View Source Charon.Config (Charon v3.2.0)

Config struct.

All config is read at runtime. So if, for example, you wish to override :session_ttl based on the username, you can simply alter the config struct in your code.

That being said, config that HAS to be read at runtime, like secrets, is stored as a getter to emphasize the fact and prevent you from accidentally setting a compile-time value even if you put the config struct in a module attribute. That is why the base secret has to be passed in via :get_base_secret.

Keys & defaults 

[
  :token_issuer,
  :get_base_secret,
  access_cookie_name: "_access_token_signature",
  access_cookie_opts: [http_only: true, same_site: "Strict", secure: true],
  # 15 minutes
  access_token_ttl: 15 * 60,
  enforce_browser_cookies: false,
  json_module: Jason,
  optional_modules: %{},
  refresh_cookie_name: "_refresh_token_signature",
  refresh_cookie_opts: [http_only: true, same_site: "Strict", secure: true],
  # 2 months
  refresh_token_ttl: 2 * 30 * 24 * 60 * 60,
  session_store_module: Charon.SessionStore.RedisStore,
  # 1 year
  session_ttl: 365 * 24 * 60 * 60,
  token_factory_module: Charon.TokenFactory.Jwt
]

Glossary

  • :access_cookie_name Name of the cookie in which the access token or its signature is stored.
  • :access_cookie_opts Options passed to Plug.Conn.put_resp_cookie/3. Note that :max_age is set by Charon.SessionPlugs based on the token TTL. Overrides are merged into the defaults.
  • :access_token_ttl Time in seconds until a new access token expires. This time may be reduced so that the token does not outlive its session.
  • :enforce_browser_cookies If a browser client is detected, enforce that tokens are not returned to it as fully valid bearer tokens, but are transported (wholly or in part) as cookies.
  • :get_base_secret Getter for Charon's base secret from which other keys are derived. Make sure it has large entropy (>= 256 bits). For example fn -> Application.get_env(:my_app, :charon_secret) end.
  • :json_module The JSON module, like Jason or Poison.
  • :optional_modules Configuration for optional modules, like Charon.TokenFactory.Jwt or CharonOauth2. See the optional module's docs for info on its configuration options.
  • :refresh_cookie_name Name of the cookie in which the refresh token or its signature is stored.
  • :refresh_cookie_opts Options passed to Plug.Conn.put_resp_cookie/3. Note that :max_age is set by Charon.SessionPlugs based on the token TTL. Overrides are merged into the defaults.
  • :refresh_token_ttl Time in seconds until a new refresh token expires. This time may be reduced so that the token does not outlive its session.
  • :session_store_module A module that implements Charon.SessionStore.Behaviour, used to store sessions.
  • :session_ttl Time in seconds until a new session expires OR :infinite for non-expiring sessions.
  • :token_factory_module A module that implements Charon.TokenFactory.Behaviour, used to create and verify authentication tokens.
  • :token_issuer Value of the "iss" claim in tokens, for example "https://myapp.com"

Summary

Types

t()

Functions

from_enum(enum)

Build config struct from enumerable (useful for passing in application environment). Raises for missing mandatory keys and sets defaults for optional keys. Optional modules must implement an init_config/1 function to process their own config at compile time.

Types

t()

@type t() :: %Charon.Config{
  access_cookie_name: String.t(),
  access_cookie_opts: keyword(),
  access_token_ttl: pos_integer(),
  enforce_browser_cookies: boolean(),
  get_base_secret: (() -> binary()),
  json_module: module(),
  optional_modules: map(),
  refresh_cookie_name: String.t(),
  refresh_cookie_opts: keyword(),
  refresh_token_ttl: pos_integer(),
  session_store_module: module(),
  session_ttl: pos_integer() | :infinite,
  token_factory_module: module(),
  token_issuer: String.t()
}

Functions

from_enum(enum)

@spec from_enum(Enum.t()) :: t()

Build config struct from enumerable (useful for passing in application environment). Raises for missing mandatory keys and sets defaults for optional keys. Optional modules must implement an init_config/1 function to process their own config at compile time.

Examples / doctests 

iex> from_enum([])
** (ArgumentError) the following keys must also be given when building struct Charon.Config: [:token_issuer, :get_base_secret]

iex> %Charon.Config{} = from_enum(token_issuer: "https://myapp", get_base_secret: "supersecure")