And the files

lib/jwt/claims_validator.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+require_relative 'error'
+
+module JWT
+  class ClaimsValidator
+    def initialize(payload)
+      Deprecations.warning('The ::JWT::ClaimsValidator class is deprecated and will be removed in future version of ruby-jwt')
+      @payload = payload
+    end
+
+    def validate!
+      Claims::Numeric.verify!(payload: @payload)
+
+      true
+    end
+  end
+end

lib/jwt/verify.rb

@@ -0,0 +1,118 @@
+# frozen_string_literal: true
+
+require 'jwt/error'
+
+module JWT
+  # JWT verify methods
+  class Verify
+    DEFAULTS = {
+      leeway: 0
+    }.freeze
+
+    class << self
+      %w[verify_aud verify_expiration verify_iat verify_iss verify_jti verify_not_before verify_sub verify_required_claims].each do |method_name|
+        define_method method_name do |payload, options|
+          new(payload, options).send(method_name)
+        end
+      end
+
+      def verify_claims(payload, options)
+        options.each do |key, val|
+          next unless key.to_s =~ /verify/
+
+          Verify.send(key, payload, options) if val
+        end
+      end
+    end
+
+    def initialize(payload, options)
+      Deprecations.warning('The ::JWT::Verify class is deprecated and will be removed in future version of ruby-jwt')
+      @payload = payload
+      @options = DEFAULTS.merge(options)
+    end
+
+    def verify_aud
+      return unless (options_aud = @options[:aud])
+
+      aud = @payload['aud']
+      raise JWT::InvalidAudError, "Invalid audience. Expected #{options_aud}, received #{aud || '<none>'}" if ([*aud] & [*options_aud]).empty?
+    end
+
+    def verify_expiration
+      return unless contains_key?(@payload, 'exp')
+      raise JWT::ExpiredSignature, 'Signature has expired' if @payload['exp'].to_i <= (Time.now.to_i - exp_leeway)
+    end
+
+    def verify_iat
+      return unless contains_key?(@payload, 'iat')
+
+      iat = @payload['iat']
+      raise JWT::InvalidIatError, 'Invalid iat' if !iat.is_a?(Numeric) || iat.to_f > Time.now.to_f
+    end
+
+    def verify_iss
+      return unless (options_iss = @options[:iss])
+
+      iss = @payload['iss']
+
+      options_iss = Array(options_iss).map { |item| item.is_a?(Symbol) ? item.to_s : item }
+
+      case iss
+      when *options_iss
+        nil
+      else
+        raise JWT::InvalidIssuerError, "Invalid issuer. Expected #{options_iss}, received #{iss || '<none>'}"
+      end
+    end
+
+    def verify_jti
+      options_verify_jti = @options[:verify_jti]
+      jti = @payload['jti']
+
+      if options_verify_jti.respond_to?(:call)
+        verified = options_verify_jti.arity == 2 ? options_verify_jti.call(jti, @payload) : options_verify_jti.call(jti)
+        raise JWT::InvalidJtiError, 'Invalid jti' unless verified
+      elsif jti.to_s.strip.empty?
+        raise JWT::InvalidJtiError, 'Missing jti'
+      end
+    end
+
+    def verify_not_before
+      return unless contains_key?(@payload, 'nbf')
+      raise JWT::ImmatureSignature, 'Signature nbf has not been reached' if @payload['nbf'].to_i > (Time.now.to_i + nbf_leeway)
+    end
+
+    def verify_sub
+      return unless (options_sub = @options[:sub])
+
+      sub = @payload['sub']
+      raise JWT::InvalidSubError, "Invalid subject. Expected #{options_sub}, received #{sub || '<none>'}" unless sub.to_s == options_sub.to_s
+    end
+
+    def verify_required_claims
+      return unless (options_required_claims = @options[:required_claims])
+
+      options_required_claims.each do |required_claim|
+        raise JWT::MissingRequiredClaim, "Missing required claim #{required_claim}" unless contains_key?(@payload, required_claim)
+      end
+    end
+
+    private
+
+    def global_leeway
+      @options[:leeway]
+    end
+
+    def exp_leeway
+      @options[:exp_leeway] || global_leeway
+    end
+
+    def nbf_leeway
+      @options[:nbf_leeway] || global_leeway
+    end
+
+    def contains_key?(payload, key)
+      payload.respond_to?(:key?) && payload.key?(key)
+    end
+  end
+end

spec/jwt/jwa_spec.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+RSpec.describe JWT::JWA do
+  describe '.create' do
+    it 'finds an algorithm' do
+      expect(described_class.create('HS256')).to be_a(JWT::JWA::Hmac)
+    end
+  end
+end