mdecrypt

#!/bin/sh

# usage: mdecrypt msgno msgno:msgno ...

# We temporarily store the passphrase in a file, which we assume is in
# an encrypted filesystem.  YMMV.  We should probably change this to
# use file descriptors instead.

MBLAZE=${MBLAZE-$HOME/.mblaze}
crypt_tmp=$(mhdr -h CryptTmp "$MBLAZE/profile")
[ -z "${crypt_tmp}" ] && crypt_tmp=$HOME/mine/tmp
crypt_file_cmd=$(mhdr -h CryptFileCmd "$MBLAZE/profile")
[ -z "${crypt_file_cmd}" ] && crypt_file_cmd="fdm -acrypto fetch"

read_password () {
	typeset something
	stty -echo
	read something
	stty echo
	echo "${something}"
}

read_passphrase () {
	typeset pp
	echo -n "passphrase: "
	pp=$(read_password)
	passphrase=${crypt_tmp}/pp
	echo ${pp} > ${passphrase}
}

passphrase=""

# scan the input files for to/cc/bcc addresses and display them.  we
# do this so the user knows what passphrase is appropriate
for picker in $*; do
	mpick ${picker} | while read filename; do
		mhdr -M -h to:cc:bcc ${filename}
	done
done 2>/dev/null | sort -u

# this drops the passphrase into the file named ${passphrase}
# it should really only be done into a cryptofs, c.f. the
# CryptoTmp profile setting
read_passphrase

# now iterate over all the messages again and run them through GnuPG
# with that passphrase.
for picker in $*; do
	mpick ${picker} | while read filename; do
		# pass the Date header around gpg's back since it
		# won't preserve it
		(echo -n 'Date: '; mhdr -h Date ${filename}; \
		 mshow -r ${filename} | gpg --passphrase-file=${passphrase}) |\
			${crypt_file_cmd}
	done
done

rm -fP ${crypt_tmp}/pp