acme-client

A simple and unopinionated ACME client.

This module is written to handle communication with a Boulder/Let's Encrypt-style ACME API.

ACME specification: https://github.com/ietf-wg-acme/acme/blob/master/draft-ietf-acme-acme.md

Information on how the Boulder/Let's Encrypt API diverges from the ACME spec: https://github.com/letsencrypt/boulder/blob/master/docs/acme-divergences.md

ACME compatibility

acme-client	API	Style
>= v2.x	ACMEv2	Promise
== v1.x	ACMEv1	callback

Installation

Notice: With the release of acme-client v3.* Node v4 and v6 is no longer supported.

$ npm install acme-client

Usage

const acme = require('acme-client');

const accountPrivateKey = '<PEM encoded private key>';

const client = new acme.Client({
    directoryUrl: acme.directory.letsencrypt.staging,
    accountKey: accountPrivateKey
});

Directory URLs

acme.directory.letsencrypt.staging;
acme.directory.letsencrypt.production;

Cryptography

For key pair generation and Certificate Signing Requests, acme-client supports multiple interchangeable cryptographic engines.

acme.forge -- docs/forge.md

Recommended when node >= v10.12.0 or OpenSSL CLI dependency can not be met.

Uses node-forge, a pure JavaScript implementation of the TLS protocol.

This engine has no external dependencies since it is completely implemented in JavaScript, however CPU-intensive tasks (like generating a large size key pair) has a performance penalty and will be slower than doing it natively.

This caveat is removed in Node v10.12.0 with the introduction of crypto.generateKeyPair(), a native Node API for key pair generation. The forge engine will automatically use this API when available.

Example

const privateKey = await acme.forge.createPrivateKey();

const [certificateKey, certificateCsr] = await acme.forge.createCsr({
    commonName: '*.example.com',
    altNames: ['example.com']
})

acme.openssl -- docs/openssl.md

Recommended when node < v10.12.0 and OpenSSL CLI dependency can be met.

Uses openssl-wrapper to execute commands using the OpenSSL CLI.

This engine requires OpenSSL to be installed and available in $PATH.

Example

const privateKey = await acme.openssl.createPrivateKey();

const [certificateKey, certificateCsr] = await acme.openssl.createCsr({
    commonName: '*.example.com',
    altNames: ['example.com']
})

Auto mode

For convenience an auto() method is included in the client that takes a single config object. This method will handle the entire process of getting a certificate for one or multiple domains.

A full example can be found at examples/auto.js.

Documentation: docs/client.md#AcmeClient+auto

Example

const autoOpts = {
    csr: '<PEM encoded CSR>',
    email: 'test@example.com',
    termsOfServiceAgreed: true,
    challengeCreateFn: async (authz, challenge, keyAuthorization) => {},
    challengeRemoveFn: async (authz, challenge, keyAuthorization) => {}
}

const certificate = await client.auto(autoOpts);

API

For more fine-grained control you can interact with the ACME API using the methods documented below.

A full example can be found at examples/api.js.

Documentation: docs/client.md

Example

const account = await client.createAccount({
    termsOfServiceAgreed: true,
    contact: ['mailto:test@example.com']
});

const order = await client.createOrder({
    identifiers: [
        { type: 'dns', value: 'example.com' },
        { type: 'dns', value: '*.example.com' }
    ]
});

HTTP defaults

This module uses axios when communicating with the ACME API, and exposes the instance through .axios.

Should you, for example, need to change the default axios configuration to route requests through an HTTP proxy, this can be achieved as follows:

const acme = require('acme-client');

acme.axios.defaults.proxy = {
    host: '127.0.0.1',
    port: 9000
};

A complete list of axios options and documentation can be found at:

• https://github.com/axios/axios#request-config
• https://github.com/axios/axios#custom-instance-defaults

Debugging

acme-client uses debug for debugging which can be enabled by running

DEBUG=acme-client node index.js

License

MIT