zvkemp/hmac_auth_ex

Elixir version of hmac auth

HMACAuth

Intended to be compatible with the ruby version at http://www.github.com/zvkemp/hmac_auth.

Note:

If used to verify POST requests, the included HMACAuthEx.Plug must be used before Plug.Parsers (it requires access to the raw request body, which is removed by json parsing et al).

Installation

If available in Hex, the package can be installed as:

1. Add hmac_auth_ex to your list of dependencies in mix.exs:

def deps do
  [{:hmac_auth_ex, "~> 0.3.0"}]
end

2. Add the required config in config/{env}.exs:

  config :hmac_auth_ex, keys: %{key => value}

3. Ensure hmac_auth_ex is started before your application:

def application do
  [applications: [:hmac_auth_ex]]
end

4. (Optional) If using the plug, add this to your endpoint (usually before the router):

plug HMACAuthEx.Plug

This will add an hmac_verified: boolean key to conn.private. A basic authentication function might look like this:

  defp authenticate(conn, _) do
    cond do
      Mix.env == :dev -> conn # to skip verification in the dev environment
      conn.private.hmac_verified -> conn
      true ->
        conn
        |> put_status(:unauthorized)
        |> json(%{error: :signature})
        |> halt
    end
  end