| 1 | #! /bin/bash |
| 2 | ### |
| 3 | ### Update the site's SSH certificates. |
| 4 | |
| 5 | set -e |
| 6 | cd "${0%/*}/.." |
| 7 | |
| 8 | ###-------------------------------------------------------------------------- |
| 9 | ### General setup stuff. |
| 10 | |
| 11 | ## Read in a configuration file. |
| 12 | if [ -f etc/config ]; then . etc/config; fi |
| 13 | : ${keytypes="rsa:3072 dsa:1024"} |
| 14 | : ${domain="your.site.example"} |
| 15 | : ${cacomment="ssh-ca@$domain"} |
| 16 | : ${scope="*.$domain"} |
| 17 | : ${validity="-1d:+7d"} |
| 18 | |
| 19 | ## The key types are adorned with bit lengths. Work out the raw key type |
| 20 | ## names. |
| 21 | cakeytypes="" |
| 22 | for kt in $keytypes; do |
| 23 | cakeytypes="$cakeytypes ${kt%:*}" |
| 24 | done |
| 25 | |
| 26 | ## Make the keys if necessary. |
| 27 | mkdir -p keys |
| 28 | for kt in $keytypes; do |
| 29 | case $kt in |
| 30 | *:*) bits=-b${kt#*:} kt=${kt%:*} ;; |
| 31 | *) bits="" ;; |
| 32 | esac |
| 33 | if [ ! -f keys/ca-$kt ]; then |
| 34 | ssh-keygen -fkeys/ca-$kt -t$kt $bits -C"$cacomment" -N "" |
| 35 | fi |
| 36 | read pub <keys/ca-$kt.pub |
| 37 | echo "@cert-authority $scope $pub" >keys/ca-$kt.entry |
| 38 | done |
| 39 | |
| 40 | ## Functions for managing concurrency. |
| 41 | kids="" |
| 42 | mkdir -p log |
| 43 | run () { |
| 44 | tag=$1; shift |
| 45 | "$@" >log/$tag 2>&1& |
| 46 | kids="$kids $tag:$!" |
| 47 | } |
| 48 | |
| 49 | reap () { |
| 50 | outcome=0 |
| 51 | for kid in $kids; do |
| 52 | tag=${kid%:*} |
| 53 | set +e; wait ${kid#*:}; rc=$?; set -e |
| 54 | case $rc in |
| 55 | 0) ;; |
| 56 | *) |
| 57 | echo >&2 "$0: $tag failed (rc = $rc)" |
| 58 | sed 's,^,| ,' log/$tag |
| 59 | outcome=1 |
| 60 | ;; |
| 61 | esac |
| 62 | done |
| 63 | return $outcome |
| 64 | } |
| 65 | |
| 66 | ## Read the hosts. |
| 67 | dohost () { |
| 68 | host=$1; shift |
| 69 | |
| 70 | set -x |
| 71 | hostkeytypes=$( |
| 72 | ssh $host " |
| 73 | cd /etc/ssh |
| 74 | for kt in $cakeytypes; do |
| 75 | if [ -f ssh_host_\${kt}_key.pub ]; then echo \$kt; fi |
| 76 | done" |
| 77 | ) |
| 78 | names="" |
| 79 | for n in "$host" "$@"; do |
| 80 | names=${names:+$names,}$n |
| 81 | case "$n" in ".") ;; *) names=${names:+$names,}$n.$domain ;; esac |
| 82 | done |
| 83 | any=nil |
| 84 | for kt in $hostkeytypes; do |
| 85 | scp $host:/etc/ssh/ssh_host_${kt}_key.pub keys/$host-$kt.pub |
| 86 | ssh-keygen -skeys/ca-$kt \ |
| 87 | -h -I"$cacomment:$host.$domain" -n$names \ |
| 88 | -V$validity \ |
| 89 | keys/$host-$kt.pub |
| 90 | scp keys/$host-$kt-cert.pub $host:/etc/ssh/ssh_host_${kt}_key-cert.pub |
| 91 | any=t |
| 92 | done |
| 93 | case "$any" in nil) echo >&2 "no matching key types"; exit 1 ;; esac |
| 94 | } |
| 95 | |
| 96 | dotry () { |
| 97 | host=$1; shift |
| 98 | ping -c5 -q $host >/dev/null 2>&1 || return 0 |
| 99 | dohost "$host" "$@" |
| 100 | } |
| 101 | |
| 102 | must () { run "$1" dohost "$@"; } |
| 103 | try () { run "$1" dotry "$@"; } |
| 104 | |
| 105 | . etc/hosts |
| 106 | reap |
| 107 | |
| 108 | last=%%% |
| 109 | for i in keys/*.pub; do |
| 110 | case "$i" in *-cert.pub) continue ;; esac |
| 111 | host=${i%-*} |
| 112 | case "$host" in "$last") ;; *) echo; echo "$host" ;; esac |
| 113 | last=$host |
| 114 | ssh-keygen -lv -f "$i" | sed 's,^,| ,' |
| 115 | done >distorted-host-keys.new |
| 116 | mv distorted-host-keys.new distorted-host-keys |