View Source Joken Overview

Joken is a JWT (JSON Web Token) library centered on 4 core operations:

  • Generating claims: for instance, time based claims.
  • Signing: using a Joken.Signer.
  • Verifying: also using a Joken.Signer.
  • Validating: running custom validations for received claims.

These core functions are not coupled which allows you to configure Joken for only what you need: verifying and validating incoming tokens, generating tokens for other consumers or both.

It is based upon the awesome erlang-jose. Besides having a friendlier Elixir API we include some extras:

  • Simple key configuration. We provide optional built-in support with Elixir's Mix.Config system. See our configuration guide for more details;
  • Portable configuration using Joken.Claim;
  • Well-organized token logic by including the use Joken.Config statement in your own module;
  • Built-in claim generation and validation. erlang-jose is responsible only for signing and verifying token signatures. Here we provide extra tools for claims validation and generation;
  • Better error handling. We provide ExUnit like error messages for claim validation and configuration errors;
  • High-quality performance analysis for ensuring this hot-path in APIs won't be your bottleneck. Please see our performance documentation to learn more;
  • Good defaults. Joken comes with chosen good defaults for parsing JSON (Jason) and generating claims;
  • Extensible Joken functionality with hooks. All core actions in Joken have a corresponding hook for extending its functionality. See our hooks guide.

JWT algorithms

Joken supports all algorithms that JOSE supports. That includes:

  • All HS, RS, ES, PS signing algorithms.
  • All Edwards algorithms (Ed25519, Ed25519ph, Ed448, Ed448ph)

See jose JWS algorithm support for more information.

Usage

As easy as:

A key configuration:

# config/dev.exs
config :joken, default_signer: "secret"

Optionally, a signer instance:

signer = Joken.Signer.create("HS256", "secret")

A token module:

# lib/myapp/token.ex
defmodule MyApp.Token do
  use Joken.Config
end

Then, just use your module :)

{:ok, token, claims} = MyApp.Token.generate_and_sign()

extra_claims = %{"user_id" => "some_id"}
token_with_default_plus_custom_claims = MyApp.Token.generate_and_sign!(extra_claims)

{:ok, claims} = MyApp.Token.verify_and_validate(token)

# Example with a different key than the default
claims = MyApp.Token.verify_and_validate!(token, another_key)

Or with explicit signer:

signer = Joken.Signer.create("HS256", "secret")

{:ok, token, claims} = MyApp.Token.generate_and_sign(%{}, signer)

extra_claims = %{"user_id" => "some_id"}
token_with_default_plus_custom_claims = MyApp.Token.generate_and_sign!(extra_claims, signer)

{:ok, claims} = MyApp.Token.verify_and_validate(token, signer)

The default is to use HS256 with the configured binary as the key. It will generate:

  • aud: defaults to "Joken"
  • iss: defaults to "Joken"
  • jti: defaults to &Joken.generate_jti/0
  • exp: defaults to 2hs
  • nbf: defaults to current time
  • iat: defaults to current time

Everything is customizable in your token module. Please, see our configuration guide for all configuration options.