gpg-key-to-s-expr.sh

   1 #!/bin/bash
   2 #
   3 # Copyright (c) 2008, Dave Korn.
   4 #
   5 #     This program is free software; you can redistribute it and/or modify
   6 #     it under the terms of the GNU General Public License as published by
   7 #     the Free Software Foundation; either version 2 of the License, or
   8 #     (at your option) any later version.
   9 #
  10 #     A copy of the GNU General Public License can be found at
  11 #     http://www.gnu.org/
  12 #
  13 # Written by Dave Korn <dave.korn.cygwin@gmail.com>
  14 #
  15 #
  16 # Converts a gpg pub key file to a text s-expr for
  17 # building into setup.exe's signature verification.
  18 # Relies on having pgpdump installed.
  19 #
  20 # Usage:
  21 #     gpg-key-to-s-expr.sh [-q|-e|-Q|-c|-C|-1] KEYFILE
  22 #
  23 #   -q means surround output in quotes to make it easier
  24 # for use in a C #include fragment.  -e means escape the
  25 # line ends.  -Q means both.  -c means output a C-style
  26 # string for printing, -C makes the strine a one-liner and
  27 # outputs a C header as well.  -1 means generate all the
  28 # output on a single line.  Only one option should be
  29 # specified or the behaviour is undefined.
  30
  31 # Usage: find_a_line ALG COEFFICIENT PGPDUMPFILE
  32 # Returns the hex data for the named coefficient..
  33 function find_a_line() {
  34   grep -m1 "$1 $2([0-9]* bits) -" < "$3" \
  35     | sed -e 's/^.*- //g' | tr -d ' '
  36 }
  37
  38 # Usage: line_to_sexpr HEXDATA
  39 # Convert hex data from find_a_line to s-expr format:
  40 # prepends 00 to avoid signedness problems if high bit
  41 # is set, and surrounds with hash marks.
  42 function line_to_sexpr() {
  43   echo "#"`echo "$1" | sed -e's/^\([89A-Fa-f]\)/00\1/g'`"#"
  44 }
  45
  46 quotes=
  47 escapes=
  48 starts=
  49 mid=
  50 header=
  51 nl="\n"
  52 ind="    "
  53
  54 if [ x$1 == x-q ] ;
  55 then
  56   quotes='"'
  57   shift ;
  58 fi
  59 if [ x$1 == x-e ] ;
  60 then
  61   escapes='\\'
  62   shift ;
  63 fi
  64 if [ x$1 == x-Q ] ;
  65 then
  66   quotes='"'
  67   escapes='\\'
  68   shift ;
  69 fi
  70 if [ x$1 == x-c ] ;
  71 then
  72   quotes='"'
  73   escapes="\\\\n$quotes"
  74   starts="$quotes"
  75   shift ;
  76 fi
  77 if [ x$1 == x-C ] ;
  78 then
  79   quotes='"'
  80   escapes="$quotes"
  81   mid="$quotes"
  82   header="\\n/*  Autogenerated from: $2\\n *\\t\\t   by: $0\\n *\\t\\t   at: `date "+%c"`\\t\\t\\t*/\\n\\n"
  83   shift ;
  84 fi
  85 if [ x$1 == x-1 ] ;
  86 then
  87   nl=
  88   ind=
  89   shift ;
  90 fi
  91
  92 if [ $# -ne 1 ] ;
  93 then
  94   echo "Missing KEYFILE arg"
  95   exit 1 ;
  96 fi
  97
  98 TMPFILE=`mktemp -t "$(basename "$1").XXXXXXXXXX"` || exit 1
  99
 100 pgpdump -milpu "$1" >"$TMPFILE" || exit 1
 101
 102 # Yes, this could be done *far* more efficiently in any one of
 103 # perl/awk/python/$YOURFAVOURITETOOL than by spawning a whole
 104 # bunch of bashes, greps and seds.  No, I don't care.  Don't bug
 105 # me about it until we have to run this script a million times a day!
 106
 107 alg=`grep -m1 "Pub alg" $TMPFILE | sed -E -e 's/^.*pub (.*)\)/\1/g'`
 108
 109 case $alg in
 110     1)
 111     rsa_n=`find_a_line RSA n $TMPFILE`
 112     rsa_e=`find_a_line RSA e $TMPFILE`
 113
 114     rsa_n=`line_to_sexpr "$rsa_n"`
 115     rsa_e=`line_to_sexpr "$rsa_e"`
 116
 117     echo -e $header$quotes"(public-key $escapes$nl\
 118 $starts$ind$mid(rsa $escapes$nl\
 119 $starts$ind$ind$mid(n $rsa_n) $escapes$nl\
 120 $starts$ind$ind$mid(e $rsa_e) $escapes$nl\
 121 $starts$ind$mid)$escapes$nl\
 122 $starts$mid)$quotes$nl";
 123     ;;
 124
 125     17)
 126     dsa_p=`find_a_line DSA p $TMPFILE`
 127     dsa_q=`find_a_line DSA q $TMPFILE`
 128     dsa_g=`find_a_line DSA g $TMPFILE`
 129     dsa_y=`find_a_line DSA y $TMPFILE`
 130
 131     dsa_p=`line_to_sexpr "$dsa_p"`
 132     dsa_q=`line_to_sexpr "$dsa_q"`
 133     dsa_g=`line_to_sexpr "$dsa_g"`
 134     dsa_y=`line_to_sexpr "$dsa_y"`
 135
 136     echo -e $header$quotes"(public-key $escapes$nl\
 137 $starts$ind$mid(dsa $escapes$nl\
 138 $starts$ind$ind$mid(p $dsa_p) $escapes$nl\
 139 $starts$ind$ind$mid(q $dsa_q) $escapes$nl\
 140 $starts$ind$ind$mid(g $dsa_g) $escapes$nl\
 141 $starts$ind$ind$mid(y $dsa_y)$escapes$nl\
 142 $starts$ind$mid)$escapes$nl\
 143 $starts$mid)$quotes$nl";
 144
 145     ;;
 146 esac
 147
 148 rm "$TMPFILE"