Missing files

lib/jwt/kms/hmac_key.rb

@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+module JWT
+  module KMS
+    # Represent a AWS HMAC key
+    # https://docs.aws.amazon.com/kms/latest/developerguide/hmac.html
+    class HmacKey
+      include JWT::JWA::SigningAlgorithm
+
+      MAPPINGS = {
+        "HMAC_256" => { alg: "HS256", mac_algorithm: "HMAC_SHA_256" },
+        "HMAC_384" => { alg: "HS384", mac_algorithm: "HMAC_SHA_384" },
+        "HMAC_512" => { alg: "HS512", mac_algorithm: "HMAC_SHA_512" }
+      }.freeze
+
+      def initialize(key_id:, key_spec: nil)
+        @key_id = key_id
+        @key_spec = key_spec
+      end
+
+      def alg
+        MAPPINGS.dig(key_spec, :alg)
+      end
+
+      def sign(data:, **)
+        KMS.client.generate_mac(key_id: key_id, mac_algorithm: mac_algorithm, message: data).mac
+      end
+
+      def verify(data:, signature:, **)
+        KMS.client.verify_mac(key_id: key_id, mac_algorithm: mac_algorithm, message: data, mac: signature).mac_valid
+      end
+
+      private
+
+      attr_reader :key_id
+
+      def key_spec
+        @key_spec ||= description.key_spec
+      end
+
+      def mac_algorithm
+        MAPPINGS.dig(key_spec, :mac_algorithm)
+      end
+
+      def description
+        @description ||= KMS.client.describe_key(key_id: key_id)
+      end
+    end
+  end
+end