diff -r 236696558ccb -r 4f50e6aa028b scratch/verify
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scratch/verify	Wed Jan 04 09:21:35 2012 +0100
@@ -0,0 +1,82 @@
+#! /usr/bin/perl
+
+use 5.010;
+use strict;
+use warnings;
+use File::Temp;
+use GnuPG;
+use autodie qw(:all);
+
+use blib;
+use Message::2822;
+
+umask(077);
+my $dir = File::Temp->newdir();
+
+my $signed = Message::2822->new(file => shift // "ex/mails/signed");
+
+# output the original message if not 'multipart/sign'
+my ($content_type) = ($signed->header_lines(qr/^content-type/i) =~ /\s+(\S+)/i);
+unless ($content_type =~ /multipart\/signed/i) {
+    print $signed->header_lines, "\n";
+    print $signed->orig_body;
+    exit 0;
+}
+
+my ($boundary) =
+  ($signed->header_lines(qr/^content-type/i) =~ /boundary=['"](.*?)['"]/);
+
+open(my $body, "+>$dir/body");
+print {$body} $signed->orig_body;
+seek($body, 0, 0);
+
+# cut the message
+open(my $message, "+>$dir/message");
+my $last_line = "";
+while (<$body>) {
+    last if ($last_line =~ /^\s+$/ and /^--\Q$boundary\E/);
+    next if (/^--\Q$boundary\E/);
+    s/\r?\n/\r\n/g;
+    print {$message} $last_line;
+    $last_line = $_;
+}
+
+# cut the signature
+open(my $signature, "+>$dir/message.sig");
+my $in_sign = 0;
+while (<$body>) {
+    if (/^-----BEGIN\s+PGP\s+SIGNATURE-----$/ or $in_sign) {
+        if (/^-----END\s+PGP\s+SIGNATURE-----$/) {
+            $in_sign = 0;
+            print {$signature} $_;
+        }
+        else {
+            $in_sign = 1;
+            print {$signature} $_;
+        }
+    }
+}
+
+seek($message,   0, 0);
+seek($signature, 0, 0);
+
+# ask GPG to verify it…
+my $gpg = new GnuPG(homedir => "ex/gpg");
+my $sign;
+eval {
+    $sign =
+      ($gpg->verify(signature => "$dir/message.sig", file => "$dir/message"));
+};
+if ($@) {
+    $signed->add_header_line("\nX-GPGate-Sign: bad signature\n");
+    print $signed->header_lines, "\n";
+    print $signed->orig_body;
+    exit 0;
+}
+
+$signed->add_header_line("\nX-GPGate-Sign: good signature\n");
+$signed->add_header_line("X-GPGate-SignUser: $sign->{user}\n");
+$signed->add_header_line("X-GPGate-KeyId: $sign->{keyid}\n");
+
+print $signed->header_lines, "\n";
+print $signed->orig_body;