# NAME
Net::ACME2 - Client logic for the ACME (Let’s Encrypt) protocol
# SYNOPSIS
package SomeCA::ACME;
use parent qw( Net::ACME2 );
use constant {
DIRECTORY_PATH => '/acme-directory',
};
# %opts are the parameters given to new().
sub HOST {
my ($class, %opts) = @_;
# You can make this depend on the %opts if you want.
return 'acme.someca.net';
}
package main;
my $acme = SomeCA::ACME->new(
key => $account_key_pem_or_der,
key_id => undef,
);
#for a new account
{
my $terms_url = $acme->get_terms_of_service();
$acme->create_account(
termsOfServiceAgreed => 1,
);
}
#Save $acme->key_id() somewhere so you can use it again.
my $order = $acme->create_order(
identifiers => [
{ type => 'dns', value => '*.example.com' },
],
);
my $authz = $acme->get_authorization( ($order->authorizations())[0] );
my @challenges = $authz->challenges();
# ... Pick a challenge, and satisfy it.
$acme->accept_challenge($challenge);
sleep 1 while 'valid' ne $acme->poll_authorization($authz);
# ... Make a key and CSR for *.example.com
$acme->finalize_order($order, $csr_pem_or_der);
while ($order->status() ne 'valid') {
sleep 1;
$acme->poll_order($order);
}
# ... and now fetch the certificate chain:
my $pem_chain = $acme->get_certificate_chain($order);
See `/examples` in the distribution for more fleshed-out examples.
To use [Let’s Encrypt](
http://letsencrypt.org), see
[Net::ACME2::LetsEncrypt](
https://metacpan.org/pod/Net::ACME2::LetsEncrypt).
# DESCRIPTION
This library implements client logic for the
ACME (Automated Certificate Management Environment) protocol, as
standardized in [RFC 8555](
https://www.rfc-editor.org/rfc/rfc8555.txt)
and popularized by [Let’s Encrypt](
http://letsencrypt.org).
# STATUS
This is a production-grade implementation. While breaking changes at this
point are unlikely, please always check the changelog before upgrading to
a new version of this module.
# FEATURES
- Support for both ECDSA and RSA encrytion.
- Support for http-01, dns-01, and [tls-alpn-01](
https://datatracker.ietf.org/doc/draft-ietf-acme-tls-alpn/) challenges.
- Comprehensive error handling with typed, [X::Tiny](
https://metacpan.org/pod/X::Tiny)-based exceptions.
- This is a pure-Perl solution. Most of its dependencies are
either core modules or pure Perl themselves. XS is necessary to
communicate with the ACME server via TLS; however, most Perl installations
already include the necessary logic (i.e., [Net::SSLeay](
https://metacpan.org/pod/Net::SSLeay)) for TLS.
In short, Net::ACME2 will run anywhere that Perl can speak TLS, which is
_almost_ everywhere that Perl runs.
# ERROR HANDLING
All thrown exceptions are instances of [Net::ACME2::X::Base](
https://metacpan.org/pod/Net::ACME2::X::Base).
Specific error classes aren’t yet defined.
# SPEED
If you notice speed problems, check to see if your [Math::BigInt](
https://metacpan.org/pod/Math::BigInt)
installation can be made faster.
# METHODS
## _CLASS_->new( %OPTS )
Instantiates an ACME2 object, which you’ll use for all
interactions with the ACME server. %OPTS is:
- `key` - Required. The private key to associate with the ACME2
user. Anything that `Crypt::Perl::PK::parse_key()` can parse is acceptable.
- `key_id` - Optional. As returned by `key_id()`.
Saves a round-trip to the ACME2 server, so you should give this
if you have it.
- `directory` - Optional. A hash reference to use as the
directory contents. Saves a round-trip to the ACME2 server, but there’s
no built-in logic to determine when the cache goes invalid. Caveat
emptor.
## $id = _OBJ_->key\_id()
Returns the object’s cached key ID, either as given at instantiation
or as fetched in `create_account()`.
## $url = _OBJ_->get\_terms\_of\_service()
Returns the URL for the terms of service.
**NOTE:** For [Let’s Encrypt](
http://letsencrypt.org) you can
unofficially resolve against
[
https://acme-v01.api.letsencrypt.org/terms](
https://acme-v01.api.letsencrypt.org/terms) to see the terms
of service.
## $created\_yn = _OBJ_->create\_account( %OPTS )
Creates an account using the ACME2 object’s key and the passed
%OPTS, which are as described in the ACME2 spec (cf. `newAccount`).
Boolean values may be given as simple Perl booleans.
Returns 1 if the account is newly created
or 0 if the account already existed.
NB: `create_new_account()` is an alias for this method.
## $order = _OBJ_->create\_order( %OPTS )
Returns a [Net::ACME2::Order](
https://metacpan.org/pod/Net::ACME2::Order) object. %OPTS is as described in the
ACME spec (cf. `newOrder`). Boolean values may be given as simple
Perl booleans.
NB: `create_new_order()` is an alias for this method.
## $authz = _OBJ_->get\_authorization( $URL )
Fetches the authorization’s information based on the given $URL
and returns a [Net::ACME2::Authorization](
https://metacpan.org/pod/Net::ACME2::Authorization) object.
The URL is as given by [Net::ACME2::Order](
https://metacpan.org/pod/Net::ACME2::Order)’s `authorizations()` method.
## $str = _OBJ_->make\_key\_authorization( $CHALLENGE )
Accepts an instance of [Net::ACME2::Challenge](
https://metacpan.org/pod/Net::ACME2::Challenge) (probably a subclass
thereof) and returns
a key authorization string suitable for handling the given $CHALLENGE.
See `/examples` in the distribution for example usage.
If you’re using HTTP authorization and are on the same server as the
domains’ document roots, then look at the handler logic in
[Net::ACME2::Challenge::http\_01](
https://metacpan.org/pod/Net::ACME2::Challenge::http_01) for a potentially simpler way to
handle HTTP challenges.
## _OBJ_->accept\_challenge( $CHALLENGE )
Signal to the ACME server that the CHALLENGE is ready.
## $status = _OBJ_->poll\_authorization( $AUTHORIZATION )
Accepts a [Net::ACME2::Authorization](
https://metacpan.org/pod/Net::ACME2::Authorization) instance and polls the
ACME server for that authorization’s status. The $AUTHORIZATION
object is then updated with the results of the poll.
As a courtesy, this returns the $AUTHORIZATION’s new `status()`.
## $status = _OBJ_->finalize\_order( $ORDER, $CSR )
Finalizes an order and updates the $ORDER object with the returned
status. $CSR may be in either DER or PEM format.
As a courtesy, this returns the $ORDER’s `status()`. If this does
not equal `valid`, then you should probably `poll_order()`
until it does.
## $status = _OBJ_->poll\_order( $ORDER )
Like `poll_authorization()` but handles a
[Net::ACME2::Order](
https://metacpan.org/pod/Net::ACME2::Order) object instead.
## $cert = _OBJ_->get\_certificate\_chain( $ORDER )
Fetches the $ORDER’s certificate chain and returns
it in the format implied by the
`application/pem-certificate-chain` MIME type. See the ACME
protocol specification for details about this format.
# TODO
- Add pre-authorization support if there is ever a production
use for it.
- Expose the Retry-After header via the module API.
- There is currently no way to fetch an order or challenge’s
properties via URL. Prior to ACME’s adoption of “POST-as-GET” this was
doable via a plain GET to the URL, but that’s no longer possible.
If there’s a need, I’ll consider adding such logic to Net::ACME2.
(It’s trivial to add; I’d just like to keep things as
simple as possible.)
- Add (more) tests.
# SEE ALSO
[Crypt::Perl](
https://metacpan.org/pod/Crypt::Perl) provides this library’s cryptography backend. See
this distribution’s `/examples` directory for sample usage
to generate keys and CSRs.
[Net::ACME](
https://metacpan.org/pod/Net::ACME) implements client logic for the variant of this
protocol that Let’s Encrypt first deployed.