View Source AshAuthentication.Jwt (ash_authentication v4.2.5)
Uses the excellent joken
hex package to generate and sign Json Web Tokens.
Configuration
There are a few things we need to know in order to generate and sign a JWT:
signing_algorithm
- the crypographic algorithm used to to sign tokens.token_lifetime
- how long the token is valid for (in hours).signing_secret
- the secret key used to sign the tokens.
These can be configured in your resource's token DSL:
defmodule MyApp.Accounts.User do
# ...
authentication do
tokens do
token_lifetime 32
signing_secret fn _, _ ->
System.fetch_env("TOKEN_SIGNING_SECRET")
end
end
end
# ...
end
The signing secret is retrieved using the AshAuthentication.Secret
behaviour, which means that it can be retrieved one of three ways:
- As a string directly in your resource DSL (please don't do this unless you know why this is a bad idea!), or
- a two-arity anonymous function which returns
{:ok, secret}
, or - the name of a module which implements the
AshAuthentication.Secret
behaviour.
Available signing algorithms are EdDSA, Ed448ph, Ed448, Ed25519ph, Ed25519, PS512, PS384, PS256, ES512, ES384, ES256, RS512, RS384, RS256, HS512, HS384 or HS256. Defaults to HS256.
We strongly advise against storing the signing secret in your mix config or
directly in your resource configuration. We instead suggest you make use of
runtime.exs
and read it from the system environment or other secret store.
The default token lifetime is 168 and should be specified in integer positive hours.
Summary
Types
"claims" are the decoded contents of a JWT. A map of (short) string keys to string values.
A string likely to contain a valid JWT.
Functions
The default signing algorithm
The default token lifetime
Given a token, read it's claims without validating.
Supported signing algorithms
Given a resource, generate a signed JWT with a set of claims.
Given a user, generate a signed JWT for use while authenticating.
Given a token, find a matching resource configuration.
Given a token, verify it's signature and validate it's claims.
Types
"claims" are the decoded contents of a JWT. A map of (short) string keys to string values.
@type token() :: String.t()
A string likely to contain a valid JWT.
Functions
@spec default_algorithm() :: String.t()
The default signing algorithm
@spec default_lifetime_hrs() :: pos_integer()
The default token lifetime
Given a token, read it's claims without validating.
@spec supported_algorithms() :: [String.t()]
Supported signing algorithms
@spec token_for_resource( Ash.Resource.t(), extra_claims :: map(), options :: keyword() ) :: {:ok, token(), claims()} | :error
Given a resource, generate a signed JWT with a set of claims.
@spec token_for_user( Ash.Resource.record(), extra_claims :: map(), options :: keyword() ) :: {:ok, token(), claims()} | :error
Given a user, generate a signed JWT for use while authenticating.
@spec token_to_resource(token(), module()) :: {:ok, Ash.Resource.t()} | :error
Given a token, find a matching resource configuration.
Warning
This function does not validate the token, so don't rely on it for authentication or authorisation.
@spec verify(token(), Ash.Resource.t() | atom()) :: {:ok, claims(), Ash.Resource.t()} | :error
Given a token, verify it's signature and validate it's claims.