Pass kid param through JWT::JWK.create_from

README.md

@@ -495,7 +495,7 @@ JWT.decode token, hmac_secret, true, { required_claims: ['exp'], algorithm: 'HS2
 JWK is a JSON structure representing a cryptographic key. Currently only supports RSA public keys.
 
 ```ruby
-jwk = JWT::JWK.new(OpenSSL::PKey::RSA.new(2048))
+jwk = JWT::JWK.new(OpenSSL::PKey::RSA.new(2048), "optional-kid")
 payload, headers = { data: 'data' }, { kid: jwk.kid }
 
 token = JWT.encode(payload, jwk.keypair, 'RS512', headers)

lib/jwt/jwk.rb

@@ -14,10 +14,10 @@ def import(jwk_data)
         end.import(jwk_data)
       end
 
-      def create_from(keypair)
+      def create_from(keypair, kid = nil)
         mappings.fetch(keypair.class) do |klass|
           raise JWT::JWKError, "Cannot create JWK from a #{klass.name}"
-        end.new(keypair)
+        end.new(keypair, kid)
       end
 
       def classes

spec/jwk_spec.rb

@@ -41,7 +41,8 @@
   end
 
   describe '.new' do
-    subject { described_class.new(keypair) }
+    let(:kid) { nil }
+    subject { described_class.new(keypair, kid) }
 
     context 'when RSA key is given' do
       let(:keypair) { rsa_key }
@@ -57,5 +58,13 @@
       let(:keypair) { ec_key }
       it { is_expected.to be_a ::JWT::JWK::EC }
     end
+
+    context 'when kid is given' do
+      let(:keypair) { rsa_key }
+      let(:kid) { "CUSTOM_KID" }
+      it 'sets the kid' do
+        expect(subject.kid).to eq(kid)
+      end
+    end
   end
 end