .pub file in an unrelated tmpfile
ssh -i "${PRIV_ID_FILE:-$L_TMP_ID_FILE}" \
-o ControlPath=none \
-o LogLevel=INFO \
-o PreferredAuthentications=publickey \
-o IdentitiesOnly=yes "$@" exit 2>"$L_TMP_ID_FILE.stderr" </dev/null
if [ "$?" = "$L_SUCCESS" ] ; then
: > "$L_TMP_ID_FILE"
else
grep 'Permission denied' "$L_TMP_ID_FILE.stderr" >/dev/null || {
sed -e 's/^/ERROR: /' <"$L_TMP_ID_FILE.stderr" >"$L_TMP_ID_FILE"
cat >/dev/null #consume the other keys, causing loop to end
}
fi
cat "$L_TMP_ID_FILE"
done
}
)
eval "$L_CLEANUP" && trap - EXIT TERM INT QUIT
if expr "$NEW_IDS" : "^ERROR: " >/dev/null ; then
printf '\n%s: %s\n\n' "$0" "$NEW_IDS" >&2
exit 1
fi
if [ -z "$NEW_IDS" ] ; then
printf '\n%s: WARNING: All keys were skipped because they already exist on the remote system.\n' "$0" >&2
printf '\t\t(if you think this is a mistake, you may want to use -f option)\n\n' >&2
exit 0
fi
printf '%s: INFO: %d key(s) remain to be installed -- if you are prompted now it is to install the new keys\n' "$0" "$(printf '%s\n' "$NEW_IDS" | wc -l)" >&2
}
# installkey_sh [target_path]
# produce a one-liner to add the keys to remote authorized_keys file
# optionally takes an alternative path for authorized_keys
installkeys_sh() {
local AUTH_KEY_FILE=${1:-.ssh/authorized_keys}
# In setting INSTALLKEYS_SH:
# the tr puts it all on one line (to placate tcsh)
# (hence the excessive use of semi-colons (;) )
# then in the command:
# cd to be at $HOME, just in case;
# the -z `tail ...` checks for a trailing newline. The echo adds one if was missing
# the cat adds the keys we're getting via STDIN
# and if available restorecon is used to restore the SELinux context
INSTALLKEYS_SH=$(tr '\t\n' ' ' <<-EOF
cd;
umask 077;
mkdir -p $(dirname "${AUTH_KEY_FILE}") &&
{ [ -z \`tail -1c ${AUTH_KEY_FILE} 2>/dev/null\` ] || echo >> ${AUTH_KEY_FILE}; } &&
cat >> ${AUTH_KEY_FILE} ||
exit 1;
if type restorecon >/dev/null 2>&1; then
restorecon -F .ssh ${AUTH_KEY_FILE};
fi
EOF
)
# to defend against quirky remote shells: use 'exec sh -c' to get POSIX;
printf "exec sh -c '%s'" "${INSTALLKEYS_SH}"
}
REMOTE_VERSION=$(ssh -v -o PreferredAuthentications=',' -o ControlPath=none "$@" 2>&1 |
sed -ne 's/.*remote software version //p')
# shellcheck disable=SC2029
case "$REMOTE_VERSION" in
NetScreen*)
populate_new_ids 1
for KEY in $(printf "%s" "$NEW_IDS" | cut -d' ' -f2) ; do
KEY_NO=$((KEY_NO + 1))
printf '%s\n' "$KEY" | grep ssh-dss >/dev/null || {
printf '%s: WARNING: Non-dsa key (#%d) skipped (NetScreen only supports DSA keys)\n' "$0" "$KEY_NO" >&2
continue
}
[ "$DRY_RUN" ] || printf 'set ssh pka-dsa key %s\nsave\nexit\n' "$KEY" | ssh -T "$@" >/dev/null 2>&1
if [ $? = 255 ] ; then
printf '%s: ERROR: installation of key #%d failed (please report a bug describing what caused this, so that we can make this message useful)\n' "$0" "$KEY_NO" >&2
else
ADDED=$((ADDED + 1))
fi
done
if [ -z "$ADDED" ] ; then
exit 1
fi
;;
dropbear*)
populate_new_ids 0
[ "$DRY_RUN" ] || printf '%s\n' "$NEW_IDS" | \
ssh "$@" "$(installkeys_sh /etc/dropbear/authorized_keys)" \
|| exit 1
ADDED=$(printf '%s\n' "$NEW_IDS" | wc -l)
;;
*)
# Assuming that the remote host treats ~/.ssh/authorized_keys as one might expect
populate_new_ids 0
[ "$DRY_RUN" ] || printf '%s\n' "$NEW_IDS" | \
ssh "$@" "$(installkeys_sh)" \
|| exit 1
ADDED=$(printf '%s\n' "$NEW_IDS" | wc -l)
;;
esac
if [ "$DRY_RUN" ] ; then
cat <<-EOF
=-=-=-=-=-=-=-=
Would have added the following key(s):
$NEW_IDS
=-=-=-=-=-=-=-=
EOF
else
cat <<-EOF
Number of key(s) added: $ADDED
Now try logging into the machine, with: "ssh $SSH_OPTS"
and check to make sure that only the key(s) you wanted were added.
EOF
fi
# =-=-=-=