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.

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"])
...>   ]
...> )

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.

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.

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

def deps do
  [
    {:x509, "~> 0.5.0"}
  ]
end

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