mdw@git.distorted.org.uk Git - distorted-keys/blob - new-recov

   1 #! /bin/sh
   2 ###
   3 ### Generate a new recovery key and split it among keepers
   4 ###
   5 ### (c) 2011 Mark Wooding
   6 ###
   7
   8 ###----- Licensing notice ---------------------------------------------------
   9 ###
  10 ### This file is part of the distorted.org.uk key management suite.
  11 ###
  12 ### distorted-keys is free software; you can redistribute it and/or modify
  13 ### it under the terms of the GNU General Public License as published by
  14 ### the Free Software Foundation; either version 2 of the License, or
  15 ### (at your option) any later version.
  16 ###
  17 ### distorted-keys is distributed in the hope that it will be useful,
  18 ### but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ### GNU General Public License for more details.
  21 ###
  22 ### You should have received a copy of the GNU General Public License
  23 ### along with distorted-keys; if not, write to the Free Software Foundation,
  24 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25
  26 set -e
  27 case "${KEYSLIB+t}" in t) ;; *) echo >&2 "$0: KEYSLIB unset"; exit 1 ;; esac
  28 . "$KEYSLIB"/keyfunc.sh
  29
  30 defhelp <<HELP
  31 RECOV [KEEPER:K ...]
  32 Generate a new recovery secret, and split it among the available keepers.
  33
  34 The new secret will be called RECOV.  For each KEEPER set, the private key
  35 wil be split into shares, and encrypted with the KEEPER's public keys; any K
  36 of these shares can be used to reveal the original key.
  37
  38 If there is already a recovery key called RECOV then it will be rolled over.
  39 The previous key must already be revealed.  If KEEPERs are listed, these
  40 replace the existing keeper sets; otherwise the same keepers as before are
  41 used.
  42
  43 If there is not a recovery key called RECOV then at least one keeper set must
  44 be specified.
  45 HELP
  46 dohelp
  47
  48 ## Parse the command line.
  49 case $# in 0) echo >&2 "$usage"; exit 1 ;; esac
  50 recov=$1; shift
  51 checkword "recovery key label" "$recov"
  52 for k in "$@"; do
  53   case "$k" in
  54     *:*) ;;
  55     *) echo >&2 "$quis: bad keeper spec \`$k'"; exit 1 ;;
  56   esac
  57   keeper=${k%:*} t=${k#*:}
  58   checkword "keeper set label" "$keeper"
  59   checknumber "keeper quorum" "$t"
  60 done
  61
  62 ## Establish the keeper parameters.
  63 rdir=$KEYS/recov/$recov
  64 if [ ! -d $rdir ]; then mkdir -m755 -p $rdir; fi
  65 case $# in
  66   0)
  67     kparam=$rdir/keepers
  68     ;;
  69   *)
  70     for k in "$@"; do
  71       keeper=${k%:*} t=${k#*:}
  72       echo $keeper $t
  73     done >$rdir/keepers.new
  74     kparam=$rdir/keepers.new
  75     ;;
  76 esac
  77 if [ ! -f $kparam ]; then echo >&2 "$quis: no keepers specified"; exit 1; fi
  78
  79 ## Make the new key and issue the shares.
  80 tmp=$(mktmp); cleanup rmtmp
  81 rm -rf $rdir/new
  82 mkdir -m755 $rdir/new
  83 cd $tmp
  84 ec_keygen secret $rdir/new/pub
  85 while read keeper k; do
  86   read n hunoz <$KEYS/keeper/$keeper/meta
  87   shamir issue $k/$n secret | {
  88     read param
  89     echo "$param" >$rdir/new/$keeper.param
  90     i=0
  91     while read share; do
  92       echo $share |
  93         ec_encrypt $KEYS/keeper/$keeper/$i.pub -o$rdir/new/$keeper.$i.share
  94       i=$(( i + 1 ))
  95     done
  96   }
  97 done <$kparam
  98 rm -f secret
  99
 100 ## If there's an existing instance of this key, transfer the recovery blobs.
 101 if [ ! -d $rdir/current ]; then
 102   seq=0
 103 else
 104   seq=$(readlink $rdir/current)
 105   mem=$(userv root claim-mem-dir </dev/null)
 106   reveal=$mem/keys.reveal/$recov.current/secret
 107   if [ ! -f $reveal ]; then
 108     echo >&2 "$quis: current $recov key not revealed"
 109     exit 1
 110   fi
 111
 112   find $rdir/current/ -type f -name '*.recov' -print | while read name; do
 113     name=${name#$rdir/current/}
 114     case "$name" in */*) mkdir -p -m755 $rdir/new/${name%/*} ;; esac
 115     ec_decrypt $reveal -i$rdir/current/$name |
 116       ec_encrypt $rdir/new/pub -o$rdir/new/$name
 117   done
 118   rm -r $mem/keys.reveal/$recov.current
 119 fi
 120
 121 ## Tidy up and commit.  Repointing the symlink is grim because, according to
 122 ## POSIX rules, `mv foo bar' should rename `foo' to `bar/foo' is `bar' is a
 123 ## symlink to a directory -- and there's no way of turning this behaviour
 124 ## off.  The subterfuge here is due to Colin Watson.
 125 cd $rdir
 126 while [ -d $seq ]; do seq=$(( seq + 1 )); done
 127 case $kparam in *.new) mv keepers.new keepers ;; esac
 128 rm -f next
 129 ln -s $seq next
 130 mv new $seq
 131 mkdir hack; mv next hack/current; mv hack/current .; rmdir hack
 132
 133 ###----- That's all, folks --------------------------------------------------