This is an Acme Protocol implementation written fully using PHP language. It allows you to create manage and revoke certificates using ACME protocol used by Let's Encrypt

Its aim is to be used by hosting control panel software and hosting companies using PHP for their hosting panel.

We use PSR-norms for PHP to build this library, mainly PSR 0,1,2,3,4. Thanks to that, you can use a composer.json description file or ./composer.phar install octopuce/acmephpc to get this library. All dependencies will follow.

The dependencies are: gree/jose for Json Web Signature implementation, phpseclib for PHP RSA and X.509 implementation, and phpunit if you want to launch unit tests.

This library consists of the following classes and interfaces:

The main Octopuce\Acme\Client class, with public methods to launch API calls to ACME-Compliant
server, creating accounts (reg) Authorization on domains (authz), solving challenges to prove you own those domains, and asking for certificates (cert) or revocation of existing ones (revoke).

This library depends on the following others, provided either with a fully-working code, or with example of Interface you'll have to customize:

• a Storage Interface implementing Octopuce\Acme\StorageInterface. a StoragePdo class is provided, along with the SQL schema for MySQL and SQLite. The schema is very simple and is known to work with Postgresql or others. This stores the private keys of accounts and certificates, the certificates and the authorization and challenges objects locally. You may want to implement a link to your favorite HSM here...

• an HTTP Client Interface, implementing Octopuce\Acme\HttpClientInterface. a HttpClientCurl class is provided, using php5-curl calls to do HTTP Get or Post calls. If you want to implement your own for some reasons, please know that we need to do Get and Post HTTP calls, and be able to get the headers answered by the HTTP, since ACME protocol use headers to provide with useful information.

• a (non mandatory) PSR-3 Logger Interface, implementing \Psr\Log\LoggerInterface. No example is provided, use existing code to store your logs where you want. Not used as of now, need code here

• an SSL Interface, implementing Octopuce\Acme\SslInterface. a SslPhpseclib class is provided, using phpseclib to provide you with the necessary SSL and X.509 methods to create RSA keys, generate CSR, revocation requests, and convert PEM-encoded X.509 structure to DER.

To prove you own a domain name, Acme ask you to solve a challenge, either :

• by publishing a HTTP page at a .well-known URL,
• or by answering a challenge using SNI on the domain's server,
• or by setting some records in your domain's DNS zone.

Those challenge need to interact with the system of your server, so you'll likely change the code we give you there. That said, we provide you with example for AlternC, a free-software web control panel for Debian GNU/Linux. Those challenge-solving classes are plugins implementing the Octopuce\Acme\ValidationPluginInterface. This is the ValidationApache class.

If your plugin can't configure a DNS, HTTP or SNI challenge immediately when called, your plugin can answer with a "in progress" reply, so the ACME Library will have to ask for it again later, and your plugin will have to check that the challenge is ready before saying "OK". Then we will ask the ACME server to check the challenge.

The tests/ folder contains unit tests you can launch using phpunit library. They test all features and exceptions and should work fine.

The example/ folder contains example you can run, after changing the config.sample.php, then launch the <10-100>_*.php scripts in that order for each step of the ACME certificate enrollment process. It also shows you how you can use this library.

Benjamin Sonntag is the main author of this library, mainly for Octopuce, his hosting company in Paris, France, and for AlternC, a hosting control panel free software.

If you want to help improving or managing this library, you can start by reporting bugs using github bug reporting, or just contact us by sending a mail to benjamin at octopuce dot fr.

We still need help

• filling the unit tests (checking JWS object signature and structure is booooring)
• implementing automatic renewal through a proposed crontab
• writing plugins for DNS and SNI validations for bind9, apache2, nginx etc.
• maybe adds new API calls to say which FQDN shall be automatically renewed (since certificates are only valid for 90 days, automatic renewal is a must having ofc)
• doing the Logging using PSR-3-style logging

• maybe use Guzzle instead of having our own HTTPClient lib ? (although we need support for multiple HTTP answer headers having the same name, like "Link")
• <insert yours here ;) >

This software is distributed under LGPLv2+ license. see the LICENSE file for complete license terms.