JWT

JSON Web Token (JWT)

Generation

JSON::JWT is a subclass of ActiveSupport::HashWithIndifferentAccess, so you can initialize it in ActiveSupport::HashWithIndifferentAccess way, and access any claims via JSON::JWT#[] like a Hash instance.

jwt = JSON::JWT.new(
  iss: 'nov',
  exp: 1.week.from_now,
  nbf: Time.now
)
jwt[:iss] # => 'nov'

To access JWT header, simply call JSON::JWT#header.

jwt.header # => {typ: :JWT, alg: :none}
jwt.header[:kid] = 'default-key'

Several common header attributes has its shortcut methods (both read & write).

jwt.kid = 'default-key'
jwt.kid # => 'default-key'

jwt.alg = :RS256
jwt.alg # => :RS256

jwt.header # => {typ: :JWT, alg: :RS256, kid: 'default-key'}

Serialization

Simply call JSON::JWT#to_s.

Compact Serialization

jwt.to_s
# => 'eyJ0eXAiOiJKV1QiLCJhbGciOiJub25lIn0.eyJpc3MiOiJub3YiLCJleHAiOjE0NDExNzk0NDEsIm5iZiI6MTQ0MDU3NDY0MX0.'

JSON Serialization

This gem also supports JWS/JWE Flattened and General JSON Serialization, multiple signature isn't supported though.

jwt.as_json(syntax: :general)
jwt.as_json(syntax: :flattened)

NOTE: Theoretically, JWT is defined as always Compact-Seiralized, so that JSON-Serialized one isn't JWT in its definition. Only JWS and JWE spec define JSON Serialization.