1 files changed, 133 insertions, 0 deletions
diff --git a/misc/poc/firma-0.2.1 b/misc/poc/firma-0.2.1
new file mode 100755
index 0000000..13ee6da
--- /dev/null
+++ b/misc/poc/firma-0.2.1
@@ -0,0 +1,133 @@
+#!/bin/bash
+#
+# firma v0.2.1: simple encrypted mailing list aliases
+# feedback: rhatto@riseup.net luis@riseup.net | GPL
+#
+# list configuration is passed thru the config file,
+# where you put PARAMETER=value (whithout spaces)
+#
+# MAIL= path for mail program
+# GPG= path for gnupg binary
+# TMP= where you want the temp files
+# LISTNAME= list email
+# LISTADMIN= list administrator email addresses (space separated)
+# GPGDIR= gpg dir for the lists' keyring
+# PASSWD= passwd for the lists' keyring
+
+# eval the config file
+source $1
+
+# declare GPG variables
+GPGCOMMAND="$GPG --quiet --homedir $GPGDIR --batch --no-tty --no-use-agent --no-permission-warning"
+GPGLIST="$GPGCOMMAND --list-keys --with-colons"
+GPGDECRYPT="$GPGCOMMAND --passphrase-fd 0 --decrypt"
+GPGENCRYPT="$GPGCOMMAND --passphrase-fd 0 --always-trust --encrypt --sign --armor --hidden-recipient"
+
+# check configuration file parameters
+# todo: check if $TMP directory/files exist and if password is at least n characters long
+if [ ! -x $GPG -o ! -f $GPG ]; then
+  echo -e "\n$1: GPG binary ($GPG) could not be found.\n"
+  exit
+elif [ ! -x $MAIL -o ! -f $MAIL ]; then
+  echo -e "\n$1: Mail program ($MAIL) could not be found.\n"
+  exit
+elif [ ! -d $GPGDIR -o ! -f $GPGDIR/pubring.gpg -o ! -f $GPGDIR/secring.gpg ]; then
+  echo -e "\n$1: GPG home directory ($GPGDIR) or the GPG keyrings could not be found.\n"
+  exit
+elif [ -z $($GPGLIST | grep -o "<$LISTNAME>") ]; then
+  echo -e "\n$1: GPG key for list \"$LISTNAME\" could not be found."
+  echo -e "$1: Note that this parameter expects an email address.\n"
+  exit
+else
+  for ADMIN in $LISTADMIN; do {
+    if [ -z $($GPGLIST | grep -o "<$ADMIN>") ]; then
+      echo -e "\n$1: GPG key for list administrator \"$ADMIN\" could not be found."
+      echo -e "$1: Note that this parameter expects one or more email addresses.\n"
+      exit
+    fi; }
+  done
+fi
+
+# declare functions
+# discard $GPGDECRYPT STDOUT and get its STDERR instead, for signature checking
+function GPGSTDERR {
+  echo "$PASSWD" | ($GPGDECRYPT --status-fd 2 $TMP.gpg 1> /dev/null) 2>&1 ;
+}
+
+# get list susbscriber addresses
+function SUBSCRIBERS {
+  $GPGLIST | sed -n "/$LISTNAME/d;/pub/p" | grep -o "<.*>" | sed -e "s/[<>]//g" ;
+}
+
+# create the temporary files and restrict their permissions
+rm -f $TMP $TMP.gpg
+touch $TMP; chmod 600 $TMP;
+touch $TMP.gpg; chmod 600 $TMP.gpg;
+
+# todo: use an array
+while read STDIN; do
+  echo $STDIN >> $TMP
+done
+
+# get the message headers
+# todo: find a better place for $FROMADD since its not part of the message headers
+FROM=$(grep -m 1 "^From:" $TMP | cut -d : -f 2- | sed "s/^ //")
+FROMADD=$(echo $FROM | if grep -q "<" ; then echo $FROM | grep -o "<.*>" | sed -e "s/[<>]//g" ; else echo $FROM ; fi)
+DATE=$(grep -m 1 "^Date:" $TMP)
+SUBJECT=$(grep -m 1 "^Subject:" $TMP | cut -d : -f 2- | sed "s/^ //")
+
+# get the encrypted message
+sed -n "/-----BEGIN PGP MESSAGE-----/,/-----END PGP MESSAGE-----/p" $TMP >> $TMP.gpg
+
+# if signature is Good, encrypt and send it for each list subscriber
+# todo: declare a function to decrypt, re-encrypt and send the list messages
+if (GPGSTDERR | grep -q "GOODSIG") ; then
+
+  for EMAIL in $(SUBSCRIBERS); do 
+
+    echo "$PASSWD
+    Message from: $FROM
+    Subject: $SUBJECT
+    $DATE
+
+    $(GPGSTDERR | grep "gpg: Signature made")
+    $(GPGSTDERR | grep "gpg: Good signature from")
+
+$(echo "$PASSWD" | $GPGDECRYPT $TMP.gpg 2> /dev/null)" | sed -e "s/=20$//" | $GPGENCRYPT $EMAIL | $MAIL -r $LISTNAME $EMAIL
+
+  done
+
+# else, if signature is BAD, email it back to sender and to list admins
+elif (GPGSTDERR | grep -q "BADSIG") ; then
+
+    echo "$PASSWD
+    Message from: $FROM
+    Subject: [BAD SIGNATURE] $SUBJECT
+    $DATE
+
+    $(GPGSTDERR | grep "gpg: Signature made")
+    $(GPGSTDERR | grep "gpg: BAD signature from")
+
+$(echo "$PASSWD" | $GPGDECRYPT $TMP.gpg 2> /dev/null)" | sed -e "s/=20$//" | $GPGENCRYPT $LISTADMIN $FROMADD | $MAIL -r $LISTNAME $LISTADMIN $FROMADD
+
+# else, probably either the message was not signed or the sender is not subscribed to the list
+# email the message back to sender including a note about this
+# todo: parse STDERR to find out why the signature couldn't be checked and send more specific errors back to sender
+else
+
+    echo "
+    Message from: $FROM
+    Subject: [RETURNED MAIL] $SUBJECT
+    $DATE
+
+    [ It was not possible to process this message. Either or both
+      the message was not encrypted and/or signed, or you are not
+      subscribed to this list.  Contact the list administrator if
+      you have any questions. ]
+
+    -- 
+    firma v0.2.1" | $MAIL -r $LISTNAME $FROMADD
+
+fi
+ 
+rm -f $TMP $TMP.gpg