commit 7d4715c9f519dfc97ca5e43b4455ab77563bd423
Author: Florian Obser <florian@narrans.de>
Date:   Sun Apr 23 09:22:00 2017 +0200

    Initial commit

diff --git a/gen_tlsa.pl b/gen_tlsa.pl
new file mode 100755
index 0000000..1d05000
--- /dev/null
+++ b/gen_tlsa.pl
@@ -0,0 +1,41 @@
+#! /usr/bin/perl
+use strict;
+use warnings;
+use 5.010;
+use autodie;
+
+use Digest::SHA;
+use MIME::Base64;
+
+
+use constant WAIT_BEGIN => 1;
+use constant WAIT_END =>2;
+
+sub usage {
+    say STDERR "$0 DNS-LABEL CERT-FILE";
+    exit(1);
+}
+
+usage() if (scalar(@ARGV) != 2);
+
+my $state = WAIT_BEGIN;
+my $pem = '';
+
+open(my $fh, '<', $ARGV[1]);
+while(my $line = <$fh>) {
+    if ($state == WAIT_BEGIN) {
+	if ($line=~/^-----BEGIN CERTIFICATE-----/) {
+	    $state = WAIT_END;
+	}
+    } elsif ($state == WAIT_END) {
+	if ($line=~/^-----END CERTIFICATE-----/) {
+	    last;
+	} else {
+	    $pem.=$line;
+	}
+    }
+}
+close($fh);
+say $ARGV[0], ' IN TLSA 1 0 1 ', Digest::SHA::sha256_hex(decode_base64($pem));
+
+#say $pem;