converted chroot-script 40_add_torprojects_key to postinst script

https://phabricator.whonix.org/T461

debian/anon-shared-build-apt-sources-tpo.postinst

@@ -0,0 +1,77 @@
+#!/bin/bash
+
+## This file is part of Whonix.
+## Copyright (C) 2012 - 2014 Patrick Schleizer <adrelanos@riseup.net>
+## See the file COPYING for copying conditions.
+
+if [ -f /usr/lib/pre.bsh ]; then
+   source /usr/lib/pre.bsh
+fi
+
+set -e
+
+tpo_keys_Add() {
+   ## The torproject archive key has been manually downloaded using the key fingerprint from
+   ## https://www.torproject.org/docs/debian.html.en and https://www.torproject.org/docs/signing-keys.html.en
+   ## using gpg:
+   ##    gpg --keyserver keys.gnupg.net --recv <long-key-id>
+   ## Verified using:
+   ##    gpg --list-sigs <long-key-id>
+   ##    gpg --check-sigs <long-key-id>
+   ## And added to Whonix source code using:
+   ##    gpg --armor --export <long-key-id> > /home/user/anon-shared-build-apt-sources-tpo/usr/share/anon-shared-build-apt-sources-tpo/tpoarchive-keys.d/torprojectarchive.asc
+
+   for key in "/usr/share/anon-shared-build-apt-sources-tpo/tpoarchive-keys.d/"*; do
+      filename="$(basename "$key")"
+      if [ "$filename" = "placeholder" ]; then
+         continue
+      fi
+      if [ "$filename" = "*" ]; then
+         ## Folder is empty.
+         continue
+      fi
+      apt-key add "$key"
+   done
+}
+
+true "
+#####################################################################
+## INFO: BEGIN: $DPKG_MAINTSCRIPT_PACKAGE $DPKG_MAINTSCRIPT_NAME ${1+"$@"}
+#####################################################################
+"
+
+case "$1" in
+   configure)
+      true "INFO: Configuring $DPKG_MAINTSCRIPT_PACKAGE..."
+
+      ## Doing this only once,
+      ## because when the user updates, the deb.torproject.org-keyring deb package is already
+      ## installed, which does a better job updating Tor Project's signing key.
+      if [ ! -f "/var/lib/anon-dist/do_once/tpo_keys_add" ]; then
+         tpo_keys_Add
+         mkdir --parents "/var/lib/anon-dist/do_once"
+         touch "/var/lib/anon-dist/do_once/tpo_keys_add"
+      fi
+
+      true "INFO: End configuring $DPKG_MAINTSCRIPT_PACKAGE."
+
+      ;;
+
+   *)
+      ;;
+esac
+
+true "INFO: debhelper beginning here."
+
+#DEBHELPER#
+
+true "INFO: Done with debhelper."
+
+true "
+#####################################################################
+## INFO: END  : $DPKG_MAINTSCRIPT_PACKAGE $DPKG_MAINTSCRIPT_NAME ${1+"$@"}
+#####################################################################
+"
+
+## Explicitly "exit 0", so eventually trapped errors can be ignored.
+exit 0