/pkix

PKIX certificates management for Erlang

Primary LanguageErlangApache License 2.0Apache-2.0

PKIX certificates management library for Erlang

CI Coverage Status Hex version

The idea of the library is to simplify certificates configuration in Erlang programs. Typically an Erlang program which needs certificates (for HTTPS/MQTT/XMPP/etc) provides a bunch of options such as certfile, chainfile, privkey, etc. The situation becomes even more complicated when a server supports so called virtual domains because a program is typically required to match a virtual domain with its certificate. If a user has plenty of virtual domains (stored somewhere in /etc/letsencrypt/live/*/*.pem) it's quickly becoming a nightmare for them to configure all this. The complexity also leads to errors: a single configuration mistake and a program generates obscure log messages, unreadable Erlang tracebacks or, even worse, just silently ignores the errors. Fortunately, the large part of certificates configuration can be automated, reducing a user configuration to something as simple as:

certfiles:
  - /etc/letsencrypt/live/*/*.pem

The purpose of the library is to do this dirty job under the hood.

System requirements

To compile the library you need:

  • Erlang/OTP ≥ 19.0
  • GNU Make. Optional: for running tests or standalone compilation.

Compiling

Since this is an embedded library, you need to add https://github.com/processone/pkix.git repo to your rebar configuration or what have you.

Usage

Start the library as a regular Erlang application:

> application:ensure_all_started(pkix).

or use pkix:start() which does the same.

Let's say you have two certificates: cert1.pem for domain1 and cert2.pem for domain2 with their private keys key1.pem and key2.pem and an intermediate CA certificate ca-intermediate.pem. Then the flow is the following:

  • Add all your PEM files to the "staged" area (the order doesn't matter):
> pkix:add_file("cert1.pem").
> pkix:add_file("cert2.pem").
> pkix:add_file("key1.pem").
> pkix:add_file("key2.pem").
> pkix:add_file("ca-intermediate.pem").
  • Commit the changes to some directory, let's say, "/tmp/certs":
> pkix:commit("/tmp/certs").

Now you're able to fetch a certificate file containing full chain and the private key for domain domain1 or domain2:

> pkix:get_certfile(<<"domain1">>).
{<<"/tmp/certs/7f9faada4a006091531cd37dafb70ca009630ac3">>,undefined,undefined}
> pkix:get_certfile(<<"domain2">>).
{undefined,<<"/tmp/certs/018e601430ed447e4bb767b2d610c6258c7a4e43">>,undefined}

The first element of the tuple is an EC certificate (presented in cert1.pem), the second element is an RSA certificate (presented in cert2.pem) and the third element is a DSA certificate (missing in our example).

API

TODO. Sorry, read the source so far.