#!/bin/bash
#
# verifygpgmail - send email to confirm e-mail of gpg keys
# Copyright (C) 2003 Jörgen Cederlöf <jc@lysator.liu.se>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
# USA

echo "Change values inside.";exit 1

me="Jorgen Cederlof <jc@lysator.liu.se>"
bcc="jc+verifygpgmail@lysator.liu.se"
mesig="Jörgen"
mykey="0xe8c80c34"
policyurl="http://www.lysator.liu.se/~jc/signing-policy.html"
codeurl="http://www.lysator.liu.se/~jc/verifygpgmail.sh"
defaultserver="x-hkp://wwwkeys.de.pgp.net"

gpg="gpg" # Change to wrapper or something if needed.

for key in "$@"; do
  if ! echo "$key" |egrep '^[0-9a-fA-F]{8}$' >/dev/null; then
    echo "Keys must be in in a format like e8c80c34." >&2
    echo "The argument \"$key\" is not." >&2
    exit 1
  fi
  if ! gpg --list-keys "0x$key" >/dev/null; then  
    gpg --recv-keys "0x$key"
  fi
  if ! gpg --list-keys "0x$key" >/dev/null; then  
    echo "Unable to retreive key $key from keyserver."
    exit 3
  fi
done

for key in "$@"; do
  key="0x$key"
  addresses="$(gpg --list-keys "$key"|\
               sed -n -e 's/^pub  [0-9]*.\/[^ ]* [0-9-]* //p' \
	              -e 's/^uid *//p')"
  fpr="$(gpg --list-keys --with-fingerprint $key |sed 's/^/  /')"

  reg="something"
  while [ "$reg" != "" ]; do
    echo "About to send mail to these addresses:"
    echo ""
    echo "$addresses"
    echo ""
    echo "for the key:"
    echo "$fpr"
    echo ""
    echo "Press return or enter address regexp for addresses to use."
    read reg
    [ "$reg" != "" ] && addresses="$(echo "$addresses" |egrep "$reg")"
  done

  indentedaddresses="$(echo "$addresses" |sed 's/^/  /')"
  
echo "$addresses" | while read address; do

  echo "Sending mail to $address"

  cookie="$(dd if=/dev/random bs=1 count=6 2>/dev/null | \
            uuencode -m - | sed -n 2p)"

  if [ "$address" == "" ] || [ "$fpr" == "" ]; then
    echo "Very strange. Key not found." >&2
    exit 2
  fi
  name=$(echo "$address" |sed 's/ *<.*$//')

  enc="$($gpg  --quiet  --no-verbose --textmode --output - \
               --encrypt --sign --armor --always-trust \
	       --encrypt-to $mykey -r $key               <<EOF
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline

($cookie)

Hello $name,

The purpose of this mail is to verify that the email-address
   $address
really belongs to the person who gave me this OpenPGP key fingerprint:

$fpr
This mail has been sent to each of these addresses:

$indentedaddresses

Each mail contains a different random string. This one contains:

  $cookie

If this key belongs to you, please reply with a signed mail containing
this random string. If there are more than one addresses, you can
either reply from each one or send a single mail containing all the
strings.

When I have received all these random strings, I will sign your key
and upload it to a random list of keyservers, and the server
$defaultserver .

If you want the key uploaded to another server or mailed back to you,
say this in your reply.

My signing policy is available at:
   $policyurl
The code generating this mail is available at:
   $codeurl

While this mail was generated automatically your answer will be
handled manually. Feel free to add comments if you want.

  $mesig
EOF
)"

  boundary="B"
  while echo "$enc" | grep -q -F "$boundary"; do
    boundary="$(dd if=/dev/urandom bs=1 count=18 2>/dev/null |\
              uuencode -m - | sed -n '2s/[/+]//gp')"
  done

  message="From: $me
To: $address
Bcc: $bcc
Subject: Key signing, address verification
Mime-Version: 1.0
Content-Type: multipart/encrypted; protocol=\"application/pgp-encrypted\";
	boundary=\"$boundary\"
Content-Disposition: inline


--$boundary
Content-Type: application/pgp-encrypted
Content-Disposition: attachment

Version: 1

--$boundary
Content-Type: application/octet-stream
Content-Disposition: inline; filename=\"msg.asc\"

$enc

--$boundary--
"

  echo "$message" | /usr/lib/sendmail -t -F "$me"
  #echo --------------------------------------------
  #echo "$message"
  #echo --------------------------------------------
  
done; done