mdw@git.distorted.org.uk Git - ssh-ca/blob - bin/update-ssh-certs

   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