feat: add accessPolicy middleware to allow or deny a list of Ips

internal/helpers.go

@@ -1,14 +1,22 @@
+/*
+ * Copyright 2024 Jonas Kaninda
+ *
+ * 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.
+ *
+ */
+
 package pkg
 
-/*
-Copyright 2024 Jonas Kaninda.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may get a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-*/
 import (
 	"context"
 	"encoding/json"
@@ -16,6 +24,7 @@ import (
 	"github.com/jedib0t/go-pretty/v6/table"
 	"golang.org/x/oauth2"
 	"io"
+	"net"
 	"net/http"
 )
 
@@ -45,6 +54,7 @@ func getRealIP(r *http.Request) string {
 	return r.RemoteAddr
 }
 
+// getUserInfo returns struct of UserInfo
 func (oauth *OauthRulerMiddleware) getUserInfo(token *oauth2.Token) (UserInfo, error) {
 	oauthConfig := oauth2Config(oauth)
 	// Call the user info endpoint with the token
@@ -68,3 +78,30 @@ func (oauth *OauthRulerMiddleware) getUserInfo(token *oauth2.Token) (UserInfo, e
 
 	return userInfo, nil
 }
+
+// validateIPAddress checks if the input is a valid IP address (IPv4 or IPv6)
+func validateIPAddress(ip string) bool {
+	return net.ParseIP(ip) != nil
+}
+
+// validateCIDR checks if the input is a valid CIDR notation
+func validateCIDR(cidr string) bool {
+	_, _, err := net.ParseCIDR(cidr)
+	return err == nil
+}
+
+// isIPOrCIDR determines whether the input is an IP address or a CIDR
+func isIPOrCIDR(input string) (isIP bool, isCIDR bool) {
+	// Check if it's a valid IP address
+	if net.ParseIP(input) != nil {
+		return true, false
+	}
+
+	// Check if it's a valid CIDR
+	if _, _, err := net.ParseCIDR(input); err == nil {
+		return false, true
+	}
+
+	// Neither IP nor CIDR
+	return false, false
+}