Class: JWT::JWK::KeyFinder

Inherits:
Object
  • Object
show all
Defined in:
lib/jwt/jwk/key_finder.rb

Overview

JSON Web Key keyfinder To find the key for a given kid

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ KeyFinder

Initializes a new KeyFinder instance.

Parameters:

  • options (Hash) —

    the options to create a KeyFinder with

Options Hash (options):

  • :jwks (Proc, JWT::JWK::Set) —

    the jwks or a loader proc

  • :allow_nil_kid (Boolean) —

    whether to allow nil kid

  • :key_fields (Array) —

    the fields to use for key matching, the order of the fields are used to determine the priority of the keys.



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# File 'lib/jwt/jwk/key_finder.rb', line 15

def initialize(options)
  @allow_nil_kid = options[:allow_nil_kid]
  jwks_or_loader = options[:jwks]

  @jwks_loader = if jwks_or_loader.respond_to?(:call)
                   jwks_or_loader
                 else
                   ->(_options) { jwks_or_loader }
                 end

  @key_fields = options[:key_fields] || %i[kid]
end

Instance Method Details

#call(token) ⇒ Object

Returns the key for the given token

Parameters:

Raises:



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# File 'lib/jwt/jwk/key_finder.rb', line 43

def call(token)
  @key_fields.each do |key_field|
    field_value = token.header[key_field.to_s]

    return key_for(field_value, key_field) if field_value
  end

  raise ::JWT::DecodeError, 'No key id (kid) or x5t found from token headers' unless @allow_nil_kid

  kid = token.header['kid']
  key_for(kid)
end

#key_for(kid, key_field = :kid) ⇒ Object

Returns the verification key for the given kid

Parameters:

  • kid (String) —

    the key id

Raises:



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# File 'lib/jwt/jwk/key_finder.rb', line 30

def key_for(kid, key_field = :kid)
  raise ::JWT::DecodeError, "Invalid type for #{key_field} header parameter" unless kid.nil? || kid.is_a?(String)

  jwk = resolve_key(kid, key_field)

  raise ::JWT::DecodeError, 'No keys found in jwks' unless @jwks.any?
  raise ::JWT::DecodeError, "Could not find public key for kid #{kid}" unless jwk

  jwk.verify_key
end