feat: add some Radius protocol code (#2351)

* feat: add radius server

* feat: parse org from packet

* feat: add comment

* Update main.go

---------

Co-authored-by: hsluoyz <hsluoyz@qq.com>

radius/server_test.go

@@ -0,0 +1,62 @@
+// Copyright 2023 The Casdoor Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !skipCi
+// +build !skipCi
+
+package radius
+
+import (
+	"context"
+	"testing"
+
+	"layeh.com/radius"
+	"layeh.com/radius/rfc2865"
+)
+
+func TestAccessRequestRejected(t *testing.T) {
+	packet := radius.New(radius.CodeAccessRequest, []byte(`secret`))
+	rfc2865.UserName_SetString(packet, "admin")
+	rfc2865.UserPassword_SetString(packet, "12345")
+	vsa, err := radius.NewVendorSpecific(OrganizationVendorID, []byte("built-in"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	packet.Add(rfc2865.VendorSpecific_Type, vsa)
+	response, err := radius.Exchange(context.Background(), packet, "localhost:1812")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if response.Code != radius.CodeAccessReject {
+		t.Fatalf("Expected %v, got %v", radius.CodeAccessReject, response.Code)
+	}
+}
+
+func TestAccessRequestAccepted(t *testing.T) {
+	packet := radius.New(radius.CodeAccessRequest, []byte(`secret`))
+	rfc2865.UserName_SetString(packet, "admin")
+	rfc2865.UserPassword_SetString(packet, "123")
+	vsa, err := radius.NewVendorSpecific(OrganizationVendorID, []byte("built-in"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	packet.Add(rfc2865.VendorSpecific_Type, vsa)
+	response, err := radius.Exchange(context.Background(), packet, "localhost:1812")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if response.Code != radius.CodeAccessAccept {
+		t.Fatalf("Expected %v, got %v", radius.CodeAccessAccept, response.Code)
+	}
+}