From 952d12825c2c480a839680d3c2ca0bd67a46aaac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C5=99emysl=20Janouch?= <p.janouch@gmail.com>
Date: Tue, 16 May 2017 20:13:29 +0200
Subject: [PATCH] Future proofing on Let's Encrypt

---
 acme-tinier.pl | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/acme-tinier.pl b/acme-tinier.pl
index 22fd443..a09f112 100755
--- a/acme-tinier.pl
+++ b/acme-tinier.pl
@@ -2,6 +2,9 @@
 # This is a simplified rewrite of acme-tiny in Perl, since Python 3 is 125 MiB
 # but Perl is everywhere and JSON::PP mostly in default installations.
 # Depends on curl and openssl.
+#
+# TODO: eventually the ACME protocol will stabilize:
+#   https://github.com/ietf-wg-acme/acme/blob/master/draft-ietf-acme-acme.md
 use strict;
 use warnings;
 use MIME::Base64 qw(encode_base64 encode_base64url);
@@ -46,7 +49,7 @@ sub communicate {
 	return $resp;
 }
 
-# Use cURL to download a file over HTTPS but parse it ourselves
+# Use cURL to download a file over HTTPS but parse it ourselves (quite silly)
 sub get {
 	my ($url, $data) = @_;
 	my @args = ('curl', '-sS', '-D-', '-H', 'Expect:');
@@ -55,7 +58,7 @@ sub get {
 	die 'cannot download' if $? >> 8;
 	my ($code, $headers, $body) =
 		$resp =~ m#\AHTTP/\d\.\d (\d+) .*?\r\n(.*?)\r\n\r\n(.*)#sm;
-	return ($code, $body, { $headers =~ /(\S+?): (.*)$/mg })
+	return ($code, $body, { $headers =~ /(\S+?): (.*)\r\n/mg })
 }
 
 # Make a signed request to an ACME endpoint
@@ -87,11 +90,12 @@ push @domains, map { substr $_, 4 } grep { /^DNS:/ } split(/, /)
 	for $csr =~ /X509v3 Subject Alternative Name: \n +([^\n]+)\n/g;
 
 # Get certificate domains and expiration
-# FIXME: don't hardcode the agreement, that may stop working
-my ($code, $result) = send_signed("$ca/acme/new-reg", {
+my ($code, $result, $headers) = get "$ca/terms";
+($code, $result) = send_signed("$ca/acme/new-reg", {
 	resource => 'new-reg',
-	agreement => 'https://letsencrypt.org/documents/'
-		. 'LE-SA-v1.1.1-August-1-2016.pdf'
+	agreement => ($code == 302 && exists $headers->{Location})
+		? $headers->{Location}
+		: 'https://letsencrypt.org/documents/LE-SA-v1.1.1-August-1-2016.pdf'
 });
 die "cannot register: $code" if $code != 201 && $code != 409;