X509

Elixir package for working with X.509 certificates, Certificate Signing Requests (CSRs), Certificate Revocation Lists (CRLs) and RSA/ECC key pairs.

Requires Erlang/OTP 20.1 or later.

Development and public release of this package were made possible by Bluecode.

Usage

As a Certificate Authority (CA)

Generate a self-signed CA certificate and private key, using the root_ca template:

iex> ca_key = X509.PrivateKey.new_ec(:secp256r1)
{:ECPrivateKey, ...}
iex> ca = X509.Certificate.self_signed(ca_key,
...>   "/C=US/ST=CA/L=San Francisco/O=Acme/CN=ECDSA Root CA",
...>   template: :root_ca
...>)
{:OTPCertificate, ...}

Use the CA certificate to issue a server certificate, using the default server template and the given SAN hostnames:

iex> my_key = X509.PrivateKey.new_ec(:secp256r1)
{:ECPrivateKey, ...}
iex> my_cert = my_key |>
...> X509.PublicKey.derive() |>
...> X509.Certificate.new(
...>   "/C=US/ST=CA/L=San Francisco/O=Acme/CN=Sample",
...>   ca, ca_key,
...>   extensions: [
...>     subject_alt_name: X509.Certificate.Extension.subject_alt_name(["example.org", "www.example.org"])
...>   ]
...> )
{:OTPCertificate, ...}

Or sign a certificate based on an incoming CSR:

iex> csr = X509.CSR.from_pem!(pem_string)
{:CertificationRequest, ...}
iex> subject = X509.CSR.subject(csr)
{:rdnSequence, ...}
iex> my_cert = csr |>
...> X509.CSR.public_key() |>
...> X509.Certificate.new(
...>   subject,
...>   ca, ca_key,
...>   extensions: [
...>     subject_alt_name: X509.Certificate.Extension.subject_alt_name(["example.org", "www.example.org"])
...>   ]
...> )

With :public_key for encryption/signing

Please refer to the documentation for the X509.PrivateKey module for examples showing asymmetrical encryption and decryption, as well as message signing and verification, with Erlang/OTP's :public_key APIs.

For TLS client/server testing

The x509.gen.selfsigned Mix task generates a self-signed certificate for use with a TLS server in development or testing.

The X509.Test.Suite and X509.Test.Server modules may be used to create test cases for TLS clients. The server_test.exs file can serve as a template: update the request/2 function to invoke of the TLS client under test, make sure it returns the expected response format, and update the test server's canned response in the test module's setup if necessary.

You may want to include the X509 package only in the 'dev' and/or 'test' environments for this use-case, by adding an only: ... clause to the dependency definition in your Mix file.

Installation

Add x509 to your list of dependencies in mix.exs:

def deps do
  [
    {:x509, "~> 0.8"}
  ]
end

Documentation can be found at https://hexdocs.pm/x509.

License

Copyright (c) 2019, Bram Verburg All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

• Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.