diff -r 236696558ccb -r 4f50e6aa028b scratch/sign
--- a/scratch/sign	Mon Dec 12 13:30:04 2011 +0100
+++ b/scratch/sign	Wed Jan 04 09:21:35 2012 +0100
@@ -4,6 +4,7 @@
 use strict;
 use warnings;
 use File::Temp;
+use GnuPG;
 use autodie qw(:all);
 
 use Digest::MD5 qw(md5_hex);
@@ -13,45 +14,71 @@
 
 umask(077);
 my $boundary = md5_hex(time);
-my $dir = File::Temp->newdir();
+my $dir      = File::Temp->newdir();
+
+my $unsigned = Message::2822->new(file => shift // "ex/mails/unsigned");
+
+# copy the changed body into a tmp file and copy there the
+# changed content-header lines
+open(my $message, "+>$dir/message");
 
-my $unsigned = Message::2822->new(file => shift//"ex/mails/unsigned");
-
+open(my $header, "+>$dir/header");
+print {$header} $unsigned->header_lines(qr/^content-/i);
+seek($header, 0, 0);
+while (<$header>) {
+    s/\r?\n/\r\n/g;
+    print {$message} $_;
+}
+print {$message} "\r\n";
 
-# copy the body into a tmp file and copy there the content-
-# header lines
-open(my $message, "+>$dir/message");
-print {$message}
-    $unsigned->header_lines(qr/^content-/i), "\n",
-    $unsigned->orig_body;
+open(my $body, "+>$dir/body");
+print {$body} $unsigned->orig_body;
+seek($body, 0, 0);
+while (<$body>) {
+    s/\r?\n/\r\n/g;
+    print {$message} $_;
+}
+
 $message->flush();
 
+# ask GPG to sign it…
+open(my $sig, "+>$dir/signature.asc");
+my $gpg = new GnuPG(homedir => "ex/gpg");
+seek($message, 0, 0);
+eval {
+    $gpg->sign(
+        plaintext     => $message,
+        'detach-sign' => 1,
+        armor         => 1,
+        output        => $sig
+    );
+};
+
+if ($@) {
+    $unsigned->add_header_line("X-GPGate-signed: not\n");
+    print $unsigned->header_lines, "\n";
+    print $unsigned->orig_body;
+    exit 0;
+}
+
 # now remove the unwanted content- header lines and add new ones
 $unsigned->remove_header_lines(qr/^content-.*?:/im);
 
 $unsigned->add_header_line("Content-Type: "
-    . "multipart/signed; micalg=pgp-sha1;\n"
-    . "\tprotocol=\"application/pgp-signature\"; boundary=\"$boundary\"");
+      . "multipart/signed; micalg=pgp-sha1;\n"
+      . "\tprotocol=\"application/pgp-signature\"; boundary=\"$boundary\"");
 $unsigned->add_header_line("Content-Disposition: inline");
 
-
-# ask GPG to sign it…
-system("gpg",
-    "--rfc1991",
-    "--detach-sign",
-    "--homedir" => "ex/gpg",
-    "--armor" => "$dir/message");
-
-open(my $sig, "$dir/message.asc");
-
+$unsigned->add_header_line("X-GPGate-signed: yes\n");
 print $unsigned->header_lines, "\n";
 
 seek($message, 0, 0);
+seek($sig,     0, 0);
 
 print "--${boundary}\n",
-      <$message>, "\n",
-      "--${boundary}\n",
-      <<___, <$sig>, "\n--${boundary}--\n";
+  <$message>, "\n",
+  "--${boundary}\n",
+  <<___, <$sig>, "--${boundary}--\n";
 Content-Type: application/pgp-signature; name="signature.asc"
 Content-Description: Digital Signature
 Content-Disposition: inline